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Biomedical subjects

A Rossi

Publications and source records attributed to A Rossi.

At least 163 records · Page 9Linked to original sources
PubMed2001

No correlation between aggression and platelet (3)H-paroxetine binding in obsessive-compulsive disorder patients.

Different findings suggest that the serotonin (5-HT) system may be involved in both the regulation of aggression and the pathophysiology of obsessive-compulsive disorder (OCD). Our study aimed to evaluate the aggressive features of a group of OCD patients and to explore possible correlations with a serotonergic marker, namely platelet 5-HT transporter. Psychopathological and biological patterns were compared with those of a group of healthy controls and those of patients with major depression. Twenty-one patients affected by OCD, 21 by depression and 21 healthy controls were included in the study. Aggressive features were measured by means of the Buss and Durkee Hostility Inventory (BDHI). The platelet 5-HT transporter was evaluated by means of the (3)H-paroxetine binding parameters (maximum binding capacity, B(max) and dissociation constant, K(d)). The OCD patients showed a total score on the BDHI not significantly different from that of healthy controls and lower than that of depressed patients. The factor profile was similar in the 3 groups, but higher in the depressed patients. The irritability, resentment, guilt, negativism and suspiciousness factors were significantly more pronounced in depressed patients. Some sex-related difference in single factors were also observed. The B(max) of (3)H-paroxetine binding was lower in OCD patients than in depressives or healthy controls. OCD patients were more similar to healthy controls than to depressed patients with regard to aggressive features measured by means of the BDHI. This suggests that aggression in OCD is a complex phenomenon that probably requires specific instruments of evaluation.

Adolescent↗
PubMed2001

mRNA expression of serotonin receptors of type 2C and 5A in human resting lymphocytes.

We investigated the presence of mRNA for serotonin receptors of type 2C (5-HT(2C)) in resting lymphocytes by means of RT-PCR and Southern blotting analyses, given their possible role in the pathophysiology of anxiety and eating disorders. At the same time, we explored also the presence of the specific mRNA for 5-HT(5A) receptors, a novel subtype for which still no functional data exist. Healthy subjects and patients with obsessive-compulsive or bipolar disorders were included in the study. The results showed the presence of the specific mRNAs for both 5-HT(2C) and 5-HT(5A) receptors in resting lymphocytes of the three groups of subjects. An additional band was also observed after the amplification of the 5-HT(5A) cDNA in each sample. These findings, while revealing the presence of 5-HT(2C) and 5-HT(5A) receptor mRNAs in an easily available tissue, can be considered preliminary for future quantitative analyses in patients with different psychiatric conditions.

Adult↗
PubMed2001

Pharmacological characterization of the serotonin transporter in young and elderly subjects.

The potency of some tricyclics (imipramine and clomipramine) and selective 5-HT reuptake inhibitors (fluoxetine, paroxetine, and citalopram) in displacing the [(3)H]paroxetine binding to platelet membranes was measured in young and elderly subjects of both sexes. The results showed that the most potent compound in all subjects was paroxetine, followed by clomipramine, citalopram, fluoxetine, and imipramine, with no differences between male and female subjects. All drugs, except paroxetine and clomipramine, showed significantly lower pKi values in the elderly subjects of both sexes. These findings would suggest that although the pharmacological profile of the 5-HT transporter is not modified qualitatively by age, quantitative changes in its affinity do perhaps occur which would justify more careful studies on this topic in order to get optimal dosages of drugs acting at this level.

Adult↗
PubMed2001

An observational study on the epidemiology of respiratory tract bacterial pathogens and their susceptibility to four injectable beta-lactam antibiotics: piperacillin, piperacillin/tazobactam, ceftazidime and ceftriaxone.

Bacterial infections of the respiratory tract account for a large proportion of total medical consultations in general practice. In recent years, antibiotic resistance has increased alarmingly in a number of bacterial species that are common causes of these infections. The aim of this observational study was to determine the antibiotic resistance of microbial agents isolated from patients with acute or acutely exacerbated respiratory infections. Subjects recruited as potential sources of bacteria were either outpatients seen in a number of specialized clinics and hospital practices, or hospitalized patients. Overall, 648 consecutive patients (67% male, mean age 48.1+/-27.0 years) with infection of the upper or lower respiratory tract were observed during a 13-month period. A total of 551 pathogenic microbial strains were isolated and tested for their in vitro susceptibility to piperacillin, piperacillin/tazobactam, ceftazidime, and ceftriaxone. Among all isolates, the four most frequent pathogens were Pseudomonas aeruginosa (132 isolates, 24%), Streptococcus pyogenes (99 isolates, 18%), Staphylococcus aureus (93 isolates, 17%), and Klebsiella pneumoniae (46 isolates, 8%). The susceptibility of gram-positive isolates ranged from 97.5% to 95.1%, and no remarkable difference was found in the antibacterial activity of tested b-lactam antibiotics. The susceptibility of gram-negative isolates to piperacillin and piperacillin/tazobactam was also similar: 96.5% and 97.1%, respectively. In contrast, differences were found between piperacillin (or piperacillin/tazobactam) and either ceftazidime (p=0.003) or ceftriaxone (p<0.0003) in gram-negative isolates. We conclude that, despite the extensive use of beta-lactam antibiotics (piperacillin, ceftazidime, and ceftriaxone) in medical practice during the past three decades, the susceptibility of the most common pathogens involved in the etiology of upper and lower respiratory tract infections to these antibiotics is still high. In particular, bacterial resistance developed by gram-positive organisms against piperacillin is negligible and not alarming.

Adolescent↗
PubMed2001

Early-onset combined methylmalonic aciduria and homocystinuria: neuroradiologic findings.

BACKGROUND AND PURPOSE: Combined methylmalonic aciduria and homocystinuria (MMA-HC) is caused by impaired hepatic conversion of dietary cobalamin to methylcobalamin and adenosylcobalamin, resulting in decreased activity of methylmalonyl-CoA mutase and methionine synthase. Patients with the early-onset variety present within 12 months of age with severe neurologic, hematologic, and gastrointestinal abnormalities. We describe the neuroradiologic features of early-onset MMA-HC and discuss related pathophysiological mechanisms. METHODS: Twelve infants with hypotonia, failure to thrive, poor feeding, and hematologic abnormalities were diagnosed with MMA-HC on the basis of a typical plasmatic and urinary metabolic profile and enzyme activity in fibroblastic cultures. Complementation studies were performed in two cases, and yielded a CblC result. MR imaging was performed at presentation in four cases and later in the others. All patients showed prompt biochemical improvement with intramuscular hydroxocobalamin administration, and most had moderate neurologic improvement. RESULTS: Diffuse supratentorial white matter edema and dysmyelination was the typical MR picture at presentation, whereas white matter bulk loss characterized later stages of the disease. Nucleocapsular areas of gliosis were an additional finding in one case. One patient had tetraventricular hydrocephalus at presentation. CONCLUSION: White matter damage is probably caused by reduced methyl group availability and nonphysiological fatty acids toxicity, whereas focal gliosis results from homocysteine-induced toxicity to the endothelium. Hydrocephalus may result from diffuse intracranial extracerebral arterial stiffness, known as reduced arterial pulsation hydrocephalus. MR imaging features at presentation and at follow-up are nonspecific.

Brain↗
PubMed2001

[Physiopathology of acute respiratory failure in COPD and asthma].

Asthma and chronic obstructive pulmonary diseases (COPD) lead to functional obstruction of airways, identified by increased inspiratory and expiratory resistances. Increased expiratory resistances cause, in turn, a reduction in expiratory flow. The analysis of flow-volume loops shows that, as the disease progresses, the flow generated during expiration of a tidal volume becomes very close to the flow generated during forced maximal expiration. In such condition, where there is little or no reserve of expiratory flow, higher tidal volumes need to be reached in order to increase the expiratory flow, and hyperinflation inevitably occurs. Hyperinflation, a key feature in COPD pathophysiology, is generated by two mechanisms: reduction of elastic recoil of the lung (static hyperinflation) and interruption of expiration at lung volumes still higher than FRC, due to reduction of expiratory flow (dynamic hyperinflation). When dynamic hyperinflation occurs, a residual positive pressure remains in the alveoli, which is defined as intrinsic positive end-expiratory pressure (PEEPi). Hyperinflation carries several consequences: 1) Respiratory mechanics: at lung volumes close to total lung capacity, lung compliance is physiologically reduced, and elastic work required to generate the same inspiratory volume is therefore increased; 2) Respiratory muscles: contractile properties of diaphragm deteriorate when the dome is pushed downward by an increased lung volume, inspiration is mainly performed by inspiratory muscles, and expiration becomes active; 3) Circulation: pulmonary vascular resistances increase due to compression exerted by hyperinflation on alveolar vessels and to hypoxic vasoconstriction; right ventricle afterload increases and right sided hypertrophy and dilation ensue; left ventricular afterload may increase due to increased negative intrapleural pressure which translates into an increased transmural pressure which needs to be overcome by ventricular contraction. Ventilatory support of COPD patients should decrease work of breathing and improve gas exchange without increasing hyperinflation. This target can be achieved during assisted ventilation by applying a positive pressure both during inspiration and expiration; the level of PEEP should equal PEEPi. During mechanical ventilation in sedated paralyzed patients hyperinflation should be limited by decreasing minute volume and by increasing expiratory time, eventually choosing controlled hypercapnia.

Airway Resistance↗
PubMed2001

The telematic network of referee hospital "V. Monaldi" in Naples: state of the art and perspectives.

The new advances in I.T. both in Hardware (wideband network) and in Software are rapidly changing the Health Information Systems scenario. In many hospitals of Campania Region this leads in many case to rebuild, starting from zero, both infrastructure and applications. Ericsson Enterprise has recently developed for the A.O. Monaldi and Integrated information System which consists of an advanced LAN (Local Area Network), a number of software infrastructures and some application systems as WEB site, Dicom PACS, E-mail server, Streaming Video from Operating Theatres, Internal TV Network. This integrated system represents the starting point for modern health information systems, which is compliant with new standards. The start-up of such systems represents always a problem for the organization and management point of view, therefore a number of problems concerning: training, education, security, privacy, operative procedures, co-ordination with existing applications, system management at the start-up and after. This paper deals with the technical aspects of this information system and discusses the problem met in introducing these IT products in a big and important hospital of Campania Region in Italy, in order to suggest a model, useful for other similar experiences.

Computer Systems↗
PubMed2001

Long-term results with the Xenomedica porcine bioprosthesis in the mitral position.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate our clinical experience with the Xenomedica heart valve prosthesis, a low-pressure glutaraldehyde-preserved porcine aortic valve with low-profile mounting. METHODS: Between January 1983 and July 1990, 242 consecutive patients (75 men, 167 women; mean age 59.8+/-8.0 years; range: 32-77 years) underwent mitral valve replacement with the Xenomedica prosthesis. Preoperatively, patients were in NYHA classes III (66%) and IV (26%); 94 patients (39%) had undergone previous cardiac surgery and 201 (83%) had chronic atrial fibrillation. Etiology was rheumatic in 51%, myxomatous in 7%, ischemic in 1%, endocarditis in 2%, and due to dysfunction of a previously implanted device in 39%. In total, 115 (47%) patients underwent an associated procedure. Mean follow up was 142+/-24 months (range: 2-181 months); total follow up was 2,627 patient-years. RESULTS: Early mortality was 8.2% (14 patients with low-output syndrome, three with multi-organ failure, one with stroke and two with major bleeding, 2). Late mortality was 45% (3.8%/pt-year) (84 cardiac deaths, 38 being valve-related). Actuarial survival at 5, 10 and 15 years was 69+/-3%, 52+/-3% and 38+/-4%, respectively. Actuarial estimates of freedom from structural valve deterioration (SVD) at 5, 10 and 15 years were 93+/-2%, 64+/-4%, and 25+/-9%; in almost all cases SVD occurred in progressive fashion. At 5, 10 and 15 years, estimates of freedom from thromboembolism were respectively 90+/-2%, 83+/-3% and 83+/-3%, for anticoagulant-related hemorrhage 96+/-1%, 88+/-3% and 88+/-3%, for endocarditis 96+/-1%, 94+/-2% and 94+/-2%, and for reoperation 93+/-2%, 67+/-4% and 54+/-6%. Estimates of freedom from all valve-related mortality at 5, 10 and 15 years were 87+/-2%, 80+/-3% and 75+/-4%. Multivariate analysis (Cox model) showed younger age to be a significant risk factor for reoperation. CONCLUSION: Long-term results with the Xenomedica device implanted in the mitral position appear in line with those achieved for other first-generation bioprostheses. However, incidence of primary tissue failure within 10 years was unsatisfactory. Although sudden dysfunction of the device never occurred, close monitoring of survivors is warranted.

Actuarial Analysis↗
PubMed2001

First report of the Italian register for diffuse infiltrative lung disorders (RIPID).

RIPID was established in 1998 as a joint project of the major Italian scientific societies for Respiratory Medicine, with the aim to create an Italian Register on diffuse infiltrative lung disorders that can provide the basis for epidemiological and clinical studies of adequate sample size. In the period from May 1998 to December 2000, 1,382 cases were submitted from 54 Centers in 15 regions of Italy, 54.2% males (mean age +/- SD 50.5 +/- 16.8 years) and 45.8% females (50.2 +/- 15.3 years). A current smoking habit emerges in 18% of subjects; former smokers and never-smokers represent 26% and 56% of the total case series, respectively. The most frequent disease registered is idiopathic pulmonary fibrosis (37.6%), followed in decreasing order by sarcoidosis (29.2%), and Langherans' cell hystiocytosis (6.6%). High resolution computed tomography (HRCT) was considered as the most important tool for final diagnosis in the majority of cases (74.4%); 39.4% of patients underwent transbronchial biopsies, 39.2% bronchoalveolar lavage (BAL). A surgical biopsy was performed in 20.5% of patients. A web site has been activated from December 2000 (www.pneumonet.it/ripid), allowing prompt access to all information and scientific material concerning the project and to an electronic form for data collection that can be completed on-line.

Adult↗
PubMed2000

Behavioral neurodevelopment abnormalities and schizophrenic disorder: a retrospective evaluation with the Childhood Behavior Checklist (CBCL).

This study is a retrospective report of childhood and adolescence neurobehavioral assessment in patients with schizophrenia and their healthy siblings using the Childhood Behavior Checklist (CBCL). The CBCL ratings were obtained from retrospective maternal reports, for five age periods (birth to 3years, 4-7years, 8-11years, 12-15years and 16-18years) in a sample of 32 patients with schizophrenia. The patients showed a variety of childhood and adolescence behavioral problems when compared with their siblings, and the various types of problems differed in the developmental course of the disease. Cluster analysis was conducted on the childhood premorbid behavior ratings for the schizophrenic patients, and two subgroups emerged: a cluster with an initially low level of behavioral abnormalities (B.A. ) that increased over the years, and a cluster with a high level of B.A. that remain relatively stable until early adulthood. The latter group showed more severe current negative symptoms.

Adolescent↗
PubMed2000

Processing of context information in schizophrenia: relation to clinical symptoms and WCST performance.

Failure in contextual information processing has been hypothesized as being the single function responsible for several impairments in cognitive tasks and symptoms, through an involvement of the prefrontal cortex, in patients with schizophrenia. A variant of the Continuous Performance Test (CPT) designed specifically to elicit deficits in the processing of contextual information has been administered to 20 schizophrenic patients and 20 healthy controls. The relation to Wisconsin Card Sorting Test (WCST), relatively specific to prefrontal damage and executive dysfunctioning, and clinical status by using scales for the assessment of positive, negative symptoms and outcome has been investigated. The data show that multi-episode schizophrenic patients manifest inability to use contextual information to inhibit habitual response to an ambiguous stimulus and to maintain information across delay, without a general attention deficit. We also found a relationship between contextual reasoning and WCST unique errors, hallucinations, formal thought disorders, and outcome evaluation. Our results further support the hypothesis that the deficit of contextual reasoning could account for cognitive impairments and symptoms of patients with schizophrenia.

Adult↗
PubMed2000

Synthesis and immunosuppressive activity of novel prodigiosin derivatives.

Prodigiosins (Ps) represent a family of naturally occurring red pigments characterized by a common pyrrolylpyrromethene skeleton. Some members of this family have been shown to possess interesting immunosuppressive properties exerted with a novel mechanism of action, different from that of currently used drugs. In fact, Ps inhibit phosphorylation and activation of JAK-3, a cytoplasmic tyrosine kinase associated with a cell surface receptor component called common gamma-chain, which is exclusive of all IL-2 cytokine family receptors. Blocking common gamma-chain transduction activity results in a potent and specific immunosuppressive activity. With respect to the interesting and unexploited immunomodulating properties of this family of compounds we initiated a medicinal chemistry program aimed at finding novel prodigiosin derivatives with improved immunosuppressive activity and lower toxicity. Utilizing an unprecedented and flexible way of assembling the prodigiosin frame, a number of new derivatives have been prepared and tested leading to the choice of 4-benzyloxy-5-[(5-undecyl-2H-pyrrol-2-ylidene)methyl]-2, 2'-bi-1H-pyrrole (PNU-156804, 16) as a lead immunosuppressant.

Animals↗
PubMed2000

p63 and p73 transactivate differentiation gene promoters in human keratinocytes.

p53 and its two homologues, p73 and p63, share considerable structural similarities, an ability to interact between themselves and to transactivate the same promoters, including for example p21. Furthermore, p73 can induce cell death via its interaction with c-Abl. In contrast, p63 has been demonstrated to be essential for limb and skin formation. We evaluated the expression of p63 and p73 in differentiating human keratinocytes in vitro. Skin biopsy and primary cultures of normal human epidermal keratinocytes (NHEK) express both p73 and p63. NHEK induced to differentiate in vitro by high calcium exposure show induction of p73 delta and downregulation of all isoforms of p63. This latter gene is predominantly expressed in its transcriptionally inactive form, DeltaNp63. We further evaluated the effect of either p73s or p63 transfected in either NHEK or transformed human keratinocytes (HaCat cells). p73 gamma, delta, and p63 were able to transactivate the promoters of loricrin and involucrin in both NHEK and HaCat cells. These results suggest the involvement of both p73 and p63 genes in keratinocyte terminal differentiation.

Calcium↗
PubMed2000

Nitric oxide inhibits apoptosis via AP-1-dependent CD95L transactivation.

Several inducers of cytotoxic stress promote apoptotic cell death, which, at least in some cases, involves the CD95/CD95 ligand (CD95L) pathway. The induction of the CD95/CD95L pathway can be activated by the activator protein-1 (AP-1)-mediated up-regulation of the CD95L promoter, which is responsible for the induction of apoptosis elicited by stimuli such as etoposide. We show that nitric oxide (NO) represents a regulatory element able to block apoptosis by interfering with this loop. Etoposide- and C6-ceramide-induced apoptosis in Jurkat T cells with different kinetics. Cell death was accompanied by an increase in DNA-binding activity of the transcription factor AP-1, transactivation of the AP-1 site-containing CD95L promoter, and caspase 3-like protease activation. Using different NO-releasing compounds, we found that apoptosis was prevented in a dose-dependent manner. Furthermore, in both models of apoptosis, NO-releasing compounds dose-dependently reduced: (a) the number of the titratable thiol groups (cysteine residues) of c-Jun; (b) induction of AP-1 DNA-binding activity; (c) AP-1-driven transactivation of the CD95L promoter; and (d) caspase activation. In conclusion, our data demonstrate that NO can modulate cell death at an upstream level, by interfering with the ability of AP-1 to induce CD95L expression.

Amino Acid Sequence↗
PubMed2000

Qualitative MRI findings in patients with schizophrenia: a controlled study.

A variety of brain structural abnormalities, which can be identified only by qualitative methods, have been shown to correlate with clinical presentation and course of schizophrenia. In the present study, MRI scans of 122 patients with DSM-IV schizophrenia and 81 non-psychiatric controls were evaluated. Among males, the frequency of CNS developmental abnormalities (CDAs) was higher in patients than in controls. Lateral ventricular enlargement (LVE) was more frequent in patients than in controls; when subjects were grouped in three age classes, LVE was more frequent in patients than in controls in the youngest and the oldest age group. Patients with LVE or third VE were older than those without these abnormalities. Schizophrenic patients with LVE or cortical atrophy (CA) had a longer duration of illness than those without these abnormalities. Both patients with LVE and those with third VE had a poorer outcome than those without these abnormalities. CDA findings add to the evidence of a higher frequency of neurodevelopmental abnormalities in male schizophrenic patients. Results concerning LVE suggest that both developmental and degenerative processes underlie this abnormality. The association of LVE and third VE with a poor outcome indicates that qualitative MRI evaluation might be of clinical relevance.

Adolescent↗
PubMed2000

Y chromosome microdeletions in infertile men with varicocele.

The pathogenic mechanisms by which varicocele disrupt spermatogenesis are not clearly understood and it is possible that when varicocele is associated with a severe bilateral testiculopathy, other causes may represent the actual aetiological factor. Since microdeletions in the Y chromosome long arm (Yq) have become in last years a major cause of male infertility, we perform a Yq microdeletion screening in infertile men with varicocele. We selected 40 patients with severe oligozoospermia (sperm count<5x10(6)/ml, group 1) and 80 with varicocele and mild oligozoospermia (sperm count 10-20x10(6)/ml, group 2). Deletions of Yq was observed in seven out of 40 patients (17.5%) of group 1, while no deletions were found in patients of group 2, suggesting that the bilateral testicular damage observed in patients of group 1 is due to the underlying genetic anomaly, and not to varicocele itself. The finding of a genetic aetiology in infertile men with varicocele suggests that in such patients a Yq microdeletion screening should be performed, both for a proper diagnosis and to avoid unnecessary treatments that will probably not improve the sperm count.

Biopsy, Needle↗
PubMed2000

Opposite effects of Ca(2+) and GTP binding on tissue transglutaminase tertiary structure.

Tissue transglutaminase (tTG) belongs to a class of enzymes that catalyze a cross-linking reaction between proteins or peptides. The protein activity is known to be finely tuned by Ca(2+) and GTP binding. In this study we report the effects of these ligands on the enzyme structure, as revealed by circular dichroism, and steady-state and dynamic fluorescence measurements. We have found that calcium and GTP induced opposite conformational changes at the level of the protein tertiary structure. In particular the metal ions were responsible for a small widening of the protein molecule, as indicated by anisotropy decay measurements and by the binding of a hydrophobic probe such as 1-anilino-8-naphthalenesulfonic acid (ANS). Unlike Ca(2+), the nucleotide binding increased the protein dynamics, reducing its rotational correlation lifetime from 32 to 25 ns, preventing also the binding of ANS into the protein matrix. Unfolding of tTG by guanidinium hydrochloride yielded a three-state denaturation mechanism, involving an intermediate species with the characteristics of the so-called "molten globule" state. The effect of GTP binding (but not that of Ca(2+)) had an important consequence on the stability of tissue transglutaminase, increasing the free energy change from the native to the intermediate species by at least approximately 0.7 kcal/mol. Also a greater stability of tTG to high hydrostatic pressure was obtained in presence of GTP. These findings suggest that the molecular mechanism by which tTG activity is inhibited by GTP is essentially due to a protein conformational change which, decreasing the accessibility of the protein matrix to the solvent, renders more difficult the exposure of the active site.

Anilino Naphthalenesulfonates↗