A comparative study of CT densitometry of vertebral cancellous bone, abdominal aorta, paravertebral fat and the relative fat volume

Fluctuations are observed in CT densitometry of cancellous bone of the lumbar vertebra in relation to age and sex and also per age/sex group. An investigation was carried out in 119 patients to possibly detect comparable fluctuations in CT measurements of other tissues. The spongiosa of the fourth lumbar vertebra, the abdominal aorta, paravertebral fat and the ratio fat volume/total irradiated volume were compared in the slice plane through the middle of the fourth lumbar vertebra. Calibration was performed using a water phantom. A correlation between the mentioned parameters could not be demonstrated. The relation between Bone Mineral Density (BMD) and age and sex showed the same values as known from the literature, being representative for a normal population. Using the aorta as a reference (which in fact is related to water) a similar curve is found as in Cann and Cann et al. The density of the aorta showed a constant value, varying between 38 and 50 HU with a mean of 45 HU. Extreme values were only found with streak artefacts. It seems useful to use the aorta values as a reference to measure the relative value of vertebral cancellous bone.

Laboratory diagnosis of Mycoplasma pneumoniae infection. 2. Comparison of methods for the direct detection of specific antigen or nucleic acid sequences in respiratory exudates

The efficiency of the direct detection of Mycoplasma pneumoniae in respiratory exudates by an antigen capture, indirect enzyme immunoassay (Ag-EIA), has been compared with its detection with a cDNA probe ('Gen-Probe assay') directed against the specific ribosomal RNA sequences of the organism ('Mycoplasma pneumoniae Rapid Diagnostic System', Gen-Probe, San Diego, California). Both assays showed excellent specificity against a range of mycoplasma species suspended in negative nasopharyngeal aspirates; only M. pneumoniae and M. genitalium reacted. In experiments with graded doses of viable M. pneumoniae cells suspended in negative nasopharyngeal aspirate, the Gen-Probe assay was more sensitive than Ag-EIA; detection limits were respectively 2 X 10(3) c.f.u./ml (3.2 X 10(5) genomes) and 2.5 X 10(4) c.f.u./ml (4 X 10(6) genomes); detection levels 10-100 times less sensitive than culture. The two assays were also tested on nasopharyngeal aspirates or sputum specimens from 90 patients with respiratory infection; 67 of these were culture- or seronegative for M. pneumoniae and 23 were culture- or seropositive. Ag-EIA detected 21 (91%) of the latter but the Gen-Probe assay detected only 5 (22%). Both assays were negative with the 67 culture-/sero-negatives; there were no Gen-Probe assay positive/Ag-EIA negatives. Overall, it is concluded that although Ag-EIA and the Gen-Probe assay are effective substitutes for culture as a diagnostic procedure, there is a significant problem with samples which are culture-negative and from patients who have good serological evidence of current infection. Possible reasons for the disparity between the two assays are advanced.

A multicenter phase II trial of cisplatin and oral etoposide (VP-16) in inoperable non-small-cell lung cancer

Sixty patients with inoperable non-small-cell lung cancer (NSCLC) were entered into a phase II study that tested the combination of cisplatin (80 mg/m2, day, etoposide intravenously (IV) (100 mg, days 1 and etoposide orally (200 mg/m2, days 3 and 5). The regimen was repeated every 28 days for six courses, after which patients were allowed to receive additional treatment at the discretion of their physician. Overall objective response rate in 51 evaluable patients was 69% (95% confidence interval: range, 56% to 81%), with 16% sustaining complete remission (CR), 53% partial remission (PR), 17% stable disease (SD), and 14% progressive disease (PD). CR was pathologically confirmed by bronchoscopy and biopsy. One patient with a clinical PR underwent surgery and was shown to have a pathologic CR. Median survival of all evaluable patients was 52 weeks, greater than 75 weeks for CR patients, 52 weeks for PR patients, 42 weeks for SD patients, and 13 weeks for PD patients. Eleven patients (21.5%) developed CNS metastases, which resulted in the deaths of ten. Survival was significantly correlated with extent of disease, performance status, and albumin level, but not with histology or weight loss. Tumor response was significantly correlated only with histology (squamous-cell and large-cell undifferentiated carcinoma greater than adenocarcinoma). Side effects were nausea, vomiting, anorexia, alopecia, bone marrow suppression, and nephrotoxicity. One patient died from leukopenia and sepsis. Pharmacokinetic studies in ten patients showed the continuous presence of etoposide in plasma for six days at a level of at least 220 to 480 ng/mL. In order to investigate whether this very effective combination of cisplatin and etoposide can prolong survival in NSCLC, it will be tested as preoperative chemotherapy in a randomized trial in operable patients with T1N1 and T2N0-1 disease.