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G Schmitt

Publications and source records attributed to G Schmitt.

At least 19 recordsLinked to original sources
PubMed2006

Effects of treatment with the atypical neuroleptic quetiapine on working memory function: a functional MRI follow-up investigation.

BACKGROUND: Working memory as a part of higher-order executive functions is defined by the parallel storage and processing of information. Recent functional fMRI studies have revealed a functional, interregional disintegration of a neuronal network connecting cortical, subcortical and cerebellar regions in schizophrenic patients (SZ). Cognitive impairment in working memory is a core psychopathological correlate of schizophrenic symptoms. Atypical neuroleptics such as quetiapine have shown good efficacy in treating positive and negative symptoms. The presented study evaluated the impact of a neuroleptic steady state treatment with quetiapine on the altered working memory activation patterns in schizophrenia. METHODS: Patients were examined by fMRI at baseline and after 12 weeks of steady state treatment with quetiapine. Matched healthy controls (HC) underwent baseline examination. In the scanner, stimuli were presented in a 2-back and 0-back condition of a working memory (wm) paradigm, whereby a degraded and a non-degraded version were used each time. Additionally, behavioural responses (reaction time to target stimuli and error ratio) were measured. RESULTS: At baseline, healthy controls revealed increased activity in the frontal lobe, especially in regions of the prefrontal cortex. Compared to HC, SZ showed hypoactivation in the right dorsolateral prefrontal cortex (DLPFC) and the ventrolateral prefrontal cortex (VLPFC) bilaterally for the 2-back condition. In the 2-back degraded condition there was a hypoactivation in both, the right DLPFC and the VLPFC. Additionally, patients showed bilaterally decreased activation in the basalganglia in the 2-back and in the right caudatus in the 2-back degraded condition compared to healthy controls. After treatment with quetiapine, patients activations patterns were increased. The pre-post comparison of the 2-back condition revealed a significant increase of activation in the left VLPFC at a significance level of 0.001 (uncorrected). The 2-back degraded condition led to a significant activation pattern in the lingual gyrus and the right precuneus. In both wm conditions, at baseline there were no differences in reaction time but only a worse performance in SZ. After treatment, behavioural measurement of responses, including reaction time and performance, showed slight improvements in SZ, although these did not reach statistical significance. CONCLUSIONS: The neuronal networks underlying working memory are clearly altered in schizophrenia. After 12 weeks of treatment with quetiapine monotherapy, patients showed significant clinical improvement and revealed increased BOLD activity in the VLPFC during a working memory task, although there was no improvement of cognitive performance.

Adult↗
PubMed2006

G-CSF during large field radiotherapy reduces bone marrow recovery capacity.

OBJECTIVE: Side effects of chemo- and radiotherapy are granulo- and thrombocytopenia. However, the long-term effects of in vivo granulocyte-colony-stimulating factor (G-CSF) stimulation of the hematopoietic system during radiotherapy are not yet completely understood. In the present study, we sought to determine the bone marrow effect of G-CSF during radiotherapy. MATERIAL AND METHODS: In a prospective, randomized clinical trial 10 patients (6 m, 4 f, 30-64 yrs, mean 50.6 yrs) were assigned to large field radiotherapy (RT). 7 patients (pat.) with non-Hodgkin lymphoma, one patient with Hodgkin's disease and 2 patients with small-cell carcinoma of the lung were included. The patients were randomized to either radiotherapy alone (group A) or radiotherapy with simultaneous G-CSF (group B) treatment and assessed for acute and late toxicity. Blood samples were drawn and analyzed before and after G-CSF stimulation. The mobilization effectivity of G-CSF on CD34 superset+ progenitor cells was measured using flow cytometry and colony forming units (CFU) testing on admission and during the complete follow-up period (1, 3 and 18 months post RTx). RESULTS: Overall, 50 pat. were intended to be included to the protocol. However, the preliminary analysis revealed a significant decrease of thrombocytes and CD34 superset+ progenitor cells in the G-CSF treatment group. According to the study protocol further treatment was stopped. Peripheral leukocyte counts ranged between 2800 - 4375 /mul in 9/10 pat. In group B mean thrombocyte levels dropped below 30.000 mg/l and CD34 superset+ progenitor cells to 50% (interruption criteria, p<0.02, Student's t-test). Hemoglobin values did not vary. Differential blood smears showed differences in granulocyte counts and a higher proportion of neutrophils in group B. Lymphocyte counts of patients randomized to group A were significantly decreased when compared to group B. In group A, 3/5 pat. developed an overshooting reaction (4,7 x increase) after G-CSF-stimulation. In arm B circulating CD34 superset+ progenitor cells dropped. In arm A, 3/5 pat. had an initial overshoot reaction when compared to none in group B. CFU (> 40 cells) and cluster (4 -39 cells) showed considerable variations. CONCLUSION: Our results demonstrate that simultaneous treatment with G-CSF during radiotherapy reduces the mobilization of CD34+ progenitor cells and exhaust the bone marrow capacity while peripheral leukocyte counts remain at baseline levels.

Adult↗
PubMed2006

Prevalence and correlates of inflammatory arthritis in Germany: data from the First National Health Survey.

The aim of this paper is to generate data on the prevalence of inflammatory arthritis in different subgroups of the population and to identify correlates on the basis of population-based cross-sectional data: the "First National Health Survey of the Federal Republic of Germany". This Survey investigated the prevalence of inflammatory arthritis, comorbidity and health-relevant behaviors on the basis of interviews with physicians and medical evaluations conducted in the period from October 1997 to March 1999. The study was based on a net sample comprising 6,461 subjects aged 18-79. Our data demonstrate an overall prevalence of 3.4% for inflammatory arthritis. The prevalence of inflammatory arthritis is significantly higher in women, the over-50, lower-income groups, and habitual smokers. Patients with inflammatory arthritis have a higher rate of numerous comorbidities such as osteoporosis, thyroid disease, chronic bronchial disease, hypertension, and elevated blood lipids versus healthy reference groups.

Adolescent↗
PubMed2006

Biomarker evidence for a major preservation pathway of sedimentary organic carbon.

Hydrogenation processes leading from biomolecules to fossil biomarkers in anoxic sediments are crucial for the preservation of organic matter. However, these processes are still poorly understood. The present identification of several reduced carotenoids in recent sediments attests that these processes operate at the earliest stages of diagenesis without structural or stereochemical specificity, implying a nonbiological reduction pathway. Sulfur species (e.g., H2S) are the hydrogen donors involved in such reduction, as demonstrated with laboratory experiments. These reactions allow the preservation of abundant organic carbon in the rock record.

Anaerobiosis↗
PubMed2005

[Prevalence and correlates of osteoarthritis in Germany. Representative data from the First National Health Survey].

BACKGROUND: The purpose of the paper was to generate up-to-date, representative osteoarthritis prevalence data for individual population subgroups and to identify potential risk factors. MATERIAL AND METHODS: A cross-sectional study, the "First National Health Survey", investigated the prevalence of osteoarthritis, comorbidity and health-relevant behaviours of the post-unification German population on the basis of interviews with physicians and medical evaluations conducted in the period from October 1997 to March 1990. The study was based on a net sample comprising 6205 subjects aged 18-79 years. RESULTS: The three main correlates for osteoarthritis are age, obesity and occupational stress factors. Osteoarthritis patients are more likely to have osteoporosis, thyroid disease, chronic bronchial disease, hypertension and elevated blood lipids, but do not tend to have a higher incidence of diabetes. CONCLUSION: Our data show the importance of preventive behavioural approaches such as weight management and workplaces designed to limit joint overuse.

Adolescent↗
PubMed2004

Polycyclic aromatic hydrocarbons (PAHs) in agricultural soil and vegetables from Tianjin.

Several types of vegetables were collected from two contaminated sites in Tianjin, China. The bulk soil and the rhizosphere soil samples were also collected from the same plots. Sixteen PAHs in the samples were measured. The total concentrations of PAH16 in the bulk soil from the two sites were 1.08 and 6.25 microg/g, respectively, with similar pattern. The concentrations of PAH16 and individual compounds in the rhizosphere were significantly higher than those in the bulk soil with mean values of 2.25 and 7.82 microg/g for the two sites, respectively. The contents of both total and dissolved organic matter in the rhizosphere were also higher than those in the bulk soil. Almost all PAH compounds studied were detected in both roots and aerial parts of the vegetables studied. Abundance of higher molecular weight PAHs in vegetable, however, was lower than that in soil. Concentrations of PAH16 in vegetable were higher than those reported in the literature for other areas. It appears that agricultural soils and vegetables in Tianjin, especially those from the site located immediately next to an urban district and irrigated with wastewater for several decades, are severely contaminated by PAHs. Among the eight types of vegetable studied, the highest concentration of PAHs was found in cauliflower. By average, the concentration of PAH16 in the aerial part of vegetables was 6.5 times higher as that in vegetable root, suggesting that foliar uptake is the primary transfer pathway of PAHs from environment to vegetables.

China↗
PubMed2003

Concentration dependency of the BAC/BrAC (blood alcohol concentration/breath alcohol concentration) conversion factor during the linear elimination phase.

According to the theoretical pharmacokinetical considerations put forward by Wehner et al. the BAC(ven)/BrAC conversion factor Q is not a constant value and varies depending on the pharmacokinetic phase deduced from the alcohol concentration curve. Based on these considerations we propose that Q must be inversely proportional to the BrAC during the postabsorptive linear elimination phase, expressed as the hyperbola Q=1/kappa+(CT)/BrAC. The constants kappa or 1/kappa and (CT)--where (CT) consists of different parameters which remain constant during the linear elimination phase--can be experimentally determined from the linear relationship BrAC = kappaBAC(ven)-kappa(CT). To test this hypothesis 12 human volunteers received parenteral doses of ethanol. During the elimination phase, BAC and BrAC of each volunteer were measured between 18 and 34 times in a BrAC range between 0.65 mg/l and 0.12 mg/l. The conversion factor Q was either expressed in the form of the hyperbola Q=1/kappa+(CT)/BrAC or directly calculated from the ratio BAC(ven)/BrAC and the results obtained using both methods were found to be very similar. The values of 1/kappa of the hyperbolic functions varied between 1.808 and 2.165 and those of (CT) between 0.004 and 0.127. For a BrAC of 0.25 mg/l, an average value of 2.308+/-0.080 could be calculated for the conversion factor Q(0.25). On average, the value of Q(0.40) amounted to 2.207+/-0.048 and that of Q(0.55) to 2.160+/-0.056.

Adult↗
PubMed2001

Hyperbaric oxygen therapy for late sequelae in women receiving radiation after breast-conserving surgery.

PURPOSE: Persisting symptomatology after breast-conserving surgery and radiation is frequently reported. In most cases, symptoms in the breast resolve without further treatment. In some instances, however, pain, erythema, and edema can persist for years and can impact the patient's quality of life. Hyperbaric oxygen therapy was shown to be effective as treatment for late radiation sequelae. The objective of this study was to assess the efficacy of hyperbaric oxygen therapy in symptomatic patients after breast cancer treatment. PATIENTS AND METHODS: Forty-four patients with persisting symptomatology after breast-conservation therapy were prospectively observed. Thirty-two women received hyperbaric oxygen therapy in a multiplace chamber for a median of 25 sessions (range, 7-60). One hundred percent oxygen was delivered at 240 kPa for 90-min sessions, 5 times per week. Twelve control patients received no further treatment. Changes throughout the irradiated breast tissue were scored prior to and after hyperbaric oxygen therapy using modified LENT-SOMA criteria. RESULTS: Hyperbaric oxygen therapy patients showed a significant reduction of pain, edema, and erythema scores as compared to untreated controls (p < 0.001). Fibrosis and telangiectasia, however, were not significantly affected by hyperbaric oxygen therapy. Seven of 32 women were free of symptoms after hyperbaric oxygen therapy, whereas all 12 patients in the control group had persisting complaints. CONCLUSIONS: Hyperbaric oxygen therapy should be considered as a treatment option for patients with persisting symptomatology following breast-conserving therapy.

Breast Diseases↗
PubMed2001

Familial adenomatous polyposis: prevalence of adenomas in the ileal pouch after restorative proctocolectomy.

OBJECTIVES: To determine the prevalence of adenomas in ileal pouches from patients with familial adenomatous polyposis (FAP) and to determine whether a correlation exists between the presence of pouch adenomas and duodenal adenomas and the site of the adenomatous polyposis coli gene mutation. SUMMARY BACKGROUND DATA: Restorative proctocolectomy can markedly reduce the risk of colorectal adenocarcinoma in FAP patients. However, adenomas with the potential to progress to adenocarcinoma can develop in the duodenum, ileum, and continent ileostomy after restorative proctocolectomy. More recently, adenomas have been described in the ileal pouch after ileoanal anastomosis. METHODS: Pouch endoscopy was offered to 167 patients with FAP who had undergone restorative proctocolectomy between January 1984 and December 1996. RESULTS: Adenomas were found in 35% of the 85 ileal pouches examined. No invasive carcinomas were noted. The risk of developing one or more adenomas at 5, 10, and 15 years was 7%, 35%, and 75%, respectively. Patients with adenomas were more likely to have duodenal and ampullary adenomas. No correlation was detected between adenoma development and the site of the adenomatous polyposis coli mutation. CONCLUSIONS: Adenomas are frequently found in the ileal pouch of patients after restorative proctocolectomy for FAP. Regular endoscopic surveillance of the pouch is recommended at a frequency similar to that of upper gastrointestinal endoscopy.

Adenomatous Polyposis Coli↗
PubMed2000

Management of postoperative peritonitis after anterior resection: experience from a referral intensive care unit.

PURPOSE: Anastomotic leakage is the main cause of death after anterior resection. If it causes a single abscess, it may be successfully cured by percutaneous drainage, but in case of extensive peritoneal infection (multiple abscesses and generalized peritonitis), it is associated with a 40 to 60 percent mortality. This study aimed at evaluating aggressive, one-stage surgical management in such cases. METHODS: All patients referred to our surgical intensive care unit during the past ten years with generalized, multilocular, intra-abdominal sepsis after anterior resection were reviewed. There were 32 patients, with a mean age of 65 years, among which 15 (47 percent) were referred from other institutions. The mean Acute Physiology and Chronic Health Evaluation II score on admission was 18. All patients underwent a laparotomy with complete peritoneal exploration, intraoperative lavage, fecal diversion, capillary drainage of the pelvis excluding the rectal stump or the leaking anastomosis from the peritoneal cavity, and primary closure of the abdomen. A Hartmann's operation was done in 22 cases, and conservation of the anastomosis with proximal colostomy was done in 10 cases. The choice was based on the size of the leak, the viability of the colon, and the site of the anastomosis. RESULTS: Four patients died (12 percent), and five patients (16 percent) had recurrent sepsis. When the anastomosis had been conserved, restoration of continuity was achieved in all cases. After Hartmann's operation 8 patients of 19 survivors kept a permanent stoma; 7 had undergone a low anterior resection. CONCLUSIONS: Extensive intra-abdominal infection after anterior resection may be efficiently controlled by a surgical approach combining peritoneal debridement, fecal diversion, and capillary drainage of the pelvis. Intestinal continuity may be restored after diversion stoma or Hartmann's procedure after high anterior resection. This is not the case after a Hartmann's operation after a low colorectal anastomosis, and this procedure should be avoided whenever possible.

Abdominal Abscess↗
PubMed2000

Interdisciplinary treatment in pediatric patients with malignant CNS tumors.

Despite sophisticated surgical methods only a few pediatric CNS tumors can be controlled by operation alone. Therefore multimodality treatment regimens are needed to improve quality of life and survival, which is most important in malignant neoplasms. Since 1998 we have treated 16 children with malignant CNS tumors. All 16 patients have been treated on an interdisciplinary basis and are therefore accompanied by a pediatric neurooncology group consisting of a neurosurgeon, pediatric oncologist, and radiotherapist. Depending on tumor histology, child's age, and extent of surgery, further adjuvant therapy is planned by this group. Newly diagnosed tumors are typically treated by a specific chemotherapy protocol according to a multi-institutional study. In recurrent tumors more individual treatment regimens are considered. Data concerning surgery, adjunctive treatment, complications, and outcome of all patients and four case reports are presented.

Adolescent↗
PubMed2000

Prognostic significance of DNA cytometry in thymoma.

PURPOSE: The aim of this work was to evaluate the prognostic significance of DNA image cytometry in thymoma. PATIENTS AND METHODS: Image cytometric studies with an automatic video-based analysis system (LEYTAS) were carried out on 47 archival specimens from 36 patients with thymomas who underwent operation at a single institution from 1954 to 1992. The significance of aneuploidy DNA-content (5c-exceeding events), and nuclear size on stage and survival were evaluated. The median follow-up was 52.7 (6-164) months. RESULTS: Masaoka's stage was predictive of aneuploidy (P < 0.01) and disease-free survival (P < 0.015). In stage I 18% of the tumors were aneuploid, in stage II 78%, in stage III 85% and in stage IV 100%. The occurrence of 5c-exceeding events was associated with both decreased disease-free survival (P < 0.01) and overall survival (P = 0.013). Nuclear size was not significantly correlated to stage. Under multivariate analysis, aneuploidy and DNA content failed to attain independent significance for stage, performance status, and histology. CONCLUSION: DNA image cytometry may provide additional information about the prognosis of resected thymoma.

Adult↗
PubMed1999

The role of CT simulation in whole-brain irradiation.

PURPOSE: Evidence is growing that incorrect field-shaping is a major cause of treatment failure in whole-brain irradiation (WBI). To evaluate the potential benefits of CT simulation in WBI we compared field-shaping based on 3D CT simulation to conventional 2D simulation. METHODS: CT head scans were obtained from 20 patients. Conventional 2D planning was imitated by drawing the block contours on digitally reconstructed radiographs (DRR) by four radiotherapists. Critical parts of the target and the eye lenses were subsequently marked and planning was repeated using 3D information ("3D planning"). The results of both methods were compared by evaluation of the minimal distance from the field edge according to each site. RESULTS: In conventional planning using DRR, major geographic mismatches (< -3 mm) occurred in the subfrontal region and both eye lenses with 1% each location. Minor mismatches (-3 to 0 mm) predominantly occurred in the contralateral lens (21%), ipsilateral lens (10%), and subfrontal region (9%). Close margins (0-5 mm) were most frequently noted at the contralateral lens (49%), ipsilateral lens (35 %), and the subfrontal region (28%). When 3D planning was used, mismatches were not found. However, close margins were inevitable at the ipsilateral lens (5%), subfrontal region (30%), and contralateral lens (70%). CONCLUSIONS: CT simulation in WBI is significantly superior to conventional simulation with respect to complete coverage of the target volume and protection of the eye lenses. The narrow passage between the ocular lenses and lamina cribrosa represents a serious limitation. These patients are safely identified with CT simulation and can be referred for modified irradiation techniques.

Brain Neoplasms↗
PubMed1999

Neonatal lethality in mice deficient in XCE, a novel member of the endothelin-converting enzyme and neutral endopeptidase family.

XCE, a new member of the endothelin-converting enzyme and neutral endopeptidase family, is preferentially expressed in specific areas of the central nervous system including spinal chord and medulla. To elucidate the importance and function of XCE, we disrupted its gene in mouse embryonic stem cells by homologous recombination and created mice deficient in XCE. The resulting phenotype is characterized by neonatal lethality. All XCE -/- homozygous mice died of respiratory failure shortly after birth, and in most cases their lungs were never ventilated. Apart from the atelectasis, anatomical and histological examinations of embryonic day 18.5 XCE -/- embryos and newborn homozygotes did not reveal any obvious abnormalities in organs and tissues. Malformations that are related to the knock-out were also not found in the skeletons of XCE -/- mice. In addition, XCE knock-out animals showed no deficiency of pulmonary surfactant proteins and had normal heart beat frequencies. Taken together, our results demonstrate that XCE is an essential gene. The phenotype of the XCE-deficient mice together with the central nervous system-specific expression further suggest that XCE may play a vital role in the control of respiration.

Animals↗
PubMed1999

Determination of ethyl glucuronide, a minor metabolite of ethanol, in human serum by liquid chromatography-electrospray ionization mass spectrometry.

A rapid and sensitive determination procedure using liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) has been developed for the determination of ethyl glucuronide (EtG) in human serum. Samples were precipitated with methanol, centrifuged and the supernatant was evaporated to dryness followed by reconstitution with distilled water. As mobile phase 30 mM ammonium acetate-acetonitrile (30:70, v/v) was utilized. The base peak observed at m/z 221 was the [M-H]- ion of EtG, which was detectable in satisfactory sense. The detection limit was 0.03 microg/ml in the selected ion monitoring mode. A calibration graph constructed for EtG in serum gave good linearity over the range from 0.1 to 25 microg/ml. This paper also presents the application of this LC-ESI-MS procedure to the analysis of authentic serum samples.

Alcohol Drinking↗
PubMed1999

Status report of the NAC particle therapy programme.

The 200 MeV cyclotron facility at the National Accelerator Centre has been operational since 1987. Between September 1988 and December 1997 a total of 973 patients (26,916 fields) had been treated on the 66 MeV p+Be isocentric neutron therapy system. Patients are currently being treated according to several protocols, including tumors of the head and neck, salivary gland and breast and soft tissue sarcomas, uterine sarcomas and paranasal sinuses. A multiblade post-collimator trimmer has recently being installed. This device provides improved neutron beam shaping capability. Between September 1993 and December 1997 a total of 243 patients (4008 fields) had been treated (mainly intracranial stereotactic irradiations) on the fixed horizontal 200 MeV proton therapy facility. The facility incorporates an innovative automatic patient positioning system. Two new fixed beam lines for proton therapy are presently being designed (horizontal and 30 degrees to the vertical) for an existing unused treatment vault. Spot scanning systems will be developed for both beam lines.

Head and Neck Neoplasms↗
PubMed1999

Radiotherapy and high-dose chemotherapy in advanced Ewing's tumors.

BACKGROUND: Ewing's tumors are sensitive to radio- and chemotherapy. Patients with multifocal disease suffer a poor prognosis. Patients presenting primary bone marrow involvement or bone metastases at diagnosis herald a 3-year disease-free survival below 15%. The European Intergroup Cooperative Ewing's Sarcoma Study (EICESS) has established the following indications for high-dose therapy in advanced Ewing's tumors: Patients with primary multifocal bone disease, patients with early (< 2 years after diagnosis) or multifocal relapse. PATIENTS AND METHOD: As of 1987, 83 patients have been treated in the EICESS group, 39 of them at the transplant center in Düsseldorf, who have been analyzed here. All individuals received 4 courses of induction chemotherapy with EVAJA and stem cell collection after course 3 and 4. Consolidation radiotherapy of the involved bone compartments was administered in a hyperfractionated regimen 2 times 1.6 Gy per day, up to 22.4 Gy simultaneously to course 5 and 22.4 Gy to course 6 of chemotherapy. The myeloablative chemotherapy consisted of melphalan and etoposide (ME) in combination with 12 Gy TBI (Hyper-ME) or Double-ME with whole lung irradiation up to 18 Gy (without TBI). RESULTS: The survival probability at 40 months was 31% (44% DOD; 15% DOC). Pelvic infiltration did not reach prognostic relevance in this cohort. Radiotherapy encompassed 75% of the bone marrow at maximum (average 20%). Engraftment was not affected by radiotherapy. CONCLUSION: High-dose chemotherapy can improve outcome in poor prognostic advanced Ewing's tumors. The disease itself remains the main problem. The expected engraftment problems after intensive radiotherapy in large volumes of bone marrow can be overcome by stem cell reinfusion.

Adolescent↗