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.     

Conservative open anterior acromioplasty

The records of 29 consecutive patients treated by a pure, open, anterior acromioplasty were reviewed retrospectively. Excluded from consideration were patients with the following pathologic diagnoses or histories: (1) previously attempted acromioplasty on the same shoulder; (2) intraoperatively confirmed rotator cuff tear; (3) any surgically treatable biceps tendon or acromioclavicular abnormality; (4) lost to follow-up study. Three different techniques were employed to perform the acromioplasties. The first technique required partial deltoid origin detachment with an osteotome. The second technique spared the deltoid origin, while again using an osteotome to perform the acromioplasty. The third technique also spared the deltoid origin but used a high-speed burr to perform the acromioplasty. Evaluated in terms of patient satisfaction, residual pain, length of convalescence, suboptimal results, and complications, the first technique proved to be the least effective. The second technique produced early, excellent results. The third technique, in which a burr was employed through an intact deltoid origin, was most effective; technically, the method was also relatively simple and reliable.     

Thermoregulation in mice following acute administration of lead acetate

Several reports in the literature suggest a relationship between lead intoxication and thermoregulatory capacity. To investigate the effects of lead on the control of body temperature, mice of the BALB/c strain were injected intraperitoneally with lead acetate (0 to 100 mg/kg) while colonic temperature was measured 30, 60, and 90 min post-injection at ambient temperatures (Ta) of 20 and 30 degrees C. Lead acetate caused a transient hypothermia, an effect which was augmented at cooler Ta's. In a second experiment, mice were injected with 100 mg/kg lead acetate and placed in a longitudinal temperature gradient to measure their preferred Ta. Lead acetate significantly reduced the preferred Ta during the first 30 min post-injection which augmented the lead-induced hypothermia. In a third experiment it was found that lead acetate-induced lethality was potentiated with increasing Ta. Hence, the hypothermic response to acute lead acetate treatment may be beneficial to survival.     

The Alaska mental health lands

The Alaska mental health program is endowed with a 1-million-acre trust fund. A coalition of groups that make up the mental health constituency of the state united in a lawsuit to establish the trust. The history of this legacy, the struggle to realize its benefits, its current status, and some of its psychopolitical significance are discussed.     

Fine structure of surviving heart muscle cells in ventricular aneurysms

Surgically-obtained tissue specimens from 41 patients with ventricular aneurysm were studied electron microscopically. The tissue from the resected aneurysms showed substantially varied morphological differences. In some, there were extensive regions of scar containing increased fibrotic material and few cells, in others there were also larger contiguous regions of myocardium with an essentially normal appearance. In the preserved myocardial regions, the cardiac cells showed moderate hypertrophy. There was an increase in contractile substance in parallel with an increase in mitochondria and enlargement of the nucleus with frequent waves and invaginations in the cell membrane. The cells at the marginal regions between fibrous tissue and preserved myocardium were frequently isolated from adjacent cells. In particular, when the isolated cells were completely surrounded by fibrous tissue, clear degeneration was apparent. These cells showed mainly a fibrillolysis with dissolution of the cross-bands and loss of the entire contractile apparatus. In compensation, occasionally there was proliferation of other cell structures, especially the free sarcoplasmatic reticulum. The hypertrophy of the still intact myocardial cells is considered compensatory for the infarct-incurred loss of tissue. The degenerative appearance is mainly attributable to fibrous tissue invasion. The diminished oxygen supply, compromised or abolished impulse conduction, loss of function and passive stretch during systole may be regarded as causes of the degeneration.     

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.     

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.