Assessment of sodium and potassium intakes

The sodium, potassium and creatinine contents of three non-consecutive 24-h urine samples collected by 34 selected adult individuals (10 m; 24 f) living in Cork City were determined. The pooled mean 24-h excretion of sodium and potassium in collections adjudged to be complete were 152 mmol and 78 mmol, respectively. There was no significant difference between group average weekday and weekend-day excretion of Na or K, for either males or females. This suggests that weekend 24-h urinary collections, which most subjects find more convenient, are suitable for studies of sodium and potassium intakes of groups. The ratios of intra- to inter-individual variation for 24-h urinary sodium were 1.4 and 2.1 for males and females, respectively. The corresponding ratios for 24-h urinary potassium were 6.6 for males and 4.9 for females. These ratios indicated that there were large individual day-to-day variations in urinary sodium and potassium excretion in this group. It was estimated that a sample size of 35-60 individuals would be required to estimate group mean sodium and potassium intakes by means of single 24-h urine collections.     

Benign intracranial hypertension and recombinant growth hormone therapy in Australia and New Zealand

Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml ^-1), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml ^-1) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-² week^-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis.     

A literature review of autograft and allograft anterior cruciate ligament reconstruction

Knee anterior cruciate ligament reconstructive surgery has significantly evolved and now includes the option of using an allograft. This has resulted in numerous studies evaluating the advantages and disadvantages of allografts. The purpose of this literature review is to evaluate this research and present important findings to allow the selection of the most appropriate graft source when considering allograft versus autograft reconstruction.     

Hemagglutination and proteoglycan binding by the Lyme disease spirochete, Borrelia burgdorferi.

The ability of the Lyme disease spirochete to attach to host components may contribute to its ability to infect diverse tissues. We present evidence that the Lyme disease spirochete expresses a lectin activity that promotes agglutination of erythrocytes and bacterial attachment to glycosaminoglycans. Among a diverse collection of 21 strains of Lyme disease spirochete, hemagglutinating activity was easily detected in all but 3 strains, and these three strains were noninfectious. The ability to agglutinate erythrocytes was associated with the ability of the spirochete to bind to the sulfated polysaccharide dextran sulfate and to mammalian cells. Soluble dextran sulfate was a potent inhibitor of both hemagglutination and attachment to mammalian cells, while dextran had no effect on either activity, suggesting that dextran sulfate may inhibit attachment by mimicking host cell glycosaminoglycans. Consistent with this, the spirochete bound to immobilized heparin, and soluble heparin inhibited bacterial adhesion to mammalian cells. The bacterium did not bind efficiently to Vero cells treated with heparinase or heparitinase or to mutant CHO cell lines that are deficient in proteoglycan synthesis. Sulfation of glycosaminoglycans was critical for efficient bacterial recognition, as Vero cells treated with an inhibitor of sulfation, or a mutant CHO cell line that produces undersulfated heparan sulfate, did not mediate maximal spirochetal binding. Binding of the spirochete to extracellular matrix also appeared to be dependent upon this attachment pathway. These findings suggest that a glycosaminoglycan-binding activity which can be detected by hemagglutination contributes to the attachment of the Lyme disease spirochete to host cells and matrix.     

Effects of probucol on renal function in rats with bilateral ureteral obstruction

To ascertain the potential role of reactive oxygen metabolites in the pathophysiology of obstructive uropathy, we examined the effect of probucol, an antioxidant agent, on renal function in normal rats and rats with unilateral release of bilateral ureteral obstruction (BUO) of 24 hours duration. Rats were fed either a standard diet or a standard diet containing one percent probucol for two weeks prior to study. Probucol lowered serum cholesterol in both normal and BUO rats. Probucol did not significantly affect renal function in normal rats. BUO rats given probucol had greater inulin and PAH clearances at three to five hours and three days following release of BUO than rats with BUO not given probucol. Kidneys from obstructed rats had higher levels of malondialdehyde, an index of lipid peroxidation, a greater number of leukocytes in the cortex, decreased levels of reduced glutathione and increased levels of oxidized glutathione. Renal cortex from obstructed rats treated with probucol had significantly higher levels of reduced glutathione than kidneys of obstructed rats not given probucol. A decrease in cholesterol, using another lipid-lowering agent, lovastatin, did not modify renal function in rats with BUO. The data can be interpreted to indicate a role for reactive oxygen species in the pathophysiology of obstructive nephropathy. The improved renal function seen in probucol-treated rats with BUO may be due to an effect of this agent in affecting accumulation of reactive oxygen metabolites and/or decreasing the number of leukocytes infiltrating the renal cortex.     

Assessment of quadriceps/hamstring strength, knee ligament stability, functional and sports activity levels five years after anterior cruciate ligament reconstruction

The purpose of this study was to examine individuals 5 years after ACL reconstruction and analyze changes involving strength, stability, function, and sports activities. Nineteen males and six females, mean age = 31.4 +/- 7.31 years, participated in this study. Fifteen subjects had received extraarticular and ten subjects had received intraarticular ACL reconstructions. Subjects completed a 100 point subjective functional activity questionnaire and a sports participation survey. Knee ligament stability was assessed during an objective knee examination. Isokinetic quadriceps and hamstring muscle strength were tested at 240 and 120 deg/sec using the Cybex II dynamometer. Anterolateral rotatory instability and positive Lachman were elicited on the operated leg for 80% of the subjects. No significant relationship was found between objective instability and the functional activity score. For the intraarticular group, a significant correlation (P less than 0.05) was found between increased quadriceps and hamstring strength on the operated leg and return to functional activities. Subjects' functional activity score was positively correlated (P less than 0.001) with their ability to participate in sports. Subjects participating in sports involving cutting and twisting motions were less successful in returning to their preinjury participation levels and reported more subjective complaints of pain, swelling, and/or instability. These results indicate that long-term progressive rehabilitation emphasizing increased quadriceps and hamstring strength to approximate the nonoperated leg may enhance successful return to functional and sports activities after ACL reconstruction.