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Biomedical subjects

M Matera

Publications and source records attributed to M Matera.

At least 19 recordsLinked to original sources
PubMed2005

Analysis of polyphosphates in fish and shrimps tissues by two different ion chromatography methods: implications on false-negative and -positive findings.

Inorganic polyphosphates (di-, tri- and higher polyphosphates) can be used to treat fish, fish fillets and shrimps in order to improve their water-binding capacity. The practical relevance of this treatment is a significant gain of weight caused by the retention/uptake of water and natural juice into the fish tissues. This practice is legal; however, the use of phosphates has to be declared. The routine control testing of fish for the presence of polyphosphates, produced some results that were difficult to explain. One of the two analytical methods used determined low diphosphate concentrations in a number of untreated samples, while the other ion chromatography (IC) method did not detect them. This initiated a number of investigations: results showed that polyphosphates in fish and shrimps tissue undergo a rapid enzymatic degradation, producing the ubiquitous orthophosphate. This led to the conclusion that sensitive analytical methods are required in order to detect previous polyphosphate treatment of a sample. The polyphosphate concentrations detected by one of the analytical methods could not be explained by the degradation of endogenous high-energy nucleotides like ATP into diphosphate, but by a coeluting compound. Further investigations by LC-MS-MS proved that the substance responsible for the observed peak was inosine monophsosphate (IMP) and not as thought the inorganic diphosphate. The method producing the false-positive result was modified and both methods were ultimately able to detect polyphosphates well separated from natural nucleotides. Polyphosphates could no longer be detected (<0.5 mg kg-1) after modification of the analytical methodology. The relevance of these findings lies in the fact that similar analytical methods are employed in various control laboratories, which might lead to false interpretation of measurements.

Animals↗
PubMed2004

Experimental study on the toxicity and the local and systemic tolerability of gemcitabine after topical treatment of the rabbit bladder.

This study investigated gemcitabine administered intravesically to establish the local and systemic tolerability necessary for clinical trials. Gemcitabine was directly administered via catheter into the bladders of 24 male New Zealand rabbits weighing an average of 1.9+/-0.08 kg. Three groups received weekly gemcitabine for 5 (50 mg/kg) or 8 (25 mg/kg or controls) weeks. Animals were inspected daily for signs of toxicity and distress, body weight changes, and water and food consumption; electrocardiogram, blood pressure, and urinalysis were recorded before dosing and after 4 and 8 weeks of treatment. The rabbits were euthanized, and a full necropsy was performed on day 1 after the last instillation. Principal organs (spleen, thymus, testis, and muscle) and plasma samples were analyzed for the systemic absorption of gemcitabine. The 25-mg/kg dose was well tolerated with no clinical side effects. At 50 mg/kg, signs of mild myelosuppression and severe symptomatic toxicity (leg weakness, and hair and body weight loss) was evident after 3 weeks of treatment and three of the seven animals in this group died after four doses. Necropsies revealed normal bone marrow cellularity and organ histology at both doses. No significant systemic drug absorption was seen. These findings suggest that intravesical administration of gemcitabine does not produce organ-specific toxicity, but the higher dose (50 mg/kg) may represent the threshold above which increasing morbidity may occur.

Absorption↗
PubMed2002

[Percutaneous lithotripsy: how to make it safer. Personal experience].

BACKGROUND: Percutaneous surgery (PCN) is now a routinary method for the treatment of the majority of renal stones, since it has become safer than in the past, because, thanks to new endourologic instruments and to ultrasounds, it has been possible to reduce the mistakes of the renal puncture. Furthermore, the use of balloons catheters for the dilatation of the nephrostomic channel allows the reduction of operating time and hemorrhage risk. In this paper, the authors expose their experience in PCN operations carried out with the help of X-ray and ultrasonography, during the indirect laying of the stones, and the use of a balloon catheter for the creation of a working channel. METHODS: The Authors report their experience with the use of ultrasounds and concomitant X-rays for renal puncture, and of balloon catheter as track dilator, during 68 consecutive PCN carried out for renal lithiasis, 55 primary and 13 secondary to ESWL treatments; every stone has been cracked by a "Swiss-lithoclast" balistic lithotripter. For every patient, time of operation, complications and hospitalization-days were registered. RESULTS: Only three patients (4.4%) had haemorrhages and in one case of A-V fistula nephrectomy was necessary. The patients stayed in hospital approx. four days; the nephrostomic drainage was generally removed 3 days after the operation. CONCLUSIONS: The very low incidence of complications and the very short time of hospitalization suggest that ultrasounds and balloon-catheters may be useful to this surgery and may make it safer than in the past. Moreover, ultrasonography reduces the rate of X-rays exposition for operators and patients; the cost of the balloon is easily balanced by the reduction of operating times and hospitalization-days.

Equipment Design↗
PubMed2002

[Chronic renal failure and tuberous sclerosis. Report of two clinical cases].

Tuberous sclerosis complex (TSC) is an autosomal dominant hereditary disease characterized by a high rate of spontaneous mutations involving at least two loci: TSC(1) (9q34) and TSC(2) (16p13). It results in hamartomas or tumours which can affect a variety of organs, most commonly the brain, skin and kidneys. At least half of patients with TSC have underlying renal pathology, most commonly angiomyolipomas (AML) and/or cysts with, more rarely, adenocarcinoma, but oncocytomas, sarcomas, interstitial fibrosis and glomerulosclerosis have all been reported. Renal disorders may be asymptomatic or associated with acute lumbar ache, hematuria, abdominal mass, retroperitoneal hemorrhage. Renal failure is infrequent. The diagnosis of this disease is often performed, as in the present cases, very late and it is made possible by radiological examinations such as TC scan o RMI (when renal failure is present), usually performed after macrohaematuria or abdominal or renal colics or renal failure. When fatty tissue cannot be demonstrated within renal lesion (as in the female case), biopsy can be undertaken to exclude malignancy. Histology at the edge of an AML may look like renal carcinoma, but recent studies suggest that it can be differentiated by staining for HMB-45 which is positive in AML and negative in carcinoma. Two cases of tuberous sclerosis with different neurological fenotype, with bilateral renal angiomyolipomatosis and heavy renal failure, are presented.

Disease Progression↗
PubMed2001

Anandamide excites central terminals of dorsal root ganglion neurons via vanilloid receptor-1 activation.

Recently, the cannabinoid (CB) receptor agonist anandamide (AEA) has been shown to excite perivascular terminals of primary sensory neurons via activation of the vanilloid receptor-1 (VR-1). To determine whether AEA stimulates central terminals of these neurons, via VR-1 activation, we studied the release of calcitonin gene-related peptide (CGRP)- and substance P (SP)-like immunoreactivities (LI) from slices of rat dorsal spinal cord. Mobilization of Ca(2+) in rat dorsal root ganglion (DRG) neurons in culture was also studied. AEA (0.1-10 micrometer) increased the outflow of CGRP-LI and SP-LI from slices of the rat dorsal spinal cord in a Ca(2+)-dependent manner and increased [Ca(2+)](i) in capsaicin-sensitive cultured DRG neurons. Both effects of AEA were abolished by capsaicin pretreatment and by the VR-1 antagonist capsazepine but not affected by the CB receptor antagonists AM281 or AM630. Both neuropeptide release and Ca(2+) mobilization induced by electrical field stimulation (EFS) were inhibited by a low concentration of AEA (10 nm). Inhibition by AEA of EFS-induced responses was reversed by AM281 and AM630, but was not affected by capsazepine. Results indicate that stimulation of VR-1 with high concentrations of AEA excites central terminals of capsaicin-sensitive DRG neurons, thus causing neuropeptide release in the dorsal spinal cord. This novel activity opposes the CB receptor-mediated inhibitory action of low concentrations AEA. However, only if large amounts of endogenous AEA could be produced at the level of the dorsal spinal cord, they may not inhibit, but rather activate, nociceptive sensory neurons.

Animals↗
PubMed2001

Role of soy diet and L-arginine in cyclosporin-A-induced osteopenia in rats.

Our previous studies show that chronic administration of L-arginine decreases cyclosporin-A-induced bone loss. The present study was designed to investigate whether a soy diet could prevent cyclosporin A-induced osteopenia and eventually improve the protective effect of L-arginine. Rats on soy diet were treated with cyclosporin-A, L-arginine, cyclosporin-A + L-arginine or saline. Control groups received a normal diet and the same pharmacological treatment. Our results show that a soy diet prevents osteopenia only in the spinal cord (+30%) and confirm the protective effect of L-arginine in cyclosporin-A-induced osteopenia in whole body, pelvis and spine of rats on a normal diet (+31%, +55%, +55%, respectively). Moreover these data show that the osteoprotective effect of L-arginine in the whole body, pelvis and spine improves in the case of soy diet (+60%, +72%, +89%, respectively). The results suggest that a soy diet exerts a positive effect in cyclosporin-A-induced osteopenia only in sites with high turn-over and improves the osteoprotective effect of L-arginine.

Animals↗
PubMed2001

[Long-term therapy of benign prostatic hyperplasia. Our experience].

BACKGROUND: In order to evaluate the benefit of long-term medical treatment (4 years) in benign prostatic hyperplasia in June 1992 we prospectively started a not randomized study in selected benign prostatic hyperplasia patients for whom surgery was not indicated because of high surgical or post-surgical risk, or when they refused the intervention. METHODS: We included in the study 239 outpatients; 118 of them were affected by concomitant cardiovascular illness, 37 by neurologic diseases, 29 by neoplastic diseases and 55 refused surgery for the possible general or specific complications like retrograde ejaculation. All subjects have been checked every six months by transabdominal ultrasonography of the urinary tract, evaluation of the prostate volume and percent of post-micturitional residue, associated with uroflussometry. The patients have been divided into three groups and treated by finasteride, mepartricin, alfuzosin, doxazosin. The enlistment concluded in December 1995 and the follow-up extended up to December 1999. RESULTS: Our data clinically and statistically allow to confirm the validity of drug therapy for benign prostatic hyperplasia, not only in selected patients with high surgical risk, but also in subjects without a significant morbidity. CONCLUSIONS: In these patients, drug therapy may resolve the pathology, or allow the use of minimally invasive surgery (i.e. lasertherapy, transuretheral incision, etc.).

Adrenergic alpha-Antagonists↗
PubMed2000

Char syndrome: an additional family with polythelia, a new finding.

This report describes a father and daughter with Char syndrome, a rare autosomal dominant disorder. Both affected individuals had typical face, strabismus, and foot anomalies. The girl also had a patent ductus arteriosus. In addition, both patients had polythelia (supernumerary nipples), a finding not described before in the Char syndrome.

Abnormalities, Multiple↗
PubMed2000

Effect of acetyl-L-carnitine on ethanol consumption and alcohol abstinence syndrome in rats.

The effect of acetyl-L-carnitine on alcohol consumption and its possible ability to alleviate all symptomatology of ethanol withdrawal syndrome has been investigated in rats. Alcohol-dependence was induced in animals (9-15 g/kg ethanol solution at 20% for a period of 4 days) in order to measure the effects of acetyl-L-carnitine on ethanol abstinence syndrome. The ethanol dependence phase was characterized by the onset of signs and responses of progressive severity: hyperactivity, tremors, spastic rigidity and spontaneous convulsive seizures. After 4 days, 8 h after the last ethanol administration, two groups of animals received acetyl-L-carnitine (125 mg/kg and 250 mg/kg intraperitoneally, respectively) and the intensity of the withdrawal syndrome was assessed on the basis of the appearance of tremors. The effect of acetyl-L-carnitine on voluntary alcohol consumption was investigated in a rat line selected for innate ethanol preference. For 15 days the animals could freely choose both water and/or a hydroalcoholic solution (10% p:v). Acetyl-L-carnitine was given intraperitoneally at a dose of 200 mg/kg twice daily. The water and the hydroalcoholic solution levels were checked at the same time daily. Acetyl-L-carnitine treatment significantly reduced the onset of tremors in ethanol withdrawal syndrome as well as the level of ethanol intake in alcohol-preferring rats. These results suggest a possible pharmacological role of acetyl-L-carnitine in the treatment of alcohol dependence.

Acetylcarnitine↗
PubMed1997

Effects of pivagabine on psychophysical performance and behavioural response in experimental models of stress.

The effect of pivagabine (4-[(2,2-dimethyl-1-oxopropyl)amino]butanoic acid, CAS 69542-93-4, Tonerg), a synthetic molecule with neuromodulatory activity, was evaluated on a series of behavioural parameters in rats exposed to various stimuli, with the aim of evaluating the response to stress (open field exploration, water maze, psychic conflict), conditioning (active and passive avoidance and avoidance retention, aggressiveness, extinction of conditioned responses), learning and performing of specific psychophysical tests (rota-rod, ballasted swimming, taut thread). Pivagabine induced significant improvement of stress-related tests by reducing the anxiety-producing reactions related to the various experimental settings. In conditioning tests an improvement in learning of conditioned responses was observed at lower dosages (10 and 50 mg/kg); an opposite effect was obtained with higher dosages (100 and 200 mg/kg). Pivagabine did not influence the retention nor the extinction of conditioned responses. Pivagabine induced a marked improvement of all motor performance tests in young and in aged animals. By contrast with benzodiazepines, pivagabine did not alter the ability of learning tasks, the motor performance and the aggressive behaviours. It is likely that the observed effects of pivagabine are mediated by inhibition of release of corticotropin-releasing factor, a neurohormone involved in stress-generating mechanisms.

Animals↗
PubMed1993

Pharmacokinetic study of the relative bioavailability and bioequivalence after oral intensive or repeated short term treatment with two polyamino acid formulations.

The authors studied the relative bioequivalence and bioavailability of two oral polyamino-acid formulations (packet and flacon), based on 4 amino acids (L-glutamine, L-phosphoserine, L-phosphothreonine and L-arginine) in association with vitamin B12 (Bio-logos, Sigma Tau Pharma S.A). Open-trial testing was carried out after intensive treatment and on the attainment of sustained levels. 50 healthy volunteers (27 males, 23 females), ranging in age from 23 to 32 years, were included in the study. The pharmacokinetic behaviour of the various active ingredients was examined at a haematic level. Possible undesirable side-effects, resulting from treatment, were also examined during the study. The mean pharmacokinetic constants considered (Ke1, Cmax and t1/2) generated an almost overlapping AUC (area under the curves) for all homologous components contained in both pharmaceutical forms. This indicates almost complete bioequivalence. The mean index for the rate of relative bioavailability was, in fact, estimated to be 106.3 +/- 12.4%. Repeated treatment did not appear to disturb the absorption mechanisms of the active ingredients contained in either of the two formulations examined, maintaining the relative bioavailability relationship within a negligible range, with a statistically non-significant difference (Student's t test for coupled data). A few episodes, characterized by slight increases in excitability, were reported for both preparations in two patients (4%).

Administration, Oral↗
PubMed1992

MAOI activity of some novel series of substituted thiazol-2-yl-hydrazines.

Three series of 2-thiazolylhydrazines were synthetized and evaluated for their MAO inhibitory (MAOI) activity, both by in vivo tests, to assay their influence on several MAOI activity-related parameters (the variation on blood pressure induced by tyramine and clonidine and L-amfetamine-induced hypermotility) and in vitro tests, to assay their effect on rat brain mitochondria by a kinuramine fluorimetric assay. In vivo, all the tested compounds significatively influenced the evaluative parameters used. As regards in vitro test, all compounds displayed MAOI activity at a concentration of 1.10(-4) mol.l-1, which was significant in several cases. In the discussion of the results, the influence of the structure on the biological activity of the prepared compounds was delineated.

Amphetamine↗