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Biomedical subjects

R S Koff

Publications and source records attributed to R S Koff.

At least 19 recordsLinked to original sources
PubMed1992

Clinical manifestations and diagnosis of hepatitis A virus infection.

Hepatitis A is an acute, necroinflammatory disease of the liver which results from infection by the hepatitis A virus (HAV). The mean incubation period is approximately 30 days. Although the disease is usually self-limited, the severity of illness is age-dependent. In children, hepatitis A is usually asymptomatic, while in adults, symptomatic infection is characteristic and jaundice is common. Fulminant hepatitis A is rare and is also age-dependent. The onset of hepatitis A is often abrupt and characteristic prodromal symptoms are followed, within a few days to a week, by dark urine and jaundice. Mild to moderate tenderness over an enlarged liver is usually detected. Serum alanine and aspartate aminotransferase levels usually both rise rapidly during the prodromal period, reach peak levels and then decrease by approximately 75% per week. Serum bilirubin concentrations reach peak levels later and decline less rapidly than serum aminotransferases. Nonetheless, the period of jaundice persists for < 2 weeks in approximately 85% of cases. Nearly all adult patients with clinically apparent disease experience complete clinical recovery with restoration of normal serum bilirubin and aminotransferase values by 6 months. Relapses and prolonged cholestasis are unusual manifestations of hepatitis A, and even in these circumstances, recovery is the rule and chronic hepatitis is not seen. The diagnosis of hepatitis A requires the detection of immunoglobulin M antibody to HAV in a patient who presents with, or has recently had, clinical features of hepatitis (icteric or anicteric disease) or in an individual with inapparent, asymptomatic infection in whom serum aminotransferase elevations may be detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Long-term hepatic memory for hypersensitivity to nitrofurantoin.

Nitrofurantoin-induced hepatic injury has been established unequivocally as an entity by rechallenge experiences. We reviewed 12 previously reported cases in which rechallenge was described. The longest reported interval between initial injury and rechallenge-provoked injury was 4 yr. We report a 56-yr-old woman who experienced severe hepatocellular injury with brief low-dose administration of nitrofurantoin 17 yr after an initial hepatitis-like illness associated with ingestion of the drug. Despite a temporal relationship to nitrofurantoin administration and histologic features compatible with drug-induced hepatitis, the initial bout of hepatitis had been termed "infectious." Our case appears remarkable for the long interval between initial injury and rechallenge-induced injury. The severity of the hepatic injury seen on rechallenge underscores the concept that the inadvertent rechallenge can be dangerous. Failure to identify the first bout of hepatitis as nitrofurantoin-related, and failure to inform the patient about the possible relationship to nitrofurantoin, raises important risk-management concerns, because hepatic memory of nitrofurantoin hypersensitivity appears to be of long duration.

Chemical and Drug Induced Liver Injury↗
PubMed1990

Effect of differentiation and cell density on glycosphingolipid class and molecular species composition of mouse neuroblastoma NB2a cells.

The effects of cell density and retinoic acid-induced differentiation on the class and molecular species composition of mouse neuroblastoma NB2a cell glycosphingolipids were examined under conditions where the period of culture was controlled. The total amount of neutral glycosphingolipids per cell decreased both with differentiation and as the cells became confluent. The relative amount of the neutral glycosphingolipid classes was not affected by differentiation, whereas there were small but significant changes in the relative amount of the neutral glycosphingolipid classes as the cells became confluent. The total amount of the gangliosides was unaffected by either differentiation or cell density, but there were significant changes in the ganglioside class composition as a result of both cell density and differentiation, and the effects were additive. The molecular species of all the major neutral glycosphingolipid and ganglioside classes were essentially identical, and were altered only slightly by either differentiation or cell density.

Animals↗