How Transgenic animals help in research ?

Transgenic animals enable scientists to understand the role of genes in specific diseases.
By either introducing or inactivating particular genes, researchers can often for the first time discover the root causes of diseases associated with gene defects
Transgenic animals allow more effective treatments to be developed.
Transgenic animals help test the safety of new medicines and vaccines
Because transgenic models can highlight specific characteristics such as certain mechanisms involved in the formation of tumours, they can demonstrate more clearly the possible side effects of new therapies
Their use in early toxicity trials may also serve to prevent the subsequent use of a larger number of animals in the development phase
Transgenics may spare the use of higher animals
Transgenic animals can produce biological products.
It may be possible to use transgenic animals to make rare biological products for medical treatment
Human alpha-1-antitrypsin, a protein used to treat the rare genetic disorder of alpha-1-antitrypsin deficiency, is just one example

Role of transgenic animals in drug development

First, one can test whether it is reasonable to pursue a certain therapeutic approach. For example, if the researchers want to know if a disease could be treated by reducing the amount of a certain protein or the activity of a particular enzyme, they can produce transgenic animals missing the corresponding gene ("gene-knockout animals")
If symptoms of the disease are ameliorated without serious side effects, then it might be worth the time and expense of producing a drug that would have the same effect

How Transgenic animals are made?

To add a gene, called a transgene, to the normal chromosome set of an animal, researchers remove a one-cell embryo (the fertilized oocyte) from the oviduct of a pregnant animal and inject a cloned segment of DNA, including a gene of interest, into the male pronucleus.
The researcher then puts the embryo into the oviduct of a surrogate pregnant female who will carry the transgenic animal to term

What are transgenic animals

Neither science nor society may be ready for the direct manipulation of the human genome, but a technique for directing the genetic make-up of animals is being used in some of the most exciting biomedical research today
This technique involves inserting a foreign gene into the chromosome of an animal
The animal, called transgenic, then expresses that gene along with its normal genes
Transgenic animals are animals whose hereditary properties have been permanently modified by the introduction of recombinant DNA into their germ cells
In animals, transgenesis either means transferring DNA into the animal or altering DNA already in the animal.

Therapeutic query

A patient receiving prednisolone for one year developed oral thrush. He stopped taking prednisolone & took ketoconazole. After 24 hrs, he developed weakness, abdominal pain, fever, nausea, vomitting, diarrhoea, confusion & hypotension. A lot of fluid & electrolytes were supplemented but the condition got deteriorated.

1. What was the cause of symptom to patient ?

2. What should be the line of management in such case ?

3. What are the precautions to prevent it ?

Androgenic Alopecia (Male pattern baldness)

Clinical Features: Miniaturization of hairs along the midline of the scalp
Recession of the anterior scalp line in men and some women

Pathogenesis:Increased sensitivity of affected hairs to the effects of testosterone

Increased levels of circulating androgens (ovarian or adrenal source in women)

Treatment: If no evidence of hyperandrogen state, then topical minoxidil; finasteridea; hair transplant

Etiology of alopecia

I. Nonscarring alopecia
A. Primary cutaneous disorders
1. Androgenetic alopecia
2. Telogen effluvium
3. Alopecia areata
4. Tinea capitis
5. Traumatic alopeciaa

B. Drugs
C. Systemic diseases
1. Lupus erythematosus
2. Secondary syphilis
3. Hypothyroidism
4. Hyperthyroidism
5. Hypopituitarism
6. Deficiencies of protein, iron, biotin, and zinc
II. Scarring alopecia
A. Primary cutaneous disorders
1. Cutaneous lupus (chronic discoid)
2. Lichen planus
3. Folliculitis decalvans
4. Linear scleroderma (morphea)
5. Central centrifugal cicatricial alopecia
B. Systemic diseases
1. Lupus erythematosus
2. Sarcoidosis
3. Cutaneous metastases