How the antibiotic Penicillin was discovered

SEPTEMBER 17, 2011

How the antibiotic Penicillin was discovered

In 1928, Alexander Fleming who was studying variants of baceria in the laboratory of St. Mary's Hospital in London noticed that one of his cultures contaminated with mold caused the bacteria in its vicinity to undergo cell destruction. The mold belonged to the genus Penicillium, which is a fungus.
Hence the name Penicillin. It was developed a decade later.

Penicillins are considered to be one of the useful and frequently prescribe antimicrobial agents. It can fight against various diseases like pneumococcal, streptococcal, staphylococccal, meningococcal, syphilis infections, and etc..

Reflexes That We Barely Notice While Walking

Reflexes That We Barely Notice While Walking

A reflex is an involuntary response to a stimulus. This reflex involves organs (eg. skeletal muscle), its nerve supply as the conducting pathway, as well as the spinal cord. It is important to understand two interesting properties of a reflex.
 (1) Law Of Reciprocal Innervation - this means that flexor and extensor reflexes of the same limb cannot be made to contract at the same time. For example, in walking, when one leg flexes (due to the activity of the flexor muscles), the extensor muscles of that same leg are inhibited to facilitate flexion and not to cause extension.

(2) Crossed Extensor Reflex - still in walking, when one leg flexes, it will cause the opposite leg to inhibit the flexor muscles and allow the extensor muscles to contract (try walking around and as you flex one leg, the opposite will be extended to support your body upright). Can you imagine how we would look like when walking if these reflexes are absent
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6 Free Ways To Prevent Hypertension

6 Free Ways To Prevent Hypertension

Before everything else, I would just like to share this information I got from the World Health Organization Hypertension fact sheet.

Hypertension is considered to be one of the most important causes of premature death worldwide and this problem is growing.

It is estimated that by year 2025, 1.56 billion adults will be living with hypertension.

Sad to say that today, nearly one billion people have hypertension (high blood pressure) and two-thirds of these are in developing countries.

Every year, 8 million people die from hypertension worldwide and about 20 percent of it come from the South-East Asia region. One-third of the adult population in the SEA region has high blood pressure.

As a future doctor, current medical student, and long-time nurse, I always believe that Prevention is better than cure. So here are some ways (lifestyle modifications) that you can do to prevent hypertension from developing or even manage your hypertension if you already have it so that you can prevent further complications.

Note: These are not substitutes to your Anti-Hypertensive medications but sure thing they’re both GOOD partners.

1. Lower the SALT in your diet

Having a dietary sodium intake to no more than 6 grams a day can give you a systolic blood pressure reduction of about 2-8 mm Hg.

2. Have a regular EXERCISE

Even brisk walking for 30 minutes a day or exercising 4 to 6 times a week can give you a 4-9 mm Hg blood pressure reduction.

3. Follow a DASH diet

DASH stands for Dietary Approaches to Stop Hypertension. This diet is rich in fruits and vegetables, and low-fat dairy products with reduced content of saturated and total fat. An 8 week DASH diet can demonstrate a blood pressure reduction of 8-14 mm Hg.

4. Limit ALCOHOL consumption

If you are a heavy drinker, I suggest that you limit your alcohol consumption to no more than two drinks per day (men) and no more than one drink per day (women and lighter-weight persons). The prize? – a 2-4 mm Hg blood pressure reduction.

  

5. Manage and reduce your WEIGHT

Your goal is to attain and maintain a body mass index (BMI) of 18.5 to 24.9. You can have a blood pressure reduction of 5-20 mm Hg per 10-kg weight loss.

There are numerous BMI calculators online; I suggest you use this: http://www.nhlbisupport.com/bmi/

6. Stop SMOKING

Even though this may be hard to give up to some individuals who are already addicted to it but Hey, this can reduce your overall cardiovascular risks like stroke and heart attack.

Those individuals who already are hypertensive can really benefit from the blood pressure reduction from each lifestyle modification. For those who do not have hypertension but is at risk, start now and prevent it from developing.

One more thing, DISCIPLINE plays a key role in implementing these practices. It is also important to get a regular blood pressure check at your nearest hospital, clinic, or health center because hypertension (high blood pressure) often has no warning signs or symptoms, and a lot of people do not realize they have it – no wonder why it’s called the “Silent Killer”.

October Is Breast Cancer Awareness Month

October Is Breast Cancer Awareness Month

Breast Cancer

By definition, it is the malignant proliferation (uncontrolled growth or multiplication) of the cells lining the ducts or lobules of the breast. As one of the most common causes of cancer (excluding Skin CA), it also accounts for about one-third of all cancer in women. It can occur in men too.

Why you should be aware

Females are mostly affected than males with a ratio of 150:1.

Breast cancer (BRCA) is linked to genetics and can be inherited from family generations. A person may have a 10-80% lifetime chance of developing breast cancer if she acquired a mutated gene from either of her parents. All women with a strong family history should be referred to genetic screening programs.

BRCA is a hormone dependent disease. Women without functioning ovaries who never receive estrogen replacement therapy do not develop it. Oral contraceptives or Postmenopausal hormonal replacement therapy (like Estrogen and Progestin) can increase risk for BRCA even though it may have substantial protective effect against ovarian tumors and endometrial cancer.

Women who are exposed to radiation before the age of 30 have a higher risk compared to those exposed after that age.

Moderate alcohol intake can also increase the risk due to “unknown” mechanism but this risk can be modified with Folic acid supplementation.

3 dates in a woman’s life (Major Impact on BRCA Incidence)

First, age at menarche (first menstrual period); women who had their menarche at the age of 16 have a 50-60% risk only compared to those who had theirs at the age of 12.

Second, age at 1^st full-term pregnancy; It is lower (30-40% risk) in women who had theirs at the age of 18 compared to women who have never given birth to a viable, or live, infant.

Third, age at menopause; the median age of menopause is at 62. Those who had theirs 10 years before the median age have lowered their risk by 35%.

What to do?

If you are concerned or worried that you may be at risk, consult a doctor, a gynecologist maybe.

Free Breast Self Exam anyone? You can do it yourself; here is a video below on how to perform it (credits to expertvillage). *For women, it is advisable to perform this a week after your menstrual period.

WHO 2011: Tuberculosis Cases Declining

WHO 2011: Tuberculosis Cases Declining

Nice to know TB cases are going down. I believe this is the result of progressive advances in medical treatment and prevention.

Tuberculosis is one the oldest diseases known to affect humans and also the major cause of mortality worldwide. This disease is caused by bacteria, Mycobacterium tuberculosis, and it usually affects the lungs. But how can one get TB?

The Transmission 

It is commonly transmitted from a person with infectious pulmonary tuberculosis to others by droplet transmission, through coughing, sneezing, or speaking. This droplet may contain as many as 3000 infectious nuclei per cough and may remain suspended in the air for several hours until it reaches the respiratory passage of another person when inhaled.

The Factors

Studies of close-contact situations have shown that TB patients whose sputum contains AFB visible by microscopy are the most likely to transmit the infection. Patients with sputum smear–negative/culture-positive tuberculosis are less infectious.

Crowding in poorly ventilated rooms is one of the most important factors in the transmission of this disease since it increases the intensity of contact with a TB-positive case.

In summary, the risk of acquiring this infection is determined mainly by exogenous factors, including the delays in seeking medical care and in making a diagnosis
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There's Probably E.Coli On Your Cellphone

There's Probably E.Coli On Your Cellphone

This is a response from the latest news I got from WebMD. A study showed that 92% of the cell phones in U.K. had bacteria on them including E. coli. Aside from cell phones, they also inspected the hands of the owners and found out that 82% of them also had bacteria on them.

Of all bacteria, why only E. coli was mentioned?

E. coli comes from fecal bacteria which can survive for several hours. It normally resides in the colon without causing diseases but can be virulent. When that happens, it can cause a wide array of signs and symptoms depending on the site of infection like:

UTI

E. coli is the most common cause of urinary tract infection and accounts for about 90% of first UTI in young women. Signs and symptoms would include frequent and painful urination, urine that contains blood or pus.

Diarrhea

This is extremely common worldwide and affects infants or adults. Traveler’s Diarrhea affects adults from developed countries who travel to undeveloped countries especially when they have not developed immunity during their childhood. It can cause death when diarrhea results into severe dehydration.

Sepsis

This results when the body defenses are weak and E. coli reaches the bloodstream. Newborns are susceptible since they still lack antibodies.

Meningitis

E. coli is considered to be one of the leading causes of meningitis in infants.

Pneumonia

It also a common cause of hospital acquired pneumonia.

*By the way, E. stands for Escherichia and was named after Theodor Escherich, who isolated this type of bacteria. 

I hope this article helps
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Effects of Toxins Produced By Staphylococcus Aureus

Effects of Toxins Produced By Staphylococcus Aureus

CYTOLYTIC TOXINS:

Alpha Toxin (a-Hemolysin)

This exhibits a wide range of activities including disruption of lysosomes, damages macrophages and platelets, and as well as producing tissue damage after the establishment of infection.

*Cytolysis means destruction of cell; Hemolysis means breakdown of a red blood cell; Lysosomes are cellular organelles responsible for breaking down waste materials and cellular debris.

Beta Toxin (Staphylococcal Sphingomyelinase)

B-toxin has the ability to produce a “hot-cold” lysis.  For example, if incubation temperature is increased, the hemolytic activity also increases; this toxin also leads to sphingomyelin degradation that leads to hemolysis when the cells are chilled.

Delta Toxin

This is a relatively active toxin whose detergent-like properties produce damaging effects on cell membranes.

Gamma Toxin

Its precise mode of action is unknown but it is said to be essential for hemolysis and toxicity.

Leukocidin

This toxin attacks polymorphonuclear leukocytes and macrophages and induce cytolysis.

ENTEROTOXINS

These toxins have the ability to induce vomiting and diarrhea in humans after oral administration. The vomiting receptor site for this toxin is the abdominal viscera; from there the sensory stimulus reaches the vomiting center through the vagus and sympathetic nerves.

The diarrhea effect has been attributed to the inhibition of water absorption from the lumen of the intestine and to increased transmucosal fluid flux into the lumen.

EXFOLIATIVE TOXINS

They cause lysis of the intracellular attachment between cells of the epidermis.

TOXIC SHOCK SYNDROME TOXIN-1

Toxic shock syndrome, a severe and fatal disorder characterized by multiple organ dysfunction, is associated with Staphylococcus aureus infection.