Influence of calcium or 1,25-dihydroxyvitamin D3 supplementation on the hepatic microsomal and in vivo metabolism of vitamin D3 in vitamin D-depleted rats.

Hypocalcemic vitamin D (D)-depleted rats were supplemented with calcium or 1,25(OH)2D3, and the metabolism of D3 to 25(OH)D3 was studied. Infusion with 7 or 65 pmol 1,25(OH)2D3 X 24 h-1 led to normal or slight hypercalcemia associated with physiological and supraphysiological plasma concentrations of the hormone while calcium supplementation normalized plasma calcium despite 1,25(OH)2D3 concentrations as low as those observed in hypocalcemic controls. Constant administrations of [14C]D3 during the supplementation regimens uncovered a stimulation of the in vivo 25(OH)D3 production by calcium supplementation; this was further confirmed in vitro by an increase in the hepatic microsomal D3-25 hydroxylase. The group supplemented with pharmacological doses of the hormone displayed lower circulating concentrations of both D3 and 25(OH)D3 while the in vitro 25(OH)D3 production remained unaffected by 1,25(OH)2D3. Investigation of the kinetics of intravenous 25(OH)[3H]D3 revealed similar elimination constants in all groups. The data indicate that calcium supplementation of hypocalcemic D-depleted rats results in an increased transformation of D3 into 25(OH)D3 while supplementation with 1,25(OH)2D3 does not affect the in vitro D3-25 hydroxylase but seems to influence the in vivo handling of the vitamin by accelerating its metabolism.

Case management: ambiguous at best.

This article defines case management with an emphasis on the functions and providers of various case management models. Nursing Case Management delivery system is compared with several other models of case management. The potential role for the nurse practitioner in case management is discussed as well as ethical pitfalls that are attributed to various case management models.

[Diagnostic value of the acid production from galacturonate to differentiate strains of "Salmonella" sub-genus I and monophasic sub-genus III from the other "Salmonella" strains belonging to sub-genera II, diphasic III, IV, "Citrobacter" and "Hafnia alvei" (author's transl)]. / Intérét de la recherche de la fermentation du galacturonate pour différencier les Salmonella des sous-genres I et III monophasiques des autres Salmonella des sous-genres II, III diphasiques, IV, et de Citrobacter et Hafnia alvei.

Two methods were compared: (1) the ability to use sodium glacturonate as source of carbon and energy in defined medium; (2) the ability to produce acid by fermentation of this substrate in peptone water with phenol red. Results of growth on, acid formation from, galacturonate are identical. Salmonella strains of sub-genus I and monophasic serotypes of sub-genus III do not use galacturonate. Salmonella of sub-genera II and IV as well as diphasic serotypes of sub-genus III use galacturonate. Glacturonate-negative Salmonella are isolated mainly from man and warm-blooded animals whereas galacturonate-positive Salmonella are most often isolated from cold blooded animals and from the enrivonment. Citrobacter and Hafnia alvei which may be confused with Salmonella spp. are galacturonate-positive.

[Utilization and fermentation of 2-ketogluconate by "Enterobacteriaceae" (author's transl)]. / Intérêt taxonomique de la recherche de l'utilisation du 2-cétogluconate par les Enterobacteriaceae.

Two methods were compared: 1) the ability to use 2-ketogluconate (2-KG) as source of carbon and energy in defined medium, and 2) the ability to produce acid by fermentation of 2-KG (0.5 g/100 ml) in peptone water with phenol red. Results of growth on, and acid production from, 2-KG were identical. A total of 990 strains was studied. No strain of Escherichia coli, Shigella (4 species), Salmonella (4 sub-genera), Yersinia pestis, Y. pseudotuberculosis, Edwardsiella (2 species), Proteus vulgaris, P. mirabilis, P. morganii, Providencia (2 species) could utilize 2-KG. All strains of Citrobacter (2 species), Levinea amalonatica, Klebsiella pneumoniae, K. oxytoca, K. ozaenae, Enterobacter (5 species), Serratia (6 species) utilize 2-KG as sole carbon source. Different reactions were given by strains of P. rettgeri, Y. enterocolitica and K. rhinoscleromatis.

[Fermentation of galacturonate by "Shigella" (author's transl)]. / Fermentation du galacturonate par les bactéries du genre Shigella.

The ability of 300 Shigella strains to produce acid from galacturonate (galacturonate test) was examined. With respect to this galacturonate test, all S. flexnerii serotypes (except serotype 6) were positive, and all S. dysenteriae serotypes (except serotypes 8 and 10) negative. In S. boydii, serotypes 5, 7 and 11-13 were positive, and 1-4, 6, 8-10, 14 and 15 negative. In S. dysenteriae (except serotype 8), S. flexnerii and S. boydii, strains of a same serotype gave always identical reactions in the galacturonate test. S. sonnei biotypes d and e and ornithine decarboxylase (ODC) negative strains of biotype a gave a positive galacturonate test. S. sonnei biotypes a (ODC positive strains), g and f were negative in this test.

[Interest of gamma-glutamyltransferase in "Enterobacteriaceae" (author's transl)]. / Intérêt taxonomique de la recherche de la gamma-glutamyltransférase chez les Enterobacteriaceae.

Gamma-Glutamyltransferase (gammaGT) could be detected in 86,6% of 3,027 strains of Enterobacteriaceae, by the use of gamma-L-glutamin-p-nitranilide acid for substrate. The following species produced gamma GT: Citrobacter freundii, Levinea malonatica, L. amalonatica, Klebsiella pneumoniae, K. oxytoca, K. ozaenae, Enterobacter aerogenes, E. cloacae, E. agglomerans, E. gergoviae, K. ozaenae, Enterobacter aerogenes, E. cloacae, E. agglomerans, E. gergoviae, Hafnia alvei, Erwinia carotovora, Serratia marcescens, S. liquefaciens, S. plymuthica, S. marinorubra, S. odorifera, S. ficaria, Proteus vulgaris, P. mirabilis, P. morganii, P. rettgeri, Providencia alcalifaciens, P. stuartii, Yersinia enterocolitica and Y. pseudotuberculosis. Most strains of Escherichia coli and Alkalescens Dispar group are gamma GT+. The following species did not produce gammaGT: Shigella sonnei, Edwardsiella tarda, Klebsiella rhinoscleromatis and Yersinia pestis. Within the Salmonella, most strains of subgenus I, II and IV, and diphasic strains of subgenus III (S. arizonae) produced gamma GT, whereas monophasic strains of subgenus III did not produce gammaGT. Salmonella enteritidis (gammaGT+) and S. dublin (gammaGT-) can readily be distinguished. This test (gammaGT) could also serve as a biochemical marker for S. typhi-murium strains. Shigella dysenteriae serotypes 3 to 9 were gammaGT+ whereas other serotypes were gammaGT-. Within S. flexneri serotype 6, varieties Boyd 88 and Newcastle were found gammaGT+; and varieties Sussex and Manchester were gammaGT-. The use of gammaGT test as an epidemiological marker for other Shigella serotypes is suggested.

[Hydrolysis of tributyrin by species of "Neisseria" and "Branhamella" (author's transl)]. / Hydrolyse de la tributyrine par les Neisseria et les Branhamella.

A comparative study of 60 strains of Neisseriaceae was done using 4 different substrates: tween 20, tween 80, tributyrin and naphthylmyristate. Production of butyric acid from tributyrin was measured by gas chromatography. Strains of the genus Branhamella produced large amounts of butyric acid, whereas strains of the genus Neisseria produced little amounts. Evidence of lipolytic activity can be used to separate Branhamella from Neisseria. A biochemical method is described using a buffered medium containing tributyrin and phenol red which can best separate lipolytic and non-lipolytic strains of Neisseriaceae. All B. catarrhalis gave positive results as well as related species B. caviae, B. ovis and B. cuniculi. All Neisseria strains gave negative results.

[gamma Glutamyltransferase activity in the genus "Yersinia" (author's transl)]. / Intérêt de la recherche de la gamma-glutamyltransférase dans le genre Yersinia.

The expression of gamma-glutamyltransferase activity was studied among 87 strains representing all the Yersinia species. Y. pestis lacked constantly this enzyme, while y. pseudotuberculosis expressed it as a rule. This test, when positive, is useful for the exclusion of a suspected Y. pestis diagnosis. All the other Yersinia species, like most of the Enterobacteriaceae, showed a gamma-glutamyltransferase activity.

Liver extraction of vitamin D3 is independent of its hepatic venous or arterial route of delivery. Studies in isolated-perfused rat liver preparations.

The hepatic extraction of a naturally occurring secosteroid, vitamin D3 (D3), in relation to its hepatic arterial or portal venous route of delivery has been studied in isolated rat liver preparations perfused at an arterial/venous flow ratio of 1:4. No significant difference in the fractional hepatic extraction of D3 was observed when the vitamin was administered via the portal venous route compared to when it was administered via the hepatic arterial route. Estimation of the uptake and clearance of D3 in relation to its route of delivery revealed, however, that due to the higher perfusion flow through the portal venous than through the arterial route, both the hepatic uptake and clearance of D3 were significantly higher after portal vein than after hepatic artery delivery. Moreover, calculation of the uptake of D3 after delivery through the portal venous route also revealed that it was not significantly different from that of the total hepatic uptake (uptake following portal vein + hepatic artery delivery). The data obtained during the present studies indicate, then, that the fractional hepatic extraction of D3 is not dependent on its route of entry into the liver; it also points out that, in experimental models such as in isolated-perfused liver preparations, the portal vein administration of D3 should represent adequately the total hepatic handling of the secosteroid by the normal rat liver.