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Biomedical subjects

M Kahl

Publications and source records attributed to M Kahl.

17 recordsLinked to original sources

15-year prospective follow-up study of behavioral therapy in a large sample of inpatients with chronic tinnitus.

CONCLUSION: The results of this study are in accordance with the assumption that cognitive-oriented therapy enabling the patient to live with tinnitus is of primary importance to enhance quality of life. BACKGROUND AND OBJECTIVES: This study describes the success of an integrative behavioral-medicine inpatient treatment for complex chronic tinnitus and presents its long-term effects. In 1987 we developed and evaluated a new treatment concept of psychological treatment of complex chronic tinnitus based on international experience and results. To evaluate the influence, effects and individual results of the specific therapy we analyzed the data of 434 consecutively treated patients. To investigate the long-term effects of the treatment, we contacted the patients 15 years after discharge from the hospital. PATIENTS AND METHODS: We used the tinnitus questionnaire (TQ) and visual analog scales (VAS) for specific tinnitus variables (loudness, discomfort, control of tinnitus, stress, general mood). The German version of the Derogatis psychopathology checklist (SCL-90-R) was used to analyze the impact of additional symptoms (depression, anxiety, introversion, etc.). RESULTS: Compared with a control group (patients on a waiting list) significant and clinically relevant effects were found. At the outcome, there were significant improvements in almost all parameters measured. For evaluation of the long-term effect we succeeded in contacting 312 of 434 former patients. Data were assessed using the same questionnaires that had been employed at the first contact. In all, 271 patients (86%) returned the questionnaires. Data for 244 cases (mean age 63 years; 79 females, 165 males) were complete enough to be used for data analysis. The results of the follow-up were as unexpected as clear: 15 years after conclusion of the treatment, the improvements of the tinnitus parameters and additional symptoms were stable when compared with the end of therapy.

Adaptation, Psychological↗

[Postoperative pain therapy in minimally invasive direct coronary arterial bypass surgery. I.v. opioid patient-controlled analgesia versus intercostal block].

OBJECTIVE: Lately introduced cardiosurgical procedures such as MIDCAB enable an early extubation immediately after surgery. This also requires an adequate anesthesia regime and especially a sufficient postoperative analgesia. Patient controlled analgesia (PCA) and intercostal nerve blockade (ICB) were evaluated for their suitability for postoperative pain relief in patients undergoing a MIDCAB procedure. MATERIAL AND METHODS: After approval by the local ethic committee and obtaining written informed consent 43 patients were included in this study. Anesthesia was induced and maintained in a total intravenous standardised manner with propofol, remifentanil, cisatracurium and additionally glyceroltrinitrate, clonidine and esmolol were given as needed. After revascularisation patients were randomly assigned to one of two groups receiving either 7.5 mg piritramid i.v. before extubation and continuing a PCA with 2 mg boli and a 10 min lockout, or an ICB with ropivacaine 1% (4 times 5 ml). Additionally all patients received 1 g paracetamol rectally before induction of anesthesia and 1 g metamizol i.v. at the end of surgery. A rescue medication of 3.75 mg piritramid i.v. was allowed. A pain score (NRS 0-10), the Aldrete score (AS 0-12) and oxygen saturation were obtained 1, 4, and 8 h after extubation. RESULTS: The ICB group showed a significantly greater pain reduction in the first (5.8 +/- 1.8 vs. 7.3 +/- 1.9; P < 0.02) and fourth h (3.6 +/- 1.3 vs. 4.6 +/- 1.4; P < 0.02), respectively. Transfer to an intermediate care ward one hr after extubation was achieved more often in the ICB group according to the AS (ICB 9.6 +/- 1.5 vs. PCA 8.9 +/- 1.2; P < 0.05), too. There was no difference with respect to the oxygen saturation. The additional piritramid demand was 9.3 mg in the ICP group and 5 mg in the PCA group in the first 8 hours postoperative. CONCLUSION: ICB gives a better pain relief in the early postoperative phase after MIDCAB procedures compared to a PCA. Both regimes are adequate in order to provide a sufficient pain relief and help to avoid prolonged postoperative mechanical ventilation. These will enable an early transfer of patients to an intermediate care station and save ICU capacity.

Adult↗

Plasma concentration of ropivacaine after intercostal blocks for video-assisted thoracic surgery.

BACKGROUND: Absorption of local anaesthetics following intercostal blocks is rapid. Therefore, plasma concentrations of ropivacaine during intercostal blocks with ropivacaine 2, 5, 7.5 and 10 mg ml-1 (ropivacaine 5 ml injected into each of four intercostal spaces) in patients undergoing video-assisted thoracic surgery were determined. METHODS: After informed consent and ethics committee approval, 64 patients were randomly allocated to four groups for intercostal nerve block (ropivacaine 2, 5, 7.5 or 10 mg ml-1 at the end of surgery). Central (mixed) venous and arterial plasma samples were collected before the start of intercostal application, and 2, 5, 10, 15, 20, 30, 45, 60 and 90 min afterwards. Plasma concentrations of ropivacaine were measured by high performance liquid chromatography. RESULTS: Maximum venous plasma concentrations occurred after the mean times of 10.7 (range, 5-15), 10.8 (5-20), 11.3 (5-20) and 12.2 (5-45) min, respectively for each group. The groups had mean concentrations of 1.3 (SD, 0.6; range, 0.3-2.3), 2.1 (1.0; 0.5-4.5), 2.4 (1.0; 1.2-5.1) and 2.5 (0.9; 1.7-5.6) micrograms ml-1, respectively. Maximum arterial plasma concentration following 1.0% ropivacaine occurred after 16 (5-45) min with a mean of 2.3 (0.6; 1.5-3.6) micrograms ml-1. No signs of central nervous system or cardiac toxicity were observed. CONCLUSIONS: After intercostal blocks the absorption of ropivacaine is rapid compared with other techniques for regional anaesthesia and results in relatively high venous and arterial plasma concentrations, especially if a dose of 100 mg or more is used.

Adult↗

Quantitative competitive NASBA for measuring mRNA expression levels of the immediate early 1, late pp67, and immune evasion genes US3, US6 and US11 in cells infected with human cytomegalovirus.

Different cell types were infected with human cytomegalovirus (HCMV) and RNA expression dynamics were analyzed by quantitative NASBA assays for IE1 (UL123), pp67 (UL65) and the immune evasion genes (US3, US6 and US11). The quantitative NASBA assays gave reproducible quantification in the range of 10(3)-10(6) RNA copies for IE1 and pp67 RNA, from 3x10(3) to 1x10(6) RNA copies for US6 and US11 RNA, and from 1x10(4) to 1x10(6) RNA copies for US3 RNA. SMC, HAEC and HUVEC cells infected with an, in endothelial cells, propagated HCMV strain (VHL/E) showed similar RNA expression dynamics for the analyzed genes. Expression of all genes studied was observed within the first 4 h post-infection. The first gene for which expression could be detected was IE1, followed by US3, US11, pp67 and US6. Fibroblasts infected with HCMV strain AD169 showed a different RNA expression pattern for US3. Translation of the mRNA studied was demonstrated by detection of the proteins 48 h post-infection by immunofluorescence.

Cells, Cultured↗

Tropism of human cytomegalovirus for endothelial cells is determined by a post-entry step dependent on efficient translocation to the nucleus.

Marked interstrain differences in the endothelial cell (EC) tropism of human cytomegalovirus (HCMV) isolates have been described. This study aimed to define the step during the replicative cycle of HCMV that determines this phenotype. The infection efficiency of various HCMV strains in EC versus fibroblasts was quantified by immunodetection of immediate early (IE), early and late viral antigens. Adsorption and penetration were analysed by radiolabelled virus binding assays and competitive HCMV-DNA-PCR. The translocation of penetrated viral DNA to the nucleus of infected cells was quantified by competitive HCMV-DNA-PCR in pure nuclear fractions. The intracytoplasmic translocation of capsids that had penetrated was followed by immunostaining of virus particles on a single particle level; this was correlated with the initiation of viral gene expression by simultaneous immunostaining of viral IE antigens. The infectivity of nonendotheliotropic HCMV strains in EC was found to be 100-1000-fold lower when compared to endotheliotropic strains. The manifestation of this phenotype at the level of IE gene expression indicated the importance of initial replication events. Surprisingly, no interstrain differences were detected during virus entry. However, dramatic interstrain differences were found regarding the nuclear translocation of penetrated viral DNA. With nonendotheliotropic strains, the content of viral DNA in the cell nucleus was 100-1000-fold lower in EC when compared to endotheliotropic strains, thereby reflecting the strain differences in IE gene expression. Simultaneous staining of viral particles and viral IE antigen revealed that interstrain differences in the transport of penetrated capsids towards the nucleus of endothelial cells determine the EC tropism of HCMV.

Active Transport, Cell Nucleus↗

Prospective evaluation of morphology, function, and quality of life after extracorporeal shockwave lithotripsy and endoscopic treatment of chronic calcific pancreatitis.

OBJECTIVE: Therapeutic endoscopy may be effective in selected patients with chronic calcific pancreatitis (CCP). We prospectively evaluated the early outcome of extracorporeal shockwave lithotripsy (ESWL) in combination with interventional endoscopy, using broad inclusion criteria. METHODS: A total of 48 consecutive patients (35 male, 13 female) were recruited for ESWL and endoscopic therapy of symptomatic CCP. Symptoms, quality of life, pancreatic morphology and function were assessed before and after. RESULTS: Multiple stones (n = 43), strictures (n = 34), and pancreas divisum (n = 11) were found. A median of 13 ESWL sessions (range 2-74) with a median of 22,100 shockwaves (1,700-150,900) were required. Endoscopic pancreatic sphincterotomy (n = 48), stricture dilation (n = 12), and/or stenting (n = 27) were performed. After therapy, drainage of the pancreatic duct system was achieved in 36, complete stone clearance in 21 patients. Follow-up (n = 38) at 7 months (range 5-9) showed a significant decrease in pancreatic duct diameter (p < 0.001) and pain score (p < 0.0001) whereas complete pain relief was observed in 45% of cases. Several quality of life scores improved significantly. Weight gain occurred in 68% of patients. Normalization of fasting blood glucose and HbA1c levels were observed in four patients, without modifying their treatment. Improvement in pain score correlated with weight gain and decrease in pancreatic duct diameter. Nonalcoholic etiology was associated with a better chance for improvement in pain score and decrease in pancreatic duct diameter. The presence of strictures did not deteriorate the clinical outcome. CONCLUSIONS: Besides pain relief, ESWL in combination with interventional endoscopy resulted in pancreatic ductal decompression, weight gain, and improvement in quality of life in a considerable number of patients with advanced CCP.

Calculi↗

Efficient lytic infection of human arterial endothelial cells by human cytomegalovirus strains.

Endothelial cells (EC) are common targets of permissive infection by human cytomegalovirus (HCMV) in vivo during acute disease. However, studies of HCMV-EC interactions in vitro have generated discordant results. While lytic infection of cultured venous EC has been well established, Fish et al. (K. N. Fish, C. Soderberg Naucler, L. K. Mills, S. Stenglein, and J. A. Nelson, J. Virol. 72:5661-5668) have reported noncytopathic persistence of the virus in cultured aortic EC. We propose that interstrain differences in viral host cell tropism rather than the vascular bed of origin of infected EC might account for these discrepancies. In the present investigation we compared the responses of EC derived from human adult iliac artery, placental microvasculature, and umbilical vein to infection with various HCMV strains. Regardless of the vascular bed of origin, infection with EC-propagated HCMV strains induced 100% efficient cytopathic change progressing to complete lysis of inoculated monolayers. While fibroblast-propagated strains persisted at low titer in infected arterial EC cultures, they were also cytolytic for individual infected cells. The finding of cytopathic lytic infection of arterial EC by HCMV implicates a mechanism of vascular injury in the pathogenesis of HCMV infection.

Adult↗

A simple and rapid method for preparation of viral DNA from cell associated cytomegalovirus.

In the field of human cytomegalovirus pathogenesis there is growing interest in analyzing recent clinical isolates rather than cell culture adapted laboratory strains. However, true low passage isolates are strictly cell associated prior to cell culture adaptation and only a minor fraction of cells are infected at low passage number. Both conditions hinder the preparation of pure viral DNA. To date, genetic analyses had been carried out mostly with supernatant associated cytomegalovirus. A rapid and simple method is described for preparation of viral DNA from low passage cell associated isolates with little cytopathogenic effect. The protocol is based on a combination of Triton X-100 lysis, nuclease treatment, and subsequent phenol chloroform extraction. Cellular background was reduced significantly to enable clear detection of all viral DNA fragments in restriction fragment length analysis. The method yielded DNA which was suitable for downstream applications like cloning of viral DNA fragments or transfection of genomic viral DNA. This method may facilitate genomic analyses of pathogenic cell associated recent cytomegalovirus isolates.

Cells, Cultured↗

Modification of human cytomegalovirus tropism through propagation in vitro is associated with changes in the viral genome.

Following extensive propagation in fibroblasts, human cytomegalovirus (HCMV) loses tropism for a number of otherwise natural host cells, in particular, endothelial cells. In this study, the hypothesis was tested that loss of endothelial tropism is associated with the appearance of genomic variants. Initial quantitative focus expansion assays on endothelial monolayers demonstrated that, while the laboratory strains AD169 and Towne failed to form detectable foci, 29 out of 30 recent clinical HCMV isolates had the potential to expand in endothelial cell culture. By long-term adaptation in fibroblast cultures, nonendotheliotropic strains could be selected from clinical HCMV isolates, while long-term endothelial-adapted strains of the same isolates retained both fibroblast tropism and endothelial tropism. Such differentially adapted isolate pairs always displayed genomic differences in restriction fragment length analyses. Coinfection of endothelial cells by two nonendotheliotropic HCMV strains yielded an endotheliotropic recombinant HCMV variant combining portions of the genomes of both parental viruses. When DNA purified from various isolates was transfected into fibroblasts, progeny virus retained the specific tropism of parental virus from which the DNA was isolated. These findings demonstrate that endothelial tropism is an inherent property of most clinical HCMV isolates and is determined by the viral genome. Although the specific determinants of HCMV cell tropism are still unknown, this study provides the first evidence for a genetic contribution.

Cells, Cultured↗

Augmentation of the neuromuscular blocking effects of cisatracurium during desflurane, sevoflurane, isoflurane or total i.v. anaesthesia.

We have evaluated the enhancement of cisatracurium-induced neuromuscular block by potent inhalation anaesthetic agents, by constructing dose-effect curves for cisatracurium in 84 patients during anaesthesia with 1.5 MAC (70% nitrous oxide) desflurane, sevoflurane, isoflurane or total i.v. anaesthesia (TIVA). Acceleromyography (TOF-Guard) and train-of-four (TOF) stimulation of the ulnar nerve were used (2 Hz every 12 s). Cisatracurium was administered in increments of 15 micrograms kg-1 until depression of T1/T0 > 95% was reached. ANOVA was used for statistical analysis (alpha = 0.05, beta = 0.2). Depression of T1/T0 during potent inhalation anaesthesia was enhanced compared with TIVA. ED50 and ED95 values of cisatracurium were 15 (SD 5) and 34 (10) micrograms kg-1 for desflurane; 15 (4) and 32 (7) micrograms kg-1 for sevoflurane; and 15 (5) and 33 (9) micrograms kg-1 for isoflurane. These were significantly lower than the values for TIVA (21 (4) and 51 (13) micrograms kg-1) (P < 0.01 in each case). After equi-effective dosing, times to T1/T0 = 25% were similar in all groups (19 (7), 19 (5), 20 (5) vs 16 (4) min). Recovery index25-75% and time to a TOF ration of 0.70 were prolonged significantly by desflurane and sevoflurane compared with TIVA (18 (5), 19 (8) vs 12 (4) min and 43 (11), 44 (10) vs 35 (5) min, respectively), whereas the difference was not significant for isoflurane (14 (6) and 41 (7) min).

Adolescent↗

Microbial transformation of 2,4,6-trinitrotoluene in aerobic soil columns.

2,4,6-Trinitrotoluene (TNT)-contaminated soil material of a former TNT production plant was percolated aerobically in soil columns. Nineteen days of percolation with a potassium phosphate buffer supplemented with glucose or glucose plus ammonium sulfate caused an over 90% decline in the amount of extractable nitroaromatics in soils containing 70 to 2,100 mg of TNT per kg (dry weight). In the percolation solution, a complete elimination of TNT was achieved. Mutagenicity and soil toxicity were significantly reduced by the percolation process. 4-N-Acetylamino-2-amino-6-nitrotoluene was generated in soil and percolation fluid as a labile TNT metabolite.

Journal Article↗

Variability of Doppler microembolic signal counts in patients with prosthetic cardiac valves.

BACKGROUND AND PURPOSE: The purpose of this study was the evaluation of intraobserver, interobserver, and intrasubject variability in the Doppler detection of microembolic signals in patients with mechanical prosthetic valves. Simultaneously, the feasibility of automated embolus detection by means of a neuronal network was investigated. METHODS: From 25 patients with mechanical prosthetic heart valves, single transcranial Doppler monitoring sessions of 30 minutes' duration were recorded on videotape, randomized, and subsequently analyzed by eight independent trained observers from three centers. Three observers evaluated these tapes on three separate occasions, blinded to their previous results. An additional 48 patients with prosthetic heart valves were repetitively monitored with transcranial Doppler ultrasonography for 30 minutes three times within 1 year to examine the long-term variability in the occurrence of microembolic signals. Finally, in an effort to assess the short-term intrasubject variability, 20 patients were examined for 90 minutes, and the results of the three 30-minute periods were compared. The interobserver, intraobserver, and intrasubject (both short- and long-term) variability was evaluated. RESULTS: No significant differences in microembolic signal counts were found among the different observers, between the human observers and the neuronal network, or among the three separate evaluations of stored data by the same observer. The same was true for repeat examinations of the same patient (P > .05, Student's two-paired t test and Friedman's test). CONCLUSIONS: The detection of microembolic signals in patients with prosthetic cardiac valves is a reproducible technique. The reliable performance of the neuronal network argues for a broader use of this device. The intrasubject stability of the microembolic rate over 1 year supports the concept that the underlying emboligenic process is associated with intrinsic mechanical properties of the valve implant and not due to a thromboembolic process in the heart.

Cerebral Arteries↗

[Morphometric, cytochemical and immunohistochemical studies on the proliferative activity of urinary bladder carcinomas].

58 carcinomas of the urinary bladder as well as 11 carcinomata in situ and 10 biopsies of normal mucosa were investigated for their proliferative activity by means of nuclear area morphometry, silver staining of nucleolar organizing regions (NOR) and immunohistochemical staining of the proliferating cell nuclear antigen (PCNA) and the Ki67 antigen. In comparison to normal bladder mucosa, the values were increased significantly (p < 0.05) in all carcinomata in situ and carcinomas. Within the carcinomas, there was an increase from G1- to G3-carcinomas. For all four parameters, the values of the carcinomata in situ and the G2-carcinomas were similar. All parameters correlated with each other and allowed a significant differentiation between G1- and G2-carcinomas (p < 0.05), whereas they allowed only a less optimal differentiation between G2- and G3-carcinomas. Of all markers of proliferation, the Ki67 antigen was the most useful criterium to differentiate between invasive and noninvasive carcinomas. A Ki67 index of 30% seems to be a borderline between these two groups. This could be of prognostic relevance especially for the heterogeneous G2-carcinomas.

Aged↗

Beta-adrenergic modulation of the alpha 2-acute phase globulin blood level in rats.

The acute phase response can be modulated by glucocorticoids and catecholamines as well. We treated Wistar rats with either epinephrine or different selective or non-selective beta-agonists in combination with beta-antagonists. The alpha 2-acute phase globulin (alpha 2-APG) serum concentrations were examined by means of electroimmunodiffusion 24 hours after drug administration. Isoprenaline, epinephrine and the beta 2-selective clenbuterol cause a dose-dependent increase in alpha 2-APG serum concentration. The increase can be inhibited by propranolol as a non-selective beta-receptor blocking agent. beta 1-antagonist talinolol has no effect on the alpha 2-APG serum level. The dose-response curve of isoprenaline is shifted to the right and that of clenbuterol is additionally depressed after treatment with propranolol. According to the alpha 2-APG level the results indicate a beta 2-receptor mediated epinephrine action.

Adrenergic beta-Agonists↗