Challenges in Accurate Diagnosis of HCC in FALD: A Case Series

Patients with single ventricle cardiac disease palliated with Fontan procedures inevitably develop Fontan-Associated Liver Disease (FALD), which poses a significant risk for hepatocellular carcinoma (HCC). Standard imaging criteria for the diagnosis of cirrhosis are not reliable due to parenchymal heterogeneity of FALD. We present 6 cases to demonstrate our center's experience and the challenges in diagnosing HCC within this patient population.

Relationship Between Myocardial Injury During Index Hospitalization for SARS-CoV-2 Infection and Longer-Term Outcomes

Background Myocardial injury in patients with COVID-19 is associated with increased mortality during index hospitalization; however, the relationship to long-term sequelae of SARS-CoV-2 is unknown. This study assessed the relationship between myocardial injury (high-sensitivity cardiac troponin T level) during index hospitalization for COVID-19 and longer-term outcomes. Methods and Results This is a prospective cohort of patients who were hospitalized at a single center between March and May 2020 with SARS-CoV-2. Cardiac biomarkers were systematically collected. Outcomes were adjudicated and stratified on the basis of myocardial injury. The study cohort includes 483 patients who had high-sensitivity cardiac troponin T data during their index hospitalization. During index hospitalization, 91 (18.8%) died, 70 (14.4%) had thrombotic complications, and 126 (25.6%) had cardiovascular complications. By 12 months, 107 (22.2%) died. During index hospitalization, 301 (62.3%) had cardiac injury (high-sensitivity cardiac troponin T≧14 ng/L); these patients had 28.6%, 32.2%, and 33.2% mortality during index hospitalization, at 6 months, and at 12 months, respectively, compared with 4.1%, 4.9%, and 4.9% mortality for those with low-level positive troponin and 0%, 0%, and 0% for those with undetectable troponin. Of 392 (81.2%) patients who survived the index hospitalization, 94 (24%) had at least 1 readmission within 12 months, of whom 61 (65%) had myocardial injury during the index hospitalization. Of 377 (96%) patients who were alive and had follow-up after the index hospitalization, 211 (56%) patients had a documented, detailed clinical assessment at 6 months. A total of 78 of 211 (37.0%) had ongoing COVID-19-related symptoms; 34 of 211 (16.1%) had neurocognitive decline, 8 of 211 (3.8%) had increased supplemental oxygen requirements, and 42 of 211 (19.9%) had worsening functional status. Conclusions Myocardial injury during index hospitalization for COVID-19 was associated with increased mortality and may predict who are more likely to have postacute sequelae of COVID-19. Among patients who survived their index hospitalization, the incremental mortality through 12 months was low, even among troponin-positive patients.

Dose-dependent toxicological effects in rats following a 90-day dietary exposure to PCB-156 include retinoid disruption

The toxicity of PCB-156 (2,3,3',4,4',5-hexachlorobiphenyl) was investigated in rats following subchronic dietary exposure. Groups of 10 male and female Sprague-Dawley rats were administered PCB-156 in the diet at 0, 0.01, 0.1, 1 or 10 ppm for 90 days. Dose-dependent increases were detected for the liver, lung and kidney weights, as well as for the liver EROD, PROD and UDPGT enzyme activities and liver uroporphyrin concentration. Dose-dependent decreases were observed in final body weight, body weight gain, and thymus weight. Apolar retinoid concentrations were decreased in the liver and lungs and increased in the kidneys. Histopathological examination of the liver, thyroid, and thymus showed mild to moderate dose-related changes. A LOAEL of 0.01 ppm was established, based on reduced apolar liver retinoid concentration. Benchmark dose-modelling corroborated the sensitivity of liver retinoid endpoints. The lower confidence limits (BMDL) for a 5% decrease in apolar liver retinoid concentrations were 0.0009 and 0.0007 ppm, respectively, in males and females, corresponding to a daily dose of 0.06 μg PCB-156 per kg body weight. Organizing dose-response data for the individual hepatic endpoints along the PCB-156 dosing scale revealed a sequence of events compatible with a causal link between depletion of apolar retinoids and the other liver biochemistry and pathology findings. Taken together, data suggest that the retinoid endpoints should be further evaluated for a causal relationship to PCB-induced liver toxicity and that retinoid system endpoints are identified and characterized to support health risk assessment in the emerging research fields of endocrine disruption and mixture toxicology.

100. Safety Analysis of Live-Attenuated Measles, Mumps, Rubella Vaccine Among Hematopoietic Cell Transplant Recipients Vaccinated Within Two Years of Transplant

Background

Measles, mumps and rubella (MMR) vaccine is a live-attenuated vaccine usually contraindicated within the first two years of hematopoietic cell transplant (HCT). During the 2019 measles outbreak at our center, the benefits of administering MMR vaccine within the first two years after HCT were weighed against the potential risks.

Methods

We conducted a retrospective review of patients who received MMR vaccination within two years of an autologous or allogeneic HCT. Patients’ demographics, date and type of HCT, underlying hematologic disease, type of immunosuppressive therapy and date of MMR vaccination were extracted from the electronic medical record. Adverse reactions that could be related to the vaccine were collected for up to 42 days post-vaccination and all hospitalizations and deaths following vaccination were reviewed.

Results

A total of 129 patients (75 autologous and 54 allogeneic HCT) were vaccinated between 300-729 days after HCT (median of 718 days). The median age at vaccination was 61 years old, 57% of the patients were male and 43% were on immunosuppressive therapy, 87% of whom were on maintenance therapy for multiple myeloma after auto-HCT. Seven patients (5%) had adverse reactions within 42 days of vaccination: six had respiratory tract infections (three with associated fever) and one had a rash leading to a brief hospitalization. This was a 37-year-old female who had an allogeneic HCT 542 days prior to MMR vaccination. She presented with a centrifugal maculopapular rash that was confirmed to be caused by the vaccine strain rubella virus (Fig 1). She fully recovered without sequalae. There was no other vaccine-associated illness identified in the cohort, after a median follow-up of 676 days.

Conclusion

MMR vaccine appears to be well tolerated in selected HCT recipients when given earlier than 2 years after transplant. No attributable severe outcomes or deaths were described. A mild uncomplicated case of vaccine-associated rubella illness was seen after vaccination. In the setting of a measles outbreak, assessment of potential risks and benefits of MMR vaccination given within two years of HCT remains important.

Disclosures

Stephen R. Walsh, MDCM, Janssen Vaccines (Scientific Research Study Investigator)Regeneron (Scientific Research Study Investigator)Sanofi Pasteur (Scientific Research Study Investigator) Matthew Cheng, MD, GEn1E Lifesciences (Advisor or Review Panel member)Kanvas Biosciences (Board Member, Shareholder)nplex biosciences (Advisor or Review Panel member) Sanjat Kanjilal, MD, MPH, GlaskoSmithKline (Advisor or Review Panel member) Nicolas C. Issa, MD, AiCuris (Scientific Research Study Investigator)Astellas (Scientific Research Study Investigator)GSK (Scientific Research Study Investigator)Merck (Scientific Research Study Investigator)

Attention and executive function are impaired during active standing in postural tachycardia syndrome

Postural tachycardia syndrome (POTS) is a chronic form of orthostatic intolerance associated with cognitive dysfunction. We hypothesized executive function and attention is impaired in POTS during active standing. Eighty-seven POTS participants and 39 healthy controls of similar age, sex, and education level completed executive function (Stroop word-color) and attention (CogState Identification) tests in supine and standing postures in a cross-sectional study. POTS participants had lower executive function (t-score: 48 ± 11 vs. 55 ± 10 control; p = 0.009) and worse attention (reaction speed: 2.78 ± 0.11 vs. 2.69 ± 0.06 control; p < 0.001) during standing. These data provide new evidence that active standing impairs attention and executive functioning in POTS.

Concentrations of bisphenol A in the composite food samples from the 2008 Canadian total diet study in Quebec City and dietary intake estimates

A total of 154 food composite samples from the 2008 total diet study in Quebec City were analysed for bisphenol A (BPA), and BPA was detected in less than half (36%, or 55 samples) of the samples tested. High concentrations of BPA were found mostly in the composite samples containing canned foods, with the highest BPA level being observed in canned fish (106 ng g(-1)), followed by canned corn (83.7 ng g(-1)), canned soups (22.2-44.4 ng g(-1)), canned baked beans (23.5 ng g(-1)), canned peas (16.8 ng g(-1)), canned evaporated milk (15.3 ng g(-1)), and canned luncheon meats (10.5 ng g(-1)). BPA levels in baby food composite samples were low, with 2.75 ng g(-1) in canned liquid infant formula, and 0.84-2.46 ng g(-1) in jarred baby foods. BPA was also detected in some foods that are not canned or in jars, such as yeast (8.52 ng g(-1)), baking powder (0.64 ng g(-1)), some cheeses (0.68-2.24 ng g(-1)), breads and some cereals (0.40-1.73 ng g(-1)), and fast foods (1.1-10.9 ng g(-1)). Dietary intakes of BPA were low for all age-sex groups, with 0.17-0.33 µg kg(-1) body weight day(-1) for infants, 0.082-0.23 µg kg(-1) body weight day(-1) for children aged from 1 to 19 years, and 0.052-0.081 µg kg(-1) body weight day(-1) for adults, well below the established regulatory limits. BPA intakes from 19 of the 55 samples account for more than 95% of the total dietary intakes, and most of the 19 samples were either canned or in jars. Intakes of BPA from non-canned foods are low.

Environmental contaminants and human health in the Canadian Arctic

The third Canadian Arctic Human Health Assessment conducted under the Canadian Northern Contaminants Program (NCP), in association with the circumpolar Arctic Monitoring and Assessment Programme (AMAP), addresses concerns about possible adverse health effects in individuals exposed to environmental contaminants through a diet containing country foods. The objectives here are to: 1) provide data on changes in human contaminant concentrations and exposure among Canadian Arctic peoples; 2) identify new contaminants of concern; 3) discuss possible health effects; 4) outline risk communication about contaminants in country food; and 5) identify knowledge gaps for future contaminant research and monitoring. The nutritional and cultural benefits of country foods are substantial; however, some dietary studies suggest declines in the amount of country foods being consumed. Significant declines were found for most contaminants in maternal blood over the last 10 years within all three Arctic regions studied. Inuit continue to have the highest levels of almost all persistent organic pollutants (POPs) and metals among the ethnic groups studied. A greater proportion of people in the East exceed Health Canada's guidelines for PCBs and mercury, although the proportion of mothers exceeding these guidelines has decreased since the previous assessment. Further monitoring and research are required to assess trends and health effects of emerging contaminants. Infant development studies have shown possible subtle effects of prenatal exposure to heavy metals and some POPs on immune system function and neurodevelopment. New data suggest important beneficial effects on brain development for Inuit infants from some country food nutrients. The most successful risk communication processes balance the risks and benefits of a diet of country food through input from a variety of regional experts and the community, to incorporate the many socio-cultural and economic factors to arrive at a risk management decision that will be the most beneficial in Arctic communities.

Persistent organic pollutants in fish oil supplements on the canadian market: polychlorinated dibenzo-p-dioxins, dibenzofurans, and polybrominated diphenyl ethers

Canadians are interested in improving their diet through the consumption of fish oil food supplements, which are marketed to be rich in omega-3 fatty acids. Convenience samples of omega-3 enriched dietary supplements (n = 30) were collected in Vancouver, Canada, between 2005 and 2007. All of the omega-3 supplements were analyzed for polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polybrominated diphenyl ethers (PBDEs) and, although every sample was found to contain detectable residues of PBDEs, only 24 samples were found to have PCDD/F concentrations above the level of detection. PCDD/F concentrations ranged from 0.05 pg TEQ/g lipid to 45.7 pg TEQ/g lipid in salmon and shark oils, respectively. Maximum PBDE concentrations similarly were observed in shark oil (113 microg/kg lipid), however, most supplements had concentrations below 5 microg/kg lipid. Average PCDD/F and PBDE intake estimates, based on consumption of maximum supplement dose following product label recommendations, were 4.32 pg TEQ/d and 25.1 ng/d lipid, respectively.

Persistent organic pollutants in fish oil supplements on the Canadian market: polychlorinated biphenyls and organochlorine insecticides

Fish and seal oil dietary supplements, marketed to be rich in omega-3 fatty acids, are frequently consumed by Canadians. Samples of these supplements (n = 30) were collected in Vancouver, Canada, between 2005 and 2007. All oil supplements were analyzed for polychlorinated biphenyls (PCBs) and organochlorine insecticides (OCs) and each sample was found to contain detectable residues. The highest SigmaPCB and SigmaDDT (1,1,1-trichloro-di-(4-chlorophenyl)ethane) concentrations (10400 ng/g and 3310 ng/g, respectively) were found in a shark oil sample while lowest levels were found in supplements prepared using mixed fish oils (anchovy, mackerel, and sardine) (0.711 ng SigmaPCB/g and 0.189 ng SigmaDDT/g). Mean SigmaPCB concentrations in oil supplements were 34.5, 24.2, 25.1, 95.3, 12.0, 5260, 321, and 519 ng/g in unidentified fish, mixed fish containing no salmon, mixed fish with salmon, salmon, vegetable with mixed fish, shark, menhaden (n = 1), and seal (n = 1), respectively. Maximum concentrations of the other OCs were generally observed in the seal oil. The hexachlorinated PCB congeners were the dominant contributors to SigmaPCB levels, while SigmaDDT was the greatest contributor to organochlorine levels. Intake estimates were made using maximum dosages on manufacturers' labels and results varied widely due to the large difference in residue concentrations obtained. Average SigmaPCB and SigmaDDT intakes were calculated to be 736 +/- 2840 ng/d and 304 +/- 948 ng/d, respectively.

Human health implications of environmental contaminants in Arctic Canada: A review

The objectives of this paper are to: assess the impact of exposure to current levels of environmental contaminants in the Canadian Arctic on human health; identify the data and knowledge gaps that need to be filled by future human health research and monitoring; examine how these issues have changed since our first assessment [Van Oostdam, J., Gilman, A., Dewailly, E., Usher, P., Wheatley, B., Kuhnlein, H. et al., 1999. Human health implications of environmental contaminants in Arctic Canada: a review. Sci Total Environ 230, 1-82]. The primary exposure pathway for contaminants for various organochlorines (OCs) and toxic metals is through the traditional northern diet. Exposures tend to be higher in the eastern than the western Canadian Arctic. In recent dietary surveys among five Inuit regions, mean intakes by 20- to 40-year-old adults in Baffin, Kivalliq and Inuvialuit communities exceeded the provisional tolerable daily intakes (pTDIs) for the OCs, chlordane and toxaphene. The most recent findings in NWT and Nunavut indicate that almost half of the blood samples from Inuit mothers exceeded the level of concern value of 5 microg/L for PCBs, but none exceeded the action level of 100 microg/L. For Dene/Métis and Caucasians of the Northwest Territories exposure to OCs are mostly below this level of concern. Based on the exceedances of the pTDI and of various blood guidelines, mercury and to a lesser extent lead (from the use of lead shot in hunting game) are also concerns among Arctic peoples. The developing foetus is likely to be more sensitive to the effects of OCs and metals than adults, and is the age groups of greatest risk in the Arctic. Studies of infant development in Nunavik have linked deficits in immune function, an increase in childhood respiratory infections and birth weight to prenatal exposure to OCs. Balancing the risks and benefits of a diet of country foods is very difficult. The nutritional benefits of country food and its contribution to the total diet are substantial. Country food contributes significantly more protein, iron and zinc to the diets of consumers than southern/market foods. The increase in obesity, diabetes and cardiovascular disease has been linked to a shift away from a country food diet and a less active lifestyle. These foods are an integral component of good health among Aboriginal peoples. The social, cultural, spiritual, nutritional and economic benefits of these foods must be considered in concert with the risks of exposure to environmental contaminants through their exposure. Consequently, the contamination of country food raises problems which go far beyond the usual confines of public health and cannot be resolved simply by risk-based health advisories or food substitutions alone. All decisions should involve the community and consider many aspects of socio-cultural stability to arrive at a decision that will be the most protective and least detrimental to the communities.

Direct thrombin injection into aneurysmal sac in a patient with a type II endoleak

Endovascular grafting of abdominal aortic aneurysms provides a good alternative to open surgery, especially in high-risk patients. Endoleaks are a well-recognized complication and are typically diagnosed on CT. We describe a case in which a patient's endoleak was evaluated by MRI and successfully treated by direct thrombin injection into the site of the leak.

Effects of caffeine on human health

Caffeine is probably the most frequently ingested pharmacologically active substance in the world. It is found in common beverages (coffee, tea, soft drinks), in products containing cocoa or chocolate, and in medications. Because of its wide consumption at different levels by most segments of the population, the public and the scientific community have expressed interest in the potential for caffeine to produce adverse effects on human health. The possibility that caffeine ingestion adversely affects human health was investigated based on reviews of (primarily) published human studies obtained through a comprehensive literature search. Based on the data reviewed, it is concluded that for the healthy adult population, moderate daily caffeine intake at a dose level up to 400 mg day(-1) (equivalent to 6 mg kg(-1) body weight day(-1) in a 65-kg person) is not associated with adverse effects such as general toxicity, cardiovascular effects, effects on bone status and calcium balance (with consumption of adequate calcium), changes in adult behaviour, increased incidence of cancer and effects on male fertility. The data also show that reproductive-aged women and children are 'at risk' subgroups who may require specific advice on moderating their caffeine intake. Based on available evidence, it is suggested that reproductive-aged women should consume </=300 mg caffeine per day (equivalent to 4.6 mg kg(-1) bw day(-1) for a 65-kg person) while children should consume </=2.5 mg kg(-1) bw day(-1).

Mixture effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and polychlorinated biphenyl congeners in rats

Concern of the toxic effects and bioaccumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls in the environment continues to be a focus of research in persistent organochlorine contaminants. Groups of five adult female S.D. rats were administered by gavage 0, 2.5, 25, 250 or 1000 ng TCDD/kg body weight/day or TCDD in combination with a mixture of PCB congeners (PCBs) at 2 or 20 microg/kg b.w./day for a period of 28 days. Growth suppression, increased absolute and relative liver weights, and decreased thymic weight were observed in either the 1000 ng TCDD group alone, or the groups receiving a mixture of 1000 ng TCDD + 2 microg PCBs. The TCDD induced increases in liver and thymic weights were not altered by co-administration with PCBs, however, growth suppression appeared to be more pronounced in the group receiving 1000 ng TCDD + 2 microg PCBs than with TCDD alone. Treatment with TCDD at 250 ng and 1000 ng/kg resulted in a significant increase in hepatic microsomal methoxy resorufin-O-demethylase and ethoxy resorufin-O-deethylase activities which were antagonized by co-administration with PCBs. Similarly, effects of 250 ng TCDD on serum cholesterol and liver UDP glucuronosyl transferase activity and ascorbic acid were significantly reduced by co-administration with 20 microg PCBs. Other biochemical effects elicited by treatment with 1000 ng TCDD, but not affected by co-administration with PCBs include the following: increased serum albumin, decreased liver vitamin A, and increased kidney vitamin A and liver microsomal glutathione-S-transferase activity. While decreased hemoglobin, platelet, packed cell volume and red cell indices were observed in TCDD treated rats, no interactive effects were seen. The above results indicate that the mixture effects of PCBs and TCDD may be additive or antagonistic depending on the dose level and endpoints measured. For the purpose of predicting mixture effects, knowledge of mechanisms of action and toxicokinetics is required.

Dioxins: WHO's tolerable daily intake (TDI) revisited

In December 1990, the World Health Organization (WHO) established a tolerable daily intake (TDI) of 10 pg/kg b.w. (body weight) for TCDD, based on liver toxicity, reproductive effects and immunotoxicity in experimental animals, and making use of kinetic data in humans and experimental animals. Since then new epidemiological and toxicological data have emerged, in particular with respect to neurodevelopmental and endocrine effects of dioxin. Therefore, the European Centre for Environment and Health of the World Health Organization (WHO-ECEH) and the International Programme on Chemical Safety (IPCS) jointly organized a consultation on the "Assessment of the health risk of dioxins: re-evaluation of the TDI", May 1998, Geneva, Switzerland. The participants discussed the health risks for infants, cancer and non-cancer endpoints in humans and animals, mechanistic aspects, kinetic behaviour, modelling, exposure, and the applicability of the toxic equivalency (TEQ) concept. For the health risk assessment of dioxin-like compounds, the WHO Consultation focused on the most sensitive effects that are considered adverse (hormonal, reproductive and developmental effects) seen at low doses in animal studies (rats and monkeys). Human daily intakes corresponding with body burdens similar to those associated with adverse effects in animals could be estimated to be in the range of 14-37 pg/kg b.w./day. To arrive at a TDI expressed as TEQ, a composite uncertainty factor of 10 was recommended. By applying this uncertainty factor a TDI range of 1-4 pg TEQs/kg body weight was established. An extensive executive summary of the results of this WHO Consultation with all the underlying background documents will be published in Food Additives and Contaminants (in press).

Health risks to infants from exposure to PCBs, PCDDs and PCDFs

Global contamination by a variety of anthropogenic persistent organic chemicals, such as dioxins and PCBs, has resulted in human exposure throughout all phases of development. Detectable concentrations of PCBs and dioxins have been found in amniotic fluid, placenta and foetal tissue samples while infants who are breast-fed can obtain blood levels greater than those of their mother's. In two separate food poisoning episodes where infants were exposed in utero to elevated levels of heat-degraded PCBs (PCBs, PCQs, PCDFs), a variety of adverse mental and physical developmental abnormalities have been observed. In additional human cohorts where exposure could be considered as environmental or background, more subtle effects, including lower birth weights, alterations in thyroid hormones and lymphocyte subpopulations and detriments in neurological development, have been consistently seen. In most instances, negative associations were made between in utero exposure to contaminants compared with lactational. Although the observed neurodevelopmental deficits have been described as subtle, there could be unknown consequences related to future intellectual functionality. Current regulatory efforts should focus on identification and control of environment and food chain contamination as in utero exposure is a direct consequence of the accumulated maternal body burdens.

The temporal relation of adherence and alliance to symptom change in cognitive therapy for depression

This study attempted to replicate an earlier study (R. J. DeRubeis & M. Feeley, 1990) of the prediction of symptom change from process variables in cognitive therapy for depressed outpatients. Measures of in-session therapist behavior and therapist-patient interactions were correlated with prior and subsequent symptom change. One of the positive findings was confirmed, but the other received only marginal support. A "concrete" subset of theory-specified therapist actions, measured early in treatment, predicted subsequent change in depression. The therapeutic alliance was predicted by prior symptom change in 1 of the 2 later assessments, but only at a trend level. Several negative findings were similar to those obtained in the earlier study. Specifically, the alliance, an "abstract" subset of theory-specified therapist actions, and facilitative conditions did not predict subsequent change. Implications for causal inferences in psychotherapy process research are discussed.

The temporal relation of adherence and alliance to symptom change in cognitive therapy for depression

This study attempted to replicate an earlier study (R. J. DeRubeis & M. Feeley, 1990) of the prediction of symptom change from process variables in cognitive therapy for depressed outpatients. Measures of in-session therapist behavior and therapist-patient interactions were correlated with prior and subsequent symptom change. One of the positive findings was confirmed, but the other received only marginal support. A "concrete" subset of theory-specified therapist actions, measured early in treatment, predicted subsequent change in depression. The therapeutic alliance was predicted by prior symptom change in 1 of the 2 later assessments, but only at a trend level. Several negative findings were similar to those obtained in the earlier study. Specifically, the alliance, an "abstract" subset of theory-specified therapist actions, and facilitative conditions did not predict subsequent change. Implications for causal inferences in psychotherapy process research are discussed.

Risk factors for predicting surgical salvage of sternal wound-healing complications

A retrospective study was performed to determine whether clinical factors can predict which complicated poststernotomy wounds can be managed successfully by debridement and reclosure, and which wounds require a muscle flap for healing. Between January 1990 and December 1996, 3,435 median sternotomies were performed at Indiana University Medical Center and affiliated hospitals. A total of 91 patients (2.6%) were reoperated for sternal wound-healing complications. Seventy-six patients (83.5%) underwent debridement and rewiring, and 15 patients (16.5%) underwent primary flap coverage. Of the 76 patients who underwent initial rewiring, 45 (59%) healed and 31 (41%) required additional operative procedures. Of the 31 rewiring failures, 26 patients (84%) were healed with muscle flaps and 4 patients (13%) were managed with a second successful rewiring. The following clinical factors were correlated with operative procedure and outcome: history of smoking, chronic obstructive pulmonary disease, steroid use, previous sternotomy, age, diabetes, harvest of the left or right internal mammary artery (IMA), emergency operation, operation time, pump time, cross-clamp time, ischemic time, coronary artery bypass grafting alone versus combined with a valve replacement, positive wound cultures, positive blood cultures, elevated white blood cell count, and fever. When comparing patients with successful rewiring with those who had a failed rewiring, positive wound and blood cultures were significant risk factors (p < 0.05) on univariate analysis. Presence of a positive wound culture was significant on multivariate analysis. When comparing risk factors in patients who were rewired successfully versus all patients who had muscle flap coverage, the presence of a positive blood culture was significant on both univariate and multivariate analyses. We conclude patients most likely to fail rewiring and to require muscle flap closure are those with infected wounds, positive blood cultures, and possibly left IMA bypasses.

Human health implications of environmental contaminants in Arctic Canada: a review

This paper assesses the impact on human health of exposure to current levels of environmental contaminants in the Canadian Arctic, and identifies the data gaps that need to be filled by future human health research and monitoring. The concept of health in indigenous groups of the Arctic includes social, cultural, and spiritual dimensions. The harvesting, sharing and consumption of traditional foods are an integral component to good health among Aboriginal people influencing both physical health and social well-being. Traditional foods are also an economic necessity in many communities. Consequently, the contamination of country food raises problems which go far beyond the usual confines of public health and cannot be resolved by health advisories or food substitutions alone. The primary exposure pathway for the contaminants considered in this paper is through the traditional northern diet. For the Inuit, the OCs of primary concern at this time from the point of view of exposure are chlordane, toxaphene, and PCBs. Exposures are higher in the eastern than in the western region of the North. For Dene/Metis, exposure to OCs is in general below a level of concern. However, estimated intake of chlordane and toxaphene has been found to be elevated for certain groups and is a cause for concern if exposures are elevated on a regular basis. The developing foetus and breast-fed infant are likely to be more sensitive to the effects of OCs and metals than individual adults and are the age groups at greatest risk in the Arctic. Extensive sampling of human tissues in the Canadian north indicate that a significant proportion of Dene, Cree and Inuit had mean maternal hair mercury levels within the 5% risk-range proposed by the WHO for neonatal neurological damage. Based on current levels, lead does not appear to pose a health threat while cadmium is likely only a major risk factor for heavy smokers or consumers of large amounts of organ meats. Consumers of traditional foods are exposed to an approximately seven-fold higher radiation dose than non-consumers of traditional foods due predominantly to the bioaccumulation of natural radionuclides in the food chain. Risk determination for contaminants in country food involves a consideration of the type and amounts of food consumed and the sociocultural, nutritional, economic, and spiritual benefits associated with country foods. Risk management options that minimize the extent to which nutritional and sociocultural aspects of Aboriginal societies are compromised must always be considered.

Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife

An expert meeting was organized by the World Health Organization (WHO) and held in Stockholm on 15-18 June 1997. The objective of this meeting was to derive consensus toxic equivalency factors (TEFs) for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxinlike polychlorinated biphenyls (PCBs) for both human, fish, and wildlife risk assessment. Based on existing literature data, TEFs were (re)evaluated and either revised (mammals) or established (fish and birds). A few mammalian WHO-TEFs were revised, including 1,2,3,7,8-pentachlorinated DD, octachlorinated DD, octachlorinated DF, and PCB 77. These mammalian TEFs are also considered applicable for humans and wild mammalian species. Furthermore, it was concluded that there was insufficient in vivo evidence to continue the use of TEFs for some di-ortho PCBs, as suggested earlier by Ahlborg et al. [Chemosphere 28:1049-1067 (1994)]. In addition, TEFs for fish and birds were determined. The WHO working group attempted to harmonize TEFs across different taxa to the extent possible. However, total synchronization of TEFs was not feasible, as there were orders of a magnitude difference in TEFs between taxa for some compounds. In this respect, the absent or very low response of fish to mono-ortho PCBs is most noticeable compared to mammals and birds. Uncertainties that could compromise the TEF concept were also reviewed, including nonadditive interactions, differences in shape of the dose-response curve, and species responsiveness. In spite of these uncertainties, it was concluded that the TEF concept is still the most plausible and feasible approach for risk assessment of halogenated aromatic hydrocarbons with dioxinlike properties.

Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife

An expert meeting was organized by the World Health Organization (WHO) and held in Stockholm on 15-18 June 1997. The objective of this meeting was to derive consensus toxic equivalency factors (TEFs) for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxinlike polychlorinated biphenyls (PCBs) for both human, fish, and wildlife risk assessment. Based on existing literature data, TEFs were (re)evaluated and either revised (mammals) or established (fish and birds). A few mammalian WHO-TEFs were revised, including 1,2,3,7,8-pentachlorinated DD, octachlorinated DD, octachlorinated DF, and PCB 77. These mammalian TEFs are also considered applicable for humans and wild mammalian species. Furthermore, it was concluded that there was insufficient in vivo evidence to continue the use of TEFs for some di-ortho PCBs, as suggested earlier by Ahlborg et al. [Chemosphere 28:1049-1067 (1994)]. In addition, TEFs for fish and birds were determined. The WHO working group attempted to harmonize TEFs across different taxa to the extent possible. However, total synchronization of TEFs was not feasible, as there were orders of a magnitude difference in TEFs between taxa for some compounds. In this respect, the absent or very low response of fish to mono-ortho PCBs is most noticeable compared to mammals and birds. Uncertainties that could compromise the TEF concept were also reviewed, including nonadditive interactions, differences in shape of the dose-response curve, and species responsiveness. In spite of these uncertainties, it was concluded that the TEF concept is still the most plausible and feasible approach for risk assessment of halogenated aromatic hydrocarbons with dioxinlike properties.

Subchronic toxicity of PCB 105 (2,3,3',4,4'-pentachlorobiphenyl) in rats

The toxicity of 2,3,3',4,4'-pentachlorobiphenyl (PCB 105) was investigated in Sprague-Dawley rats following dietary exposure to this substance at levels of 0, 0.05, 0.5, 5 or 50 ppm for 13 weeks. Growth rate and food consumption were not affected and no clinical signs of toxicity were observed. Increased incidences of enlarged, fatty liver and decreased thymic weight were observed in the highest-dose groups of both genders; these groups also had elevated hepatic microsomal ethoxyresorufin deethylase activity and uroporphyrin. Significant increases in serum cholesterol and hepatic pentoxyresorufin dealkylase activity were observed in the highest-dose males and two highest-dose females. By contrast, liver UDP-glucuronosyl transferase activity was elevated in the two highest-dose males and the highest-dose females. Urinary ascorbic acid excretion was increased in the highest-dose males. While the amount of vitamin A was decreased dose-dependently, starting at 0.5 ppm in the liver of both sexes and in the lung of the females, the level in the kidney of the highest-dose group was increased. Administration of PCB 105 resulted in decreased dopamine in the caudate nucleus region of the brain in males and homovanillic acid in caudate nucleus and nucleus accumbens of females. Increased 5-hydroxytryptamine and 5-hydroxyindoleacetic acid were observed in the substantia nigra region of both sexes, with most of the increases being seen in highest-dose females. Anemia, characterized by decreased hemoglobin, hematocrit and red cell indices, occurred in the highest-dose group, as did eosinophilia. Treatment with PCB 105 caused dose-dependent histopathological changes in the liver and thyroid. Thymic changes were observed in the highest-dose males and two highest-dose females. Tissue residue data showed a dose-dependent accumulation of this congener in fat, liver and spleen, kidney and brain. Based on these data the no-observable-effect level of PCB 105 was judged to be 0.05 ppm or 3.9 microg kg(-1) body wt. day(-1) in males and 4.2 microg kg(-1) body wt. day(-1) in females.

Subchronic toxicity of 2,2',3,3',4,4'-hexachlorobiphenyl in rats

The subchronic toxicity of 2,2',3,3',4,4'-hexachlorobiphenyl (PCB 128) was investigated in rats following dietary exposure at 0, 0.05, 0.5, 5, or 50 ppm for 13 wk. The growth rate was not affected by treatment and no apparent clinical signs of toxicity were observed. There was a significant increase in liver weight in the 50 ppm females. The liver ethoxyresorufin deethylase (EROD) activity was increased by five- and fourfold in the highest dose males and females, respectively, while aminopyrine demethylase (ADPM) activity was significantly increased only in the highest dose females. Liver vitamin A was significantly reduced in the highest dose females. No other biochemical or hematological effects were observed. Treatment-related histopathological changes were seen in the thyroid and liver, and to a lesser extent in the bone marrow and thymus. Residue data showed a dose-dependent accumulation of PCB 128 in the following tissues: fat, liver, kidney, brain, spleen, and serum, with the highest concentration being found in fat followed by liver and kidney. Based on these data, the no-observable-adverse-effect level of PCB 128 was judged to be 0.5 ppm in diet or 42 micrograms/kg body weight.

Toxicity of 2,4,4'-trichlorobiphenyl in rats following 90-day dietary exposure

The toxicity of 2,4,4'-trichlorobiphenyl (PCB 28) was investigated in rats after a 90-d dietary exposure. Groups of 10 male and 10 female weanling Sprague-Dawley rats were administered PCB 28 in the diet at 0, 0.05, 0.50, 5.0, or 50.0 ppm for 13 wk. Growth rate and food consumption were not affected by treatment, and no clinical signs of toxicity were observed. Mottled liver was noted in both control and PCB-treated males, but was found with increased incidence in the highest treatment group. Increased urinary ascorbic acid and hepatic microsomal ethoxyresorufin O-deethylase activity were observed in the 50.0 ppm group of both sexes. The vitamin A content in liver, lung, and kidney was not significantly affected by treatment. Analysis of brain biogenic amines showed a decreased dopamine concentration in the substantia nigra region of female rats receiving 0.5 ppm PCB 28 and higher doses. Female rats appeared to be more sensitive than males to the neurochemical effects of PCB 28. Dose-dependent histologic changes were observed in the thyroid and liver, with biologically significant changes occurring at 5.0 ppm and above. Based on these data, the no observable-adverse-effect level (NOAEL) for this PCB congener was considered to be 0.5 ppm in diet or 36 micrograms/kg body weight/d.

Toxicity of 2,2',4,4',5,5'-hexachlorobiphenyl in rats: effects following 90-day oral exposure

The subchronic toxicity of 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) was investigated in rats after 13 weeks of dietary exposure. Groups of 10 male and 10 female rats were administered PCB 153 in their diet at levels of 0.05, 0.50, 5.0 or 50 ppm for 13 weeks. The control groups received the diet containing 4% corn oil. Growth rate and dietary consumption were not affected by treatment. Clinical signs of toxicity were not observed. Enlarged, fatty liver was observed in treated animals at necropsy, but most were confined to the two highest dose groups. Increased hepatic microsomal ethoxyresorufin-O-deethylase, aminopyrine-N-demethylase and aniline hydroxylase activities occurred in high-dose groups of both sexes, with increased ethoxyresorufin-O-deethylase activity being observed starting at 0.05 ppm in females and at 0.5 ppm in males. Treatment-related reduction in hepatic and pulmonary vitamin A was seen in the highest dose group of both sexes. Changes in brain biogenic amines and intermediate products were observed mainly in females; these included decreased dopamine and 5-hydroxytryptamine concentrations in the frontal cortex region, and dihydroxyphenylacetic acid in the caudate nucleus region at 5.0 and 50 ppm. Female rats appeared to be more sensitive to the neurotoxic effects of PCB 153 than males. Dose-dependent histological changes were observed in the thyroid and liver of rats of both sexes and significant changes occurred at 5.0 and 50 ppm. Based on these data, the no-observable-adverse-effect level (NOAEL) of PCB 153 was judged to be 0.5 ppm in the diet or 34 micrograms kg-1 body wt. day-1.

Subchronic toxicity of 3,3',4,4',5-pentachlorobiphenyl in the rat. I. Clinical, biochemical, hematological, and histopathological changes

The systemic toxicity of 3,3',4,4',5-pentachlorobiphenyl (PCB 126) following subchronic dietary exposure was investigated in Sprague-Dawley rats. PCB 126 was administered to rats of both sexes at concentrations of 0.1, 1.0, 10, or 100 ppb in their diet for 13 weeks. Another group of rats received a loading dose of 5 micrograms PCB/kg body wt at the start of the feeding period followed by exposure to 10 ppb PCB diet for the same period of time as the other groups. Growth suppression and decreased food consumption were observed in the highest dose groups of both sexes. Increased organ/body weight ratios for the liver occurred in the 10 and 100 ppb groups of both sexes. Rats of both sexes exposed to the highest dose of the PCB also exhibited increased relative kidney, spleen, and brain weights. Hematological and most serum biochemical changes were confined to the 100 ppb groups. These included elevated alkaline phosphatase, bilirubin, cholesterol, and aspartate aminotransferase, and decreased serum glucose, hemoglobin, erythrocytes, hematocrit, and platelets. A dose-dependent increase in liver ethoxyresorufin-O-deethylase activity was observed in rats of both sexes starting at 0.1 ppb. A dose-dependent increase in liver uroporphyrin levels was observed in both sexes and significant changes occurred in the female rats at 1.0 ppb and higher dose groups. Decreased liver vitamin A was observed in the 10 ppb group and higher in both sexes. Kidney vitamin A was elevated in the 100 ppb group. No statistically significant changes were noted in concentrations of brain biogenic amines. PCB 126 residues were 10-fold higher in liver than in fat. Treatment-related histopathological changes were observed in the thymus, thyroid, bone marrow, and liver of rats exposed to the 10 ppb diet, but increased frequency of mild changes was observed in most of these tissues at the 1.0 ppb level. Based on the above data, the no adverse effect level was judged to be 0.1 ppb in the diet or 0.01 micrograms/kg body wt/day.

Role of xanthine oxidase inhibition in survival from hemorrhagic shock

The irreversible loss of adenine nucleotides and the formation of free radicals have both been suggested as causes of irreversibility following prolonged hemorrhagic shock. This study was performed to assess the effect of xanthine oxidase inhibition (allopurinol 50 mg/kg/day), free radical scavenging (superoxide dismutase 15,000 u/kg, catalase 15,000 u/kg, dimethylsulfoxide 20 mg/kg, and alpha tocopherol 100 mg/kg/day) or both, on the 24-hr survival of dogs subjected to irreversible haemorrhagic shock. Twenty anesthetized dogs were bled to a mean arterial pressure of 30 mm Hg for 4 hr. The dogs were allocated to a control, an allopurinol pretreated, a free radical scavenger, or a combined treatment group. Both groups pretreated with allopurinol had significantly improved survival (P < 0.05) over that seen in the control group, but the free radical scavenger treated group was not significantly different from the control group. This study demonstrates the beneficial effect of xanthine oxidase inhibition on survival, and suggests that it may be due to preservation of adenine nucleotides rather than prevention of free radical formation.

Staff distress among haemophilia nurses

To investigate the severity, sources, and means used to cope with the distress experienced by haemophilia nurses as a result of the widespread infection with Human Immunodeficiency Virus among haemophiliacs, we collected anonymous questionnaire data from all nurses in the Haemophilia Nursing Network Directory, compiled by the National Haemophilia Foundation in June, 1990. Questionnaires were returned by 136 of the 181 (75%) nurses in the sample. Over 50% of the sample gave distress responses to 15 of 44 statements. Areas associated with the greatest distress were: (1) Failure of patients to take steps to prevent transmission of HIV; (2) Fear of getting infected, and (3) the repeated loss experienced as patients died from infection. Nurses working with haemophiliacs for 11-15 years were particularly vulnerable to feelings of guilt for having participated in the treatment that resulted in HIV infection. Fear of contagion and distress from patient deaths were mutually exclusive ways of reacting to HIV in haemophiliacs. Looking for a new job was related to all major sources of distress. Interaction with peers was perceived as being the most useful source of emotional support.

Hyperthermic potentiation of BCNU toxicity in BCNU-resistant human glioma cells

Experimental evidence indicating potentiation of the cytotoxic effect of drugs at high temperatures suggests that the utilization of drug-heat combinations for gliomas of the brain might be therapeutically useful. Hyperthermia may increase the cytotoxicity of a particular drug in areas of low drug concentration/time and in cell populations resistant to the drug. We report in vitro experiments with a BCNU resistant, U-373MG, and a BCNU sensitive, U-87MG, human derived glioma cell lines under hyperthermic conditions. Temperatures equal or above 42 degrees C potentiate BCNU cell kill in both lines. The thermo-sensitizer lidocaine increases thermal cell kill but only minimally with concentrations corresponding to therapeutic plasma lidocaine levels. Within our experimental conditions, the best strategy to overcome BCNU resistance involved a combination of heat, BCNU and cis-DDP. BCNU resistant cells have no cross resistance to cis-DDP and the combination of BCNU and cis-DDP is synergistic. At modest hyperthermic conditions (42 degrees C) 99.4% BCNU resistant cells are killed by a combination of BCNU and cis-DDP at drug concentrations identical to plasma concentrations after standard IV doses. Clinical protocols using heat and drug may need to incorporate two or more drugs for optimal effects.

Upper limb embolus: a timely diagnosis

In a ten year period, 36 patients were treated surgically for embolic occlusion of upper limb vessels. The sources of embolus were cardiac (58%), peripheral aneurysm (22%) and unknown (20%). Brachial embolectomy was performed in all cases. Six out of eight peripheral aneurysms were resected. A patency rate of 94% was achieved at five years. Hospital mortality and morbidity rates were 3% and 10%, respectively. One patient died of a myocardial infarct one week postoperatively. Three patients suffered ischemic contracture or amputation; all three presented after 36 hours. We conclude that upper limb emboli are usually easy to recognize and treat. Prompt surgery (less than 24 hours) produces the most satisfactory results. Late presentation or delay in treatment can result in limb loss.

Inhibitors of repair of potentially lethal damage and DNA polymerases also influence the recovery of potentially neoplastic transforming damage in C3H10T-1/2 cells

The effects of aphidicolin and beta Ara A on radiation sensitivity were evaluated in terms of cell killing, recovery, and neoplastic transformation in the C3H10T-1/2 cell system. When cells were held in plateau phase, recovery of potentially lethal damage (PLD) and potentially transforming damage (PTD) occurred. The addition of beta Ara A resulted in reduced PLD recovery for both the survival and neoplastic transformation end points. The addition of aphidicolin did not affect recovery of PLD or PTD. These data show that the inhibition of polymerase alpha by aphidicolin does not affect recovery of damage leading to cell death or neoplastic transformation. However, the inhibition of both polymerase alpha and beta by beta Ara A resulted in inhibition of recovery of damage leading to both cell death and neoplastic transformation. These data indicated that polymerase beta may be involved in both PLD and PTD recovery.

Congenital arteriovenous malformation of the scalp with high output cardiac failure: a case report

A 19-year-old man was diagnosed with a rapidly enlarging arteriovenous malformation of the scalp and a mild degree of cardiomegaly. Operation to excise the large fistula took place under general anesthesia. Both external carotid arteries and their branches were controlled to prevent intraoperative hemorrhage, and dissection took place down to the periosteum. A split skin graft from the thigh was applied to the scalp defect. The patient recovered well with no further evidence of dyspnea or high output cardiac failure.

Morphological effects of lonidamine on two human-tumor cell culture lines

Lonidamine, 1-(2-4-dichlorobenzyl)-1-H-indazol-3-carboxylic acid, is an anticancer drug that has its primary action on cellular metabolism rather than cell division. Since lonidamine is not effective in all tumor cells, we have tested it in two human-tumor cell culture lines: MOLT-4, a T-leukemia and U-87 MG, a glioma. Lonidamine exposure of MOLT-4 cells at 50 micrograms/mL and pH 6.7 disrupted the mitochondria within 1 h of treatment. The mitochondria were swollen and the cristae were disrupted. When the treated cells were re-incubated in fresh medium at pH 7.4 the mitochondria rapidly returned to their normal morphology. The U-87 MG glioma cells did not show ultrastructural disruption after 1-h treatment with lonidamine at concentrations up to 200 micrograms/mL at pH 6.7. In the concentration range of 25 micrograms/mL to 200 micrograms/mL, lonidamine did not produce any cell killing in MOLT-4 after a 1-h exposure at pH 7.4, although the drug had some limited effectiveness at pH 6.7. Compared to sham-treated controls, long exposures to 100 micrograms/mL of lonidamine at pH 6.7 reduced survival in MOLT-4 to 92% and 53% after 6-h and 24-h exposures, respectively. Survival of U-87 MG glioma cells was also strongly pH dependent, a 2-h exposure to 50 micrograms/mL lonidamine at pH 7.4 did not cause cell death; however, survival dropped to 84% of the control at pH 6.65.

Can pre-operative duplex scanning replace pre-operative short saphenous venography as an aid to localizing the sapheno-popliteal junction?

The accuracy of Duplex ultrasound scanning in locating the sepheno-popliteal junction (SPJ) was assessed by comparison with clinical examination and short saphenous venography. Twenty-three legs with varicosities of the short saphenous system had their SPJ located by Duplex scanning and marked pre-operatively. Varicography was performed on all patients. Clinical examination localised the junction to within 2 cm in 8/23 (37%) compared to 16/23 (74%) for Duplex ultrasonography and 21/23 (93%) venography. Ihis study shows that Duplex ultrasonography while more accurate than clinical evaluation, should not replace venography in the pre-operative localisation of the SPJ.

Simultaneous protective and damaging effects of cysteamine on intracellular DNA of leukocytes

Incubation of human leukocytes with cysteamine can lead to the induction of DNA strand breaks. The induction of breaks is biphasic with increasing concentration of scavenger. The number of breaks increases in a dose-dependent manner to a maximum and then decreases at higher concentrations. Catalase has been shown to prevent the production of breaks, indicating an involvement of hydrogen peroxide. Cysteamine reacts with oxygen to generate hydrogen peroxide but at higher concentrations it also reacts with hydrogen peroxide. Thus, the biphasic effect of cysteamine on leukocyte DNA may be due to the sum of two separate reaction pathways. (i) Cysteamine reacts with oxygen to generate hydrogen peroxide which leads to DNA strand breakage. (ii) At higher concentrations, it eliminates hydrogen peroxide by reacting with it, thereby protecting the cellular DNA. Other antioxidant scavengers such as WR2721, acetylcysteine and ascorbate can also autooxidize to produce strand breaks. Thiourea and tetramethylurea do not. When tested for their ability to protect cells against DNA damage from added H2O2, the agent which most damaging by itself, cysteamine, was also the most protective.

Potentially lethal radiation damage repair and its inhibition by hyperthermia in normal hamster cells, mouse cells, and transformed mouse cells

The capacity of plateau-phase Chinese hamster V79 and normal and transformed C3H-10T1/2 cells for repair of potentially lethal radiation damage (PLD) was evaluated for cells irradiated alone or given combined treatments of heat and radiation. The data show that all cell lines tested could repair PLD and that transformation to the tumorigenic state may reduce the capacity to repair PLD, especially if cells are evaluated at equal survival levels. Hyperthermia treatments before irradiation produced less sensitization than treatments after irradiation. In addition, hyperthermia treatment led to the inhibition of cellular capacity to repair PLD. This effect was the greatest for cells heated after irradiation, and repair of PLD could be completely eliminated. Several temperature isodose heat treatments were evaluated, and the lower temperature heat treatments were more effective in the inhibition of PLD than the higher temperature heat treatments; this is consistent with earlier results indicating temperature dependence in thermal radiosensitization (S. A. Sapareto et al., Int. J. Radiat. Oncol. Biol. Phys. 5, 343-347 (1979)).

Drug cytotoxicity at elevated temperature. In vitro study on the U-87MG glioma cell line

The malignant glioma cell line U-87MG was used for 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), aziridinylbenzoquinone (AZQ), cis-diaminodichloroplatinum (II) (cis-DDP), and spirohydantoin mustard (SHM) treatments at 37 degrees and 42 degrees C. With the exception of SHM, all drugs killed a greater proportion of cells at the higher temperature, as assessed by the colony-formation assay. Drug-dose enhancement ratios were 1.6, 2.8, 2, and 1:1 for BCNU, AZQ, cis-DDP, and SHM, respectively. Because methods to heat discrete volumes of brain are now available, we conclude that hyperthermic increase of BCNU, AZQ, and cis-DDP cytotoxicity might have therapeutic application for malignant gliomas.

A critical assessment of fluoroscopy in peroperative cholangiography

In a prospective study of 248 patients undergoing peroperative cholangiography fluoroscopy improved the quality of radiographs by ensuring the use of a volume of contrast medium appropriate to each patient's duct capacity and the correct positioning of the ducts away from obscuring objects. Failure of contrast medium to enter the duodenum is usually considered to be an indication for choledochotomy. Although this occurred in 35 patients, the use of fluoroscopy and the injection of an anticholinergic drug without further contrast medium showed the choledochoduodenal junction to be normal, making choledochotomy unnecessary, in 28. The low negative duct exploration rate (3 of 56 patients) and the virtual elimination of false positive peroperative postexploratory cholangiograms (1 of 50 patients) provide further evidence of the value of fluoroscopy.