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S McVey

Publications and source records attributed to S McVey.

10 recordsLinked to original sources
PubMed1997

Effects of active chronic cocaine use on cardiac sympathetic neuronal function assessed by carbon-11-hydroxyephedrine.

UNLABELLED: Cardiac toxicity of cocaine has been linked to its inhibitory effect on norepinephrine reuptake by sympathetic nerve terminals of the heart. Carbon-11-hydroxyephedrine is a positron-emitting tracer that has been validated as a highly specific marker for norepinephrine transporter activity of the sympathetic nerve terminals and thus makes possible in vivo assessment of the effect of cocaine on norepinephrine reuptake and storage in the cardiac sympathetic nerve terminals. The aim of the study was to use the catecholamine analog 11C-hydroxyephedrine with PET to determine whether active chronic use of cocaine in women modifies the function of sympathetic nerve terminals of the heart. METHODS: Six normal female volunteers and nine female active chronic cocaine users were studied. Cardiac regional 11C-hydroxyephedrine uptake and blood flow, as assessed with 13N-ammonia, were determined using semi-quantitative polar map analysis of myocardial tracer distribution. Carbon-11-hydroxyephedrine cardiac retention was quantified using dynamic data acquisition and kinetic analysis of blood and tissue activity. RESULTS: Active chronic cocaine users showed small areas of abnormal blood flow and 11C-hydroxyephedrine retention in the heart in comparison with normal volunteers. The extent of abnormalities expressed as a percent of the total polar map area averaged 2.0% +/- 2.6% and 2.5% +/- 2.7% for blood flow and 11C-hydroxyephedrine uptake, respectively. Myocardial 11C-hydroxyephedrine retention was significantly reduced by 22% in active cocaine users (0.109 +/- 0.017 min-1), as compared to normal controls (0.140 +/- 0.027 min-1). CONCLUSION: PET imaging with 11C-hydroxyephedrine permits quantitative assessment of cardiac norepinephrine transporter function in active chronic cocaine users. The results of this study suggest prolonged reduction of norepinephrine uptake and storage capacity in the cardiac sympathetic nerve terminals which may reflect the effect of repetitive elevation of norepinephrine levels induced by cocaine exposure.

Adult↗
PubMed1995

Combined PCR-oligonucleotide ligation assay for rapid detection of Salmonella serovars.

We have developed a rapid and sensitive assay for the detection of Salmonella serovars in veterinary clinical specimens. This method utilizes a short cultivation period followed by PCR. For detection of the amplified product, an enzyme-linked immunosorbent assay (ELISA)-based oligonucleotide ligation assay (OLA) was used. In this study, the PCR-OLA technique was compared with conventional culture and membrane hybridization for the detection of Salmonella bacteria. In evaluating the PCR-OLA with Salmonella serovars and non-Salmonella strains of bacteria, A490 readings for 51 Salmonella strains, representing 28 serovars, were significantly higher (P < 0.05) than those for 25 non-Salmonella bacteria. With serial 10-fold dilutions of Salmonella CFU or with known concentrations of purified chromosomal DNA from Salmonella typhimurium ATCC 29946, the PCR-OLA was able to detect > or = 20 CFU per assay or > or = 80 fg of chromosomal DNA (corresponding to 160 molecules of DNA). Of 102 suspect clinical specimens screened, 15 were positive for Salmonella bacteria by both culture and the PCR-OLA procedure (100% sensitivity), and 3 samples were positive only by PCR-OLA (96.6% specificity), indicating a positive predictive value of 83.3% and a negative predictive value of 100%. In all experiments, the PCR-OLA was as sensitive as membrane hybridization. These results indicate that a limited enrichment cultivation and PCR-OLA could be used as a presumptive screening test for the detection of Salmonella serovars from any sample that currently requires extensive cultivation and that this assay would be adaptable to automation.

Animals↗
PubMed1995

Detection of Salmonella typhimurium from rectal swabs of experimentally infected beagles by short cultivation and PCR-hybridization.

A rapid and sensitive cultivation and PCR-hybridization procedure for the detection and identification of Salmonella typhimurium was evaluated over a 42-day period with eight experimentally infected beagles. Rectal swabs were taken at several times postinfection, inoculated into selenite-cystine broth, and plated onto Hektoen-Enteric Enteric agar immediately after incubation for 4 and 24 h. PCRs and hybridizations were also conducted with each sample, and the results were compared with those of standard culture techniques to evaluate the efficiency of the PCR-hybridization procedure. The PCR-hybridization procedure was more sensitive than standard culture techniques at each enrichment incubation (P < 0.05). In addition, the PCR-hybridization procedure was significantly better than culture up through 3 days postinfection (P < 0.05). A nonspecific amplified product, relatively close in size to the 457-bp specifically amplified product, did not hybridize to an internal oligonucleotide probe or to a random-primed labeled probe. Subsequent sequence information revealed that the product had very little similarity to the 457-bp product but had significant similarity to an Escherichia coli aldehyde dehydrogenase gene. This study indicated that a cultivation and PCR-hybridization procedure is significantly better than culture for the identification of S. typhimurium. Additionally, the results confirm the importance of determining specificities of PCR products beyond the gel electrophoresis level by hybridization with a specific probe.

Animals↗
PubMed1995

Acridine orange differential staining of total DNA and RNA in normal and galactosemic lens epithelial cells in culture using flow cytometry.

The lens epithelial cells are a primary site of involvement in galactosemia. Changes in their size, shape and proliferative capacity have been observed upon exposure to high galactose. In this report, changes in the cell cycle pattern of normal and galactosemic lens epithelial cells were examined by use of flow cytometry. Both changes in DNA and RNA were observed using the fluorochrome, acridine orange. Under the appropriate conditions acridine orange can be used to differentiate double-stranded DNA from single-stranded RNA. Using this approach, the DNA and RNA of normal and galactosemic (1, 4, or 7 days) lens epithelial cells can be compared. The results indicate that lens epithelial cells, when exposed to 40 mM galactose media or 30 mM glucose for 7 days, are induced to enter mitosis. Mannitol did not mimic these results. Changes in the cell cycle pattern were not observed when the cells were treated for 1 or 4 days. Although higher numbers of cells in mitosis were observed after 7 days exposure to 40 mM galactose, a correlation between proliferation, as measured by 3H-thymidine uptake, and mitosis was not possible. Apoptosis was evaluated as a possible explanation for these results. The changes in the DNA staining pattern could be use to monitor lens epithelial cells during galactosemia.

Acridine Orange↗
PubMed1994

Detection of Salmonella serovars from clinical samples by enrichment broth cultivation-PCR procedure.

To overcome problems associated with application of PCR to clinical samples, we have combined a short cultivation procedure with a Salmonella-specific PCR-hybridization assay to specifically identify Salmonella serovars from clinical samples of various animal species. The technique was investigated by using fecal samples seeded with known numbers of Salmonella organisms and cultivated for different lengths of time in assorted selective and nonselective enrichment media. The ability of PCR to amplify a Salmonella-specific DNA product (457-bp sequence covering the Salmonella invE and invA genes) was examined in Southern hybridizations with an internal oligonucleotide probe. Forty-seven Salmonella isolates representing 32 serovars were evaluated, and all Salmonella isolates resulted in a 457-bp product that hybridized with the oligonucleotide probe, whereas no hybridizations were evident with 53 non-Salmonella organisms. The assay detected as few as 9 CFU of Salmonella organisms in pure culture and as little as 300 fg of purified chromosomal DNA. Rappaport-Vassiliadis and tetrathionate broths were inhibitory to PCR, whereas brain heart infusion and selenite-cystine broths were not. The PCR-hybridization assay coupled with a brain heart infusion enrichment culture incubated for 2 h detected as few as 80 CFU of Salmonella organisms in seeded feces. We have successfully identified Salmonella serovars in clinical samples from swine, horses, and cattle more rapidly than with conventional culture techniques. The sensitivity and specificity of this assay were both 100% compared with culture results. These results indicate that a combined cultivation-PCR-hybridization assay could be applicable and advantageous in the rapid identification of Salmonella serovars in routine diagnostic situations.

Animals↗
PubMed1993

Prevalence of Salmonella in raw meat used in diets of racing greyhounds.

One hundred twelve samples of commercial raw meat used in greyhound diets were collected and cultured for Salmonella using standard procedures. Fifty (44.64%) of these samples were positive for Salmonella. Salmonella typhimurium was the most frequently isolated serovar (48%), followed by S. newport (12.76%), S. agona (8.51%), and S. muenster (6.38%). The remaining 10 serovars recovered in this study represented 27.59% of the total Salmonella isolates. In addition, the meat samples were screened for Salmonella using a commercial DNA probe. Of the 106 samples tested, 70 (66.03%) were positive for Salmonella, which indicated that the DNA probe assay was more sensitive than the culture method for screening of Salmonella in raw meat. Antimicrobial susceptibility testing revealed that most of the Salmonella isolates were sensitive to a variety of antimicrobials, particularly amikacin and apramycin, and resistant to some others, such as clindamycin, erythromycin, penicillin, and sulfadimethoxine. The cumulative percentages of susceptibility (MIC50 and MIC90) of the Salmonella isolates were also determined. Most isolates were susceptible (MIC90) to low concentrations of gentamicin (2.0 micrograms/ml), imipenem (< or = 0.25 microgram/ml), and ciprofloxacin (< or = 0.5 microgram/ml). Marked resistance was found with the other antimicrobial agents. However, the high MIC values found for these isolates would not be achievable in vivo with the normal recommended doses of antimicrobial agents, so their use would not be beneficial. Numerous plasmid patterns were found in 17 randomly selected Salmonella isolates. Eight of the 17 isolates had 2-7 plasmids ranging from 2.4 to 15 kilobases in size. Eight isolates also exhibited large plasmids in the range of 50-60 and 95-105 kilobases.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1993

Application of polymerase chain reaction for the correlation of Salmonella serovars recovered from greyhound feces with their diet.

The polymerase chain reaction was employed to correlate Salmonella serovars isolated from fecal material of greyhounds suffering from gastroenteritis with those isolated from the diet fed to the greyhounds prior to onset of diarrhea. Kennels around the Abilene, Kansas, area were contacted and supplied with materials needed to collect a portion of the diet each day. With the onset of diarrhea, the kennels were instructed to ship the fecal material and diet from the previous 10 days to the laboratory for testing. Forty-one fecal samples and corresponding diets were screened for Salmonella, Clostridium perfringens, Campylobacter jejuni, Staphylococcus aureus, Staphylococcus intermedius, and pathogenic (piliated) Escherichia coli by direct culture using standard procedures. The fecal material was also screened for coronavirus and parvovirus using electron microscopy. Thirty-five "normal" fecal samples were screened for all of the above mentioned microorganisms as a control. In addition, the fecal material was screened for E. coli verotoxins I and II and clostridial enterotoxins. A total of 61 Salmonella isolates were recovered from the 41 samples of feces and diet submitted for testing; 31 were recovered from the feces and 30 from the diet. Four Salmonella isolates were recovered from the normal fecal samples. Results obtained by PCR, plasmid profiles, antigenic analysis, and antibiogram profiles indicated that 16 of the 31 isolates recovered from the fecal material were the same strain as that recovered from the diet.

Animal Feed↗
PubMedDate not supplied

Bosnia in our homes.

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Bosnia and Herzegovina↗