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.     

Antiaggregatory and anticoagulant effects of oligoamines. 7. Benzene-1,3,5-trialkaneamines

Platelet Aggregation Inhibiting and Anticoagulant Effects of Oligoamines, VII: Benzene-1,3,5-trialkanamines Seventeen title compounds were synthesized. Platelet aggregation induced by collagen in vitro is inhibited by 9 of them at IC₅₀ = 2–4 μmol/L. Seven compounds depress the formation of fibrin to ≦ 25 % of normal in concentrations below 50 μmol/L. Compound 15 [4-(2-thienylbutyl)benzene-1,3,5-trimethanamine is the first oligoamine which shows anticoagulant and antiplatelet effects at the same concentration (25 μmol/L).     

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.