Search PubMed⌕ Search

Biomedical subjects

V M Young

Publications and source records attributed to V M Young.

At least 37 records · Page 2Linked to original sources
PubMed1978

Evaluation of a multitest system for identification of saccharolytic pseudomonads.

The API-20 Enteric Strip has been proposed to have the capacity to differentiate the nonfermentative gram-negative bacilli. This multitest strip serves as the basis of an evolving system, which first provided a Register, then a Selector, and more recently a computer Index. Twenty-three strains of Pseudomonas aeruginosa and P. putida, 21 of P. fluorescens, 27 of P. maltophilia, and 33 of P. cepacia were investigated by duplicate test runs to determine reproducibility. The results were then evaluated at each of the three stages to determine accuracy of identification and the effect of the system evolution on the identification rate. Seventy-one of the 127 pseudomonads gave reproducible results in the multitest strips. Approximately half of them were correctly grouped or speciated by the Register, whereas 80 to 83% were similarly identified by both the Selector and Index. Of the clinically important pseudomonads, 61 to 65% of P. aeruginosa and 93% of P. maltophilia strains were correctly speciated; neither P. putida nor P. fluorescens strains were speciated, although most were correctly grouped. P. cepacia was speciated by the Index with only 55 to 58% accuracy. Although the present stage of the evolving system offers improvement over the Register, further modifications are needed to eliminate identification problems and to increase speciation.

Bacteriological Techniques↗
PubMed1978

Infection in acute leukemia patients receiving oral nonabsorable antibiotics.

During a 20-month period all acute nonlymphocytic patients (87 patient trials) receiving cytotoxic chemotherapy were placed on an oral nonabsorbable antibiotic regimen consisting of gentamicin, vancomycin, and nystatin in addition to an intensive program of infection prevention aimed at reducing exogenously acquired and body-surface potential pathogens. Although side effects of anorexia, diarrhea, and nausea were common, gentamicin-vancomycin-nystatin was ingested 80% of the study time. Microbial growth in gingival and rectal cultures was substantially reduced. The incidence of bacteremias and other serious infections was low. Pseudomonas aeruginosa, other gram-negative bacilli, and Candida species caused few infections along the alimentary canal, whereas infections of the skin (especially Staphylococcus aureus) were not reduced compared with those occurring in former years. A total of the 104 acquired gram-negative bacilli were gentamicin resistant; 5 subsequently caused infection. Thus, despite certain definite drawbacks, the use of oral nonabsorbable antibiotics to suppress alimentary tract microbial flora in combination with other infection prevention techniques in granulocytopenic cancer patients has proven feasible and tolerable and has been associated with a low order of life-threatening infections.

Acute Disease↗
PubMed1978

Effect of two cancer chemotherapeutic agents on the antibacterial activity of three antimicrobial agents.

Cancer chemotherapeutic agents and antibacterial antibiotics are often given concomitantly. Daunorubicin, cytosine arabinoside, and three antibiotics (gentamicin, amikacin, and ticarcillin) were tested individually and in combinations to determine their antimicrobial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. These cytotoxic agents are commonly employed in the therapy of acute nonlymphocytic leukemia for remission induction therapy, and these antimicrobial agents are used in infection therapy. The maximum concentrations of the two cytotoxic drugs were chosen to be twice the known peak plasma levels of commonly employed dosage schedules. Neither of the cancer chemotherapeutic agents, alone or in combination, demonstrated bactericidal activity at the levels tested. However, in the presence of these agents, the antimicrobial activity of gentamicin and amikacin, although not that of ticarcillin, was depressed for 11 of 15 K. pneumoniae strains and 8 of 15 P. aeruginosa strains, but for none of the strains of E. coli. This level of decreased activity occasionally resulted in a minimal inhibitory concentration of the tested aminoglycoside well above the standard serum levels. Daunorubicin was more likely to antagonize gentamicin than was cytosine arabinoside.

Amikacin↗
PubMed1978

Role of nonagglutinating antibody in the protracted immunity of vaccinated mice to Pseudomonas aeruginosa infection.

Effective immunization against infection with Pseudomonas aeruginosa is difficult to evaluate because agglutinin levels decline rapidly. Because fractionation of hyperimmune sera often yields more specific antibody than can be accounted for by direct agglutination tests, an immunoglobulin-specific assay based on antiglobulin augmentation was used to characterize antibody responses of C3H/HeJ mice vaccinated with P. aeruginosa type 2 lipopolysaccharide. Nonagglutinating antibodies, initially detected at 2 weeks post-primary vaccination, were predominantly immunoglobulin G after 5 weeks, and they remained elevated at levels usually 32-fold higher than the direct titer throughout the 4-month study period. The sequential production of immunoglobulin M, then immunoglobulin G, followed that found in orthodox immunological responses. Sera that contained nonagglutinating antibodies but not direct agglutinins (14 to 16 weeks) enhanced phagocytosis of P. aeruginosa type 2 by macrophages from unimmunized mice and passively immunized mice against lethal challenge doses; bactericidal activity of these sera was not demonstrated in the presence or absence of complement. When challenged with 1, 10, and 100 50% lethal doses at 16 weeks, survival rates of actively immunized mice were significantly higher than those of unvaccinated mice (P < 0.001). Thus, at a time when no direct agglutinins were detectable, the augmented system detected nonagglutinating antibodies that could confer protracted resistance in vaccinated mice to pseudomonas infection.

Agglutinins↗
PubMed1977

Amikacin and cephalothin: empiric regimen for granulocytopenic cancer patients.

Amikacin (15 mg/kg per day) was used in combination with cephalothin (7 g/m(2) per day) as an empiric regimen for de novo febrile (>101 degrees F [38.3 degrees C]) episodes in 93 granulocytopenic (<1,000/mm(3)) cancer patients. Both drugs were given intravenously in four equal doses every 6 h. The response rate for all documented infections was 83%, including 11 of 17 (65%) bacteremias. Escherichia coli (14 cases) was the most common pathogen, whereas Pseudomonas aeruginosa (2 cases) caused fewer infections. Mean amikacin serum levels were 8.7 mug/ml at 1 h and 2.2 mug/ml at 5 h. Failure of bone marrow recovery in association with a bacteremia was a bad prognostic sign (only two of eight improving). Ototoxicity occurred in two (2%) patients, whereas presumed antibiotic-induced nephrotoxicity developed in six (7%) patients. Surveillance cultures (nose, gums axilla, and rectum) of all hospitalized patients revealed no significant change in the incidence of amikacin resistance. The combination of amikacin and cephalothin in this dose and schedule was safe and efficacious in these granulocytopenic patients.

Adult↗
PubMed1976

Torulopsis glabrata infections in patients with cancer. Increasing incidence and relationship to colonization.

Torulopsis glabrata, an opportunistic pathogen, was found to be the etiologic agent of infections in patients with cancer. This observation prompted a retrospective review to determine the incidence and underlying factors of infection with this organism. This study showed that T. glabrata had been cultured frequently and that the incidence of infection has been progressively increasing. During a 48-month period (9/70-8/74), T. glabrata was cultured from routine surveillance and diagnostic cultures in 167 patients, 27 of whom had either presumed or documented infection. Review of clinical and necropsy records implicated T. glabrata infections as a contributory factor in the death of 14 of the 27 patients. Etiologic diagnosis of infection was established antemortem in only three patients. Pulmonary isolation in pure growth occurred in 24 of the 27 patients. Seventeen of 19 infected patients who had prior routine surveillance cultures were colonized prior to infection. Infection occurred in the setting of far advanced malignancy or leukopenia and followed the use of systemic, broad spectrum antibiotics. T. glabrata is a frequently overlooked opportunistic pathogen which, in the proper setting, appears to be producing increasing numbers of infections.

Bone Neoplasms↗
PubMed1976

Ticarcillin in combination with cephalothin or gentamicin as empiric antibiotic therapy in granulocytopenic cancer patients.

Ticarcillin was used in combination with either cephalothin or gentamicin as initial empiric antibiotic therapy for 127 patient trials of suspected infection in granulocytopenic cancer patients. Bacteremia was present in 20%, nonbacteremic microbiologically documented infections in 21%, clinically documented infections in 23%, and possible infections in 5%; infection was doubtful in 31%. Although Staphylococcus aureus was the most common single organism isolated (23%), gram-negative bacilli accounted for 54% of all pathogens. Both antibiotic regimens were highly efficacious, with complete resolution in 46% of bacteremias, 88% of nonbacteremic microbiologically documented infections, and 95% of clinically documented infections. Among bacteremias, 8 of 9 caused by S. aureus but only 4 of 15 (27%) caused by gram-negative bacilli were completely resolved with these antibiotic combinations. Reasons for nonresponse in bacteremias were persistent granulocytopenia, mixed infection and, in two patients, antibiotic-resistant organisms. Toxicities other than hypokalemia were minimal. Although the rate of further infections was high overall (18/127), only one occurred among the 39 patients with <4 days of antibiotic therapy. Ticarcillin in combination with either cephalothin or gentamicin was effective as initial empiric therapy of suspected infection in granulocytopenic cancer patients.

Adult↗
PubMed1975

Infection prevention in acute nonlymphocytic leukemia. Laminar air flow room reverse isolation with oral, nonabsorbable antibiotic prophylaxis.

Reverse isolation and prophylactic oral nonabsorbable antibiotics were evaluated among 64 consecutive noninfected adults with acute nonlymphocytic leukemia admitted for remission induction. Patients were randomly allocated to laminar air flow room reverse isolation with oral nonabsorbable antibiotics (LAF plus A), routine hospital ward care with antibiotics (W plus A), or ward care alone (W). The LAF plus A patients had a significantly decreased incidence of total infection, bacteremias, pneumonias, rectal abscesses, urinary tract infection, and pharyngitis. Infectious deaths were reduced in the LAF plus A group and the time to the first infection or to fatal infection was delayed. The W plus A patients who regularly ingested the antibiotics had a reduction in infections similar to that of the LAF plus A patients but those who could not tolerate the antibiotics had an incidence of infection comparable to the ward patients. The LAF plus A and the W plus A patients also had higher complete remission rates and longer median survival than the unprotected ward patients.

Acute Disease↗
PubMed1974

Comparative activity of tobramycin, amikacin, and gentamicin alone and with carbenicillin against Pseudomonas aeruginosa.

The effect of gentamicin against 130 clinical isolates of Pseudomonas aeruginosa was compared with that of two investigational aminoglycoside antibiotics, tobramycin and amikacin. Minimal inhibitory concentration data indicated that, on a weight basis, tobramycin was two to four times as active as gentamicin against most isolates. However, 14 of 18 organisms highly resistant to gentamicin (>/=80 mug/ml) were also highly resistant to tobramycin. Amikacin was the least active aminoglycoside on a weight basis, but none of the isolates were highly resistant to this antibiotic. When therapeutically achievable concentrations were used, adding carbenicillin to gentamicin or to tobramycin enhanced inhibitory activity against those isolates susceptible (</=5 mug/ml) or moderately resistant (10 to 40 mug/ml) to the aminoglycoside. Such synergy was seldom demonstrated for isolates highly resistant to gentamicin or tobramycin. The combination of carbenicillin and amikacin enhanced inhibition against all but two of the isolates. Both tobramycin and amikacin offer in vitro advantages over gentamicin against P. aeruginosa.

Amikacin↗