Speciation of arsenic metabolites in the urine of occupational workers and experimental rats using an optimised hydride cold-trapping method

A hydride cold-trapping technique was developed and optimised for the measurement of urinary arsenic metabolites. The analytical precision of the method was found to be 6.1, 4.0 and 4.8% (n = 5) for inorganic arsenic (ASi), monomethylarsonate (MMA) and dimethylarsinate (DMA), respectively, with recoveries close to 100%. The detection limits were 1.0, 1.3 and 3 ng for ASi, MMA and DMA, respectively. The method was then used to analyse urine samples obtained from three groups of workers for occupational exposure in three companies where copper chrome arsenate was used for timber treatment. The results were compared with those for a normal control group of laboratory workers. Arsenic and its metabolites were also measured in experimental rats given 5 mg As kg-1 body mass by oral gavage in the form of sodium arsenite, calcium arsenite or sodium arsenate. Occupational workers showed a significantly higher excretion of ASi. Up to two fold increases of urinary ASi excretion in rats compared with control rats were also observed in animals dosed with various forms of arsenicals. The method is suitable for the measurement of arsenic metabolites in urine of both humans and experimental animals.     

The Diabetes in Early Pregnancy Study: beta-hydroxybutyrate levels in type 1 diabetic pregnancy compared with normal pregnancy. NICHD-Diabetes in Early Pregnancy Study Group (DIEP). National Institute of Child Health and Development

OBJECTIVE: The objective was to assess relationships between beta-hydroxybutyrate (beta-OHB) level and pregnancy outcome in human pregnancy in light of the fact that high levels of beta-OHB cause malformations and growth retardation in in vitro studies. RESEARCH DESIGN AND METHODS: We analyzed beta-OHB in prospectively collected specimens from the National Institute of Child Health and Human Development-Diabetes in Early Pregnancy Study, in gestational weeks 6-12 in diabetic (n = 204-239) and nondiabetic (n = 316-332) pregnant women. RESULTS: Levels of beta-OHB in diabetic women were 2.5-fold higher than in nondiabetic pregnant women at 6 weeks' gestation and declined to 1.6-fold above nondiabetic women by 12 weeks' gestation (P < 0.0001 at all times). beta-OHB was positively correlated with glucose levels (P < 0.0001) in diabetic mothers, probably reflecting degree of diabetic control. beta-OHB correlated inversely with glucose (P < 0.0003) (gestational week 6 only) in nondiabetic mothers, possibly reflecting caloric intake. beta-OHB tended to be lower (not higher) in diabetic and nondiabetic mothers with malformed infants or pregnancy losses, but the difference was not statistically significant. beta-OHB in diabetic mothers at 8, 10, and 12 weeks correlated inversely with birth weight (P = 0.004-0.02), even after adjusting for maternal glucose levels. beta-OHB levels were also generally lower in diabetic mothers of macrosomic infants, and week 12 ultrasound crown-rump measurements were inversely related to beta-OHB levels. CONCLUSIONS: The lst trimester beta-OHB is significantly higher in diabetic than nondiabetic pregnant women. In both groups, beta-OHB tended to be lower, not higher, in mothers who had a malformed infant or pregnancy loss. beta-OHB was inversely related to crown-rump length and birth weight. The modest beta-OHB elevation in the 1st trimester of reasonably well-controlled diabetic pregnancy is not associated with malformations, probably because beta-OHB levels causing malformations in embryo culture models are 20- to 40-fold higher. The mechanism of the beta-OHB association with impaired fetal growth is unknown.     

Ehlers-Danlos syndrome type II in pregnancy

The Allen test was performed by four physician examiners on 200 hands of healthy volunteers. Positive results were found in 5.5% of hands. There was not a single case in which all four observers agreed. Considerable inter-observer disagreement is associated with the Allen test.     

Disposition kinetics of cobalt mesoporphyrin in mouse, rat, monkey and dog

1. Radiometric and UV analyses indicated > 95% unchanged cobalt mesoporphyrin (CoMP) in plasma after i.v. or i.m. administration. Blood clearance of CoMP is < 2% of hepatic blood flow in mouse and rat, and < 0.5% of hepatic blood flow in monkey and dog. CoMP elimination t1/2 ranged from 3.1 to 9.9 days in animals after i.v. administration. 2. CoMP is highly (> 99.5%) bound to plasma proteins, but has low affinity for blood cells (Kp < 0.15). The volume of CoMP distribution (Vss < 0.91/kg) is reflective of a distribution to total body water following i.v. administration to mouse, rat, monkey and dog. 3. [14C]CoMP reached highest levels in rat tissue between 1 and 4 days following i.m. injection. Liver, kidney cortex, lymph node, adrenal and spleen demonstrated greatest uptake of radiolabel. Concentration in tissues was readily detectable at 60 days post-dose. 4. CoMP was slowly absorbed after i.m. administration showing dose-dependent pharmacokinetics. The major route of radiolabel elimination was faecal excretion (54% of dose) in rat after an i.m. dose of [14C]CoMP. Approximately 1% of the 14C dose was recovered in the urine over 7 days post-dose. 5. As a polar metalloporphyrin, CoMP has low clearance, restricted tissue distribution and long elimination t1/2 in the laboratory animals.     

Does publishing the parameters that trigger review of Medicare claims change provider behavior? Results of the parameter release study

In April 1989, the Health Care Financing Administration stopped publishing the parameters that trigger review of Medicare claims because they thought that knowledge of the parameters would permit providers to schedule visits to avoid review. In this article, the authors report the results of an experimental study where previously unrevealed parameters were revealed to some providers of Medicare services and not to others. The authors find little evidence to suggest that providers schedule procedures to avoid review when they know the parameters. There is some evidence, however, that providers may be responding to the release of the parameters in other ways.     

Use of spiral computed tomography for multiplanar dental reconstruction

This was a community-based study to evaluate the prevalence and characteristics of female urinary incontinence in women aged 18 and above in the Shatin District of Hong Kong. Of a total of 1018 female households contacted, 362 individuals were successfully interviewed and 123 women (34%) reported they had experienced at least one episode of urinary incontinence as adults. Of these, 18.5% reported persistent incontinence and 15.5% reported absence of incontinence after a single episode of urine loss. The risk factors for incontinence revealed by this study were body mass index and parity. Women who had never been incontinent had a lower body mass index and were usually nulliparous. Most of the respondents (43.9%) who had urinary incontinence considered the condition to be a minor problem and did not seek professional advice. This investigation indicates that a territory-wide study should be carried out to determine the incidence of urinary incontinence throughout Hong Kong.     

Comparative pulmonary absorption, distribution, and toxicity of copper gallium diselenide, copper indium diselenide, and cadmium telluride in Sprague-Dawley rats

Copper gallium diselenide (CGS), copper indium diselenide (CIS), and cadmium telluride (CdTe) are novel compounds used in the photovoltaic and semiconductor industries. This study was conducted to characterize the relative toxicities of these compounds and to evaluate the pulmonary absorption and distribution after intratracheal instillation. Female Sprague-Dawley rats were administered a single equimolar dose (70 mM) of CGS (21 mg/kg), CIS (24 mg/kg), CdTe (17 mg/kg), or saline by intratracheal instillation. Bronchoalveolar lavage fluid (BALF) protein, fibronectin, inflammatory cells, lung hydroxyproline, and tissue distribution were measured 1, 3, 7, 14, and 28 days after instillation. Relative lung weights were significantly increased in CIS- and CdTe-treated rats at most time points. Inflammatory lesions in the lungs consisting of an influx of macrophages, lymphocytes, and PMNs were most severe in CdTe-treated rats, intermediate in CIS-treated rats, and minimal in rats receiving CGS. Hyperplasia of alveolar type 2 cells was present in CIS- and CdTe-treated rats and was greatest in CdTe-treated rats. Pulmonary interstitial fibrosis was observed in CdTe-treated rats at all time points. All three compounds caused marked increases in total BALF cell numbers, with the greatest increase observed in CIS-treated rats. BALF protein, fibronectin, and lung hydroxyproline were significantly increased in all treated animals and were highest in CdTe-treated animals. There was no apparent pulmonary absorption or tissue distribution of CGS. Indium levels increased in extrapulmonary tissues of CIS-treated rats, although Cu and Se levels remained unchanged. CdTe was absorbed from the lung to a greater extent than CGS and CIS. Cd and Te levels decreased in the lung and increased in extrapulmonary tissues. Of these compounds CdTe presents the greatest potential health risk because it causes severe pulmonary inflammation and fibrosis and because it is readily absorbed from the lung may potentially cause extrapulmonary toxicity.