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Biomedical subjects

H Koch

Publications and source records attributed to H Koch.

At least 613 records · Page 34Linked to original sources
PubMedDate not supplied

Isolation of Chlamydia trachomatis from the lower digestive tract.

Chlamydia trachomatis was isolated from ten of 188 biopsies (5.3%) obtained from different parts of the lower digestive tract. Patients (mean age 37.0 years) presented with ulcerative proctitis, Crohn's disease, mild colitis or ulcerative colitis. Seven rectal biopsies, two biopsies from the sigmoid flexure and one caecal biopsy were positive for chlamydial isolation whereas all biopsies taken from the colon ascendens, transversum or descendens and from the terminal ileum were negative. We conclude that isolation of C. trachomatis is most effective from rectal and sigmoidal biopsies and is a rare event from other sites of the lower digestive tract.

Adult↗
PubMedDate not supplied

X-chromosomal (p21) muscular dystrophy and left ventricular diastolic and systolic function.

In order to screen for cardiac abnormalities, we prospectively studied 15 patients (age 8-25 years, mean 15.5 years) with Duchenne's (DMD) (n = 9) and Becker's (BMD) (n = 6) muscular dystrophy using the echocardiogram. Data were compared to a control group of 92 healthy individuals (age 7.9-25 years, mean 14.3 years). Left ventricular filling in diastole showed a different pattern when comparing echocardiographic Doppler results in patients and controls: Patients had lower peak velocity of early left ventricular diastolic filling (E-vmax)(P < 0.0001) and smaller time velocity integral of the E-wave (E-tvi)(P < 0.0001). In contrast, the atrial component (A-vmax, A-tvi) of diastolic filling in DMD/ BMD showed no significant difference to controls. The mean area of the mitral valve orifice was significantly larger in patients (P < 0.0001) without presence of mitral regurgitation. Systolic left ventricular function was significantly impaired in the DMD/BMD group; we found lower heart rate corrected fiber shortening velocity VCFc (P < 0.001) and higher peak systolic wall stress (P < 0.001) in DMD/BMD. In 8 of 15 patients, peak systolic wall stress was above 95th percentile of controls. In 6 of 15 patients, VCFc was lower than the 5th percentile of controls. Systolic and diastolic myocardial impairment was found even in young patients and at low stages of disability--equally among patients with DMD or BMD. Diastolic left ventricular impairment predominantly affected the early diastolic filling, but atrial compensation was poor. Peak systolic wall stress measurements were particularly useful in patients with CMP, reflecting the left ventricular afterload.

Adolescent↗
PubMedDate not supplied

[Implantation of a Harms titanium mesh cylinder for vertebral body replacement in spinal metastases].

OBJECTIVE: Vertebral metastases are quiet common and may result in vertebral collapse, spinal instability, and progressive neurological compromise. An anterior approach is the accepted method for decompression and stabilization by vertebral replacement. There is still need for discussion regarding the material of the replacement device. Here, the authors report on Harms' titanium cage (DePuy-Motech) for vertebral replacement. METHODS: From 1992 until 1995 17 patients with spinal metastases were treated by anterior vertebral replacement at the Orthopaedic Department, University of Magdeburg. Indications for the procedure were single metastases and respectively, progressive neurological deficit with vertebral destruction seen radiologically. Implantation of the cage was performed solely or in combination with anterior or posterior instrumentation. Pre- and postoperative assessments were evaluated by clinical scores. RESULTS: Mean follow-up was 9.3 months. At the end of our study 11 patients had died (mean survival 6.7 months). Mean follow-up of the surviving 6 was 9.8 months. Patient's daily activity (Karnofsky) improved in 8 cases, became worse in 4 cases, and did not change in 5 cases. Neurologically (Frankel) there was improvement in 3 patients, deterioration in 4 patients, and no change in 10 patients. Walking ability showed improvement in 6 cases, deterioration in 3 cases and no change in 8 cases. Relief of pain (Moskowitz) was reported by 12 patients, no patient complained of increasing pain, 5 patients reported no change, and 10 patients were pain-free. CONCLUSION AND CLINICAL RELEVANCE: In most cases with spinal metastases, the quality of life may be improved by vertebral replacement with Harms' titanium cage. Amelioration of clinical symptoms such as neurological deficit, pain, and tack of walking ability occurred in most patients.

Adult↗
PubMedDate not supplied

["Interface problems" in medical rehabilitation: development of a brief questionnaire for assessing the need for information and communication among general practitioners].

Against the background of current and future demographic changes the relevance of medical rehabilitation in the German health care system is generally acknowledged. It is a central element of treatment programmes especially for elderly and chronically ill patients. In recent years, problems due to lack of co-operation and communication as well as insufficient links between acute care and rehabilitation treatment have found increasing attention. Previous attempts to increase involvement especially of general practitioners in the rehabilitation process were only slightly successful. In a pilot study conducted by the Rehabilitationswissenschaftlicher Arbeitskreis Schleswig-Holstein a new procedure was tested to increase involvement of general practitioners. A brief questionnaire was attached to the report of discharge of rehabilitation patients and was sent to 130 practitioners. With this questionnaire the general attitude and need for information of the practitioners should be analysed. Knowledge about these variables should help to improve communication and co-operation. The response rate was quite high: about 75% of the contacted practitioners answered the questionnaire. All practitioners described medical rehabilitation as important and also had a quite positive attitude toward the same. Two-thirds of the physicians were interested in more intensive contacts and requested further information.

Aged↗
PubMedDate not supplied

[Doppler echocardiographic investigation of left ventricular diastolic function in preterm infants with and without a patent ductus arteriosus].

We studied the influence of preload augmentation on Doppler-derived left ventricular diastolic function parameters in infants with a birth weight <1500 g. In 44 neonates with a closed duct and 29 neonates with an open ductus arteriosus a complete echocardiographic study including Doppler investigations of the mitral inflow signals and analysis of diastolic time intervals was performed. Neonates with an open duct had a lower median gestational age (27.1 vs. 29, P<0.01), a higher cardiac index (425 vs. 260 ml/min/kg, P<0.001), and a different M-mode left atrial to aortic diameter ratio (1.36 vs. 0.79, P<0.001), but birth weight, age at examination (6.6 vs. 7.9 days), and heart rate were similar compared to the neonates with a closed duct. Main differences in diastolic indexes existed in early and atrial filling integrals and peak velocities, early filling acceleration time, and isovolumic relaxation time. Most informative in neonates with an open ductus peak early filling velocity (41.2 vs. 30.4 cm, P<0.01) and peak atrial filling velocity (49.2 vs. 35.9, P<0.001) are higher, and isovolumic relaxation time is shorter (45 vs. 53 ms, P<0.001) than in closed duct peers. Isovolumic relaxation time is inversely correlated with the cardiac index (R = -0.78). These parameter changes can be interpreted as incipient left ventricular diastolic failure in extremely low birth weight infants in the presence of a preload challenge. The coincidence of higher peak velocities with a shortened isovolumic relaxation time is very likely a result of left atrial pressure elevation. Preload mismatch has to be considered in preterm infants with a persistent ductus arteriosus. The results of this study can be helpful to find the indication for PDA-closure and to adjust volume replacement therapy, and catecholamine medication to a level appropriate for the individual cardiac performance.

Blood Flow Velocity↗
PubMedDate not supplied

[The effect of growth/differentiation factor-5 (GDF-5) on genotype and phenotype in human adult mesenchymal stem cells].

AIM: To evaluate the effects of GDF-5 on genotype and phenotype of human mesenchymal stem cells (hMSC). HYPOTHESIS: GDF-5 leads to up-regulation of the Type I-collagen (Col) gene without altering bone marker genes or alkaline phosphatase activity. METHODS: To test our hypothesis hMSC were treated with rmGDF-5. Using quantitative real-time PCR we analyzed mRNA for Col, Runx2 and Osterix (Osx). Furthermore, we analyzed alkaline phosphatase activity (ALP) as a phenotypical bone marker. ANOVA and post hoc statistical analyses were used to determine differences among treatments (p < 0.05). RESULTS: HMSC showed a biphasic response in both Col and Runx2 after rmGDF-5. Initial up-regulation was followed by a significant down-regulation below controls. Interestingly, the controls presented with changes for Col and Runx2 over time. There was no Osx expression in either treated hMSC or controls. No significant differences could be detected in ALP. CONCLUSION: Increased expression of Col and Runx2 might indicate differentiation towards both osteoblast and fibroblast lineage. However, no Osx expression and no change in ALP support the assumption that rmGDF-5 does not lead to an osteoblast phenotype in hMSC. Our in vitro studies confirm a possible therapeutic benefit of GDF-5 in the treatment of tendon and ligament injuries and tissue engineering approaches. Further research is necessary to prove its clinical value.

Alkaline Phosphatase↗
PubMedDate not supplied

[Refined adenoviral transduction for controlled gene transfer into human adult mesenchymal stem cells].

AIM: Adenoviral gene transfer remains a powerful tool for basic research purposes. We hypothesize that adenoviral transduction of human mesenchymal stem cells (hMSC) in vitro can be improved by refined use of experimental parameters. METHODS: hMSCs were transduced by adenoviral vectors encoding Luciferase or BMP-2 at a selection of multiplicities of infection (MOI) and exposure times. Transgene production and total protein content were measured. To determine practical relevance, expression of the bone marker genes Runx2 and Type I collagen was analyzed by quantitative PCR. As a phenotypic marker alkaline phosphatase was assessed. ANOVA and post hoc statistical analyses were used to determine differences among data (p < 0.05). RESULTS: Prolonged exposure led to a decrease in transgene production and total protein content. Increasing MOI at exposure of up to 4 hours resulted in a higher production of the transgene. Transfer of the hBMP-2 gene promoted an enhanced lineage progression to the osteoblast phenotype indicating biological activity. CONCLUSION: Time of exposure is of major importance for toxicity in vitro and should not exceed 4 hours for hMSC. While increase in exposure time leads to cell death, surviving cells, up to a certain limit, seem to compensate by increasing production of the transgene indicating that transduction efficiency cannot be positively measured in a binary yes-or-no scheme.

Adenoviridae↗
PubMedDate not supplied

[Osteoblastic differentiation of human adult mesenchymal stem cells after through gene transfer of BMP-2 in the absence of dexamethasone].

AIM: Mesenchymal stem cells (MSC) of various species appear to require different cues to differentiate towards the osteoblastic lineage. For MSC of human origin, recombinant hBMP-2 is reported to be not sufficient but dexamethasone seems to be essential. The aim of this study was to analyse changes in genotype and phenotype of hMSC after adenoviral transfer of the BMP-2 gene in the absence of dexamethasone. METHODS: We employed hMSC and analysed changes in expression of the Runx2, Osterix and type I collagen gene by quantitative PCR after adenoviral transfer of the human BMP-2 gene in the absence of dexamethasone. As a phenotypic marker alkaline phosphatase activity was assessed. ANOVA and post hoc statistical analyses were used to determine differences among data (p < 0.05). RESULTS: Transfer of the hBMP-2 gene and consecutive production of transgenic BMP-2 up-regulated bone marker gene expression and increased alkaline phosphatase activity and thus promoted an enhanced lineage progression to the osteoblast phenotype without the addition of dexamethasone. CONCLUSION: These findings are noteworthy in the light of a possible superiority of endogenous transgenic proteins compared to exogenous recombinant proteins.

Adult↗
PubMedDate not supplied

[Long-term study of anthracycline-induced cardiomyopathy in children and adolescents].

In order to detect changes in cardiac function, electrocardiographic, echocardiographic and radiologic studies were performed in 71 patients (age 1-26 yrs) who had been treated at the University Children's Hospital Berlin because of malignant diseases according to protocols of the DAL/GPO and had received anthracyclines (doxorubicin or daunorubicin) at cumulative doses up to 480 mg/m2 (median 280 mg/m2). Clinically overt cardiomyopathy was observed in one girl and required transient administration of digoxin. In 2 patients echocardiographic changes led to a reduction of the scheduled anthracycline doses. No patient died from congestive heart failure. During treatment, an increase in the cardiothoracic index was observed in 14 children, and in 16 the ECG showed pathological findings. A decrease in contractility to 25% or less as detected by ultrasound was seen in 15 patients. More than 50% of patients developed echocardiographical signs indicating an impairment of myocardial function. However, persistent changes were only found in 1 patient after discontinuation of treatment. Long-term echocardiographic follow-up studies for 4-48 months (median 14 months) after completion of anthracycline therapy were performed in 18 patients and the findings compared to matched-pair controls. The observed M-mode parameters were completely normal, and the ejection fractions calculated from the two-dimensional ultrasound investigations were in the normal range but slightly diminished compared to controls. Cardiac ultrasound is a non-invasive, reproducible and tolerable procedure for early detection of an anthracycline cardiomyopathy. In our patients, time of occurrence and the extent of pathological changes were not associated with the cumulative applied anthracycline doses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[In vitro transfer of genes in spinal tissue].

INTRODUCTION: It is well known that cytokines are involved in the induction of intervertebral disc and articular cartilage destruction. Therapeutic proteins are of great potential as locally produced drugs after transfer of their cognate genes to the sites of interest. METHODS: Chondrocytic cells from bovine os coccygis and discal chondrocytes from 6 wistar rats were isolated and cultured in vitro. The bacterial beta-galactosidase (LacZ) gene and the cDNA of the human interleukin-1 receptor antagonist (IL-1ra) were introduced into the cells by retrovirus mediated gene transfer. LacZ activity was determined by Xgal staining, IL-1ra protein was determined by ELISA. RESULTS: Our study confirms that isolation and cultivation of bovine chondrocytic end plate cells and of rat discal cells in possible. Transfer of both LacZ and of the IL-1ra cDNA to cultured cells was successfull. DISCUSSION: The introduction of exogenous therapeutical genes into cells from the intervertebral disc and the end plate opens the possibility for a local gene therapy of IVD degeneration. This therapy has the potential to be specific, effective and appropriate to the chronicity of the disease.

Animals↗
PubMedDate not supplied

A new method for strengthening palatal closure defects of the hard palate.

Closure of minor defects in the hard palate can be done with local flaps. There is often a risk of perforation of the reconstructed area. In the case reported this complication was obvious due to a large, thin, flap-covered area. In strengthening the reconstruction fascia lata and Surgicel was used. The postoperative result was excellent and the rehabilitation of the patient was without complications.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Circulatory changes after surfactant bolus instillation in lung-lavaged adult rabbits.

Following surfactant instillation in infants treated for respiratory distress syndrome, a mean arterial blood pressure (MABP) decrease is often observed. Its etiology and pathogenesis are still unknown. In this study various circulatory parameters were recorded continuously after surfactant instillation to elucidate the role of pulmonary vascular resistance as one possible cause for the MABP drop. Seven anesthetized adult New Zealand white rabbits were artificially ventilated after tracheotomy. Arterial and right atrial pressure were recorded continuously. Pulmonary artery pressure and cardiac output were determined by means of a thermodilution catheter. After inducing surfactant deficiency by repeated saline lavages, 200 mg/kg body weight of a natural surfactant preparation was administered by tracheal bolus instillation. PaO2 increased rapidly from 8.0 +/- 1.3 kPa to 51.2 +/- 8.8 kPa (mean +/- standard deviation) within 2 min (p < .05). MABP dropped from 12.1 +/- 1.9 kPa to 8.9 +/- 2.3 kPa within 2 min (p < .05). Pulmonary artery pressure, cardiac output, and right atrial pressure did not change during the observation period of 60 min. The results suggest that a peripheral vasodilatation is the most likely cause for the drop in MABP.

Animals↗
PubMedDate not supplied

Circannual period of physical performance analysed by means of standard cosinor analysis: a case report.

Variation of physical fitness during the day is well investigated and is used both in athletes training as well as during sports contests. Circannual periodicities, on the other hand, seem to exist but have not been investigated systematically so far. The present case report shows that absolute increase in the number of press-ups varies during the year and can be modelled by means of standard cosinor analysis. Moreover, published data dealing with circannual rhythm of muscle strength could be fitted into a cosinor model. These results indicate a circannual increase of performance and warrant further controlled investigations. Due to methodological problems in trials for circannual rhythms, population cosinor models may be a suitable approach.

Adult↗
PubMedDate not supplied

[Handicap caused by clefts of the lips, jaws and/or palate and velum].

Due to clefts of the lips, jaws and/or palate and velum no normal structures are formed in the orofacial system, and thus all processes of growth and development as well as function are disturbed to an extent varying with the extension of the malformation. Integration of these children in kindergartens or regular schools is impossible unless surgery is performed. Apart from qualified interdisciplinary initial care the acknowledgement of these children as severely handicapped persons in accordance with the law could be of great help and relief for the parents. The German law for securing the integration of severely handicapped persons in work, profession and society (Schwerbehindertengesetz) pays particular attention to severely handicapped children. The basic considerations in writing medical opinions are described.

Child↗