Katsunori Ishibashi

Leukoplakia‐associated multiple carcinomas in patients with tongue carcinoma

A series of 522 patients with a diagnosis of squamous cell carcinoma or carcinoma in situ of the tongue were reviewed and followed. Leukoplakia was found in 88 of these patients before and after the diagnosis of tongue carcinoma. A high incidence of multiple carcinomas in the oral cavity and pharynx (116 times greater than expected) was encountered in tongue carcinoma patients. The observed incidence of multiple oral carcinomas in the group with tongue carcinoma with leukoplakia was five times greater than that of the subjects without leukoplakia. The incidence of secondary esophageal carcinomas was also high, 12 times greater than the statistical expection. However, there was no increased occurrence of secondary esophageal carcinomas in the patients with leukoplakia.

Time-dependent Changes of Collagen Crosslinks in the Socket after Tooth Extraction in Rabbits

Time-dependent changes of the reducible collagen crosslinks in the healing tissue of rabbit tooth extraction wounds were analyzed chromatographically. The ratio of dihydroxylysinonorleucine to hydroxylysinonorleucine in the collagen from normal alveolar bone was 4.4. This value increased about four times, on the 10th day after tooth extraction, coinciding with the phase of active woven bone formation, and then decreased rapidly toward a normal value on the 14th day after tooth extraction. The data suggest that active biosynthesis and fibrillogenesis of bone collagen precede the morphological completion of lamellar bone formation.

Pseudogout of the temporomandibular joint. A case report.

A case of pseudogout occurring in the temporomandibular joint of a 76-year-old man is reported. The diagnostic work-up and its differential diagnosis is discussed.

Postnatal changes in the nicotinic acetylcholine receptor subunits in rat masseter muscle

No published study on synaptogenesis in masseter muscle has focused on the shift of nicotinic acetylcholine receptors (nAChRs) from the embryonic type (alpha(2)-, beta-, gamma- and delta-subunits) to the adult-type (alpha(2)-, beta-, epsilon- and delta-subunits) and the elimination of nAChRs outside the neuromuscular junction. To identify the time course of the nAChR transitions in rat masseter muscle between 1 and 63 days of age, the expression of delta-, epsilon- and gamma-subunit mRNAs was analysed by competitive polymerase chain reaction in combination with reverse transcription. The expression of the delta-subunit was high between 1 and 7 days of age, then decreased by 95% (P<0.0001) between 7 and 28 days, suggesting that the nAChR elimination occurs during this period. The quantity of the epsilon-subunit increased by approximately 600% (P<0.0001) between 1 and 21 days of age, whereas the quantity of the gamma-subunit decreased by 85% (P<0.0001) during the same period. This result indicates that the nAChR type shift is terminated at 21 days of age. The feeding behaviour of the rats inevitably changed from suckling to biting after 19 days of age, because they were weaned at that age. As the nAChR type shift was terminated soon after weaning, the termination could be related to the change in feeding behaviour. However, it might also be the case that nAChR elimination is not directly related to the change in feeding behaviour, as the elimination continued at the same rate for 9 days after weaning (from 19 to 28 days of age).

Hyaluronidase activity in human pus from which Streptococcus intermedius was isolated

Hyaluronidase (HAase) activity was detected in both a human pus sample and the culture supernatant of the only bacterial isolate from the pus, Streptococcus intermedius, using a zymographic technique. The optimum pH range for HAase activity was similar for both samples. Although the bands showing the strongest HAase activity of these samples differed from each other with respect to molecular size, both samples were equally inhibited by an antiserum raised against HAase of S. intermedius. These results suggest that S. intermedius may produce HAase in vivo as well as in vitro, and that this enzyme and/or its fragments may play an important role in host tissue degradation.

Changes in the mRNA Expressions of Insulin-like Growth Factors, Their Receptors, and Binding Proteins during the Postnatal Development of Rat Masseter Muscle

Abstract Morphological, biochemical, and functional changes in rat masseter muscle reportedly occur during the shift of rat feeding behavior from suckling to chewing. To determine whether insulin-like growth factors (IGFs), their receptors (IGFRs), and binding proteins (IGFBPs) are involved in the changes in rat masseter muscle during the shift of rat feeding behavior, we analyzed the expressions of IGF-I, IGF-II, IGFR1, IGFR2, and IGFBP1∼6 mRNAs in rat masseter muscle between 0 and 70 days after birth using the competitive, reverse transcriptase-polymerase chain reaction (RT-PCR) method. Between 14 and 19 days of age, sharp falls in the quantities of IGF-I, IGF-II, IGFR1, IGFR2, IGFBP3, IGFBP5, and IGFBP6 mRNAs were observed, whereas the quantity of IGFBP4 mRNA rose sharply during the same period. IGFBP1 and 2 mRNAs were not detectable during the postnatal development. In the present study, the shift of rat feeding behavior from suckling to chewing occurred between 14 and 19 days of age, since the pups took residues of a pellet diet which had been dropped in a cage after 14 days of age, and we removed the pups from the dams and fed them on a pellet diet at 19 days of age. Thus, the drastic changes in the quantities of IGF, IGFR, and IGFBP mRNAs in the rat masseter muscle between 14 and 19 days of age seem to be involved in the shift of rat feeding behavior.

Rectal adenocarcinoma metastatic to the masseter muscle

Muscle is thought to be highly resistant both to involvement by primary and metastatic carcinoma, and it is apparently vulnerable mainly to invasion of malignant tumors from the adjacent tissues. Metastatic tumors to muscle are distinctly uncommon,1-3 although intramuscle metastases have been reported in skeletal muscle,1 the diaphragm,4 the extraocular muscles,5 and the tongue.6,7 Tumors metastatic to the masseter muscle have not been reported in the literature. This report is the first to describe a case of metastatic tumor of the masseter muscle that originated in the rectum.

Chondroma of the hyoid bone: A case report

Chondroma of the hyoid bone is extremely rare. We report the case of a 24-year-old woman with a chondroma of the greater cornu of the hyoid bone. In addition, we discuss the clinical and pathologic differential diagnoses.

Gastrointestinal absorption of insulin-like growth factor in the mouse in the absence of salivary insulin-like growth factor binding protein

Based on previous observations of the presence of both insulin-like growth factors I and II (IGF-I and IGF-II) in murine saliva (kerr et al., Biochem Pharmacol 49: 1521-1531, 1995), the saliva from BALB/c and Non-obese diabetic (NOD) mice was examined for the presence of insulin-like growth factor binding proteins (IGFBPs). Using a western-blot type ligand binding assay with 125I-labeled IGF-I, a series of binding proteins with molecular masses (M), between 25 and 45 kDa were detected in the sera, but not saliva, from both BALB/c and diabetic NOD mice. In the diabetic NOD mice, there were detectable changes in the concentrations of several of the IGFBPs relative to BALB/c mice. Using specific antibody to the binding proteins, one of these was identified as IGFBP-2. Gavage administration of [125I]IGFI indicated substantial uptake from the gastrointestinal tract and significant tissue distribution. There was an increase in serum concentrations of radiolabeled IGF-I in diabetic NOD mice over that in BALB/c mice but less recovered from most of the tissues. Intact 125I-labeled IGF-I was extracted and purified from various tissues, following gavage, and shown to retain biological activity. Thus, the uptake of biologically active IGFs from saliva would appear to take place independently of specific binding proteins.

A Case of Squamous Cell Carcinoma Arising from Branchial Cleft Cyst

Carcinoma arising from the remnant of branchial epithelium or branchial cleft cyst is known as branchiogenic carcinoma. It is very rare, and its existence is a matter of controversy. We report a case of cystic carcinoma of the upper neck that fully met Martins criteria for branchiogenic carcinoma. A 53-year-old male visited Tsurumi University Dental Hospital with a swelling on the left side of the neck. Three tumors were excised from the neck, and histopathology revealed squamous cell carcinoma in a cystic lesion. As metastatic carcinoma of the cervical lymph nodes was suspected, the appropriate clinical tests and imaging were performed to determine the possible presence of a primary tumor. However, no primary carcinoma was found. These findings suggest that this was a case of branchiogenic carcinoma. The patient was treated with radiotherapy and followed up over an 8-year period. No evidence of recurrence was found.