PubMed Health⌕ Search

Biomedical subjects

R Bruns

Publications and source records attributed to R Bruns.

At least 19 recordsLinked to original sources
PubMed2005

Molecular and clinical characteristics of respiratory syncytial virus infections in hospitalized children.

The objective of this study was to determine the importance of respiratory syncytial virus (RSV) for hospitalization in the north east of Germany and to obtain molecular epidemiological data of the circulating strains. Using a rapid and sensitive reverse transcriptase-PCR, it was found that a quarter of pediatric respiratory disease admissions were due to RSV. Infections caused by RSV in hospitalized patients were determined over the whole year. Both RSV groups A and B were identified with a predominance of RSV A (86%) over the entire period. The analysis of the deduced amino acid sequences by direct sequencing showed that very similar RSV strains are circulating in the community.

Child↗
PubMed2004

Comparison of human herpesvirus 8 and Epstein-Barr virus seropositivity among children in areas endemic and non-endemic for Kaposi's sarcoma.

Human herpesvirus 8 (HHV-8) is the etiologic agent of Kaposi's sarcoma (KS). Several studies indicate horizontal HHV-8 transmission among children in areas where KS is endemic, but few studies have assessed acquisition of HHV-8 by children in low seroprevalence areas. Antibody screening was carried out for HHV-8 and Epstein-Barr virus (EBV) on 787 serum specimens from children living in two areas where HHV-8 is not endemic, the United States (US) and Germany, and on 184 specimens from children living in a KS-endemic area (Nigeria). For children in the US and Germany, the results showed low HHV-8 seroprevalence rates (3-4%). However, US children aged 6 months to 5 years had higher HHV-8 antibody titers than did 6-17-year-old children (P < 0.01), a finding consistent with more recent infections being detected in the younger children. Compared with seroprevalence rates and antibody titers in US and German children, those in Nigerian children were significantly higher, and seroprevalence increased with age. There was no evidence of cross-reactivity between assays for HHV-8 and EBV, despite the genetic similarity of these two herpesviruses. The data indicate that HHV-8 transmission among children where HHV-8 is not endemic occurs, but is uncommon. The findings also suggest that HHV-8 antibodies, as measured by current tests, may not persist for long periods in populations at low risk for KS and that vertical transmission is rare, although longitudinal studies are necessary to address directly these issues.

Adolescent↗
PubMed2003

Real-time PCR to improve the diagnosis of respiratory syncytial virus infection.

Respiratory syncytial virus (RSV) is one of the most important virus respiratory pathogens in infants and young children. A rapid and sensitive diagnosis is essential to focus any outbreak due to this virus. A real-time RT-PCR method was designed using a primer/probe pair from the F gene. Simultaneously with nested RT-PCR and antigen ELISA, 71 consecutive specimens from hospitalized children with clinical symptoms of acute respiratory distress were evaluated to confirm the incidence of RSV infection. RSV was detected in 25 (35.2 %) specimens by real-time RT-PCR and in 19 (26.7 %) by nested RT-PCR. The assay was specific for RSV. The procedure offers a rapid and sensitive alternative to conventional RT-PCR. Closed-tube detection eliminates the risk of contamination.

Antigens, Viral↗
PubMed2001

Tuning pacemaker frequency of individual dopaminergic neurons by Kv4.3L and KChip3.1 transcription.

The activity of dopaminergic (DA) substantia nigra (SN) neurons is essential for voluntary movement control. An intrinsic pacemaker in DA SN neurons generates their tonic spontaneous activity, which triggers dopamine release. We show here, by combining multiplex and quantitative real-time single-cell RT- PCR with slice patch-clamp electrophysiology, that an A-type potassium channel mediated by Kv4.3 and KChip3 subunits has a key role in pacemaker control. The number of active A-type potassium channels is not only tightly associated with the pacemaker frequency of individual DA SN neurons, but is also highly correlated with their number of Kv4.3L (long splice variant) and KChip3.1 (long splice variant) mRNA molecules. Consequently, the variation of Kv4alpha and Kv4beta subunit transcript numbers is sufficient to explain the full spectrum of spontaneous pacemaker frequencies in identified DA SN neurons. This linear coupling between Kv4alpha as well as Kv4beta mRNA abundance, A-type channel density and pacemaker frequency suggests a surprisingly simple molecular mechanism for how DA SN neurons tune their variable firing rates by transcriptional control of ion channel genes.

Action Potentials↗
PubMed2001

Bronchial Chlamydia pneumoniae infection, markers of allergic inflammation and lung function in children.

A relationship between respiratory Chlamydia pneumoniae infection (RCPI) and bronchial asthma is under discussion. Our objective was to study the frequency of RCPI and whether it is associated with markers of asthma in children with recurrent or chronic bronchitis as well as pneumonia. One-hundred and forty-eight children who underwent bronchoscopy were enrolled; 42 children with additional respiratory infections were excluded. Therefore, 106 children were examined, regarding a RCPI, by polymerase chain reaction (PCR) of tracheobronchial aspirate, eosinophilic inflammation of respiratory mucosa (cytology, eosinophilic cationic protein [ECP]), total serum immunoglobulin E (IgE) and specific IgE for six important allergens, as well as lung function tests if possible. There was a RCPI in 55 of 106 children (51.9%); 25.4% of PCR positives (14/55) were weakly positive (double cut-off), which was more prevalent in the 2-5-year age-group and teenagers. Children with RCPI, inclusive of weak positives, showed a milder eosinophilia of nasal mucosa than children without RCPI (5.58% vs. 9.35%, p=0.039). Eosinophilia of > or =13% in nasal- and/or bronchial swab, as a marker for respiratory allergy, was less frequent in patients with RCPI too (7.3% vs. 21.6%, p=0.035). There were no differences in ECP. Total IgE was lower in PCR-positive children (101 vs. 179 IU/ml, p=0.032). Specific IgE with a radioallergosorbent test (RAST) of at least class 3 (as a marker for a relevant allergy), as well as any RAST above zero (to characterize early forms of allergy), were both less frequent in the RCPI group. In contrast, weak positives showed the highest rates of sensitization, surpassing RCPI negatives. In lung-function tests, vital capacity was lower in RCPI patients (87.5% vs. 95.3%, p=0.045); all parameters characterizing obstructive disturbance tended to be higher. Weak positives had both the greatest reduction of vital capacity (75.3%) and the most impaired obstructive parameters. All differences were accentuated in children of 11-18 years of age. Hence, our results indicate that in the children selected, a RCPI is common and not associated with allergic respiratory inflammation. Weak positives, however, differ, having the highest rate of allergic sensitization, reduction of lung volume, and obstructive disturbance. This group might be important in clinically observed asthma after pneumonia caused by C. pneumoniae. In these children, early diagnosis and treatment of a RCPI is recommended.

Adolescent↗
PubMed2000

Partially hydroxylated 2,5-disubstituted bis-tetrahydrofurans from carbohydrates

The diverse bioactivities of annonaceous acetogenins have recently attracted increasing interest. Many of these natural products contain one or more 2,5-disubstituted tetrahydrofuran rings as a core unit; these are important for the bioactivity, since it is believed that these anchor the compounds to the surface of the membrane. Therefore, the synthesis of functionalized bis-tetrahydrofurans is an important task and we have developed a synthetic pathway to all four diastereomeric, partially hydroxylated bis-tetrahydrofurans, that is, 3,6:7,10)-dianhydro-2,8,9-trideoxy-L-erythro-D-ido-undecitol (1), 3,6:7,10-dianhydro-2,8,9-trideoxy-D-threo-D-ido-undecitol (2), 3,6:7,10-dianhydro-2,8,9-trideoxy-L-threo-D-ido-undecitol (3), and 3,6:7,10-dianhydro-2,8,9-trideoxy-D-erythro-D-ido-undecitol (4) starting from D-glucose. The reaction of the aldose with Meldrum's acid led to the C-glycosidic 3,6-anhydro-1,4-lactone 6, which was converted to the aldehyde building block 2,5-anhydro-3,4,7-tri-O-benzyl-6-deoxy-aldehydo-D-ido-heptose (11). Chain elongation of 11 with the Grignard reagent derived from 1-bromo-3-butene gave the diastereomers 3,6-anhydro-1,4,5-tri-O-benzyl-2,8,9,10,11-pentadeoxy-L-glycero-D-ido-undec-10-enitol (12) and 3,6-anhydro-1,4,5-tri-O-benzyl-2,8,9,10,11-pentadeoxy-D-glycero-D-ido-undec-10-enitol (13). The relative threo configuration of the major product 12 was confirmed by X-ray structure analysis. Epoxidation and subsequent cyclization afforded the cis and trans diastereomers 19 and 20, respectively, in a 1:1 ratio. Subsequent cleavage of the protecting groups and separation of the isomers furnished the target compounds in good overall yields.

Journal Article↗
PubMed2000

Regional variations in cortical modeling in the femoral mid-shaft: sex and age differences.

Modern lifestyle changes may result in site-specific alterations in the skeleton. Our aim was to determine sex and age differences in regional geometry at the mid-femur. Complete cross sections from 113 individuals aged 20-97 years from a modern Australian population were obtained. A further subsample of 24, in whom the precise orientation of specimens was known, was subsequently collected. Microradiographs were made of 100-microm sections and the bone was analyzed using image processing software (Optimas, Media Cybernetics). The periosteal boundary was extracted automatically and the centroid of the periosteal outline was calculated. Fourier shape analysis was used to delineate the endocortical surface. Radial and cortical widths in each quadrant were determined. The posterior was identified by the linea aspera, and the medial and lateral were indistinguishable and therefore grouped together. For analysis, the entire sample was divided into three groups: young (20-40 years), middle (41-60 years), and old (61+ years). Raw and height-normalized values were analyzed with SPSS using t-tests, analysis of variance, and Tukey's honestly significant difference (HSD) tests. The results show that with age the femoral mid-shaft in both sexes becomes larger and more circular, with a slight shift towards the anterior. Apposition is least on the posterior and resorption greatest on the anterior, the latter being particularly evident in postmenopausal females. The greatest sex differences are seen in the middle years, lessening again in the old. We conclude that differential circumferential modeling in response to functional and postural changes occurs in both sexes with age.

Adult↗
PubMed2000

General non-specific morbidity is reduced after vaccination within the third month of life--the Greifswald study.

OBJECTIVES: The incidence of many serious infectious diseases fundamentally decline as a success of consequent vaccination regimens. However, it is a matter of discussion if vaccination might cause unspecific negative side effects on the immune system. To answer this, we performed a clinical study on children with the question as to whether there is an enhanced frequency of infection diseases after vaccination or not. METHODS: The study population (n=496) was randomized to a group of vaccinated children (first vaccination on the 60th day of life, n=201) and a group of unvaccinated children (first vaccination on the 90th day of life, n=295). Frequencies of unspecific, morbidity-related signs were recorded by the mothers with a diary card. These data were taken for further statistical analysis to determine if the factor "vaccination" does have a significant effect on the variable "morbidity". RESULTS: Various infectious disease-associated symptoms (vomiting, coughing, signs of rhinitis, restlessness, rash and pain) were significantly less often seen in vaccinated than in non-vaccinated children. CONCLUSIONS: Our study revealed that children who received vaccination against diphtheria, pertussis, tetanus, HiB and poliomyelitis simultaneously within the third month of life do not exhibit enhanced frequencies of infectious disease-associated symptoms. In contrary, the frequencies of infection-associated symptoms were found to be significantly reduced. This might be caused by a vaccination-associated unspecific enhancement of immunological activity (e.g. mediated by interleukin 2) or by other presently still unknown factors.

Age Factors↗
PubMed2000

Time dependent effects of glucocorticoids on adrenocorticotropin secretion of rat pituitaries ex-vivo.

Different glucocorticoids have been compared with respect to the inhibition of corticotropin-releasing factor (CRF)-mediated adrenocorticotropin (ACTH) secretion from pituitary fragments of the rat. The influence of time of exposure to glucocorticoids and glucocorticoid concentration has been investigated. CRF-stimulated ACTH secretion of perifused rat pituitary fragments was measured by a chemiluminescence immunoassay. ACTH secretion was monitored over three days. Inhibition of CRF-stimulated ACTH secretion by glucocorticoids was quantified by the area under the curve of CRF-stimulated ACTH secretion over baseline. Concentrations needed to inhibit ACTH secretion decreased with the receptor affinities of the glucocorticoids as follows: fluticasone propionate; receptor affinity 1800, concentration 10(-8) M; budesonide, 935 and 3-2.5 x 10(-8) M; flunisolide, 478 and 5 x 10(-7) M; prednisolone, 10 and 10(-6) M. CRF-stimulated secretion was inhibited by glucocorticoids after incubation for 1 min at concentrations between 10(-8) and 10(-6) M. The same absolute quantity of the glucocorticoids produced no inhibition when incubation was prolonged to 50 min or when a lower concentration was used. Immediately after the perifusion stimulation of ACTH secretion was observed. The results suggest the possibility of minimizing the side effects of glucocorticoids by prolonging drug release.

Administration, Topical↗
PubMed1999

Alternative sulfonylurea receptor expression defines metabolic sensitivity of K-ATP channels in dopaminergic midbrain neurons.

ATP-sensitive potassium (K-ATP) channels couple the metabolic state to cellular excitability in various tissues. Several isoforms of the K-ATP channel subunits, the sulfonylurea receptor (SUR) and inwardly rectifying K channel (Kir6.X), have been cloned, but the molecular composition and functional diversity of native neuronal K-ATP channels remain unresolved. We combined functional analysis of K-ATP channels with expression profiling of K-ATP subunits at the level of single substantia nigra (SN) neurons in mouse brain slices using an RT-multiplex PCR protocol. In contrast to GABAergic neurons, single dopaminergic SN neurons displayed alternative co-expression of either SUR1, SUR2B or both SUR isoforms with Kir6.2. Dopaminergic SN neurons expressed alternative K-ATP channel species distinguished by significant differences in sulfonylurea affinity and metabolic sensitivity. In single dopaminergic SN neurons, co-expression of SUR1 + Kir6.2, but not of SUR2B + Kir6.2, correlated with functional K-ATP channels highly sensitive to metabolic inhibition. In contrast to wild-type, surviving dopaminergic SN neurons of homozygous weaver mouse exclusively expressed SUR1 + Kir6.2 during the active period of dopaminergic neurodegeneration. Therefore, alternative expression of K-ATP channel subunits defines the differential response to metabolic stress and constitutes a novel candidate mechanism for the differential vulnerability of dopaminergic neurons in response to respiratory chain dysfunction in Parkinson's disease.

ATP-Binding Cassette Transporters↗
PubMed1996

Evaluation of immunoassays for detection of antibodies to human herpesvirus 7.

An enzyme immunoassay (EIA), an immunoblot assay (IB), and an indirect immunofluorescence assay were developed for detection of human herpesvirus 7 (HHV-7) antibodies in human serum. Cross-absorption studies with EIA or IFA using HHV-7 and human herpesvirus 6 (HHV-6) antigens indicated that most human sera contain cross-reactive HHV-6 and HHV-7 antibodies and that the degree of cross-reactivity varies between individual serum specimens. Inhibition of homologous antibody activity by absorption with heterologous virus ranged from 0 to 57% by EIA. However, for every sample tested, absorption with homologous virus removed more activity than did heterologous virus. An 89-kDa protein was identified as an HHV-7-specific serologic marker by IB. Activity to this protein was not removed by absorption with HHV-6 antigen. Of the three assays, the EIA was the most sensitive (94%), while the IB was the most specific (94%). Approximately 80% of specimens collected from German adults and children older than 2 years were positive for HHV-7 antibodies by these assays.

Adolescent↗
PubMed1996

Anchoring complex components laminin-5 and type VII collagen in intestine: association with migrating and differentiating enterocytes.

Anchoring complex component laminin-5 and its subunits laminin (Ln)-alpha3 and Ln-beta3 chains, Type VII collagen, and integrin chains alpha3, alpha6, and beta4 were studied in developing and adult human intestine and compared with findings on Ln-alpha1 and Ln-alpha2 chains. In adult human duodenum, jejunum, and ileum, Ln-5 detected with a polyclonal antiserum and Ln-alpha3 and Ln-beta3 chains, detected with monoclonal antibodies (MAbs), were restricted to the epithelial basement membranes (BMs) of villi, whereas Ln-alpha2 chain was seen only focally in crypt bottoms. In double labeling experiments, the stretch of crypt BM corresponding to the proliferative cell compartment was found to be devoid of both Ln-alpha3 and Ln-alpha2 chains. Double labeling for Ln-5 and proliferating cell nuclear antigen also showed an abrupt onset of Ln-5 expression exactly at the upper edge of the proliferative cell compartment. Type VII collagen was negligible in duodenum and showed a rising duodenal-ileal gradient localizing to villar BMs. Double labeling for Ln-5 and Type VII collagen, however, indicated only partial co-distribution in the intestine. Electron microscopy of ileum revealed both anchoring filaments and anchoring fibrils but no hemidesmosomal plaques. Our results demonstrate the expression of Ln-5 in BMs outside of stratified epithelia and indicate that Ln-5 in the intestine is associated with the compartment of migrating and differentiating enterocytes. Absence of hemidesmosomes and the presence of other anchoring complex components, such as Ln-5, Type VII collagen, and integrin chains alpha3, alpha6, and beta4, suggests unique properties for epithelial cell attachment in the intestine.

Adult↗
PubMed1995

On the mechanism of skin wound "contraction": a granulation tissue "knockout" with a normal phenotype.

This report explores the mechanism of spontaneous closure of full-thickness skin wounds. The domestic pig, often used as a human analogue for skin wound repair studies, closes these wounds with kinetics similar to those in the guinea pig (mobile skin), even though the porcine dermis on the back is thick and nearly immobile. In the domestic pig, as in the guinea pig, daily full-thickness excisions of the central granulation tissue up to but not including the wound edges in both back and flank wounds do not alter the rate or completeness of wound closure or the final pattern of the scar. A purse-string mechanism of closure was precluded by showing that surgical interruption of wound edge continuity does not alter closure kinetics or wound shape. We conclude that "tightness" of skin is not a key factor nor is the central granulation tissue required for normal wound closure. These data imply that in vitro models such as contraction of isolated granulation tissue or of the cell-populated collagen lattice may not be relevant for understanding the cell biology of in vivo wound closure. Implications for the mechanism for wound closure are discussed.

Animals↗