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Biomedical subjects

C J Mitchell

Publications and source records attributed to C J Mitchell.

At least 37 records · Page 2Linked to original sources
PubMed1999

Safety of pancreatic surgery in a small DGH.

The Combined Gastroenterology Service at Scarborough Hospital has a particular interest in pancreatic disease. The claim that pancreatic surgery should only be performed in larger, specialised units prompted a review of our experience in a small district general hospital (DGH). The case notes of 63 patients who had undergone pancreatic surgery over a 7-year period were examined retrospectively. The 30-day mortality was 8%, while 14 complications were recorded. Of 16 patients with acute pancreatitis, three died before discharge and three had long-term complications. Five patients who underwent surgery for chronic pancreatitis were discharged safely. There were 11 curative and 29 palliative procedures for patients with malignant disease. Median survival was 8 months (range 1-32 months) and median hospital stay was 16.8 days (range 7-89 days). Successful pancreatic surgery can be performed safely in a DGH setting. Patient selection and expertise are more important than numbers.

Adult↗
PubMed1998

Alterations in intestinal barrier function do not predispose to translocation of enteric bacteria in gastroenterologic patients.

Bacterial translocation from the intestinal lumen has been demonstrated in humans. Three mechanisms have been suggested to explain the phenomenon: altered intestinal barrier function, bacterial overgrowth, and impaired host defense. The aim of this study was to determine whether changes in intestinal barrier function assessed by measurement of intestinal permeability and morphology were associated with alteration in bacterial translocation. Intestinal permeability was assessed in 43 patients by the lactulose/L-rhamnose test with a 5-h urine collection. Mucosal atrophy was assessed from the villus height-to-mucosal thickness ratio in small-bowel biopsies. Bacterial translocation was determined by microbiologic analysis of harvested mesenteric lymph nodes. No significant differences were apparent in the incidence of bacterial translocation in patients with normal permeability (5 [23%] of 22 patients translocated) compared with patients with increased permeability (4 [19%] of 21 patients translocated). Similarly, no correlation was apparent between the incidence of bacterial translocation and the index of villus atrophy. The degree of villus atrophy failed to correlate with gastrointestinal permeability. These data suggest that the incidence of bacterial translocation is not related to increased intestinal permeability or mucosal atrophy.

Adult↗
PubMed1998

A prospective study of serum pancreatic elastase-1 in the diagnosis and assessment of acute pancreatitis.

BACKGROUND: Serum amylase gives a poor estimate of both the true incidence and the severity of acute pancreatitis (AP). METHODS: We evaluated serum pancreatic elastase-1 (PE-1) prospectively in 567 patients in whom AP was suspected. In established AP, severity was assessed using the Glasgow Criteria, and C-reactive protein, amylase, and serum PE-1 were evaluated over 5 days. RESULTS: The sensitivity, specificity, and diagnostic efficiency of serum PE-1 were 0.66, 0.85, and 0.84, respectively. The diagnostic accuracy of serum PE-1 was 0.80, and that of amylase 0.97. Serum PE-1 did not correlate with disease severity or the development of complications, but it fell more slowly than the serum amylase in the week after admission. CONCLUSIONS: The serum PE-1 level correlated closely with the serum amylase but conferred no benefit as a diagnostic test, nor did it provide further prognostic information.

Acute Disease↗
PubMed1998

Isolation of La Crosse, Cache Valley, and Potosi viruses from Aedes mosquitoes (Diptera: Culicidae) collected at used-tire sites in Illinois during 1994-1995.

Prospective studies were conducted at used-tire sites in Illinois during 1994-1995 in an effort to isolate arboviruses from mosquitoes, particularly Aedes albopictus (Skuse) and Aedes triseriatus (Say). Three isolates of Potosi virus were obtained from Ae. albopictus collected at a waste tire site in Jasper County during 1994 and 1995. Also, a single isolate of Cache Valley virus was obtained from Ae. albopictus collected at the Jasper County site during 1995. These are the first records of arbovirus isolations from Ae. albopictus in Illinois and the first isolate of Cache Valley virus from this mosquito species. During 1994, two isolates of La Crosse virus were made from Ae. triseriatus collected at a used-tire site in Peoria County in proximity to the residence of a human La Crosse encephalitis case. This is the first evidence in Illinois that indicates increased risk to humans living near used-tire sites, which may serve as foci for production of Ae. triseriatus, the vector of La Crosse virus. Tire removal and improved environmental sanitation at such sites may greatly reduce the abundance of vector mosquitoes, and, therefore, the risk of arbovirus transmission.

Aedes↗
PubMed1998

Microbiology of bacterial translocation in humans.

BACKGROUND: Gut translocation of bacteria has been shown in both animal and human studies. Evidence from animal studies that links bacteria translocation to the development of postoperative sepsis and multiple organ failure has yet to be confirmed in humans. AIMS: To examine the spectrum of bacteria involved in translocation in surgical patients undergoing laparotomy and to determine the relation between nodal migration of bacteria and the development of postoperative septic complications. METHODS: Mesenteric lymph nodes (MLN), serosal scrapings, and peripheral blood from 448 surgical patients undergoing laparotomy were analysed using standard microbiological techniques. RESULTS: Bacterial translocation was identified in 69 patients (15.4%). The most common organism identified was Escherichia coli (54%). Both enteric bacteria, typical of indigenous intestinal flora, and non-enteric bacteria were isolated. Postoperative septic complications developed in 104 patients (23%). Enteric organisms were responsible in 74% of patients. Forty one per cent of patients who had evidence of bacterial translocation developed sepsis compared with 14% in whom no organisms were cultured (p < 0.001). Septic morbidity was more frequent when a greater diversity of bacteria resided within the MLN, but this was not statistically significant. CONCLUSION: Bacterial translocation is associated with a significant increase in the development of postoperative sepsis in surgical patients. The organisms responsible for septic morbidity are similar in spectrum to those observed in the mesenteric lymph nodes. These data strongly support the gut origin hypothesis of sepsis in humans.

Adolescent↗
PubMed1997

Independent effects of palatability and within-meal pauses on intake and appetite ratings in human volunteers.

The effects of the introduction of timed pauses within meals and palatability on food intake and changes in rated appetite during a meal were assessed in three experiments in which volunteers ate a lunch of pasta with a tomato sauce. Eating was monitored using a disguised electronic balance attached to a micro-computer, which also allowed the introduction of timed pauses within meals. In the first experiment, 16 subjects were tested with both a bland and palatable food (with 0.27% oregano), with eating uninterrupted or with pauses after every 50 g consumed during which appetite ratings were completed. Both the addition of oregano and the introduction of regular within-meal pauses enhanced overall intake. Rated hunger increased in the early stages of eating the palatable food in the interrupted condition, and then declined, whereas hunger declined throughout with the bland food. Similarly, the linear function relating intake to time in the uninterrupted condition was greater with the palatable food. In the second experiment, nine subjects ate the palatable food with no pauses within meals, with 30-second pauses with appetite ratings or with 30-second pauses in a non-appetite task. Intake was greater in both pause conditions than when eating was uninterrupted. In Experiment 3, the effect of pause duration was investigated in a further 16 subjects, with either no pause or a pause of 5, 30 or 60 seconds. Subjects ate more in all pause conditions than with no pauses, while ratings of hunger and fullness suggested that subjects were less satisfied at the end of the meal with longer pauses. These data confirm previous work which suggests that palatability exerts its effect by stimulating appetite and eating rate, but also suggest that the introduction of pauses within meals enhances intake as well, contradicting the idea that pausing within meals should reduce intake by allowing more time for post-ingestive satiety to develop.

Adolescent↗
PubMed1997

Epidemiological typing of coagulase-negative staphylococci from nosocomial infections.

Biotyping, antibiograms, bacteriophage typing, plasmid profile analysis and SDS-PAGE protein profiles were used to determine the relatedness of 44 Staphylococcus epidermidis and four S. haemolyticus isolates from 14 patients. A selection of these were further characterised by ribotyping. Biotyping classified the isolates into three major groups but was considered a poor strain marker. Although antibiograms classified the S. epidermidis isolates into 20 groups, some changes in the susceptibility patterns of related isolates from a single patient were demonstrated. Bacteriophage typing was the least discriminatory of the methods used. SDS-PAGE gave highly related patterns for the majority of S. epidermidis isolates. Plasmid profile analysis and ribotyping, with a minimum of two restriction endonucleases, were the most discriminatory methods for typing S. epidermidis. Nonetheless, some isolates from the same patient - probably representing a single strain - varied in plasmid profile indicating plasmid instability. One of six related isolates from a single patient lacked two bands from the ribotyping pattern of the other isolates. Although no single method proved entirely satisfactory on all occasions, the combination of typing methods was sufficient to provide evidence of the relatedness of S. epidermidis isolates from individual patients.

Adult↗
PubMed1996

Prospective study of the aetiology of infusion phlebitis and line failure during peripheral parenteral nutrition.

Four techniques of administering peripheral parenteral nutrition (PPN) were examined prospectively to investigate the role of mechanical trauma in the development of infusion phlebitis. Patients in group 1 (n = 15) were fed via a standard 18-G Teflon cannula which was removed on completion of the infusion and was rotated to the contralateral arm every day. Group 2 patients (n = 15) had a similar catheter sited in each forearm simultaneously, with rotation of the side of infusion each day. Patients in group 3 (n = 17) had a 15-cm Silastic rubber catheter inserted into a forearm vein and a standard cannula sited in the contralateral forearm, with alternation of infusion each day. Those in group 4 (n = 13) had a fine-bore 23-G silicone catheter sited in one arm only. Patients in groups 1, 2 and 3 were fed over 12-h cycles and those in group 4 for a 24-h continuous cycle. A total of 408 patient-days of PPN were given. Mean duration of PPN in groups 1-4 was 7.5, 9, 5.5 and 5 days respectively. Infusion phlebitis was not recorded in patients who had a daily change of cannula (group 1), but occurred in four patients in group 2, eight in group 3 and eight in group 4. Phlebitis scores were 0, 9, 15 and 12 for groups 1-4 respectively. Severe phlebitis and line occlusion occurred more frequently in patients with a 15-cm catheter (group 3) and in those fed continuously over 24 h (group 4). These results suggest that mechanical trauma is an important factor in the aetiology of infusion phlebitis. This can be minimized by reducing the time for which the vein wall is exposed to nutrient infusion and by reducing the amount of prosthetic material within the vein.

Adult↗
PubMed1996

Administration of peripheral parenteral nutrition: a prospective study comparing rotation of venous access sites with ultrafine cannulas.

Peripheral veins have been used successfully for patients requiring short- to medium-term total parenteral nutrition. This study prospectively compares two methods of peripheral parenteral nutrition (PPN). Forty-six patients requiring parenteral nutrition (PN) were identified prospectively. Fifty courses of PPN were prescribed using a standardized PPN formula of 9.3 g nitrogen, 1400 kCal, 2500 ml (KABI II, Pharmacia). Patients were randomized to receive PPN via 23G, 15 cm flexane catheters (Nutriline) inserted into an antecubital vein which remained in-situ with a continuous infusion over 24 h, or to receive 12-h cyclical infusions through peripherally sited 18G catheters (Venflon) which were removed postinfusion and reinserted into the contralateral forearm on alternate days. Data collected included duration, complications and cost of materials for each prescribed course. A scoring system to determine patient anxiety and depression and a questionnaire regarding patients' perspectives were evaluated. Fifty courses were prescribed, 26 by rotation of veins (RV) and 24 by Nutriline (N). Mean duration of feeding was 7.9 and 8.6 days, respectively; cost of materials were comparable 6.48/day (RV) vs 5.17/day (N); 2 RV patients failed to complete their course (no access [P< 0.05], whilst 9 N patients failed to complete their course (4 severe phlebitis, 2 no venous access, 2 septicaemia, 1 dislodged). Five patients required CPN (RV, N 3) while 4 remaining patients were fed by an alternative PPN method. The overall incidence of anxiety was 20% and of depression 16%, with no significant difference between groups. The majority of patients (87%) found mobility restricted. Twelve-hourly infusions via alternate forearm veins were significantly more successful than continuous infusions via Nutriline, both in terms of completion of the prescribed course and less venous morbidity. This study confirms that rotation of forearm veins allows affordable and successful PN administration to the majority of patients, with low PN-related morbidity.

Journal Article↗
PubMed1996

Detecting bunyaviruses of the Bunyamwera and California serogroups by a PCR technique.

Many bunyaviruses of the Bunyamwera and California serogroups are medically important human pathogens. The development of an effective technique to detect the viruses by using molecular biologic tools, such as PCR, improves not only clinical diagnosis but also virologic surveillance of mosquito vectors in the field. In this study, we evaluated eight pairs of primers for reactivity with 44 viruses of the genus Bunyavirus, using a reverse transcriptase PCR technique. With a pair of serogroup-specific primers we designed, all viruses of the serogroups tested could be detected. Further, virus-specific primer pairs were identified for California encephalitis virus, Jamestown Canyon virus, La Crosse virus, and snowshoe hare virus for use in North America. Using this technique, we could detect one La Crosse virus-infected mosquito in a pool of 100 mosquitoes with undetectable plaque titers.

Animals↗
PubMed1996

Assessment of arthropod vectors of infectious diseases in areas of U.S. troop deployment in the Persian Gulf.

Beginning in August 1990, approximately 800,000 coalition troops were deployed to the Persian Gulf during Operations Desert Shield and Desert Storm. There was substantial concern about arthropod-borne diseases, particularly sand fly fever and cutaneous leishmaniasis, because of high morbidity rates in the Persian Gulf during World War II (WWII). In sharp contrast to WWII, there was no report of sand fly fever among coalition forces and only 31 cases of leishmaniasis among 697,000 U.S. troops. To further evaluate the risk of arthropod-borne diseases, an entomologic survey was conducted in 12 areas of Kuwait and Saudi Arabia. A total of 1,556 arthropods was collected during four survey periods in 1992. The suspected vectors of cutaneous Leishmania major infection, sand fly fever, West Nile fever, Rift Valley fever, and Crimean-Congo hemorrhagic fever were identified; however, there was no evidence of arboviruses or Leishmania among collected specimens nor from 51 trapped rodents. There are several possible reasons for the low risk of arthropod-borne infectious diseases among Desert Shield/Storm troops in an area where suspected vectors frequently were found: the use of insecticides and repellents, and the deployment of most ground troops to the open desert during the cooler, winter period--conditions least favorable for the transmission of arthropod-borne diseases.

Animals↗
PubMed1996

Isolations of Potosi virus from mosquitoes collected in the United States, 1989-94.

Potosi (POT) virus, a recently characterized Bunyamwera serogroup virus, was discovered when it was isolated from Aedes albopictus collected at a waste-tire site in Potosi, Washington County, Missouri, during 1989. During the following year, POT virus was not isolated from 39,048 mosquitoes, including 17,519 Ae. albopictus, collected in Washington County. In 1991, mosquito collections from South Carolina, Ohio, and Michigan yielded 8 strains of POT virus: 6 from Coquillettidia perturbans and one each from Culex restuans and Psorophora columbiae. Additional collections of Ae. albopictus from several states during 1990-93 failed to yield further isolates of POT virus. In 1994, POT virus was isolated from Ae. albopictus and Anopheles punctipennis in North Carolina and from Ae. albopictus in Illinois. These represent the first virus isolations of any type for Ae. albopictus in those states. Thus far, POT virus has been isolated from 5 mosquito species in different genera in 6 states. The known geographic range of POT virus, based on virus isolations, has been extended from Missouri to the upper Midwest and the Atlantic seaboard. Potential vector relationships and possible transmission cycles of POT virus are discussed.

Animals↗
PubMed1996

Arbovirus titer variation in field-collected mosquitoes.

Patterns in the distribution of titers in arbovirus-positive mosquito pools were examined. Virus isolation records from the Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention, from 1974 through 1993 were used to estimate virus titers in field-collected pools. Pools were classified as either low titer (< or = 3.0 log10 plaque-forming units [PFU]/ml) or high titer (> 3.0 log10 PFU/ml). The proportion of virus-positive pools that had high titers varied among the different domestic arboviruses, within viruses among field sites and years, and within viruses among mosquito species tested. Alphaviruses produced a greater proportion of pools with high titers than did the flaviviruses. Variation in the proportion of pools with high titers among sites and years suggested variation in mosquito and/or virus strains. Variation in the proportion of pools with high titers among mosquito species indicated species-specific differences in vectorial capacity. The results show that information about the titer of virus in mosquito pools can complement other parameters, such as the minimum infection rate, currently used in mosquito-based arbovirus surveillance programs.

Animals↗
PubMed1996

Arboviruses associated with mosquitoes from nine Florida counties during 1993.

Mosquitoes were collected for virus isolation tests from 36 sites in Bradford, Lake, Leon, Manatee, Orange, Osceola, Pasco, Putnam, and Sarasota counties, FL, from April 6 through October 11, 1993. A total of 158,129 adult specimens were collected in 726 trap nights using CDC light traps, usually baited with dry ice. At least 35 species were represented, although 60% of the collections was made up of 3 species (Aedes infirmatus, 6.5%; Anopheles crucians, 14.4%; and Culex nigripalpus, 39.4%). Four of the 36 collecting sites were located at waste-tire sites, where 254 trap nights yielded 27,455 specimens (17.4% of 9-county total). Forty-three virus strains were isolated from 2,812 mosquito pools consisting of 158,129 specimens. The viruses isolated include eastern equine encephalitis (EEE), 5 strains; Everglades (EVE), 2 strains; Keystone (KEY), 6 strains; Tensaw (TEN), 21 strains; trivittatus (TVT), one strain; Shark River (SR), one strain; and Flanders (FLA), one strain. In addition, 2 strains that are either KEY or Jamestown Canyon (JC) virus, and 4 ungrouped viruses remain to be identified. Twenty-one (48.8%) of the 43 virus strains were isolated from mosquitoes collected at waste-tire sites as follows: EEE (1), KEY (5), KEY/JC (1), TEN (13), and one ungrouped virus. The vector relations of the viruses are discussed and the potential importance of waste-tire sites as breeding habitats and harborages for vector and nuisance species is emphasized.

Aedes↗
PubMed1995

Preoperative total parenteral nutrition is not associated with mucosal atrophy or bacterial translocation in humans.

Concerns have recently been expressed at suggestions that postoperative sepsis may be more common in patients who have received preoperative total parenteral nutrition (TPN). The mechanism suggested for this is that TPN causes intestinal mucosal atrophy leading to increased bacterial translocation from the gut as a source of systemic sepsis. This hypothesis was examined in 203 patients who had an elective laparotomy, 28 of whom required at least 10 days of preoperative TPN. Neither mucosal atrophy nor bacterial translocation was more common in parenterally fed patients than in enterally fed controls. In humans theoretical concerns about the adverse effects of TPN on intestinal integrity are unfounded.

Atrophy↗
PubMed1995

Sensitive and specific colorimetric dot assay to detect eastern equine encephalomyelitis viral RNA in mosquitoes (Diptera: Culicidae) after polymerase chain reaction amplification.

A sensitive and specific colorimetric dot assay following polymerase chain reaction (PCR) method has been developed to detect 0.1 pg of eastern equine encephalomyelitis viral (EEEV) RNA. The assay is 250-fold more sensitive than analysis by electrophoresis and is based on converting a 291-nucleotide sequence of the viral coat protein amino terminus into a double-stranded DNA (dsDNA) and amplifying the DNA using a specific primer pair and PCR. The amplified complementary DNA (cDNA) is denatured adsorbed onto a nylon strip, baked, and detected with a digoxigenin-labeled probe. Dots with viral cDNA are stained dark red, whereas controls do not stain or stain lightly. The assay is very specific and sensitive and detects only EEEV. RNA of Venezuelan equine encephalitis, St. Louis encephalitis, Keystone, Flanders, Tensaw, and western equine encephalitis viruses were not detected. EEEV (Ten Broeck) RNA was detected at the 10-ng level, indicating that the prototype we used may have different nucleotides in the region where the primer pair binds. The PCR amplified EEEV cDNA that was 92% homologous to the consensus sequence of EEEV. The detection of EEEV in the liver of an infected Emu bird and in field-collected mosquitoes from Florida and Massachusetts that were analyzed concurrently as blind samples by tissue culture plaque assay and by PCR dot analysis proved that the assay is sensitive and can be used to detect infected mosquitoes. The assay can detect at least 1 infected mosquito in a pool of 1,000 uninfected mosquitoes.

Animals↗
PubMed1995

Experimental infection of wading birds with eastern equine encephalitis virus.

To study the susceptibility of wading birds to eastern equine encephalitis (EEE) virus and to determine their potential as reservoir or amplifying hosts, fledgling glossy ibises (Plegadis falcinellus) and snowy egrets (Egretta thula) were captured in New Jersey (USA) and shipped to Colorado (USA) where they were experimentally inoculated with EEE virus. All 16 snowy egrets and 14 (93%) of 15 of the glossy ibises inoculated became viremic with moderate titers, and all survivors developed neutralizing antibody. Six ibises and two egrets died during the first week after inoculation, and EEE virus was isolated from the tissues of three birds. Our experimental results support field evidence about the relative involvement of glossy ibises and snowy egrets in the epizootiology of EEE virus in New Jersey.

Animals↗