Search

A case of intrapleural displacement of a piece of catheter as a complication of subclavian vein catheterization is reported. A brief review of the literature concerning complications of subclavian catheterization is presented, together with a logical classification and methods of prevention.

A series of 58 cases of traumatic diaphragmatic hernia following blunt and penetrating injury is reviewed. The problems of radiodiagnosis are outlined and the need for barium contrast studies of the entire gastrointestinal tract to ensure recognition of isolated small bowel herniation is emphasized. Surgical access via laparotomy is recommended in the immediate post-traumatic presentation, whereas thoracotomy is preferable in cases diagnosed after a latent interval. Penetrating injury resulted in smaller diaphragmatic defects, greater morbidity and higher mortality due mainly to infective complications.

Tropolone (TR) and 3-hydroxy-4-pyrone were investigated for antithyroid activity following the finding that the 2-hydroxy-oxo pyridine, 3-hydroxy-4(1H)-pyridone (DHP, I), is goitrogenic. Both compounds inhibited the thyroidal uptake of radioiodine in rats and resembled the thioamide drugs in inhibiting the organic binding of iodine by the thyroid gland rather than the trapping of iodide, but were weaker binding inhibitors than 6-methyl-2-thiouracil (MeTU). Both compounds also inhibited the iodination of bovine serum albumin and thyroglobulin, catalyzed by thyroidperoxidase (TPO), lactoperoxidase (LPO), chloroperoxidase (CPO) and horseradish peroxidase (HPO) in vitro. The inhibitory effect of TR but not that of 3-hydroxy-4-pyrone was antagonized by ferrous ions. When fed to mice at levels of intake expected to produce goitre both compounds were toxic and caused severe liver damage. Thyroid enlargement was not observed in any of these feeiding experiments, but the thyroids of mice fed 0.1% TR showed moderate hyperplasia. It was concluded that both compounds are weakly goitrogenic. Hyperactivity was observed in the mice fed TR which may be associated with inhibition of catechol methyl transferase (COMT).

Chronic active hepatitis was selectively induced in mice by the feeding of a diet containing 3-hydroxy-4-pyrone (0.5% by weight) for periods of 6 weeks and longer. This model should be of particular value in elucidating the pathogenesis of drug-induced forms of chronic active hepatitis. Maltol (3-hydroxy-2-methyl-4-pyrone) did not produce any liver lesion.

Mimosine was administered orally to Merino sheep once daily for periods of 1-3 days, either as the isolated compound or in the foliage of Leucaena leucocephala. A single daily dose of mimosine of 450 or 600 mg/kg body weight was effective for defleecing sheep. A daily dose rate of 300 mg/kg was effective for defleecing sheep if given on two successive days. The effectiveness of a treatment for defleecing sheep was related to the concentration of mimosine in plasma following dosing; defleecing ensued when the concentration of mimosine in plasma was maintained above 0-1 mmol/l for at least 30 h. The main products excreted in urine were mimosine and 3,4-dihydroxypyridine (DHP); small amounts of mimosinamine were also excreted. During the first day following dosing, the major excretory product was mimosine; DHP was an important component during the second and third days. In the three days following the start of dosing, between 32 and 53% of the mimosine given was accounted for as mimosine in the urine. Following an intravenous infusion of mimosine, no DHP was detected in urine; most of the mimosine was excreted intact but a small amount (c. 9%) was excreted as mimosinamine.

Mice fed a diet containing 1% (w/w) 3-hydroxy-4(1H)-pyridone (DHP) developed goitre even with a diet high in iodine whereas mimosine (0.5% w/w) did not produce goitre even with a low-iodine diet. Thyroid enlargement was apparent (measured morphometrically) by the 7th week and was advanced by the 11th week. Histologically the goitre was hyperplastic in type. No marked histological changes were found in other organs of mice fed DHP or any organs of mice fed mimosine, except for some atrophy of hair follicles. A single intragastric dose of DHP inhibited the uptake of 125I by the thyroid in the rat but an equivalent dose of mimosine did not. Evidence is presented that the inhibition occurs at the iodine binding step, as with methyl thiouracil, rather than at the iodide trapping step, as with thiocyanate. Chronic treatment of mice with DHP, as with 6-methyl thiouracil, increased the avidity of the thyroid in taking up 125I. The major conjugated form of DHP in mammals, DHP-3-O-glucuronide, was almost as effective a goitrogen as the unconjugated compound when given by mouth but considerably less active than the free form in the blood stream. It was concluded that DHP is a potent antithyroid compound of the thiouracil type with low general toxicity, since mammals can tolerate a level of intake sufficient to produce goitre in spite of iodine supplementation.

An outbreak of liver disease which killed more than 30 dogs at Alice Springs was associated with feeding meat from horses, some of which had developed Indigofera linnaei poisoning (Birdsville horse disease). Affected livers were small, nodular and yellow. There was associated jaundice, ascites, elevation of alanine aminotransferase levels in serum, a tendency to bleed, and signs of hepatic encephalopathy. Histologically, livers showed periacinar necrosis, collapse and haemorrhage, with severe swelling, vacuolation and cholestasis in remaining hepatocytes. Indospicine, a toxic amino acid found in the genus Indigofera, was detected in samples of suspect horsemeat. Experimental feeding of horsemeat containing 16 mg indospicine/kg for 32 days produced periacinar necrosis and hepatocellular swelling in 2 dogs, although neither died nor showed clinical illness. In another experiment, intakes of as little as 0.13 mg indospicine/kg bodyweight/day for 70 days produced periacinar liver lesions, and indospicine concentrations in serum, muscle and liver rose during this period to 3.9, 7.9 and 17.5 mg/kg, respectively. It was concluded that meat from horses grazing I. linnaei can be hepatotoxic for dogs, and that this toxicity may be related to its indospicine content.

One hundred and fifty one patients with symptoms of urinary tract infection were treated randomly in a double blind study with a slow release form of trimethoprim or with co-trimoxazole. Similar cure rates were seen. There was no difference between the proportions of patients in the two groups who acquired trimethoprim-resistant Enterobacteriaceae. Further clinical trials with slow release trimethoprim should be performed.

The non-protein amino acid indospicine, which occurs in the free state in high concentration in the tropical pasture legume Indigofera spicata, causes toxic liver lesions in ruminants. Indospicine is a specific antagonist of arginine and an inhibitor of protein synthesis. The liver lesion was studied in rats at four dose levels by feeding diets containing 96, 48, 24 and 15 per cent. of the seed. The too higher levels caused death of most animals in 2-6 wk. Females were more susceptible than males. The rats fed the 24 per cent. seed diet developed a nodular cirrhosis by 6 wk and survived up to 18 wk. The rats fed the 15 per cent. seed diet developed cirrhosis at 16 wk and survived up to 28 wk. Prior to the onset of cirrhosis the liver showed a characteristic lesion consisting of hepatomegaly, periportal fatty change, portal cellularity due to proliferation of ovoid and cuboidal duct cells, gross enlargement of the hepatocyte cytoplasm nuclei and nucleoli in spite of brisk mitotic activity, and focal centrilobular necrosis. The lesion was interpreted as a restricted hepatic response to a growth stimulus, possibly the mobilisation of tissue amino acids. Improvement occurred in the rats fed the two lower dosage levels after nodular cirrhosis developed, producing a new parenchyma. An attempt is made to relate the lesions to the biochemical derangement induced by a specific amino acid antagonist.

One hundred and thirty-one cases of penetrating injuries of the chest were reviewed prospectively. A policy of conservative management is advocated, based on the intercostal drainage of moderate or large collections of fluid and/or air. The site of the intercostal drain is not an important factor in the management.