Nerdy Science Blog

Egg is revealed to have more nutritional benefits in many studies presented at Experimental Biology 2009.  Both researchers from University of Connecticut  and University of Kansas Medical Center found that having eggs for breakfast can reduce the consumption of calories throughout the day.  People who eat protein-rich eggs actually feel less hungry and more satisfied.  According to a journal published in 2008’s International Journal of Obesity (1), having eggs for breakfast can help in weight loss.  Researchers from Florida State University also found that eggs do not cause cardiovascular disease.

Reference:

1. Vander Wal JS, Gupta A, Khosla P, and Dhurandhar NV (2008), Egg breakfast enhances weight loss, International Journal of Obesity, 32(10):1545-51.

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Ever heard pick-up gurus always tell people try to make skin contact?  They claimed skin contact can create a special attachment between the target and you.  Researchers at Sahlgrenska Acamedy, Sweden, proves the pick-up artists are correct.

Researchers discovered that there are specialized nerve fibres in the skin for skin stroking, called CT nerves or C-tactile, which have direct route to the brain. Line Löken, a postgraduate student in neurophysiology at Sahlgrenska Acamedy said that the skin stroking impulses can travel to the brain that plays a role in emergence of feelings directly without any obstacle.  They even found that when pain and skin stroking were introduced at the same place, the stroking impulses actually halted the pain impulses.

According to Associate Professor Håkan Olausson, researchers used a technique call microneurography to detect the signals.  They insert a thin electrode into a nerve in the forearms to detect the impulses.  The researchers then use a robot that brush the same square centimetres area of skin to determine which nerve fibre is responsible for the pleasant or unpleasant feeling.  Researcher Johan Wessberg said that they found CT nerves are the one that responsible for the pleasant touch sensation.

The paper is published in April issue of Nature Neuroscience.  The authors include Line S Löken, Johan Wessberg, India Morrison, Francis McGlone, and Håkan Olausson

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As the name denotes, Hepatitis B is a disease caused by Hepatitis B virus. It causes inflammation to take place in the liver, thus the name of hepar (liver) and –itis (inflammation). The Hepatitis B virus is composed of a surface protein coat, a nucleocapsid and internal proteins and nucleic acid. It has three antigens, the surface, core and the ‘e’ antigens. The surface antigen is found in an excessive amount during infection while the core antigen is found only in the blood as an internal part of a complete Hepatitis B virion. The ‘e’ antigen is associated with complete infectious Hepatitis B virion, thus the existence of such antigen in the blood denotes the infectivity of a person.

Hepatitis B is a serious endemic disease throughout the world. Today, at least 280 million cases had been recorded. The natural reservoirs of this virus are humans and probably chimps and monkeys.

Hepatitis B virus is transmitted parenterally by needles and intravenous equipment, sexually, unscreened blood products and perinatally. Thus, risk factors include: spouse of an acutely infected person, individuals who have unprotected sex, health care workers exposed to blood, drug abusers who share needles, recipients of repeated transfusions, patients on hemodialysis, recipients of a transplanted organ and children born to an infected mother.

Once the virus enters the body, the virus will first infect the liver cells (hepatocytes). Their nucleocapsid proteins will invite cytolitic T cells to destroy the infected liver cells. The differences of T cell responsiveness in a patient determine two outcomes – those who recover after acute hepatitis and those who progress to chronic hepatitis.

One of the main sequels of Hepatitis B infection is hepatocellular carcinoma, which is a major health problem worldwide. 80% of the world’s hepatocellular carcinoma is caused by Hepatitis B virus.

Most primary Hepatitis B infections are self-limiting and resolve by itself within 3 to 6 months. Most infections are asymptomatic. Prodromal symptoms (before the acute onset of the disease) includes – anorexia, nausea, vomiting, fatigue, malaise, arthralgias, myalgias, headache, photophobia, pharyngitis, cough and low-grad fever. When the liver is damaged to certain degree, symptoms related to liver dysfunction present themselves. This include – jaundice, dark urine, clay-colored stools, tender hepatomegaly and right upper-quadrant pain.

In the diagnostic laboratory tests, changes in serum alanine aminotransferase and aspartate aminotransferase levels are expected. Jaundice is usually visible in the sclera or on the skin when the serum bilirubin is more than 2.5mg/dl. There will also be changes in Prothrombin time and albumin level. Liver biopsy is usually unnecessary.

With the help of the results from laboratory tests, physicians could differentiate Hepatitis B with other diseases which could also cause inflammation of the liver for example infectious mononucleosis, cytomegalovirus, herpes simplex and other diseases which could produce similar presentations, signs and symptoms; for example toxoplasmosis, leptospirosis, alcoholic hepatitis, acute cholecystitis, common duct stone, ascending cholangitis and carcinoma of the pancreas. Other diseases which could cause metabolic liver disorders include Wilson disease, alpha1-antitrypsin deficiency, hemochromatosis, and sometimes a doctor would even need to rule out metastasis to the liver from another cancer site, which could also produce similar clinical presentations.

All patients with suspected hepatitis should undergo serologic tests such as – Serum HBsAg, Serum IgM anti-HBc, Serum immunoglobulin G anti-HBc, HBeAg, Serum anti-HBs and quantitative HBV DNA. The positive tests could proves that the patient is infected by Hepatitis B virus instead of all the other diseases stated above. In a patient infected with Hepatitis B, HBsAg presents except in patients without ongoing viral activity. Immunoglobulin G anti-hepatitis B core antigen is also present. The immunoglobulin M anti-HBc is present with acute or recent infection. It is useful for distinguishing acute from chronic infection in patients found to be HBsAg positive for unknown during (for example blood donors). HBeAg and HBV DNA are qualitative markers for active Hepatitis B virus replication.

Putting the result of serological tests and other additional laboratory findings of elevated ALT and AST level, elevated alkaline phosphatase level, elevated serum bilirubin level, hypoalbuminemia and prolonged prothrombintime, a doctor could end up with the diagnosis of chronic Hepatitis B.

Treatment of acute Hepatitis B includes:

1. Supportive care – high-calorie diet, intravenous hydration and parenteral nutrition if patients are vomiting or unable to maintain oral intake. Avoid alcohol and drugs metabolized by the liver. Bile-salt sequestrant resins can be given if there is severe itch, for example Cholestyramine.
2. Antiviral therapy – in rare instances, treatment with Lamivudine (antiviral medication) has been successful.
3. Liver transplantation for fulminant hepatic failure and grade III or IV encephalopathy.

Future care of the patient includes

1. Monitor for clinical and biochemical recovery – disappearance of HBsAg after apparent clinical recovery from acute Hepatitis B. Those who failed to be HBsAg-negative could be inactive carriers. Such patients are the source of infection and should take good care of their conduct so that the virus could not be spread to other people around them. The likelihood of becoming a HBsAg carrier is high among neonates, patients who receive hemodialysis and immunosuppressed patients.
2. Monitor for possible complications such as – serum sickness-like syndrome which includes arthralgia, arthritis, rash, angioedema, hematuria and proteinuria. Other comaplications are glomerulonephritis, nephrotic syndrome, polyarteristis nodosa, fulminant hepatitis, chronic hepatitis and last but not least, hepatocellular carcinoma.

The treatment for chronic Hepatitis B.

Five medications are approved for treatment. They are interferon alpha, pegylated interferon alpha, Lamivudine, Adefovir dipivoxil and Entecavir. Among these five available drugs, PEG IFN (pegylated interferon alpha) has supplanted standard IFN (interferon).

Researches show that PEG IFN benefits by achieving the highest rate of HBeAg responses after a year of therapy and does not readily induce viral mutations. It requires finite-duration of therapy. While the disadvantages of PEG IFN is that it is administered through subcutaneous injections, associated with inconvenience and intolerability and not safe in patients with cirrhosis. Thus, oral antiviral is better tolerated by the patients even though it requires long-term therapy in most patients.

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Congratulations to Datuk Dr Maximus Ongkili and Fadillah Yusof for staying in Malaysia new Prime Minister Datuk Seri Najib Razak’s cabinet.  The Najib administration was announced on Thursday.  Datuk Dr Maximus Ongkili is still the minister of Science, Technology and Innovation ministry, and Fadillah Yusof remains as deputy.

Previous year has been quiet but we will continue to watch you.

The scientific name for flatworms is Platyhelminthes (platy- is Greek and it means flat, while helminth- means worm). In basic zoology, the Platyhelminthes can be divided into Turbellaria (non-parasitic animals) and 3 other parasitic groups – the Cestoda, Trematoda and Monogenea. Even thou four of them belong to the same phylum, in the medical world, only 2 out of 3 of the parasitic group could play the role of being parasitic in the human body. They are the Cestoda and Trematoda. Monogeneas in the other hand are mostly parasites which require a host, in most of the cases being fish, amphibians or reptiles.

Cestodes (tapeworms) and Trematodes (flukes) have very complex life-cycles but generally, it could be divided into few stages. In the mature stages, these flatworms live as parasites in the digestive systems of vertebrates until they are mature enough to release gravid ‘eggs’ or part of their body (segment). These eggs or segments would then be released to the outside world together with the feces of the definitive host. Another person could be infected by such parasites if they consumed undercooked protein of infected fish or pork. Such parasites are generally transmitted via the oral-fecal route.

The Platyhelminthes are bilaterally symmetrical animals. The have a distinct top, head and tail ends.

The Cestodes have a very distinct head and body structure. The Cestode’s head (scientifically called the Scolex) enables the parasite to attach itself to the intestine of its definitive host. This is achieved by the existence of sucking grooves around the head which function like suction cups. This would prevent them from being ‘flushed out’ by the peristalsis of the intestines. Its long body is segmented, and these segments are known as proglottids. The whole strip of segments resembles a tape, which gave them the name “tapeworm”. The mature proglottids are released by the tapeworm and later on mixed together with the feces while they leave the host. The genesis of such infestation is by oral-fecal route. Some of the well known tapeworm parasites are Diphyllobothrium latum. A person is infected through the ingestion of infected fishes. Another popular example is the Taenia solium, whose eggs and larvae could be found in fecal-contaminated water and pork. Taenia solium can cause a serious disease called the neurocysticercosis where the cysticerci are found in the brain. Taenia Saginata is yet another example of tapeworm where a person is infected by ingesting undercooked beef.

The Trematodes usually infect mollusks as the first host in its life cycle. Eggs are shed with the definitive host’s feces. If the eggs are released into water, it will releases free-swimming larval forms which could infect other intermediate host. The flukes can be divided into 2 groups – the tissue flukes, which infect the lungs, bile ducts and other biological tissues. Examples of tissue flukes include Paragonimus westermani, Clonorchis sinensis and Fasciola hepatica. The other group is called the blood flukes. They inhabit the blood in part of their life cycle and one of the examples is Schistosoma.

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