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Biomedical subjects

J B Rose

Publications and source records attributed to J B Rose.

At least 55 records · Page 3Linked to original sources
PubMed1996

Prevalence of shigellosis in the U.S.: consistency with dose-response information.

Every year there are estimated 300000 cases of Shigella in the United States (Bennett et al., 1987, Am. J. Prev. Med. 3, 102-114). A beta-poisson model was fit to human dose-response information on pathogenic Shigella using the Maximum Likelihood Estimation technique (Haas, 1983, Am. J. Epidemiol. 118, 573-582). Pooled and separate data sets for the Shigella species were fit to the beta-Poisson model and 95% confidence limits and regions were calculated. Shigella dysentariae and Shigella flexneri confidence regions and limits overlapped with each other and with the pooled data set, suggesting that this model can describe Shigella in general. The pooled Shigella model as well as the upper and lower confidence limits of the three data sets showed average exposures based on the estimated U.S. caseload of pathogenic Shigella of 0.01 to 0.014 organisms (confidence limits 0.001-0.05) for a 7-day per annum period of exposure and ranges from 0.07 to 0.1 organisms (confidence limits 0.006-0.4). for a 1-day per annum period of exposure. The plausibility of the pooled dose-response model was then evaluated by comparison with two known cruise ship outbreaks. The pooled model estimated that the two outbreaks studied could have been due to ingestion of 344 (confidence limits 72-915) Shigella cells per meal and 10.5-12 (confidence limits 1-44) Shigella cells per glass of water by passengers.

Dysentery, Bacillary↗
PubMed1996

Sensitive populations: who is at the greatest risk?

The purpose of this article was to review the existing literature to define those groups of individuals who would be at the greatest risk of serious illness and mortality from water and foodborne enteric microorganisms. This group was found to include the very young, the elderly, pregnant women, and the immunocompromised. This segment of the population currently represents almost 20% of the population in the United States and is expected to increase significantly by the beginning of the next century, because of increases in life-span and the number of immunocompromised individuals. More than half of documented deaths from gastroenteritis and hepatitis A illness occur in the elderly in developed countries. The overall case fatality ratio for foodborne bacterial gastroenteritis outbreaks in nursing homes is 10 times greater than the general population. Pregnant mothers suffer from a case fatality ratio from hepatitis E infections ten times greater than the general population during waterborne disease outbreaks. Enteric diseases are most common and devastating among the immunocompromised. Cryptosporidium is a serious problem among patients with acquired immuno-deficiency syndrome (AIDS). Cancer patients undergoing chemotherapy and transplant patients, are also at significantly greater risk of dying from enteric viral infections than the general population. This review indicates the need for consideration of enhanced protection for certain segments of the population who will suffer the most from food and waterborne pathogens.

AIDS-Related Opportunistic Infections↗
PubMed1996

Preoperative oral ondansetron for pediatric tonsillectomy.

This prospective, randomized, double-blind, placebo-controlled study evaluated the antiemetic efficacy of preoperative oral ondansetron, 0.075 mg/kg or 0.15 mg/kg, in 136 preadolescent children premedicated with midazolam 0.5 mg/kg per os and dexamethasone 0.1 mg/kg intravenously prior to undergoing tonsillectomy with isoflurane anesthesia. The incidence of vomiting during the 24 h after tonsillectomy was significantly reduced (P < 0.04) by ondansetron 0.15 mg/kg compared with placebo and ondansetron 0.075 mg/kg (15%, 38%, and 36%, respectively). There was a significant reduction (P < 0.03) in the mean number of vomiting episodes per patient during the 24 h immediately after tonsillectomy in the ondansetron 0.15 mg/kg group compared with the placebo and ondansetron 0.075 mg/kg study groups (0.2 +/- 0.6, 0.8 +/- 1.3, and 0.8 +/- 1.3, respectively). The need for antiemetic rescue therapy (ondansetron 0.15 mg/kg intravenously after three episodes of emesis prior to discharge) was significantly greater in children who received placebo compared with the ondansetron 0.15 mg/kg study group (13% vs 0%, P < 0.05). We conclude that ondansetron 0.15 mg/kg, administered orally prior to tonsillectomy, is associated with reduced postoperative vomiting in preadolescent children. In addition, the preoperative oral administration of ondansetron 0.075 mg/kg is no more effective than placebo in preventing posttonsillectomy vomiting in preadolescent children.

Administration, Oral↗
PubMed1996

Posttonsillectomy vomiting. Ondansetron or metoclopramide during paediatric tonsillectomy: are two doses better than one?

This randomized, double blinded, placebo controlled, prospective study compared the anti-emetic efficacy of one preoperative dose of metoclopramide 0.25 mg.kg-1 intravenously or ondansetron 0.15 mg.kg-1 intravenously with two doses of the same drugs (second dose administered one h postoperatively) in 200 preadolescent children undergoing tonsillectomy with either isoflurane or propofol anaesthesia. The incidence of posttonsillectomy vomiting was significantly reduced (P < 0.005) by two doses of either metoclopramide or ondansetron (18% and 8%, respectively) compared with placebo (50%). No difference in posttonsillectomy vomiting exists between the children who received isoflurane and those who received a propofol infusion. Our results suggest that two doses of metoclopramide 0.25 mg.kg-1 intravenously, like two doses of ondansetron 0.15 mg.kg-1, are effective in reducing vomiting after tonsillectomy in children who have received either isoflurane or propofol anaesthesia.

Analysis of Variance↗
PubMed1995

Gene structure, chromosomal localization, and expression of the murine homologue of human proteinase inhibitor 6 (PI-6) suggests divergence of PI-6 from the ovalbumin serpins.

Human proteinase inhibitor 6 (PI-6) is a recently described protein belonging to the serine proteinase inhibitor (serpin) superfamily. Sequence similarity suggests that PI-6 most resembles the ovalbumin (ov) serpins which include plasminogen activator inhibitor-2, the squamous cell carcinoma antigen, monocyte/neutrophil elastase inhibitor, and maspin. Although these proteins are associated with carcinomas and inflammation, they appear to have diverse functions and little is known of their physiological roles. In this study we have characterized cDNA and genomic clones encoding mouse PI-6 in order to analyze the localization, structure, and expression of the gene. The reactive center residues (Arg-Cys) are conserved in the mouse molecule, and recombinant mouse PI-6 was shown to bind thrombin, indicating that it has similar inhibitory properties to its human counterpart. Using reverse transcriptase-polymerase chain reaction assays on RNA isolated from 15-day-old embryos and adult mice, we have shown that mouse PI-6 expression is developmentally regulated, and that, unlike human PI-6, it is absent from the placenta. The mouse homologue of the human PI-6 gene has been designated Spi3 and was mapped to chromosome 13 between the Pl1 and ctla2 alpha genes. It spans 20 kilobases, consists of 7 exons and 6 introns, and contains a TATA motif 24 nucleotides upstream of the transcriptional start site. A 680-base pair DNA fragment containing this motif and 31 nucleotides of the 5'-untranslated region of the structural gene directed transcription of a bacterial cat gene, demonstrating the presence of a functional promoter. The PI-6 gene lacks an intron present in the ovalbumin and PAI-2 genes; otherwise it is identical in terms of the numbers, position, and phasing of the intron/exon boundaries. These results suggest that PI-6 and the ov-serpin genes have diverged and do not belong to the same subgroup.

Amino Acid Sequence↗
PubMed1995

The infectivity of Cryptosporidium parvum in healthy volunteers.

BACKGROUND: Small numbers of Cryptosporidium parvum oocysts can contaminate even treated drinking water, and ingestion of oocysts can cause diarrheal disease in normal as well as immunocompromised hosts. Since the number of organisms necessary to cause infection in humans is unknown, we performed a study to determine the infective dose of the parasite in healthy adults. METHODS: After providing informed consent, 29 healthy volunteers without evidence of previous C. parvum infection, as determined by the absence of anti-cryptosporidium-specific antibodies, were given a single dose of 30 to 1 million C. parvum oocysts obtained from a calf. They were then monitored for oocyst excretion and clinical illness for eight weeks. Household contacts were monitored for secondary spread. RESULTS: Of the 16 subjects who received an intended dose of 300 or more oocysts, 14 (88 percent) became infected. After a dose of 30 oocysts, one of five subjects (20 percent) became infected, whereas at a dose of 1000 or more oocysts, seven of seven became infected. The median infective dose, calculated by linear regression, was 132 oocysts. Of the 18 subjects who excreted oocysts after the challenge dose, 11 had enteric symptoms and 7 (39 percent) had clinical cryptosporidiosis, consisting of diarrhea plus at least one other enteric symptom. All recovered, and there were no secondary cases of diarrhea among household contacts. CONCLUSIONS: In healthy adults with no serologic evidence of past infection with C. parvum, a low dose of C. parvum oocysts is sufficient to cause infection.

Adult↗
PubMed1995

Water chlorination: essential process or cancer hazard?

Chlorine has been successfully used for the control of waterborne infectious disease for nearly a century. In the 1970s it was found that chlorine reacted with natural organic matter present in surface waters to produce disinfection by-products (DBP). Concern focused initially on the trihalomethanes (THM), but a wide variety of DBPs are now known to result from chlorination. Chlorination of drinking water has been one of the most effective public health measures ever undertaken. There are a number of alternatives to chlorination that are in active use in many parts of the world, but the risks associated with their by-products are even less well established than for chlorination. Moreover, the use of these alternatives vary in their effectiveness and some require greater sophistication in their application. This can mean less protection to public health as a result of inappropriate application and control. Therefore, hazards associated with the use of such a clearly beneficial process as chlorination must be carefully considered not only in an absolute sense, but also in the context of alternative approaches for producing a safe drinking water. The key question is whether the hazards associated with by-products have been sufficiently well established to warrant regulations that will undoubtedly have both positive and negative impacts on the public health. This symposium examined the toxicological and epidemiological data on chemical hazards associated with chlorination and attempted to measure this hazard against competing microbial risks. The first presentation discussed the available analytical epidemiological studies. A second presentation dealt with the importance of chlorination to the prevention of waterborne infectious disease. Pharmacokinetic, mechanistic, and modeling information on the prototypical DBP, chloroform, were discussed and contrasted with data on brominated THMs to determine if it was scientifically appropriate to regulate THMs as a single toxicological class. The fifth presentation dealt with the carcinogenic properties of a potent mutagen that is produced by chlorination. The final presentation discussed the haloacetates, carcinogenic DBPs whose concentrations approach and occasionally exceed those of the THMs. Clearly, there is a need to carefully weigh these different types and sometimes competing risks when considering the delivery of drinking water to ever-increasing populations for which there are finite sources of fresh water.

Animals↗
PubMed1995

Rapid intravenous administration of ondansetron or metoclopramide is not associated with cardiovascular compromise in children.

This double blinded, placebo controlled, randomized, and prospective study investigated the effect of the rapid intravenous administration of ondansetron 0.15 mg.kg-1 or metoclopramide 0.25 mg.kg-1 on the heart rate, haemoglobin saturation, systolic blood pressure, and diastolic blood pressure in 45 ASA PS I-II children between two and 16 years of age prior to elective tonsillectomy. The study groups were not significantly different with respect to age, weight, or gender. We were unable to detect a change in heart rate, systolic or diastolic blood pressure, or haemoglobin saturation following the rapid administration of ondansetron or metoclopramide. We conclude intravenous ondansetron or metoclopramide (for the prevention of postoperative vomiting) are not associated with cardiovascular instability when administered rapidly to healthy children prior to elective surgery.

Adolescent↗
PubMed1995

Development of a PCR protocol for sensitive detection of Cryptosporidium oocysts in water samples.

The development of a reliable method of using PCR for detection of Cryptosporidium oocysts in environmental samples with oligonucleotide primers which amplify a portion of the sequence encoding the small (18S) subunit of rRNA producing a 435-bp product was demonstrated. The PCR assay was found to provide highly genus-specific detection of Cryptosporidium spp. after release of nucleic acids from oocysts by a simple freeze-thaw procedure. The assay routinely detected 1 to 10 oocysts in purified oocyst preparations, as shown by direct microscopic counts and by an immunofluorescence assay. The sensitivity of the PCR assay in some seeded environmental water samples was up to 1,000-fold lower. However, this interference was eliminated by either flow cytometry or magnetic-antibody capture. Sensitivity was also improved 10- to 1,000-fold by probing of the PCR product on dot blots with an oligonucleotide probe detected by chemiluminescence. Confirmation of the presence of Cryptosporidium oocysts in water samples from the outbreak in Milwaukee, Wis., was obtained with this technique, and PCR was found to be as sensitive as immunofluorescence for detection of oocysts in wastewater concentrates.

Animals↗
PubMed1995

Viral tracer studies indicate contamination of marine waters by sewage disposal practices in key largo, Florida.

Domestic wastewater disposal practices in the Florida Keys are primarily limited to on-site disposal systems such as septic tanks, injection wells, and illegal cesspits. Poorly treated sewage is thus released into the highly porous subsurface Key Largo limestone matrix. To investigate the fate and transport of sewage in the subsurface environment and the potential for contamination of marine surface waters, we employed bacteriophages as tracers in a domestic septic system and a simulated injection well in Key Largo, Florida. Transport of bacteriophage (Phi)HSIC-1 from the septic tank to adjacent surface canal waters and outstanding marine waters occurred in as little as 11 and 23 h, respectively. Transport of the Salmonella phage PRD1 from the simulated injection well to a canal adjacent to the injection site occurred in 11.2 h. Estimated rates of migration of viral tracers ranged from 0.57 to 24.2 m/h, over 500-fold greater than flow rates measured previously by subsurface flow meters in similar environments. These results suggest that current on-site disposal practices can lead to contamination of the subsurface and surface marine waters in the Keys.

Journal Article↗
PubMed1995

Occurrence of fecal indicator bacteria in surface waters and the subsurface aquifer in Key Largo, Florida.

Sewage waste disposal facilities in the Florida Keys include septic tanks and individual package plants in place of municipal collection facilities in most locations. In Key Largo, both facilities discharge into the extremely porous Key Largo limestone. To determine whether there was potential contamination of the subsurface aquifer and nearby coastal surface waters by such waste disposal practices, we examined the presence of microbial indicators commonly found in sewage (fecal coliforms, Clostridium perfringens, and enterococci) and aquatic microbial parameters (viral direct counts, bacterial direct counts, chlorophyll a, and marine vibriophage) in injection well effluent, monitoring wells that followed a transect from onshore to offshore, and surface waters above these wells in two separate locations in Key Largo in August 1993 and March 1994. Effluent and waters from onshore shallow monitoring wells (1.8- to 3.7-m depth) contained two or all three of the fecal indicators in all three samples taken, whereas deeper wells (10.7- to 12.2-m depth) at these same sites contained few or none. The presence of fecal indicators was found in two of five nearshore wells (i.e., those that were < or = 1.8 miles [< or = 2.9 km] from shore), whereas offshore wells (> or = 2.1 to 5.7 miles [< or = 3.4 to 9.2 km] from shore) showed little sign of contamination. Indicators were also found in surface waters in a canal in Key Largo and in offshore surface waters in March but not in August. Collectively, these results suggest that fecal contamination of the shallow onshore aquifer, parts of the nearshore aquifer, and certain surface waters has occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Clostridium perfringens↗
PubMed1994

A massive outbreak in Milwaukee of cryptosporidium infection transmitted through the public water supply.

BACKGROUND: Early in the spring of 1993 there was a widespread outbreak of acute watery diarrhea among the residents of Milwaukee. METHODS: We investigated the two Milwaukee water-treatment plants, gathered data from clinical laboratories on the results of tests for enteric pathogens, and examined ice made during the time of the outbreak for cryptosporidium oocysts. We surveyed residents with confirmed cryptosporidium infection and a sample of those with acute watery diarrhea consistent with cryptosporidium infection. To estimate the magnitude of the outbreak, we also conducted a survey using randomly selected telephone numbers in Milwaukee and four surrounding counties. RESULTS: There were marked increases in the turbidity of treated water at the city's southern water-treatment plant from March 23 until April 9, when the plant was shut down. Cryptosporidium oocysts were identified in water from ice made in southern Milwaukee during these weeks. The rates of isolation of other enteric pathogens remained stable, but there was more than a 100-fold increase in the rate of isolation of cryptosporidium. The median duration of illness was 9 days (range, 1 to 55). The median maximal number of stools per day was 12 (range, 1 to 90). Among 285 people surveyed who had laboratory-confirmed cryptosporidiosis, the clinical manifestations included watery diarrhea (in 93 percent), abdominal cramps (in 84 percent), fever (in 57 percent), and vomiting (in 48 percent). We estimate that 403,000 people had watery diarrhea attributable to this outbreak. CONCLUSIONS: This massive outbreak of watery diarrhea was caused by cryptosporidium oocysts that passed through the filtration system of one of the city's water-treatment plants. Water-quality standards and the testing of patients for cryptosporidium were not adequate to detect this outbreak.

Adolescent↗
PubMed1994

Ondansetron reduces the incidence and severity of poststrabismus repair vomiting in children.

This prospective, randomized, placebo-controlled, double-blinded study evaluated the antiemetic efficacy of ondansetron and metoclopramide in 90 ASA physical status I or II children, 2-17 yr of age, undergoing strabismus repair. After anesthetic induction and prior to eye muscle manipulation, subjects received normal saline 0.3 mL/kg (Group 1), metoclopramide 0.25 mg/kg (Group 2), or ondansetron 0.15 mg/kg (Group 3), intravenously. There were no differences between groups with respect to age, weight, gender, fluids received, number of eye muscles repaired, anesthetic technique, or time in the operating room. The incidence of vomiting in Groups 1, 2, and 3 was 50%, 27%, and 10% prior to discharge, and 67%, 53%, and 30% during the 24 h after surgery, respectively. The number of children vomiting prior to discharge and within 24 h of surgery was significantly reduced in Group 3 compared with Group 1 (P < 0.003 and P < 0.015, respectively). The number of vomiting episodes per patient in Groups 1, 2, and 3 was 1.1, 0.5, and 0.1 prior to discharge, and 4.5, 2.6, and 1.2 during the 24 h after surgery (P < 0.0005 and P < 0.004, respectively). Ondansetron 0.15 mg/kg intravenously after the induction of anesthesia reduces the incidence and severity of vomiting after strabismus repair both prior to discharge from the hospital and during the 24 h after surgery.

Adolescent↗
PubMed1993

Risk assessment of virus in drinking water.

The reevaluation of drinking water treatment practices in a desire to minimize the formation of disinfection byproducts while assuring minimum levels of public health protection against infectious organisms has caused it to become necessary to consider the problem of estimation of risks posed from exposure to low levels of microorganisms, such as virus or protozoans, found in treated drinking water. This paper outlines a methodology based on risk assessment principles to approach the problem. The methodology is validated by comparison with results obtained in a prospective epidemiological study. It is feasible to produce both point and interval estimates of infection, illness and perhaps mortality by this methodology. Areas of uncertainty which require future data are indicated.

Epidemiologic Methods↗
PubMed1993

Distribution of viral abundance in the reef environment of Key Largo, Florida.

The distribution of viral and microbial abundance in the Key Largo, Fla., reef environment was measured. Viral abundance was measured by transmission electron microscope direct counts and plaque titer on specific bacterial hosts in water and sediment samples from Florida Bay (Blackwater Sound) and along a transect from Key Largo to the outer edge of the reef tract in Key Largo Sanctuary. Water column viral direct counts were highest in Blackwater Sound of Florida Bay (1.2 x 10(7) viruses per ml), decreased to the shelf break (1.7 x 10(6) viruses per ml), and were inversely correlated with salinity (r = -0.97). Viral direct counts in sediment samples ranged from 1.35 x 10(8) to 5.3 x 10(8)/cm(3) of sediment and averaged nearly 2 orders of magnitude greater than counts in the water column. Viral direct counts (both sediment and water column measurements) exceeded plaque titers on marine bacterial hosts (Vibrio natriegens and others) by 7 to 8 orders of magnitude. Water column viral abundance did not correlate with bacterial direct counts or chlorophyll a measurements, and sediment viral parameters did not correlate with water column microbial, viral, or salinity data. Coliphage, which are indicators of fecal pollution, were detected in two water column samples and most sediment samples, yet their concentrations were relatively low (<2 to 15/liter for water column samples, and <2 to 108/cm(3) of sediment). Our findings indicate that viruses are abundant in the Key Largo environment, particularly on the Florida Bay side of Key Largo, and that processes governing their distribution in the water column (i.e., salinity and freshwater input) are independent of those governing their distribution in the sediment environment.

Animals↗
PubMed1992

The mouse gastric H,K-ATPase beta subunit. Gene structure and co-ordinate expression with the alpha subunit during ontogeny.

The gastric H,K-ATPase (EC 3.6.1.3) is responsible for acid secretion into the stomach and is composed of two subunits, alpha and beta. The structure of the gene encoding the mouse beta subunit and the expression of both subunits during ontogeny are reported. The gene spans approximately 12 kilobase pairs and contains 7 exons. The positions at which introns interrupt the coding regions of the mouse H,K-ATPase beta subunit and mouse Na,K-ATPase (EC 3.6.1.37) beta 2 subunit genes are identical. The alternative beta subunit isoform of the Na,K-ATPase, beta 1, has a similar but not identical gene structure. Primer extension and S1 nuclease analysis of RNA isolated from mouse stomachs aged between 2 and 25 days indicated that major transcription-initiation sites are between 22 and 25 base pairs 5' of the translation initiation site at all ages. The expression of the H,K-ATPase alpha and beta subunit genes during ontogeny (day 1-40) was found to be co-ordinated. Protein levels of both the ATPase alpha and beta subunits were very low until day 15 and then increased to adult levels by day 30. In any mucosal cell throughout ontogeny, expression of the beta subunit gene invariably coincided with the expression of the alpha subunit gene. Cells detected by anti-H,K-ATPase beta subunit antibodies in sections from 10- and 30-day-old mice all had typical morphology of parietal cells and were arranged in glandular structures. Co-ordinate expression of the two subunit genes suggest that the regulatory mechanisms will be similar and that the beta subunit may be required for localization and function of the catalytic alpha subunit.

Adenosine Triphosphatases↗