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Biomedical subjects

M C Díaz

Publications and source records attributed to M C Díaz.

At least 55 records · Page 3Linked to original sources
PubMed1986

[Acute hepatitis in childhood. Study of 96 cases and 1-year follow-up].

Authors studied 96 children, 56 boys and 40 girls, aged 1 to 16 years, with acute viral hepatitis. 53 patients were diagnosed of hepatitis a virus (HAV) detecting antibodies to HAV of the IgM class; 11 patients were diagnosed of hepatitis B virus (HBV) detecting serologic markers; 32 patients were diagnosed of non A-non B hepatitis. There were no serologic evidence of infection with cytomegalovirus and Epstein-barr virus. They report an analytical and clinical comparative study of acute viral hepatitis, and their evolution during a year, not finding any significative statistic difference. Two patients with HBV remained chronically infected.

Acute Disease↗
PubMed1986

[Levels of serum immunoreactive trypsin in children with intra- and extrahepatic cholestasis].

Serum levels of immunoreactive trypsin (TIRS) were determined in 61 children having either alpha 1 antitrypsin deficit, chronic hepatitis, syndromic or non-syndromic ductular hypoplasia, or extrahepatic biliary atresia. Fasting TIRS values in both patients with chronic hepatitis (213 M 81 ng/ml) and with extrahepatic biliary atresia (159 +/- 88 ng/ml) didn't show statistically significant differences in relation to control values (172 +/- 44 ng/ml). However, in children with alpha 1-antitrypsin deficit (518 +/- 275 ng/ml; p less than 0.02) or syndromic (594 +/- 331 ng/ml; p less than 0.01) and non-syndromic ductular hypoplasia (558 +/- 183 ng/ml; p less than 0.02) TIRS levels were significantly above control values. Even more, in these last three groups of patients, their TIRS values were clearly greater than in extrahepatic biliary atresia patients. According to the above findings, we suggest that TIRS values may be a valuable marker for the differential diagnosis between intra and extrahepatic cholestasis.

Adolescent↗
PubMed1986

[Hepatic lesions caused by alpha 1-antitrypsin deficiency in childhood. Review of 14 cases].

Fourteen cases of alpha-1-antitrypsin deficiency are presented. All of them had a PIZZ phenotype except two in which a PIMZ phenotype was found. It must be pointed out that histological findings show a great variability among the different patients most of which did not have intracellular PAS-positive amylase inclusions in liver biopsy specimens. Clinical course did not correlate with either the age of onset of the disease or the phenotype found, thus indicating that other additional factors are involved in determining prognosis. We insist on the importance of a careful study of all neonatal hepatitis syndromes in order to rule out a alpha-1-antitrypsin deficiency.

Biopsy↗
PubMed1986

[Pediatric-social aspects of the acute and chronic viral types of hepatitis in childhood].

This study analyzes the sanitary, sociofamiliar, cultural and economic aspects of children who have been diagnosed of acute and chronic viral hepatitis. Retrospective data was collected of 249 children. A questionnaire was given to the parents and the information collected was processed in a computer. The results showed that most children had been sent to the hospital without a diagnosis and in chronic hepatitis the diagnosis was delayed for more than a year. The social status did not influence the type of hepatitis. Children with chronic hepatitis active had a worse performance in school. The disease was transmitted to other family members in 30% of cases and hospital expenses were high.

Acute Disease↗
PubMed1985

Effect of GABA-T inhibitors on prolactin secretion in vitro.

A study was made of the effect of GABA-transaminase (GABA-T) inhibitors on the in vitro release of prolactin by pituitaries of male and female rats. Aminooxyacetic acid (AOAA) and gamma-acetylenic GABA (GAG) added to the incubation medium decreased prolactin release from both male and female rat pituitaries. Additive effects on prolactin release were only observed when male rat pituitaries were incubated with AOAA plus GABA. Prolactin concentration in the pituitary gland was also decreased by AOAA in both sexes. The present results lend support to the idea of an inhibitory action of GABA on prolactin release by the pituitary gland.

4-Aminobutyrate Transaminase↗
PubMed1985

Unusual viruslike particles in chronic non-A, non-B hepatitis in childhood.

Liver biopsies from 16 children with clinical and pathologic evidence of chronic hepatitis have been examined by electron microscopy for cytoplasmic and nuclear changes. Parallel studies by radioimmunoassay on sera from the same patients support the diagnosis of all these cases as non-A, non-B hepatitis (NANB). Ultrathin sections of the liver biopsies demonstrated in one case intranuclear hepatitis B virus-like core particles, 25 nm diameter. In a second biopsy from the same patient, the corelike particles could still be observed. This finding could be used either to support the thesis that a NANB virus is a member of the hepadnavirus group or to reflect the existence of seronegative cases of chronic HBV infection. Furthermore, we have observed in some mononuclear cells from the inflammatory infiltrate of a portal tract, some structures that resemble virus budding. There is a striking similarity between the morphology of these particles (which are enveloped and possess projections) and the ultrastructure of retrovirus.

Antigens, Viral↗
PubMed1984

The effect of ethanol on prolactin secretion in vitro.

In order to investigate the action of ethanol on the anterior pituitary gland, the effect of ethanol on prolactin secretion in vitro was studied. Ethanol significantly increased the in vitro incorporation of 3H-leucine into both prolactin contained within the pituitary gland and that released into the medium. The enhancement of 3H labelled-prolactin synthesis induced by ethanol was suppressed by cycloheximide. These results support the hypothesis that ethanol stimulates the in vitro synthesis and release of prolactin by the pituitary gland.

Acetaldehyde↗
PubMed1984

[Serum profile of bile acids in children with neonatal hepatitis and extrahepatic biliary atresia].

A bile acid analysis by a fluorometric-enzymic method was carried out in serum from infants with neonatal hepatitis and biliary atresia. Serum bile acids were determined in 51 infants: 34 with extrahepatic biliary atresia and 17 with neonatal hepatitis syndrome. The following results were obtained: 1) There were no significant differences between neonatal hepatitis and biliary atresia concerning total serum bile acids. 2) The ratio of trihydroxylated to dihydroxylated bile acids in serum was less than one in 30 patients with biliary atresia and greater than one in 15 patients with neonatal hepatitis. 3) Conventional hepatic tests did not show any statistically significant difference between these types of patients. These results suggest that trihydroxy/dihydroxy bile acid ratio may be of clinical interest to differentiate biliary atresia from neonatal hepatitis in infants.

Bile Acids and Salts↗
PubMedDate not supplied

Effect of passive immunization against substance P in rats with hyperprolactinemia.

Substance P, an undecapeptide isolated from gut and brain tissues, was reported to stimulate prolactin release. It was suggested that substance P may play a role in the control of prolactin secretion. In this investigation we studied the effects of the blockade of endogenous substance P by the administration of a specific anti-substance P serum on serum prolactin levels in rats in the evening of proestrus, in lactating rats after suckling, and in male rats with hyperprolactinemia induced by grafting 2 anterior pituitary glands under the kidney capsule. The injection of the anti-substance P serum was followed by a significant decrease of the prolactin surge induced by 30 min suckling in lactating rats, when the antiserum was administered 24 hr but not 5.30 hr earlier. Anti-substance P serum also induced a significant decrease in serum prolactin levels in pituitary grafted rats, but induced no change in the proestrous surge of prolactin and LH. These results show that substance P may be involved in the release of prolactin induced by suckling and that this peptide may have an intrapituitary role in the process of prolactin release. On the other hand, substance P does not seem to play a significant role in the proestrous peak of prolactin and LH.

Animals↗
PubMedDate not supplied

Substance P affects the GABAergic system in the hypothalamo-pituitary axis.

In the present work we examined the effect of the neutralization of endogenous substance P by the administration of an anti-substance P serum (ASPS) on GABA concentration in the anterior pituitary in hyperprolactinemic conditions induced by 5-hydroxytryptophan or by grafting anterior pituitaries. ASPS reduced the increase in the anterior pituitary GABA concentration induced by hyperprolactinemia. In vitro experiments showed that substance P inhibited K(+)-evoked GABA efflux from hypothalamic fragments and decreased GABA concentration in the anterior pituitary but ASPS increased it. Our results demonstrate that substance P modifies hypothalamic GABA release and anterior pituitary GABA concentration and suggest that an interaction exists between substance P and GABA.

Animals↗
PubMedDate not supplied

[Update on coronary syndrome X].

Syndrome X is not a well-defined clinical entity. Patients included are those with typical effort angina with angiographically normal coronary arteries and with no evidence of other causes of chest pain. The pathophysiologic mechanisms involved in this syndrome could be a reduced vasodilatory capacity. The prognosis is usually good, but a subgroup of patients with left bundle brunch block in the ECG may develop a dilated cardiomyopathy. To present it lacks a full effective treatment.

Algorithms↗
PubMedDate not supplied

[Evaluation of the Program of the Feeding and Language Stimulation Centers in 3 Chilean regions].

To evaluate the effect of attendance to a non traditional day care center ("CADEL") on physical and psychomotor development, 366 children aged 2-5 years belonging to 22 centers were studied. Weight and height were measured at 0, 4 and 8 months and weight for age, height for age and weight for height indexes were calculated from WHO/NCHS standards. Psychomotor development at the beginning of the study and 8 months latter through a standard test (TEPSI) was evaluated. Mean weight and height monthly increments were 144 +/- 83 g and 0.54 +/- 0.16 cm, 72 and 90% respectively of normal growth. Protein energy malnutrition prevalence (30.8%) was not modified but subnormal values of psychomotor development (40.9%) decreased during the study (p less than 0.05 global, coordination and motor function). Language retardation did not improve with the attendance to the program. These centers represent low cost alternatives to extended coverage of preschool services for low income families. More active family integration and reinforcement of stimulation and educational activities may improve program effectiveness.

Child Day Care Centers↗