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Biomedical subjects

G Messer

Publications and source records attributed to G Messer.

At least 73 records · Page 4Linked to original sources
PubMed1987

Cytostatic effect of DL-alpha-difluoromethylornithine against Plasmodium falciparum and its reversal by diamines and spermidine.

DL-alpha-difluoromethylornithine (DFMO) inhibited ornithine decarboxylase (ODC) activity and arrested the growth of Plasmodium falciparum at the early trophozoite stage. The inhibition of ODC activity did not result in the formation of an alternative diamine such as cadaverine. When putrescine or spermidine were added to the parasites grown in culture, the arrest was reversed, and normal schizogony was completed even in the presence of DFMO. Some reversal of the inhibition was achieved with cadaverine at high concentrations, while 1,3-diaminopropane and spermine failed to restore the development. Resumption of growth could be detected when putrescine was added even after 67 h of DFMO treatment. Electron microscopy did not reveal any changes in the morphology of parasites treated for 47 h, while 73 h of treatment with DFMO induced massive accumulation of pigment. Death was observed a few hours later. These results suggest that DFMO acts as a cytostatic rather than as a cytocidal agent. The four carbon diamine restored cell growth while the shorter or the longer homologous compounds showed little activity.

Animals↗
PubMed1987

Dorfman-Chanarin syndrome. A case report and a review.

Dorfman-Chanarin syndrome in two sisters of Jewish Iraqi origin is reported. This heritable disorder of the metabolism of neutral lipids was manifested by congenital ichthyosis, vacuoles in the leukocytes, and variable involvement of liver, muscle, central nervous system, and the auditory system. In two asymptomatic members of the family leukocyte vacuoles were found as the only sign of the syndrome. Clinical, pathologic, ultrastructural, and biochemical findings are described. Previous reported cases are reviewed.

Adult↗
PubMed1986

Primary inflammatory malignant fibrous histiocytoma of the colon.

A unique case of inflammatory malignant fibrous histiocytoma of the large bowel is presented. This lesion occurred in the colon of an elderly man suffering from weakness, anemia, anorexia, and weight loss. A right hemicolectomy was performed, and six months later, on follow-up, he was found to be well. The literature on visceral involvement by malignant fibrohistiocytic tumors is reviewed.

Aged↗
PubMed1986

Leishmania major: antileishmanial activity of methylbenzethonium chloride.

Methylbenzethonium chloride (MBCl) decreased the growth of Leishmania major promastigotes and amastigotes in vitro. This decrease occurred during 4 days of exposure to the drug at concentrations of 0.1 to 2.5 micrograms ml-1. MBCl at 2 micrograms ml-1 killed almost 100% of the free living promastigotes and 87% of amastigotes within 4 days of treatment. Electron microscopy studies showed marked swelling of mitochondria in treated parasites. A possible additional effect on the parasite surface membrane is discussed.

Benzethonium↗
PubMed1986

Studies on the effect of intralipid on human monocyte functions in vitro.

Intralipid (IL) particles were ingested by human monocytes in culture. These particles remained within the cells for periods of up to 3 weeks in culture. The presence of IL particles did not alter the normal secretion of lysozyme or prostaglandin E2 (PGE2), nor was the normal process of biochemical activation altered, as evidenced by the expected increase in PGE2 secretion and superoxide anion production by stimulated monocytes. Phagocytosis of zymosan particles was increased in monocytes that had ingested IL. These results indicate that in this in vitro system essential monocyte functions were not altered following ingestion of IL.

Dinoprostone↗
PubMed1984

Growth inhibition of Leishmania tropica amastigotes in vitro by rifampicin combined with amphotericin B.

Rifampicin and Amphotericin B (AMB) were studied separately and in combination to determine their effect in vitro on intracellular Leishmania tropica amastigotes. On the fourth day of treatment, rifampicin at 200 micrograms ml-1 or AMB at 0.15 microgram ml-1 reduced the parasites' survival index (PSI) to 10% compared with the untreated control. In combination, there was a significant synergistic effect at several concentrations. The synergistic therapeutic effects were not accompanied by toxicity to the host cells, although each drug alone caused cellular degeneration in the ultrastructure of the parasites with the formation of large autophagic-like vacuoles, while the combination increased the percentage of degenerate cells.

Amphotericin B↗
PubMed1984

Comparison of the effect of various stimuli on the leishmaniacidal capacity of human monocytes in vitro.

Leishmania organisms are obligate intracellular parasites of mammalian mononuclear phagocytes in vivo. In order to study the interactions of these parasites and mononuclear phagocytes, we have used a model of infection of Leishmania major in human monocytes in vitro. The presence of intracellular parasites did not alter the normal secretion of lysozyme or result in increased secretion of prostaglandin E2 (PGE2) or superoxide anion by the monocytes. Addition of concanavalin A (Con A), which binds to a specific membrane receptor, zymosan particles or endotoxin to infected monocyte monolayers, resulted in the expected increase in PGE2 secretion. In addition, the production of superoxide by infected monocytes treated with phorbol myristate acetate was not different from control uninfected cultures. Despite this evidence of biochemical activation, neither endotoxin, zymosan nor Con A had any parasiticidal effect on the intracellular parasites. In contrast, Con A-induced lymphokines from human mononuclear cells resulted in an increased killing of the intracellular amastigotes. These studies have shown that the induction of leishmaniacidal capacity of human monocytes is dependent on the type of stimulus used to induce activation.

Cells, Cultured↗
PubMed1983

Ultrastructural localization of glucose-6-phosphatase in renal glomerulus of the adult dog.

The ultrastructural distribution of glucose-6-phosphatase activity was investigated in renal glomeruli of adult dogs by electron-microscopic cytochemistry. The enzymatic activity was found mainly in the parietal epithelial cells of Bowman's capsule. Weaker activity occurred in visceral epithelial cells. No activity was found in either the endothelial or the mesangial cells. Strong activity of glucose-6-phosphatase was commonly found in the nuclear envelope, and occasionally in the rough endoplasmic reticulum. The distribution of the enzyme and its functional significance are discussed in relation to previously reported data.

Animals↗
PubMed1983

Posttraumatic recurrent corneal erosion, #2. Ultrastructural findings in epithelium and stroma.

Basement membrane deficiency, accompanied by alterations in basal epithelial cells, was shown in a case of posttraumatic recurrent corneal erosion (RCE) by Goldman et al. [1] and in other corneal disorders [2, 3, 4, 5, 6]. We have previously [7] described a case of posttraumatic RCE which was treated successfully by surgical procedure. This report presents electron microscopic observations of the excised tissues which indicate significant changes in the corneal stroma as well as in its epithelium and basement membrane.

Cornea↗
PubMed1982

Keratinization index.

A method to decrease subjectivity in assessing hyperkeratosis by application of quantitative measurements is proposed. The proportion of the depth of the stratum corneum to that of the total epidermis was measured on stained sections of tissue and termed the keratinization index (K.I.). Determinations showed that the K.I. varied with anatomical regions and was greater in different types of ichthyosis than in normal samples. Two indices were assessed, namely, K.I. which describes the ratio of cornified layer to total epidermis measured to the tips of the dermal papillae, and K.I. measured to the bases of the rete ridges. These two indices reflect the contour of the dermo-epidermal junction.

Ankle↗
PubMed1982

[Scrotal leiomyosarcoma].

A case of leiomyosarcoma of the scrotum in a 65 year old man is presented. It is, we believe, the sixth case reported in the literature. A hemiscrotectomy was performed with preservation of both testes. Three years after the operation the patient is well and free of metastases. The electron microscopy study is reported and the features are discussed.

Aged↗
PubMed1982

Posttraumatic recurrent corneal erosion. 1. Clinical and histological studies.

A severe, bilateral, posttraumatic recurrent corneal erosion in a 29-year-old woman was treated by bilateral lamellar keratectomy. The surgical procedure was performed first in the right eye. Under local anesthesia the defective corneal region stained by fluorescein was completely removed. It comprised a lamella measuring 2 X 3 mm and included epithelium and underlying superficial stroma, both of which showed abnormal features. Following this procedure, her right eye was asymptomatic for over 6 yr. Surgical procedure in the left eye was performed in the same manner except that only a part of the stained cornea containing superficial layers of epithelium was removed, in order to prevent central scarring. Despite surgery, the recurrent painful attacks in this eye continued.

Adult↗
PubMed1981

Evaluation of prajmalium-induced cholestasis by immunologic tests.

Cholestatic jaundice developed in four patients after the administration of prajmalium bitartrate. The clinical, histologic, ultrastructural, and immunologic findings were determined. In all patients, the clinical and morphologic features indicated idiosyncrasy. Two antibodies distributed in a granular pattern along the bile canaliculi were detected by immunofluorescence in all patients. In one patient, autoimmune markers were found in the serum, and in two instances, the migration-inhibition factor assay against the offending drug was found to be positive. The data support the concept that immunologic processes may participate in the production of the cholestatic syndrome.

Aged↗
PubMed1981

Ophthalmoplegia-plus.

The occurrence of chronic progressive external ophthalmoplegia, pigmentary retinal dystrophy and cardiac disturbances associated with arachnodactily, sternal deformity, high arched palate and severe myopia is reported. A pedigree analysis of this Jewish-Iranian family strongly suggests that the condition is inherited as autosomal recessive trait. The terminology of the condition and the spectrum of it variable phenotypic expression is described.

Adult↗
PubMed1980

Ultrastructure of the conjunctiva, skin, and gingiva: a case of Sandhoff's disease in a Jewish patient.

Pleomorphic membranous cytoplasmic bodies that indicated glycolipid storage were found in the conjunctiva, skin, and gingiva of a Jewish patient with Sandhoff's disease. The clinical symptoms were typical of GM2 gangliosidosis. Both hexosaminidase A and hexosaminidase B activities were deficient in the leukocytes and serum. Glycosaminoglycan levels in cultured fibroblasts were elevated. Membranous cytoplasmic bodies were observed in high concentrations in a large proportion of the vascular endothelial cells, pericytes, and Schwann cells and to a somewhat lesser extent in the fibrocytes of all tissues studied. Ultrastructural analysis of the conjunctiva, skin, and gingiva as an aid for the diagnosis of Sandhoff's disease is suggested.

Capillaries↗