CT-guided vertebral biopsy. A report of 89 cases.

The authors report the results of 89 vertebral biopsies performed under CT guidance, classified according to the type of pathology and the site of the lesion. A correct diagnosis was obtained in 89 cases. No complication was observed. The value of CT guidance in vertebral biopsy is emphasized.     

Characterization of mutations in Mycobacterium smegmatis involved in resistance to fluoroquinolones.

Fluoroquinolone-resistant mutants of Mycobacterium smegmatis have been obtained in vitro by using ofloxacin as a selecting agent. Two types of mutants were identified according to their quinolone resistance patterns. Type 1 showed a low level of resistance to ofloxacin (MIC of 8 micrograms/ml), whereas a high level of resistance to this drug (MICs of 32 to 64 micrograms/ml) characterized type 2. By using two oligonucleotide primers homologous to DNA sequences flanking the quinolone resistance-determining region (QRDR) in the gyrA gene of Escherichia coli and Staphylococcus aureus, a 150-bp DNA fragment was obtained by PCR amplification from total DNA of two wild-type and five mutant strains of M. smegmatis. The nucleotide sequences of the amplified fragments were determined. The deduced amino acid sequence from the wild-type strains showed ca. 79% similarity with the QRDR in the gyrase A subunit from other gram-positive and gram-negative bacteria. The DNA sequences obtained from the fluoroquinolone-resistant mutants of M. smegmatis exhibited nucleotide modifications compared with the wild-type QRDR. The QRDR from type 1 mutants had a C-T or an A-G transition leading to a change from Ala-83 to Val or Asp-87 to Gly, respectively. The QRDR from type 2 mutants had a Val-83 mutation or both Val-83 and Gly-87 mutations detected in the type 1 mutants. These results suggest that point mutations in the QRDR of the mycobacterial gyrA gene are responsible for acquired quinolone resistance in M. smegmatis.     

Assessing disability and quality of life in systemic sclerosis: Construct validities of the Cochin Hand Function Scale,Health Assessment Questionnaire (HAQ), Systemic Sclerosis HAQ,and Medical Outcomes Study 36‐Item Short Form Health Survey

Objective

To assess the construct validity of the Cochin Hand Function Scale (CHFS) and the relevance of using aggregate scores for the scleroderma Health Assessment Questionnaire (sHAQ) and Medical Outcomes Study 36‐Item Short Form Health Survey (SF‐36) in systemic sclerosis (SSc).

Methods

We evaluated 50 patients with SSc (mean ± SD age and disease duration 54 ± 12 years and 9 ± 8 years, respectively), of which 26 had limited cutaneous SSc (lcSSc) and 23 diffuse SSc (dSSc). Quality of life was assessed by the SF‐36, global disability by the Health Assessment Questionnaire (HAQ) and sHAQ, and hand disability by the CHFS. Construct validity was assessed by convergent and divergent validity (Spearman's rank correlation coefficient) and factor analysis.

Results

The CHFS had good construct validity and its total score explained 75% of the variance of the HAQ. The HAQ had better construct validity than the aggregate sHAQ and their scores correlated well (r = 0.88). The aggregate sHAQ was no better than the HAQ in discriminating between lcSSc and dSSc. SF‐36 physical and mental components had acceptable convergent and divergent validity. Factor analysis of the 8 subscales extracted 3 factors explaining 72% of the variance, which differed from the a priori stratification with physical and mental subscales extracted in the same factor.

Conclusion

In patients with SSc, the CHFS has good construct validity, the HAQ should be preferred over the aggregate sHAQ for assessing physical functioning, and use of SF‐36 physical and mental components aggregate scores is questionable.     

Disability in adults with hip and knee arthroplasty: a French national community based survey

OBJECTIVES: To compare levels of disability of people with and without hip and knee arthroplasty in a random national sample. METHODS: In 1999 a screening questionnaire to classify people into groups of increasing probabilities of disability was sent to 417 500 people; response rate 86%. The study population was obtained by a stratified randomisation, with a high sampling rate for the most severely disabled group and a minimum sampling rate for people without daily living restrictions. A computer assisted interview to assess levels of disability, dependence, and handicap was given to 21 760 people; response rate 78%. A weighting factor was applied to obtain estimates representative of the French population. The presence of chronic conditions, impairments, and disability was ascertained from the subjects' reports. RESULTS: The hip and knee arthroplasty group comprised 815 subjects in the sample, indicating an estimated 691 000 subjects (95% confidence interval (CI) 597 000 to 785 000) in the French non-institutionalised population. The prevalence of arthroplasty is estimated at 1.2%. After adjustments for confounding factors, activity limitations were greater among subjects with arthroplasty for the following activities: climbing stairs (odds ratio (OR)=4.0, 95% CI 2.8 to 5.8); walking distance (OR=3.4, 95% CI 2.5 to 4.6 for a walking distance less than 500 m); bending forward (OR=3.2, 95% CI 2.2 to 4.7); cutting toenails (OR=2.8, 95% CI 1.9 to 3.9); carrying (OR=2.6, 95% CI= 1.8 to 3.8); shopping (OR=2.1, 95% CI 1.5 to 2.9). CONCLUSIONS: This study would be useful to policy-makers considering population strategies for managing disabling arthritis.     

Assessment of a model for overall left ventricular three-dimensional motion from MRI data

In this paper we present a complete methodology to evaluate a model for overall three-dimensional (3D) motion of the human left ventricle (LV) from MRI data. The left ventricular motion is approximated by a linear model associated with an affine transformation to determine parameters for non-rigid motion of the LV. The proposed method has been applied to a normal patient and to a patient with cardiac disease. Results obtained show that the linear model provides a fairly good approximation of normal left ventricular motion, whereas serious cardiac disease produces abnormal motion, yielding altered model performances.     

Effects of granulocyte colony-stimulating factor and stem cell factor, alone and in combination, on the mobilization of peripheral blood cells that engraft lethally irradiated dogs

The effects of recombinant canine granulocyte colony-stimulating factor (rcG-CSF) and recombinant canine stem cell factor (rcSCF), a c-kit ligand, on the circulation of hematopoietic progenitor and stem cells were studied in a canine model. Administration of rcG-CSF (10 micrograms/kg) for 7 days led to a 5.4-fold increase in CFU-GM/mL of blood, while 7 days of rcSCF (200 micrograms/kg) led to an 8.2-fold increase. Although treatment with low-dose rcSCF (25 micrograms/kg) had no effect on the level of peripheral blood progenitors, 7-day exposure to a combination of G-CSF plus low dose SCF led to a 21.6-fold increase (P = .03). To assess the ability of these factors to increase the circulation of cells capable of rescuing animals after lethal total body irradiation (TBI), 1 x 10(8) peripheral blood mononuclear cells (PBMC)/kg were collected and cryopreserved from animals after 7 days of treatment with G-CSF, SCF or a combination of the two. One month later, animals were exposed to 9.2 Gy TBI and transplanted with the previously collected cells. Control animals transplanted with 1 x 10(8) PBMC/kg collected without pretreatment died with marrow aplasia 11 to 29 days after TBI as did animals treated with only low-dose SCF before cell collection. In contrast, all animals given PBMC collected after G-CSF, high-dose SCF, or a combination of G-CSF plus low-dose SCF recovered granulocyte function. Recovery to 500 granulocytes/microL after transplant took 17, 18.8, and 13.6 days, respectively, (P = .056 for the difference between the combination G-CSF-SCF group and the other two groups). In both the G-CSF and SCF groups, 4 of 5 animals completely recovered while 1 of 5 in each group died with prolonged thrombocytopenia. In the combination group, all 5 animals became long- term survivors. These studies demonstrate that both G-CSF and SCF dramatically increase the level of peripheral blood hematopoietic progenitor and stem cells and support the view that these factors can act synergistically.