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Biomedical subjects

G K Harding

Publications and source records attributed to G K Harding.

At least 55 records · Page 3Linked to original sources
PubMed1988

Urine specimen collection with external devices for diagnosis of bacteriuria in elderly incontinent men.

We determined the validity of using external devices for urine specimen collection from 24 elderly incontinent men residing in a nursing home by collecting three sequential specimens, two with external devices and then one by catheterization. The positive predictive value of organisms isolated in quantitative counts of greater than or equal to 10(5) CFU/ml in external devices for bladder bacteriuria was 86% for either sterile or clean collecting devices and 93% for the same organism in two consecutive specimens. The negative predictive value for organisms present in quantitative counts of less than 10(5) CFU/ml was 90% for both sterile and clean devices and 86% when the organism was present in both specimens. Contamination in external collection devices was not influenced by whether the device was clean or sterile, circumcision of the resident, or duration of time between device application and specimen collection. These data suggest that urine specimens collected by ward nursing staff with external devices are reliable for the diagnosis of bacteriuria in this patient population.

Aged↗
PubMed1987

Prospective assessment of risk of bacteremia with colonoscopy and polypectomy.

A prospective assessment was made of the frequency of positive blood cultures in patients undergoing colonoscopy with or without polypectomy. A total of 270 patients underwent 280 colonoscopies, of these, there were 105 patients that had 111 polypectomies. Blood cultures were taken prior to and within 15 min following each procedure. Six of 280 (2.1%) preprocedural blood cultures were positive. Seven of 169 (4%) blood cultures were positive within 15 min of insertion of the colonoscope in the colonoscopy only group. Eight of 223 (3.6%) blood cultures were positive within 10 min of the polypectomy. There was no clinical evidence of sepsis during the 24 hr following these procedures. In order to determine appropriate postprocedural sampling intervals, we induced a Staphylococcus epidermidis bacteremia with a mean of 1.16 X 10(6) colony forming units/ml on 10 occasions in seven dogs. Within 30 min of inoculation, we were able to detect only one colony forming unit/ml. The rate of positive blood cultures during colonoscopy alone and following polypectomy during colonoscopy is comparable to other gastrointestinal endoscopy procedures. The most optimal time to collect blood cultures in order to detect transient bacteremia is as soon after the procedure as is feasibly possible.

Animals↗
PubMed1987

Clinical significance of a test for slime production in ventriculoperitoneal shunt infections caused by coagulase-negative staphylococci.

Coagulase-negative staphylococci (CNST) are the most-common cause of ventriculoperitoneal shunt infections. Some of these strains produce a slime-like substance. We reviewed 19 episodes of ventriculoperitoneal shunt infections due to CNST in 17 patients. Eleven episodes of infection were caused by slime-producing CNST and eight by non-slime-producing CNST. Shunt obstruction and abdominal pain occurred more frequently when infectious episodes were due to slime-producing CNST than to non-slime-producing CNST (P less than .05). Despite appropriate antimicrobial therapy, the mean duration of fever was longer and the failure to eradicate the infecting organisms was more frequent when the infectious episodes were due to slime-producing CNST than to non-slime-producing CNST (P less than .025). Discriminate function analysis found, however, that only failure to eradicate the infecting organism (by antimicrobial therapy) occurred more frequently in infectious episodes due to slime-producing CNST than to non-slime-producing CNST (P = .01).

Adolescent↗
PubMed1987

A prospective randomized trial of ceftazidime versus cefazolin/tobramycin in the treatment of hospitalized patients with pneumonia.

Ceftazidime and cefazolin/tobramycin were compared in the treatment of hospitalized patients with pneumonia. Iv doses 8-hourly were: ceftazidime--2 g, cefazolin--1.5 g, tobramycin--1.7 mg/kg. For patients with pseudomonas infection randomized to cefazolin/tobramycin, ticarcillin (3 g iv 4-hourly) was used instead of cefazolin. One hundred and ten of 129 patients were evaluable (ceftazidime = 52, cefazolin/tobramycin = 58). Seventy five cases (68%) had documented pathogens of which 81% were aerobic Gram-negative bacilli. Analysis of clinical response showed no difference in overall results (P = 0.77), or separate outcomes: cured (P = 0.85), improved (P = 0.62), failed (P = 0.53), or relapsed (P = 0.50). No differences in bacteriological response were noted either: eradication (P greater than 0.10), elimination with recurrence (P greater than 0.10), persistence (P greater than 0.10). The incidence of enterococcal and fungal colonization and superinfection was the same for both regimens. There was a greater incidence of Coombs' test positivity with ceftazidime (P less than 0.01) but greater nephrotoxicity with cefazolin/tobramycin (P less than 0.02). Ceftazidime appears to be as efficacious as cefazolin/tobramycin in the treatment of hospitalized patients with pneumonia, and is less nephrotoxic.

Adolescent↗
PubMed1987

Epidemiology of an outbreak of infectious syphilis in Manitoba.

An outbreak of 82 cases of infectious syphilis (primary, secondary, and early latent) which occurred in 1984 in the province of Manitoba was analyzed by age, sex, geographic distribution, and stage of disease. In the preceding four years, from 1980-1983, there were 19, 24, 13, and 32 cases, respectively, of infectious syphilis, of which 89% involved males. Compared with 1983, the overall crude incidence rate in 1984 increased by 259%, from 2.9 to 7.5/100,000 population, with a peak incidence in the 25- to 29-year age group of 25.8/100,000 population. This increase was predominantly due to a striking increase in incidence in females which rose 6.3-fold, from 0.4 to 2.5/100,000 females, compared with a 2.3-fold increase in males. This increase was accompanied by a decline in the male-to-female ratio, from 15.0 to 4.9. Of the 68 males, 45 named women as their sexual contacts. Females were 2.4 times more likely to present with early latent disease, whereas males were 7.0 times more likely to present with primary disease (p less than 0.01). There was clustering in suburban locations with regard to clinical presentation (60% primary disease) and overall incidence (46% of all cases). These data suggest the occurrence of a major change in the epidemiology of syphilis in the province of Manitoba, with a shift from homosexual to heterosexual transmission.

Adolescent↗
PubMed1987

The nature of antibody to hepatitis B surface antigen in high-risk persons negative for other hepatitis B viral markers.

Persons with antibody to hepatitis B surface antigen (anti-HBs) activity in their serum that is entirely immunoglobulin M (IgM) in nature appear not to be protected against hepatitis B virus infection. Because commercially available anti-HBs kits do not distinguish between IgM and immunoglobulin G anti-HBs activity, the question of whether or not to immunize high-risk persons with anti-HBs alone has recently been the subject of much controversy. The present study in Calgary and Winnipeg, 1984-1985, documents the nature of anti-HBs activity in sera from three groups of "high-risk" persons. Group I consisted of 26 health care employees positive for anti-HBs but negative for other hepatitis B serologic markers. Group II consisted of 26 members of high-risk ethnic populations who were also positive for anti-HBs alone. Group III consisted of 29 persons from both populations (16 health care workers and 13 members of high-risk ethnic populations) positive for both anti-HBs and antibody to hepatitis B core antigen (anti-HBc). The majority of persons in groups I and II (58% and 50%, respectively) had low levels of anti-HBs activity (sample/negative control ratio (ratio unit) less than 10), as compared with only three of group III (p less than 0.00001 and 0.0001, respectively). Of the remaining persons with presumably protective levels of anti-HBs (ratio unit greater than or equal to 10), treatment with 0.2 mM dithiothreitol, an agent that completely destroys IgM immunoglobulin activity, resulted in less inhibition of anti-HBs activity in sera from groups I and II (48.2 +/- 31.1 and 51.9 +/- 19.5, mean +/- standard deviation, respectively) than group III sera (69.9 +/- 22.0) (p less than 0.05). In no case was anti-HBs activity completely eliminated following dithiothreitol treatment. The results of this study indicate that anti-HBs activity in the majority of high-risk persons with presumably protective levels of anti-HBs is not exclusively IgM in nature.

Adult↗
PubMed1987

Antibiotic therapy in exacerbations of chronic obstructive pulmonary disease.

The effects of broad-spectrum antibiotic and placebo therapy in patients with chronic obstructive pulmonary disease in exacerbation were compared in a randomized, double-blinded, crossover trial. Exacerbations were defined in terms of increased dyspnea, sputum production, and sputum purulence. Exacerbations were followed at 3-day intervals by home visits, and those that resolved in 21 days were designated treatment successes. Treatment failures included exacerbations in which symptoms did not resolve but no intervention was necessary, and those in which the patient's condition deteriorated so that intervention was necessary. Over 3.5 years in 173 patients, 362 exacerbations were treated, 180 with placebo and 182 with antibiotic. The success rate with placebo was 55% and with antibiotic 68%. The rate of failure with deterioration was 19% with placebo and 10% with antibiotic. There was a significant benefit associated with antibiotic. Peak flow recovered more rapidly with antibiotic treatment than with placebo. Side effects were uncommon and did not differ between antibiotic and placebo.

Aged↗
PubMed1987

The association of bacteriuria with resident characteristics and survival in elderly institutionalized men.

Ninety-one elderly male residents of a skilled nursing facility were classified as nonbacteriuric (41%), intermittently bacteriuric (34%), or continuously bacteriuric (25%) on the basis of urine cultures obtained over a 3-year period. Bacteriuric and nonbacteriuric residents were similar in age, number of diagnoses and medications, and mobility. However, bacteriuric residents were more frequently confused or demented, whether continuously bacteriuric (78%) or intermittently bacteriuric (62%) compared with nonbacteriuric residents (42%) (p less than 0.04). In addition, bacteriuria was significantly associated with incontinence of bladder (96% of continuous, 66% of intermittent, and 25% of nonbacteriuric; p less than 0.001) and bowel (52%, 39%, and 5.5%, respectively; p less than 0.002). At 6 years of follow-up there were no differences in survival among the three groups. Urinary tract infection caused or contributed to only two (2.9%) deaths. Thus, in this population, bacteriuria was associated with higher functional disability but not with increased mortality.

Aged↗
PubMed1987

Bacillus cereus endophthalmitis.

The authors present a case of a young man with post-traumatic endophthalmitis caused by Bacillus cereus. The clinical course was typical of the panophthalmitis caused by this toxin-producing organism: rapid onset of signs of systemic infection, a corneal ring abscess and eventual loss of the globe requiring enucleation. Studies of experimental rabbit models of the infection have indicated that the most efficacious regimen consists of systemic and topical clindamycin and gentamicin. Successful therapy depends upon immediate systemic administration of these agents when the clinical setting suggests Bacillus cereus infection.

Adult↗
PubMed1987

Risk of bacteremia with endoscopic sphincterotomy.

A prospective assessment of the risk of bacteremia with endoscopic sphincterotomy was made in 81 patients who underwent 95 procedures. Blood samples were taken for culture in all patients before and at 5 and 10 minutes after the last incision of the sphincter by the papillotome. An additional blood sample was obtained for culture within 30 seconds of the final incision in 32 of the 95 procedures. The rate of blood-culture positivity before the procedure was not significantly different from the post-incisional rate (1% compared with 3%, p greater than 0.05). No patient suffered from fever or chills during the 24 hours after sphincterotomy.

Duodenoscopy↗
PubMed1986

Pseudomonas cepacia colonization and infection in intensive care units.

Pseudomonas cepacia has become a prominent epidemic nosocomial pathogen over the past 15 years. Between December 1982 and September 1983 it was isolated from 29 patients in two intensive care units (ICUs) at one hospital. Twelve infections--five bacteremias, four pneumonias and three urinary tract infections--occurred. Most of the isolates (25/29) were from the respiratory tract, and most (23/29) had the same antibiogram as the only environmental isolate, which was cultured from a contaminated ventilator thermometer, a previously unrecognized source of nosocomial infection. The ventilator thermometers were calibrated in a bath whose water had not been changed for months and contained P. cepacia. Despite elimination of this reservoir, P. cepacia was eradicated from the ICUs only after intensive infection control efforts were instituted.

Aged↗
PubMed1986

Cefoxitin plus tobramycin and clindamycin plus tobramycin. A prospective randomized comparison in the therapy of mixed aerobic/anaerobic infections.

The efficacy of therapy with cefoxitin sodium plus tobramycin sulfate, with the tobramycin therapy discontinued if no cefoxitin-resistant pathogens grew from appropriate cultures, was compared with clindamycin phosphate plus tobramycin therapy in mixed aerobic/anaerobic intra-abdominal and female pelvic infections. Of 96 evaluable patients, 39 (76%) of 51 randomized to cefoxitin and 38 (84%) of 45 randomized to clindamycin were cured and an additional seven (14%) of 51 and three (6.7%) of 45, respectively, were improved. Bacteroides fragilis "group" was isolated from 44 (54%) of 82 patients with appropriate specimens. Duration of aminoglycoside therapy was significantly shorter in patients randomized to cefoxitin and tobramycin (mean, 4.1 +/- 1.8 days vs 7.0 +/- 3.2 days). There was a tendency to greater nephrotoxic reactions in patients randomized to clindamycin and tobramycin. We conclude that cefoxitin plus tobramycin with selective early discontinuation of aminoglycoside therapy is an acceptable regimen for the therapy of mixed aerobic/anaerobic infections.

Adolescent↗
PubMed1986

Pharmacokinetics of cefixime (CL 284,635; FK 027) in healthy subjects and patients with renal insufficiency.

The pharmacokinetics of the extended-half-life, broad-spectrum oral cephalosporin cefixime (CL 284,635; FK 027) were studied in 7 healthy volunteers and 35 patients with various degrees of renal insufficiency, including patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis. Apparent total body, renal, and apparent nondialysis-nonrenal clearances and protein binding declined and elimination half-life increased with decreasing creatinine clearance. All of these alterations became statistically significant as the creatinine clearance fell below 20 ml/min per 1.73 m2. Cefixime concentrations in urine exceeded the MICs for most urinary tract pathogens for up to 24 h postdose, even in patients with severe renal insufficiency. CAPD removed an insignificant fraction of cefixime body burden over the 72-h study period (1.57 +/- 0.60% [mean +/- the standard error of the mean]). Area under the curve data suggested that hemodialysis similarly removed an insignificant fraction of the cefixime body burden. Volume of distribution at steady state was not altered significantly by renal insufficiency. It is recommended that standard doses of cefixime be administered at extended intervals, especially in patients with creatinine clearances less than 20 ml/min per 1.73 m2. In addition, supplemental doses are not necessary during CAPD and at the end of hemodialysis.

Adult↗
PubMed1986

Survey of anaerobic susceptibility patterns in Canada.

The in vitro activity of penicillin, cefoxitin, moxalactam, ticarcillin, clindamycin, chloramphenicol, and metronidazole against 590 anaerobic isolates collected from five Canadian hospitals during 1984 was determined by an agar dilution technique. Cefoxitin, clindamycin, chloramphenicol, and metronidazole were very active against most of the isolates. No major regional differences in the susceptibility patterns were observed.

Bacteria, Anaerobic↗
PubMed1986

Infectious complications of endoscopic injection sclerotherapy.

We prospectively assessed the infectious complications of esophageal injection sclerotherapy (EIS) in 38 patients who underwent 104 procedures. Blood cultures were taken prior to and five and ten minutes after injection of the sclerosing agent in all procedures in an attempt to determine the frequency of positive blood cultures. Surveillance cultures were obtained from each patient's pharynx and from the biopsy channel of the endoscope to identify potential sources of bacteremia. The rate of blood culture positivity before injection was not significantly different from that after injection (1.9% vs 4.3%). In only one procedure was the same organism isolated five and ten minutes after sclerotherapy. The isolate in both samples was a Corynebacterium species. Endoscope surveillance cultures were positive prior to 42 of 102 procedures, although none of those organisms subsequently were isolated in the blood cultures. Since the rate of positive blood cultures following EIS is no greater than that before the procedure, the use of prophylactic antibiotics is unnecessary.

Corynebacterium↗
PubMed1985

Adherence of Escherichia coli to epithelial cells in the pathogenesis of urinary tract infection.

The role of bacterial adherence in the pathogenesis of recurrent urinary tract infection was investigated using an I125 E. coli-epithelial cell assay. In vitro bacterial adhesion to buccal, vaginal epithelial and uroepithelial cells of periurethral or rectal E. coli isolated from each subject was measured in 21 patients with recurrent urinary tract infection and 10 normal controls. Percent adherence of E. coli to buccal, vaginal, and uroepithelial cells was significantly (p less than .005) greater in patients with recurrent infection, compared with controls (32.9 +/- 4.0 vs. 14.1 +/- 7.3; 32.3 +/- 8.1 vs. 15.4 +/- 6.6; 34.7 +/- 5.6 vs. 17.1 +/- 4.2, mean +/- S.D., respectively). For both patients and controls, correlation in adherence between vaginal, uroepithelial, and buccal cells was observed. There were no differences in adherence between patients with or without periurethral colonization with E. coli, and adherence was not influenced by age. Patients receiving antimicrobial prophylaxis had a significantly (p less than .005) lower mean adherence to vaginal (26.7 +/- 3.7 vs. 35.1 +/- 4.1) and uroepithelial (30.4 +/- 2.8 vs. 34.6 +/- 3.2) cells, but not for buccal epithelial cells, compared with patients not receiving prophylaxis. These data support the hypothesis that increased receptivity of epithelial cells for bacteria plays a role in the increased frequency of vaginal colonization and subsequent infection in women who experience recurrent urinary tract infection.

Adhesiveness↗
PubMed1984

Urinary schistosomiasis: a report of four cases and a review.

Urinary schistosomiasis is a common cause of hematuria in tropical regions, where it most often affects teenage boys. Children presenting with hematuria in the developed world are usually considered to have bacterial cystitis or a structural lesion and are investigated and treated accordingly. The authors report on a family recently returned to Canada from Nigeria in which all four children had urinary schistosomiasis. Nocturnal enuresis was the presenting symptom in the index case; this patient also had hematuria and dysuria. Nocturia occurred in a second child, and the other two children were asymptomatic. All four were cured by a single dose of praziquantel, a new schistosomicide. The life cycle of the causative organism, the clinical manifestations of schistosomiasis, the host response and treatment with praziquantel are reviewed.

Child↗