Cyclopentadithiophene (CPDT) dimer dication: bipolaron model for quaterthiophenes.

[structure: see text] Cyclopentadithiophene (CPDT) dimers in which both 3,3' and 4' ',3' " positions were bridged with 1,3-dioxalane, carbonyl, or dicyanovinylidene were prepared. These compounds have small HOMO-LUMO gaps (1.03-2.25 eV). The electrochemical oxidation of a dicyanovinylidene-bridged CPDT dimer gave a dication that had a quinoid-like structure.

Immunohistochemical analysis of cytokeratin expression in dog skin.

The expression of cytokeratins and involucrin was analyzed to identify the skin cells which compose the epidermis of dogs. The distribution of cytokeratins and involucrin in normal dog skin was immunohistochemically examined with 27 commercial monoclonal antibodies for human use. Antibodies, No.4. OV-TL12/13, 35betaH11, 4.1.18, CAM5.2, NCL5D3, Ks.13.1, Ks.18.04, Ks.19.1, 170.2.]4 and Ks.20.8 stained hair follicles and/or the sweat gland duct, but not the epidermis. Antibodies, 34betaB4, AE3, 34betaE12. LP34, RCK102, MNF116, AE1, KLI, DE-K10 and DE-K13 reacted with every layer of the epidermis, hair follicles and the sweat gland duct. These results were similar to those reported in the human skin. No positive staining, however, could be detected in the epidermis, hair follicles and the sweat gland duct with commercial antibodies, 6B10, Ks.7.18, Mu146-uc, E3, RCK108 and involucrin. Therefore, immunohistochemical investigation with these commercial antibodies developed for human skin examination might be available for investigating the origin of skin tumors in dogs.

Synthesis and preliminary testing of molecular wires and devices.

Presented here are several convergent synthetic routes to conjugated oligo(phenylene ethynylene)s. Some of these oligomers are free of functional groups, while others possess donor groups, acceptor groups, porphyrin interiors, and other heterocyclic interiors for various potential transmission and digital device applications. The syntheses of oligo(phenylene ethynylene)s with a variety of end groups for attachment to numerous metal probes and surfaces are presented. Some of the functionalized molecular systems showed linear, wire-like, current versus voltage (I(V)) responses, while others exhibited nonlinear I(V) curves for negative differential resistance (NDR) and molecular random access memory effects. Finally, the syntheses of functionalized oligomers are described that can form self-assembled monolayers on metallic electrodes that reduce the Schottky barriers. Information from the Schottky barrier studies can provide useful insight into molecular alligator clip optimizations for molecular electronics.

A comparison of prednisolone and methylprednisolone for renal transplantation.

A large difference in immunosuppressive potency between methylprednisolone and prednisolone has been suggested in vitro. However, the selection of the best glucocorticoid for renal transplantation has been seldom considered so far. Thus, the present study was undertaken to compare therapeutic efficacy between prednisolone and methylprednisolone in renal transplantation. We studied 42 renal transplant recipients who were operated on between 1990 and 1994. The patients were divided into two treatment groups: a methylprednisolone/ cyclosporine group (n = 19) and a prednisolone/cyclosporine group (n = 23). Clinical outcome and drug side effects were compared retrospectively between the treatment groups 24-84 months after transplantation. The overall graft survival time in patients treated with methylprednisolone/cyclosporine was superior to that in patients treated with prednisolone/cyclosporine (p < 0.05). Among the recipients from cadaver donors, 5/16 (31.3%) treated with prednisolone required nephrectomy, whereas none of the 10 patients treated with methylprednisolone received nephrectomy (p < 0.01). An examination of the recipients from living related donors revealed that serum creatinine levels 24-36 months after operation were significantly lower in the methylprednisolone group (p < 0.05). Cyclosporine trough levels and glucocorticoid side effects were similar between the treatment groups. The results raised the possibility that methylprednisolone is superior to prednisolone when combined with cyclosporine for maintenance immunosuppressive therapy in renal transplantation.

Lymphocyte-sensitivity to glucocorticoid correlates with the sensitivity to cyclosporin A and tacrolimus in chronic renal failure patients.

AIMS: Association between lymphocyte-sensitivity to immunosuppressants in transplant recipients in vitro and clinical outcomes has been demonstrated. In general, renal transplant recipients are treated with a combination of immunosuppressants such as either glucocorticoid/cyclosporin A (CsA) or glucocorticoid/tacrolimus (FK506) but the pharmacological complementarity of these drugs is still controversial. We examined relationships between the lymphocyte-sensitivities to these immunosuppressants. METHODS: We examined lymphocyte-sensitivities to prednisolone (PSL), CsA, and FK506 in vitro in a total of 190 chronic renal failure (CRF) patients and 140 healthy subjects. The lymphocyte-sensitivity was evaluated from the IC50 value against mitogen-stimulated lymphocyte-blastogenesis in vitro. RESULTS: Statistically significant correlations of the IC50 values in CRF patients between the following pairs of drugs were observed: PSL and CsA (P<0.0001; n=129, r=0.419), PSL and FK506 (P<0.001; n=54, r=0. 441), and CsA and FK506 (P<0.0001; n=45, r=0.608). Similar correlations were also observed in lymphocytes from healthy subjects. The population of CRF patients who exhibited high IC50 values (low sensitivities) to PSL and FK506 was significantly larger than that of healthy subjects (P<0.05). CONCLUSIONS: Patients who showed low lymphocyte-sensitivity to either of the drugs also may exhibit low sensitivity to the others, and thus they may have a high risk of unsatisfactory outcome under combination therapy after renal transplantation. To overcome this risk, the selection of immunosuppressants is recommended to be restricted according to individual lymphocyte-sensitivities to these drugs in vitro, or alternatively, by addition of other drugs with different mechanisms for immunosuppression.

The effects of nitric oxide on shock caused by temporary hepatic inflow occlusion in pigs.

BACKGROUND/AIMS: Nitric oxide (NO) plays an important role in the regulation of systemic hemodynamics in various shock status. The effect of NO on shock induced by hepatic inflow occlusion has not been previously investigated. METHODOLOGY: We examined the effects of NO on systemic hemodynamics and oxygen metabolism in shock caused by temporary hepatic inflow occlusion without bypass in pigs using NO synthase inhibitor, NG-nitro-L-arginine methyl ester (NAME group) and the substrate for NO synthesis, L-arginine (ARG group). RESULTS: All animals in the control and ARG group tolerated the surgery, while 2 of 5 animals in the NAME group died during the occlusion period. Cardiac output and mixed venous oxygen saturation (SvO2) in the NAME group was significantly reduced compared with the other two groups during and after hepatic inflow occlusion. In contrast, SvO2 in the ARG group was maintained at higher levels throughout the study period, and the recovery time of cardiac output following reperfusion was earlier than that of the other two groups. CONCLUSIONS: Endogenous NO inhibition exacerbates the shock status induced by hepatic inflow occlusion. Exogenous administration of NO donor may improve the shock status induced by hepatic inflow occlusion.

Role of machine perfusion preservation in kidney transplantation from non-heartbeating donors.

The shortage of kidneys for transplantation is a universal problem. If the viability of the kidney can be assured, organ procurement from non-heartbeating donors will be greatly enhanced. This study evaluates the usefulness of machine perfusion preservation parameters as an index of kidney graft viability. We report our experience with 77 non-heartbeating donor kidneys preserved with machine perfusion technique. Sixty-eight grafts demonstrated excellent perfusion (mean flow 0.79 ml/min/g) with low vascular resistance (55.4 mmHg/ml/min/g). Early graft function occurred in all of these kidneys. Nine kidneys demonstrated poor perfusion (mean flow 0.35 ml/min/g) and elevated pressures with high vascular resistance (132.5 mmHg/ml/min/g). Four kidneys with poor perfusion and elevated pressures was discarded after perfusion. The four mates of these discarded at our center were primarily non-functional when transplanted at another transplant center. All five of the poorly perfused kidneys experienced primary non-function. We conclude that the use of quantitative values of perfusion flow (> 0.4 ml/min/g) and no increased pressure pattern allow safe utilization of grafts from non-heartbeating donors and can predict early postoperative function.