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Biomedical subjects

M Klein

Publications and source records attributed to M Klein.

At least 19 recordsLinked to original sources
PubMed2007

[The central island tongue flap for the reconstruction of the anterior floor of the mouth].

BACKGROUND: There are several techniques described for the reconstruction of the anterior floor of mouth after tumour surgery. Here, we point out the advantages of the central island tongue flap for this indication. PATIENTS AND METHODS: We report on 20 patients with medium sized defect in the anterior floor of mouth, which was reconstructed with the central island tongue flap. Besides this surgical technique, we discuss the results of oral rehabilitation after a follow-up period of at least 3 months. RESULTS: There was now flap necrosis or loss, and the median time for flap formation was less than 45 min. In the follow-up we found successful oral rehabilitation in speech and swallowing.

Aged↗
PubMed2006

Recurrent apical ballooning despite treatment with verapamil.

OBJECTIVE: To report a case of recurrent tako-tsubo syndrome that developed despite treatment with calcium channel antagonists. CASE SUMMARY: A 76-year-old woman with past medical history of ischemic heart disease and mild chronic asthma presented in 2001 with clinical characteristics and laboratory markers consistent with myocardial ischemia. Coronary angiogram was done with successful balloon angioplasty to LAD stenosis. Ventriculogram and echocardiography demonstrated apical ballooning believed to represent aneurysm formation. Several months later, a follow-up echocardiogram (ECG) revealed normal LV size and function with no wall motion abnormalities. ECG was unremarkable. In 2004, the patient was admitted with dyspnea, chest pain and ST elevation in ECG with normal troponin. Coronary angiogram demonstrated patent coronary tree. Left ventriculogram revealed apical ballooning sparing the base of the heart. Medically controlling the asthma attack led to clinical, echocardiographic and remarkable electrocardiographic normalization within days. Rest thallium perfusion scan done within 48 h demonstrated isolated fully reversible defect in the apex after 24 h suggesting a microvessel etiology. CONCLUSION: Tako-tsubo cardiomyopathy is an increasingly recognized condition. We report here the first case of tako-tsubo recurrence despite treatment with verapamil, and suggest a microvessel pathophysiology supported by rest thallium scan.

Aged↗
PubMed2006

Interstitial gas and density segregation of vertically vibrated granular media.

We report experimental studies of the effect of interstitial gas on mass-density segregation in a vertically vibrated mixture of equal-sized bronze and glass spheres. Sufficiently strong vibration in the presence of interstitial gas induces vertical segregation into sharply separated bronze and glass layers. We find that the segregated steady state (i.e., bronze or glass layer on top) is a sensitive function of gas pressure and viscosity, as well as vibration frequency and amplitude. In particular, we identify distinct regimes of behavior that characterize the change from bronze-on-top to glass-on-top steady state.

Journal Article↗
PubMed2006

Proxy measurements in multiple sclerosis: agreement between patients and their partners on the impact of multiple sclerosis in daily life.

BACKGROUND: The use of self-report measurements in clinical settings has increased. The underlying assumption for self-report measurements is that the patient understands the questions fully and is able to give a reliable assessment of his or her own health status. This might be problematic in patients with limitations that interfere with reliable self-assessment such as cognitive impairment or serious mood disturbances, as may be the case in multiple sclerosis. In these situations proxies may provide valuable information, provided we can be certain that proxies and patients give consistent ratings. OBJECTIVE: To examine whether patients with multiple sclerosis and their partners agree on the impact of multiple sclerosis on the daily life of the patient by using the Multiple Sclerosis Impact Scale (MSIS-29). METHODS: 59 patients with multiple sclerosis and their partners completed the MSIS-29. Agreement was examined, comprehensively at scale score levels and item functioning, using both traditional and less conventional psychometric methods (Rasch analysis). RESULTS: Agreement between patients and partners was good for the physical scale, and slightly less but still adequate for the psychological scale. Mean directional differences did not show considerable systematic bias between patients and proxies. Intraclass correlation coefficients (ICCs) satisfied the requirements for agreement, but were higher for the physical scale (0.81) than for the psychological scale (0.72). These findings were supported by Rasch analyses. CONCLUSION: In this sample, albeit small, partners provided accurate estimates of the impact of multiple sclerosis. This supports the value of self-rating scales and indicates that partners might be useful sources of information when assessing the impact of multiple sclerosis on the daily life of patients.

Adult↗
PubMed2006

[Modern pacing therapy].

Since pacemakers first have been implanted in 1958 considerable technical progress has been achieved. The devices are more efficient today, have complex diagnostic functions, memory capacity and it is even possible to get telemetric software updates. Automatic mode switch due to changing heart rhythm, adaptation of AV-delay, auto sensing and auto stimulation threshold are available and facilitate pacemaker follow up. Because of continuously progress in pacing therapy guidelines have to be updated very often. The newest German and international guidelines for pacing therapy have been published in 2005 by Deutsche Gesellschaft für Kardiologie/ Herz- und Kreislaufforschung (DGK). Indications for pacing therapy increases continuously. Not only bradycardia, but also heart failure, prophylactic pacing to prevent and to terminate tachyarrhythmias are modern fields of pacing therapy.

Bradycardia↗
PubMed2006

[The rare malformation of nasal aplasia].

BACKGROUND: After presenting two sisters with the rare form of congenital arrhinia, this syndrome is reviewed, an explanation of the pathogenesis is offered and the therapeutic options of the functional and aesthetic reconstruction are discussed. DISCUSSION: In cases of congenital arrhinia different degrees of respiratory distress, cyanotic episodes, and impaired food intake are described. Therefore after birth respiration and food intake need to be monitored to alleviate the situation through intubation or tracheotomy. The following conclusions could be made based on the literature overview. Little is known about the pathophysiology and a great variety of therapeutic interventions and reconstruction solutions with a wide spectrum of complications are described. Due to the numerous forms of complications, which need to be compared with the reconstructive results, indications for surgical reconstruction of the airway and plastic reconstruction of the nose during childhood must be defined very stringently. CONCLUSION: One method to achieve a satisfactory plastic result is with an osseointegrated prosthesis. This facial prosthesis can be inserted without complications and can guarantee an adequate result, whereas no impairment of maxillofacial development was noted.

Adolescent↗
PubMed2006

Clinical evaluation of endosseous implants in nonvascularized fibula bone grafts for reconstruction of the severely atrophied mandibular bone.

PURPOSE: The purpose of the present study was to assess changes in graft height after augmentation of the severely atrophied mandibula with the use of avascular fibula bone grafts, as well as evaluation of the clinical success of endosseous implants placed in the grafted mandibula. PATIENTS AND METHODS: This retrospective study included 10 patients with a mean observation period of 31 months (range, 3 to 76 months). A total of 40 implants were placed. Clinical criteria included implant success, graft success, and crestal bone resorption. RESULTS: The grafting procedure was successfully performed in all patients. All implants were integrated, 2 implants could not be used for prosthetic rehabilitation. One implant was lost 2 years after abutment connection. The maximum bone resorption of 7.21% (+/- 2.7%) was seen within the first year; no significant resorption was seen thereafter. CONCLUSION: In this clinical and radiographic evaluation, it was found that nonvascular fibula graft is a reliable material for augmentation procedures. The resorption takes place within the first year after augmentation. The possibility of improving the clinical results in bone grafting situations with avascular fibula grafts will be further evaluated in a prospective follow-up study providing long-term assessment of this procedure.

Aged↗
PubMed2006

Clinically applicable 7-Tesla magnetic resonance visualization of transplanted human adult stem cells labeled with CliniMACS nanoparticles.

BACKGROUND: Intra-myocardial transplantation of bone marrow derived cells is currently under clinical evaluation as a therapy for heart failure. A major limitation of all clinical studies for myocardial restoration through cell transfer is the inability to track the fate of the transplanted cells. We present a clinically applicable technique using advanced ultra high-field 7-Tesla (7T) magnetic resonance imaging (MRI) of nanoparticle-labeled transplanted human EPCs in porcine ischemic hearts. METHODS: CD133 positive cells were isolated from bone marrow by magnetic bead selection. Positive cells (5 - 8 x 10 (6) cells) were transplanted into porcine ischemic myocardium (n = 8). Control animals (n = 3) received a medium injection. MRI on a 7T scanner was performed to demonstrate the distribution of the EPCs. RESULTS: CD133+ cells were identified on gradient echo images (T(1)-weighted) within the myocardium 4 weeks after transplantation. CONCLUSIONS: Magnetically labeled EPCs transplanted for therapeutic neovascularization or reduction of infarct size in myocardial ischemia can be visualized by MRI at high-field strengths.

Adult Stem Cells↗
PubMed2006

Emergency department delays in acute stroke - analysis of time between ED arrival and imaging.

We determined the factors leading to emergency department (ED) delays in patients with acute stroke. Data were collected prospectively in four Berlin inner-city hospitals by ED documentation, medical records, imaging files and patient interviews. An extended Cox proportional hazards model was fitted to the data. Analyses were performed in 558 patients with confirmed diagnosis of stroke. Median time from admission at ED to beginning of computed tomography/magnetic resonance imaging (CT/MRI) was 108 min. In a subgroup of patients potentially eligible for thrombolysis with a pre-hospital delay <120 min and a National Institutes of Health Stroke Scale (NIHSS) >4 (n = 74), the median interval to imaging was 68 min. Multivariable analysis revealed that a more severe initial NIHSS, a pre-hospital delay <3 h, admission at two specific hospitals, admission at weekends, and private health insurance were significantly associated with reduced delays. In stroke patients, the time interval between ED admission and imaging depends both on factors that emerge from clinical needs and on factors independent of clinical necessities. Considering the urgency of therapeutic measures in acute stroke, there is necessity and room for both improvement of in-hospital management and of medical and non-medical factors influencing pre-hospital delays.

Aged↗
PubMed2005

Interleukin-1 receptor antagonist is upregulated during diet-induced obesity and regulates insulin sensitivity in rodents.

AIMS/HYPOTHESIS: The IL-1 receptor antagonist (IL-1Ra) is an anti-inflammatory cytokine known to antagonise the actions of IL-1. We have previously shown that IL-1Ra is markedly upregulated in the serum of obese patients, is correlated with BMI and insulin resistance, and is overexpressed in the white adipose tissue (WAT) of obese humans. The aim of this study was to examine the role of IL-1Ra in the regulation of glucose homeostasis in rodents. METHODS: We assessed the expression of genes related to IL-1 signalling in the WAT of mice fed a high-fat diet, as well as the effect of Il1rn (the gene for IL-1Ra) deletion and treatment with IL-1Ra on glucose homeostasis in rodents. RESULTS: We show that the expression of Il1rn and the gene encoding the inhibitory type II IL-1 receptor was upregulated in diet-induced obesity. The blood insulin:glucose ratio was significantly lower in Il1rn ( -/- )animals, which is compatible with an increased sensitivity to insulin, reinforced by the fact that the insulin content and pancreatic islet morphology of Il1rn ( -/- ) animals were normal. In contrast, the administration of IL-1Ra to normal rats for 5 days led to a decrease in the whole-body glucose disposal due to a selective decrease in muscle-specific glucose uptake. CONCLUSIONS/INTERPRETATION: The expression of genes encoding inhibitors of IL-1 signalling is upregulated in the WAT of mice with diet-induced obesity, and IL-1Ra reduces insulin sensitivity in rats through a muscle-specific decrease in glucose uptake. These results suggest that the markedly increased levels of IL-1Ra in human obesity might contribute to the development of insulin resistance.

Adipose Tissue↗
PubMed2005

Genotype-phenotype correlations of 39 patients with Cornelia De Lange syndrome: the Dutch experience.

BACKGROUND: Cornelia de Lange syndrome (CdLS) is a multiple congenital anomaly syndrome characterised by a distinctive facial appearance, prenatal and postnatal growth deficiency, psychomotor delay, behavioural problems, and malformations of the upper extremities. Recently mutations in NIPBL, the human homologue of the Drosophila Nipped-B gene, were found to cause CdLS. Mutations have been found in 39% of reported cases. METHODS: Patients were enrolled in the study and classified into one of four groups based on clinical examination: classic, mild, possible, or definitively not CdLS. Three dimensional photography was taken of 20 subjects, and compared between groups. Behaviour was assessed with specific attention to autism. We searched for mutations in NIPBL and correlated genotype with phenotype. RESULTS: : We found mutations in 56% of cases. CONCLUSIONS: Truncating mutations were generally found to cause a more severe phenotype but this correlation was not absolute. Three dimensional facial imaging demonstrated the potential for classifying facial features. Behavioural problems were highly correlated with the level of adaptive functioning, and also included autism. No correlation of behaviour with the type of mutation was found.

Autistic Disorder↗
PubMed2005

Functional role of Na+-HCO3- cotransport in migration of transformed renal epithelial cells.

Cell migration is crucial for immune defence, wound healing or formation of tumour metastases. It has been shown that the activity of the Na(+)-H(+) exchanger (NHE1) plays an important role in cell migration. However, so far it is unknown whether Na(+)- HCO(3)(-) cotransport (NBC), which has similar functions in the regulation of intracellular pH (pH(i)) as NHE1, is also involved in cell migration. We therefore isolated NHE-deficient Madin-Darby canine kidney (MDCK-F) cells and tested whether NBC compensates for NHE in pH(i) and cell volume regulation as well as in migration. Intracellular pH was measured with the fluorescent pH indicator 2'7'-bis(carboxyethyl)-5-carboxyfluorescein (BCECF). The expression of NBC isoforms was determined with semiquantitative PCR. Migration was monitored with time-lapse video microscopy and quantified as the displacement of the cell centre. We found that MDCK-F cells express the isoform NBC1 (SLCA4A gene product) at a much higher level than the isoform kNBC3 (SLCA4A8 gene product). This difference is even more pronounced in NHE-deficient cells so that NBC1 is likely to be the major acid extruder in these cells and the major mediator of propionate-induced cell volume increase. NHE-deficient MDCK-F cells migrate more slowly than normal MDCK-F cells. NBC activity promotes migration during an acute intracellular acid load and increases migratory speed and displacement on a short timescale (< 30 min) whereas it has no effect on the long-term behaviour of migrating MDCK-F cells. Taken together, our results show that NBC actvity, despite many functional similarities, does not have the same importance for cell migration as NHE1 activity.

Animals↗
PubMed2005

Hypothyroidism in rats decreases peripheral glucose utilisation, a defect partially corrected by central leptin infusion.

AIMS/HYPOTHESIS: The aims of this work were to determine the effect of hypothyroidism on insulin-stimulated glucose turnover and to unravel the potential mechanisms involved in such an effect. METHODS: Hypothyroidism was induced by administration of propylthiouracil, with partial T4 substitution. Euglycaemic-hyperinsulinaemic clamps, associated with the labelled 2-deoxy-D-glucose technique for measuring tissue-specific glucose utilisation, were used. To assess a possible involvement of leptin in the modulation of glucose metabolism by hypothyroidism, leptin was infused intracerebroventricularly for 6 days. A group of leptin-infused rats was treated with rT3 to determine a potential role of T3 in mediating the leptin effects. RESULTS: Compared with euthyroid rats, hypothyroid animals exhibited decreased overall glucose turnover and decreased glucose utilisation indices in skeletal muscle and adipose tissue. Leptinaemia in hypothyroid rats was lower while resistin mRNA expression in adipose tissue was higher than in euthyroid animals. Intracerebroventricular leptin infusion in hypothyroid rats partially restored overall, muscle and adipose tissue insulin-stimulated glucose utilisation and improved the reduced glycaemic response observed during insulin tolerance tests. The leptin effects were due neither to the observed increase in plasma T3 levels nor to changes in the high adipose tissue resistin expression of hypothyroid rats. The administration of leptin to hypothyroid animals was accompanied by increased expression of muscle and adipose tissue carnitine palmitoyl transferases, decreased plasma NEFA levels and reduced muscle triglyceride content. CONCLUSIONS/INTERPRETATION: Hypothyroidism is characterised by decreased insulin responsiveness, partly mediated by an exaggerated glucose-fatty acid cycle that is partly alleviated by intracerebroventricular leptin administration.

Adipose Tissue↗
PubMed2005

[Extended hemodynamic monitoring using transpulmonary thermodilution Influence of various factors on the accuracy of the estimation of intrathoracic blood volume and extravascular lung water in critically ill patients].

BACKGROUND: The transpulmonary thermal-dye dilution (TDD) is the clinical gold standard for measurement of intrathoracic blood volume (ITBV) and extravascular lung water (EVLW). Recently, experimental and clinical studies found that ITBV and EVLW can be derived reliably by single transpulmonary thermodilution (TD), however, dependency from various factors of lung function has been discussed. PATIENTS AND METHODS: We retrospectively analyzed data from 174 critically ill patients who had undergone hemodynamic monitoring by TDD. We calculated the differences of simultaneous TD and TDD determined by ITBV or EVLW measurements. Bias and standard deviations (SD) were calculated and extended Bland-Altman regression analyses were performed. Association of the differences and the potential confounders gender, age, PEEP, p(a)O(2)/F(I)O(2) ratio and the corresponding TDD measurement were analyzed by multiple linear regression and LOWESS regression. RESULTS: Overall results (bias+/-SD) were 1+/-58 ml/m(2) for ITBV and 0.0+/-1.4 ml/kg bw for EVLW, but TD overestimated TDD results in patients with higher ITBV and underestimated those for lower ITBV values. The deviations were small, and the dependence of ITBV could be explained completely by dependence on PEEP and age. However, low values of EVLW are overestimated by TD. CONCLUSION: Single transpulmonary thermodilution for estimation of ITBV or EVLW is reliable in patients with severe lung injury for normal and higher values.

Adolescent↗
PubMed2005

[Symptoms, risk factors, and etiology of transient ischemic attack and stroke].

BACKGROUND: It is unclear whether clinical signs and symptoms differ in the presentation of transient ischemic attack (TIA) and stroke, apart from temporal dynamics. METHODS: Signs and symptoms of patients diagnosed with TIA or stroke were prospectively collected and compared by means of an age-adjusted logistic regression analysis. Risk factors, prehospital medication, and diagnostic workup were obtained from the charts. RESULTS: Four hundred five patients diagnosed with stroke (68+/-12 years old, 45% female) and 143 diagnosed with TIA (64+/-14 years old, 48% female) were included. Signs and symptoms of patients with TIA were less often "classic" such as paresis (48% vs 71%, P<0.001) or sensory loss (38% vs 48%, P=0.03). The etiology of TIA was more often classified as "undetermined" (57% vs 46%, P<0.05). CONCLUSIONS: Transient ischemic attack needs special attention and intensive diagnostic workup, because it bears a considerable risk of death and disability but presents less often with classic signs and symptoms and its etiology often remains undetermined.

Aged↗
PubMed2005

[Analysis of quality of life in patients with a facial prosthesis].

OBJECTIVE: This clinical study examined the quality of life of face-disabled patients who had received a facial prosthesis. PATIENTS AND METHODS: The examination of the 58 patients was performed using different questionnaires. For the evaluation of the subjective health-related quality of life an instrument constructed by the WHO was used (WHOQOQL-Bref). The Frankfurter Scales of Body Concepts (FKKS) was chosen to measure the self-assessment of the patient's own body perception. For the assessment of the present general quality of life a visual analogue scale was used (Anamnestic Comparative Self-Assessment, ACSA). Additionally an ad hoc questionnaire was used, which registers the post-therapeutic epithetic rehabilitation. The health-related quality of life of this sample was compared to a healthy one of the normal population. RESULTS: The examinations showed that the quality of life of the patients is reduced in contrast to the healthy group when the acquired defects were located in the region of the eye and the nose. The evaluation of the scales of body concepts showed that the patient's own body image was significantly altered. Body contact with other persons and their own sexual attraction was perceived as remarkably diminished. The patients believed that they spread an unpleasant odor. It is surprising that the wearers of a facial prosthesis indicated that they did not notice a restriction in the acceptance of their body by others. The influence of the application of camouflage did not have an impact on the quality of life. CONCLUSION: To improve the restricted quality of life, to the raise the reduced well-being and to strengthen the altered body experience, psychological care should be provided besides further optimization of the surgical-epithetic therapy and the camouflage technique.

Adaptation, Psychological↗