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Biomedical subjects

B Kremer

Publications and source records attributed to B Kremer.

At least 37 records · Page 2Linked to original sources
PubMed2004

Differential gene expression in human brain pericytes induced by amyloid-beta protein.

Cerebral amyloid angiopathy is one of the characteristics of Alzheimer's disease (AD) and this accumulation of fibrillar amyloid-beta (Alphabeta) in the vascular wall is accompanied by marked vascular damage. In vitro, Abeta1-40 carrying the 'Dutch' mutation (DAbeta1-40) induces degeneration of cultured human brain pericytes (HBP). To identify possible intracellular mediators of Abeta-induced cell death, a comparative cDNA expression array was performed to detect differential gene expression of Abeta-treated vs. untreated HBP. Messenger RNA expression of cyclin D1, integrin beta4, defender against cell death-1, neuroleukin, thymosin beta10, and integrin alpha5 were increased in DAbeta1-40-treated HBP, whereas insulin-like growth factor binding protein-2 mRNA expression was decreased. Corresponding protein expression was investigated in AD and control brains to explore a potential role for these proteins in pathological lesions of the AD brain. Cyclin D1 expression was increased in cerebral amyloid angiopathy and cells in a perivascular position, suggesting that the cell cycle may be disturbed during Abeta-mediated degeneration of cerebrovascular cells. Moreover, cyclin D1 expression, but also that of integrin beta4, defender against cell death-1, neuroleukin and thymosin beta10 was found in a subset of senile plaques, suggesting a role for these proteins in the pathogenesis of senile plaques.

Alzheimer Disease↗
PubMed2003

[Quality management in surgery--an overview of methods and possibilities].

Numerous methods of assessing quality in health care have been presented over the last years. Since the German health care reform of 2000 introduced a legal obligation to quality assurance, hospitals have to meet that condition. However, no specific system of quality assurance was implicated. Therefore, many potential users search for systems suiting their own needs. However, German hospitals can benefit from international experience in quality management. Accreditation, visitation, excellence schemes, and certification seem to be the dominant methods. Every method is worthy of hospital evaluation. Certifications illustrate the quality system view without regard to profession, while excellence schemes evaluate the development of quality management in hospitals. Accreditation portrays a specific hospital as a whole, while visitations follow the professional perspective of quality assurance. Depending on the perspective and aims, there are advantages and disadvantages in each method. Finally, a combination of two may also be helpful. Indeed, no "role model" exists yet for assessing quality in health care. These methods of quality management are applicable especially in surgery, because a variety of standard outcome parameters such as length of stay, duration of procedure, and complication and relapse rates are already available.

Accreditation↗
PubMed2003

Salivary cortisol patterns and cognitive speed in major depression: a comparison with allergic rhinitis and healthy control subjects.

Few studies have investigated the relationship between cortisol and cognitive functions other than memory in depression. This study investigated daily salivary cortisol patterns (basal cortisol levels at 08:00, 16:00, and 21:00 h and flatness of the diurnal curve) in relation to cognitive speed and memory. Twenty-seven unmedicated outpatients with major depressive disorder (MDD) were compared with 36 healthy controls and with 20 allergic rhinitis patients, to determine whether effects should be ascribed to MDD or to more general disease-related processes. MDD patients were characterised by a flatter diurnal cortisol curve and by reduced cognitive speed. Flatter cortisol curves were associated with cognitive slowness. However, this relationship is unlikely to be causal; after control for depressive symptoms and group membership, flatness of the diurnal cortisol curve was no longer a significant predictor of cognitive slowness. Thus, MDD and related depressive symptoms appeared to be independently associated with altered cortisol secretory patterns and with decrements in cognitive speed.

Adult↗
PubMed2003

Cognitive functioning in young and middle-aged unmedicated out-patients with major depression: testing the effort and cognitive speed hypotheses.

BACKGROUND: Cognitive deficits are common in major depressive disorder, but their nature is unclear. The effort hypothesis states that performance on effortful tasks is disproportionately impaired compared with the performance on automatic tasks. The cognitive speed hypothesis states that depression is characterized by cognitive slowness, which is a source of cognitive dysfunctioning. The present study investigated both theories in unmedicated adult depressive patients. It was also investigated whether the cognitive deficits can be attributed to more general physical illness-related factors or specifically to depressive disorder. METHOD: Thirty non-psychotic depressive out-patients were compared with 38 healthy control subjects and 25 patients with severe allergic rhinitis. The effects of group on more automatic and more effortful aspects of cognitive tasks measuring cognitive speed (Concept Shifting Task, Stroop Colour Word Test, Memory Scanning Test) and memory retrieval (Visual Verbal Learning Task, Verbal Fluency Test) were evaluated by MANCOVA. Age, sex, education and pre-morbid intelligence were treated as covariates. RESULTS: The depressive group had cognitive deficits in the automatic processing subtask of the Stroop, memory scanning and memory span. Performance on more effortful tasks was not impaired. CONCLUSIONS: Our results are more consistent with the cognitive speed hypothesis. Cognitive functioning in depressive disorder seems to be characterized by a reduced speed of information processing in automatic subtasks.

Adult↗
PubMed2003

Therapy of anastomotic leaks by means of covered self-expanding metallic stents after esophagogastrectomy.

BACKGROUND AND STUDY AIMS: The mortality rate for surgical revision of gastroesophageal anastomotic leakage after resection for cancer approximates 60 %. The efficacy of endoscopically placed covered metallic stents for treatment of gastroesophageal leakage was evaluated. PATIENTS AND METHODS: Between June 1996 and June 2002 we treated 21 patients with proven gastroesophageal leakage; 18 had anastomotic leakage and three patients had perforation for different reasons. The extent of the leaks ranged from one-quarter of the intestinal circumference to its complete dehiscence. The average time from surgery to detection of leakage was 6.1 days (range 3 - 15 days). Mortality, healing rate, length of hospital stay, and complications were assessed. RESULTS: The insertion of stents was performed endoscopically under radiological guidance without any complication in all patients. In 9.5 % (2/21) of patients complete sealing of the leak was not achieved. The mortality associated with anastomotic leakage was 23.8 % (5/21). In 80.1 % (17/21) patients complete healing of the leakage was achieved. The average hospital stay was 67 days (range 14 - 158 days). Of 23 stents, 13 (56.5 %) were removed, and three patients developed stenosis after removal. CONCLUSION: The treatment of gastroesophageal leakage with covered stents appears to reduce mortality and the complication rate associated with major leakage. Therefore this technique seems to be a reasonable alternative in the treatment of clinically relevant anastomotic leakage.

Adult↗
PubMed2003

Long-term culture and differentiation of rat embryonic stem cell-like cells into neuronal, glial, endothelial, and hepatic lineages.

The in vitro differentiation of mouse embryonic stem cells into different somatic cell types such as neurons, endothelial cells, or myocytes is a well-established procedure. Long-term culture of rat embryonic stem cells is known to be hazardous, and attempts to differentiate these cells in vitro so far have been unsuccessful. We herein describe stable long-term culture of an alkaline phosphatase-positive rat embryonic stem cell-like cell line (RESC) and its differentiation into neuronal, endothelial, and hepatic lineages. RESCs were characterized by typical growth in single cells as well as in embryoid bodies when cultured in the presence of leukemia inhibitory factor. RESC expressed stage-specific-embryonic antigen-1 and the major histocompatibility complex class I molecule. For neuronal differentiation, cells were incubated with medium containing 10(-6) M retinoic acid for 14 days. For endothelial differentiation, RESCs were grown on Matrigel for 14 days, and for induction of hepatocyte-specific antigen expression, RESCs were grown in medium supplemented with fibroblast growth factor-4. Differentiated cells exhibited typical morphological changes and expressed neuronal (nestin, mitogen-activated protein-2, synaptophysin), glial (S100, glial fibrillary acid protein), endothelial (panendothelial antibody, CD31) and hepatocyte-specific (alpha-fetoprotein [alphaFP], albumin, alpha-1-antitrypsin, CK18) antigens. In addition, expression of hepatocyte-specific genes (alphaFP, transthyretin, carbamoyl-phosphate synthetase, and coagulation factor-2) was detected by reverse transcription polymerase chain reaction. We were able to culture RESCs under stable, long-term conditions and to initiate programmed differentiation of RESCs to endothelial, neuronal, glial, and hepatic lineages in the rat species.

Animals↗
PubMed2003

Effects of dimethindene maleate nasal spray on the quality of life in seasonal allergic rhinitis.

OBJECTIVE: To determine if the H1-receptor antagonist dimethindene maleate (DMM), topically applied, is able to improve the quality of life (QoL) in patients with seasonal allergic rhinitis better than placebo. METHODS: The study was a multi-centre, randomised, placebo-controlled, double-blinded phase III trial including 157 patients. Two parallel groups received either DMM nasal spray or placebo for 2 weeks. Patients answered 5 QoL questionnaires (Rhinoconjunctivitis QoL Questionnaire (LQ-AR), Munich Life Dimension List (MLDL), Profile of Mood States (POMS), 2 Visual Analogue Scales (VAS-QoL, VAS-GES)) on days 1, 4, 8, and 15. RESULTS: QoL improved significantly in all scales and groups. Statistically significant differences between groups were achieved in the sub-scales LQ-AR Eye Symptoms and Daily Activities, MLDL Total, POMS Depression and Energy, VAS-QoL and VAS-General Health. All differences favoured the DMM group and were present initially but disappeared in visit 4, except MLDL Total and POMS Energy. Almost all other scores had a better tendency of DMM. CONCLUSION: A significant improvement of QoL was found in both groups. Only weak differences between groups (in favour of DMM) were found. There are several reasons explaining this outcome, mainly the rainy weather during the study period (mean weather index 10-20% less sunny than in previous seasons).

Administration, Intranasal↗
PubMed2002

The ex utero intrapartum treatment (EXIT) procedure in fetal neck masses: a case report and review of the literature.

Large fetal neck masses can cause airway obstructions with potential fetal demise after delivery. The relationship of the neck mass to airway structures can be defined prenatally with ultrasound and magnetic resonance imaging (MRI). The ex utero intrapartum treatment (EXIT) procedure can be used to obtain a fetal airway while feto-maternal circulation is preserved to optimise fetal outcome. We present a case in which prenatally a large fetal neck mass was diagnosed on ultrasound and a successful EXIT procedure was performed. A review of the literature is given and the prenatal use of ultrasonography and MRI in case of fetal neck masses is discussed.

Adult↗
PubMed2002

Relationship between allergic rhinitis, disturbed cognitive functions and psychological well-being.

BACKGROUND: Symptomatic allergic rhinitis reduces quality of life as a result of the symptoms experienced and possibly as a result of impaired psychological well-being and cognitive functioning. Few investigations have measured cognitive functions objectively and it remains uncertain whether allergic rhinitis leads to an objective reduction in cognitive functions. OBJECTIVE: To evaluate the relationship between symptomatic allergic rhinitis, cognitive functions and psychological well-being. Differences between subjective and objective cognitive impairments were evaluated. METHODS: The cognitive functions (working memory, memory retrieval, speed of information processing and flexibility of information processing) and psychological well-being of 26 patients with symptomatic allergic rhinitis and 36 healthy controls matched for intelligence, education, age and sex were compared. The influence of education, intelligence, sex and age was considered. RESULTS: Overall, psychological well-being was significantly impaired in the patient group, as shown by higher scores in feelings of insufficiency, complaints of somatization, sleep disturbances and depressive feelings, whereas cognitive function was not. CONCLUSIONS: Allergic rhinitis was related to significantly impaired psychological well-being and to perceived impaired cognitive functioning. However, no significant objective impairment of cognitive functioning was found. Allergic patients may temporarily put more effort into sustaining performance, resulting in earlier exhaustion, which is not noticed during assessment but which impairs psychological well-being.

Adult↗
PubMed2002

Indications, complications, and surgical techniques for pediatric tracheostomies--an update.

BACKGROUND: With the decrease of life-threatening obstructive upper airway infections and the ongoing improvement of intensive care medicine, the role of tracheostomy in children has been changing considerably, until now. The aim of this study was to establish data regarding indications, complications, and techniques of pediatric tracheostomy, which would reflect the current state of science. METHODS: The authors analyzed the international literature as well as their own experience with 25 children less than 6 years of age who were operated on between 1980 and 1996. RESULTS: Literature proved to be very heterogeneous in terms of terminology, patient groups, operation techniques, indications, and complications. Within the past decades, long-term intubation and congenital anomalies of the upper respiratory tract have become increasingly prevalent, whereas inflammatory diseases were less and less an indication for tracheostomy. Endotracheal intubation as an alternative has resulted in less frequent tracheostomies in general. Today, children can be ventilated for months without considerable complications. However, individual, clinical, and fiberoptical controls are necessary. Tracheostomy-related complications have not changed significantly. Fatalities are mostly caused by the underlying disease. The most frequent causes of tracheostomy-related death are cannula obstruction and accidental decannulation. The most frequent early complications are pneumomediastinum, pneumothorax, wound complications, and bleedings. Subsequent complications most often are granulations and tracheal stenosis. CONCLUSIONS: The authors' research agreed widely with that in the literature. However, no tracheostomy-related death occurred. Possibly, this was because of their operative technique. In the opinion of the authors, establishing a cartilage window facilitates cannula exchange and reduces the risk of a fatal accidental decannulation.

Age Distribution↗
PubMed2001

Late lethal secondary hemorrhage after laser supraglottic laryngectomy.

Since 1971, a number of articles have been published regarding the complications encountered with laser surgery of the larynx. Most investigations focus on complications such as accidental burns caused by the reflection of the laser beam, endotracheal explosion, special anesthesiologic problems, edema of the mucosa leading to airway obstruction, and abnormal scar formation with functional problems. Secondary hemorrhage has played a subordinate role, and in the few articles that have focused on it, cases requiring postoperative treatment have been reported only sporadically. All of these cases occurred within the first postoperative week, and no case resulting in the death of a patient was reported. We describe a patient in whom a lethal secondary hemorrhage occurred 10 days after a laser supraglottic laryngectomy. Because of the increase of laser applications in the treatment of laryngeal carcinoma, similar complications may be encountered. We comment on possible pathophysiological mechanisms and consequences.

Carcinoma, Squamous Cell↗
PubMed2001

Clinical value of bacteriological examinations of nasal and paranasal mucosa in patients with chronic sinusitis.

Although many investigations on the bacteriology of chronic sinusitis have been reported, there is still much discussion about the physiological flora of the nose and paranasal sinuses, the role of the various aerobic and anaerobic "pathogenic" bacteria, and the influence of the anatomical location from which samples for bacteriology are taken. We conducted a qualitative and semi-quantitative bacteriological examination of patients with chronic sinusitis undergoing a transnasal sinus operation (patient group), and of patients without chronic sinusitis undergoing a septoplasty (control group). In both groups brush smears of the inferior nasal turbinate and biopsies of the middle nasal turbinate were taken, with additional biopsies of the maxillary sinus and ethmoidal bulla in the chronic sinusitis group. In both groups coagulase-negative staphylococci were identified in almost all samples. Staphylococcus aureus was found in 22% (middle turbinate) to 33% (inferior turbinate) of the samples from the control group and in 33% (maxillary sinus, middle turbinate) to 50% (inferior turbinate) of the samples from the patient group. Other (pathogenic) aerobic bacteria were found much more rarely and only slight distinctions between control and patient group were observed. The concentrations of the different bacterial species (colony-forming units) were comparable in both groups. Strictly anaerobic bacteria and fungi were not identified. Only small discrepancies between the various methods and/or locations of sampling were found. Based on our bacteriological findings a differentiation between patients with and without chronic sinusitis was not possible. These results shed doubt on the clinical value of bacteriological examinations of nasal and paranasal mucosa in patients with chronic sinusitis.

Adolescent↗
PubMed2001

Overexpression of phosphatidylinositol 3-kinase in human lung cancer.

BACKGROUND: This study was conducted to investigate the expression of phosphatidylinositol 3-kinase (PI3K) and AKT2, a downstream effector, in primary human lung carcinomas of different histological type. METHODS: Specimens from 105 human lung carcinomas and their corresponding lymph nodes and liver metastases were examined using immunohistochemistry and Northern-blot assays to study the PI3K p85 and p110 subunits and the AKT2-expression patterns. RESULTS: The p85 and p110 subunits of PI3K were overexpressed at the protein level in 77% and 59% of 80 primary lung carcinomas, respectively, irrespective of the histological type. PI3K overexpression was correlated with tumor grading. In contrast, no overexpression of PI3K subunits was observed in normal lung tissue and benign lung tumors. Consistent with these findings, upregulation of p110 mRNA transcripts was restricted to primary lung carcinomas. Overexpression of AKT2 was observed in 10% of the investigated lung tumor specimens, but in none of the healthy lung sections. A profound increase of PI3K expression was uniformly observed in lung tissue specimens and in corresponding extra-pulmonary lymph-node and liver metastases with low-differentiation grades. CONCLUSION: PI3K appears to be associated with the process of tumor-cell transformation and proliferation. One of its major downstream effector molecules, AKT2, which contributes to apoptotic cell death, was not upregulated by PI3K overexpression in primary lung carcinomas.

Adult↗
PubMed2001

The carcinoembryonic antigen and its prognostic impact on immunocytologically detected intraperitoneal colorectal cancer cells.

BACKGROUND: Carcinoembryonic antigen (CEA) has been suggested to promote colon cancer progression. In this study we analyzed the prognostic impact of CEA expression on intraperitoneally detected single colon cancer cells. METHODS: Peritoneal lavage samples of 135 colorectal cancer patients were immunocytologically analyzed, including a staining of cellular CEA; serum CEA levels were measured; and 5-year survival rates were calculated according to immunocytological findings and CEA expression. RESULTS: The worst survival rate of 20% was found in patients suffering from CEA-expressing intraperitoneal tumor cells (P = 0.0006). The prognostic impact of an intraperitoneal tumor cell finding significantly increased when serum CEA levels were elevated: only 23% survived 5 years in contrast to a 85% 5-year survival rate of patients who neither had signs of dissemination nor showed elevated serum CEA values (P = 0.0010). CONCLUSIONS: This study shows that the determination of CEA expression improves the prognostic impact of an intraperitoneal tumor cell finding.

Carcinoembryonic Antigen↗
PubMed2001

Generic or disease-specific quality of life scales to characterize health status in allergic rhinitis?

BACKGROUND: In patients with allergic rhinitis (AR), various instruments have been validated for the measurement of quality of life (QOL), which may be greatly reduced. However, it is not clear which QOL instruments should be used for the different types of AR and whether they are sensitive to treatment. METHODS: The QOL of patients suffering from symptomatic seasonal AR (sSAR) (before and during treatment with a topical or systemic antihistamine), symptomatic perennial AR (sPAR), and asymptomatic seasonal AR (aSAR) was determined with the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) as disease specific and with the Munich Life Dimension List (MLDL) and the Visual Analogue Scale for Quality of Life (VAS-QOL) as generic QOL instruments. RESULTS: The different forms of AR were associated with typical QOL patterns. In sSAR, we found severe limitation of the global QOL, reduced global life satisfaction, high ranking of practical problems, high limitation of activity, and a high degree of disturbance in all subscales of the RQLQ. In sPAR, there were moderate limitation of the global QOL, normal global life satisfaction, high ranking of practical problems, moderate limitation of activity, and a high degree of disturbance by common symptoms. Under antihistamine treatment, both systemic and nasal, a significant improvement of QOL parameters was found, reaching the levels of patients with aSAR after 2 weeks. CONCLUSION: QOL instruments can distinguish the impairment resulting from sSAR from that of sPAR and are sensitive to treatment with topical and systemic antihistamines. However, as the RQLQ was not designed to measure the short-term variations of disease status that appear in SAR, it may not demonstrate the rapid improvement of QOL under antihistamine treatment.

Adult↗