Search PubMed⌕ Search

Biomedical subjects

G Calabrese

Publications and source records attributed to G Calabrese.

At least 127 records · Page 7Linked to original sources
PubMed1991

Chromosome abnormalities in breast fibroadenomas.

A cytogenetic study on 25 breast fibroadenomas from 17 women is reported. Seven tumors in five patients showed clonal structural chromosome changes. In three patients the breaks involved chromosome 12, occurring in two tumors in band 12p12 and in band 12q15 in all three tumors of one patient. The finding of an identical aberration, t(11;12)(q21;q15), in three adenomas from the same patient strongly suggests a clonal origin of multiple fibroadenomas of the breast.

Adenofibroma↗
PubMed1991

Cytogenetic survey of 31 patients treated with bone marrow transplantation for acute nonlymphocytic and acute lymphoblastic leukemias.

The authors report on a sequential cytogenetic study carried out on 31 patients with acute leukemia (20 with acute lymphoblastic leukemia and 11 with acute non-lymphocytic leukemia) who underwent bone marrow transplantation (BMT). Engraftment was documented in all patients with sex-mismatched donors and with donor constitutional aberrations. During the follow-up, ranging from 6 to 110 months, clinical and hematologic relapse was observed in 11 patients (35.5%). Five of these cases showed a normal karyotype, 3 were of undefined relapse origin, 2 were aneuploid karyotypes, and one was donor (male) metaphases. Cytogenetic and immunologic data in the latter patient were suggestive of relapse in donor cells.

Adolescent↗
PubMed1991

Effects of oral lacidipine on cardiopulmonary function at rest and during exercise in normal subjects.

A randomized, double-blind, crossover, placebo-controlled study was carried out to evaluate the effects of a single oral 4-mg dose of lacidipine vs. placebo on cardiopulmonary circulation at rest and during exercise. Twelve healthy volunteers were randomized to receive either placebo or 4 mg of lacidipine once daily for 2 days, followed by a 3-day washout period, after which they received alternate treatment. Patients were assessed before and at 60, 90, and 180 min after dosing. At 120 min, a maximum exercise test with a treadmill was performed according to the Bruce protocol. No relevant changes with placebo or lacidipine were observed in the respiratory function tests whereas 4 mg of lacidipine increased pulmonary effective blood flow (Qp. eff.) and stroke volume index (SVI) at 60 min, reaching a peak at 90 min; at 180 min, these effects, although diminished, were still present. The arteriovenous oxygen difference [C(a-v)O2] decreased, but reverted to normal values by 180 min. No differences in maximum attained Qp. eff. and oxygen consumption (VO2) during exercise were observed. Only the heart rate was higher both before and after treatment with lacidipine. Lacidipine increased Qp. eff. in these normal subjects without relevant effects on respiratory function. Performance on exercise testing after dosing was normal, although drug-induced vasodilation was present.

Adult↗
PubMed1991

Effects of antihypertensive therapy with lacidipine on ambulatory blood pressure in the elderly.

Recent multicenter trials have demonstrated that, in hypertensive elderly people, blood pressure control can significantly decrease the rate of cardiovascular and cerebrovascular events. Twenty-four-hour ambulatory blood pressure monitoring has proved to be superior to isolated sphygmomanometer blood pressure readings in the diagnostic evaluation of hypertension and in assessing the blood pressure response to treatment. We used 24-h ambulatory monitoring in a small, double-blind, randomly-allocated, placebo-controlled, parallel-group study of antihypertensive treatment with lacidipine given once a day at 2 or 4 mg. In our elderly subjects, the lacidipine treatment provided adequate blood pressure control both by day and by night with no effect on the heart rate profile. Furthermore, after drug therapy, we found a significant reduction in systolic blood pressure variability (standard deviation). This study shows that lacidipine can provide adequate control of arterial hypertension in the elderly.

Aged↗
PubMed1991

Time delay compensation for closed-loop insulin delivery systems: a simulation study.

Closed loop insulin therapy certainly represents the best possible approach to insulin replacement. However, present limitations preclude wider application of the so-called artificial pancreas. Therefore, a thorough understanding of these limitations is needed to design better systems for future long-term use. The present simulation study was design: to obtain better information on the impact of the measurement delay of currently available closed-loop devices both during closed-loop insulin delivery and blood glucose clamp studies, and to design and test a time delay compensator based on the method originally described by O.J. Smith. Simulations were performed on a Compaq Deskpro 486/25 personal computer under MS-DOS operating system using Simnon rel. 3.00 software. There was a direct relationship between measurement delay and amount of insulin delivered, i.e., the longer the delay the higher the insulin dose needed to control a rise in blood glucose; the closed-loop response in presence of a time delay was qualitatively impaired both during insulin delivery and blood glucose clamp studies; time delay compensation was effective in reducing the insulin dose and improving controller stability during the early phase of clamp studies. However, the robustness of a Smith's predictor-based controller should be carefully evaluated before implementation in closed-loop systems can be considered.

Computer Simulation↗
PubMed1990

In situ Hpa II endonuclease digestion on fixed chromatin of solid tumor cells.

Neoplastic cells from different tumors (lung, colon, rectal, and pancreatic carcinoma, synovial sarcoma, and Wilm's tumor) were fixed on slides and in situ digested with Hpa II and Msp I restriction enzymes. Staining of samples with the DNA specific fluorochrome ethidium bromide showed a clearcut decreased fluorescence after Hpa II digestion in neoplastic cells as compared to normal controls, whereas Msp I digestion produced the same pattern in neoplastic and in normal cells. The authors hypothesize that the altered state of methylation in neoplastic cells could affect the Hpa II activity on fixed chromatin.

Chromatin↗
PubMed1990

Growth delay in Down syndrome and zinc sulphate supplementation.

Children affected with Down syndrome (DS) show deficient growth, immunodeficiency--especially concerning the T-cell population--and low plasma zinc levels. New growth charts have been recently proposed, and zinc supplementation to the diet has been reported to improve transiently the efficiency of the immune system. The aim of this study was to evaluate if in DS children zinc sulphate therapy could improve the growth rate and affect some endocrine parameters. We studied 22 patients (16 males and 6 females) who received zinc sulphate for 6 to 9 months. Fifteen of 22 patients studied reached a higher centile in their growth rate, whereas the remaining seven showed no change, at least to date. The average height velocity changed from 23.84 +/- 7.98 mm/6 months to 40.80 +/- 7.68 mm/6 months. Growth hormone serum level was 5.94 +/- 4.89 ng/ml compared with 7.49 +/- 6.75 ng/ml before and after therapy, respectively. Somatomedin serum level was 160.27 +/- 68.88 mU/ml and 205 +/- 124.07 mU/ml before and after therapy, respectively. In conclusion, zinc sulphate therapy of patients with DS affects not only the immune system, as previously reported, but can also accelerate growth.

Adolescent↗
PubMed1990

Cytogenetic study of the heterochromatic polymorphisms in 100 subjects with Down syndrome and their parents.

We report on a cytogenetic study of 100 subjects with Down syndrome (DS), diagnosed from 1980 to 1988, and their parents. Free trisomy was present in 95% of the patients; 5% had trisomy due to an unbalanced translocation. Approximately 60% of patients were born to mothers younger than age 35 years, the highest number of DS births being in the group of mothers between ages 25 and 29 years. These findings are clearly related to the higher number of pregnancies in this group. However, the prevalence of DS births increased significantly in women older than age 35 years, as expected. A cytogenetic study of heterochromatic polymorphisms showed a significant increase of polymorphisms in DS children and in their parents, mostly in mothers, compared with a control group. Since heterochromatic blocks of acrocentric and nonacrocentric chromosomes are frequently associated during interphase, we discuss a possible correlation between nondisjunction and heterochromatic polymorphism.

Adult↗
PubMed1990

Karyotypic changes identified by HaeIII restriction endonuclease banding in a patient with M2 acute non-lymphoblastic leukemia.

A patient with acute non-lymphoblastic leukemia, FAB type M2, showed a complex karyotype involving chromosomes 1 and 11. The breakpoints could not be exactly identified by GTG and QFQ banding. A subsequent analysis with Alul and HaeIII restriction enzyme staining allowed the detection of a translocation of the heterochromatic region of chromosome 1 to 11q21.

Aged↗
PubMed1990

Asymmetrical distribution of beta-endorphin in cerebral hemispheres of suicides: preliminary data.

The assessment of beta-endorphin levels in several symmetrical brain regions of seven suicides and seven sudden death controls reveals a decreased concentration in the left temporal cortex, the left frontal cortex, and the left caudate nucleus of suicides compared to controls. Moreover, the comparisons of beta-endorphin concentrations in the symmetrical brain regions reveals an asymmetrical concentration in suicides (left less than right) in frontal cortex and caudate nucleus. These data confirm previous reports of abnormalities of neurochemical pathways in the brains of suicides and suggest that suicidal behavior might be related to the lateralized mechanisms of mood control.

Adult↗
PubMed1990

Cytogenetic survey of sixty-one patients with preleukemic syndrome including myeloproliferative and myelodysplastic diseases.

The authors report on a cytogenetic survey of 61 patients with preleukemic syndrome (PLS). Of these, 41 had a myeloproliferative disease (MPD) and 20 a myelodysplastic syndrome (MDS). Clonal chromosome abnormalities appeared in 24 patients (39.3%) at disease onset. Such changes had a frequency of 26.8% in patients with MPD and 65% in those with MDS. The authors stress the usefulness of ethidium bromide high resolution techniques. They allow obtaining a larger number of metaphases and elongated chromosomes with higher banding resolution and could account for the frequent detection of chromosome changes in most groups of MDS patients in the present series. Moreover, they discuss the possible significance of some chromosome aberrations suggesting that patients with MPD may live longer than those with MDS because of their higher frequency of normal karyotypes.

Adult↗
PubMed1990

Hinf I restriction endonuclease digestion on human fixed metaphase chromosomes.

The authors report on the activity of Hinf I restriction endonuclease on human fixed metaphase chromosomes. Experiments performed by digesting chromosomes just after harvesting or after ageing in methanol-acetic acid displayed a different pattern of digestion on metaphases, since only aged preparations showed gaps on heterochromatic regions of chromosomes 1, 9 and 16 and C-like bands on other chromosomes. In this view, the authors suggest that structural modifications of the DNA, induced by acid fixation, can influence Hinf I activity on fixed metaphase chromosomes.

Chromosomes↗
PubMed1990

[ST-T segment alternans in ventricular tachycardia associated with inversion of the U wave in Prinzmetal angina during exercise test. Description of a clinical case].

A case of ST segment alternans during effort angina is described. This is the seventh such case in the literature. Here the alternans appeared during a ventricular tachycardia. As with the other cases in literature, the alternans took place during an ischemic attack which affected the anterior wall.

Angina Pectoris, Variant↗