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Rastogi S, Höhne GWH, Keller A. Unusual Pressure-Induced Phase Behavior in Crystalline Poly(4-methylpentene-1): Calorimetric and Spectroscopic Results and Further Implications. Macromolecules 1999. [DOI: 10.1021/ma9912958] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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377
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Keller A, Zerlik H, Wintermantel E. Bastfaserverstärkte, biologisch abbaubare Polyester - Einfluß der Faserverfeinerung durch Dampfdruckaufschluß. ACTA ACUST UNITED AC 1999. [DOI: 10.1002/(sici)1522-9505(19991201)272:1<46::aid-apmc46>3.0.co;2-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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378
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Keller A. Alignment of linear molecules with an intense IR laser: a rigid rotor high frequency Floquet treatment. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0166-1280(99)00230-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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379
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Bennek C, Gehrt I, Keller A, Keller E, Kratzsch J, Blum WF, Kiess W. Arginine infusion and/or acute changes of growth hormone levels do not acutely alter leptin serum levels. J Pediatr Endocrinol Metab 1999; 12:847-51. [PMID: 10614542 DOI: 10.1515/jpem.1999.12.6.847] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
UNLABELLED Leptin, the ob gene product, is produced by differentiated adipocytes. It functions as an afferent signal to the central nervous system indicating satiety and fat mass status. It acts upon the hypothalamic-pituitary axis. Growth hormone (GH) secretion is thought to be stimulated by leptin. Conversely, leptin secretion and ob gene expression are regulated by classical neuroendocrine networks. Whether or not acute changes of GH concentrations directly alter leptin serum levels in vivo is still debated. We investigated whether or not acute changes in GH serum concentrations during arginine infusion (0.5 g/kg b. wt.) alter leptin serum levels in 45 children and adolescents (33 M, 12 F). GH and leptin serum levels were determined at -30, 0, 30, 60, 90, 120 min after arginine infusion using specific radioimmunoassays. Leptin serum concentrations remained unaltered throughout the arginine infusion in all children and adolescents whether or not GH secretion was normal. IN CONCLUSION (1) Acute changes of GH levels do not alter leptin serum levels during acute arginine infusions over 120 min. (2) Arginine does not acutely modulate leptin secretion.
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380
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Keller A, Hermanussen M, Vogtmann C, Kiess W, Keller E. Effect of erythrocyte transfusion on longitudinal bone growth of premature infants assessed by mini-knemometry. Eur J Pediatr 1999; 158:871-2. [PMID: 10486102 DOI: 10.1007/s004310051230] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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381
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Abstract
Retrograde axonal transport of cholera toxin B subunit (CTB) was used to compare the development of intracortical and thalamocortical connections in normal rats with those in rats in which all of the whiskers were trimmed continuously from birth. In normal animals, injections of CTB into a single barrel column resulted in an asymmetrical labeling of cells that were distributed preferentially within columns related to the same row in which the injection was placed. This anisotropy in the patterns of intracortical connections was not observed in whisker-clipped animals. In these animals, there was a significant reduction in the mean number of labeled cells in the infragranular layers, and labeled cells were distributed symmetrically around the injection site. The same injections of CTB also labeled thalamocortical neurons in the ventrobasal thalamus. Analysis of the distribution of these cells revealed that, in both control and experimental animals, the vast majority of labeled cells were restricted to a homologous (i.e., corresponding to the injected cortical barrel) thalamic barreloid. These findings indicate that manipulations of sensory experience alter patterns of intracortical, but not thalamocortical, connections.
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382
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Keller A, Matusiak R. Synthesis and catalytic activity of dinitosylchromium complexes of the type [Cr(NO)2(CO)2L2]2+, {Cr(NO)2(OR)2}n (R=Et, i-Pr) and Cr(NO)2(O2CPh)2. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s1381-1169(99)00020-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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383
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Mahairas GG, Wallace JC, Smith K, Swartzell S, Holzman T, Keller A, Shaker R, Furlong J, Young J, Zhao S, Adams MD, Hood L. Sequence-tagged connectors: a sequence approach to mapping and scanning the human genome. Proc Natl Acad Sci U S A 1999; 96:9739-44. [PMID: 10449764 PMCID: PMC22280 DOI: 10.1073/pnas.96.17.9739] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The sequence-tagged connector (STC) strategy proposes to generate sequence tags densely scattered (every 3.3 kilobases) across the human genome by arraying 450,000 bacterial artificial chromosomes (BACs) with randomly cleaved inserts, sequencing both ends of each, and preparing a restriction enzyme fingerprint of each. The STC resource, containing end sequences, fingerprints, and arrayed BACs, creates a map where the interrelationships of the individual BAC clones are resolved through their STCs as overlapping BAC clones are sequenced. Once a seed or initiation BAC clone is sequenced, the minimum overlapping 5' and 3' BAC clones can be identified computationally and sequenced. By reiterating this "sequence-then-map by computer analysis against the STC database" strategy, a minimum tiling path of clones can be sequenced at a rate that is primarily limited by the sequencing throughput of individual genome centers. As of February 1999, we had deposited, together with The Institute for Genomic Research (TIGR), into GenBank 314,000 STCs ( approximately 135 megabases), or 4.5% of human genomic DNA. This genome survey reveals numerous genes, genome-wide repeats, simple sequence repeats (potential genetic markers), and CpG islands (potential gene initiation sites). It also illustrates the power of the STC strategy for creating minimum tiling paths of BAC clones for large-scale genomic sequencing. Because the STC resource permits the easy integration of genetic, physical, gene, and sequence maps for chromosomes, it will be a powerful tool for the initial analysis of the human genome and other complex genomes.
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384
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Nozais M, Merkulova T, Keller A, Janmot C, Lompré AM, D'Albis A, Lucas M. Denervation of rabbit gastrocnemius and soleus muscles: effect on muscle-specific enolase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 263:195-201. [PMID: 10429204 DOI: 10.1046/j.1432-1327.1999.00486.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report here, for the first time, the expression of the muscle-specific isoform of the glycolytic enzyme, enolase (EC 4.2.1. 11) (beta enolase), in rabbit skeletal muscles. We have analysed the fast-twitch gastrocnemius and the slow-twitch soleus muscles during normal postnatal development and following denervation. We show that, in rabbit, as already described in rodents, beta enolase gene expression behaves as a good marker of the fast-twitch fibers. In soleus muscle, the beta enolase transcript level is 10-20% of that found in gastrocnemius. Denervation, performed at 8 postnatal days, induces an important drop of beta enolase transcript levels in both developing soleus and gastrocnemius muscles, with a 80% decrease observed 1 week after denervation in the operated muscles, as compared to the corresponding contralateral muscles. Thereafter, the beta enolase transcript level continues to decrease in the fast-twitch muscle, with the beta enolase subunit being detectable only in the atrophic fast-twitch fibers. In contrast, the beta transcript level tends to increase in the denervated slow-twitch muscle, reaching about 50% of that in contralateral soleus, at 7 weeks after surgery. The level of beta enolase transcripts still expressed after denervation seems to stabilize at the same low level in both types of inactive muscles. This suggests that the small fraction of beta enolase expression which is not controlled by the nerve, or by the contractile activity imposed by it, is independent of the muscle phenotype.
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385
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Keller A, Matusiak R. Metathesis polymerization of substituted acetylenes by Mo(NO)2(O2CR)2–Lewis acid catalysts. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s1381-1169(98)00300-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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386
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Dion C, Bandrauk A, Atabek O, Keller A, Umeda H, Fujimura Y. Two-frequency IR laser orientation of polar molecules. Numerical simulations for HCN. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)00123-2] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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387
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Foucault G, Vacher M, Merkulova T, Keller A, Arrio-Dupont M. Presence of enolase in the M-band of skeletal muscle and possible indirect interaction with the cytosolic muscle isoform of creatine kinase. Biochem J 1999; 338 ( Pt 1):115-21. [PMID: 9931306 PMCID: PMC1220032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Glycerol-skinned skeletal muscle fibres retain the defined sarcomeric structure of the myofibrils. We show here that a small fraction of two enzymes important for energy metabolism, the cytosolic muscle isoform of creatine kinase (EC 2.7.3.2), MM-creatine kinase (MM-CK), and enolase (EC 4.2.1.11), remains bound to skinned fibres. CK is slowly exchangeable, whereas enolase is firmly bound. Two-dimensional gel electrophoresis followed by Western blot analyses demonstrates that both alpha (ubiquitous) and beta (muscle-specific) subunits of enolase are present in these preparations. Enolase and CK were co-localized at the M-band of the sarcomeres, as observed by indirect immunofluorescence and confocal microscopy. Cross-linking experiments were performed on skinned fibres with three bifunctional succinimidyl esters of different lengths and yielded a protein complex of 150 kDa that reacted with antibodies directed against either M-CK or beta-enolase. The cross-linking efficiency was greatest for the longest reagent and zero for the shortest one. The length of the cross-linker giving a covalent complex between the two enzymes does not support the notion of a direct interaction between M-CK and enolase. This is the first demonstration of the presence of an enzyme of energy metabolism other than CK at the M-band of myofibres.
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388
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Keller A, Johansen JG, Hellesnes J, Brox JI. Predictors of isokinetic back muscle strength in patients with low back pain. Spine (Phila Pa 1976) 1999; 24:275-80. [PMID: 10025023 DOI: 10.1097/00007632-199902010-00016] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Testing for trunk muscle strength was performed on 105 patients with chronic low back pain. OBJECTIVES To investigate prediction of isokinetic back muscle strength in patients with low back pain. SUMMARY OF BACKGROUND DATA The clinical evaluation of patients with chronic low back pain often in difficult because of discrepancy between disability and impairment. The isokinetic trunk device was developed as a tool for objective assessment of back muscle strength. However, the performance of patients depends on radiologic abnormalities of the spine, conditions of the back muscles, and various psychosocial factors. Studies are warranted that address how these variables influence back muscle strength. METHODS The patients with chronic low back pain were tested by an isokinetic trunk muscle strength test (Cybex TEF, Ronkonkoma, NY). In addition, the following variables were recorded: gender, age, body mass index, emotional distress, pain on exertion, self-efficacy for pain, degenerative changes of the lumbar spine, cross-sectional area, and density of the erector spinae muscles. The three latter variables were estimated by computed tomography scans. The sum of the total work performed during isokinetic extension strength test was the dependent variable in a multiple regression analysis, and anthropometric, demographic, psychological, and radiologic factors were independent variables. RESULTS Gender, cross-sectional muscle area, and pain on exertion were the most powerful predictors of isokinetic back muscle strength. The final regression model, which included these variables, could account for approximately 40% of the variability in back muscle strength. CONCLUSION For assessing the results of an isokinetic trunk muscle strength test, cross-sectional muscle area, gender, and pain on exertion should be taken into account.
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389
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Dempfle CE, Keller A, Argirion S, Heene DL. A 96-well microfiltration assay for measurement of total clottable fibrinogen. Thromb Haemost 1999; 81:264-7. [PMID: 10064004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
In clinical routine use, fibrinogen is measured by clotting-time methods, or by clot turbidity in photometric prothrombin time determination. For calibration of these assays measurement of total thrombin-clottable protein has been recommended. We have now developed a microfiltration assay for total thrombin-clottable protein. Plasma samples were mixed with thrombin in a 96-well microfiltration device. After clot formation, the fluid was extracted by vacuum suction, and fibrin adherent to the filter membranes washed with buffer. Membrane segments with adherent fibrin were recovered from the 96-well manifold with a punch and transferred to tubes containing denaturing buffer solution. After dissolution of fibrin, protein concentration was determined by optical absorption at 280 nm. The microfiltration assay displayed a high correlation with the total clottable protein method (R = 0.95), and fibrinogen antigen (r = 0.96). Correlation with clotting time assays, and PT-derived fibrinogen in 150 clinical plasma samples was in the range of r = 0.84 to r = 0.97. Intraassay and day-to-day variability of the assay was comparable to the conventional total clottable fibrinogen assay. The novel microfiltration assay appears to be well suited for measurement of large series of samples for calibration, screening purposes, and clinical trials.
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390
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Cipolloni PB, Kimerer L, Weintraub ND, Smith DV, Keller A. Distribution of inhibitory synapses on the somata of pyramidal neurons in cat motor cortex. Somatosens Mot Res 1999; 15:276-86. [PMID: 9875546 DOI: 10.1080/08990229870691] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The mechanisms by which cortical neurons perform spatial and temporal integration of synaptic inputs are dependent, in large part, on the numbers, types, and distributions of their synapses. To further our understanding of these integrative mechanisms, we examined the distribution of synapses on identified classes of cortical neurons. Pyramidal cells in the cat motor cortex projecting either to the ipsilateral somatosensory cortex or to the spinal cord were labeled by the retrograde transport of horseradish peroxidase. Entire soma of selected corticocortical and corticospinal cells were examined using serial-section electron microscopy. The profiles of these somata and the synapses formed with each of these profiles were reconstructed from each thin section with a computer-aided morphometry system. All somatic synapses were of the symmetrical, presumably inhibitory type. For both cell types, these synapses were not homogeneously distributed over the somatic membrane, but were clustered at several discrete zones. The number and density of synapses on the somata of different corticocortical and corticospinal neurons were not significantly different. However, the density of these synapses was inversely correlated with the size of their postsynaptic somata. We discuss the significance of these findings to the integrative properties of cortical neurons.
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391
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Keller A, Argirion S, Heene DL, Dempfle CE. A 96-well Microfiltration Assay for Measurement of Total Clottable Fibrinogen. Thromb Haemost 1999. [DOI: 10.1055/s-0037-1614455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryIn clinical routine use, fibrinogen is measured by clotting-time methods, or by clot turbidity in photometric prothrombin time determination. For calibration of these assays measurement of total thrombinclottable protein has been recommended. We have now developed a microfiltration assay for total thrombin-clottable protein. Plasma samples were mixed with thrombin in a 96-well microfiltration device. After clot formation, the fluid was extracted by vacuum suction, and fibrin adherent to the filter membranes washed with buffer. Membrane segments with adherent fibrin were recovered from the 96-well manifold with a punch and transferred to tubes containing denaturing buffer solution. After dissolution of fibrin, protein concentration was determined by optical absorption at 280 nm. The microfiltration assay displayed a high correlation with the total clottable protein method (R = 0.95), and fibrinogen antigen (r = 0.96). Correlation with clotting time assays, and PT-derived fibrinogen in 150 clinical plasma samples was in the range of r = 0.84 to r = 0.97. Intraassay and day-to-day variability of the assay was comparable to the conventional total clottable fibrinogen assay. The novel microfiltration assay appears to be well suited for measurement of large series of samples for calibration, screening purposes, and clinical trials.
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392
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Merkulova T, Thornell LE, Butler-Browne G, Oberlin C, Lucas M, Lamandé N, Lazar M, Keller A. The beta enolase subunit displays three different patterns of microheterogeneity in human striated muscle. J Muscle Res Cell Motil 1999; 20:55-63. [PMID: 10360234 DOI: 10.1023/a:1005428328913] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In higher vertebrates, the glycolytic enzyme enolase (2-phospho-D-glycerate hydrolyase; EC 4.2.1.11) is active as a dimeric protein formed from three subunits--alpha: ubiquitous, beta: muscle specific, and gamma: neuron specific--encoded by different genes. In the present study, we have shown that an antiserum previously produced against the mouse beta beta enolase is also a specific reagent for the muscle specific human enolase. Using this antiserum to study human muscles, we demonstrated novel patterns of the beta subunit microheterogeneity which are distinctive from those observed previously in rodents and which appear to be independent of age, gender and muscular activity. Two variants of the beta subunit differing by their size have been detected: one heavy form of 46 kDa (beta H) and one light form of 45 kDa (beta L). Muscle biopsies expressed either beta H or beta L or beta H + beta L, and all muscles of an individual expressed the same variants. The products of in vitro translation of RNA prepared from human muscle displayed beta subunit variants identical to those of the protein present in the biopsy. Therefore the differences observed between individuals reveal a difference already present at the level of the RNA transcripts. These observations suggest the existence of an yet undescribed polymorphism of the human beta enolase gene which could affect the coding sequence. Comparative immunocytochemical and histochemical analyses of biopsies demonstrated that the beta subunit was expressed in all fast fibres (type II), but not in slow fibres (type I). No difference was observed in the intensity of beta enolase immunolabelling between the various types (IIA, IIAB, IIB) of fast fibres. No significant difference in fibre type composition and histological appearance was visible between muscles presenting either one of the three patterns of microheterogeneity.
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393
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Mattos RC, Gregory RM, Meirelles LS, Malschitzky E, Castilho LFF, Pires Neves A, Gelpi Mattos AL, Jöchins Vieira M, Keller A, Hött AK. Oxytocin and plasma containing leukocytes or a combination of both as treatment of postbreeding endometritis in the horse. PFERDEHEILKUNDE 1999. [DOI: 10.21836/pem19990618] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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394
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Keller A, Schretzmann B, Stegie R. Job Satisfaction amongst Visually Impaired People in Germany: Results of a Study. BRITISH JOURNAL OF VISUAL IMPAIRMENT 1999. [DOI: 10.1177/026461969901700106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Eighty German working men and women were questioned on their attitudes to their work and how it's importance related to that of other aspects of life. They were generally satisfied with their work situation; some with an above average rating; but many were worried about their promotion prospects and opportunities for training. Without exception they considered work to be as important or more important for visually impaired people than sighted peers and they rated work at least as important as other aspects of their lives.
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395
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Keller A, Sobczak J, Matusiak R. Catalytic activity of Mo(NO)2(HSO4)2L2 and [Mo(NO)2L4](HSO4)2 (L=MeCN, EtOH) in reaction of metathesis and epoxidation of olefins. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s1381-1169(98)00056-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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396
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Mueller BU, Lewis LL, Yuen GJ, Farley M, Keller A, Church JA, Goldsmith JC, Venzon DJ, Rubin M, Pizzo PA, Balis FM. Serum and cerebrospinal fluid pharmacokinetics of intravenous and oral lamivudine in human immunodeficiency virus-infected children. Antimicrob Agents Chemother 1998; 42:3187-92. [PMID: 9835513 PMCID: PMC106021 DOI: 10.1128/aac.42.12.3187] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We studied the pharmacokinetics of intravenously and orally administered lamivudine at six dose levels ranging from 0.5 to 10 mg/kg of body weight in 52 children with human immunodeficiency virus infection. A two-compartment model with first-order elimination from the central compartment was simultaneously fitted to the serum drug concentration-time data obtained after intravenous and oral administration. The maximal concentration at the end of the 1-h intravenous infusion and the area under the concentration-time curve after oral and intravenous administration increased proportionally with the dose. The mean clearance of lamivudine (+/- standard deviation) in the children was 0.53 +/- 0.19 liter/kg/h (229 +/- 77 ml/min/m2 of body surface area), and the mean half-lives at the distribution and elimination phases were 0.23 +/- 0.18 and 2.2 +/- 2.1 h, respectively. Clearance was age dependent when normalized to body weight but age independent when normalized to body surface area. Lamivudine was rapidly absorbed after oral administration, and 66% +/- 25% of the oral dose was absorbed. Serum lamivudine concentrations were maintained above 1 microM for >/=8 h of 24 h on the twice daily oral dosing schedule with doses of >/=2 mg/kg. The cerebrospinal fluid drug concentration measured 2 to 4 h after the dose was 12% (range, 0 to 46%) of the simultaneously measured serum drug concentration. A limited-sampling strategy was developed to estimate the area under the concentration-time curve for concentrations in serum at 2 and 6 h.
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397
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Bourge R, Eisen H, Hershberger R, Keller A, Radovancevic B, Schreier G, Kastner P, Hutten H, Wery S, Mehta N. Noninvasive rejection monitoring of cardiac transplants using high resolution intramyocardial electrograms: initial US multicenter experience. Pacing Clin Electrophysiol 1998; 21:2338-44. [PMID: 9825344 DOI: 10.1111/j.1540-8159.1998.tb01178.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Endomyocardial biopsy (EMB) remains the mainstay for the diagnosis of acute cellular rejection in cardiac transplant patients. A noninvasive alternative that would supplant or reduce the number of EMBs would be a highly desirable and cost-effective tool. To evaluate one potential alternative, a pacemaker with high resolution telemetry capabilities and two fractally coated epimyocardial leads were implanted in 30 patients at five transplant centers during the heart transplant procedure. Ventricular electrograms were recorded during intrinsic and paced activity and digitized to a laptop-based data acquisition device. Electrograms were recorded at frequent intervals and systematically on days when EMBs were performed. The electrogram data were then transferred via the Internet to a central data processing site. Clinical patient management was blinded to the electrogram results and varied considerably among the five centers. Using EMB together with clinical assessment of the transplant revealed 18 cases of clinically significant rejection beyond postoperative day 27 that required antirejection therapy. The normalized parameter values extracted from the electrogram recordings during pacing (the ventricular evoked response) that were associated with significant rejection were statistically lower (86% +/- 16% versus 96% +/- 22%, P < 0.005). The application of a single-threshold diagnosis model to the parameter values allowed detection of significant rejection with a negative predictive value of 98%. This analysis also showed that as many as 55% of the routine surveillance EMBs could have been eliminated had the pacemaker monitoring technique been used as a screening tool prior to EMB. A prospective study should further define the role of this technique in the detection and management of cardiac transplant patients.
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398
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Friedenberg WR, Keller A, Young J, Oken MM. Infusional chemotherapy for non-Hodgkin's lymphoma. Cancer Invest 1998; 16:544-6. [PMID: 9774963 DOI: 10.3109/07357909809011710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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399
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McKinney RE, Johnson GM, Stanley K, Yong FH, Keller A, O'Donnell KJ, Brouwers P, Mitchell WG, Yogev R, Wara DW, Wiznia A, Mofenson L, McNamara J, Spector SA. A randomized study of combined zidovudine-lamivudine versus didanosine monotherapy in children with symptomatic therapy-naive HIV-1 infection. The Pediatric AIDS Clinical Trials Group Protocol 300 Study Team. J Pediatr 1998; 133:500-8. [PMID: 9787687 DOI: 10.1016/s0022-3476(98)70057-5] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE The Pediatric AIDS Clinical Trials Group (PACTG) Protocol 300 assessed the clinical efficacy and safety of combination zidovudine/lamivudine (ZDV/3TC) compared with either didanosine (ddI) alone or combination ZDV/ddI. STUDY DESIGN Children with symptomatic human immunodeficiency virus (HIV) infection, 6 weeks through 15 years of age, were stratified according to age and randomly assigned to receive ddI, ZDV/3TC, or ZDV/ddI. The primary endpoint was time to first progression of HIV disease or death. Enrollment in the ZDV/ddI arm stopped after 11 months on the basis of results of PACTG Protocol 152, but blinded follow-up continued. RESULTS For the 471 children who could be evaluated, the median age was 2.7 years, median CD4 cell count was 699 cells/mm3, and median log10 HIV RNA was 5.1/mL. Median follow-up was 9.4 months. Patients receiving ZDV/3TC had a lower risk of HIV disease progression or death than those receiving ddI alone (15 vs 38 failures, P = .0006) and a lower risk of death (3 vs 15 deaths, P = .0039). Weight and height growth rates, CD4+ cell counts, and RNA concentrations showed results favoring ZDV/3TC. For patients concurrently randomized to all 3 treatment arms, both ZDV/3TC and ZDV/ddI recipients had lower risk of HIV disease progression than those who received ddI alone (P = .0026 and P = .0045). CONCLUSIONS Combination therapy with either ZDV/3TC or ZDV/ddI was superior, as determined by clinical and laboratory measures, to monotherapy with ddI.
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400
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Dempfle CE, Keller A, Kirchner A, Heene DL. The influence of hirudin on plasma fibrinogen assays. Thromb Haemost 1998; 80:716-7. [PMID: 9799005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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