Development of an Electrochemical Device for Removal of Arsenic from Drinking Water

The forthcoming introduction of lower standards for arsenic in drinking water requires new technologies for arsenic removal. We report the development of an electrochemical unit for remediating domestic water supplies for homes without municipally treated water. Electrolysis in a two‐anode system provides oxidants to convert As(III) to As(V) in situ, and a sacrificial anode to deliver iron into solution. Conditioning tanks after each electrolysis step ensure completion of the chemical reactions. At the pH of domestic water, As(V) co‐precipitates with Fe(OH)₃; subsequent filtration leaves <10 ppb of inorganic arsenic in solution.     

Relation between sexual abuse in childhood and adult depression: case-control study

OBJECTIVE: To examine the association between sexual abuse in childhood and adult depression in women. DESIGN: Two stage, case detection and case identification design, using the 30-item general health questionnaire and the Beck depression inventory for screening and the affective items relating to current functioning on the schizophrenia and affective disorders schedule to identify depressed cases. Details of sexual abuse in childhood were elicited retrospectively by semistructured interview, and social problems by the social problems questionnaire. SETTING: Three general practices, in middle class suburban, deprived inner city, and rural areas. SUBJECTS: 1189 women were screened and 237 subsequently interviewed; 132 were depressed. RESULTS: 49 (37%) of the depressed interviews and 24 (23%) of the non-depressed interviews reported experience of sexual abuse when they were aged under 16 years. A positive association existed between the more severe abuse and depression--all those who had experienced penetration were depressed as adults. A relation was also found between sexual abuse in childhood and sexual problems, housing problems, and problems with their children at school. CONCLUSION: A positive association between child sexual abuse and depression was confirmed, but this was confined to more severe abuse (penetration or attempted penetration).     

Quantitation of three-month intraindividual variability and influence of sex and menstrual cycle phase on CYP1A2, N-acetyltransferase-2, and xanthine oxidase activity determined with caffeine phenotyping

OBJECTIVE: To evaluate intraindividual variability and the effects of sex and menstrual cycle phase on the activity of cytochrome P450 1A2 (CYP1A2), N-acetyltransferase 2 (NAT2), and xanthine oxidase. METHODS: Ten white men were given 2 mg/kg caffeine orally every 14 days for 3 months. The same dosage of caffeine was given to 10 premenopausal white women during the midfollicular and midluteal phases of three complete menstrual cycles. Phenotype was determined with urinary caffeine metabolite ratios. RESULTS: For CYP1A2, mean metabolic ratio (+/- SD) was 5.97 +/- 2.78 during the midfollicular phase and 5.32 +/- 1.99 during the midluteal phase (p = 0.2). For extensive and poor metabolizer of NAT2. Mean midfollicular phase metabolite ratios were 0.71 +/- 0.060 and 0.37 +/- 0.030, and mean midluteal phase metabolite ratios were 0.69 +/- 0.076 and 0.39 +/- 0.053 (p = 0.9). For xanthine oxidase, mean midfollicular phase metabolite ratio was 0.63 +/- 0.06 and mean midluteal phase metabolite ratio was 0.63 +/- 0.05 (p = 0.3). Among the men, mean CYP1A2, NAT2 rapid and slow acetylator, and xanthine oxidase indices were 9.42 +/- 10.18, 0.66 +/- 0.021, 0.31 +/- 0.056, and 0.64 +/- 0.03. There were no differences in metabolite ratios between men and women for CYP1A2, NAT2 extensive metabolizers, or xanthine oxidase. A statistically significant sex difference was found for poor metabolizers of NAT2 (p < 0.05). Median coefficients of variation for CYP1A2, NAT2 extensive and poor metabolizers, and xanthine oxidase ratios were 16.8% (range, 4.5% to 49.3%), 2.9% (range, 2.2% to 4.7%), 13.4% (range, 7.5% to 27.2%), and 4.5% (range, 2.3% to 13.0%). CONCLUSION: Stratification by menstrual cycle phase or sex need not be performed for pharmacokinetic or clinical investigations of substrates for CYP1A2, NAT2, or xanthine oxidase in which the subject are adults.     

Hepatitis among plasma fractionation workers. An industry-wide study

An industry-wide survey of plasm fractionation facilities in the United States was conducted during 1973-74. Hepatitis was reported among the workers with varying degrees of plasma contact at all plant sites. For each of fourteen facilities in this investigation, field inspections disclosed: (1) numerous overt instances of employee-product contact: (2) inconsistent methodologic approaches at virtually all stages of the plasma fractionation process; (3) at low level of management and employee awareness regarding the potential bio-hazard identified; and (4) disparate examples of hepatitis surveillance and prophylaxis. Our data suggests that there is a high risk of hepatitis among plasma fractionation workers and, as such, much more attention needs to be focused on the reduction of health hazards within this industry.     

Activation of calcium channels by cAMP in STC-1 cells is dependent upon Ca2+ calmodulin-dependent protein kinase II

Activation of L-type calcium channels in the neuroendocrine, cholecytstokinin-secreting cell line, STC-1, is vital for secretion of CCK. In the present study, the regulation of L-type Ca2+ channels by cAMP and Ca2+ calmodulin dependent protein kinase II (CaM-KII) in STC-1 cells was investigated. Exposure to 3-isobutyl-1-methylxanthine (IBMX) increased intracellular cAMP levels, whole cell Ca2+ currents and activated Ca2+ channels in cell-attached membrane patches. Furthermore, in Fura-2AM loaded cells, cytosolic Ca2+ levels increased upon exposure to IBMX. By contrast, pretreatment of cells with the CaM-KII inhibitor KN-62, prevented IBMX activation of Ca2+ channels in cell-attached patches or increases in cytosolic Ca2+ levels. Inclusion of the synthetic peptide fragment 290-309 of CaM-KII, a CaM-KII antagonist, in the pipette solution, blocked the activation of whole cell Ca2+ currents upon addition of IBMX. These results indicate a unique mechanism of L-type Ca2+ channel activation involving two phosphorylation events.     

Nitrogen mustard up-regulates Bcl-2 and GSH and increases NTP and PCr in HT-29 colon cancer cells

We hypothesized that unexplained increases in nucleoside triphosphates (NTP) observed by 31P magnetic resonance spectroscopy (MRS) after treatment of tumours by DNA-damaging agents were related to chemotherapy-induced up-regulation of the bcl-2 gene and DNA damage prevention and repair processes. To test this hypothesis, we treated HT-29 cells with 10(-4) M nitrogen mustard (HN2) and performed sequential perchloric acid extractions in replicate over 0-18 h. By reference to an internal standard (methylene diphosphonic acid), absolute changes in 31P-detectable high-energy phosphates in these extracts were determined and correlated with changes in bcl-2 protein levels, cell viability, cell cycle, apoptosis and total cellular glutathione (GSH) (an important defence against DNA damage from alkylating agents). After HN2 administration, bcl-2 protein levels in the HT-29 cell line rose at 2 h. Cell viability declined to 25% within 18 h, but apoptosis measured using fluorescence techniques remained in the 1-4% range. Increased cell division was noted at 4 h. Two high-energy interconvertible phosphates, NTP (P < or = 0.006) and phosphocreatine (PCr) (P < or = 0.0002), increased at 2 h concurrently with increased levels of bcl-2 protein and glutathione. This study demonstrates that bcl-2 and glutathione are up-regulated by HN2 and links this to a previously unexplained 31P MRS phenomenon: increased NTP after chemotherapy.     

An examination of the distinction between nouns and verbs: associations with two different kinds of motion

Four experiments provide evidence that people are biased to associate particular types of motion with nouns and different types of motion with verbs. Novel nouns and verbs were related to two types of motion: (1) path, or the direction of motion of one character with respect to the other character, and (2) movement orientation, or the direction a character was facing as it moved. Subjects associated verbs more strongly with path than with movement orientation. In contrast, they associated nouns more strongly with movement orientation than with path. Movement orientation was associated with both object categories and verbs, inconsistent with a complete division of labor between these two types of categories. These results are consistent, however, with the notion that people are biased to associate verbs with relations between objects, whereas they are biased to associate object categories with motions defined with respect to the object carrying out those motions.