1201
|
Straub RH, Weidler C, Demmel B, Herrmann M, Kees F, Schmidt M, Schölmerich J, Schedel J. Renal clearance and daily excretion of cortisol and adrenal androgens in patients with rheumatoid arthritis and systemic lupus erythematosus. Ann Rheum Dis 2004; 63:961-8. [PMID: 15249323 PMCID: PMC1755103 DOI: 10.1136/ard.2003.014274] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND In rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), patients demonstrate low levels of adrenal hormones. OBJECTIVE To investigate whether increased renal clearance and daily excretion contribute to this phenomenon. METHODS Thirty patients with RA, 32 with SLE, and 54 healthy subjects (HS) participated. Serum and urinary levels of cortisol, cortisone, 17-hydroxyprogesterone (17OHP), androstenedione, dehydroepiandrosterone (DHEA), and DHEA sulphate (DHEAS) were measured. RESULTS Clearance of DHEAS and DHEA was lower in patients than in HS, and clearance of androstenedione was somewhat higher in patients than in HS, but daily excretion of this latter hormone was low. Clearance of cortisol, cortisone, and 17OHP was similar between the groups. The total molar amount per hour of excreted DHEA, DHEAS, and androstenedione was lower in patients than HS (but similar for cortisol). Serum DHEAS levels correlated with urinary DHEAS levels in HS and patients, whereby HS excreted 5-10 times more of this hormone than excreted by patients. Low serum levels of adrenal androgens and cortisol in patients as compared with HS were confirmed, and proteinuria was not associated with changes of measured renal parameters. CONCLUSIONS This study in patients with RA and SLE demonstrates that low serum levels of adrenal androgens and cortisol are not due to increased renal clearance and daily loss of these hormones. Decreased adrenal production or increased conversion or conjugation to downstream hormones are the most likely causes of inadequately low serum levels of adrenal hormones in RA and SLE.
Collapse
|
1202
|
Tanner B, Schiffer I, Heimerdinger C, Glawatz C, Schmidt M, Brulport M, Hermes M, Pasuello V, Boehm D, Neubert S, Naumann G, Kölbl H, Hengstler J. Perspektiven HER-2 blockierender Therapiestrategien im Mausmodell: Rasche Tumorremission in Abhängigkeit vom Tumorstadium, aber keine dauerhafte Heilung. Geburtshilfe Frauenheilkd 2004. [DOI: 10.1055/s-2004-821037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
|
1203
|
Aust DE, Muders M, Köhler A, Schmidt M, Diebold J, Müller C, Löhrs U, Waldman FM, Baretton GB. Prognostic relevance of 20q13 gains in sporadic colorectal cancers: a FISH analysis. Scand J Gastroenterol 2004; 39:766-72. [PMID: 15513363 DOI: 10.1080/00365520410003191] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Amplification of 20q13 is a frequent chromosomal alteration in solid tumors and harbors a number of putative oncogenes (CAS/CSE1-L, NABC1, or Aurora2). Amplifications on 20q13 have been identified as an independent prognostic marker indicating worse survival in breast and ovarian cancer. However, little is known about the prognostic significance of 20q13 gains in sporadic colorectal cancers. The aim of this study was to correlate 20q13 gains in sporadic colorectal cancers with other known prognostic factors, tumor progression, and overall survival. METHODS Nuclei were extracted from 146 paraffin-embedded colorectal cancers of different UICC stages and used for fluorescence in situ hybridization (FISH) with a directly labeled probe for 20q13.2 (VYSIS). Signals were counted in 120 nuclei per sample. 20q13 was considered gained when > or =40% of the nuclei showed 3 or more FISH signals. Statistical correlations were tested with log-rank tests and Kaplan-Meier survival curves. RESULTS Signal numbers for 20q13.2 were gained in 78 cases (53%). Cases with gains on 20q13.2 showed worse outcome than cases without: the gain of 20q13.2 was an independent prognostic marker for overall survival (P=0.006) as well as tumor progression (P=0.012) in univariate and multivariate analyses. Gains on 20q13.2 did not correlate with tumor stage. However, there was a significant association between 20q13.2 gains and tumor location in the left-sided colon and an inverse correlation between histologic grade and 20q13.2 gains. CONCLUSION These data indicate that gains on 20q13.2 correlate with faster tumor progression and worse patient survival independent from tumor size and lymph node involvement. Therefore, alterations on 20q13 are an important biological event in colorectal tumor progression with independent prognostic relevance.
Collapse
|
1204
|
Schmidt M, Schmalenbach M, Jungehülsing M, Theissen P, Dietlein M, Schröder U, Eschner W, Stennert E, Schicha H. 18F-FDG PET for detecting recurrent head and neck cancer, local lymph node involvement and distant metastases. Comparison of qualitative visual and semiquantitative analysis. NUKLEARMEDIZIN. NUCLEAR MEDICINE 2004; 43:91-101;quiz 102-4. [PMID: 15201950 DOI: 10.1267/nukl04030091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
AIM Assessment of the clinical value of (18)F-FDG-PET for detection of recurrent head and neck cancer, local lymph node involvement and distant metastases comparing a qualitative visual with a semiquantitative analysis (SUV values). PATIENTS, METHODS Retrospective evaluation of 73 (18)F-FDG PET studies in 55 patients by use of a four-step qualitative visual grading system and calculation of standard uptake values in pathological lesions. Calculation of SUV values in normal regions for generating a map of physiological (18)F-FDG distribution. Correlation to histopathological findings and clinical follow-up. RESULTS 1. Qualitative visual analysis of (18)F-FDG PET studies: a) local recurrence sensitivity 79%, specificity 97%, positive predictive value 95%, negative predictive value 85%, and diagnostic accuracy 89%; b) local metastatic lymph nodes 100%, 95%, 85%, 100%, 96%; c) distant metastases 100%, 98%, 86%, 100%, 98%, respectively. 2. Semiquantitative analysis had only little incremental, non-significant value in comparison to qualitative visual analysis for the detection of a local recurrence in two patients: a) local recurrence: sensitivity 83%, specificity 100%, positive predictive value 100%, negative predictive value 88%, and diagnostic accuracy 93%; b) local metastatic lymph nodes or c) distant metastases did not change in comparison to qualitative visual analysis. CONCLUSION (18)F-FDG PET is an effective tool for re-staging of patients with suspected recurrence after therapy for head and neck cancer.
Collapse
|
1205
|
Huber RM, Flentje M, Gosse H, Poellinger B, Schmidt M, Willner J, Ulm K. Induction chemotherapy and following simultaneous radiochemotherapy versus induction chemotherapy and radiotherapy alone in inoperable NSCLC (Stage IIIA/IIIB): Update of CT/RT 99/97. J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.7075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
1206
|
Borgmeier A, Huber R, Flentje M, Willner J, Schmidt M, Manegold C, Debus J. A phase I study of concurrent chemoradiotherapy with docetaxel-cisplatin followed by docetaxel consolidation therapy in inoperable stage IIIA/B non-small cell lung cancer (NSCLC). J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.7350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
1207
|
Lindner LH, Schlemmer M, Hohenberger P, Wust P, Abdel-Rahman S, Schmidt M, Judson I, Blay JY, Verweij J, Issels RD. First interim report on the randomized EORTC 62961/ESHO-RHT 95 Intergroup Study (phase III) combined with regional hyperthermia (RHT) versus chemotherapy alone in the treatment of high-risk soft tissue sarcomas (HR-STS) in adults. J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.9015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
1208
|
Hövelmann S, Beckers TL, Schmidt M. Molecular alterations in apoptotic pathways after PKB/Akt-mediated chemoresistance in NCI H460 cells. Br J Cancer 2004; 90:2370-7. [PMID: 15150572 PMCID: PMC2409515 DOI: 10.1038/sj.bjc.6601876] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Protein kinase B/Akt has been described as a central mediator of antiapoptotic signals in cancer cells. Furthermore, Akt has been shown to affect cell cycle progression and proliferative pathways and to possess a potential function in tumorigenesis and chemoresistance. In this study, we show that the ectopic expression of a constitutively active form of Akt1 (CA-Akt1) results in enhanced chemoresistance of NCI H460 human NSCLC cells towards a panel of chemotherapeutic agents. To understand the molecular alterations leading to impaired chemosensitivity mediated by activated Akt, we analysed various apoptotic pathways, including the activation of p53, caspases 3, 7, 8, and 9, release of cytochrome c from mitochondria, and the expression levels of pro- and antiapoptotic proteins such as Bcl-2, Bcl-xL, Bcl-xs, Bax, or Bfl-1. We observed that expression of CA-Akt did not interfere with single defined apoptotic switches, but modulated the apoptotic threshold of several apoptotic pathways towards increasing the threshold of onset. In particular, we found that CA-Akt-expressing cells displayed increased expression of the antiapoptotic Bcl-2 family member protein Bcl-xl, and a delayed onset of the p53 pathway after treatment with cisplatin or Mitoxantrone. Thus, our data suggest that Akt mediates chemoresistance in NHI H460 cells by interfering with and delaying the onset of various apoptotic pathways. A complete inactivation of apoptotic pathways was observed in none of the molecular alterations investigated. Our data strengthen the role of Akt as a central mediator of cell survival signals and/or chemoresistance and as an attractive target for cancer cell chemosensitisation.
Collapse
|
1209
|
Budnyk S, Prots Y, Schmidt M, Schnelle W, Kuz'ma Y, Grin Y. Yb2+3—xPd12—3+xP7 (x = 0.40): Different Ytterbium Species in a Substituted Structural Motif of the Zr2Fe12P7 Type. Z Anorg Allg Chem 2004. [DOI: 10.1002/zaac.200400113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
1210
|
Krause U, Lohrer C, Schmidt M. Bewertungskriterien für die Selbstentzündung von Schüttgütern, Stäuben und porösen Feststoffen. CHEM-ING-TECH 2004. [DOI: 10.1002/cite.200400072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
1211
|
Schmidt M, Sangild PT, Blum JW, Andersen JB, Greve T. Combined ACTH and glucocorticoid treatment improves survival and organ maturation in premature newborn calves. Theriogenology 2004; 61:1729-44. [PMID: 15019468 DOI: 10.1016/j.theriogenology.2003.10.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2003] [Revised: 10/07/2003] [Accepted: 10/08/2003] [Indexed: 12/01/2022]
Abstract
Glucocorticoids play an important role in prenatal organ maturation in many species. In humans, maternal treatment with synthetic glucocorticoids improves neonatal adaptation of prematurely born infants. In cows, pre-term calf survival is improved following a single maternal glucocorticoid administration. We hypothesized that stimulation of endogenous cortisol secretion by adrenocorticotropin (ACTH) treatment combined with maternal dexamethasone treatment, would be even more efficient in stimulating organ maturation in the prematurely delivered calf. Three groups of premature calves were delivered by caesarian section at 90% of gestation length from dams which were either untreated or injected with dexamethasone before delivery, combined with either prenatal or postnatal ACTH treatment to the calf. During the first 24h after birth, thermoregulation, blood chemistry, liver values and organ weights were recorded. In the untreated calves, survival was significantly correlated with blood oxygenation, sodium and calcium levels at the moment of birth. There were marked maturational effects of the treatments on body temperature regulation, blood acid-base status, oxygenation, glucose, insulin, IGF-1 levels, weight of the heart, liver, gastrointestinal tract and thymus weight. For many of the measured metabolic, endocrine and organ weight parameters, the intrauterine ACTH treatment was associated with improved values relative to the postnatal ACTH treatment, which appeared to have no immediate effect on calf viability. In conclusion, the premature calf delivered by caesarian section at 90% of gestation length showed blood chemistry, metabolic, endocrine and organ growth characteristics that indicated severe prematurity. However, the maturation of organ function in newborn premature calves following maternal glucocorticoid injections was further enhanced if is was preceded by intra-fetal injections of ACTH.
Collapse
|
1212
|
Bolte G, Schmidt M, Maziak W, Keil U, Nasca P, von Mutius E, Weiland SK. The relation of markers of fetal growth with asthma, allergies and serum immunoglobulin E levels in children at age 5-7 years. Clin Exp Allergy 2004; 34:381-8. [PMID: 15005731 DOI: 10.1111/j.1365-2222.2004.01890.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND It has been suggested that fetal growth and maturation have an impact on the development of allergic diseases later in life. OBJECTIVE To examine the association between measures of fetal growth and allergic disease in children at age 5-7 years. METHODS As part of the German International Study of Asthma and Allergies in Childhood phase II surveys, a random sample of school beginners (n=1138) was examined in 1995. Data on anthropometric measures at birth and gestational age were obtained from maternal copies of birth records. Data on symptoms and doctor-diagnosed asthma, atopic dermatitis and hayfever were gathered by parental questionnaires. Atopic sensitization was assessed by serum IgE and skin prick tests to common aeroallergens. Children (741) had complete data for the explanatory variables of interest and were thus eligible for this analysis. Confounder-adjusted prevalence odds ratios (PORs) and means ratios with 95% confidence intervals (CI) were calculated using multiple logistic and linear regression. RESULTS Birth weight and gestational age were positively associated with atopic sensitization (Ptrend=0.025 and 0.035, respectively). Children with a low birth weight relative to head circumference had a decreased risk of sensitization (POR 0.44, 95% CI 0.21-0.91; Ptrend=0.020). Moreover, total serum IgE increased with increasing birth weight (Ptrend=0.042). No consistent relationship was observed between markers of fetal growth and wheezing, doctor-diagnosed asthma, atopic dermatitis and hayfever. CONCLUSION These data suggest that fetal growth and maturity are associated with atopic sensitization and total serum IgE levels in childhood.
Collapse
|
1213
|
Schmidt M, Ewald B, Prots Y, Cardoso-Gil R, Armbrüster M, Loa I, Zhang L, Huang YX, Schwarz U, Kniep R. Growth and Characterization of BPO4 Single Crystals. Z Anorg Allg Chem 2004. [DOI: 10.1002/zaac.200400002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
1214
|
Wästlund C, Schmidt M, Schantz S, Maurer FHJ. Free volume, mobility, and structural relaxations in poly(ethylene oxide)/poly(methyl methacrylate) blends. POLYM ENG SCI 2004. [DOI: 10.1002/pen.10299] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
1215
|
Arnold JFT, Fidler F, Wang T, Pracht ED, Schmidt M, Jakob PM. Imaging lung function using rapid dynamic acquisition of T 1-maps during oxygen enhancement. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2004; 16:246-53. [PMID: 15042464 DOI: 10.1007/s10334-004-0034-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Accepted: 12/19/2003] [Indexed: 10/26/2022]
Abstract
This paper describes imaging of lung function with oxygen-enhanced MRI using dynamically acquired T1 parameter maps, which allows an accurate, quantitative assessment of time constants of T1-enhancement and therefore lung function. Eight healthy volunteers were examined on a 1.5-T whole-body scanner. Lung T1-maps based on an IR Snapshot FLASH technique (TE = 1.4 ms, TR = 3.5 ms, FA = 7 (composite function )) were dynamically acquired from each subject. Without waiting for full relaxation between subsequent acquisition of T1-maps, one T1-map was acquired every 6.7 s. For comparison, all subjects underwent a standard pulmonary function test (PFT). Oxygen wash-in and wash-out time course curves of T1 relaxation rate (R1)-enhancement were obtained and time constants of oxygen wash-in (w(in)) and wash-out (w(out)) were calculated. Averaged over the whole right lung, the mean w(out) was 43.90 +/- 10.47 s and the mean (w(in)) was 51.20 +/- 15.53 s, thus about 17% higher in magnitude. Wash-in time constants correlated strongly with forced expired volume in one second in percentage of the vital capacity (FEV1 % VC) and with maximum expiratory flow at 25% vital capacity (MEF25), whereas wash-out time constants showed only weak correlation. Using oxygen-enhanced rapid dynamic acquisition of T1-maps, time course curves of R1-enhancement can be obtained. With w(in) and w(out) two new parameters for assessing lung function are available. Therefore, the proposed method has the potential to provide regional information of pulmonary function in various lung diseases.
Collapse
|
1216
|
Schmidt M, Renner H. Totaler Muttermundverschluss mit Cerclage als operativer Therapieansatz bei drohendem Spätabort und sehr früher Frühgeburt. Z Geburtshilfe Neonatol 2004. [DOI: 10.1055/s-2003-818153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
1217
|
Huber RM, Gamarra F, Flentje M, Willner J, Borgmeier A, Schmidt M, Manegold C, Debus J, Pöllinger B. Simultane Radiochemotherapie (SRCHT) mit Docetaxel und Cisplatin, gefolgt von einer Konsolidierungschemotherapie mit Docetaxel bei Patienten mit inoperablem, nicht kleinzelligem Bronchialkarzinom im Stadium IIIA/B: eine Phase-I-Studie. Pneumologie 2004. [DOI: 10.1055/s-2004-819733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
1218
|
Wahn H, Kaufmann H, Finter F, Schmidt M. Anhaltende PAP-Senkung und Gewebs-cGMP-Restauration ohne systemische NO-Entstehung durch aerosoliertes PAPA-NONOate in einem pulmonalen Hypertoniemodell an isolierten Kaninchenlungen. Pneumologie 2004. [DOI: 10.1055/s-2004-819603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
1219
|
Priller H, Schmidt M, Dremel M, Grün M, Toropov A, Ivchenko E, Kalt H, Klingshirn C. Density dependent luminescence properties of CdS/ZnSe single quantum wells. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/pssc.200304131] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
1220
|
Weichert W, Denkert C, Schmidt M, Gekeler V, Wolf G, Köbel M, Dietel M, Hauptmann S. Polo-like kinase isoform expression is a prognostic factor in ovarian carcinoma. Br J Cancer 2004; 90:815-21. [PMID: 14970859 PMCID: PMC2410182 DOI: 10.1038/sj.bjc.6601610] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2003] [Revised: 11/07/2003] [Accepted: 12/01/2003] [Indexed: 12/12/2022] Open
Abstract
The Polo-like kinase (PLK) family comprises three serine/threonine kinases, functionally involved in signal transduction pathways essential for the accomplishment of mitosis in both normal and malignant cells. Moreover, certain PLKs have been functionally linked to cytoskeletal reorganisation. In this study, the expression of PLK1 and PLK3 was determined immunohistochemically in tissue specimen of normal ovaries (n=9), cystadenomas (n=17), borderline tumours (n=13) and ovarian carcinomas (n=77). PLK 1 and PLK3 expression was low in normal ovarian surface epithelium and borderline tumours, with moderately higher expression levels in cystadenomas. In ovarian carcinomas, 26% of cases were PLK1 positive and 50.6% of cases were PLK3 positive. A positive correlation of both PLK1 and PLK3 expression with indicators of mitotic frequency could be established. The overexpression of either isoenzyme had an impact on patient prognosis with shortened survival time for patients with tumours positive for PLK1 (P=0.02) and PLK3 (P=0.02), but only PLK1 expression remained a prognostic factor in multivariate survival analysis (P=0.03). The results of this study, if interpreted in the context of recently published functional data, suggest that inhibition of PLKs might represent an interesting new targeted approach for chemotherapy of epithelial ovarian cancer. Furthermore, this study suggests that PLK1 is a novel independent prognostic marker in ovarian carcinomas.
Collapse
|
1221
|
Schmidt M, Ratcliff W, Radaelli PG, Refson K, Harrison NM, Cheong SW. Spin singlet formation in MgTi2O4: evidence of a helical dimerization pattern. PHYSICAL REVIEW LETTERS 2004; 92:056402. [PMID: 14995323 DOI: 10.1103/physrevlett.92.056402] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2003] [Indexed: 05/24/2023]
Abstract
The transition-metal spinel MgTi2O4 undergoes a metal-insulator (M-I) transition on cooling below T(M-I)=260 K. A sharp reduction of the magnetic susceptibility below T(M-I) suggests the onset of a magnetic singlet state. Using high-resolution synchrotron and neutron powder diffraction, we have solved the low-temperature crystal structure of MgTi2O4, which is found to contain dimers with short Ti-Ti distances (the locations of the spin singlets) alternating with long bonds to form helices. Band structure calculations based on hybrid exchange density functional theory show that, at low temperatures, MgTi2O4 is an orbitally ordered band insulator.
Collapse
|
1222
|
Schmidt M, Löffler F. 89. Untersuchungen zum Einfluß elektrostatischer Effekte auf die Naßentstaubung. CHEM-ING-TECH 2004. [DOI: 10.1002/cite.330650991] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
1223
|
Brauer H, Mühle J, Schmidt M. Untersuchungen an einer mehrstufigen Rieselboden-Wirbelschicht. CHEM-ING-TECH 2004. [DOI: 10.1002/cite.330420715] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
1224
|
Schmidt M, Sangild PT, Jacobsen H, Greve T. A method to reduce the invasiveness of fetal catheterization in the cow. Anim Reprod Sci 2004; 80:193-200. [PMID: 15036496 DOI: 10.1016/j.anireprosci.2003.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2002] [Revised: 06/05/2003] [Accepted: 06/20/2003] [Indexed: 11/22/2022]
Abstract
Surgical intervention in general anesthesia (GA) of the cow in late gestation is a stressful condition for both mother and fetus, potentially leading to premature delivery or fetal death. The present study hypothesized that fetal catheterization at days 246-253 (90% of gestation) is done with less physical and metabolic stress for the mother and fetus, when the surgery is performed on a standing cow and local anesthesia (LA) rather than on a recumbent cow in general anesthesia. Fetal and uterine maternal intra-vascular catheters were implanted during general anesthesia (GA, n=24) or local analgesia (LA, n=7). Blood gases and metabolite levels in the fetal calves and their mothers were measured during surgery and for 5 days post-operatively. During surgery, venous blood pH was higher (7.44 +/- 0.01 versus 7.39 +/- 0.01, P<0.05) and hemoglobin and oxygen contents lower in LA cows compared with GA cows (9.3 +/- 0.3 mg/dl versus 11.8 +/- 0.2 mg/dl, P<0.001 and 10.0 +/- 0.3 ml/dl versus 12.6 +/- 0.6 ml/dl, P<0.05). The differences between the two groups of fetuses reflected those of their dams in that LA fetuses showed lower arterial oxygen pressure (18.3 +/- 1.4 mmHg versus 24.8 +/- 1.4 mmHg, P<0.05) and hemoglobin (7.81 +/- 0.30 mg/dl versus 9.22 +/- 0.21 mg/dl P<0.01) and furthermore, they also showed higher blood glucose (2.4 +/- 0.2 mM versus 1.4 +/- 0.1 mM, P<0.01). During the 5 days post-surgery, 10 GA fetuses (42%) and 1 LA fetus (14%) died in utero. Bacterial contamination was implicated in six of the GA deaths and in the one LA death. In the dams with surviving calves, differences in hemoglobin (9.49 +/- 0.21 mg/dl versus 11.17 +/- 0.23 mg/dl P<0.001) and O2ct (10.9 +/- 0.3 ml/dl versus 12.5 +/- 0.5 ml/dl, P<0.05) were still present, and in addition, blood glucose was higher in LA versus GA cows (4.3 +/- 0.2 mM versus 3.8 +/- 0.1 mM, P<0.05). The choice of surgical method did not affect post-surgery blood chemistry in the surviving fetuses, except that the higher blood glucose in the LA fetuses at surgery tended to be maintained also post-operatively (2.0 +/- 0.2 mM versus 1.5 +/- 0.1 mM, P=0.07). The observed differences in blood chemistry parameters between the two methods of surgery and possibly in the fetal death may be explained by differences in catheterization method and the associated differences in physical and metabolic stress during and after surgery. Thus, surgery upon a standing cow in local anesthesia should be considered as an alternative to surgery in universal anesthesia for fetal catheterization in the cow in late gestation.
Collapse
|
1225
|
Kaczmarek I, Meiser B, Mueller M, Groetzner J, Adamidis I, Landwehr P, Ertl B, Uberfuhr P, Knez A, Stempfle HU, Schmidt M, Reichart B. Which immunosuppressive combination is most efficacious for prevention of graft vessel disease? Thorac Cardiovasc Surg 2004. [DOI: 10.1055/s-2004-816679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|