Stepwise effects of the BCR sequential chemical extraction procedure on dissolution and metal release from common ferromagnesian clay minerals: a combined solution chemistry and X-ray powder diffraction study.

Sequential extraction procedures (SEPs) are commonly used to determine speciation of trace metals in soils and sediments. However, the non-selectivity of reagents for targeted phases has remained a lingering concern. Furthermore, potentially reactive phases such as phyllosilicate clay minerals often contain trace metals in structural sites, and their reactivity has not been quantified. Accordingly, the objective of this study is to analyze the behavior of trace metal-bearing clay minerals exposed to the revised BCR 3-step plus aqua regia SEP. Mineral quantification based on stoichiometric analysis and quantitative powder X-ray diffraction (XRD) documents progressive dissolution of chlorite (CCa-2 ripidolite) and two varieties of smectite (SapCa-2 saponite and SWa-1 nontronite) during steps 1-3 of the BCR procedure. In total, 8 (+/-1) % of ripidolite, 19 (+/-1) % of saponite, and 19 (+/-3) % of nontronite (% mineral mass) dissolved during extractions assumed by many researchers to release trace metals from exchange sites, carbonates, hydroxides, sulfides and organic matter. For all three reference clays, release of Ni into solution is correlated with clay dissolution. Hydrolysis of relatively weak Mg-O bonds (362 kJ/mol) during all stages, reduction of Fe(III) during hydroxylamine hydrochloride extraction and oxidation of Fe(II) during hydrogen peroxide extraction are the main reasons for clay mineral dissolution. These findings underscore the need for precise mineral quantification when using SEPs to understand the origin/partitioning of trace metals with solid phases.

Effect of hypohydration on core temperature during exercise in temperate and hot environments.

The purpose of this study was to compare directly the physiological consequences of 5% hypohydration or euhydration during exercise in both temperate (23 degrees C) and hot (33 degrees C) environments. The subjects were eight male volunteers. Each performed four 1-h exercise bouts at 60% maximum oxygen uptake, one in each of the following conditions: hot-hypohydrated, hot-euhydrated, temperate-hypohydrated, and temperate-euhydrated. Heart rate (HR), rectal temperature (Tre), forearm blood flow, and oxygen uptake were measured after 20, 40, and 60 min exercise. Whole-body sweat rate was also determined for each exercise bout. Hypohydration increased Tre significantly (P<0.05) more in the hot environment (0.16 degrees C per 1% decrease in body mass) than in the temperate environment (0.08 degrees C per 1% hypohydration). Furthermore, compared with euhydration, hypohydration decreased forearm blood flow and whole-body sweat rate significantly more during exercise in the hot than in the temperate environment. The reductions in forearm blood flow and whole-body sweat rate appear to have decreased heat loss, thus accounting for the increase in Tre during exercise in the heat while hypohydrated. In conclusion, this study illustrates that the physiological consequences of hypohydration during exercise are exacerbated in the heat.

Diagnosis of Wilson's disease: an experience over three decades.

BACKGROUND: Wilson's disease is a rare but treatable condition that often presents diagnostic dilemmas. These dilemmas have for the most part not been resolved by the identification and cloning of the Wilson's disease gene. AIMS: To report our experience over three decades with patients with Wilson's disease in order to illustrate the diverse patterns of presentation and thereby broaden the approach to diagnosis. METHODS: Clinical and laboratory findings of 30 patients with Wilson's disease were reviewed. RESULTS: Twenty two patients presented with liver manifestations (eight with fulminant hepatic failure and 14 with chronic liver disease), three with neurological disease, and one with haemolysis; four were asymptomatic siblings of patients with Wilson's disease. Seventy per cent were diagnosed within six months of the onset of symptoms, but diagnosis was delayed for up to nine years. Age range at diagnosis was wide (7-58 years) and five patients were over 40. In patients presenting with non-fulminant disease, 18% had neither Kayser-Fleischer rings nor low caeruloplasmin concentrations. Increased liver copper concentrations were found in all but one patient who had undergone six years of penicillamine treatment. In fulminant hepatic failure (n=8) additional features helpful in the diagnosis included evidence of haemolysis, increased urinary copper (range 844-9375 microg/24 h), and a high non-caeruloplasmin copper (range 325-1743 microg/l). CONCLUSIONS: The diagnosis of Wilson's disease still depends primarily on the evaluation of clinical and laboratory evidence of abnormal copper metabolism. No one feature is reliable, but the diagnosis can usually be made provided that it is suspected. Wilson's disease should be considered in patients of any age with obscure hepatic or neurological abnormalities.

A survey of red cell use in 45 hospitals in central Ontario, Canada.

BACKGROUND: The purpose of this survey was to establish baseline information on blood component use in relation to patient diagnoses, procedures, and demographics and to identify patterns of blood use that may be used for blood program planning and transfusion audits. STUDY DESIGN AND METHODS: A cross-sectional survey of the transfusion of blood components in teaching and nonteaching hospitals in central Ontario between September 1991 and August 1992 was carried out. Coders of hospital medical records routinely record demographics, procedures, diagnoses, and other relevant information. A protocol was created by which medical records coders could add the components transfused to the discharge abstract for this study. Red cell use is reported here. RESULTS: Of the 61 hospitals invited to participate, from which 547,279 patients were discharged during the 12-month period of the study, 45 (74%) agreed to participate. Information was collected on 439,373 discharged patients. Of these, 26,611 (6.1%) received at least 1 unit of red cells. Of a total of 101,116 red cell units transfused, more than 74 percent were used in patients discharged with neoplasms, gastrointestinal diseases, circulatory system diseases, and trauma. High-transfusion-use procedures included operations and procedures on the digestive and cardiovascular systems, diagnostic and therapeutic procedures, musculoskeletal system, and hemic or lymphatic system procedures. CONCLUSION: This survey provides baseline blood transfusion information for a specific period that can help determine the need for hospital audits and maximum surgical blood-order schedule guideline reviews. This information is relevant to current recommendations to reduce patient's exposure to blood components. These transfusion data will assist in blood program planning based on known disease trends, demographics, and population changes.

Stent placement in coeliac and superior mesenteric arteries to restore vascular perfusion following aortic dissection.

The main trunks of both coeliac and superior mesenteric arteries were sheared off the abdominal aorta by an anterior dissection that spared the renal arteries. Both vessels were cannulated and a Walstent inserted across the false lumen to restore normal coeliac and superior mesenteric perfusion. This produced a successful haemodynamic and angiographic result with improvement in the patient's clinical condition.

Effects of a chromated-copper-arsenate wood preservative on the bacterial degradation of pentachlorophenol.

The effect of a chromated-copper-arsenate wood preservative on the degradation of pentachlorophenol by Flavobacterium sp. strain ATCC 53874 was examined in liquid culture. Both a commercially available and a laboratory-prepared formulation were tested. Each increased the lag time required for measurable pentachlorophenol degradation and the time required for complete degradation to nondetectable levels. This response was noted at all pentachlorophenol concentrations examined (10, 25, 50, 75, and 100 micrograms.mL-1). The commercial formulation of chromated-copper-arsenate had the more significant impact on pentachlorophenol degradation. Inhibitory effects were evident at chromated-copper-arsenate component metal concentrations 0.1-0.5 mg.L-1. These levels are thousands of times below those used commercially.

Group homes in North Carolina for children and adults with autism.

Autistic people not living with their families live in 11 group homes throughout North Carolina. These homes, funded by both state and federal sources, are affiliated with TEACCH, the state agency for the identification and treatment of autism. This article looks at several aspects of group homes including cost effectiveness, staff selection and training, level of structure and programming, composition of the client group, adherence to a central philosophy, and the role of administration. Evidence suggests that group homes are a viable and cost-effective residential option for autistic people. While more group homes are needed, development of other residential options is encouraged.

Diagnosis and management of acute diarrhoea in adults.

Acute diarrhoea is a frequent, worldwide complaint. On any given day, 200 million people suffering from gastroenteritis will pass a volume of diarrhoeal water comparable with the flow of water over the Victoria Falls in one minute. In most attacks, routine microbiological techniques will fail to demonstrate the cause.

Factors influencing small bowel changes in dermatitis herpetiformis.

Factors influencing small bowel morphology in dermatitis herpetiformis (DH) were investigated by comparing patients with DH and normal small bowel biopsies to patients with DH and abnormal small bowel biopsies. The mean age of 18 patients with morphological changes in small bowel (38 years) was significantly lower (P less than 0-001) than the mean age of nine patients with normal bowel mucosa (60 years). HLA typing confirmed the high frequency of HLA-B8 in DH (64%) but HLA-B8 was unrelated to the presence or severity of small bowel lesions. Four patients had diarrhoea with progressive weight loss or abdominal cramps subsequently responsive to gluten withdrawal. In this subgroup serum levels of IgG and IgM were significantly lower than in patients with normal small bowel mucosa. Small bowel involvement appeared to be independent of the duration and severity of skin disease, and the deposition of immunoglobulin and complement (C3) in the dermal papillae of skin adjacent to skin lesions.

Fatal hepatic coma complicating oxymetholone therapy in multiple myeloma.

Two patients with multiple myeloma died in acute liver failure. Both had been treated with the anabolic steroid oxymetholone and both subsequently developed severe cholestatic hepatitis. In one the histological lesion progressed despite cessation of oxymetholone therapy. Myeloma infiltration of the liver and peliosis hepatis were not seen. As a fatal outcome from cholestatic hepatitis due to oxymetholone is rare it is possible that an unknown potentiating factor is present in multiple myeloma that can lead to a fatal outcome. If oxymetholone therapy is to be used in such patients then close clinical and laboratory assessment of liver function should be carried out in an attempt to prevent this unusual and fatal complication.

Retrograde gastric mucosal prolapse as a cause of haematemesis.

Three cases of haematemesis associated with alcohol abuse are described. Early fibreoptic endoscopical examination in each showed a focal, well demarcated area of gastric mucosal haemorrhage, close to the oesophagogastric junction. Two patients showed prolapse of the lesion into the lower part of the oesophagus, and the third had coexistent Mallory-Weiss tears. Our observations suggest that forceful vomiting is responsible for this lesion, by causing abrupt retrograde gastrooesophageal prolapse. The prognosis of the lesion appears good.

A controlled trial of azathioprine in Crohn's disease.

To determine the efficacy of azathioprine in the treatment of Crohn's disease, a 26-week double-blind trial was performed. 20 patients with Crohn's disease, requiring at least 10 mg of prednisone/day over the 3 months prior to entering the study were randomized into placebo (10 patients) and major criterion of success in the trial. There were 7 relapses in the placebo group (5 patients) and 2 relapses in the azathioprine group (2 patients). Complications including fistulae were not affected by the medications. The mean reduction in steriod dosage in the azathioprine group at the end of the trial (-15.5 mg) was greater than in the placebo group (-6.1 mg). These results suggest that azathioprine may permit reduction or discontinuation of steroids without the worsening of symptoms in some patients who appear to require steroids for control of their symptoms. The clinical features of this "AZA-responsive subgroup" remain to be defined.

A controlled trial of azathioprine in the management of chronic ulcerative colitis.

To determine the efficacy of azathioprine in the treatment of ulcerative colitis, a 6-month double blind trial was carried out. Thirty patients with chronic ulcerative colitis who required the equivalent of at least 10 mg of prednisone per day over the 3 months prior to entering the study were randomized into placebo and azathioprine (1.5 mg per kg) treatment groups. Reduction of steriods was a major objective of the trial. Age and sex distribution, number of bowel movements, sense of well being, steroid dosage, and findings on proctoscopy, rectal biopsy, and colon X-ray initially were similar in the two groups. No side effects were associated with azathioprine. Although steroid dose was lower (p less than 0.05) in the azathioprine group at the termination of the study, no difference between the two groups could be detected in the number of bowel movements, sense of well being, and findings on proctoscopy during the first 3 weeks compared with the last 3 and during the first 3 months compared with the last 3. Although azathioprine does not confer dramatic benefit upon patients with chronic ulcerative colitis who require steroids, it does permit reduction of steroid dosage without apparent worsening of the disease. Its major value in ulcerative colitis may be in facilitating significant decreases or complete discontinuance of steroids.