Biofilm assemblage and activity on plastic in urban streams at a continental scale: Site characteristics are more important than substrate type

The fate of plastics in rivers is a key component of the global plastic cycle. Plastics entering freshwater ecosystems are colonized by microbial biofilms, and microbe-plastic interactions can influence ecosystem processes and plastic fate. While literature examining the role of geographic region on plastic biofilms is quickly expanding, research which covers large (i.e., continental) spatial scales and includes freshwater ecosystems is warranted. In addition, most research focuses on bacterial communities, while biofilm eukaryotes are less commonly studied. We assessed biofilm metabolism and community structure on plastic (foamed polystyrene and polyvinyl chloride; PVC) and natural substrates (unglazed ceramic tile) in urban streams spanning a nested geographic gradient in the continental United States. We measured biofilm biomass, community respiration, and chlorophyll a, in addition to assessing marker gene-based community diversity of bacterial, fungal, and algal assemblages. Results demonstrated some substrate-specific trends in biofilm characteristics, including higher biofilm biomass on polystyrene across sites, and lower diversity of bacterial assemblages on both types of plastic litter versus tile. However, there were no differences among substrates for chlorophyll, respiration, and the abundance and diversity of algal and fungal assemblages. Thus, we concluded that the primary driver of biofilm metabolism and community composition were site characteristics, rather than substrate type. Additional studies are needed to quantify which site-specific characteristics drive biofilm dynamics on plastic litter in streams (e.g., water chemistry, light, seasonality, hydrology). These results add to the growing literature on the biofilm 'plastisphere' in aquatic ecosystems, demonstrating that the factors which control the assembly and activity of biofilm communities on plastic substrates (including bacteria, algal, and fungal assemblages together) in urban streams are similar to those driving biofilm dynamics on natural substrates.

O7: APPARENT PATHOLOGICAL COMPLETE RESPONSE TO NEOADJUVANT THERAPY LEADS TO SELECTION OF TREATMENT RESISTANT CANCER STEM CELLS IN OESOPHAGEAL ADENOCARCINOMA

Introduction

In oesophageal adenocarcinoma with an apparent pathological complete response (pCR) to neoadjuvant therapy (NAT) there remains debate as to whether oesophagectomy is required. Single Cell RNA sequencing (scRNAseq) enables identification and characterisation of cell populations at higher resolution than diagnostic techniques.

Method

ScRNAseq was used to determine transcriptomic profiles of cell populations in 24 OAC tumours and 13 matched normal samples. Five were also analysed using bulk RNA sequencing and high-precision mass spectrometry proteomics. Immunohistochemistry (IHC) was used to validate pCR. Paired scRNAseq analysis of pre-and post-treatment specimens from three further patients was used to compare transcriptomic profiles before and after NAT. Cancer cells (CCs) were assigned a cancer stem cell (CSC) score curated from published gene sets.

Result

We analysed a total of 22,738 single cells forming 29 different cell phenotypes. In two samples with apparent pCR, IHC staining, bulk RNA sequencing and proteomics of post-treatment samples failed to identify CCs. ScRNAseq, conversely, revealed persistent CCs (12/978 and 45/774). Transcriptomic analysis identified upregulation of stem cell markers and high CSC scores in these cells.

Conclusion

We have shown that CCs persist beneath the lower detection limit of standard approaches in apparent pCR. These cells express marker genes and expression programs consistent with CSCs. CSCs are a critical subpopulation that drive tumour initiation, growth, invasion, metastasis and resistance to therapy. These gene expression programs are not enriched in non-responders and straight to surgery samples. Oesophagus sparing treatment algorithms in pCR may subject patients to unnecessary risk of progression.

Take-home message

Cancer cells remain within tumours after apparent complete pathological response. These cells express stem cell markers associated with resistance to therapy and cancer progression.

Microplastic in riverine fish is connected to species traits

Microplastic is a contaminant of concern worldwide. Rivers are implicated as major pathways of microplastic transport to marine and lake ecosystems, and microplastic ingestion by freshwater biota is a risk associated with microplastic contamination, but there is little research on microplastic ecology within freshwater ecosystems. Microplastic uptake by fish is likely affected by environmental microplastic abundance and aspects of fish ecology, but these relationships have rarely been addressed. We measured the abundance and composition of microplastic in fish and surface waters from 3 major tributaries of Lake Michigan, USA. Microplastic was detected in fish and surface waters from all 3 sites, but there was no correlation between microplastic concentrations in fish and surface waters. Rather, there was a significant effect of functional feeding group on microplastic concentration in fish. Neogobius melanostomus (round goby, a zoobenthivore) had the highest concentration of gut microplastic (19 particles fish^-1) compared to 10 other fish taxa measured, and had a positive linear relationship between body size and number of microplastic particles. Surface water microplastic concentrations were lowest in the most northern, forested watershed, and highest in the most southern, agriculturally dominated watershed. Results suggest microplastic pollution is common in river food webs and is connected to species feeding characteristics. Future research should focus on understanding the movement of microplastic from point-source and diffuse sources and into aquatic ecosystems, which will support pollution management efforts on inland waters.

The effect of neoadjuvant chemotherapy and chemoradiotherapy on exercise capacity and outcome following upper gastrointestinal cancer surgery: an observational cohort study

Background

In 2014 approximately 21,200 patients were diagnosed with oesophageal and gastric cancer in England and Wales, of whom 37 % underwent planned curative treatments. Potentially curative surgical resection is associated with significant morbidity and mortality. For operable locally advanced disease, neoadjuvant chemotherapy (NAC) improves survival over surgery alone. However, NAC carries the risk of toxicity and is associated with a decrease in physical fitness, which may in turn influence subsequent clinical outcome. Lower levels of physical fitness are associated with worse outcome following major surgery in general and Upper Gastrointestinal Surgery (UGI) surgery in particular. Cardiopulmonary exercise testing (CPET) provides an objective assessment of physical fitness. The aim of this study is to test the hypothesis that NAC prior to upper gastrointestinal cancer surgery is associated with a decrease in physical fitness and that the magnitude of the change in physical fitness will predict mortality 1 year following surgery.

Methods

This study is a multi-centre, prospective, blinded, observational cohort study of participants with oesophageal and gastric cancer scheduled for neoadjuvant cancer treatment (chemo- and chemoradiotherapy) and surgery. The primary endpoints are physical fitness (oxygen uptake at lactate threshold measured using CPET) and 1-year mortality following surgery; secondary endpoints include post-operative morbidity (Post-Operative Morbidity Survey (POMS)) 5 days after surgery and patient related quality of life (EQ-5D-5 L).

Discussion

The principal benefits of this study, if the underlying hypothesis is correct, will be to facilitate better selection of treatments (e.g. NAC, Surgery) in patients with oesophageal or gastric cancer. It may also be possible to develop new treatments to reduce the effects of neoadjuvant cancer treatment on physical fitness. These results will contribute to the design of a large, multi-centre trial to determine whether an in-hospital exercise-training programme that increases physical fitness leads to improved overall survival.

Trial registration

ClinicalTrials.gov NCT01325883 - 29^th March 2011.

Cancer among circumpolar populations: an emerging public health concern

OBJECTIVES

To determine and compare the incidence of cancer among the 8 Arctic States and their northern regions, with special focus on 3 cross-national indigenous groups--Inuit, Athabaskan Indians and Sami.

METHODS

Data were extracted from national and regional statistical agencies and cancer registries, with direct age-standardization of rates to the world standard population. For comparison, the "world average" rates as reported in the GLOBOCAN database were used.

FINDINGS

Age-standardized incidence rates by cancer sites were computed for the 8 Arctic States and 20 of their northern regions, averaged over the decade 2000-2009. Cancer of the lung and colon/rectum in both sexes are the commonest in most populations. We combined the Inuit from Alaska, Northwest Territories, Nunavut and Greenland into a "Circumpolar Inuit" group and tracked cancer trends over four 5-year periods from 1989 to 2008. There has been marked increase in lung, colorectal and female breast cancers, while cervical cancer has declined. Compared to the GLOBOCAN world average, Inuit are at extreme high risk for lung and colorectal cancer, and also certain rare cancers such as nasopharyngeal cancer. Athabaskans (from Alaska and Northwest Territories) share some similarities with the Inuit but they are at higher risk for prostate and breast cancer relative to the world average. Among the Sami, published data from 3 cohorts in Norway, Sweden and Finland show generally lower risk of cancer than non-Sami.

CONCLUSIONS

Cancer among certain indigenous people in the Arctic is an increasing public health concern, especially lung and colorectal cancer.

Cancer disparities among Alaska native people, 1970-2011

INTRODUCTION

Cancer is the leading cause of death among Alaska Native people. The objective of this study was to examine cancer incidence data for 2007-2011, age-specific rates for a 15-year period, incidence trends for 1970-2011, and mortality trends for 1990-2011.

METHODS

US data were from the Surveillance, Epidemiology, and End Results (SEER) Program SEER*Stat database and from the SEER Alaska Native Tumor Registry. Age-adjusted cancer incidence rates among Alaska Native people and US whites were compared using rate ratios. Trend analyses were performed using the Joinpoint Regression Program. Mortality data were from National Center for Health Statistics.

RESULTS

During 2007-2011 the cancer incidence rate among Alaska Native women was 16% higher than the rate among US white women and was similar among Alaska Native men and US white men. Incidence rates among Alaska Native people exceeded rates among US whites for nasopharyngeal, stomach, colorectal, lung, and kidney cancer. A downward trend in colorectal cancer incidence among Alaska Native people occurred from 1999 to 2011. Significant declines in rates were not observed for other frequently diagnosed cancers or for all sites combined. Cancer mortality rates among Alaska Native people during 2 periods, 1990-2000 and 2001-2011, did not decline. Cancer mortality rates among Alaska Native people exceeded rates among US whites for all cancers combined; for cancers of the lung, stomach, pancreas, kidney, and cervix; and for colorectal cancer.

CONCLUSION

Increases in colorectal screening among Alaska Native people may be responsible for current declines in colorectal cancer incidence; however; improvements in treatment of colon and rectal cancers may also be contributing factors.

HPV genotypes detected in cervical cancers from Alaska Native women, 1980-2007

Background

Human papillomavirus (HPV) vaccine prevents cervical pre-cancers and cancers caused by HPV types 16 and 18. This study provides information on the HPV types detected in cervical cancers of Alaska Native (AN) women.

Methods

Cases of invasive cervical cancer diagnosed in AN women aged 18 and above between 1980 and 2007 were identified from the Alaska Native Tumor Registry. A representative formalin-fixed, paraffin-embedded archived pathology block was retrieved and serially sectioned to allow histologic confirmation of lesion (first and last sections) and PCR testing of intervening sections. Extracted DNA was tested for HPV using Linear Array HPV Genotyping Test (Roche Diagnostics) with additional INNO-LiPA HPV Genotyping Assay (Innogenetics) testing on negative or inadequate specimens. All specimens were tested for a minimum 37 HPV types.

Results

Of 62 cervical cancer specimens evaluated, 57 (91.9%) contained one or more HPV types. Thirty-eight (61.2%) cancers contained HPV types 16 or 18, and 18 (29%) contained an oncogenic type other than type 16 or 18.

Conclusions

Overall, almost two-thirds (61.2%) of the archived cervical cancers had detectible HPV types 16 or 18, a finding similar to studies of US women. As expected, a proportion of cancers would not be prevented by the current vaccines. HPV vaccination and cervical cancer screening are important prevention strategies for AN women.

A prospective comparison of totally minimally invasive versus open Ivor Lewis esophagectomy

The majority of esophagectomies in Western parts of the world are performed by a transthoracic approach reflecting the prevalence of adenocarcinoma of the lower esophagus or esophagogastric junction. Minimally invasive esophagectomy (MIE) has been reported in a variety of formats, but there are no series that directly compare totally minimally invasive thoracolaparoscopic 2 stage esophagectomy (MIE-2) with open Ivor Lewis (IVL). A prospective single-center cohort study of patients undergoing elective MIE-2 or IVL between January 2005 and November 2010 was performed. Short-term clinicopathologic outcomes were recorded using validated systems. One hundred and six patients (median age 66, range 36-85, 88 M : 18 F) underwent two-stage esophagectomy (53 MIE-2 and 53 IVL). Patient demographics (age, sex, body mass index, American Society of Anesthesiologists grade, tumor characteristics, neoadjuvant chemotherapy, and TNM stage) were comparable between the two groups. Outcomes for MIE-2 and IVL were comparable for anastomotic leak rates (5 [9%] vs. 2 [4%], P= 0.241), resection margin clearance (R0) (43 [81%] vs. 38 [72%], P= 0.253), median lymph node yield (19 vs. 18, P= 0.584), and median length of stay (12 [range 7-91] vs. 12 [range 7-101] days), respectively. Blood loss was significantly less for MIE-2 compared with IVL (median 300 [range 0-1250] mL vs. 400 [range 0-3000] mL, respectively, P= 0.021). MIE-2 in this series of selected patients supports its efficacy, when performed by an experienced minimally invasive surgical team. A well-designed multicenter trial addressing clinical effectiveness is now required.

Colorectal cancer in alaska native people, 2005-2009

BACKGROUND

Colorectal cancer (CRC) is the most frequently diagnosed cancer among Alaska Native (AN) people, and the second leading cause of cancer death. The incidence rate for the combined years 1999 through 2003 was 30% higher than the rate among U.S. whites (USWs) for the same period. Current incidence rates may serve to monitor the impact of screening programs in reducing CRC in the AN population.

METHODS

Incidence data are from the Alaska Native Tumor Registry and the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) Program. We compared AN CRC incidence, survival rates, and stage at diagnosis with rates in USWs for cases diagnosed from 2005 through 2009. Relative survival calculations were produced in SEER*Stat by the actuarial method.

RESULTS

The CRC age-adjusted incidence rate among AN men and women combined was higher than those in USW men and women (84 vs. 43/100,000; P < .05; AN:USW rate ratio [RR] = 2.0). The greatest differences between rates in AN people and USWs were for tumors in the hepatic flexure (RR = 3.1) and in the transverse (RR = 2.9) and sigmoid (RR = 2.5) regions of the colon. Rectal cancer rates among AN people were significantly higher than rates in USWs (21 vs.12/100,000). Five-year relative survival proportions by stage at diagnosis indicate that the CRC 5-year relative survival was similar in AN people and USWs for the period 2004 through 2009.

CONCLUSIONS

The high rate of CRC in AN people emphasizes the need for screening programs and interventions to reduce known modifiable risks. Research in methods to promote healthy behaviors among AN people is greatly needed.

The Alaska Education and Research Towards Health (EARTH) Study: cancer risk factors

The Alaska Education and Research Towards Health (EARTH) Study assessed cancer risk among 3,821 Alaska Native people (AN). We present the prevalence of selected cancer risk factors and comparison with Healthy People 2010 goals. Participants completed extensive computer-assisted self-administered questionnaires on diet, physical activity, tobacco and alcohol use, cancer screening, family history of cancer, and environmental exposures. Measurement data were collected on blood pressure, height, weight, waist/hip circumference, fasting serum lipids, and glucose. Cancer risk factors are high for the Alaska EARTH study population. For all risk factors studied except for vegetable consumption, Alaska EARTH Study participants did not meet Healthy People 2010 goals. This study is unique in providing questionnaire and measurement data of cancer risk factors on a larger study sample than any previous study among AN living in Alaska. Data show that the prevalence of most cancer risk factors exceeded national recommendations. Given the disease disparities that exist for the AN population, these data provide important baseline data that can be used to target health interventions and reduce health disparities.

Occurrence of pancreatic, biliary tract, and gallbladder cancers in Alaska Native people, 1973-2007

Objectives

To describe the occurrence of pancreatic, biliary tract, and gallbladder cancers within the Alaska Native (AN) population.

Study design

Population-based analysis utilizing a tumor registry and comparative population data.

Methods

Pancreaticobiliary cancers rates for AN people during 1973–2007 were determined from the Surveillance, Epidemiology, and End Results (SEER) AN Tumor Registry. Cancer incidence rates were age-adjusted to the World Standard Million and compared over 2 time periods with US white and black rates.

Results

During 1973–2007, 213 AN people developed pancreatic cancer, 73 gallbladder cancer and 61 biliary tract cancer. Pancreatic cancer occurs at similar rates in AN men and women, but data for 1993–2007 indicate that the rates among AN men may be increasing. The incidence rate in AN women (9.5/100,000) was statistically higher than in US white women (5.8/100,000). The incidence for biliary tract cancer in AN men and gallbladder cancer in AN men and women is statistically higher than that for US whites and blacks.

Conclusions

Pancreaticobiliary cancers, particularly biliary tract and gallbladder cancers, in both AN men and women and pancreatic cancer in women occur at an increased rate in AN people. Risk factors relating to the elevated rate are discussed. Certain factors are potentially modifiable, such as the use of tobacco and obesity.

Development of gap junctional intercellular communication within the lateral wall of the rat cochlea

Auditory function depends on gap junctional intercellular communication (GJIC) between fibrocytes within the cochlear spiral ligament, and basal cells and intermediate cells within stria vascularis. This communication within the lateral wall is hypothesized to support recirculation of K+ from perilymph to the intra-strial space, and thus is essential for the high [K+] measured within endolymph, and the generation of the endocochlear potential. In rats, the [K+] within endolymph reaches adult levels by postnatal day 7 (P7), several days before hearing onset, suggesting that GJIC matures before auditory responses are detectable. In this study we have mapped the postnatal development of GJIC within the cochlear lateral wall, to determine the stage at which direct communication first exists between the spiral ligament and stria vascularis. Connexin 30 immunofluorescence revealed a progressive increase of gap junction plaque numbers from P0 onwards, initially in the condensing mesenchyme behind strial marginal cells, and spreading throughout the lateral wall by P7-P8. Whole-cell patch clamp experiments revealed compartmentalized intercellular dye-coupling in the lateral wall between P2 and P5. There was extensive dye-coupling throughout the fibrocyte syncytium by P7. Also, by P7 dye introduced to fibrocytes could also be detected within strial basal cells and intermediate cells. These data suggest that lateral wall function matures several days in advance of hearing onset, and provide anatomical evidence of the existence of a putative K+ recirculation pathway within the cochlear lateral wall.

Measurements of the electric form factor of the neutron up to Q2=3.4 GeV2 using the reaction 3He(e,e'n)pp

The electric form factor of the neutron was determined from studies of the reaction 3He(e,e'n)pp in quasielastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the Q2 range over which it is known, we find G(E)(n)=0.0236±0.0017(stat)±0.0026(syst), 0.0208±0.0024±0.0019, and 0.0147±0.0020±0.0014 for Q(2)=1.72, 2.48, and 3.41 GeV2, respectively.

Primary liver cancer incidence among American Indians and Alaska Natives, US, 1999-2004

BACKGROUND

American Indians and Alaska Natives (AI/AN) experience higher morbidity and mortality from primary liver cancer than other United States (US) populations, but racial misclassification in medical records results in underestimates of disease burden.

METHODS

To reduce misclassification, National Program of Cancer Registries and Surveillance, Epidemiology, and End Results data were linked with Indian Health Service (IHS) enrollment records to compare primary liver cancer incidence and stage at diagnosis between AI/AN and non-Hispanic whites (NHW) living within the regionalized IHS Contract Health Service Delivery Area counties. Incidence rates are expressed per 100,000 persons and age-adjusted by 19 age groups to the 2000 US standard population.

RESULTS

Overall, AI/AN have a higher proportion of hepatocellular carcinoma compared with NHW, 77.8% versus 66.7%. Liver cancer incidence rates among AI/AN males and females were higher than those among NHW males and females for all regions except for the East. Among males, rates ranged from 7.3 (95% confidence interval [CI], 3.8-12.6) in the East to 17.2 (95% CI, 10.4-26.3) in Alaska. Among females, rates ranged from 3.8 (95% CI, 1.4-8.2) in the East to 6.9 (95% CI, 3.6-11.6) in Alaska. The AI/AN rates for all regions were consistently higher than the NHW rates at every age. An increasing trend among AI/AN was suggested but did not achieve statistical significance.

CONCLUSIONS

Reducing racial misclassification revealed higher disparities in primary liver cancer incidence between NHW and AI/AN populations than previously reported. Further description of the reasons for regional differences in this disparity is needed, as are programs to reduce risk factors and to diagnose primary liver cancer at earlier, more treatable stages.

Incidence of cancers of the oral cavity and pharynx among American Indians and Alaska Natives, 1999-2004

BACKGROUND

Previous studies identified disparities in incidence rates of cancers of the oral cavity and pharynx between American Indians/Alaska Natives (AI/AN) and non-Hispanic whites (NHW) and differences between various AI/AN populations. Reporting among AI/AN has been hampered by: 1) heterogeneity among various anatomic sites of oral cavity and pharyngeal cancers obscuring unique patterns of individual anatomic sites; 2) race misclassification and underreporting of AI/AN; and 3) sparseness of data needed to identify regional variations.

METHODS

To improve race classification of AI/AN, data from US central cancer registries were linked with Indian Health Service (IHS) records. AI/AN incidence data from 1999 to 2004 were stratified by sex, age, stage at diagnosis, and anatomic subsite for 6 IHS geographic regions and compared with NHW populations.

RESULTS

For all oral cavity and pharynx cancers combined, among residents of Contract Health Service Delivery Area counties, AI/AN overall had significantly lower incidence rates than NHW (8.5 vs 11.0). However, AI/AN rates were significantly higher in the Northern Plains (13.9 vs 10.5) and Alaska (16.3 vs 10.6), significantly lower in the Pacific Coast (7.7 vs 11.6) and Southwest (3.3 vs 10.4), and similar in the Southern Plains (11.4). Overall AI/AN males had higher incidence rates than AI/AN women. Nasopharyngeal cancer was more frequent (1.1AI/AN vs 0.4 NHW), and tongue cancer less frequent (1.6 AI/AN vs 2.9 NHW) in AI/AN than NHW populations; however, rates varied by region. Stage distribution was modestly less favorable for AI/AN compared with NHW populations.

CONCLUSIONS

Variation by region, anatomic site, and sex indicates a need for research into etiologic factors and attention to regional risk factor profiles when planning cancer control programs.

Cancers of the urinary tract among American Indians and Alaska Natives in the United States, 1999-2004

BACKGROUND

Assessment of the kidney parenchyma ("kidney") and urinary bladder ("bladder") cancer burden among American Indians and Alaska Natives (AI/AN) has been limited. Using a database with improved classification for AI/AN, the authors described patterns of these 2 cancers among AI/AN and non-Hispanic whites (NHW) in the United States.

METHODS

Cases diagnosed during 1999 to 2004 were identified through National Program of Cancer Registries and the Surveillance, Epidemiology and End Results program and linked to the Indian Health Service (IHS) registration records. Age-adjusted incidence rates, rate ratios (RR), annual percent change, and stage at diagnosis were stratified by IHS Contract Health Service Delivery Area (CHSDA) counties to adjust for misclassification.

RESULTS

Kidney cancer incidence among AI/AN in CHSDA counties exceeded that among NHW (RR, 1.51; 95% confidence interval [CI], 1.42-1.61), and was highest among AI/AN in the Northern Plains, Southern Plains, Alaska, and Southwest. Average annual increases were highest among AI/AN (5.9%) and NHW (5.9%) males aged 20 to 49 years, although statistically significant only among NHW. Conversely, bladder cancer incidence was significantly lower among AI/AN than NHW (RR, 0.40; 95% CI, 0.37-0.44). For both sites, AI/AN were significantly less likely to be diagnosed at an earlier stage than NHW.

CONCLUSIONS

AI/AN have about 50% greater risk of kidney cancer and half the risk of bladder cancer than NHW. Although reasons for these enigmatic patterns are not known, sustained primary prevention efforts through tobacco cessation and obesity prevention are warranted.

Disparities in cancer mortality among Alaska Native people, 1994-2003

OBJECTIVE

To provide current data on cancer mortality among Alaska Native people for the period of 1994-2003, and to identify and quantitate cancer disparities.

METHODS

Cancer mortality rates for Alaska Native (AN), U.S., White (USW) and other populations were calculated using SEERStat. Ratios of age-adjusted incidence rates with 95% confidence intervals are provided.

RESULTS

Data were from SEERStat. Age-adjusted cancern mortality rates for Alaska Native exceeded those of USW population by 20%. For specific cancer sites, rates were significantly higher among AN people: oral cavity and pharynx (RR=1.9), esophagus (RR=2.0), stomach (RR=3.9), colon and rectum (RR=1.8), liver (RR=1.9), gallbladder (RR=2.6), pancreas (RR=1.3), lung and bronchus (RR=1.2), and kidney and renal pelvis (RR=2.2). In contrast, mortality rates among AN people were significantly lower than USW rates for cancers of the prostate (RR=0.7), brain and nervous system (RR=0.3), lymphoma (RR=0.6), and leukemia (RR=0.4).

CONCLUSION

Marked disparities in cancer mortality exist among the Alaska Native population compared to the US White population. Excess mortality is documented for all sites combined and for many cancer specific sites. Rates for all cancers combined and for select sites are among the highest of any racial/ethnic group in the United States.

Women's cancers among Alaska Natives: [corrected] 1969-2003

INTRODUCTION

Alaska Native (AN) people include multiple, diverse ethnic groups whose ancestors occupied what is now the state of Alaska. Cancer incidence rates among Alaska Native women for breast, cervix, uterus and ovary are presented here. Current rates and trends over time are compared with U.S. White rates.

OBJECTIVE

To describe cancer incidence patterns for cancer of the breast, cervix, uterus and ovary among Alaska Native women.

METHODS

Cancer incidence data for Alaska Natives are from the Alaska Native Tumor Registry, in Anchorage, Alaska. Incidence rates for U.S. Whites are from the National Cancer Institute Surveillance, Epidemiology, and End Results Program.

RESULTS

Breast and cervical cancer incidence rates among Alaska Natives are similar to U.S. White rates, whereas rates for cancer of the uterus and ovary are significantly less than those of U.S. Whites. Thirty-five year trends show increasing rates in breast cancer and decreasing rates of cervical cancer.

CONCLUSION

The burden of cancer among Alaska Native women for cancers unique to women is significant. Increasing breast cancer rates among Alaska Natives has greatly contributed to this burden.

Onset of quark-hadron duality in pion electroproduction

A large data set of charged-pion (pi+/-) electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-->pion production mechanisms.

Women's cancers among Alaska Natives 1969-2003

INTRODUCTION

Alaska Native people include multiple, diverse ethnic groups whose ancestors occupied what is now the state of Alaska. Cancer incidence rates among Alaska Native women for breast, cervix, uterus and ovary are presented here. Current rates and trends over time are compared with US White rates.

OBJECTIVE

To describe cancer incidence patterns for cancer of the breast, cervix, uterus and ovary among Alaska Native women.

METHODS

Cancer incidence data for Alaska Natives are from the Alaska Native Tumor Registry, in Anchorage, Alaska. Incidence rates for US Whites are from the National Cancer Institute Surveillance, Epidemiology, and End Results Program.

RESULTS

Breast and cervical cancer incidence rates among Alaska Natives are similar to US White rates, whereas rates for cancer of the uterus and ovary are significantly less than those of US Whites. Thirty-five year trends show increasing rates in breast cancer and decreasing rates of cervical cancer.

CONCLUSION

The burden of cancer among Alaska Native women for cancers unique to women is significant. Increasing breast cancer rates among Alaska Natives has greatly contributed to this burden.

Insulin resistance and protein catabolism in non-diabetic hemodialysis patients

Chronic kidney disease (CKD) is associated with complex metabolic changes including insulin resistance. Siew et al. have highlighted an important relationship between insulin resistance and skeletal muscle protein turnover. If insulin resistance is implicated in sarcopenia of CKD, further research will be required to determine whether interventions that improve insulin sensitivity improve clinical outcomes and cardiovascular risk in CKD.

Differences in cancer incidence among Indians in Alaska and New Mexico and U.S. Whites, 1993-2002

Cancer incidence for American Indians and Alaska Natives is typically reported as a single rate for all U.S. indigenous populations combined. Previously reported combined rates suggest that American Indians and Alaska Natives have lower cancer incidence rates compared with the U.S. population. Alaska Native people comprise three major ethnic groups: Eskimo, Indian, and Aleut people. We examined cancer incidence from only Alaska Indians and compared incidence rates with an American Indian population living in New Mexico. These data indicate striking differences in cancer patterns between two American Indian populations. Cancer data for the years 1993 to 2002 for American Indians of New Mexico and U.S. Whites are from the National Cancer Institute Surveillance, Epidemiology, and End Results Program Public-use data set. Data for Alaska Indians are from the Alaska Native Tumor Registry, which is also a Surveillance Epidemiology and End Results Program participant. Overall, cancer incidence rates for all sites combined in New Mexico Indian men and women were lower than U.S. White rates, whereas Alaska Indian men and women exceeded U.S. rates. In comparing Alaska and New Mexico Indians, we observed a 2.5-fold higher incidence of cancer among Alaska Indians. The largest differences between the two Indian populations were noted primarily in cancers associated with tobacco use, including cancers of the oral cavity/pharynx, esophagus (only in men), colon and rectum, pancreas, larynx (men), lung, prostate, and urinary bladder (men). Lung cancer rates in Alaska Indian men and women were 7 and 10 times those of New Mexico Indian men and women.

Postoperative sleep disturbance in pediatric patients using patient-controlled devices (PCA)

BACKGROUND

Sleep disturbance has not been well quantified in pediatric postoperative management, yet has broad implications in pain management as well as upon the physical and psychological well-being of the young patient admitted for surgery. We aimed to describe sleep disturbance in this population using patient-controlled analgesia (PCA) and then identify the predictors of disturbed sleep.

METHODS

A retrospective audit and analysis of sleep disturbance in postoperative pediatric patients using PCA devices were performed in a postoperative surgical ward population of a major tertiary referral center. PCA presses were used as a proxy measure of sleep. The description of the sleep disturbance included an unadjusted and adjusted analysis of the proposed predictors of sleep disturbance: age, sex, nature of presentation, operation type, PCA opioid type, presence of background infusion, postoperative night number, and adjuvant medication. All data were entered into an access database developed for the audit and analyzed using stata 8.0.

RESULTS

The first 126 children prescribed PCA devices in the year 2004 were audited. One-third of patients in the population prescribed PCA experienced sleep disturbance. Observed predictors of sleep disturbance include older children (OR: 0.86, P=0.001) and those receiving a background infusion (OR: 0.19, P=0.002). Other predictors were not significant.

CONCLUSIONS

Sleep disruption is common in children-prescribed PCA opioid analgesia. Older children and those receiving a background infusion were observed to experience less sleep. Other proposed predictors were not found to be reliable. Further investigation into the predictors of disturbed sleep in the postoperative patient is warranted.

Prostate cancer in Alaska Native men, 1969-2003

OBJECTIVES

The incidence of prostate cancer differs significantly between US race groups. In prior reviews of cancer in Alaska Natives, the incidence of prostate cancer has been observed to occur at a low rate compared to US Whites and Blacks. However, a detailed report of prostate cancer in this population has not been previously published.

STUDY DESIGN

Incidence of prostate cancer in Alaska Native men was determined for the time period 1969-2003 using data from the Alaska Native Tumor Registry. The registry is a population-based registry which participates in the National Cancer Institute Surveillance, Epidemiology and End Results Program, and has collected cancer information on Alaska Natives since 1969.

METHODS

Incidence rates were calculated for all Alaska Natives and for each of the three major ethnic groups (Aleut, Eskimo, Indian). Comparisons of incidence rates between Alaska Natives and US Whites were performed using odds ratios. Temporal changes were identified by a Chi square analysis for trend.

RESULTS

During the 35-year period of review, 332 Alaska Native men were diagnosed with prostate cancer. The age-adjusted incidence rate of 69.5 per 100 000 in Alaska Native men during 1994-2003 was significantly higher than the rate of 45.5 per 100 000 for the earlier period 1969-1983. The US White rate for 1994-2002 of 169.5 per 100 000 was significantly higher than the rate for Alaska Native men for 1994-2003. Results of comparisons between Alaska Native ethnic groups for 1969-2003 showed that prostate cancer was highest in Indians and Aleuts and lowest among Eskimos.

CONCLUSIONS

Compared to the US White population, the incidence of prostate cancer in Alaska Native men is significantly lower. Prostate cancer rates among Alaska Native ethnic groups differ. The reason for these differences remains undetermined.

Occurrence of esophageal and gastric cancer in Alaska Natives, 1969-2003

BACKGROUND

Early reports of esophageal and gastric cancer in American Indians/Alaska Natives documented high rates.

METHODS

Esophageal and gastric cancers in Alaska Natives were reviewed for 1969-2003 using the Alaska Native Tumor Registry database. Alaska Native incidence rates were age-adjusted and compared to rates of several US populations.

RESULTS

The incidence of esophageal and gastric cancer has remained relatively stable during the 35-year period. Gastric cancer is higher than that seen in US Whites, Blacks and American Indians of New Mexico and similar US Asian/Pacific Islanders. Esophageal cancer incidence is higher than US Whites, Asian/Pacific Islanders and American Indians of New Mexico but similar to US Blacks.

CONCLUSION

The rates of esophageal and gastric cancer in the Alaska Native population have remained high over 35 years. While the rate of gastric cancer has declined among US Whites, a similar decline has not been seen in Alaska Natives.

Pharmacokinetics of levobupivacaine after caudal epidural administration in infants less than 3 months of age

BACKGROUND

There are few data describing levobupivacaine pharmacokinetics in infants (<3 months) after caudal administration.

METHODS

An open-label study was undertaken to examine the pharmacokinetics of levobupivacaine 2.5 mg ml(-1), 2 mg kg(-1) in children aged less than 3 months after single-shot caudal epidural administration. Plasma concentrations were determined at intervals from 0.5 to 4 h after injection. A population pharmacokinetic analysis of levobupivacaine time-concentration profiles (84 observations) from 22 infants with mean postnatal age (PNA) 2.0 (range 0.6-2.9) months was undertaken using non-linear mixed effects models (NONMEM). Time-concentration profiles were analysed using a one-compartment model with first-order input and first-order elimination. Estimates were standardized to a 70 kg adult using allometric size models.

RESULTS

Population parameter estimates (between-subject variability) for total levobupivacaine were clearance (CLt) 12.8 [coefficient of variation (CV) 50.6%] litre h(-1) 70 kg(-1), volume of distribution (Vt) 202 (CV 31.6%) litre 70 kg(-1), absorption half-life (Tabs) 0.323 (CV 18.6%) h 70 kg(-1). Estimates for the unbound drug were clearance (CLfree) 104 (CV 43.5%) litre h(-1) 70 kg(-1), volume of distribution (Vfree) 1700 (CV 44.9%) litre 70 kg(-1), absorption half-life (Tabsfree) 0.175 (CV 83.7%) h 70 kg(-1). There was no effect attributable to PNA on CL or V. Time to peak plasma concentration (Tmax) was 0.82 (CV 18%) h. Peak plasma concentration (Cmax) was 0.69 (CV 25%) microg ml(-1) for total levobupivacaine and 0.09 (CV 37%) microg ml(-1) for unbound levobupivacaine.

CONCLUSIONS

Clearance in infants is approximately half that described in adults, suggesting immaturity of P450 CYP3A4 and CYP1A2 enzyme isoforms that metabolize levobupivacaine in infants. This lower clearance delays Tmax, which was noted to occur approximately 50 min after administration of caudal epidural levobupivacaine.

Recoil polarization for delta excitation in pion electroproduction

We measured angular distributions of recoil-polarization response functions for neutral pion electroproduction for W = 1.23 GeV at Q(2) = 1.0 (GeV/c)(2), obtaining 14 separated response functions plus 2 Rosenbluth combinations; of these, 12 have been observed for the first time. Dynamical models do not describe quantities governed by imaginary parts of interference products well, indicating the need for adjusting magnitudes and phases for nonresonant amplitudes. We performed a nearly model-independent multipole analysis and obtained values for Re (S(1+)/M(1+)) = -(6.84 +/- 0.15)% and Re (E(1+)/M(1+)) = -(2.91 +/- 0.19)% that are distinctly different from those from the traditional Legendre analysis based upon M1+ dominance and ll(pi) < or = 1 truncation.

Quasielastic 3He(e,e'p)2H reaction at Q2 = 1.5 GeV2 for recoil momenta up to 1 GeV/c

We have studied the quasielastic 3He(e,e(')p)2H reaction in perpendicular coplanar kinematics, with the energy and the momentum transferred by the electron fixed at 840 MeV and 1502 MeV/c, respectively. The 3He(e,e(')p)2H cross section was measured for missing momenta up to 1000 MeV/c, while the A(TL) asymmetry was extracted for missing momenta up to 660 MeV/c. For missing momenta up to 150 MeV/c, the cross section is described by variational calculations using modern 3He wave functions. For missing momenta from 150 to 750 MeV/c, strong final-state interaction effects are observed. Near 1000 MeV/c, the experimental cross section is more than an order of magnitude larger than predicted by available theories. The A(TL) asymmetry displays characteristic features of broken factorization with a structure that is similar to that generated by available models.

Measurement of the 3He(e,e'p)pn reaction at high missing energies and momenta

Results of the Jefferson Lab Hall A quasielastic 3He(e,e'p)pn measurements are presented. These measurements were performed at fixed transferred momentum and energy, q=1502 MeV/c and omega=840 MeV, respectively, for missing momenta p(m) up to 1 GeV/c and missing energies in the continuum region, up to pion threshold; this kinematic coverage is much more extensive than that of any previous experiment. The cross section data are presented along with the effective momentum density distribution and compared to theoretical models.

Use of a laparoscopic hand-assist device for accessory splenectomy

BACKGROUND

The use of a laparoscopic hand-assist device may aid in the identification of accessory spleens (ASs) and provide similar benefits to a conventional laparoscopic procedure. A patient with previous splenectomy for immune thrombocytopenic pupusa (ITP) and recurrent thrombocytopenia is reported.

METHOD

A computed tomography scan and RBC scan identified several nodules consistent with ASs. Initial laparoscopic exploration could not identify all the ASs seen on preoperative imaging. A hand-assist device was placed and a total of five nodules of splenic tissue were identified without conversion to laparotomy.

RESULTS

The patient had a brief and uncomplicated postoperative course with a return of platelet counts to 350,000 at 1-month follow-up.

CONCLUSION

We propose that in the scenario of recurrent ITP following laparoscopic splenectomy, repeat laparoscopy is the first step once an AS is identified by preoperative imaging. If the AS is not identified at laparoscopy, the insertion of a hand-assist device is an alternative to a full laparotomy.

Wide energy-window view on the density of states and hole mobility in poly(p-phenylene vinylene)

Using an electrochemically gated transistor, we achieved controlled and reversible doping of poly(p-phenylene vinylene) in a large concentration range. Our data open a wide energy-window view on the density of states (DOS) and show, for the first time, that the core of the DOS function is Gaussian, while the low-energy tail has a more complex structure. The hole mobility increases by more than 4 orders of magnitude when the electrochemical potential is scanned through the DOS.

Measurement of the generalized polarizabilities of the proton in virtual Compton scattering at Q2=0.92 and 1.76 GeV2

We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P(LL)-P(TT)/epsilon and P(LT), and the electric and magnetic generalized polarizabilities (GPs) alpha(E)(Q2) and beta(M)(Q2) at momentum transfer Q(2)=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q2, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q2, compensated at higher Q2 by a paramagnetic contribution from piN intermediate states.

Hand-assisted laparoscopic splenectomy in the setting of splenomegaly

BACKGROUND

Hand-assisted laparoscopic surgery (HALS) devices may be well suited to splenectomy in cases of splenomegaly.

METHODS

All cases of HALS for splenectomy between 1997 and 2001 were reviewed. Patient characteristics, operative details, and morbidity and mortality were analyzed.

RESULTS

HALS for splenectomy was performed in 54 patients. A total of 39 patients with massive splenomegaly (MS) (>600 g) were identified. The average weight of the MS group was 1285 +/- 505 g. There was one (3%) conversion. Operative time was 159 +/- 65 min, estimated blood loss was 257 +/- 240 ml, and length of hospital stay was 5.4 +/- 2.9 days. Morbidity was limited to 13 patients (24%), and there were two postoperative mortalities (5.1%).

CONCLUSIONS

HALS for splenectomy in the setting of splenomegaly is feasible and safe. For the surgeon considering a laparoscopic approach in the setting of splenomegaly, a hand-assisted technique is ideally suited for removal of the enlarged spleen.

Measurements of GnE/GnM from the 2H(e-->,en-->)1H Reaction to Q2=1.45 (GeV/c)2

We report new measurements of the ratio of the electric form factor to the magnetic form factor of the neutron, G(n)(E)/G(n)(M), obtained via recoil polarimetry from the quasielastic 2H(e-->,e(')n-->)1H reaction at Q2 values of 0.45, 1.13, and 1.45 (GeV/c)(2) with relative statistical uncertainties of 7.6% and 8.4% at the two higher Q2 points, which points have never been achieved in polarization measurements.

Polarization transfer in the 4He(e-->,e'p-->)3H reaction up to Q2=2.6 (GeV/c)2

We have measured the proton recoil polarization in the 4He(e-->,e(')p-->)4H reaction at Q(2)=0.5, 1.0, 1.6, and 2.6 (GeV/c)(2). The measured ratio of polarization transfer coefficients differs from a fully relativistic calculation, favoring the inclusion of a medium modification of the proton form factors predicted by a quark-meson coupling model. In addition, the measured induced polarizations agree reasonably well with the fully relativistic calculation indicating that the treatment of final-state interactions is under control.

Laparoscopic management of complications following laparoscopic Roux-en-Y gastric bypass for morbid obesity

BACKGROUND

We reviewed our experience with complications following laparoscopic Roux-en-Y gastric bypass (LRYGB) that were managed laparoscopically.

METHODS

A total of 246 consecutive morbidly obese patients (mean body mass index, 50.9 kg/m2) underwent LRYGB by three surgeons at two institutions. All patients met National Institutes of Health criteria for surgical treatment of morbid obesity. Patients were followed prospectively.

RESULTS

A total of 62 patients (25.2%) developed 64 complications, 34 of which (13.8%) required a surgical intervention. Twenty-seven of the 34 procedures were performed laparoscopically. Gastrojejunostomy stricture was the most common complication (8.9%), followed by intestinal obstruction (7.3%) and gastrointestinal bleeding (4%). The intestinal obstruction was secondary to adhesions (n = 6), internal hernia at the level of the transverse mesocolon (n = 3), jejunojejunostomy stricture (n = 3), and cicatrix around the Roux limb at the level of the transverse mesocolon (n = 3). Other complications included gastrojejunostomy leak (1.6%), symptomatic gallstone disease (2.8%), and gastric remnant perforation (0.8%). One patient underwent a negative laparoscopy to rule out anastomotic leak. There were 3 deaths in this series of patients, 2 attributable to anastomotic leak.

CONCLUSIONS

A variety of complications can present after LRYGB. Laparoscopy is an excellent technique to treat these complications.

Possible approaches to improving the international comparability of immigration and emigration statistics: an illustration of the Canadian situation

"This article seeks to highlight the extent of the lack of standardization which exists in the field of international migration statistics and, using statistics for Canada as an example, to illustrate how significant progress towards resolving this problem could be made if sufficient numbers of countries made their immigration and emigration statistics gradually comply more fully with the United Nations recommendations."

Macroporous germanium by electrochemical deposition

Germanium is electrodeposited in a template formed from a dried suspension of silica spheres. The germanium completely fills the pores of the silica matrix. The semiconductor, as deposited, is amorphous but can be crystallized by annealing. Selective dissolution of the silica template gives a macroporous germanium-air sphere matrix, which offers interesting possibilities for photonic applications.

Staircase in the electron mobility of a ZnO quantum dot assembly due to shell filling

Electron transport in an assembly of ZnO quantum dots has been studied using an electrochemically gated transistor. The electron mobility shows a stepwise increase as a function of the electron occupation per quantum dot. When the occupation number is below two, transport occurs by tunneling between the S orbitals. Transport becomes 3 times faster when the occupation number is between two and eight; tunneling now occurs between the P orbitals. Electron transport is thus critically determined by the quantum properties of the building blocks.

Measurement of G(E(p))/G(M(p)) in e(-->)p---> e(-->)p to Q(2) = 5.6 GeV(2)

The ratio of the electric and magnetic form factors of the proton G(E(p))/G(M(p)), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic e(-->)p---> e(-->)p reaction. The new data presented span the range 3.5< Q(2)< 5.6 GeV(2) and are well described by a linear Q(2) fit. Also, the ratio sqrt[Q(2)] F(2(p))/F(1(p)) reaches a constant value above Q(2) = 2 GeV(2).

Glucocorticoid-induced hypertension: from mouse to man

1. Adrenocorticotrophic hormone (ACTH) raises blood pressure in humans, sheep, rat and mouse. In rat and humans, but not sheep, the hypertension can be explained by glucocorticoid excess. 2. In both rat and humans, the hypertension is associated with a rise in cardiac output and renal vascular resistance. 3. In both rat and humans, the nitric oxide system is implicated in glucocorticoid hypertension. 4. In both rat and humans, hypertension due to naturally occurring glucocorticoids is not prevented by drugs that block classical glucocorticoid or mineralocorticoid receptors. 5. Abnormalities in glucocorticoid metabolism may contribute to some forms of 'essential' hypertension.

Cancer incidence in Alaska Natives thirty-year report 1969-1998

The Alaska Native Tumor Registry includes data from 1969 to the present. This report provides incidence rates over the thirty year period, 1969 through 1998, and compares trends over time for Alaska Natives (AN) with those of US Whites and Blacks. To examine current rates, average annual age-adjusted incidence rates for AN for 1984-98 are compared with US Whites. Data from the registry document numerous differences in rates of occurrence of specific cancers compared to US Whites and Blacks. Studies of these differences may provide clues to the causes and risk factors for the cancers. Most importantly, these data show that although cancer was considered a rare disease in the Alaska Native population as recently as the mid-twentieth century, the incidence rate for all cancers combined among Alaska Natives is now as high as that of US Whites, and even higher in women. On the other hand, despite relative differences in rates, the most frequently diagnosed cancers among Alaska Natives are the same as US Whites. Cancers of the lung, colon/rectum, breast, and prostate are most frequently diagnosed among Alaska Natives and in the U.S. These four cancers comprise over 50% of all diagnosed invasive cancers. Cancer of the lung is almost entirely preventable by eradication of tobacco use. Screening and early detection have been proven to reduce mortality for cancers of the colon/rectum and breast. Primary and secondary prevention of these cancers could markedly improve morbidity and mortality.

Dynamics of the 16O(e, e'p) reaction at high missing energies

We measured the cross section and response functions for the quasielastic 16O(e,e'p) reaction for missing energies 25< or =E(m)< or =120 MeV at missing momenta P(m)< or =340 MeV/c. For 25<E(m)<50 MeV and P(m) approximately 60 MeV/c, the reaction is dominated by a single 1s(1/2) proton knockout. At larger P(m), the single-particle aspects are increasingly masked by more complicated processes. Calculations which include pion exchange currents, isobar currents, and short-range correlations account for the shape and the transversity, but for only half of the magnitude of the measured cross section.

Hand-assisted laparoscopic surgery in the United States: an overview

Hand-assisted laparoscopic surgery (HALS) was developed to bridge the gap between open surgery and advanced laparoscopic surgery. Advantages of the hand in the abdomen include tactile feedback, the ability to palpate, blunt dissection, organ retraction, control of bleeding, and rapid organ removal. There are 3 commercially available devices in the United States, as well as a fourth in Europe and a fifth in Japan. Uses for HALS include procedures requiring intact specimen removal, complex laparoscopic procedures, preventing open conversion, and overcoming a technical obstacle. HALS procedures, such as esophagectomy, gastrectomy, hepatectomy, pancreatectomy, splenectomy, bariatric surgery, colectomy, nephrectomy, hysterectomy, and aortobifemoral bypass, have all been reported in the literature. Improvement in instrumentation, specifically with newer generation devices, will allow HALS to become more popular. We advocate the use of HALS specifically for laparoscopic colectomy, laparoscopic splenectomy for massive splenomegaly, and for living-related donor nephrectomy.