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Biomedical subjects

C Gomez

Publications and source records attributed to C Gomez.

At least 91 records · Page 5Linked to original sources
PubMed1988

Restricted use of T cell receptor V genes in murine autoimmune encephalomyelitis raises possibilities for antibody therapy.

Experimental allergic encephalomyelitis (EAE) is a paralytic autoimmune disease induced in susceptible animals by active immunization with myelin basic protein (MBP) or by passive transfer of MBP-specific T helper (TH) lymphocytes. We have analyzed the T cell receptor genes of 33 clonally distinct TH cells specific for a nonapeptide of MBP inducing EAE in B10.PL (H-2u) mice. All 33 TH cells used two alpha variable gene segments (V alpha 2.3, 61%; V alpha 4.2, 39%), the same alpha joining gene segment (J alpha 39), and two V beta and J beta gene segments (V beta 8.2-J beta 2.6, 79%; V beta 13-J beta 2.2, 21%). The anti-V beta 8 monoclonal antibody F23.1 was found to block completely recognition of the nonapeptide by V beta 8 TH cells in vitro and to reduce significantly the susceptibility of B10.PL mice to peptide-induced EAE.

Animals↗
PubMed1988

Levo-carnitine, its derivatives, and free fatty acids in serum, heart, liver, and muscle of both tumoral and alcoholic rats.

We present a comparative study of carnitine-related fatty acid metabolism in rats bearing a Yoshida sarcoma, in chronic alcoholic rats, and in control rats. Levels of levo-carnitine, acetylcarnitine, acylcarnitine, and free fatty acids were studied in serum and in different tissues--liver, heart, and skeletal muscle--of each group of rats. Chronic alcoholic rats showed high levels of free fatty acids and elevated levo-carnitine and acetylcarnitine levels relative to those of the controls. Biosynthesis of carnitine appeared to be increased, whereas fatty acid oxidation was depressed. Tumor-bearing rats also showed high levels of free fatty acids in both serum and tissues. However, levels of levo-carnitine were decreased in this group. It seems that the tumor not only utilizes the precursors of carnitine biosynthesis but also increases carnitine expenditure.

Alcoholism↗
PubMed1988

Scanning electron microscopy and electron probe microanalyses of the crystalline components of human and animal dental calculi.

A review of the use of scanning electron microscopy (SEM) and electron probe microanalyses in the study of dental calculus showed that such studies provided confirmatory and supplementary data on the morphological features of human dental calculi but gave only limited information on the identity of the crystalline or inorganic components. This study aimed to explore the potential of combined SEM and microanalyses in the identification of the crystalline components of the human and animal dental calculi. Human and animal calculi were analyzed. Identification of the crystalline components were made based on the combined information of the morphology (SEM) and Ca/P molar ratios of the crystals with the morphology and Ca/P molar ratio of synthetic calcium phosphates (brushite or DCPD; octacalcium phosphate, OCP; Mg-substituted whitlockite, beta-TCMP; CO3-substituted apatite, (CHA); and calcite. SEM showed similarities in morphological features of human and animal dental calculi but differences in the forms of crystals present. Microanalyses and crystal morphology data suggested the presence of CaCO3 (calcite) and CHA in the animal (cat, dog, tiger) and of OCP, beta-TCMP and CHA in human dental calculi. X-ray diffraction and infrared (IR) absorption analyses confirmed these results. This exploratory study demonstrated that by taking into consideration what is known about the crystalline components of human and animal dental calculi, combined SEM and microanalyses can provide qualitative identification.

Adult↗
PubMed1987

Xyloside inhibits synthesis of the class II-associated chondroitin sulfate proteoglycan and antigen presentation events.

An alternative form of the human invariant chain exists as a chondroitin sulfate proteoglycan (CSPG) with invariant chain as the core protein. The selective inhibitor of proteoglycan synthesis, p-nitrophenyl beta-D-xyloside was used to study the role of this CSPG in class II biology. At xyloside concentrations of 2.5 and 5.0 mM, CSPG synthesis was completely inhibited with marginal inhibition of protein synthesis. The inhibitory effect on CSPG synthesis was completely reversible. The number of class II molecules on the cell surface was not affected by xyloside, but biosynthesis and appearance of newly synthesized class II molecules at the cell surface were both decreased by xyloside. Recognition of influenza virus-infected cells by class II-restricted, virus-specific cytotoxic T lymphocytes was not diminished by the presence of xyloside in the effector phase of the cytotoxicity assay. However, sensitization of target cells was markedly inhibited when target cells were exposed to virus in the presence of xyloside. These results are consistent with the hypothesis that the CSPG form of invariant chain has a role in antigen processing.

Antigen-Presenting Cells↗
PubMed1987

Calcium and calcitonin responses to calcium infusion in type I diabetes mellitus.

We studied calcium and calcium and calcitonin responses to intravenous calcium infusion (3 mg of elemental calcium/kg of body weight in 10 minutes) in 21 type I diabetic males and 17 age-matched normal males. Baseline total calcium, parathyroid hormone and calcitonin levels were normal in the diabetic group, but ionized calcium was lowered. Cortical bone status and osteocalcin levels were normal, suggesting a normal osteoblastic function. Total calcium and ionized calcium responses to calcium infusion were lowered in the diabetic group. Despite these lowered calcaemic responses, calcitonin secretion was normal.

Adult↗
PubMed1986

AB variant GM2 gangliosidosis: cerebrospinal fluid and neuropathologic characteristics.

A child with AB variant GM2 gangliosidosis who had progressive intellectual deterioration and seizures commencing at the age of 12 months is described. Neuronal loss, and neuronal and astrocytic inclusions characteristic of the gangliosidoses, were seen on cortical biopsy. GM2 ganglioside was detected in the CSF. As CNS ganglioside accumulation in this condition occurs in the presence of normal leukocyte hexosaminidase A and B levels, spinal fluid assay for GM2 ganglioside may serve as a valuable aid in diagnosis.

Cerebral Cortex↗
PubMed1985

A comparative analysis of the development of the primary somatosensory cortex: interspecies similarities during barrel and laminar development.

The development of the barrels and layers II-V was examined in Nissl-stained preparations of the primary somatosensory cortex in six species--hamster, mouse, rat, gerbil, rabbit, and guinea pig--that have increasingly longer gestation periods. The barrels and layers II-V begin to differentiate postnatally during the first week postpartum in the hamster, mouse, rat and gerbil; perinatally in the rabbit; and approximately 4 weeks prenatally in the guinea pig. The structure of the barrels and layers II-V is similar at the onset of their differentiation in each species, even though there are interspecies differences in the mature structure of the barrels and layer V. The rate of the initial differentiation of the barrels and layers II-V is also similar in each species, even though there are considerable interspecies differences in the duration of the preceding period of development. In each species, layer V begins to differentiate first from the cortical plate and, within 1 or 2 days, contains sublayers that eventually disappear in the rabbit and guinea pig. About 3 days after the initial differentiation of layer V, layers II-IV begin to differentiate, seemingly simultaneously, causing the cortical plate to have a trilaminar appearance. Barrels are first evident just before the appearance of the trilaminar plate in hamsters; concomitant with the trilaminar plate in mice, rats, and guinea pigs; and just after the trilaminar plate in gerbils and rabbits. Septa appear 1 or 2 days after the barrels except in rabbits, which never have septa. Barrel maturation proceeds rapidly after the initial appearance in all species except the hamster, in which continued maturation seems to be delayed until the appearance of the trilaminar plate. The barrels in immature rats and rabbits become more prominent than they will eventually be in the adults. Our results indicate a close and rapid developmental affiliation between layers II-V, especially layers II-IV, that seems quite separate from the development of layers I and VI. However, barrel development and differentiation of layers II-IV seem to be closely, but independently initiated. Secondary remodeling occurs in layer V and the barrels of some species.

Animals↗
PubMed1985

No influence of number of donor CFU-GM on granulocyte recovery in bone marrow transplantation for acute leukemia.

The possible interrelation between infused bone marrow CFU-GM and peripheral granulocyte recovery was studied in 16 patients transplanted for acute leukemia. The influence of several clinical events that could modify the graft fate were also analysed. Our results show that: 1) There was no correlation between the number of infused nucleated cells and granulocyte recovery. 2) There was no correlation between the number of infused CFU-GM and granulocyte regeneration. 3) There were significant differences between the day of engraftment in patients with clinically documented HSV infection compared to patients without infection.

Acute Disease↗
PubMed1985

Predictive value of HLA antigen for methotrexate-induced liver damage in patients with psoriasis.

For an investigation of a possible association between HLA antigens and postmethotrexate liver damage, the A, B, C, and Dr loci of the HLA antigens were determined in thirty-two patients with severe psoriasis who had been treated with methotrexate. There was no association between HLA antigens and increasing severity of liver disease in these patients. HLA-A3 was increased in frequency in the group of patients with the more severe liver damage but was not significant when corrected for the number of antigens tested. There appears to be no predictive value in HLA typing of psoriasis patients prior to starting methotrexate therapy.

Adult↗
PubMed1978

[The determination of salivary pH by contact pH meter in individuals receiving psychotropic therapy. Study of pH on the tongue and at the orifice of Wharton's and Stenon's ducts (author's transl)].

The authors studied salivary pH at different sites in 172 patients receiving psychotropic therapy in hospital. For statistical purposes, the study was limited to individuals receiving a "moderate" dose of: --a benzodiazepine derivative --a neuroleptic and benzodiazepine --antidepressant, neuroleptic and benzodiazepine. Regardless of the type of psychotropic therapy and of the site of measurement, acidification of salivary pH which was statistically significant in comparison with values found in healthy subjects was noted. This acidification was particularly marked with regard to "lingual" pH. In addition, regardless of the site of measurement, a higher degree of acidification of salivary pH was seen in individuals receiving a combination of psychotropic agents. This acidification was particularly striking with regard to salivary pH in patients given a combination of antidepressant, neuroleptic and a benzodiazepine derivative. The cause of this acidification is not definitely known. A number of hypotheses may be put forward: decrease in salivary volume (Laudenbach, 6, and Vermeil, 7), excretion of acid metabolites by the salivary glands, effect of psychotropic agents upon the action itself of the salivary glands.

Antidepressive Agents↗