Biomedical subjects

A Barletta

Publications and source records attributed to A Barletta.

At least 37 records · Page 2Linked to original sources

PubMed1996

[Medium-term clinical experience with automatic transvenous defibrillators implanted in the chest area without subcutaneous electrodes].

From March 1992 to April 1996 a pectoral biphasic transvenous implantable cardioverter defibrillator without subcutaneous leads was implanted in 35 patients with life threatening ventricular tachyarrhythmias. Mean age was 58 +/- 9 years; 23 patients had coronary artery disease, 10 non ischemic dilated cardiomyopathy and 2 arrhythmogenic right ventricular dysplasia. All were in NYHA functional class I and II and 4 in class III: mean ejection fraction was 35 +/- 12%. The mean duration of the implantation procedure was 85 +/- 35 min. The mean defibrillation threshold, measured in 23 active-CAN devices was 8.8 +/- 5 J. There were no operative complications except in one case of transient ischemic electromechanical dissociation. The mean hospital stay from the time of implant to predischarge evaluation was 6.2 +/- 2 days. The average follow-up period was 18.5 +/- 11 months. Two patients had non sudden and non arrhythmic cardiac death in the third and sixth month, respectively. In 19 patients 171 implantable cardioverter defibrillator interventions were reported: in 5 patients five inappropriate interventions were reported and in the remaining 14 were reported: 35 ventricular fibrillation and 131 ventricular tachycardia. The short duration of the procedure, brief hospitalization with very low perioperative morbidity, high efficacy and low mid-term complications give a new image to this therapeutic option.

Adult↗

PubMed1995

Heterogeneity of intratumour proliferative activity in primary breast cancer: biological and clinical aspects.

The present retrospective study was undertaken to verify whether the extent of intratumour proliferative activity variation or the method of quantifying tumour proliferative activity is related to biological characteristics and clinical outcome in a series of operable node-negative breast cancer patients. For tumour proliferative activity evaluation, the 3H-thymidine autoradiographic assay was used. After incubation of 3-8 samples from different areas of the equatorial section of each tumour for 1 h at 37 degrees C with 3H-thymidine, the following methods were used for evaluation of tumour cell labelling: mean tumour labelling index (LI), the highest labelling value from a specific area (LI-max), and the extent of intratumour labelling variation from several samples (LI-CV). LI-max was related to ER and PgR status, and linearly correlated with LI (c.c. = 0.92, P < 10(-6)) whereas LI-CV was independent of tumour size, grade ER and PgR status, but dependent on the number of tumour samples analysed for each tumour. After 5 years of median follow-up, disease-free survival was only related to tumour size (T1 versus T2: 84 versus 64%, P < 0.04 by log rank analysis) and different LI values (low versus high 3H-Tdr-LI:86 versus 61%, P < 0.03 by log rank analysis). LI-max and LI-CV values were not significantly related to clinical outcome. Cox multivariate analysis confirmed the independent prognostic value of LI and tumour size on disease-free survival.

Breast Neoplasms↗

PubMed1995

Hepatic mitochondrial respiration and transport of reducing equivalents in rats fed an energy dense diet.

OBJECTIVE: To measure hepatic mitochondrial respiration as well as the ability of hepatic mitochondria to transport reducing equivalents by shuttle systems in rats fed an energy dense diet. DESIGN: Rats were fed a control (CD) or energy dense (ED) diet for 15 days. MEASUREMENTS: State 3 and State 4 oxygen consumption were measured in isolated mitochondria using glutamate+malate or pyruvate+malate as substrate. We also measured malate-aspartate shuttle activity and mitochondrial alpha-glycerophosphate dehydrogenase activity. RESULTS: ED rats, in comparison with CD rats, showed a significantly greater energy intake without a corresponding greater body weight gain and carcass lipid content. Compared to CD rats, ED rats also showed a significant increase in resting metabolic rate, which was abolished by propranolol. Hepatic mitochondrial state 3 respiration using glutamate+malate or pyruvate+malate as substrate as well as malate-aspartate shuttle activity significantly decreased, while mitochondrial alpha-glycerophosphate dehydrogenase significantly increased in ED rats compared to CD rats. CONCLUSIONS: Mitochondrial NADH oxidation is reduced and a greater fraction of cytoplasmic NADH can be transported to the mitochondria through the alpha-glycerophosphate shuttle and oxidized through the respiratory chain from complex II onwards. This mechanism could lead to a decrease in hepatic metabolic efficiency which is in line with the increased energy expenditure occurring in rats fed an energy dense diet.

Animals↗

PubMed1995

Sympathetically-mediated thermogenic response to food in rats.

The aim of this work was to assess the participation of the sympathetic nervous system in the thermogenic response to food in control and hyperphagic rats. Rats were fed either a control (CD) or energy dense (ED) diet. After 15 days, CD rats received a small (7 kJ) meal composed of either control or energy dense diet, while ED rats received a small meal composed of energy dense diet. The experiment was then repeated, with the exception that rats received a larger portion (35 kJ) of the test meal. The postprandial increase in oxygen consumption was measured for 30 min after the small meal and 90-180 min after the completion of the large meal. The measurements were made in saline-injected and propranolol-injected rats. ED rats exhibited hyperphagia as well as an increase of 32% in resting metabolic rate after a 16 h fast. The sympathetically-mediated postprandial increase in oxygen consumption was greater after an energy dense meal than after a control meal in CD rats, and was higher in ED rats than in CD rats fed an energy dense meal. It was concluded that the sympathetically-mediated increase in the thermogenic response to food, as well as the increase in fasting metabolic rate can help prevent obesity development in hyperphagic rats.

Animals↗

PubMed1994

Different effects of cold exposure and cold acclimation on rat liver mitochondrial fatty acid oxidation and ketone bodies production.

1. We have studied fatty acid oxidation and ketone bodies production in liver mitochondria from rats exposed to cold for 10 days and in rats adapted to cold for 40 days. We have examined State 3 respiration and ketone bodies production with palmitoylcarnitine as substrate in isolated mitochondria, together with mitochondrial protein mass and hepatocyte oxygen consumption. 2. Mitochondrial protein mass increases both in cold exposed and in cold adapted rats. 3. State 3 respiration and hepatocyte respiration increase only in cold exposed rats. 4. Ketone bodies production increases in cold adapted rats. 5. Taken together, our results suggest that the increased hepatic mitochondrial protein mass and the increased fatty acid oxidation subserve two different roles: an increase in ATP production in cold exposed rats and an increase in ketone bodies production in cold adapted rats.

Acclimatization↗

PubMed1993

Mammography and morphobiologic characteristics of human breast cancer.

AIMS: A comparative analysis was performed to verify a possible correlation between mammographic features and morphobiologic characteristics of the tumor in a series of 176 invasive primary breast cancer patients. METHODS: Breast cancers were grouped according to mammographic features as follows: tumor mass with spiculated borders; tumor mass with well-circumscribed borders; tumor with density alteration of parenchyma with no clear borders; a cluster of microcalcifications as the only sign of tumor presence; tumor without mammographic abnormality. The tumor tissue biologic characteristics investigated were: hormone receptor content, tumor proliferative activity, DNA content and cytohistologic tumor-grade differentiation. RESULTS: Spiculated tumors showed a significantly higher percentage of estrogen-receptor-positive cases with respect to circumscribed tumors, independently of the patient's menopausal status. Tumors with only microcalcifications were all from premenopausal patients and showed a significantly higher percentage of progesterone-receptor-positive cases (83%). Tumor proliferative activity did not significantly differ in the 5 mammographic breast cancer groups; aneuploidy was less frequent in tumors with spiculated borders than in mammographic types (39% vs 57%; p = 0.05); percentages of G1-G2-G3 tumors did not differ significantly among the mammographic groups considered. CONCLUSIONS: Certain relationships between mammographic features and biologic characteristics could be of potential clinical interest and stimulate more detailed studies on this issue.

Adult↗

PubMed1993

Randomised clinical trial of adjuvant chemotherapy in patients with node-negative, fast-proliferating breast cancer.

A prospective randomised clinical trial in patients with node-negative, fast-proliferating breast cancer was initiated in January 1990 to verify the feasibility and reliability of a 3H-thymidine (3H-Tdr) autoradiographic assay in a prospective and consecutive series of node-negative patients and the therapeutic effect of adjuvant chemotherapy in patients with node-negative breast cancer and high tumour proliferative activity. Node-negative patients with a high 3H-Tdr Labelling Index (3H-Tdr-LI) were randomised to receive either no further treatment or combination chemotherapy consisting of fluorouracil, epirubicin plus cyclophosphamide (FEC) for 6 cycles. The autoradiographic assay was performed in 307 of 317 patients (97%) and was evaluable in 291 of 317 patients (92%). A total of 176 patients with a high 3H-Tdr-LI entered the clinical randomised study: 91 in the FEC arm and 85 in the control arm. Patient groups were fairly well balanced regarding the most important clinical and pathological characteristics. In total, 530 FEC cycles have been administered with an actual dose intensity of 90%. Patients receiving FEC demonstrated leucopenia in 35% of cases, alopecia in 70%, and loss of menses in premenopausal patients in an age-dependent manner. Patients are still being entered into the study.

Aged↗

PubMed1992

Different assays for HER-2/neu evaluation in breast cancer.

To evaluate different methodologic approaches for HER-2/neu analysis, we performed Southern, Northern, Western blot and histochemical assay on 112 samples from 86 primary tumors and 26 synchronous axillary metastatic lymph nodes of patients affected by operable breast cancer. Simultaneous statistical analysis of data obtained with the four methods (31 samples) showed that Western blot detected a higher percentage of alterations than the other assays (Cochran and Victor tests, 0.01 less than p less than 0.05). The same result was emphasized by pair analysis (McNemar, p less than 0.05), which evaluated the assay data two by two. Immunohistochemical evaluations were more in accord with immunoprecipitation data when performed on frozen or Bouin-fixed, paraffin-embedded tissues than on formalin-fixed, paraffin-embedded tissues.

Blotting, Northern↗

PubMed1992

Metabolic activity in isolated hepatocytes from cold exposed rats subjected to 24-hour fasting.

The aim of this work was to study the metabolic activity in isolated hepatocytes from control rats and rats exposed for 15 or 30 days to cold, all subjected to 24-h fasting. Hepatocyte oxygen consumption was used as an index of metabolic activity. The results show that 24-h fasting induces a decrease in energy expenditure at the level of the liver in cold-exposed rats but not in control animals.

Acclimatization↗

PubMed1992

Rat liver response elicited by long-term cold exposure.

We measured mitochondrial protein mass as well as State 4 and 3 respiratory rates using different substrates in isolated liver mitochondria from 30-day cold-exposed rats. In addition, we measured the respiration under different conditions of stimulation in isolated hepatocytes from long-term cold-exposed rats. The results show that long-term cold exposure elicits a significant increase in hepatic mass and mitochondrial protein mass. No variation was found in oxygen consumption of isolated mitochondria and hepatocytes. On the whole, the results indicate that long-term exposure elicits an increase in hepatic mitochondrial protein mass but not in hepatic oxygen consumption.

Adaptation, Physiological↗

PubMed1992

Relationship between resting metabolism and hepatic metabolism: effect of hypothyroidism and 24 hours fasting.

In this paper, we have examined the relationship between the changes in the resting metabolic rate (RMR) and the changes in hepatic metabolism induced by hypothyroidism and 24 h fasting. The results show that hypothyroidism induces a significant decrease in RMR, while 24 h fasting reduces RMR in euthyroid but not in hypothyroid rats. We have also measured oxygen consumption in isolated hepatocytes from euthyroid and hypothyroid rats, fed or fasted for 24 h. The results show that hypothyroidism is characterized by reduced hepatic oxygen consumption. On the other hand, 24 h fasting induces an increase in oxygen consumption in both euthyroid and hypothyroid rat liver cells, although the respiratory rates of hypothyroid rats were lower than those of euthyroid rats. The above findings, as a whole, show that hypothyroidism and 24 h fasting have similar effects on RMR but opposite effects on hepatic metabolism. In addition, a normal thyroid state does not appear to be necessary for the observed changes in hepatic metabolism due to 24 h fasting.

Animals↗

PubMed1992

Advanced prostate cancer follow-up with prostate-specific antigen, prostatic acid phosphatase, osteocalcin and bone isoenzyme of alkaline phosphatase.

We report our experience in the follow-up of 63 patients with advanced prostate adenocarcinoma. We used prostate-specific antigen and prostatic acid phosphatase in 27 patients; in 36 patients we evaluated osteocalcin and bone isoenzyme of alkaline phosphatase, two markers of bone metabolism which seem to be good markers in the follow-up of patients with bone metastases.

Acid Phosphatase↗

PubMed1992

Relationship between the resting metabolic rate and hepatic metabolism in rats: effect of hyperthyroidism and fasting for 24 hours.

We have examined the relationship between the changes in resting metabolic rate (RMR) and those in hepatic metabolism induced by hyperthyroidism and fasting for 24 h. We found that hyperthyroidism induced a significant increase in RMR, while fasting for 24 h reduced RMR in euthyroid but not in hyperthyroid rats. We have also measured oxygen consumption in isolated hepatocytes from euthyroid and hyperthyroid rats, fed or fasted for 24 h. Hyperthyroidism induced an increase in oxygen consumption in rat liver cells; fasting for 24 h increased respiratory rates in isolated liver cells from euthyroid but not from hyperthyroid rats. The findings showed that hyperthyroidism and fasting for 24 h have opposite effects on RMR but similar effects on hepatic metabolism. The results also indicated that the increase in RMR found in hyperthyroid rats is partly due to an increase in hepatic metabolism, while no correlation exists between variations in resting and hepatic metabolism induced by 24-h fasting.

Animals↗

PubMed1992

[Therapy of subcutaneous cystic lymphangioma with ultrasound-guided puncture and alcoholization].

The sclerosing treatment of subcutaneous cystic lymphangioma was repeatedly attempted in the past, but only to be abandoned owing to the high frequency of inflammatory complications. The authors repropose this treatment method under US guidance and using 98% sterile ethanol. In 6 patients with subcutaneous cystic lymphangioma in only one location, a US-guided puncture was performed which was followed by complete drainage of the cystic cavity and alcoholization. US follow-up 2-18 months from treatment showed the complete disappearance of cystic cavities. The method was found to be simple, reliable, and to present no complications.

Adult↗

PubMed1991

Hepatic selective adjustments in short-term cold exposed rats.

The metabolic adjustments which occur in rat liver cells during the first days of cold exposure have been investigated. We have measured both mitochondrial mass and oxidative capacities as well as ATP production after five and 10 days of cold exposure. In addition, we have measured plasma membrane Na+/K(+)-ATPase activity. Cold exposure elicited a significant increase in mitochondrial mass as well as in state 3 oxidative rates and ATP production in isolated mitochondria using various substrates. Moreover, our results show that Na(+)-pumping activity significantly increased after both five and 10 days of cold exposure. Our results suggest that during the first days of cold exposure liver cells undergo alterations which are useful for survival in the cold.

Animals↗

PubMed1991

The effect of thyroid state and cold exposure on rat liver oxidative phosphorylation.

In this paper we have examined the effect of cold exposure on hepatic mitochondrial state 3 respiration and ATP synthesis, using succinate as the substrate, in euthyroid, hypothyroid and hyperthyroid rats. The results show that cold exposure does not elicit any variation in the above parameters in euthyroid and hyperthyroid rats, whereas when hypothyroid rats are exposed to cold, a significant increase (about +45%) occurs in state 3 respiration and ATP synthesis. We have also measured succinic dehydrogenase specific activity and uncoupled respiration during cold exposure in various thyroid states. The finding that cold exposure elicits no variation in the above parameters indicates that there is some control on ATP synthase and/or adenine nucleotide translocator. The above findings, as a whole, suggest that cold exposure acts on oxidative phosphorylation only if triiodothyronine is lacking, by controlling ATP synthase and/or adenine nucleotide translocator.

Adenosine Triphosphate↗

PubMed1991

The effect of cold exposure on rat liver mitochondrial respiratory capacity.

1. The effect of cold exposure on the respiratory capacity of rat liver mitochondria has been studied using succinate as the substrate. 2. The mitochondria obtained in this study were well coupled, as shown by the RCR and ADP/O ratios. 3. In addition, durohydroquinone was used to eliminate the regulation of substrate supply. Likewise, we measured uncoupled respiration to evaluate the maximal electron flow through the respiratory chain. 4. We found that oxygen consumption using succinate or durohydroquinone + FCCP as substrates, as well as ATP production were not affected by cold exposure. 5. Our results also show that, when succinate is used, the maximal capacity of the respiratory chain is measured. 6. The data obtained do not support a role of the electron transport chain as a target of cold action.

Adenosine Diphosphate↗

PubMed1991

Effect of thyroid state and cold exposure on rat liver mitochondrial protein mass and function.

The effects of thyroid state on liver mitochondrial protein mass was investigated in rats at 24 and 4 degrees C, as was oxidative phosphorylation using substrates which represent the final catabolic products of the metabolic fuels. In rats at 24 degrees C, a significant increase in mitochondrial protein mass (about +40%) was observed only in hyperthyroid animals, while a significant increase due to cold exposure was found in hypothyroid (+45%) and euthyroid (+35%) rats. In rats at 24 degrees C, hypothyroidism significantly decreased the oxidation of glutamate and palmitoyl carnitine but not of pyruvate, while hyperthyroidism only increased the oxidation of palmitoyl carnitine. On the other hand, exposure to cold significantly increased the oxidation of glutamate and pyruvate only in the presence of tri-iodothyronine. Our results underline not only the fact that a simple and single hypothesis for thyroid effects cannot be adopted, but also that any study concerning oxidative metabolism should be carried out using different substrates and involving different pathways of oxidation.

Animals↗