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H Díaz

Publications and source records attributed to H Díaz.

16 recordsLinked to original sources
PubMed2004

Postovulatory ageing induces structural changes in the mouse zona pellucida.

The structure of the zona pellucida (ZP) was analyzed in mouse oocytes collected soon after ovulation and in others retrieved 20 h after. The conventional methods for electron microscopy and the alcoholic PTA staining procedure which preferentially contrasts lysine-rich proteins were employed. The ZP of aged oocytes showed several structural changes which were particularly observed after using the PTA procedure. In 82.14% of the aged oocytes the ZP appeared clearly composed of two different regions: an inner dense and an outer of low density. The ZP showed a fibrillar banded structure with a parallel arrangement of fibrillar threads in both the outer and inner regions. The in vitro fertilization analysis showed that only 16.85% of the aged gametes attained the two cell embryo stage in comparision to 66.93% shown by the freshly ovulated eggs. The non-fertilized oocytes showed that no sperm penetration through the ZP occurred.

Aging↗
PubMed2000

Cruzipain induces autoimmune response against skeletal muscle and tissue damage in mice.

The goal of the current study was to investigate whether cruzipain, a major Trypanosoma cruzi antigen, is able to induce in mice an autoimmune response and skeletal muscle damage. We demonstrate that immunization with cruzipain triggers immunoglobulin G antibody binding to a 210-kDa antigen from a syngeneic skeletal muscle extract. The absorption of immune sera with purified myosin completely eliminated this reactivity, confirming that the protein identified is really myosin. We also found that spleen cells from immunized mice proliferated in response to a skeletal muscle extract rich in myosin and to purified myosin. Cells from control mice did not proliferate against any of the antigens tested. In addition, we observed an increase in plasma creatine kinase activity, a biochemical marker of muscle damage. Histological studies showed inflammatory infiltrates and myopathic changes in skeletal muscle of immunized animals. Electromyographic studies of these mice revealed changes such as are found in inflammatory or necrotic myopathy. Altogether, our results suggest that this experimental model provides strong evidence for a pathogenic role of anticruzipain immune response in the development of muscle tissue damage.

Animals↗
PubMed1997

[Prevalence of neurocysticercosis in individuals affected by epilepsy].

INTRODUCTION: In this investigations, was carried out a neurocysticercosis (NC) prevalence study during seven months in the Instituto Neurológico de Antioquia with the purpose of known neurocysticercosis frequency as cause of epilepsy in patients older than ten years that we attended in our institute. MATERIAL AND METHODS: Computerized tomographies (CT) were made to 503 patients, with epilepsy, 24.7% of them were CT positive for NC. Cysticercosis enzyme linked immunoelectrotransfer blot (EITB) and enzyme linked immunoabsorbent assay (ELISA) test were made to 178 patients, 19.6% were EITB positive for NC and 5% ELISA positive for NC. Results. From this result it is possible to infer that about 8% of the 503 patients with epilepsy had cysticercosis, according to EITB that is the golden assay for NC. The CT and ELISA test had 94.3% and 27.7% sensitivity, respectively, according to EITB. The specificity of the CT for NC was 49.2% and specificity for ELISA test was 100% as compared to EITB. The multivariate analysis with logistic regression allowed to establish association of positive EITB with factors such as male sex, eating pork, headaches and multiple lesions in CT. CONCLUSIONS: Prevention and education actions are necessary for the interruption of the neurocysticercosis transmission chain in order to diminish the high prevalence of epilepsy in the country and its complication and consequences.

Adult↗
PubMed1995

Neuritogenic effect of estradiol on rat ventromedial hypothalamic neurons co-cultured with homotopic or heterotopic glia.

In sexually segregated cultures of dissociated neurons taken from ventromedial hypothalamus of rat fetuses at embryonic day 16 (E16), it is demonstrated that only neurons from males respond with increased axonal growth to the addition of 17-beta-estradiol 100 nM (E2) to the culture medium. Moreover, this response is contingent upon co-culture with heterotopic glia from a target region (amygdala), whereas in the presence of homotopic glia or in cultures without glia, E2 has no effect. It is concluded that before neurons are exposed to gonadal steroids in utero there is a sexual difference in the response to E2, probably explained by earlier maturation of neurons from males as compared to females. The possibility that the observed axogenic effect may be the consequence of an interaction among E2, cells equipped with specific receptors, and glia-producing trophic factors is discussed.

Animals↗
PubMed1995

[Jejuno-ileal volvulus, a rare cause of intestinal obstruction].

Volvulus of the small bowel without predisposing anatomical defects is a rare cause of acute intestinal obstruction in the Western world, and its incidence is decreasing in Europe and America, although it is common in others parts of the world. The causes of primary volvulus of the small bowel and the mechanism of rotation of the entire root of the mesentery remain unexplained. Several anatomical and dietary factors have been implicated. This theory requires strong peristalsis, tense, firm abdominal muscles and feeding pattern of very bulky meals taken at long intervals. In the present case, a large quantity of bulky poorly digested food consumed previously, and strong abdominal muscles are in keeping with the above theory.

Abdominal Muscles↗
PubMed1992

Time lapse study of neurite growth in hypothalamic dissociated neurons in culture: sex differences and estrogen effects.

Cultures of dissociated hypothalamic cells taken from rat fetuses of 19 days of gestation were studied using time-lapse recording and sequential microphotography from 1 to 5 days in vitro (DIV) and at 7 and 21 DIV. Cultures were seeded with cells taken from fetuses grouped by sex or sexually mixed; experimental cultures were raised in medium containing 17-beta-estradiol 100 nM (E2). Cells were plated on poly-D-lysine-coated coverslips at a culture density of approximately 4,000 cells/cm2. Immunocytochemistry of cell cultures was performed using a Tau monoclonal antibody (clone Tau-1 PC1C6) and a monoclonal antibody against MAP-2 (clone AP-20). Cells started to produce lamellipodia and neuritic processes approximately 4 hr after plating. Forty-eight hours later a few neurons had defined their morphological polarity by the differentiation of an axon-like process that grows faster than the others; at 5 DIV almost all neurons had defined their axons. At this time, monoclonal antibody against MAP-2 clearly stained soma and dendrites, but not axons. Tau immunoreactivity (lots CCA101 and CCA101N from Boeringher Mannheim) was differentially distributed, with a clear predominance in axon and soma. Results on the morphometric analysis of control and E2 treated neurons provide direct evidence for the existence of sex related differences in the neurite outgrowth response of hypothalamic neurons, since cultured neurons taken from female fetuses differentiated axons later and had fewer primary neurites and shorter dendrites than neurons taken from male fetuses or sexually mixed cultures. Also, it was demonstrated in living neurons that E2 effectively enhances outgrowth and elongation in axons. The frequency distribution curves of axonal length for control and E2 treated cultures was unimodal, suggesting that the effect of E2 was a uniform increase in the axonal length of all neurons. The structural differences between neurons from both sexes and the changes induced by E2 may contribute to explain the differences in brain function found between the sexes.

Animals↗
PubMed1992

Amygdala neurons in vitro: neurite growth and effects of estradiol.

Dissociated cell cultures from embryonic rat medial amygdala were studied using sequential photography and immunocytochemical staining for cytoskeletal proteins and substance P (sP). Cultures were seeded with cells taken from fetuses grouped by sex; experimental cultures were raised in medium containing 17-beta-estradiol (E2). Forty-eight hours after plating a few neurons begin to define their morphological polarity by the differentiation of an axon-like process; at 5 days in vitro (DIV) almost all neurons had developed an axon. Tapering, daughter branch ratio and branch power coefficient coincided with identification of dendrites which could be confirmed by retrospective analysis of immunocytochemically stained cultures: at 5 DIV MAP-2 was restricted to dendrites whereas Tau immunoreactivity was differentially localized with a clear predominance in the axon. At 21 DIV neuronal shape parameters were strikingly like those of amygdaloid neurons in vivo. It was demonstrated in living neurons that E2 increased total dendritic length and that this is due to increased ramification of third or higher order dendritic segments whose individual lengths are not different from controls. Densitometric measurement of MAP-2 stained neurons showed a highly significant increase of immunoreactive material in cells grown in the presence of E2; readings for alpha-tubulin were not different between controls and E2 treated cultures. The effect of E2 on dendritic length was just as manifest in sP-positive as in sP-negative neurons. No sexual differences in morphological parameters, growth characteristics or effects of E2 were found in neurons taken from female fetuses versus neurons from male fetuses. The significance of these results for the generation of sexual differences in the amygdala in vivo is discussed and contrasted with reported results on the effects of E2 in cultures of different neural regions.

Amygdala↗
PubMed1991

[Laparoscopy: 15 years experience].

The authors reveal an experience of 3453 laparoscopies, with a great percentage of diagnostic and therapeutic success. The procedure was used in 1,880 tubal sterilization, 1463 diagnostic cases of infertility studies and pelvic inflammatory diseases and 92 cases of ectopic intrauterine device.

Female↗
PubMed1989

Secretory character of a group of isoproterenol-induced polypeptides in mouse parotid glands.

The secretory nature of the isoproterenol-induced mouse parotid polypeptides C, D, E, F, and G (molecular weights 64,000, 61,000, 51,500, 38,000, and 37,000, respectively) is documented. Polypeptides C, D, E, F, and G, accumulated in response to successive daily stimulations with isoproterenol, were detected in a fraction enriched in hypertrophic parotid acinar cells. These cells, characterized by an increased content of cytoplasmic granules, maintain a secretory responsiveness to isoproterenol, which has been evidenced by light microscopy, enzymatic analysis, and unidimensional SDS-polyacrylamide gel electrophoresis. Thus, a parallelism in the loss and recovery of both secretory granules, alpha-amylase and polypeptides C, D, E, F, and G, was observed. Moreover, after secretion stimulation, polypeptides C, D, E, F, and G were detected in the fluid collected directly from parotid gland cannulation. Given the secretory character of polypeptides C, D, E, F, and G, mechanisms explaining both their progressive accumulation along the chronic administration of isoproterenol, as well as their progressive disappearance observed after suspending that treatment, are discussed.

Animals↗
PubMed1989

[Colonic lesion caused by acute pancreatitis. Use of minimal catheter jejunostomy. Apropos of 6 cases].

Colonic affectation in the context of acute pancreatitis is undoubtedly a rare complication to judge from the number of cases reported in the literature, but its appearance is increasing, perhaps because it is receiving more attention. The "infrequent" complications of so-called acute pancreatitis range from massive necrosis of the colon to fistula of the transverse colon, colonic stricture as a chronic manifestation and finally, colonic varices as a sign of segmental portal hypertension due to involvement of the mesenteric portal axis. A retrospective study was made of 6 cases treated in our General and Digestive Surgery Department and the literature on this etiopathogenic situation was reviewed to study the clinical manifestations, diagnosis and treatment of these uncommon complications. We propose minimal catheter jejunostomy as a technique for the prevention and treatment of possible complications, with epidural analgesia of these patients.

Acute Disease↗
PubMedDate not supplied

Evaluation of enzyme linked immunosorbent-assay and western blot for diagnosis of histoplasmosis.

This study evaluates the use of a enzyme linked immunosorbent assay (ELISA) for the diagnosis of histoplasmosis and it compares it with a complement fixation test. The results showed a sensitivity of 86% in this diagnosis of acute pulmonary histoplasmosis and specificity of 91% using anti-human IgG. For antihuman IgM the sensitivity was 66% and the specificity 100%. There was a good correlation between the titer of complement fixation test and the optical density index by ELISA. Neither ELISA or complement fixation were useful for the diagnosis of disseminated histoplasmosis in immunocompromised patients. Using Western blot we identified antibodies against four different histoplasma antigens (91, 83, 70 and 38 kD) in sera from patients with histoplasmosis. These antigens were identified also in patients with disseminated histoplasmosis. We conclude that ELISA is a useful test for the diagnosis of histoplasmosis, and the Western blot could be useful for the diagnosis of disseminated histoplasmosis.

AIDS-Related Opportunistic Infections↗