Biofilm structures (EPS and bacterial communities) in drinking water distribution systems are conditioned by hydraulics and influence discolouration

High-quality drinking water from treatment works is degraded during transport to customer taps through the Drinking Water Distribution System (DWDS). Interactions occurring at the pipe wall-water interface are central to this degradation and are often dominated by complex microbial biofilms that are not well understood. This study uses novel application of confocal microscopy techniques to quantify the composition of extracellular polymeric substances (EPS) and cells of DWDS biofilms together with concurrent evaluation of the bacterial community. An internationally unique, full-scale, experimental DWDS facility was used to investigate the impact of three different hydraulic patterns upon biofilms and subsequently assess their response to increases in shear stress, linking biofilms to water quality impacts such as discolouration. Greater flow variation during growth was associated with increased cell quantity but was inversely related to EPS-to-cell volume ratios and bacterial diversity. Discolouration was caused and EPS was mobilised during flushing of all conditions. Ultimately, biofilms developed under low-varied flow conditions had lowest amounts of biomass, the greatest EPS volumes per cell and the lowest discolouration response. This research shows that the interactions between hydraulics and biofilm physical and community structures are complex but critical to managing biofilms within ageing DWDS infrastructure to limit water quality degradation and protect public health.

Genetic and morphological features of human iPSC-derived neurons with chromosome 15q11.2 (BP1-BP2) deletions

BACKGROUND

Copy number variation on chromosome 15q11.2 (BP1-BP2) causes deletion of CYFIP1, NIPA1, NIPA2 and TUBGCP5; it also affects brain structure and elevates risk for several neurodevelopmental disorders that are associated with dendritic spine abnormalities. In rodents, altered cyfip1 expression changes dendritic spine morphology, motivating analyses of human neuronal cells derived from iPSCs (iPSC-neurons).

METHODS

iPSCs were generated from a mother and her offspring, both carrying the 15q11.2 (BP1-BP2) deletion, and a non-deletion control. Gene expression in the deletion region was estimated using quantitative real-time PCR assays. Neural progenitor cells (NPCs) and iPSC-neurons were characterized using immunocytochemistry.

RESULTS

CYFIP1, NIPA1, NIPA2 and TUBGCP5 gene expression was lower in iPSCs, NPCs and iPSC-neurons from the mother and her offspring in relation to control cells. CYFIP1 and PSD95 protein levels were lower in iPSC-neurons derived from the CNV bearing individuals using Western blot analysis. At 10 weeks post-differentiation, iPSC-neurons appeared to show dendritic spines and qualitative analysis suggested that dendritic morphology was altered in 15q11.2 deletion subjects compared with control cells.

CONCLUSIONS

The 15q11.2 (BP1-BP2) deletion is associated with reduced expression of four genes in iPSC-derived neuronal cells; it may also be associated altered iPSC-neuron dendritic morphology.

Socioeconomic and racial disparities in the selection of chest wall boost radiation therapy in californian women after mastectomy

To better elucidate the socioeconomic and racial differences in women who received postmastectomy radiation therapy with or without a chest wall boost, the records from 4747 women included in the California Cancer Registry were reviewed. Poor and Hispanic women were more likely to receive a chest wall boost than were more affluent and non-Hispanic women.

INTRODUCTION

Healthcare disparities in breast cancer treatment have been well documented. We investigated the socioeconomic status (SES) and racial factors in women with locally advanced breast cancer from the California Cancer Registry who had received postmastectomy radiation therapy (PMRT) with or without a chest wall boost (CWB).

PATIENTS AND METHODS

The records of 4747 women with invasive breast cancer, diagnosed from 2005 to 2009, who had undergone PMRT, were reviewed and stratified by treatment with (n = 2686 [57%]) or without (n = 2061 [43%]) a CWB. Various patient demographic and biologic factors were analyzed using univariate and multivariate analysis.

RESULTS

Receipt of a CWB was associated with race/ethnicity (P < .001), SES (P < .001), tumor size (P = .038), tumor grade (P = .033), human epidermal growth factor 2 (HER2) status (P = .015), American Joint Committee on Cancer stage (P = .001), number of nodes examined (P = .001), and number of positive nodes (P = .037) on univariate analysis. After controlling for confounding factors, race/ethnicity and SES remained independently predictive of a CWB. Hispanic women were more likely to receive a CWB than Asian (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.60-0.90), black (HR, 0.63; 95% CI, 0.48-0.83), or white (HR, 0.81; 95% CI, 0.69-0.95) women. Also, women of low SES were more likely to receive a CWB than women of high SES (HR, 0.74; 95% CI, 0.64-0.86).

CONCLUSION

We found that poor and Hispanic women were more commonly treated with a CWB than were more affluent and non-Hispanic women with a similar cancer stage, cancer biology, and treatment paradigm.

Socioeconomic and racial disparities in the selection and outcomes of a chest-wall boost in post-mastectomy radiation therapy

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Background: We investigated socioeconomic and racial disparities in the selection and outcomes of patients from the California Cancer Registry receiving post-mastectomy radiation therapy (PMRT) with or without a chest-wall boost (CWB). Methods: Records of 5,586 women with invasive breast cancer, diagnosed from 2005-2009, treated with PMRT were reviewed and stratified based on treatment with (n=2,482 [44%]) or without (n=3,104 [56%]) a CWB. Race and socioeconomic status (SES) between the cohorts were analyzed. Bivariate analyses of the impact of race and socio-demographic factors on breast cancer-specific survival (BCS) and overall survival (OS) were performed using the Kaplan-Meier method. Adjusting for potential confounders, we used multivariate proportional hazards models to identify predictors of BCS and OS, reported as hazard ratios (HR) with 95% confidence intervals (CI). Results: The majority of PMRT patients were white (58%), compared to Hispanic (20%), Asian/Pacific-Islander (15%), and black (6%). Most were of high SES (50%), compared to middle (21%) or low (29%). Non-white patients were more frequently of low SES (59% vs. 40%). Hispanic frequency (61%) of advanced-stage (3-4) disease was the highest of all races. Low SES was also associated with higher stage (37% vs. 60%) compared to high SES, which comparatively presented with lower-stage (1-2) disease (42% vs. 57%, p=0.0187). Low-SES patients were more likely to receive a CWB (31 vs. 26%) while high-SES patients were less likely (48% vs. 53%, p<0.0001). White women were more likely to be treated without a CWB (60 vs. 57%), while Hispanic women were less likely (23% vs. 18%, p=0.0003). Women not treated with a CWB with low SES had a lower BCS (HR 1.541 p=0.0114) and OS (HR 1.794. p=<0.001) compared to women of high SES. Black women not treated a CWB had lower OS (HR 1.712, p=0.0249) compared to similarly-treated white women. Conclusions: Low SES and Hispanic race were associated with advanced stage, and more commonly treated with a CWB. Low-SES and black women treated without a CWB had lower OS, while the former also had lower BCS. These findings suggest that economic and racial health-care disparities contribute to worse outcomes.

Cancer incidence trends among Asian American populations in the United States, 1990-2008

BACKGROUND

National cancer incidence trends are presented for eight Asian American groups: Asian Indians/Pakistanis, Chinese, Filipinos, Japanese, Kampucheans, Koreans, Laotians, and Vietnamese.

METHODS

Cancer incidence data from 1990 through 2008 were obtained from 13 Surveillance, Epidemiology, End Results (SEER) registries. Incidence rates from 1990 through 2008 and average percentage change were computed using SEER*Stat and Joinpoint software. The annual percentage change (APC) in incidence rates was estimated with 95% confidence intervals (95% CIs) calculated for both the rate and APC estimates. Rates for non-Hispanic whites are presented for comparison.

RESULTS

Prostate cancer was the most common malignancy among most groups, followed by lung, colorectal, liver, and stomach cancers. Breast cancer was generally the most common cancer in women, followed by colorectal and lung cancers; liver, cervix, thyroid, and stomach cancers also ranked highly. Among men, increasing trends were observed for prostate (Asian Indians and Pakistanis: APC 1990-2003 = 2.2, 95% CI = 0.3 to 4.1; Filipinos: APC 1990-1994 = 19.0, 95% CI = 4.5 to 35.4; Koreans: APC 1990-2008 = 2.9, 95% CI = 1.8 to 4.0), colorectal (Koreans: APC 1990-2008 = 2.2, 95% CI = 0.9 to 3.5), and liver cancers (Filipinos: APC 1990-2008 = 1.6, 95% CI = 0.4 to 2.7; Koreans: APC 1990-2006 = 2.1, 95% CI = 0.4 to 3.7; Vietnamese: APC 1990-2008 = 1.6, 95% CI = 0.3 to 2.8), whereas lung and stomach cancers generally remained stable or decreased. Among women, increases were observed for uterine cancer (Asian Indians: APC 1990-2008 = 3.0, 95% CI = 0.3 to 5.8; Chinese: APC 2004-2008 = 7.0, 95% CI = 1.4 to 12.9; Filipina: APC 1990-2008 = 3.0, 95% CI = 2.4 to 3.7; Japanese: APC 1990-2008 = 1.1, 95% CI = 0.1 to 2.0), colorectal cancer (Koreans: APC 1990-2008 = 2.8, 95% CI = 1.7 to 3.9; Laotians: APC: 1990-2008 = 5.9, 95% CI = 4.0 to 7.7), lung cancer (Filipinas: APC 1990-2008 = 2.1, 95% CI = 1.4 to 2.8; Koreans: APC 1990-2008 = 2.1, 95% CI = 0.6 to 3.6), thyroid cancer (Filipinas: APC 1990-2008 = 2.5, 95% CI = 1.7 to 3.3), and breast cancer in most groups (APC 1990-2008 from 1.2 among Vietnamese and Chinese to 4.7 among Koreans). Decreases were observed for stomach (Chinese and Japanese), colorectal (Chinese), and cervical cancers (Laotians and Vietnamese).

CONCLUSIONS

These data fill a critical knowledge gap concerning the cancer experience of Asian American groups and highlight where increased preventive, screening, and surveillance efforts are needed-in particular, lung cancer among Filipina and Korean women and Asian Indian/Pakistani men, breast cancer among all women, and liver cancer among Vietnamese, Laotian, and Kampuchean women and Filipino, Kampuchean, and Vietnamese men.

Cancer incidence trends among native Hawaiians and other Pacific Islanders in the United States, 1990-2008

BACKGROUND

Lack of annual population estimates for disaggregated Native Hawaiian and Other Pacific Islander (NHOPI) populations limits the ability to examine cancer incidence rates and trends to understand the cancer burdens among NHOPIs.

METHODS

Utilizing 1990 and 2000 population census data, we estimated the annual populations by age and sex for Native Hawaiians, Samoans, and Guamanians/Chamorros for 1990-2008 in regions covered by 13 of the National Cancer Institute's SEER registries. Cancer diagnoses during 1990-2008 from these registries were used to calculate the age-adjusted (2000 US Standard) incidence rates by sex, calendar year/period, and cancer type for each population. The annual percentage change (APC) in incidence rates was estimated with the 95% confidence intervals (95% CIs) calculated for both the rate and APC estimates.

RESULTS

Statistically significant declining trends were found in Native Hawaiians, in men for lung and stomach cancers (APC = -2.3%; 95% CI = -3.3 to -1.3; and APC = -3.8%; 95% CI = -6.0 to -1.6, respectively), and in women for breast cancer (APC = -4.1%; 95% CI = -5.7 to -2.5) since 1998 and lung cancer (APC = -6.4%; 95% CI = -10.7 to -1.8) since 2001. Rising incidence trends were experienced by Samoans, especially by Samoan women for breast (APC = 2.7%; 95% CI = 0.9 to 4.5) and uterus (APC = 7.3%; 95% CI = 6.2 to 8.4) cancers. With limited data, Guamanians/Chamorros demonstrated lower, but increasing, incidence rates than other NHOPIs.

CONCLUSIONS

Population-based cancer incidence rates for disaggregated NHOPI populations help identify disparities in cancer burden and provide valuable information to improve cancer control efforts among NHOPIs.

Examining the association between socioeconomic status and invasive colorectal cancer incidence and mortality in California

BACKGROUND

Colorectal cancer (CRC) incidence and mortality rates vary across race/ethnicity. Socioeconomic status (SES) also influences CRC rates; however, these associations might be inconsistent across racial/ethnic groups and tumor subsite. We examined associations between area-level SES and CRC incidence and mortality in a population-based registry study of non-Hispanic Whites, African Americans, Hispanics, and Asians/Pacific Islanders from California.

METHODS

Data on 52,608 incident CRC cases (1998-2002) and 14,515 CRC deaths (1999-2001) aged ≥50 years were obtained from the California Cancer Registry. Based on 2000 U.S. Census data, each cancer case and death was assigned a multidimensional census tract-level SES index. SES-specific quintiles of CRC incidence and mortality rates, incidence rate ratios (IRR) and mortality rate ratios, and 95% confidence intervals (CI) were estimated. Analyses were stratified by anatomical site, including left- versus right-sided tumors, race/ethnicity, and stage of disease.

RESULTS

Overall CRC incidence and SES did not show a clear association, yet patterns of associations varied across tumor subsite and race/ethnicity. Positive associations between SES and CRC incidence were found in Hispanics [SES Q5 v. Q1: IRR = 1.54, CI = 1.39-1.69], irrespective of the subsite. For Whites [SES Q5 v. Q1: IRR = 0.80, CI = 0.77-0.83], and African Americans [SES Q5 v. Q1: IRR = 0.83, CI = 0.70-0.97] inverse associations were observed, predominantly for left-sided tumors. Mortality rates declined with increasing SES in Whites, whereas in Hispanics mortality rates significantly increased with SES.

CONCLUSIONS

Our findings show that SES differences in CRC incidence and mortality vary considerably across anatomical subsite and race/ethnicity.

IMPACT

Studies combining area- and individual-level SES information are warranted.

Gastric cancer incidence among Hispanics in California: patterns by time, nativity, and neighborhood characteristics

BACKGROUND

Better understanding about gastric cancer incidence patterns among Hispanics by birthplace, socioeconomic status (SES), and acculturation can improve preventive strategies and disease models.

METHODS

Incidence rates, rate ratios, and estimated annual percent change (EAPC) in rates of anatomic and histologic subtype-specific gastric cancer were calculated by age, sex, and nativity among Hispanics using California Cancer Registry data from 1988 through 2004. Incidence rates in 1998 to 2002 were compared by neighborhood SES and Hispanic enclave status according to 2000 US Census data.

RESULTS

Incidence rates of diffuse gastric cancer increased from 1988 through 2004 among foreign-born Hispanic men (EAPC: 3.5%, 95% CI: 1.5%-5.5%) and U.S.-born Hispanic women (EAPC: 3.0%, 95% CI: 0.7%-5.3%). During the same time period, incidence rates of intestinal gastric cancer declined significantly and both cardia and noncardia gastric cancer were steady or declined among foreign-born and U.S.-born Hispanic men and women. Noncardia and both intestinal and diffuse gastric cancer were more common in foreign-born than U.S.-born Hispanic men and women, and in those from lower SES, higher enclave neighborhoods. By contrast, among younger and middle-aged Hispanic men, cardia tumors were more common in the U.S.-born than the foreign-born, and in higher SES, lower enclave neighborhoods.

CONCLUSIONS

Varying gastric cancer risk factors among Hispanic subgroups and increasing rates of diffuse gastric cancer in foreign-born Hispanic men and U.S.-born Hispanic women merit further investigation to identify separate disease etiologies.

IMPACT

Age, sex, birthplace, SES, and acculturation modify gastric cancer incidence in Hispanics and should be considered when examining disease risk and prevention.

Cardiac gene therapy in large animals: bridge from bench to bedside

Several clinical trials are evaluating gene transfer as a therapeutic approach to treat cardiac diseases. Although it has just started on the path to clinical application, recent advances in gene delivery technologies with increasing knowledge of underlying mechanisms raise great expectations for the cardiac gene therapy. Although in vivo experiments using small animals provide the therapeutic potential of gene transfer, there exist many fundamental differences between the small animal and the human hearts. Before applying the therapy to clinical patients, large animal studies are a prerequisite to validate the efficacy in an animal model more relevant to the human heart. Several key factors including vector type, injected dose, delivery method and targeted cardiac disease are all important factors that determine the therapeutic efficacy. Selecting the most optimal combination of these factors is essential for successful gene therapy. In addition to the efficacy, safety profiles need to be addressed as well. In this regard, large animal studies are best suited for comprehensive evaluation at the preclinical stages of therapeutic development to ensure safe and effective gene transfer. As the cardiac gene therapy expands its potential, large animal studies will become more important to bridge the bench side knowledge to the clinical arena.

JNK modulates FOXO3a for the expression of the mitochondrial death and mitophagy marker BNIP3 in pathological hypertrophy and in heart failure

Bcl-2 E1B 19-KDa interacting protein 3 (BNIP3) is a mitochondrial death and mitophagy marker, which is involved in inducing cardiac remodeling post myocardial infarction. In this study, we show that BNIP3 expression increases in stressed cardiomyocytes in vitro and in response to pressure overload in vivo, and that its transcription is directly related to JNK activity. BNIP3 expression gradually increased in the first weeks after pressure overload and peaked at the heart failure stage. Ultrastructurally, the mitochondrial area was inversely proportional to BNIP3 expression. Both JNK and AKT activities increased with pressure overload; however, JNK signaling dominated over AKT signaling for the activation of the transcription factor FOXO3a and for the transcription of its effector, BNIP3. 3-methyladenine attenuated JNK signaling and significantly decreased BNIP3 expression and reversed cardiac remodeling in heart failure. Ultrastructurally, the mitochondrial area was significantly increased in the 3-methyladenine group compared with placebo. Moreover, adenoviral gene delivery of dominant negative JNK in a rat model of pressure overload hypertrophy abolished the increase in BNIP3 expression in response to pressure overload. These results suggest that JNK signaling is a critical modulator of the transcription factor FOXO3a driving the expression of its effector, BNIP3, in heart failure and that JNK, through BNIP3, induces mitochondrial apoptosis and mitophagy.

Racial patterns of extranodal natural killer/T-cell lymphoma, nasal type, in California: a population-based study

In order to investigate whether the clinical behaviour of extranodal natural killer/T-cell lymphoma, nasal type (ENKTL) varies by race within a geographic region, we identified a total of 213 non-Hispanic whites, Hispanics and Asians/Pacific islanders (APIs) diagnosed with ENKTL in the California Cancer Registry between 2001 and 2008. The incidence and outcomes of the disease in these racial groups were analysed. The incidence rates in non-Hispanic whites, Hispanics and APIs were 0.05, 0.18 and 0.23 per 100,000 person-years, respectively, among males; and 0.03, 0.07 and 0.10 per 100,000 person-years, respectively, among females. The overall survival (OS) at 5 years was 28.6% in non-Hispanic whites, 30.4% in Hispanic, and 24.0% in APIs. In multivariate analysis, distant versus local/regional disease (Hazard Ratio [HR]=2.01, 95% confidence interval [CI]: 1.36, 2.96), initial treatment with chemotherapy plus radiotherapy (HR=0.39, 95% CI: 0.22, 0.70) or radiotherapy alone (HR=0.48, 95% CI: 0.23, 0.99) versus no therapy were associated with OS. However, OS was not affected by age, sex, race, chemotherapy alone, socioeconomic status, or human immunodeficiency virus infection. In conclusion, ENKTL is more common and clinically more similar among Hispanics and APIs than non-Hispanic whites with poor outcome in all racial groups.

Survival following non-small cell lung cancer among Asian/Pacific Islander, Latina, and Non-Hispanic white women who have never smoked

BACKGROUND

Lung cancer is the leading cause of cancer death among U.S. Asian/Pacific Islander (API) and Latina women despite low smoking prevalence. This study examined survival patterns following non-small cell lung cancer in a population-based sample of lung cancer cases from the San Francisco Bay Area Lung Cancer Study (SFBALCS).

METHODS

Women diagnosed with lung cancer from 1998 to 2003 and 2005 to 2008 and identified through the Greater Bay Area Cancer Registry were telephone-screened for eligibility for the SFBALCS. The screener data were linked to the cancer registry data to determine follow-up. This analysis included 187 non-Hispanic (NH) white, 23 U.S.-born Latina, 32 foreign-born Latina, 30 U.S.-born API, and 190 foreign-born API never-smokers diagnosed with lung cancer and followed through 2008.

RESULTS

All-cause survival was poorer among APIs [HR=1.7 (95% CI: 1.0-2.8) among U.S.-born APIs and HR=1.2 (95% CI: 0.9-1.5) among foreign-born APIs] and Latinas [HR=2.1 (95% CI: 1.2-3.6) among U.S.-born Latinas; HR=1.4 (95% CI: 0.9-2.3) among foreign-born Latinas] relative to NH whites. These survival differences were not explained by differences in selected sociodemographic or clinical factors.

CONCLUSIONS

Further research should focus on factors such as cultural behaviors, access to or attitudes toward health care, and genetic variations as possible explanations for these striking racial/ethnic differences.

IMPACT

Latina and API female never-smokers diagnosed with lung cancer were up to two times more likely to die than NH whites, highlighting the need for additional research to identify the underlying reasons for the disparities and heightened clinical awareness.

Lifetime risks of specific breast cancer subtypes among women in four racial/ethnic groups

Introduction

Breast cancer comprises clinically distinct subtypes, but most risk statistics consider breast cancer only as a single entity. To estimate subtype-specific lifetime breast cancer risks, we took advantage of population-based data for which information regarding tumor expression of estrogen receptor (ER), progesterone receptor (PR) and HER2/neu (HER2) was newly available.

Methods

We included women whose breast cancer was diagnosed in the state of California from 2006 to 2007 and was reported to the National Cancer Institute's Surveillance, Epidemiology and End Results Program (N = 40,936). We calculated absolute lifetime and age-specific probabilities (percent, 95% confidence interval) of developing breast cancer subtypes defined by ER, PR, and HER2 status - luminal (ER and/or PR-positive, HER2-negative), HER2-positive (ER and PR-positive or negative, HER2-positive), and triple-negative (ER-negative, PR-negative, and HER2-negative) - separately for white, black, Hispanic, and Asian women.

Results

The luminal breast cancer subtype predominates across racial/ethnic groups, with lifetime risk lowest in Hispanic women (4.60%, 4.41-4.80%) and highest in white women (8.10%, 7.94-8.20%). HER2-positive breast cancer varies less by race (1.56-1.91%). Lifetime risk of triple-negative breast cancer is highest in black women (1.98%, 1.80-2.17%), compared to 0.77% (0.67-0.88%) for Asians, 1.04% (0.96-1.13%) for Hispanics and 1.25% (1.20-1.30%) for whites. Across racial/ethnic groups, nearly half of all luminal breast cancers occur after age 70.

Conclusions

These absolute risk estimates may inform health policy and resource planning across diverse populations, and can help patients and physicians weigh the probabilities of developing specific breast cancer subtypes against competing health risks.

Testing internal consistency and construct validity during evaluation of performance in a patient simulator

The primary goal of this study was to test the items in a rating system developed to evaluate anesthesiologists' performance in a simulated patient environment. A secondary goal was to determine whether the test scores could discriminate between resident and staff anesthesiologists. Two 5-item clinical scenarios included patient evaluation and induction and maintenance of anesthesia. Rating scales were no response to the problem (score = 0), compensating intervention (score = 1), and corrective treatment (score = 2). Internal consistency was estimated using Cronbach's coefficient alpha. Scores between groups were compared using the Cochran-Mantel-Haenszel test. Subjects consisted of 8 anesthesiology residents and 17 university clinical faculty. The Cronbach's coefficient alpha was 0.27 for Scenario A and 0.28 for Scenario B. Two items in each scenario markedly decreased internal consistency. When these four items were eliminated, Cronbach's coefficient alpha for the remaining six items was 0.66. Faculty anesthesiologists scored higher than residents on all six items (P < 0.001). A patient simulator-based evaluation process with acceptable reliability was developed.

IMPLICATIONS

The reliability of anesthesia clinical performance in a patient simulation environment was assessed in this study. Of 10 items, 4 were poor in the evaluation process. When these items were removed, the reliability of the instrument improved to a level consistent with other studies. Because faculty scored higher than resident anesthesiologists, the instrument also showed discriminant validity.

Testing the raters: inter-rater reliability of standardized anaesthesia simulator performance

PURPOSE

Assessment of physician performance has been a subjective process. An anaesthesia simulator could be used for a more structured and standardized evaluation but its reliability for this purpose is not known. We sought to determine if observers witnessing the same event in an anaesthesia simulator would agree on their rating of anaesthetist performance.

METHODS

The study had the approval of the research ethics board. Two one-hour clinical scenarios were developed, each containing five anaesthetic problems. For each problem, a rating scale defined the appropriate score (no response to the situation: score = 0; compensating intervention defined as physiological correction: score = 1; corrective treatment: defined as definitive therapy score = 2). Video tape recordings, for assessment of inter-rater reliability, were generated through role-playing with recording of the two scenarios three times each resulting in a total of 30 events to be evaluated. Two clinical anaesthetists, uninvolved in the development of the study and the clinical scenarios, reviewed and scored each of the 30 problems independently. The scores produced by the two observers were compared using the kappa statistic of agreement.

RESULTS

The raters were in complete agreement on 29 of the 30 items. There was excellent inter-rater reliability (= 0.96, P < 0.001).

CONCLUSIONS

The use of videotapes allowed the scenarios to be scored by reproducing the same event for each observer. There was excellent inter-rater agreement within the confines of the study. Rating of video recordings of anaesthetist performance in a simulation setting can be used for scoring of performance. The validity of the scenarios and the scoring system for assessing clinician performance have yet to be determined.

Isolation and characterization of a low-abundance splice variant from the human cytomegalovirus major immediate-early gene region

The major immediate-early (IE) gene region of human cytomegalovirus (HCMV) encodes several proteins as a result of differential RNA splicing events. By expression vector cloning of HCMV IE mRNA, we isolated and characterized a cDNA for a novel splice variant from the major IE gene region. The RNA product is a derivative of the IE55 mRNA and contains an additional splice from nucleotides 170,635 to 170,307 in the IE2 gene region (UL122), resulting in a 1.4-kb mRNA. The predicted open reading frame codes for a 164-amino-acid protein with a calculated molecular mass of 18 kDa (IE18). Mung bean nuclease analysis and PCR were used to characterize expression of IE18 mRNA in HCMV-infected cells. While the 1.4-kb mRNA was detected in infected human fibroblasts in the presence of a protein synthesis inhibitor, it was not detectable during a normal infection. However, the 1.4-kb mRNA was readily detected in infected human monocyte-derived macrophages at IE times. These results suggest that the novel IE18 mRNA exhibits cell type-specific expression indicating differential regulation of the major IE gene region in different permissive cell types.

An isoform variant of the cytomegalovirus immediate-early auto repressor functions as a transcriptional activator

The major immediate-early promoter (MIEP) of human cytomegalovirus directs the expression of several differentially spliced and polyadenylated mRNAs. These mRNAs encode nuclear phosphorproteins (IE55, IE72, and IE86), which consist of common and unique amino acid sequences. To date, very little is known of the functional role of the 55-kDa (IE55) protein. Here we present evidence that the IE55 protein is a positive activator of the MIEP. In human fibroblast cells IE55 protein activated the MIEP between 10- and 30-fold. Fusion of IE55 to the GAL4 DNA binding domain resulted in a chimeric protein capable of trans-activating a reporter with GAL4 recognition sequences. These results strongly suggest that IE55 is a bona fide transcriptional activator protein. In addition, the IE55 protein was found not to act synergistically with the IE72 activator protein. The IE55 protein shares the same amino acid sequence as IE86 except for a 154-amino-acid deletion at the C-terminal end of the protein. These proteins were functionally antagonistic; IE55 relieved repression by IE86 and, conversely, IE86 negated IE55 activation. Mutagenesis of the MIEP revealed that the target sequence for activation by IE55 is different from the IE86 autorepressive response element. These experiments suggest that the mechanism of action of the IE55 and IE86 isoforms is distinct. Moreover, from these results it is apparent that the interplay of these factors might be critical in determining the level of HCMV replication in the host.

A cluster of severe postoperative bleeding following open heart surgery

OBJECTIVE

To investigate a cluster of postoperative bleeding following open heart surgery.

DESIGN

A cohort and case/control study.

SETTING

Palo Alto Veterans Administration Medical Center, Palo Alto, California.

PARTICIPANTS

Six (21.4%) of 28 patients undergoing open heart surgery who developed severe, nonsurgical, postoperative bleeding from July 1 through August 30, 1988 (outbreak period). All case-patients had chest tube drainage of greater than or equal to 1000 ml within 4 hours of surgery but did not have identifiable bleeding vessel(s) on exploration.

RESULTS

Upon comparison of the pre-outbreak (January 1986 through June 1988) and the outbreak period, a significant increase was found in the incidence of postoperative nonsurgical bleeding (5/440 versus 6/28, p = .0006), but not of postoperative surgical bleeding (8/440 versus 0/28, p = 1.0). Of all patients undergoing open heart surgery during the outbreak period, case patients were found to be older (67.8 versus 60.6, p = .02) and to have received a larger volume of hetastarch (HES), a synthetic colloidal plasma-volume expander (mean = 19.4 ml/kg versus 14.1 ml/kg, p = .02).

CONCLUSIONS

We conclude that the use of large volumes of HES during surgery in the elderly open heart surgery patient may increase the risk for severe, nonsurgical postoperative bleeding, probably caused by alterations of the coagulation system. As the incidence of open heart surgery increases among the elderly, surgeons and anesthesiologists should be alert to possible adverse reactions from exposures not associated with adverse reactions in younger patients.

Renal function in Fischer 344 rats with chronic renal impairment after administration of enflurane and gentamicin

To assess the potential for producing nephrotoxicity in rats with abnormal renal function, the renal effects of enflurane or halothane anesthesia, 1 MAC for two hours, were examined in six groups of six Fischer 344 rats each with surgically induced chronic renal impairment. As an additional predisposing factor, gentamicin, 5 mg/kg/day, was administered for one week before and for one week after anesthesia to three of the groups, one anesthetized with enflurane, one anesthetized with halothane, and one unanesthetized. No significant change in renal function could be attributed to either anesthetic agent. Serum inorganic fluoride levels four hours and 24 hours after enflurane anesthesia were similar in the gentamicin-treated and the non-gentamicin-treated groups. Clinically small but statistically significant increases in serum creatinine concentration and urinary flow occurred in all three gentamicin-treated groups during the period of treatment. Anesthesia with either enflurane or halothane in rats with chronic renal impairment treated with gentamicin did not result in additional renal damage.