Inhalation of tetranitromethane causes nasal passage irritation and pulmonary carcinogenesis in rodents.

Fischer 344 rats and B6C3F1 mice were exposed for 2 years to vapors of tetranitromethane at concentrations below (0.5 ppm) and slightly above (2 or 5 ppm) the current U.S. recommended occupational exposure limit. Under the conditions of exposure of 6 h/day, 5 days/week, tetranitromethane was found to cause mild irritation and hyperplastic lesions in the nasal passages, but not nasal cavity neoplasms were observed. In contrast, nearly all animals exposed to the higher TNM concentrations, and the majority of animals exposed to the lower concentrations developed alveolar/bronchiolar adenoma or carcinoma; squamous cell neoplasms of the lung also occurred in exposed rats. The extent of the lung tumor response, and the low concentrations of tetranitromethane required for this response, are unprecedented in National Toxicology Program (NTP) studies.     

Hepatocellular failure from hepatitis C infection in two recipients of a single batch infusion of plasma-derived blood products

We report two patients with mild inherited bleeding disorders who acquired hepatitis C infection after receiving single infusion of plasma-derived concentrates prior to the introduction of donor screening and viral inactivation procedures. Both these patients became clinically jaundiced at the time of hepatitis C infection. Despite being HIV antibody negative, an absence of other risk factors of chronic liver disease and treatment with interferon, they progressed to hepatocellular failure in 5 and 12 years following seroconversion. The natural history of hepatitis C infection is still uncertain [1], although it is usually considered that hepatitis C infection progresses slowly, only resulting in clinically manifest liver disease after several decades. In view of the apparent rapidity of onset of liver damage in these two patients, we wonder if older age at time of infection, jaundice during the seroconversion illness or a mild coagulopathy with consequent infrequent exposure to blood products are adverse prognostic features.     

Hemiballismus as a presenting sign of hyperglycemia

A 53-year-old man arrived at the emergency department after the onset of progressive hemiballismus. This movement disorder was the only manifestation of his hyperglycemic state. Prompt recognition of the association of unusual movement disorders with nonketotic hyperglycemia will allow for prompt treatment.     

Turnover of very low-density lipoprotein-apoprotein B is increased by substitution of soybean protein for meat and dairy protein in the diets of hypercholesterolemic men

The effect of dietary protein source on the kinetics of plasma very low-density lipoprotein (VLDL) (Sf 60 to 400) in hypercholesterolemic men was investigated. Using a crossover design, five subjects received sequentially either 1) a high polyunsaturated fat, low cholesterol control diet containing mixed protein from meat, dairy products, and plant sources or 2) an all-plant protein experimental diet in which the meat and dairy protein of the former diet was replaced by soybean protein and soy milk. There was no significant change in the mean values for fasting serum cholesterol and triglycerides over the 6-wk period of administration of the control versus experimental diets. The kinetics of VLDL (Sf 60 to 400) apolipoprotein B were studied at the end of each dietary period after reinjection of 125I-labeled autologous VLDL (Sf 60 to 400). The VLDL apolipoprotein B pool size was similar during the experimental and control protocols; however, the fractional catabolic rate was consistently higher during the experimental protocol (8.5 +/- 1.3 versus 6.5 +/- 1.2 day-1, p less than 0.01) and the production rate of apoprotein B was higher than control in four of five subjects (mean values 18.6 +/- 3 versus 12.6 +/- 1 mg/day/kg, respectively). Administration of an all-plant protein diet significantly increased the fractional turnover rate of VLDL apolipoprotein B, even when no changes in VLDL ago B pool size or VLDL lipid concentrations were observed.