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Biomedical subjects

A Valentini

Publications and source records attributed to A Valentini.

At least 55 records · Page 3Linked to original sources
PubMed1995

Human galanin reduces plasma norepinephrine levels in man.

The neuropeptide galanin (GAL) is widely distributed in the peripheral and central nervous systems, where it often coexists with catecholamines. To gain insight into the action of human GAL on sympathetic nervous system activity in man, we investigated the effects of a 60-min infusion of human (h) GAL (80 pmol/kg.min) or saline on peripheral norepinephrine (NE) and epinephrine concentrations, heart rate (HR), and systolic and diastolic blood pressure (BP) in the supine position as well as after assumption of the upright posture (UP) in eight healthy male volunteers. hGAL depressed supine plasma NE (0.84 +/- 0.06 vs. 0.33 +/- 0.02 nmol/L) and blunted the NE response to assumption of the UP (1.68 +/- 0.03 vs. 0.44 +/- 0.03 nmol/L), but caused a significant enhancement of the epinephrine response to assumption of the UP (0.22 +/- 0.02 vs. 0.65 +/- 0.06 nmol/L). hGAL significantly increased supine HR (70 +/- 2 vs. 99 +/- 4 beats/min) and potentiated the HR response to assumption of the UP (82 +/- 3 vs. 107 +/- 4 beats/min). hGAL did not alter supine systolic and diastolic BP, but caused a significant decrease in the systolic (121 +/- 3 vs. 98 +/- 2 mm Hg) and diastolic (74 +/- 2 vs. 62 +/- 2 mm Hg) BP responses to assumption of the UP. Our data show that hGAL decreases supine position- and UP-stimulated release of NE, suggesting an inhibitory modulation of hGAL on sympathetic outflow in man. The finding that hGAL induces an increase in HR, both in the supine position and after UP, and an inhibition of the systolic and diastolic BP response to UP provides further support for an involvement of hGAL in regulation of the cardiovascular and autonomic nervous systems in man.

Adult↗
PubMed1995

Effect of human galanin on the response of circulating catecholamines to hypoglycemia in man.

Human galanin (hGAL) is a neuropeptide with 30 amino acid residues that has been found in the peripheral and central nervous system, where it often co-exists with catecholamines. In order to clarify the possible role of hGAL in the regulation of sympathoadrenomedullary function, the effect of a 60-min infusion of hGAL (80 pmol.kg-1.min-1) on plasma epinephrine and norepinephrine responses to insulin-induced hypoglycemia in nine healthy subjects was investigated. Human GAL administration significantly reduced both the release of basal norepinephrine and the response to insulin-induced hypoglycemia, whereas it attenuated the epinephrine response by 26%, with the hGAL-induced decrease in epinephrine release failing to achieve statistical significance. Human GAL significantly increased the heart rate in resting conditions and clearly exaggerated the heart rate response to insulin-induced hypoglycemia, whereas it had no effect on the blood pressure. We conclude that GAL receptor stimulation exerts an inhibitory effect on basal and insulin-induced hypoglycemia-stimulated release of norepinephrine. These findings provide further evidence that GAL may modulate sympathetic nerve activity in man but that it does not play an important role in the regulation of adrenal medullary function.

Adrenal Medulla↗
PubMed1995

[Radiotherapy of T1N0 neoplasms of the glottis. Analysis of the parameters that influence local control].

Treatment and tumor-related parameters were reviewed in 176 patients with T1N0 carcinoma of the glottic larynx submitted to primary radiation therapy from 1980 to 1992. Our aim was to analyze local control and treatment-related toxicity. Over-all local control rates at 10 years were 88.3% with irradiation alone and 94.5% after salvage surgery (larynx preservation: 91%). Verrucous histology was a negative factor affecting local control and anterior commissure involvement exhibited only a negative trend but had no statistical significance. Among treatment-related factors, local control was 76.5% after split-course and 91.1% after continuous-course irradiation (p < 0.05). With continuous-course irradiation, the total dose influenced local control only for single of 2 Gy (local control rates were 69% with 60 Gy and 93% at > or = 64 Gy; p < 0.05), but not for single doses of 2.25 Gy and total doses ranging 56.25-65.25 Gy (local control failed in 55 patients). Early and late complications did not increase with single doses > or = 2.25 Gy. Our current policy in T1N0 nonverrucous glottic carcinoma is to use a single fraction of 2.25 Gy and a total dose ranging 56.25-63 Gy according to tumor size, with a continuous course.

Actuarial Analysis↗
PubMed1994

Evidence that enhancement of cholinergic tone increases basal plasma levels of calcitonin gene-related peptide in normal man.

To investigate the influence of the cholinergic system on the modulation of the circulating levels of calcitonin gene-related peptide (CGRP) under basal conditions in normal man, the effects of an acetylcholinesterase inhibitor, pyridostigmine bromide, and a muscarinic receptor blocker, pirenzepine, were studied in 16 normal subjects (8 females and 8 males). Pyridostigmine (120 mg, orally) induced a significant (P < 0.01) rise in basal plasma CGRP, while it reduced systolic and diastolic blood pressure. In all subjects, pirenzepine (0.6 mg/kg, i.v. bolus) was unable to modify the basal CGRP level. In conclusion, a pharmacologically induced enhancement of cholinergic tone resulted in an increase in CGRP, whereas muscarinic receptor blockade had no effect on CGRP levels or blood pressure. Therefore, the cholinergic system seems to be involved in the control of CGRP release in man, acting as a positive modulator. However, the available data do not indicate that there is a tonic cholinergic tone responsible for CGRP secretion under physiological conditions.

Adult↗
PubMed1994

Acute stress- or lipopolysaccharide-induced corticosterone secretion in female rats is independent of the oestrous cycle.

The aim of the present study was to test whether oestrous cycle is associated with the hypothalamus-pituitary-adrenal (HPA) axis function. Thus, corticosterone secretion in rats was investigated following lipopolysaccharide (LPS), acute cold-swimming or ether stress or synthetic corticotrophin-releasing factor (CRF) administration throughout the oestrous cycle. Moreover, plasma corticosterone response to cold-swimming stress or LPS administration also was studied at different times of day on pro-oestrus of di-oestrus-I. The following observations were obtained: the morning plasma corticosterone levels in control rats did not differ with the stage of the oestrous cycle; plasma corticosterone levels increased significantly following LPS administration (2 mg/kg, ip) or following acute exposure to cold (4 degrees C)-swimming or ether stress. However, this increase in plasma corticosterone levels was not related to the stage of the oestrous cycle; synthetic CRF injection induced an increase in plasma corticosterone levels constant on di-oestrus-I and pro-oestrus; plasma corticosterone response to LPS administration or acute cold-swimming stress showed diurnal changes, with the lowest values at 18.00 h, which was independent of the oestrous cycle. By showing the unchanged corticosterone response to LPS, to acute stress and to exogenous CRF throughout the oestrous cycle, and the independence of the diurnal pattern of stress response on the oestrous cycle, the present study suggests that the oestrous cycle has no influence on the HPA activity under the present experimental conditions in rats.

Animals↗
PubMed1993

Fat absorption and gastroenteric pH profile in postsurgical pancreatic insufficiency: role of the association of H2-receptor antagonists with pancreatic enzymes.

The complete control of steatorrhea in post-surgical exocrine pancreatic insufficiency is difficult. The aim of this study was to evaluate the effect of the association of ranitidine with pancrelipase om fecal fat excretion in patients who had undergone a pancreatoduodenectomy with suppression of the exocrine pancreatic secretion by Neoprene injection. Ten patients were studied 1 year after surgery. Steatorrhea was measured as an integrated test of 3-day stools, while patients were kept on a diet of 100 g lipid/day, with their usual enzyme supplementation therapy (16,050 USP units of lipase/meal). A basal 24-h gastroenteric pH profile was also obtained. In the following month, patients had ranitidine (150 mg twice a day) in addition to pancrelipase. Then steatorrhea and gastroenteric pH were reassessed. Mean fecal fat was 26.9 (SD 13.7) g/day without ranitidine and 30.5 (SD 13.9) g/day during combined treatment. Body weight and nutritional parameters did not show any significant variation after ranitidine administration. Even in the absence of ranitidine, postprandial gastroenteric pH values were always > 4; the H2-receptor antagonist only reduced fasting gastric acidity. In conclusion, the gastroenteric pH and fecal fat determinations showed that ranitidine is not useful in patients with total postsurgical exocrine pancreatic insufficiency.

Adult↗
PubMed1993

Diagnostic performance: a comparative study of the leukocyte differential count on four automated haematology analysers.

The diagnostic performance of the haematology analysers, Technicon H1, Sysmex NE 8000, Coulter STKS and Sequoia Cell Dyn 3000 was determined by comparing their results for automated differential counting with the result obtained for 400 cells by the manual microscopic method. These comparative studies were performed on a group of adults, containing both normal individuals (n = 150) and those affected by various pathologies (n = 113). The number of morphologically false negatives is low for all the systems (from 1.8% for the Cell Dyn 3000 to 6.2% for the NE 8000), while the number of distributionally false negatives was slightly higher (from 4.4% for the Cell Dyn 3000 to 7% for the H1 and NE 8000). The morphological flags, though useful for improving the diagnostic performance of the instruments, show a rather modest sensitivity when taken individually: immature granulocytes/bands from 71% for the STKS to 43% for the NE 8000; blasts from 66.6% for the H1 to 53.3% for the STKS, atypical lymphocytes from 59% for the H1 to 13.6% for the NE 8000; erythroblasts from 42.8% for the STKS to 7% for the NE 8000.

Adult↗
PubMed1993

[Quality assurance of mammography in the province of Trent].

In 1991, a second program for quality control in mammography was carried out in the Physics Department of the Trento Hospital. All the six mammographic centers around Trento entered the study and 9 mammographic units were thus considered. Two main types of measurements were obtained: a) determination of the physical variables affecting radiologic system optimization; b) evaluation of image quality and average breast dose, according to DQM program criteria. The film variables, mean gradients and base plus fog level, the half-value layer (HVL) and the entrance exposure free in air were scored as acceptable in all cases. The average breast dose was calculated on the basis of literature data, given the entrance exposure free in air, the HVL and the focus-skin distance values. All the mammographic units but one were scored as "D" (acceptable) on the average breast dose curve, which is defined by the national average value obtained during phase II of the DQM program. This Quality Control program allowed all mammographic units to be optimized and also emphasized the need for periodical quality controls.

Italy↗
PubMed1992

Evaluation of four automated hematology analyzers. A comparative study of differential counts (imprecision and inaccuracy).

The authors evaluated the performance of four modern, commercially available hematology analyzers for imprecision and inaccuracy in determining the leukocyte differential count. The evaluation was performed according to International Committee for Standardization in Haematology protocols and the National Committee for Clinical Laboratory Standards H20-T standard, using the same group of patients simultaneously. Imprecision was very low among all the analyzers for neutrophils and lymphocytes (coefficient of variation maximum = 4.12%), whereas for the other leukocyte populations it tended to increase as their presence percentage decreased. The imprecision of the analyzers was still lower than that of the microscopic method. The correlation with the manual 800 cell count (inaccuracy) was good for neutrophils, lymphocytes, and eosinophils (r = 0.974 to 0.888), less so for monocytes (r = 0.757 to 0.490), whereas it was poor for basophils (r = 0.532 to 0.078).

Adolescent↗
PubMed1992

Dose-response effects of oral loxiglumide on postprandial gall-bladder emptying in man.

The effect of two different single oral doses of loxiglumide (CR 1505, CAS 107097-80-3) on gall-bladder emptying induced by a 550-cal standard mixed meal in 6 healthy volunteers was studied. Following placebo, the maximal gall-bladder emptying occurred about 90 min after the meal (minimal residual gall-bladder volume 27.4% of basal volume). Loxiglumide 400 or 800 mg dose-dependently inhibited the physiologica gall-bladder emptying. Loxiglumide plasma levels dose-dependently increased. The inhibition of gall-bladder emptying and the kinetic of loxiglumide plasma levels were temporally related. The results of the present study confirm that oral loxiglumide is a potent orally active cholecystokinin (CCK) antagonist in man and that CCK is the major physiological mediator of gallbladder emptying in response to meal.

Adult↗
PubMed1991

Local-regional recurrences of breast cancer: treatment with radiation therapy and local microwave hyperthermia.

From October 1981 through September 1988, 31 local-regional recurrences of breast cancer in 26 patients were treated at the Oncology Center in Trento, Italy, with a combination of external radiation therapy (XRT) and superficial local microwave hyperthermia (Ht). The mean total XRT dose was 37.40 Gy, ranging from 19.80 to 60.00 Gy, depending on the extent of previous irradiation. Ht was delivered using the same superficial mw applicator, operating at frequencies between 280 and 480 MHz. The goal was to obtain a minimum intra- and peritumoral temperature of 42.5 degrees C for 30 min. Ht was applied immediately after XRT, 2 or 3 times per week for a total of 1-9 sessions (median 2). Thirty lesions (97%) could be evaluated for response 3 months after the end of the combined treatment. Twenty (66.6%) complete responses, seven (23.3%) partial responses, and three (10%) with no change were observed. No significant acute local side effects were noted, with the exception of two thermal burns and one ulceration. Patients achieving complete response show actuarial long-term local control of 87.8% at 3 years. In our experience, Ht combined with a low/moderate XRT dose may be particularly valuable in the palliation of recurrences in previously irradiated regions. Excellent response rates can be obtained when Ht is combined with a radical dose of irradiation.

Aged↗
PubMed1991

Moxibustion and breech presentation: preliminary results.

Moxibustion at the Zhiyin acupuncture point (67 B) is an ancient method of obtaining the version of abnormal presentation of the fetus during the last three months of pregnancy. The authors reviewed the Chinese references on this subject and stressed the importance of parity and gestational age in testing the efficacy of this therapy. Preliminary results are described and compared with those reported in Chinese articles. Success rates in version by moxibustion versus spontaneous version are also compared.

Breech Presentation↗
PubMed1991

[Radiotherapy, radiotherapy combined with surgery, radiotherapy combined with chemotherapy in the treatment of carcinoma of the pyriform sinus. A retrospective study].

A rectrospective analysis was performed of the results of 104 consecutive patients with carcinoma of the pyriform sinus, who underwent radiation therapy. Thirty-four patients underwent radical surgery and postoperative radiation therapy (group 1); 36 patients received radical radiation therapy alone (group 2); neoadjuvant chemotherapy was administered prior to full-dose radiation to 20 patients (group 3); 14 patients received palliative radiation therapy (group 4). Loco-regional control and survival rates at 5 years were 60.4% and 34.3% in group 1, 23.8% and 23.8% in group 2, 17.5% and 23.8% in group 3; no patients in group 4 survived at 5 years. Patients in group 1 experienced significantly better survival and local control than those in groups 2 and 3. No differences were observed between groups 2 and 3. Loco-regional recurrence was the main cause of failure in group 2 (69.4%) and 3 (70.0%). In group 1, 20.3% of cases developed distant metastases. Overall 5-year survival rate was 23.7%, confirming the poor prognosis of this disease. These results provide further support to the need of improving prevention and early diagnosis to improve both results and outcome in patients with carcinoma of the pyriform sinus.

Adult↗
PubMed1990

Effect of loxiglumide on gallbladder contractile response to cerulein and food in humans.

The present study investigated the effect of loxiglumide, a new selective cholecystokinin-receptor antagonist, on the gallbladder contractile responses to caerulein and to food in humans. In 6 healthy men, the gallbladder emptying driven by intravenous infusion of stepwise increasing doses of cerulein (10-80 ng/kg . h) and that induced by a 550-cal standard meal were monitored by ultrasonography. In both sets of experiments, the effect of loxiglumide was tested at various infusional rates against a control infusion of saline. An infusional rate of 2.5 mg/kg . h of loxiglumide abolished the gallbladder response even to maximal doses of cerulein, whereas a rate of 1.0 mg/kg . h counteracted the cholecystokinetic activity of cerulein up to the dose of 20 ng/kg . h. In postprandial experiments, the cholecystokinin antagonist dose-dependently inhibited the physiologic gallbladder contraction. The maximal gallbladder emptying, which always occurred 85 min after the meal, was 71.1% +/- 3.3% of basal volume in control studies, 39.2% +/- 1.8% during infusion of 2.5 mg/kg . h of loxiglumide, and 17.3% +/- 5.9% when 5.0 mg/kg . h were infused. A dose of 7.5 mg/kg . h of loxiglumide was able to prevent any postprandial emptying of the gallbladder. The present study shows that a selective cholecystokinin receptorial blockade competitively antagonizes cerulein-induced gallbladder contraction and dose-dependently inhibits postprandial gallbladder emptying.

Adult↗
PubMed1990

[Intraoperative radiotherapy with electrons: construction of facilities and dosimetry].

The technical complexity of intraoperative radiotherapy (IORT) requires modification of the standard physical and dosimetric methods used in external electron beam therapy. At the Radiotherapy Department of Ospedale S. Chiara in Trento a number of technical innovations have been developed, including an electron beam applicators system and related devices. Ionometric and film dosimetry have been used to obtain relative dose distributions of clinical electron beams in phantoms.

Combined Modality Therapy↗
PubMed1990

[Radical radiation therapy of carcinoma of the rhinopharynx: analysis of 80 cases].

From 1976 to 1987, 98 patients affected with nasopharyngeal carcinoma were observed at the Oncology Center, Trento, Italy. Eighty of them were treated with radical radiation therapy (average total dose: 6432 Gy, range: 5500-7400 Gy) on primary tumor and positive neck nodes. The clinically negative neck received 5000 Gy. Each dose ranged from 180 to 250 Gy. Fifty-nine patients were treated with the split-course technique with an interval of about 15 days after receiving 4000 cGy. The patients were 60 males and 20 females, their age ranging 17-81 years (mean: 57 years). Histology diagnosed squamous cell carcinoma in 15 cases and undifferentiated carcinoma in 65 cases. All patients were staged according to TNM (UICC, 1978) criteria. Ten patients were stage I/II. Complete local control was obtained in 81.3% of cases. Actuarial global survival at 10 years was 52%, actuarial relapse-free survival was 49%. Mean follow-up is 33 months (range: 4-122 months). Squamous cell carcinoma at histology and advanced nodal involvement (N2-N3) were negative prognostic factors. Six patients had a relapse in the nasopharynx and 5 in the neck; the incidence of distant failures was 20%. The most frequent mid-/long-term side-effect was xerostomia.

Adolescent↗
PubMed1989

Comparative study of two neoadjuvant protocols (VBM and DDP-BLM) combined with radiation therapy in advanced head and neck cancer.

Forty-five patients with epidermoid cancer of the head and neck were either treated with cisplatin and bleomycin (DDP-BLM) or with vincristine, bleomycin and methotrexate (VBM) as neoadjuvant chemotherapy before radical radiation therapy (XRT). Chemotherapy with DDP-BLM provided a tumoral response of 80% [20% complete response (CR), 60% partial response (PR)]; VBM showed a response of 60% (12% CR, 48% PR). At the end of XRT-program (65 Gy total dose, 2-2.5 Gy dose per fraction, 5 times a week) complete response rates were similar in VBM-pretreated group (52.5%) and DDP-BLM pretreated group (50%). Analysis of survival shows no significant difference between the two inductive schemes: 8% vs 7.5% at 72 months. Our study suggests an increased initial response rate but no advantage in survival with combined therapy in comparison with standard XRT: long-term benefits were not apparent in these two groups of patients.

Adult↗