Applied biology / Applied chemistry

Tissues and Organ transplantation

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• 1967 = heart transplant first receive - Donor Organ Immunosuppressant drugs.
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• When a person is seriously injured or the Organ is damaged, the damaged issue or Organ is replaced with healthier and functional tissue or Organ. This medical procedure is called transplantation.
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• The tissue is transplanted from one side to another side of same person therefore there is no chance of rejection.
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• The Organ is transplanted from one person to another who are genetically different therefore, immune system of receiver synthesises antibodies against the transplanted Organ. This phenomenon is called rejection and can be prevented by adminenistri a group of drugs called immuno suppressant drug like cyclo.

Types of transplantation:

The Organ or tissue which is transplanted is called transplant or graft. Based on genetic relationship between donar and receiver transplantation is of following types -

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• (a) Autografting: When the graft is taken from one site and is transplanted to another site in same person it is called Autografting. Skin grafting is an example. This type doesn't have chance of rejection.
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• (b) Isografting: The grafting between genetically identical members of a species is called Isografting. It also doesn't have chance of rejection. Kidney transplantation betⁿ the twins is an example.
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• (c) Allografting or (Homografting): When grafting is done between the members of same species it is called Allografting / Homografting. In this case chance of rejection is higher because donar and receiver have different genetic makeup. Blood transfusion is an example.
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• (d) Xenografting or (Heterografting): When grafting is done below the members of different species it is called xenografting. In this case chance of rejection is maximum. To reduce rejection the donar species is already genetically modified. The transplantation of valves of pig to replace disfunctional human valves is an example.

Testtube baby technique (In vitro fertilization technique)

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• In vitro = out of the body
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• In vivo = within the body

testtube = embryo = uterus
Ovary, fallopian tube -> cause

Sperm count = less In male
per ml of semen 15-20 million sperm
less than 15-20 million fertilization doesn't occurs.

Fertilization in Ampula of fallopian tube. Also required sperm movability.

In human fertilization is internal and this kind of fertilization is called In vivo fertilization. When couples have disorders in their reproductive part they cannot conceive baby. The medical assistant which helps such couples to have their own babies is called in vitro fertilization technique. In this method fertilization is performed out of the body in test tube. Therefore In vitro fertilization technique is called test tube baby technique.

This technique is only applied when other method are failed because this method is expensive, time consuming and has low success rate. It is performed when Ovary is disfunctional fallopian tube are blocked and uterus has any disorder. Like wise it is used when sperm count is low & sperm have lost movelity. To be a fertile male the sperm count must be 15-20 million sperms per ml of semen.

The first test tube baby of world is louis joy brown who was born in 25th july 1978 with the help of doctor patrick steptoe and robert edward. The first test tube baby of nepal is om mani tamang who was born in 3rd march 2005 in Om hospital.

Procedure in IVF

a) Superovulation

The women desired for IVF is injected with human menopouse gonadotropin (HMG) Hormone in below 5th and 9th day of menstrual cycle. It stimulates many primary Oocytes to become secondary Oocytes. The women is then injected with progestrone in order to stimulate uterus to be ready for conceiving zygote.

B) Collection of Oocytes and semen

By surgical method secondary Oocytes are collected and are transferred into culture medium where the Oocytes are evulated and abnormal oocytes are removed.

The semen is collected either from husband or from sperm bank the collected semen is evulated & healthier and functional sperm are selected.

c) Fertilization:

The healthier sperms are transfered into culture medium where secondary Oocytes are available. The sperm fertilize the Oocytes and form zygote. The zygote are left their for few days and began to divide. The zygote which fails to divide or divides slowly is removed.

d) Embryo transfer:

The zygote multiplies and forms embryo. The fast growing healthier embryos are selected and best growing embryo is selected for transfer. The embryo is transfer to the uterus of same mother or another mother. The mother with whom secondary Oocytes donot belong & only gives the space for growth and delivery of fetus is called surrogate mother or substitute mother.

Aminocentesis

A medical procedure of testing amino fluid inorder to diagnohe alth of growing fetus is called aminocentesis. It is performed be low 14th to 16th weeks of Pregency.

The uterus of pregent women have a sac called amino centesis sack where a fluid called amino centesis fluid is present. The fetus freely rotates in aminocentesis fluid and uses the fluid as a medium. The fluid contains wastes and cells of fetus.

When amino centesis fluid is withdrawn with the help of surgical needle & the cells are also withdrawn this fluid is cultured in culture medium where cells are multiplied this cells are examined under microscope to evulate chromosome number and shape & size of the chromosome number. The process is called karyotyping. Some time the chemical of aminocentesis fluid is also examiner In order to detect any chemical disorder. This kind of test is called bio-chemical test.

Aminocentesis is recommended to the couple who have geneticaly disorder children, family history having genetically abnormal babies and if the pregnant women is over the age of 35 years. The aminocentesis is also tells the gender of fetus. In some societies aminocentesis is misused to abort female fetus. Therefore aminocentesis is band in nepal.

Advantages:-

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• I) To ensure medical condition of growing fetus timely.
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• II) It prepares the parent financially emotionally, psychologically about the fetus.
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• III) It informs parents timely for taking decision about continuity of the fetus.

Disadvantages:-

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• I) It can cause miscarriage.
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• II) Repeated amino centesis may cause uterine cramping which may cause Preterm birth.
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• III) It may cause respiratory problems in the fetus.

Transgenic animal

Genografting first transgenic animal is mouse...

Human population is increasing rapidly and so the human needs therefore it is essential to improve qualotive and quantity of the resources, specially animals. For this purpose scientist modified genome of a species by indroducing gene of interest. The gene of interest is taken from another animal and is rejoined with hostgeno. The animal that contains foreign DNA is called transgenes and the process is called transgenesis.

Transgeneic animal are also called geneticaly modified organism and first transgenic animal is mouse which was prepared by Rodul genenics in 1974. Then after many animal pig, cattle, dog, fish etc have been genetically modified to produce more economical, disease resistance and better yield animals. The transgenic pigs are used in Organ transplantation and synthesis of human insulin. like wise cattles are genetically modified for milk and meat. The fish is genetically modified to obtain proteins and growth hormone.

Poultry farming

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• For rearing of birds
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• For meat, Egg & fertilizer.
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• In nepal it is commercial rearing of chickens
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• Criteria to be considered:        
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  • Breed type -> Layers.
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  • -> Broilers.
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The commerical rearing of birds for the purpose of meat, egg and manure is called poultry farming. It includes the farming chickens, Osterich, duck.

In Nepal poultry farming refers to commerical farming of chicken for meat egg and manure. During establishement of poultry farming the breed to be cultivated must be selected. The chickens are of two kinds boilers and layers.

The breed for meat is called broilers which must have fast growth rate with protenish meat. The common broilers are white plymouth rock new hampshire turken, Big red, cornish crosh. The breed for laying eggs is caused layers which include rhode island, white leg horn single comb rock etc.

Steps in Poultry farming

Poultry farming needs well managed house for different life cycle stage of chicken. The shed are breeder shed, hatchary and growing shed following are the steps -

a) Breeding :

The healthier cock and then hen are placed in breeding shed in the ratio of 1:8 to ensure fertilization. The cock and hen must weight about 2-3 kg with shiny eyeball. After 2 days of copulation the hens begans to lay eggs.

b) Heatching :

The laid eggs are collected wash and disinfected with chlorinated water the fertilized egg are then transfermed to incubator where temperature is maintain around 31°C. The machine which regulates temp^r & stimulates embryonic development of fertilized eggs is called incubator. Each week 3°C temp^r is lowered for 21 days then after the egg are hatched and the hatchlings are called pullets.

c) Brooding :

The pullets are moved off to growing shed where temp^r is maintained to provide warmth to the pullet. This phenomenon is called Brooding. After four weeks the pullets are moved off to another shed for their feeding.

d) Rearing :

The pullets are vaccinated against poultry disease like fowl pox, fowl chora, ranikhet (New castle disease). Aspergillosis. The rearing is of three kinds: free range, semi intesive and intensive.

but poultry farming adopt intensive where chickens are grown in the shed where chickens are not allowed to move freely. The floor of shed is covered with sand, sawdust Husk etc to provide warm and make easy in cleaning.

The shed is well supplied with water and water pot shall be regularly replaced and cleaned. They are feed well and after 8 to 10 week, they attain the weigh of 2-3 kg. They are herbested, shed is cleaned and another flock of pullets are transfer there.