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Biomedical subjects

G Carta

Publications and source records attributed to G Carta.

At least 73 records · Page 4Linked to original sources
PubMed1996

Chronic morphine increases hippocampal acetylcholine release: possible relevance in drug dependence.

Previous studies have shown that cocaine and amphetamine stimulate acetylcholine release in the hippocampus via an action of endogenously released dopamine on dopamine D1 and D2 receptors. The present study was aimed at clarifying if the property of stimulating hippocampal acetylcholine release was shared by morphine. The acute administration of morphine (10 mg/kg i.p.) failed to modify acetylcholine release in the hippocampus. However, after repeated administration (10 mg/kg i.p. twice daily) morphine acquired the ability to stimulate hippocampal acetylcholine release. Thus, at days 5 and 7 of chronic morphine treatment, a challenge dose of morphine (10 mg/kg i.p.) increased acetylcholine release by 50 and 100%, respectively. Concomitantly with the development of the stimulant property on acetylcholine release, morphine also acquired that of producing behavioural stimulation and lost that of producing sedation and catalepsy. The morphine-induced increase in acetylcholine output was suppressed by the blockade of dopamine D1 receptors with SCH 23390 (R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4, 5-tetrahydro-1H-3-benzazepine) (0.1 mg/kg s.c.), which also suppressed the morphine-induced motor stimulation. Moreover, repeated morphine administration markedly potentiated the stimulant effect of the dopamine D1/D2 receptor agonist apomorphine (R(-)-10, 11-dihydroxyaporphine) (0.1 or 0.5 mg/kg s.c.) both on hippocampal acetylcholine release and on behaviour. These results may suggest that the enhancement of hippocampal acetylcholine release as well as the development of behavioural sensitisation after chronic morphine could be related to the development of dopamine receptor supersensitivity. Moreover, increased acetylcholine transmission in the hippocampus may play a role in the 'memory' of the rewarding effects of drugs of abuse.

Acetylcholine↗
PubMed1996

Chronic ethanol consumption in rats: correlation between memory performance and hippocampal acetylcholine release in vivo.

The effects of chronic alcohol consumption on memory performance and hippocampal acetylcholine release in vivo were investigated in rats. Rats were allowed to drink 25% (v/v) ethanol solution as the only source of fluid for nine consecutive months, whereas control rats received only tap water. Memory performance was tested by the acquisition of shuttle box active and passive avoidance. Chronic ethanol-consuming rats were not impaired in the acquisition of the active avoidance response task, whereas in the passive avoidance task, latency scores of treated rats were significantly lower than in controls. The basal release of acetylcholine in freely moving rats, assessed by the microdialysis technique, was significantly decreased in ethanol-treated rats. Impairment in memory performance, as assessed in the passive avoidance task, was significantly correlated with hippocampal acetylcholine release in vivo.

Acetylcholine↗
PubMed1996

A novel approach to study linoleic acid autoxidation: importance of simultaneous detection of the substrate and its derivative oxidation products.

In this paper we have proposed a novel approach for studying the reaction of lipid oxidation by using the simplest chemical system available. Neat linoleic acid was incubated for 24 hours at 37 degrees C in the air. The course of lipid oxidation was followed by measuring simultaneously by HPLC with a diode array detector 1) linoleic acid decrease, 2) the products formed by radical attack, namely four hydroperoxy-octadeca-dienoic acid (HPODE) isomers, two c,t (c,t) and two trans,trans (t,t). 3) the byproducts formed by HPODE degradations, the four oxo-octadeca-dienoic acid (oxo-ODE) isomers. In HPODEs the presence of conjugated diene chromophore was confirmed by second derivative spectrophotometry. c,t HPODEs were also identified for their positional isomerism, while for t,t molecules the lack of suitable reference compound makes unfeasible the identification of their positional isomerism. As in the case of the latter two c,t and two t,t oxo-ODE isomers were characterized. This simple system appears to be useful for studying the activity exherted by lipophilic molecules that, like alpha-tocopherol, may act as antioxidants and/or as hydrogen atom donating molecules. The presence of alpha-tocopherol in different concentration for 24 hours in the reaction environment, shifts the reaction of linoleic acid autoxidation towards different byproduct formations. From the results obtained it is evident that alpha-tocopherol acts as hydrogen atom donor at all concentration tested, shifting the reaction toward a prevalent formation of c,t isomer of both HPODEs and oxo-ODEs. At concentration lower than 40 nmoles, when the ratio between alpha-tocopherol and linoleic acid was 1:100, the reaction of autoxidation is strongly inhibited, while at higher concentration alpha-tocopherol acted as a prooxidant. In these experimental conditions, alpha-tocopherylquinone was spectrophotometrically identified as the predominant oxidation product of alpha-tocopherol.

Chromatography, High Pressure Liquid↗
PubMed1995

[Malignant gynecologic neoplasms during menopause. Authors' experience].

From January 1991 to December 1993 409 post-menopausal women were observed at the Center for the Study of Climateric Disorders of the Department of Obstetrics and Gynecology of the University of L'Aquila. The aim of the study was to evaluate the incidence of gynecologic neoplasm among this group of women. A total of 48 women at risk for malignant tumors were detected. The relationship between the climateric age and the oncologic risk is discussed.

Adult↗
PubMed1995

[Parvovirus B19 infection: the general aspects and gestational problems].

Parvovirus B19 is a small, heat-stable, single-strained DNA virus (5.5 kb), with 23 nm icosahedral capsid discovered in 1975. Since its discovery, the virus has been shown to be a causative agent of erythema infectiosum (fifth disease). Under specific circumstances it can cause transient aplastic crisis, chronic anemia, arthritis and fetal death. Laboratory diagnosis of recent or past B19 infection usually relies on the demonstration of virus-specific IgM or IgG antibodies in patient's serum. The aim of this study was to evaluate the prevalence of Parvovirus B19 infection among 87 pregnant patients. Our study on anti-B19 antibody prevalence indicates that about 64% of pregnant women in our country lack specific antibodies and are at risk of B19 infection. One intrauterine death was encountered in a patient with specific IgM antibodies. The authors suggest the detection of IgG and IgM anti-B19 antibodies as a routine screening practice during pregnancy.

Adolescent↗
PubMed1994

Neuroleptics cause stimulation of dopamine D1 receptors and their desensitization after chronic treatment.

Recent evidence indicates that the neuroleptic-induced increase of in vivo acetylcholine output in the striatum does not depend on the relief of cholinergic neurons from the inhibitory control by dopamine, but on increased dopamine output onto dopamine D1 receptors. The present microdialysis study was aimed at finding if the neuroleptic-induced increase in striatal acetylcholine release persists after chronic treatment, and how it is correlated with dopamine output. Rats were chronically treated with the dopamine D2 receptor antagonists, haloperidol and (-)-sulpiride (0.5 mg/kg and 50 mg/kg i.p., respectively, daily, for 30 days). The stimulant effect of both neuroleptics on striatal dopamine release persisted unaltered throughout the chronic treatment (by about 100% over basal values). In contrast, the enhancing effects of haloperidol and (-)-sulpiride on striatal acetylcholine release remained unchanged up to day 12 of treatment. Thereafter, tolerance developed, so that both neuroleptics became totally ineffective on day 30 of treatment. Both on day 1 and 30, the neuroleptic-induced dopamine release was reversed by gamma-butyrolactone (gamma-hydroxybutyric acid lactone), suggesting that this effect is mediated by enhanced neuronal activity. On day 1 and day 10, the neuroleptic-induced acetylcholine release was antagonized by the blockade of dopamine D1 receptors with SCH 39166 (trans-(-)-(6aS,13bR)-11-chloro-6,6a,7,8,9,13b- hexahydro-7-methyl-5H-benzo[d]napht[2,1-b]azepine-12-ol, hydrochloride) (0.5 mg/kg i.p.). SKF 38393 (1-phenyl-2,3,4,5-tetrahydro-(1H)-3- benzazepine-7,8-diol hydrochloride) (5 mg/kg i.p.) increased acetylcholine release by about 50% in control rats and in rats treated with (-)-sulpiride or haloperidol for up to 7 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1994

Co-dergocrine (Hydergine) regulates striatal and hippocampal acetylcholine release through D2 receptors.

The effect of Co-dergocrine (Hydergine) on acetylcholine (ACh) release in the striatum and hippocampus has been studied by means of brain microdialysis and compared to the effect of SKF 38393 and of LY 171555 selective D1 and D2 dopamine (DA) receptor agonists, respectively. Co-dergocrine (1 and 5 mg kg-1 i.p.) as well as LY 171555 (0.2 and 0.5 mg kg-1 i.p.) decreased the extracellular concentration of ACh in the striatum, whereas SKF 38393 (5 and 10 mg kg-1 i.p.) increased it. On the other hand, Co-dergocrine (1 and 5 mg kg-1), LY 171555 (0.2 and 0.5 mg kg-1) and SKF 38393 (5 and 10 mg kg-1) increased ACh release in the hippocampus in a dose-dependent way. These results show that Co-dergocrine, which is widely used in the treatment of senile mental decline, enhances the release of ACh in the hippocampus in a similar manner to both D1 and D2 DA agonists. This effect might be relevant for the amelioration of cognitive processes. Moreover, our results which demonstrate that Co-dergocrine is able to decrease the release of ACh in the striatum, as are selective D2 agonists, suggest that Co-dergocrine may have a potential therapeutic benefit in Parkinsonian dementia.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1994

[Diagnostic methods compared in neoplastic pathology of the endometrium].

Preoperative staging is fundamentally important in endometrial carcinoma. The presence of lymph node metastasis and the risk of tumour recidivation are correlated to the degree of myometrial invasion by the tumour. The preoperative diagnosis of the absence of myometrial invasion may render pelvic lymphadenectomy superfluous. A group of 24 patients suffering from endometrial carcinoma underwent transvaginal ultrasonography and nuclear magnetic resonance prior to surgery in order to evaluate possible myometrial invasion. The study was integrated by computerised tomography (CT) to obtain a clearer image of the retroperitoneum. The authors aim to ascertain the accuracy, sensitivity and specificity of these methods in the preoperative evaluation other degree of myometrial infiltration.

Adult↗
PubMed1994

[Transvaginal ultrasonography and nuclear magnetic resonance. Comparison of techniques in the evaluation of ovarian lesions].

A total of 53 patients were included in this study, aged between 21 and 72 years old and hospitalised with the diagnosis of ovarian tumour. All patients underwent a clinical examination, ultrasonography and NMR prior to surgery. The findings of ultrasonography and NMR were correlated with histological results in order to evaluate the value of these methods in the differential diagnosis of benign and malignant ovarian tumours. Histological tests revealed 46 benign tumours, 3 borderline cases and 4 malignant growths. Transvaginal ultrasonography revealed precisely 47 out of 53 ovarian tumours, and NMR 49 out of 53. The main limitation of both techniques was the tendency to overestimate ovarian lesions (specificity: ultrasonography 89%, NMR 93%). As far as concerns the identification of malignant lesions NMR does not appear to offer significant advantages in comparison to ultrasonography (sensitivity 85% ultrasonography = NMR).

Adenocarcinoma, Papillary↗
PubMed1994

[Chlamydia trachomatis infection and its correlation with cervical preoncogenesis].

Among 612 patients included in this open study, serologic detection of Chlamydia infection was compared with cervical cytologic, histologic and colposcopic abnormalities. Serologic and cytologic evidence of elevated exposure to Chlamydia among patients with squamous intraepithelial lesions was found. Nevertheless, whether the Chlamydia infection represents a non casual association resulting from the correlation with sexual activity or it plays independent or supporting etiologic roles is an issue that warrants further investigations.

Adolescent↗
PubMed1993

Assay for recombinant and native human intraacrosomal antigen SP-10.

PROBLEM: To develop a method to measure a recombinant sperm protein, SP-10, during scale up and purification for a contraceptive vaccine formulation. METHOD: A quantitative assay method for the human intraacrosomal protein SP-10 was developed utilizing the format of indirect capture enzyme-linked immunosorbent assay (ELISA). A SP-10 specific monoclonal antibody mAb, MHS-10, was used as the capture antibody. Two recognition reagents, a rabbit polyclonal anti-SP-10 antisera (pAb) and a biotin-labeled mAb, MHS-10, were used as the recognition antibodies, respectively. A SP-10 recombinant fusion protein consisting of 125 SP-10 amino acids linked to glutathione transferase was used as a working SP-10 standard. The coefficient of variance for the assay system using the rabbit pAb was in the range of 0.099 to 0.157, and for the assay system using the biotinylated mAb MHS-10 was in the range of 0.081 to 0.084. RESULTS: Employing biotinylated MHS-10 as the recognition antibody, it was found that the native SP-10 molecule had more than one MHS-10 epitope. The concentration of SP-10 in a pool of human sperm extracts was found to be approximately 1% of the total proteins, assayed by both of the recognition antibody systems. CONCLUSIONS: The assay system described is useful to monitor the yield of recombinant SP-10 during scale-up production of the SP-10 vaccine.

Acrosome↗
PubMed1992

Synthesis of esters using a nylon-immobilized lipase in batch and continuous reactors.

Direct esterifications using a nylon-immobilized lipase from Candida cylindracea were carried out in batch and continuous-flow reactors. The immobilized enzyme was effective in catalyzing the synthesis of ethylpropionate, isoamylpropionate, and isoamylbutyrate. With ethanol dissolved in hexane as a substrate, the maximum initial esterification rate was 0.02 mole/(h x g of immobilized protein), but the enzyme was stable only when the substrate concentrations were lower than 0.2 M. With isoamyl alcohol in hexane as a substrate, esterification rates as high as 0.085 mole/(h x g of immobilized protein) were observed and the immobilized enzyme was stable over a much broader concentration range. However, in this case, the use of a solvent, such as hexane, was not necessary for esterification, and the enzyme could be employed in equimolar acid/alcohol mixtures. A packed-bed reactor was operated successfully for the continuous synthesis of esters. The reactor was stable for long periods of time, and the steady-state performance could be accurately predicted on the basis of batch reaction experiments.

Candida↗
PubMed1992

[Synchronous associations of tumors in the pelvic organs of the female genital tract].

The Authors report their findings concerning the synchronous associations of tumours involving pelvic organs in the female genital tract observed at the Gynecological Clinic, Aquila. From January 1980 to December 1991, 9 cases (4.28%) of synchronous tumours were found in a total of 210 cases of womb, ovary and vagina tumours. The paper examines the clinical problems and questions of anatomopathological characterisation raised by these associations.

Endometrial Neoplasms↗
PubMed1992

[The clinical evaluation of the hypocholesterolemic effects of an inhibitor of cholesterol synthesis: mevalonic acid].

Twenty eight patients with heterozygous familial hypercholesterolemia were treated with mevalonic acid (an inhibitor of cholesterol synthesis) for 45 days. Patients received a daily dose of 750 to 1500 mg mevalonic acid depending on plasma cholesterol levels. Results showed a significant reduction in cholesterol values whereas no significant difference was observed in HDL cholesterol and triglyceride levels.

Adult↗
PubMed1991

[Evaluation in experimental animals of a mathematical model of foreseeing variations in values of stable glycosylated hemoglobin].

Assay of glycosylated hemoglobin provides reliable information on metabolic control in diabetes mellitus over a period of about 90 days. This is why it is currently used as a parameter of blood glucose control in diabetic patients. However, at present little is known about the kinetics of stable glycosylated hemoglobin variations as a result of circadian changes in blood glucose level. The authors describe a mathematical model which allows to foresee glycosylated hemoglobin variability as a result of alterations of blood glucose equilibrium.

Animals↗
PubMed1990

[Evaluation of the changes in glycosylated hemoglobin in a sample of hospitalized diabetic patients. Significance and limitations of this diagnostic method].

Stable glycosylated hemoglobin measurement provides an index for plasma glucose control over an average three month period. It is not clear whether stable HbA1C can undergo rapid changes induced by short-term variations in glucose concentration. The present study was aimed at investigating whether variation of total HbA1C in response to changes in blood glucose, over a short period can be detected by routine methods of determination. Our result show that due to the sensitivity of the methods, stable HbA1C has to be considered only as an index of glucose control over long period of time.

Adult↗