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F Von Lichtenberg

Publications and source records attributed to F Von Lichtenberg.

At least 19 recordsLinked to original sources
PubMed1992

Combined microautoradiographic and histopathologic analysis of the fate of challenge Schistosoma mansoni schistosomula in mice immunized with irradiated cercariae.

Combined microautoradiographic and histopathologic methods were used to locate and examine schistosomula of Schistosoma mansoni in the lungs of irradiated cercaria-immunized mice 21 days after percutaneous challenge infection with 75Se-labeled cercariae. Of 75 schistosomula examined in serial sections, 53% were located in the pulmonary microvasculature, 23% in alveolar spaces, 3% with one end in a vessel and the other in an alveolar space, and the locations of 21% were not identified. Inflammatory reactions of variable intensity were observed around schistosomula in both vascular and alveolar sites, although the most intense category of reactions was associated almost entirely with alveolar larvae. All autoradiographic foci contained recognizable schistosomula. Although the concentration of reduced silver grains precluded cyto-structural analysis, observations on schistosomular contour and shape provided no evidence of larval damage. Our findings suggest that immune elimination of schistosomula in mice immunized with irradiated cercariae is partly or largely effected by a process of alveolar extrusion of viable parasites during their lung migration.

Animals↗
PubMed1991

Leishmania (Viannia) braziliensis: comparative pathology of golden hamsters infected with isolates from cutaneous and mucosal lesions of patients residing in Tres Bracos, Bahia, Brazil.

The histopathology of primary forepaw and metastatic lymph node, spleen, and liver lesions produced in golden hamsters infected with cutaneous leishmaniasis (CL) strains (LTB 111 and LTB558) and mucocutaneous leishmaniasis (MCL) strains (LTB12 and LTB201) of Leishmania (Viannia) braziliensis isolated from patients residing in Tres Bracos, Bahia, Brazil is described. No pathological features providing clear differentiation of the CL and MCL strains were found. Although amastigotes were plentiful early in the development of primary forepaw lesions, they were either absent or could not be identified with certainty in sections of late stage lesions. Similarly, amastigotes were not found in histologic lesions at metastatic sites; however, leishmanial DNA was detected in both early and late stage forepaw lesions and metastatic lesions using Leishmania kinetoplast DNA and the gene coding for gp63 as hybridization probes. The DNA recovered from metastatic lesions was extracted from formalin-fixed paraffin-embedded tissues that had been stored at room temperature for prolonged periods.

Animals↗
PubMed1987

In vivo T cell depletion regulates resistance and morbidity in murine schistosomiasis.

These studies assessed the roles of subpopulations of T lymphocytes in inducing and modulating resistance to schistosomiasis and thereby influencing subsequent morbidity. C57BL/6 mice were depleted in vivo of Lyt-1+, Lyt-2+, and L3T4+ cells by the daily administration of monoclonal antibodies. The development of protective immunity, induced by exposure to irradiated Schistosoma mansoni cercariae as expressed in depleted animals, was compared to that demonstrated in undepleted, normal, and congenitally athymic C57BL/6 mice. The development of morbidity was determined by spleen weight, portal pressure and reticuloendothelial system activity. The results indicated that depletion of specific subpopulations of T lymphocytes minimally affected the primary development of parasites; however, depletion strongly influenced the development of resistance to the parasite and subsequent morbidity due to infection. Depletion of T lymphocytes by anti-Lyt-1+ or anti-L3T4+ antibody decreased the development of resistance, antibody and delayed-type hypersensitivity directed against schistosome antigens. Morbidity due to disease was increased. Depletion of Lyt-2+ cells produced opposite changes with augmented resistance and reduced morbidity. Congenitally athymic mice developed minimal resistance and morbidity. Moreover, resistance was inversely related to the morbidity shown by a given animal. These studies indicate that the development of protective immunity to S. mansoni cercariae is regulated by discrete subpopulations of T lymphocytes. The feasibility of decreasing morbidity by increasing specific immunologically mediated resistance is suggested.

Animals↗
PubMed1985

The fate of challenge schistosomula in the murine anti-schistosome vaccine model.

Mice exposed to irradiated cercariae of Schistosoma mansoni develop a partial resistance to subsequent parasite challenge. In this study we utilized histopathologic methods to investigate the fate of both the immunizing and challenge cercariae in C57BL/6J mice. After immunization by percutaneous infection, a large number of the 50 Kr irradiated organisms could be detected in tissue sections of lung. However, as early as 2 weeks after immunization, the majority of these schistosomula apparently had died, leaving residual inflammatory foci. The numbers of these foci then gradually declined during the next 4 weeks of examination. Cercarial challenge of mice vaccinated 4 weeks previously provoked an intense eosinophil-enriched inflammatory response in percutaneously exposed ear pinnae. Despite these pronounced tissue reactions, no evidence of significant parasite damage or attrition was detected in this migration site. In contrast, schistosomula arriving in the lungs of vaccinated mice produced a greater number of residual inflammatory foci than did larvae appearing in the lungs of normal mice. In addition, challenge schistosomula were cleared from the lungs of vaccinated mice at a slower rate than they were from the lungs of control mice. These observations suggest that the lung is a major site of parasite attrition for both immunizing and challenge infections in the mouse irradiated vaccine model.

Animals↗
PubMed1983

Necrotizing granulomatous gastritis and gastric perforation of unknown etiology: a first case report.

A unique case of granulomatous gastritis of unknown etiology is reported. The patient, a 43-year-old Haitian woman, suffered a gastric perforation from a disease process limited to the stomach. The stomach was markedly enlarged and edematous with transmural, serpiginous granulomatous tracks throughout the gastric wall, but most numerous in the fundic region. Accompanying acute and chronic inflammatory infiltrates were scant. No microorganisms, parasites, foreign body particles, or other known granulogenic materials could be identified. Clinical and pathologic features also differed markedly from granulomatous gastritis seen in sarcoidosis, Crohn's disease, or isolated granulomatous gastritis as defined by Fahmi et al. Infection by a parasite for which man is not the definitive host seems the most likely etiology.

Adult↗
PubMed1975

Effects of portacaval shunting on Schistosoma japonicum infection in chimpanzees: dissociation of pipe-stem fibrosis and glomerulopathy.

Eight of 10 young chimpanzees were infected with the Japanese strain of Schistosoma japonicum. In 6 of these, and in 1 normal chimpanzee, a surgical end-to-side portacaval shunt was constructed during the 8th week of infection. One additional infected chimpanzee was treated successfully with the nitrovinylfuran, SQ 18,506. In the four animals surviving both infection and shunting hepatic portal fibrosis was either absent or mild. In the 7-month survivors and in the drug-treated control animals there was evidence of healed portal endophlebitis and arterialization, but no active schistosomal liver lesion was found. Nevertheless, three of these animals showed variable degrees of active schistosomal glomerulopathy, similar to that seen in the unshunted infected control and to that described in earlier studies. There was a shift of the egg burden from the liver to the lungs, as well as evidence that the number of surviving adult worms had decreased following portacaval shunting. These observations sugggest that schistosomal nephropathy in chimpanzees is more closely related to infection intensity per se than to the degree of liver damage caused by infection.

Animals↗
PubMed1973

Comparative histopathology of schistosome granulomas in the hamster.

When uniform histologic criteria are applied to staging schistosome egg and granuloma development in the hamster liver, the evolution of the egg foci is shown to be monophasic, albeit with considerable variation of the individual cell response. Both real and artifactual egg-granuloma asynchrony are demonstrable. Alternate granuloma stages occur simultaneously within the same single organ, so that necrosis or fibrous scarring may result in some lesions but not in others. The granulomas of Schistosoma japonicum, S mansoni and S haematobium show both shared and distinctive features. Thus, oviposition is serial in S mansoni but clustered in the other two species. Neutrophils are common in S japonicum granulomas but are rare in the others. The differential features, listed in detail, will usually permit histologic identification of species during the early stages of infection; subsequently, the species-specific features and the overall intensity of host reaction tend to decline. At comparable egg loads and time spans, the liver pathology of S japonicum is the most severe. This is not related to granuloma size, but rather to more exudation and necrosis in early S japonicum granulomas, their tendency to encroach on adjacent liver tissue and to more extensive diffuse inflammatory infiltration. Hoeppli phenomena occur around S japonicum eggs both in stellate form, and as intraovular "reverse" precipitates. Plasma cells and amyloid deposition are frequent. Conversely, S haematobium lesions are less destructive than those of S mansoni. These findings can be correlated, to some extent, with current knowledge of the biology of schistosomes and of the antigenic components of their eggs, but several key problems concerning the immunologic host response remain to be solved.

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