It's called mad cow disease because it affects a cow's nervous system, causing a cow to act strangely and lose control of its ability to do normal things, such as walk.
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is the only internal human organ which can regenerate
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Skin fungus infections are hard to recognize. The itching, flaking, redness, and thickened skin of fungal infections can look just like other types of dermatitis or skin allergies. In fact, eczematous skin often becomes infected with fungi, so both are present simultaneously. Doctors use microscopes to help them diagnose skin fungus infections, so there’s no way you can really be sure at home. The Advisory will focus on the five most easily recognized skin fungus infections, but even after looking at the pictures don’t be too confident.
Every year, over 10% of the U.S. population develops this problem. Probably 75% of us will have athlete’s foot at some time during our lives. The most common form occurs between your third, fourth, and fifth toes, sometimes spreading to the sole. Between the toes, your skin becomes white, moist, and easily rubbed off; the tops of the toes may be red, dry, and flaky. Intense itching and burning are the rule. Athlete’s foot usually occurs with hot, moist conditions, or if you wear shoes constantly.
Jock Itch (tinea cruris). The same conditions of heat, moisture (sweat) and poor air circulation leading to athlete’s foot also cause fungus infections of the groin, or jock itch. As its name implies, intense itching and burning are the usual symptoms. You will also find redness, flaking and peeling on the inner thighs, pubic area, and scrotum.
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Theis brownish-red, itchy discoloration affects the underarms, corners of the mouth, rectal area, and beneath the breasts. The same type of fungus causes vaginal yeast infections (candida albicans).
Tinea Versicolor. This fungus actually changes the color of the skin it infects; the patches may be lighter or darker than your normal surrounding skin. This spotted pattern and the fine scaly flakes at the
margins make this fungal infection the easiest to identify. Since itching and irritation are mild, it’s also the least bothersome.
Warmth, humidity, sweating, and poor air circulation all help bring about these fungal infections. But they are contagious, too. Athlete’s foot is believe to be passed on locker room and shower floors, and by sharing footwear and socks; you can acquire tinea versicolor from vinyl surfaces of weight lifting benches; and of course ringworm is contagious through direct contact (usually kids).
Because of all these factors, prevention is a matter of both personal hygiene and minimizing contact with potential carriers or contaminated objects.
There are several effective OTC anti-fungal medications. Because different fungi affect different locations, medications are sometimes specific for those locations. The recommendations below should help you sort it out.
Athlete’s Foot - Tolnaftate is the only OTC medicine approved for both prevention and treatment of athlete’s foot. Be patient, though. It could take a month or more of daily treatment for it to completely clear. Consider preventive use if the condition recurs.
Tinea Versicolor - Although not a Category I agent, selenium sulfide shampoo is universally recognized by dermatologists as an effective OTC remedy for tinea versicolor. Since it often affects large areas of the trunk, applying this shampoo once a day for five minutes, then washing off, is a lot easier and cheaper than using a whole tube of anti-fungal cream twice daily. Tinea versicolor also tends to recur easily, but this shampoo can prevent it if used once a week after the initial 2-4 week treatment cycle.
Candidiasis, Ringworm, and Jock Itch - Miconazole or clotrimazole are quickly effective (1-2 weeks) for each one of these conditions, and come in cream, lotion, or spray. Avoid alcohol-based products since they can sting chafed and delicate skin.
Courtesy--http://quickcare.org/skin/fungus.html
Images-- Wikipedia,Flickr
Bacille Calmette Guerin (BCG) is the current vaccine for tuberculosis. It was first used in 1921. BCG is the only vaccine available today for protection against tuberculosis.It is most effective in protecting children from the disease.
Bacille Calmette Guerin (BCG) containes a live attenuated (weakened) strain of Mycobacterium bovis. It was originally isolated from a cow with tuberculosis by Calmette and Guren who worked in Paris at the Institute Pasteur. This strain was carefully subcultured every three weeks for many years. After about thirteen years the strain was seen to be less virulent for animals such as cows and guinea pigs. During these thirteen years many undefined genetic changes occurred to change the original stain of M. bovis. This altered organism was called BCG. In addition to the loss of virulence, other changes to BCG were noted. These included a pronounced change in the appearance of colonies grown in the laboratory. Colonies of M. bovis have a rough granular appearance whereas colonies of BCG are moist and smooth.
BCG was first used as a vaccine to protect humans against tuberculosis in 1921.At first, cultures of BCG were maintained in Paris. Later, it was subcultured and distributed to several laboratories throughout the world where the vaccine strain called BCG continued to be maintained by continuous subculture. After many years it became clear that the various strains maintained ain different laboratories were no longer identical to each other. Indeed, it was likely that all the various strains maintained by continuous subculture continued to undergo undefined genetic changes. Indeed, the "original" strain of BCG maintained at in Paris had continued to change during the subcultures needed to maintain the viability of the culture. To limit these continuing changes the procedures needed to maintain the strain were modified. Today, the organism is maintained in several laboratories using a "seed lot" production technique to limit further genetic variation using freeze-dried (also called lyphilized) cells so that each batch starts with the same cells.
After extensive tests in animals, BCG was first used as a vaccine in 1921. It was given orally to infants. Since this time the vaccine has been widely used. Today, it is estimated that more than 1 billion people have received BCG.
BCG is widely used and the safety of this vaccine has not been a serious issue until recently. There is a concern that use of the vaccine in persons who are immune compromised may result is an infection caused by the BCG itself. Also, even among immune competent persons, local reactions, including ulceration at the site of vaccination may result in shedding of live organisms which could infect others who may be immune compromised.
The early use of BCG was marked by a tragic accident. In Lubeck more than 25% of the approximately 250 infants who received a batch of the vaccine developed tuberculosis. It was later recognized that this batch was accidentally contaminated with a virulent strain of M. tuberculosis.
The BCG vaccines that are currently in use are produced at several (seven?) sites throughout the world. These vaccines are not identical. To what extent they differ in efficacy and safety in humans is not clear at present. Some differences in molecular and genetic characteristics are known. What is not known is if the "BCG" from one manufacturer is "better" than one produced at another site. Each BCG is now know by the location where it is produced. For example, we have BCG (Paris), BCG (Copenhagen), BCG (Tice) and BCG (Montreal) among others.
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I Cancer - Practical Applications and Cellular Reproduction
A) Definition of Cancer
1) neoplasm of proliferating cells, cell division out of control, cells
produced are useless, compete with healthy cells for nutrients
and oxygen
2) Benign versus malignant
a) benign is a sedentary mass of cancerous cells
b) malignant is a moving mass of cancerous cells
metastasis
3) Basic types
a) carcinoma - arises from body's outer coverings and inner linings
b) sarcoma - arises from body's supporting structures
c) lymphoma - arises from lymph system
d) leukemia - arises from blood marrow in bone, spleen
B) Causes of Cancer
1) Carcinogenic chemicals
2) UV Light
3) Viruses
4) Mechanism - mutations and oncogenes
a) cell growth is no longer under control, mutagenic agents
cause mutations in proto-oncogenes (genes that encode for
proteins that stimulate cell division and growth), these genes become
oncogenes that cause cancer
| Problem | Effect |
| Mutation in proto-oncogene | creates hyperactive protein |
| Multiple copies of a gene | produces excess amount of protein |
| Movement of gene locus | no longer under control from original locus, produces excess amount of protein |
5) Mechanism - mutations to tumor-suppressing genes
a) mutation in a gene that inhibits cell division, produces
a faulty protein that can not stop cell division
C) Consequences
1) alteration of DNA
2) Cancerous growth - tumor or polyp
D) Diagnosis
1) Radiology (x-rays and dyes)
2) Ultrasound imaging
3) Endoscopy - fiber optics (example - colonoscopy, inside the esophagus)
4) Biopsy
5) Monitoring chemical levels in the blood (blood testing)
6) Mammogram for breast cancer
E) Treatments
1) Surgery (physical removal)
2) Radiation Therapy (Radiation - high energy particle beams)
3) Chemotherapy (cytotoxic drugs - chemotherapeutic agents)
disrupts DNA synthesis or mitosis, affects normal cells also
some bad side-effects
4) Hormone therapy - used for cancers associated with sex hormones
tamoxifen suppresses estrogen used to treat breast cancer
anti-androgens used to treat prostate cancer (reduce androgen levels)
5) Boosting the immune system (stimulate the production of cells that
recognize healthy versus unhealthy or cancerous cells)
6) Diet
7) Monoclonal antibodies - silver bullets, respond to protein on cancer cell
surface and deliver cytotoxic drug
F) Types of Cancers - some examples of virus related cancers
1) Leukemia - associated with bone marrow cancer
2) HIV - associated with cancers in blood vessels (Kaposi's Sarcoma)
3) Hepatitis B, C virus - associated with liver cancer
4) Papilloma virus - causes genital warts and benign cancers, associated with cervical cancer
G) Types of Cancers - some examples of Carcinogen related cancers
1) Lung cancer - tobacco
2) oral cancer - chewing tobacco
3) Bladder and rectal cancer
H) Types of Cancers - some examples of Light related Cancers
1) UV light - lesions and melanomas
I) Other cancers
Breast cancer in females and males
Prostate cancer in males
J) Summary - types and incidence
II Cellular Reproduction
A) Two types of cell division
1) Mitosis and Fission- results in exact duplication of parent cell (2N to 2N)
Binary Fission - special cell division in bacteria
2) Meiosis - results in production of gametes (2N to 1N)
B) Mitosis
1) Functions
a) cell reproduction
b) replacement of cells
c) healing
d) growth
e) regeneration (in some organisms)
2) Phases
a) Cell cycle (cell division, G1, S - duplication phase, G2)
b) S phase - duplication of chromosomes, sister
chromatids bound by centromere
c) Prophase (appearance of chromosomes)
d) Metaphase (lining up along the equator)
e) Anaphase (splitting of the chromosomes)
f) Telophase (segregation, cell plate appears in plants)
g) Differs between plants and animals
animals (see whitefish blastula above)
plants (onion root tip you will observe in lab)
h) Cytokinesis (splitting of cytoplasm) not part of mitosis
in animals
C) Meiosis - characteristics
1) Function - sexual reproduction
a) diploid (2N) adult produce gametes (sperm, eggs = haploid - 1N)
2) two cell divisions in order to produce haploid gametes
3) restricted to gonads
D) Meiosis - mechanics of the phases
1) Meiosis I: prophase I, metaphase I, anaphase I, telophase I
a) metaphase I - homologous pairs line up across the equator
from each other
b) anaphase I - homologous pairs are split (reduction of
chromosomes = 2N - 1N condition)
2) Meiosis II: prophase II, metaphase II, anaphase II, telophase II
a) metaphase II - chromosomes line up along the equator
like they were going through a mitotic division
b) anaphase II - chromatids are split by breaking the
centromere (in animal cells)
E) From Meiosis to gamete production
1) Making sperm
| Cell Type | Cell Division | Product |
| Spermatagonium (2N) | Undergoes Mitosis | Primary Spermatocyte (2N) |
| Primary Spermatocyte (2N) | Undergoes Meiosis I | 2 Secondary Spermatocytes (1N) |
| Secondary Spermatocyte (1N) | Undergoes Meiosis II | Spermatid (1N) |
| Spermatid (1N) | Maturation - no cell division | Sperm cell (1N) |
2) Making eggs| Cell Type | Cell Division | Product |
| Oogonium (2N) | development - no cell division | Primary Oocyte (2N) |
| Primary Oocyte (2N) | Undergoes Meiosis I | Secondary Oocyte (1N) and First Polar Body (1N) |
| Secondary Oocyte (1N) | Undergoes Meiosis II (stimulated by fertilization from sperm) | Ovum (1N) and Second Polar Body (1N) |
F) Maintaining Genetic Variation
1) Genetic Recombination
2) Crossing Over 
