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Biomedical subjects

S Castillo

Publications and source records attributed to S Castillo.

At least 55 records · Page 3Linked to original sources
PubMed1992

[The cytogenetics of premature ovarian failure].

Premature ovarian failure is defined as the occurrence of menopause before the age of 40 years. Etiology has been related to genetic, autoimmune or infectious factors, resistance to gonadotropins and others. Forty-seven patients with this diagnosis were referred for cytogenetic analysis. Sixty-eight percent of the cases had a normal karyotype. In 10.7% there was one 45,X cell and they were catalogued as normal. In 15% of the patients there was a mosaicism with normal cell lines and additional 45,X, 47,XXXX and 48,XXXX ones. Two women had a chromosomal constitution 47,XXX. In one 22-year old patient there was a reciprocal balanced translocation 46,X t(X; 18) (q21.2;q22). The presence of different cell lines, including 45,X cells, could explain an accelerated loss of gametes in the ovary. In women with 47,XXX karyotype, fertility problems and premature menopause have been described. The study of the balanced X-autosome translocation with DNA technics could allow to find the molecular basis of the ovarian failure, permitting the direct search of the gene involved at the site of disruption.

Adolescent↗
PubMed1991

[Results of chromosomal studies in 270 couples with reproductive problems].

Cytogenetic study in couples with recurrent reproductive failure allows the detection of structural chromosome anomalies which don't have a phenotypic effect in carriers, but permit the explanation of the production of genetically unbalanced gametes. We present the investigation performed in 270 couples which demonstrated a chromosomal alteration in 9.2% of them. This allows genetic counselling in respect of the importance of the finding, recurrence risk and reproductive alternatives. In 8.6% we found some cellular lines with aneuploidies in sexual chromosomes, which don't represent a such concrete risk.

Adult↗
PubMed1991

[Clinical and legal aspects of brain death criteria: evaluation of the degree of knowledge of neurologists and neurosurgeons].

The level of knowledge of clinical and legal aspects of brain death criteria was tested in 25 neurologists and 15 neurosurgeons. The answers were wrong or the questionnaire had not been responded in 36.9% of the cases. The highest percentage of mistakes concerned the apnea test and what Chilean law said regarding brain death. No differences were found between neurologists and neurosurgeons. Physicians with less than 10 years were better informed than those with more than 10 years of medical practice (p < 0.005). Although brain death as a criterion of death is accepted by Chilean law in order to donate organs for transplantation, a considerable percentage of physicians (30%) rejected this concept. The significant lack of knowledge found in this study may suggest that brain death diagnosis is being inadequately performed in many cases. This fact raises important medical, ethical and legal considerations.

Brain Death↗
PubMed1991

[Lesions of the fallopian tube following tube occlusion].

This is a study using light microscopy and electronic microscopy of Fallopian tube subjected to sterilization; and compare it with a control group. A total of 60 samples from patients with different surgical procedures, whose age was from 20 to 40 years; they were amenorrheic, without antecedents of pelvic inflammatory disease nor endometriosis. Among the control group, there were lesions as isthsmical nodular salpingitis in 30.7%. There was chronic salpingitis in 15.3%; follicular salpingitis in 23%, and polyps in 15%. In the group with OTB antecedents, endosalpingiosis was found in 20%; follicular salpingitis in 30% and chronic salpingitis in the remaining 50%. By means of electronic, ultrastructural microscopy, were seen lesions at myosalpinx level, that is, alterations in myofilaments, formation, much fibrosis and descilliation in the adjacent to OTB. It may be concluded that these findings, never seen before, may condition an alteration of tubal motility in patients subjected to rechannelization procedures, that condition an alteration in gametes transportation, avoiding fecundation or a greater incidence ectopic pregnancy incidence.

Adult↗
PubMed1989

[Incidence of congenital malformations in Chile from 1969 to 1986. Results of a Latin-American collaborative study].

At present, congenital malformations contribute more to infant mortality, given the significant decrease in overall infant mortality rate observed in Chile. A significant and steady increase in the prevalence of congenital malformations was demonstrated at the Clinical Hospital, University of Chile, from 1969 to 1986. Better epidemiologic surveillance is needed to accurately estimate the magnitude of this problem and give orientation for preventive measures.

Chile↗
PubMed1989

[Nuclear magnetic resonance in the diagnosis of multiple sclerosis. A critical review of the literature].

Nuclear magnetic resonance (NMR) has been proposed to be the best diagnostic test for multiple sclerosis (MS). We performed a critical analysis of 13 papers evaluating the use of NMR in MS. Out of an ideal 17 criteria for validation and reproducibility, a top of 11 (65%) was the maximum found. Foremost deficiencies were a lack of blind analysis and inadequate patient samples. Thus the claim that NMR is the diagnostic tool of choice in MS remains to be proven.

Humans↗
PubMed1989

[Medical care to cerebrovascular syndrome].

We analyzed clinical data from all patients with a stroke admitted to the Emergency Service of a General Hospital in Santiago, from 1984 to 1986. 371 patients (196 women and 175 men) were diagnosed as having thrombosis (43%), embolic occlusion (18%), intracerebral hemorrhage (36%) and subarachnoid hemorrhage (3%). CAT scans were performed in 25% and angiography in 16%. The diagnosis was considered proven in 40% of cases. Overall hospital mortality was 46%, raising to 66% for hemorrhages. Prevention of cerebral edema was the main medical treatment. The present data suggest that primary prevention of and technological facilities to treat cerebrovascular episodes are inadequate at a general hospital level in Santiago.

Adult↗
PubMed1989

[Computerized registry of medical procedures and diagnostic codification].

Retrospective analysis of clinical information requires easy access to reliably stored data. We developed a program running on a microcomputer and using codes from the International classification of diseases, to be used on line. The program stores diagnostic codes, medical actions and a summary for each case. It uses inexpensive hardware and is friendly to inexperienced users.

Emergency Service, Hospital↗
PubMed1988

Smoking, caffeine, and stress: effects on blood pressure and heart rate in male and female college students.

This study examined the independent and joint effects of cigarette smoking and caffeine consumption on blood pressure (BP) and heart rate (HR) reactions to stress in male and female college students. Following an initial physiological baseline, participants received one of four experimental treatments (paced smoking, caffeine, smoking plus caffeine, or neither) and had BP and HR measured before, during, and after two stressful tasks. The results revealed that, compared with the control condition, caffeine ingestion enhanced the magnitude of stress-induced systolic BP and HR reactions. Smoking combined additively with stress, and the joint effect of smoking and caffeine was no greater than either taken alone. Males and females were generally similar in their BP and HR responses to smoking, caffeine, and stress. Inconsistencies with previous research and possible physiological mechanisms underlying the observed effects are discussed.

Blood Pressure↗
PubMed1987

An abnormal terminal X-Y interchange accounts for most but not all cases of human XX maleness.

To determine if human XX maleness results from an abnormal chromosomal X-Y interchange, we studied the inheritance of the paternal pseudoautosomal region in nine patients. Those six patients in whom Y-specific DNA was found (Y(+)) inherited the entire pseudoautosomal region from the paternal Y chromosome and lost that of the paternal X chromosome. Moreover, in three Y(+) cases, we observed the deletion of a paternal Xp locus tightly linked to the pseudoautosomal region. These results definitively show that an abnormal and terminal X-Y interchange during paternal meiosis causes Y(+)XX maleness. In contrast, no abnormal X-Y interchange was observed in any of the three Y(-) cases analyzed, suggesting that maleness can occur in the absence of any Y-specific DNA.

Alleles↗
PubMed1986

Experimental rabies: ultrastructural quantitative analysis of the changes in the sciatic nerve.

To study the pathology of peripheral nerves in experimental rabies infection, street rabies virus ws inoculated into the right footpad of two groups of mice, A and B, which received, respectively, 10(4.5) LD50 and 10(3.5) LD50 of the virus. Paralysis was observed in 60% of animals of group A and 20% of group B. The main ultrastructural abnormality present in the sciatic nerves was degeneration of about 40% of myelinated axons. Only occasional unmyelinated axons were degenerated. Figures were similar for nerves of either side and for both groups. Frequency histograms of axonal diameter showed axons of all sizes to be altered in group A, whereas in group B there was tendency for larger axons to be damaged. Electron microscopy showed no typical bullet-shaped viral particles. Asymptomatic animals which received the higher dose of the inoculum showed a small (less than 1%) percentage of necrotic myelinated axons.

Animals↗
PubMed1980

Serum calcitonin after pentagastrin stimulation in patients with bronchogenic and breast cancer compared to that in patients with medullary thyroid carcinoma.

Serum immunoreactive calcitonin (iCT) was measured in the peripheral blood of 29 normocalcemic patients with bronchogenic carcinoma of various pathological types and nine patients with breast cancer before and after pentagastrin stimulation. These results were compared to those found in 22 normal subjects and 30 patients with histologically proven medullary carcinoma of the thyroid. Our results revealed that 1) serum iCT levels may be abnormally high in all pathological types of bronchogenic carcinoma and in patients with breat cancer; 2) the basal level of serum iCT may be normal, but it is abnormally high after pentagastrin stimulation; 3) the increment rise of iCT after pentagastrin stimulation in the bronchogenic and breast cancer patients was significantly less than that seen in patients with medullary carcinoma of the thyroid (P less than 0.001).

Adenoma↗