A new schematic for poly(3-alkylthiophene) in an amorphous film studied using a novel structural index in infrared spectroscopy.

The molecular structure of poly(3-alkylthiophene-2,5-diyl) in an amorphous film reveals that the short axis of the thiophene ring is kept highly oriented parallel to the substrate, whereas the long axis along the polymer chain is largely disordered. This is unveiled by infrared p-polarized multiple-angle incidence resolution spectroscopy (pMAIRS), achieved by analyzing the orientation angles of three mutually orthogonal vibrational modes localized on the thiophene ring with the aid of a newly developed structural index. This new analytical technique is useful irrespective of the crystallinity of the thin film. As a result, the intrinsic chemical parameters controlling the molecular orientation are understood in a unified manner, and the reason that the hexyl group gives the best results for a photovoltaic cell is also revealed.

Characterization of new monoclonal antibodies against porcine lymphocytes: molecular characterization of clone 7G3, an antibody reactive with the constant region of the T-cell receptor delta-chains.

A battery of mouse monoclonal antibodies (mAbs) reactive with porcine peripheral blood (PB) leukocytes was generated. Among the mAbs, 6F10 was found to react probably with cluster of differentiation (CD)8 alpha-chain, while 7G3 and 3E12 were found to recognize gammadelta T-cells, as revealed by two-color flow cytometric and immunoprecipitation studies. 7G3 was shown to react with the constant (C) region of the T-cell receptor (TCR) delta-chain by the following facts: (1) 7G3 immunoprecipitated full-length TCR delta-chain protein fused with glutathione S-transferase (GST) produced by Esherichia coli and (2) 7G3 reacted with TCR delta-chain expressing Cos-7 cells transfected with either full-length or N-terminal deleted mutant cDNA, but did not react with Cos-7 cells transfected with C-terminal deleted mutant TCR delta-chain cDNA. All three mAbs produced high-quality immunostaining results on frozen sections, revealing a distinct distribution of gammadelta T-cells and CD8(+) cells. This report precisely characterizes mAbs against porcine TCR for the first time, facilitating molecular biological investigations of the porcine immune system.

Influence of castration on development of the thymus in neonatal male rats.

The influence of castration on the development of the thymus in neonatal rats was studied to elucidate when after birth the thymus comes under inhibitory regulation by the testis in rats. The relative and absolute weights of the thymus were measured five days after castration these cases. No excessive changes in the weights of the thymus with castration were observed by 31 days after birth. Significant changes in the thymus appeared in the relative weight at 36-day-castration. The absolute weight of the thymus was also significantly increased after 41-day-castration. These findings suggest that in rats the inhibitory regulation of the thymus by testis development does not appear before at least 31 days of age.

Pretreatment of human keratinocyte sheets with laminin 5 improves their grafting efficiency.

Laminin 5 is essential in epithelial attachment to stromal tissues, suggesting that it might improve keratinocyte attachment in a variety of clinical situations. In this study, we examined the effect of exogenous laminin 5 upon the efficiency of transplantation of keratinocyte sheets in animal models. Keratinocyte sheets were prepared according to the method of Rheinwald & Green (1975). Purified laminin 5 was added to the sheets of group 1 (1.0 microg per cm2), Dulbecco's modified Eagle's medium alone was added to group 2. The sheets were grafted to the panniculus carnosus of nude mice (BALB/C nu/nu) (n = 12) and nude rats (Fisher 344) (n = 15). The take rate was assessed by measurement of the area of surviving epithelium at 7 d postgrafting. Laminin 5 bound the keratinocyte sheets of group 1. At 7 d postgrafting, the area of epithelialization of group 1 was significantly larger than that of group 2. Immunohistochemistry staining showed that collagen IV, laminin 5, and collagen VII stained more strongly at the dermal-epidermal junction in group 1 than in group 2. Integrin chains alpha6 and beta4 were similar in both groups. Electron microscopy at day 3 after grafting, showed the lamina densa of group 1 to be more continuous than in group 2. Pretreatment of cultured human keratinocyte sheets with laminin 5 improved the extent of epithelial coverage and increased the rate of neobasement membrane formation. The results suggest that laminin 5 promotes epithelial attachment by increasing the rate of basement membrane assembly.

Histodifferentiation of hair follicles in grafting of cell aggregates obtained by rotation culture of embryonic rat skin.

We have previously reported reconstruction of hair follicles from a single cell suspension of rat fetal upper lip by a two-step culture method consisting of rotation and flotation cultures. Rotation sorted out the cells and flotation facilitated histodifferentiation. In the present study, we added grafting procedures to the previous method to see whether cell aggregates obtained this way were graftable, and whether the grafting promoted histodifferentiation. The aggregates before and after flotation were grafted, and differentiation of hair follicles comparable to those in vivo was confirmed 10 days after grafting. There was no difference in the degree of differentiation between the two kinds of grafts. The grafting procedure therefore resulted in an appreciable increase in histodifferentiation even when aggregates obtained after flotation were grafted.

Effect of a collagen matrix containing epidermal growth factor on wound contraction.

Excessive wound contraction is known to lead to pathological wound contracture. Using a rabbit model, we applied a bovine type I collagen matrix sponge as a dermal substitute and human epidermal growth factor to full-thickness excisional wounds. Wound contraction was assessed 14 and 28 days after wounding. It was found that both collagen matrix and epidermal growth factor significantly inhibited wound contraction (p < 0.001) in all wounds treated with collagen matrix alone or treated with 0.1 and 1 microg of epidermal growth factor 28 days after wounding. Interestingly, the combination of collagen matrix with epidermal growth factor strongly inhibited wound contraction over matrix alone (p < 0.01 on day 28). Histological analyses showed a regular horizontal arrangement of collagen fibers in the dermis under wounds treated with these substances but not under untreated wounds. Furthermore, using a fibroblast-populated collagen gel, the direct inhibitory effect of epidermal growth factor on gel contraction by fibroblasts was also observed. Collagen gels without stimulation contracted to 29.5 +/- 0. 6% of their original size, as determined 6 days after culturing. At 3 days or more, epidermal growth factor inhibited collagen gel contraction by fibroblasts (after 6 days: 34.2 +/- 1.8%, p > 0.05; 36.5 +/- 2.8%, p < 0.05; and 39.8 +/- 2.1%, p < 0.001 at 1, 10, and 100 ng/ml of epidermal growth factor, respectively). In conclusion, collagen matrix and epidermal growth factor, particularly in combination, may be useful in the prevention of wound contracture.

In vivo bioactivities and kinetic parameters of rat luteinizing hormone components: discrepancy between in vitro and in vivo assays.

Rat pituitary LH shows an electrical charge heterogeneity owing to their carbohydrate moiety. The biological potencies of these isoelectric components increase with increasing pI when examined by in vitro testosterone production in isolated rat Leydig cells. The present study was carried out to clarify if this tendency was also true with of in vivo action and to estimate their kinetic parameters. Seven isoelectric components of LH, i.e. X (pI 7.9), A (8.4), B (8.8), C (9.1), D (9.3), E (9.6) and F (9.8), were administered to cannulated adult male rats. Blood samples were serially collected over a 5 h period from the conscious animal, and rat LH and testosterone were assayed by RIA. The doses of a single component showed a linear relationship with the areas under the curve (AUC) of the blood LH. The testosterone AUC also correlated well with LH AUC. It was found that the components with lower pIs had longer half-lives and larger LH AUC, and smaller total body clearance rates with highly significant correlation coefficients. The in vivo bioactivities of the components expressed as testosterone AUC increased with decreasing pIs, indicating that the in vivo bioactivity was much influenced by the total body clearance rate. The intrinsic activities of the components were calculated as ratios of testosterone AUC to LH AUC where the effect of the clearance rate (or biological half-life) was eliminated. The intrinsic activities of components were not significantly different among the components except component X which showed a smaller activity. These data indicated that, with the exception of component X, an LH component with a lower pI has a longer biological half-life, resulting in a higher in vivo potency, quite contrary to the tendency of in vitro potency.

Eyelid reconstruction using a vascularized composite flap.

For reconstruction of full-thickness eyelid defects, it is optimal to use the eyelid. As a new surgical technique, we reconstructed these defects using a composite flap with vascular pedicles. A composite flap was prepared using the inferior medial palpebral artery as a nutrient vessel for reconstruction in two cases. After surgery, partial necrosis of the skin in the composite flap occurred, and ciliary loss was observed; however, the tarsoconjunctival layer could be reconstructed, and good results were obtained in terms of function and morphology.

Extended lid-splitting surgery of marginal eyelid defects.

The technique of extended lid-splitting surgery is described. This procedure was used to repair marginal defects of the lower and upper lid, and provided postoperative results that were excellent both functionally and cosmetically, principally because the technique allowed the anatomical structures to be maintained.

Unilateral multiple adenolymphomas originating in the parotid gland: a clinicopathological study.

The validity of Seifert's hypothesis about growth pattern of adenolymphomas has been evaluated in three of five patients with adenolymphomas of the parotid gland, who at the time of a parotidectomy, were found to have multiple unilateral adenolymphomas in the intraglandular lymph nodes. This evaluation, which was based on assessing the epithelial: lymphoid tissue ratio in excised adenolymphomas and the growth in tumor size, showed that there was no association between the histological changes in the epithelial:lymphoid tissue and the tumor size. Adenolymphomas seem to have no consistent growth pattern and develop independently. However, as multiple tumors were detected histopathologically in lymph nodes as small as 5 mm in diameter the importance of a detailed examination of patients with adenolymphomas is stressed, so that other tumours are not overlooked.