Three-dimensional spinal curvature in idiopathic scoliosis

Scoliosis is usually considered as a deformity of the spine in the frontal plane, without reference to curvatures in other planes. In this study, the three-dimensional shape of the spine of 104 patients with untreated idiopathic scoliosis (5-55 degrees Cobb) was studied by means of stereo radiographs to determine relationships between curvature of the spine in the frontal plane view, in the lateral view, and in the intermediate views. There was a weak but statistically significant correlation (r = 0.2) relating greater scoliosis with lesser kyphosis or greater lordosis. In the thoracic region, the sagittal plane spinal curvature was less than that measured in a population without scoliosis (mean difference, 7.72 +/- 9.9 degrees). Seventy-four of 76 scolioses in the upper region of the spine with lateral curvature greater than 5 degrees Cobb were kyphotic. Sixty-four of 84 curves greater than 5 degrees Cobb in the lower region were lordotic. Measuring curvatures in the plane of symmetry of the rotated apical vertebra altered these ratios to 69 of 76 kyphotic in the upper region and 68 of 84 lordotic in the lower region. The plane of maximum curvature of sections of the spine with scoliosis was not related to the plane of symmetry of the rotated apical vertebra, for in kyphotic regions of the spine the rotations of these two planes were in opposite directions. In all cases, the magnitudes of the rotations were quite different, i.e., by a factor of -0.22 for curves in thoracic region and by a factor of 0.24 for curves in the lumbar region. This implies that mechanical measures to correct this spinal deformity or to prevent progression should apply different rotations to the apex from those applied to the curve as a whole and, in opposite senses, in curves in kyphotic regions. There was no evidence of an abnormality of sagittal curvature of a magnitude to implicate it in the etiology or in the treatment.     

Predicting failure in polytetrafluoroethylene vascular access grafts for hemodialysis: a pilot study

In order to determine if serial, noninvasive evaluation of polytetrafluoroethylene (PTFE) vascular access grafts could identify a subgroup of patients at risk for thrombosis, the authors studied flow characteristics, using duplex ultrasonic scanning, in 18 hemodialysis patients with forearm loop grafts. On average, five examinations were performed per patient over the 10-month study period. Seven episodes of thrombosis occurred in six patients. The mean Doppler flow in grafts that subsequently thrombosed was significantly lower than in those that did not (544 +/- 218 ml/min versus 843 +/- 391 ml/min, p less than 0.001). The interval from last examination to thrombosis ranged from 13 to 58 days. At a defined cut-off flow of 450 ml/min, this test yielded a sensitivity of 83% and a specificity of 75% for episodes of thrombosis occurring within 2 to 6 weeks. The authors conclude that episodes of thrombosis in PTFE arm loop grafts are usually preceded by significantly lower Doppler-measured flow than grafts that do not thrombose and that it may be possible, by this means, to identify grafts at risk.     

The mechanism of action of tumor necrosis factor (TNF) on tumor vascularity--study using a transparent chamber

Effects of human recombinant TNF on the tumor blood vessels and on the thrombus formation were investigated in relation to its mode of antitumor action against Meth-A sarcoma transplanted in BALB/c mice. The extent of the blood vessel lesion was evaluated by using transparent chamber placed in the mouse skin. Bleeding, hyperemia and congestion were observed at 1-2h, 4-6h and 24h after TNF (1 X 10(4)U/mouse) administration, respectively. In contrast, no histological changes in the normal blood vessels were observed microscopically following TNF injection. Thrombus formation was evoked in the tumor vessels 4h after TNF injection. However, when thrombus formation was prevented by heparin, no difference was observed among antitumor action of TNF against Meth-A fibrosarcoma necrotic response and the rate of complete cure. These results suggest that the direct effects of TNF causing lesions in the tumor blood vessels plays an important role in its antitumor action.     

Gamma-glutamyl transpeptidase activity during carcinogenesis of hamster buccal pouch epithelium

Gamma-glutamyl transpeptidase (GGT) activity has been demonstratedhistochemically in a number of experimentally induced neoplasmsand has been suggested as a label for potential precursors forthe development of squamous cell carcinomas. This study exploresthe kinetics of GGT-stained cell populations, their correlationwith the hypothesized initiated cells and evidence of malignanttransformation of epithelium in hamster buccal pouch by a 15-weekregime of tri-weekly topical application of 7,12-dimethylbenz[a]anthracene(DMBA) in mineral oil. GGT-positive foci were detected histochemicallyin tissue sections as early as 1 week after application of thecarcinogen, when there was no morphological evidence of dysplasia.The average number of the GGT-positive foci in each experimentalperiod was found to increase with time. Even though the majorityof the foci were small, consisting of only a single cell ora small group of cells, a few larger GGT-positive lesions werenoted, particularly in the later period of the experiment. Atotal of 66 grossly visible neoplasms were found. Thirty-sevenof these were submitted for GGT staining. Thirty-two (86.5%)of these showed patchy GGT activity, primarily in the superficialepithelial cells and/or the keratin. In the non-neoplastic epithelium,the GGT staining could involve any or all layers of cells. GGTactivity was not detected in untreated or mineral oil-treatedmucosa. The results of this study support the hypothesis thatGGT activity may label potential precursors for the developmentof squamous cell carcinomas.     

Comparative toxicity of total lymphoid irradiation and immunosuppressive drug treated patients with intractable rheumatoid arthritis

Outcomes were compared between consecutive patients who had received either total lymphoid irradiation (TLI) or immunosuppressant treatment for intractable rheumatoid arthritis (RA). There were 33 TLI and 32 immunosuppressive recipients; all patients had failed standard therapy. Average followup from the start of therapy was 2.7 years for TLI and 5.9 years for immunosuppressive recipients. Final disability levels were the same in both groups; mortality was equal in both groups as well. There were more hospitalizations for infections in the TLI group and the infecting organisms tended to be staphylococcus or gram negative organisms. Apart from infections, there were more adverse effects reported in the immunosuppressive therapy group.     

Human factors in chemical containment laboratory design

A human factors engineering analysis of a chemical containment laboratory was performed to develop appropriate standards for future laboratory design. In order to perform this evaluation, a state-of-the-art facility was studied in depth. Measurements and observations were made of key operating areas. In addition, technicians were observed and interviewed as they performed various tasks. Compiled data were compared to existing ergonomic standards. The occupational implications of instituting ergonomically developed laboratory design standards are as follows: increased worker health, safety and productivity, improved work quality and reduced stress.     

The relationship between communication and marital satisfaction: a review

This paper provides a comprehensive methodological review of the literature assessing the relationship between marital satisfaction and communication. The investigations vary greatly in the adequacy of their assessment measures and soundness of their research design. Although it is generally concluded that both content and process communication are related to marital satisfaction, replication of the better designs is necessary. Specific findings and their practical implications for both future research and marital therapy are discussed.