Favourable swallowing outcomes after subtotal glossectomy with laryngeal suspension.

Subtotal or total glossectomy for advanced tongue cancer has an adverse impact on swallowing. The purpose of this retrospective study was to analyse postoperative swallowing outcomes and to determine the ideal reconstruction method in these patients. The clinical and swallowing data of patients with tongue cancer who underwent subtotal glossectomy at the study institution between 2005 and 2019 were reviewed retrospectively. Data were available for 101 patients. The most common reconstruction method was a free rectus abdominis musculocutaneous flap (69 cases). The postoperative feeding tube dependency rate was 11.1% at discharge and 9.4% at 1 year. During the study period, laryngeal suspension and/or a cricopharyngeal myotomy was performed in 39 patients (38.6%), with 25 of these operations performed after 2017. Patients treated in 2017-2019 were significantly more able to take thin liquid (P < 0.001) and lost less weight (P = 0.015) compared to those treated in 2005-2016. Multivariate analysis of 61 patients who did not undergo laryngeal suspension and/or cricopharyngeal myotomy showed significant feeding tube dependency in those aged 65 years and older (P = 0.004). Thin liquid intake was significantly improved after subtotal glossectomy with laryngeal suspension, which led to better postoperative swallowing and improved quality of life.

The medaka rs-3 locus required for scale development encodes ectodysplasin-A receptor.

The bodies of most teleost fish species are covered with specialized subepithelial structures known as scales. The scale is an epithelial appendage that differentiates from the dermal mesenchyme. Mammals, on the other hand, have no scales, but instead their bodies are covered with hair. Although their appearances are quite different, scales and hair can be considered structurally similar in that both of them are epithelial appendages distributed over the body surface in an orderly pattern. This analogy suggests that they may have the same evolutionary origin. But, to date, no molecular evidence has been presented that links scales and hair. A mutation at the rs-3 locus of medaka (Oryzias latipes) leads to almost complete loss of scales. We demonstrated that the rs-3 locus encodes ectodysplasin-A receptor (EDAR), which is required for the initiation of hair development in mammals. We identified a novel transposon inserted in the first intron of EDAR, which causes aberrant splicing. This work shows that EDAR is required for scale development in fish and suggests that it is an evolutionarily conserved molecule that is required for the development of epithelial appendages in vertebrates.

Ixodes philipi (Acari: Ixodidae): phylogenetic status inferred from mitochondrial cytochrome oxidase subunit I gene sequence comparison.

Ixodes philipi ticks were collected from the nest burrows of streaked shearwaters, Calonectris luecomelas, on 3 different islands of Japan (Awashima: 38 degrees 45'N, 139 degrees 24'E; Mikurajima: 33 degrees 52'N, 139 degrees 36'E; and Omorijima: 36 degrees 8'N, 133 degrees 10'E). The mitochondrial cytochrome oxidase subunit I (COI) gene sequence was determined for each tick. The COI sequences of 9 other ixodid tick species also were determined, and they were used for taxonomic positioning of I. philipi. A metastriata tick, Amblyomma triguttatum, was used as an outgroup reference for the analysis. Phylogenetic examination indicated that the I. philipi ticks are on the branch with Ixodes turdus and Ixodes acutitarsus weakly, and the bootstrap value of this branching was low. Three different analyses, maximum parsimony, genetic distance, and maximum likelihood, support this conclusion. To further refine this analysis, 2761 base pairs (bp) of sequence, which included the genes for tRNA(Met), NADH dehydrogenase subunit 2 (ND2), tRNA(Trp), tRNA(Cys), tRNA(Tyr), and COI, were determined and compared for 6 I. philipi ticks from the 3 different collection sites. Although a base substitution (T to C in the ND2 gene for an Awashima tick) and 2 transitions (G to A in the COI gene for 1 Omorijima tick) have occurred, the overall sequences were highly conserved. Preserved mitochondrial sequences in the ticks from 3 widely separated locations suggest the possibility of gene flow, which was probably accomplished by migratory seabirds.

Compressive force induces osteoblast apoptosis via caspase-8.

Periodontal remodeling during orthodontic tooth movement is a result of mechanical stresses. The application of excessive orthodontic force induces cell death. However, the nature of compressive force-induced cell death is unclear. We examined whether the in vitro application of continuous compressive force would induce apoptosis in human osteoblast-like cells (MG-63 cells), and investigated the mechanism by which apoptosis was initiated. The cells became aligned irregularly, and cell viability decreased, indicating that the compressive force caused cell death. According to the TUNEL analysis, the number of apoptotic cells increased significantly in a time-and force-dependent manner. Caspase-3 activity increased with the magnitude of the compressive force, and this effect was reduced significantly by a caspase-8 inhibitor, whereas a caspase-9 inhibitor had no such effect. We conclude that the in vitro application of compressive force can induce apoptosis in MG-63 cells through the activation of caspase-3 via the caspase-8 signaling cascade.

Clodronate inhibits PGE(2) production in compressed periodontal ligament cells.

Periodontal ligament (PDL) cells play an essential role in orthodontic tooth movement. We recently reported that clodronate, a non-N-containing bisphosphonate, strongly inhibited tooth movement in rats, and thus could be a useful adjunct for orthodontic treatment. However, it is not clear how clodronate affects the responses of PDL cells to orthodontic force. In this study, we hypothesized that clodronate prevents the mechanical stress-induced production of prostaglandin E(2) (PGE(2)), interleukin-1beta (IL-1beta), and nitric oxide (NO) in human PDL cells. A compressive stimulus caused a striking increase in PGE(2) production, while the responses of IL-1beta and NO were less marked. Clodronate concentration-dependently inhibited the stress-induced production of PGE(2). Clodronate also strongly inhibited stress-induced gene expression for COX-2 and RANKL. These results suggest that the inhibitory effects of clodronate on tooth movement and osteoclasts may be due, at least in part, to the inhibition of COX-2-dependent PGE(2) production and RANKL expression in PDL cells.

Cyclical tensile force on periodontal ligament cells inhibits osteoclastogenesis through OPG induction.

The periodontal ligament (PDL) maintains homeostasis of periodontal tissue under mechanical tensile-loading caused by mastication. Occlusal load inhibits atrophic alveolar bone resorption. Previously, we discovered that continuous compressive force on PDL cells induced osteoclastogenesis-supporting activity, with up-regulation of RANKL. We hypothesized that, unlike compression, cyclical tensile force up-regulates OPG expression in PDL cells via TGF-beta up-regulation, and does not induce osteoclastogenesis-supporting activity. PDL cells were mechanically stimulated by cyclical tensile force in vitro. The conditioned media of PDL cells that had been subjected to cyclical tensile force inhibited osteoclastogenesis. Cyclical tensile force up-regulated not only RANKL mRNA expression, but also OPG mRNA expression in PDL cells. Tensile force up-regulated TGF-beta expression in PDL cells as well. Administration of neutralizing antibodies to TGF-beta inhibited OPG up-regulation under cyclical tensile-force stimulation in a dose-dependent manner. Additionally, the osteoclastogenesis-inhibitory effect of the conditioned media of PDL cells under cyclical tensile force was partially rescued by the administration of TGF-beta neutralizing antibodies. In conclusion, tensile force inhibited the osteoclastogenesis-supporting activity of PDL cells by inducing the up-regulation of OPG via TGF-beta stimulation.

Different concanavalin A binding patterns of malignant and nonmalignant mouse mammary epithelia in monolayer culture.

Concanavalin A (Con A) binding of fixed malignant and nonmalignant C3H/He mouse mammary epithelia in monolayer cultures was examined with markers and labels of various sizes. In Con A-mediated hemadsorption, high epithelial cell densities resulted in the adsorbance of more guinea pig red blood cells per culture dish but fewer per cell. Malignant epithelia adsorbed twice as many red blood cells as did nonmalignant cells at the same cell density. Ferritin-Con A tagged the budding particles of mouse mammary tumor virus and other parts of the epithelial surface evenly. Hemadsorption occurred at the particle-free part of the apical membrane. The amount of 125I-Con A bound per dish, however, was not related to cell density but was almost identical for cells from the same source. Nonmalignant cells bound twice as much 125I-Con A as did malignant cells. The calculated association constants of Con A-binding sites on malignant cells, however, were twice as large as those on nonmalignant cells. This explains, at least partly, the greater number of red blood cells adsorbed by malignant cells. Con A-labeled Sepharose 4B beads were not useful for our purposes, and fluorescein isothiocyanate-Con A did not distinguish between malignant and nonmalignant epithelia.

Allelic loss at the predisposing gene locus in spontaneous and chemically induced renal cell carcinomas in the Eker rat.

Hereditary renal carcinoma (RC) in the rat, originally reported by Eker in 1954, is an example of a Mendelian dominant predisposition to a specific cancer in an experimental animal. We previously reported that ionizing radiation induces additional tumors in a linear dose-response relationship, suggesting that in heterozygotes two events (one inherited, one somatic) are necessary to produce tumors. Recently, the predisposing gene has been mapped to rat chromosome 10. This study was designed to examine loss of heterozygosity (LOH) at chromosome 10 in the RCs developed from hybrid F1 rats carrying Eker mutation. In spontaneous RCs, 6 of 10 (60%) showed loss of the wild-type allele covering over 30 cM, consistent with two-hit hypothesis. Individual tumors have different patterns of LOH even from the same kidney, showing independent clonal origins of RCs. In contrast, none of N-ethyl-N-nitrosourea-induced RCs had allelic loss (0 of 9 = 0%, P < 0.01). Thus, the nature of the second event differs between spontaneous and chemically induced tumors in the Eker rat. These results suggest that chemically induced tumors in experimental animals involve intragenic mutations and so do not cause LOH of syntenic markers. Interestingly, 1 of 5 spontaneous pituitary tumors that developed in the Eker rat showed LOH for chromosome 10 markers.

Genetic predisposition to transplacentally induced renal cell carcinomas in the Eker rat.

N-Ethyl-N-nitrosourea-induced transplacental renal carcinogenesis in the rat results primarily in Wilms' tumors, apparently because primitive nephroblasts are the preferred target. Our question is whether N-ethyl-N-nitrosourea-induced mutations in the fetal kidney would increase the number of adult-type renal cell carcinomas in the Eker rat, which is heterozygous for a mutation that predisposes to renal cell carcinoma. Surprisingly, renal cell tumors but no Wilm's tumors began to appear from as early as 1 week after birth. Thus, the inheritance of a renal cell carcinoma mutation determines the specificity of tumor histology even with in utero carcinogenesis.

Renal carcinogenesis, hepatic hemangiomatosis, and embryonic lethality caused by a germ-line Tsc2 mutation in mice.

Germ-line mutations of the human TSC2 tumor suppressor gene cause tuberous sclerosis (TSC), a disease characterized by the development of hamartomas in various organs. In the Eker rat, however, a germ-line Tsc2 mutation gives rise to renal cell carcinomas with a complete penetrance. The molecular mechanism for this phenotypic difference between man and rat is currently unknown, and the physiological function of the TSC2/Tsc2 product (tuberin) is not fully understood. To investigate these unsolved problems, we have generated a Tsc2 mutant mouse. Tsc2 heterozygous mutant (Tsc2+/-) mice developed renal carcinomas with a complete penetrance, as seen in the Eker rat, but not the angiomyolipomas characteristic of human TSC, confirming the existence of a species-specific mechanism of tumorigenesis caused by tuberin deficiency. Unexpectedly, approximately 80% of Tsc2+/- mice also developed hepatic hemangiomas that are not observed in either TSC or the Eker rat. Tsc2 homozygous (Tsc2-/-) mutants died around embryonic day 10.5, indicating an essential function for tuberin in mouse embryonic development. Some Tsc2-/- embryos exhibited an unclosed neural tube and/or thickened myocardium. The latter is associated with increased cell density that may be a reflection of loss of a growth-suppressive function of tuberin. The mouse strain described here should provide a valuable experimental model to analyze the function of tuberin and its association with tumorigenesis.

Hyperlipidemia enhancement of renal preneoplasia but not tumor formation is due to elevated apoptosis in the Eker rat.

The influence of a high-fat diet on the appearance of renal tumors was assessed in the Eker rat model of hereditary renal carcinoma. Examination of H&E-stained sections showed a significant increase in the number of microscopic solid adenomas in the high-fat group compared with the low-fat group, whereas there was no significant difference in the number of macroscopic tumors between the two groups. Where had the tumor buds gone? Staining for apoptotic bodies occasionally revealed apoptosis in and around the microscopic adenomas. In addition, an Eker rat renal tumor-derived cell line showed apoptosis when it was cultured with high concentrations of native and acetylated low-density lipoprotein. These findings suggested that tumor buds repeatedly appeared and disappeared in Eker rats on a high-fat diet.

Quantitative alterations of hyaluronan and dermatan sulfate in the hairless mouse dorsal skin exposed to chronic UV irradiation.

The quantitative alterations of hyaluronan and dermatan sulfate in the upper dermis (fibrous tissue) and the lower dermis (adipose tissue) of the hairless mouse skin chronically exposed to the UV irradiation as solar-simulating irradiation (lambda(max) 352 nm, UV distribution: 300-310 nm, 0.9%; 310-320 nm, 2.0%; 320-420 nm, 97.1%) were evaluated. Hyaluronan and dermatan sulfate contents in each part of dermis were determined as follows: skin sections on a glass slide prepared by histological technique were processed into the upper dermis and the lower dermis with a small surgical knife, and treated with chondroitinase ABC and ACII in the presence of bacterial collagenase. The resulting unsaturated disaccharides were determined by HPLC method. By applying this method to the UV-irradiated hairless mouse skin, it was found that the chronic UV irradiation increased dermatan sulfate in the upper dermis, whereas an increase of hyaluronan content was not statistically significant. In the lower dermis, on the contrary, both hyaluronan and dermatan sulfate contents remarkably increased as compared with the control mice. Furthermore, the histological study showed the accumulation of the collagen fibers in the lower dermis of the UV-irradiated hairless mouse skin following the disappearance of adipocytes. These findings indicate that the increases of glycosaminoglycan contents in the UV-irradiated skin are related to the accumulation of the extracellular matrix components in the lower dermis.

A detailed linkage map of medaka, Oryzias latipes: comparative genomics and genome evolution.

We mapped 633 markers (488 AFLPs, 28 RAPDs, 34 IRSs, 75 ESTs, 4 STSs, and 4 phenotypic markers) for the Medaka Oryzias latipes, a teleost fish of the order Beloniformes. Linkage was determined using a reference typing DNA panel from 39 cell lines derived from backcross progeny. This panel provided unlimited DNA for the accumulation of mapping data. The total map length of Medaka was 1354.5 cM and 24 linkage groups were detected, corresponding to the haploid chromosome number of the organism. Thirteen to 49 markers for each linkage group were obtained. Conserved synteny between Medaka and zebrafish was observed for 2 independent linkage groups. Unlike zebrafish, however, the Medaka linkage map showed obvious restriction of recombination on the linkage group containing the male-determining region (Y) locus compared to the autosomal chromosomes.

Large-scale isolation of ESTs from medaka embryos and its application to medaka developmental genetics.

The medaka is becoming an attractive model organism for the study of vertebrate early development and organogenesis and large-scale mutagenesis projects that are aimed at creating developmentally defective mutants are now being conducted by several groups in Japan. To strengthen the study of medaka developmental genetics, we have conducted a large-scale isolation of ESTs from medaka embryos and developed tools that facilitate mutant analysis. In this study, we have characterized a total of 132,082 sequences from both ends of cloned insert cDNAs from libraries generated at different stages of medaka embryo development. Clustering analysis with 3-prime sequences finally identified a total of 12,429 clusters. As a pilot analysis, 924 clusters were subjected to in situ hybridization to determine the spatial localization of their transcripts. Using EST sequence data generated in the present study, a 60-mer oligonucleotide microarray with 8,091 unigenes (Medaka Microarray 8K) was constructed and tested for its usefulness in expression profiling. Furthermore, we have developed a rapid and reliable mutant mapping system using a set of mapped EST markers (M-marker 2003) that covers the entire medaka genome. These resources will accelerate medaka mutant analyses and make an important contribution to the medaka genome project.

Osteoclastogenic activity during mandibular distraction osteogenesis.

Mandibular distraction osteogenesis is a well-developed clinical modality for the treatment of craniofacial deformities and dental arch discrepancies, in combination with orthodontic treatment. However, in our previous study, orthodontic tooth movement into the distraction gap caused severe root resorption. The present study aimed to clarify the osteoclastogenic activity of cells in the distraction gap. We hypothesized that the gene expression of osteoclastogenic- and osteoclast-supporting molecules in osteoblasts and stromal cells would increase at distraction sites during the consolidation period. An animal model experiment involving rabbits was designed for mandibular distraction osteogenesis and subjected to in situ hybridization analysis. The number of osteoclasts was larger in the distraction gap during the early consolidation period than in normal controls, due to an increase of gene expression for osteoclastogenic cytokines in osteoblasts. It was concluded that osteoclastogenic and osteoclastic activities are stimulated at distraction sites during the early consolidation period.

[Successful removal of an intrapulmonary aberrant needle under video-assisted thoracoscopic surgery; report of a case].

Intrapulmonary aberrant needles are rare in clinical practice. We report the successful removal of intrapulmonary aberrant needle. A 59-year-old man, though he was asymptomatic, was referred to our department after an abnormal shadow had been detected on a chest X-ray. Chest X-ray and chest computed tomography (CT) showed a foreign body suspected to be a metal artifact in the left upper lobe. It was diagnosed as an intrapulmonary aberrant needle and an operation under video-assisted thoracoscopic surgery was performed. Using perioperative fluoroscopy, we could confirm the location of the needle and remove it successfully. An intrapulmonary aberrant needle should be removed surgically, even if the patient is asymptomatic, due to the development of lung abscess or pyothorax and the risk containing harmful matter to health.

Novel cerebral lesions in the Eker rat model of tuberous sclerosis: cortical tuber and anaplastic ganglioglioma.

The Eker rat is a model for human tuberous sclerosis (TSC) caused by a mutation in the Tsc2 gene. We describe here histological and immunohistochemical findings of the brain lesions in Eker rats, with emphasis on 2 novel lesions found in this study: a cortical tuber and an anaplastic ganglioglioma. The rat cortical tuber resembled those of humans, and further confirmed the value of this animal model as a tool for investigating the molecular pathology of tuberous sclerosis. On the other hand, the rat anaplastic ganglioglioma had features of a malignant neoplasm that are absent from human subependymal giant cell astrocytomas.

Identification and characterization of two distinct GnRH receptor subtypes in a teleost, the medaka Oryzias latipes.

We report the identification and characterization of two distinct GnRH receptor (GnRH-R) subtypes, designated GnRH-R1 and GnRH-R2, in a model teleost, the medaka Oryzias latipes. These seven-transmembrane receptors of the medaka contain a cytoplasmic C-terminal tail, which has been found in all other nonmammalian GnRH-Rs cloned to date. The GnRH-R1 gene is composed of three exons separated by two introns, whereas the GnRH-R2 gene has an additional intron and therefore consists of four exons and three introns. The GnRH-R1 and GnRH-R2 genes, both of which exist as single-copy genes in the medaka genome, were mapped to linkage groups 3 and 16, respectively. Inositol phosphate assays using COS-7 cells transfected with GnRH-R1 and GnRH-R2 demonstrated that they had remarkably different ligand sensitivities, although both receptors showed highest preference for chicken-II-type GnRH. Phylogenetic analysis showed the presence of three paralogous lineages for vertebrate GnRH-Rs and indicated that neither GnRH-R1 nor GnRH-R2 is the medaka ortholog to mammalian GnRH-Rs that lack a cytoplasmic tail. This, together with an observation that medaka-type GnRH had low affinity for GnRH-R1 and GnRH-R2, suggests that a third GnRH-R may exist in the medaka.

Effects of expansive force on the differentiation of midpalatal suture cartilage in rats.

In an attempt to clarify the effects of biomechanical tensional force on chondrogenic and osteogenic differentiation of secondary cartilage, the midpalatal sutures of 4-week-old Wistar male rats were expanded by orthodontic wires which applied 20 g force for 4, 7, 10, and 14 days. The differentiation pathways in the midpalatal suture cartilage were examined by immunohistochemistry for osteocalcin, type I and type II collagen, and von Kossa histochemistry. Although the midpalatal sutures of the control animals consisted mainly of two separate secondary cartilages with mesenchyme-like cells at their midlines, type I collagen-rich fibrous tissue began to appear at day 4 and increased at the midline of the cartilage with days of experiment. At the end of the experiment, type I collagen-rich and calcified bone matrix appeared at the boundary between the precartilaginous and the cartilaginous cell layers. Most of the cartilaginous tissues were separated from each other and the midpalatal suture was replaced by osteocalcin-positive intramembranous bone and fibrous sutural tissue. These results strongly suggest that tensional force changed the phenotypic expression of collagenous components in secondary cartilage, which may reflect the differentiation pathway of osteochondro progenitor cells.

Serial automated three-dimensional intravascular ultrasound analysis of the self-expanding Radius stent.

Automated 3-dimensional intravascular ultrasound (IVUS) analysis was used to assess status of the treated coronary artery immediately and 6 months after placement of a self-expanding Radius stent in 15 patients. Serial 3-dimensional IVUS analysis demonstrated gradual stent expansion that countered neointimal proliferation and preserved the lumen.