Untreated Tap Water Research Articles

Abstracts

Abstracts

High sodium chloride intake decreases betaine-homocysteine S-methyltransferase expression in guinea pig liver and kidney.

Betaine-homocysteine S-methyltransferase (BHMT) is the only enzyme known to catabolize betaine. In addition to being a substrate for BHMT, betaine also functions as an osmoprotectant that accumulates in the kidney medulla under conditions of high extracellular osmolarity. The mechanisms that regulate the partitioning of betaine between its use as a methyl donor and its accumulation as an osmoprotectant are not completely understood. The aim of this study was to determine whether BHMT expression is regulated by salt intake. This report shows that guinea pigs express BHMT in the liver, kidney, and pancreas and that the steady-state levels of BHMT mRNA in kidney and liver decrease 68% and 93% in guinea pigs consuming tap water containing high levels of salt compared with animals provided untreated tap water. The animals consuming the salt water also had approximately 50% less BHMT activity in the liver and kidney, and steady-state protein levels decreased approximately 30% in both organs. Pancreatic BHMT activity and protein levels were unaffected by the high salt treatment. The complex mechanisms involved in the downregulation of hepatic and renal BHMT expression in guinea pigs drinking salt water remain to be clarified, but the physiological significance of this downregulation may be to expedite the transport and accumulation of betaine into the kidney medulla under conditions of high extracellular osmolarity.

Microchip capillary electrophoresis with electrochemical detection of thiol-containing degradation products of V-type nerve agents.

A microchip protocol for the capillary electrophoresis separation and electrochemical detection of thiol-containing degradation products of V-type nerve agents is described. The microchip assay relies on the derivatization reaction of 2-(dimethylamino)ethanethiol (DMAET), 2-(diethylamino)ethanethiol (DEAET), and 2-mercaptoethanol (ME) with o-phthaldialdehyde in the presence of the amino acid valine along with amperometric monitoring of the isoindole derivatives. Both off-chip and on-chip derivatization reactions have led to highly sensitive and rapid detection of the thiol degradation products. Various parameters influencing the derivatization, separation, and detection processes were examined and optimized. These include the amino acid co-reagent, reagent-mixing ratio, reaction time, injection time, separation voltage, and detection potential. The chip microsystem offers a rapid (<4 min) simultaneous detection of micromolar concentrations of DMAET, DEAET, and ME. Linear calibration plots were observed for the V-type nerve agent thiol degradation products, along with good stability and reproducibility (RSD < 8.0%). Detection limits of 5 and 8 microM were obtained for the off-chip reaction of DMAET and DEAET, respectively, following a 2-s injection. The suitability for assays of environmental matrixes was demonstrated for the determination of DMAET and DEAET in untreated tap and river water samples. The favorable analytical performance makes the new microfluidic device attractive for addressing the needs of various security scenarios.

Effect of water softening on the colour intensity of routine haematoxylin and eosin stain

Haematoxylin and eosin (H&E) is the most popular routine stain used in pathology laboratories for highlighting cellular structures. To study the effect of tap water'softening' (i.e. calcium extraction) on H&E stains, 5 sets of slides from 30 different paraffin-embedded human pathologic tissue blocks were prepared in the same way except for washing with 5 different types of water. Slides washed in untreated tap water showed the best results concerning differentiation and colour intensity, while slides washed with softened or other treated water showed poorer degrees of differentiation and colour intensity. The worst results were obtained from slides washed with water containing sodium bicarbonate. Low calcium and magnesium ions and high sodium ions in soft water adversely affect the results of routine H&E stain.

Ultra-low-pressure water softening with pore-filled membranes

The design parameters for high-performance, ultra-low-pressure water softening membranes based on a construct involving pore-filling microporous substrates with polyelectrolyte gels are presented. The design parameters were then used to make a series of gel-filled membranes by in situ crosslinking of poly(vinylbenzyl chloride) with diamines (piperazine and 1,4-diazabicyclo[2.2.2]octane) or poly(4-vinylpyridine) with dihalides such as α,α'-dichloro- p-xylene in DMF solutions in the pores of either a TIPS poly(propylene) or non-woven ultra-high molecular weight poly(ethylene) support. The separation properties of these membranes were tested under ultra-low pressure (100 kPa) using untreated municipal tap water. These membranes exhibit excellent separation properties, comparable to those of a commercial thin-film nanofiltration membrane (Desal-51, Osmonics), and productivity (flux) markedly higher than that of the thin-film membrane. The results of this study clearly show the importance of the mechanical strength (rigidity) of the microporous supports in designing high-performance pore-filled membranes.

TAP WATER AND THE MALONE ANTEGRADE CONTINENCE ENEMA: A SAFE COMBINATION?

The Malone antegrade continence enema provides independence and improved quality of life in patients with fecal incontinence or intractable constipation. However, isolated reports of fatal hypernatremia after irrigation with normal saline have raised safety concerns about frequent colonic irrigation in children. Significant electrolyte abnormalities have also been reported with hypertonic phosphate and high colonic tap water enemas. Because our patients routinely use tap water for Malone antegrade continence enema irrigations, we examined the safety profile of this practice In the last 3.5 years 71 patients at our institution have used antegrade tap water enemas for managing fecal incontinence or intractable constipation. Standard serum electrolytes were measured We obtained 101 sets of serum electrolyte measurements in 71 patients at a mean of 8.4 months postoperatively (range 1 to 33). A girl who presented with severe hyponatremia and hypochloremia had not used the Malone antegrade continence enema for several days. The most interesting finding was significantly elevated sodium and chloride in 1 case 6 weeks after surgery that was associated with tap water treated with a home softening system. Electrolytes reverted to normal 1 week after using untreated tap water We did not detect significant hyponatremia or hypochloremia in any patient using tap water for Malone antegrade continence enema irrigation. Although dangerous electrolyte abnormalities are rare, potential morbidity in those cases warrants periodic evaluation. Due to the elevated sodium content in softened tap water families should be alerted to use untreated tap water for preparing enemas.

THE ROLE OF NITRIC OXIDE IN OBSTRUCTIVE NEPHROPATHY

Ureteral obstruction leads to tubulointerstitial fibrosis and loss of renal function. Nitric oxide production ameliorates fibrosis due to obstructive uropathy. However, nitric oxide is produced by 3 isoforms of the enzyme, nitric oxide synthase. We evaluated the role of inducible nitric oxide synthase in obstructive uropathy using nitric oxide synthase knockout mice, and determined whether the administration of L-arginine to promote nitric oxide synthesis by alternative nitric oxide synthase isoforms modulates renal fibrosis in these animals. Complete unilateral ureteral obstruction was created in wild-type C57 and inducible nitric oxide synthase knockout mice. Control animals of each strain underwent sham surgery. Throughout the experiment mice had free access to untreated tap water or water supplemented with 10 gm./l. L-arginine. Animals were sacrificed 1 and 2 weeks, respectively, after creation of unilateral ureteral obstruction. We obtained serum as well as bladder and obstructed renal pelvic urine, and determined the nitrite level in each fluid. Renal cortical thickness was measured in the normal and obstructed kidneys. The degree of tubulointerstitial fibrosis was evaluated by trichrome staining and type I collagen deposition in kidney tissue specimens. Nitrite was significantly decreased in the serum, bladder and renal pelvic urine of inducible nitric oxide synthase knockout mice with unilateral ureteral obstruction compared with that in wild-type C57 mice at 1 and 2 weeks (p<0.05). In knockout mice with unilateral ureteral obstruction 1 week in duration that drank tap or L-arginine supplemented water nitrite in serum and each urine sample was higher than in sham operated knockout controls. The level returned to baseline after 2 weeks of obstruction (p<0.05). After 2 weeks of obstruction there was significantly greater cortical thinning in knockout than in C57 mice (p<0.05). Moreover, knockout mice given L-arginine supplemented water for 2 weeks had even greater cortical thinning than after 1 week or than mice given tap water for 1 to 2 weeks (p<0.05). Decreased renal cortical thickness in knockout mice after 2 weeks of obstruction was associated with less intense trichrome staining and a virtual absence of type I collagen deposition compared with findings in the wild-type C57 strain. Inducible nitric oxide synthase knockout mice with unilateral ureteral obstruction have significantly lower nitrite in serum and urine than wild-type C57 mice. Knockout mice also have more severe renal cortical thinning than C57 animals after creation of unilateral ureteral obstruction. Providing L-arginine supplemented water to inducible nitric oxide synthase knockout mice exacerbates the loss of cortical thickness. Alterations in cortical thinning that we observed in knockout mice were associated with decreased tubulointerstitial fibrosis and a decreased net renal extracellular matrix accumulation. These data indicate that endothelial or neuronal nitric oxide synthase may be more important than inducible nitric oxide synthase for modulating renal fibrosis in obstructive uropathy.

Timidity in Japanese Quail: Effects of Vitamin C and Divergent Selection for Adrenocortical Response

Male Japanese quail chicks of two genetic lines selected for low (LS) or high (HS) adrenocortical responses to mechanical restraint were housed in mixed-line groups of 24 in four compartments of a multitier brooder battery at 20 days of age. Quail in two of the four compartments were given vitamin C (ascorbyl-2-polyphosphate, APP, 1 g l-ascorbic acid/L) solution for 48 h, whereas the other birds received untreated tap water as usual before they were tested at 23 days of age. At test, each quail was placed individually in a dark, sheltered compartment of an emergence box and allowed 1 min to acclimatise before a door was raised allowing access to an illuminated and exposed area. Vocalisation and the latencies to head and full emergence were then recorded to measure its fear levels. More LS quail vocalised than did HS ones. They also emerged more rapidly from the sheltered compartment into the illuminated one than HS birds. These findings further support our hypothesis that decreased fearfulness has accompanied genetic selection for reduced adrenocortical responsiveness. Treatment with APP reduced the latency to emerge fully into the exposed compartment, and there were no line × treatment interactions. These results suggest that vitamin C supplementation alleviated fearfulness, regardless of existing line differences in this behavioural trait.

Health problems of corporate travelers: risk factors and management.

Numerous studies have been done regarding health problems experienced by tourists in developing countries; however, little data exist about these health risks and illnesses experienced by corporate travelers. The authors examined by electronic survey the health risks encountered, compliance with pretravel health recommendations, and illnesses and injuries experienced by employees of the Coca-Cola Company who travel internationally. Two hundred twenty-six travelers responded. Although most travelers ate meals at their hotels and chose foods that were cooked and still hot, over half also ate foods that remained at room temperature for prolonged periods and/or ate from cold salad bars. Almost half drank untreated tap water. Thirty-five percent of travelers developed diarrhea and 29% reported respiratory illnesses, with 12% seeking medical attention for their problems. Forty-three percent of those traveling to malarious regions admitted to noncompliance with antimalarial recommendations. Health kits provided were used by only 51% of travelers. Although many corporate travelers followed pretravel health recommendations, some did not. Injuries, fever, and illnesses such as diarrhea and respiratory infections occurred. Strategies to improve access to the travel clinic and the acquisition of health information and travel health kits are being implemented. The health risks and behaviors of corporate travelers, including the potential impact of psychosocial stressors, need greater attention.

Low pressure chromatographic separation of inorganic arsenic species using solid phase extraction cartridges

Routine water analysis of arsenic species requires simple, inexpensive, rapid and sensitive methods. To this end, we have developed two methods, which are based on the use of inexpensive solid phase extraction (SPE) cartridges as low pressure chromatographic columns for separation and hydride generation atomic absorption spectrometry (HGAAS) and hydride generation atomic fluorescence spectrometry (HGAFS) for detection of arsenic. Both anion exchange and reverse phase cartridges were successfully used to separate arsenite [As(III)] and arsenate [As(V)]. The composition, concentration, and pH of eluting buffers and the effect of flow rate were systematically investigated. Speciation of inorganic As(III) and As(V) were achieved within 1.5 min, with detection limits of 0.2 and 0.4 ng/ml, respectively. Both isocratic and step gradient elution techniques were suitable for the baseline resolution of As(III) and As(V) using anion exchange cartridges. Application of the methods to the speciation of As(III) and As(V) in untreated water, tap water, and bottled water samples were demonstrated. Results from the speciation of arsenic in a standard reference material water sample using these methods were in good agreement with the certified value and with inter-laboratory comparison results obtained using HPLC separation and inductively coupled plasma mass spectrometric detection (HPLC–ICPMS).

The Effect of Angiotensin Converting Enzyme Inhibition and Angiotensin II Receptor Antagonism on Obstructed Rat Bladder

Purpose Others have demonstrated that inhibition of angiotensin II production partially ameliorates obstructive changes in the neonatal rabbit bladder. We examined the effect of angiotensin II converting enzyme inhibition and receptor antagonism on the obstructed rat bladder. Materials and Methods Three groups of animals were investigated. Partial bladder neck obstruction was created in 23 rats by placing a 2-zero silk ligature around the vesicourethral junction. Eight rats were given untreated tap water, 9 were given water supplemented with 50 mg./kg. of the angiotensin-converting enzyme inhibitor captopril and 6 were given water with 30 mg./kg. of the angiotensin II subtype AT1 receptor antagonist losartan potassium. Eight unobstructed rats served as controls. After 2 weeks of partial outlet obstruction the animals were sacrificed and bladders were harvested. Routine histological evaluation and assays for total protein, deoxyribonucleic acid and collagen content were performed. Results Histological evaluation revealed that administration of captopril or losartan potassium resulted in a mild decrease in the degree of obstructive bladder changes. Biochemically neither captopril nor losartan potassium caused a significant decrease in the amount of total deoxyribonucleic acid, protein or collagen content per bladder compared to untreated obstructed bladders. Conclusions In contrast to previous studies in neonatal rabbits, neither captopril nor losartan potassium significantly ameliorated the histological or biochemical features of partial bladder outlet obstruction in the rat. Further investigation is necessary into species specific differences to understand better the role that angiotensin II may have in mediating the bladder changes of experimentally induced obstruction.

The effect of angiotensin converting enzyme inhibition and angiotensin II receptor antagonism on obstructed rat bladder.

Others have demonstrated that inhibition of angiotensin II production partially ameliorates obstructive changes in the neonatal rabbit bladder. We examined the effect of angiotensin II converting enzyme inhibition and receptor antagonism on the obstructed rat bladder. Three groups of animals were investigated. Partial bladder neck obstruction was created in 23 rats by placing a 2-zero silk ligature around the vesicourethral junction. Eight rats were given untreated tap water, 9 were given water supplemented with 50 mg./kg. of the angiotensin-converting enzyme inhibitor captopril and 6 were given water with 30 mg./kg. of the angiotensin II subtype AT1 receptor antagonist losartan potassium. Eight unobstructed rats served as controls. After 2 weeks of partial outlet obstruction the animals were sacrificed and bladders were harvested. Routine histological evaluation and assays for total protein, deoxyribonucleic acid and collagen content were performed. Histological evaluation revealed that administration of captopril or losartan potassium resulted in a mild decrease in the degree of obstructive bladder changes. Biochemically neither captopril nor losartan potassium caused a significant decrease in the amount of total deoxyribonucleic acid, protein or collagen content per bladder compared to untreated obstructed bladders. In contrast to previous studies in neonatal rabbits, neither captopril nor losartan potassium significantly ameliorated the histological or biochemical features of partial bladder outlet obstruction in the rat. Further investigation is necessary into species specific differences to understand better the role that angiotensin II may have in mediating the bladder changes of experimentally induced obstruction.

Field evaluation of synthetic compounds mediating oviposition inCulex mosquitoes (Diptera: Culicidae)

3-Methylindole (skatole), a compound shown to be an oviposition attractant/stimulant forCulex quinquefasciatus in laboratory tests, was evaluated against natural populations of mosquitoes in the field. In experiments using paired black plastic tubs that contained water treated with an attractant solution containing a mixture of 3-methylindole, 4-methylphenol, 4-ethylphenol, phenol, and indole or that contained only tap water, the attractantbaited traps received significantly moreCx. quinquefasciatus egg rafts than did the untreated tap water. Gravid female traps that were baited with attractant solution collected significantly moreCx. quinquefasciatus females than did traps containing only tap water. There was no significant difference in number ofCx. quinquefasciatus collected in the traps baited with the attractant solution compared to the traps that contained water with 3-methylindole alone, indicating that 3-methylindole was solely responsible for the attraction. In replicated experiments conducted in experimental ponds, ponds that were treated with 3-methylindole received significantly moreCx. quinquefasciatus, Cx. tarsalis, andCx. stigmatosoma egg rafts than did untreated ponds. Experimental ponds treated with 3-methylindole at two levels (0.12 and 0.6 mg/liter) were equally attractive to ovipositingCx. quinquefasciatus. This is the first record of 3-methylindole showing attractancy/stimulation to ovipositingCx. stigmatosoma andCx. tarsalis under field or laboratory conditions.

PREVENTION OF TRAVELER'S DIARRHEA

Preventing traveler's diarrhea is usually a matter of common sense, good luck, and the host's ability to defend against enteric pathogens, particularly enterotoxigenic Escherichia coli. Untreated tap water, ice cubes, unpasteurized milk products, salads, food from street vendors, and dining in unhygienic-appearing restaurants should be avoided. Well-cooked food that is served hot and carbonated, commercially bottled beverages are usually safe. Food and water precautions, however, are no guarantee of success in preventing traveler's diarrhea. Bismuth subsalicylate used prophylactically is somewhat inconvenient and is only moderately effective. Although antibiotic prophylaxis is very effective for traveler's diarrhea, particularly the quinolones, it should be reserved for high-risk travelers.

Bacterial contamination of dialysate in dialysis-associated endotoxaemia

Bacteriological investigations and endotoxin (ET) determinations were performed during a routine haemodialysis session for six patients. The glucose free dialysate was prepared with untreated tap water. All patients were dialysed for 5 h. Pseudomonas aeruginosa was regularly isolated in numbers up to 10 7 cfu ml −1 from samples of the dialysate inflow, the dialysate site and the dialysate outflow. ET levels in the plasma of the patients increased continuously during haemodialysis and were always higher in the blood outflow line of the dialyzer than in the blood inflow. Despite the high bacterial counts in the dialysate and the increasing ET levels in the patients plasma neither bacteraemia nor fever was observed. The former is due to the impermeability of the dialyzer membrane for bacteria, the latter is explained by low pyrogenicity of P. aeruginosa endotoxin. Inspection of the dialyzer machines revealed that air-traps and heater-unit for the incoming (untreated) tap water before mixing with the dialysate concentrate were the only sites where high bacterial release was feasible, as this part of the machine escaped disinfection due to the construction of these devices. We recommend the regular disinfection of all parts of a dialyzer machine, including heating units, air traps and valves.

Efficacy of Two Temephos Formulations Against Mosquito Larvae, 1986

Abstract Two deep metal containers, measuring 45 inches (length) × 24 inches (width) × 20 inches (depth) and 2 shallow metal containers, 95 inches (length) × 27 inches (width) × 8 inches (depth), each filled with 70 gal of water, were used in simulated field tests. Test I utilized tap water only; 25 lb of fresh cow manure were added to the water in test II to determine the effect of organic matter on the residual activity of both temephos formulations. A 2% plaster formulation of temephos was applied at a rate of 5mg/gal and compared to a 2% celatom formulation (Abate 2-CG) at a rate of 5mg/gal. Each formulation was replicated twice in both deep and shallow containers. In test II, only 1 deep container was utilized for each of the above formulations. Because water evaporated in the containers during each test period, additional tap water was added to all containers prior to sampling. At each sampling interval the water in all containers was stirred slowly to attain as equal mixing as possible without disturbing the pesticide formulation granules in the bottom of each container. After 5 min, 3 random 600 ml water samples were taken for subsequent mosquito larval bioassays. Laboratory reared Aedes aegypti and wild collected Culex pipiens larvae were used in test I, while Ae. aegypti larvae were used in test II. About 200 ml of water from each water sample were placed in separate 250 ml glass beakers and bioassayed against 25 3rd-instar mosquito larvae. Untreated tap water was used as a control. All treatments and controls were replicated 3 times. Larval mortality was based on the inability of larvae to move when the side of the beaker was tapped at 24 h, posttreatment.

Carcinogenicity study of sodium hypochlorite in F344 rats

The carcinogenic potential of sodium hypochlorite was examined in F344 rats. Groups of 50 males or 50 females were given sodium hypochlorite in their drinking-water, at concentrations of 0.1 and 0.05% for males and 0.2 and 0.1% for females, for 104 wk. Similar numbers of male and female rats received distilled water without supplement throughout the experiment. All surviving rats were killed at wk 112 (after 8 wk on untreated tap-water). Rats of both sexes given the chemical showed a reduction in body-weight gain, but haematological and biochemical examination of the blood showed no changes due to treatment, and no significant lesions attributable to the treatment were detected in any tissue in the histopathological investigation. Although a variety of tumours developed in all groups, no dose-related change in either the incidence or latent period of tumours was observed for any organ or tissue in either sex. Under the experimental conditions described, therefore, sodium hypochlorite was not carcinogenic in F344 rats.