Large Volumes Of Tap Water Research Articles

Steroid hormone release as well as renal water and electrolyte excretion of mice expressing PKB/SGK-resistant GSK3

Insulin and insulin-like growth factor (IGF1) participate in the regulation of renal electrolyte excretion. Insulin- and IGF1-dependent signaling includes phosphatidylinositide-3 (PI3)-kinase, phosphoinositide-dependent kinase PDK1 as well as protein kinase B (PKB) and serum and glucocorticoid inducible kinase (SGK) isoforms, which in turn phosphorylate and thus inhibit glycogen synthase kinase GSK3alpha,beta. Replacement of the serines in the PKB/SGK consensus sequences by alanine (gsk3 ( KI )) confers resistance of GSK3 to PKB/SGK. To explore the role of PKB/SGK-dependent inhibition of GSK3 in the regulation of water/electrolyte metabolism, mice carrying the PKB/SGK resistant mutant (gsk3 ( KI )) were compared to their wild-type littermates (gsk3 ( WT ) ). Body weight was similar in gsk3 ( KI ) and gsk3 ( WT ) mice. Plasma aldosterone at 10 A.M: . and corticosterone concentrations at 5 P.M: . were significantly lower, but 24-h urinary aldosterone was significantly higher, and corticosterone excretion tended to be higher in gsk3 ( KI ) than in gsk3 ( WT ) mice. Food and water intake, fecal excretion, glomerular filtration rate, urinary flow rate, urine osmolarity, as well as urinary Na+, K+, urea excretion were significantly larger, and plasma Na+, urea, but not K+ concentration, were significantly lower in gsk3 ( KI ) than in gsk3 ( WT ) mice. Body temperature was significantly higher in gsk3 ( KI ) than in gsk3 ( WT ) mice. When allowed to choose between tap water and saline, gsk3 ( WT ) mice drank more saline, whereas gsk3 ( KI ) mice drank similar large volumes of tap water and saline. During high-salt diet, urinary vasopressin excretion increased to significantly higher levels in gsk3 ( KI ) than in gsk3 ( WT ) mice. After water deprivation, body weight decreased faster in gsk3 ( KI ) than in gsk3 ( WT ) mice. Blood pressure, however, was significantly higher in gsk3 ( KI ) than in gsk3 ( WT ) mice. The observations disclose a role of PKB/SGK-dependent GSK3 activity in the regulation of steroid hormone release, renal water and electrolyte excretion and blood pressure control.

Some Limits in Current Adsorption-Elution Methods for the Detection of Viruses in Large Volumes of Tap Water

Two types of electropositive filters (1 MDS double sheet - Cuno and AS - Seitz) were compared for Poliovirus 1, Coxsackie virus B3, Coxsackie virus A9 and E.C.H.O. virus 1 recovery from tap water with different pH levels. For small volumes of tap water sampled, both adsorbents gave equally satisfactory recoveries of Poliovirus 1 (46% to 82%) at pH 6.7, 7.9, or 9. However, elution percentages using 3% beef-extract solution pH 9.5 were generally better for 1 MDS than for AS filters. As the volume of tap water sampled increased, increasing amounts of Poliovirus were unadsorbed onto both types of filters at pH 7, 7.9, or 9. Lowering the pH to 6 gave better Poliovirus 1 and Coxsackie B3 recoveries with AS (respectively 61% and 95%) and 1 MDS filters (respectively 67% and 91%). E.C.H.O. virus 1 recovery was not affected by acidification and was lower with 1 MDS (6%) than with AS filters (37%). Coxsackie virus A9 recovery was very low for both filters (≤11%). As for electronegative adsorbents, currently available methods for concentrating viruses using electropositive filters have to be optimized to recover most enteric viruses occurring in waters.

Concentration of viruses from tap water and sewage with a charge-modified filter aid

Positively charged microporous filters have been shown to have definite advantage over negatively charged filters for concentrating viruses from water as they eliminate the need of water conditioning (acidification and multivalent cation addition) prior to filtration. The present study was designed to evaluate the use of a charge-modified (Zeta plus) filter aid (AMF CUNO, Meriden, CT) for the concentration of viruses (Poliovirus-1, Coxsackievirus B-3 and ECHO virus-7) from large volumes of tap water. Charge-modified filter aid could efficiently adsorb polio, coxsackie and ECHO viruses from water. The adsorbed viruses from both tap water and secondary sewage were most efficiently eluted with 4% beef extract — 0.5 M NaCl, pH 9.5. The efficiency of recovery of poliovirus, coxsackievirus and ECHO virus from 10- to 20-1 vols, of tap water ranged between 32 and 98%, 67 and 100% and 69 and 100%, respectively. This technique appears to have distinct advantages over previous methods as it requires low cost equipment (47 mm polypropylene filter housing) and materials, is simple and easy to handle, can filter large volumes of water (⩾20 l) with good recoveries at ambient pH and can be efficiently used to monitor viral water quality.

Virus Concentration from Water Using High-Rate Tangential-Flow Hollow Fiber Ultrafiltration

The efficacy of tangential flow hollow fiber Ultrafiltration (TFHFU) as a means of concentrating poliovirus 2 (Sabin) from large volumes of tap water was studied. Initially, hydrodynamic studies using 50-1 tap water feed solutions were conducted to evaluate transmembrane flux as a function of axial flow rates (or Reynold's numbers, Re). With increasing Reynold's number, flux-decline rates were reduced. As a result, experimental duration was shortened from 110 min at Re=300 to 30 min at Re=1728. In all cases, radial flow was assisted by a vacuum force applied to the outside of the hollow fibers. Virus recovery capability was evaluated using 20-, 50-, and 100-1 feed samples seeded with poliovirus 2 from 604 to 0.5 pfu/ml. All virus experiments were conducted at Re=1728 and a vacuum force of 3.27 × 104 Pa. The mean duration of the 20-, 50-, and 100-1 experiments was 13, 42, and 79 minutes, respectively. The overall average virus recovery from all experiments was 69.1 ± 24.6%. In operating the tangential-flow hollow fiber ultrafiltration module in its normal recycle-mode with low turbidity waters (<10 NTU), the expected steady flux-decline resulting from membrane fouling was not observed. Instead, the transmembrane permeation flux was maintained at a relatively constant value especially near the end of the experiments when the solute concentration in the feed increased the fastest. Increased feed water temperature resulting from the addition of pumping energy during recycle is responsible for this unexpected advantage. Final temperatures never exceeded a point at which virus inactivation would occur. For high turbidity feed waters (75 to 85 NTU), obtained by the addition of kaolin clay, virus recoveries varied from 30 to 49%, Final turbidities at the termination of a 50-1 run were from 950 to >1000 NTU. In spite of the high turbidity, the mean experiment duration for dehydrating 50 liters of turbid feed water was 39 minutes; approximately the same as for the low-turbidity tap water runs.

Simple method for concentration of bacteria from large volumes of tap water.

Membrane adsorption-elution techniques have made it possible to concentrate and detect small numbers of viruses in large volumes of water and wastewater, but no such methods are available for quantitative recovery of bacteria. A number of waterborne disease outbreaks of "unknown etiology" in the United States are suspected to have been caused by pathogens present in numbers too small to be detected by currently available methodology. The present study reports on the use of positively charged depth filters for the concentration and detection of bacteria in large volumes of tap water. In this method, dechlorinated tap water was passed, under positive pressure, through positively charged filter media (Zetaplus, 05S). More than 90% of seeded bacteria adsorbed to these filters at ambient pH levels. Adsorbed bacteria were eluted by passing a small volume of Trypticase soy broth in the direction opposite of the influent flow. By this method, Escherichia coli and Salmonella serovar B organisms in 20 liters of tap water were concentrated in a final volume of 50 ml, with an average recovery efficiency of greater than or equal to 30%.

Transmissiveness of ultrasound through tap water, glycerin, and mineral oil.

Transmissiveness of ultrasonic energy through large volumes of tap water, glycerin, and mineral oil was studied to determine whether there was a meaningful difference in the liquids' capability to allow energy transfer from the transducer to the receiver (patient). The experimental design was intended to simulate clinical conditions in which immersion techniques would be used. There were statistically significant differences (p > .01) in energy transfer among each of the liquids at each intensity and each distance. Significant differences (p > .05) in temperature changes occurred in each of the liquids and at each intensity.

Evaluation of the Tentative Standard Method for Enteric Virus Concentration From Large Volumes of Tap Water

During 24 months of evaluation the tentative standard method was found to be inefficient—and sometimes ineffective—for concentrating low levels of laboratory‐grown and naturally occurring sewage‐extracted enteric viruses from 380‐L (100‐gal) volumes of experimentally contaminated tap water.

Concentration of enteroviruses from large volumes of tap water, treated sewage, and seawater

Methods are described for the efficient concentration of an enterovirus from large volumes of tap water, sewage, and seawater. Virus in acidified water (pH 3.5) in the presence of aluminum chloride was adsorbed to a 10-inch (ca. 25.4 cm) fiberglass depth cartridge and a 10-inch pleated epoxy-fiberglass filter in a series at flow rates of up to 37.8 liters (10 gallons) per min. Adsorbed viruses were eluted from the filters with glycine buffer (pH 10.5 to 11.5), and the eluate was reconcentrated by using a combination of aluminum flocculation followed by hydroextraction. With this procedure, poliovirus in large volumes of tap water, seawater, and sewage could be concentrated with an average efficiency of 52, 53, and 50%, respectively. It was demonstrated that this method is capable of detecting surface solid-associated viruses originating from sewage treatment plants. No difference in virus recovery between laboratory batch studies and a set-up with acid-salt injection was found. This unified scheme for the concentration of viruses has many advantages over previously described systems. These include: high operating flow rates, low weight and small size, effectiveness with a variety of waters with widely varying qualities, and filters with a high resistance to clogging.

Concentration of poliovirus from tap water onto membrane filters with aluminum chloride at ambient pH levels.

A method is described for the concentration of an enterovirus from large volumes of tap water by addition of small amounts of aluminum chloride to enhance virus removal by membrane filters. Tap water treated with 2 X 10(-5) M aluminum chloride showed a slight decrease in pH (less than 0.5), a slight increase in turbidity, and enhanced removal of poliovirus by membrane filters. Virus was quantitatively recovered by treating the filters with a basic buffer, and this eluate was reconcentrated to a small volume by adsorption to aluminum hydroxide flocs. Using these procedures, virus from 1,000 liters of water was reduced to a final eluate of 20 to 80 ml with a mean recovery of 70%.

Regeneration of pleated filters used to concentrate enteroviruses from large volumes of tap water

Pleated cartridge filters are capable of concentrating enteroviruses from large volumes (well over 2,000 liters) of tap water. These epoxy-fiberglass filters can be regenerated if they are treated with 0.1 N NaOH or autoclaved to inactivate any contaminating virus. The regenerated filters regained their ability to concentrate viruses from water at high flow rates.

Concentration of viruses from large volumes of tap water using pleated membrane filters

A method is described for the efficient concentration of viruses from large volumes of tap water in relatively short time periods. Virus in acidified tap water in the presence of aluminum chloride is adsorbed to a 10-inch (ca. 25.4 cm) fiberglass depth cartridge and a 10-inch pleated epoxy-fiberglass filter in series at flow rates of up to 37.8 liters/min (10 gallons/min). This filter series is capable of efficiently adsorbing virus from greater than 19,000 liters (5,000 gallons) of treated tap water. Adsorbed viruses are eluted from the filters with glycine buffer (pH 10.5) and the eluate is reconcentrated using an aluminum flocculation process. Viruses are eluted from the aluminum floc with glycine buffer (pH 11.5). Using this procedure, viruses in 1,900 liters (500 gallons) of tap water can be concentrated 100,000-fold in 3 h with an average recovery of 40 to 50%.

Detection of viruses in large volumes of natural waters by concentration on insoluble polyelectrolytes

Abstract A method is described for recovering small amounts of virus from very large volumes of water. When poliovirus was added to large volumes of tap water, it could be recovered by adsorbing the virus onto thin layers of an insoluble polyelectrolyte (a crosslinked copolymer of isobutylene maleic anhydride), with subsequent concentration into small volumes of eluent for assay purposes. Virus contained in 25, 50, 75 and 100 gal of water was recovered with efficiencies ranging from 60 to 80 per cent. Poliovirus added to a 17,000-gal swimming pool was recovered with an efficiency of about 40 per cent by passing 300 gal of the pool water through a thin 3 mm polyelectrolyte layer 293 mm in diameter, with subsequent elution of the virus from the layer, and reconcentration into a smaller volume for assay.