Measuring blood pressure in the elderly: does atrial fibrillation increase observer variability?

OBJECTIVE--To compare the interobserver and intraobserver variability of blood pressure measurements in geriatric patients in atrial fibrillation and in sinus rhythm. DESIGN--Prospective assessment of blood pressure measurements carried out in random order in two groups of elderly patients by five doctors unaware of the aims of the study. SETTING--Acute assessment wards for geriatric medicine, Cardiff Royal Infirmary. PATIENTS--50 Elderly patients in sinus rhythm and 50 in atrial fibrillation. MAIN OUTCOME MEASURES--Interobserver and intraobserver variability of blood pressure measurements in the two groups expressed as the coefficient of variability and compared by the Mann-Whitney U test. RESULTS--Interobserver variability was significantly greater in the patients with atrial fibrillation for both systolic and diastolic pressures. Intraobserver variability was significantly greater in the atrial fibrillation group for diastolic pressures but the difference was not significant for systolic pressures. These differences were not related to pulse rate, age, or level of blood pressure. CONCLUSIONS--The findings suggest that in the presence of atrial fibrillation physicians'' interpretations of Korotkoff sounds are less uniform, which may have important clinical implications. Possibly a standardised methodology may overcome this problem.     

Sequencing of the Dutch Elm Disease Fungus Genome Using the Roche/454 GS-FLX Titanium System in a Comparison of Multiple Genomics Core Facilities

As part of the DNA Sequencing Research Group of the Association of Biomolecular Resource Facilities, we have tested the reproducibility of the Roche/454 GS-FLX Titanium System at five core facilities. Experience with the Roche/454 system ranged from <10 to >340 sequencing runs performed. All participating sites were supplied with an aliquot of a common DNA preparation and were requested to conduct sequencing at a common loading condition. The evaluation of sequencing yield and accuracy metrics was assessed at a single site. The study was conducted using a laboratory strain of the Dutch elm disease fungus Ophiostoma novo-ulmi strain H327, an ascomycete, vegetatively haploid fungus with an estimated genome size of 30–50 Mb. We show that the Titanium System is reproducible, with some variation detected in loading conditions, sequencing yield, and homopolymer length accuracy. We demonstrate that reads shorter than the theoretical minimum length are of lower overall quality and not simply truncated reads. The O. novo-ulmi H327 genome assembly is 31.8 Mb and is comprised of eight chromosome-length linear scaffolds, a circular mitochondrial conti of 66.4 kb, and a putative 4.2-kb linear plasmid. We estimate that the nuclear genome encodes 8613 protein coding genes, and the mitochondrion encodes 15 genes and 26 tRNAs.     

Chloride transport in Anacystis nidulans

Summary Anacystis nidulans will take up and accumulate chloride ions. When the external concentration was 0.2 mM Cl^- the level in the cells was 2.8 mM Cl^- and under these conditions the flux across the cell surface was in the region of 10^-13equiv Cl^-·sec^-1·cm^-2. It is suggested that this Cl^- influx is active and operates against an electrochemical potential gradient estimated to be 117 mV or 2.68 kcal/mole. The uptake of ³⁶Cl was inhibited by low temperatures and there was a net loss of Cl^- from the cells with the level decreasing towards the equilibrium value as estimated from K⁺ distribution. Although the active influx of Cl^- was often stimulated by light this was not always the case. Dark storage treatment and regulation of the chlorophyll a/phycocyanin ratios as well as total pigment content of the cells did not clarify the conditions which brought about light stimulation. Moreover, the metabolic inhibitors CCCP and CMU and also the use of anaerobic conditions did not clearly indicate the relationship between the influx mechanism and light-dark metabolism and no firm conclusions could be made about the nature of the energy source. The variation in the degree of light stimulation probably reflects the fact that in this procaryotic organism the photosynthetic and respiratory units are located on the same membrane systems and are in very close proximity to the probable site of the Cl^- pump, the plasmalemma.Abbreviations CCCP carbonyl cyanide m-chlorophenylhydrazone - CMU 3-(4-chlorophenyl)-1,1-dimethylurea     

大鼠胼胝体内神经肽Y免疫反应阳性纤维的发育

本实验用免疫组织化学ＡＢＣ法研究了大鼠胼胝体内神经肽Ｙ免疫反应阳性（ＮＰＹ－ＩＲ）纤维的生后发育。结果发现,许多ＮＰＹ－ＩＲ纤维在大鼠出生时便存在于胼胝体内。ＮＰＹ－ＩＲ胼胝体纤维的密度在生后１周内继续逐渐增高,在第２周内达到最高峰。之后,ＮＰＹ－ＩＲ胼胝体纤维的密度逐渐下降,至第３周末时接近成年时的水平,即仅有少量ＮＰＹ－ＩＲ纤维存在于胼胝体内。这些结果提示在大鼠早期生后发育过程中许多ＮＰＹ－ＩＲ胼胝体纤维是暂时性的,其作用可能与大脑皮质的机能发育有关。