Solid-solid-liquid phase transfer reactions catalyzed by polymer-supported ureas

Polymer-supported ureas were prepared by copolymerization of the corresponding vinyl monomers and divinylbenzene with 2,2′-azoisobutyronitrile. These polymers show catalytic activity in the reaction of 1-bromooctane with solid potassium thiocyanate, although the corresponding monomeric ureas are inactive. The catalytic activity is enhanced remarkably by replacing the amino hydrogen for a methyl group. Further, the catalytic activity is affected by some experimental parameters such as stirring, particle size of the catalyst, degree of crosslinking, and solvent. On the basis of the above results, a plausible catalytic reaction mechanism consiting of collisional contact between the solid catalyst and the reagent is proposed.     

The effect of different routes of administration on the metabolism of morphine: The disposition of morphine and its metabolites after topical application

The disposition of morphine (MOR) and its metabolites in the rabbit was measured after topical administration of its hydrochloride salt (MOR · HCl), and their time course was compared with those after intravenous and oral administration. The area under the plasma concentration—time curve (AUC) ratio of metabolites/MOR after the topical application of MOR · HCl was similar to that after intravenous injection, but differed from that after oral administration. Pharmacokinetic parameters of the disposition of MOR and its metabolites were obtained by a general curve fitting of the time course of plasma concentrations of these compounds after intravenous injection of MOR · HCl and its metabolites, respectively. On the other hand, the time courses of plasma concentrations of the metabolites after intravenous, oral, and topical administration of MOR · HCl were simulated using a simple compartment model without consideration of enterohepatic circulation and the pharmacokinetic parameters obtained as above. The resulting curves of the metabolites agreed well with the observed values except for those after oral administration. These results suggest that no first-pass metabolism of MOR · HCl occurs after percutaneous administration, and that topical administration of this salt is more advantageous than oral administration in terms of bioavailability.     

Role of CD4+ T cells in the rat to mouse cardiac xenotransplantation

Abstract T cell subsets involved in rejection of xenografts were analyzed using a rat to mouse cardiac xenotransplant model. Proliferating response and interleulin-2 (IL-2) production in recipients' spleen cells were almost completely abrogated by elimination of L3T4⁺ T cells, but not by elimination of Lyt2.1⁺ T cells. Cytotoxic T lymphocyte (CTL) activities were mediated by both L3T4⁺ and Lyt2.1⁺ T cells with the help of IL-2-producing L3T4⁺ T cells. Administration of anti-L3T4 monoclonal antibody (mAb) into recipient mice resulted in a significant prolongation of graft survival (mean graft survival was 29.2 days). Moreover, anti-L3T4 mAb treatment plus thymectomy led to indefinite graft survival. Anti-rat endothelial cell (EC) antibody production in the grafted mice was remarkably suppressed by anti-L3T4 mAb treatment. In contrast, Lyt2.1 mAb treatment did not prolong the graft survival and did not suppress anti-EC antibody production. These results indicated the absolute requirement of L3T4⁺ T cells in the rejection of rat to mouse cardiac xenografts.     

Tissue factor in plasma of patients with disseminated intravascular coagulation

Recently it has been shown that tissue factor (TF), an important trigger for initiating blood coagulation, is present in the circulating plasma. In order to assess the clinical implications of TF in plasma, plasma concentration of TF was quantitated in 65 patients with disseminated intravascular coagulation (DIC). The mean concentration of plasma TF was elevated in patients with DIC at presentation as compared with healthy subjects (446 ± SD 536 pg/ml vs. 138 ± 51 pg/ml, P < 0.001). Abnormally high levels were found only in 46.2% of the patients, predominantly in patients with non-hematological solid tumors and acute leukemia. Plasma TF did not correlate with hemostatic markers of DIC such as thrombinantithrombin III complex, prothrombin fragment 1 + 2, plasmin-α₂-plasmin inhibitor complex, FDP, D-dimer, or fibrinogen. Serial determinations of plasma TF demonstrated that plasma TF changes roughly in parallel with the course of DIC in most patients with elevated TF at presentation of DIC. These findings suggest that plasma TF is potentially valuable for monitoring the progress of DIC in a limited population of patients. © 1994 Wiley-Liss, Inc.     

Selective jugular cannulation for hypothermic retrograde cerebral perfusion in thoracic aortic operations (reverse over the wire-catheter method)]

We have employed hypothermic retrograde total body perfusion via the caval cannulae as a supportive measures to protect the brain and other systemic organs in operations for aortic arch aneurysms or acute aortic dissection. But occasionally unsatisfactory results ensued, because competent valves located in the internal jugular vein near the jugulo-subclavian junction may block retrograde blood flow to the brain from the caval cannula. To cope with this problem, we designed an easy and safe method to cannulate the internal jugular vein transatrially utilizing guidewire and central venous catheter, and thereafter we have used this technique clinically and obtained good results.