Question

1. How does lead and mercury poisoning affect the body?

2. Answer the following questions about hepatitis:

     A. List and discuss the several types of hepatitis.

     B. Give the disease progression (pathophysiology) of hepatitis.

     C. What are the signs and symptoms of hepatitis?

     D. What is toxic or nonviral hepatitis?

Answer 1

Ans) 1) Toxic effects of Lead:

bone, gut, kidney, blood, CNS, cellular metabolism, gametotoxicity, immune system

Skeletal changes- in bone shape
kidney Damage- chronic exposure (nephritis)

Interferes with neurotransmitter function and metabolism- dopamine, GABA acetylcholine
Interacts and competes with Ca+ function
causes encephalopathy -brain damage- characterized by delusions hallucination and ataxia.

Elemental Mercury - absorbed as a vapor and HIGHLY TOXIC -it readily vaporizes at room temperature and exposure can lead to damage of CNS.
Readily uptake from lungs and oxidized in red blood cells causing mainly neurological damage.

2) A. Types of Hepatitis:

- Hepatitis A:

accounts for about 20% of acute cases of viral hepatitis in US. spread via fecal contamination and poor hand washing. strictly an acute infection- patient either makes a full recovery or dies of acute hepatic failure

Hepatitis B
accounts for about 60% of acute viral hepatitis in US. spread via blood/body fluids. blood transfusions, needle sticks, sexual contact. a person can be asymptomatic carrier of this. can become chronic hepatitis.

Hepatitis C
most common form of Non A, non- B hepatitis. first identified in 1970s. spread via blood/body fluids. can also get from contaminated shellfish that is eaten raw or undercooked. 85% patients will develop chronic hepatitis.

Hepatitis D
uncommon in north america. prevalently seen in eastern europe, mediterranean, african, and out america. mainly seen in IV drug users. first identified in 1977 as antigen, then separate virus in 1980. must co-excist with hepatitis B (chronic)

Hepatitis E
similar to hepatitis A in symptoms/prognosis. causes up to 20% mortality in pregnant women in the 3rd trimester. first in 1980. transmitted via fecal contamination, but person to person transmission is uncommon. typically transmitted via water or food that is contained with fecal matter. cause of most of the water-contamination epidemics in india. seen anywhere that fecal contamination of water is present. some say this may become the world's most common hepatitis

Hepatitis G
does not seem to make people more than mildly sick. transmitted via blood/body fluids. genetically very similar to hepatitis C. appears to have protective effect in HIV patients. 75% people who contract will recover completely but most carry the virus in their bloodstream for a long time. 25% develop chronic hepatitis.

B.Pathophysiology of hepatitis virus infection and related liver disease:

Persistent infection appears to be due to weak CD4+and CD8+ T-cell responses during acute infection, which fail to control viral replication. When chronic infection is established, HCV does not appear to be cytopathic.

C. Signs and symptoms of Hepatitis:

- Hepatitis A (HAV)

Jaundice - few days of onset
<70% Adults are symptomatic
Clinical Illness 1-2 weeks

- Hepatitis B (HBV)
Asymptomatic in 50% of adults
Prodromal Phase
Icteric Phase (1-3 weeks)
Chronic infection: 10% of acute cases
Fulminating: fatal cases of acute hepatic necrosis

- HBV Prodromal Phase
Anthralgias and rash
dark urine 1-2 before jaundice

- HBV Icteric Phase
1-3 ( Jaundice Phase)
Grey stool
Hepatomegaly (fat liver)

- Hepatitis C (HCV)
Symptoms range from mild to asymptomatic
>90% are asymptomatic
>20-30% have Jaundice
>10-20% Abdominal Discomfort

- HCV Long term outcomes
Liver failure/ Cancer
Cirrhosis 50% of chronic cases

- Hepatitis D (HDV)
Same as HBV

- Hepatitis E (HEV)
Same as HAV

D. Non-viral hepatitis is an inflammation of the liver that can cause scarring on the liver (cirrhosis), liver cancer, liver failure and death. There are 3 types of non-viral hepatitis: Toxic hepatitis is caused by chemicals, drugs (prescription and over-the-counter) and nutritional supplements.