Tolerance induced by thymic epithelial grafts in birds.

Grafts of the anterior limb bud introduced at embryonic day 4 between histoincompatible chick embryos were subject to chronic, mild rejection beginning from several weeks to several months after birth. In contrast, quail wing buds similarly grafted into chickens started to be rejected at the first or second week after birth and finally autoamputated. Embryonic thymus epithelium from donor quail (before it had been colonized by hemopoietic cells) was grafted into chicks. A chimeric thymic epithelial stroma was generated in which the lymphocytes of the chick acquired the capacity to recognize the grafted limb as self either permanently or for a protracted period of time. In such thymic chimeras the grafted wings were not rejected.

Further characterization of the binding of plasminogen to heparin: evidence for the involvement of lysine residues.

We have previously demonstrated that the heparin-binding site of plasminogen is located in Val442-plasminogen region (kringle 5 domain plus light (B) chain) (Soeda, S., Kakiki, M., Shimeno, H., and Nagamatsu, A. (1987) Biochim. Biophys. Acta 916, 279-287). The chemical modification of Val442-plasminogen with a lysine reagent, pyridoxal 5'-phosphate (PLP), and sodium borohydride resulted in the incorporation of 8-10 PLP moieties per molecule of the zymogen. This PLP-labeled zymogen had no affinity for a heparin-Sepharose column, whereas the non-labeled one bound to the column. Modification in the presence of heparin decreased the extent of labeling by 1-2 mol of PLP per mol of Val442-plasminogen. To further examine the binding site of plasminogen to heparin, functionally active A and B chains were separated from Lys-plasmin after mild reduction and S-carboxymethylation. Only B chain possessed affinity for heparin-Sepharose. Furthermore, plasmin(ogen) bound to heparin was protected from alpha 2-antiplasmin inhibition. These results indicate that one or two lysine residues located in the catalytic region (B chain) of plasmin(ogen) are essential to heparin binding, and that the binding of plasminogen to heparin or heparin-like substance in extracellular matrix environments may be important for the localization and activation of plasminogen and for the prolongation of the resultant plasmin activity.

Comparison of biliary excretion and metabolism of lithocholic acid and its sulfate and glucuronide conjugates in rats.

Biliary excretion and biotransformation of tracer doses of [14C]lithocholic acid and its sulfate and glucuronide intravenously injected into bile-drainaged rats were compared. Biliary excretion efficiency was in the order of unconjugate sulfate glucuronide and all conjugates were completely excreted into bile within 60 min after injection. Only tracer doses of radioactivity were found in the liver and urine. About 90% of radiolabeled bile acids in bile were conjugated with taurine immediately after injection of lithocholic acid, whereas lithocholic acid-glucuronide was only partly conjugated with taurine all the time (less than 6%) and excreted into bile mainly as native compound. In the first 10 min, 66% of lithocholic acid-sulfate was conjugated with taurine and it gradually proceeded up to 87%. Hydroxylation at C-6 and C-7 positions of lithocholic acid proceeded time-dependently up to 45%. No hydroxylation was observed with lithocholic acid-sulfate or glucuronide. Differences of biliary excretion rate of these conjugates may be one of the reasons for the delayed decrease of sulfated and glucuronidated bile acids in serum after bile drainage to patients with obstructive jaundice of during the recovery of acute hepatitis than non-esterified bile acids.

Cholestasis induced by lithocholate and its glucuronide: their biliary excretion and metabolism.

We studied the effects of the infusion of lithocholate and lithocholate-3-sulfate and 3-glucuronide in rats (0.29 mumol/min per 100 g body weight for 40 min) on bile flow, together with their biliary excretion and metabolism. Lithocholate-glucuronide had a higher cholestatic effect than lithocholate, whereas lithocholate-sulfate had almost no effect on bile flow. Lithocholate was mainly converted to taurine or glucuronide conjugates in the bile, serum and liver and hydroxylation of the tauro-conjugate proceeded. Lithocholate-sulfate was almost completely excreted in the bile, mainly as tauro-conjugate. Lithocholate-glucuronide was excreted in bile almost without conjugation, while some taurine conjugation occurred in the serum and liver. These results suggest that the poor biotransformation of lithocholate-glucuronide is related to its higher cholestatic potency than lithocholate.

Synthesis of taurine- and/or acetyl group-conjugated poly(D-Glu, D-Lys) derivatives and their effects on fibrinolysis.

A series of C-sulfoethylated and/or N-acetylated poly(D-Glu, D-Lys) (polyGL) derivatives was synthesized and their effects on tissue-type plasminogen activator (t-PA)-induced fibrinolysis were investigated. These derivatives accelerated t-PA-induced plasma (fibrin) clot lysis and t-PA-catalyzed plasminogen activation with the following order of potency: C-sulfoethylated and N-acetylated polyGL greater than N-acetylated polyGL greater than C-sulfoethylated polyGL greater than polyGL. The most potent stimulator C-sulfoethylated and N-acetylated polyGL associated with both t-PA and plasminogen under low ionic conditions, whereas it did not prevent the bindings of t-PA and plasminogen to fibrin. These results suggest that t-PA and plasminogen preferentially bind to sulfated or carboxylated polyanions, which may be required to possess certain neutral groups, and such complex formation may improve the plasminogen activation kinetics in a different manner from that of fibrin.

Initiation of alveolar ridge augmentation in the rat mandible by subperiosteal implantation of octacalcium phosphate.

The study was designed to investigate the process of bone formation caused by implantation of octacalcium phosphate as well as stability of the bone formed at the alveolar ridge. Synthetic octacalcium phosphate was implanted into a subperiosteal pocket in the rat mandible. Bone formation at the alveolar ridge was examined radiographically and histologically between 1 and 48 week(s) after implantation. Radiopacity of the octacalcium phosphate implant became obvious in week 2. Osteogenesis was initiated from the bone surface near the implantation site and multinucleated giant cells appeared on the implanted octacalcium phosphate in week 1. More apposition of new bone was observed on the implanted octacalcium phosphate in week 2 or later. Some implants were directly enclosed by newly formed bone and no cellular component was seen between the implant and the bone matrix. Many octacalcium phosphate implants were enclosed by bone, whereas the augmented ridge was not seen radiographically in week 24 or later. If its persistence can be improved, octacalcium phosphate could be used to augment atrophic alveolar ridges.

Effect of lavage with injection of sodium hyaluronate for patients with nonreducing disk displacement of the temporomandibular joint.

OBJECTIVE: The purpose of this study was to determine whether lavaging of the superior joint space with injection of sodium hyaluronate can be used as an alternative treatment method for nonreducing disk displacement of the temporomandibular joint. STUDY DESIGN: In 26 patients with nonreducing disk displacement of the temporomandibular joint, the superior joint space was rinsed with 1% xylocaine, and then sodium hyaluronate was injected there (experimental group). As a control group, 50 patients with nonreducing disk displacement of the temporomandibular joint who received no treatment were used (control group). The frequency of the patients with successful clinical resolution was evaluated in each group during 6 months. RESULTS: The frequency of the patients with successful clinical resolution in the experimental group (73.1%) was significantly higher than that in the control group (36.0%) at the 6-month follow-up (chi-squared test, p < 0.05). CONCLUSIONS: This therapy appears to represent an alternative treatment method for nonreducing disk displacement of the temporomandibular joint.

Intraoral reconstruction with innervated forearm flap: a comparison of sensibility and reinnervation in innervated versus noninnervated forearm flap.

OBJECTIVE: To evaluate the cutaneous sensibility and sensory reinnervation in patients who underwent intraoral reconstruction with an innervated or noninnervated forearm flap. STUDY DESIGN: Results of the use of innervated forearm flaps in oral reconstruction was compared with the use of noninnervated flaps. The evaluation of sensibility and reinnervation comprised clinical sensibility tests and immunohistochemical investigation of postoperative biopsy specimens against S-100 and neurofilament. RESULTS: The innervated flaps (4 patients) provided earlier and qualitatively better recovery of sensation than the noninnervated flaps (9 patients). Immunohistochemical investigation revealed the existence of a larger number of regularly arranged sensory nerve fibers in the cutaneous tissue of the innervated flaps than in the noninnervated flaps. Examination with an electron microscope found the structure of these nerve fibers to be well preserved in the innervated flaps, whereas nerve fibers in the noninnervated flaps were degenerative. CONCLUSION: These findings suggest (1) that the innervated flaps are superior to the noninnervated flaps not only for the repair of defects but also for the restoration of function and (2) that the innervated flaps contribute to the improvement of the quality of life for patients.

Prosthetic restorations with osseointegrated implants after bone grafts to correct large jaw defects caused by extraction of multi-impacted teeth: a case report.

A case is reported of a 21-year-old Japanese man examined for unerupted molar teeth on the left side of both jaws. Intraoral examination revealed edentulous regions from the second premolar to the molar, with moderate atrophy of the upper alveolar ridge. A panoramic X-ray revealed eight impacted teeth. The impacted mandibular teeth were extracted through decortication and bone replacement. The impacted maxillary teeth were extracted following reflection of a mucoperiosteal flap. The large defects caused by the extractions in both jaws were filled with autogenous cancellous marrow and bone chips. Eleven months later, in the first stage of the Branemark implant procedure, fixtures were placed in the edentulous regions of both jaws, with simultaneous additional corticocancellous block onlay bone grafting in the maxilla to correct slight resorption. After another seven months, second-stage abutment surgery was performed. Occlusion was then restored through a prosthetic procedure. Next, orthodontic treatment was commenced, using the implant supported teeth as an anchor. Despite the slight resorption in the maxilla, implantation was successful and occlusion was restored in the previously edentulous regions. This suggests that application of a simultaneous corticocancellous block onlay bone graft is a valuable basis for implant procedures in the maxilla.

Full-thickness reconstruction of cheek defect involving oral commissure with forearm tendinocutaneous flap.

An 82-year-old man underwent full-thickness reconstruction of the cheek for a defect of the oral commissure resulting from a T3N1M0 squamous cell carcinoma. He had previously had both radiotherapy and chemotherapy. A tendinocutaneous flap from the forearm incorporating palmaris longus was used for static reconstruction. The vermilion was then reconstructed with rotation flaps from the contralateral vermilion. Oral function was restored, and he had no problems with drooling or speech.

Immunohistochemical demonstration of chromogranin A in endocrine organs of the rat and horse by use of region-specific antibodies.

Chromogranin A (CgA) is an acidic glycoprotein that is co-stored with hormones or neurotransmitters in granular components of endocrine cells and neurons, and released together with them in response to adequate stimulation. In addition to acting as a packaging protein, CgA functions as a precursor molecule that yields several bioactive peptides by proteolytic cleavage. The purpose of this study is to elucidate how different the processing of CgA is among endocrine tissues by immunostaining using multiple region-specific antisera, and to evaluate the availability of region-specific antisera. When various endocrine organs of rats were immunostained with four region-specific antisera against rat CgA (CgA 1-28, 94-130, 296-314, and 359-389), all amine/peptide-secreting endocrine tissues except the pineal body were stained positively. The adrenal medulla and gastric endocrine cells were equally intensely immunoreactive to all four antisera, while the other endocrine tissues, represented by pancreatic islets, showed different staining patterns depending on the antiserum. These results suggest that the processing of CgA differs from tissue to tissue. An antiserum against horse CgA 335-365, corresponding to rat CgA 359-389 which shows the highest concentration in the plasma and urine of the rat, again stained all endocrine tissues of the horse except the pineal body. Therefore, the anti-horse CgA 335-365 serum is useful for immunohistochemical survey of horse CgA, and may make possible the establishment of a CgA assay system for the measurement of CgA in the plasma, urine and saliva.

(10)B-NMR determination of (10)B-BPA, (10)B-BPA-fructose complex and total (10)B in blood for BNCT.

First spontaneous, noninvasive determination method of (10)B-BPA, (10)B-BPA-fructose complex, and total (10)B in blood is described. (10)B-NMR measurement with 100,000 FT accumulation enables us to obtain the result within 100min/sample. The detection limits for the simultaneous analysis were 3ppm, 3ppm and 6ppm for (10)B-BPA, (10)B-BPA-fructose complex and total (10)B respectively in this study. By this method, we can actually discuss behavior of the (10)B-BPA-fructose complex in blood.

Biological evaluation of dopamine analogues containing phenylboronic acid group as new boron carriers.

As new BNCT reagents, we designed and synthesized dopamine analogues containing phenylboronic acid group, N-3,4-dihydroxyphenethyl-4-dihydroxyborylbenzamide (dopamine-PCBA) and N-[2-(3,4-dihydroxyphenetyl)ethyl]-3-(4-dihydroxyborylphenyl)promionamide (dopamine-CEBA). The efficacies of these compounds have not been investigated for biological samples. Therefore we have carried out experiments with cultured tumor cells and tumor-bearing mice, and evaluated possibility of these compounds as boron carriers. Dopamine-PCBA and dopamine-CEBA were synthesized by coupling between p-carboxyphenylboronic acid (PCBA) or 4-(2-carboxyethyl)benzeneboronic acid (CEBA) and 3,4-(dibenzyloxy)phenethylamine hydrochloride (DBPA-HCl) followed by catalytic hydrogenation using Pd catalyst. The effect of compounds on cell vitality was determined by MTT assay in various cells. In vivo biodistribution of compounds was determined in Balb/c and DDY mice in bearing implanted CT26 cells. These results have demonstrated that dopamine-CEBA was less toxic.

Unusual radiographic appearance of ossifying fibroma in the left mandibular angle.

Ossifying fibroma is usually a unilocular lesion with a well-defined, thinly corticated margin radiographically, although various patterns have been noted. The patient was a 27-year-old woman with a painless radiolucent lesion demonstrated on panoramic radiography to involve the root-apex area of the left lower second and third molars. Radiographically, the lesion had some features of a benign tumour, such as an odontogenic myxoma. However, the deep invaginations towards the interalveolar septa suggested a simple bone cyst, whereas the irregular margin and lack of expansion or mandibular canal displacement were consistent with a malignant lesion. A hard tissue component was confirmed only by soft-tissue mode CT. Although this lesion was histopathologically diagnosed as ossifying fibroma, the conflicting imaging findings were challenging and very intriguing.