Biomedical subjects
Publications and source records attributed to W Kaplan.
The second human subcutaneous infection due to Exophiala spinifera from the United States is described. Identification was based on the morphology of the fungus in tissue and the morphological features of the culture obtained from the biopsy material. Correct diagnosis and treatment with ketoconazole and 5-fluorocytosine cured the infection.
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Cytologic and direct fluorescent antibody techniques were used to detect the presence of Actinomyces israelii and Arachnia propionica in cervicovaginal smears collected from 100 women, 94 of whom did not use intrauterine contraceptive devices. In no case were these organisms found. The possible significance of these results is discussed.
We report disseminated, fatal fungal disease involving subcutaneous and visceral tissues in 4 captive snakes (1 Elaphe guttata, 2 Crotalus horridus, and 1 Pituophis melanoleucus). The etiologic agent, which was abundant in the lesion, had a rounded form in vivo with a prominent nucleus. These cells averaged 17 microns in diameter and reproduced by fission, forming clusters of two or four daughter cells. The etiologic agent was isolated on Sabouraud dextrose agar from one of the snakes. It also grew well on various mycologic media, forming soft, raised, glabrous, tannish colonies. The colonies were composed of large spherical cells with prominent nuclei that reproduced by fission like those seen in tissue. In addition, some of the cells were observed to germinate, forming rudimentary hyphal filaments that were up to 8 microns in diameter and 100 microns in length, with occasional septa and thick-walled structures regarded as azygospores. We consider the fungus to be a zygomycete that may belong to the order Entomophthorales.
Infection by unicellular green algae has not been described in humans. A case is reported in a 30-year-old woman who developed persistent infection of a healing operative wound on the dorsum of the right foot, after possible contamination by river water while canoeing. The wound was debrided 2 months later. Histologically, infected tissues contained mixed suppurative and granulomatous inflammation associated with endosporulating, round to oval microorganisms, ranging from 6-9 microns in diameter. Many of these organisms contained multiple, strongly periodic acid-Schiff, Gomori methenamine-silver, and Gridley fungus-positive granules in the cytoplasm. The organisms in tissue did not stain with fluorescent antibody conjugates specific for the two known pathogenic Prototheca species. In some organisms, electron microscopy revealed membranous cytoplasmic profiles considered to be remnants of degenerated chloroplasts. These findings are consistent with the presence of a green algal infection.
We prepared fluorescent-antibody reagents to detect and identify Pseudallescheria boydii in tissue. Antisera to broken mycelium and condidia (particulate antigens) and to culture filtrates (soluble antigens) of P. boydii were produced in rabbits. Antisera and globulin fractions of the antisera were labeled with fluorescein isothiocyanate and evaluated for their ability to stain P. boydii in tissues. The conjugates were first tested with cultures of 25 P. boydii isolates and 26 heterologous fungi that are morphologically similar to P. boydii in tissues. Labeled antibody to the soluble antigens reacted only weakly with cultures of P. boydii. Labeled antibody to particulate antigens brightly stained all P. boydii isolates and cross-reacted with Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus niger, Aspergillus terreus, Fusarium oxysporum, Fusarium solani, and a Scopulariopsis sp. The cross-reacting antibodies were removed by adsorption with A. fumigatus and F. oxysporum. The adsorbed conjugates stained P. boydii in Formalin-fixed tissues from experimentally infected mice and in Formalin-fixed tissues from humans and animals with natural infections. They did not stain the heterologous fungi in tissues.
Unicellular green algae infected and disseminated in two adult Nellore brown rams in India. At necropsy multiple green lesions were observed in the lungs, liver and kidneys of both sheep. Histological examination revealed necrotizing granulomas that contained numerous spheroidal to elliptical organisms ranging from 5-20 micrometers in diameter. These organisms occurred in several reproductive stages: small (5-9 micrometers) single, undifferentiated cells; intermediate (9-15 micrometers) cells undergoing nuclear and cytoplasmic cleavage; and large, mature, endosporulating cells containing two to six or more endospores. In addition, occasional large (20-35 micrometers), round thick-walled forms were among the typical cells. The cytoplasm of the algal cells contained numerous, large, irregularly-shaped and densely packed granules of varying sizes, which were strongly stained by the Gridley fungus, periodic acid-Schiff, and Gomori methenamine silver procedures. Electron microscopic studies revealed chloroplasts in the cytoplasm of these organisms. The chloroplasts consisted of smoothly contoured electron-lucent or electron-dense granules, 0.5 to 3.0 micrometers in diameter, that were either surrounded by or contiguous to two or more tightly appressed membranes or multidisc bands. Some of the alternating membranes appeared to be spirally twisted or associated with several cytoplasmic granules in one plane of section. This is the first record of algal infections in India.
Monoclonal antibody B6.2 reacts with a protein found on the surface of primary and metastatic human mammary tumors. B6.2 immunoglobulin G (IgG) was purified, F(ab')2 and Fab' fragments were generated by pepsin digestion, and the IgG and its fragments were radiolabeled with 125I; all were successful in localizing human mammary tumors transplanted into athymic mice, with tumor:tissue ratios increasing over a 4-day period. The 125I-labeled IgG gave tumor:spleen, tumor:liver, and tumor:kidney ratios of greater than 10:1 and tumor:brain and tumor:muscle ratios of 50:1 to 110:1. The F(ab')2 fragment gave higher tumor:tissue ratios than did the IgG, with tumor:liver and tumor:spleen ratios of 15:1 to 20:1. No localization of the labeled B6.2 monoclonal antibody or its fragments was observed in athymic mice bearing a human melanoma or with isotype-identical control immunoglobulin or its fragments in athymic mice bearing the mammary tumors. Imaging experiments confirmed the ability of radiolabeled monoclonal antibody B6.2 and its fragments to detect the presence of transplanted human mammary tumor lesions of less than 0.4 cm without the aid of background subtraction manipulations.
A review of protothecosis in dogs revealed that this malady usually begins in the gastrointestinal tract and progresses to systemic involvement. Clinical signs generally include bloody diarrhea or blood-stained feces as well as blindness, ataxia, and polyuria. Histologically, myriads of protothecal organisms in different stages of development are found in the granulomatous lesions. Two main species have been culturally identified: Prototheca zopfii and P wickerhamii. In the absence of cultural studies, species identification can be accomplished readily by immunofluorescence. The present case involved P zopfii infection in a 5-year-old female Cocker Spaniel that had bloody diarrhea, with a history of bloody diarrhea 6 months earlier.
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Two cases of disseminated systemic zygomycosis caused by Cunninghamella bertholletiae in compromised persons were studied. The underlying disease in one patient was hematopoietic dysplasia (preleukemic syndrome) and in the other, postnecrotic hepatic cirrhosis. A definitive diagnosis of zygomycosis caused by C bertholletiae is achieved only by isolation and identification of the fungus and by demonstration of tissue invasion.
We investigated the potential of 33 different zygomycete isolates to cause cerebral disease following the intranasal instillation of their spores into ketotic rabbits with alloxan induced diabetes. The isolates represented six thermotolerant species of Rhizopus (R. arrhizus, R. chinensis, R. microsporus, R. oligosporus, R. oryzae, and R. rhizopodiformis), Absidia corymbifera, Cunninghamella bertholletiae, and Rhizomucor pusillus. All 13 isolates of the thermotolerant Rhizopus species proved to be cerebral pathogens as confirmed by culture and histopathology. One isolate of R. oligosporus and one isolate of R. rhizopodiformis, however, were less pathogenic than isolates of other Rhizopus species tested. Cerebral pathogenicity was noted with 2 of 5 isolates of Rh. pusillus and only 1 of 13 A. corymbifera isolates. Two thermotolerant C. bertholletiae cultures, recovered from human lesions, did not cause either cerebral or pulmonary disease in ketotic rabbits. The incidence of pulmonary zygomycosis caused by the isolates of the species of the four genera under study was as follows: Rhizomucor 24%, Rhizopus 22%, Absidia 9%, and Cunninghamella 0%. This study confirms the pathogenic potential of the thermotolerant species of Rhizopus to cause cerebral zygomycosis in ketotic diabetic rabbits and also revealed the potential of Rh. pusillus and A. corymbifera occasionally to cause the same disease in animals and humans.
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Four serotypes of Cryptococcus neoformans designated A, B, C, and D are currently recognized. Although an agglutination test is most often used to serotype C. neoformans in cultures, this test is not appropriate for typing the fungus in fixed tissues. A study to prepare fluorescent-antibody reagents for typing C. neoformans in cultures and to determine whether they can be used to type this fungus in fixed tissues was carried out. Antisera to one strain belonging to each of the four serotypes were prepared in rabbits by intravenous injection of whole Formalin-killed cryptococci. Each antiserum was labeled with fluorescein isothiocyanate and then adsorbed with cells of each of the heterologous serotypes. The adsorbed conjugates were then tested against six serotype A isolates and five isolates of each of the other three serotypes. Labeled serotype A or D antiserum adsorbed with either B or C cells stained the A and D, but not the B or C, isolates. Labeled serotype B antiserum adsorbed with A cells stained the B and C, but not the A or D, isolates. Labeled A antiserum absorbed with D cells differentiated A from D; labeled C antiserum absorbed with B cells differentiated C from B. Of the 21 test isolates, 17 could be serotyped in paraffin sections of tissues of experimentally infected mice.
Petriellidium boydii infection of the sphenoid sinus in a previously healthy woman was initially diagnosed by immunofluorescent staining of biopsy tissue sections. The diagnosis was confirmed by demonstrating P. boydii precipitins in serum and by isolating the infecting fungus. Despite surgical drainage and intensive therapy with miconazole nitrate, the outcome, because of intracranial extension, was fatal.
A patient with a past history of sporadic parenteral drug abuse had communicating hydrocephalus associated with arachnoiditis over the lumbar spinal cord. The diagnosis of aspergillosis was made by a newly described immunofluorescent staining procedure and was later confirmed by culture. The spectrum of central nervous system aspergillosis associated with drug abuse is reviewed.
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In December 1975 and January and February 1976, an epidemic of cutaneous sporotrichosis occurred in Mississippi among forestry workers and other persons exposed to sphagnum moss used in packing pine seedlings. Seventeen cases were identified, 15 of which were from patients who had been exposed to sphagnum moss from a single source. Attack rates were significantly higher among workers exposed to this moss than among those not exposed. Sporothrix schenckii was cultured from the implicated batch of sphagnum moss but not from other batches. The source of contamination of the sphagnum moss that caused this epidemic and sphagnum moss associated with similar epidemics is unknown. One worker without cutaneous sporotrichosis may have had asymptomatic pulmonary sporotrichosis.