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Biomedical subjects

D L Gibbs

Publications and source records attributed to D L Gibbs.

26 records · Page 2Linked to original sources

Cefoperazone disk diffusion susceptibility test: confirmation of the tentative interpretive criteria, Pseudomonas aeruginosa cross-resistance, and determination of quality control performance limits.

Cefoperazone disk diffusion test and minimum inhibitory concentration comparison studies were performed on 421 recent bacterial isolates, using 30- and 75-micrograms commercially prepared disks. Acceptable correlation coefficients (-0.82 to -0.86) and very major (false-susceptible) interpretive error rates (less than 1%) were obtained with both disk concentrations. The interpretive criteria for both disks were identical. Using the preferred 75-micrograms disk, the Thornsberry et al. criteria (J. Clin. Microbiol. 15:769-776, 1982) of greater than or equal to 18 mm = susceptible (less than or equal to 32 micrograms/ml) and less than or equal to 14 mm = resistant (greater than 64 micrograms/ml) resulted in only 5.5% of strains having indeterminate-range zone diameters; the 30-micrograms disk had 6.9% of strains with indeterminate zone diameters. The 75-micrograms disk, excluding the testing of enterococci, minimized the very major and other interpretive errors to less than 5%. Larger zone diameters will contribute few technical problems with either disk concentration. Data from 1,320 zone diameters submitted for each quality control strain indicated no significant (P greater than 0.05) difference between disks made by the three major manufacturers, and consistent results were obtained within each laboratory with numerous lots of Mueller-Hinton agar (except for one manufacturer). Individual daily test and accuracy quality control ranges were calculated from clinical investigator laboratory data at 16 hospitals based on mean zone sizes and from an additional 8 laboratories with both mean and median calculations. The quality control data were nearly identical, and ranges calculated by the two methods were very similar. Susceptibility tests of Pseudomonas aeruginosa indicate that the cefoperazone disk or minimum inhibitory concentration test would accurately predict P. aeruginosa susceptibility test results for other pseudomonas-active cephalosporins (cefsulodin and ceftazidime), thus producing no very major interpretive errors.

Cefoperazone↗

Vibrio parahaemolyticus in Brazilian coastal waters.

Vibrio parahaemolyticus has been increasingly recognized as an important cause of acute diarrheal illness in Asia, Europe, Africa, Australia, and North America. We investigated whether this pathogen was also present in Brazil and found that 10% of the fish samples studied were contaminated with this halophilic vibrio. Positive cultures were obtained in three of 64 fish (5%) and in seven of 36 shell fish (19%).

Animals↗

The interaction in vitro between human polymorphonuclear leukocytes and Neisseria gonorrhoeae cultivated in the chick embryo.

Cultivation of Neisseria gonorrhoeae in the allantoic cavity of 10-day chick embryos ensured the following necessary properties for subsequent quantitive in vitro phagocytosis studies of viable gonococci: log phase of growth, resistance to the cidal effect of fresh human serum, maintenance of colonial type, and absence of clumping. Employing a modification of the Maaloe technique, phagocytosis of log-phase type 1 and 2 gonococci by human PMN leukocytes did not occur in the presence or absence of serum. These findings indicate that log-phase type 1 and 2 gonococci possess antiphagocytic surface factors Stationary-phase organisms of the same colonial type were ingested and rapidly killed by human PMN leukocytes under similar experimental conditions, thus emphasizing the necessity to employ log-phase gonococci in the study of phagocytosis and antiphagocytic surface factors. Log-phase type 4 gonococci were ingested and rapidly killed by human PMN leukocytes in the presence of fresh human serum but not heat-inactivated serum or in the absence of serum. Morphologic studies demonstrated that log-phase viable gonococci attach to the surface membrane of human PMN leukocytes. Interiorization of avirulent but not virulent organisms was observed in the presence of fresh human serum. Gonococci-human PMN leukocyte interactions thus provide a model for the investigation of the nonimmunologic and immunologic parameters associated with the attachment and ingestion stages of phagocytosis.

Animals↗

Chorioamniotic membrane separation: a potentially lethal finding.

Sonographic detection of chorioamniotic membrane separation (CMS) has been considered a benign incidental finding. We now report 6 cases of CMS identified by prenatal ultrasound; 1 in an otherwise normal pregnancy and 5 following fetal surgery. Following membrane separation, amniotic bands formed and compromised the umbilical cord in 4 cases leading to 2 fetal deaths. In the first case, CMS was detected by ultrasound at 22 weeks' gestation in an otherwise uncomplicated pregnancy. Because CMS was considered benign and umbilical cord blood flow was ample, the mother was followed by intermittent sonographic examinations. Fetal demise occurred 2 weeks later, clearly due to umbilical cord strangulation by an amniotic band. Surprised by this unexpected outcome, we reviewed our experience with CMS after hysterotomy for fetal surgery. Out of more than 40 fetal surgical cases, we have 5 cases in which CMS was recognized after hysterotomy. Three of these fetuses had umbilical cord compromise by a band of amniotic membrane leading to 1 fetal death. This experience demonstrates that membrane separation may be associated with amniotic band formation which can lead to cord strangulation and fetal compromise. Following fetal surgery, serial ultrasound evaluation and close fetal monitoring are indicated. In otherwise unremarkable pregnancies, clinician awareness of the possibility of amniotic band formation following CMS should be heightened. In either situation, knowledge of this potential life-threatening complication may identify cases in which cord compromise requires emergent delivery or fetoscopic release of the strangulating amniotic band.

Adult↗

Comparative and non-comparative studies of the efficacy and tolerance of tioconazole cream 1% versus another imidazole and/or placebo in neonates and infants with candidal diaper rash and/or impetigo.

Eleven open multicentre studies were conducted to evaluate the efficacy of tioconazole cream 1% as a treatment for diaper rash with or without fungal (Candida) involvement, or impetigo in neonates and infants. In the dermal candidiasis/diaper rash group, 320 patients had either tioconazole (n = 220), a comparative imidazole (n = 43), or vehicle cream (n = 57) applied to the affected area twice daily. Twenty-one impetigo patients had only tioconazole cream 1% applied three times daily to lesions. The overall cure rate (patients with both clinical and mycological cure) at the end of treatment for tioconazole treated patients was 78%, for the comparative imidazole group it was 76% and for vehicle cream it was 39%. At the long-term follow-up evaluation approximately 6 weeks after treatment for patients with diaper rash, the overall cure rate was about the same in both tioconazole- and comparative imidazole-treated patients (87% and 90%, respectively), and 14% in patients using vehicle cream. Side-effects were coincident with disease symptoms and consisted primarily of erythema localized to the treatment area; they occurred in 5.4% (13/241) of the patients who received tioconazole and in 21% (9/43) of the patients who received comparative imidazole (econazole or miconazole). No side-effects were reported in this open study for the 57 patients who used vehicle cream. The results of these studies show that tioconazole cream 1% is safe and effective for the treatment of neonates and infants with dermal candidiasis, diaper rash and impetigo.

Adolescent↗