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Biomedical subjects

J M Horton

Publications and source records attributed to J M Horton.

17 recordsLinked to original sources

Recurrent pneumococcal pneumonia in an HIV-positive patient with lymphoid interstitial pneumonitis.

Lymphoid interstitial pneumonitis (LIP) is a rare complication of AIDS in adults. Patients with AIDS and LIP are at high risk for bacterial pneumonia caused by Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus. We have described an HIV-positive patient with LIP complicated by recurrent pneumonia due to Streptococcus pneumoniae; recurrence was apparently prevented by maintenance penicillin therapy.

AIDS-Related Opportunistic Infections↗

Growth of Leishmania donovani amastigotes in the continuous human macrophage cell line U937: studies of drug efficacy and metabolism.

We have developed a simple and reproducible system for infecting a human macrophage cell line (U937) with stationary-phase Leishmania donovani promastigotes. Four days after infection, greater than 90% of the promastigotes had transformed to amastigotes. The antileishmanial agents allopurinol riboside, formycin B, 9-deazainosine, and sodium stibogluconate effectively inhibited the growth of L. donovani amastigotes in this cell line. To study the capability of amastigotes in the U937 cell line to carry out biochemical reactions that could be monitored experimentally, we incubated the cells with radiolabeled 9-deazainosine. This purine analogue underwent metabolism in the amastigote phase similar to that occurring in the promastigote phase. This cell line should be useful for studies of parasite maturation and differentiation, parasite-human interactions, and antiparasitic drugs.

Allopurinol↗

The spectrum of relapsing fever in the Rocky Mountains.

Between 1940 and 1976, two cases of tick-borne relapsing fever were reported in Colorado, but since 1977, 23 confirmed cases have occurred. All patients had fever, with a mean of 2.8 febrile episodes (range, one to six). Complications included thrombocytopenia, endophthalmitis, meningitis, abortion, in utero infection, and erythema multiforme. All treated patients were eventually cured with antibiotics, although two pregnant patients failed to be cured by their initial courses of antibiotics. Seven of 21 treated patients had Jarisch-Herxheimer reactions, three of whom required intensive care. Five of nine patients who received tetracycline at an initial dose of 5 mg/kg or more had reactions v none of four patients treated with lower doses. Possible causes of the recent increased incidence include increased physician awareness and reporting, improved diagnostic techniques, and an actual increase due to a larger population at risk. Because summertime visits to the Rocky Mountains are becoming increasingly popular, physicians elsewhere should know how to recognize and treat this condition.

Adolescent↗

Pneumonia in the elderly.

The organisms to which the elderly are most susceptible are different from those affecting younger pneumonia patients. Furthermore, the pathogenesis of the disease varies with age, partly because of an increased incidence of underlying disease in older persons and partly because of the effects of the aging process itself. Presenting symptoms of pneumonia may be more subtle in the elderly than in younger patients, and clinical findings may also vary. Elderly pneumonia patients should always be hospitalized and treated immediately and aggressively with parenteral antibiotics according to results of the Gram stain. Once the pathogen involved is identified, more specific antibiotic therapy is begun. If physicians understand the unique characteristics of pneumonia in the elderly and act accordingly, they should play an important part in decreasing the relatively high mortality from the disease in this age-group.

Aged↗

The immediate care of head injuries.

Anaesthetists have much to contribute as members of a team concerned with the management of a severe head injury. Many factors have been discussed but it must be remembered that their most important duty is to maintain a clear airway.

Airway Obstruction↗