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Thomas Schneider

Publications and source records attributed to Thomas Schneider.

36 records · Page 2Linked to original sources
PubMed2005

Pulmonary melioidosis associated with bronchiolitis obliterans organizing pneumonia.

We report a case of pulmonary melioidosis associated bronchiolitis obliterans with organizing pneumonia (BOOP). While antibiotic treatment alone did not show any major effect, addition of corticosteroids resulted in rapid clinical improvement. To our knowledge this is the first documented case of melioidosis associated with organising pneumonia. The possible therapeutic implications for the treatment of severe pulmonary melioidosis are discussed.

Adult↗
PubMed2005

Determinants of airborne fiber size in the glass fiber production industry.

Size distributions of airborne fiber exposures should be characterized for studies of respiratory disease because size determines the region of the lung where a fiber will deposit and its ability to produce toxic effects in cells. Yet fiber size is not measured precisely with standard air sampling methods. Specific fiber dimensions hypothesized to have biologic activity have been proposed, but these have not been evaluated in epidemiologic studies because there has not been a way to account for fiber size in historical air monitoring data. In this study, methods were developed to predict fibrous aerosol size fractions generated during glass wool fiber production using regression models and factors related to bulk fiber products and processing. A set of air samples representing a range of products and process applications was collected in eight fiber glass production facilities. The samples were analyzed more intensively than standard methods require. For each air sample, total fiber size distributions were measured using electron microscopy and two proportions were then calculated: (1) fibers meeting the size criteria of the standard NIOSH Method 7400 B rules method (pB), and (2) fibers meeting the size criteria for a biologically based exposure index, the hypothetically active fiber (HAF1) index (pH1). The fiber size proportions were used as dependent variables in regression models with production process factors. It was found that two factors, the nominal diameter of the bulk fiber product and whether oil was applied to it, determine more than 80% of the variability in the proportions (for the pB model, R2 = 0.86; for the pH1 model, R2 = 0.82). Using these two predicted proportions, it is possible to estimate the concentration of fibers in the biologically based HAF1 size fraction from a standard fiber concentration measurement. The models developed here can be used to size-adjust historical fiber concentration measurements for use in epidemiologic studies of respiratory disease.

Air Pollution, Indoor↗
PubMed2005

Leptospirosis in Germany, 1962-2003.

Epidemiologic trends of human leptospirosis in Germany were investigated by analyzing national surveillance data from 1962 to 2003 and by conducting a questionnaire-based survey from 1997 to 2000. After a steady decrease of leptospirosis incidence from 1962 to 1997, surveillance data indicate an increase in disease incidence to 0.06 per 100,000 (1998-2003). Of 102 laboratory-confirmed cases in humans from 1997 to 2000, 30% were related to occupational exposures. Recreational exposures were reported in 30% (including traveling abroad in 16%), whereas residential exposure accounted for 37% of the cases. Direct contact with animals, mostly rats and dogs, was observed in 31% of the cases. We conclude that recent changes in transmission patterns of leptospirosis, partially caused by an expanding rat population and the resurgence of canine leptospirosis, may facilitate the spread of the disease in temperate countries like Germany. Preventive measures should be adapted to the changing epidemiology of leptospirosis.

Adolescent↗
PubMed2004

The crystallographic structure of the aldose reductase-IDD552 complex shows direct proton donation from tyrosine 48.

The X-ray crystal structure of human aldose reductase (ALR2) in complex with the inhibitor IDD552 was determined using crystals obtained from two crystallization conditions with different pH values (pH 5 and 8). In both structures the charged carboxylic head of the inhibitor binds to the active site, making hydrogen-bond interactions with His110 and Tyr48 and electrostatic interactions with NADP+. There is an important difference between the two structures: the observation of a double conformation of the carboxylic acid moiety of the inhibitor at pH 8, with one water molecule interacting with the main configuration. This is the first time that a water molecule has been observed deep inside the ALR2 active site. Furthermore, in the configuration with the lower occupancy factor the difference electron-density map shows a clear peak (2.5sigma) for the H atom in the hydrogen bond between the inhibitor's carboxylic acid and the Tyr48 side-chain O atom. The position of this peak implies that this H atom is shared between both O atoms, indicating possible direct proton transfer from this residue to the inhibitor. This fact agrees with the model of the catalytic mechanism, in which the proton is donated by the Tyr48 hydroxyl to the substrate. These observations are useful both in drug design and in understanding the ALR2 mechanism.

Aldehyde Reductase↗
PubMed2004

Factors associated with health-related quality of life in chronic pancreatitis.

OBJECTIVES: Chronic pancreatitis may lead to considerable reduction in health-related quality of life, but factors associated with a poor perceived health status have not been investigated. METHODS: We recruited 265 patients with chronic pancreatitis from a tertiary care gastroenterology clinic. Health-related quality of life was assessed using the Short Form-36 Health Survey. Data were compared with age- and gender-adjusted values from the German general population (6964 adults). Factors associated with poor perceived health status were identified by logistic regression. RESULTS: All domains of health-related quality of life were reduced in chronic pancreatitis. Decrements were most pronounced in role limitations caused by physical (-25%) and emotional health problems (-15%), and general health perceptions (-19%). Severity of abdominal pain, chronic pancreatic diarrhea, low body weight, and loss of work independently contributed to the physical component score of the Short Form-36 (adjusted R2= 33.8%) and were the factors most closely associated with poor health status perception. The etiology and duration of the disease or changes in pancreatic morphology had no impact on health-related quality of life. CONCLUSIONS: Patients with chronic pancreatitis experience substantial impairments in health-related quality of life. The severity of chronic pancreatitis-related symptoms is directly associated with patient function and well-being. These data offer further insight into the impact of chronic pancreatitis on patient health status and may serve as the basis for the development of disease-specific instruments, which are needed to measure the effect of therapeutic interventions on patient-derived health outcomes.

Adult↗
PubMed2003

Percutaneous US-guided radiofrequency ablation with perfused needle applicators: improved survival with the VX2 tumor model in rabbits.

PURPOSE: To evaluate survival, metastases, tumor necrosis, and prediction of local recurrence after percutaneous ultrasonographically (US) guided radiofrequency (RF) thermal ablation with electrodes perfused continuously with isotonic saline. MATERIALS AND METHODS: VX2 liver tumors were implanted in 31 rabbits according to a standardized protocol. After 21 days, 16 animals were treated percutaneously with RF ablation. Four animals died of complications related to anesthesia, and 12 animals were evaluated. All animals were followed for 110 days and monitored with computed tomography (CT) and US at 1, 7, and 30 days. A control group of 15 animals did not receive treatment. Autopsy was performed at the end of scheduled follow-up or immediately after death. For survival analysis, the Kaplan-Meier method was used; for nominal data, the Fisher exact test was used. RESULTS: In comparison to controls, animals in the treatment group showed significantly prolonged survival (P <.001). Eight of 12 animals (67%) treated with RF ablation survived to 110 days, while none of the controls did so. Metastases developed in all controls (100%) and in eight of 12 treated animals (67%) (P =.001). In comparison with controls, animals that developed metastases despite treatment also showed significantly prolonged survival (P =.02). Local recurrence was observed in three of 12 animals (25%) in the treatment group. CT and US performed 1 week after treatment did not allow prediction of local recurrence. CONCLUSION: RF ablation of liver tumors with perfused needle applicators prolongs survival in the VX2 rabbit liver tumor model, regardless of whether complete remission is achieved. In comparison with controls, RF ablation results in a lower frequency of metastases.

Animals↗
PubMed2003

[Nephrogenic fibrosing dermopathy].

Nephrogenic fibrosing dermopathy (NFD) is a scleromyxoedema-like disease favoring the extremities and trunk. Histologically there is a cellular fibrosis throughout the entire dermis. NFD is associated with renal insufficiency and dialysis, although the pathogenesis has not been elucidated. A 71-year-old woman developed classical symptoms of NFD on both legs within a few weeks after initiation of hemodialysis and concomitant antibiotic treatment followed by presumed drug eruption.

Aged↗
PubMed2003

Mucosal immune response to Tropheryma whipplei.

Whipple's disease is a rare infectious disease caused by the ubiquitously occurring Tropheryma whipplei in predisposed persons. Genetic or acquired defects in the mucosal and peripheral immune system become apparent as diminished Th1 immune functions with decreased production of IL-12 and IFN-gamma accompanied by an increased secretion of IL-4. These defects may enable T. whipplei to survive and replicate. The recently established cultivation of the bacterium in HEL cells and the isolation from infected intestinal biopsies enable a multitude of experimental possibilities which may lead to an improved diagnosis as well as understanding of the etiology and pathogenesis of Whipple's disease.

Actinomycetales↗
PubMed2003

Immunoglobulin E production in chronic pancreatitis.

OBJECTIVES: Serum immunoglobulin E (IgE) was investigated in patients with chronic pancreatitis in order to elucidate possible disease mechanisms linking pancreatitis, adverse reaction to foods and allergy. DESIGN AND METHODS: Serum IgE was analysed in 86 non-atopic patients with advanced chronic pancreatitis and 54 non-atopic controls. IgE detection was performed by enzyme-linked immunofluorescence. RESULTS: Mean IgE levels (+/- standard error of mean) in chronic pancreatitis patients (286.1+/-49 kU/l) were found to be significantly elevated compared to controls (67.7+/-11 kU/l; P<0.0001). Normal IgE levels (<100 kU/l) were present in 40/54 control patients (74.1%), but only 39/86 pancreatitis patients (45.3%). Of the patients with chronic pancreatitis, 47/86 (54.6%) had clearly elevated IgE levels of >100 kU/l and their IgE values did not show a Gaussian distribution. However, nine-fold higher IgE levels were found in chronic pancreatitis patients with alcohol consumption of >25 g/day and exocrine insufficiency (915.5+/-240 kU/l) than in pancreatitis patients with normal exocrine function and no alcohol consumption (103.4+/-43 kU/l; P<0.001). Moreover, acute episodes of chronic pancreatitis were found to increase serum IgE levels. CONCLUSIONS: In patients with chronic pancreatitis, serum IgE production is markedly enhanced, especially during acute inflammatory episodes or when alcohol is consumed. Since abstinence from alcohol and pancreatic enzyme substitution are associated with clearly lower IgE levels, it may be concluded that pancreatic insufficiency with reduced nutrient digestion and alcohol consumption stimulate IgE production. This finding gives rise to the speculation that, apart from pancreatic inflammation, cross-linking of IgE with alimentary or other antigens might be involved in the pathophysiology of a sub-population of patients with chronic pancreatitis and manifest pancreatic insufficiency.

Adult↗
PubMed2003

Lack of awareness of community-acquired adverse drug reactions upon hospital admission : dimensions and consequences of a dilemma.

OBJECTIVE: Adverse drug reactions (ADRs) are a well-known cause of hospital admission. Nevertheless a quantitative estimate of the preventability of and physicians' awareness of these reactions is lacking. STUDY DESIGN AND METHODS: Using intensive bedside and computer-assisted drug surveillance methods a 13-month prospective pharmacoepidemiological survey was carried out on patients admitted to two medical wards of the Erlangen-Nuremberg University Hospital in Erlangen, Germany. This study aimed to define the incidence of preventable and unavoidable ADRs. In addition we investigated the awareness of the physicians to ADRs at the time of admission and the rate of contraindicated pre-admission prescriptions. RESULTS: In 78 (8.5%) of 915 (10.9%) admissions a total of 102 (42 preventable) community-acquired ADRs were detected on admission. In 45 (3.8%) of the admissions ADRs led directly to hospitalisation. 56.9% of the ADRs were not recognised by the attending physician on admission. Marked correlation was found between the awareness of ADRs and their probability and severity scores (r = 0.85 and r = 0.94, respectively; p < 0.05). The most frequently detected ADRs were due to direct toxicity and secondary pharmacological effects. Idiosyncratic reactions were often missed and 18.6% of all drugs prescribed prior to admission were contraindicated. Leading the list were diuretics, analgesics/NSAIDs and antipsychotics/sedatives. CONCLUSIONS: Awareness of existing ADRs on hospital admission and appropriate prescribing prior to hospital admission require attention. Early detection of ADRs on hospital admission can be achieved by the use of computer support systems. Many ADRs could be prevented by adhering to indications and contraindications.

Adolescent↗
PubMed2002

Impact of simian immunodeficiency virus (SIV) infection on lymphocyte numbers and T-cell turnover in different organs of rhesus monkeys.

HIV infection leads to reduced numbers and increased turnover of CD4(+) T cells in blood. However, blood represents only 2% of the total lymphocyte pool, and information about other organs is lacking, leading to controversy about the effects of HIV infection on T-cell homeostasis. Therefore, we have determined phenotype and turnover of lymphocyte subsets in various tissues of macaques. Infection with simian immunodeficiency virus (SIV) resulted in increased proliferation rates of T cells in all organs. Despite reduced CD4 counts in blood, absolute numbers of CD4(+) T cells were increased in spleen and lymph nodes and remained stable in nonlymphoid organs such as liver, lung, bone marrow, and brain during the asymptomatic phase, indicative for an altered tissue distribution. In animals killed with first signs of AIDS, total body CD4 counts and proliferation rates had returned to control levels, whereas thymocytes were almost completely absent. Our data show that a drastically increased turnover in the early stages of HIV infection, driven by a generalized immune activation rather than a homeostatic response to CD4(+) T-cell destruction, is followed by exhaustion of the regenerative capacity of the immune system.

Animals↗
PubMed2002

The thrust plate prosthesis in patients with aseptic osteonecrosis of the femoral head.

BACKGROUND: The thrust plate prosthesis (TPP) is an implant with a metaphyseal fixation at the proximal femur that transmits the load forces of the hip onto the femoral neck. The osseous incorporation of the TPP and the adaptation of the bone to this force transmission depend on the bone quality, which is reduced to minor vitality and stability in patients with osteonecrosis of the femoral head. Depending on the etiology of the femoral head necrosis, the TPP might lead to early failures. METHODS: In a prospective study, 63 patients with 72 cementless TPP due to femoral head osteonecrosis were examined. A clinical and radiological evaluation was performed preoperatively, 3 and 6 months postoperatively, and every year thereafter. The average follow-up period was 4.8+/-1.3 years with a minimum of 3 years. The pathogenesis of femoral head necrosis included alcoholism (n=19), subsequent to renal transplantation (n=11), during cortisone therapy of other dyscrasia (n=9), preceding a polychemotherapy (n=4), diabetes (n=3), sickle cell anemia (n=1), and idiopathic osteonecrosis (n=25). RESULTS: The Harris Hip Score increased continuously from 50.0 points beyond 79.8 points after 3 months to 86.8 points within the 1st year, and subsequently remained stable at this level. Revision was necessary in six cases (8.3%). Of these, three had an aseptic loosening of the implant: 2 cases with renal transplantation and 1 of alcoholism with an extension of the necrotic area to the seating of the TPP. The other three patients showed septic implant loosenings: 2 cases with renal transplantation and 1 of alcoholism. Radiolucent lines were found in 9 cases (12.5%), mostly in zones 1 and 2 underneath the TPP. Of these, 1 with an idiopathic osteonecrosis was assessed to be radiologically loosened. The overall failure rate was 9.7%, with a proportion of 36.4% in patients with renal transplantation. Excluding this specific patient group, the failure rate was 4.9%. CONCLUSIONS: Femoral head necrosis following renal transplantation and extension of the necrotic area into the femoral neck are contraindications for TPP. Excluding these patients, the TPP shows comparable mid-term results to cementless stemmed prostheses and supplies advantages especially for younger patients, because of its metaphyseal, bone-preserving fixation. However, evaluation of the clinical impact of the TPP in comparison with other cementless femoral stem systems requires long-term examinations in the future.

Adult↗
PubMed2002

Dysregulated peripheral and mucosal Th1/Th2 response in Whipple's disease.

BACKGROUND & AIMS: An impaired monocyte function and impaired interferon (IFN)-gamma production has been suggested as a possible pathogenetic factor in Whipple's disease (WD) and as a cause for the delayed elimination of Tropheryma whipplei in some patients. METHODS: We studied, in a series of 20 WD patients with various degrees of disease activity, cellular immune functions. RESULTS: We found an increased in vitro production of interleukin (IL)-4 by peripheral mononuclear blood cells as determined by enzyme-linked immunosorbent assay, but reduced secretion of IFN-gamma and IL-2 as compared with age- and sex-matched controls. In addition, we observed a significantly reduced monocyte IL-12 production in response to various stimuli in WD patients whereas other cytokines were comparable with controls; these immunologic alterations were not significantly different in patients with various disease activities. At the mucosal level, we found decreased CD4 T-cell percentage and a significantly impaired IFN-gamma secretion. CONCLUSIONS: Our data define a defective cellular immune response in a large series of WD patients and point to an important pathogenetic role of impaired Th1 responses. The decreased monocyte IL-12 levels may result in reduced peripheral and mucosal IFN-gamma production and lead to an increased susceptibility to T. whipplei infection in certain hosts.

Adult↗
PubMed2002

Effect of methylprednisolone on reperfusion after femoral head ischemia.

An episode of ischemia and reperfusion of the femoral head is thought to be the common pathway in the pathogenesis of femoral head necrosis. The influence of short-term high-dose steroid treatment on femoral head reperfusion after ischemia was investigated in a porcine model. Twenty-two pigs were randomized to receive methylprednisolone 20 mg/day/kg bodyweight intramuscularly for 3 days followed by methylprednisolone 10 mg/day/kg bodyweight for 11 days (n = 11), whereas the control group (n = 11) received no treatment. Femoral head ischemia was achieved by 6 hours of unilateral intraarticular hip pressure increase to 250 mm Hg. Femoral head blood flow was estimated using radiolabeled microspheres (15 microm in diameter) before ischemia, during hip tamponade, and 4 hours after tamponade release. Femoral head blood flow was lower in the corticosteroid treated pigs. Subtotal femoral head ischemia was documented in both groups during joint tamponade. Apart from two femoral head epiphyses in either group, reperfusion after tamponade release on the average occurred to a blood flow level similar to that before ischemia. Short-term high-dose methylprednisolone treatment depressed bone perfusion in general, but had no effect on reperfusion after femoral head ischemia in the porcine model.

Animals↗
PubMed2002

Electromagnetic field hazards involving adjustable shunt valves in hydrocephalus.

OBJECT: Standard therapy for hydrocephalus involves shunts and valves, which are frequently adjustable. Because of increasing "electromagnetic smog" (for example, that generated by cellular phones), these valves are often exposed to electromagnetic fields. METHODS: Various magnetic fields were tested for their effects on two different kinds of adjustable valves. The minimum magnetic flux density affecting the adjustment of the valve was determined. Results were compared with magnetic fields found in contemporary everyday life. In homogeneous magnetic fields the adjustment of one valve (Sophysa model SM8) was changed at 5 mT, whereas the second valve (Codman Hakim model CM) was not affected. In nonhomogeneous fields the SM8 valve was affected at 25 mT and the CM valve at 15 mT. Thus, these valves may be affected by headphones and telephone receivers. Surroundings such as the Japanese magnetic suspension railway and the lead cabin of electrical railway engines, in which critical levels of magnetic flux may be present, may also affect adjustable valves. The high-frequency fields of cellular phones, however, have no effect on these valves. CONCLUSIONS: Every surgeon who implants these valves and every patient who receives them should know the possible hazards. The valve selection should be adapted to the environment of the patient. Devices with critical levels of electromagnetic flux that are used in the homes of patients should be replaced by ones with lower magnetic fields. The future construction of these valves should be modified in such a way that their adjustment requires a higher magnetic flux density, so that the valves become less sensitive to unwanted effects from environmental magnetic fields.

Cerebrospinal Fluid Shunts↗
PubMedDate not supplied

Investigation on the clinical efficacy and safety of meloxicam (Metacam) in the treatment of non-infectious locomotor disorders in pigs.

The clinical efficacy and safety of meloxicam (Metacam 20 mg/ml) in the treatment of non-infectious locomotor disorders in pigs was investigated in a randomised double-blind, placebo controlled, multi-centre field study. A total of 220 pigs were examined, 211 pigs were suitable for evaluation. Treatment was performed on Day 1 with meloxicam (0.4 mg meloxicam/kg) or placebo by intramuscular injection. If necessary, treatment was optionally repeated on Day 2. Clinical examinations were conducted daily from Day 1 (immediately prior to initiation of therapy) to Day 4. The primary parameter, mean "Clinical Lameness Score" (CLS, a sum of the scores of "Lameness at Rest" and "Lameness at Walk"; range 2 to 11) improved from 6.8 and 6.3 on Day 1, to 3.5 and 4.7 on Day 4 in the meloxicam and placebo groups respectively (p < 0.001). At the final examination mean changes from baseline for CLS (Day 1) were 3.25 for meloxicam treated animals and 1.7 for placebo treated animals (p < 0.001). Behaviour score and feed intake improved during the study period with statistically significant differences in favour of meloxicam at all time points after initiation of therapy. Significantly fewer pigs received a second treatment in the meloxicam group than in the placebo group, 46% versus 73% (p < 0.001). A 'very good' or 'good' clinical efficacy assessment was recorded in 83% of the meloxicam cases compared to 42% of the placebo controls at the final examination (p < 0.001). No adverse events were reported due to the use of meloxicam. Furthermore safety of meloxicam in pregnant sows was demonstrated. It is concluded that intramuscular injection of meloxicam (Metacam) at a dosage of 0.4 mg/kg is efficacious and safe for the treatment of non-infectious locomotor disorders in pigs.

Analgesics, Non-Narcotic↗