Development of a colorimetric colony-screening assay for detection of defluorination by micro-organisms.

AIMS: To develop a colorimetric colony-screening assay to facilitate the isolation of micro-organisms capable of defluorination. METHODS AND RESULTS: A metal-dye chelate, zirconium-xylenol orange was used to detect fluoride ions released from a fluorinated substrate through microbial metabolism. Depolymerised zirconium reagent gave the greatest visual contrast for the presence of fluoride compared to more polymerised forms of zirconium reagent. The sensitivity of the assay was greatest when the molar ratio of depolymerised zirconium to xylenol orange was 1:2. Using depolymerised zirconium and xylenol orange (150 and 300 nmol l(-1) respectively), the assay could detect a fluoride application spot (5 mmol l(-1)) containing 50 nmoles of fluoride ions. Most media constituents were well tolerated by the assay, although phosphate ions needed to be restricted to 0.1 g l(-1) and some proteins digest to between 1 and 5 g l(-1). A microbial enrichment culture growing on solidified medium containing 20 mmol l(-1) fluoroacetate was screened using the assay, and defluorinating bacteria belonging to the genus Burkholderia isolated. CONCLUSIONS: A method was developed that is sensitive, rapid and reliable for detecting defluorination by micro-organisms growing on solidified medium. SIGNIFICANCE AND IMPACT OF THE STUDY: This method can be used to facilitate the isolation of micro-organisms capable of defluorination.

Disaccharidase activities and fat assimilation in pediatric patients after intestinal transplantation.

BACKGROUND: Intestinal transplantation has become an accepted therapy for short bowel syndrome and other types of intestinal failure. In order to assess digestive capabilities and feeding practices in a group of 22 pediatric patients after intestinal transplantation, we assessed mucosal disaccharidase activities and assimilation of total dietary lipid and vitamin E. Twelve of the patients had undergone contemporaneous liver transplantation. METHODS: Mucosal biopsies were assayed for disaccharidase activities between 15 and 412 days after transplantation in 7 of the 22 when all were receiving some enteral nutrition and were free of rejection. Coefficients of lipid absorption were determined in those patients receiving total enteral feeding (two-thirds polymeric/one-third elemental) between 43 and 1032 days after transplantation; oral vitamin E tolerance tests were done at about the same time. RESULTS: Activities of lactase, sucrase, maltase, and palatinase consistently exceeded reference ranges (P<0.05). Mean coefficient of lipid absorption equaled 86+/-12% and was not influenced by duration of time after transplantation. No patient required dietary lipid restriction. No significant absorption of vitamin E was demonstrated until 160 days after transplantation. Vitamin E absorption did correlate with length of time elapsed after surgery (r=0.64, P<0.0011). CONCLUSIONS: The results of this investigation show that, in the absence of histologic or clinical indications of allograft rejection, pediatric intestinal transplant recipients do not have primary disaccharidase deficiencies. Similarly, absorption of usual dietary lipid content is adequate once weaning from parenteral nutrition is complete. In contrast, early assimilation of vitamin E is poor. Vitamin E absorption subsequently improves, but the mechanism is obscure.

1991 outlook: progress will require partnerships, improved productivity--roundtable discussion.

To address the myriad problems and challenges in the next year, the operative word will be partnership. That's according to members of Modern Healthcare's editorial advisory board in their discussion of the healthcare industry in 1991. The experts see the need for hospitals, physicians and the business community to team up to control costs, solve staffing woes and take initial steps toward healthcare reform.

Deemed status for CHAP. A new standard for health care.

The board chair of the Community Health Accreditation Program (CHAP) reflects on the implications of federal recognition of CHAP. In challenging the status quo, CHAP has shown that a voluntary, consumer-based alternative can protect the public and promote excellence.

Correlation of ultrasonic gallbladder studies with operative findings.

In a retrospective study to correlate preoperative ultrasonic findings with operative findings in 80 patients with symptoms of biliary tract disease, ultrasound was 75% accurate in predicting the presence or absence of gallstones. Of all positive ultrasonic studies, 95% correlated with gallbladder disease of some kind. The diseased gallbladder without stones may still produce ultrasonic abnormalities, allowing detection of inflammatory changes. Ultrasound is indicated in acute conditions of the abdomen, in patients with jaundice or allergy to contrast agents, and as an adjunct to other diagnostic modalities.

Fatal complication of hepatic cystic disease.

Hepatic cysts are found incidentally and cause few if any symptoms. Simple unroofing of such cysts to provide drainage is adequate therapy when symptoms occur, but such patients must be followed up. Disease progression can result in serious or even life threatening complications, as demonstrated in the case reported here.

The Hospital Information Planning Study at Groote Schuur Hospital, Cape Town.

Information is an increasingly important resource in an academic hospital. Effective planning and control of this resource are essential in order to maximize its usefulness. The Hospital Information Planning Study (HIPS) undertaken at Groote Schuur Hospital, and based on the Business Systems Planning (BSP) methodology, is outlined, as are the results of the study. The recommendations arising from the study, which are of considerable significance to the hospital, are mentioned briefly.

Emu oil(s): a source of non-toxic transdermal anti-inflammatory agents in aboriginal medicine.

The 'oil' obtained from emu fat can be a very effective inhibitor of chronic inflammation in rats when applied dermally (with a skin penetration enhancer). Assays for this activity using the adjuvant-induced arthritis model have shown: i. Considerable variability in potency of some commercial oil samples; ii. Little or no correlation of activity with colour or linolenic acid (18:3) content of the oil; iii. Relative stability of some active oils (to heat, ageing at room temperature); iv. The bulk of the anti-inflammatory activity was present in a low triglyceride fraction; and v. Potential arthritis-suppressant/immunoregulant activity of these active fractions. These studies point to the need for more rigid quality control before considering such a (now proven) traditional medicine as a complementary therapy.Repeated applications of selected oils did not induce any of the more prominent side-effects associated with NSAIDs (e.g. platelet inhibition, gastrotoxicity) or certain anti-arthritic drugs (proteinuria, leukopenia).

Uptake of palmitate by hepatocyte suspensions: facilitation by albumin?

Albumin-dependent uptake of unbound [3H]palmitic acid by hepatocytes isolated from female rat livers was studied and the experimental results compared with the predictions of a noncompartmental diffusion-reaction theory for the cellular uptake of protein-bound ligands. The outright theoretical predictions involve values for the parameters of the system, some newly measured (hepatocyte radii and the rate constant for the dissociation of palmitate-albumin complex) and some taken from the literature (diffusion coefficients and the equilibrium association constant for the palmitate-albumin complex). The measured unbound clearance of [3H]palmitic acid, defined as the initial uptake velocity divided by the unbound [3H]palmitic acid concentration in the medium, was enhanced 6.6-fold as the concentration of human serum albumin was increased from approximately 5 to 480 microM. This enhancement factor was predicted by the theory, according to which the enhancement reflects codiffusion of bound ligand across the unstirred layer adjacent to the cell membrane and, therefore, an increased delivery of unbound ligand to the cell surface. In contrast, the absolute magnitude of the unbound clearance was consistent with the theory only for the lowest published value for the equilibrium association constant, 15 microM-1. For higher published values (62 and 94 microM-1), the magnitude of the unbound clearance observed experimentally was severalfold higher than that predicted by the theory. If in fact the association constant exceeds 30 microM-1, the data would imply that an albumin-dependent facilitation mechanism exists which enhances the availability of palmitate to the cell over and above the enhancement predicted by the diffusion-reaction theory.