First clinical experience with a new concentrate system for dialysis with dry sodium chloride

Clinical investigation of a new concentrate system for preparing the acid concentrate in bicarbonate dialysis was performed to evaluate handling, safety aspects, and correct mixing of the final dialysis fluid. The system is characterized by an acid concentrate prepared from two components: a cartridge containing 1.1 kg dry sodium chloride and a concentrate bag with 500 ml of a highly concentrated solution of electrolytes (KCl, MgCl2, CaCl2) and acetic acid. The investigation comprised a total of 142 treatments. The concentrate system was well accepted by the clinical staff and considered safe and easy to handle. Marginal deviations in electrolyte concentration of the dialysis fluid relative to set values were observed, but were considered to lack biologic or clinical relevance. The new concentrate system will facilitate the handling of dialysis concentrates and provide a convenient means for individual tailoring of the dialysis fluid composition.     

In situ activation of the type 2 ryanodine receptor in pancreatic beta cells requires cAMP-dependent phosphorylation

Molecular mechanisms that regulate in situ activation of ryanodine receptors (RY) in different cells are poorly understood. Here we demonstrate that caffeine (10 mM) released Ca2+ from the endoplasmic reticulum (ER) in the form of small spikes in only 14% of cultured fura-2 loaded beta cells from ob/ob mice. Surprisingly, when forskolin, an activator of adenylyl cyclase was present, caffeine induced larger Ca2+ spikes in as many as 60% of the cells. Forskolin or the phosphodiesterase-resistant PKA activator Sp-cAMPS alone did not release Ca2+ from ER. 4-Chloro-3-ethylphenol (4-CEP), an agent that activates RYs in other cell systems, released Ca2+ from ER, giving rise to a slow and small increase in [Ca2+]i in beta cells. Prior exposure of cells to forskolin or caffeine (5 mM) qualitatively altered Ca2+ release by 4-CEP, giving rise to Ca2+ spikes. In glucose-stimulated beta cells forskolin induced Ca2+ spikes that were enhanced by 3,9-dimethylxanthine, an activator of RYs. Analysis of RNA from islets and insulin-secreting betaTC-3-cells by RNase protection assay, using type-specific RY probes, revealed low-level expression of mRNA for the type 2 isoform of the receptor (RY2). We conclude that in situ activation of RY2 in beta cells requires cAMP-dependent phosphorylation, a process that recruits the receptor in a functionally operative form.     

Rhabdomyolysis in autosomal dominant progressive external ophthalmoplegia

Multiple mtDNA deletions have been reported to be a cause of inherited recurrent myoglobinuria. We report a 57-year-old man with autosomal dominant progressive external ophthalmoplegia and multiple mtDNA deletions who developed acute rhabdomyolysis provoked by alcohol. A repeated alcohol intake resulted in a 57-fold increase in serum myoglobin. Patients with mitochondrial myopathy and multiple mtDNA deletions, regardless of associated phenotype and mode of inheritance, may develop rhabdomyolysis.     

Artificial insemination by husband in unexplained infertility compared with infertility associated with peritoneal endometriosis

There have been numerous inconclusive studies examining the differences between unexplained and peritoneal endometriosis-associated infertility. Hence, the choice of artificial reproductive technique may be difficult. This prospective study compares outcome in couples with unexplained infertility and with minimal or mild endometriosis-associated infertility, undergoing treatment with ovarian stimulation combined with artificial insemination by husband. No differences were found between the unexplained infertile and the endometriosis group as to patient characteristics, response to ovarian stimulation and semen qualities. There was a significantly higher total pregnancy rate, with more multiple gestations, in the unexplained infertile compared with the endometriosis group. The difference in outcome could reflect differences in pathogenesis and aetiology for the two groups.     

Locally applied antisense oligonucleotide to proliferating cell nuclear antigen inhibits intimal thickening in experimental vein grafts

This study examines the effect of antisense oligonucleotide to proliferating cell nuclear antigen (PCNA) on the formation of vein graft intimal hyperplasia in vivo, using localized administration. Twenty-four New Zealand white rabbits had a right carotid interposition bypass graft using the external jugular vein and were sacrificed on the 28th postoperative day. To determine the effect of PCNA on the development of intimal hyperplasia, 6 animals had their grafts coated with a pluronic gel containing 18 base antisense oligonucleotide to PCNA (1 mg/ml), 6 received a pluronic gel containing an 18 base nonsense oligonucleotide (1 mg/ml), and 12 animals were controls (6 with and 6 without pluronic gel). These grafts were harvested for morphology and videomorphometry. There was no change in the intimal thickness between the control and gel-treated groups. (70 +/- 4 microm versus 72 +/- 4 microm; mean +/- s.e.m.; p = ns). The presence of nonsense oligonucleotide had no further effect. Antisense PCNA produced a 26% decrease in intimal thickness to 50 +/- 4 microm in the treated vein grafts (p < 0.03) without a change in medial thickness. This study shows that a local single application of antisense oligonucleotide to PCNA will reduce the intimal hyperplasia in experimental vein grafts over 28 days.     

Willingness to pay for community-based ivermectin distribution: a study of three onchocerciasis-endemic communities in Nigeria

OBJECTIVE: To determine the willingness to pay (WTP) for local ivermectin distribution in a community financing framework. METHOD: Contingent valuation in three communities in Nigeria, using randomly selected household heads. WTP was elicited using a bidding game, and for collecting information on the households' socio-economic status, level of knowledge, priority ranking and perception of risk of contracting the disease, structured questionnaires were used. Ordinary least squares (OLS) multiple regression analysis was used to analyse factors associated with WTP. RESULTS: Between 92.1% and 93.3 % of respondents were willing to pay amounts ranging from 5 Naira (US$ 0.06) to 100 Naira (US$ 1.25) (median: 20 Naira, US$ 0.25) in the three communities, more than three times the modelled unit direct cost of distributing ivermectin by the communities themselves. Occupation of the respondent, marital status, average monthly expenditure on health care, manifestations of onchocerciasis, the type of savings scheme embarked on by the respondent, age-group, level of education and type of property were statistically significant (P < 0.05) variables affecting WTP. CONCLUSION: This study shows that there is WTP for local ivermectin distribution in the three study communities, and that it should be assessed before instituting community-directed treatment with ivermectin.     

Gastrectomy osteopenia in the rat: the role of vitamin B12 deficiency and the type of reconstruction of the digestive tract

1. The mechanisms underlying gastrectomy osteopenia are not yet clear. The gastrectomy-associated cobalamin (vitamin B12) deficiency may favour osteopenia and skeletal fractures. Also, the exclusion of the duodenum from the food passage may contribute to gastrectomy osteopenia. To investigate this, rats were gastrectomized and the passage of nutrients restored either with the duodenum excluded (Roux Y) or included (Longmire). Sham-operated rats served as controls. In half of the rats in each gastrectomy group the serum B12 levels were normalized by parenteral administration of B12.2. Four months post operation, both gastrectomy groups showed a similar degree of osteopenia. There was normal bone mineralization; serum levels of parathyroid hormone were normal, but decreased for 25-hydroxyvitamin D, and elevated for 1,25-dihydroxyvitamin D; in urine there was decreased pH and excessive hyperphosphaturia.3.B12 therapy had no influence on any of the essential bone and mineral metabolic parameters.4. We conclude that osteopenia in the gastrectomized rat (i) is not due to B12 or folic acid deficiency, calcium deficiency or secondary hyperparathyroidism; (ii) is independent of the type of anatomic reconstruction of the digestive tract; (iii) appears to be related to disturbed vitamin D, phosphorus and acid-base metabolism.