Point mutation in the parkin gene on patients with Parkinson’s disease

Summary To investigate the distribution of possible novel mutations from parkin gene in variant subset of patients with Parkinson’s disease (PD) in China and explore whether parkin gene plays an important role in the pathogenesis of PD, 70 patients were divided into early-onset group and late-onset group; 70 healthy subjects were included as controls. Genomic DNA from 70 normal controls and from those of PD patients were extracted from peripheral blood leukocytes by using standard procedures. Mutations of parkin gene (exon 1–12) in all the subjects were screened by PCR-single strand conformation polymorphism (SSCP), and further sequencing was performed in the samples with abnormal SSCP results, in order to confirm the mutation and its location. A new missense mutation Gly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 patients were found. All the DNA variants were sourced from the samples of the patients with early-onset PD. It was concluded that Parkin point mutation also partially contributes to the development of early-onset Parkinson’s disease in Chinese. WANG Tao, male, born in 1961, Associate Professor This work was supported by grants from the key program of the special scientific project of Scientific & Technologic Agency of Hubei Province (Serial No. 2001AA308B01) and the Hygienic Research Project of Hygienic Agency of Hubei province (Serial No. WJ 01529).     

POTASSIUM ACCELERATES URINARY SODIUM EXCRETION DURING SALT LOADING WITHOUT STIMULATING ATRIAL NATRIURETIC POLYPEPTIDE SECRETION

1. Effects of potassium (K) supplementation (100 mEq/day) on urinary sodium (Na) excretion and on the secretion of atrial natriuretic polypeptide (ANP) during salt loading (350 mEq/day) were studied in 12 healthy salt-resistant normotensives under strictly controlled metabolic ward conditions. 2. Urinary volume and Na excretion on the first day of the high salt period (HSP) were significantly greater in the K-supplemented group (KG) than in the control group (CG). 3. There was a significant gain in bodyweight after salt loading in both groups, with a significantly greater gain in CG on the second day of HSP. Haematocrit decreased significantly during salt loading in both groups, the degree of which was significantly greater in CG. 4. Plasma norepinephrine decreased significantly during salt loading in both groups, the degree of which was significantly less in KG than in CG. A significant increase in plasma ANP was observed in CG on and after the second day of HSP, while a significant increase in plasma ANP was observed on the fifth day of HSP in KG. 5. These findings indicate that K supplementation accelerates diuresis and natriuresis, resulting in moderate suppression of volume expansion induced by salt loading and that this accelerated diuresis and natriuresis is not a result of the action of ANP.     

Measuring the Quality of Healthcare

Recently, enormous efforts to measure the quality of healthcare have been made to attain information on ways to improve the quality of healthcare. However, this area of research is still at an early stage of development and more research is required. This article outlines a framework by which the quality of healthcare can be analyzed on the basis of the three quality dimensions introduced by Donabedian. The article then goes on to test the validity of this (theoretical) framework within an empirical analysis.Because of increasing financial shortages within health systems, this article focuses on the treatment of myocardial infarction, which is one of the costliest and most prevalent diseases. This approach establishes a link between medical and economic problems. The variables for structure quality (i.e. number of cardiologists, number of catheterization facilities) were sourced and evaluated from the ‘Herzberichte der Jahrgänge’ (‘heart reports’) compiled by Bruckenberger for the period 1994–2004 for the 16 German federal states. Data from the Federation of Quality Assurance (BQS) were used for the evaluation of process quality (i.e. adequacy of indication for coronary angiography). Finally, administrative data from the German Federal Statistical office for 1994–2004 were used to determine the variables of outcome quality (i.e. standardized mortality rate due to myocardial infarction, potential years of life lost <70 years due to myocardial infarction).Three hypotheses were tested using panel data: (i) a better structure and/or process quality increases the probability of getting a better outcome quality for the clinical picture under observation; (ii) by employing additional input factors (such as additional catheterization facilities), the probability of getting a good outcome quality is increased; and (iii) in addition to structure quality and process quality, factors lying outside of the sphere of influence of the health system have an additional influence on outcome quality (marginal gains would decrease in this case). Three models were used to test these hypotheses using fixed effects estimation.The empirical analysis produced three results. First, the analysis confirms the predicted causality between the different dimensions of quality of care for the German federal states. Notably, the number of catheterization facilities has a highly significant positive influence on the outcome quality. Second, support is found for decreasing marginal gain of inputs. Third, a good structure and a good process quality alone cannot guarantee good outcome quality. However, the analysis also showed that, in addition to healthcare provided, there are other determinants that also affect the outcome quality of healthcare. Further empirical investigation regarding the influence of these factors on the outcome dimension could elaborate on our findings and deliver additional insights.     

Controlling for occasion-specific effects when assessing the test–retest reliability of self-report health questionnaires

OBJECTIVE: This study proposes a method for self-report health questionnaires to adjust test-retest reliability for changes during the test-retest interval based on an external measure, and to distinguish such changes from random response errors. METHODS: In our application, eighty participants completed the Symptoms of Illness Checklist (SIC) on two occasions, two weeks apart, immediately before interviews given on each occasion by one of two physicians in a crossover design. The physician interview scores served as external measures, and structural equation modeling was used to estimate the parameters of a model that corrected for the occasion-specific effect of participants' responses using information from the interviews. RESULTS: Correcting for changes in symptoms during the test-retest interval increased SIC test-retest reliability from .744 to .804 and significantly improved model fit (chi2(diff)(1) = 30.78, p < .001). CONCLUSIONS: The results suggest methods that can improve the evaluation of self-report health questionnaire test-retest reliability by identifying changes using an external measure, and distinguishing these from random response errors; these increased the estimated SIC test-retest reliability and indicated that the SIC was indeed able to measure changes over the studied time interval. This method can be applied across a broad range of questionnaires.     

Effects of residence and race on burden of travel for care: cross sectional analysis of the 2001 US National Household Travel Survey

Background  

Travel burden is a key element in conceptualizing geographic access to health care. Prior research has shown that both rural and minority populations bear disproportionate travel burdens. However, many studies are limited to specific types of patient or specific locales. The purpose of our study was to quantify geographic and race-based differences in distance traveled and time spent in travel for medical/dental care using representative national data.