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Biomedical subjects

G D Taylor

Publications and source records attributed to G D Taylor.

At least 19 recordsLinked to original sources
PubMed1995

Disseminated Mycobacterium genavense infection in Canadian AIDS patients.

Mycobacterium genavense is a recently described mycobacterial species which thus far has been identified only in persons with advanced HIV disease. It appears to be a rare pathogen with an undefined reservoir. We describe the first two cases of M. genavense infection in Canadian AIDS patients. The clinical presentation of fever and wasting with extremely low CD4 lymphocyte counts was indistinguishable from disseminated M. avium complex (MAC) infection. However, blood cultures in BACTEC 13A medium required a mean of 58 days (range 41-87) to detect growth of M. genavense in contrast to a mean of 10 days for MAC in our laboratory. M. genavense infection is underdiagnosed due to the lack of universal use of BACTEC liquid medium and the use of relatively short incubation times (only 6 weeks) by some laboratories. The value of antimycobacterial therapy for M. genavense is unknown, but anecdotal data suggest that treatment with a regimen appropriate for MAC may be beneficial.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Computer simulation of the probability of detecting low volume carcinoma of the prostate with six random systematic core biopsies.

OBJECTIVES: Six random systematic core biopsies (SRSCB) of the prostate (biopsies from apex, middle, and base of each lobe) have been commonly used in detection of prostate carcinoma. The objective of this study was to verify the validity of the SRSCB technique in detecting cancer in prostates with low-volume tumor (less than 6 cc). METHODS: We developed a computer model of the prostate to simulate the SRSCB technique. The data for development of this model were taken from 159 radical prostatectomy specimens in which 112 patients had tumor volumes measured and in which 91 prostates had tumors with volumes less than 6 cc (by whole-mount sectioning). RESULTS: The simulation shows that only 20.3% of the simulated prostates, with total aggregate tumor volume between 0.034 and 5.1 cc, had a tumor distribution for which the SRSCB technique has a 95% probability of detecting the tumor. In fact, 26.8% had a tumor distribution that was completely disjointed from the six recommended biopsy regions. To compare these results with other possible occurrence, various biases for the angle of biopsy and the distribution of cancer foci were incorporated into the model. Study results should be viewed with the understanding that any simulated model has its limitations. In our simulated model, the shape of the simulated tumor foci (spherical) does not represent all the possible shapes of prostate cancer. However, these results indicate that detection of cancer with biopsies taken from the apex, middle, and base of each lobe of a prostate with tumor volumes of less than 6 cc may not be as effective as it is in prostates with larger tumor volumes or patients with an abnormal digital rectal examination. The study of bias models suggests that the distributional pattern of cancerous foci can have a significant impact on the effectiveness of a given biopsy strategy. CONCLUSIONS: We concluded that future attempts to improve systematic biopsy strategies for detection of low-volume cancer should include biomechanical characteristics of prostate cancer, including gland volume and tumor distribution. Driven by the conclusions from this idealized model, we have developed a three-dimensional model of the prostate gland from its whole-mount histologic maps. It is anticipated that this continuing investigation will lead to realistic guidelines for improving biopsy techniques.

Biopsy↗
PubMed1995

Bacteremic nosocomial pneumonia. A 7-year experience in one institution.

STUDY OBJECT: To describe the epidemiology, microbiology, and outcome of nosocomial pneumonia with secondary bloodstream infection. DESIGN: Prospective cohort study. SETTING: Tertiary care Canadian teaching hospital. PATIENTS: Inpatients. MEASUREMENT: All inpatient blood cultures were concurrently monitored over an 89 month period. Following chart review, patients experiencing nosocomial bloodstream infection due to pneumonia were identified. A standardized definition of pneumonia was used. RESULTS: One hundred forty-nine episodes occurred in 145 patients, 0.66/1,000 hospital admissions, 8.4% of all nosocomial bloodstream infections. No change in rate occurred in the study period. Fifty-four percent of episodes developed in one of seven ICUs. Staphylococcus aureus was the most frequently identified etiologic organism (27%). The ICU and non-ICU cases did not differ in etiology. No organism became more prevalent during the study period. Twenty percent of patients died within 1 week of first positive culture; episodes associated with Pseudomonas species had a much higher mortality rate (45%) than other infections (14%) (p = 0.002). The ICU and non-ICU infections had a similar mortality rate. CONCLUSION: Pneumonia is an important cause of nosocomial bloodstream infection, but it is not increasing in frequency or changing in etiology in our institution. The ICUs are a major contributor to this problem but have the same case short-term mortality rate and microbial etiology as non-ICU cases. Cases associated with Pseudomonas have a much higher mortality rate.

Alberta↗
PubMed1995

The effect of surgical wound infection on postoperative hospital stay.

OBJECTIVE: To determine the effect of surgical wound infection on postoperative duration of hospital stay. DESIGN: A case-control study nested within a cohort. SETTING: A tertiary-care hospital. PATIENTS: Selected from a cohort of 4702 inpatients who underwent surgical procedures over a 12-month period. There were 3602 patients, 1100 having been excluded because of lack of infection associated with a particular surgical procedure, because of "lumping" of procedures under a nonhomogeneous heading or because a procedure was unlikely to be the reason for the patient's hospitalization. MAIN OUTCOME MEASURE: Postoperative duration of hospital stay. RESULTS: In the cohort 89 wound infections were identified, 73 of these occurring with procedures selected for study. Five patients were excluded from the study because of data deficiencies, leaving 68 patients who underwent 15 different procedures. These were compared with 136 control patients selected by stratified random sample from a list of patients who underwent the same risk-indexed procedure in the same surgical division. Wound infection patients and controls did not differ in anesthetic risk score or procedure duration. Patients with infection remained in hospital 19.5 days longer than controls (95% confidence interval, range from 11.0 to 27.9 days). Deep-seated infections prolonged the hospital stay more than superficial incisional infections (24.3 versus 13.2 days). CONCLUSIONS: Surgical wound infection markedly prolonged the duration of hospitalization in the University of Alberta Hospitals, longer than that documented in previous studies in other countries. Maximizing opportunities to prevent wound infection would be beneficial to both patients and hospitals.

Case-Control Studies↗
PubMed1994

Rat microglial interleukin-3.

Interleukin-3 (IL-3, multi-CSF) is a growth factor for a variety of hematopoietic progenitor cells. Recently, microglial cells, the resident macrophages of the central nervous system (CNS) have been shown to proliferate in the presence of IL-3 both in vivo and in culture. Data obtained from cultured astrocytes gave rise to the hypothesis that astrocytes synthesize the microglial growth factor. This is the first report identifying rat microglial cells themselves as a source of IL-3. Culture media conditioned by isolated microglia enhanced microglial proliferation above fresh media controls. IL-3 polypeptide was detected in both conditioned media (CM) and in microglial cells by Western blotting and immunoprecipitation. Furthermore, anti-IL-3 antibodies were able to inhibit microglial proliferation induced by conditioned media. mRNAIL-3 was present in single microglial cells as revealed by in situ hybridization. Total RNA prepared from purified microglia yielded a single PCR amplification product. Identity of the PCR product was confirmed by Southern blot hybridization using a cDNAIL-3 probe and by DNA sequencing. Expression of mRNAIL-3 was observed in both absence and presence of lipopolysaccharide, a bacterial endotoxin, that commonly induces expression of inflammatory cytokines and inhibits microglial proliferation. It is concluded that IL-3 expression in ensuring the recruitment of enhanced numbers of immunocompetent cells at sites of lesion. In the light of weak immune reactions in the brain, it is hypothesized that the expression of a characteristic T cell feature in monocyte-derived microglia may be a partial compensation of T cell functions in brain lesions.

Animals↗
PubMed1994

Wound infection in total joint arthroplasty: effect of extended wound surveillance on wound infection rates.

OBJECTIVE: To determine the effects of a wound monitoring program on infection rates after total joint arthroplasty. DESIGN: Case series, comparing postoperative wound infection rates before and after hospital discharge. SETTING: A university-affiliated tertiary-care hospital. PATIENTS: A group of 865 patients who underwent primary or revision total hip or knee arthroplasty between September 1989 and September 1991 followed by in-hospital and post-discharge wound monitoring was compared with a baseline group of 204 patients who had undergone an arthroplasty procedure and in-hospital wound monitoring between March and September 1988; only 38 of these patients were selected for post-discharge monitoring. INTERVENTIONS: In the study group, wounds were monitored every 48 to 72 hours to the time of patient discharge and at 30 days post-discharge. Monthly reports of surgeon-specific and overall infection rates were sent to each surgeon during both baseline and study periods. MAIN OUTCOME MEASURES: Presence or absence of surgical wound infection. RESULTS: The initial overall wound infection rate was 9.9%. This decreased to 3.8% in the study group, after the wound monitoring program had been in place for at least 18 months. Post-discharge monitoring accounted for the majority of wound infections diagnosed. CONCLUSIONS: A wound monitoring program may be an important tool in lowering wound infection rates associated with total joint arthroplasty. Post-discharge monitoring is important in determining true wound infection rates.

Alberta↗
PubMed1992

PI-specific phospholipase C "alpha" from sheep seminal vesicles is a proteolytic fragment of PI-PLC delta.

Phosphatidylinositide-specific phospholipase C enzymes (PLCs) catalyze the conversion of the phosphoinositides to biologically important signal transducing molecules. These enzymes may be grouped into "families" which share similar structures and modes of regulation. The existence of a structurally distinct family of PLC termed "alpha" has been recently called into question. In the current paper we show by immunoblotting experiments that PLC "alpha" from sheep seminal vesicles is recognized by monoclonal antibodies raised against the delta 1 isoform of bovine brain PLC, and appears to be derived from a higher molecular weight band at 85 kDa. We also show that antibodies raised against PLC alpha efficiently immunoprecipitate the 85-kDa PLC delta 1 isoform from bovine brain and Chinese hamster lung fibroblasts. These data provide strong evidence that the PLC alpha from sheep seminal vesicles is a proteolytic fragment of PLC delta 1. Thus, there is still no conclusive evidence for a separate "alpha" class of PLC.

Animals↗
PubMed1992

Predominance of staphylococcal organisms in infections occurring in a burns intensive care unit.

To assess the sites, incidence, and bacteriology of infections in intensive care burn patients, a prospective survey of all admissions to a tertiary care institution burn unit was carried out over a 12-month period. One hundred and sixteen patients were admitted, 106 with a diagnosis of thermal burns. Forty patients developed 90 infections. Only two deaths occurred, one in a patient with sepsis. In order of frequency, pneumonia, burn infection, UTI and primary bacteraemia were most common. Staphylococcal species accounted for a majority of infections at all body sites except UTI (47 per cent of all infections, including 11 of 14 bacteraemic infections). Staph. aureus sepsis was more common in those carrying the organism on admission. Strain typing of paired admission and subsequent clinical isolates in 19 patients with Staph. aureus sepsis indicated that eight (42 per cent) became infected with a strain they carried on admission. Further reductions in septic complications of burns in our center would be best directed at staphylococcal species, particularly Staph. aureus. Both eradication of carrier state, and prevention of acquisition of Staph. aureus strains could be explored.

Alberta↗
PubMed1987

Rhinofacial zygomycosis caused by Conidiobolus coronatus: a case report including in vitro sensitivity to antimycotic agents.

A case of zygomycosis caused by Conidiobolus coronatus, occurring in a 31-year-old priest from the Ivory Coast, is reported. Lesions eventually resolved after 2 1/2 years, during which the patient was variously treated with intravenous amphotericin B and miconazole as well as surgical resection. It is difficult to be certain which, if any, of these treatments contributed to resolution of lesions. A report of in vitro sensitivity data to a variety of antifungal agents is included.

Adult↗