Biomedical subjects

Klaus Mann

Publications and source records attributed to Klaus Mann.

57 records · Page 4Linked to original sources

PubMed2002

Sensitive calcitonin measurement by two-site immunometric assays: implications for calcitonin screening in nodular thyroid disease.

The aim of this study was to investigate the impact of analytical aspects on the clinical usefulness of calcitonin (CT) measurement. In a retrospective analysis, CT levels measured by a polyclonal immunometric assay (Scantibodies Laboratory, CA, USA) were evaluated in various clinical situations. CT in newly diagnosed medullary thyroid cancer (MTC) (n = 20) ranged from 15.5-87130 pg/ml (median 661 pg/ml). Levels >10 pg/ml were seen in 7.3% of 314 patients with benign nodules, 48.9% of 45 patients with impaired kidney function, 97.7% of 87 patients on hemodialysis, 30.2% of 43 patients after renal transplantation, and in 71.0% of 31 patients with critical illnesses. Subgroups of patients were reevaluated by two monoclonal immunometric assays specific for mature CT. CT levels measured by the monoclonal immunometric assays were highly correlated to the polyclonal assay results in MTC patients, but were significantly different with a lower incidence of elevated levels in patients with renal disease and critical illnesses. In conclusion, highly sensitive assays with cut-off values of 10 pg/ml or below are mandatory for CT screening in nodular thyroid disease. The specificity of CT measurement in patients with renal disease and critical illnesses is higher with monoclonal assays specific for monomeric CT. These methodological aspects have to be regarded if CT measurement is used for decision making in nodular thyroid disease.

Adult↗

PubMed1999

Ferro- and Antiferromagnetic Coupling through 1,n-Dithiosquarate Bridges (n = 2, 3) in Copper(II) Dimers. Syntheses, Crystal Structures, and Magnetic Properties of [Cu(2)(bpca)(2)(1,2-dtsq)(H(2)O)].2H(2)O and [Cu(2)(bpca)(2)(1,3-dtsq)].2H(2)O.

The preparation, crystal structures, and variable-temperature magnetic susceptibility data for two dithiosquarate-bridged copper(II) complexes of formulas [Cu(2)(bpca)(2)(1,2-dtsq)(H(2)O)].2H(2)O (1) and [Cu(2)(bpca)(2)(1,3-dtsq)].2H(2)O (2) (where bpca = the bis(2-pyridylcarbonyl)amide anion, 1,2-dtsq = dianion of 3,4-dimercapto-3-cyclobutene-1,2-dione, and 1,3-dtsq = dianion of 3-hydroxy-4-mercapto-2-thioxo-3-cyclobuten-1-one) are reported herein. 1 and 2 crystallize in the triclinic system, space group P&onemacr;, with a = 9.3243(4) Å, b = 10.9036(5) Å, c = 15.5432(4) Å, alpha = 90.276(2) degrees, beta = 100.009(2) degrees, gamma = 94.139(2) degrees, and Z = 2 for 1 and a = 7.656(2) Å, b = 9.351(3) Å, c = 11.587(2) Å, alpha = 109.02(2) degrees, beta = 97.40(2) degrees, gamma = 110.27(2) degrees, and Z = 1 for 2. Their structures consist of the neutral dithiosquarate-bridged copper(II) units [Cu(2)(bpca)(2)(1,2-dtsq)(H(2)O)] (1) and [Cu(2)(bpca)(2)(1,3-dtsq)] (2) and water molecules of crystallization. The copper environment is distorted square pyramidal CuN(3)SO in both compounds. Bpca acts as a tridentate end-cap ligand with its three nitrogen atoms occupying three of the four basal positions. 1,3-Dithiosquarate adopts a centrosymmetric bis-bidentate bridging mode with the sulfur atom filling the fourth equatorial position around each copper atom and the oxygen at the apical site. 1,2-Dithiosquarate acts also as a bridging ligand but in an asymmetrical manner, chelating through the two sulfur atoms at one copper atom and unidentate through one sulfur at the other copper atom. The bridging sulfur occupies one equatorial position at a copper atom and the apical site at the other one. The metal-metal separations through the extended 1,2- and 1,3-dtsq bridges are 5.1654(8) and 7.212(3) Å, respectively. The exchange pathways accounting for the intermediate ferro- (1, J = +32.4 cm(-)(1)) and antiferromagnetic (2, J = -33.5 cm(-)(1)) couplings (H = -JS(A).S(B)) observed in these dithiosquarate-bridged compounds are analyzed and discussed in the light of density functional theory (DFT) calculations.

Journal Article↗

PubMedDate not supplied

Increased cerebellar PET glucose metabolism corresponds to ataxia in Wernicke-Korsakoff syndrome.

AIMS: To investigate a possible relationship between cerebellar glucose metabolism and recovery from ataxia in the first months of acute Wernicke-Korsakoff syndrome. METHODS: Two cases of alcoholic Wernicke-Korsakoff syndrome were followed up with the clinical status and cerebral glucose metabolism over a 4- and 9-month period. RESULTS: Initially both patients showed severe ataxia and elevated cerebellar glucose metabolism that decreased corresponding to the restitution of stance and gait. CONCLUSION: Increased cerebellar glucose metabolism at the onset of the illness may reflect the reorganization process of disturbed motor skills and may indicate cerebellar plasticity.

Adult↗