Corneal ulceration, measles, and childhood blindness in Tanzania

One hundred and thirty Tanzanian children with corneal ulceration were clinically examined to determine the cause of the ulceration. 37% of the ulcers were associated with recent measles infection and 38% of the children had bilateral ulceration. Herpes simplex virus infection was the commonest cause of ulceration in the series, but vitamin A deficiency was the major cause of bilateral ulceration, subsequent blindness, and mortality in this series. Other significant causes of childhood corneal ulceration were the use of traditional eye medicines, confluent measles keratitis, and ophthalmia neonatorum. We discuss the various mechanisms by which measles causes corneal ulceration, and the priorities in prevention and management of corneal ulceration in African children.

Biliary and urinary excretion of peptide leukotrienes in the domestic pig

The metabolism of leukotriene (LT)C4 and its major routes of elimination in vivo have been studied in four anesthetized domestic pigs administered intravenous [3H]-LTC4 (0.5 microCi/kg). The kinetic profile of LTC4 in the blood was followed for 60 min after administration while the biliary and urinary excretion of LTC4 and its metabolites were determined over a 120 min interval. The total recovery of radioactivity in bile and urine was 45% +/- 1 (n = 3) and 18% (n = 2) respectively. Examination of the radioactive metabolites in bile showed LTD4 (44% of biliary content) and LTE4 (21% of biliary content) as the major identified lipoxygenase products at t 1/2 (27 min). The only identified cysteinyl leukotriene observed in the urine was LTE4 (13% of urinary content). In both bile and urine substantial amounts of radioactivity were detected at the solvent front of the reverse phase chromatographic system indicating the presence of additional unidentified metabolites. We suggest that measurement of metabolites using these sampling methods may be useful for the detection and measurement of peptide leukotriene production in vivo.

Cataract blindness in Africa

Of the estimated 17 million blind from cataract in the world, two to three million live in Africa, where manpower and material resources are inadequate to meet the increasing backlog of treatable blindness. The training of primary health care workers to screen rural Africans for cataract, and of eye auxiliaries and general doctors to select patients and perform surgery, is essential. Motivation for surgery will increase if eye services are made more accessible and reliable. This requires more motivated trained staff and appropriately equipped static eye facilities.

Vitamin A supplements and mortality related to measles: a randomised clinical trial

One hundred and eighty children admitted with measles were randomly allocated to receive routine treatment alone or with additional large doses of vitamin A (200,000 IU orally immediately and again the next day). Baseline characteristics of the two groups were virtually identical for age, severity of measles, and vitamin A and general nutritional states. In 91% of the children serum vitamin A concentrations were less than 0.56 mumol/l. Of the 88 subjects given vitamin A supplements, six (7%) died; of the 92 controls, 12 (13%) died (p = 0.13). This difference in mortality was most obvious for children aged under 2 years (one death out of 46 children receiving supplements versus seven deaths out of 42 controls; p less than 0.05) and for cases complicated by croup or laryngotracheobronchitis. Mortality was several times higher in marasmic than in better nourished children, regardless of study allocation (p less than 0.01).

Trachoma: evaluation of a new grading scheme in the United Republic of Tanzania

A new simplified grading system for trachoma, which is based on the presence or absence of five selected key signs, has been assessed. The level of inter-observer variation and of variation for individual observers (intra-observer variation) showed that the system had good reproducibility following a training period that included interactive clinical teaching. The grading scheme was quickly learned by experienced ophthalmologists and auxiliary health personnel (ophthalmic nurses). The scheme should therefore be suitable for widespread application in field surveys of trachoma.

Histamine releases PGI2 from human pulmonary artery

Histamine caused a triphasic response of human pulmonary artery strips in vitro, consisting of a small initial contraction followed by pronounced relaxation preceding a second contractile response. These characteristics were not seen with other contractile stimuli including 5-hydroxytryptamine, leukotriene D4, and KCl. The relaxant component of this response was ablated by removal of endothelium from the vascular strips or by pretreatment of the tissue with 1 microM indomethacin. Measurement of the PGI2 degradation product 6-keto-PGF1 alpha in supernatants from histamine-challenged tissues confirmed the synthesis of PGI2. Supernatants from unstimulated or leukotriene-challenged tissues contained no detectable amounts of 6-keto-PGF1 alpha. The histamine H1 antagonist diphenydramine inhibited both the contractile and relaxant responses to histamine whereas the H2 antagonist cimetidine affected neither component. The released PGI2 significantly altered the dose-response curve to histamine without inhibiting the maximal contractile responses. We conclude that histamine induces PGI2 formation from pulmonary arterial endothelium via an H1 receptor.

Immune abnormalities in patients with autism

We have begun an investigation on the immune systems of patients with autism in attempt to determine if immune mechanisms are involved in the development of this severe developmental disorder. A study of 31 autistic patients has revealed several immune-system abnormalities, including reduced responsiveness in the lymphocyte blastogenesis assay to phytohemagglutinin, concanavalin A, and pokeweed mitogen; decreased numbers of T lymphocytes; and an altered ratio of helper to suppressor T cells. Immune-system abnormalities may be directly related to underlying biologic processes of autism, or these changes may be an indirect reflection of the actual pathologic mechanism.

The synthesis of N-acetyl-leukotriene E4 and its effects on cardiovascular and respiratory function of the anesthetized pig

The effects of the putative biliary metabolite of the peptido-leukotrienes, N-acetyl-leukotriene (LT) E4 has been investigated in the anesthetized pig. Intravenous bolus doses of synthetic N-acetyl-LTE4 produced minimal respiratory and cardiovascular actions in the pig. N-acetyl-LTE4 was approximately 100-fold less active than LTC4. The actions of N-acetyl-LTE4 were not blocked by pretreatment of the animals with indomethacin (5 mg/kg iv) or with a selective LTD4 antagonist L-649,923 (5 mg/kg plus 2 mg/kg/hr iv). In summary, N-acetyl-LTE4 exerts weak actions in the pig which is consistent with the acetylation process being a mechanism of detoxification.

A simple surveillance system for xerophthalmia and childhood corneal ulceration

A simple cost-effective surveillance system is described for reporting cases of xerophthalmia and childhood corneal ulceration. The system is suitable for use by ophthalmic auxiliaries in developing countries.Presented are the results of a 2-year surveillance involving 15 hospitals in 11 areas of the United Republic of Tanzania. Cases of xerophthalmia in its early stages (characterized by night blindness or Bitot's spots) were found in all areas surveyed. Of almost 300 cases of unilateral and bilateral corneal ulceration, 46% and 79%, respectively, followed a recent infection with measles. The single most important cause of bilateral corneal ulceration was vitamin A deficiency. The surveillance system has proved to be particularly useful as a first step in defining the type and distribution of serious corneal disease in children.

Childhood blindness from corneal ulceration in Africa: causes, prevention, and treatment

Corneal scarring is responsible for approximately 70% of blindness in children in African countries. Recent studies confirm that measles infection is a common predisposing factor and that vitamin A deficiency is responsible for the majority of bilateral corneal ulceration. Herpes simplex keratitis (caused by human (alpha) herpesvirus types 1 and 2), ophthalmia neonatorum, and the use of traditional eye medicines also constitute significant causes of corneal ulceration in children in Africa. Intervention strategies, the management of corneal ulceration in children, and areas for future investigation are discussed.

Differential activity of leukotrienes upon human pulmonary vein and artery

Responses to leukotrienes B4, C4, D4 and E4 were examined in human pulmonary artery and pulmonary vein preparations from surgical specimens. Leukotrienes C4 (LTC) and D4 (LTD) were potent contractants of pulmonary vein over the dose range of 10(-10) M to 10(-6) M, whereas they produced minimal contractions of human pulmonary artery only at concentrations of 10(-8) M or greater. Leukotriene E4 was less potent than LTC or LTD, and leukotriene B4 (LTB) at concentrations up to 10(-6) M had no effect upon either pulmonary veins or pulmonary arteries. Contractions of pulmonary vein by LTD were inhibited in a competitive manner by FPL 55712. Dose response characteristics of LTD and inhibition by FPL 55712 were similar for pulmonary venous and bronchial smooth muscle. We conclude that pulmonary vein smooth muscle has leukotriene receptors comparable to those of bronchial smooth muscle whereas pulmonary artery does not.

In vitro responses of human asthmatic airway and pulmonary vascular smooth muscle

Airway and pulmonary vascular smooth muscle was obtained from the surgically resected lobe of a human asthmatic allergic to grass pollen who presented with an endobronchial carcinoid tumor. Grass antigen induced sustained contractions of bronchial and pulmonary vein, but not pulmonary artery tissue. Capsaicin did not alter the bronchial response to grass antigen. Contractions to leukotrienes B4, C4, D4 and E4 and methacholine were equivalent to those seen in nonasthmatic human lung tissue, whereas those to histamine were strikingly greater and disproportionate to methacholine. The C3a octapeptide Ala-Ala-Ala-Leu-Gly-Leu-Ala-Arg produced contractions of pulmonary vein and pulmonary artery. These findings are compared with those obtained using human lung samples from nonasthmatic individuals.

Professional flab fighting at district level

A health care planning team set up in Harrow to tackle the problem of obesity has started a slimming club with ten-week courses. Authors explain the club's methods and review its progress so far.

The psychological and social effects of myocardial infarction on wives

Eighty-two wives of men suffering a first myocardial infarction were interviewed while their husbands were in hospital, and again two months and a year after they went home. The wives had substantial and persistent psychological symptoms, and the husbands' illness had continuing effects on their work, leisure and social activities, and family life and marriage, their psychosocial disability being comparable to that of the patients. Measures of psychosocial adjustment before the illness and the quality of the marriage and of family life were good predictors of outcome for the wives. The women had a major role in the patients' readjustment during convalescence, and their attitudes and behaviour as well as the general quality of family life were important determinants of the rate and extent of the patients' recovery. The wives of patients with myocardial infarction should have more practical help and advice during the hospital period, and the whole family should be given advice and help throughout the convalescence.

Hospital-treated myocardial infarction and the general practitioner

Patients who had a myocardial infarction were interviewed with their spouses in hospital and after returning home. Advice about rehabilitation, such as that recently recommended by the Working Party of the Royal College of Physicians, was often not received. General practitioners have great opportunities for organising a graded programme of rehabilitation and may often communicate ideas more easily to their patients than hospital staff. However, some practitioners are reluctant to do this work.

Attitudes and advice after myocardial infarction

While medical opinion increasingly favours an active approach to rehabilitation after myocardial infarction, interviews with 40 patients and their relatives showed a low degree of understanding of medical advice and information. There was general satisfaction with treatment, but communication was seen as often being inadequate, vague, and conflicting.