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H Moore

Publications and source records attributed to H Moore.

84 records · Page 5Linked to original sources
PubMedDate not supplied

Potassium, but not atropine-stimulated cortical acetylcholine efflux, is reduced in aged rats.

Using in vivo microdialysis, cortical acetylcholine (ACh) efflux was measured in freely moving Brown Norway/Fischer 344 F1 rats, aged 4 or 22 months. The effects of local, intracortical perfusion of atropine (1.0 or 100.0 microM) via the dialysis probe were compared to local K+ (100.0 mM) stimulation in the presence of elevated extracellular Ca2+ (2.5 mM). Basal cortical ACh efflux in aged rats was similar to that of young animals. Administration of atropine (1.0 or 100.0 microM) via the cortical dialysis probe substantially increased cortical ACh efflux, but did not differentially stimulate ACh efflux in young and aged rats. In contrast, ACh efflux stimulated locally with K+ and Ca2+ was significantly reduced in aged rats relative to young adults. The implications of the dissociable effects of K(+)-depolarization and muscarinic blockade for local regulation of cortical ACh efflux in aged animals are discussed.

Acetylcholine↗
PubMedDate not supplied

InterRett--The application of bioinformatics to International Rett syndrome research.

InterRett, International Rett Syndrome Association (IRSA) Rett Phenotype Database, is a unique international project funded by the IRSA, which brings together child neurologists, geneticists, paediatricians, epidemiologists, researchers and families of affected children. The principal aim of InterRett is to increase the clinical understanding of Rett syndrome throughout the world and with the statistical power of large case numbers, determine any correlations between genotype and the phenotypic characteristics. Since establishment of the database in January 2003, InterRett has registered 286 cases from 24 countries, with family questionnaire data submitted on 242 cases and clinician data on 116 cases. Collated de-identified data gathered from families and clinicians have been incorporated into a searchable online database allowing simple and complex interrogation of the clinical phenotype information. InterRett will also serve as a clearing house for data to encourage inter-country collaboration between researchers and negotiations are in place with several countries for data contributions in excess of 1000 cases. The resulting online database will be an invaluable resource for understanding the nature and management of Rett syndrome, as well as providing a model for other rare childhood disorders.

Child↗
PubMedDate not supplied

Experimental models to investigate the pathology of antisperm antibodies: approaches and problems.

Antisperm antibodies (ASA) can interfere with sperm function and fertilization. But we still know relatively little about the specific mechanisms that elicit an auto-immune response and we have a poor appreciation of the profile of ASA that lead to antibody-mediated infertility in the male. This brief review explores some of the experimental models, the current approaches and the problems associated with investigations of ASA.

Animals↗
PubMedDate not supplied

Lean body mass estimation by creatinine kinetics, bioimpedance, and dual energy x-ray absorptiometry in patients on continuous ambulatory peritoneal dialysis.

Lean body mass (LBM), which is fat free body mass, can be used as an index of nutritional status. We evaluated three techniques for LBM estimation, including dual energy x-ray absorptiometry (DEXA), creatinine kinetics (CrKin), and bioimpedance (BI) in 10 patients on continuous ambulatory peritoneal dialysis (CAPD). Two different formulae were applied for BI LBM estimation, Segal (S) and Deurenberg (D). Mean values (+/- SEM) of LBM estimated were 48.2 +/- 3.6, 46.12 +/- 2.87, 43.32 +/- 3.87, and 41.27 +/- 4.26 by DEXA, BI-S, BI-D, and CrKin, respectively. LBM by CrKin was significantly lower than that by DEXA and BI-S values. There was no statistically significant difference between DEXA and BI-S values. Statistically significant correlations were found between LBM values by all methods. Particularly strong correlations were found between DEXA versus BI-S (r = 0.976) and BI-S versus BI-D (r = 0.98). Because clinical assessment of hydration status is inaccurate, and both BI and DEXA measure excess extracellular water in LBM, falling muscle mass may be missed by these techniques. The CrKin technique for estimating LBM at normal body fluid volumes (dry weight) may be a better index of nutritional status in patients on CAPD because this may truly reflect the dry LBM and changes in muscle mass. Both DEXA and BI include excess body water in LBM and may mask malnutrition in the presence of subclinical or clinical overhydration, which is common in patients on peritoneal dialysis.

Absorptiometry, Photon↗
PubMedDate not supplied

Longitudinal evaluation of a renal Kt/V(urea) of 2.0 as a threshold for initiation of dialysis.

We (Perit Dial Int 17:426 and 497, 1997) and the Dialysis Outcomes Quality Initiative guidelines (Am J Kidney Dis 30:S69, 1997) have reported evidence that protein intake often is < 0.8 g/kg standard weight when renal weekly urea clearance (L) normalized to total body water (V, L) is less than 2.0, and that initiation of dialysis should be considered if nutritional status is decreasing. We have prospectively followed renal urea (C(urea)) and creatinine clearances (C(cr)) in 20 patients with chronic renal failure. Nine patients received dietary counseling, but we have previously shown this has minimal effects on protein intakes (Perit Dial Int 17:497, 1997). In 16 patients (group 1), glomerular filtration rate (GFR) estimated as (C(urea) + C(cr))/2 decreased from 14.6 +/- 1.5 (mean +/- SEM) to 9.8 +/- 0.9 (ml/min/1.73 m2 BSA) over a mean interval of 10.3 +/- 1.6 months; in the other 4 patients (group 2), mean GFR did not decrease and was initially 17.6 +/- 3.8 and 21.7 +/- 2.2 after 8.5 +/- 2.3 months. In group 1, Kt/V went from 2.5 +/- 0.3 to 1.7 +/- 0.2; in group 2, Kt/V went from 3.1 +/- 1.0 to 3.7 +/- 0.6. In group 1, protein intake as assessed from the normalized equivalent of protein nitrogen appearance calculated from urea nitrogen and protein losses in urine (nPNA; g/kg standard weight) went from 1.0 +/- 0.1 to 0.8 +/- 0.1. In group 2, mean nPNAs were 1.1 +/- 0.3 and 1.1 +/- 0.1. In all measurements with Kt/V less than 2.0 (n = 18), 10 (56%) were with nPNA less than 0.8. In all measurements of Kt/V > or = 2.0 (n = 22), only 3 (13.6%) were with an nPNA of less than 0.8. These percentage values were different (p < 0.0001) by chi-squared analysis. Changes in nPNA correlated directly (but insignificantly, probably because of a small n) with C(cr), GFR, and Kt/V. These prospective results provide additional evidence that protein intakes decrease to dangerously low levels (without intense dietary monitoring) in most patients when renal weekly Kt/V decreases to below 2.0, which is similar to findings in patients on continuous ambulatory peritoneal dialysis.

Adult↗
PubMedDate not supplied

Effects of dipyridamole on peritoneal clearances.

To see if oral dipyridamole increases peritoneal clearances in humans undergoing peritoneal dialysis, two types of double-blind clinical studies were undertaken. In a single-dose study, 7 patients were randomized to take dipyridamole or placebo early in a peritoneal dialysis with 2 L, hourly cycles; later in the same dialysis a crossover administration was studied. In a multidose study, 17 patients were randomized to take dipyridamole or placebo three times daily and clearance studies were performed on days 1, 4, and 8 during 2 L, hourly peritoneal dialysis cycles. Neither the single dose of dipyridamole or placebo significantly altered drainage volumes, clearances, or dialysate protein from control periods. In the multidose study, mean values on dipyridamole or placebo were not significantly changed from respective baseline predrug values. Mean values with dipyridamole and placebo usually were not significantly different. Dipyridamole did not appear to improve peritoneal clearances even with repeated ingestion.

Adult↗
PubMedDate not supplied

Lack of significant circadian and post-prandial variation in phosphate levels in subjects receiving chronic hemodialysis therapy.

BACKGROUND: The present study was designed to determine the reliability of the current practice of random pre-dialysis phosphate testing in subjects receiving hemodialysis therapy, since phosphate levels exhibit a significant variation in a 24-hour period under usual physiologic conditions. METHODS: Subjects receiving chronic hemodialysis (HD) were invited to participate during an incidental hospitalization. In Study A subjects (n=31) had serum phosphate tested three times on a single non-dialysis day, between 6 to 7 am (A1), between 11 am to 12:30 pm (A2), and 3:45 pm to 4:45 pm (A3). In study B subjects (n=25) had serum phosphate tested just before (B1) and 2 hours after lunch (B2), on a non-dialysis day. For Study A the collection times coincided with the start times of the out-patient dialysis shifts at our institution. All patients continued their usual phosphate binder therapy, if any. For study A the results were analyzed using one-way repeated measures analysis of variance or Friedman repeated measures analysis of variance on ranks, as opposite. Paired t-test was used for Study B. Results are expressed as mean+/- standard deviation. RESULTS: Twenty-three men and eight women (mean age 62.2+/-15.2 years) were enrolled in Study A (24 Caucasian, 7 African-American). Nineteen men and six women (mean age 65.5+/-12.8 years) participated in study B (19 Caucasian, 6 African-American). In Study A, there was no significant difference in the mean serum phosphate levels in the samples collected through the day A1 (4.5+/-1.3 mg/dL), A2 (4.5+/-1.3 mg/dL) and A3 (4.7+/-1.5 mg/dL) (p=0.19 for comparison of the three). The mean amplitude of circadian variation (peak minus trough) was 0.64+/- 0.37 mg/dL. Similarly, there was no significant difference in the mean serum phosphate before (4.4+/-1.4 mg/dL) and two hours after lunch (4.4+/-1.5 mg/dL) (p =0.6). The mean of the difference in serum phosphate (post-prandial minus pre-prandial) was 0.2+/-0.4 mg/dL. CONCLUSION: Our results in hospitalized HD subjects indicate there is no significant difference in phosphate levels at different times of a single day or in relation to meals.

Aged↗
PubMedDate not supplied

The effect of antibiotic prophylaxis on the healing of exit sites of peritoneal dialysis catheters in rats.

OBJECTIVE: To evaluate the influence of intraperitoneal (i.p.) antibiotic (AB) prophylaxis on the quality of healing and infection rates of exit sites in peritoneal dialysis catheters. STUDY DESIGN: Twenty-one Sprague-Dawley rats were dialyzed 3 times per day for 6 weeks. Dianeal solution containing AB was used for all the rats during the first 5 days. The animals were randomized on the sixth day into three groups: group A (AB-free after randomization), group B (AB for 3 weeks), and group C (AB during 6 weeks). Scores were given to each exit site according to the observation. Mean scores from each group were compared in an attempt to find significant differences between the groups. Dialysate and exit-site drainage samples were taken weekly for microbiology. RESULTS: Eight episodes of peritonitis were diagnosed, six in group A and two in group B. The most common bacteria causing peritonitis were gram-negative rods. The mean scores were not significantly different between groups C and B throughout the study, even after the discontinuation of the prophylaxis. Group A, when compared to the other two groups, had significantly higher scores after the second week and throughout the rest of the study. CONCLUSION: Intraperitoneal antibiotic prophylaxis for 3 weeks after catheter implantation is an effective way to prevent early colonization of exit sites, providing a better healing quality and lower incidence of catheter-related infection. Although the extension of the prophylaxis for 6 weeks seems to be beneficial, it was not statistically proven in this study.

Animals↗
PubMedDate not supplied

The absence of toxicity in intraperitoneal iron dextran administration: a functional and histological analysis.

OBJECTIVE: To determine the influence of iron dextran intraperitoneal administration on the function and histology of the peritoneum in rats undergoing chronic peritoneal dialysis. DESIGN: Prospective, randomized experimental study. MATERIALS: Fifty-four Sprague-Dawley rats were divided into five groups: 3 study groups--high dose group (H), n = 12; intermediate dose (M), n = 12; and low dose group (L), n = 12--a dialysis control group (D), n = 12; and a tissue control (C), n = 7. INTERVENTIONS: The study groups were given Dianeal containing iron dextran in a concentration of 0.5, 0.25, and 0.125 mg/L (groups H, M, and L respectively). Group D was given standard Dianeal. Group C was never dialyzed. MAIN OUTCOME MEASURES: A 2-hour peritoneal equilibrium test (PET) was performed on the eighth day, at 3 months, and at 6 months. After the final PET, the animals were sacrificed and the peritoneal membrane was evaluated by gross inspection and light microscopy (silver, prussian blue, and trichrome staining). RESULTS: Peritoneal transport of small solutes followed the same pattern in all groups, increasing over time. The peritonitis index was similar in the groups. No iron deposits or morphologic differences were seen in the gross inspection of the peritoneal cavity. No peritoneal iron deposition was detected in the histological analysis with prussian blue staining. No differences were noted in the light microscopic analysis of the mesothelial cell layer (silver staining), nor did the morphometric analysis of the submesothelial space show any differences in thickness between the groups. CONCLUSION: These findings suggest the absence of toxic effects of iron dextran on the peritoneal cavity of rats in the concentrations studied. Further studies should be performed to evaluate the effectiveness of these dosages delivered intraperitoneally to maintain iron homeostasis.

Animals↗