Measurement of Electron-Neutrino Charged-Current Cross Sections on ^{127}I with the COHERENT NaIνE Detector

Using an 185-kg NaI[Tl] array, COHERENT has measured the inclusive electron-neutrino charged-current cross section on ^{127}I with pion decay-at-rest neutrinos produced by the Spallation Neutron Source at Oak Ridge National Laboratory. Iodine is one the heaviest targets for which low-energy (≤50  MeV) inelastic neutrino-nucleus processes have been measured, and this is the first measurement of its inclusive cross section. After a five-year detector exposure, COHERENT reports a flux-averaged cross section for electron neutrinos of 9.2_{-1.8}^{+2.1}×10^{-40}  cm^{2}. This corresponds to a value that is ∼41% lower than predicted using the MARLEY event generator with a measured Gamow-Teller strength distribution. In addition, the observed visible spectrum from charged-current scattering on ^{127}I has been measured between 10 and 55 MeV, and the exclusive zero-neutron and one-or-more-neutron emission cross sections are measured to be 5.2_{-3.1}^{+3.4}×10^{-40} and 2.2_{-0.5}^{+0.4}×10^{-40}  cm^{2}, respectively.

Treatment patterns for locoregional esophageal carcinoma according to race/ethnicity, histology, and insurance

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Background: Esophageal carcinoma (EC) is a disease with a poor prognosis. There has been a rise in incidence of EC in many western countries, including the United States. African Americans (AA) have a higher mortality rate from EC than any other ethnic group in the U.S. We investigated if there were differences in treatment and clinical characteristics in AA patients with locoregional EC compared to whites.

Methods: We used the National Cancer Data Base (NCDB), a national hospital-based cancer of registry to study 20,056 adults diagnosed with locoregional EC from 2004-2007. Treatment and outcome data were obtained from the NCDB. Multivariate log binomial models were used to estimate relative risk ratios (RR) and 95% confidence intervals (CI) of receiving surgery, surgery plus systemic treatment vs. surgery alone, and margin status among patients undergoing surgery.

Results: Compared to whites, AA were younger, more likely to have proximal tumors and squamous cell carcinoma, and to be uninsured. AA patients had a lower likelihood of surgery compared to whites (RR = 0.71, 95% CI = 0.66-0.77). Patients who were uninsured, Medicaid insured or younger Medicare patients had a lower likelihood of surgery. Other important predictors of surgical treatment included age, tumor location, size and histology type. Facility level factors impacted surgical treatment as well. Among patients receiving surgery, there were no differences in receipt of systemic treatment by race/ethnicity and insurance status. Younger Medicare patients and uninsured patients were more likely to have positive margins while there was no difference by race/ethnicity.

Conclusions: AA patients were less likely than whites with locoregional EC to receive surgery, however, there were no treatment disparities among AA receiving surgery. Tumor characteristics, patient, provider and/or institutional factors that may influence lower receipt of surgical treatment and survival among AA should be further explored.

No significant financial relationships to disclose.

Race, neighbourhood characteristics and disparities in chemotherapy for colorectal cancer

BACKGROUND

Studies have found significant race/ethnic and age differences in receipt of adjuvant chemotherapy for stages III colon and II/III rectal cancers. Little is known about the role of neighbourhood factors in these disparities.

METHODS

The 4748 Black and White patients from the Georgia Comprehensive Cancer Registry were diagnosed with stages III colon and II/III rectal cancers between 2000 and 2004. Neighbourhood poverty, segregation (% Black residents) and rurality were linked to each patient using census tract identifiers. Multilevel analyses explored the role of neighbourhood characteristics and the nested association of patient race within categories of neighbourhoods in receipt of chemotherapy.

RESULTS

Odds of receiving chemotherapy for urban and suburban patients were 38% (95% CI 1.09 to 1.74) and 53% (95% CI 1.20 to 1.94) higher than for rural patients. However, odds of receiving chemotherapy for urban Black patients were 24% (95% CI 0.62 to 0.94) lower than for their White counterparts. Receipt of chemotherapy did not significantly differ between Blacks and Whites residing in suburban or rural areas.

CONCLUSION

Black-White disparities in receipt of chemotherapy among Georgia colorectal cancer patients were confined to urban patients. Disparities in receipt of this treatment for rural patients were found irrespective of patient race. Our findings highlight geographic areas where targeted interventions might be needed.

Hospital characteristics associated with surgery for non-small cell lung cancer

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Background: Previous research suggests that black patients are less likely to undergo curative-intent surgery for early stage non-small cell lung cancer (NSCLC) compared to whites, holding all else constant. Among Medicare beneficiaries 65 and older, the likelihood of patients undergoing surgery is significantly reduced in hospitals with racial compositions of > 30% black patients after controlling for hospital and patient characteristics. This study analyzes whether hospital racial composition is associated with curative-intent surgery among early stage NSCLC patients of all ages. Methods: All adult patients ages 19–104 diagnosed with an invasive initial primary early stage (TNM I-II) NSCLC during 2003–2005 were selected from the National Cancer Data Base (NCDB). Facility characteristics were extracted from the NCDB and American College of Surgeons (ACoS) Commission on Cancer (CoC) Facility Information Profile System (FIPS). Hospital racial composition of lung cancer patients, operationalized as percent black, was initially divided into tertiles; sensitivity analyses used dichotomous definitions. Generalized estimating equations with a logistic model were used to control for clustering by facility. Results: Of 52,853 evaluable patients seen at CoC-approved hospitals, blacks were primarily (74%) seen at hospitals with a racial composition of > 11% black patients. Hispanics (72%), non-Hispanic whites (69%), and Asians or other (72%) were primarily seen at hospitals with < 11% black patients. In sensitivity analyses, irrespective of the cutpoint used to classify hospitals by racial composition of black patients (10, 20, or 30%), black patients seen at hospitals with a high black racial composition were significantly less likely to undergo curative-intent surgery than black patients seen at hospitals with a lower black racial composition. After controlling for patient characteristics in multivariate models, however, high black racial composition at the facility level was no longer significant. Conclusions: Hospital racial composition (% black) was not predictive of reduced likelihood of curative-intent surgery among patients > 18 years of age with NSCLC. Patient-level predictors accounted for the majority of the variation in likelihood of curative-intent surgery.

No significant financial relationships to disclose.

Increased frequency of chromosome translocations in airline pilots with long-term flying experience

BACKGROUND

Chromosome translocations are an established biomarker of cumulative exposure to external ionising radiation. Airline pilots are exposed to cosmic ionising radiation, but few flight crew studies have examined translocations in relation to flight experience.

METHODS

We determined the frequency of translocations in the peripheral blood lymphocytes of 83 airline pilots and 50 comparison subjects (mean age 47 and 46 years, respectively). Translocations were scored in an average of 1039 cell equivalents (CE) per subject using fluorescence in situ hybridisation (FISH) whole chromosome painting and expressed per 100 CE. Negative binomial regression models were used to assess the relationship between translocation frequency and exposure status and flight years, adjusting for age, diagnostic x ray procedures, and military flying.

RESULTS

There was no significant difference in the adjusted mean translocation frequency of pilots and comparison subjects (0.37 (SE 0.04) vs 0.38 (SE 0.06) translocations/100 CE, respectively). However, among pilots, the adjusted translocation frequency was significantly associated with flight years (p = 0.01) with rate ratios of 1.06 (95% CI 1.01 to 1.11) and 1.81 (95% CI 1.16 to 2.82) for a 1- and 10-year incremental increase in flight years, respectively. The adjusted rate ratio for pilots in the highest compared to the lowest quartile of flight years was 2.59 (95% CI 1.26 to 5.33).

CONCLUSIONS

Our data suggests that pilots with long-term flying experience may be exposed to biologically significant doses of ionising radiation. Epidemiological studies with longer follow-up of larger cohorts of pilots with a wide range of radiation exposure levels are needed to clarify the relationship between cosmic radiation exposure and cancer risk.

Audit of suspected chronic intestinal pseudo-obstruction in patients with gynecologic cancer

PURPOSE

To describe chronic intestinal pseudo-obstruction (IPO) syndromes that occur after radiotherapy or chemotherapy (or both) for gynecologic cancer.

METHODS

All 48 patients in the study population had a history of gynecologic cancer, treatment with radiotherapy or chemotherapy (or both), and suspected chronic IPO. The final diagnosis was based on clinical symptoms, radiographic imaging, motility studies, and surgical findings. Treatment was expectant for 27 patients and surgical for 21.

RESULTS

In six of the 21 surgical patients, the final diagnosis was mechanical obstruction. In the other 15, it was IPO syndrome: six had an idiopathic dysfunction (ID) and nine had a thick fibrinous coating (FC) on the serosal surface. Intestines of these 15 patients had patent lumens but decreased motility. The ID and FC groups differed in mean age, chemotherapy administration, and mean time from radiotherapy to surgery. Symptoms improved in 67% of FC patients compared with 17% of ID patients. Among patients treated expectantly, symptoms improved in 50% of the ID patients and in 38% of the FC patients. Motility studies were useful for distinguishing ID from FC or mechanical obstruction.

CONCLUSION

Clinical history and motility studies may assist in diagnosing IPO syndrome in gynecologic cancer patients treated with radiotherapy or chemotherapy (or both) and in identifying patients who might benefit from surgical intervention.

The Upper Midwest Health Study: A Case-Control Study of Primary Intracranial Gliomas in Farm and Rural Residents

Since several studies indicated that farmers and agricultural workers had an excess risk of brain cancer, the National Institute for Occupational Safety and Health initiated the Upper Midwest Health Study to examine risk of intracranial glioma in the non-metropolitan population. This population-based, case-control study evaluated associations between gliomas and rural and farm exposures among adults (ages 18 to 80) in four upper midwestern states (Iowa, Michigan, Minnesota, Wisconsin). At diagnosis/selection, participants lived in non-metropolitan counties where the largest population center had fewer than 250,000 residents. Cases were diagnosed 1 January 1995 through 31 January 1997. Over 90% of 873 eligible ascertained cases and over 70% of 1670 eligible controls consented to participate. Participants and nonparticipants, evaluated for "critical questions" on main and refusant questionnaires, differed significantly in farming and occupational experience, ethnicity, education, and lifestyle. The 1,175 controls were more likely than the 798 cases to have reported ever drinking alcohol (77% vs. 73%, adjusted odds ratio (OR) 0. 73, 95% confidence interval (CI) 0.59-0.92) and having had panoramic dental x-rays (34% vs. 29%, OR 0. 75, CI 0.61-0.92). Controls spent a greater percentage of their lives in non-metropolitan counties (78% vs. 75%, OR 0.81, CI 0.67-1.09). Among ever-farmers, controls were more likely to have had exposure to farm insecticides (57% vs. 50%, OR 0.75, CI 0.59-0.95) and farm animals (96% vs. 91%, OR 0.48, CI 0.25-0.90). Moving to a farm as an adolescent (ages 11 to 20) vs. as an adult was associated with a greater risk of glioma. In our study sample, farm or rural residence and summary farm exposures were associated with decreased glioma risk. However, nonparticipation by never-farming eligible controls could have affected results. Comparisons of farm chemical exposures may clarify associations between farming and glioma that others have reported.

Bacillus anthracis contamination and inhalational anthrax in a mail processing and distribution center

AIMS

Four inhalational anthrax cases occurred in a large mail processing and distribution center in Washington, DC, after envelopes containing Bacillus anthracis spores were processed. This report describes the results of sampling for B. anthracis spores during investigations conducted in October and December 2001.

METHODS AND RESULTS

Wet swabs, wet wipes, vacuum sock, and air-filter samples were collected throughout the facility to characterize the extent of building contamination. The results showed widespread contamination of B. anthracis spores, particularly associated with one delivery bar code sorter (DBCS) machine that had sorted the spore-containing envelopes and an area where the envelopes were handled by postal workers. Spore concentrations decreased as distance from the DBCS machine increased, but spores were widely dispersed into surrounding areas.

CONCLUSION

The spatial distribution of culture positive samples was closely related to the work areas of the inhalational anthrax cases and supported epidemiological evidence that the workers became ill from exposure to B. anthracis spores in areas where the contaminated envelopes had travelled.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this investigation were used to guide decontamination efforts and provided baseline spore concentrations for follow-up measurements after the building had been cleaned. Implementing methods to reduce aerosolization and dispersion of dust within the facility would reduce postal workers' potential exposures to bioterrorism agents.

Successful oesophageal pH monitoring with a catheter-free system

BACKGROUND

Traditional catheter-based oesophageal pH testing is limited by patient discomfort and the tendency for patients to alter their diet and activities during the study. A catheter-free pH monitoring system (Bravo) designed to avoid these problems has recently become available, but the advantages and limitations of this device have not been fully explored.

AIM

To report our initial experience with this new technology.

METHODS

The records of consecutive patients undergoing Bravo pH monitoring were reviewed. The squamo-columnar junction was localized endoscopically and the pH capsule was placed 6 cm above this junction. All patients were re-endoscoped immediately following placement to document mucosal attachment. Patients were monitored for 24-48 h and then returned the radiotelemetry recording device. Data were subsequently downloaded to a personal computer.

RESULTS

Sixty studies were performed over an 11-month period. In seven of the 60 (12%), the probe did not attach properly, but in six of these a replacement probe was prepared and deployed without difficulty. In one case, the probe could not be attached after two attempts and the procedure was abandoned. During one procedure, the probe was attached to the mucosa at a point 9 cm from the squamo-columnar junction, but a positive test result was obtained. In two cases, the data were not initially retrievable from the recorder, but in one case the manufacturer was able to retrieve the data overnight. Finally, two patients were away from the data recorder for extended periods, resulting in a loss of data, in two cases, but there was sufficient information for interpretation in both studies. Therefore, adequate diagnostic data were obtained in 58 of the 60 (97%) studies.

CONCLUSIONS

Catheter-free pH testing is a major advance in patient convenience and comfort. The technical difficulties associated with this new technology are minimal and appear to be no more frequent than those seen with catheter-based systems.

Mortality among a cohort of uranium mill workers: an update

AIMS

To evaluate the mortality experience of 1484 men employed in seven uranium mills in the Colorado Plateau for at least one year on or after 1 January 1940.

METHODS

Vital status was updated through 1998, and life table analyses were conducted.

RESULTS

Mortality from all causes and all cancers was less than expected based on US mortality rates. A statistically significant increase in non-malignant respiratory disease mortality and non-significant increases in mortality from lymphatic and haematopoietic malignancies other than leukaemia, lung cancer, and chronic renal disease were observed. The excess in lymphatic and haematopoietic cancer mortality was due to an increase in mortality from lymphosarcoma and reticulosarcoma and Hodgkin's disease. Within the category of non-malignant respiratory disease, mortality from emphysema and pneumoconioses and other respiratory disease was increased. Mortality from lung cancer and emphysema was higher among workers hired prior to 1955 when exposures to uranium, silica, and vanadium were presumably higher. Mortality from these causes of death did not increase with employment duration.

CONCLUSIONS

Although the observed excesses were consistent with our a priori hypotheses, positive trends with employment duration were not observed. Limitations included the small cohort size and limited power to detect a moderately increased risk for some outcomes of interest, the inability to estimate individual exposures, and the lack of smoking data. Because of these limitations, firm conclusions about the relation of the observed excesses in mortality and mill exposures are not possible.

Prevalence of respiratory symptoms among female flight attendants and teachers

BACKGROUND

Potential health effects of the indoor environment in office buildings and aircraft have generated considerable concern in recent years.

AIMS

To analyse the prevalence of self reported respiratory symptoms and illnesses in flight attendants (FAs) and schoolteachers.

METHODS

Data were collected as part of a study of reproductive health among female FAs. The prevalences of work related eye, nose, and throat symptoms, wheezing, physician diagnosed asthma, chest illness, and cold or flu were calculated and stratified by smoking status in 1824 FAs and 331 schoolteachers.

RESULTS

FAs and teachers were significantly more likely to report work related eye (12.4% and 7.4 %, respectively), nose (15.7% and 8.1%), and throat symptoms (7.5% and 5.7%) than were other working women (2.9% eye, 2.7% nose, and 1.3% throat symptoms). FAs were significantly more likely than teachers and referent working women to report chest illness during the prior three years (32.9%, 19.3%, 7.2%, respectively). Both study groups were more likely to report five or more episodes of cold or flu in the past year than were other working women (10.2% of FAs, 8.2% of teachers, 2.3% of referents), and both groups were more likely to report wheezing than other working women (22.8% of FAs, 28.4% of teachers, 16.4% of referents). FAs were significantly less likely than teachers and other working women to report ever having been diagnosed with asthma (8.2%, 13.3%, 11.8%, respectively).

CONCLUSIONS

Overall, FAs and schoolteachers report a higher prevalence of work related upper respiratory symptoms, chest illness, and cold or flu than the general working population.

Painless pancreatitis after implantation of a biventricular assistive device

This young cardiac transplant patient developed painless acute pancreatitis within 10 days of implantation of a biventricular assist device (BIVAD). Historical, physical, laboratory, and imaging data allowed conservative management leading to a favorable outcome. Acute pancreatitis after cardiac transplantation is common with a significant mortality rate. Immunosuppression may play an important role in this process as well as infectious and pancreaticobiliary etiologies. Whereas acute pancreatitis is a well-documented complication of cardiac transplantation, this event has not previously been reported in patients who have received a BIVAD. The mechanism by which BIVAD placement may result in pancreatitis is unknown.

Review article: the non-inherited gastrointestinal polyposis syndromes

The non-inherited gastrointestinal polyposis syndromes represent a group of rare disorders characterized by the presence of multiple, non-adenomatous polyps on the gastrointestinal mucosa occurring in unrelated patients. We present here a review of the clinical and histo- pathological aspects of the syndromes to include the Cronkhite-Canada syndrome, hyperplastic polyposis and lipomatous polyposis. While infrequently encountered, these diseases can have devastating clinical effects that may be aggravated by delays in diagnosis and treatment. Prompt accurate diagnosis and treatment of these uncommon disorders depend on a sound working knowledge of the distinct clinical and pathological features described herein.

Benefits and safety of CT fluoroscopy in interventional radiologic procedures

PURPOSE

To determine the benefits and safety of computed tomographic (CT) fluoroscopy when compared with conventional CT for the guidance of interventional radiologic procedures.

MATERIALS AND METHODS

Data on 203 consecutive percutaneous interventional procedures performed with use of CT fluoroscopic guidance and 99 consecutive procedures with conventional CT guidance were obtained from a questionnaire completed by the radiologists and CT technologists who performed the procedures. The questionnaire specifically addressed radiation dose measurements to patients and personnel, total procedure time, total CT fluoroscopy time, mode of CT fluoroscopic guidance (continuous versus intermittent), success of procedure, major complications, type of procedure (biopsy, aspiration, or drainage), site of procedure, and level of operator experience.

RESULTS

The median calculated patient absorbed dose per procedure and the median procedure time with CT fluoroscopy were 94% less and 32% less, respectively, than those measurements with conventional CT scanning (P <.05). An intermittent mode of image acquisition was used in 97% of the 203 cases. This resulted in personnel radiation dosimetric readings below measurable levels in all cases.

CONCLUSION

As implemented at the authors' institution, use of CT fluoroscopy for the guidance of interventional radiologic procedures markedly decreased patient radiation dose and total procedure time compared with use of conventional CT guidance.

Hemoglobin adducts and sister chromatid exchanges in hospital workers exposed to ethylene oxide: effects of glutathione S-transferase T1 and M1 genotypes

Ethylene oxide (EtO) is a genotoxic carcinogen with widespread uses as an industrial chemical intermediate and sterilant. We examined the effects of glutathione S-transferase T1 (GSTT1) and M1 (GSTM1) genotypes on the levels of N-(2-hydroxyethyl)valine (HEV) adducts in the erythrocytes and sister chromatid exchange (SCE) in lymphocytes from a group of 58 operators of sterilizers that used EtO and nonexposed workers from nine hospitals in the United States and one hospital in Mexico City. Cumulative exposure to EtO was estimated during the 4-month period before the collection of blood samples. Results showed that EtO exposure was significantly associated with the levels of HEV adducts and SCE after adjusting for cigarette smoking and other potential confounders. A significantly higher HEV adduct level (0.17 +/- 0.03 versus 0.08 +/- 0.01, mean +/- SE; P = 0.02) but lower SCE frequency (5.31 +/- 0.39 versus 6.21 +/- 0.17; P = 0.04) was observed in subjects with homozygous deletion of the GSTT1 gene (null genotype) as compared with those with at least one copy of the gene (positive genotype). In multiple regression analysis, the GSTT1-null genotype was associated with an increase in HEV adduct level (beta = 1.62; P = 0.02) and a decrease in SCE frequency (beta = -1.25; P = 0.003) after adjusting for age, gender, race, education, cigarette smoking, and EtO exposure status. The inverse SCE-GSTT1 relationship remained unchanged when SCE was further examined in relation to HEV adducts as an indicator of the internal EtO dose. The GSTM1 genotype was not associated with the level of either HEV adduct or SCE. These data indicate that the GSTT1-null genotype is associated with increased formation of EtO-hemoglobin adducts in relation to occupational EtO exposure, suggesting that individuals with homozygous deletion of the GSTT1 gene may be more susceptible to the genotoxic effects of ETO: The unexpected finding of decreased SCEs, which is less clear, may be attributed to the nonchemical specificity of this end point and the lack of expression of the GSTT1 enzyme in lymphocytes.

Estimating historical exposures of workers in a beryllium manufacturing plant

BACKGROUND

Beryllium is known to be toxic to the lungs, causing beryllium lung disease and associated with increased lung cancer risk. Airborne beryllium exposures have been monitored since the 1940s. This study describes methods used to measure airborne beryllium concentrations and how historical measurements from a beryllium manufacturing plant were used to estimate workers' exposures in a lung cancer case-control study.

METHODS

Airborne beryllium concentrations had been measured using all-glass impingers, high-volume air filters, and personal respirable and total dust samplers. To provide consistency in exposure estimates over time, measurements collected by the other monitoring methods were converted to approximate the most frequently used high-volume, time-weighted average measurements. Because industrial hygiene measurements were not collected in every year for all jobs throughout the duration of the case-control study, exposure estimates had to be extrapolated from the existing measurements over time and across jobs.

RESULTS

Over 7,000 historical measurements were available to estimate beryllium exposures of workers over time. Average exposures between jobs varied considerably and exposures for all jobs decreased dramatically between the 1940s and 1970s due to major plant production changes.

CONCLUSIONS

Although error in the exposure metrics for the cases and controls likely occurred due to limitations of the exposure assessment data, the exposure estimates for each job over time provided a reasonable, objective mechanism for categorizing workers by the relative exposures they were likely to have encountered during their tenure. Published 2001 Wiley-Liss, Inc.

Mortality in dry-cleaning workers: an update

BACKGROUND

A cohort of 1,708 dry-cleaning workers identified from union records was exposed to perchloroethylene (PCE), a known animal carcinogen and probable human carcinogen, for at least 1 year before 1960. Many workers also had exposure to Stoddard solvent, a petroleum-based dry-cleaning solvent.

METHODS

Vital status was updated through 1996 and life table analyses conducted.

RESULTS

The cohort had excess cancer mortality (271 deaths, standardized mortality ratio [SMR] 1.25, 95% confidence interval [CI] 1.11-1.41). Elevated SMRs for tongue, bladder, esophagus, intestine, lung, and cervical cancer, pneumonia, and diseases of the stomach and duodenum were statistically significant.

CONCLUSION

The current study confirms findings of prior updates and other studies that dry-cleaning workers have excess cancer mortality at several sites. Although important lifestyle and socioeconomic risk factors exist for both cervical and esophageal cancer mortality, excesses of these sites in the PCE only subcohort and among workers with longer duration of PCE exposure suggest an association with PCE exposure.

Lung cancer case-control study of beryllium workers

BACKGROUND

Cohort mortality studies have found elevated lung cancer mortality among beryllium-exposed workers, but none evaluated the association between beryllium exposure level and lung cancer risk. A nested case-control study of lung cancer within a beryllium processing plant was conducted to investigate the relationship between level of beryllium exposure and lung cancer.

METHODS

Lung cancer cases were identified by mortality follow-up through 1992 of a cohort of male workers at a beryllium alloy production plant. Each of 142 lung cancer cases was age-race-matched to five controls. Calendar-time-specific beryllium exposure estimates were made for every job in the plant and were used to estimate workers' cumulative, average, and maximum exposures. The potential confounding effects of smoking were also evaluated.

RESULTS

Lung cancer cases had shorter tenures and lower lifetime cumulative beryllium exposures than controls, but higher average and maximum exposures. However, after applying a 10- and 20-year lag, exposure metrics were higher for cases. Odds ratios in analyses lagged 20 years were significantly elevated for those with higher exposure compared to the lowest exposure category. Significant positive trends were seen with the log of the exposure metrics. Smoking did not appear to confound exposure-response analyses.

CONCLUSION

Increased lung cancer among workers with higher lagged beryllium exposures and lack of evidence for confounding by cigarette smoking, provide further evidence that beryllium is a human lung carcinogen. Published 2001 Wiley-Liss, Inc.

Serum organochlorine levels and breast cancer: a nested case-control study of Norwegian women

This study investigated the potential association between organochlorine exposure and breast cancer using stored sera collected from 1973 through 1991 from the Janus Serum Bank in Norway. Breast cancer cases were ascertained prospectively from among 25,431 female serum bank donors. A total of 150 controls were matched to cases by birth dates and dates of sample collection. One g of serum per subject was analyzed for a total of 71 organochlorine compounds. For 6 pesticides [B-hexachlorocyclohexane, heptachlor epoxide, oxychlordane, trans-nonachlor, p, p'-1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene, and p, p'-2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane] and 26 individual polychlorinated biphenyl (PCB) congeners there were >90% of samples over the limit of detection. There was no evidence for higher mean serum levels among cases for any of these compounds, nor any trend of increasing risk associated with higher quartiles of exposure. The remaining compounds (including dieldrin) were analyzed with respect to the proportion of cancer cases and controls having detectable levels; no positive associations were noted in these analyses. Our study did not confirm the recent findings of a Danish study of increased concentrations of dieldrin in the serum of breast cancer cases. The evidence to date on the association between serum organochlorines is not entirely consistent, but there is accumulating evidence that serum levels of p, p'-1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene and total PCBs are not important predictors for breast cancer in the general population. Studies to date have not been able to evaluate whether exposure to highly estrogenic, short-lived PCB congeners increases breast cancer risk, nor have they fully evaluated the risk associated with organochlorine exposure in susceptible subgroups or at levels above general population exposure, including women with occupational exposure.

Mortality among rubber chemical manufacturing workers

BACKGROUND

A retrospective cohort mortality study evaluated ischemic heart disease (IHD) among workers in the "rubber chemicals" manufacturing department of a Western New York plant. A previous study at the plant found elevated chest pain and angina among workers in this department.

METHODS

Mortality experience of workers employed from 1946-1988 was followed through December 31, 1994. Mortality was compared to U.S. population rates and to local Niagara county rates by using the NIOSH life table analysis system. Poisson regression was used to examine patterns of IHD within the cohort.

RESULTS

The standardized mortality ratio (SMR) for IHD among workers in the rubber chemicals department was 1.51 (U.S. rates) and 1.19 (Niagara county rates). Increased mortality from IHD in the rubber chemicals department was most pronounced at younger ages (< 50, SMR = 2.4); workers in a second chemical production department also had an elevated (but not statistically significant) SMR of 1.5 for IHD.

CONCLUSIONS

IHD mortality among workers in the rubber chemicals department was elevated, particularly among those under 50 years of age. Potential occupational risk factors for IHD include the rotating shift pattern for employees assigned to two chemical production departments and chemical exposures present in the rubber chemicals department.

Ethical issues in the use of genetic markers in occupational epidemiologic research

This review was conducted to characterize the nature of contemporary occupational epidemiologic research involving genetic markers, consider how genetic information is unique with regard to its social applications, and examine some of the ethical dilemmas that may arise over the course of studies. We have reviewed the literature and the lessons from our experience in conducting occupational epidemiologic research involving genetic markers. This review describes how occupational epidemiologic studies differ from other epidemiologic studies on issues of participation, confidentiality, and the history of including genetic markers. Of primary concern in occupational studies are genes that have multiple alleles and are sometimes referred to as "metabolic polymorphisms." They generally do not confer risk on their own but rather only in combination with a specific exposure. There is a need for a clear policy and guidelines for the conduct of occupational epidemiologic studies using genetic material. This policy should address all of the steps in study design, implementation, interpretation, and communication of results.

Underlying and multiple cause mortality in a cohort of workers exposed to aromatic amines

BACKGROUND

The National Institute for Occupational Safety and Health (NIOSH) has previously conducted studies of bladder cancer incidence and mortality at a synthetic dye plant that manufactured beta-naphthylamine from 1940 through 1979. This report extends the period of mortality follow-up 13 years and analyzes both underlying and nonunderlying causes of death.

METHODS

The vital status of each cohort member, as of December 31, 1992, was determined by using the National Death Index and information from the Internal Revenue Service and the U.S. Postal Service. The NIOSH life table analysis system (LTAS) was used to generate person-year-at-risk and the expected numbers of death for 92 categories of death, using several referent rates (U.S. underlying, Georgia underlying, U.S. multiple cause).

RESULTS

There were three bladder cancer deaths listed as underlying cause, yielding a standardized mortality ratio (SMR) based on U.S. rates of 2.4 (95% confidence interval (CI) = 0.5, 7.0) and a total of eight bladder cancers listed anywhere on the death certificates (SMR based on multiple cause referent rates = 5.6; 95% CI = 2.4, 11.1). Mortality from esophageal cancer, which had been significantly elevated in the previous study, was no longer significantly elevated (SMR = 2.0; 95% CI = 0.8, 4.1). Mortality from all causes was significantly higher than expected (SMR = 1.5; 95% CI = 1.3, 1.6).

CONCLUSIONS

The elevated bladder cancer risk in this cohort was detected by the multiple cause, but not the underlying cause, analysis. Elevated mortality from other causes of death, especially among short-term workers, may be related to regional and lifestyle factors.

Immunologic findings among lead-exposed workers

A comprehensive panel of immune parameters was evaluated among 145 lead-exposed workers with a median blood lead level (BLL) of 39 micrograms/dL (range: 15-55 micrograms/dL) and 84 unexposed workers. After adjusting for covariates, we found no major differences in the percentage of CD3+ cells, CD4+ T cells, CD8+ T cells, B cells, or NK cells between lead-exposed and unexposed workers, although the association between lead exposure and the number of CD4+ T cells was modified by age. We also found no differences between exposed and unexposed workers in serum immunoglobulin levels, salivary IgA, C3 complement levels, or lymphoproliferative responses. However, among exposed workers, the percentage and number of B cells were positively associated with current BLL, serum IgG was negatively associated with cumulative lead exposure, and the percentage and number of CD4+/CD45RA+ cells were positively associated with cumulative lead exposure. We found no evidence of a marked immunotoxic effect of lead at the exposure levels studied, although some subtle differences in immunologic parameters were noted.

Industries and cancer

Epidemiologic evidence on the relationship between selected industries and cancer is reviewed. This article will focus on several industries which have not been covered elsewhere in this volume, briefly describe current research on cancer in the agricultural and construction industries, and discuss surveillance data on cancer mortality in relation to industry listed on US death certificates. Employment in the rubber industry has been associated with bladder cancer, leukemia, stomach, and lung cancer and is considered by the International Agency for Research on Cancer (IARC) to have 'sufficient evidence of carcinogenicity in humans.' Studies of workers exposed to polychlorinated biphenyls (PCBs) have reported excess mortality from gastrointestinal neoplasms, hematologic neoplasms, and skin cancer (specifically malignant melanoma); IARC considers that the evidence for carcinogenicity in humans is 'limited.' Employment in the boot and shoe industry has been associated with nasal adenocarcinomas in England and Italy ('sufficient'). Hairdressers and barbers have been found to have excess bladder cancer and less consistent evidence for several other sites ('limited'). Workers exposed to wood dust have excess mortality from cancer of the nasal sinuses and paranasal cavities; there is less consistent evidence for excess laryngeal cancer ('sufficient'). Workers employed in the petroleum industry have limited evidence for excess leukemia and other lymphatic and hematopoietic neoplasms, and skin cancer (particularly malignant melanoma) ('limited').

Mortality study of workers employed in 1,3-butadiene production units identified from a large chemical workers cohort

The IARC has given the designations of "sufficient evidence" of carcinogenicity of 1,3-butadiene in experimental animals and "limited evidence" of carcinogenicity in humans. To investigate the carcinogenic effect in humans, a cohort mortality study was conducted among 364 men who were assigned to any of three 1,3-butadiene production units located within several chemical plants in the Kanawha Valley of West Virginia, including 277 men employed in a U.S. Rubber Reserve Plant which operated during World War II. The butadiene production units included in this study were selected from an index developed by the Union Carbide Corporation which listed for each chemical production unit within their South Charleston and Institute plants all products, by-products and reactants. Departments included in the study were those where butadiene was a primary product and neither benzene nor ethylene oxide was present. A total of 185 deaths were observed; the standardized mortality ratio (SMR) for all causes of death was 91, reflecting lower mortality among the study population than the U.S. population. The study found a significantly elevated standardized mortality ratio (SMR) for lymphosarcoma and reticulosarcoma based on four observed cases (SMR = 577; 95% confidence interval (CI) = 157-1480), which persisted in an analysis using county referent rates. An excess of lymphosarcoma and reticulosarcoma among all workers and among workers with routine exposure to 1,3-butadiene was also observed in the only other cohort of 1,3-butadiene production workers previously studied. A statistically non-significant excess of stomach cancer was observed in the overall cohort (five cases; SMR = 243; CI = 79-568) that was most pronounced among workers employed in the Rubber Reserve plant for 2 or more years (five cases; SMR = 657; CI = 213-1530). We conclude that the results of this study add to the weight of evidence suggesting that butadiene is carcinogenic in humans.

Monitoring of aromatic amine exposures in workers at a chemical plant with a known bladder cancer excess

BACKGROUND

In April 1991, an excess of bladder cancer cases among workers employed at a chemical manufacturing facility in Niagara Falls, NY, was reported. This excess was primarily confined to 708 workers who had ever been employed in the rubber chemicals manufacturing area of the plant, where the aromatic amines aniline and o-toluidine have historically been used.

PURPOSE

An environmental and biological monitoring survey was conducted to evaluate current exposures to aniline and o-toluidine in the rubber chemicals department.

METHODS

Personal air sampling for aniline and o-toluidine was conducted with the use of a modified Occupational Safety and Health Administration (OSHA) 73 method. Urine samples were collected before and after work (i.e., pre-shift and post-shift, respectively) and stored at -70 degrees C. Base hydrolysis was used to convert acetanilide and N-acetyl-o-toluidine, metabolites of aniline and o-toluidine present in the urine, to the parent compounds. The parent compounds were extracted from the alkaline urine into butyl chloride and then back-extracted from the butyl chloride into aqueous hydrochloric acid. An aliquot of each acidic extract was subjected to ion-interaction reversed-phase liquid chromatography with coulometric electrochemical detection. Hemoglobin (Hb) was extracted from blood and stored at -70 degrees C. For the measurement of adducts of aniline, o-toluidine, and 4-aminobiphenyl (4-ABP), precipitated Hb was dissolved in 0.1 M sodium hydroxide in the presence of recovery standards, and the hydrolysate was extracted with hexane, derivatized with pentafluoropropionic anhydride, and analyzed by gas chromatography-mass spectrometry with negative chemical ionization.

RESULTS

A total of 73 workers, including 46 of 64 exposed workers who were employed in the rubber chemicals department and had the potential for exposure to aniline and o-toluidine and 27 of 52 unexposed workers employed in other departments where aniline and o-toluidine were not used or produced, had data available for both aniline and o-toluidine and Hb adducts; 28 of the workers in the former group also had personal air-sampling data. Personal air sample measurements showed that airborne concentrations of aniline and o-toluidine were well within the limits allowed in the workplace by OSHA. Urinary aniline and o-toluidine levels, however, were substantially higher among exposed workers than among unexposed control subjects. The most striking differential was for post-shift urinary o-toluidine levels, which averaged (+/- standard deviation) 2.8 micrograms/L (+/- 1.4 micrograms/L) in unexposed subjects and 98.7 micrograms/L (+/- 119.4 micrograms/L) in exposed subjects (P = .0001). Average aniline-Hb and o-toluidine-Hb adduct levels were also significantly higher (P = .0001) among exposed workers than among unexposed control subjects. Average levels of adducts to 4-ABP, a potential contaminant of process chemicals, were not significantly different (P = .48), although three exposed workers had 4-ABP levels above the range in unexposed workers.

CONCLUSIONS

The adduct data suggest that, among current workers, o-toluidine exposure substantially exceeds aniline exposure and that 4-ABP exposure, if it occurs at all, is not widespread. These data support the conclusion that occupational exposure to o-toluidine is the most likely causal agent of the bladder cancer excess observed among workers in the rubber chemicals department of the plant under study, although exposures to aniline and 4-ABP cannot be ruled out.

Acute and chronic liver toxicity resulting from exposure to chlorinated naphthalenes at a cable manufacturing plant during World War II

Historical records were used to reconstruct an outbreak of chlorance and acute liver toxicity due to chlorinated naphthalene exposure at a New York State plant which manufactured "Navy cables" during World War II. A cohort mortality study was conducted of the population (n = 9,028) employed at the plant from 1940 to 1944. Vital status was followed through December 31, 1985. The study found an excess of deaths from cirrhosis of the liver [observed (OBS) = 150; standardized mortality ratio (SMR) = 1.84; 95% confidence interval (CI) = 1.56-2.16]; cirrhosis deaths were elevated to a similar degree in the 460 individuals who had chlorance (OBS = 8; SMR = 1.51; CI = 0.65-2.98). The SMR for "non-alcoholic cirrhosis" (OBS = 83; SMR = 1.67; CI = 1.33-2.07) was similar to the SMR for "alcoholic cirrhosis" (OBS = 59; SMR = 1.96; CI = 1.49-2.53). There was no evidence for increased alcoholism in the overall cohort based on mortality from alcohol-related causes of death other than cirrhosis (SMR for esophageal cancer = 1.01 and for deaths from alcoholism = 0.99). We conclude that the excess mortality from cirrhosis of the liver observed in this cohort is due to the chronic effect of chlorinated naphthalene exposure.

Barium enema: detection of colonic lesions in a community population

OBJECTIVE

The purposes of this study were to assess the prevalence of colonic lesions detected at barium enema in a community practice, to compare the findings at barium enema between patients who are asymptomatic and have no known risk factors for colorectal cancer (screening group) and patients who have symptoms of colonic disease or have known risk factors, and to determine if a questionnaire about symptoms and risk factors is an appropriate screening tool.

SUBJECTS AND METHODS

A self-administered questionnaire about colorectal symptoms and risk factors was given to 1779 patients scheduled for barium enema examination. On the basis of their responses, patients were divided into three groups: screening group (asymptomatic, without risk factors), symptomatic, and asymptomatic with risk factors. Each patient underwent a fluoroscopic barium enema. We then compared the results (number, histologic type, size of lesion(s), location in the colon, and Patient's age) and risk factors among the three groups.

RESULTS

At least one lesion within the colorectum was found in 166 (9%) of 1779 patients at combined proctosigmoidoscopy and barium enema. The prevalence of lesions in the 111 patients with at least one lesion above the rectum at barium enema was 4% (32 of 738) for the screening group, 8% (38 of 476) for asymptomatic patients with risk factors, and 7% (41 of 565) for symptomatic patients (p = .015 when comparing the prevalence in the screening group with the prevalences in the other two groups). Twenty-nine percent of all colonic lesions were found in the screening group. Among the asymptomatic patients, risk factors that included a history of colorectal polyps and advanced age were associated with a significantly higher prevalence of colonic polyps found at barium enema. In the symptomatic group, if patients with histories of polyps were excluded, we were unable to identify other risk factors that led to a significantly higher prevalence of polyps.

CONCLUSION

Asymptomatic patients without known risk factors have a significantly lower prevalence of colonic polyps than either symptomatic patients or patients with risk factors alone. Despite this lower prevalence, 29% of all lesions in our series were in the screening group. Assessment of risk factors through a patient questionnaire was not helpful in identifying a group of patients with a higher prevalence of lesions--except for a history of polyps. Management decisions based on a patient questionnaire should be approached with caution. When low-risk patients are denied screening examinations, a significant number of lesions will be missed.

Single-pass CT of hepatic tumors: value of globular enhancement in distinguishing hemangiomas from hypervascular metastases

OBJECTIVE

The purpose of this study was to evaluate the sensitivity and specificity of globular enhancement for differentiating hepatic hemangiomas from hypervascular metastases on single-pass, contrast-enhanced CT scans. Globular enhancement was defined as enhancing nodules less than 1 cm seen within a lesion.

MATERIALS AND METHODS

Fifty CT examinations were retrospectively evaluated in a blinded fashion by two independent reviewers. The CT studies were done with nonhelical technique after the IV injection of 150 ml of contrast material. The series included 25 patients with histologically proven hypervascular hepatic metastases (carcinoid, islet cell carcinoma, and leiomyosarcoma) and 25 patients with clinically proven hepatic hemangiomas. Patients with hemangiomas were clinically stable for at least 2 years after the CT studies. A single lesion was isolated from the first-pass, contrast-enhanced portion of each examination; the remainder of the examination was excluded from the review to minimize reviewer bias. Each lesion was evaluated for (1) the presence or absence of globular enhancement (defined as enhancing nodules less than 1 cm seen within a lesion), (2) the density of globular enhancement relative to that of the aorta, (3) the degree of border definition (well or poorly marginated), and (4) the presence or absence of a hypodense halo. A diagnostic impression was then recorded for each lesion.

RESULTS

Globular enhancement was 88% sensitive and 84-100% specific for differentiating hepatic hemangiomas from hypervascular metastases (p < .001). A mean of 62% of hemangiomas showed globular enhancement isodense relative to that of the aorta; none of the metastases showed globular, isodense enhancement. The majority of the metastases showed nonglobular enhancement (mean, 92%). The reviewers showed 84% agreement in the identification of (1) globular enhancement in hemangiomas, (2) lack of globular enhancement in metastases, and (3) globular enhancement in the combined set of all lesions. Neither the presence of a hypodense halo nor the degree of border definition was significant in distinguishing between the two groups of lesions. The reviewers showed 96% agreement in the categorization of metastases and 76% agreement in the categorization of hemangiomas. There was 86% agreement in the categorization of all lesions. Overall, reviewers diagnosed a mean of 89% of lesions correctly. A mean of 98% of metastases and a mean of 80% of hemangiomas were diagnosed correctly.

CONCLUSIONS

Globular enhancement is highly sensitive (88%) and specific (84-100%) for differentiating hepatic hemangiomas from hypervascular metastases on single-pass, contrast-enhanced CT scans.

Imaging after laparoscopic cholecystectomy

Imaging for laparoscopic cholecystectomy involves preoperative imaging of the gallbladder and bile ducts, usually by sonography. Post-operative imaging is usually necessary only for suspected surgical complications. Cross-sectional imaging identifies most patients with postoperative complications. Cholangiography is needed to characterize all biliary abnormalities. Interventional radiologic techniques are helpful to aspirate or drain abdominal fluid collections, provide temporary biliary drainage, or cure cystic stump leaks or treat complications of choledochojejunostomy.

Mortality study of workers in 1,3-butadiene production units identified from a chemical workers cohort

The International Agency for Research on Cancer has given the designations of "sufficient evidence" of carcinogenicity of 1,3-butadiene in experimental animals and "limited evidence" of carcinogenicity in humans. To investigate the carcinogenic effect in humans, we conducted a cohort mortality study among 364 men who were assigned to any of three 1,3-butadiene production units located within several chemical plants in the Kanawha Valley of West Virginia, including 277 men employed in a U.S. Rubber Reserve Plant which operated during World War II. The butadiene production units included in this study were selected from an index developed by the Union Carbide Corporation, which listed for each chemical production unit within their South Charleston, West Virginia and Institute, West Virginia, plants all products, by-products, and reactants. Departments included in the study were those where butadiene was a primary product and neither benzene nor ethylene oxide was present. A total of 185 deaths were observed; the standardized mortality ratio (SMR) for all causes of death was 91, reflecting lower mortality among the study population than the U.S. population. The study found a significantly elevated standardized mortality ratio (SMR) for lymphosarcoma and reticulosarcoma based on four observed cases (SMR = 577; 95% CI = 157-1480), which persisted in an analysis using county referent rates. An excess of lymphosarcoma and reticulosarcoma among all workers and among workers with routine exposure to 1,3-butadiene was also observed in the only other cohort of 1,3-butadiene production workers previously studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Cancer mortality in female and male dry-cleaning workers

A cohort study of dry-cleaning workers (1109 women, 592 men) in the mid-1980s revealed significant excess bladder cancer mortality. This article updates vital status through 1990. Significant excesses were seen for bladder cancer (nine deaths, standardized mortality ratio [SMR] = 2.54, 95% confidence interval [CI] = 1.16-4.82), esophageal cancer (10 deaths, SMR = 2.14, 95% CI = 1.02-3.94), and intestinal cancer (26 deaths, SMR = 1.56, 95% CI = 1.02-2.29). In a subcohort exposed only to perchloroethylene (PCE), those with 5 or more years of employment and 20 or more years since first exposure had a significant increased risk of esophageal cancer (four deaths, SMR = 7.17, 95% CI = 1.92-19.82). Women had significant excess esophageal cancer (five deaths, SMR = 3.24, 95% CI = 1.05-7.58) and elevated SMRs for intestinal, pancreatic, and bladder cancer mortality. This study confirms the esophageal cancer risk among dry-cleaning workers seen in another study and suggests an association with PCE. It further documents the risks for intestinal, pancreatic, and bladder cancers in this industry.

Cancer mortality patterns among female and male workers employed in a cable manufacturing plant during World War II

A cohort mortality study was conducted among 9028 (3042 women, 5986 men) workers potentially exposed to chlorinated naphthalenes (chloracnegens structurally similar to dioxins) and asbestos in the manufacture of Navy cable during World War II. Based on mortality through December 31, 1985, standardized mortality ratios (SMRs) for all cancers was 1.03 in women (95% confidence interval [CI] = 0.9 to 1.17) and 1.18 in men (95% CI = 1.10 to 1.26). There were no significant elevations in causes of death hypothesized a prior to be associated with chlorinated naphthalene exposure (malignant neoplasms [MN] of connective tissue, liver, and lymphatic and hematopoietic organs). An excess of MN of the connective tissue was suggested for workers with over 1 year of exposure and 25 years of latency (SMR = 3.54; 95% CI = 0.97 to 9.07). Among cancer sites not hypothesized to be related a priori, three showed concordant excesses among both genders (MN of stomach; rectum; and trachea, bronchus, and lung). No significant elevations occurred in hormonally related cancers among women. Cancer mortality among 460 individuals with chloracne (431 men, 29 women) was similar to that of the entire cohort, although the chloracne subcohort showed significant excesses in two rare causes of death (MN of esophagus, SMR = 3.26; "benign and unspecified neoplasms," SMR = 4.93). Use of county referent rates decreased SMRs for stomach, rectal, and buccal cavity cancer, suggesting a role for nonoccupational risk factors. It is difficult to draw conclusions about carcinogenicity of chlorinated naphthalenes because of study limitations, most importantly, concomitant asbestos exposure and the relatively short duration of exposure to chlorinated naphthalenes among most of the cohort.

Lack of effect of lamotrigine against HPNS in rodent and primate models

The neurophysiological effects of the novel anticonvulsant lamotrigine on the high pressure neurological syndrome, HPNS, were investigated in the rat and nonhuman primate Papio anubis. Rats were exposed to pressure at a rate of 3 ATA per min in a helium/oxygen environment. They were pretreated with either lamotrigine isethionate 15, 30, or 60 mg/kg IP or control vehicle. After 15 and 30 mg/kg there were no changes in onset pressures for any of the grades of tremor or myoclonus. After 60 mg/kg, tremor was much slower, at 7-9 Hz, than the 15-20 Hz seen in controls. Four baboons were exposed to pressure at 0.33 ATA per min in the same environment and treated with lamotrigine isethionate at 7.5 mg/kg/h i.v. Each animal underwent a control and a drug-treated exposure. No changes in the onset or severity of HPNS behavioural signs were observed. However, an increase in alpha wave amplitude of the EEG was almost prevented. In both species sustained myoclonic jerking occurred at pressures similar to those at which seizure activity was observed in control exposures. It is concluded that although lamotrigine is protective in several models of neuronal excitation, it is ineffective in protecting against behavioural signs associated with high atmospheric pressure.

Protection from high pressure induced hyperexcitability by the AMPA/kainate receptor antagonists GYKI 52466 and LY 293558

The neurophysiological effects of 2 novel AMPA/kainate receptor antagonists, GYKI 52466 and LY 293558, on the high pressure neurological syndrome have been investigated in the rat and baboon (GYKI 52466) and rat (LY 293558). Rats were exposed to increasing ambient pressures of helium and oxygen at 3 ATA/min, on one occasion each. GYKI 52466 at 20 mumol/kg i.v. immediately before, followed by 70 mumol/kg/hr i.v. during compression delayed tremor by 85% and myoclonus by 30%, compared with control vehicle, and no side effects were observed. Seizure activity was not affected by any of the doses used. LY 293558 at 36 mumol/kg i.p. delayed tremor and myoclonus (44% and 12%), LY 293558 72 mumol/kg additionally delayed seizure activity (21%). Side effects, principally tranquilization at the higher dose, were also noted. Six baboons were exposed to a maximum pressure of 91 ATA at 0.3 ATA/min, in the same environment, on two occasions. One exposure was treated with an i.v. infusion of GYKI 52466 15.2 mumol/kg/hr, the other with the same volume of control vehicle. Limb and face tremor and myoclonus were delayed and the severity of signs reduced. No seizures were observed in the drug treated group before 91 ATA. EEG changes associated with exposure to pressure were not affected. It is concluded that antagonism at the AMPA/kainate receptor by GYKI 52466 and LY 293558 beneficially alters HPNS signs but in a manner which is dependent on both the drug and species being studied.

The orally active NMDA receptor antagonist CGP 39551 ameliorates the high pressure neurological syndrome in Papio anubis

The neurophysiological effects of a novel, orally active, competitive N-methyl-D-aspartate (NMDA) receptor antagonist (DL-(E)-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester), CGP 39551, on the high pressure neurological syndrome (HPNS) were investigated in the non-human primate Papio anubis. Six animals were exposed to maximum pressures of 81 ATA in a helium and oxygen environment, on two occasions. One exposure was pretreated orally with CGP 39551 100 mg/kg 24 h before compression, the other pretreated with an equivalent volume of vehicle, in this case water. CGP 39551 significantly ameliorated the signs of HPNS, compared with controls, at pressures above 31 ATA and prevented the severe signs from occurring at the higher pressures. Onset pressures of the mild signs at low pressures were, however, unaffected. Among EEG changes, the pressure induced reduction in delta wave amplitude was prevented by CGP 39551, but the increase in the amplitude of the 7-9 Hz band was not. It is concluded that CGP 39551 may play an important role in the prophylactic treatment of HPNS.

MRI of pancreatic islet cell carcinoma

OBJECTIVE

The purpose of this study is to report the spectrum of MR findings of pancreatic islet cell carcinoma.

MATERIALS AND METHODS

The MR scans of 33 patients with islet cell carcinoma were retrospectively reviewed. Magnetic resonance detected the primary tumor in 21 of 27 patients (78%) who had not had prior resection of their primary tumor. Mean tumor diameter was 7.1 cm (range 3.5-13.0 cm).

RESULTS

In all patients, the primary tumor on T1-weighted images (TR/TE = 250/15) was of signal intensity equal to or lower than that of the adjacent normal pancreas. The primary tumor on T2-weighted images (TR/TE = 2,000/> or = 100) was of signal intensity the same as or higher than fat in 18 of 21 patients (86%) and had mixed signal intensity in the other 3 (14%). Hepatic metastases were found in 28 of 33 patients (85%). Liver metastases were categorized as "usual" (variably circumscribed, homogeneous lesions of medium signal intensity on T2-weighted images) in 19 of 28 patients (68%), necrotic in 8 of 28 (29%), hemorrhagic in 3 of 28 (11%), and calcified in 1 of 28 (4%). Extrahepatic metastases were found in 18 of 33 patients (55%).

CONCLUSION

We conclude that MRI is an excellent modality for the diagnosis and routine follow-up of patients with islet cell carcinoma.

Randomised controlled trial of nasal ventilation in acute ventilatory failure due to chronic obstructive airways disease

Acute exacerbations of chronic obstructive airways disease (COAD) are a common cause of admission to hospital, and have a high mortality. Nasal intermittent positive pressure ventilation (NIPPV) has been used successfully in patients with respiratory failure due to neuromuscular and skeletal disorders, but the outcome of treatment in patients with COAD is less well known. We carried out a prospective randomised controlled trial of conventional treatment versus conventional treatment plus NIPPV, in 60 patients with acute ventilatory failure due to exacerbations of COAD. For the NIPPV group there was a rise in pH, compared with a fall in the controls (mean difference of change between the groups 0.046 [95% CI 0.06-0.02, p < 0.001]), and a larger fall in PaCO2 (mean difference in change between the groups 1.2 kPa [95% CI 0.45 to 2.03, p < 0.01]). Median visual analogue scores over the first 3 days of admission showed less breathlessness in the NIPPV group (2.3 cm [range 0.1-5.5]) than in the control group (4.5 cm [range 0.9-8.8]) (p < 0.025). Survival rates at 30 days were compared for intention-to-treat and efficacy populations. In the efficacy mortality comparison, mortality in the NIPPV group was reduced: 1/26 vs 9/30 (relative risk = 0.13, CI = 0.02-0.95, p = 0.014). This effect was less in the intention-to-treat analysis: 3/30 vs 9/30 (relative risk = 0.33, CI = 0.10-1.11, p = 0.106). In patients with acute ventilatory failure due to COAD who received NIPPV there was a significant rise in pH, a reduction in PaCO2 and breathlessness, and reduced mortality.

Diagnostic features and clinical outcome of ischemic-type biliary complications after liver transplantation

The clinical significance and outcome of nonanastomotic strictures and dilatations involving only the biliary tree of the graft with a radiological appearance of biliary ischemia is unknown. Therefore we analyzed the grafts of 128 patients to evaluate the biochemical, radiological and histological features that prompted the diagnosis of ischemic-type biliary stricture and the clinical outcome of this complication. Ischemic-type biliary strictures were diagnosed in 25 patients (19%). Initial graft function was similar in all patients, whether or not this complication developed. Most ischemic-type biliary strictures occurred between 1 and 4 mo after orthotopic liver transplantation. However, the appearance of ischemic-type biliary stricture in the month after transplantation was predictive for a poor outcome in all six grafts with early onset of ischemic-type biliary strictures. Eighteen patients (72%) were treated with biliary stents and repeated dilatations. Long-term patency was achieved in 88% of these patients. Repeat transplantation was performed in six patients (24%); five survived. Finally, patients with ischemic-type biliary strictures spent more time in the hospital during the first year after orthotopic liver transplantation than did patients without the complication (62 +/- 27 days vs. 37 +/- 20 days; p < or = 0.001). This was due to repeated hospitalizations and a higher incidence of retransplantation. One-year graft survival was lower in patients with ischemic-type biliary strictures than in patients without ischemic-type biliary strictures (69% vs. 88%; p = 0.006). However, 1-yr patient survival was similar in the two groups (91% vs. 89%). In conclusion, early appearance of ischemic-type biliary stricture features is associated with poor graft prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Nasal intermittent positive-pressure ventilation in weaning intubated patients with chronic respiratory disease from assisted intermittent, positive-pressure ventilation

Nasal intermittent positive-pressure ventilation (NIPPV) has been used for domiciliary ventilatory support, and to avoid intubation for acute respiratory failure in patients with chronic airflow limitation (CAL). Its role in weaning patients from assisted ventilation in intensive care has not been defined. We have used NIPPV to wean 14 patients with respiratory disease who were referred either because of predicted difficulty in weaning or failure to wean using standard techniques. Twelve patients were ventilated for acute respiratory failure; eight patients had CAL and four had chest wall or neuromuscular disease. Two further patients with chest disease were difficult to wean following surgery. Weaning was successful in 13 patients. NIPPV corrected hypoxia, reduced hypercapnia and was well tolerated. Weaning from NIPPV was achieved in all patients with CAL, although three patients with chest wall disease later required domiciliary ventilatory support. All but one of the patients survived to leave hospital. NIPPV may have an important role in weaning from assisted ventilation, particularly in patients with underlying chronic respiratory disease. This preliminary report needs to be followed by a controlled study comparing NIPPV with established weaning methods.

Comparison of nasal pressure support ventilation with nasal intermittent positive pressure ventilation in patients with nocturnal hypoventilation

Nasal intermittent positive pressure ventilation (NIPPV) provides effective ventilatory support in patients with nocturnal hypoventilation. Nasal pressure support ventilation (NPSV), which only provides ventilation in response to patient triggering, may also be effective, simpler, and cheaper, but has not been evaluated. NIPPV and NPSV were compared in 12 patients with nocturnal hypoventilation, requiring domiciliary ventilatory support. The patients were studied on three consecutive nights, in random order: a control night without ventilation and a night on each mode of ventilatory support using the bilevel positive airway pressure (BiPAP) ventilator. Both NIPPV and NPSV significantly increased mean arterial oxygen saturation (SaO2) compared to the control night (NIPPV mean increase 4.1%; 95% confidence interval (CI) 2.2 to 6.1, NPSV 4.4%; CI 2.1 to 6.6) with no significant difference between the two modes. The percentage of the study night spent below 90% SaO2 was significantly reduced by both ventilator modes compared to the control night (median reduction on NIPPV 37%; CI -54 to -10, reduction on NPSV 31%; CI -53 to -9, with no significant difference between NPSV and NIPPV. NPSV was as effective as NIPPV in patients with nocturnal hypoventilation, which suggests that these patients are able to trigger the ventilator adequately. The lower cost of NPSV will make it accessible to more patients with chronic lung disease.

Comparison of nasal pressure support ventilation with nasal intermittent positive pressure ventilation in patients with nocturnal hypoventilation

Nasal intermittent positive pressure ventilation (NIPPV) provides effective ventilatory support in patients with nocturnal hypoventilation. Nasal pressure support ventilation (NPSV), which only provides ventilation in response to patient triggering, may also be effective, simpler, and cheaper, but has not been evaluated. NIPPV and NPSV were compared in 12 patients with nocturnal hypoventilation, requiring domiciliary ventilatory support. The patients were studied on three consecutive nights, in random order: a control night without ventilation and a night on each mode of ventilatory support using the bilevel positive airway pressure (BiPAP) ventilator. Both NIPPV and NPSV significantly increased mean arterial oxygen saturation (SaO2) compared to the control night (NIPPV mean increase 4.1%; 95% confidence interval (CI) 2.2 to 6.1, NPSV 4.4%; CI 2.1 to 6.6) with no significant difference between the two modes. The percentage of the study night spent below 90% SaO2 was significantly reduced by both ventilator modes compared to the control night (median reduction on NIPPV 37%; CI -54 to -10, reduction on NPSV 31%; CI -53 to -9, with no significant difference between NPSV and NIPPV. NPSV was as effective as NIPPV in patients with nocturnal hypoventilation, which suggests that these patients are able to trigger the ventilator adequately. The lower cost of NPSV will make it accessible to more patients with chronic lung disease.