Dietary mercury exposure in a population with a wide range of fish consumption--self-capture of fish and regional differences are important determinants of mercury in blood.

Human, low level, chronic exposure to mercury (Hg) from fish is of concern because of potential neurodevelopmental and cardiovascular toxicity. The purpose of the study was to 1) measure total mercury (THg) in blood and estimate dietary exposure in a population group with a wide range of seafood consumption, 2) assess the intake and blood concentration in relation to tolerable intake values, 3) characterise dietary sources, and 4) to investigate the relationship between dietary THg with THg in blood (BTHg), including factors that can explain the variance in BTHg concentrations. The participants (n=184) filled in an extensive food frequency questionnaire which was combined with a database on THg concentrations in Norwegian food, and donated blood and urine. Median consumption of seafood was 65 g/day (range 4 to 341 g/day). The calculated mean dietary THg exposure was 0.35 (median 0.30) µg/kg body weight/week. Seafood contributed on average 95% to the exposure. The JECFA Provisional Tolerable Weekly Intake (PTWI) of 1.6 µg MeHg/kg bw/week was not exceeded by any of the participants. BTHg ranged from 0.6 to 30 µg/L, with a mean of 5.3 (median 4.0 µg/L). There was a strong relationship between total seafood consumption and BTHg concentrations (r=0.58 95%CI: 0.48, 0.67) and between estimated THg dietary exposure and BTHg (r=0.46 95%CI: 0.35, 0.57). Fish consumption, sex, catching >50% of their seafood themselves, and living in coastal municipalities were significant factors in linear regression models with lnBTHg. Including urinary Hg in the regression model increased the explained variance from 54% to 65%. In a toxicokinetic model, the calculated dietary intake appeared to moderately underestimate the measured BTHg among the participants with the highest BTHg. Only two of the participants had BTHg slightly above a value equivalent to the JECFA PTWI, but none of them were women in fertile age.

Climate variability and forecasting surface water recovery from acidification: modelling drought-induced sulphate release from wetlands.

Climate-induced drought events have been shown to have a significant influence on sulphate (SO(4)(2-)) export from forested catchments in central Ontario, subsequently delaying recovery of surface waters from acidification. Field and modelling studies have demonstrated that water table drawdown during drought periods promotes oxidation of previously stored (reduced) sulphur (S) compounds in wetlands, with subsequent efflux of SO(4)(2-) upon re-wetting. Although climate-induced changes in processes are generally not integrated into soil-acidification models, MAGIC (Model of Acidification of Groundwater in Catchments) includes a wetland compartment that incorporates redox processes driven by drought events. The potential confounding influence of climate-induced drought events on acidification recovery at Plastic Lake, south-central Ontario (under proposed future S emission reductions) was investigated using MAGIC and two climate scenarios: monthly precipitation and runoff based on long-term means (average-climate scenario), and variable precipitation and runoff based on the past 20 years of observed monthly data (variable-climate scenario). The variable-climate scenario included several periods of summer drought owing to lower than average rainfall and higher then average temperature. Nonetheless, long-term regional trends in precipitation and temperature suggest that the variable-climate scenario may be a conservative estimate of future climate. The average-climate scenario indicated good recovery potential with acid neutralising capacity (ANC) reaching approximately 40 micromol(c)L(-1) by 2020 and 50 micromol(c)L(-1) by 2080. In contrast, the forecasted recovery potential under the variable-climate scenario was very much reduced. By 2080, ANC was forecasted to increase to 2.6 micromol(c)L(-1) from -10.0 micromol(c)L(-1) in 2000. Elevated SO(4)(2-) efflux following drought events (introduced under the variable-climate scenario) has a dramatic impact on simulated future surface water chemistry. The results clearly demonstrate that prediction of future water quality, using models such as MAGIC, should take into account changes or variability in climate as well as acid deposition.

The occurrence of asymptomatic and symptomatic simple hepatic cysts. A prospective, hospital-based study.

AIM: To examine the prevalence of asymptomatic and symptomatic liver cysts in a university hospital patient population using modern US equipment. METHODS: Abdominal US scans of 1541 cases referred during the period 21 January to 11 November 2000 were examined for hepatic cysts. RESULTS: Of 1541 cases, 174 (11.3%) were found to have hepatic cysts, i.e. 109 female (12.5%) and 65 (9.7%) male patients (9.7%). In 413 individuals younger than 40 years, no cysts were found. Above the age of 40 years, prevalence increased with age. CONCLUSION: By using modern US equipment, we found a higher prevalence of hepatic cysts than that reported in previous studies. Patient selection and the prevalence of liver cysts in the population from which the patients were referred may have influenced our results.

Biochemical and cytologic analysis of cystic contents in benign non-parasitic symptomatic hepatic cysts before and after ethanol sclerotherapy.

PURPOSE: To examine the fluid of liver cysts by cytologic and biochemical analysis before and after ethanol sclerotherapy in order to explore the etiology of cystic fluid reproduction after sclerotherapy. MATERIAL AND METHODS: The contents of 11 cysts in 11 patients were examined on the day of sclerotherapy, and 2-8 (mean 4.5) days later, and analysed for cytologic and biochemical parameters. RESULTS: Cytologic signs of acute or subacute inflammatory reaction were absent before and present in all cysts after sclerotherapy. Biochemical parameters reflecting the acute inflammatory reaction (CRP, orosomucoid and haptoglobine), changes in capillary permeability (protein, albumin), and the cystic epithelial function (bilirubin, alkaline phosphatase) were significantly elevated after sclerotherapy. CONCLUSION: The post-sclerotherapy fluid production is probably due to an inflammatory reaction. This may explain the success of performing sclerotherapy in one single session.

Complications and late outcome following percutaneous drainage of the gallbladder in acute calculous cholecystitis.

BACKGROUND: Acute septic cholecystitis (AC) remains a difficult problem in patients with coexisting severe illness, and ultrasonographically guided percutaneous puncture and drainage of the gallbladder (PTBD) may be an alternative treatment in this context. SETTING: University Hospital, Norway. METHODS: Retrospective study of the safety and efficacy of this approach in 86 consecutive patients treated from 1992 to 1999. RESULTS: Five patients died. Drainage did not seem to influence the condition in these patients, who were drained for a mean of 8 days after admission compared to 4 days for the survivors (p = 0.01), and had a higher S-bilirubin on the day of the drainage, 46 and 29 micromol/l (p = 0.05), respectively. Seven patients had an intraperitoneal bile leak and 2 had worsening septicemia. One of these patients had both, and the gallbladder was removed. An open cystic duct demonstrated at catheter cholangiography was associated with a bile leak in 3 (4%) of 76 patients as opposed to 4 (40%) of 10 patients with obstruction (p = 0.001). Only 60 patients survived another 6 months because of general debility and other diseases. Twenty-seven (45%) of these were asymptomatic during follow-up. Twenty-eight (47%) of the remaining patients had at least one recurrent episode of AC. One patient who was readmitted due to AC had urgent cholecystectomy and 8 others had elective cholecystectomy during follow-up for a total cholecystectomy rate of 12%. A common bile duct stone was demonstrated in 4 patients after ERCP and indicative signs were found in another 5 (10%). CONCLUSIONS: PTBD remains a good option in patients with septic AC who have severe coexisting disease and may be too ill to undergo an operation. It may not be necessary to remove the gallbladder in 45% or more of the patients as many remain asymptomatic after PTBD.

Nitrogen deposition and leaching from two forested catchments in Southwest China--preliminary data and research needs.

Increased nitrogen deposition has resulted in increased nitrogen pools and nitrogen leaching in European and North American forest soils. The development in Asia in general, and China in particular, suggests increased deposition of reduced nitrogen from changes in agricultural practices and of oxidized nitrogen from rapid growth of the transportation sector. Decreased nitrogen retention in forested areas in the future may cause increased NO3- leaching and, thus, acidification and eutrophication in surface waters. The differences in climate, ecosystems, land use, and deposition history make direct application of knowledge from studies in Europe and North America difficult. In Southwest China the potential for nitrogen mobilization from forest soils may be high because of the warm and humid climate, resulting in high decomposition rates of soil organic matter. However, there are very few data available for quantifying the suspected potential for increased nitrogen leaching in forest ecosystems. Here we present data from two forested catchments, dominated by Masson pine (Pinus massoniana), near Guiyang and Chongqing, respectively, in Southwest China. The present nitrogen deposition is moderate, estimated in the range from 10 to 40 kg N ha(-1) year(-1). The C/N ratios of the soils are generally below 15. Nitrate concentrations in soil water are rather variable in space, with highest values of several hundred microequivalents per liter. The turnover rate of nitrogen in the forest ecosystem is quite high compared to the atmospheric deposition rate. At present, nitrate runoff from the catchments is low and intermediate in Guiyang and Chongqing, respectively. More research is needed to improve our ability to predict future nitrogen leaching from subtropical Asian coniferous forests.

The value of ultrasonography in predicting autoimmune thyroid disease.

Ultrasonography (US) may demonstrate a diffuse reduction in thyroid echogenicity (low-amplitude echoes) in autoimmune thyroid disease (AITD), which includes chronic lymphocytic thyroiditis and Graves' disease, as well as in subacute thyroiditis. The reported occurrence of this finding in AITD varies from 19% to 95%. To assess the validity of diffuse reduction in thyroid echogenicity as a predictor of AITD, 3,077 patients referred for US of the thyroid were examined prospectively with regard to reduced versus normal thyroid echogenicity. The most frequent reasons for referral were goiter, thyroid dysfunction, neck discomfort, and/or difficulty in swallowing. Ultrasonography demonstrated diffuse reduction in thyroid echogenicity in 485 patients. Of these, 452 patients had available records of fine-needle aspiration biopsy (FNAB), and were included in the study. From the remaining patients, with normal thyroid echogenicity, 100 consecutive patients were selected as controls. In 411 of the 452 study patients (90.9%) there was at least one laboratory finding consistent with possible AITD: cytology indicating lymphocytic thyroiditis, 287 of 363 patients (79.1%) with diagnostic specimens; elevated levels of peroxidase antibodies (TPOAb), 225 of 337 (66.8%); elevated thyrotropin (TSH) levels, 290 of 450 (64.4%); or low TSH levels, 79 of 450 (17.6%). The final diagnosis was: chronic autoimmune (Hashimoto's) thyroiditis in 352 patients; Graves' disease in 47 patients; subacute (granulomatous) thyroiditis in 7 patients; toxic nodular goiter in 3 patients; and toxic adenoma in 2 patients. In the remaining 41 patients, those without laboratory results consistent with AITD, the final diagnosis was colloid goiter in 37 and thyroid cancer in 4 patients. In the 100 controls, laboratory results were consistent with possible AITD in 14 patients: elevated TPOAb levels in 5 of 49 patients with retrieved antibody results; lymphocytic thyroiditis in 2 patients; elevated TSH levels in 2 patients; and low TSH levels in 2 patients. In these controls, the final diagnosis was: chronic autoimmune thyroiditis in 7; toxic nodular goiter in 6 patients, and toxic adenoma in 1 patient. The corresponding positive and negative predictive values of reduced thyroid echogenicity as an indicator of AITD were 399 of 452 (88.3% [95% CI, 85% to 91%]), and 93 of 100 (93.0% [95% CI, 88% to 98%]), respectively. Thus, diffuse reduction in thyroid echogenicity was a valid predictor of AITD.

Evaluation of different approaches for modeling effects of acid rain on soils in China.

Acid deposition is an environmental problem of increasing concern in China. Acidic soils are common in the southern part of the country and soil acidification caused by acid deposition is expected to occur. Here we test and apply two different approaches for modeling effects of acid deposition and compare results with observed data from sites throughout southern China. The dynamic model MAGIC indicates that, during the last few decades, soil acidification rates have increased considerably due to acid deposition. This acidification will continue if sulfur deposition is not reduced, and if reduced more rapidly than base cation deposition. With the Steady State Mass Balance model (SSMB), and assuming that a molar ratio of Ca2+/Al3+ < 1 in soil water is harmful to vegetation, we estimate a slight probability for exceedance of the critical load for present deposition rates. Results from both modeling approaches show a strong dependence with deposition of base cations as well as sulfur. Hence, according to the models, changes in emission control of alkaline particulate matter prior to sulfur dioxide will be detrimental to the environment. Model calculations are, however, uncertain, particularly because available data on base cation deposition fluxes are scarce, and that model formulation of aluminum chemistry does not fully reproduce observations. An effort should be made to improve our present knowledge regarding deposition fluxes. Improvements to the model are suggested. Our work indicates that the critical loads presented in the regional acid deposition assessment model RAINS-Asia are too stringent. We find weaknesses in the SSMB approach, developed for northern European conditions, when applying it to Chinese conditions. We suggest an improved effort to revise the risk parameters for use in critical load estimates in China.

Acid rain and acidification in China: the importance of base cation deposition.

Acid deposition has been recognized as a serious environmental problem in China. Most acid deposition studies have focused on sulfur deposition and the pH of precipitation. However, as high concentration of alkaline dust is an important feature of the atmosphere in large parts of China, base cation deposition must be taken into account when discussing possible effects on soils and vegetation from acid deposition. We estimate the deposition of sulfur as well as calcium, i.e. the dominating anion and cation, on a regional scale in China using data both from measurements and modeling. The ratio of sulfur/calcium in deposition is then used as an indicator for identifying areas where deposition acidity exceeds alkalinity, and where soils may be at risk to acidification. The dynamic soil acidification model MAGIC is applied with data from two sites receiving high deposition loads in southwest China. The model predictions indicate that considerable soil acidification has been going on for the last decades due to acid deposition inputs. Effects on the spatial distribution of acidic deposition in China, using different future deposition scenarios, are illustrated. As the size of the anthropogenic fraction of the base cation deposition is unknown, different possible future trends in calcium deposition were used. Soil response, according to the model, using different combinations of sulfur and calcium deposition scenarios is shown. Applying the most strict measures to reduce sulfur emission will almost eliminate the acid deposition problem; however, such a scenario is not economically feasible in the short term. A strict, but possibly realistic, future scenario for sulfur may be enough to keep the situation at the present level, assuming only moderate reductions in calcium deposition. With large decreases in base cation deposition, increased soil acidification can be expected even with considerable sulfur emission reductions.

Single-session alcohol sclerotherapy in symptomatic benign hepatic cysts. Long-term results.

PURPOSE: To evaluate the long-term results of single-session alcohol sclerotherapy of symptomatic benign liver cysts. MATERIAL AND METHODS: 23 cysts in 19 patients were treated by single-session percutaneous catheterization and injection of 96% ethanol. Evaluation of long-term results was possible in 11 cysts (volume 200-2,700 ml, mean 1,317 ml) in 11 patients. Time of observation was 12-67 months, mean 38.3 months. RESULTS: The reduction of volume was 93-100% (mean 98%). The re-accumulation of fluid after therapy seen in 9 patients proved to be transitory. Except for pain there were no complications. CONCLUSION: Single-session sclerotherapy resulted in satisfactory cyst volume reduction in all 11 long-term follow-up patients.

Hydrosonography of the small intestine: comparison with radiologic barium study.

BACKGROUND: Transabdominal ultrasonography of the small intestine is hampered by luminal gas. We have developed a new sonographic method (hydrosonography) that largely eliminates the gas problem and have compared this method with radiologic barium study. METHODS: Fifty-six patients admitted for X-ray examination of the small bowel because of abdominal pain, diarrhoea, weight loss and/or known inflammatory bowel disease were examined. To remove luminal gas before performing transabdominal ultrasonography, 21 of polyethylene glycol solution was inserted through a nasojejunal tube by means of a peristaltic pump. Wall thickness, peristalsis, luminal narrowing, prestenotic dilatation, and extraintestinal complications were recorded. RESULTS: On ultrasonography we were able to visualize the terminal part of the ileum in 98% of the patients. Perfect agreement between hydrosonography and barium studies was seen in 50 of 55 patients. However, 44 patients had normal findings on both examinations. The sensitivity and specificity of hydrosonography were 64% and 100%, respectively. The positive predictive value was 100%. For X-ray examination sensitivity and specificity were 91% and 100%, respectively. Four patients with minor mucosal abnormalities or pathologic findings in the upper part of the small intestine accounted for the relatively low overall sensitivity found for hydrosonography compared with roentgenography. However, important extraintestinal complications were disclosed by ultrasound. CONCLUSIONS: Hydrosonography of the small bowel is a new, convenient, and reliable method for examining the lower part of the small intestine. However, it cannot replace barium studies in patients with mucosal abnormalities. especially in the upper part of the small bowel.

Single-session alcohol sclerotherapy in benign symptomatic hepatic cysts.

PURPOSE: To evaluate the results of single-session alcohol sclerotherapy in benign symptomatic liver cysts. MATERIAL AND METHODS: Ten cysts (volume 200-4,800 ml) in 10 patients were treated by percutaneous catheterization and injection of 96% ethanol at a dose of 10% of the cyst volume but never more than 100 ml. The treatment was applied for a maximum of 20 min, after which the alcohol and catheter were removed. RESULTS: A satisfactory reduction in cyst volume was achieved in all patients. In 8 patients there was a re-accumulation of fluid during the first period after therapy, followed by a significant reduction in volume on later follow-up examinations. Except for pain, there were no complications. CONCLUSION: Sclerotherapy as a single-session procedure resulted in a significant reduction in cyst volume in all 10 patients. The postprocedural re-accumulation of fluid seen in 8 patients proved to be temporary. It was not necessary to repeat the sclerotherapy procedure in any patient.

Successful management of eleven splanchnic artery aneurysms.

OBJECTIVE: To describe our experience with the management of aneurysms of the splanchnic arteries. DESIGN: Retrospective study. SETTING: Teaching hospital, Norway. SUBJECTS: Eleven consecutive patients with aneurysms of the splanchnic arteries treated between 1986 and 1996, six of them between 1994 and 1996. Four aneurysms were hepatic (37%), two splenic (18%), one coeliac (9%), one gastroepiploic (9%), one pancreaticoduodenal (9%), one superior mesenteric (9%), and one jejunal (9%). Five were pseudoaneurysms (46%). INTERVENTIONS: Six patients (55%) were treated by operation, four (36%) by embolisation and one (9%) expectantly. RESULTS: The pathogenesis was inflammatory (acute pancreatitis, anastomotic leak) in four patients (36%), athero-sclerotic in three (27%), arterial infusion of cytotoxic drugs in one (9%), and unknown in four (36%). Seven patients (64%) presented with rupture, two (18%) with other symptoms, and two patients (18%) were diagnosed incidentally. There was no mortality. CONCLUSION: There may be an increased incidence in splanchnic artery aneurysms, particularly those created by inflammatory lesions. The diagnosis should be suspected if acute bleeding occurs during the course of severe intra-abdominal inflammation. Arteriography should be used to diagnose an aneurysm in haemodynamically stable patients. Control of bleeding is obtained either by transarterial catheter embolisation or by operation.

Trends in and value and consequences of radiologic imaging of perforated gastroduodenal ulcer. A 50-year experience.

The trends in and value and consequences of radiologic imaging in 1128 patients with perforated gastroduodenal ulcer have been studied over the 50-year period 1935-1985. The proportion of patients undergoing plain X-ray studies increased from 4% in the first 5-year period (1935-1939) to 94% in the last (1980-1985). Pneumoperitoneum was found in 77% of those undergoing X-ray studies. Water-soluble contrast studies were introduced in 1960, and in the three 5-year periods 1970-1985 from 8% to 13% underwent such imaging. Leakage was demonstrated in 60% of those undergoing contrast studies. Contrast studies have had a limited role in the pretreatment evaluation of these patients. The frequency of pneumoperitoneum was fairly constant over the 50-year period, and the only patient characteristic that influenced the occurrence of free gas in the abdominal cavity was age, with a higher proportion of patients with pneumoperitoneum in old patients. Any radiologic study increased treatment delay by at least 2 h.

Fine-needle aspiration cytology of focal liver lesions. Advantages and limitations.

Fine-needle aspiration cytology of focal liver lesions was performed 192 times in 175 patients over a 5-year period. Ultrasonic guidance was used for 153 punctures; the others were done peroperatively or on a palpable mass. A correct diagnosis of malignancy was obtained in 89/111 cases (80.2%), and of metastases (adenocarcinoma) to the liver in 71/84 (84.5%). The total of nonrepresentative aspirates was 26 (13.5%). The overall accuracy of cytologic evaluation was 87.5%, with 79.5% sensitivity and 100% specificity in malignant disease. The predictive values of positive and negative results were, respectively, 100% and 75.8%. There were no false positive tests, but 12.5% false negatives. No complications following the aspiration procedure were seen. Fine-needle aspiration biopsy is simple and safe, but the relatively high proportion of nonrepresentative aspirates is a problem. Possibly a more aggressive approach with multiple punctures may lessen this incidence and enhance the diagnostic accuracy in hepatic malignancy.

Ultrasonically and fluoroscopically guided therapeutic percutaneous catheter drainage of the gallbladder.

Percutaneous gallbladder drainage was performed in 16 poor surgical risk patients; 13 had acute cholecystitis, 1 had cholangitis and septicemia, 1 had undergone removal of a gallbladder calculus, and 1 had pancreatic carcinoma with bile duct occlusion. Catheterization and drainage of the gallbladder succeeded primarily in all patients. Catheter dislodgement occurred within 24 h in 1 patient without any side effects. One 87-year-old patient died 14 h after the insertion of the catheter from reasons unrelated to the drainage procedure. Percutaneous removal of gallbladder calculi failed in 3 patients, 2 of whom had been successfully treated for cholecystitis by catheter drainage. Percutaneous gallbladder drainage is a fast, low-risk, inexpensive procedure well suited for the treatment of acute, poor surgical risk patients.