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Biomedical subjects

C W Norden

Publications and source records attributed to C W Norden.

At least 19 recordsLinked to original sources

Clinical infections in the noninstitutionalized geriatric age group: methods utilized and incidence of infections. The Pittsburgh Good Health Study.

Because noninstitutionalized senior citizens comprise over 95% of the population 65 years of age and older, their health needs are a major concern. Data regarding infections in this population including the epidemiology, morbidity, and mortality are lacking. The authors recruited a study population of 417 free-living persons, all 65 years of age or older, from two neighborhoods in Pittsburgh, Pennsylvania. After the collection of self-reported baseline information from these persons, they were monitored for all clinical infections for 2 years, beginning July 1986 and through June 1988, using clinic visits, hospitalizations, or phone calls when needed. The baseline information showed the study population of 417 persons to be comparable with a neighborhood comparison group and with established populations for epidemiologic studies of the elderly in three other states. The 24 months of infection surveillance yielded 494 diagnosed infections in 224 or 54% of the subjects. Respiratory infections were most frequent with 259 or 52% of the total, followed by genitourinary infections with 24%, skin infections with 18%, gastrointestinal infections with 4%, and other types of infection with 2%. By comparing 22 self-reported baseline conditions with the occurrence of infection, 10 historic factors were univariately significant for infection. Of these 10 factors, only history of a lung problem (relative risk = 1.7, 95% confidence interval (CI) 1.1-2.9) and history of difficulty controlling urination (relative risk = 2.7, 95% CI 1.3-4.9) were statistically significant in multivariate analysis. To our knowledge, this study represents the first prospective data on infections in the noninstitutionalized elderly. The data demonstrate the wide variety of infections that occurred in this population and suggest that persons with a history of any one of several medical problems were possibly at greater risk for infection.

Aged↗

Treatment of hospitalized patients with complicated skin and skin structure infections: double-blind, randomized, multicenter study of piperacillin-tazobactam versus ticarcillin-clavulanate. The Piperacillin/Tazobactam Skin and Skin Structure Study Group.

We compared the efficacy and safety of two beta-lactam-beta-lactamase inhibitor combinations, namely, piperacillin-tazobactam and ticarcillin-clavulanate, in the treatment of complicated bacterial infections of skin that required hospitalization. The study was a randomized, double-blind, comparative trial involving 20 centers. The infections were classified as (i) cellulitis with drainage, (ii) cutaneous abscess, (iii) diabetic or ischemic foot infection, and (iv) infected wounds and ulcers with drainage. The clinical response rates were comparable for the two treatment regimens (61% of the patients were cured with piperacillin-tazobactam and ticarcillin-clavulanate and improvement was seen in 15 and 16% of patients treated with piperacillin-tazobactam and ticarcillin-clavulanate, respectively). Both regimens were found to be safe and well tolerated. These data support the use of piperacillin-tazobactam for initial empiric therapy of hospitalized patients with complicated skin and skin structure infections.

Bacteroides Infections↗

Pharmacokinetics of cephradine administered intravenously and orally to young and elderly subjects.

The pharmacokinetics of IV and oral cephradine in healthy young male and female volunteers (ages 19 to 25, n = 10) were compared to those of older individuals (ages 65 to 81, n = 9). Subjects received 1 gram of cephradine by a 5-minute intravenous (IV) infusion followed the next day by a 1-gram oral dose. Serial serum and urine samples collected over a period of 12 hours after the dose were analyzed for cephradine concentration by a microbiologic assay. After IV administration, mean serum cephradine concentrations in the elderly group were significantly higher at both 6 hours (1.52 +/- 0.41 mcg/mL) and 8 hours (0.73 +/- 0.22 mcg/mL) than in the young group at 6 hours (0.43 +/- 0.11 mcg/mL). Total systemic clearance was significantly lower (2.64 +/- 0.34 vs. 4.81 +/- 0.59 ml/min/kg) and the elimination half-life was significantly longer (1.71 +/- 0.20 vs 1.12 +/- 0.13 hours) in the elderly group (P = .0001). Systemic cephradine clearance correlated positively with creatinine clearance (r2 = 0.34, P = .0110) and negatively with age (r2 = 0.79, P = .0052). The mean volume of distribution was not significantly different between the two groups. Mean renal clearance was significantly lower in the elderly group (P = .0001), but more than 80% of the dose was excreted in the urine within 6 hours in both groups. After oral administration, the mean peak concentration and time to peak concentration did not differ between groups. The relative oral bioavailability was approximately 94% in both groups. The mean serum concentrations in the elderly were higher at both 6 and 8 hours than in the young group at 6 hours. There were no differences in pharmacokinetic parameters between male and female subjects. Because of reduced cephradine clearance secondary to an age-related decline in renal function, administration of cephradine every 8 hours, rather than every 6 hours, may be sufficient in elderly patients.

Administration, Oral↗

Treatment of experimental chronic osteomyelitis due to Staphylococcus aureus with ampicillin/sulbactam.

Ampicillin/sulbactam was used for the treatment of experimental osteomyelitis due to Staphylococcus aureus in rabbits. Treatment with 200 mg/kg (ampicillin) three times a day sterilized 40% of infected rabbit bones. The results of 4 weeks of treatment with ampicillin/sulbactam for chronic experimental staphylococcal osteomyelitis were comparable to those obtained previously with cephalothin and with oxacillin in previous studies and were not as good as those with clindamycin alone or combination therapy that included rifampin.

Ampicillin↗

Fatal adult respiratory distress syndrome in a patient with Lyme disease.

A dry cough, fever, generalized maculopapular rash, and myositis developed in a 67-year-old woman; she also had markedly abnormal liver function test results. Serologic tests proved that she had an infection of recent onset with Borrelia burgdorferi, the agent that causes Lyme disease. During a two-month course of illness, her condition remained refractory to treatment with antibiotics, salicylates, and steroids. Ultimately, fatal adult respiratory distress syndrome developed; this was believed to be secondary to Lyme disease.

Aged↗

Value of needle aspiration in bacteriologic diagnosis of cellulitis in adults.

We prospectively studied 30 adult patients with cellulitis, including many who were hospitalized with significant underlying medical problems. Needle aspiration of both central and leading edge areas of their lesions was performed in an attempt to establish a bacteriologic diagnosis. Potential pathogens were isolated by this technique in only 10% of the patients. Neither site of aspiration was clearly superior in terms of culture yield. Because aspirate Gram stains and cultures so rarely provided useful bacteriologic information, they were seldom helpful in guiding antibiotic selection or in influencing the outcome of treatment in most patients. However, clinical information, as well as results of primary lesion cultures when obtainable, may be used to successfully select therapy in most cases of adult cellulitis. On the basis of our results, needle aspiration may not be justified as a routine diagnostic procedure for all adults with cellulitis, though it may still be useful in selected patients.

Adolescent↗

In vitro activity of BMY-28100, a new oral cephalosporin.

BMY-28100 is a new orally absorbed cephalosporin whose in vitro activity was compared with that of cefaclor. BMY-28100 was more active against Staphylococcus aureus and Haemophilus influenzae than was cefaclor. In addition, there was only a small rise in MIC50 and MIC90 values for BMY-28100 when the inoculum size was increased 100- or 10,000-fold. In contrast, MIC50 and MIC90 values increased significantly for cefaclor with similar increases in inoculum size. These data suggest that BMY-28100 may be a promising agent to test for oral administration in infections caused by S. aureus and H. influenzae.

Cefaclor↗

In vitro activity of BMY-28142, a new cephalosporin.

BMY-28142 was compared in vitro with ceftazidime, cefotaxime and cefoperazone and was found to be more active against Pseudomonas aeruginosa and Staphylococcus aureus. Essentially no effect of increasing inoculum size 100-fold was seen-on MICs with BMY-28142 or ceftazidime; some effect was noted with cefotaxime and cefoperazone.

Bacteria↗

Clindamycin treatment of experimental chronic osteomyelitis due to Staphylococcus aureus.

Clindamycin was used alone for treatment of experimental osteomyelitis due to Staphylococcus aureus in rabbits. Treatment with 30 mg/kg of body weight three times a day for 14 days was ineffective in sterilizing infected rabbit bones. In contrast, when given for 28 days, clindamycin sterilized the infected bones of 16 (84%) of 19 rabbits treated. Only one of 14 isolates of S. aureus from rabbits treated for two weeks developed resistance to clindamycin (minimal inhibitory concentration, greater than 100 micrograms/ml); none of three isolates from rabbits in which treatment failed in the four-week treatment group showed resistance to clindamycin. The results of four weeks of treatment with clindamycin for chronic experimental staphylococcal osteomyelitis were significantly better than those obtained with any other single agent used in prior studies and were generally as good as those with combination therapy that included rifampin.

Animals↗

Chronic osteomyelitis caused by Staphylococcus aureus: controlled clinical trial of nafcillin therapy and nafcillin-rifampin therapy.

A controlled trial of treatment of chronic osteomyelitis caused by Staphylococcus aureus compared nafcillin alone with nafcillin plus rifampin for a six-week period. Treatment was well tolerated, the only adverse effect being mild neutropenia in four of 18 patients; no toxicity was observed from rifampin. Eight of ten patients in the combined treatment group had a favorable clinical response (with follow-up of two to four years) as compared to four of eight in the nafcillin group (P = .2). Despite the failure to show a statistically significant advantage of rifampin plus nafcillin, we conclude that the combination, along with appropriate surgery, should be considered for patients with chronic staphylococcal osteomyelitis.

Administration, Oral↗

Diagnosis and treatment of osteomyelitis.

The diagnosis and management of osteomyelitis continues to present problems. Technetium bone scans may identify acute osteomyelitis before the characteristic disease changes are visible on x-ray studies, but they have a number of drawbacks. Microbiological studies are critical in making precise diagnoses of the cause so that proper therapy will be given. In treatment of acute osteomyelitis, several investigators report good results from four-week administration of parenteral antibiotic, or one week of parenteral treatment followed by three weeks of oral therapy. Chronic osteomyelitis requires surgical removal of dead tissue followed by lengthy parenteral and oral antibiotic therapy. Chronic forms of the disease caused by resistant gram-negative organisms may prove responsive to quinoline therapy. These agents may attain inhibitory levels on oral administration, and have proved to be effective in animal models. Clinical trials, however, are required to determine their usefulness in the treatment of clinical disease.

Anti-Bacterial Agents↗

Prevention of bone and joint infections.

The importance of preventing infections in bone and joint surgery is clear because of the devastating clinical and economic consequences. Prophylactic antibiotics have reduced the incidence of wound infection in surgery of noncompound hip fractures. Five studies of antibiotic prophylaxis in total hip replacement have concluded that prophylaxis has reduced the frequency of deep wound infection after surgery. The use of operating rooms supplied with ultra-clean air was also associated with a reduction in infection after insertion of a prosthetic joint. These studies suggest that ultra-clean air and antibiotic prophylaxis have independent and cumulative effects in preventing joint infection following surgery. Foci of infection elsewhere in the body can seed a prosthetic joint and, therefore, must be treated vigorously. However, there are no convincing data as to the potential risk to the prosthetic joint of procedures such as dental work or gastrointestinal or genitourinary tract manipulation. Currently, antibiotic prophylaxis for all patients with prosthetic joints about to undergo such procedures cannot be recommended.

Air Microbiology↗