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Biomedical subjects

D H Connor

Publications and source records attributed to D H Connor.

At least 37 records · Page 2Linked to original sources

Progressive disseminated penicilliosis caused by Penicillium marneffei. Report of eight cases and differentiation of the causative organism from Histoplasma capsulatum.

Eight patients with fatal penicilliosis caused by Penicillium marneffei are reported. All were natives of southern rural Guangxi, and none had a predisposing illness or evidence of altered immunity. The distinctive features of P. marneffei include proliferation of yeast-like cells within histiocytes, followed by the development of focal necrosis and, eventually, large abscesses. Outside the histiocytes, the fungi elongate, become slightly curved, and form septa. In vitro, P. marneffei produces a red pigment which diffuses into the culture medium. The differentiation between P. marneffei and Histoplasma capsulatum is described, and possible reservoirs for P. marneffei are discussed.

Adolescent↗

Chromomycosis in Zaire.

Biopsy specimens from 17 Zairians with chromomycosis are described. Patients ranged in age from 20 to 50 years, with a mean of 37.2 (+/- 10.2). Chromomycosis was suspected clinically in only 3 of the 17 patients. In 14 patients the lesions were on the lower limbs and in 3 on the arms. The lesions were chronic, in one patient persisting for 9 years. The diagnosis was established in each patient by finding typical thick-walled brown fungi within the lesions. Some fungi were in abscesses, others were in histiocytes or giant cells. The fungi and the inflammatory reaction were concentrated in the upper dermis. Acanthosis, hyperkeratosis, and parakeratosis were constant features and pseudoepitheliomatous hyperplasia (PEH) was a feature in 10 patients. Transepithelial elimination (TEE) of fungi was a conspicuous feature in eight specimens. Microscopic features suggested TEE in an additional three. PEH and TEE were associated in all specimens. In patients with TEE, the diagnosis may be confirmed quickly by smearing surface scrapings and finding the characteristic brown fungi.

Adult↗

The onchocercal nodule: interrelationship of adult worms and blood vessels.

This study of onchocercal nodules reveals an intimate relationship between the cuticle of Onchocerca volvulus and the capillaries of the host. Perfusion of blood vessels with India ink and other special techniques reveal a proliferation of capillaries around the worms and communication between small vessels and the spaces around the worms. The space around the worm is continuous with the central fibrin lake. These findings, together with the fact that the worm's gut contains hemosiderin, suggest that the worm subverts the vascular reaction and causes within the nodule a controlled hemorrhage that serves the worm's nutritional needs. We believe this explains, in part, how worms survive in fibrous nodules for many years.

Animals↗

Loiasis: "Calabar" swellings and involvement of deep organs.

The authors report clinical and histopathologic changes in six patients with symptomatic loiasis. One patient had cutaneous swellings, three patients presented with hydrocele, one patient developed bowel obstruction, and one had generalized fatal loiasis. The first five patients had localized lesions provoked by adult worms; all were surgically removed. The sixth patient died of disseminated loiasis that included a severe loal encephalitis. The authors discuss the mechanism of "Calabar" swellings, the reaction to adult Loa loa worms and loal encephalitis.

Adult↗

Studies on a focus of yaws in Ubangi, Zaire.

Yaws (buba, Frambösie, pian), a non-venereal treponematosis of skin and bones is a tropical disease that affects primarily children. Eradication programs launched between 1950 und 1970 reduced the incidence substantially; resurgences, however, have been reported from several countries. We have studied a geographically isolated focus of yaws in the Ubangi area of northwestern Zaire. In survey I, in 1981, of the 4.407 participants from 11 villages, 348 (7.9%) had active lesions of yaws. All patients and their contacts were treated immediately with benzathine penicillin G. In survey II, in 1982, in 6 of the previously studied villages, of 5,390 participants, 136 (2.5%) had active lesions of yaws. In 1981, the predominance of primary lesions (86%) and high numbers of patients in all age groups, with the highest prevalence (23.4%) in children 10-14 years of age, suggest that yaws recently recurred at this focus. In 1982, only 25.7% of the lesions were primary and the highest prevalence (6.5%) had shifted to the younger age group of 5-10 years-old. In survey I more males (63%) were infected in the age group 0-24 years, and more females (89%) in those over 40 years. In survey II, more males (61.3%) were infected in the age group 0-14 years, and only females (100%) in the age groups 25 years and older. Seventy-one percent (1981) and 86% (1982) of the initial lesions were on the lower limbs. Participation of the population in survey I was 41.7% and was greatest (62%) in the locality where there was a newly established dispensary. In survey II, participation rose to 73.8%. Areas adjacent to the focus of yaws with longstanding dispensaries were free of yaws.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

A diagnostic "patch test" for onchocerciasis using topical diethylcarbamazine.

There is great need for a simple, inexpensive, and sensitive diagnostic test for onchocerciasis, especially in endemic areas where trained personnel and laboratory facilities are limited. Diethylcarbamazine (DEC) was applied as a "patch test" to the skin of 45 patients with onchocerciasis in the Southern Sudan. 75 tests were done on these 45 patients, and 69 (92%) were positive. A positive reaction was a papular eruption beneath the patch. Histopathological studies of the skin beneath the patch revealed the microscopic features of a severe Mazzotti reaction, including degenerating microfilariae in the upper dermis and within epidermal eosinophilic abscesses.

Administration, Topical↗

Cardiac fungal infections: review of autopsy findings in 60 patients.

An autopsy study of 60 patients with fungal infections of the heart was undertaken. The patients ranged in age from 2 months to 79 years. Fifteen of the patients had undergone cardiac surgery; neoplasms were found in 13, renal failure in eight, bacterial infections in five, liver disease in five, gastrointestinal disorders in five, and immune disease in four; two had been intravenous drug abusers; other miscellaneous disorders were observed in three. The fungal infection was limited to the myocardium in 27 patients and to the endocardium in 17 patients. Myocardium and endocardium were involved in nine patients and pericardium and myocardium in five; two patients had pericarditis alone. The most frequent organism was Candida (62 per cent). Aspergillus (12 per cent) and Phycomycetes (12 per cent) were also found frequently. In 51 patients (85 per cent) other deep organs, usually lung, kidney, brain, or spleen were involved. Cultures for fungus had been positive in 26 patients prior to death, and postmortem cultures were positive in 29 patients. Patients who had undergone cardiac surgery had a higher incidence of endocarditis (93 per cent), with Candida (53 per cent) being the most frequent cause. Patients who had received antineoplastic drugs, antibiotics, or corticosteroids had a higher incidence of myocarditis (79 per cent), again most often due to Candida (60 per cent).

Adolescent↗