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Biomedical subjects

A M Gonzales

Publications and source records attributed to A M Gonzales.

8 recordsLinked to original sources
PubMed2006

Cytokine responses in gnotobiotic pigs after infection with virulent or attenuated human rotavirus.

To understand the role of cytokines during rotavirus infection, we assessed the kinetics of tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) (proinflammatory), IL-12 (Th1 inducer), gamma interferon (IFN-gamma) (Th1), IL-4 and IL-10 (Th2), and transforming growth factor beta (Th3) cytokine responses by enzyme-linked immunosorbent assay in serum and intestinal contents of neonatal gnotobiotic pigs and IL-12, IFN-gamma, IL-4, and IL-10 cytokine-secreting cell (CSC) responses of mononuclear cells from ileum, spleen, and blood by ELISPOT. Pigs received the virulent Wa P1A[8]G1 strain of human rotavirus (HRV) (VirHRV), attenuated Wa HRV (AttHRV), or mock (controls). The TNF-alpha levels peaked earlier and remained elevated in serum of the VirHRV group but peaked later in the AttHRV group. In serum, IL-6 was significantly elevated at postinoculation day (PID) 1 in the VirHRV group and at PID 3 in both HRV groups. The IL-12 was detected in serum of all pigs including controls with significantly elevated peaks in both HRV-infected groups, indicating a role for IL-12 in the induction of immune responses to rotavirus infection. Only low and transient IFN-gamma responses occurred in serum and intestinal contents of the AttHRV-infected pigs, compared to significantly higher and prolonged IFN-gamma responses in the VirHRV-infected pigs. This observation coincides with the diarrhea and viremia induced by VirHRV. The number of IFN-gamma-secreting cells was significantly higher in the ileum of the VirHRV group than in that of the controls. The number of IL-4 CSCs was significantly higher in ileum of both HRV groups than in that of the controls. Significantly higher levels of IL-10 in the serum occurred early in the VirHRV group, compared to lower levels in the AttHRV group. However, the number of IL-10 CSCs was significantly higher later in ileum and spleen of the AttHRV than in the VirHRV group, suggesting a delayed initiation of a Th2 response induced by AttHRV. A significantly higher percentage of pigs had IFN-gamma and IL-10 responses in serum after VirHRV infection than after AttHRV infection or in controls. These data indicate a balanced Th1/Th2 response during rotavirus infection, with higher cytokine levels early after infection with VirHRV compared to that with AttHRV. Mapping the kinetics and patterns of cytokine responses after rotavirus infection has important implications for induction of protective immunity by HRV vaccines. Higher protection rates may be associated with more balanced Th1- and Th2-type responses, but induction of higher earlier IFN-gamma (Th1) and proinflammatory cytokines triggered by VirHRV may also play an important role in the higher intestinal immunoglobulin A responses and protection rates induced by VirHRV.

Animals↗
PubMed2000

Angiogenesis and angiogenic growth factors in middle ear cholesteatoma.

HYPOTHESIS: This study aimed to analyze the localization and distribution of vessels and of these angiogenic growth factors: basic fibroblast growth factor (FGF-2), transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta1 (TGF-beta1), and vascular endothelial growth factor (VEGF) in middle ear cholesteatoma in comparison with normal middle ear mucosa and auditory meatal skin. BACKGROUND: Angiogenesis is particularly important in many normal and pathologic processes, including wound healing and inflammation. Because proliferating tissues require an enhanced blood supply, angiogenesis appears to be a prerequisite for the expansion of cholesteatoma. METHODS: The expression of FGF-2, TGF-alpha, TGF-beta1, and VEGF was studied by immunohistochemistry. The amount of vessels (collagen type IV staining) was determined by an automatic imaging analyzing system. RESULTS: The results showed an altered expression and distribution of VEGF, FGF-2, TGF-alpha, and TGF-beta1 in cholesteatoma in relation to middle ear mucosa and auditory meatal skin. The results were consistent with rapidly growing, activated keratinocytes and stromal cells. Vascularization within the perimatrix of cholesteatoma showed a 4.3-fold increase compared with middle ear mucosa and a twofold increase compared with ear canal skin. An increase of 3.2- to 4-fold in the number of vessels was observed. A close relationship was seen between the density of capillaries, degree of inflammation, and expression of the angiogenic factors investigated, and an increased number of microvessels in cholesteatoma tissue. CONCLUSIONS: Angiogenesis enables and supports the sustained migration of keratinocytes into the middle ear cavity. Therefore, it is a pivotal factor in the destructive behavior of middle ear cholesteatoma.

Angiogenesis Inducing Agents↗
PubMed2000

Immunology of gangliosides.

This review discusses the immunology of gangliosides from the perspective of tumor, neuronal and general immunology. Antiganglioside antibodies in human sera are invariably IgM and are found in healthy individuals. Their titers decline with age. Persistent high titer of IgM is associated with several diseases, particularly neuropathies. Membrane-bound gangliosides are important tumor-associated antigens and targets for immune attack. Cells enriched with gangliosides can be used as cancer vaccines. Efficacy of these vaccines depends on the viability of whole cells, integrity of the cell membranes, adjuvants and topography of the tumor-associated antigens. The role of antiganglioside IgM is to eliminate the immunosuppressive gangliosides shed from tissues during ageing, degeneration of neural and extraneural tissues, and tumor growth and necrosis. In addition, in vitro observations with human and murine monoclonal antibodies suggest that they are capable of complement dependent cytotoxicity and apoptosis.

Animals↗
PubMed1995

Central action of basic fibroblast growth factor on ingestive behaviour in mice.

Intracerebroventricular (ICV) infusion of basic fibroblast growth factor (FGF-2) at 50 ng/h for 5 days in male BALB/c mice suppressed the daily intakes of water and food (n = 4). Intakes were reduced on the second day, and were suppressed until the second day after stopping the infusion. The same infusion for 4 days had little effect on the high intakes of 0.3 M NaCl solution and water induced by prolonged ICV infusion of angiotensin II, or the daily food intake in these experiments (n = 7). However, the same infusion for 3-4 days reduced the increased intake of NaCl solution in Na-depleted mice (n = 8), reduced the increased water intake of water-restricted mice (n = 6 or n = 7), and reduced daily food intake in both experiments. Ventricular enlargement was noted in mice at the end of these experiments but, for reasons advanced, did not appear to account for the responses. The results indicate that FGF-2 may have an inhibitory role in these ingestive behaviours.

Angiotensin II↗
PubMed1979

[Metabolism of ammonium compounds by Azotobacter chroococcum (author's transl)].

A study on the metabolism of ammonium sulphate, amino acids, peptides, and nutrient broth by Azotobacter chroococcum is presented in this paper. Some of the amino acids studied lowered the pH of the medium while others alkalinized it. After prolonged incubation desamination could be observed. Peptides were hydrolyzed in some cases, although glycyl-glycyl-glycin was not degraded. A certain amount of growth could be observed with peptone as a sole source of carbon. Both nitrogen fixation and growth were stimulated by nutrient broth, but the medium was alkalinized when a higher concentration of nutrient broth was used, due to the production of ammonia.

Amines↗
PubMedDate not supplied

Age-dependent changes in Fibroblast growth factor 2 (FGF-2) expression in mouse cerebellar neurons.

Fibroblast growth factor 2 (FGF-2) is a neurotrophic factor that regulates many neuronal functions and survival. We have characterised FGF-2 expression immunohistochemically in the cerebellum of young (4 months) and old (22 months) mice. About half of the population of the granule cells (GC), and all Purkinje cells (PC) expressed FGF-2 in all folia of the cerebellum at both ages. FGF-2 showed differential intracellular localization: predominantly localised to the nuclei of GC and present mainly in the cytosol of PC. There was a statistically significant (P = 0.0028) reduction in the number of FGF-2-positive GC in the cerebella of old (41.3+/-0.91%) compared to young (48.5+/-1.67%) mice, whereas no statistically significant age-dependent difference occurred in the number of FGF-2 positive PC. These results indicate a possible role of FGF-2 in cerebellar ageing.

Age Factors↗