bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chelation and determination of labile iron in primary hepatocytes by pyridinone fluorescent probes
Authors: Ma Yongmin , de Groot Herbert , Liu Zudong , Hider Robert C. , Petrat Frank 
Published: March 2006

A series of fluorescent iron chelators has been synthesized such that a fluorescent function is covalently linked to a 3-hydroxypyridin-4-one. In the present study, the fluorescent iron chelators were loaded into isolated rat hepatocytes. The intracellular fluorescence was not only quenched by an addition of a highly lipophilic 8-hydroxyquinoline–iron(III) complex but also was dequenched by the addition of an excess of the membrane-permeable iron chelator CP94 (1,2-diethyl-3-hydroxypyridin-4-one). The time course of uptake of iron and iron chelation in single, intact cells was recorded on-line by using digital fluorescence microscopy. Intracellular concentrations of various fluorescent iron chelators were determined by using a spectrofluorophotometer subsequent to lysis of probe-loaded cells and were found to depend on their partition coefficients; the more hydrophobic the compound, the higher the intracellular concentration. An ex situ calibration method was used to determine the chelatable iron pool of cultured rat hepatocytes. CP655 (7-diethylamino-N-[(5-hydroxy-6-methyl-4-oxo-1,4-dihydropyridin-3-yl)methyl]-N-methyl-2-oxo-2H-chromen-3-carboxamide), which is a moderately lipophilic fluorescent chelator, was found to be the most sensitive probe for monitoring chelatable iron, as determined by the intracellular fluorescence increase induced by the addition of CP94. The concentration of the intracellular chelatable iron pool in hepatocytes was determined by this probe to be 5.4±1.3 μM.
Bax translocates to mitochondria of heart cells during simulated ischaemia: involvement of AMP-activated and p38 mitogen-activated protein kinases
Authors: Capano Michela , Crompton Martin 
Published: March 2006

The cytosolic protein Bax plays a key role in apoptosis by migrating to mitochondria and releasing proapoptotic proteins from the mitochondrial intermembrane space. The present study investigates the movement of Bax in isolated rat neonatal cardiomyocytes subjected to simulated ischaemia (minus glucose, plus cyanide), using green fluorescent protein-tagged Bax as a means of imaging Bax movements. Simulated ischaemia induced Bax translocation from the cytosol to mitochondria, commencing within 20 min of simulated ischaemia and progressing for several hours. Under the same conditions, there was an increase in the active, phosphorylated forms of p38 MAPK (mitogen-activated protein kinase) and AMPK (AMP-activated protein kinase). The AMPK activators AICAR (5-aminoimidazole-4-carboxamide ribonucleoside) and metformin also stimulated Bax translocation. Inhibition of p38 MAPK with SB203580 attenuated the phosphorylation of the downstream substrates, MAPK-activated protein kinases 2 and 3, but not that of the upstream MAPK kinase 3, nor of AMPK. Under all conditions (ischaemia, AICAR and metformin), SB203580 blocked Bax translocation completely. It is concluded that Bax translocation to mitochondria is an early step in ischaemia and that it occurs in response to activation of p38 MAPK downstream of AMPK.
Bile acid profiles by capillary electrophoresis in intrahepatic cholestasis of pregnancy
Authors: Castaño Gustavo , Lucangioli Silvia , Sookoian Silvia , Mesquida Marcelo , Lemberg Abraham , Di Scala Mirta , Franchi Paula , Carducci Clyde , Tripodi Valeria 
Published: March 2006

ICP (intrahepatic cholestasis of pregnancy) is characterized by pruritus and biochemical cholestasis, including raised SBAs (serum bile acids) and, usually, elevated aminotransferases levels. However, AHP (asymptomatic hypercholanaemia of pregnancy) is defined as the presence of total SBA levels above the cut-off value (11 μM) in healthy pregnant women, thus elevation of total SBAs do not necessarily reflect an ICP condition. The aim of the present study was to describe clinical, obstetric, perinatal and biochemical findings, as well as the SBA profile, in pregnant women studied in the third trimester of pregnancy in order to define characteristic patterns of individual bile acids that enable women with ICP to be distinguished from AHP and healthy pregnancies. Free and conjugated ursodeoxycholic (UDCA), cholic (CA), lithocholic (LCA), deoxycholic (DCA) and chenodeoxycholic (CDCA) acids were evaluated by CE (capillary electrophoresis) in 41 patients (15 of them simultaneously by HPLC), in 30 healthy pregnant women and in 10 non-pregnant women. A highly significant correlation between CE and HPLC for total SBAs (r=0.990) and for individual SBAs was found. Normal pregnant women had higher total SBA levels than non-pregnant women (due to an increase in taurine-conjugated dihydroxy SBAs). Women with ICP had higher levels of total SBAs, the free/conjugated ratio, LCA, CA, CDCA and DCA than normal pregnant women. Newborns from women with ICP had lower birth weight and gestational age. Women with AHP had higher levels of conjugated dihydroxy SBAs than normocholanaemic patients, without any evidence of a clinical difference. In conclusion, the present study has shown a clear difference in SBA profiles between ICP and normal pregnancies (including AHP), involving a shift towards a characteristic hydrophobic composition in women with ICP.
Determinants of short-term variation in arterial flow-mediated dilatation in healthy young men
Authors: Järvisalo Mikko J. , Jartti Laura , Marniemi Jukka , Rönnemaa Tapani , Viikari Jorma S. A. , Lehtimäki Terho , Raitakari Olli T. 
Published: March 2006

Brachial artery FMD (flow-mediated dilatation) is widely used as a marker of systemic arterial endothelial function. FMD, however, shows considerable 25% day-to-day variation that hinders its clinical use. The reasons for this variability are poorly characterized. Therefore the present study was designed to clarify factors responsible for the hourly variation in endothelial function, including consuming a low-fat meal and circadian rhythms in endogenous hormonal levels. Brachial artery FMD, along with serum glucose, triacylglycerols (triglycerides) and levels of several hormones were measured six times per day on two separate days 1 week apart. On one day, the subjects (healthy males: n=12, mean age, 24 years) ate a light breakfast and a standardized lunch (23.5% fat, 48.7% carbohydrate and 27.8% protein). On the other day, they had a similar breakfast after which they fasted. Postprandial FMD values (both after breakfast and after lunch) were similar to baseline FMD. FMD showed a 28% hourly variation and 27% weekly variation. Variation in plasma levels of insulin (P=0.02) associated negatively and DHPG (3,4-dihydroxyphenylglycol) (P=0.001), a marker of sympathetic nervous activation, associated positively with variation in FMD. The effects of DHPG and insulin on FMD were independent of changes in baseline brachial artery diameter, although DHPG was also inversely associated with baseline diameter. Eating a regular low-fat meal does not have any measurable effects on brachial artery endothelial function. These data suggest that strict requirements for fasting conditions may be unnecessary when measuring peripheral endothelial function using the ultrasound technique. Circadian variation in serum insulin and sympathetic tone are physiological determinants of endothelial function.
Abnormal rhythmic oscillations of atrial natriuretic peptide and brain natriuretic peptide in chronic renal failure
Authors: Pedersen Erling B. , Bacevicius Egidijus , Bech Jesper N. , Solling Karsten , Pedersen Henrik B. 
Published: March 2006

Secretion of ANP (atrial natriuretic peptide) and BNP (brain natriuretic peptide) is pulsatile in healthy humans. However, the patterns of secretion of ANP and BNP have not been studied in chronic renal failure. The aim of the present study was to test the hypotheses that ANP and BNP are secreted in pulses in dialysis patients, and that pulsatile secretion is regulated by prostaglandins. Blood samples were drawn every 2 min through an intravenously inserted plastic needle over a period of 1–2 h in 13 dialysis patients and 13 healthy control subjects (Study 1), and in 15 healthy control subjects, who participated in a randomized placebo-controlled cross-over study after treatment with indomethacin and placebo (Study 2). Plasma concentrations of ANP and BNP were determined by RIAs, and the results were analysed for pulsatile behaviour by Fourier transformation. The results from Study 1 showed that the secretion of ANP and BNP was pulsatile in nine patients with chronic renal failure. The maximum amplitude was significantly higher in chronic renal failure compared with control subjects for both ANP and BNP (ANP, 4.3 compared with 0.7 pmol/l; BNP, 2.0 compared with 0.3 pmol/l; values are medians) and correlated positively with the mean plasma level of ANP (ρ=0.900, P=0.001; n=9) and BNP (ρ=0.983, P=0.000; n=9). The frequency was the same for patients and controls. The results from Study 2 demonstrated pulsatile secretion in all subjects, but both the amplitude and frequency were unaffected by indomethacin. The maximum amplitude correlated positively with the mean plasma level of ANP and BNP during both placebo and indomethacin treatment. It can be concluded that the secretion of ANP and BNP is pulsatile with abnormally high amplitude in chronic renal failure, that prostaglandins apparently are not involved in the secretion of these peptides in healthy subjects and that the high secretion rate in chronic renal failure results in higher ANP and BNP in plasma.
Assessment of the Compliance of Nigerian Dentists With Infection Control: A Preliminary Study
Authors: Sofola Oyinkansola Olulola , Savage Kofo Olaide 
Published: March 2006

AbstractObjective:To assess the compliance of a group of Nigerian dentists with standard infection control practices.Method:A confidential self-administered questionnaire survey was conducted among dentists engaged in active clinical practices in public hospitals in Lagos, Nigeria (n = 185).Results:One hundred forty-six questionnaires were returned (response rate, 78.9%). Most (70.6%) of the dentists always wore gloves when treating patients, whereas 29.4% sometimes did. Regarding facemasks, 45.9% always wore them, 52.7% sometimes wore them, and 1.4% never wore them. Protective eye wear was always worn by 4.8% of the dentists, sometimes worn by 52.7%, and never worn by 42.5%. Approximately half (50.7%) of the respondents had received hepatitis B vaccination. Sterilization was performed using a combination of methods, including auto-claving (84.1%), boiling (19.3%), dry heat (17.5%), and chemicals (29.7%). Nonavailability of materials was the major reason for noncompliance with infection control practices.Conclusions:Nigerian dentists need continuous education regarding infection control. Also, Nigerian hospitals urgently need adequate funding for up-to-date and functional equipment and materials.
Activity of Three Disinfectants and Acidified Nitrite AgainstClostridium difficileSpores
Authors: Wullt Marlene , Odenholt Inga , Walder Mats 
Published: March 2006

AbstractObjective:To identify environmentally safe, rapidly acting agents for killing spores ofClostridium difficilein the hospital environment.Design:Three classic disinfectants (2% glutaraldehyde, 1.6% peracetyl ions, and 70% isopropanol) and acidified nitrite were compared for activity againstC. difficilespores. Four strains ofC. difficilebelonging to different serogroups were tested using a dilution–neutralization method according to preliminary European Standard prEN 14347. For peracetyl ions and acidified nitrite, the subjective cleaning effect and the sporicidal activity was also tested in the presence of organic load.Results:Peracetyl ions were highly sporicidal and yielded a minimum 4 log10reduction of germinating spores already at short exposure times, independent of organic load conditions. Isopropanol 70% showed low or no inactivation at all exposure times, whereas glutaraldehyde and acidified nitrite each resulted in an increasing inactivation factor (IF) over time, from an IF greater than 1.4 at 5 minutes of exposure time to greater than 4.1 at 30 minutes. Soiling conditions did not influence the effect of acidified nitrite. There was no difference in the IF among the 4 strains tested for any of the investigated agents. Acidified nitrite demonstrated a good subjective cleaning effect and peracetyl ions demonstrated a satisfactory effect.Conclusions:Cidal activity was shown againstC. difficilespores by glutaraldehyde, peracetyl ions, and acidified nitrite. As acidified nitrite and peracetyl ions are considered to be environmentally safe chemicals, these agents seem well suited for the disinfection ofC. difficilespores in the hospital environment.
Theoretical Risk for Occupational Blood-Borne Infections in Forensic Pathologists
Authors: Nolte Kurt B. , Yoon Steven S. 
Published: March 2006

AbstractUsing a cumulative probability analysis and published data, we calculated the theoretical career risk of occupational HIV (2.4%) and HCV (39%; possible range, 13% to 94%) infections for forensic pathologists. Serologic studies of these physicians are needed to clarify occupational exposure and infection risks. Autopsy personnel should wear cut-resistant undergloves to decrease percutaneous injuries.
Ten-Year Persistence of Antibody to Hepatitis B Surface Antigen in Healthcare Workers Vaccinated Against Hepatitis B Virus, and Response to Booster Vaccination
Authors: Durlach Ricardo , Laugas Stella , Freuler Cristina B. , Rodríguez Viviana E. , Costa Marta 
Published: March 2006

AbstractThis study estimated the number of HCWs with protective antibody levels 5 and 10 years after HBV vaccination. Kaplan-Meier probabilities of protective levels were 0.95 at 60 days after vaccination, 0.87 at 5 years, and 0.79 at 10 years. Those without protective levels displayed good response 7 and 30 days after a booster
Elevated Preoperative Fasting Serum Glucose Levels Increase the Risk of Postoperative Mediastinitis in Patients Undergoing Open Heart Surgery
Authors: Wilson Stephen J. , Sexton Daniel J. 
Published: March 2006

AbstractWe conducted a case-control study to investigate the relationship between preoperative fasting serum glucose and postoperative mediastinitis in patients undergoing open heart surgery. Multivariate analysis revealed that a glucose level of 126 mg/dL or greater was associated with a significantly increased risk of mediastinitis (OR, 5.25;P= .002).
Meningitis Due to Enterobacter aerogenes Subsequent to Resection of Acoustic Neuroma and Percutaneous Endoscopic Gastrostomy Tube Placement: A Rare Nosocomial Event
Authors: Poetker David M. , Edmiston Charles E. , Smith Michelle M. , Meyer Glenn A. , Wackym Phillip A. 
Published: March 2006

AbstractWe present a case of meningitis after percutaneous endoscopic gastrostomy (PEG) tube placement subsequent to acoustic neuroma resection and cranioplasty. Four days following PEG tube placement the patient developed Enterobacter aerogenes meningitis, requiring explantation of infected cranioplasty material. His condition subsequently improved. Etiology and future intervention strategies are discussed (Infect Control Hosp Epidemiol 2003;24:780-782).
Relative Versus Absolute Noncontagiousness of Respiratory Tuberculosis on Treatment
Authors: Long Richard , Bochar Karen , Chomyc Sylvia , Talbot James , Barrie James , Kunimoto Dennis , Tilley Peter 
Published: March 2006

AbstractObjective:To assess the validity of current estimates of the noncontagiousness of sputum smear-positive respiratory tuberculosis (TB) on treatment.Design:A descriptive analysis of the mycobacteriologic response to treatment.Setting:A TB inpatient unit of a Canadian hospital.Patients:Thirty-two HIV-seronegative patients with moderate to advanced sputum smear-positive respiratory TB were treated with uninterrupted, directly observed, weight-adjusted isoniazid, rifampin, and pyrazinamide. Each patient's initial isolate was drug susceptible and each patient's sputum mycobacteriology was systematically followed until 3 consecutive sputum smears were negative on 3 separate days.Results:The time to smear conversion varied remarkably (range, 8 to 115 days; average, 46 days) and was influenced by sputum sampling frequency. Only 3 patients (9.4%) had smear conversions by 14 days and only 8 (25%) had smear conversions by 21 days, the average time it took for drug susceptibility test results to become available. During the first 21 days of treatment, the semiquantitative sputum smear score decreased rapidly and the time to detection of positive cultures doubled. Within the time to smear conversion, virtually all smear-positive specimens (98%) were culture positive and only 34% of the patients had culture conversions (ie, 3 consecutive negative cultures).Conclusion:Current estimates of the noncontagiousness of sputum smear-positive respiratory TB on treatment (for 14 days, for 21 days, or until smear conversion) are estimates of relative noncontagiousness. They do not signal absolute noncontagiousness (culture conversion). Semiquantitative smear and time-to-detection data suggest that respiratory isolation beyond 21 days of optimal treatment should be selective.
Outcomes of Nosocomial Bloodstream Infections in Adult Neutropenic Patients: A Prospective Cohort and Matched Case-Control Study
Authors: Wisplinghoff Hilmar , Cornely Oliver A. , Moser Susanne , Bethe Ullrich , Stützer Hartmut , Salzberger Bernd , Fätkenheuer Gerd , Seifert Harald 
Published: March 2006

AbstractObjective:To examine the clinical and epidemiologic features, excess length of stay, extra costs, and mortality attributable to bloodstream infection (BSI) in neutropenic patients with hematologic malignancies.Design:Prospective cohort and matched case-control study.Patients:All adult neutropenic patients with hematologic malignancies admitted to Cologne University Hospital between May 1, 1997, and April 30, 1998, were prospectively observed. Case-patients were defined as patients with nosocomial BSI; control-patients were selected among patients without BSI.Results:During the study period, the BSI rate in neutropenic patients was 14.3 per 100 neutropenic episodes. Eighty-four case-patients were included. Matching was successful for 96% of the cohort; 81 matched pairs were studied. The mean total length of stay was significantly longer for patients with BSI than for control-patients (37 vs 29 days;P= .002). Extra costs attributable to the infection averaged $3,200 (U.S.) per patient. The crude mortality rates of case-patients and control-patients were 16% and 4%, respectively (P= .013), with an attributable mortality of 12% (odds ratio, 11). Eighty-seven percent of patients met the criteria for sepsis according to the American College of Chest Physicians/Society of Critical Care Medicine. Severe sepsis or septic shock occurred in 13% of patients and was correlated with mortality (55% vs 10% in patients without severe sepsis or septic shock;P=.01).Conclusions:Nosocomial BSI in neutropenic patients is significantly associated with an excess length of hospital stay, extra costs, and excess mortality. Severe sepsis and septic shock are closely correlated with an adverse outcome.
Preventing Central Venous Catheter-Associated Primary Bloodstream Infections: Characteristics of Practices Among Hospitals Participating in the Evaluation of Processes and Indicators in Infection Control (EPIC) Study
Authors: Braun Barbara I. , Kritchevsky Stephen B. , Wong Edward S. , Solomon Steve L. , Steele Lynn , Richards Cheryl L. , Simmons Bryan P. ,   Evaluation of Processes and Indicators in Infection Control (EPIC) Study Group
Published: March 2006

AbstractObjectives:To describe the conceptual framework and methodology of the Evaluation of Processes and Indicators in Infection Control (EPIC) study and present results of CVC insertion characteristics and organizational practices for preventing BSIs. The goal of the EPIC study was to evaluate relationships among processes of care, organizational characteristics, and the outcome of BSI.Design:This was a multicenter prospective observational study of variation in hospital practices related to preventing CVC-associated BSIs. Process of care information (eg, barrier use during insertions and experience of the inserting practitioner) was collected for a random sample of approximately 5 CVC insertions per month per hospital during November 1998 to December 1999. Organization demographic and practice information (eg, surveillance activities and staff and ICU nurse staffing levels) was also collected.Setting:Medical, surgical, or medical-surgical ICUs from 55 hospitals (41 U.S. and 14 international sites).Participants:Process information was obtained for 3,320 CVC insertions with an average of 58.2 (± 16.1) insertions per hospital. Fifty-four hospitals provided policy and practice information.Results:Staff spent an average of 13 hours per week in study ICU surveillance. Most patients received nontunneled, multiple lumen CVCs, of which fewer than 25% were coated with antimicrobial material. Regarding barriers, most clinicians wore masks (81.5%) and gowns (76.8%); 58.1% used large drapes. Few hospitals (18.1%) used an intravenous team to manage ICU CVCs.Conclusions:Substantial variation exists in CVC insertion practice and BSI prevention activities. Understanding which practices have the greatest impact on BSI rates can help hospitals better target improvement interventions.
Bloodstream Infections in a Community Hospital: A 25-Year Follow-Up
Authors: Scheckler William E. , Bobula James A. , Beamsley Mark B. , Hadden Scott T. 
Published: March 2006

AbstractObjective:To examine the current status of bloodstream infections (BSIs) in a community hospital as part of a 25-year longitudinal study.Design:Retrospective descriptive epidemiologic study.Setting:Community teaching hospital.Patients:All inpatients in 1998 with a positive blood culture who met the CDC NNIS System case definition of BSI.Methods:Cases were stratified by underlying illness category using case mix adjustment categories (after McCabe) and reviewed for associations among mortality, underlying illness severity, and multiple clinical and laboratory parameters.Results:Of 19,289 patients discharged in 1998,185 had an episode of infection documented by blood culture (96 cases per 10,000 inpatients). BSI was twice as frequent in patients 65 years and older compared with younger patients. BSIs caused or contributed to the deaths of 22 patients for an overall case-fatality rate of 11.9% compared with 20.7% in 1982 (P = .02). Striking decreases were noted for in-hospital patient mortality in 1998 for BSIs with ultimately and rapidly fatal underlying illnesses (P = .02 and P < .10, respectively). Primary bacteremia decreased compared with 1982. Antibiotic use was vigorous, but resistance was modest in both nosocomial and community-acquired organisms and had changed little from 1982 and 1987.Conclusions:Compared with previous studies, case-fatality rates in patients with BSI were substantially lower in rapidly fatal and ultimately fatal underlying illness categories. Antibiotic use was extensive but prompt and appropriate. Microorganism resistance to antibiotics changed little from the 1980s.