Clinical Application of a Self-Sealing Poly(ether-urethane) Graft Applicable to Blood Access for Hemodialysis

A poly(ether-urethane) graft (PEU) has been developed by our group and examined clinically. From July 1986, four straight and 11 loop grafts were implanted in 15 patients on maintenance hemodialysis. One straight and three loop grafts thrombosed between 1-6 months after the operation. One loop graft was ligated to remedy edema caused by a preexisting subclavian vein thrombosis. Angiographic findings of the grafts revealed a smooth positioning of the graft in most of the cases with minimal to moderate stenosis at anastomotic sites. Punctured sites were identified as tiny filling defects on the wall. However, neither stenosis nor aneurysmal dilatation were observed. Specimens of the graft were obtained from three patients to examine histological findings. Neointimal coverage was observed near the anastomotic site in a specimen obtained 6 months after the operation. The bare luminal surface still remained at the center of the graft. No clinical sign of peripheral thrombi was found. In addition to the clinical experience, this study is supplemented with the preliminary result of an animal experiment using a newly modified PEU graft with an open structure on the luminal surface.     

Production of denture by preform compression molding method. Part 3. Retentive strength of artificial teeth

A preform compression molding method to make a polysulfone denture has been reported. Retentive strength of artificial teeth to the denture base was examined to select artificial teeth for the compression molding method. Ceramic teeth with metal pins and polysulfone teeth heated at above 140 degrees C were retained to the denture base by useful retentive strength. Acrylic teeth on which the adhesive was used were also retained by useful strength. Each of the teeth, acrylic teeth, ceramic teeth and polysulfone teeth, could be used in the compression molding method.     

Muscle layer and regional differences in autonomic innervation and responsiveness to transmitter agents in swine myometrium

1 To clarify possible regional and muscle layer differences in adrenergic innervation of swine myometrium, functional, biochemical and histochemical experiments were performed on longitudinal (LM) and circular (CM) muscle isolated from nonpregnant uteri of 84 gilts. 2 Transmural stimulation (TMS) in the presence of propranolol evoked tetrodotoxin-sensitive contractions in a frequency-dependent manner (2–20 Hz) in LM and CM. The cornual LM contractions were attenuated by phentolamine (1 μm ) and by guanethidine (10 μm ) though unaffected by atropine (1 μm ). Contractions in cervical LM were diminished by atropine but not by phentolamine, and the corpus LM contractions were reduced incrementally by atropine and phentolamine when added sequentially. In CM, the TMS-induced contractions were abolished by tetrodotoxin and atropine in all three regions. 3 In response to noradrenaline (NA) and acetylcholine (ACh), LM contractile intensity was the most potent in cornua, slightly weaker in the corpus and weakest in the cervix. CM was insensitive to NA, and contractile responses elicited by ACh indicated no regional variation. 4 NA content, significantly greater in LM than in CM, was most highly concentrated in cornual LM. Nerves exhibiting glyoxylic acid-induced histofluorescence occurred in both LM and CM, though more abundantly in LM and with notable density in the cornual LM. Cholinesterase activity, distributed evenly throughout the three myometrial regions studied, was more intense in LM than in CM. 5 These results show that, in swine myometrium, innervation in cornual LM is predominantly noradrenergic, cervical LM is mostly cholinergic, and throughout the myometrium the CM layers are principally cholinergic.     

Bioavailability of calcium from oyster shell electrolysate and DL-Calcium lactate in vitamin D-replete or vitamin D-deficient rats

Bioavailability of calcium (Ca) from oyster shell electrolysate (Active Absorbable Ca: AACa) and DL-Ca lactate in rats was investigated. Plasma Ca metabolism, bone mineral density and vitamin D-deficient rats were measured and compared each other. Vitamin D-deficient rats were fedad libitum a vitamin D-free diet containing 0.44 % Ca or 1.20 % Ca adjusted with either AACa or DL-Ca lactate with or without oral supplementation of physiological dose (10 IU/rat/day) of vitamin D₃ for 28 days. During and after feeding, concentrations of Ca, phosphorus, parathyroid hormone (PTH), 25-hydroxyvitamin D₃ (25-OH-D₃), 1α, 25-dihydroxyvitamin D₃ [1, 25(OH)₂D₃] and alkaline phosphatase (Alp) activity in plasma were measured. Furthermore, femoral Ca and phosphorus contents, mineral density and mechanical strength were also measured. Despite of the differences of contents and chemical forms of Ca in diets, all the groups showed prompt and complete recoveries in both Ca and vitamin D malnutritions under vitamin D-replete condition and there was no significant difference among all the groups in increases of body weight gains and plasma Ca levels, and in decreases of plasma PTH level and Alp activity. In contrast, the groups fed the same diets under vitamin D-deficient condition showed no significant recoveries in both plasma Ca metabolism and bone mineralization although Ca bioavailability of AACa appeared to be slightly better than that of DL-Ca lactate. These results suggest that bioavailability of Ca from AACa and DL-Ca lactate are substantially equal in increasing plasma Ca levels, bone mineral density and mechanical strength in both vitamin D-replete and vitamin D-deficient rats.