Variation between hospitals in outcomes following cardiac surgery in the UK.

INTRODUCTION: We examine the influence of variations in provision of cardiac surgery in the UK at hospital level on patient outcomes and also to assess whether there is an inequality of access and delivery of healthcare. Cardiothoracic surgery has pioneered the reporting of surgeon-specific outcomes, which other specialties have followed. We set out to identify factors other than the individual surgeon, which can affect outcomes and enable other surgical specialties to adopt a similar model. MATERIALS AND METHODS: A retrospective analysis of prospectively collected data of patient and hospital level factors between 2013 and 2016 from 16 cardiac surgical units in the UK were analysed through the Society for Cardiothoracic Surgery of Great Britain and Ireland and the Royal College of Surgeons Research Collaborative. Patient demographic data, risks factors, postoperative complications and in-hospital mortality, as well as hospital-level factors such as number of beds and operating theatres, were collected. Correlation between outcome measures was assessed using Pearson's correlation coefficient. Associations between hospital-level factors and outcomes were assessed using univariable and multivariable regression models. RESULTS: Of 50,871 patients (60.5% of UK caseload), 25% were older than 75 years and 29% were female. There was considerable variation between units in patient comorbidities, bed distribution and staffing. All hospitals had dedicated cardiothoracic intensive care beds and consultants. Median survival was 97.9% (range 96.3-98.6%). Postoperative complications included re-sternotomy for bleeding (median 4.8%; range 3.5-6.9%) and mediastinitis (0.4%; 0.1-1.0%), transient ischaemic attack/cerebrovascular accident (1.7%; range 0.3-3.0%), haemofiltration (3.7%; range 0.8-6.8%), intra-aortic balloon pump use (3.3%; range 0.4-7.4%), tracheostomy (1.6%; range 1.3-2.6%) and laparotomy (0.3%; range 0.2-0.6%). There was variation in outcomes between hospitals. Univariable analysis showed a small number of positive associations between hospital-level factors and outcomes but none remained significant in multivariable models. CONCLUSIONS: Variations among hospital level factors exists in both delivery of, and outcomes, following cardiac surgery in the UK. However, there was no clear association between these factors and patient outcomes. This negative finding could be explained by differences in outcome definition, differences in risk factors between centres that are not captured by standard risk stratification scores or individual surgeon/team performance.

Assessing the pathogenicity of RYR1 variants in malignant hyperthermia.

BACKGROUND: . Missense variants in the ryanodine receptor 1 gene ( RYR1 ) are associated with malignant hyperthermia but only a minority of these have met the criteria for use in predictive DNA diagnosis. We examined the utility of a simplified method of segregation analysis and a functional assay for determining the pathogenicity of recurrent RYR1 variants associated with malignant hyperthermia. METHODS: . We identified previously uncharacterised RYR1 variants found in four or more malignant hyperthermia families and conducted simplified segregation analyses. An efficient cloning and mutagenesis strategy was used to express ryanodine receptor protein containing one of six RYR1 variants in HEK293 cells. Caffeine-induced calcium release, measured using a fluorescent calcium indicator, was compared in cells expressing each variant to that in cells expressing wild type ryanodine receptor protein. RESULTS.: We identified 43 malignant hyperthermia families carrying one of the six RYR1 variants. There was segregation of genotype with the malignant hyperthermia susceptibility phenotype in families carrying the p.E3104K and p.D3986E variants, but the number of informative meioses limited the statistical significance of the associations. HEK293 functional assays demonstrated an increased sensitivity of RyR1 channels containing the p.R2336H, p.R2355W, p.E3104K, p.G3990V and p.V4849I compared with wild type, but cells expressing p.D3986E had a similar caffeine sensitivity to cells expressing wild type RyR1. CONCLUSIONS: . Segregation analysis is of limited value in assessing pathogenicity of RYR1 variants in malignant hyperthermia. Functional analyses in HEK293 cells provided evidence to support the use of p.R2336H, p.R2355W, p.E3104K, p.G3990V and p.V4849I for diagnostic purposes but not p.D3986E.

Diverse mechanisms underlying the regulation of ion channels by carbon monoxide.

Carbon monoxide (CO) is firmly established as an important, physiological signalling molecule as well as a potent toxin. Through its ability to bind metal-containing proteins, it is known to interfere with a number of intracellular signalling pathways, and such actions can account for its physiological and pathological effects. In particular, CO can modulate the intracellular production of reactive oxygen species, NO and cGMP levels, as well as regulate MAPK signalling. In this review, we consider ion channels as more recently discovered effectors of CO signalling. CO is now known to regulate a growing number of different ion channel types, and detailed studies of the underlying mechanisms of action are revealing unexpected findings. For example, there are clear areas of contention surrounding its ability to increase the activity of high conductance, Ca(2+) -sensitive K(+) channels. More recent studies have revealed the ability of CO to inhibit T-type Ca(2+) channels and have unveiled a novel signalling pathway underlying tonic regulation of this channel. It is clear that the investigation of ion channels as effectors of CO signalling is in its infancy, and much more work is required to fully understand both the physiological and the toxic actions of this gas. Only then can its emerging use as a therapeutic tool be fully and safely exploited.

Epidemiology and prospects for prevention of rotavirus disease in India.

CONTEXT: With rotavirus vaccines now available globally, it will be useful to assemble the available evidence on the epidemiology and burden of rotavirus gastroenteritis in India, in order to weigh the urgency of introducing a vaccine to help control rotavirus disease. EVIDENCE ACQUISITION: We reviewed published studies on rotavirus infection and genotype distribution in India, as well as safety and immunogenicity studies of currently available vaccines. PubMed was searched for papers published after 1990, and several authors who are experts in the field recommended papers of known significance. RESULTS: Rotavirus accounts for close to 40% of hospitalizations for diarrhea in India, with more recent studies showing an increased proportion compared with older studies. There is substantial serotype diversity in India, although there is less intra-country variation than previously thought. Two genotypes, G1P[8] and G2P[4], account for roughly 50% of symptomatic infections in non-neonates. Currently licensed vaccines are safe, and although the efficacy appears lower in developing countries, given the extremely high incidence of diarrhea these could still be cost-effective interventions. CONCLUSIONS: The epidemiology and burden of rotavirus diarrhea is fairly well characterized in India. Introducing rotavirus vaccine into the UIP, along with adequate surveillance, should be an important part of efforts to reduce diarrhea mortality, the third leading cause of death among Indian children, and achieve the country's MDG goals.

Sexual selection and temporal phenotypic variation in a damselfly population.

Temporal variation in selection can be generated by temporal variation in either the fitness surface or phenotypic distributions around a static fitness surface, or both concurrently. Here, we use within- and between-generation sampling of fitness surfaces and phenotypic distributions over 2 years to investigate the causes of temporal variation in the form of sexual selection on body size in the damselfly Enallagma aspersum. Within a year, when the average female body size differed substantially from the average male body size, male body size experienced directional selection. In contrast, when male and female size distributions overlapped, male body size experienced stabilizing selection when variances in body size were large, but no appreciable selection when the variances in body size were small. The causes of temporal variation in the form of selection can only be inferred by accounting for changes in both the fitness surface and changes in the distribution of phenotypes.

An ACE unit with a delirium room may improve function and equalize length of stay among older delirious medical inpatients.

BACKGROUND: Patients with delirium, compared with those without, are at increased risk for loss of function, longer hospital stays, and increased mortality. We studied the effect that an Acute Care of the Elderly Unit, which includes a delirium room, has on patients with delirium. METHODS: Retrospective observational study. Charts of 148 patients (≥65 years) admitted to an Acute Care of the Elderly Unit with a delirium room during a 4-month period were reviewed. Delirium on admission (prevalence) was based on physician-performed Confusion Assessment Method; delirium during hospital stay (incidence) was based on nurse-performed Confusion Assessment Method. Patients with delirium were compared with those without delirium regarding change in function between admission and discharge (activities of daily living), hospital length of stay, and mortality. RESULTS: The prevalence of delirium was 16.2% (24/148), and the incidence was 16.1% (20/124). There were no significant differences between delirious and non-delirious patients in demographics or comorbidity scores. A significant interaction effect (p < .001) indicated improved activities of daily living (mean ± SD; scale 0-12) between admission and discharge among delirious patients (4.1 ± 4.6 and 6.1 ± 3.9) compared with non-delirious patients (7.4 ± 4.7 and 6.9 ± 4.5). There were no differences between delirious and non-delirious patients with reference to mean length of stay (6.4 ± 3.1 vs 5.9 ± 3.6 days, respectively; p = .461) and mortality (2 [4.5%] versus 2 [1.9%], respectively; p = .582). CONCLUSIONS: Although this study sample was small, the results suggest that an Acute Care of the Elderly Unit with a delirium room may improve function among delirious patients and may equalize other outcomes compared with non-delirious patients.

Genetic variation in RYR1 and malignant hyperthermia phenotypes.

BACKGROUND: Malignant hyperthermia (MH) is associated, in the majority of cases, with mutations in RYR1, the gene encoding the skeletal muscle ryanodine receptor. Our primary aim was to assess whether different RYR1 variants are associated with quantitative differences in MH phenotype. METHODS: The degree of in vitro pharmacological muscle contracture response and the baseline serum creatine kinase (CK) concentration were used to generate a series of quantitative phenotypes for MH. We then undertook the most extensive RYR1 genotype-phenotype correlation in MH to date using 504 individuals from 204 MH families and 23 RYR1 variants. We also determined the association between a clinical phenotype and both the laboratory phenotype and RYR1 genotype. RESULTS: We report a novel correlation between the degree of in vitro pharmacological muscle contracture responses and the onset time of the clinical MH response in index cases (P<0.05). There was also a significant correlation between baseline CK concentration and clinical onset time (P=0.039). The specific RYR1 variant was a significant determinant of the severity of each laboratory phenotype (P<0.0001). CONCLUSIONS: The MH phenotype differs significantly with different RYR1 variants. Variants leading to more severe MH phenotype are distributed throughout the gene and tend to lie at relatively conserved sites in the protein. Differences in phenotype severity between RYR1 variants may explain the variability in clinical penetrance of MH during anaesthesia and why some variants have been associated with exercise-induced rhabdomyolysis and heat stroke. They may also inform a mutation screening strategy in cases of idiopathic hyperCKaemia.

Epigenetic allele silencing and variable penetrance of malignant hyperthermia susceptibility.

BACKGROUND: Tissue-specific monoallelic silencing of the RYR1 gene has been proposed as an explanation for variable penetrance of dominant RYR1 mutations in malignant hyperthermia (MH). We examined the hypothesis that monoallelic silencing could explain the inheritance of an MH discordant phenotype in some instances. METHODS: We analysed parent-offspring transmission data from MH kindreds to assess whether there was any deviation from the expected autosomal dominant Mendelian inheritance pattern. We also evaluated informative single-nucleotide polymorphism (SNP) genotypes in a cohort of unrelated MH patients using genomic DNA (gDNA, prepared from leucocytes) and coding DNA (cDNA, prepared from skeletal muscle). Finally, we examined the segregation of specific mutations at the gDNA and cDNA level within MH families where positive RYR1 gDNA genotype/normal MH phenotype discordance had been observed. RESULTS: In 2113 transmissions from affected parents, there was a consistent parent-of-origin effect (P<0.001) with affected fathers having fewer affected daughters (20%, 95% CI 17-22%) than affected sons (25%, 95% CI 23-26%) or unaffected daughters (27%, 95% CI 25-30%). No discrepancies were observed between the RYR1 SNP genotypes recorded at the gDNA and cDNA levels. In 14 MH negative individuals from 11 discordant families, the familial mutation was detected in skeletal muscle cDNA in all cases. CONCLUSIONS: Epigenetic allele silencing may play a role in the inheritance of MH susceptibility, but this is unlikely to involve silencing of RYR1.

Analysis of RYR1 haplotype profile in patients with malignant hyperthermia.

This study represents a new approach to characterising patients at risk of malignant hyperthermia (MH) through the use of a recently published method for identifying high-risk haplotypes in candidate genes. We present analysis based upon the largest standardised and genotyped database of MH patients worldwide. We used unphased RYR1 SNP data directly to (1) assess RYR1 haplotype frequency differences between susceptible cases and control groups and (2) analyse population-based association via clustering of RYR1 haplotypes based on disease risk. Our results show a significant difference in RYR1 haplotype frequency between susceptible cases and UK Caucasian population controls. Furthermore we identify a high-risk cluster of haplotypes that is associated with the commonest UK MH mutation p.G2434R/c.7300G>A. These results demonstrate the applicability of this new and practical method for population based association analysis.

Surface energy of microcrystalline cellulose determined by capillary intrusion and inverse gas chromatography.

Surface energy data for samples of microcrystalline cellulose have been obtained using two techniques: capillary intrusion and inverse gas chromatography. Ten microcrystalline cellulose materials, studied using capillary intrusion, showed significant differences in the measured surface energetics (in terms of total surface energy and the acid-base characteristics of the cellulose surface), with variations noted between the seven different manufacturers who produced the microcrystalline cellulose samples. The surface energy data from capillary intrusion was similar to data obtained using inverse gas chromatography with the column maintained at 44% relative humidity for the three samples of microcrystalline cellulose studied. This suggests that capillary intrusion may be a suitable method to study the surface energy of pharmaceutical samples.

Molecular profiling pleomorphic lobular carcinomas of the breast: evidence for a common molecular genetic pathway with classic lobular carcinomas.

Pleomorphic lobular carcinomas (PLC) of the breast display histological features associated with classic invasive lobular carcinoma (ILC), yet they also exhibit more conspicuous nuclear atypia and pleomorphism, and an aggressive clinical behaviour. From a breast cancer progression perspective, it is unclear whether PLC is a variant of ILC or is a high-grade invasive ductal carcinoma (IDC) that has lost E-cadherin. The molecular features of 26 PLC were studied using immunohistochemistry [oestrogen receptor (ER), progesterone receptor (PR), HER2, p53 and E-cadherin], 0.9 Mb resolution, microarray-based comparative genomic hybridization (aCGH), fluorescent (FISH) and chromogenic (CISH) in situ hybridization and loss of heterozygosity. Comparative analysis was performed with aCGH data from PLC with classic ILC (16 cases) and high grade IDC (35 cases). PLCs were frequently ER- and PR-positive, E-cadherin-negative and occasionally HER2- and p53-positive. Recurrent copy number changes identified by aCGH included gains on 1q, 8q, 11q, 12q, 16p and 17q and losses on 8p, 11q, 13q, 16q and Xq. Highly recurrent 1q+ (100% of cases), 16p+ (93%), 11q- (53%) and 16q- (93%) and evidence of the der(1;16)/der(16)t(1;16) rearrangement, as detected by FISH, suggested that PLC had a 'lobular genotype'. Focal amplifications were evident at 8p12-p11, 8q24, 11q13.1-q14.1, 12q14, 17q12 and 20q13. Loss of BRCA2 was detected in 40% of PLC by LOH. Comparative analysis of aCGH data suggested the molecular features of PLC (ER/PR-positive, E-cadherin-negative, 1q+, 11q(-), 16p+ and 16q(-)) were more closely related to those of ILC than IDC, implicating an overlapping developmental pathway for these lobular tumour types. Molecular alterations found in PLC that are more typical of high-grade IDC than ILC (p53 and HER2 positivity, 8q+, 17q24-q25+, 13q(-) and amplification of 8q24, 12q14, 17q12 and 20q13) are likely to drive the high-grade and more aggressive biology of PLC.

1-year follow-up of autologous muscle-derived stem cell injection pilot study to treat stress urinary incontinence.

We hereby report a 1-year follow-up on eight women in the first North America trial in which stress urinary incontinence (SUI) was treated with muscle-derived stem cell injections. Mean and median follow-up in this group was 16.5 and 17 months (range 3-24 months). Improvement in SUI was seen in five of eight women, with one achieving total continence. Onset of improvement was between 3 and 8 months after injection. Cure or improvement continued at a median of 10 months. No serious adverse events were reported.

Hypoxia can be detected in irradiated normal human tissue: a study using the hypoxic marker pimonidazole hydrochloride.

Chronic tissue hypoxia may play a role in the pathogenesis of late radiation fibrosis. In order to investigate this hypothesis, the immunohistochemical distribution of pimonidazole hydrochloride (n = 14 patients) and carbonic anhydrase IX (CAIX) (n = 38 patients) was studied in samples of previously irradiated normal human tissue. One sample of irradiated breast tissue, which also showed marked histological features of radiation injury, stained positive for pimonidazole hydrochloride. No CAIX staining was seen in irradiated tissue other than some evidence of physiological hypoxia in the epidermis of two samples of irradiated skin; both were positive for pimonidazole and one was focally positive for CAIX. Pimonidazole hydrochloride staining of tissue with morphological changes of radiation injury could support a role for hypoxia in the pathogenesis of late normal tissue fibrosis in humans.

Localization and trafficking of cardiac voltage-gated potassium channels.

The proper trafficking and localization of cardiac potassium channels is profoundly important to the regulation of the regionally distinct action potentials across the myocardium. These processes are only beginning to be unravelled and involve modulators of channel synthesis and assembly, post-translational processing, various molecular motors and an increasing number of modifying enzymes and molecular anchors. The roles of anchoring proteins, molecular motors and kinases are explored and recent findings on channel internalization and trafficking are presented.

Vitamin D levels and early mortality among incident hemodialysis patients.

Vitamin D deficiency is associated with cardiovascular disease, the most common cause of mortality in hemodialysis patients. To investigate the relation between blood levels of 25-hydroxyvitamin D (25D) and 1,25-dihydroxyvitamin D (1,25D) with hemodialysis outcomes, we measured baseline vitamin D levels in a cross-sectional analysis of 825 consecutive patients from within a prospective cohort of incident US hemodialysis patients. Of these patients, 78% were considered vitamin D deficient with 18% considered severely deficient. Calcium, phosphorus, and parathyroid hormone levels correlated poorly with 25D and 1,25D concentrations. To test the association between baseline vitamin D levels and 90-day mortality, we selected the next 175 consecutive participants who died within 90 days and compared them to the 750 patients who survived in a nested case-control analysis. While low vitamin D levels were associated with increased mortality, significant interaction was noted between vitamin D levels, subsequent active vitamin D therapy, and survival. Compared to patients with the highest 25D or 1,25D levels who received therapy, untreated deficient patients were at significantly increased risk for early mortality. Our study shows that among incident hemodialysis patients, vitamin D deficiency is common, correlates poorly with other components of mineral metabolism and is associated with increased early mortality.

[Relationship between severity of rotavirus diarrhea and serotype G and genotype].

OBJECTIVE: To learn the relationship between severity of rotavirus diarrhea and serotype G and genotype P. METHOD: The clinical information and fecal specimens of hospitalized children less than 5 years of age with acute diarrhea in four sentinel hospitals were collected from Aug 2001 to July 2003. Specimens were tested and typed for rotavirus. Each child with rotavirus infection was assessed for severity of diarrhea according to the 20-points scoring system of Vesikari. RESULTS: When combined with P[8], the severity scores for rotavirus diarrhea of P[8]G1 and P[8]G3 were 13 and 12 points, respectively, and the durations of diarrhea were 6 days and 5 days, respectively. The percentage of fever in patients with diarrhea caused by P[8]G1 was higher than that in those with diarrheas caused by P[8]G3 (97 percent vs. 73 percent). And the highest temperature in the cases with diarrheas caused by G1 and G3 was 39 degrees C and 38.6 degrees C, respectively. When combined with G3, the difference of diarrhea severity scores between P[4]G3 and P[8]G3 was not significant. But duration of diarrhea caused by P[4] was longer than that of diarrheas caused by P[8] (6.5 days vs. 5 days) and the maximum times of vomiting in P[8] cases was higher than in p[4] cases (4 times vs. 3 times per day). There was no significant difference in other clinical features between P[8] and P[4] infected cases. CONCLUSION: When combined with P[8], RV diarrhea caused by G1 was associated with higher severity scores than diarrhea caused by G3. When combined with G3, there was no significant difference in severity scores between P[4] and P[8] infected cases.