Use of ThinPrep processing for studying breast cancer cell lines.
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Breast Neoplasms↗
Biomedical subjects
R Wagner
Publications and source records attributed to R Wagner.
Early postoperative transcranial sonography (TCS), CT, and MRI after resection of high grade glioma: evaluation of residual tumour and its influence on prognosis.
PURPOSE: In this prospective study the results of multimodal postoperative neuro-imaging were related to the survival of patients with high grade gliomas. METHODS: All 73 patients included underwent microsurgical tumour resection and had postoperative CT and transcranial sonography (TCS) examinations. In addition, 35 of the 73 patients received an early postoperative MRI. Patients were followed up for at least one year. FINDINGS: At the end of the 7 year study period 56 patients had died. The median survival time was 371 days. Survival rate was significantly higher in patients with anaplastic astrocytomas and inpatients displaying complete tumour resection on MRI (log-rank-test, p < 0.05) or a small postoperative residual tumour bulk on TCS (log-rank-test, p < 0.05). Cox proportional hazards model identified histological tumour grade, postoperative Karnofsky index, complete resection based on MRI and small postoperative residual tumour mass on TCS as independent predictors of survival. INTERPRETATION: This study demonstrates that early postoperative neuro-imaging has prognostic implications for the survival of patients with high grade gliomas. According to our results postoperative imaging with MRI and TCS is a valuable prognostic with regard to patient survival and should therefore be implemented in postoperative follow-up. It also helps to evaluate the efficacy of adjuvant therapy.
Adolescent↗
Developments and improvements in the manufacturing of human therapeutics with mammalian cell cultures.
During recent years, biopharmaceutical products manufactured by processes that use mammalian cell cultures have gained increasing importance. At the same time, a strong awareness of the importance of the safety and quality of such products has also emerged. This has led to improvements in cultivation and production technology, validation procedures and process organization.
Animals↗
Thermal damage threshold at 633 nm of tympanic membrane of pig.
Doppler vibrometers are used by many research groups to monitor the motion of the tympanic membrane (TM) and of middle ear ossicles for in vivo and in vitro studies. Power densities in these applications reach 80 W/cm(2). To determine the safe limit of exposure, a cw dye laser at a wavelength of 633 nm was used to investigate the threshold of thermal damage of TM of pigs under exposure times of 60 s. To determine the applied power density accurately, the spot size of the laser beam was monitored by an objective lens and a CCD camera. Twenty-six laser exposed samples of TM were stained by haematoxylin and eosin stain and the semi-thin sections were examined microscopically. In none of the sections was any laser induced damage observed with power densities below 7.1 kW/cm(2), whereas serious damage occurred showing coagulation, carbonisation and perforation in all cases with laser powers above 8.2 kW/cm(2). The threshold for damage and the conical shape of the damage zone is explained by photon propagation and absorption in the tissue especially by the increase of the scattering factor at higher tissue temperature. The thermal damage threshold of 8 kW/cm(2) is compared to the maximum permissible exposure given in laser safety standards for skin.
Absorption↗
The transport machinery for the import of preproteins across the outer mitochondrial membrane.
In order for proteins to be imported into subcellular compartments, they must first traverse the organellar membranes. In mitochondria, hydrophilic protein channels in both the outer and inner membranes serve such a purpose. Recently, the channel protein of the outer mitochondrial membrane was identified to be Tom40. Tom40 is found in a high molecular weight complex termed the general import pore (GIP) complex where it is tightly associated with the receptor protein Tom22 along with Tom7, Tom6 and Tom5. Tom7 and Tom6 seem to modulate the dynamics of the GIP complex while Tom5 is involved in preprotein transfer from receptors to Tom40. The receptor proteins Tom70 and Tom20 associate with this complex in a weaker manner where they are involved in the initial recognition of preproteins. This review focuses on the identification and characterisation of the transport machinery of the outer mitochondrial membrane and how they are involved in the co-ordination and regulation of events required for the translocation of preproteins into mitochondria.
Animals↗
. . . response: the chloroplast outer envelope: a molecular sieve?
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Chloroplasts↗
Glucose metabolism of the thyroid in autonomous goiter measured by F-18-FDG-PE.
The radiolabeled glucose analogue F-18-Fluoro-Deoxyglucose (F-18-FDG) and Positron Emission Tomography (PET) were used to measure glucose metabolism of the thyroid in vivo. We evaluated patients with autonomous goitre before therapy with radioiodine in comparison to patients with normal thyroids. 30 patients with autonomous goitre underwent scanning the day before radioiodine therapy. 19 patients with head or brain tumours and normal thyroids were the controls. Overall F-18-FDG uptake was determined for all thyroids and proved to be significantly higher in autonomy patients compared to controls and in disseminated autonomous goitre slightly but not significantly higher than in focal autonomy. In autonomy patients F-18-FDG uptake increased with increasing radioiodine uptake and shorter radioiodine half-life. These results indicate that glucose metabolism is enhanced in the thyroids of patients with focal and disseminated autonomy. The negative correlation of radioiodine half-life and glucose metabolism as well as the positive correlation of radioiodine uptake and glucose metabolism suggest connections of glucose metabolism and iodine-dependent hormone synthesis in thyroid cells.
Adenoma↗
Hospital human resource planning in Slovakia.
The study is an attempt to provide empirical evidence, in the context of acute hospital care, of the current human resource practices in the health sector of the Slovak Republic. Using a sample of 72 acute care hospitals the research explored the perceived functions, typical customers and priorities of hospital human resource departments, ownership of a workforce plan, and the relationships between ownership of a workforce plan and type of hospital, as well as the degree to which different human resource activities are given priority. Cross-tabulation procedure revealed statistically significant relationships between ownership of a workforce plan and the degree of priority given to having a quick, efficient and cost-effective recruitment and selection system and, not surprisingly, the degree of priority given to ensuring that the human resource department has a workforce plan. The study evidence also indicates that, although the human resource staff in hospitals seem to be aware of their role in assisting hospital management in decision making, the human resource function in the Slovak hospitals still rather resembles that of a personnel administration than that of an important strategic human resource activity.
Health Services Research↗
Interdependence of hemagglutinin glycosylation and neuraminidase as regulators of influenza virus growth: a study by reverse genetics.
The hemagglutinin (HA) of fowl plague virus A/FPV/Rostock/34 (H7N1) carries two N-linked oligosaccharides attached to Asn123 and Asn149 in close vicinity to the receptor-binding pocket. In previous studies in which HA mutants lacking either one (mutants G1 and G2) or both (mutant G1,2) glycosylation sites had been expressed from a simian virus 40 vector, we showed that these glycans regulate receptor binding affinity (M. Ohuchi, R. Ohuchi, A. Feldmann, and H. D. Klenk, J. Virol. 71:8377-8384, 1997). We have now investigated the effect of these mutations on virus growth using recombinant viruses generated by an RNA polymerase I-based reverse genetics system. Two reassortants of influenza virus strain A/WSN/33 were used as helper viruses to obtain two series of HA mutant viruses differing only in the neuraminidase (NA). Studies using N1 NA viruses revealed that loss of the oligosaccharide from Asn149 (mutant G2) or loss of both oligosaccharides (mutant G1,2) has a pronounced effect on virus growth in MDCK cells. Growth of virus lacking both oligosaccharides from infected cells was retarded, and virus yields in the medium were decreased about 20-fold. Likewise, there was a reduction in plaque size that was distinct with G1,2 and less pronounced with G2. These effects could be attributed to a highly impaired release of mutant progeny viruses from host cells. In contrast, with recombinant viruses containing N2 NA, these restrictions were much less apparent. N1 recombinants showed lower neuraminidase activity than N2 recombinants, indicating that N2 NA is able to partly overrule the high-affinity binding of mutant HA to the receptor. These results demonstrate that N-glycans flanking the receptor-binding site of the HA molecule are potent regulators of influenza virus growth, with the glycan at Asn149 being dominant and that at Asn123 being less effective. In addition, we show here that HA and NA activities need to be highly balanced in order to allow productive influenza virus infection.
Animals↗
Concerted action of multiple cis-acting sequences is required for Rev dependence of late human immunodeficiency virus type 1 gene expression.
Based on the human immunodeficiency virus type 1 (HIV-1) gag gene, subgenomic reporter constructs have been established allowing the contributions of different cis-acting elements to the Rev dependency of late HIV-1 gene products to be determined. Modification of intragenic regulatory elements achieved by adapting the codon usage of the complete gene to highly expressed mammalian genes resulted in constitutive nuclear export allowing high levels of Gag expression independent from the Rev/Rev-responsive element system and irrespective of the absence or presence of the isolated major splice donor. Leptomycin B inhibitor studies revealed that the RNAs derived from the codon-optimized gag gene lacking AU-rich inhibitory elements are directed to a distinct, CRM1-independent, nuclear export pathway.
Base Sequence↗
A recent outbreak of human immunodeficiency virus type 1 infection in southern China was initiated by two highly homogeneous, geographically separated strains, circulating recombinant form AE and a novel BC recombinant.
New outbreaks of human immunodeficiency virus type 1 (HIV-1) among injecting drug users (IDUs) are spreading in China along heroin trafficking routes. Recently, two separate HIV-1 epidemics among IDUs were reported in Guangxi, Southern China, where partial sequencing of the env gene showed subtype C and circulating recombinant form (CRF) AE. We evaluated five virtually full-length HIV-1 genome sequences from IDUs in Guangxi to determine the genetic diversity and the presence of intersubtype recombinants. Sequence analysis showed two geographically separated, highly homogeneous HIV-1 strains. B/C intersubtype recombinants were found in three IDUs from Baise City, in a mountainous region near the Yunnan-Guangxi border. These were mostly subtype C, with portions of the capsid and reverse transcriptase (RT) genes from subtype B. The subtype B portion of the capsid was located in the N-terminal domain, which has been shown to influence virus core maturation, virus infectivity, and binding to cyclophilin A, whereas the subtype B portion of RT was located in the palm subdomain, which is the active site of the enzyme. These BC recombinants differed from a BC recombinant found in Xinjiang Province in northwestern China. CRF AE strains were found in IDUs from Nanning, the capital of Guangxi, and in IDUs from Pingxiang City near the China-Vietnam border. The AE and BC recombinants were both remarkable for their low interpatient diversity, less than 1% for the full genome. Rapid spread of HIV-1 among IDUs may foster the emergence of highly homogeneous strains, including novel recombinants in regions with multiple subtypes.
Acquired Immunodeficiency Syndrome↗
Characterization of a virtually full-length human immunodeficiency virus type 1 genome of a prevalent intersubtype (C/B') recombinant strain in China.
A molecular epidemiology study was conducted among more than 100 human immunodeficiency virus type 1 (HIV-1) subtype C seropositive intravenous drug users (IDUs) from China. Genotyping based on the envelope C2V3 coding region revealed the highest homology of the most prevalent virus strains circulating throughout China to subtype C sequences of Indian origin. Based on these results, a virtually full-length genome representing the most prevalent class of clade C strains circulating throughout China was directly amplified from peripheral blood mononuclear cells of a selected HIV-infected IDU and subcloned. Sequence analysis identified a mosaic structure, suggesting extensive intersubtype recombination events between genomes of the prevalent clade C and (B')-subtype Thai virus strains of that geographic region. Recombinant Identification Program analysis and phylogenetic bootstrapping suggested that there were 10 breakpoints (i) in the gag-pol coding region, (ii) in vpr and at the 3' end of the vpu gene, and (iii) in the nef open reading frame. (B')-sequences therefore include (i) several insertions in the gag-pol coding region; (ii) 3'-vpr, the complete vpu gene, and the first exons of tat and rev; and (iii) the 5' half of the nef gene. Breakpoints located in the vpr/vpu coding region as well as in the nef gene of 97cn54 were found at almost identical positions of all subtype C strains isolated from IDUs living in different areas of China, suggesting a common ancestor for the C/B' recombinant strains. More than 50% of well-defined subtype B-derived cytotoxic T-lymphocyte epitopes within Gag and Pol and 10% of the known epitopes in Env were found to exactly match sequences within in this clade C/B' chimeric reference strain. These results may substantially facilitate a biological comparison of clade C-derived reference strains as well as the generation of useful reagents supporting vaccine-related efforts in China.
Amino Acid Sequence↗
Oestrogen metabolism in lymphangioleiomyomatosis: catechol-O-methyltransferase pathway is not involved.
BACKGROUND: Lymphangioleiomyomatosis (LAM) is an uncommon lung disease for which no effective method of treatment has been found. The predilection of LAM for premenopausal women has led to the assumption that hormonal factors play an important role in the pathogenesis of this disease. The aim of this study was to determine if women with LAM manifest alterations in the catechol-O-methyltransferase (COMT) pathway which is essential for preventing the generation of oestrogen derived reactive oxygen species (ROS). METHODS: Blood samples were collected from 15 women with LAM and compared with appropriate controls. The distribution of high and low activity alleles of COMT was determined with a PCR based RFLP assay. The enzymatic activity of COMT was measured in each sample and the potential presence of a circulating inhibitor of COMT was determined. Since an alteration in the COMT pathway could increase the oxidative stress, the plasma concentration of malondialdehyde (MDA), a secondary product generated from lipid peroxidation, has been used as an internal marker. RESULTS: The distribution of high and low activity alleles of COMT (named COMT(HH), COMT(LL), and COMT(HL)) was similar in the two groups with proportions of 40%, 7%, and 53%, respectively, in the women with LAM and 38%, 6%, and 56% in the control subjects. The mean (SD) COMT activity was 24.2 (12.3) pmol/min/mg protein in women with LAM and 24.1 (6.3) pmol/min/mg protein in the control group. Incubation of plasma from women in the two groups with a preparation of commercial COMT showed that no detectable COMT inhibitor was present. The plasma concentration of MDA in the women with LAM was also not significantly different from control subjects. CONCLUSIONS: This study shows that there are no significant alterations in the COMT pathway of women with LAM. It is therefore unlikely that alterations in oestrogen mediated cell signalling pathways are mediated by oxidants derived from an excess of catecholoestrogens in LAM.
Adult↗
Time relationship between circadian variation of serum levels of leptin, insulin and cortisol in healthy subjects.
BACKGROUND: Leptin is involved in the regulation of eating behavior. Its serum levels are determined by fat mass but a diurnal rhythm is also described. It is not clear whether leptin levels are also controlled in vivo by hormonal stimuli, like insulin or cortisol. METHODS AND RESULTS: This possible temporal relation was investigated by serial measurements during 24 h (group A) and 46 h (group B) in 15 healthy volunteers and another 10 subjects (group C) while fasting for 72 h. Maximal leptin levels were observed at 4:00 a.m. and 4:00 p.m. in subjects on a normal diet. During 24 h starvation (group B), there was a 40% decrease of mean leptin concentration when compared to baseline values. In group C, the leptin concentration under starvation dropped to 25% of basal levels after 72 h. Pooled data from group A and the nonfasting data from group B showed an insulin increase preceding leptin increase by 6 h (r = 0.405, p < 0.0001), while cortisol decreased 4 h (r = 0.361, p < 0.001) after leptin decrease. CONCLUSION: Starvation results in a fall of circulating leptin, ending leptin rhythmicity. Food intake is causally involved in the fluctuation of leptin levels in serum. Presumably this effect is mediated by insulin, while cortisol does not seem to affect leptin release directly in vivo.
Circadian Rhythm↗
Variability of leptin values measured from different sample matrices.
Leptin concentrations are usually determined in serum or EDTA-treated plasma. Our aim was to evaluate the precision and accuracy of leptin measurement from serum and various kinds of plasma. Blood samples were collected from healthy volunteers and divided into aliquots of serum and plasma with administration of K(2)-EDTA, citrate, fluoride and lithium-heparinate, respectively. Leptin concentrations were measured by a specific radioimmunoassay. There were clear differences between the leptin values from the different matrices. The coefficient of variation (CV) was highest in serum samples (CV: 11.9 %) and very low in K(2)-EDTA-treated plasma samples (CV: 5.3%). Leptin measurements from serum yielded significantly lower results than the respective K(2)-EDTA-treated plasma samples (p < 0.05). The measurement in Li-heparinate-treated plasma revealed similar results to that in K(2)-EDTA-treated plasma. The lowest CV was determined in fluoride-treated plasma (5.2%). A higher CV was determined in citrate-treated plasma (5.8%) and the values were about 25% lower than in the respective K(2)-EDTA-treated plasma samples (p < 0.0001). Lower leptin measurements in citrate-treated plasma may partially, but not in total, be a consequence of dilution by anticoagulating additives. Because of the low CV K(2)-EDTA- and Li-heparinate-treated plasma samples appear most reliable for the measurement of leptin. The usage of these sample matrices is therefore recommended.
Adult↗
Performance measurement through audit, feedback, and profiling as tools for improving clinical care.
Clinical audits and practice profiling have become popular tools in the attempt to change physician behavior to improve quality of care. Unfortunately, the growing need for information on quality of care has often outpaced the development of standard, valid, and reliable approaches to using these tools. The studies of performance measurement published in the literature to date demonstrate varying impact on ability to improve clinical care; few are randomized controlled trials. While performance measurement has become a common practice, the science surrounding this field is still in its early stages of development; while it seems promising, it should be viewed as largely experimental.
Benchmarking↗
The use of immobilized mismatch binding protein in mutation/SNP detection.
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Adenosine Triphosphatases↗
Longitudinal changes of circadian leptin, insulin and cortisol plasma levels and their correlation during refeeding in patients with anorexia nervosa.
OBJECTIVE: To study the longitudinal changes in plasma levels of leptin, insulin and cortisol during the transition from the state of starvation to the state of refeeding focussing on diurnal secretion characteristics and their temporal relationships. DESIGN: Leptin, insulin and cortisol were measured every 2h for 24h during acute starvation (T1). Sampling was repeated after reaching half the target-body mass index (BMI) (T2) and again at target-BMI (17. 5kg/m(2); T3). The temporal relationships between the diurnal secretion patterns were assessed by cross-correlation analysis. RESULTS: Although BMIs at T1 were uniformly low, leptin levels varied widely within a range clearly below normal levels (0.03-1. 7microg/l). With increasing body fat during the course of refeeding, mean leptin levels increased from 0.64microg/l (range: 0.27-1. 73microg/l) (T1) to 1.61microg/l (range: 0.36-4.2microg/l) (T2) and to 3.67microg/l (range: 0.7-9.8microg/l) (T3). Circadian leptin secretion patterns showed maximal values uniformly around 0200h and minimal values around 0800h at all stages of the study. At all three weight levels, plasma leptin levels were highest between midnight and the early morning hours and lowest around the late morning hours. Refeeding neither profoundly changed secretion patterns of leptin nor did it change the positive, time-delayed relationship between leptin and insulin with increments in insulin secretion preceding those of leptin by 6h. A temporal relationship between leptin and cortisol could not be demonstrated in the state of semistarvation but emerged after a substantial weight gain; at that time, leptin increases preceded cortisol increases by 8h. CONCLUSIONS: Absolute leptin, insulin and cortisol levels are profoundly changed during starvation in anorectic patients, while refeeding, paralleled by a BMI gain, reverses these changes. During refeeding the relationship between leptin and cortisol changed profoundly, showing no significant correlation in the state of starvation, whereas at T3 after refeeding a strong inverse relationship could be observed. Leptin and insulin did not correlate significantly at any of the three stages studied.
Adult↗