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M Hübner

Publications and source records attributed to M Hübner.

At least 19 recordsLinked to original sources
PubMed2006

A prospective comparison between clinical outcome and open-configuration magnetic resonance defecography findings before and after surgery for symptomatic rectocele.

BACKGROUND: The correlation between clinical symptoms and anatomical findings by conventional imaging is poor in patients with rectoceles. The aim of this prospective study was to assess and to correlate symptomatic changes after anterior levatorplasty with morphologic changes visualized by magnetic resonance defecography (MRD). METHOD: Fourteen women with a median age of 57 (range 37-83) accepted to participate. Seven of 14 had previous hysterectomy. Patients underwent MRD before surgery and again 6 months postsurgery. Pre- and postoperative symptoms and quality of life (QoL) (Eypasch) were assessed. Faecal and urinary incontinence were graded (Wexner- / Hanley-score). RESULTS: The median Eypasch-score improved from 90 (range 38-106) to 106 (range 29-133) after surgery (P = 0.016). Similarly, the Wexner-score ameliorated from 8 (range 0-20) to 4.5 (range 0-18; P = 0.02). Seven patients described new dyspareunia postoperatively. The median follow up was 16.5 months (range 9-45). The median rectocele size decreased from 37 mm (range 30-48) preoperatively to 12 mm (range 0-42) postoperatively (P = 0.004). Furthermore, enteroceles were corrected and pelvic floor descent was significantly reduced after surgery. Only the clinical symptom of incomplete evacuation strongly correlated with the respective radiological finding of contrast dye trapping (Rho = 0.822; P = 0.001). CONCLUSION: Anterior levatorplasty improved QoL in patients with symptomatic rectocele. Postsurgical correction of rectocele is accurately documented by MRD. Only moderate correlation between morphologic and clinical improvements was observed.

Adult↗
PubMed2006

How useful is PET/CT imaging in the management of post-transplant lymphoproliferative disease after liver transplantation?

Post-transplant lymphoproliferative disease (PTLD) is a serious and potentially life-threatening complication after solid organ transplantation. Here, we report our first experience with the use of PET/CT (positron emission tomography combined with computed tomogram) for the management of patients with PTLD after liver transplantation. Four patients with histologically proven PTLD were analyzed. Conventional work-up included physical examination and head-to-pelvis CT. PET/CT was used in one patient for initial staging and in all patients for follow-up. PET/CT positive findings underwent biopsy. Information provided by PET/CT resulted in a change of medical management in three of the four patients. Conventional work-up missed residual disease after surgery in one and failed to detect a tumor relapse in another patient. However, one patient disclosed a false positive PET/CT finding in the lungs. In conclusion, PET/CT may be a useful tool for staging and therapy monitoring of PTLD after liver transplantation.

Adolescent↗
PubMed2005

[Surgical therapy of liver tumors: resection vs. ablation].

A few years ago surgical resection was the only treatment modality for primary and metastatic liver tumors. However, most of the liver tumors are diagnosed at advanced stage and are unresectable. Criteria for unresectability are: uncontrolled extrahepatic disease, extensive intrahepatic tumor growth, insufficient remnant liver volume and severe co-morbid disease. Several therapeutic strategies have been developed to deal with primarily unresectable tumors. A downstaging ("downsizing") of hepatocellular carcinoma (HCC) can be reached by transarterial chemoembolisation (TACE) or local tumor ablation using ethanol injection, cryosurgery and radiofrequency. Preoperative unilateral portal vein embolization resulting in hypertrophy of the remnant liver volume permits to resect some patients with former unresectable liver tumors. Furthermore, liver transplantation is an option for patients with early stage HCC and liver cirrhosis. Preoperative downstaging of colorectal metastases can be achieved with neoadjuvant chemotherapy, whereas TACE, ethanol injection and liver transplantation are no established options for these patients. So far, there are no standardized guidelines for the treatment of patients with unresectable primary or metastatic liver tumors. In this review we aim to describe the different approaches suggested in the literature and to present our algorithms for the management of patients with liver tumors.

Algorithms↗
PubMed2005

Diode laser spectroscopy of the fundamental bands of 12C14N, 13C14N, 12C15N, 13C15N free radicals in the ground 2 Sigma+ electronic state.

Rotationally resolved spectra of the fundamental band of the CN free radical in four isotopic forms have been measured using tunable diode laser absorption spectroscopy. The source of the radical was a microwave discharge in a mixture of isotopically selected methane and nitrogen diluted with argon. The lines were measured to an accuracy of 5 x 10(-4) cm(-1) and fitted to the formula for the vibration rotation spectrum of a diatomic molecule, including quartic distortion constants. The band origins of each of the isotopomers from the five parameter fits were found to be 12C14N: 2042.42115(38) cm(-1), 13C14N: 2000.08479(23) cm(-1), 12C15N: 2011.25594(25) cm(-1), 13C15N: 1968.22093(33) cm(-1) with one standard deviation from the fit given in parenthesis. Some of the lines showed a resolved splitting due to the spin rotation interaction. This was averaged for fitting purposes. The average equilibrium internuclear distance derived from the upsilon = 0 and 1 rotational constants of the four isotopomers is 1.171800(6) A which is in good agreement with the value determined from microwave spectroscopy.

Absorption↗
PubMed2005

[Study of the quality of codification of diagnoses and procedures under DRG conditions].

UNLABELLED: A system based on Diagnosis Related Groups was introduced in Germany and is mandatory for hospitals from 2004. Hospitals, health care providers and the Medical Service of Social Security-Health Insurance (MDK) face a common effort. Proper codification of diagnoses and procedures is essential. The Medical Service in the State of Hessen, the Techniker Krankenkasse and the Burgerhospital Frankfurt am Main combined forces to assess codification under the DRG system. GOALS: The partners cooperated to assess actual codification and to identify starting points for improvement. METHODS: A random sample was taken from all in-patient cases (all departments) over a 6-month-period (n = 309). Codification or coding was checked according to German Coding Rules (Deutsche Kodierrichtlinien) from the complete hospital records. Different codification, or coding, was discussed between MDK and Hospital doctors. RESULTS: The actual data revealed overcoding in 34 per cent of diagnoses and in 15 per cent of procedures. Undercoding was present in 9 per cent of diagnoses and in 2 per cent of procedures. The DRG grouping changed in 68 cases (22 per cent) after scrutiny by the Medical Service (MDK). The case-mix index (CMI) calculated from relative weights as coded by the hospital was 0.84. The case-mix index calculated from coding by MDK was 0.81. The CMI calculated from effective weights was 0.77 (hospital) and 0.75 (MDK). DISCUSSION: Causes of faulty coding and possible remedies are presented. CONCLUSIONS: Further systematic reviews are required to develop the DRG System and identify faulty trends.

Adolescent↗
PubMed2003

The effect of temporal structure on rustling-sound detection in the gleaning bat, Megaderma lyra.

For a gleaning bat hunting prey from the ground, rustling sounds generated by prey movements are essential to invoke a hunting behaviour. The detection of prey-generated rustling sounds may depend heavily on the time structure of the prey-generated and the masking sounds due to their spectral similarity. Here, we systematically investigate the effect of the temporal structure on psychophysical rustling-sound detection in the gleaning bat, Megaderma lyra. A recorded rustling sound serves as the signal; the maskers are either Gaussian noise or broadband noise with various degrees of envelope fluctuations. Exploratory experiments indicate that the selective manipulation of the temporal structure of the rustling sound does not influence its detection in a Gaussian-noise masker. The results of the main experiment show, however, that the temporal structure of the masker has a strong and systematic effect on rustling-sound detection: When the width of irregularly spaced gaps in the masker exceeded about 0.3 ms, rustling-sound detection improved monotonically with increasing gap duration. Computer simulations of this experiment reveal that a combined detection strategy of spectral and temporal analysis underlies rustling-sound detection with fluctuating masking sounds.

Acoustic Stimulation↗
PubMed2001

Cloning and function of the rat colonic epithelial K+ channel KVLQT1.

KVLQT1 (KCNQ1) is a voltage-gated K+ channel essential for repolarization of the heart action potential that is defective in cardiac arrhythmia. The channel is inhibited by the chromanol 293B, a compound that blocks cAMP-dependent electrolyte secretion in rat and human colon, therefore suggesting expression of a similar type of K+ channel in the colonic epithelium. We now report cloning and expression of KVLQT1 from rat colon. Overlapping clones identified by cDNA-library screening were combined to a full length cDNA that shares high sequence homology to KVLQT1 cloned from other species. RT-PCR analysis of rat colonic musoca demonstrated expression of KVLQT1 in crypt cells and surface epithelium. Expression of rKVLQT1 in Xenopus oocytes induced a typical delayed activated K+ current, that was further activated by increase of intracellular cAMP but not Ca2+ and that was blocked by the chromanol 293B. The same compound blocked a basolateral cAMP-activated K+ conductance in the colonic mucosal epithelium and inhibited whole cell K+ currents in patch-clamp experiments on isolated colonic crypts. We conclude that KVLQT1 is forming an important component of the basolateral cAMP-activated K+ conductance in the colonic epithelium and plays a crucial role in diseases like secretory diarrhea and cystic fibrosis.

1-Methyl-3-isobutylxanthine↗
PubMed2000

Quantum correlations in the nonperturbative regime of semiconductor microcavities.

The nonlinear optical response of semiconductor microcavities in the nonpertubative regime is studied in resonant single-beam-transmission and pump-probe experiments. In both cases a pronounced third transmission peak lying spectrally between the two normal modes is observed. A fully quantized theory is essential for the agreement with the experimental observations, demonstrating that quantum fluctuations leading to intraband polarizations are responsible for this effect.

Journal Article↗
PubMed2000

[Evaluation of the appropriateness of hospital care in internal medicine. Reliability of a German adaptation of the procedure].

BACKGROUND AND OBJECTIVE: The evaluation of the appropriateness of hospital admissions and hospital stays has become an increasingly important issue in Germany. Evaluations by the German Physicians Review Organizations (MDS, MDK) demonstrated the need for a standardized, valid and reliable assessment tool for inappropriate hospital use. Objective of this study was to test the reliability of a German adaptation of the "Appropriateness Evaluation Protocol" (AEP). PATIENTS AND METHODS: From the 2317 admissions to medical wards of a teaching hospital in Hessia in 1997 we randomly selected 52 patients to test the inter-rater-reliability (54% female, mean age = 66 years +/- 18). Another 49 patients were randomly selected to test the intra-rater-reliability of the AEP (53% female, mean age = 61 years +/- 20). We estimated general agreement, specific agreement and Kappa statistics for the agreement of the evaluation of hospital admissions and hospital days. 95% confidence intervals were reported. RESULTS: The German adaptation of the AEP showed an inter-rater-agreement of 92% (88-96%) for hospital admissions and 76% (73-80%) for hospital days. Correspondingly, we observed an intra-rater-agreement of 96% (88-100%) for hospital admissions and 93% (91-95%) for hospital days. The high agreement was independent of the length of hospital stay and independent of the proportion of inappropriate hospital days. CONCLUSION: A standard instrument for the assessment of the appropriateness of hospital care with known metric properties may be useful for quality management in hospitals and provide competitive advantages in a consolidating health care market. The AEP could be such an instrument.

Aged↗
PubMed2000

[Reproducibility of a German scale for assessing the need for inpatient treatment in surgery].

During the past years, the assessment of the appropriateness of hospital utilization has become increasingly important in the German health care system. Previous evaluations by regional review organizations in several states demonstrated the need for a standardized, reliable, and valid instrument to evaluate the appropriateness of inpatient care. Objective of the study is to test the reliability of a German adaptation of the "Appropriateness Evaluation Protocol" (AEP). Among all 2672 admissions from the department of surgery of a regional medical center during one calendar year, 54 patients were randomly selected to evaluate the inter-rater reliability and 51 patients to test intra-rater reliability. Overall agreement, specific agreement and Kappa statistics were estimated for every hospital admissions and all consecutive hospital days. The German AEP showed an inter-rater agreement of 74% (62-86%) for hospital admissions (Kappa = 0.44) and 84% (79%-88%) for all hospital days (K = 0.55). Intra-rater reliability was 88% (79%-97%) for hospital admissions (K = 0.60) and 88% (85%-92%) for all hospital days (K = 0.70). The observed agreement is independent of length of hospital stay and proportion of appropriate days. A standardized instrument with known metric properties is essential for quality management in hospitals to prepare for an increasingly consolidating health care market in Germany. The German AEP is a reliable instrument, which will allow to identify inefficiencies in the management of surgical inpatients.

Adult↗
PubMed2000

KCNE1 reverses the response of the human K+ channel KCNQ1 to cytosolic pH changes and alters its pharmacology and sensitivity to temperature.

Previous studies have shown that heteromultimeric KCNQ1/KCNE1 (KvLQT1/minK) channels and homomultimeric KCNQ1 (KvLQT1) channels exhibit different current properties, e.g. distinct kinetics and different sensitivities to drugs. In this study we report on the divergent responses to internal pH changes and further characterize some of the current properties of the human isoforms of KCNQ1 and KCNE1 expressed in Chinese hamster ovary (CHO) cells or Xenopus laevis oocytes. Decreasing the bath temperature from 37 degrees C to 20 degrees C increased the half-activation time by a factor of 5 for KCNQ1/KCNE1 currents (IKs) but by only twofold (not significant) for KCNQ1 currents (IK) in CHO cells. Acidification of cytosolic pH (pHi) increased IKs but decreased 1K whereas intracellular alkalinization decreased I(Ks) but increased IK. pHi-induced changes in intracellular Ca2+ activity ([Ca2+]i) did not correlate with the current responses. At 20 degrees C mefenamic acid (0.1 mM) significantly augmented IKs but slightly decreased IK. It changed the slow activation kinetics of I(Ks) to an instantaneous onset. The form of the current/voltage (I/V) curve changed from sigmoidal to almost linear. In contrast, at 37 degrees C, mefenamic acid also increased I(Ks) but slowed the activation kinetics and shifted the voltage activation to more hyperpolarized values without markedly affecting the sigmoidal shape of the I/V curve. The potassium channel blockers clotrimazole and tetrapentylammonium (TPeA) inhibited I(Ks) with a lower potency than I(K). These results show that coexpression of KCNE1 reversed pH regulation of KCNQ1 from inhibition to activation by acidic pHi. In addition, KCNE1 altered the pharmacological properties and sensitivity to temperature of KCNQ1. The pH-dependence of I(Ks) might be of clinical and pathophysiological relevance in the pathogenesis of ischaemic cardiac arrhythmias.

Animals↗
PubMed2000

Effect of genistein on native epithelial tissue from normal individuals and CF patients and on ion channels expressed in Xenopus oocytes.

The flavonoid genistein has been shown to activate a Cl(-) conductance in various cell types expressing CFTR. We examined if similar effects can be observed when genistein is applied to native ex vivo tissues from human respiratory tract and rectum. We further compared the effects when genistein was applied to oocytes of Xenopus laevis expressing CFTR. In oocytes, both wtCFTR and DeltaF508-CFTR were activated by genistein while both cyclic AMP (K(v)LQT1) and Ca(2+) (SK4) activated K(+) channels were inhibited at high concentrations of genistein. Biopsies from nasal polyps and rectal mucosa were obtained from normal individuals (non-CF) and CF patients and in the presence of amiloride (10 micromol l(-1); mucosal side) the effects of genistein were assessed using a perfused Ussing chamber. In non-CF airway epithelia, genistein (50 micromol l(-1); mucosal side) increased lumen negative I(sc) but had no additional effects on tissues pre-stimulated with IBMX and forskolin (100 micromol l(-1) and 1 micromol l(-1); both sides). In non-CF rectal biopsies, in the presence of amiloride (10 micromol l(-1); mucosal side) and indomethacin (10 micromol l(-1); basolateral side), genistein increased lumen negative I(sc) and enabled cholinergic (carbachol; CCH, 100 micromol l(-1); basolateral side) stimulation of Cl(-) secretion indicating activation of luminal CFTR Cl(-) channels. However, after stimulation with IBMX/forskolin, genistein induced opposite effects and significantly inhibited CCH activated I(sc). In CF airway and intestinal tissues genistein failed to induce Cl(-) secretion. Thus, genistein is able to activate luminal CFTR Cl(-) conductance in non-CF tissues and mutant CFTR in oocytes. However, additional inhibitory effects on basolateral K(+) conductance and missing effects in native CF tissues do not support the use for pharmacological intervention in CF.

1-Methyl-3-isobutylxanthine↗
PubMed2000

[Certification according to DIN EN ISO 9001 in MDK in Hessia--a report of experiences].

Quality assurance is a routine and indispensable part of the work of the Medizinische Dienst der Krankenversicherung (MDK) (Medical Services of statutory health insurance bodies in Germany). To optimize the internal organisational processes, a quality assurance system (QAS), certified by EQ Zert, Ulm (an accredited certifier of the TGA), was implemented for the first time in one of the departments of the MDK, namely, the hospital department. Employees and management consider the advantages to be as follows: the aims of the department are clearly described. the processes are now self-evident and more strictly observed, overlaps to other fields of the company are defined. Both an Error Management System with follow up measures, and a Project Management System to control projects have been implemented. The documentation system was standardized, and consequently relocating documents has become more streamlined. An MDK self-evaluation was performed as part of an internal audit. The audit showed that the QAS of the hospital department of the MDK in Hesse is indeed highly developed. It is anticipated that gradually other fields of the MDK will also be certified, to comply with the changing requirements.

Certification↗
PubMed2000

[Corroboration of concurrent assessment of inappropriate hospitalization with retrospective evaluation based on patient records].

BACKGROUND AND PURPOSE: Since the availability of a German adaptation of the "appropriateness Evaluation Protocol" (AEP) for hospital utilization review, physicians and health care managers were concerned about a potential overestimation of the extent of inappropriate hospital use in a retrospective assessment. The objective was to assess the agreement of concurrent and retrospective assessment of inappropriate hospital use. METHODS: The appropriateness of 42 admissions to surgical wards in a teaching hospital was tested concurrent to the admission. In 25 hospitalized patients the appropriateness of hospital days was assessed. Results were compared with the retrospective testing of the same patients after three months. RESULTS: Agreement between concurrent and retrospective assessment within the same reviewer was 86% of admissions (95% CI = 75%-96%) and 96% of hospital days (88%-100%). Kappa showed values of 0.85 and 0.78, which can be described as excellent. A comparison of two different reviewers, one testing concurrently, the other retrospectively showed agreements of 86% and 90%. The proportion of inappropriate days was the same in both designs. CONCLUSIONS: The results refute prior concerns that a retrospective assessment of the appropriateness of hospital use is impossible because in a retrospective design important clinical information would remain unconsidered or clinical information not yet available at that time would be used for the evaluation. The possibility of an incorrect assessment due to a retrospective design is within the variability inherent to the instrument. Despite the strong agreement, the small sample of surgical patient limits the generalizability of results.

Concurrent Review↗
PubMed2000

[How many intensive care beds are necessary? A quantitative study with the Therapeutic Intervention Scoring System (TISS) in 5 Hessian hospitals)].

In five major Hessian hospitals all patients of critical care units have been grouped according to the Therapeutic Intervention Scoring System (TISS) over a time span of four weeks. The objective was to establish the critical care patient capacity needed in accordance with the Hessian Guidelines for Critical Care. Sample surveys showed that the ascertained data are highly reliable. 10,756 TISS-classifications have been evaluated in total. 9.4% of the classifications have been assigned to general ward, 27.5% to intensive monitoring and 63.1% to intensive treatment. Assuming a standard rate of use of 85% over the year this revealed an average requirement of critical care patient capacity of 6.1% of the total number of beds. The results of the investigation were readily accepted by health insurances and hospitals involved.

Bed Occupancy↗
PubMed2000

A Bartter's syndrome mutation of ROMK1 exerts dominant negative effects on K(+) conductance.

Mutations in the gene encoding the renal epithelial K(+) channel ROMK1 (Kir 1.1) is one of the causes for Bartter's syndrome, an autosomal recessive disease. It results in defective renal tubular transport in the thick ascending limb of the loop of Henle that leads to hypokalemic metabolic alkalosis and loss of salt. Two novel ROMK1 mutations, L220F/A156V, have been described recently in a compound heterozygote patient demonstrating typical manifestations of Bartter's syndrome. Functional properties of these ROMK1 mutants were studied by coexpressing in Xenopus oocytes and by means of double electrode voltage clamp experiments. When both ROMK1 mutants were coexpressed no K(+) conductance could be detected. The same was found in oocytes expressing A156V-ROMK1 only or coexpressing wild type (wt) ROMK1 together with A156V-ROMK1. In contrast, K(+) conductances were indistinguishable from that of wt-ROMK1 when L220F-ROMK1 was expressed alone. Activation of protein kinase C signaling inhibited the conductance in both L220F-ROMK1 and wt-ROMK1 expressing oocytes. These effects were not seen in A156V-ROMK1 expressing oocytes. Because no further abnormalities in the properties or regulation of L220F-ROMK1 were detected, we conclude that A156V-ROMK1 has a dominant negative effect on L220F-ROMK1 thereby causing Bartter's syndrome type two in this patient.

Bartter Syndrome↗
PubMed1999

Feedback inhibition of epithelial Na(+) channels in Xenopus oocytes does not require G(0) or G(i2) proteins.

Regulation of amiloride-sensitive epithelial Na(+) channels (ENaC) is a prerequisite for coordination of electrolyte transport in epithelia. Downregulation of Na(+) conductance occurs when the intracellular Na(+) concentration is increased during reabsorption of electrolytes, known as feedback inhibition. Recent studies have demonstrated the involvement of alphaG(0) and alphaG(i2) proteins in the feedback control of ENaC in mouse salivary duct cells. In this report, we demonstrate that Na(+) feedback inhibition is also present in Xenopus oocytes after expression of rat alpha,beta, gamma-ENaC. Interfering with intracellular alphaG(0) or alphaG(i2) signaling by coexpression of either constitutively active alphaG(0)/alphaG(i2) or dominant negative alphaG(0)/alphaG(i2) and by coinjecting sense or antisense oligonucleotides for alphaG(0) had no impact on Na(+) feedback. Moreover, no evidence for involvement of the intracellular G protein cascade was found in experiments in which a regulator of G protein signaling (RGS3) or beta-adrenergic receptor kinase (betaARK) was coexpressed together with alpha,beta, gamma-ENaC. Although some experiments suggest the presence of an intracellular Na(+) receptor, we may conclude that Na(+) feedback in Xenopus oocytes is different from that described for salivary duct cells in that it does not require G protein signaling.

Animals↗