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Biomedical subjects

M Schmitz

Publications and source records attributed to M Schmitz.

At least 37 records · Page 2Linked to original sources
PubMed2002

Predictors of treatment discontinuity in outpatient mental health care.

BACKGROUND: Discontinuity of service utilisation among newly referred community outpatients is a common concern. However, knowledge about factors associated with service utilisation is inconsistent. METHOD: This study examined service utilisation of 323 newly referred patients in three community mental health centres (CMHCs) in Vienna, Austria over a 4-month period. Of this original cohort, 111 patients were interviewed at treatment start to identify factors associated with treatment discontinuity. RESULTS: After 4 months, one-third of the 323 newly referred patients had dropped out of CMHC treatment; one-third discontinued treatment at the CMHCs because of referrals or mutual agreement on treatment termination, and one-third was still in CMHC treatment. Multivariate analyses yielded a negative association between treatment discontinuity and the diagnosis of schizophrenia, availability of home care, living alone, and a high quality of life in the domains living situation and family/significant others. A positive association was found with unemployment, previous psychiatric admissions, low patient satisfaction with staff competence, and high self-assessment in global functioning. CONCLUSION: In treatment, differing perceptions of a patient's health status by the patient and by the psychiatrist should be addressed. Professionals should be aware that patients' difficulties in private social relations might affect both treatment alliance and service utilisation.

Adult↗
PubMed2002

Efficient transduction and long-term retroviral expression of the melanoma-associated tumor antigen tyrosinase in CD34(+) cord blood-derived dendritic cells.

Differentiation of genetically modified CD34(+) hematopoietic stem cells into dendritic cells (DCs) will contribute to the development of immunotherapeutic anticancer protocols. Retroviral vectors that have been used for the transduction of CD34(+) cells face the problem of gene silencing when integrated into the genome of repopulating stem cells. We reasoned that a high copy number of retroviral DNA sequences might overcome silencing of transgene expression during expansion and differentiation of progenitor cells into functional DCs. To prove this, we utilized a retroviral vector with bicistronic expression of the melanoma-associated antigen tyrosinase and the enhanced green fluorescent protein (EGFP). Human cord blood CD34(+) cells were transduced with vesicular stomatitis virus G-protein (VSV-G) pseudotyped Moloney murine leukemia virus (MoMuLV) particles using 100-150 multiplicity of infection. During expansion of transduced cells with immature phenotype, transgene expression was strongly silenced, but upon differentiation into mature DCs, residual transgene expression was retained. Intracellular processing of the provirally expressed tyrosinase was tested in a chromium release assay utilizing a cytotoxic T cell clone specific for a HLA-A*0201-restricted tyrosinase peptide. We suggest that retroviral transduction of tumor-associated antigens in hematopoietic progenitor cells and subsequent differentiation into DCs is a suitable basis for the development of potent anti-tumor vaccines.

Antigens, CD34↗
PubMed2002

[Validity of nonspecific bronchial provocation tests for the diagnosis of airway hyperresponsiveness--a comparison of different methods].

OBJECTIVE: To compare the validity of different methods for the assessment of bronchial hyperresponsiveness used by different centers. METHODS: Case series of 648 subjects referred to six pulmonary centers, all with a history of shortness of breath without airway obstruction, without use of medication that might influence the tests and without viral infections during the previous two weeks. All subjects answered a questionnaire of recent symptoms and underwent bronchial challenge with a chemical stimulus according to each center's protocol. Analysis was performed by receiver operating characteristic (ROC) plots using the questionnaire's answers as the gold standard. Diagnostic test sensitivities at the cut-offs for bronchial hyperresponsiveness indicated by each center were compared. RESULTS: ROC plots showed poor validity of all tests, i.e. both acceptable sensitivity and specificity were not observed with any test. There was no obvious difference of the slope of the ROC plots between the different centers. However, maximal sensitivity differed considerably: for "wheeze during the previous 12 months", sensitivity at each center's cut-off for the definition of bronchial hyperresponsiveness varied between 0.35 and 0.73. The choice of the question used as the standard had little influence on test validity. CONCLUSION: Although some of the differences between centers may be explained by subject characteristics, the large differences of the test sensitivities are unacceptable and underscore the need for standardization of these tests, primarily with respect to sufficient sensitivity.

Adolescent↗
PubMed2002

Evidence for a negative feedback in the control of eel growth hormone by thyroid hormones.

The regulation of growth hormone (GH) by thyroid hormones (THs) has been shown to present species variation. We investigated the regulation of GH in the eel, a representative of an ancient group of teleosts. In vivo administration of triiodothyronine (T(3)) or thyroxine (T(4)) significantly reduced pituitary and serum GH levels, as measured by homologous RIA. In order to investigate the ability of THs to regulate GH production directly at the pituitary level, we used a long-term, serum-free primary culture of eel pituitary cells. Both T(3) and T(4) inhibited GH release in a concentration-dependent manner, producing up to 50% inhibition at 10 nM, with an ED(50) of <0.2 nM, within the range of their physiological circulating levels. Other hormones also acting via the nuclear receptor superfamily, such as sex steroids (testosterone, estradiol and progesterone) and corticosteroid (cortisol), had no effect on GH release in vitro, underlining the specificity of the regulatory effect of THs on GH. Measurement of both GH release and cellular content for calculation of GH production in vitro indicated that THs not only inhibited GH release but also GH synthesis. Dot-blot assay of GH messenger RNA (mRNA) using an homologous eel cDNA probe showed a decrease in GH mRNA levels in cells cultured in the presence of T(3), as compared with control cells. This demonstrated that the inhibition of T(3) on GH synthesis was mediated by a decrease in GH mRNA steady state levels. In conclusion, we demonstrate inhibitory regulation of eel GH synthesis and release by THs, exerted directly at the pituitary level. These data contrast with the rat, where THs are known to have a stimulatory effect and suggest that the pattern observed here in an early vertebrate and also found in birds, reptiles and some mammals including humans, may represent an ancestral and more generalized vertebrate pattern of TH regulation of pituitary GH.

Analysis of Variance↗
PubMed2001

Increased survivin transcript levels: an independent negative predictor of survival in soft tissue sarcoma patients.

Survivin, a recently identified inhibitor of apoptosis protein (IAP), is expressed in diverse embryonic tissues and in various human cancers. We have investigated the quantitative expression of survivin mRNA by a sensitive TaqMan-based RT-PCR assay in tissue samples from 94 patients with soft tissue sarcomas (STS). Survivin transcript levels were measured and normalized to GAPDH transcripts. By using a multivariate Cox regression analysis, we found an inverse correlation between the level of survivin mRNA (ratio >2 zmol survivin/amol GAPDH) and the rate of overall survival (p = 0.009, RR = 2.7). Survivin transcript variants as detected by qualitative RT-PCR analysis were revealed in 36 of 56 STS patients (64%). Only survivin DeltaEx3 and/or full-length survivin variants but not survivin 2B were identified. Our results suggest that a higher level of survivin mRNA is an independent predictor of survival for STS patients.

Adolescent↗
PubMed2001

Attention-deficit hyperactivity disorder: a study of association with both the dopamine transporter gene and the dopamine D4 receptor gene.

Attention-deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders of childhood. The role of genetic factors in its etiology is strongly supported by family, adoption, and twin studies. Several investigations have reported associations between ADHD and both the 7-repeat allele of the 48 bp VNTR at the DRD4 gene and the 10-repeat allele of the 40 bp VNTR at the DAT1 gene, but the results have been inconsistent. A sample of 81 Brazilian ADHD children and adolescents and their parents were screened for these DRD4 and DAT1 VNTRs. An excess of the DRD4 7-repeat allele was observed when both ADHD probands and their parents were compared with an ethnically matched control sample (chi-square = 11.55, P = 0.03; chi-square = 12.17, P = 0.03, respectively). However, haplotype relative risk (HRR) analysis showed no preferential transmission of the DRD4 7-repeat allele. No evidence of association with the DAT1 polymorphism was detected by both approaches. Nevertheless, an interaction effect of both genes on ADHD hyperactive/impulsive dimension was observed (F = 4.68; P = 0.03). These results add to the group of studies that together suggest a small effect of these genes in the susceptibility to ADHD.

Adolescent↗
PubMed2001

Intake of dioxins and related compounds from food in the U.S. population.

The first U.S. nationwide food sampling with measurement of dioxins, dibenzofurans, and coplanar, mono-ortho and di-ortho polychlorinated biphenyls (PCBs) is reported in this study. Twelve separate analyses were conducted on 110 food samples divided into pooled lots by category. The samples were purchased in 1995 in supermarkets in Atlanta, GA, Binghamton, NY, Chicago, IL, Louisville, KY, and San Diego, CA. Human milk also was collected to estimate nursing infants' consumption. The food category with highest World Health Organization (WHO) dioxin toxic equivalent (TEQ) concentration was farm-grown freshwater fish fillet with 1.7 pg/g, or parts per trillion (ppt), wet, or whole, weight. The category with the lowest TEQ level was a simulated vegandiet, with 0.09 ppt. TEQ concentrations in ocean fish, beef, chicken, pork, sandwich meat, eggs, cheese, and ice cream, as well as human milk, were in the range O.33 to 0.51 ppt, wet weight. In whole dairy milk TEQ was 0.16 ppt, and in butter 1.1 ppt. Mean daily intake of TEQ for U.S. breast-fed infants during the first year of life was estimated at 42 pg/kg body weight. For children aged 1-11 yr the estimated daily TEQ intake was 6.2 pg/kg body weight. For males and females aged 12-19 yr, the estimated TEQ intake was 3.5 and 2.7 pg/kg body weight, respectively. For adult men and women aged 20-79 yr, estimated mean daily TEQ intakes were 2.4 and 2.2 pg/kg body weight, respectively. Estimated mean daily intake of TEQ declined with age to a low of 1.9 pg/kg body weight at age 80 yr and older. For all ages except 80 yr and over, estimates were higher for males than females. For adults, dioxins, dibenzofurans, and PCBs contributed 42%, 30%, and 28% of dietary TEQ intake, respectively. DDE was also analyzed in the pooled food samples.

Adolescent↗
PubMed2001

Long-term persistence of monoclonal B cells after cure of Helicobacter pylori infection and complete histologic remission in gastric mucosa-associated lymphoid tissue B-cell lymphoma.

PURPOSE: Cure of Helicobacter pylori infection is associated with remission induction in the majority of patients with low-grade gastric mucosa associated lymphoid tissue (MALT) lymphoma in localized stages; however, limited data exist as to whether these patients may be cured of their lymphoma. The present study was performed to investigate whether the polymerase chain reaction (PCR) for the rearranged immunoglobulin heavy chain region may be used to define "molecular" remission. PATIENTS AND METHODS: Ninety-seven patients who suffered from low-grade gastric MALT lymphoma stage I(E) were observed with central pathology and molecular biology after cure of H pylori infection. PCR was performed with the use of consensus primers for the framework regions 1, 2, and 3 and monoclonality was corroborated by sequence analysis. In selected cases, microdissection was performed to study the origin of the monoclonal B cells. RESULTS: Of the 97 patients, 77 obtained complete endoscopic and histologic remission (CR). Twenty of 44 patients with PCR monoclonality at diagnosis and with sufficient molecular follow-up displayed monoclonal bands for a median time of 20.5 months after CR (range, 0 to 50.4 months). These B cells were related to the original lymphoma clone by sequence analysis. Microdissection analysis identified basal lymphoid aggregates as the source of these monoclonal B cells. Local relapse occurred in and was observed by PCR in four patients. All four patients displayed monoclonal PCR before relapse, and three of these four showed ongoing PCR monoclonality throughout their course, indicating the persistence of malignant cells. CONCLUSION: Half of all patients with gastric MALT lymphoma show long-term PCR monoclonality up to several years after cure of H pylori infection and CR. Patients with monoclonal PCR should be observed closely, whereas long-term PCR negativity may indicate cure of the disease.

Adult↗
PubMed2001

Alterations of apolipoprotein B metabolism in HIV-infected patients with antiretroviral combination therapy.

BACKGROUND: Dyslipidemia (predominantly hypertriglyceridemia) is frequently seen in patients receiving antiretroviral combination therapy (ART). However, the underlying mechanisms and long-term risks (e.g., cardiovascular events) are still unclear. OBJECTIVES/METHODS: In 5 patients with ART-associated dyslipidemia, stable isotope labeled amino acid tracer (d3-Leu) kinetic analysis over 12 days was used to investigate the metabolism of apolipoprotein B-containing lipoproteins (very low density lipoproteins [VLDL]1, VLDL2, intermediate density lipoproteins [IDL] and low density lipoproteins [LDL]). Data were compared with those in 6 healthy normolipidemic controls. RESULTS: The patients under ART showed significantly increased fasting triglycerides (359 vs. 77 mg/dl) and VLDL (54 vs. 15 mg/dl), compared with controls. They had significantly higher total cholesterol (213 vs. 157 mg/dl) and there was a nonsignificant trend toward higher LDL (136 vs. 93 mg/dl), and toward lower HDL (26 vs. 46 mg/dl). The ratio of large, buoyant LDL1 over small, dense LDL2 was markedly reduced in patients under ART (0.80 vs. 2.00). Total apo B synthesis was significantly increased (25.5 vs. 14.5 mg/kg/d) and shifted toward triglyceride rich VLDL1 (18.5 vs. 8.7 mg/kg/d) in patients receiving ART. There was also a significantly reduced rate of apo B lipoprotein transfer from VLDL1 to VLDL2 (3.7 vs. 20.7 pools/d). In addition, all patients revealed insulin resistance. CONCLUSIONS: These data indicate that increased triglycerides in HIV-infected patients with ART are primary due to reduced rates of VLDL transfer into denser lipoproteins implying a lower rate of lipoprotein lipase-mediated delipidation. In addition, total apo B synthesis was increased and shifted toward triglyceride-rich VLDL1. Overall, this lipoprotein profile in patients with ART-associated dyslipidemia implies an increased risk for cardiovascular events.

Adult↗
PubMed2001

[Left ventricular diastolic function parameters after PTCA and stent implantation].

UNLABELLED: This study was designed to determine the effect of successful coronary revascularisation on left ventricular diastolic function. METHODS: We consecutively studied the time course of diastolic function by Doppler echocardiography in 100 patients with one-vessel disease before and 48 hours after elective coronary angioplasty. Three abrupt vessel closures occurred within 24 hours after intervention. These three patients were excluded from the study. 58 patients were initially successful treated with coronary angioplasty (residual stenosis < 40%). In 39 patients stents were used to improve an inadequate result after coronary angioplasty. The following parameters of left ventricular diastolic function were evaluated before and 48 hours after coronary intervention: peak early (VE, m/s) and peak late diastolic (VA, m/s) flow velocity, E/A ratio, acceleration time (AT, ms), deceleration time (DT, ms) and isovolumetric relaxation time (IVRT, ms). Ejection fraction (EF; %) was determined and used to characterise systolic left ventricular function. RESULTS: Both patient groups (58 patients with coronary angioplasty and 39 patients with combined coronary angioplasty and stent implantation) showed no relevant differences concerning sex, age, atherosclerotic risk factors, exercise capacity and results of exercise electrocardiography. All patients who underwent stent implantation showed an early improvement of left ventricular diastolic function 48 hours after revascularisation. Surprisingly there was no significant short-term improvement (48 hours) of diastolic function in patients with initially successful angioplasty. CONCLUSION: We suppose that stent implantation faster normalises coronary blood flow than coronary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed2001

Secretion of GM-CSF and M-CSF by human renal cell carcinomas of different histologic types.

OBJECTIVES: To analyze the secretion of hematopoietic growth factors and the expression of their corresponding receptors in 40 newly established renal cell carcinoma (RCC) cell lines of different histologic types. Little is known about the secretion and function of hematopoietic growth factors by human RCCs. METHODS: The expression of the hematopoietic growth factors (ie, erythropoietin, interleukin [IL]-3, IL-5, granulocyte colony-stimulating factor [G-CSF], granulocyte-macrophage colony-stimulating factor [GM-CSF], and macrophage colony-stimulating factor [M-CSF]) was determined by enzyme-linked immunosorbent assay analysis under different culture conditions, including suspension culture and monolayer cultures (plastic and Matrigel-coated culture flasks). The expression of their corresponding receptors was defined by fluorescence activated cell scanner analysis and by reverse-transcriptase polymerase chain reaction. The response of the RCC cell lines to exogenous hematopoietic growth factors was analyzed by MTT assay. RESULTS: In almost all of the cell lines, significant amounts of GM-CSF and M-CSF were secreted, and in four cell lines, a secretion of G-CSF was detected. Fourteen RCC cell lines showed secretion of IL-3, and production of IL-5 and erythropoietin was not observed in any cell line. Secretion of GM-CSF and M-CSF was affected by the substratum offered for cell attachment in the adherent cultures. GM-CSF secretion was more pronounced under culture conditions with a reduced frequency of cell-to-cell contacts. Two cell lines were shown to express receptors for M-CSF, but receptors for G-CSF and GM-CSF could not be detected in any cell line. Exposure to exogenous G-CSF, GM-CSF, and M-CSF did not affect the proliferation of our RCC cell lines. CONCLUSIONS: The results of our study clearly demonstrate that human RCC cells can secrete significant amounts of G-CSF, GM-CSF, M-CSF, and IL-3, and are thereby theoretically able to modulate the host's tumor-directed immune response.

Carcinoma, Renal Cell↗
PubMed2001

Satisfaction of inpatients and outpatients with staff, environment, and other patients.

The study described here compared levels of satisfaction with staff, environment, and other patients among 420 first-time and long-term patients in psychiatric outpatient and inpatient settings. The demographic, clinical, and outcome variables associated with satisfaction were explored. Patient satisfaction was related to quality of life, social functioning, treatment expectations, and one-year psychological and physical prognoses. Perceptions of other patients were significantly more positive among long-term patients than among first-time patients. The concerns of first-time patients about other patients are of special importance, and they should be addressed during initial treatment.

Adult↗
PubMed2001

Explaining retrospective reports of symptoms in patients undergoing chemotherapy: anxiety, initial symptom experience, and posttreatment symptoms.

This study evaluated different perspectives on the relationship of trait anxiety to symptom report. Baseline trait anxiety was related to (a) initial symptoms reported 2 days after beginning chemotherapy, (b) posttreatment symptoms reported 2 days after cessation of medication, and (c) retrospective reports of initial symptoms (made concurrently with posttreatment reports). Associations were significant for vague psychophysiological symptoms but not for concrete visible symptoms. Path models indicated that the relationship of anxiety to retrospective report of vague symptoms was due to both enhanced encoding and facilitated recall of symptoms. Further analyses revealed, however, that this relationship reflects symptoms stability rather than anxiety-related differences in attention. Anxious and nonanxious patients appear to be equally accurate in their retrospective report of symptoms.

Adult↗
PubMed2000

Generation of survivin-specific CD8+ T effector cells by dendritic cells pulsed with protein or selected peptides.

The identification of tumor-associated antigens recognized by CD8+ cytotoxic T cells paved the way to new concepts in adjuvant anticancer therapy. However, the number of tumor-associated proteins found to be expressed in the majority of human cancers is still rather limited. Recently, the newly identified apoptosis inhibitor protein survivin has been recognized as a widely occurring tumor-associated protein. In the present study, we demonstrate that survivin is capable of inducing specific CD8+ effector T cells in vitro. T cells from healthy donors were subjected to several cycles of stimulation by autologous dendritic cells (DCs) pulsed with soluble recombinant survivin protein. Activation of CD8+ cytotoxic T cells by survivin-derived peptides cross-presented by DCs was demonstrated by lysis of autologous survivin-expressing B cell transfectants. Using a peptide-motif scoring system, two survivin peptides (ELTLGE-FLKL and TLPPAWQPFL) were predicted and proved to bind to the HLA-A*0201 molecule. Both peptides were shown to induce CD8+ effector T cells when presented on DCs; one peptide could be verified to result from natural intracellular processing of survivin. These findings recommend survivin as a new and widely applicable target for protein- and peptide-based immunotherapy of tumors.

Amino Acid Sequence↗
PubMed2000

Preparation, characterization, and X-ray crystal structures of helical and syndiotactic zinc-based coordination polymers.

The reactions of (facac)2Zn.2H2O (facac = 1,1,1,5,5,5-hexafluoroacetylacetonate) with 2,5-bis(4-ethynylpyridyl)furan (1) and 1,2-bis(4-ethynylpyridyl)benzene (2) yield, upon crystallization, coordination polymers. The former polymer, ((facac)2Zn.1)n, has an isotactic, helical structure in the solid state [monoclinic space group P2(1)/n; a = 11.0374(3) A, b = 24.2179(10) A, c = 14.3970(4) A, beta = 92.880(2) degrees; Z = 4]. The latter polymer, ((facac)2Zn.2)n, adopts a syndiotactic structure in the solid state [monoclinic space group P2(1)/n; a = 9.1344(1) A, b = 21.7985(5) A, c = 16.0322(4) A, beta = 99.6680(11) degrees; Z = 4]. The solution structures of the corresponding oligomers have been studied by low-temperature 1H and 19F NMR spectroscopy. Chiral polymers were prepared using the fragment [(+)-tfc]2Zn ((+)-tfc = 3-((trifluoromethyl)hydroxymethylene)-(+)-camphorate). A linear, zigzag structure was found for ([(+)-tfc]2Zn.1)n [triclinic space group P1; a = 7.4833(2) A, b = 14.1563(5) A, c = 21.21230(5) A, alpha = 78.4440(15) degrees, beta = 81.5644(15) degrees, gamma = 76.4976(13) degrees; Z = 1]. Reaction with tris(4-pyridyl)methanol (3) yielded a homochiral, helical polymer, ([(+)-tfc]2Zn.3)n [monoclinic space group C2; a = 25.0633(12) A, b = 11.8768(7) A, c = 17.1205(9) A, alpha = 90 degrees, beta = 117.954(3) degrees, gamma = 90 degrees; Z = 4].

Journal Article↗
PubMed2000

Rational design of chiral nanoscale adamantanoids

[formula: see text] Utilizing coordination as a motif, the self-organization of six ditopic and four tritopic building blocks leads to the formation of nanoscale adamantanoid frameworks.

Journal Article↗