Wednesday, 20 May 2015





science

Add viral or bacterial or protozoal or fungal or rickettsial, mycoplasmal, chlamydial:) algal(as well) DNA whose protein to be used as a recombinant vacccine add the DNA strand to a dividing stem cell n see whether protein is synthesised n released into the body, this will not need multiple dosing n the antigen will be released till the stem cell divides.Or else use bacteria n create recombinant vaccine.

Earlier thought about adding the dna strand that coded for the protein into a cancer cell like the hybridoma technology but that will just act like the bacteria, a continuously dividing cell.

Add a cancer nucleus to an ovum after removing the nucleus n u will have a person who will live forever:) but this will not work the zygote will turn into something like H mole. One will have to study what genes responsible for a long life cycle and add those genes n then cud increase the life span of human beings.

One cud use cancer cells for production of different proteins---
Like liver cancer cell---for albumin synthesis,
Insulinoma cell for insulin synthesis,
Dopaminergic cell tumor-- Dopamine production,
Adrenal medulla tumor--Epinephrine n Norepinephrine prodn..
Instead of recombinant DNA technology using bacteria one cud use cancer cells n culture them to produce various proteins.


Similarly one cud add the genes responsible for different vit synthesis like folic acid n other vit synthesis from other living beings into the human zygote by gene therapy.

DNA synthesis--Base syntheis, bases come into the body from the food we take, normally we consume cereals n pulses i.e. seeds n vegetables n fruits n eggs etc egg albumin is free of DNA, seeds similarly contain less of DNA but vegetables contain a lot of DNA n fruits pbly is poor in DNA as far as the seed is concerned contains  endosperm n embryo but the pericarp mesocarp n endocarp should contain DNA, check out this section, bcoz storage material in plants stored in vacuoles in cells which will contain DNA as well, but in either case will have relatively less DNA.sO In a patient suffering from gout one should not consume food rich in DNA bcoz that will break down to form uric acid n cause problems. A di had asked me about what to consume when person suffering from gout.

We were talking about source of DNA bases by salvage pathway the body will get some bases from the cellular turnover n from food we consume rest will be synthesized, even a simple bacteria synthesizes DNA bases then in the presence of DNA polymerase enzyme a complementary strand is synthesized where Adenine pairs with Thymine  n Guanine   pairs with Cytosine n thus DNA can be synthesised. We can also synthesize DNA bases using the knowledge  of the enzymes required at different steps .

Synthesis of PURINE---(Sources  of individual atoms in purine syntheis (Adenine , Guanine)--Aspartate -N1, N10 Formyl THF- C2 n c8, Glutamine--N3 n N9, CO2-c6, Glycine-C4, c5, N7.
Create a ribose sugar first then make ribose 5 phosphate then make 5-phosphoribosyl 1-pyrophasphate then see the chart of synthesis of purine nucleotides will try to put up the cycle from the net if i get.)

or synthetically by using the knowledge of organic chemistry n then syntheize DNA using the enzyme polymerase, all organisms have the same Dna except Teven phage which contains the base 5-hydroxymethyl cytosine instead of cytosine n has a no of these residues in glucosylated form, find out other exceptions.


synthesis of pyrimidine-- Sources of Carbon n Nitrogen--Glutamine --One N atom, CO2--One carbon atom, Aspartic acid --Three carbon n one nitrogen.
Unlike the synthesis of purine ring where the ring is constructed on a pre -existing ribose 5- phosphate the pyrimidine ring is not synthesised from  ribose 5 po4 .
Glutamine +2ATP+co2----Carbamoyl phosphate synthetase2---Carbamoyl Po4---Aspartate-------Carbamoyl aspartate----Dihydroorotase+H2O---Dyhydroorotate----Nad+---NADH+H+-----orotate---Orotate phosphoribosyl transferase-----Orotidine 5' monoPO4----OMP decarboxylase----Uridine 5' monoPo4.
Fetal cancer can be detected by using radiowaves in Mri or a radioimager which will detect the tumor mass, any suspected area with too much of negative charge could be cancer bcoz in malignant cells increase in negative surface charge of cell membrane, these charge differences can be easily detected by radio waves bcoz they are affected by electric feild changes, there is disturbance in radiosound when switch switched on or off.
One cud use gama rays to destroy malignant cells in the very early stage, taking care not too much of fetal tissue destruction.

See whether tumor of the hippocampal area improves memory if yes then inject stem cells mri guided n see if in improves memory in old people.

Creation of artificial antibody--Take the epitope amino acid sequence, check the amino acid sequence in the variable region of the antibody if it is the complementary DNA'S RNA's protein then by using that amino acid sequence in the variable region n keeping the constant region constant one can create artificial antibodies.
For passive immunisation with core proteins inject it into a SLE pt  n produce antibodies n then by hybridoma technology collect abs n infuse it into a pt, will be protective may not be that antigenic to a normal person. core antigens less antigenic bcoz hidden  so the titer does not persist for long one can give recombinant vaccine of the core antigen from outside, one can further increase the antigenicity of antigen by adsorbing them onto large inert molecules like kaolin n bentonite etc, find out what causes some antigens to be more antigenic n causes antibody production for long. Some points already mentioned like presence of aromatic radical like the amino acid tyrosine, large mol weight, presence of epitopes(antigenic determinant), polypeptides contain L-amino acids...COMBINE a less antigenic substance to a more antigenic one n see whether will work.Exposure for long may work.




Why the bact viral ....vaccines may work --The term pseudo cryptantigen has been used for serological rks due to steric hinderance as they are hidden or buried beneath the surface. Antibodies to sperms n lens is a hint how antibodies can be formed n act against a hidden structure one exposed to the blood.Similarly antirabies vaccine contains large amount of partially denatured brain tissue. in man they induce an immunological response causing damage to human brain.

T/t of AIDS n HEP b--Give protease or RT vaccine will augment antibody formation and give the drugs antiprotese n anti RT+ ANTICANCER+ radioactive p in the form of NaPO4...
CAUSE OF mutations in AIDS N iNFLUENZA-- pbly NO repair enzymes after DNA synthesis.

By gene therapy increase the quality n quantity of proteins in seeds, rice, wheat n pulses, proteins wanted by all living beings so grow more of proteins.

BY genetic manipulations one can create new plants, fruits, vegetables,flowers, animals..:).






Saturday, 16 May 2015

Science.

Vaccine against all bacterial infections--All prokaryotes i.e organisms with nuclear membrane lacking eg--bacteria n blue green algae( have now been included in bacteria) have a cell wall that contains amino sugars and muramic acid, in eukaryotes when cell wall present does not have these substances. Similarly peptidoglycan cell wall is unique to bacteria.
In Gram positive the cell wall is entirely made up of peptidoglycan in gram negative it consists of alternating layers of lipoproteins n peptiodoglycan each layer 1-2 molecule thick with little cross linking-- Peptidoglycan is composed of 1)a backbone of two alternating sugars , N acetylglucosamine n N acetyl muramic acid 2)A chain of four amino acids that extend down from (stem peptides) 3)a peptide bridge that cross links the peptide chains. Peptidoglycan is formed by addition of subunits (a sugar with its five attached amino acids)that are assembled in the cytoplasm n transported through the cytoplasmic membrane to the cell surface. subsequent cross linking is driven by cleavage of terminal stem peptide amino acids.
If we inject high doses of the above chemicals into the body of man n animal antibodies will be formed in high titres if exposure is for long i.e multiple doses of this vaccine is given. And this will protect against all bacterial infections, When we give a vaccine like BCG or DPT the antibodies are formed against the antigens on the surface that the B n Tlymphocyte is exposed to, the above mentioned antigens remain hidden beneath just like the bacterial commensals like Ecoli etc that remain hidden in the gut n are not exposed to the antibody producing cell n antibodies are not formed in high titre against them, to produce high antibody titre we will inject the above antigens into the blood stream.
Any protein or polysaccharide that is specific to a bacteria can be used as a bacterial vaccine cud be a an enzymatic protein or a structural protein once antibodies are formed in high titre they will react with the antigen even if the antigen is present inside the cell, though the antigen will not have easy access to the lymphocytes in the next antigenic exposure the high antibody titre will take care of the antigen. (To augment the immune response one cud take another dose of vaccine during an episode of infection in case the antigen stays hidden within the the deeper layers of the cell wall n the antigen exposure is not high, cell lysis will expose the lymphocytes to the cell wall components. Eg of Ecoli will come to rescue. one cud target bacterial enzymes like the one that helps in folic acid synthesis in bacteria from PABA, inhibited by sulphonamides n Trimethoprim.
PABA----folate synthase----DHFA Inhibited by Sulphonamide.
DHFA----Dyhydrofolate reductase----THFA Inhibited by Trimethoprim.
Other enzymes that cud act as ag are enzyme isoleucine tRNA synthetase, check whether DNA gyrase n Topoisomerase4 are bacteria specific search for other antigens. These are just the antigens that are drug targets.
Antigens are proteins or large polysaccharides n they initiate acquired immunity. For a substance to be antigenic they have to have a very high molecular weight, 8000 or greater, furthermore the process of antigenicity depends on regularly recurring molecules called epitopes on the surface of large molecules which explains why proteins n large polysaccharides are almost always antigenic bcoz they both have this type of stereochemical characteristic, if the molecular weight is less than 8000 then known as hapten, if this combines with substance that is antigenic such as a protein then the combination can elicit an mmune response (accordingly can make a substance antigenic ) The antibodies or activated lymphocytes that develops against the combination will then react often seperately against either the protein or the hapten.Therefore on second exposure to the hapten some of the antibodies or activated lymphocytes will react with it before it can spread thru the body and cause damage.
The haptens that elicit immune response of this type are usually low molecular weight drugs, chemical constituents in dust, breakdown products of dandruff from animals, degenrative products of scaling skin , various industrial chemicals, the toxin of poison ivy and so forth.
Most antigens activate the B n Tlymphocytes at the same time. Some of the Tcells that are formed called helper cells in turn secrete specific subst collectively called lymphokines that further activate the B lymphocytes.Indeed without the help of these Tcells the quantity of antibodies formed by B lymphocyte is usually slight.
Formation of antibodies by plasma cells--Before exposure to a specific antigen, the clones of Blymphocytes remain dormant in the lymphoid tissue. On entry of a foreign antigen, the macrophages in the lymphoid tissue phagocytose the antigen n then present it to the adjacent B lymphocyte. In addition the antigen is presented to T cells at the same time and activated helper Tcell then also contribute to the activation of B lymphocytes.Those B lymphocytes specific for the antigen immediately enlarge n take on the appearance of lymphoblasts..Some of them further differentiate to form plasmablasts, which are the precursor of plasma cells. In these cells, the cytoplasm expands and the rough endoplasmic reticulum vastly proliferates .They then begin to devide at a rate of about once every ten hours for about 9 divisions giving in 4 daysa total population of about 500 cells for each original plasmablast. The mature plasma cell then produces gama globulin antibodies at an extremely rapid rate --About 2000 molecules per second for each plasma cell.The antibodies are secreted into the lymph and carried to the circulating blood. This process continues for several days or weeks until the final exhaustion n death of the plasma cells.
Formation of memory cells--Some of the lymphoblasts formed by activation of a clone of Blyphocytes do not go on to form plasma cells but instead form moderate no of new B lymphocytes similar to those of original clone. In other words the B cell population of the specifically activated clone becomes greatly enhanced, and the new B lymphocyte are added to the original clone of lymhocytes. They also circulate thruout the body to populate all lymphoid tissue , but immunologically they remain dormant until activated once again by a new quantity of the same antigen.These lymphocytes are called memory cells.Subsequent exposure to the same antigen will then cause a muuch more rapid n much more potent antibody response because there are many more memory cells than there were original B lymphocytes of the specific clone.
A secondary response begins rapidly after exposure to an antigen (often within hours) is far more potent and forms antibodies for many months rather than for a few weeks. The increased potency and duration of secondary response explains why vaccination is usually accomplished by injecting antigen in multiple doses with periods of several weeks or several monts between injections.
Similarly one cud make a vaccine against fungi either take an antigen an inject or make a component antigenic n then inject into the body as a vaccine.
Thought about this yesterday evening, God is  gr8:)!












 

Science

Leading cause of death--Heart disease, cancer, infections, genetic diseases....see the latest chart ---
Coronary artery disease n stroke can be prevented by statins n weight control, one cud create a cancer vaccine n give a vaccine against all common infections.

Cancer vaccine--Culture cancer cells n kill them n use their antigens to create a vaccine against all the cancers.

Vaccine against Infections

Gram negative cocci
Moraxella  catarrhalis
Neisseria gonorrhoeae
Nesseria meningitidis

Gram positive cocci
Streptococcus pneumoniae
Streptococcus, haemolytic groupA,B,C,G
viridans streptococci
Staphylococci
Enterococcus faecalis
Enterococcus faecium

Gram negative rods
Acinetobacter
Prevotella
Bacteroides
Brucella
Campylobacter jejuni
Enmterobacter
Haemophilus
Helicobacter pylori
Klebsiella
Legionella
Proteus mirabilis
Proteus vulgaris n other species (morganella , providentia)
Pseudomonas aeruiginosa
Burkholderia pseudomallei
Burkholderia mallei
Salmonella
Serratia
Vibrio
Yersinia pestis

Gram positive rods
Actinomyces
Bacillus (including anthrax)
Clostridium (eg, gas gangrene, tetanus)
Corynaebacterium diptheriae
Corynaebacterium jeikeium
Listeria

Acid fast rods
Mycobacterium tb
Mycobacterium leprae
Mycobacterium kansasi
Mycobacterium avium complex
Mycobacterium fortuitum chelonei
Nocardia

Spirochaetes
Borellia burgdorferi
Borellia recurrentis
Leptospira
Treponema pallidum
Treponema pertenue

Mycoplasma

Chlamydia
C psittaci
C trachomatis
C pneumoniae

Richettsiae


Vaccine against all common infections could be given 2 man n animals,cows given similar vaccine could be a source of passive immunisation thru the antibodies passed thru the milk. The vaccine cud be live attenuated or killed both will help produce antibodies  n the live attenuated may also be passed on.

Leprosy caused by M.leprae, have affinity for schwann cells n cells of the reticuloendothelial system .Numerous antigens (more than 20 ) have been detected in M.leprae by electrophoretic techniques.Some of these are shared by pathogenic n non pathogenic mycobact eg--BCG,M smegmatis,M.vacca, M.tb.Most interesting of these is the phenolic glycolipid (PGI) which may be specific M.leprae antigen .Large quantities of M.leprae produced by multiplication in 9 banded armadillo n nude mouse. Despite repeated claims M.leprae has not yet been  conclusively shown to grow in artificial medium .Perhaps mainly for this reason that progress in research has lagged behind than that of many other disease.These are the practical problems--One cud try n grow them in tissue culture of skin n nervous tissue  n produce killed or live attenuated / recombinant vaccine.


Viral vaccines -- Apart from live n killed one more variety recombinant vaccine could be tried---Virus most probably has genes for pathogenicity that is why viral live attenuated genes have been produced like for yellow fever n oral polio one cud remove the genes responsible for the pathogenicity or the cytopathic effect n create recombinant vaccines.

Genetic diseases--With the help of radioimaging/gamma imaging /electron microscopy one will be able to study the entire human chromosome.To find out which gene is responsible for which which protein synthesis take the eg of insulin, Find out the sequence of amino acids in insulin that way will be able find out the mRNA sequence responsible n the DNA segment or gene responsible, isolate the gene for insulin n introduce it into a bacterium like E.coli n then collect the insulin protein produced.
Take a zygote let it divide upto the eight cell stage then record all the proteins synthesised in the cells from day 1 every cell will synthesize an mRNA n  protein find out what by radioimaging , find out all the proteins synthesized from every cell n find out the corresponding gene  being activated in the different cells --This way one will be able to find out the gene responsible for the diff proteins n slowly one will be able to map out all the genes responsible for a particular phenotype along with the activation of different regulator genes.
Different cells in a developing zygote will produce different factors which will cause the differentiation of  different stem cells into different  tissues blood, bone, connective, cartilage, muscular, nervous n there will be formation of different systems  Cardiovascular, Lymphatic, Endocrine, Integumentary, Respiratory, Digestive, Urinary , Reproductive etc

Thus one can find out all the coding n non coding sequence  of DNA n find out all the genes n their products.

Different people have different skin colors , eye color n hair color this depends on the level of tyrosinase, absent in albino n different shades according to the level of activity.

Different heights and different shapes of body all guided by different genes n by finding out what gene or genes correspond to what phenotype one can create designer babies,work on this was going on in 1998 n might be progressing by leaps n bounds.

Similarly one can find out the gene responsible for a pathology n go for gene therapy n correct that pathology.

Towards a more beautiful world--It seems no chemical has yet been discovered that can antagonise tyrosinase, one cud try this--Tyrosinase or melanin cud be injected in horse or a man who is an albino Collect antibodies produced or else collect the B cells producing antibody and fuse it with a Bcell tumor cell---by hybridoma technology collect antibodies AND inject it into a normal person pigmented:)The antibody will react with the antigen n the picture will be similar to vitiligo but in vitiligo the non pigmented areas are patchy check whether here also is patchy, in vitiligo an autoimmune condn, antibodies are formed against melanin. One cud take the precursors of melanin as well like dihydroxyindole n prepare antibodies similarly. Or else prepare a recombinant antigen that has some components of tyrosinase/melanin n some components of another protein n allow antibody formation the antibody thus formed will cross react with melanin or tyrosinase (as happens in Rheumatic heart disease).

Find out the components involved in the formation of tyrosinase n modify them.

Just like dopamine receptor antagonist or oestrogen receptor antagonist --Make an antagonist of tyrosinase  that binds to tyrosine --Check the binding area see the amino acid sequence n add some a.a sequence or protein to the binding area of the key and prepare an antagonist.  

Tuesday, 5 May 2015

science..

Enzyme antigen vaccines
Nuclease  ag --could be used as anti DNA vaccine.
Reverse transcriptase --Could be used as anti Retroviral vaccine.

 Enzymes DNase  cause the breakdown of bacterial DNA. T4 phage DNA is resistant to  attacks of DNase bcoz it contains  the base 5- hydroxymethyl cytosine instead of cytosine and has a number of these residues in the glucosylated form.

Degradative enzyme deoxycytidine triPO4 that prevents incorporation of cytosine in phage DNA by breaking down cytidine triPO4 n diPO4 into monoPO4.

Enzymes for the synthesis of hydroxymethylcytosine which is required instead of cytosine in phage DNA.

Glucosyl transferases which transfer glucosyl groups to hydroxymethyl cytosine.

All the above three enzyme proteins could be used as a vaccine if T4 phage infected man, so formula is find out the unique enzyme that is present only in the virus like reverse transcriptase, integrase, nuclease n use it as a vaccine.

A  virus usually multiplies in specific cells derived from animals in which the virus normally grows. Such cells are called permissive cells. Cells in which the virus do not grow are called non permissive  cells.

Viruses on entry into the host cells undergo one of the two types of behaviour
1).They enter the lytic phase and multiply within the host cell ultimately killing them, this type of infection is called lytic infection.

2) THe viral DNA may be inserted into the DNA  of the host chromosome and becomes an integral part of host DNA, the virus is now said to become a provirus.Transformation of normal cells into cancer cells is often due to integration of viral genes into the chromosomes of the host cell. The  gene of cancer causing virus which is responsible for transformation is called an oncogene.



Vaccine for herpes--Antitegument vaccine for herpes bcoz transcription of immediate early genes requires the virus tegument protein n preexisting cellular transcription factors.
Anti early gene transcription protein cud also be used as a vaccine, when this factor is docked into the cytoplasm in neurons HSV-1 goes into a latent state in neurons.

AntiRNA n DNA polymerase drugs  cud be tried similar to base analogues used as anticancer drugs, antiprotease will be effective, anti RNA, DNA  polymerase or reverse transcriptase will not be  100% effective.


RNA VIRUS
sINGLE STRANDED
+RNA + Cell's enzyme---
-RNA +  RNA  polymerase---
+RNA---Encapsidated in the cytoplasm.

-RNA+ RNA polymerase---
-RNA +          mRNA---
+RNA +RNA polymerase +Str proteins +Accessory factors---Encapsidated in the cytoplasm.

Influenza  virus is unusual negative strand  RNA virus that transcribes its m RNA n -RNA in the nucleus but it assembles in the cytoplasm like all RNA virus, RNA  virus transcribe, translate n replicate n assemble entirely in the cytoplasm.


Double stranded segmented RNA--These viruses which are groupred into the reovirus family have 10 to 12 RNA segments that make up their genome. Medically imp viruses in this grp include- colorado tick fever virus and rotavirus. Reovirus  virion includes an RNA polymerase complex. Reoviruses replicate n assemble in the cytoplasm.


Apoptosis gene cud be introduced into cancer cells if the virus has affinity for the cancer cell ie the cancer cells have receptors for the virus.

Adeno associated virus  has been touted as a potentially safe human gene vector bcoz of its Rep protein causes its integration at a single chromosomal site.
Viruses cud  insert into the germ line genome  of the host cell n behave as a transposable or movable genetic element that cud help in correcting genetic deficiencies.

The retroviral RNA is not translated instead it is transcribed into double stranded DNA .The DNA form of the retroviral genome is called a provirus. This provirus moves into the nucleus n integrates into the  host cell genome , this integration is permanent. Although  some animal retrovirus  integrate into single specific site of the host genome in every infected cell, the 4 known pathogenic retroviruses (HTLV-1, HTLV-2, HIV-1,HIV-2 )integrate randomly.

The pathogenesis of neoplastic transformation relies on the chance integration of the provirus at a spot in the genome that will result in the expression of a cellular gene proto-oncogene that becomes transforming by virtue of its unregulated expression. For  eg--avian leukosis virus causes  Bcell leukemia  by inducing the expression of  myc.

Retroviruses can be either exogenously acquired or by infection  with a virion capable of replication  or transmitted in the germ line  as endogenous virus. Endogenous retroviruses  are often replication defective.  The human genome contains endogenous retroviral sequences  but there are no known replication competent retroviruses in humans.

Some retroviruses posses  captured and altered cellular genes near their integration site and these viral oncogenes are capable of  transforming the infected host cells . Viruses that have oncogenes often have  lost a portion of their genome that is required for replication . Such viruses need helper viruses to reproduce, a feature  that may explain  why these acute transforming retroviruses are rare in nature. All retro viruses  identified to date are exogenous and not acutely transforming.


These remarkable properties of retroviruses have led to  experimental  efforts to use them as  vectors to insert  specific genes  into particular cell types, a process  ka gene transfer or therapy. The process cud be used to  repair a genetic defect  or to introduce  a new property  that cud be used therapeutically for eg-- a gene  (eg--thymidine kinase ) that wud make a tumor cell susceptible to  killing  by a drug ( eg-ganciclovir)cud be inserted.
One source of concern  about the use of  retroviral vectors in humans is that replication competent viruses might rescue  endogenous viral replication  with unpredictable results.THis concern is not merely hypothetical. The detection of proteins encoded  by endogenous retroviral sequences on the surface of cancer cells implies that genetic  events leading to cancer  were able to  activate the synthesis of these usually silent genes.   


Proviral integration occurs during the Sphase of the cell cycle thus in general non dividing cells are resistant to viral infection, only lentiviruses are able to infect nondividing cells how ? find out

 Lentiviruses can infect non dividing cells, largely owing to effects mediated by Vpr. Vpr  facilitates transport of  provirus in2 the nucleus n can induce other cellular changes  such as G2 growth arrest n differentiation  of some target cells. Vpx is structurally related to Vpr but its function is not fully defined. Vpu promotes the degradation of CD4 in the endoplasmic reticulum  and stimultes the release of virions from infected cells.


Like Herpes virus, poxvirus encode several enzymes that increase deoxynucleotide triPO4 precursor levels n thus facilitates DNA synthesis. One cud use that enzyme as an antigen n create a vaccine.

Viruses with both RNA n DNA genomes --Retroviruses, lentiviruses and hepatitis virus are not purely RNA or DNA virus. Retrovirus n lentiviruses are enveloped RNA viruses with two identical sense positive strand genome associated with reverse transcriptase and integrase enzymes.These two proteins reverse transcriptase and integrase cud be used for vaccine preperation.


From stem cells produce melanocytes n inject them into hair follicles.

Genesis of blood cells
Pleuripotent haematopoetic stem cells

CFU-E----4 growth inducers ------>-----differentiation inducer--->---outside factors--->Induces RBCs


Embryonic Stem cells----------> Primary oocyte----->Ovum.

Stem cells to help in recovery after brain and heart stroke.
Stem cells to improve brain functioning due to aging.
Upto the 8 cell stage of the zygote  each cell can give rise to a clone, one cud try making a clone by transferring another nucleus from a somatic cell n see it works, we cud transfer our nucleus to the above or make a clone from n ovum n use it to collect stem cells n use it later to prepare beta cells, skin cells, ,blood cells, ovum n sperm.

Do chemical carcinogens directly transform cells to malignancy or do they affect malignant cells?--Yes transform cells directly

Do carcinogens transform cells directly or indirectly by activating oncogenic viruses already  present in the cell?--Both

Is the chemical transformation mechanism a mutagenic one involving DNA sequences or one involving gene expression?
Widely considered a mutagenic one. There is chemical interaction of chemical  oncogenes possibly with DNA resulting in alteration of primary sequence of DNA.
However it has already been suggested that cancers could result from abnormal differentiation involving alteration of gene expression eg-from  interaction of carcinogen with repressor protein.

 Many chemical carcinogens may not have  direct mutagenic activity .On entering the cells however carcinogens are chemically transformed  into derivatives that may be more carcinogenic than their precursors.
For eg-- Nitrates are not carcinogenic or mutagenic but may become converted to nitrosamines which are powerful mutagens and carcinogen, it has been stated that most carcinogenesis is the result of changes in DNA.
Most carcinogenic substances known are nitrosamines. THey are suspected to be the major  causative agent of human cancer.Any secondary amine on reaction with nitrous acid forms nitrosamines. Absorption of nitrosamines from stomach could result in cancer in various organs.All plants contain nitrates which could be reduced to nitrites.Many meats contain both nitrates n nitrites.The  nitrite could react with secondary amines in the stomach to produce nitrosamines. Sec amines are found in  many drugs and natural foods.

What is the mechanism by which carcinogens induce cancers?
 1.Accumulation of mutational defects brought about by carcinogens-- Carcinogens may cause alterations in DNA (mutations).Several mutational defects in the cell may result in the cell becoming cancerous(multi hit initiation).

2.Repression of normal gene activities--Carinogens or their reactive  metabolic derivatives may bind with DNA and cause disorganisation in the decoding of DNA information. This may bring about repression of certain normal gene activities in precancerous cells. Repression could also take place by combination with products of genes eg--enzymes rather than genes themselves. Both these activities are not somatic mutations since the DNA itself is not altered.

3. Derepression of forbidden gene activities-- Carcinogens may induce forbidden gene transcriptions for enzymes that stimulate late cell division. This is brought about by derepression of certain info in DNA that is normally repressed. Probably the most acceptable suggestion of how transformation occurs is that the products of viral gene s derepress extensive regions of cellular genome.

Oncogene theory--Huebner n Todaro (1969, 1972) have proposed their 'oncogene theory' according to which  all cells carry genetic information for malignancy and in most cases for cancer generating viruses (oncogenic viruses).According to the hypothesis carcinogens switch on oncogenic viruses that cause transformation of  normal cells into malignant cells. There is considerable chemical evidence for this. Oncoviruses have been found in a number of chemically induced tumors.However it is not known whether the viruses actually cause tumors or whether they are harmless passengers. Mutations cud occur in the cellular genome or the viral genome--summary.

Defective immunity hypothesis--The rate of spontaneous mutation is much greater than observed frequency of tumors. From this it can be concluded that
1.There must be some mechanism for supressing mutations resultiong in cancer or
2 the newly formed cancer cells must be destroyed in some way.It is now beleived that the latter possibility is correct.Newly formed casncer cells are destroyed by immunological responses of the cell. This is called immunological surveillence.Cancerous cells have been found to caontain antigens not found in ordinary cells.
According to defective immunity hypothesis the defense mechanism fails under certain conditions n tumors are formed. This may be bcoz the no of lymphocytes may not be large enough to block tumor development.What causes production of insufficient no of lymphocytes is not known.It must be mutation in the lymph cells, poor nutrition, emotional stress and other factors.

Oncogenic viruses-- In the case of oncogenic DNA viruses, the viral Dna (or a portion of it) is integrated with host cell genome .The viral DNA being incomplete or defective., no infectious virus is produced.But under its influence  the host cell undergoes malignant transformation. A virus transformed cancer cell is in many ways anologous to a bacterium lysogenised by a defective phage.In both the cases the cell is not destroyed and no virus is produced. Aquisition of new  characters by transformed cell resembles lysogenic conversion in bacteria.

In the case of oncogenic retroviruses the viral RNA is first converted into RNA :DNA hybrid. This is due to action the action of unusual enzyme RNA directed DNA polymerase(reverse transcriptase) which is characteristic of all retroviruses.The RNA:DNA hybrid is in turn  converted into double stranded DNA form by DNA directed DNA polymerase. This double stranded DNA version  of retrovirus genome is called provirus and is integrated into host cell genome.The integrated provirus acts as a template for viral RNA synthesis and also induces cell transformation. The transforming ability of retroviruses is due to specific genes carried by them. Genes that are responsible for induction of tumors are called oncogenes. Oncogenes are not essential for the replication of retroviruses and mutants occur that lack oncogenes. Such mutants can replicate normally but are incapable of transforming cells or inducing tumors. Rous sarcoma virus carries the oncogene src which is responsible for transforming and tumor producing capacity. RSV mutants lacking src replicate normally, but are not oncogenic.

The oncogenes present in retroviruses  are called viral oncogenes. Genes with sequences similar to retroviral oncogenes exist in host cells also not only in tumor cells but also in normal cells of man, animals n birds.These genes are called cellular oncogenes. Cellular oncogenes are not of viral origin.On the contrary it has been established that viral oncogene s are in fact of host cell origin.Cellular oncogenes are widespread in vertebrates and are well conserved at constant sites in their genomes.They contain introns  characteristic of eukaryotic genes.It is beleived that retroviruses may have picked up these oncogenes from host cells during infection at some remote time during evolution.

Cellular oncogenes are beleived to have some imp controlling function  on cell growth and regulation. Some viral oncogenes also code for substances that influence cell growth and and regulation.For eg--V-src oncogene of RSV codes for a phosphoprotein , phosphokinase which phosphorylate tyrosinase.This phosphoprotein appears to be concentrated along plasma membranes of infected cells and in adhesion  plaques which anchor cells to surfaces, indicating that it may influence cell growth n replication.
One of the methods for studying oncogenesis is by transfection . Certain mouse fibroblast cell lines  can take up foreign DNA, incorporate them into their genome and express them. This method of gene transfer is called transfection. By this technique DNA extracted from human tumor cells has been shown to transform 3T3 cells, and such transforming genes have been shown to be identical with cellular oncogenes.

Not all oncogenic retroviruses contain oncogenes. Some such as avian leukosis virus initiate oncogenesis by activating host cell oncogenes (oncogenesis by promotor insertion).
Cancer is not one disease and not all cancers may have the same cause. It is possible that various theories of origin of cancer--viruses, chemicals, environmental factor, heredity, immunological factors etc--may all be true in parts. As a unified theory of oncogenesis  it has been been suggested   that cancer results when cellular oncogenes overact following infection with oncogenic viruses oe when their expression is modified by the effects of other carcinogens.

Conclusions --Any person infected with an oncogenic viruses, take an anticancer vaccine. Nuclease causes the release of the integrated DNA in Dna virus if deficient bcoz of anti nuclease vaccine, will stay integrated then one may need to take an anticancer vaccine in case they cause cell transformation.
Similarly those people exposed to carcinogens should also take cancer vaccines. 


























 

Monday, 27 April 2015

Ye kaisa?

Ye kaisa dhara tune bhes,
kaun sa hai tera des?

Kya karta rahta tu talas,
kyun nahi bujhti teri pyas?

 Khush hai tu sab kuch ko tyag,
har taraf hai bhagam bhag.

Kyun hai tujhe jag se bairag,
bujhte bujhte bujhti kuch aag.

Pure hon sab ke sanjoye sapne,
sab hain paraye sab hain apne.

Kiski karta hai tu aas,
bas kuch din ki hai ye sans.

Prabhu karta har man me vas,
chala tu kyun kaba kailaas.

Sab se tu kar bande preet,
 ye prakriti hai teri meet.

sabad ko jhadnedo jaise moti,
jalne do har dil me jyoti.

Sabhi to sun rahe  teri geet,
phir se ched ek surila sangeet.

I wrote n sang this song and all my bunnies listened with their eyes closed so beautiful on saturday morning.

Some science.

  Vaccine against all viral infections--Anti protease vaccines will be a cure against all viral infections.

Try regulatory proteins cud be used as  vaccine against viral infection we have to choose a protein that is only present in the virus n not in the host.

One cud give gp 120 n gp 41 after viral infection they will bind to the CD4 receptors n prevent further viral infection  so the load of virus will be decreased, every virus infects a cell with a particular receptor the variety of cells the virus will infect may vary. One cud also give an infusion of T lymphocytes after culture in a proper media, different stem cells differentiate into different cells by finding out the factors n providing them even outside the body one cud produce the different cells from  the stem cell like some factors enlisted in Gyton for RBC culture, some still being discovered, sperm cell culture came into news in 2007, similarly one cud culture primaey oocyte n inject them into the ovary for continuing fertility n delaying menopause, one will have to create a radio imager n find out the factors playing a role n create diff cells from stem cells.  


DNA polymerase is common to man animal n virus, some virus use the host DNA polymerase while some have their own DNA polymerase.

Anti integrase cud also act as vaccine needed for the retroviral multiplication.
After integration of the virus, overexpression of viral early proteins and excessive stimulation of cellular growth results in  devpt of cancer,  anti integrase protective against ca as well.
Antinuclease antiDNA vaccine..

Anti early proteins to stop DNA replication. This cud be used as a vaccine against DNA virus.  Early genes encode proteins that are necessary for viral DNA synthesis and for the turn on of late transcription  which encode viral structural proteins or viral proteins necessary for assembly and egress of virus from infected cell.

The assembly and egress of mature  infectious virus marks the end of eclipse phase of infection during which infectious virus cannot be recovered from infected cells.During eclipse phase the various proteins will be formed from the DNA n released into the cell.

Take the viral DNA genes n grow them in bacteria will form mRNA n later translate to proteins. Using recombinant DNA technology collect the various proteins like early proteins that help in DNA synthesis , reverse transcriptase vaccines to be prepared similarly . One cud use different cell cultures not necessarily bacteria.

Anti transcriptase and anti protease--Will act  as anti Retrovirus n Antivirus vaccine :).

We cud make vaccines n drugs directed against each viral protein and or enzyme, where there is a lot of antigenic variation will not work.

Inhibition of DNA synthesis by nucleoside analogues--DNA  chain  growth can be blocked by incorporation of certain nucleotide analogs that have been modified in the sugar portion  of the nucleotide, eg--OH grp removal frm the 3'C of deoxyribose ring.
2'3' Dideoxyinosine (ddl) or conversion of dedeoxyribose to another sugar eg --arabinose prevents further chain elongation. By blocking Dna  replication these  compounds slow the division of  rapidly growing cells n viruses

BUT purine that results from normal turnover of cellular nucleic acid  or that obtained  from diet are not degraded  and can be reconverted  into nucleotide triPO4 n used by the body  so  nucleoside reverse transcriptase inhibitors will not be 100% efficient, but protese inhibitors will be.eg-- Cytosine arabinoside  has been used as anticancer chemotherapy, whereas adenine arabinoside as an antiviral agent. chemically modifying the sugar moiety as seen in zidovudine n acyclovir accomplishes the same goal of termination of DNA elongation. So the drg won't be 100% effective. Antiprotese is the drg of choice..

RetroVirus  normally grow in multiplying cells other than lentivirus details later..so if we give anticancer drugs can prevent viral replication.

Antimetabolites--details refer book

Methotrexate--Antifolate,structurally related to folic acid and act as antagonist of that vitamin by inhibiting dihydrofolate reductase the enzyme that converts folic acid to its active  coenzyme form, tetrahydrofolic acid , there4 acts as an antagonist of that vitamin. folic acid plays a role in a variety of metabolic reactions  involving  the transfer of one carbon unit, needed for cell multiplication.


6- Mercaptopurine--This is thiol analogue of hypoxanthine, it n thioguanine were first purine analogs to prove beneficial for treating neoplastic diseases.Azathioprine an immunosupressant  exerts its effect after conversion to 6- MP.

6-thioguanine-- Another purine analogue, inhibits the biosynthesis of the purine ring n the phosphorylation of GMP to GDP,can also be incorporated into DNA n RNA.

5--Fluorouracil-- A pyrimidine analog, has stable fluorine  atom in place  of hydrogen atom at position 5 of the uracil ring. The fluorine interferes with conversion of deoxyuridylic acid to thymidylic acid thus depriving the cell of one of the essential precursors of DNA synthesis.


cytarabine-- Pyrimidine antagonist.

Fludarabine-- Unnatural purine nucleotide, exact cytotoxic lesion uncertain, the triPO4 incorporated in2 both DNA n RNA to decrease their synth n alter their               function.

Antibiotics---

Dactinomycin--Interferes with dna dependant rna polymerase, also hinders dna synthesis.
Doxorubicin n daunorubicin--Intercalates nonspecifically in between adj base pairs n binds to sugar PO4 backbone of DNA causing local uncoiling thus  blocking  DNA n RNA synth.These two drgs can be given to pts with cardiomyopathy toxic to the heart as well:).

Bleomycin--Cause scission of DNA by oxidative process.
Plicamycin-- Exerts cytotoxicity through restriction of DNA directed RNA synthesis.


Alkylating agents--
Mechlorethamine--Facilitates DNA strand breakage.

Cyclophosphamide n Ifosfamide-- The hydroxylated intermediates undergo breakdown to form the active compounds, phosphamide mustard n acrolein , rkn with dna is coinsidered to be cytotoxic.

Nitrosureas--Carmustine N lOmustine--Cross links strands of DNA to inhibit its replication and eventually RNA n protein synthesis.

Microtubule inhibitors--
vincristine n Vinblastine---Cells frozen in metaphase, prevents chromosomal segregation n cell proliferation.
Paclitaxel-- It promotes polymerisation n stabilization Of the polymer rather than dissasembly...The overly stable microtubules formed in the presence are dysfunctional n thereby cause death of the cell.


Other chemotherapeutic drugs--

Cisplatin n  Carboplatin-- Binds to N7 of guanine  of DNA forming inter n intra strand crosslinks , the resulting cytotoxic lesions inhibit both DNA N RNA  synthesis

Etoposide are semisynthetic derivatives of the plant alkaloid podophyllotoxin .They block cells  in the late S-G2 phase  of the cell cycle .Their major target is topoisomerasell. Binding of the drug to the enzyme -DNA complex  results in persistence  of transient cleavable form of the complex and thus renders it susceptible  to irrevesible double strand breaks.

Procarbazine--inhibits DNA n RNA synthesis.

 ANTIVIRAL cHEMOTHERAPY--
Amantadine n Rimantadine--Antiviral activity limited to Influenza A virus--whose replication they inhibit  by interfering with the uncoating of virus after infection.

Ribavirin--Ribavirin in synthetic nucleoside that inhibits a wide range of RNA n DNA viruses.

Zanamivir N Oseltamivir--This enzyme cleaves terminal sialic acid residues thus destroying the cellular receptors recognized by viral haemagglutinin.

Acyclovir n Valacyclovir--This compd is first phosphorylated to  to acyclovir monophosphate , this occurs efficiently in herpes infected cells by means of virus coded thymidine kinase, in uninfected mammalian cell little phosphorylation of acyclovir occurs n the drg is concentrated in herpes infected cells. acyclovir monopo4 is converted by host cell kinases to tripo4 that is potent inhibitor of virus induced dna polymerase but has little effect on host cell polymerase.acyclovirtripo4 can also be incorporated in2 viral DNA with early chain termination.

Cidofovir--Is a phosphonate nucleotide analogue of cytosine.

Fomivirsen--This phosphorothionate oligonucleotide, 21 nucleotide in length, inhibits CMV replication thru interaction with CMV mRNA.

Ganciclovir--An analogue Of Acyclovir, ganciclovir is active against HSV n VZV and is more active than acyclovir against CMV. Ganciclovir TRIpo4 inhibits CMV DNA polymerase and can be incorporated into CMV dna whose elongation it eventually terminates.

Famciclovir n Penciclovir--Famciclovir is the diacetyl 6-deoxyester of guanosine analogue Penciclovir. Famciclovir is rapidly converted by deacetylation n oxidation to Penciclovir, whose spectrum of activity n mechanism of action are similar to those of acyclovir.

Foscarnet-- This is a pyrophosphate  containing compd that potently inhibits herpesvirus including CMV.This drug inhibits DNA polymerases at the pyropo4 binding site at concentrations that have relatively little effect on cellular polymerases, also inhibits the reverse transcriptase of hiv n is active against hiv in vivo.

Idoxuridine--
Trifluridine--Trifluridine monoPO4 irreversibly inhibits thymidylate synthetase n trifluridine TriPO4 inhibits viral n to a lesser extent cellular DNA polymerase.Because of systemic toxicity used topically.

Vidarabine-- Purine nucleoside analogue. Inhibits viral DNA synthesis thru its 5'triphosphorylated metabolite.

Other antiviral agents--Lamivudine is a pyrimidine nucleoside  analogue.

Lobucavir--Synthetic  cyclobutane nucleoside analogue with activity against a broad range of herpesvirus, HIV N HBV.
These drgs been made using the same principle as anticancer drugs.

This rakshas has been torturing me watching me 24 hrs with his radio n gamma camera has  produced cuts n lesions on the body n produces lesions at wrong places n tortures like an animal everyday every hour and there is no law n order, he killed my newly born bunnies 3 in no, day b4 yesterday n left the weakest one after opening their eyes with cuts produced by gamma rays, the 3rd one got blind bcoz of the eye being opened early cud not blink n got blind within hours n today while torturing me with pain in heart n abd killed her to divert my attention, he produces so severe pain abd that it leads to bleeding did it on the 18th when periods had to begin 14 days later, today also there was bleeding he has been torturing me everyday n produces amnesia after that n I forget n forgive, he is trying to kill me he said, all my hair turning grey, friends do something he is a silent killer, he has been doing negative from the very beginning like a mad person n he fears that his reality will be out so has been destroying me since more than a decade doesn't let me study, this is all too superficial study n God's blessing.