Biomedical subjects

S Costa

Publications and source records attributed to S Costa.

At least 73 records · Page 4Linked to original sources

PubMed2000

New classification of haemodynamics of vasovagal syncope: beyond the VASIS classification. Analysis of the pre-syncopal phase of the tilt test without and with nitroglycerin challenge. Vasovagal Syncope International Study.

We believe that the pattern of blood pressure response to tilt during the time preceding the development of the vasovagal reaction may provide adjunctive diagnostic information. A group of 101 consecutive patients affected by syncope of uncertain origin underwent passive tilt testing for 45 min at 60 degrees followed, if negative, by oral (sublingual) trinitroglycerin (TNG) 0.4 microg with continuation of the test for 20 min. Three main patterns were observed: the classic (vasovagal) syncope pattern was observed in 36 patients who, during the preparatory phase, had a rapid and full compensatory reflex adaptation to upright position, resulting in stabilization of their blood pressure values until abrupt onset of the vasovagal reaction; the dysautonomic (vasovagal) syncope pattern was observed in 47 patients in whom steady-state adaptation to upright position was not possible. There was thus a progressive fall in their blood pressure until the occurrence of a typical vasovagal reaction; the orthostatic intolerance pattern was observed in 18 patients in whom there was a progressive fall in blood pressure, similar to that of the dysautonomic group, but this was not followed by a clear vasovagal reaction. Compared with the classic, the dysautonomic patients were older, had a higher prevalence of co-morbidities, a very much shorter history of syncopal episodes, and a prevalence of mixed and vasodepressor forms of the VASIS classification. The patients with orthostatic intolerance had clinical characteristics similar to the dysautonmic group but they could not be classified according to the VASIS classification. In conclusion, in patients with syncope, a variety of abnormal responses is observed during tilt testing, suggesting that different syndromes can be diagnosed by the test. A more detailed, although still arbitrary, classification may form the basis of a number of future drug and pacemaker trials, as well as help towards a greater understanding of the different mechanisms of tilt-induced syncope.

Autonomic Nervous System↗

PubMed2000

Comparison of three methods to recover vancomycin-resistant enterococci (VRE) from perianal and environmental samples collected during a hospital outbreak of VRE.

OBJECTIVE: To establish an efficient and sensitive technique for recovering vancomycin-resistant enterococci (VRE) from perianal and environmental samples collected during implementation of control measures for an outbreak of VRE. DESIGN: Perianal and environmental samples were collected in triplicate on sterile swabs. One swab was used to inoculate a selective broth medium containing 6 pg of vancomycin and 8 pg of ciprofloxacin per mL, one to inoculate Campylobacter agar containing 10 microg/mL of vancomycin, and one to inoculate Enterococcosel agar containing 8 microg/mL of vancomycin. SETTING: Samples were collected in the intensive care units of a 600-bed university hospital over a period of 2 months. SAMPLE SELECTION: Patients and their immediate environment were sampled if they resided in a ward with a patient known to be colonized or infected with VRE. RESULTS: Of the 88 perianal samples obtained from 63 patients, 37 were positive for VRE by broth culture, with 36 also recovered on both types of solid media (sensitivity, 97.3%; negative predictive value, 98.1%). Of the initial samples collected from each of the 63 patients, 20 were positive for VRE by all methods. Of the 500 environmental samples cultured, 139 were positive for VRE in broth, with only 33 recovered on Campylobacter agar (sensitivity, 23.7%; negative predictive value, 77.2%) and 22 on Enterococcosel agar (sensitivity, 15.8%; negative predictive value, 75.2%). CONCLUSIONS: Our data indicate that, when performing surveillance cultures during an outbreak of VRE, use of an enrichment broth medium is required to recover VRE contaminating environmental surfaces; however, direct inoculation to selective solid medium is adequate to recover VRE in patient perianal specimens.

Agar↗

PubMed2000

Differential gene expression in p53-mediated G(1) arrest of human fibroblasts after gamma-irradiation or N-phosphoacetyl-L-aspartate treatment.

In human fibroblasts, N:-phosphoacetyl-L-aspartate (PALA) and gamma-radiation induce reversible and irreversible p53-mediated G(1) cell cycle arrest, respectively. By coupling the premature chromosome condensation technique to fluorescence in situ hybridization, we found no evidence of DNA damage after PALA treatment. We used representational difference analysis (cDNA-RDA) to study changes in gene expression after PALA treatment and gamma-radiation in normal human fibroblasts. The mammary-derived growth inhibitor (MDGI) gene was expressed in PALA-treated cells. Ectopic MDGI expression arrested PALA-treated but not irradiated RKO cells. Expression of an antisense RNA against MDGI resulted in partial G(1) escape of PALA-treated human fibroblasts. The tumor necrosis factor stimulated gene 6, TSG-6, seems to be under the control of p53 and is only and specifically induced upon PALA treatment. In irradiated cells we have identified 'novel' genes that are differentially expressed, along with known genes not previously linked to cell cycle control. Some of these 'novel' genes correspond to clones in the expressed sequence tag (EST) database; one of them shows identity with ESTs mapping to a region on chromosome 7, where gene(s) involved in replicative senescence and frequently deleted in tumors are located. Thus, PALA treatment and gamma-irradiation elicit a pattern of differential gene expression that could contribute to a quiescence or senescence-like phenotype.

Aspartic Acid↗

PubMed2000

Decolorization and detoxification of textile dyes with a laccase from Trametes hirsuta.

Trametes hirsuta and a purified laccase from this organism were able to degrade triarylmethane, indigoid, azo, and anthraquinonic dyes. Initial decolorization velocities depended on the substituents on the phenolic rings of the dyes. Immobilization of the T. hirsuta laccase on alumina enhanced the thermal stabilities of the enzyme and its tolerance against some enzyme inhibitors, such as halides, copper chelators, and dyeing additives. The laccase lost 50% of its activity at 50 mM NaCl while the 50% inhibitory concentration (IC(50)) of the immobilized enzyme was 85 mM. Treatment of dyes with the immobilized laccase reduced their toxicities (based on the oxygen consumption rate of Pseudomonas putida) by up to 80% (anthraquinonic dyes). Textile effluents decolorized with T. hirsuta or the laccase were used for dyeing. Metabolites and/or enzyme protein strongly interacted with the dyeing process indicated by lower staining levels (K/S) values than obtained with a blank using water. However, when the effluents were decolorized with immobilized laccase, they could be used for dyeing and acceptable color differences (DeltaE*) below 1.1 were measured for most dyes.

Coloring Agents↗

PubMed2000

Clinical features of adenosine sensitive syncope and tilt induced vasovagal syncope.

AIM: To evaluate the possible relation between adenosine sensitive syncope and tilt induced vasovagal syncope. METHODS: An ATP test and a head up tilt test were performed in 175 consecutive patients with syncope of uncertain origin. The ATP test consisted of the rapid intravenous injection of 20 mg of ATP; a positive response was defined as the induction of a ventricular pause (maximum RR interval) >/= 6000 ms. The head up tilt test was performed at 60 degrees for 45 minutes; if negative, 0.4 mg oral glyceryl trinitrate spray was given and the test continued for a further 20 minutes; a positive response was defined as induction of syncope in the presence of bradycardia, hypotension, or both. RESULTS: Of the 121 patients with a positive response, 77 (64%) had a positive head up tilt alone, 18 (15%) had a positive ATP test alone, and in 26 (21%) both ATP and head up tilt were positive. Compared with the patients with isolated positive head up tilt, those with isolated positive ATP were older (mean (SD) age, 68 (10) v 45 (20) years), had a lower median number of syncopal episodes (2 v 3), a shorter median duration of syncopal episodes (4 v 36 months), a lower prevalence of situational, vasovagal, or triggering factors (11% v 64%), a lower prevalence of warning symptoms (44% v 71%), and a higher prevalence of systemic hypertension (22% v 5%) and ECG abnormalities (28% v 9%). The patients with a positive response to both tests had intermediate features. Of the 44 positive responses to the ATP test, atrioventricular block was the cause of the ventricular pause in 43; of the 29 positive cardioinhibitory responses to head up tilt, sinus arrest was present in 23 cases and atrioventricular block in six. CONCLUSIONS: ATP and head up tilt tests identify different populations of patients affected by syncope; these have different general clinical features, different histories of syncopal episodes, and different mechanism sites of action. Therefore, adenosine sensitive syncope and tilt induced vasovagal syncope are two distinct clinical entities.

Adenosine Triphosphate↗

PubMed2000

Alterations in nitric oxide/cyclic-GMP pathway in nondiabetic siblings of patients with type 2 diabetes.

In this study, we have compared resistance to insulin-mediated glucose disposal and plasma concentrations of nitric oxide (NO) and cyclic-GMP in healthy volunteers with (n = 35) or without (n = 27) at least one sibling and one parent with type 2 diabetes. The 62 volunteers were further divided into groups of those with normal glucose tolerance or impaired glucose tolerance. Insulin-mediated glucose disposal was quantified by determining the insulin sensitivity index (ISI) in response to a low-dose, constant infusion of insulin (25 mU/kg x h) and glucose (4 mg/kg x min) for 150 min. The mean (+/-SEM) ISI [(mL kg(-1) min(-1)/pmol/L) x 10(3)] was significantly greater in those without a family history (30.3 +/- 2.3) as compared with nondiabetic volunteers with a family history of type 2 diabetes, whether they had normal glucose tolerance (17.0 +/- 7.2) or impaired glucose tolerance (9.5 +/- 1.4). In addition, basal NO levels, evaluated by the measurement of its stable end products [i.e. nitrite and nitrate levels (NO2-/ NO3-)], were significantly higher, and cyclic-GMP levels, its effector messenger, were significantly lower in those with a family history, irrespective of their degree of glucose tolerance, when compared with healthy volunteers without a family history of type 2 diabetes. Furthermore, when the 62 volunteers were analyzed as one group, there was a negative correlation between ISI and NO2-/NO3- levels (r = -0.35; P < 0.005) and a positive correlation between ISI and cyclic-GMP levels (r = 0.30; P < 0.02). These results have shown that alterations of the NO/cyclic-GMP pathway seem to be an early event in nondiabetic individuals with a family history of type 2 diabetes and these changes are correlated with the degree of insulin resistance.

Blood Glucose↗

PubMed2000

In middle-aged siblings of patients with type 2 diabetes mellitus normal glucose tolerance is associated with insulin resistance and with increased insulin secretion. The SPIDER study.

OBJECTIVES: To evaluate the frequency of impaired glucose tolerance (IGT) and of Type 2 diabetes mellitus (Type 2 DM) in siblings of patients with Type 2 DM, and to assess insulin release and insulin sensitivity in siblings with normal glucose tolerance (NGT), compared with NGT spouses of probands without family history of Type 2 DM. DESIGN AND METHODS: We evaluated 87 families including 103 Type 2 DM patients (87 probands), and we carried out an oral glucose tolerance test (OGTT) in 130 siblings and in 60 spouses. Among NGT subjects, 12 siblings and 16 spouses underwent a low-dose insulin-glucose infusion test (LDIGIT) to evaluate C-peptide release and insulin sensitivity. RESULTS: After the OGTT, 24 siblings were classified as having Type 2 DM, 31 as IGT, and only 14 spouses as IGT (P=0.0012 vs siblings). NGT siblings (n=75) showed higher insulin levels at 120 min than NGT spouses (n=46) at OGTT, in spite of identical blood glucose levels; at LDIGIT, NGT siblings secreted more C-peptide and showed a lower insulin sensitivity than NGT spouses. CONCLUSIONS: These data indicate that middle-aged siblings of probands with Type 2 DM have a high frequency of IGT and Type 2 DM, and that NGT siblings have increased insulin resistance and increased insulin secretion when compared with adequate controls.

Blood Glucose↗

PubMed2000

Factors associated with cone margin involvement in CIN patients undergoing conization-equivalent electrosurgical procedure.

BACKGROUND: Most studies of cervical conization have considered the frequency of complications and the outcome of follow-up. The determinants of cone margin positivity have been inadequately described. In a series of CIN patients undergoing conization-equivalent electrosurgical procedure, we evaluated the factors associated with (i) any cone margin involvement, and (ii) endocervical margin involvement (with or without other locations) as contrasted with all other conditions. METHODS: Study population included 718 patients. Potential determinants of margin involvement were or were treated as categorical. Univariate analysis was based on the chi-square test. Multivariate associations were estimated by multiple logistic regression models. RESULTS: Cone margin involvement was observed in a total of 195 patients (27%). In univariate analysis, the frequency was positively related to histologic grade, time period, lesion size, and cone width and depth. In multivariate analysis, histology diagnosis and time period retained a strong association. The effect of lesion size was of borderline significance. The endocervical location emerged as a multivariate determinant of margin positivity. The effect of cone width and depth was not confirmed. Endocervical margin involvement was observed in 98 cases (14%). In univariate analysis, the frequency was positively associated with histologic grade, time period, and age, and inversely related to the visibility of the squamous-columnar junction. Multivariate analysis confirmed the strong effect of histology diagnosis and time period. The association with age and visibility of the squamous-columnar junction was weaker. CONCLUSIONS: Histology diagnosis and time period were the strongest determinants of cone margin involvement. Endocervical margin positivity was also related to patient age and visibility of the squamous-columnar junction. Cone width and depth had no protective effect.

Adolescent↗

PubMed2000

[Neonatal anthropometry and early differentiations in embryo-fetal growth].

It is well known that the biologic variability in fetal size increases as pregnancy advances, although the embryonal and early fetal growth patterns as well as how early and how much the genetic, hormonal and environmental variables play a role in its modulation are still debated. It is accepted that growth in the first trimester of pregnancy is relatively uniform, with a minimal biologic variability; this variability may be underestimated, because the transversal studies do not permit the identification of the growth pattern. The aim of this work is to evaluate, by means of a longitudinal study, the time of embryo-fetal growth differentiation related at neonatal anthropometric measurements. We evaluated 238 neonates (123 female; 115 male) delivered at term after low risk, uncomplicated pregnancies. The subjects were divided into three tertles (low, mid and high) according to birth weight, length and head circumference. For each tertle, distance curves, velocity curves, and rate of increase were calculated by using respectively fetal abdominal circumference (for birth weight), fetal femural length (for neonatal length) and fetal head circumference (for neonatal circumference). The distance curves showed clear differences among the tertles only in the second period of pregnancy, whereas the velocity curves showed clear differences among tertles already in the first 12 weeks. The value of growth rates were similar for all the variables during the entire time considered. This study shows that the anthropometric differences between newborn subgroups exist already at the end of the first trimester of pregnancy and, in physiological conditions, until the end of pregnancy. The anthropometric differences observed early in our study, at twelve weeks of gestational age, are still present at the end of pregnancy and let us suppose a very early expression of the genetic potential for individual growth.

Anthropometry↗

PubMed2000

[Various features of neonatal outcome in assisted fertilization pregnancies].

Assisted pregnancies have been often considered as high risk pregnancies because of several factors as increased maternal age, primary sterility, pharmacological treatments, embryos and gametes manipulation in the first weeks of life. Many studies showed high rates of perinatal morbidity (especially low birth weight and prematurity), and an increase of maternal morbidity and mortality. The present study was designed to analyse correlation between morbidity and twinning rate, and to show the distribution of birth weight in a population of neonates after assisted reproductive techniques (ART). We studied 352 newborns (168 singletons, 126 twins, 42 triplets, 16 quadruplets) from assisted pregnancies; morbidity was 7.1% in singletons, 11.9% in twins, 21.4% in triplets, raising to 56.3% in quadruplets. Our experience suggests that multiple gestations after ART seem to have an increased incidence of neonatal complications.

Humans↗

PubMed2000

[Use of recombinant human erythropoietin in newborns with very low weight: efficacy monitoring].

Chronic anemia is very frequent in very low birth weight (VLBW) infants. Lowered red cells life span, hemolysis, low production of erythropoietin, phlebotomies, excessive body growth are its most important causes. A reduction of the number of transfusions to babies with chronic anemia was obtained through r-HuEpo. A serie accounting for 89 newborns < 1500 g (18 < 1000 g) with a mean weight of 1069 g (+/- 238) in whom early treatment with r-HuEpo was performed (from 9.55 +/- 3.04 day), 300 UI three times a week s.c., is presented. Therapy with r-HuEpo was carried out for 6 weeks, or until the baby weighed 1800 g. During the treatment, each baby received iron, folic acid, multivitaminic supplements. Patients were monitored with red blood cells count, comprehensive of reticolocytes, ipochromic cells (Ipo-cells), content of hemoglobin of reticolocytes (CHr), each week. Iron, ferritine and transferrine were obtained only twice a month, as they required further blood sampling. 10.1% neonates received transfusions: the percentage of transfused VLBW infants was much higher (55.5%) before than after the introduction of r-HuEpo (p = 0.0002). 33.3% extremely low birth weight (ELBW) infants required transfusions (vs 95.5% in pre r-HuEpo period) (p < 0.0001). Our results confirm the importance of Ipo-cells and CHr to monitor early alterations of iron cellular employment.

Anemia, Neonatal↗

PubMed2000

[Early protected discharge of the mother and the neonate: case-control study].

Aim of this study is to compare traditional post-partum hospital stay to hospitalization associated with early protected discharge: a case-control study has been performed to evaluate outcome as mother's appreciation of the experience as well as breastfeeding. The study included 50 healthy-term newborns and their mothers, discharged within 24 and 48 hours of life, and 44 controls, who had traditional "rooming-in" stay, delivered at the Department of Neonatology--University of Turin. The protocol included a midwife daily home visits and a neonatologist and nurse visit within 4th to 5th day of life, to evaluate mother's and baby's health status and to perform metabolic screenings. An ambulatorial follow-up visit at 1 month of life and 2 telephone interviews, at 3rd and 6th month, were also planned. During the first week of life 45 (90%) early discharged newborns had complete nursing (breastfeeding + water or other fluids), 4 (8%) had complementary nursing (breastfeeding + formula) and 1 (2%) received formula. Among controls, 46 (92%) babies received complete nursing, 2 had complementary nursing and 2 had artificial nursing. At 6 months of life breastfeeding was complete for 2% of cases and 6% of controls; in 44% of cases and 56% of controls nursing was complementary. Readmissions to our Birth Center were 2 among early discharged newborns, 1 in the control group. About project's appreciation, 96% of early discharged and 98% of control group mothers declared their availability to repeat the experience. Caring and supporting were judged adequate in 94% of both group. By adequate supporting of mother and newborn, short and traditional hospitalization are both pleasant and don't seem to present significant differences in type and length of nursing.

Breast Feeding↗

PubMed1999

Endothelial and metabolic characteristics of patients with angina and angiographically normal coronary arteries: comparison with subjects with insulin resistance syndrome and normal controls.

OBJECTIVES: This study was performed to characterize the endothelial and metabolic alterations of patients with angina and angiographically normal coronary arteries ("cardiac" syndrome X [CSX]) compared with subjects with insulin resistance syndrome ("metabolic" syndrome X [MSX]) and normal controls. BACKGROUND: Previous studies have found high endothelin-1 levels, impaired endothelium-dependent vasodilation and insulin resistance in patients with angina pectoris and angiographically normal coronary arteries. On the other hand, subjects with insulin resistance syndrome have shown high endothelin-1 levels. METHODS: Thirty-five subjects were studied: 13 patients with angina pectoris and angiographically normal coronary arteries (CSX group); 9 subjects with insulin resistance syndrome (MSX group) and 13 normal controls. All subjects received an acute intravenous bolus of insulin (0.1 U/kg) combined with a euglycemic clamp and forearm indirect calorimetry. Endothelin-1 levels, nitrite/nitrate (NOx) levels, end products of nitric oxide metabolism, glucose infusion rates (index of insulin sensitivity) and their incremental areas (deltaAUCs [area under curves]) were measured during this period. RESULTS: Basal endothelin-1 levels were higher in CSX and MSX groups than in normal controls (8.19 +/- 0.46 and 6.97 +/- 0.88 vs. 3.67 +/- 0.99 pg/ml; p < 0.01), while basal NOx levels were significantly higher in MSX group than in CSX and normal controls (36.5 +/- 4.0 vs. 24.2 +/- 3.3 and 26.8 +/- 3.2 mol/liter, p < 0.05). After insulin administration, the deltaAUCs of NOx (p < 0.05) were lower in CSX group than in MSX and normal controls, and the deltaAUCs of endothelin-1 were lower in group CSX than in normal controls. Glucose infusion rate was significantly lower in CSX and MSx groups than in normal controls (p < 0.01), suggesting that in both CSX and MSX groups insulin resistance is present. A positive correlation was found between the deltaAUCs of nitric oxide and the AUCs of glucose infusion rate. CONCLUSIONS: Blunted nitric oxide and endothelin responsiveness to intravenously infused insulin is a typical feature of patients with angina pectoris and angiographically normal coronary arteries and may contribute to the microvascular dysfunction observed in these subjects.

Calorimetry, Indirect↗

PubMed1999

HIV testing after implementation of name-based reporting.

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AIDS Serodiagnosis↗

PubMed1999

Impact of tuberculosis on the body composition of HIV-infected men in Brazil.

OBJECTIVE: Tuberculosis (TB) is the commonest HIV-related opportunistic infection in many developing countries and is thought to be a frequent underlying cause of HIV-associated wasting. We have used reference water dilution methods to examine the body composition changes associated with TB and to assess the severity and pattern of wasting. METHODS: The study was conducted at a charitable support house for poor and homeless HIV-infected people in Rio de Janeiro, Brazil. Male patients who were HIV-positive and receiving treatment for active TB (HIVTB+) and HIV-infected controls without TB (HIVTB-) were studied. Total body water (TBW) and extracellular water (ECW) were measured by giving oral doses of deuterium oxide and sodium bromide, respectively, and determining enrichment in plasma after 4 hours. Intracellular water (ICW), body cell mass (BCM), lean body mass (LBM) and fat mass were calculated from these parameters using standard equations. RESULTS: HIVTB+ (n = 11) and HIVTB- (n = 12) groups were similar in age, height, CD4 count and HIV risk factors. HIVTB+ men had significantly lower mean ICW (13.2 versus 16.6 kg; p = .02) and BCM (18.4 versus 23.0 kg; p = .02), a relative expansion of ECW (35.0 versus 30.0 L/kg body weight; p = .04), and small and nonsignificant reductions in total body weight (58.0 versus 62.1 kg; p = .26), LBM (45.5 versus 47.7 kg; p = .33) and fat mass (12.5 versus 14.4 kg; p = .51) compared with HIVTB- controls. BCM in the HIVTB+ group was similar to reference values for severe malnutrition. The relative depletion of BCM appeared excessive in comparison with reference values for uncomplicated starvation. CONCLUSION: The nutritional status of HIVTB+ patients was significantly worse than HIVTB- patients. Body weight and LBM underestimated the nutritional deficit, and measurement of BCM is therefore necessary to appreciate the extent of malnutrition in such patients. Malnutrition in HIVTB+ patients is severe and may therefore contribute to decreased survival. Hypermetabolism appears to play a role in the wasting process in patients coinfected with HIV and TB.

AIDS-Related Opportunistic Infections↗

PubMed1999

Chronic supranigral infusion of BDNF in normal and MPTP-treated common marmosets.

BDNF or vehicle were administered by unilateral supranigral infusion in normal and chronically lesioned MPTP-treated common marmosets (Callithrix jacchus) for four weeks and locomotor activity, disability and response to apomorphine were assessed with nigral TH, GFAP and GAD immunoreactivity and striatal [3H]mazindol autoradiography. Selective contraversive orientation and ipsilateral neglect evolved in MPTP-treated marmosets receiving BDNF with no significant difference in disability or locomotor activity when compared to the vehicle-infused group. Apomorphine produced an ipsiversive rotational bias in BDNF-treated animals. In normal animals infused with BDNF contralateral neglect, ipsiversive turning, postural instability and ataxia rapidly evolved. In MPTP-treated marmosets BDNF caused increased ipsilateral striatal [3H]mazindol binding with increased somatic size and staining intensity in GAD-immunoreactive cells and a 10-20% loss of nigral TH-immunoreactive cells with increased GFAP staining. In normal common marmosets, both vehicle and BDNF infusion decreased nigral TH-immunoreactivity. Chronic supranigral infusion of BDNF alters motor behaviour and spatial attention in MPTP-treated marmosets which may reflect altered function in residual nigral dopaminergic neurons and brainstem GABAergic neurons and in normal animals produces behavioural and histological signs of nigrostriatal hypofunction.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1999

Hepatitis B and C virus markers among new entrant medical students.

AIM: To investigate the presence of hepatitis B and C virus markers in new entrant medical students at the Faculty of Medicine, University of Kelaniya. METHOD: 456 students (mean age 24 years, SD 3.5, 257 men) were investigated before they were exposed to clinical work, using a questionnaire to assess sociodemographic factors and possible risk factors for contracting hepatitis B or C. Blood samples were tested for HBs Ag and anti HBs (n = 456), and anti-HCV (n = 162 randomly selected samples) with a third generation sandwich radioimmunoassay technique. RESULTS: The students were from 20 of the 25 districts in the country, although their distribution was not inform. A past history of hepatitis or jaundice was obtained from 24 (5.3%) and 6 (1.3%) students respectively. None of them had been vaccinated against hepatitis B. At least one risk factor for hepatitis B or C was present in 32 (7%) of them. None of the samples were positive for HBsAg or anti-HCV, and only two (0.44%) were positive for anti-HBs. CONCLUSION: Our results support the view that exposure to hepatitis B and C seems to be uncommon in this country, at least up to young adulthood. As most new entrant medical students are not immune to these infections there is a strong case to vaccinate them against hepatitis B before they are exposed to clinical work.

Adult↗

PubMed1998

Bacterial lipopolysaccharide induces uncoupling protein-2 expression in hepatocytes by a tumor necrosis factor-alpha-dependent mechanism.

The liver is a target for bacterial lipopolysaccharide (LPS) and participates in the metabolic response to endotoxemia. Recently published evidence indicates that LPS increases the expression of mitochondrial uncoupling protein-2 (UCP-2) mRNAs in several tissues, including the liver. Because hepatocytes in the healthy liver do not express UCP-2, LPS was thought to induce UCP-2 in liver macrophages, which express UCP-2 constitutively. However, the present studies of cultured peritoneal macrophages indicate that LPS reduces steady state levels of UCP-2 mRNAs in these cells. In contrast, UCP-2 mRNAs are induced in hepatocytes isolated from LPS treated rats and transfection of these hepatocytes with UCP-2 promoter-reporter constructs demonstrates substantial increases in UCP-2 promoter activity. LPS induction of hepatocyte UCP-2 expression is virtually abolished by prior treatment of rats with neutralizing antibodies to tumor necrosis factor alpha (TNF). Futhermore, TNFalpha treatment induces UCP-2 mRNA accumulation in primary cultures of hepatocytes from healthy rats. Thus, hepatocytes are likely to be important contributors to endotoxin-related increases in liver UCP-2 via a mechanism that involves the LPS-inducible cytokine, TNFalpha.

Animals↗