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Biomedical subjects

M Imhof

Publications and source records attributed to M Imhof.

At least 37 records · Page 2Linked to original sources
PubMed2000

Microsatellite variability differs between dinucleotide repeat motifs-evidence from Drosophila melanogaster.

Recently, the use of microsatellites as genetic markers has become very popular. While their evolutionary dynamics are not yet fully understood, the emerging picture is that several factors are influencing microsatellite mutation rates. Recent experiments demonstrated a significant effect of repeat motif length on microsatellite mutation rates. Here, we studied the influence of the base composition of the microsatellite. Forty-two microsatellite loci on the second chromosome with the three most abundant dinucleotide repeat motifs (TC/AG, AT/TA, GT/CA) were characterized for six different Drosophila melanogaster populations. Applying ANOVA to the variance in repeat number, we found a significant influence of repeat motif on microsatellite variability. Calculating relative mutation rates, GT/CA appears to have the highest mutation rate, and AT/TA appears to have the lowest. Similar differences in mutation rates were obtained by an alternative method which estimates microsatellite mutation rates from their genomic length distribution.

Alleles↗
PubMed1999

[Efficacy of metoprolol in prevention of supraventricular arrhythmias after coronary artery bypass grafting].

Atrial fibrillation is in 20-50% the most frequent dysrhythmia after coronary artery bypass grafting (CABG) and a possible cause for hemodynamical complications and prolongation off the medical treatment in patients. Therefore, the effect of beta-blocking with metoprolol for prevention of supraventricular arrhythmias (SVA) was investigated in a prospective and randomized trial. 200 patients after CABG were randomized in a drug and control group (average age 63.2 years, 154 male, 46 female). Patients of the drug group (n=100) were treated with metoprolol (1mg/kg/BW) beginning on day one after operation, whereas patients of the control group (n=100) received therapy only in case of occurrence of atrial fibrillation. ECG, blood pressure, and electrolyte concentrations were measured regularly until the tenth day after surgery. Reasons for exclusion were an ejection fraction (< 30%, SA- and AV-block or simultaneous application of epinephrine and metoprolol. There were no significant differences between the patients of drug and control group with respect to age, sex ejection fraction, previous medication, number and type of bypass grafts, cardiopulmonary bypass time, and perioperative ischemic events. However, a statistically significant difference was seen in the occurrence of supraventricular arrhythmias in both groups, 4 patients of the therapy group (4%) in contrast to 37 patients of the control (37%) developed supraventricular arrhythmias during the postoperative observation period (p<0.0001). Both groups differed in total time of hospital stay by 1.5 days (control group: 9.83+/-2.88 days; drug group: 8.42+/-2.81 days), which was statistically significant (p<0.05). All patients of the drug group could be discharged with a stable sinus rhythm, whereas 7 patients of the control group were discharged with persistent atrial fibrillation. The difference was statistically significant as well (p<0.01). Neither typical side effects of metoprolol, nor AV-blocks, bradycardia (f<60/min) or symptoms of low blood pressure could be observed. The conclusion of this trial is a recommendation for a preventive application of 50mg metoprolol/day after coronary artery bypass surgery, which can reduce the incidence of SVA as well as the hospital stay statistically significant.

Adult↗
PubMed1999

Video assistance reduces complication rate of thoracoscopic sympathicotomy for hyperhidrosis.

BACKGROUND: Thoracoscopic sympathicotomy has proved successful in the treatment of palmar hyperhidrosis. However, up to 8% of patients experience Horner's syndrome, and about 50% show compensatory sweating. This study evaluates the role of video assistance in thoracoscopic sympathicotomy for primary hyperhidrosis of the upper limb. METHODS: Six hundred fifty-six thoracoscopic sympathicotomies were performed from below T1 to T4 in 369 patients. Of the operations, 558 were done under direct view (CTS group) and 98, with video assistance (VATS group). Follow-up was complete for 78.3% of patients after a median observation period of 16 years. RESULTS: Dry limbs were immediately achieved in 93% of the CTS group and 98% VATS group (p = 0.98). In the CTS group, Horner's syndrome occurred after 2.2% of all operations and rhinitis in 8.3%. No patient in the VATS group showed any symptom of Homer's triad (p = 0.03 versus CTS group) or rhinitis (p = 0.02 versus CTS group). Compensatory sweating was observed in 66.8% in the CTS group versus 69% in the VATS group (p = 0.73) and gustatory sweating, in 50.4% versus 27.6%, respectively (p = 0.01). CONCLUSIONS: In performing thoracoscopic sympathicotomy for excessive upper-limb hyperhidrosis, we observed a significant decrease in the incidence of Horner's syndrome, rhinitis, and gustatory sweating when the procedure was guided by video imaging.

Adolescent↗
PubMed1999

Low dose oral contraceptives and quality of life.

This study investigated the effects of a low dose oral contraceptive (OC) (Mercilon) on women's satisfaction and quality of life based on a detailed questionnaire. A total of 614 first-time users of oral contraceptives were enrolled by 102 gynecologists for a treatment period of > or = 4 months. The Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q) was filled in both before and during pill intake. The total quality of life score was significantly increased under OC intake. In contrast to older preparations, modern low dose OCs appear to act favorably on a number of psychological parameters, thus increasing satisfaction with various aspects of daily life and, consequently, improving quality of life.

Adult↗
PubMed1999

Long-term results of 45 thoracoscopic sympathicotomies for primary hyperhidrosis in children.

BACKGROUND/PURPOSE: Thoracoscopic sympathicotomy (TS) is successful in treatment of excessive hyperhidrosis of the upper limb after limited follow-up observation. The aim of the study was to assess for the first time long-term results of TS in children. METHODS: A total of 26 children (9 boys, 17 girls) aged 11 to 17 years with severe palmar or axillar hyperhidrosis underwent TS, and 19 patients were treated bilaterally. A total of 19 patients were observed after a median follow-up period of 16 years by questionnaire or clinical examination. RESULTS: Permanent relief from palmar hyperhidrosis was given in all examined patients. Twelve patients had compensatory and 12 patients gustatory sweating. Postoperatively, 1 subcutaneous emphysema and 1 temporary miosis and ptosis were noted. Eleven patients were fully satisfied with the result. Seven patients were only partially satisfied because of compensatory or gustatory sweating but would again undergo operation. One patient was not satisfied because of excessive compensatory sweating. CONCLUSIONS: TS is a safe and efficient procedure even after long-term follow-up. Severe palmar hyperhidrosis often starts in childhood; thus, early surgical treatment can improve social development. Compensatory and gustatory sweating are the most frequent and enduring side effects and should be mentioned in preoperative patient and parent information.

Adolescent↗
PubMed1999

Comparative cytogenetic mapping of COL14A1, the gene for human and mouse collagen XIV.

Utilizing the FISH technique, the gene for collagen XIV was mapped in the human and the mouse genome. The human gene (COL14A1) was assigned to chromosome bands 8q23-->q24.1. This assignment is in agreement with the localization of the undulin gene (UND), whose product has been suggested to be a variant of collagen XIV. The mouse gene (Col14a1) was assigned to chromosome 15 band D. Thus, collagen XIV represents another example of a gene that belongs to human/mouse homology group 90.

Amino Acid Sequence↗
PubMed1999

[Ovarian tissue banking--primary results].

Lifelong hormone replacement therapy and infertility often follow oncological therapy in young women due to a dramatic reduction of the primordial follicle reserve. Reimplantation and function of frozen ovarian tissue slices were successfully demonstrated in animal models, but the durability is limited. Cryopreservation of a whole ovary could reestablish an almost normal ovarian function. Experiments with porcine ovaries showed histological viability. Cryopreservation and retransplantation of sheep ovaries should demonstrate success by hormonal response and pregnancy.

Animals↗
PubMed1999

[Use of the harmonic scalpel (Ultracision) in laparoscopic antireflux surgery].

Gastroesophageal reflux disease can effectively be treated by laparoscopic fundoplication. A new multifunctional device has recently been introduced, Ultracision (UC), which can be expected to be especially effective in laparoscopy. Since 9/1995 laparoscopic fundoplication is being performed at our institution. We routinely divide the "short-gastric vessels" and have been using clip-appliers and Endo-GIAs before dividing the vessels with endo-scissors. Since 2/1997 we also use the UC, which applies ultrasonic energy to cause denaturing of proteins and subsequent hemostasis and dissection. This open, non-randomized study compares operative time, intra- and postoperative complications and conversion rates as well as costs of both methods. Between 2/1997 and 12/1997 20 consecutive patients received a floppy Nissen fundoplication by 2 surgeons. In 8 patients clips/EndoGIA were used (m:w = 5:3, mean age 52 years [33-69]), in 12 patients UC (m:W = 10:2, 53 years [25-74]) was used. 2 patients in each group had had previous open abdominal surgery. In the first group 2 procedures had to be converted to open surgery (1 bleeding, 1 anatomical problem), median operative time was 214 min (135-360). In the UC group all procedures were completed laparoscopically, median operative time 132 min (75-240). Postoperative major complication and mortality rates were 0 in both groups. Use of the harmonic scalpel reduced operative time and costs without increasing conversion rates and perioperative complications.

Adult↗
PubMed1998

An alternative insert of three amino acids is incorporated into collagen XIV in a developmentally regulated fashion.

We have identified a novel splice variant of chicken collagen XIV which contains an insert of three amino acids (Val-Arg-Thr) in the sixth fibronectin type III-like (FNIII) domain. The codons for these amino acids are inserted into the mRNA by skipping of a splice donor site and usage of another donor site 9 bp further downstream in the collagen XIV gene. The percentage of the new splice variant in the total collagen XIV mRNA varies between 22 and 46% in different embryonic tissues. After hatching, however, this percentage increases dramatically and reaches 86% in adult skeletal muscle and 58% in adult gizzard, indicating developmental regulation of this splicing event. Computer modeling suggests that the three extra amino acids cause an increase in the size of a flexible loop connecting two beta-strands in the sixth FNIII domain. This increase might affect the exact arrangement of the FNIII domain in the collagen XIV molecule, thereby modulating its interactions with other matrix molecules.

Alternative Splicing↗
PubMed1998

Multiple mating in wild Drosophila melanogaster revisited by microsatellite analysis.

The occurrence of multiple mating in Drosophila melanogaster is of particular interest to evolutionary biologists, as seminal fluid has some toxic effects for females. Thus, it has been predicted that the number of matings per females should be low. We have tested this prediction with seven highly polymorphic microsatellite loci in inseminated females from a Viennese D. melanogaster population. In contrast to the predicted low number of matings and previous studies in natural populations, we identified the genotypes of four to six different males fertilizing the offspring of each female tested. Potential causes and consequences are discussed.

Animals↗
PubMed1998

Long-term results of 630 thoracoscopic sympathicotomies for primary hyperhidrosis: the Vienna experience.

OBJECTIVE: To evaluate of the results of thoracoscopic sympathicotomy for upper limb hyperhidrosis with a median observation period of more than 15 years. DESIGN: Retrospective clinical observation study. SETTING: University-affiliated tertiary referral centre. SUBJECTS: 630 consecutive operations in 352 patients (median age 30.1 yrs) for primary palmar (68%), axillary (12.7%) and combined hyperhidrosis (19.3%). INTERVENTIONS: Thoracoscopic sympathicotomy from below T1 to T4 including the fibres of Kuntz using electrocautery through single site access. MAIN OUTCOME MEASURES: Perioperative success and complication rates (all patients); long-term follow-up by a questionnaire and/or clinical examination (83.3% of patients) after a median period of 16 yrs. Calculation of statistical significance of differences between groups with c2-test. RESULTS: 67.8% of patients were fully satisfied, 25.7% were partially satisfied and would again agree to the operation. In 93% the procedure cured hyperhidrosis permanently. Compensatory and gustatory sweating was observed in 67% and 47% of cases, respectively. Overall success was significantly (p < 0.001) lower in the group with axillary hyperhidrosis. Main complications: drainage for pneumothorax 1.3%, Horner's syndrome in 3.8%, subcutaneous emphysema 2.1%. CONCLUSION: Thoracoscopic sympathicotomy proved to be highly effective even after long-term follow-up. Compensatory sweating impairs patients' satisfaction in some cases.

Adolescent↗
PubMed1998

Catheter-induced thrombus in the superior vena cava diagnosed by transesophageal echocardiography.

BACKGROUND: To present the role of transesophageal echocardiography (TEE) in the diagnosis and management of catheter-related superior vena cava thrombosis. CASE HISTORY: A 42-year-old woman with severe Crohn's disease presented with septic shock and pulmonary embolism three weeks after emergency laparotomy and ileocolic resection for small-bowel perforation with peritonitis. Cardiopulmonary evaluation with ECG, pulmonary artery catheter and TEE demonstrated no evidence of acute myocardial ischemia or ventricular dysfunction; hemodynamic indices were consistent with severe sepsis. TEE revealed a large sheathing thrombus surrounding a central venous catheter used for parenteral nutrition. A spiral CT scan of the chest confirmed multiple peripheral pulmonary emboli. Treatment consisted of systemic anticoagulation and antibiotics. To avoid further pulmonary embolism, the central venous catheter was not removed until six days later under TEE monitoring, which revealed that the thrombus was firmly adherent to the superior vena cava. The patient made an uneventful recovery and was discharged from hospital on long-term anticoagulant therapy. CONCLUSION: In a case of catheter-induced superior vena cava thrombosis with septicemia and pulmonary embolism, bedside TEE was very helpful to make the correct diagnosis early, assess thrombus size during anticoagulation, and monitor cardiac performance and thrombus disposition during central venous catheter removal.

Adult↗
PubMed1998

Impact of early operation on the mortality from bleeding peptic ulcer --ten years' experience.

In 1984, a risk-dependent combined endoscopic and operative approach for the treatment of bleeding peptic ulcer was developed. This treatment policy has as its major feature an early elective operation in patients with arterial bleeding and a visible vessel, providing that endoscopic control of the bleeding could be achieved. Using this concept in a prospective series resulted in a mortality of 5% compared to a mortality of 14% in a historical control group, where an operation was performed only on demand in case of recurrent bleeding. In 1986, the treatment policy was introduced into clinical routine circumstances at the University Hospital of Düsseldorf. In this paper the results of routine clinical application are presented. The treatment policy was followed in 47% of patients treated respectively primarily transferred to the surgical department. Mortality in arterial bleeding and visible vessel in the conservatively treated group was double the mortality in the early elective operated group (14 vs. 7%). The mortality in patients treated primarily in the department of internal medicine was double the mortality of patients treated at the surgical department (18 vs. 9%). The differences in mortality are mainly due to the procedure in the elderly patients. In patients aged 70 years or more, the mortality rate of patients treated in internal medicine was 31% compared to 16% in the surgery department. Younger patients do not seem to benefit from early elective operation. Our study clearly demonstrates the importance of avoiding late recurrent bleeding. Patients at high risk of this complication should therefore be identified as early as possible and early surgical intervention should be considered by agreed interdisciplinary and evaluated treatment concepts.

Adult↗
PubMed1998

[Restorative surgery of a Hartmann status for relief of chronic sphincter problems].

The Hartmann situation is a temporary intestinal diversion to treat diseases of the rectosigmoid. In case of benign rectosigmoidal disorders the entirely laparoscopic performance of the colon disconnection and reconstruction is an advantage due to its minimal invasive nature. A patient suffering from chronic anorectal fistula with temporary relief exclusively performed by laparoscopic approach is reported.

Adult↗
PubMed1998

Multiparameter analysis of clastogenic factors, pro-oxidant cytokines, and inflammatory markers in HIV-1-infected patients with asymptomatic disease, opportunistic infections, and malignancies.

HIV-1-infected patients are in chronic oxidative stress and clastogenic factors (CFs) are present in their plasma. CFs from patients with HIV are formed via superoxide anion radical and stimulate further superoxide production. The pathophysiolgic significance and the exact composition of the circulating clastogenic material in patients with HIV is unknown. Cytokines, such as tumor necrosis factor-alpha (TNF-alpha), are increased in the plasma of patients with HIV and TNF-alpha shows clastogenic activity in vitro. The aim of this clinical study was to compare levels of CF in HIV-1-positive patients with asymptomatic disease, opportunistic infections, and malignancies with those in HIV-1-negative control groups and to correlate CF activity with CD4+ T cell numbers, the cytokines (TNF-alpha, interleukin-2 [IL-2], IL-6), and the inflammatory markers (C-reactive protein [CRP], neopterin, granulocyte elastase). CFs were significantly increased in all HIV-1-positive patients and in HIV-1-negative patients with malignant tumors. HIV-1-positive patients with Kaposi's sarcoma showed the highest CF activity in their plasma (p < 0.08). CFs appear very early in HIV infection, and they correlate negatively with CD4+ T cells, which are an indicator of disease activity. The presence of CF in the plasma of HIV-infected patients is not a general response to a viral infection because these factors are not increased in HIV-1-negative patients with viral infection (zoster). CFs are not specific for the HIV-1 infection; they also occur in HIV-1-negative patients with malignant tumors. There was a tendency towards a positive correlation (p < 0.14) between CF and TNF-alpha but there was no positive correlation of CF with IL-2, IL-6, CRP, elastase, and neopterin levels. This indicates that TNF-alpha may be among the components of CF in HIV-1-infected patients. In addition, other unidentified components may contribute to the clastogenic activity of the plasma or the composition of CF may vary from patient to patient. Further clinical studies with larger sample populations are necessary to analyze the composition of CF in HIV-1-positive patients.

AIDS-Related Opportunistic Infections↗
PubMed1997

Prevalence of hepatitis C virus antibodies and evaluation of hepatitis C virus genotypes in patients with lichen planus.

BACKGROUND: Several cases of lichen planus (LP) associated with hepatitis C virus (HCV) infection have been described. The reported prevalence rates of anti-HCV in patients with LP show wide geographical variations. An association of HCV-associated disorders with certain HCV geno/subtypes has not been investigated so far. OBJECTIVE: The aim of the present study was to define the prevalence rate of anti-HCV in German patients with LP and to determine the distribution of HCV geno/subtypes. METHODS: All patients with LP of the present study (n = 84) were tested for anti-HCV antibodies by an enzyme-immunoassay (second generation). HCV RNA was detected by reverse-transcription polymerase chain reaction (RT-PCR) and HCV geno/subtyping was performed by the reverse hybridization assay. Serum samples of 87 patients with various cutaneous diseases excluding LP served as control group. RESULTS: Anti-HCV antibodies were detected in 13/84 patients with LP (16%), and 12/13 anti-HCV-positive patients were viraemic as assessed by the presence of HCV RNA. Most patients were infected with subtype HCV-1b (10/12 patients), while the 2 remaining patients were infected with HCV-2b and HCV-3a, respectively. In the control group, anti-HCV antibodies were only observed in 1/87 patients (1.1%), infected with subtype HCV-1b. CONCLUSION: The statistically significant (p < 0.002) high prevalence of HCV RNA in patients with LP is suggestive of an aetiological role of HCV in the pathogenesis of LP. Compared to the geno/subtype distribution of patients with chronic hepatitis C without LP of the same geographical area, no convincing correlation between geno/subtype and the presence of LP was obtained.

Adolescent↗