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Biomedical subjects

G Corsini

Publications and source records attributed to G Corsini.

At least 19 recordsLinked to original sources
PubMed1996

Application of non-linear filters based on the median filter to experimental and simulated multiunit neural recordings.

Two non-linear, high-pass filters based on the median filter are proposed and tested as substitutes for linear filtering in applications involving multiunit neural recordings. The first, the median-based high-pass (MH) filter, operates by subtracting the output from the input of the median filter; it is aimed at preserving the shape of the impulses. The second, the negative median-based high-pass (NMH) filter, sets at zero the positive values in the output of the MH filter; it is aimed at transforming the impulses into monophasic waves placed on a flat baseline. When applied to experimental recordings and to a template action potential, the two median-based filters clearly outperformed two corresponding procedures based on a linear filter (moving-average filter). They did not produce appreciable distortions of the impulses, whereas their two counterparts induced or enlarged lateral lobes, as is the rule for linear high-pass filters. The recording display was much improved and impulse identification was made easier. When the two filters were applied to simulated recordings and the mean output was estimated by averaging and cross-correlation, a certain degree of performance deterioration was assessed in conditions of sustained activity and/or noise, with a resulting growing similarity to the mean output of the two corresponding, moving-average-based filters.

Animals↗
PubMed1995

Raised plasma arginine vasopressin concentrations during cluster headache attacks.

To obtain data about peripheral concentrations of arginine vasopressin in head pain syndromes, the plasma arginine vasopressin secretory pattern in 12 adult male patients with cluster headache was evaluated. Blood samples for plasma arginine vasopressin and osmolality determinations were collected before, and at 15, 30, 45, 60, 90, and 120 minutes during a cluster attack. Blood pressure was also monitored. The same sampling was repeated during an asymptomatic period. During cluster attacks, the mean values of plasma arginine vasopressin before an attack (2.3 (0.1) ng/l) significantly increased, reaching their peak at 45 minutes (4.8 (0.5) ng/l; P < 0.01 v baseline). No significant variations were found in mean arterial pressure and plasma osmolality. These data suggested involvement of neurotransmitter mechanisms regulating arginine vasopressin secretion and a possible role of arginine vasopressin in vasomotor phenomena accompanying cluster attacks.

Adult↗
PubMed1995

Lichen planus induced by interferon-alpha-2a therapy for chronic active hepatitis C.

OBJECTIVE: To report the development of hepatitis C virus (HCV)-positive chronic active hepatitis with lichen planus in a patient during interferon treatment. DESIGN: Case report and literature review. PATIENT: A 64-year-old anti-HCV and HCV-RNA-positive woman. INTERVENTIONS: The patient received interferon-alpha-2a treatment for histologically proven chronic active hepatitis. RESULTS: Four months after the start of treatment the patient developed multiple cutaneous lesions on her hands, feet and back. A skin biopsy led to the diagnosis of lichen planus. The withdrawal of interferon was followed by a marked improvement in the cutaneous lesions, but not complete regression. CONCLUSION: This case shows that HCV-positive patients with chronic active hepatitis may develop lichen planus during interferon therapy.

Female↗
PubMed1994

[Medical students and psychiatry. A survey of students' opinion].

In the last years research on the didactics of Psychiatry and opinions of medical students on Psychiatry has gained great interest. The authors think that this research could be useful for the improvement of didactics, for better understanding the meanings of professional choice, the identity of psychiatrist and their relationship with colleagues in other medical field. The goal of this research work was a preliminary survey of Genoese University Medical Student's opinions about psychiatry didactics, and choice of specialization. A questionnaire was submitted to all the students who passed Clinical Psychiatry examination in the period from November 1987 to December 1988. The students were divided in two randomized groups: the first group of students (224) was submitted to the questionnaire immediately after Clinical Psychiatry examination; while to the second group of students (66) the questionnaire was mailed. The aim of the questions was to assess the student's opinions on psychiatry, psychoanalysis, psychotherapy, the career they wanted to take up, and the difficulties of studying psychiatry: 69% of the students of the first group and 42% of the students of the second group answered the questionnaire. Female students answered that they preferred psychiatric specialization more than their male colleagues did, but the difference has no statistical importance. In most cases, the students who answered that they have taken into account psychiatry as a choice of specialisation, are more interested in medical specialties (primary care, etc.) than in surgical specialties. Most of the medical students declare some emotional troubles (anxiety, sleeplessness, problem in social relations).(ABSTRACT TRUNCATED AT 250 WORDS)

Career Choice↗
PubMed1994

Biphasic diurnal periodicity in bleeding from peptic ulcer.

OBJECTIVE: To evaluate if there was periodicity in the manifestations of gastrointestinal bleeding (hematemesis and melena). METHOD: This is a multicenter prospective study carried out in the Endoscopy Units of eight hospitals. At the time of the emergency endoscopy, the following data were collected: age, sex, endoscopic diagnosis, solar hour of the first hematemesis (vomiting of bright red or tarry black material) and of the first melena (black or bloody soft stools), and any drugs taken during the week before the bleeding episode, regardless of the dose. RESULTS: 806 patients were studied. Bleeding was from peptic ulcer in 405 patients (50%), from esophageal varices in 197 (24%), and from other sources in the remainder. Analysis using single cosinor statistics showed a nonrandom distribution in bleeding from peptic ulcer, whether presenting first with hematemesis (p = 0.02) or melena (p = 0.03). There were two peaks at 6:45 AM and 6:45 PM for hematemesis and at 7:25 AM and 7:25 PM for melena, representing a biphasic diurnal (ultradian) rhythm. CONCLUSIONS: This study shows that bleeding due to peptic ulcer has a biphasic diurnal periodicity. This has potential importance for the pathogenesis of bleeding, for the management of gastrointestinal hemorrhage and the administration of drugs known to cause peptic ulcer bleeding.

Adolescent↗
PubMed1993

Effects of thrombolysis and atenolol or metoprolol on the signal-averaged electrocardiogram after acute myocardial infarction. Late Potentials Italian Study (LAPIS).

Late potentials (LPs) detected on the signal-averaged (SA) electrocardiogram (ECG) predict arrhythmic events after acute myocardial infarction (AMI). The effect of thrombolysis on the incidence of LPs after AMI is controversial and its impact on subsequent arrhythmic events is not known. Moreover, the effects of beta blockers on the SAECG have not been studied. Six hundred eighteen patients with AMI were studied; thrombolysis was given to 228 (37%). In comparison with patients treated conventionally, those receiving thrombolysis were significantly younger and more frequently male, had higher peak values of creatine kinase, a lower prevalence of non-Q-wave AMI, and a higher incidence of ventricular fibrillation in the acute phase, and more frequently received beta blockers. An SAECG obtained 6 to 8 days after AMI showed LPs in 24% of patients receiving and in 25% not receiving thrombolysis (p = NS). On admission, intravenous beta blockers were administered to 110 patients (18%); those receiving beta blockers were younger, had lower peak values of creatine kinase and more frequently received thrombolysis. LPs were less frequently found in patients treated than in those not treated with beta blockers (15 vs 27%; p = 0.007); however, this effect was found only in those with an ejection fraction > or = 40%. Independent predictors of LPs by multivariate analysis were an ejection fraction < 40% (p = 0.007), ventricular fibrillation in the acute phase (p = 0.02), and absence of beta-blocking therapy (p = 0.03). During a mean follow-up of 12 +/- 7 months, there were 39 cardiac deaths (6%), 13 of which were sudden (2%), and 9 sustained ventricular tachycardias.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Calcitonin and beta-endorphin secretion.

Calcitonin is a peptide hormone secreted by the C-cells of the thyroid gland. This hormone mainly acts in preventing bone resorption. Furthermore, calcitonin is involved in other biological actions, and in particular it is able to relieve pain independently of its peripheral effects on bone. Here, we examine the possible mechanisms of calcitonin-induced analgesia, with particular regard to the opioid system involvement. Several studies in animals and in humans demonstrate that calcitonin increases plasma beta-endorphin levels, acting at the hypothalamic and/or at the pituitary level, either directly or indirectly, through monoaminergic neurotransmitters. However, this calcitonin-induced beta-endorphin release has not always been observed. These different results are discussed, and a possible implication of sex and/or calcitonin dose employed has been examined. We conclude that the analgesic effects of calcitonin are multifactorial, and beta-endorphin plays its own specific role.

Analgesics↗
PubMed1992

[Effects of metadoxine on main biohumoral changes induced by chronic alcoholism].

The paper aims to evaluate the effects of metadoxine on liver function tests in chronic alcohol abusers without a clear alcohol dependence, by means of an open trial carried out in 7 hospitals in Tuscany. The study comprised 72 patients with a daily alcohol intake of at least 80 g for men and 30 g for women, over a period of at least 5 years. The patients were urgently requested to stop drinking, and were randomly divided into 2 groups, of which the first (52 subjects) was treated with metadoxine (500 mg twice a day) and the second (20 subjects) received only some vitamins. Interviews and blood tests were performed 1 and 2 months after the trial began. Statistical calculations were made using the chi-square and Student's tests. Metadoxine induced a more rapid reduction of SGOT and SGPT and, possibly, of Gammagt; these effects were especially evident, and were associated with a significant reduction of MCV, in 20 patients (12 in the first group and 8 in the second) in whom blood test abnormalities were greatest. No unfavorable side effects were observed that could be attributed to the drug. Metadoxine can therefore be considered a valuable resource in the treatment of alcoholic liver disease.

Adult↗
PubMed1989

[Spontaneous grade I bundle of His block. Clinical, electrocardiographic and electrophysiological studies in 37 patients].

The clinical, ECG and electrophysiological data of 37 patients (28 males and 9 females) with spontaneous intra-hisian block are reported. Of these patients, 11 had hypertensive heart disease and 5 had ischemic heart disease with previous myocardial infarction; in 21 patients, clinical signs of heart disease were not evident. In 18 patients, a single or recurrent episode of syncope had occurred. One patient had junctional rhythm and 36 sinus rhythm; among these, 12 patients presented PR greater than 200 msec (7 with a narrow and 5 with a wide QRS); 12 patients had a single or bilateral bundle branch block; 12 had a normal ECG. The electrophysiological study showed a split H-H1 in 22 patients, a wide His deflection (H greater than 25 msec) in 4 and HV greater than 65 msec with narrow QRS in 11. In 17 patients a more or less marked sinoatrial node and/or atrioventricular node dysfunction was present. Atrial pacing, performed in all, induced 2nd degree Mobitz 2 intra-hisian block in 9 patients. Ajmaline was used in 16 patients but induced a complete intra-hisian block in only one. In 28 patients a preventive pacemaker was implanted after electrophysiological study. During the follow-up (mean 25 months/pt.), 38% of the patients developed complete atrioventricular block. No recurrence of syncope occurred in the paced patients. Comparison of patients who developed atrioventricular block and those who maintained normal atrioventricular conduction did not show differences as far as heart disease, previous syncope, ECG pattern and results were concerned.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Effects of dynorphin on the PHA-induced lymphocyte proliferation in vitro.

The effect of the opioid peptide dynorphin (DYN) on PHA-induced lymphocyte proliferation has been evaluated in the present study. A significant increase in PHA-induced lymphocyte activation was observed when DYN was added to cultures 48 hr after the mitogenic stimulation. This effect occurred at suboptimal (3.12 and 6.25 micrograms/ml) PHA concentrations and at DYN doses ranging from 10(-9) to 10(-12) M. Conversely, DYN did not affect the lymphocyte blastogenic process either when added before, or simultaneously or after intense PHA (12.5 micrograms/ml) stimulation. Naloxone preincubation did not modify the above described effects. Results suggest that DYN might play a role in neuroendocrine regulation of the lymphocyte blastogenic process.

Adult↗
PubMed1987

Nizatidine in the short-term treatment of duodenal ulcer--an Italian Multicenter Study.

One hundred and seventy three patients suffering from duodenal ulcer, were selected for a double-blind, controlled and randomized parallel multicenter study, with interval endoscopic examinations. This study was undertaken to compare the efficacy and safety of nizatidine administered at a single dose (300 mg "nocte") versus ranitidine (300 mg "nocte") in the treatment of acute duodenal ulcer. One hundred and sixty five patients were found to meet every admission criterion and completed the study (86 on nizatidine and 79 on ranitidine). On admission to the study, both groups were seen to have been correctly selected and epidemiologically well-distributed as to history of duodenal ulcer, previous treatments and pre-study symptoms. The ulcer was considered healed when complete re-epithelialization had occurred in areas of ulcerated mucosa. Healing rates of duodenal ulcer proved to be globally similar in the two groups, both in the 4th week (nizatidine, 78%; ranitidine, 78%) and in the 8th week (nizatidine, 91%; ranitidine, 95%). After four weeks of treatment, 67% of the patients treated with nizatidine no longer had any symptoms, while 87% patients no longer suffered from day pain, and 91% had no nocturnal pain. As a result, intake of antacids quickly decreased during the first four weeks. A similar response was observed in the group receiving ranitidine. After administration at a single dose of 300 mg in the evening, nizatidine proved to be at least as effective and safe as 300 mg of ranitidine administered in the same way, with respect both to ulcer healing and symptom response.

Adult↗
PubMed1987

The long-term treatment of peptic ulcer after a bleeding episode.

We have studied 51 consecutive patients bleeding from peptic ulcer which was duodenal (D.U.) in 30, gastric in 17 (G.U.), anastomotic in 3 (Billroth 2), and oesophageal in 1 of them. One patient with G.U. was sent for surgery and 2 patients with D.U. died early; the others recovered through medical treatment and the ulcer healed after 6-8 weeks of treatment with ranitidine in 46 out of 48 patients. Subsequently, all the healed patients have been treated with ranitidine (150 mg at bedtime) for 6 months; by this time a new endoscopy showed an erosive antral gastritis in 2 patients with G.U. and 2 recurrences of D.U. Then the patients and their family doctors were invited to choose between the interruption of the treatment and its prolongation. 8 patients with previous G.U. preferred to stop treatment, and up to 1-2 years they did not show any recurrence; the remaining 5 patients carried on the maintenance treatment, and up to one year one of them showed an erosive antral gastritis. 15 patients with previous D.U. stopped the treatment and 5 of them after 1-24 months presented a recurrence with a new haemorrhage; 8 patients chose to continue the treatment and none of them for 6-24 months had recurrence. The limited number of the patients obviously does not allow a sound conclusion, but a trend is clearly seen which favours a prolonged maintenance treatment in patients with D.U. which has bled.

Aged↗
PubMed1986

Prevention of relapse with various antiulcer drugs.

The relative value of maintenance therapy with cimetidine, ranitidine, pirenzepine, and antacids only (when used for symptomatic relief) has been evaluated in 205 patients with a subsequent follow-up period of 2 years. The patients had a completely healed duodenal ulcer after 8 weeks of treatment and were then randomly allocated to four groups, which were as follows: group 1: 60 patients treated with 400 mg cimetidine at night; group 2: 55 patients treated with 150 mg ranitidine at night; group 3: 50 patients treated with 50 mg pirenzepine at night; and group 4: 40 patients treated only with antacids as needed for symptomatic relief. Endoscopy was repeated after 6, 12, 18, and 24 months of treatment, and whenever symptoms suggested recurrence. Although the number of dropouts was high (27 in group 1, 20 in group 2, 18 in group 3 and 12 in group 4), statistical analysis by the life-table method showed that cimetidine, ranitidine, and pirenzepine had similar therapeutic value. After 1 and 2 years the relapse rate of duodenal ulcer was 17.5% and 43.6% respectively, for cimetidine, 21% and 69.3% for ranitidine, 21.7 and 50.2% for pirenzepine, and 49.8% and 77.7% for antacids. The incidence of erosions was lower in those groups with the higher ulcer relapse rate, a point discussed in the present study.

Adult↗
PubMed1985

Influence of beta-endorphin on phytohemagglutinin-induced lymphocyte proliferation and on the expression of mononuclear cell surface antigens in vitro.

Recent evidence suggests that opiates can modulate the immune responses. In particular it has been shown that beta-endorphin and morphine are able to depress some T lymphocyte functions in humans. In the present study, experiments were designed to evaluate the effect of beta-endorphin phytohemagglutinin-induced lymphocyte proliferation and determine the mechanism of this action. The ability of naloxone to block the effect of beta-endorphin was also investigated, and the influence of beta-endorphin on the expression of mononuclear cell surface antigens using the OKT3, OKT4, OKT8, anti-HLA-DR and anti-beta 2-microglobulin monoclonal antibodies was evaluated. Phytohemagglutinin-induced lymphocyte proliferation was significantly inhibited by beta-endorphin. This effect occurred when beta-endorphin was added to cells at the beginning of the culture period (30 min before, simultaneously or 30 min after phytohemagglutinin), but not when added after 48 h of incubation. The preincubation of cells with BEP for 1 h, 4 h or 24 h did not affect lymphocyte activation by phytohemagglutinin. A ten-fold excess of naloxone, added to cultures 30 min prior to beta-endorphin, did not block the inhibitory effect. Incubation with beta-endorphin had different effects on each surface antigen tested. The OKT8+ and beta 2-microglobulin+ cells did not show significant variations. The OKT4+ cells significantly decreased, after 4 h of incubation with beta-endorphin, both in mononuclear cell and in purified T lymphocyte cultures and, after 24 h, in mononuclear cell cultures only. The OKT3+ cells decreased, in mononuclear cell cultures only, after 24 h beta-endorphin incubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗