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Biomedical subjects

A Rossini

Publications and source records attributed to A Rossini.

At least 19 recordsLinked to original sources

CYP2A6 and CYP2E1 polymorphisms in a Brazilian population living in Rio de Janeiro.

Cytochrome P450 (CYP) is a superfamily of enzymes involved in the metabolism of endogenous compounds and xenobiotics. CYP2A6 catalyzes the oxidation of nicotine and the activation of carcinogens such as aflatoxin B1 and nitrosamines. CYP2E1 metabolizes ethanol and other low-molecular weight compounds and can also activate nitrosamines. The CYP2A6 and CYP2E1 genes are polymorphic, altering their catalytic activities and susceptibility to cancer and other diseases. A number of polymorphisms described are ethnic-dependent. In the present study, we determined the genotype and allele frequencies of the main CYP2A6 and CYP2E1 polymorphisms in a group of 289 volunteers recruited at the Central Laboratory of Hospital Universitário Pedro Ernesto. They had been residing in the city of Rio de Janeiro for at least 6 months and were divided into two groups according to skin color (white and non-white). The alleles were determined by allele specific PCR (CYP2A6) or by PCR-RFLP (CYP2E1). The frequencies of the CYP2A6*1B and CYP2A6*2 alleles were 0.29 and 0.02 for white individuals and 0.24 and 0.01 for non-white individuals, respectively. The CYP2A6*5 allele was not found in the population studied. Regarding the CYP2E1*5B allele, we found a frequency of 0.07 in white individuals, which was statistically different (P < 0.05) from that present in non-white individuals (0.03). CYP2E1*6 allele frequency was the same (0.08) in both groups. The frequencies of CYP2A6*1B, CYP2A6*2 and CYP2E1*6 alleles in Brazilians are similar to those found in Caucasians and African-Americans, but the frequency of the CYP2E1*5B allele is higher in Brazilians.

Adult↗

Acute torsion of uterine leiomyoma: CT features.

Acute torsion of a subserosal leiomyoma is a rare acute condition that is infrequently diagnosed preoperatively. It is a recognized surgical emergency, especially when additional systemic symptoms are associated. There are two main differential diagnoses: ovary/adnexal torsion and massive infarct inside a common leiomyoma. The diagnosis can be established by computed tomographic features. Ultrasound examination is less sensitive.

Adult↗

Interleukin-3 receptor in acute leukemia.

Recent studies indicate that abnormalities of the interleukin-3 receptor (IL-3R) are frequently observed in acute myeloid leukemias (AMLs) and may contribute to the proliferative advantage of leukemic blasts. This review analyzes the evidences indicating that the IL-3R represents one of the target molecules involved in the stimulation of proliferation of AMLs, and the overexpression of the IL-3Ralpha chain may represent one of the mechanisms contributing to the development of a highly malignant leukemic phenotype. Furthermore, there is evidence that the IL-3Ralpha is a marker of leukemic stem cells, at variance with normal stem cells that are IL-3Ralpha-. Finally, the IL-3R may represent an important target for the development of new antileukemic drugs.

Acute Disease↗

Lack of a strong association between HLA class II, tumour necrosis factor and transporter associated with antigen processing gene polymorphisms and virological response to alpha-interferon treatment in patients with chronic hepatitis C.

The aim of the study was to investigate whether polymorphisms of the HLA class II, tumour necrosis factor (TNF) and transporter associated with antigen processing (TAP) genes influence the response to alpha-interferon in patients with chronic hepatitis C. Twenty-seven sustained responders and 55 non-responders to alpha-interferon monotherapy were investigated. HLA-DRB1, DQA1, DQB1, TNFA, TNFB, TAP1 and TAP2 alleles were determined by PCR-based molecular techniques. Sustained virological response was defined as undetectable serum hepatitis C virus (HCV) RNA for at least 3 years after the end of treatment. Probability (P) values were corrected for the number of alleles tested (Pc). Viral genotype 1b was more frequent in responders than in non-responders (56% vs. 26%, P = 0.009). HLA-DQB1*02 occurred less frequently in responders than in non-responders (14.8% vs. 29%, Pc not significant). HLA-DRB1*11 and DQB1*0602 were found in 22.2% and 9.3% of responders and in 10.9% and 1.8% of non-responders, respectively (Pc not significant). There was no difference in the distribution of TNF alleles in the two groups. Twenty-four (88.8%) responder patients as compared with 34 (61.8%) non-responders were TAP1*0101 homozygous (Pc not significant). Thus, in European Caucasoids with chronic hepatitis C, we could not demonstrate a strong association between HLA class II, TNF, and TAP gene polymorphisms and response to interferon treatment.

ATP-Binding Cassette Transporters↗

Requests of medical examinations after pneumococcal & influenza vaccination in the elderly.

BACKGROUND & OBJECTIVES: There are no specific recommendations about pneumococcal vaccination (PV) in Italy. There are limited data on the requests of medical examination or hospitalization due to side effects of pneumococcal vaccination. In the present study we present our analyses on the requests of medical examination due to side effects of pneumococcal vaccination (PV) in 29,086 elderly aged >/=65 yr. METHODS: Vaccination with influenza vaccine (IV) alone or in association with PV was offered during the IV campaign in the winter 1999-2000 in 8 counties of Sicily. General practitioners (GPs) provided the vaccination and, 72 h later, recorded local and systemic side effects by a telephonic interview with the waccinees. GPs recorded also the requests of medical treatments. RESULTS: A total of 16,601 subjects (57.1%) were vaccinated with IV alone and 12,485 (42.9%) with the association IV+PV. Adverse effects were reported by 14.7 per cent of vaccinees. Out of 4,289 subjects with side effects, 305 (7.1%) looked for a medical examination. The factors associated with a significantly increased risk for medical examination after vaccination were symptoms duration >72 h (OR 2.04; 95% CI 1.38-3.01; P=0.0002); local induration (OR 3.26; 95% CI 2.07-5.13; P<0.0001); general malaise (OR 2.05; 95% CI 1.34-3.13; P=0.0009); fever >/=38 degrees C (OR 3.34; 95% CI 1.90-5.86; P<0.0001); myalgia (OR 2.80; 95% CI 1.46-5.37; P=0.0018) and dyspnea (OR 37.86; 95% CI 9.65-148.60; P=0.0001). INTERPRETATION & CONCLUSION: The few requests for medical examination and the low rate of adverse effects confirmed the tolerability and safety of PV+IV; GPs consultation were related to the severity and duration of symptoms, but independent of the type of vaccine administered.

Aged↗

Factors influencing hospital infection control policies in Italian hospitals.

A study was undertaken to determine the resources available in Italian hospitals for the control of nosocomial infections and the factors favouring a successful approach. During January-May 2000 a questionnaire about infection control was sent to the hospital health director of all Italian National Health System hospitals treating acute patients and with more than 3500 admissions in 1999. An active programme was defined as a hospital infection control committee (HICC) meeting at least four times in 1999, the presence of a doctor with infection control responsibilities, a nurse employed in infection control and at least one surveillance activity and one infection control guideline issued or updated in the past two years. There was a response rate of 87.5% (463/529). Almost fifteen percent (69/463) of hospitals had an active programme for Infection Control and 76.2% (353/463) had a HICC. Seventy-one percent (330/463) of the hospitals had a hospital infection control physician and 53% (250/463) had infection control nurses. Fifty-two percent (242/463) reported at least one surveillance activity and 70.8% (328/463) had issued or updated at least one guidance document in the last two years. The presence of regional policies [odds ratio (OR) 8.7], operative groups (OR 4.2), at least one full-time nurse (OR 4.6) and a hospital annual plan which specified infection control (OR 2.1) were statistically associated with an active programme in the multivariate analysis.

Cross Infection↗

Cytogenetic biomonitoring of workers from laboratories of clinical analyses occupationally exposed to chemicals.

A cytogenetic monitoring study was carried out on a group of workers in clinical analysis laboratories to investigate the risk of occupational exposure to chronic low levels of chemicals.Thirty-four clinical laboratories have been involved in the study. In these laboratories, toxicants and analytical procedures utilized have been characterized. The individual occupational exposure of workers was assessed by use of a questionnaire concerning the chemical substances utilized. About 300 different chemicals have been identified. Cytogenetic analyses (chromosomal aberration and micronucleus tests) were carried out on a strictly selected group of 50 workers enrolled from these laboratories and compared to 53 controls (healthy blood donors) matched for gender and age. The exposed group shows a significantly higher frequency of genetic damage than the control group. Both chromatid and chromosome aberration frequencies in workers appear significantly higher than in controls. Similarly, comparison between micronucleated cells rates of exposed and unexposed groups show significantly higher frequencies of binucleated cells with micronucleus (BNMN) and of total micronuclei (MN tot) in workers than in controls.

Adult↗

Quantitative analysis of hepatitis B virus DNA by real-lime amplification.

Diagnostic assays allowing the quantification of hepatitis B virus (HBV) DNA over a wide range of concentrations are important for monitoring patients during antiviral therapy. The aim of this study was to develop a new real-time method for HBV DNA quantification. Primers and probe were selected in a highly conserved region of the HBV S gene, and a plasmid containing the pre-S/S region was used as a standard. Linear quantification of the standard was obtained between 10 and 10(9) copies/reaction, with high correlation between ayw and adw genomes (P<0.001). HBV DNA was detected in serial dilutions of a high-titer serum sample with linear results until 2.4 x 10(3) copies/ml. One hundred eight serum samples positive for hepatitis B surface antigen were tested in both the real-time assay and the Digene Hybrid Capture assay (Digene, USA). HBV DNA could be detected by both assays in 70 samples, with significant correlation of results (P<0.001). Results for 38 samples were below the sensitivity limit of the Digene assay, but they could be quantified by the real time polymerase chain reaction assay. These results show that real-time polymerase chain reaction allows sensitive, rapid and linear quantification of HBV DNA in serum.

Base Sequence↗

Prevalence and genomic variability of transfusion transmitted virus in Italian cryptogenic chronic liver disease and healthy blood donors.

BACKGROUND: Infection with transfusion transmitted virus, a new member of the Parvoviridae family, has been found in patients both with chronic and fulminant post-transfusion cryptogenic hepatitis. AIM: To evaluate the prevalence and clinical impact of transfusion transmitted virus infection in Italy. PATIENTS AND METHODS: Studies were carried out on 256 patients and control subjects from three centres from Northern, Central and Southern Italy (92 nonA-nonC chronic hepatitis, 10 acute non fulminant cryptogenic hepatitis, 41 hepatitis C virus-related chronic hepatitis and 113 blood donors). Serum transfusion transmitted virus was detected by nested polymerase chain reaction using two overlapping sets of primers. RESULTS: A total of 52 of the 92 patients (54.3%) with chronic cryptogenic liver disease and 17 of the 41 hepatitis C virus chronic hepatitis patients (41.4%) were transfusion transmitted virus-DNA positive. Transfusion transmitted virus co-infection in hepatitis C virus patients was not associated with either a higher severity of liver histology or higher alanine transaminase levels or signs of cholestasis, transfusion transmitted virus was found in 48 out of 113 (42.4%) blood donors. In the majority of samples, transfusion transmitted virus DNA was detected with only one of the two sets of primers used. Genotyping and phylogenetic analysis performed on 21 randomly selected viral isolates showed the presence of both type 1 and type 2 transfusion transmitted virus and allowed identification of two isolates with high homology to genotype 6, described, so far, mostly in Japan. CONCLUSIONS: Transfusion transmitted virus type 1 and 2 infection is common among blood donors and patients with liver disease in Italy. The pathogenic potential of transfusion transmitted virus type 1 and 2 in nonA-nonC hepatitis patients is unlikely but further studies are needed to evaluate the epidemiological and clinical impact of other transfusion transmitted virus subtypes.

Adolescent↗

Hepatitis C virus (HCV) RNA determination after two weeks of induction interferon treatment is an accurate predictor of nonresponse: comparison of two treatment schedules.

The aim of this study was to analyze of HCV kinetics during interferon treatment administered daily or three times weekly. Seventy-seven naive patients were randomized to two treatment courses starting with four weeks of high-dose interferon administered daily or three times weekly. Twenty-two patients (28.6%) achieved end-of-treatment response and nine (11.7%, four of whom received daily induction) sustained response. The initial decline of viral load was sharper in patients receiving daily induction, but the rates of early RNA clearance were independent of treatment schedule, being higher in patients with genotype non-1. Detectable HCV RNA during treatment predicted nonresponse more significantly than high pretreatment viral load or genotype 1. HCV RNA at week 2 was the best predictor (100% sensitivity in patients receiving daily induction). In conclusion, daily induction increased the HCV decline slope, but not the rate of virological response. HCV RNA at week 2 reliably identified nonresponders.

Alanine Transaminase↗

Hepatocyte proliferation and risk of hepatocellular carcinoma in cirrhotic patients.

OBJECTIVES: High hepatocyte proliferation has been recently proposed as a risk factor for the development of hepatocellular carcinoma (HCC). The aim of this study was to assess whether hepatocyte proliferation is an independent risk factor for HCC when considered together with clinical and demographic characteristics. METHODS: We retrospectively evaluated 97 consecutive patients with a histological diagnosis of cirrhosis and preserved liver function, enrolled in a surveillance program for early diagnosis of HCC. Hepatocyte proliferation was evaluated by flow-cytometric analysis in liver samples collected at the time of histological diagnosis of cirrhosis. All patients were followed with abdominal US and serum alpha-fetoprotein (AFP) assays every 6 months. RESULTS: During a mean follow-up of 53 months (range, 12-120 months), 12 patients developed HCC, giving an annual incidence of 2.8%. The mean S-phase fraction was 2.5%+/-1.6 in patients who developed HCC and 0.9%+/-0.6 in those who did not (p < 0.0001). By univariate analysis, S-phase fraction 1.8% or higher and AFP higher than 20 ng/ml were the only two variables significantly correlated with the development of HCC (p < 0.0001, p < 0.0001). Multivariate analysis found that both variables were independently associated with HCC development (p < 0.003 and p < 0.005, respectively), with hazard ratios of 8.0 and 7.3 (confidence intervals, 2.1-31.2 and 1.8-29.2). Among patients with high AFP and/or high S-phase fraction, 11 (39%) developed HCC, compared with only one (1%) with a low S-phase fraction and normal AFP, corresponding to HCC yearly incidences of 9.5% and 0.3% (p < 0.00009). CONCLUSIONS: Patients with high S-phase fraction and/or above-normal serum AFP are at higher risk of developing HCC and should be offered a close surveillance program.

Adult↗

[Survey of disinfectant usage in a polyclinic in Rome: preliminary results].

The authors describe the survey that was conducted in the largest hospital in Rome. The aim was to estimate the disinfectants and chemical sterilizers employed and asses possible hazards for patients and workers arising from the use of disinfectants, together with the problem of waste disposal. The study was conducted by means of a survey form that was distributed to 39 departments/institute in the whole hospital of which 24 (61%) responded. Overall 635 charts were collected listing 886 usage procedures and 110 formulations with 40 different active ingredients. The disinfection fields of use were: skin(52.4%) environment (28.8%) and hospital equipment (20.8%) This study shows that a modern hospital should select very few disinfectants and prepare a handbook that can explain disinfectant usage procedures and concentrations. In the guidelines the problem of waste disposal and employee safety should also be considered.

Containment of Biohazards↗

[Simultaneous measurements of electrical coupling and action potential transfer in pairs of ventricular cardiomyocytes].

Spread and modulation of electrical activity in cardiac tissue requires intercellular transfer of current via gap junctions, specialised regions of densely packed ionic channels. Electrotonic interaction is determined not merely by intercellular electrical resistance (Rj) but rather by the interplay of Rj and sarcolemmal passive and active electrical properties (Zaniboni et al., Spitzer et al.). In this work we combined a well established protocol to measure Rj in cell pairs (Weingart e Maurer) with a stimulation protocol which allowed to simultaneously study parameters relative to action potential transfer during sequential stimulation. Current clamp experiments, performed on cardiomyocyte pairs held in double-patch configuration, allowed to simultaneously monitor, at a relatively high frequency (1 Hz), membrane resistance (Rm), resting potential (Vm), maximum depolarization rate (dv/dtmax) and time to peak of dv/dtmax in both cells as well as Rj. Spontaneous electrical uncoupling was observed in guinea pig cell pairs with little or no effect on action potential transfer. Pharmacological uncoupling with 40 microM beta-glycyrrhetinic acid reached, in one case, a much higher level of Rj and dramatically increased time delay for action potential appearance. When only Rj was measured over a short time interval after approximately two minutes from cell-attachments, values of Rj approximately 40 M omega in rat cell pairs (n = 20) and Rj approximately 15 M omega in guinea pig cell pairs (n = 24) were obtained. The possibility of monitoring simultaneously active and intercellular/cellular passive electrical properties makes this protocol particularly suitable to study dynamic changes in Rj during action potential transfer.

Action Potentials↗

Early physiological and cytological events induced by wounding in potato tuber.

The response of potato tuber (Solanum tuberosum L. cv. Kennebec) to mechanical wounding was investigated at different times. Changes in the levels of indole-3-acetic acid (IAA), polyunsaturated fatty acids (PUFAs) and lipid hydroperoxides (LOOHs) were monitored up to 120 min after wounding and related to the cytological events occurring up to 24 h. Twenty minutes after injury, an increase in IAA and LOOH levels and a decrease in the levels of PUFAs was observed. Wounding induced mitoses in differentiated (parenchyma) cells starting at 120 min, and promoted an increase of mitotic activity in the meristematic cells (procambium and bud dome), after 360 min. The inhibition of the increase in LOOHs and IAA by lipoxygenase (LOX) inhibitors, as well as the ability of in vitro peroxidated linoleic acid to enhance IAA production, suggest a close relationship among lipoperoxidation, IAA and mitotic activity in the response of potato tuber cells to injury, resulting in a specific growth response, i.e. bud growth and periderm formation.

Fatty Acids, Unsaturated↗

Tc-99m-leukocytes--is it an intracellular labelling?

Radiolabeled leukocytes have a potential for clinical use in detecting sites of inflammation. The increasing interest in the use of Tc-99m-labeled white blood cells (WBC) encourages exploration into the site(s) of binding of Tc-99m to the WBC components. Here we present the differential centrifugation study of the labeled leukocytes using a simple and low cost technique (SnTec). The results show most part of radioactivity bound to cytosol. We concluded that this is an intracellular labeling procedure that has the citoplasm, ribosomes unbound to membrane and soluble molecules as targets.

Binding Sites↗