Morphological concordance between CBCT and MDCT: a paranasal sinus-imaging anatomical study.

PURPOSE: Cone-beam computed tomography (CBCT) is an imaging technique, first developed for use during oral and pre-implant surgery. In sinonasal surgery, CBCT might represent a valuable tool for anatomical research given its high spatial resolution and low irradiation dose. However, clinical and anatomical evidence pertaining to its efficacy is lacking. This study assessed the morphological concordance between CBCT and multislice detector computed tomography (MDCT) in the context of sinonasal anatomy. METHODS: We performed an anatomical study using 15 fresh cadaver heads. Each head underwent both CBCT and MDCT. Two independent reviewers evaluated 26 notable anatomical landmarks. The primary outcome was the overall morphological concordance between the two imaging techniques. Secondary objectives included assessment of inter-rater agreement and comparison of the radiation doses received by different parts of the anatomy. RESULTS: Overall morphological concordance between the two imaging techniques was excellent (>98 %); the inter-rater agreement for CBCT was approximately 97 %, which is highly similar to MDCT, but achieved using a significantly decreased irradiation dose. CONCLUSION: Our preliminary study indicates that CBCT represents a valid, reproducible, and safe technique for the identification of relevant sinonasal anatomical structures. Further research, particularly in pathological contexts, is required.

Ex Vivo Assessment of an Ultrasound-Guided Injection Technique of the Navicular Bursa in the Horse.

Synovitis of the navicular bursa is common in performance horses. The objective of this study was to describe an ultrasound-guided technique to inject a distended navicular bursa and to evaluate its feasibility for use by a clinician not trained in the technique. Twenty distal limbs of horses of various breeds and sizes were used. To produce synovial distension, the navicular bursa of each limb was injected with contrast medium using a lateral approach and radiography was performed to confirm that the contrast medium was distending the bursa. The digit was positioned with the distal interphalangeal joint in hyperextension. A microconvex ultrasound probe was placed in the hollow of the pastern, palmar to the middle phalanx and the region was assessed in a transverse plane slightly oblique to the horizontal plane. The ultrasound probe was rotated to visualize both the lateral and medial recesses and to select which side was more distended to inject. A 21G 0.8 × 50 mm needle was inserted abaxially to the probe in the plane of the ultrasound beam into the proximal recess of this navicular bursa and a methylene blue solution was injected. Following injection, dissection was performed to assess whether the navicular bursa had been successfully injected. This ultrasound-guided technique was reliably performed with a success rate of 68%. The success of injection is influenced by hyperextension of the foot, quality of ultrasound images and degree of distension of the bursa.

Clostridium difficile and its cytotoxin in diarrhoeic stools of hospitalized patients. Toxigenic potential of the isolates.

Cytotoxin assay and culture for Clostridium difficile were performed on 303 diarrhoeic stools from 261 hospitalized patients. Specimens from 42 patients were positive by at least one of the methods, and 40 of them had an antibiotic-associated diarrhoea. The cytotoxin assay was positive in 5 of 7 patients with pseudomembranous colitis. Thirteen had an appropriate response to specific therapy and the remainder have resolved of diarrhoea without C. difficile directed chemotherapy. These findings show the lack of reliability of the cytotoxin assay for the diagnosis of C. difficile antibiotic-associated diarrhoea. The 6 strains isolated from patients with pseudomembranous colitis were examined for enterotoxin by the rabbit ileal loop test: 4 produced both toxins, 2 only enterotoxin. Both toxins could therefore not be essential for the clinical expression of the disease.

[Comparative in vitro effect of 7 quinolones on Ureaplasma urealyticum]. / Activité comparée in vitro de sept quinolones sur Ureaplasma urealyticum.

Some new quinolones may be used for the treatment of gonococcal urethritis. U. urealyticum is considered as a potential agent of urethritis. This report describes the in vitro antimicrobial activity of seven quinolones against 45 clinical isolates of U. urealyticum. The MIC's geometric mean is (microgram/ml): rosoxacin (1,74), pefloxacin (4,6), oxolinic acid (9), flumequin (12,12), norfloxacin (15,75), nalidixic acid (27). Pipemidic acid is constantly inactive (greater than 128 micrograms/ml). The results of these susceptibility studies provide support for undertaking clinical evaluations of new quinolones against infections with U. urealyticum.

[Antibiotic sensitivity of Mycoplasma pathogenic for man]. / Sensibilité aux antibiotiques des mycoplasmes pathogenes pour l'homme.

Human pathogen mycoplasmas (Mycoplasma pneumoniae, Mycoplasma hominis, Ureaplasma urealyticum) are intrinsically resistant to antibiotics which inhibit the cell wall biosynthesis (beta-lactams, vancomycin, bacitracin), to polymyxins, rifamycins, sulfonamides, trimethoprim, 5-nitroimidazoles, nitrofurans and to presently available quinolones. These three species are moderately susceptible to aminoglycosides, susceptible to chloramphenicol and highly susceptible to tetracyclines. M. pneumoniae is susceptible to macrolides, lincosamins and streptogramins. M. hominis is resistant to early macrolides (erythromycin, oleandomycin, spiramycin) and susceptible to new macrolides (josamycin, midecamycin, rosaramicin), lincosamins and streptogramins. U. urealyticum is resistant to lincosamins and susceptible to macrolides and streptogramins. Discordant results from various reports can be explained by differences in methods and breakpoint concentration values. In M. pneumoniae species, two strains resistant to macrolides and lincosamins have been described. In M. hominis species, one strain resistant to tetracyclines and another one resistant to tetracyclines and chloramphenicol have been reported. Two to ten percent of U. urealyticum strains are resistant to tetracyclines. These resistances are likely to be plasmid-mediated.

[Comparative activity of minocycline and doxycycline on mycoplasmas pathogenic for man]. / Activité comparée de la minocycline et doxycycline sur les mycoplasmes pathogènes pour l'homme.

Susceptibility of Mycoplasma pneumoniae (10 strains), Mycoplasma hominis (20 strains) and Ureaplasma urealyticum (100 strains) to minocycline and doxycycline was studied in vitro. Minimal inhibitory concentrations were determined using an agar dilution method for M. pneumoniae and M. hominis and a metabolic inhibition test for U. urealyticum. M. pneumoniae strains were highly susceptible to minocycline and doxycycline (MIC less than or equal to 0.1 mg/l). Among M. hominis strains, 17 were susceptible (MIC less than or equal to 0.1 mg/l), whereas 3 were inhibited only by concentrations ranging from 4 to 16 mg/l. Among the 100 U. urealyticum strains, 95 were inhibited by 4 mg/l minocycline and 94 by 4 mg/l doxycycline. Both antibiotics exhibited similar activities against the three species (same ranges, same mode MICs).

[Urogenital infections and mycoplasms]. / Infections urogénitales et mycoplasmes.

The role of genital mycoplasmas, e.g. M. hominis and U. urealyticum in urogenital infections is controversial. 120 samples were taken in 95 men and 25 women with urogenital infections and examined in the laboratory. Mycoplasmas were found in about 32% of men and 52% of women. M. Hominis is often associated with gonococcal infection and seems to play only a secondary role. The frequent isolation of U. urealyticum in various types of urethritis (gonococcal and non-gonococcal) is roughly the same. In the absence of a control investigation in healthy subjects, it is not possible to say whether it plays any role in urethritis.