Search PubMed⌕ Search

Biomedical subjects

D H Rice

Publications and source records attributed to D H Rice.

At least 19 recordsLinked to original sources
PubMed1998

Multiple sources of Escherichia coli O157 in feedlots and dairy farms in the northwestern USA.

Samples from cattle, other domestic and wild animals, flies, feeds, and water-troughs were collected from 12 cattle farms and tested for Escherichia coli O157. E. coli O157 was isolated from bovine fecal samples on all 12 farms with a within herd prevalence ranging from 1.1% to 6.1%. E. coli O157 was also found in 1 of 90 (1.1%) equine fecal samples, 2 of 65 (3.1%) canine fecal samples, 1 of 200 pooled bird samples (0.5%), 2 of 60 pooled fly samples (3.3%), and 10 of 320 (3.1%) water-trough sample sets (biofilm and water). No E. coli O157 were isolated from 300 rodents, 33 cats, 34 assorted wildlife, or 335 cattle feed samples. Indistinguishable pulsed-field gel electrophoresis patterns of XbaI digested chromosomal DNA and Shiga toxin types were observed for bovine and water-trough isolates from two farms and for one equine and two bovine isolates from one farm.

Animals↗
PubMed1998

An outbreak of Escherichia coli O157:H7 infections associated with leaf lettuce consumption.

In July 1995, 40 Montana residents were identified with laboratory-confirmed Escherichia coli O157:H7 infection; 52 residents had bloody diarrhea without laboratory confirmation. The median age of those with laboratory-confirmed cases was 42 years (range, 4- 86); 58% were female. Thirteen patients were hospitalized, and 1 developed hemolytic-uremic syndrome. A case-control study showed that 19 (70%) of 27 patients but only 8 (17%) of 46 controls reported eating purchased (not home-grown) leaf lettuce before illness (matched odds ratio, 25.3; 95% confidence interval, 3.9-1065.6). Pulsed-field gel electrophoresis identified a common strain among 22 of 23 isolates tested. Implicated lettuce was traced to two sources: a local Montana farm and six farms in Washington State that shipped under the same label. This outbreak highlights the increasing importance of fresh produce as a vehicle in foodborne illness. Sanitary growing and handling procedures are necessary to prevent these infections.

Adolescent↗
PubMed1998

The occurrence and replication of Escherichia coli in cattle feeds.

Sixty-three of 209 (30.1%) samples of cattle feed that were collected from multiple commercial sources and from farms were found to contain Escherichia coli. However, none of the feed samples examined were culture-positive for E. coli O157. Replication of fecal E. coli, including E. coli O157, was demonstrated in a variety of feeds at temperatures that were similar to those found on farms in summer months. Fresh mixed rations containing corn silage were sampled from 16 dairies. Rations from 12 of these dairies were found to contain E. coli, and the rations from 5 dairies had concentrations of E. coli that were greater than 1000 cfu/g. The ability of experimental mixed rations to support the replication of E. coli was correlated with the concentration of organic acids in the corn silage that was used in the ration. Widespread contamination of cattle feeds with E. coli and the ability of E. coli to replicate in feeds suggest that feeds are a potentially important factor in the ecology of organisms that can be transmitted from feces to mouth, such as E. coli O157.

Acetates↗
PubMed1998

Association of herd management factors with colonization of dairy cattle by Shiga toxin-positive Escherichia coli O157.

Management factors in 36 Pacific Northwest dairy herds were evaluated for their association with the prevalence of Shiga toxin-positive Escherichia coli O157 (E. coli O157) in dairy cattle. The within-herd prevalence of E. coli O157 was estimated by bacteriological culture of fecal pat samples, collected monthly for 6 months (approximately 60 per visit), from heifer cattle. During the first visit to each farm, a management questionnaire was administered that covered a broad range of animal husbandry practices. On each subsequent visit, a brief questionnaire was administered to detect changes in management practices. A significantly higher prevalence of E. coli O157 was noted in herds that fed corn silage to heifers compared to herds that did not feed corn silage. More tentative associations of E. coli O157 prevalence were observed for weaning method, protein level of calf starter, feeding of ionophores in heifer rations, feeding of grain screens to heifers, and feeding of animal by-products to cows.

Animals↗
PubMed1997

An outbreak of Escherichia coli O157:H7 infections traced to jerky made from deer meat.

OBJECTIVE: To investigate a 1995 outbreak of Escherichia coli O157:H7 infections and to assess the safety of meat dehydration methods. DESIGN: Survey subsequent to routine surveillance report, environmental investigations, and laboratory experimentation. SETTING: Oregon community. PARTICIPANTS: Members of an extended household and their social contacts with confirmed or presumptive E coli O157:H7 infections. RESULTS: A total of 6 confirmed and 5 presumptive cases were identified. Homemade venison jerky was implicated as the source of transmission. E coli O157:H7 with the same distinctive, pulsed-field gel electrophoresis pattern seen in the case isolates was recovered from leftover jerky, uncooked meat from the same deer, a saw used to dismember the carcass, and fragments of the deer hide. In a subsequent survey, E coli O157:H7 was recovered from 3 (9%) of 32 deer fecal pellets collected in nearby forest land. In the laboratory, inoculated venison was dried at several time and temperature combinations, ranging up to 10 hours at 62.8 degrees C. Viable organisms were recovered under all conditions tested. CONCLUSIONS: Deer can be colonized by E coli O157:H7 and can be a source of human infections. Conditions necessary to ensure the safety of dried meat deserve further review. Game should be handled with the same caution indicated for commercially slaughtered meat.

Adolescent↗
PubMed1997

Epidemiology and virulence assessment of Salmonella dublin.

Six strains of Salmonella dublin with distinct antimicrobial susceptibility patterns and/or plasmid profiles were repeatedly isolated from calves in a calf rearing facility. Three of the six strains were isolated from numerous calves during outbreaks of clinical salmonellosis while the other three were not. These strains were compared for their ability to adhere to and internalize in human intestinal epithelial cells (Caco-2) and in bovine alveolar macrophages (BAM), to survive in BAM, and to cause lethal infection in female BALB/c mice. All six strains of S. dublin demonstrated an ability to adhere to and internalize in both Caco-2 cells and in BAM. However, strain differences in the level of adhesion and/or internalization in Caco-2 cells and BAM were demonstrated. Most strains were able to persist but not proliferate in BAM. One outbreak-associated strain which readily attached and internalized in eukaryotic cells in vitro was avirulent to mice at the dose tested. The remaining five strains were virulent to mice. In vitro measures of virulence attributes were not clearly correlated with virulence among S. dublin strains measured either as prevalence in calves during outbreaks of disease or as mouse lethality. Also, there was no association between prevalence of strains in calves during outbreaks of clinical salmonellosis and lethality in mice.

Animals↗
PubMed1997

A longitudinal study of Escherichia coli O157 in fourteen cattle herds.

Escherichia coli O157 shedding in 14 cattle herds was determined by faecal culture at intervals of approximately 1 month for up to 13 months. The overall prevalence was 1.0% (113/10832 faecal samples) and 9 of the 14 herds were detected as positive. Herds positive 2 years previously (n = 5) had a higher prevalence of positive cattle (median = 1.9%) than herds which had been negative on a previous sampling (n = 8, median = 0.2%). Weaned heifers had a higher prevalence (1.8%) than did unweaned calves (0.9%) or adults (0.4%). For all herds the highest prevalence occurred in the summer months, which resulted in most of the positive faecal samples being collected on a minority of sampling visits.

Age Factors↗
PubMed1997

Duration of detection of fecal excretion of Escherichia coli O157:H7 in cattle.

To better define the bovine reservoir of Escherichia coli O157:H7, cattle were tested monthly by bacteriologic culture for fecal excretion of E. coli. E. coli O157:H7 was isolated from feces of 56 cattle sampled an average of 6.98 times (2-12 samples). By broth enrichment culture, immunomagnetic separation, or both, 35 cattle had 1 positive sample, 12 had 2, 7 had 3, and 1 each had 4 and 5. Five cattle with > or = 2 positive samples were in a herd in which 5 pulsed-field gel electrophoretic (PFGE) types were simultaneously present; in 3 of these cattle, different PFGE types were detected in different samples. The duration of detected excretion E. coli O157:H7 by individual cattle in this study was <1 month in 35 (63%) of 56 cattle. Both serial and concurrent excretion of different E. coli O157:H7 strains by individual cattle was observed.

Animals↗
PubMed1996

Use of a mechanical microvascular anastomotic device in head and neck free tissue transfer.

BACKGROUND: The use of mechanical microvascular anastomotic systems for free tissue transfer has previously been reported. Currently, a commercially available coupling device (3M Healthcare, St. Paul, Minn) is widely used for various microvascular free flaps. However, to our knowledge, there are no reports in the literature describing the efficacy of this particular device in regard to free tissue transfer in head and neck reconstruction. OBJECTIVE: To describe the surgical technique, limitations, and guidelines for application of this system for vascular anastomosis in head and neck free tissue transfer. DESIGN: The microvascular anastomotic device was used in 79 head and neck free flaps: radial forearm (n = 28), rectus abdominis (n = 27), fibula (n = 12), lateral thigh (n = 4), iliac crest (n = 3), gracilis (n = 2), jejunum (n = 1), pectoral (n = 1), and lateral arm (n = 1). Follow-up ranged from 6 months to 2.5 years. SETTING: Two major teaching/referral medical centers. PARTICIPANTS: Seventy-six patients ranging in age from 19 to 86 years. INTERVENTION: A total of 105 anastomoses (17 arterial and 88 venous) were performed. OUTCOME MEASURES: Anastomotic times and patency rates were evaluated. RESULTS: the anastomotic times ranged from 8 to 18 minutes for the arteries (average, 10 minutes) and from 4 to 16 minutes for the veins (average, 5 minutes). None of the flaps resulted in venous congestion due to thrombosis at the anastomosis. Two arterial anastomoses resulted in thrombosis, one of which was detected intra-operatively and successfully salvaged with conventional suture anastomosis. CONCLUSIONS: The patency rates with the microvascular anastomotic system appear to compare favorably with those of standard suture techniques. The major advantage is that the time of venous anastomosis is reduced, thereby decreasing the total ischemic time. An additional advantage is the ease with which anastomoses can be performed when the vessels are deep within a wound, where suture placement is difficult.

Adult↗
PubMed1996

Autologous fat injection for unilateral vocal fold paralysis.

This study evaluates the efficacy of autologous fat injection for medialization of the paralyzed vocal fold. In 21 patients with unilateral vocal fold paralysis, autologous abdominal fat was injected into the thyroarytenoid muscle to achieve medialization. All patients were followed up with serial videolaryngoscopy and voice evaluation. At 2 months' follow-up, the voice was judged to be excellent in 10 patients, slightly breathy but significantly better than the preoperative voice in 6 patients, and markedly breathy in 4 patients. At 3 to 4 months' follow-up, of the 10 patients with excellent results, 5 maintained an excellent voice, 3 had developed slight breathiness, and 1 had developed severe breathiness. Long-term (6 to 12 months) results were available in 11 patients, and all of them maintained the same voice quality that was noted during the 3 to 4 months' examination. Magnetic resonance imaging of the larynx was obtained in 7 patients at intervals ranging from 1 to 7 months and compared to the baseline scan obtained at 1 week postoperative to assess the amount of fat remaining in the muscle. The images showed fat volume to persist, but a decrease in the fat signal was observed over time. The results suggest that the duration of medialization with autologous fat is variable, but appears to last at least 2 to 3 months. This loss of volume after 3 months seems to be due to absorption of the fat and possibly muscle atrophy. Autologous fat injection is relatively safe and easy to perform, and is an ideal method of temporary vocal fold medialization in patients in whom return of vocal fold function is expected.

Adipose Tissue↗
PubMed1996

Surgery of the parathyroid glands.

The otolaryngologist-head and neck surgeon is increasingly called upon to perform surgery on the parathyroid glands. It is required, therefore, that one have a thorough understanding of the various possible pathologic conditions and the appropriate operative approach for each condition. There is not universal agreement on every aspect of the treatment of various parathyroid entities, however, and they are briefly discussed in this article.

Humans↗