Search PubMed⌕ Search

Biomedical subjects

A Voss

Publications and source records attributed to A Voss.

At least 73 records · Page 4Linked to original sources
PubMed2001

Association of beta2-glycoprotein I IgG and IgM antibodies with thrombosis and thrombocytopenia.

Antiphospholipid antibodies (APA) have been known for decades. Their relation to clinical manifestations, primarily thromboses and thrombocytopenia, was recognised in the 1980s. In this clinical study two cohorts of patients, a population-based (84 patients with systemic lupus erythematosus (SLE)) and a hospital-based (87 patients with SLE and 53 with other connective tissue diseases) were investigated for APA and associated clinical manifestations. Anticardiolipin antibodies (ACA) of IgG and IgM classes were found in 13 and 38% of the population-based patients and in 29 and 58% of the hospital-based patients, respectively. The corresponding figures for antibodies against beta2-glycoprotein I (anti-beta2GPI) were 15 and 10% in the population-based patients and 14 and 8% in the hospital-based cohort. Anti-beta2GPI antibodies were always found in association with the corresponding immunoglobulin class of ACA. In both cohorts anti-beta2GPI of the IgG class were associated with arterial/venous occlusion, a result concordant with other studies. A novel finding in both cohorts, however, was an association between thrombocytopenia and IgM anti-beta2GPI.

Adolescent↗
PubMed2001

Hospital sources of Aspergillus: New routes of transmission?

With the continuing increase in the number of severely immunocompromised patients, hospitals are faced with the growing problem of invasive aspergillosis and other opportunistic fungal infections. Since treatment of these infections are difficult and outcome is often fatal, preventive measures are of major importance in the control of invasive filamentous fungal infections. Until recently, inhalation of airborne conidia was believed to be the primary route of acquiring Aspergillus infection. Despite the fact, that efforts to filter the hospital air has led to a reduction of airborne conidia paralleled by a decrease in the frequency of invasive infections, the correlation between the concentration of Aspergillus conidia in hospital air and the risk of invasive infections remains unclear. Furthermore, alternative modes of transmission may exist and should be recognized and investigated. The discovery of hospital water as a potential source of Aspergillus fumigatus and other filamentous fungi may suggest a new route for the transmission of invasive filamentous fungal infections. Epidemiological studies, based on molecular characterization and comparisons of fungal isolates recovered from patients and environment, are needed to expand our understanding of these alternative routes of transmission.

Journal Article↗
PubMed2000

Evaluation of renormalised entropy for risk stratification using heart rate variability data.

Standard time and frequency parameters of heart rate variability (HRV) describe only linear and periodic behaviour, whereas more complex relationships cannot be recognised. A method that may be capable of assessing more complex properties is the non-linear measure of 'renormalised entropy.' A new concept of the method, RE(AR), has been developed, based on a non-linear renormalisation of autoregressive spectral distributions. To test the hypothesis that renormalised entropy may improve the result of high-risk stratification after myocardial infarction, it is applied to a clinical pilot study (41 subjects) and to prospective data of the St George's Hospital post-infarction database (572 patients). The study shows that the new RE(AR) method is more reproducible and more stable in time than a previously introduced method (p<0.001). Moreover, the results of the study confirm the hypothesis that on average, the survivors have negative values of RE(AR) (-0.11+/-0.18), whereas the non-survivors have positive values (0.03+/-0.22, p<0.01). Further, the study shows that the combination of an HRV triangular index and RE(AR) leads to a better prediction of sudden arrhythmic death than standard measurements of HRV. In summary, the new RE(AR) method is an independent measure in HRV analysis that may be suitable for risk stratification in patients after myocardial infarction.

Electrocardiography↗
PubMed2000

Incidence of surgical site infections in pediatric patients: a 3-month prospective study in an academic pediatric surgical unit.

During a 3-month period 259 pediatric surgical procedures in 236 patients were followed for the development of surgical site infections (SSI): 17 sites became infected, an overall infection rate of 6.6%. The incidence in our study was therefore higher than expected. As expected, the infection rate increased according to wound contamination: dirty sites had a SSI rate of 30%. Emergency procedures, operation duration over 1 h, and inpatients showed a statistically significant higher risk of developing SSI. Although there were differences between males and females, individual surgeons, and the use of antibiotic prophylaxis, these differences were not statistically significant.

Ambulatory Surgical Procedures↗
PubMed2000

Prevalence of vancomycin-resistant enterococci in Europe.

The aim of the present study was to determine the prevalence of vancomycin-resistant enterococci (VRE) in Europe. Overall, 49 laboratories in 27 countries collected 4,208 clinical isolates of enterococci. Species identification, susceptibility testing, and van gene determination by polymerase chain reaction were performed in a central laboratory. Overall, 18 vanA and 5 vanB isolates of VRE were found. The prevalence of vanA VRE was highest in the UK (2.7%), while the prevalence of vanB VRE was highest in Slovenia (2%). Most vanA and vanB VRE were identified as Enterococcus faecium. Most VRE isolates originated from the patient's urogenital tract, skin, or digestive tract. VRE were equally distributed among clinical departments, with no clear preponderance in any single patient group. A total of 71 isolates containing the vanC gene were identified. The prevalence of vanC VRE was highest in Latvia and Turkey, where rates were 14.3 and 11.7%, respectively. Two-thirds of these isolates were identified as Enterococcus gallinarum and one-third as Enterococcus casseliflavus; the majority of these isolates were cultured from feces. Almost all isolates were obtained from hospitalized patients, mostly children. The highest prevalence of high-level gentamicin-resistant enterococci was seen in Turkey and Greece. In general, the distribution of this resistance type seemed unrelated to the occurrence of VRE. The prevalence of vanA/ vanB VRE in Europe is still low; the majority of the VRE isolates exhibit the vanC genotype and colonize the gastrointestinal tract of hospitalized children.

Adolescent↗
PubMed2000

Baroreflex sensitivity, heart rate, and blood pressure variability in normal pregnancy.

Heart rate variability is a relevant predictor of cardiovascular risk in humans. However, to use heart and blood pressure (BP) variability or baroreflex sensitivity as markers for hypertensive pregnancy disorders, it is first necessary to describe these parameters in normal pregnancy. To accommodate the complexities of autonomic cardiovascular control we added parameter domains of nonlinear dynamics to conventional linear methods of time and frequency domains. The BP of 27 women with normal pregnancy and 14 nonpregnant women were monitored at a high resolution (200 Hz sampling frequency) using a Portapres for 30 min. The pregnant women were divided into groups of 32 or less or greater than 32 weeks of gestation. Pregnant and nonpregnant women were classified into subclasses of maternal age of less than 28 or 28 or more years. Except for two single parameter domains, we found no significant differences in heart rate and BP variability for pregnant women with different gestational age or different maternal age. Moreover, no significant differences in spontaneous baroreflex sensitivity could be found between pregnant women regardless of either their age or gestational age. In contrast, all measures of nonlinear dynamics of heart rate variability as well as all parameter domains of spontaneous baroreflex sensitivity showed significant changes between pregnant and nonpregnant women, whereas BP variability did not differ between those groups. This complex assessment of autonomic cardiovascular regulation has shown that the parameters tested are stable in the second half of normal pregnancy, and might have the potential to be excellent indicators of pathophysiologic conditions.

Adult↗
PubMed2000

Expression of PTTG and prc1 genes during telencephalic neurogenesis.

We present the first time/space analysis using in situ hybridization for PTTG and prc1 genes during development of the mouse telencephalon. During the stages E11.5-E13.5 PTTG and prc1 are expressed in most tissues of the embryo. Within the telencephalon, PTTG and prc1 are found exclusively inside of the ventricular zone (VZ). The intensity of the expression of both genes in the ventricular zone reaches its peak by E15.5. Expression starts to decrease by E18.5, it is still visible at least up to P2 and not detectable in the adult brains. Expression of the prc1 gene, but not that of the PTTG, is also found in the mitoticaly active cells outside of the VZ within the telencephalon. Most of the cells expressing the PTTG gene were found in the lower part of the ventricular zone suggesting that the level of PTTG mRNA is regulated during different phases of the mitotic cycle.

Animals↗
PubMed2000

Complexes of serum amyloid P component and DNA in serum from healthy individuals and systemic lupus erythematosus patients.

Serum amyloid P component (SAP) binds in vitro to DNA; based on findings in SAP-deficient mice it was proposed that SAP's role is to handle chromatin and DNA, thereby preventing formation of anti-DNA antibodies. For the first time we have shown the presence of Ca2+-dependent SAP-DNA complexes, measured by ELISA, in sera from both healthy volunteers and systemic lupus erythematosus patients (SLE). The concentration of SAP-DNA complexes in SLE sera was significantly lower than in normal sera and particularly low in sera from patients with anti-DNA titers exceeding 50. The complexes were dissociated by the SAP ligand heparin and were not demonstrable in EDTA plasma. Normal sera showed similar capacity to form SAP-DNA complexes with both thymus and Escherichia coli DNA, whereas significantly lower amounts of complexes, in particular with E. coli DNA, were formed in SLE sera. SLE patients with moderate to high anti-DNA titers showed a significant negative correlation between serum SAP's binding of E. coli DNA and the anti-DNA titer.

Antibodies, Antinuclear↗
PubMed2000

Enterobacter cloacae outbreak in the NICU related to disinfected thermometers.

In the first week ot December 1997, an increasing incidence of neonates colonized with multi-drug resistant Enterobacter cloacae (MR-E. cloacae) was observed in the neonatal Intensive care unit of our 950-bed university hospital. Initially, re-enforcement of infection control practices including hand disinfection and cohort isolation seemed to be sufficient to control the outbreak. Nevertheless, an increasing number of newly admitted patients was paralleled by another rise in the incidence of colonized neonates. Since E. cloacae was initially found in urine specimens of the patients, surveillance and environmental cultures were aimed at procedures and instruments that might colonize the gastro-intestinal and/or urinary tract. E, cloacae was isolated from a single cap of an electronic digital thermometer. Despite banning of this possible source, newly admitted neonates still became colonized. The unit was closed for further admissions and a second round of extensive screening was started; this time including all available thermometers and continuous rectal temperature probes. Ready-to-use 'disinfected thermometers and probes were found to be colonized with MR-E. cloacae. Observation of disinfection procedures and a laboratory investigation revealed that 'rushed disinfection with alcohol 80% led to a 1 in 10 chance of thermometers still being contaminated. Furthermore, alcoholic hand rub used for convenience disinfection failed to disinfect thermometers in 40% and 20% of the cases when done in a 'rushed' or 'careful' fashion, respectively. Adequate disinfection of the thermometers led to the control of the outbreak, with no new occurrence of MR-E. cloacae in the following months.

Cross Infection↗
PubMed2000

Short-course of oral miltefosine for treatment of visceral leishmaniasis.

A total of 54 Indian patients with visceral leishmaniasis were treated with oral miltefosine, 50 mg given twice daily, for 14 days (18 patients; group A), 21 days (18; group B), or 28 days (18; group C). Cure was achieved in 89% of group A, 100% of group B, and 100% of group C. Adverse reactions were self-limited and primarily mild. The 21-day miltefosine regimen combines high-level efficacy, convenient dosing, and a relatively short duration.

Administration, Oral↗
PubMed2000

Prevalence and determinants of fecal colonization with vancomycin-resistant Enterococcus in hospitalized patients in The Netherlands.

OBJECTIVE: To determine the prevalence and determinants of fecal carriage of vancomycin-resistant enterococci (VRE) in intensive care unit (ICU), hematology-oncology, and hemodialysis patients in The Netherlands. DESIGN: Descriptive, multicenter study, with yearly 1-week point-prevalence assessments between 1995 and 1998. POPULATION: All patients hospitalized on the testing days in ICUs and hematology-oncology wards in nine hospitals in The Netherlands were included. METHODS: Rectal swabs obtained from 1,112 patients were screened for enterococci in a selective broth and subcultured on selective media with and without 6 mg/L vancomycin. Resistance genotypes were determined by polymerase chain reaction. Further characterization of VRE strains was done by pulsed-field gel electrophoresis (PFGE). We studied possible determinants of VRE colonization with a logistic regression analysis model. Determinants analyzed included gender, age, and log-transformed length of prior hospital stay. RESULTS: The results showed that 614 (55%) of 1,112 patients were colonized with vancomycin-sensitive enterococci, and 15 (1.4%) of 1,112 carried VRE. No increase in VRE colonization was observed from 1995 to 1998. Eleven strains were identified as Enterococcus faecium and four as Enterococcus faecalis. All E faecium and one E faecalis carried the vanA gene; the other E faecalis strains harbored the vanB gene. PFGE revealed that three vanB VRE isolated from patients hospitalized in one single ICU were related, suggesting nosocomial transmission. Though higher age seemed associated with VRE colonization, exclusion of patients with the nosocomial strain from the regression analysis decreased this relation to nonsignificant. Duration of hospital stay was not associated with VRE colonization. CONCLUSION: VRE colonization in Dutch hospitals is an infrequent phenomenon. Although nosocomial spread occurs, most observed cases were unrelated, which suggests the possibility of VRE acquisition from outside the hospital. Prolonged hospital stay, age, and gender proved unrelated to VRE colonization.

Adolescent↗
PubMed2000

Short-term forecasting of life-threatening cardiac arrhythmias based on symbolic dynamics and finite-time growth rates.

Ventricular tachycardia or fibrillation (VT-VF) as fatal cardiac arrhythmias are the main factors triggering sudden cardiac death. The objective of this study is to find early signs of sustained VT-VF in patients with an implanted cardioverter-defibrillator (ICD). These devices are able to safeguard patients by returning their hearts to a normal rhythm via strong defibrillatory shocks; additionally, they store the 1000 beat-to-beat intervals immediately before the onset of a life-threatening arrhythmia. We study these 1000 beat-to-beat intervals of 17 chronic heart failure ICD patients before the onset of a life-threatening arrhythmia and at a control time, i.e., without a VT-VF event. To characterize these rather short data sets, we calculate heart rate variability parameters from the time and frequency domain, from symbolic dynamics as well as the finite-time growth rates. We find that neither the time nor the frequency domain parameters show significant differences between the VT-VF and the control time series. However, two parameters from symbolic dynamics as well as the finite-time growth rates discriminate significantly both groups. These findings could be of importance in algorithms for next generation ICD's to improve the diagnostics and therapy of VT-VF.

Algorithms↗
PubMed2000

Altered heart rate and blood pressure variability in mice lacking the Mas protooncogene.

Heart rate variability is a relevant predictor of cardiovascular risk in humans. A significant genetic influence on heart rate variability is suggested, although the genes involved are ill-defined. The Mas-protooncogene encodes a G-protein-coupled receptor with seven transmembrane domains highly expressed in testis and brain. Since this receptor is supposed to interact with the signaling of angiotensin II, which is an important regulator of cardiovascular homeostasis, heart rate and blood pressure were analyzed in Mas-deficient mice. Using a femoral catheter the blood pressure of mice was measured for a period of 30 min and 250 data values per second were recorded. The mean values and range of heart rate and blood pressure were then calculated. Neither heart rate nor blood pressure were significantly different between knockout mice and controls. However, high resolution recording of these parameters and analysis of the data by non-linear dynamics revealed significant alterations in cardiovascular variability in Mas-deficient animals. In particular, females showed a strong reduction of heart rate variability. Furthermore, the data showed an increased sympathetic tone in knockout animals of both genders. The marked alterations detected in Mas-deficient mice of both genders suggest that the Mas-protooncogene is an important determinant of heart rate and blood pressure variability.

Angiotensin II↗
PubMed2000

[Role of chemokines in human skin wound healing].

The healing process of skin wounds is regulated by growth factors which stimulate proliferation of resident cells and their synthesis of extra cellular matrixcomponents. Different leukocyte subtypes (neutrophils, macrophages, lymphocytes and mast cells) participate in wound healing not only as immunological effector cells but also as an important source of inflammatory and growth promoting cytokines. Rapid recruitment of leukocytes and their positioning is tightly regulated by a temporally and spatially changing set of chemokines. Whereas expression of IL-8 and GRO (growth related oncogene) direct early neutrophil recruitment, migration of macrophages is stimulated by MCP-1 (monocyte chemoattractant protein-1) and later, lymphocytes are attracted by IP-10 (gamma-interferon inducible protein-10) and Mig (monokine induced by interferon-gamma). Since chemokines as IL-8 and GRO also stimulate angiogenesis and keratinocyte proliferation, they integrate the inflammatory events with the reparative processes and are potential candidates in the search of wound healing agents.

B-Lymphocytes↗