Idiopathic pulmonary haemosiderosis is a rare cause of diffuse alveolar haemorrhage of unknown aetiology. It occurs most frequently in children, has a variable natural history with repetitive episodes of diffuse alveolar haemorrhage, and has been reported to have a high mortality. Many patients develop iron deficiency anaemia secondary to deposition of haemosiderin iron in the alveoli.Examination of sputum and bronchoalveolar lavage fluid can disclose haemosiderinladen alveolar macrophages (siderophages), and the lung biopsy shows numerous siderophages in the alveoli, without any evidence of pulmonary vasculitis, nonspecific/ granulomatous inflammation, or deposition of immunoglobulins. Contrary to earlier reports, corticosteroids alone or in combination with other immunosuppressive agents may be effective for either exacerbations or maintenance therapy of idiopathic pulmonary haemosiderosis.

Intact and thoracic duct-cannulated rats were dialyzed at various intraperitoneal pressures with 5% bovine serum albumin solutions containing 125I-fibrinogen or 51Cr-erythrocytes. Lymphatic transport rates were calculated from the mass of tracer passing into the plasma space as function of tracer concentration in the peritoneal fluid during dialysis periods ranging between 143 and 360 min. Peritoneal protein concentrations were constant over the duration of the experiments. The calculated lymph flow rate was independent of intraperitoneal pressure and in intact rats averaged 2.85 +/- 1.22 microliters/min for uptake of 125I-fibrinogen and 2.60 +/- 1.17 for uptake of 51Cr-erythrocytes. However, the observed fluid loss rates from the peritoneal cavity were sensitive to the intraperitoneal pressure and were 5 to 20 times the calculated lymph flow rate. Mass balance experiments in two rats dialyzed with 125I-fibrinogen indicated that a significant proportion (28%) of tracer leaving the peritoneal cavity is absorbed by the anterior muscle wall of the abdomen and is probably trapped there because of its large molecular weight. Results from 125I-fibrinogen and 51Cr-erythrocyte uptake experiments both indicated that only approximately 30% of the total lymphatic drainage of the peritoneal cavity passes through the thoracic duct in rats.

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Because of reports on tumorigenic activity in different animal species exposed to DDT a decision was made in 1969 to evaluate the long-term effects of DDT on 24 cynomolgus and rhesus monkeys. DDT (20 mg/kg) was given in the diet for 130 months, followed by an observation period that ended in 1994. The two cases of malignant tumor detected in the DDT group included a metastatic hepatocellular carcinoma in a 233-month-old male and a well-differentiated adenocarcinoma of the prostate in a 212-month-old monkey. Benign tumors detected in the DDT group included three cases of leiomyoma, two of which were uterine and one, esophageal. No tumor was detected in the control group of 17 monkeys. Fatty changes in the liver were observed in 52.9% of the DDT group and 29.4% of the control group. More specific signs of hepatotoxicity were documented microscopically in seven DDT monkeys. Severe tremors and histological evidence of CNS and spinal cord abnormalities were observed in six DDT monkeys. The present findings show clear evidence of hepatic and CNS toxicity following long-term DDT administration to cynomolgus and rhesus monkeys. However, the two cases involving malignant tumors of different types are inconclusive with respect to a carcinogenic effect of DDT in nonhuman primates.