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Biomedical subjects

R Gatti

Publications and source records attributed to R Gatti.

At least 163 records · Page 9Linked to original sources
PubMed1988

The ultrastructure of the thyroid parafollicular cells of the marmot (Marmota marmota). Immunocytochemical localization of calcitonin and somatostatin.

We studied the topographical and ultrastructural characteristics of the parafollicular cells in the Marmota marmota and their seasonal changes. The parafollicular cells, together with the follicular cells, form the follicular epithelium occupying a peculiar basal position. Furthermore these cells are characterized by a clear cytoplasmic matrix and well developed cytoplasmic organelles. The latter synthesize and condense the secretory product which ultrastructurally is organized in secretory granule-vesicles with a scarcely electron-dense cottony content. Histochemically the secretion consists in a proteic complex (rich in alpha-amino acids and sulphonate proteins) with a minor glucidic component. The above metabolic activity closely relates with the seasonal metabolic changes and namely with calcium metabolism. The immunocytochemical reactions revealed the presence of calcitonin and, to a lesser extent, somatostatin. The morphological findings were compared with those observed in other hibernating mammalians and related to the calcium homeostasis.

Animals↗
PubMed1988

[The hypothalamic-hypophyseal neurosecretory system of the Alosa fallax nilotica. A histological and ultrastructural study].

We studied the morphological, histochemical and ultrastructural aspects of the hypothalamic-pituitary system in the Alosa fallax nilotica. The secretory activity of the preoptic nucleus and of the lateral tuberal nucleus was also investigated with regard to the gonadal growth and development during the reproductive sexual cycle and the changing migrational environmental conditions (anadromous and catadromous phases). The hypothalamic-pituitary system is formed by: centers of neurosecretion synthesis (parvo and magnocellular preoptic nucleus and lateral tuberal nucleus), a conduit system (preoptic infundibular-neurohypophyseal tract) and a collecting center (neurohypophysis intermediate lobe). The neurosecretory cells show two distinct types of secretory granules with different ultrastructural features probably representing the morphological expression of two distinct hormones. These cells show also characterizations of cytoplasmic areas related to peculiar cyclic functional stages concerned with the reproductive sexual cycle. We observed significant quantitative and qualitative changes of the neurons both in the parvo- and magnocellular preoptic nucleus and in the lateral tuberal nucleus during anadromous migration and during spawning and fertilization. Almost insignificant changes of the neurosecretory material were observed in the preoptic-pituitary tract and in the intermediate-neurohypophyseal lobe. The results show that the hypothalamic-pituitary neurosecretory system play an important role in the osmoregulation (magnocellular preoptic nucleus) and on the reproductive cycle (lateral tuberal nucleus). The system probably also controls some other metabolic activities (utilization of the stored material) linked to peculiar environmental and feeding conditions.

Animals↗
PubMed1988

Topography and ultrastructure of kidney lymphatics in some hibernating bats.

The kidney lymphatic system of some bats consists of intraparenchymal (interlobar, arcuate, and interlobular) and extraparenchymal vessels (capsular and prehilar connective). These vessels drain lymph via precollecting and prenodal collecting lymphatics into a hilar lymph node. There are no lymphatics in the renal medulla. The lymphatic vasculature (precollecting vessels excluded) is characterized by an endothelial wall lacking basal lamina and fenestrations. The endothelial cells, mostly rectangular in shape, are joined together by overlapping, end-to-end, and complex interdigitating junctions. Cytoplasmic expansions profile and thickness, intercellular junctions and particularly the different categories of uncoated vesicles (free or opened on luminal or abluminal surface) show qualitative and quantitative seasonal variations. Luminal and abluminal cytoplasmic processes appear (when analyzed in tridimensional reconstructions) as "intraendothelial channels." The increased number of these structures during summer characterizes them as dynamic elements and supports the concept of an active role played by them in transendothelial transport. Nevertheless, the main functional role is still ascribed (in addition to membrane transport mechanisms) to the vesicular system, also defined as the "vesicular route." We did not find any open intercellular junctions.

Animals↗
PubMed1987

First-trimester prenatal diagnosis of Sanfilippo C disease.

At 10 weeks' gestation, chorionic villus biopsy was obtained from a woman at risk for Sanfilippo type C disease. Acetyl-CoA: alpha-glucosaminide N-acetyltransferase activity was markedly deficient. The pregnancy was terminated at 12 weeks' gestation and follow-up study on fetal fibroblasts confirmed the diagnosis.

Adult↗
PubMed1987

Experimental infection of calves with strains of Bovid herpesvirus-4.

Fourteen calves were inoculated intranasally (i.n.) with the viral isolates as follows: 5 with 85/BH 16TV, 1 with 85/BH 17TV, 1 with 85/BH 18TV, 2 with 85/BH 231TN and 5 with 85/BH 232TN. Strain 85/BH 16TV was the only one which caused overt respiratory-like disease in all inoculated calves. Onset of the disease was observed after 7-8 days of incubation and was characterized by fever, depression, nasal discharge and coughing. Virus was isolated from the nasal swabbings of calves obtained from post-infection day (PID) 2-10. The other viral strains did not cause any sign of disease although virus was isolated regularly from the nasal swabbings of the inoculated calves. Virus was recovered from central nervous system tissues of calves that were infected with 85/BH 16TV or 85/BH 232TN strains and were killed on PID 4 or 8. Virus was also isolated from other tissues, such as lymph node, nasal mucosa (PID 8), or lung (PID 4). It was speculated that the nervous system could be one of the target areas of the virus of the naturally occurring infection by BHV-4. This might indicate a possible role of the nervous system (site of latency?) in the pathogenesis of BHV-4 as is the case in certain herpesviral infections of man and the lower animals.

Animals↗
PubMed1987

Reactivation in calves of latent infection by Bovid herpesvirus-4.

Nine calves, six of which had been infected with strain 85/BH 16TV and three with strain 85/BH 232TN of Bovid herpesvirus-4 (BHV-4), were treated with dexamethasone (DMS) three months after infection. DMS administration did not induce any clinical signs of disease, but BHV-4 was isolated from the nasal swabbings of all calves for a maximum of 8 days after the start of DMS treatment. The virus was also isolated from the nerve tissues, nasal mucosa, lymph nodes, lung and spleen of 4 calves that were killed at different stages (3, 5, 7 days) of the DMS treatment. Intranuclear inclusions associated with cellular shrinkage were found in the neural tissues of calves killed either 3 or 5 days after the start of DMS treatment. Unexpectedly, a latent infection by infectious bovine rhinotracheitis (IBR) virus was reactivated. The virus was isolated from the nasal swabbings of two calves and also from the brain, cerebellum and nasal mucosa of one calf killed 5 days after the start of DMS treatment.

Animals↗
PubMed1987

Plasma carnitine and acetyl-carnitine levels at different times of the day.

An interest in both biochemical and clinical carnitine investigation has recently developed. A more complete and extensive study is obtained if acetyl-carnitine as well as carnitine are investigated. This research, using an improved and simplified method for carnitine and acetyl-carnitine determination in the same sample (1 ml) without radioisotopic tracer use, investigates if there are the same differences in their plasma levels at different times of the day. The sample was eluted in a chromatographic column (55 X 15 mm) containing Sephadex G-25M with phosphate buffer (25 mmol/l, pH 7.4). The fraction containing acetyl and free carnitine was divided and employed separately for two assays. The carnitine assay uses an enzymatic reaction catalyzed by carnitine acetyl-transferase (CAT) and measurements are carried out spectrophotometrically. The calibration curve shows r = 0.987 and sensitivity at 5 mumol/l (reference plasma values: 38 +/- 3 mumol/l in 9 subjects). The acetyl-carnitine assay is carried out concentrating the sample by lyophilization and then measuring the enzymatic coupled reactions catalyzed by CAT, malate dehydrogenase and citrate synthase fluorimetrically. The calibration curve gives r = 0.991 and sensitivity at 1.4 mumol/l (reference plasma values: 2.8 +/- 0.3 mumol/l in 9 subjects). Both assay methods are measured at the end point. The carnitine and acetyl-carnitine measured in the plasma of 6 normal subjects at different times of the day vary respectively from 28 to 37 mumol/l and from 1.1 to 5.2 mumol/l in agreement with plasma free fatty acid (FFA) variation from 230 to 779 microEq/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcarnitine↗
PubMed1986

Human T-cell receptor genes: organization, diversity, and polymorphism.

The analysis of 27 human beta cDNA clones has revealed striking insights as to the germ line, combinatorial, and somatic mechanisms that operate to diversify V beta gene segments. It appears that the repertoire of human V beta genes is limited to 60 or so functional gene segments. Deletional mapping together with the analysis of large DNA fragments by field inversion gel electrophoresis and the isolation of cosmid clones should permit us to map the entire human V beta gene family. The polymorphisms that are present in these V beta gene segments will facilitate a search for interesting disease associations. A detailed comparison of the mouse and human V beta loci should permit us to come to understand in more detail the evolutionary mechanisms that have created these fascinating gene families.

Base Sequence↗
PubMed1985

A comparison of rotavirus strains of bovine, simian and porcine origin.

Three rotavirus strains of bovine, simian and porcine origin, respectively, were compared. The 3 viruses induced a classic rotaviral infection in newborn, conventionally reared calves. The cross neutralization tests revealed an antigenic identity of simian and porcine rotaviruses and a slight serologic correlation of these two viruses with the bovine rotavirus strain. However, in reciprocal cross protection tests carried out in calves, the simian rotavirus antiserum afforded weak protection to challenge infection with either the porcine or the bovine viruses. By contrast, the protective level of the bovine and the porcine rotavirus antisera was relatively high. It was speculated that the 81/36F bovine rotavirus could be considered, tentatively, as an antigenic reassortant rotavirus strain.

Animals↗
PubMed1985

Homozygosity for the variant alpha-L-fucosidase trait and mucolipidosis III.

The variant alpha-L-fucosidase genotype, phenotypically observed as a low plasma level of alpha-L-fucosidase in healthy individuals, can modify the plasma expression of the primary genetic defect in mucolipidosis III. Three patients with clinical, radiological, and biochemical features of mucolipidosis III, had a normal plasma level of alpha-L-fucosidase activity. The thermostability curves for the plasma alpha-L-fucosidase from these patients and the plasma alpha-L-fucosidase of the parents of one of them, are discussed to support the suggestion that they are homozygous for the autosomal recessive variant alpha-L-fucosidase trait. From a practical point of view, these observations warn against the use of the plasma alpha-L-fucosidase assay as a screening test for mucolipidoses.

Female↗
PubMed1985

Local hemostasis after tooth extraction in patients with abnormal hemostatic function. Use of human fibrinogen concentrate.

Tooth extraction was carried out in 405 patients with various hemostatic disorders due to thrombocytopenia, chronic liver disease, hemophilia A and B, von Willebrand's disease and oral anticoagulants. Human fibrinogen concentrate was used as local hemostatic agent. Prophylactic replacement therapy (platelets or plasma concentrates) and antifibrinolytic agents were not administered. Oral anticoagulants were not discontinued. Minor postextraction bleeding occurred only in severe hemophilia A and occasionally in the oral anticoagulant group.

Blood Coagulation Disorders↗
PubMed1985

Richner-Hanhart syndrome spares a plantar autograft.

A patient with Richner-Hanhart syndrome had thigh skin grafted onto her heel in an attempt to improve her walking. The graft seemed to be spared by the hyperkeratosis that arrested at the periphery of the graft and formed a keratotic wall. A low-tyrosine, low-phenylalanine diet was effective in clearing hyperkeratosis.

Adult↗