Biomedical subjects

A Rossi

Publications and source records attributed to A Rossi.

At least 253 records · Page 14Linked to original sources

PubMed1999

Induction of ferritin and heat shock proteins by prostaglandin A1 in human monocytes. Evidence for transcriptional and post-transcriptional regulation.

Prostaglandins of the A type (PGA) exert a cytoprotective activity during hyperthermia and virus infection. This effect is associated with induction of heat shock proteins (HSP) in mammalian cells. We now report that, in human monocytes, PGA1 is able to induce the synthesis of the iron-binding, redox-regulated protein ferritin. L-chain ferritin induction is consequent to a substantial increase in the accumulation of L-chain ferritin transcripts in PGA1-treated cells, whereas H-chain ferritin is regulated post-transcriptionally, consequently to reduction of iron-regulatory protein binding to iron-responsive elements in ferritin mRNA. Ferritin induction is specific for cyclopentenone prostaglandins (PGA1, PGA2, PGJ2, Delta12-PGJ2), whereas other arachidonic acid (AA) metabolites have no effect. In human monocytes, PGA1 also induces heat shock gene transcription via heat shock factor activation, as well as the synthesis of the oxidative-stress protein heme oxygenase (HOS). Differently from HSP, the induction of ferritin by PGA1 is specific for monocytes. Monocytes/macrophages play a pivotal role in inflammation, controlling iron metabolism and releasing a variety of mediators, including proinflammatory reactive oxygen species (ROS), cytokines and AA metabolites. As ferritin, together with hsp70 and HO, plays a key role in protection from oxidant damage, these results suggest that PGA1 may have cytoprotective activity also during oxidative injury.

Arachidonic Acid↗

PubMed1999

Radiation protection in radioguided surgery of breast cancer.

The protocols for sentinel lymph node biopsy and radioguided occult lesion localization could potentially be of great value in the management of breast cancer patients. Both involve the injection of a 99Tcm-labelled radiopharmaceutical close to or into the lesion, localization of the sentinel lymph node or occult lesion by scintigraphy, and surgical removal with the aid of a hand-held gamma-ray detector. We present dosimetric data on patients and hospital personnel involved in these procedures. For evaluation of radiation protection, we measured the absorbed dose and air kerma rate. Activity levels in excised tissues and surgical instruments were also determined. For patients, the mean absorbed dose to the abdomen was 0.45 mGy, which is low compared to doses received from other diagnostic examinations. For surgeons after 100 operations, the mean absorbed dose to the hands was 0.45 mGy and the mean effective dose 0.09 mSv. Absorbed doses to all hospital personnel involved in the procedures were very low compared to recommended annual limits stipulated by the International Commission on Radiological Protection. We conclude that these procedures, performed according to protocols laid down by the European Institute of Oncology, Milan, are safe from the point of view of radiological protection and that only routine precautions are necessary.

Breast Neoplasms↗

PubMed1999

Regulation of transglutaminases by nitric oxide.

Nitric oxide (NO) is an inorganic diffusible molecular messenger that plays several central roles in pathophysiology. NO can affect the biological activity of proteins through the direct or indirect (via intermediate S-nitrosothiols) S-nitrosylation of protein thiol groups. Transglutaminases (TGases), Ca(++)-dependent enzymes that modify proteins by cross-linking reactions, require a cysteine residue in the active site as a prerequisite for their catalytic activity. Therefore, NO may regulate enzymatic activity of TGases and their biological effects, via S-nitrosylation of their crucial thiol groups. We here review the effects of NO on coagulation factor XIII (fXIII, or plasma TGase) and TGase 2 (or tissue transglutaminase). NO has an inhibitory effect on fXIII, thus suppressing the gamma-chain cross-linking in fibrin gels, and subsequent clot formation. Tissue transglutaminase, an apoptotic effector molecule, also represents a molecular target for NO. Accordingly, the inhibition of tissue transglutaminase enzymatic activity by NO is able to prevent the induction of apoptosis.

Animals↗

PubMed1999

Pharmacokinetics and pharmacodynamics of amoxicillin-sulbactam, a novel aminopenicillin-beta-lactamase inhibitor combination, against Escherichia coli.

We evaluated the pharmacokinetics of amoxicillin-sulbactam (AMX-SUL), a novel drug combination, and its pharmacodynamics against Escherichia coli in 12 volunteers receiving a single oral dose (1, 000 mg). Peak serum bactericidal and urine inhibitory activities in most volunteers were observed against E. coli strains for which AMX-SUL MICs were low (2- to 4-mg/liter) (2 strains) and high (>/=16-mg/liter) (47 strains), respectively.

Adult↗

PubMed1999

Determination of trimethoprim-sulfamethoxazole resistance in Streptococcus pneumoniae by using the E test with Mueller-Hinton agar supplemented with sheep or horse blood may be unreliable. The Pneumococcal Study Group.

An international, multicenter study compared trimethoprim-sulfamethoxazole MICs for 743 Streptococcus pneumoniae isolates (107 to 244 isolates per country) by E test, using Mueller-Hinton agar supplemented with 5% defibrinated horse blood or 5% defibrinated sheep blood, with MICs determined by the National Committee for Clinical Laboratory Standards broth microdilution reference method. Agreement within 1 log2 dilution and minor error rates were 69.3 and 15.5%, respectively, on sheep blood-supplemented agar and 76.9 and 13.6%, respectively, with horse blood as the supplement. Significant interlaboratory variability was observed. E test may not be a reliable method for determining the resistance of pneumococci to trimethoprim-sulfamethoxazole.

Animals↗

PubMed1999

Physiologic response of ventilator-dependent patients with chronic obstructive pulmonary disease to proportional assist ventilation and continuous positive airway pressure.

To investigate the physiologic effects of proportional assist ventilation (PAV) in difficult-to-wean, mechanically ventilated patients with advanced COPD, we measured in eight ICU patients the breathing pattern, neuromuscular drive (P0.1), lung mechanics, and inspiratory muscle effort (PTPdi and PTPpl) during both spontaneous breathing (SB) and ventilatory support with PAV, CPAP, and CPAP + PAV (in random sequence). PAV (volume assist [VA] and flow assist [FA]) was set as follows: dynamic lung elastance and inspiratory pulmonary resistance were measured during SB; then VA and FA were set to counterbalance the elastic and resistive loads exceeding the normal values, respectively, the inspiratory muscles bearing a normal elastic and resistive workload. CPAP was set close to dynamic intrinsic PEEP (8.3 +/- 3.4 cm H2O). We found significant reductions in P0.1 and PTPdi during both CPAP (-45 and -37%, respectively) and PAV (-50 and -48%, respectively). However, only the combination of PAV and CPAP brought P0.1 (1.69 +/- 0.97 cm H2O) and PTPdi (100 +/- 68 cm H2O. s) within normal values, and ameliorated the breathing pattern compared with SB (tidal volume: 0.69 +/- 0.33 versus 0.33 +/- 0.14 L; breathing frequency, 14.6 +/- 4.6 versus 21.0 +/- 6.5 breaths/min, respectively), without generating ineffective inspiratory efforts. We conclude that in difficult-to-wean COPD patients, (1) PAV improves ventilation and reduces both P0.1 and inspiratory muscle effort; (2) the combination of PAV and CPAP can unload the inspiratory muscles to values close to those found in normal subjects.

Aged↗

PubMed1999

Awareness of illness and subjective experience of cognitive complaints in patients with bipolar I and bipolar II disorder.

OBJECTIVE: The authors' goal was to investigate the awareness of illness and subjective cognitive complaints of patients with either bipolar I disorder or bipolar II disorder during a phase of clinical stabilization. METHOD: They used a structured clinical interview, the Frankfurt Complaints Questionnaire, to determine subjective cognitive complaints, and the Scale of Unawareness of Mental Disorder to assess 57 consecutively enrolled patients with bipolar I or bipolar II disorder. RESULTS: Patients with bipolar II disorder had significantly less insight and a higher level of subjective complaints of stimulus overload than patients with bipolar I disorder. CONCLUSIONS: These results suggest that a severe deficit in self-awareness may constitute a distinguishing psychopathological characteristic of patients with bipolar II disorder. Further studies are required to determine if there are associated neuropsychological dysfunctions.

Adult↗

PubMed1999

Gemcitabine as second-line treatment for advanced non-small-cell lung cancer: A phase II trial.

PURPOSE: To investigate the activity and toxicity of gemcitabine as a single agent in patients with advanced non-small-cell lung cancer (NSCLC) after recurrence or failure of previous treatment with a platinum-containing regimen. PATIENTS AND METHODS: From November 1995 to October 1997, 83 patients with stage IIIB or IV NSCLC received gemcitabine 1,000 mg/m(2) once a week for 3 weeks every 28 days. Responses were assessed every two treatment courses. The median age of the patients was 63 years; Eastern Cooperative Oncology Group performance status was 0 to 1 in 62 patients and 2 in 21 patients. The predominant histology was squamous (39 patients); 49 patients had stage IV disease and 34 patients had stage III disease (33 stage IIIB and one stage IIIA). RESULTS: Sixteen patients (19%) achieved a partial response to treatment; the median duration of response was 29 weeks (range, 6 to 50 weeks). Treatment was well tolerated: grade 2 to 3 (World Health Organization standardized response criteria) leukopenia and thrombocytopenia occurred in 23% and 20% of patients, respectively. Mild asthenia was observed in 16% of patients, and peripheral edema in 5% of patients. Nausea and vomiting were present in 16% of patients. CONCLUSION: In this experience, gemcitabine showed significant activity without relevant toxicity, mainly in patients who were previously responsive to chemotherapy. This suggests a possible role for gemcitabine as a second-line treatment in patients who had a previous response or achieved stable disease with a platinum-containing regimen.

Adult↗

PubMed1999

Risk factors and course of illness among children with invasive penicillin-resistant Streptococcus pneumoniae. The Streptococcus pneumoniae Working Group.

OBJECTIVES: To assess differences in risk factors, clinical presentation, and course of illness between children infected with penicillin-sensitive and drug-resistant Streptococcus pneumoniae (DRSP). DESIGN: A retrospective cohort study conducted in Uruguay and Argentina using information from a hospital-based surveillance system. Hospitalized children 5 years of age and younger who had S pneumoniae isolated from a normally sterile site between June 1993 and October 1996 were eligible. Hospital records were linked with surveillance data. Both stratified univariate analysis and logistic regression was completed. RESULTS: Of the 380 children eligible for the study, 274 records (72%) were available for review. Ninety-nine children (36%) had DRSP; 46 showed intermediate susceptibility (minimum inhibitory concentration, 0.12-1.0 microg/mL) and 53 showed high-level resistance (minimum inhibitory concentration >/=2.0 microg/mL). Children with meningitis were less likely to have DRSP than those with other forms of invasive disease (relative risk = 0. 5; 95% confidence interval [CI], 0.2-0.9). Risk factors associated with DRSP were use of penicillin or ampicillin in the 3 months before illness (odds ratio = 2.9; 95% CI, 1.5-5.7) and possession of private medical coverage (odds ratio = 2.4; 95% CI, 1.2-5.0). Response to therapy, including response to penicillin or ampicillin among children with nonmeningeal invasive disease, course of illness, and clinical outcome did not differ significantly between children infected with penicillin-susceptible or penicillin-resistant isolates. CONCLUSION: In this study, previous use of penicillin or ampicillin and private medical coverage were associated with having DRSP. Children with nonmeningeal invasive disease responded equally well to penicillin regardless of the penicillin susceptibility of their pneumococcal isolate.

Ampicillin↗

PubMed1999

[Measles seroprevalence among pediatricians in a teaching hospital].

OBJECTIVE: A measles outbreak occurred in S. Paulo state, during 1996 and 1997, resulting in 20,921 cases. Forty seven percent of the cases occurred in people between 20 and 29 years of age, and one of the control strategies of the Department of Health was the vaccination of health care workers. The prevalence of antibodies against measles among the hospital pediatricians was investigated. METHODS: One hundred and fifty samples were taken from volunteer pediatricians to test for measles antibodies using ELISA. A questionnaire about their having had measles and the vaccine was filled out. RESULTS: Of the 150 doctors, 122 (81.4%) were female and 28 (18.6%) male, of between 23 and 46 years of age (mean and median 27 years). The majority (98%-147/150) had protective levels of antibodies against measles (>100 UI/ml); 118 (80.3%-118/147) without and 29 (19.7%-29/147) with a history of measles. Only 3 pediatricians (2%-3/150), had negative serology, 2 without and 1 with a history of measles. Out of the 118 without history of measles, 79 (67%-39/118) in spite of the protective level of antibodies against measles, did not know if they, had been vaccinated. Out of the 79 vaccinated pediatricians, 64 (81%-64/79), had been vaccinated 25 years before, and still maintained protective levels of antibodies. Of the 3 doctors with negative serologies only one declared that he had been vaccinated. CONCLUSIONS: Measles seroprevalence among pediatricians of this hospital is high, especially due to preceding vaccination. On the other hand, the 2% of pediatricians with negative serology, in an epidemic situation could constitute a significant population for the acquisition and dissemination of the disease.

Adult↗

PubMed1999

[Monitoring antibiotic resistance in Argentina. The WHONET program, 1995-1996].

The World Health Organization has implemented a surveillance program for antimicrobial resistance that is known as WHONET. In Argentina the program was developed through a network of 23 public and private hospitals that participate in national and international quality-control programs. Between January 1995 and December 1996, the antimicrobial susceptibility of 16,073 consecutive clinical isolates was determined, using the recommended standards of the National Committee for Clinical Laboratory Standards of the United States of America. More than half of the Escherichia coli urinary isolates were resistant to ampicillin and more than 30% to trimethoprim/sulfamethoxazole (SXT). When the percentage of resistant isolates from outpatients (OPs) was compared to that observed in hospitalized patients (HPs), a marked difference in antimicrobial activity was noted in the case of gentamicin (2% from OPs resistant vs. 8% from HPs resistant), norfloxacin (2% vs. 6%), and third-generation cephalosporins (7% vs. 15%). Of the Klebsiella pneumoniae isolates recovered from blood cultures, 71% and 60% showed resistance to third-generation cephalosporins and to gentamicin, respectively. The overall rate of oxacillin resistance in Staphylococcus aureus was 39%. Around half of the Enterococcus spp. isolates showed high resistance to aminoglycosides, but resistance to glycopeptides was not found. In Argentina, ampicillin and SXT were not suitable for treating diarrhea. Shigella flexneri had a higher number of isolates resistant to both of those drugs (87% and 74%, respectively) than Sh. sonnei did (47% and 71%, respectively). About 40% of the Salmonella spp. isolated in pediatric hospitals were resistant to third-generation cephalosporins. When microorganisms causing bacterial meningitis were examined, Streptococcus pneumoniae showed a resistance rate of 18% to penicillin and Haemophilus influenzae a resistance rate of 19% to ampicillin. These rates are within the intermediate range reported for other countries of the Americas and for Europe.

Cephalosporins↗

PubMed1999

The emergence of social phobia during clozapine treatment and its response to fluoxetine augmentation.

BACKGROUND: The underlying neurochemical basis of social phobia has yet to be fully explained, but there are suggestions of serotonergic and dopaminergic dysfunction. The atypical neuroleptic clozapine has been reported to induce anxiety symptoms, probably owing to its effect on serotonergic pathways. We report 12 cases of schizophrenic patients who developed social phobia during clozapine treatment. METHOD: Patients were assessed using the Structured Clinical Interview for DSM-III-R, Patient Version, Scale for the Assessment of Negative Symptoms, Scale for the Assessment of Positive Symptoms, the Liebowitz Social Phobia Scale, and the Brief Psychiatric Rating Scale. They were reevaluated after 12 weeks of cotreatment with clozapine and fluoxetine. RESULTS: In 8 of the 12 cases, symptoms responded (> or = 35% reduction in Liebowitz Social Phobia Scale score) with an adjunctive regimen of fluoxetine. CONCLUSION: Data are discussed in light of neurochemical mechanisms and cognitive adaptations that could explain the onset of anxiety spectrum disorders (such as social phobia) in clozapine-treated schizophrenic subjects during remission of psychotic symptoms.

Adult↗

PubMed1999

Intrapericardial yolk sac tumor associated with acute myocarditis.

An occult intrapericardial yolk sac tumor occurred in a 3-year-old girl with a fatal outcome. At autopsy, a 5.5-cm mass surrounded the base of the heart and compressed the left atrium posteriorly. Histologically, the tumor was a pure yolk sac tumor. Postmortem chemical analyses of the blood revealed an alpha-fetoprotein level greater than 7000 microg/L. Acute myocarditis of both ventricles was also found.

Acute Disease↗

PubMed1999

Segmental spinal dysgenesis: neuroradiologic findings with clinical and embryologic correlation.

BACKGROUND AND PURPOSE: Segmental spinal dysgenesis (SSD) is a rare congenital abnormality in which a segment of the spine and spinal cord fails to develop properly. Our goal was to investigate the neuroradiologic features of this condition in order to correlate our findings with the degree of residual spinal cord function, and to provide insight into the embryologic origin of this disorder. We also aimed to clarify the relationship between SSD and other entities, such as multiple vertebral segmentation defects, congenital vertebral displacement, and caudal regression syndrome (CRS). METHODS: The records of patients treated at our institutions for congenital spinal anomalies were reviewed, and 10 cases were found to satisfy the inclusion criteria for SSD. Plain radiographs were available for review in all cases. MR imaging was performed in eight patients, one of whom also underwent conventional myelography. Two other patients underwent only conventional myelography. RESULTS: Segmental vertebral anomalies involved the thoracolumbar, lumbar, or lumbosacral spine. The spinal cord at the level of the abnormality was thinned or even indiscernible, and a bulky, low-lying cord segment was present caudad to the focal abnormality in most cases. Closed spinal dysraphisms were associated in five cases, and partial sacrococcygeal agenesis in three. Renal anomalies were detected in four cases, and dextrocardia in one; all patients had a neurogenic bladder. CONCLUSION: SSD is an autonomous entity with characteristic clinical and neuroradiologic features; however, SSD and CRS probably represent two faces of a single spectrum of segmental malformations of the spine and spinal cord. The neuroradiologic picture depends on the severity of the malformation and on its segmental level along the longitudinal embryonic axis. The severity of the morphologic derangement correlates with residual spinal cord function and with severity of the clinical deficit.

Coccyx↗

PubMed1999

Extraventricular neurocytoma with ganglionic differentiation associated with complex partial seizures.

We report an unusual case of extraventricular ("cerebral") neurocytoma with ganglion cells located in the right temporal lobe in a 9-year-old girl with complex partial seizures and precocious puberty. CT showed a calcified mass with central cystic zones. MR imaging showed a markedly hyperintense predominately solid tumor on both T1- and T2-weighted images, without appreciable contrast enhancement. Cerebral neurocytomas are histologically benign and radical surgery is curative; they should be included in the differential diagnosis of temporal lobe tumors in children.

Brain Neoplasms↗

PubMed1999

Marie Unna hereditary hypotrichosis.

Hereditary congenital hypotrichosis is an autosomal dominant pilar dysplasia first described by Marie Unna in an extended German family. The diffuse hair defect typically occurs as an isolated phenomenon and the ultrastructural hair findings consist of both torsion and longitudinal grooving of the hair shaft. A large pedigree comprising 6 generations with 20 members affected by Marie Unna hypotrichosis from Italy is reported.

Adult↗

PubMed1999

Immobilization of enzymes on spongy polyvinyl alcohol cryogels: the example of beta-galactosidase from Aspergillus oryzae.

The catalytic properties of a beta-galactosidase from Aspergillus oryzae, entrapped into a spongy polyvinyl alcohol cryogel, were studied. This polymeric matrix was selected because of its mild conditions of preparation and its stability, biocompatibility, structural strength and diffusive properties. The enzyme was entrapped, in high percentage, into cryogel sponges and its activity and kinetic parameters were determined and compared with those of the free enzyme, using as substrates o-nitrophenyl-beta-galactopyranoside (ONPG) or lactose. The immobilized enzyme showed a reduced activity with ONPG and lactose, probably because of substrate diffusion limitations through the matrix, but it was more stable to temperature, pH and ionic strength than the free enzyme. Lactose hydrolysis under continuous experimental conditions was performed using the matrix-enzyme cited above.

Animals↗

PubMed1999

[In vitro activity of trovafloxacin, of other fluoroquinolones and of related antimicrobials against clinical isolates. Grupo colaborativo WHONET-Argentina].

The in vitro activity of trovafloxacin (TRV) has been evaluated in comparison with that of other antimicrobial agents against 5671 clinical isolates recovered by representative institutions of different provinces in our country. The resistance percentage to gentamicin and third generation cephalosporins among enterobacteriaceae was high: 17% and 16% respectively, with a considerable variation according to the analyzed species. The resistance to ciprofloxacin (CIP) and TRV affected approximately 9% of the isolates, without significant differences between both drugs. Fluoroquinolones (FQ) presented excellent activity on 166 isolates of Salmonella spp., 208 of Shigella flexneri and 76 of Shigella sonnei, where only one S.sonnei isolate was resistant to CIP, but susceptible to TRV. About half the isolates of Salmonella spp. and S.sonnei and almost all S.flexneri isolates were resistant to ampicillin, and more than 60% of Shigella spp. isolates were resistant to trimethoprim-sulfamethoxazole. A 41% of Staphylococcus aureus and 55% of coagulase-negative staphylococci isolates were resistant to oxacillin, presenting a highly associated multi-resistance. The resistance to FQ was also strongly related to oxacillin resistance, but the resistance to TRV was significantly lower than the CIP resistance: 9% vs 57% for S.aureus and 4% vs 41% for coagulase-negative staphylococci. A similar behavior was observed with Enterococcus spp., where 54% of the isolates were resistant to norfloxacin and only 13% were resistant to TRV. Neither Streptococcus pneumoniae (n = 193) nor Haemophilus influenzae (n = 139) isolates presented resistant to TRV.

Anti-Bacterial Agents↗