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C Bartel

Publications and source records attributed to C Bartel.

6 recordsLinked to original sources
PubMed2002

[Problems in defining obesity in prepubescent children: consequences for assessing the requirements for medical rehabilitation].

INTRODUCTION: Prevalence of obesity has been on the increase in recent years. In contrast to obesity in adulthood, childhood obesity is still not uniformly defined. This results in problems to determine the need for medical rehabilitation. METHODS: The Kiel Obesity Prevention Study (KOPS) is a cross-sectional study assessing the nutritional status of 5-7 year-old German children. Three different definitions of overweight and obesity (German reference data for triceps skinfold thickness [90(th) percentile] and BMI [90(th)/97(th) percentile] as well as an international standard for BMI [extrapolated to levels of adults]) were applied to 1,643 children of KOPS enrolled between 1996 and 2000 (19 % of all first-graders in Kiel in this period). RESULTS: The prevalence of overweight varies from 9 to 21 % depending on the applied definition. With the definitions of overweight and obesity based on newer BMI percentiles a part of overweight children are not classified as such. The present state of art is that there is only a need for obese children for medical rehabilitation: these are 3.3 and 3.5 % of 5-7 year-old children in Kiel, respectively. CONCLUSIONS: Experts should work out an agreement concerning a uniform definition of childhood obesity. Currently, medical rehabilitation services are offered only to extremely obese children. There is a need for more and earlier preventive measures.

Body Mass Index↗
PubMed2001

Syntheses of halogenated ethenyl isocyanide chromium complexes as organometallic precursor molecules for ethenyl and ethynyl isocyanides.

The radical alkylation of tetraethylammonium pentacarbonyl(cyano)chromate 1 yielded the halogenated ethyl isocyanide complexes [(CO)5Cr(CN-CClX-CClYF)] 3 (a, X= Cl, Y= F; b, X = F, Y= F and c, X=Y= Cl). Dehalogenation of 3 using zinc in diethyl ether gave [(CO)5Cr(CN-CX=CFY)] 4. The compounds 4a, b reacted with various nucleophiles exclusively at the difluoromethylene group. The unstable phosphorane 5, which is formed on reaction of 4b with trimethylphosphane, decomposed thermally and on hydrolysis yielding pentacarbonyl(1,2-difluoroethenyl isocyanide)chromium (6). The cyano substituent can be introduced in the beta position of the isocyanide function by reaction of 4a, b with potassium cyanide, leading to the formation of [(CO)5Cr(CN-CX=CF-CN)] (7). Reactions of 4a, b with organolithium or organomagnesium compounds yielded [(CO)5Cr(CN-CX=CF-R)] (8) and [(CO)5Cr(CN-CF=CF-C...C-CF=CF-NC)Cr(CO)5] (10). The trimethylsilyl group in 8a, b, d could be removed by a solution of potassium carbonate in methanol leading to [(CO)5Cr(CN-CX=CF-Cn-H)] (11) (n=2,4). Octacarbonyldicobalt reacted with 8e under coordination of the C-C triple bond to the hexacarbonyldicobalt fragment, resulting in the cluster compound 12. The crystal and molecular structure of 8i, 11 a, b, and 12 were elucidated by X-ray crystallography. The alkenyl and alkynyl isocyanides CN-CCl=CF2 (13a), CN-CF=CF2 (13b), CN-CCl=CClF (13c), CN-CF=CFH (14), CN-CC-H (15), CN-CC-CN (16), and CN-CCl=CF-CN (17) were obtained by flash vacuum pyrolysis of 4a, 4b, 4c, 6, and 7a, respectively.

Journal Article↗
PubMed1993

Interaction of thiazide and loop diuretics with the basolateral para-aminohippurate transport system in isolated S2 segments of rabbit kidney proximal tubules.

The effect of thiazide and loop diuretics on the tubular uptake of [3H]para-aminohippurate ([3H]PAH), a marker of the organic anion transport system, was tested in vitro on single S2 segments of the proximal tubule of rabbit kidneys. Because the tubules were not perfused, and hence were collapsed, the tubular [3H] PAH uptake reflects [3H]PAH transport across the contraluminal membrane. The diuretics were added to the bath solution in at least six different concentrations. The concentration of [3H]PAH in the bath solution amounted to 1.3 mumol/l, and was 12 times lower than the PAH concentration (16 mumol/l) at half-maximum PAH uptake. The results show that all of the nine diuretics tested inhibited [3H]PAH uptake. The IC50 values of the individual drugs ranged from 3 to 400 mumol/l. In general, thiazide diuretics had a lower affinity to the PAH transporter than loop diuretics. This probably results from differences in the pKa values which range from 3.6 to 4.1 for the loop diuretics and from 9.2 to 10 for the thiazide diuretics. Furthermore, there was a highly significant dependence of affinity on the hydrophobic properties of the diuretics. At concentrations 10- to 100-fold lower than the IC50 values all diuretics stimulated [3H]PAH uptake which may indicate a positive cooperative interaction of these drugs with the PAH transporter. Within the group of loop diuretics the order of the affinity to the PAH transporter and to the Na, 2 Cl, K cotransporter in the thick ascending limb of Henle's loop was identical.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗