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Biomedical subjects

A Claro

Publications and source records attributed to A Claro.

10 recordsLinked to original sources
PubMed1999

BRCA1 screening in patients with a family history of breast or ovarian cancer.

Several studies have shown that the frequency of BRCA1 mutations in high-risk families differs widely between populations. In a recently published study from the Stockholm region, we found BRCA1 mutations in about 35% of the breast/ovarian families, but only in 1% of the families with site-specific breast cancer. To determine the frequency of BRCA1 mutations in families with a less increased risk for breast or ovarian cancer, a second study was performed. A total of 94 families with two and six families with only one affected member were included. Six mutations were found, all localized in exon 11, and five of them were previously known Swedish founder mutations. The mutation frequency was 6%, similar to the finding in families fulfilling the criteria for hereditary breast cancer (7%) that was disclosed in our first study. All families with a mutation had at least one individual with ovarian cancer. Thus, our study further implies that for a woman with breast cancer, a family history of ovarian cancer is far more important than a family history of breast cancer for predicting a BRCA1 mutation. Our results can be used to increase the specificity in selection of families for genetic testing.

Adult↗
PubMed1997

A screening for BRCA1 mutations in breast and breast-ovarian cancer families from the Stockholm region.

To identify BRCA1 germ-line mutations in the breast and breast-ovarian cancer families in the Stockholm region, a total of 127 families were screened. DNA from 174 patients from these families were studied using various mutation screening techniques, followed by direct DNA sequencing. Mutations were identified in 7 of 20 families with breast and ovarian cancer and in one family with ovarian cancer only, whereas only 1 family of 106 with breast cancer showed a mutation. Thus, germ-line mutations in BRCA1 were found in one-third of the families with both breast and ovarian cancer, but in only 1% of the breast cancer families. The low frequency of germ-line mutations in the site-specific breast cancer families means that other genes are likely to segregate in these families.

Breast Neoplasms↗
PubMed1997

Screening for TP53 mutations in patients and tumours from 109 Swedish breast cancer families.

To estimate the prevalence of TP53 mutations in familial breast cancer, constant denaturant gel electrophoresis (CDGE) was used to screen exons 5-8 of the TP53 gene for germline mutations. Genomic DNA from 128 breast cancer patients belonging to 109 families with familial cancer were screened. No germline mutations were found in any of the patients. We also studied TP53 mutations in tumour DNA from 51 of the same individuals and found mutations in 14%. This is similar to what has been reported in sporadic breast cancer.

Breast Neoplasms↗
PubMed1979

A comparative study of two diets in the treatment of primary exogenous obesity in children.

One hundred four children, six to fourteen years of age, with primary exogenous obesity were randomly distributed in order to be subjected to two different diets, ketogenic (low carbohydrate) and hypocaloric, for eight weeks. Body weight, serum triglycerides, cholesterol, a glucose tolerance test, blood glucose and plasma insulin determination were performed before and after both diets. The results revealed significant differences in body weight and triglyceride concentrations with the two diets although they were more remarkable with the ketogenic diet. There were significant differences in the fasting insulin levels, insulinogenic index, and insulin concentration after a glucose tolerance test in the patients subjected to a ketogenic diet.

Adolescent↗
PubMed1977

Studies on the mechanisms of somatostatin action on insulin release. IV. effect of somatostatin on cyclic AMP levels and phosphodiesterase activity in isolated rat pancreatic islets.

The effects of somatostatin on insulin release and cyclic AMP metabolism were studied in collagenase-isolated islets of Langerhans from the rat. Ceoncentrations from 500 to 2000 ng/ml significantly inhibited glucose stimulated insulin release, while 100 and 200 ng/ml were ineffective. Somatostatin (2000 ng/ml) inhibited insulin release and [3H]-cyclic AMP accumulation induced by 16.7 mM glucose after 10 and 30 min of incubation. In dose-response studies, the inhibition by somatostatin of the effect of glucose on [3H]cyclic AMP and insulin release could be overcome by a high concentration of the hexose (44.9 mM), suggesting competitive inhibition. In the absence of glucose, somatostatin inhibited [3H]cyclic AMP accumulation induced by the phosphodiesterase inhibitor, IBMX, while no inhibition was seen, again in the absence of hexose, when the [3H]cyclic AMP levels had been raised by the adenyl cyclase stimulator, cholera toxin. Somatostatin did not affect phosphodiesterase activity when added to islet homogenates, but preincubation of the islets with the peptide before homogenization decreased the activity by about 30%. It is suggested that somatostatin-induced inhibition of insulin release is, at least partially, mediated by cyclic AMP, probably through an action on islet adenyl cyclase.

Adenylyl Cyclases↗
PubMed1976

Studies on the mechanism of somatostatin action on insulin release in man. II. Comparison of the effects of somatostatin on insulin release induced by glucose, glucagon and tolbutamide.

Somatostatin in as small a dose as 70 mug given over a period of 90 min to seven healthy subjects inhibited insulin release induced by glucose (500 mg/kg as a bolus + 20 mg/kg/min). This inhibition seemed to be of competitive nature since the effect was nearly overcome when the glucose dose was raised considerably. Somatostatin in nine subjects also inhibited insulin release induced by glucagon and tolbutamide, and this inhibition was of the same order of magnitude as that of glucose induced insulin release. Since all these insulinogogues enhance of the accumulation of cyclic AMP in the beta-cells, it is suggested that the edenylate cyclase-cylic AMP system might be involved in the action of somatostatin. Somatostatin did not seem to interfere with the glycogenolytic effect of glucagon on the liver.

Adult↗
PubMed1976

Studies on the mechanism of somatostatin action on insulin release. III. Effect of somatostatin on arginine induced release of insulin and glucagon in man and perfused rat pancreas.

In man, 3 mug per kg per 90 min of linear somatostatin significantly inhibited basal as well as arginine induced insulin and glucagon release. One mug per kg per 90 min of somatostatin significantly inhibited basal insulin release but not basal glucagon release or arginine induced insulin and glucagon release. In the perfused rat pancreas, as little as one ng per ml of perfusate of somatostatin significantly inhibited argine induced insulin but not glucagon release, while 10 ng per ml of somatostatin by more than 50 per cent reduced the effect of arginine on insulin and glucagon release. Thus, linear somatostatin seemed to be a slightly more potent inhibitor of insulin than of glucagon release in man and in the perfused rat pancreas.

Adult↗
PubMedDate not supplied

Virgin and martyr.

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Abortion, Illegal↗