Biomedical subjects

D Weinman

Publications and source records attributed to D Weinman.

At least 19 recordsLinked to original sources

PubMed1992

Endoscopic laser therapy in gastroenterology.

Endoscopic laser therapy has become an important and widely used tool in gastroenterology. It has become important for outpatient palliative therapy for ablating obstructing gastrointestinal neoplasms. This method has often circumvented the need for major palliative surgical resections. Caution must be applied to laser therapy for potentially curable malignant neoplasms because, with vaporization of the target tissue, no tissue specimen is available to assure that local or invasive residual carcinoma is excluded. Therefore, in good surgical candidates, surgical resection of potentially curable cancers is always recommended. In the future, however, the combination of refined endoscopic ultrasonography and laser fluorescence techniques may lead to earlier detection, more precise localization, and even curative ablation of gastrointestinal malignancy.

Ambulatory Care↗

PubMed1991

Epidermolysis bullosa acquisita (EBA) and esophageal webs: a new association.

Epidermolysis bullosa acquisita (EBA) is a well-defined, blistering disorder of the skin associated with autoantibodies to type VII collagen. Although esophageal pathology is common in children with hereditary dystrophic forms of epidermolysis bullosa, esophageal problems have not been reported previously in patients with bona fide EBA. In this report, a 71-yr-old white female with longstanding EBA presented with recurrent dysphagia and multiple esophageal webs that responded to esophageal dilatation.

Aged↗

PubMed1984

Trypanosoma lucknowi, a new species of trypanosome from Macaca mulatta with observations on its fine structure.

Trypanosoma lucknowi n. sp. was isolated in culture from one of 126 Macaca mulatta originating from the vicinity of Lucknow, Uttar Pradesh, India. Trypanosoma lucknowi is distinctive because of the large number of epimastigotes and trypomastigotes which, in culture, exhibit no movement or only a slight bending of the flagellar end. This limited motility coincides with a free flagellum which is either completely absent or rudimentary. The microorganism is cloned readily, and the description is based upon such cultures. Trypanosoma lucknowi shows pronounced differences from other trypanosomes of South Asian macaques and from "aflagellar" African trypanosomes. The ultrastructural demonstration of a cytostome and contractile vacuole suggests ultimate grouping with stercorarian trypanosomes. A 3-D reconstruction of the flagellar pocket/cytostome region is included.

Animals↗

PubMed1978

Mitosis in the hemoflagellate Trypanosoma cyclops.

The ultrastructure of interphase and mitotic nuclei of the epimastigote form of Trypanosoma cyclops Weinman is described. In the interphase nucleus the nucleolus is located centrally while at the periphery of the nucleus condensed chromatin is in contact with the nuclear envelope. The nucleolus fragments at the onset of mitosis, but granular material of presumptive nucleolar origin is often recognizable in the mitotic nucleus. Peripheral chromatin is in contact with the nuclear envelope throughout mitosis, and it seems reasonable to assume that the nuclear envelope is involved in its segregation to the daughter nuclei. Spindle microtubules extend between the poles of the dividing nucleus and terminate close to the nuclear envelope. The basal body and kinetoplast divide before the onset of mitosis and do not appear to have any morphologic involvement in that process. Spindle pole bodies, kinetochores, and chromosomal microtubules have not been observed.

Animals↗

PubMed1978

Triatomines as experimental vectors of trypanosomes of Asian monkeys.

Systematic surveys of the wild macaques of South Asia by blood culture resulted in the discovery that trypanosomiasis is enzootic in the simians of Indonesia, Malaysia, India, and Thailand. The isolates obtained differ in morphology, metabolism, and ability to multiply in arthropods. Following this discovery, interest focused on possible transmissions of these trypanosomiases. Laboratory-reared and wild-caught insects were studied to determine which are satisfactory intermediate hosts and potential natural vectors. Successful results were obtained with insectary-reared reduviids and Indonesian isolates. In Rhodnius prolixus and Triatoma rubrofasciata the Indonesian trypanosomes multiply for periods which can exceed 40 days. The flagellate infections are in the digestive tract, whereas trypanosomes have never been seen in the salivary glands or in the hemolymph. The feces of trypanosome-carrying reduviids are infective, suggesting a stercoreal method of infection of mammals, and infection was produced in experiments in which feeding by the insects was not possible. The relevance of these findings to natural transmission in Indonesia is not known. Experiments with insects and all other trypanosomal isolates have been negative. The natural transmission mechanism(s) of the simian trypanosomiases in South Asia remains an unsolved problem.

Animals↗

PubMed1977

Antibody-independent activation of the alternative complement pathway in human serum by parasitic cells.

The lysis of the monocellular parasite Trypanosoma cyclops by normal human serum (NHS) was found to be complement-dependent and to follow activation of the alternative pathway without apparent requirement for conventional antibodies. Lysis of the organisms was inhibited by heat-inactivating NHS at 56 degrees, preincubation of NHS with cobra venom factor or chelation of divalent cations with EDTA. It took place, however, in human C2-deficient serum and was inhibited by prior heating of NHS at 52 degrees to destroy the activity of factor B of the alternative pathway. Moreover, the lytic reaction was magnesium- but not calcium-dependent. Repeated low-temperature (0 degrees) absorption of either human hypogammaglobulinaemic serum or NHS with the parasite failed to remove or significantly decrease their lytic activities.

Complement System Proteins↗

PubMed1974