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Biomedical subjects

M R Britt

Publications and source records attributed to M R Britt.

At least 19 recordsLinked to original sources
PubMed1986

Serum and crevicular fluid concentrations after a single oral dose of metronidazole.

Previous studies have shown that metronidazole is an effective chemotherapeutic agent in the treatment of certain types of periodontal disease. The purpose of this study was to assess, over 18 hours, the concentration of the drug in serum and gingival crevicular fluid after a single oral dose. Six female volunteers with gingivitis created by cessation of brushing for 2 weeks, took 250 mg of metronidazole orally. Micropipettes were used to collect 20 microliters of serum and 4 to 5 microliters of gingival fluid hourly for 8 hours, and at the 12th and 18th hours. Samples were assayed with a high pressure liquid chromatograph. Mean drug levels in serum closely matched those reported by Stephen et al. (Br Dent J 7: 313, 1966) with polography. Mean serum drug levels peaked at 6.09 micrograms/ml at the 2nd hour, and mean gingival crevicular fluid drug levels peaked at 3.62 micrograms/ml at the 2nd and 7th hours. The drug was detectable in both fluids for up to 18 hours. Mean serum concentrations remained greater than mean gingival fluid concentrations at all time intervals, though the differences were not significant (P less than 0.05) as determined by a Hoteling's T2 test. Using reported minimal inhibitory concentration values of metronidazole for various periodontopathogens, it was concluded that a single oral dose of metronidazole will deliver potentially inhibitory levels of the drug to the periodontium in serum and in gingival crevicular fluid.

Administration, Oral↗
PubMed1981

Prevention of catheter-associated urinary tract infections. Efficacy of daily meatal care regimens.

To evaluate the efficacy of daily cleansing of the urethral meatus-catheter junction in preventing bacteriuria during closed urinary drainage, randomized, controlled trials of two widely recommended regimens for meatal care were completed. In 32 (16.0 percent) of 200 patients given twice daily applications of a povidone-iodine solution and ointment bacteriuria was acquired, as compared with 24 (12.4 percent) of 194 patients not given this treatment. In 28 (12.2 percent) of 229 patients given once daily meatal cleansing with a nonantiseptic solution of green soap and water bacteriuria was acquired, as compared with 18 (8.1 percent) of 23 patients not given special meatal care. There was no evidence in either trial of a beneficial effect of meatal care. Moreover, each of four different statistical methods indicated that the rates of bacteriuria were higher in the treated groups than in the untreated groups. In subsets of female patients at high risk in both studies significantly higher rates of bacteriuria were noted in the treated groups than in the untreated groups. Current methods of meatal care appear to be hazardous, as well as expensive, and cannot be recommended as measures to control infection.

Administration, Topical↗
PubMed1981

Risk factors for postoperative pneumonia.

Prospectively studied were 520 patients undergoing elective thoracic, upper abdominal and lower abdominal surgeries to analyze risk factors for postoperative pneumonias. Over-all, pneumonias developed in 91 of the 520 patients studied (17.5 percent). The acquisition of pneumonia was highly associated with preoperative markers of the severity of underlying diseases such as low serum albumin concentrations on admission (P less than 0.005) and high American Society of Anesthesiologists pre-anesthesia physical status classification (P less than 0.0001). History of smoking (P less than 0.001), longer preoperative stays (P less than 0.0001), longer operative procedures (P less than 0.0001) and thoracic or upper abdominal sites of surgery (P less than 0.0001) were also significant risk factors for postoperative pneumonias. Although massive obesity, old age and male sex were also associated with increased incidences of pneumonia, statistical significance was lost when these variables were controlled for site or duration of surgery. We were able to identify risk factors for pneumonia and to define a subpopulation of patients in which the risk of pneumonia was negligible. The acquisition of pneumonia by a low-risk patient should alert the physician to the possibility of a potentially preventable nosocomial infection.

Adult↗
PubMed1981

Failure of bacterial filters to reduce the incidence of pneumonia after inhalation anesthesia.

The authors prospectively studied 520 patients undergoing inhalation anesthesia to evaluate the efficacy of low resistance 0.22-micron bacterial filters in preventing postoperative pneumonias. Patients undergoing elective thoracic, upper abdominal and lower abdominal surgeries were randomly assigned preoperatively to filtered and nonfiltered anesthesia circuits by a study nurse. A second study nurse, who was unaware of patient assignments, followed each patient for five postoperative days to identify possible pulmonary complications. Both groups of patients were similar in age, sex distribution, smoking history, prior pulmonary disease, types and duration of surgery, ASA physical status classification, and receipt of intraoperative antibiotics. No differences in rates of postoperative pneumonia were observed between patients assigned to filtered and nonfiltered circuits (16.7 per cent vs. 18.3 per cent, respectively, P = 0.73). Also no differences were observed when the incidences of other outcome criteria such as postoperative fever, abnormal chest x-ray, sputum production, or abnormal pulmonary physical exam findings were evaluated. The results suggest that bacterial gas filters do not influence the incidence of postoperative pneumonias and that routine use of these devices for this purpose is not cost-effective.

Anesthesia, Inhalation↗
PubMed1980

Topical agents alone in acne. A blind assessment study.

The comparative effectiveness of three comprehensive therapeutic programs was studied in 118 patients with mild to moderate acne vulgaris. A topical program of tretinoin, benzoyl peroxide, and water avoidance was found to be as effective as the more commonly employed program of systemic tetracycline therapy with topically applied tretinoin and better than a program using systemic tetracycline therapy with abradant cleansers. At 16 weeks of therapy for all groups, the degree of skin dryness correlated with lack of improvement. Skin dryness is established as an aggravating factor in both the pathogenesis and treatment of acne. The topical program was nonirritating, well accepted by patients, and less expensive than the other two regimens.

Acne Vulgaris↗
PubMed1980

Membrane filter contact technique for bacteriological sampling of moist surfaces.

We used a membrane filter contact technique to pick up and grow bacteria from artificially contaminated surfaces. We were able to recover individual colony-forming units (CFU) of Staphylococcus aureus from a moist agar surface more efficiently with 3- and 5- micron membrane filters than with Rodac plates, velvet pads, velveteen pads, or smaller-pore membrane filters. The effective transfer of bacteria with the 3- and 5-micron membrane filters was 0.96 +/- 0.04 (standard error of the mean) and 0.99 +/- 0.04, respectively, as compared to 0.49 +/- 0.03 for Rodac plates, 0.09 +/- 0.01 velvet pad imprints, 0.05 +/- 0.01 for velveteen pad imprints, 0.27 +/- 0.02 for velvet pad rinses, 0.005 +/- 0.001 for velveteen pad rinses, 0.39 +/- 0.02 for 0.45-micron filters, and 0.85 +/-0.05 for 1.2 micron filters. In addition, the recovery of S. aureus from contaminated bovine muscle surfaces with the 5-microns membrane filter was similar to that of quantitative dilutions of biopsy material and was significantly higher than the recovery from Rodac plates. The 5-microns membrane filters on a paddle recovered 52 +/- 5 CFU/cm2 from artificially contaminated bovine skeletal muscle, the quantitative dilutions of biopsy recovered 69 +/- 5 CFU/cm2, and the Rodac plate recovered 5 +/- 3 CFU/cm2. Sampling of moist surfaces by the membrane filter contact technique is easy to perform and highly efficient; our data suggest that it could be employed for cultures of clinical surfaces such as surgical wounds or burns.

Agar↗
PubMed1978

Severity of underlying disease as a predictor of nosocomial infection. Utility in the control of nosocomial infection.

In a prospective study, we determined that severity of underlying disease at time of admission indicates medical patients at unusual risk of nosocomial infection. The nosocomial infection rate was 23.6% in patients with fatal underlying disease, 9.6% in those with ultimately fatal disease, and 2.1% in those with nonfatal disease. After an awareness program that promoted the use of established methods for prevention of nosocomial infections was established, there was a decline of overall incidence of endemic nosocomial infections from 9.2% to 4.8% (P less than .001) within an eight-month period. With subsequent discontinuation of the program, the infection rate rose to 8.1%. Reinstitution of the program resulted in a decline to 5.2% (P = .05).

Cross Infection↗
PubMed1978

Haemophilus aphrophilus cholecystitis.

Cultures from the gallbladder and blood of a 60-year-old man with acute cholecystitis grew Haemophilus aphrophilus. This organism, an unusual isolate in clinical specimens, is most frequently seen in patients with either endocarditis or brain abscesses. Haemophilus aphrophilus may be distinguished from Eikenella corrodens and Actinobacillus actinomycetemcomitans on the basis of colonial morphology and the biochemical tests for oxidase and catalase production and fermentation of lactose, sucrose, glucose, mannitol, xylose, and trehalose.

Cholecystitis↗
PubMed1978

Infectious diseases in small hospitals. Prevalence of infections and adequacy of microbiology services.

In a 1-day prevalence survey nosocomial infections were found in 7.2% and community acquired infections in 20.4% of 525 patients hospitalized in 18 small hospitals. Pneumonia was the reason for admission in 11% of patients in small hospitals. The patterns of nosocomial infections and antibiotic usage in small hospitals are similar to those found in large hospitals. The adequacy of bacteriologic services was assessed using a process audit technique. The routine approach to common bacteriologic specimens and antibiotic disk susceptibility tests was frequently inadequate. Approaches used in large hospitals for the control of nosocomial infection and the performance of bacteriology tests were not practical for most small hospitals. Specific research into methods for doing clinically adequate bacteriology and approaches for the control of nosocomial infection in the small hospital setting are needed.

Anti-Bacterial Agents↗
PubMed1977

Antimicrobial prophylaxis for catheter-associated bacteriuria.

We evaluated short-term systemic antimicrobial prophylaxis for catheter-associated bacteriuria in women undergoing elective gynecological operations in a prospective, controlled, double-masked study. Nine of 100 placebo-treated patients acquired bacteriuria during catheterization compared with 3 of 96 of the drug-treated group. However, at the time of hospital discharge, clean-voided urine specimens were positive as frequently in the drug-treated group (8 of 82 patients cultured) as in the placebo group (8 of 75 patients cultured). No difference in febrile morbidity due to bacteriuria was noted between the prophylaxis and placebo groups. The incidence of catheter-associated bacteriuria may be reduced by antimicrobial prophylaxis. However, because the protective effect is transient and is associated with the selection of resistant organisms, prophylaxis is not indicated for patients at low risk for acquired bacteriuria and in whom the sequelae of catheter-associated infections are infrequent.

Anti-Infective Agents↗
PubMed1976

Infection control in small hospitals. Prevalence surveys in 18 institutions.

In prevalance surveys of 18 small hospitals in the intermountain region, 20.4% of the patients had community-acquired infections and 7.2% had infections acquired in the hospital. The types of nosocomial infections and patterns of antibiotic usage were similar to those encountered in large hospitals. In the small hospitals, 49% of the suspected bacterial infection were cultured, whereas at a nearby large hospital 77% were cultured. Seventeen of these small hospitals had an infection-control committee but these committees were unable to assess adequately the extent of their nosocomial infection problems. Monitoring of the environment with bacterial cultures was a frequent practice; overall, a ratio of one environmental culture was performed to each three diagnostic cultures. These results indicate the need to develop and evaluate nosocomial infection control programs in small hospitals.

Anti-Bacterial Agents↗
PubMed1976

Nosocomial infections in a newborn intensive-care unit. Results of forty-one months of surveillance.

We detected a 24.6 per cent nosocomial infection rate (222 infections in 138 infants) among 904 infants hospitalized for over 48 hours in a regional newborn intensive-care during 41 months of surveillance. Surface infections accounted for 40.1 per cent of the total, pneumonia for 29.3 per cent, bacteremia for 14.0 per cent, surgical-wound infection for 8.1 per cent, urinary-tract infection for 4.5 per cent, and meningitis for 4.0 per cent. Staphylococcus aureus (47.3 per cent) and gram-negative enteric bacilli (45.1 per cent) were the most common organisms recovered. Nosocomial infection rates were significantly higher in infants with a birth weight less than 1500 g (P less than 0.001). The mortality rate in infants with any nosocomial infection was 33 per cent in contrast to 14 per cent in non-infected babies (P less than 0.001). Nosocomial infections are a major problem in newborn intensive-care units.

Birth Weight↗
PubMed1974

Evaluation of miniature test for bacteriuria using dehydrated media and nitrite pads.

A new dip-inoculum method for detecting bacteriuria which utilizes dehydrated media pads and a nitrite pad attached to a small plastic strip was evaluated in hospitalized patients. Discrepant interpretations were made by independent observers in 9.3% of the specimens with > 10(5) colonies per ml. The media pads failed to support growth of yeast and gave variable results with Staphylococcus epidermidis and non-group D streptococci. False-negative culture results commonly occurred if the patients were receiving antibiotics. The nitrite test occasionally remained positive for brief periods after the elimination of bacteriuria by antibiotics. Conditions and drugs (especially phenazopyridine) which discolor urine interfered with reading both the culture and nitrite tests. Although not suitable for hospital use, or for monitoring therapy, the test strip is probably as reliable as the calibrated loop-streak plate culture for office screening.

Anti-Bacterial Agents↗