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Biomedical subjects

C Schmidt

Publications and source records attributed to C Schmidt.

At least 145 records · Page 8Linked to original sources

Lipopolysaccharide-binding protein accelerates and augments Escherichia coli phagocytosis by alveolar macrophages.

BACKGROUND: The first step in bacterial clearance by leukocytes is attachment and phagocytosis. Although lipopolysaccharide-binding protein (LBP) is best known for potentiating LPS-induced cytokine production through a CD14-dependent pathway, recent studies suggest that LBP plays a critical role in clearance of gram-negative bacteria and is essential for survival after bacterial challenge. We therefore sought to examine LBP's effect on Escherichia coli phagocytosis by alveolar macrophages (AMs) and to determine if this effect is mediated through CD14. MATERIALS AND METHODS: Phosphatidylinositol-specific phospholipase C (PIPLC)-treated and untreated rat AMs were incubated in the presence of increasing doses of recombinant LBP or negative control protein (choramphenicol acetyltransferase) prior to E. coli-FITC (Ec-F) BioParticle challenge. Phagocytosed bacteria were assayed by fluorescence measurement. A time course study was also performed. RESULTS: LBP potentiated phagocytosis of Ec-F BioParticles by AMs in a dose-dependent fashion. Kinetic studies showed that LBP augmented Ec-F phagocytosis by 76% at 30 min. Treatment of AMs with PIPLC to remove CD14 resulted in only a partial decrease in LBP-mediated enhancement of phagocytosis. CONCLUSION: These results clearly demonstrate that LBP plays an important role in enhancing Ec-F binding and phagocytosis in a time- and dose-dependent manner. This observed increase may not require the presence of CD14 as significant potentiation of phagocytosis still occurred after PIPLC treatment. We postulate that the LBP-mediated increase in Ec-F phagocytosis can occur in the absence of CD14 through the presence of another receptor.

Acute-Phase Proteins↗

Wound complications after left ventricular assist device implantation.

BACKGROUND: Wound necrosis and infection pose a tremendous risk for patients with left ventricular assist devices. METHODS: We analyzed our database of patients with left ventricular assist devices for those who developed wound dehiscence and concomitant infection after left ventricular assist device implantation. RESULTS: Three of our 66 patients (4.5%) with implantable ventricular assist devices had had severe wound complications with necrosis of the abdominal or thoracic wall uncovering part of the device. The predominant impact on the development of these complications was presumably related to multiple surgical interventions on the same site. CONCLUSIONS: Nevertheless, these patients can recover and undergo successful heart transplantation if adequately managed.

Abdominal Muscles↗

Gamma-hydroxybutyric acid as a signaling molecule in brain.

Gamma-hydroxybutyric acid was synthesized 35 years ago to obtain a GABAergic substance that penetrates the brain freely. Since then, gamma-hydroxybutyric acid has been used in human beings for its sedative and anesthetic properties when administered at high doses, and most of the studies on gamma-hydroxybutyric acid have focused on its pharmacological effects. However, gamma-hydroxybutyric acid is also an endogenous substance, which is synthesized and released in the brain by specific neuronal pathways, implicated in the control of the GABAergic, dopaminergic, and opioid systems. This control is mediated by specific gamma-hydroxybutyric acid receptors with a unique distribution in brain and a specific ontogenesis and pharmacology. Stimulation of these receptors induces specific cellular responses. Taken together, these results suggest that gamma-hydroxybutyric acid possesses most of the properties required of a neurotransmitter/neuromodulator in the brain.

Animals↗

Selection and management of ventricular assist device patients: the Muenster experience.

BACKGROUND: Because of the growing discrepancy between the availability of donor organs and the number of patients with end-stage heart disease who need heart transplantation, a larger proportion of patients waiting for a suitable donor heart require pre-operative mechanical circulatory assistance. The criteria for the selection and management of these patients as applied at Muenster University Hospital are reviewed. METHODS: The study population consists of 631 patients referred to our center for transplantation between January 1, 1990, and December 31, 1996. Two hundred ninety-seven patients were listed for transplantation and 157 were transplanted. Of 41 patients who underwent implantation of a ventricular assist device (n = 34, Novacor; n = 6, TCI HeartMate; n = 1, Medos), 39 received the device as a bridge to transplantation and 2 as permanent support. For the purpose of the analysis, the study population was divided into 3 groups (elective bridging, urgent bridging, emergency bridging) and compared with heart transplant candidates who did not require mechanical circulatory assistance. RESULTS: Patients who underwent elective or urgent assist-device implantation were younger and had greater hemodynamic compromise than the remainder of patients waiting for heart transplantation, as suggested by a higher functional class and lower mean arterial pressure, cardiac index, serum sodium, and pulmonary artery wedge pressure. Survival of patients who electively underwent implantation of an assist device was better than that of patients who were stable on the waiting list and did not undergo heart transplantation during follow-up. CONCLUSIONS: This finding suggests that earlier implantation of assist devices may facilitate resolution of organ dysfunction before heart transplantation.

Adult↗

[Decontamination of highly polychlorinated biphenyl contaminated indoor areas by complete removal of primary and secondary sources].

A new sanitization concept in a school highly contaminated with polychlorinated biphenyls (PCBs) is described. The maximum indoor air concentration was 13,100 ng/m3 PCB. Initially the average indoor PCB concentrations attained 6,000-7,000 ng/m3. A reduction to 226 +/- 89.1 ng/m3 (n = 24) was achieved. Ten months later the PCB concentration was 171 +/- 57.6 ng/m3 (n = 3). Primary sources were PCB-contaminated elastic sealants and the paint of radiators or heating elements. Also PCB-contaminated materials were walls, floors and ceilings. These secondary contaminations were also relevant for PCB indoor air concentrations. The primary sources were removed dust-free by manual procedures. Contrary to other sanitization concepts all secondary-contaminated PCB materials were also removed with a high-pressure water method specially developed for such cases. Because of the removal of all relevant primary and secondary PCB deposits, a lasting effect can be expected. By this sanitization concept, the use of new and less intensively explored products suppressing the diffusion of PCBs into the indoor air and whose toxicity is hardly known, may be prevented, thus avoiding the need for prolonged control measurements. Before using the above-mentioned new sanitization concept, another concept had been rejected for lack of efficiency, thus avoiding unnecessary costs. The companies performing sanitization should be compelled to accept a defined lowest PCB concentration.

Adult↗

Economic aspects of different muscle relaxant regimens.

OBJECTIVE: At a time of cost reduction in medical care efforts to manage the ever-increasing costs of new pharmaceutical drugs become increasingly important. Costs of four different muscle relaxant regimens including the new intermediate-acting neuromuscular blocking drugs (NMBD) cisatracurium and rocuronium will be analyzed. METHODS: Eighty patients undergoing laparoscopic cholecystectomy were prospectively studied. All patients received standardized general anaesthesia with desflurane/fentanyl. Muscle relaxation was achieved with atracurium, cisatracurium, vecuronium, or rocuronium with 20 patients in each group. Intraoperatively muscle relaxants were added to maintain two twitches of the train-of-four (TOF) assessment. RESULTS: There were no differences among the four groups regarding biometric data, duration of surgery and anesthesia, number of patients with reversal of neuromuscular blockade, and time of extubation. Length of stay in the postanesthesia care unit (PACU) and the incidence of side effects were similar in all groups. Total costs of used drugs were significantly lowest in the atracurium-treated patients (per patient: 18.27 Euro) and significantly highest in the cisatracurium group (26.71 Euro) compared with the other groups (vecuronium: 22.61 Euro; rocuronium: 22.63 Euro). CONCLUSION: It is summarized that the use of cisatracurium was associated with higher costs compared to a standard muscle relaxant regimen using atracurium, whereas patient outcome was the same in all study groups. The routine use of the newer NMBDs can only be justified economically, if considerable improvements to clinical practice can be demonstrated.

Adult↗

[Dynamic imaging in diagnosis of dysphagia and globus sensation].

BACKGROUND: Videofluoroscopy has gained high significance for the evaluation of deglutition disorders. Imaging alone cannot clarify whether the subjective symptom is represented morphologically or whether it is the substrate of a functional disorder. METHOD: The videofluoroscopies of 101 patients with dysphagia (n = 55) and globus pharyngitis (n = 46) were evaluated. Morphologic abnormalities were registered as well as sequential movement patterns. These data were compared with clinical and endoscopic findings. RESULTS: In 87% of the dysphagia and 74% of the globus patients videofluoroscopy revealed pathologic findings. Functional disorders were seen significantly more often than morphologic abnormalities. Highest incidence was found for cricopharyngeal dyskinesia (42%). Hypopharyngeal pouches and degeneration signs of the cervical spine with bolus impression less than 40% are common but functionally not important. Additional esophago-gastroduodenoscopy was pathological in 83% in the dysphagia group and 96% in the globus group. CONCLUSION: Videofluoroscopy is indispensable for the differential diagnosis of dysphagia and globus sensation, especially for the detection of functional disorders in the pharyngoesophageal segment thus documenting the dynamic aspect of deglutition. Videofluoroscopy should be completed by a gastroenterologic examination in order to improve diagnosis.

Adult↗

Diagnosis, treatment and outcome of patients with Askin-tumors.

Askin tumors are highly malignant small-round-cell tumors of the thoracopulmonary region, which occur rarely. Therefore, we report on our experiences with eight patients (5 male, 3 females), who were treated in our department between 11'94 and 10'97 (age: 9-40 years, mean age: 20.5 years). All Askin tumors were diagnosed by histological and immunohistochemical examinations as well as molecular genetic proof of characteristic translocations. In all patients, the tumor arose from the chest wall, infiltrating adjacent ribs and parts of the lung. At the time of first diagnosis, five patients did not reveal any metastases. One patient suffered from intrapulmonary metastases and two patients from an infiltration of the diaphragm and of adjacent vertebral bodies. Treatment consisted of a pre- and postoperative (radio-) chemotherapy according to the EVAIA protocol and a radical tumor resection in all patients. The postoperative course was uneventful in seven patients, one patient suffered from pneumonia after multiple wedge resections for intrapulmonary metastases. Four patients, in whom primary tumor resection was complete, are alive 14, 20, 35 and 84 months after first diagnosis - only one patient had to undergo a second operation for a local relapse 17 months after first diagnosis. The other 4 patients, who suffered from a very extensive primary tumor, expired 13, 17, 18 and 39 months after the diagnosis was made. Our data demonstrate that Askin tumors require an aggressive multimodality treatment consisting of pre- and postoperative chemotherapy, radical surgical resection and postoperative irradiation, which may be performed preoperatively in selected cases, too.

Adolescent↗

The bad ventricle--revascularization versus transplantation.

BACKGROUND: The proportion of patients with left-ventricular dysfunction (LVD) undergoing high risk revascularization is increasing. In this patient group, the perioperative risk is elevated because of the pre-existing pathophysiology. Detailed evaluation and interdisciplinary differential therapeutic considerations on the basis of the comparative benefit rationale, with cardiac transplantation alternative, is mandatory. METHODS: Among 7275 patients who underwent coronary artery bypass grafting between 1990 and 1998 in our institution, we found 51 patients who had had an ejection fraction <20%, and thus were candidates for transplantation (group CABG); these were compared with 163 patients who were listed for cardiac transplantation because of ischemic cardiomyopathy (group HTX). The survival analysis was performed on the basis of the intention-to-treat principle independent of subsequent transplantation. RESULTS: Both groups were comparable with regard to left-ventricular ejection fraction; pulmonary capillary wedge pressure and serum creatinine, but patients in the CAGB group were older (63+/-11 vs 56+/-8; p = 0.001) and included a higher percentage of women (m/f: 42/9 vs 152/11; p = 0.03). Nevertheless, there was a similar 1-year survival in both groups (group BP 71.9% vs group HTX 66.3%; p = ns). Looking at the CABG group, the internal thoracic artery was used in 36/51 patients, an intra-aortic balloon pump was used preoperatively in 26 patients, and intraoperatively in 6. Left-ventricular assist devices had to be inserted in three patients, extracorporeal membrane oxygenation once. Perioperative (30 day) survival was 88.2 %. An elevated preoperative serum creatinine and the nonusage of the internal thoracic artery predicted an adverse outcome. In the long-term course, the NYHA functional class improved in most cases from III preoperatively to I after 26 (2-66) months. CONCLUSION: We conclude that patients with ischemic cardiomyopathy, viable myocardium, and graftable vessels can be revascularized with acceptable risk. Since for these patients a standby of mechanical circulatory support must be anticipated perioperatively, this infrastructure should be established within the center.

Aged↗

The mouse brain transcriptome by SAGE: differences in gene expression between P30 brains of the partial trisomy 16 mouse model of Down syndrome (Ts65Dn) and normals.

Trisomy 21, or Down syndrome (DS), is the most common genetic cause of mental retardation. Changes in the neuropathology, neurochemistry, neurophysiology, and neuropharmacology of DS patients' brains indicate that there is probably abnormal development and maintenance of central nervous system structure and function. The segmental trisomy mouse (Ts65Dn) is a model of DS that shows analogous neurobehavioral defects. We have studied the global gene expression profiles of normal and Ts65Dn male and normal female mice brains (P30) using the serial analysis of gene expression (SAGE) technique. From the combined sample we collected a total of 152,791 RNA tags and observed 45,856 unique tags in the mouse brain transcriptome. There are 14 ribosomal protein genes (nine under expressed) among the 330 statistically significant differences between normal male and Ts65Dn male brains, which possibly implies abnormal ribosomal biogenesis in the development and maintenance of DS phenotypes. This study contributes to the establishment of a mouse brain transcriptome and provides the first overall analysis of the differences in gene expression in aneuploid versus normal mammalian brain cells.

Animals↗

Chlamydia pneumoniae seropositivity is associated with carotid artery intima-media thickness.

BACKGROUND AND PURPOSE: Infection may both augment the atherosclerotic process and contribute to later manifestations of overt clinical disease. Chlamydia pneumoniae elementary bodies have been detected in atherosclerotic lesions. The aim of the present study was to investigate whether elevated titers of antibodies and circulating immune complexes to C pneumoniae were associated with ultrasound findings indicating presence of atherosclerosis in the carotid artery. METHODS: Serum titers of antibodies to C pneumoniae (IgM, IgA, IgG, and circulating immune complex) were related to intima-media thickness (IMT) and plaque status measured by B-mode ultrasound in the carotid artery in 113 men with treated hypertension and at least 1 of the following risk factors: hypercholesterolemia, smoking, or diabetes. RESULTS: Any of the titers was elevated in 56 (50%) men, and common carotid artery IMT was thicker in this group compared with the 57 men without any elevated titers (1.00 versus 0.92 mm, P<0.05). There were no accompanying differences in blood pressure, lipid levels, blood glucose, or smoking. Elevation of separate antibody types and circulation immune complex were also associated with increased IMT. In the latter group, systolic blood pressure was higher among seropositive patients compared with those who had no circulating immune complex. Seropositivity was not related to plaque status. CONCLUSIONS: Seropositivity for C pneumoniae was associated with an increased intima-media thickness in the common carotid artery but not plaque status in hypertensive men at high risk for cardiovascular disease.

Aged↗

Sclerotomal origin of the ribs.

The somites of vertebrate embryos give rise to sclerotomes and dermomyotomes. The sclerotomes form the axial skeleton, whereas the dermomyotomes give rise to all trunk muscles and the dermis of the back. The ribs were thought to be ventral processes of the axial skeleton and therefore to be derived from the sclerotomes; however, recently a dermomyotomal origin of the distal rib (the costal shaft) was suggested, with only the proximal parts (head and neck of the rib) being of sclerotomal origin. We have re-investigated the development of the ribs in quail-chick chimeras and carried out three experimental series. (1) Single dermomyotomes and (2) single sclerotomes were grafted homotopically, and (3) the ectoderm overlying the unsegmented paraxial mesoderm was removed in the prospective thoracic region. We found that the cells of the dermomyotome gave rise to epaxial and hypaxial trunk muscles, dermis of the back and endothelial cells, but not to ribs. Cells of the sclerotome formed the axial skeleton and all parts of the ribs. Ablation of the ectoderm, which affects dermomyotome development, results in severe malformations of the ribs, probably due to disturbed interactions between dermomyotome and sclerotome. Our results strongly confirm the traditional view of the sclerotomal origin of the ribs.

Animals↗

Economic evaluations of influenza vaccination in healthy working-age adults. Employer and society perspective.

OBJECTIVE: To determine what benefits to the employer and to society are associated with influenza (flu) vaccination in healthy adults. DESIGN AND METHODS: We performed a literature review concerning cost-benefit and cost-effectiveness evaluations of influenza vaccination in healthy, working-age adults. Up to the end of 1999, we found 6 published economic evaluations on the use of influenza vaccine in healthy, working-age adults: 3 prospective studies, 1 retrospective evaluation and 2 model-based simulations. Evaluations were performed from the perspective of an employer or society. Costs were reported in the local currency used in the published evaluation, with conversions into US dollars (when not provided in the article), for comparative purposes only, according to the exchange rates of June 8 1998. MAIN OUTCOME MEASURES AND RESULTS: Estimations of the cost-benefit of vaccination, compared with a no vaccination strategy, varied widely from a net loss of $US106.59 per infection averted in one study to savings of varying sizes in the 5 others (savings ranged from $US2.58 per dollar invested to $US46.85 per vaccinee). Studies differed in the definition of illness and the measurement of costs associated with vaccination or illness. CONCLUSIONS: Decision makers have not yet extended existing vaccine recommendations to cover healthy, working-age adults, partly because of the disparity among economic studies in their methods of estimating costs and measuring effects. However, the published studies seem to suggest that influenza vaccination in the healthy, working adult would be a cost-effective health intervention, at least from the perspective of an employer.

Adult↗

[Teaching targets in vascular medicine].

The reference list presented here is a selection of educative objectives performed by the French "Collège des Enseignants de Médecine Vasculaire" for the different levels of the medical initial education course. It was produced through a collective procedure, after selecting the most relevant topics and setting up writing rules based upon docimology, and favoring practical rather than theoretical objectives. The main topics are peripheral obstructive arterial disease, polyatherosclerosis, atherosclerosis risk factors, venous thromboembolic disease, thrombophilia, chronic venous insufficiency, lymphatic insufficiency, leg ulcers, vascular acrosyndromes, cerebrovascular diseases and connective tissue diseases, vascular occupational diseases, vascular adverse effects of drugs, diabetic vascular disease, the vascular consequences of hypertension, vascular malformations and angiodysplasia, inflammatory arterial diseases, and vascular explorations. As a whole they include about 300 objectives for the five teaching levels. We hope that this list will help stimulate production of training courses and documents strongly needed in this field.

Education, Medical↗

[Relationship between self concept and obesity in children and adolescents in various spheres of daily life].

This article considers the relation between overweight and the self-concept of children and adolescents in different living areas. The visibility and perceived controllability of obesity is considered. Results of previous studies about this topic are inconsistent. Self-esteem as one aspect of the self-concept is measured by the "list of statements for children and adolescents". Comparing a group of obese (N = 56) with a group of children and adolescents who suffered from other chronic illnesses (N = 22), the obese had a lower self-esteem for the public living areas "school" and "leisure time", but not for the private area "family". A further result shows that the visibility of the illness is significantly related to self-esteem; again this relation is only revealed for the public living areas "school" and "leisure time".

Adolescent↗