Biomedical subjects

J B Rose

Publications and source records attributed to J B Rose.

72 records · Page 4Linked to original sources

PubMed1991

Multilaboratory evaluation of methods for detecting enteric viruses in soils.

Two candidate methods for the recovery and detection of viruses in soil were subjected to round robin comparative testing by members of the American Society for Testing and Materials D19:24:04:04 Subcommittee Task Group. Selection of the methods, designated "Berg" and "Goyal," was based on results of an initial screening which indicated that both met basic criteria considered essential by the task group. Both methods utilized beef extract solutions to achieve desorption and recovery of viruses from representative soils: a fine sand soil, an organic muck soil, a sandy loam soil, and a clay loam soil. One of the two methods, Goyal, also used a secondary concentration of resulting soil eluants via low-pH organic flocculation to achieve a smaller final assay volume. Evaluation of the two methods was simultaneously performed in replicate by nine different laboratories. Each of the produced samples was divided into portions, and these were respectively subjected to quantitative viral plaque assay by both the individual, termed independent, laboratory which had done the soil processing and a single common reference laboratory, using a single cell line and passage level. The Berg method seemed to produce slightly higher virus recovery values; however, the differences in virus assay titers for samples produced by the two methods were not statistically significant (P less than or equal to 0.05) for any one of the four soils. Despite this lack of a method effect, there was a statistically significant laboratory effect exhibited by assay titers from the independent versus reference laboratories for two of the soils, sandy loam and clay loam.

Enterovirus↗

PubMed1991

Detection of Giardia cysts with a cDNA probe and applications to water samples.

Giardiasis is the most common human parasite infection in the United States, causing a lengthy course of diarrhea. Transmission of Giardia species is by the fecal-oral route, and numerous waterborne outbreaks have been documented. The Environmental Protection Agency has regulated Giardia species in drinking water through the Surface Water Treatment Rule. Current methods for detection of Giardia species in water rely primarily on microscopic observation of water concentrates with immunofluorescence techniques. We evaluated the efficacy of using a gene-specific probe for the detection of Giardia species in water. A cDNA probe, 265 bp long, from the small subunit of rRNA of Giardia lamblia was used for detection of cysts. The replicative form of the M13 vector with an insert was isolated from lysed host Escherichia coli XL1-Blue and used for production of the cDNA probe by nick translation with 32P-labeled nucleotides. Six different protocols were tested for extracting nucleic acids from the cysts. With the most efficient procedure, disrupting Giardia cysts with glass beads in the presence of proteinase K, as few as 1 to 5 cysts per ml can be detected in water sample concentrates with dot blot hybridization assays.

Animals↗

PubMed1991

Concentration of viruses and dissolved DNA from aquatic environments by vortex flow filtration.

Vortex flow filtration (VFF) was used to concentrate viruses and dissolved DNA from freshwater and seawater samples taken in Florida, the Gulf of Mexico, and the Bahamas Bank. Recoveries of T2 phage and calf thymus DNA added to artificial seawater and concentrated by VFF were 72.8 and 80%, respectively. Virus concentrations determined by transmission electron microscopy of VFF-concentrated samples ranged from 3.4 x 10(7)/ml for a eutrophic Tampa Bay sample to 2.4 x 10(5) for an oligotrophic oceanic surface sample from the southeastern Gulf of Mexico. Viruslike particles were also observed in a sample taken from a depth of 1,500 m in the subtropical North Atlantic Ocean. Filtration of samples through Nuclepore or Durapore filters (pore size, 0.2 micron) prior to VFF reduced phage counts by an average of two-thirds. Measurement of dissolved-DNA content by Hoechst 33258 fluorescence in environmental samples concentrated by VFF yielded values only ca. 35% of those obtained for samples concentrated by ethanol precipitation (the standard dissolved-DNA method). However, ethanol precipitation of VFF-concentrated extracts resulted in an increase in measurable DNA, reaching 80% of the value obtained by the standard method. These results indicate that a portion of the naturally occurring dissolved DNA is in a form inaccessible to nucleases and Hoechst stain, perhaps bound to protein or other polymeric material, and is released upon ethanol precipitation. Viral DNA contents estimated from viral counts averaged only 3.7% (range, 0.9 to 12.3%) of the total dissolved DNA for samples from freshwater, estuarine, and offshore oligotrophic environments.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Risk assessment and control of waterborne giardiasis.

BACKGROUND: Waterborne giardiasis has been increasing in the United States with 95 outbreaks reported over the last 25 years. The Safe Drinking Water Act has mandated control of this pathogen. METHODS: A risk assessment model was developed to estimate risk of infection after exposure to treated waters containing varying levels of Giardia cysts. The model was defined by a dose-response curve developed from human feeding studies for Giardia and assumed 2L of water consumption per day. Data on concentrations and distribution of the organism in source waters were used to assess exposure after varying reductions achieved through treatment. RESULTS: In surveys reporting prevalence and levels of Giardia cyst contamination, average levels of cysts in surface waters ranged from 0.33 to 104/100L; from pristine watersheds (protected from all human activity) 0.6 to 5/100L. Yearly risks were 4.8 x 10(-3) for systems using polluted waters and 1.3 x 10(-4) for pristine waters with a 10(-3) treatment reduction. CONCLUSION: Public Health officials will need to work with the water industry to ensure a risk of less than 1/10,000 for source waters with 0.7 to 70 cysts per 100 liters through treatment achieving reduction of 10(-3) to 10(-5), respectively, of Giardia cysts.

Agriculture↗

PubMed1990

Waterborne cryptosporidiosis.

Awareness of the importance of Cryptosporidium as a gastrointestinal parasite of developed countries not only stems from its prevalence in AIDS patients but also from its recent recognition as a possible contaminant of drinking water supplies. The importance of Cryptosporidium to public health has recently been revealed by a series of major epidemics of diarrhoeal disease in the USA and UK. In this review, Huw Smith and Joan Rose document what is known of the causes of some of these outbreaks and explain why this parasite can escape the battery of treatment processes normally used for drinking water supplies in these countries.

Journal Article↗

PubMed1989

Large community outbreak of cryptosporidiosis due to contamination of a filtered public water supply.

Between January 12 and February 7, 1987, an outbreak of gastroenteritis affected an estimated 13,000 people in a county of 64,900 residents in western Georgia. Cryptosporidium oocysts were identified in the stools of 58 of 147 patients with gastroenteritis (39 percent) tested during the outbreak. Studies for bacterial, viral, and other parasitic pathogens failed to implicate any other agent. In a random telephone survey, 299 of 489 household members exposed to the public water supply (61 percent) reported gastrointestinal illness, as compared with 64 of 322 (20 percent) who were not exposed (relative risk, 3.1; 95 percent confidence interval, 2.4 to 3.9). The prevalence of IgG to cryptosporidium was significantly higher among exposed respondents to the survey who had become ill than among nonresident controls. Cryptosporidium oocysts were identified in samples of treated public water with use of a monoclonal-antibody test. Although the sand-filtered and chlorinated water system met all regulatory-agency quality standards, sub-optimal flocculation and filtration probably allowed the parasite to pass into the drinking-water supply. Low-level cryptosporidium infection in cattle in the watershed and a sewage overflow were considered as possible contributors to the contamination of the surface-water supply. We conclude that current standards for the treatment of public water supplies may not prevent the contamination of drinking water by cryptosporidium, with consequent outbreaks of cryptosporidiosis.

Cryptosporidiosis↗

PubMed1989

Evaluation of immunofluorescence techniques for detection of Cryptosporidium oocysts and Giardia cysts from environmental samples.

Cryptosporidium and Giardia species are enteric protozoa which cause waterborne disease. The detection of these organisms in water relies on the detection of the oocyst and cyst forms or stages. Monoclonal and polyclonal antibodies were compared for their abilities to react with Giardia cysts and Cryptosporidium oocysts after storage in water, 3.7% formaldehyde, and 2.5% potassium dichromate, upon exposure to bleach, and in environmental samples. Three monoclonal antibodies to Cryptosporidium parvum were evaluated. Each test resulted in an equivalent detection of the oocysts after storage, after exposure to bleach, and in environmental samples. Oocyst levels declined slightly after 20 to 22 weeks of storage in water, and oocyst fluorescence and morphology were dull and atypical. Oocyst counts decreased after exposure to 2,500 mg of sodium hypochlorite per liter, and fluorescence and phase-contrast counts were similar. Sediment due to algae and clays found in environmental samples interfered with the detection of oocysts on membrane filters. Two monoclonal antibodies and a polyclonal antibody directed against Giardia lamblia cysts were evaluated. From the same seeded preparations, significantly greater counts were obtained with the polyclonal antibody. Of the two monoclonal antibodies, one resulted in significantly lower cyst counts. In preliminary studies, the differences between antibodies were not apparent when used on the environmental wastewater samples. After 20 to 22 weeks in water, cyst levels declined significantly by 67%. Cysts were not detected with monoclonal antibodies after exposure to approximately 5,000 mg of sodium hypochlorite per liter.

Analysis of Variance↗

PubMed1987

Occurrence of Cryptosporidium oocysts in sewage effluents and selected surface waters.

An existing method for the detection of Cryptosporidium oocysts in water was modified to investigate oocyst prevalence in large volumes of water. Surface waters and sewage effluents were filtered, eluted from the filter, and concentrated using centrifugation. The resultant pellet was then homogenized, sonicated, and placed on a sucrose gradient to separate oocysts from the sediment. The uppermost gradient layer was then examined by immunofluorescence using a labeled monoclonal antibody. Using this technique, average numbers of oocysts detected in raw and treated sewage were 5.18 X 10(3) and 1.30 X 10(3)/L, respectively. Filtered sewage effluents had significantly lower numbers of oocysts (10.0/L). These data show that sand filtration may reduce the concentrations of this parasite in waste waters. Highly variable oocyst numbers were encountered in surface waters. Since Cryptosporidium oocysts are frequently present in environmental waters, they could be responsible for waterborne outbreaks of disease.

Animals↗

PubMed1984

Comparison of microporous filters for concentration of viruses from wastewater.

The 1-MDS Virosorb filter and the 50S and 30S Zeta-plus filters, all with a net positive charge, were compared with the negatively charged Filterite filter for concentration of naturally occurring coliphages and animal viruses from sewage effluent. When Filterite filters were used, the effluent was adjusted to pH 3.5 and AlCl3 was added before filtration to facilitate virus adsorption. No adjustment was required with the positively charged filters. Sets of each filter type were eluted with 3% beef extract (pH 9.5) or eluted with 0.05 M glycine (pH 11.5). A maximum volume of 19 liters could be passed through 142-mm diameter Filterite filters before clogging, whereas only 11, 11, and 15 liters could be passed through the 1-MDS, 50S, and 30S filters, respectively. For equal volumes passed through the filters, coliphage recoveries were 14, 15, 18, and 37% in primary effluent and 40, 97, 50, and 46% in secondary effluent for the Filterite , 1-MDS, 50S, and 30S filters, respectively. No statistically significant difference was observed in the recovery of animal viruses among the filters from secondary effluent, whereas in the Filterite and 50S filters, higher numbers of viruses from primary effluent were recovered than in the 1-MDS and 30S filters in two of three collections. Glycine was found to be a less-efficient eluent than beef extract in the recovery of naturally occurring viruses.

Animals↗

PubMed1984

Detection of enteric viruses in treated drinking water.

The occurrence of viruses in conventionally treated drinking water derived from a heavily polluted source was evaluated by collecting and analyzing 38 large-volume (65- to 756-liter) samples of water from a 9 m3/s (205 X 10(6) gallons [776 X 10(6) liters] per day) water treatment plant. Samples of raw, clarified, filtered, and chlorinated finished water were concentrated by using the filter adsorption-elution technique. Of 23 samples of finished water, 19 (83%) contained viruses. None of the nine finished water samples collected during the dry season contained detectable total coliform bacteria. Seven of nine finished water samples collected during the dry season met turbidity, total coliform bacteria, and total residual chlorine standards. Of these, four contained virus. During the dry season the percent removals were 25 to 93% for enteric viruses, 89 to 100% for bacteria, and 81% for turbidity. During the rainy season the percent removals were 0 to 43% for enteric viruses, 80 to 96% for bacteria, and 63% for turbidity. None of the 14 finished water samples collected during the rainy season met turbidity standards, and all contained rotaviruses or enteroviruses.

Coliphages↗

PubMed1983

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 NaC1, 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 (greater than or equal to 20 1) with good recoveries at ambient pH and can be efficiently used to monitor viral water quality.

Adsorption↗

PubMed1979

Triplet state of tryptophan in proteins. 2. Differentiation between tryptophan residues 62 and 108 in lysozyme.

We have used optically detected magnetic resonance (ODMR) to characterize the degree of solvent availability of the tryptophan residues in lysozyme that are likely to be responsible for the observed phosphorescence. From the phosphorescence spectra, ODMR zero-field splittings (zfs), and ODMR line widths, we concur with the X-ray structure [Blake, C. C., Mair, G. A., North, A. C. T., Phillips, D. C., & Sarma, V. R. (1967) Proc. R. Soc. London, ser. B 167, 365-377] that Trp-62 behaves as an exposed residue and Trp-108 is buried. In addition, we present evidence that ODMR can be used in conjunction with conventional phosphorescence to evaluate the degree of order in the microenvironments of tryptophan in a protein containing several tryptophans. By the specific modification of residues Trp-62 and Trp-108, we have identified those portions of the ODMR lines in the native enzyme that are due to those specific residues. Barring major enzyme conformational changes in the vicinity of unmodified tryptophan residues when Trp-62 or Trp-108 are selectively modified, we find that Trp-108 dominates both the phosphorescence and the ODMR signals in native lysozyme. The results are discussed in view of previous fluorescence findings.

Luminescent Measurements↗

PubMed1979

Stability of peripheral blood lymphocyte count and E-rosette forming lymphocytes in healthy adults.

Highly reproducible peripheral blood lymphocyte (PBL) count and percent E-rosette forming lymphocyte (%E-RFL) assays were developed by modifying existing procedures. PBL count assay variation was reduced by using replicate electronic white blood cell (WBC) counting and 2,000 WBC differentials. The %E-RFL assay modifications reduced variation and include the use of: (a) a capillary buffy coat isolation procedure that recovered more than 85% of the PBL without the use of chemical separation media, (b) centrifugation temperatures of 20--22 degrees C, and (c) toluidine blue staining that allowed enumeration of %E-RFL and not E-rosette forming cells, by exclusion of nonlymphoid cells. Day-to-day variation of PBL count and %E-RFL was defined by making serial determinations over a period of months. The data indicate that healthy adults maintain PBL counts and %E-RFL within narrow ranges that are specific for each individual.

Adolescent↗

PubMed1977

Tricyclic antidepressant toxicity.

Tricyclic antidepressants are dibenzazepine derivatives with adrenergic, anticholinergic, and direct cardio-depressant activity. Double-blind clinical studies show TCAD to be efficacious for two-thirds of depressed patients. Cardiac toxicity is significant, especially on diseased myocardium. Serious arrhythmias and intracardiac blocks have been reported on therapeutic doses. Tricyclic antidepressant overdose is a serious condition which is becoming progressively more common. The agents' principal toxicities are to the nervous system and the heart. The syndrome can be divided into three stages of varying severity. The vast majority of cases are in the mild Stage I. Some patients reach Stage II with major CNS effects and increasing intracardiac block. Stage III, which encompassed less than 5% of poisonings, is a potentially fatal situation with respiratory arrest, convulsions, and ventricular arrhythmias. Prevention is extremely important in poisoning therapy. Supportive measures are all that is generally needed for mild poisoning. Moderate and severe overdoses will require respiratory support, anticonvulsants, physostigmine, and beta-blockers. Cardioversion and pacing may be necessary.

Adolescent↗

PubMed1973

Alcohol.

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Alcohol Drinking↗

PubMed1972

tobacco.

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Humans↗

PubMedDate not supplied

A field study of virus removal in septic tank drainfields.

Two field studies were conducted at a research station in Tampa, Florida to assess the removal of bacteriophage PRD1 from wastewater in septic tank drainfields. Infiltration cells were seeded with PRD1 and bromide and the effects of effluent hydraulic loading rate and rainfall on virus removal were monitored. Septic tank effluent samples were collected after passage through 0.6 m of unsaturated fine sand and PRD1 was detected over an average of 67 d. Bacteriophage PRD1 breakthrough was detected at approximately the same time as bromide in all three cells except for the low-load cell (Study 1), where bromide was never detected. Log10 removals of PRD1 were 1.43 and 1.91 for the high-load cells (hydraulic loading rate = 0.063 m/d) and 2.21 for the low-load cell (hydraulic loading rate = 0.032 m/d). Virus attenuation is attributed to dispersion, dilution, and inactivation. Significant increases in PRD1 elution with rainfall were observed in the first 10 d of the study. Approximately 125 mm of rainfall caused a 1.2 log10 increase of PRD1 detected at the 0.6-m depth. Current Florida onsite wastewater disposal standards, which specify a 0.6-m distance from the drainfield to the water table, may not provide sufficient removal of viruses, particularly during the wet season.

Bacteriophages↗

PubMedDate not supplied

Reduction of enteric microorganisms at the Upper Occoquan Sewage Authority Water Reclamation Plant.

The Upper Occoquan Sewage Authority (UOSA) Water Reclamation Plant, Centreville, Virginia, is a state-of-the-art wastewater treatment plant that was created to treat area wastewater and provide protection for the Occoquan Reservoir. This study investigated UOSA's unit processes as barriers to pathogenic as well as altemative and traditional-indicator microorganisms. Samples were collected once a month for 1 year from eight sites within UOSA's advanced wastewater reclamation plant. The eight sites were monitored for indicator bacteria total and fecal coliforms, enterococci, Clostridium, coliphage (the virus that infects Escherichia coli), human enteroviruses, and enteric protozoa. Overall, the plant was able to achieve a 5- to 7-log10 reduction of bacteria, 5-log10 reduction of enteroviruses, 4-log10 reduction for Clostridium, and 4.6-log10 reduction of protozoa. Total coliforms, enterococci, Clostridium, coliphage, Cryptosporidium, and Giardia were all detected in four or fewer samples of the final effluent. No enteroviruses or fecal coliforms were detected in the final effluent. The microbiological quality of reclaimed water and the reservoir water were compared. In every case, the treated wastewater was of a better quality than the ambient water in the reservoir, thus indicating that the reclaimed water will not adversely affect the water quality for downstream users.

Animals↗