Evaluation by dental cone-beam computed tomography of the incidence and sites of branches of the inferior dental canal that supply mandibular third molars.

Our aim was to assess the incidence and anatomical site of branches of the inferior dental canal that supply mandibular third molars using dental cone-beam computed tomography (CT). We evaluated the incidence and diameter of branches of the inferior dental canal using 272 cone-beam CT mandibular scans from 172 patients referred for imaging before the extraction of impacted mandibular third molars. We found three typical branching patterns from the inferior dental canal in the third molar region: the retromolar canal (in the retromolar triangle), the dental canal (that courses directly beneath the socket of the third molar), and the accessory canal (that courses through the socket and leads from the inferior dental canal to a bony ridge). The incidences of retromolar, dental, and accessory canals were 75 (28%), 223 (82%), and 21 (8%), respectively, with mean diameters of 0.9 (0.4), 0.7 (0.5), and 1.1 (0.4) mm, respectively. Operative injury to the neurovascular contents within the branches of the inferior dental canal can lead to excessive bleeding and postoperative paraesthesia, so identification of its branches on preoperative cone-beam CT images may prove useful during extraction of impacted mandibular third molars or when harvesting bone blocks from the region of mandibular third molars. We also describe two cases of branches detected on panoramic and cone-beam CT images that prompted this research.

Diversity and Distribution of Rice Blast (Pyricularia oryzae Cavara) Races in Bangladesh.

The pathogenicity of 331 blast isolates (Pyricularia oryzae Cavara) collected from different regions and ecosystems for rice cultivation in Bangladesh was evaluated by compatibility on 23 differential varieties (DV), each harboring a single blast resistance gene, and susceptible 'Lijiangxintuanheigu' (LTH). A wide variation in virulence was found among the isolates, and 267 races were classified using a new designation system. Virulence of blast isolates against DV carrying the resistance genes Pia, Pib, Pit, Pik-s, Piz-t, Pi12(t), Pi19(t), and Pi20(t), as well as avirulence against those carrying Pish, Pi9, Pita-2, and Pita, was distributed widely in Bangladesh. Cluster analysis of the compatibility data on the DV initially classified the isolates into groups I and II. The virulence spectra of the two groups differed mainly according to the reactions of the DV to Pii, Pi3, Pi5(t), Pik-m, Pi1, Pik-h, Pik, Pik-p, and Pi7(t). Group I isolates were distributed mainly in rainfed lowlands, whereas group II isolates were found mainly in irrigated lowlands; however, there were no critical differences in geographic distribution of the blast isolates. In total, 26 isolates, which could be used to identify the 23 resistance genes of the DV on the basis of their reaction patterns, were selected as a set of standard differential blast isolates. To our knowledge, this is the first clear demonstration of the diversity and differentiation of blast races in Bangladesh. This information will be used to develop a durable blast protection system in that country.

Diversity and Distribution of Rice Blast (Pyricularia oryzae Cavara) Races in Japan.

In total, 310 rice blast (Pyricularia oryzae Cavara) isolates from Japan showed wide variation in virulence. Virulence on rice (Oryza sativa L.) differential varieties (DV) harboring resistance genes Pish, Pia, Pii, Pi3, Pi5(t), Pik-s, and Pi19(t) ranged from 82.9 to 100.0%. In contrast, virulence on DV possessing Pib, Pit, Pik-m, Pi1, Pik-h, Pik, Pik-p, Pi7(t), Pi9(t), Piz, Piz-5, Piz-t, Pita-2, Pita, Pi12(t), and Pi20(t) ranged from 0 to 21.6%. Cluster analysis using the reaction patterns of the DV classified isolates into three groups: I, virulent to Pik, Pik-h, Pik-p, Pik-m, Pi1, and Pi7(t); IIa, avirulent to the preceding 6 genes and virulent to Pia, Pii, Pi3, and Pi5(t); and IIb, avirulent to all 10 genes. Group I was limited to northern Japan and group IIb to central Japan, while group IIa was distributed throughout Japan. We estimate that group IIa represents the original population and that groups I and IIb arose from it through minor changes in pathogenicity. We classified these isolates into 123 races by a new designation system and conclude that the rice blast races in Japan are less diverse than previously thought.

Treatment results of oral verrucous carcinoma and its biological behavior.

The biologic behavior of and optimal treatment for oral verrucous carcinoma (VC) remain controversial. We analyzed the clinicopathological characteristics of 12 patients with oral VC. Immunohistochemical techniques were used to evaluate p53 protein, CD44 variant 9, and proliferating cell nucleus antigen. The TNM classification (UICC, 1997) was T1 in 1 patient, T2 in 3, T3 in 4, and T4 in 4. All patients were classified as N0M0. Four patients were treated by surgery alone and 8 by surgery after chemotherapy, radiotherapy, or both. After surgery, two patients had primary recurrence of disease. Immunohistochemically, the proliferative activity of tumor cells as evaluated by proliferating cell nuclear antigen labeling index and p53 protein expression was similar in VC and well-differentiated squamous cell carcinoma. However, CD44 varient 9 expression was positive in 8 of 10 VC, suggesting that oral VC is associated with a low risk of lymph node metastasis. Positive CD44 variant 9 expression by most oral VCs, indicating a low risk of cervical lymph node metastasis, suggests that most cases can be controlled by surgical intervention.

Mapping of quantitative trait loci associated with ultraviolet-B resistance in rice (Oryza sativa L.).

The detection of quantitative trait loci (QTLs) associated with UV-B resistance in rice should allow their practical application in breeding for such a complex trait, and may lead to the identification of gene characteristics and functions. Considerable variation in UV-B resistance exists within cultivated rice (Oryza sativa L.), but its detailed genetic control mechanism has not been well elucidated. We detected putative QTLs associated with the resistance to enhanced UV-B radiation in rice, using 98 BC(1)F(5) (backcross inbred lines; BILs) derived from a cross between Nipponbare (a resistant japonica rice variety) and Kasalath (a sensitive indica rice variety). We used 245 RFLP markers to construct a framework linkage map. BILs and both parents were grown under visible light with or without supplemental UV-B radiation in a growth chamber. In order to evaluate UV-B resistance, we used the relative fresh weight of aerial parts (RFW) and the relative chlorophyll content of leaf blades (RCC). The BIL population exhibited a wide range of variation in RFW and RCC. Using composite interval mapping with a LOD threshold of 2.9, three putative QTLs associated with both RFW and RCC were detected on chromosomes 1, 3 and 10. Nipponbare alleles at the QTLs on chromosome 1 and 10 increased the RFW and RCC, while the Kasalath allele at the QTL on chromosome 3 increased both traits. Furthermore, the existence of both QTLs on chromosomes 1 and 10 for UV-B resistance was confirmed using chromosome segment substitution lines. Plants with Kasalath alleles at the QTL on chromosome 10 were more sensitive to UV-B radiation than plants with them on chromosome 1. These results also provide the information not only for the improvement of UV-B resistance in rice though marker-associated selection, but also for the identification of UV-B resistance mechanisms by using near-isogenic lines.

Molecular marker dissection of rice (Oryza sativa L.) plant architecture under temperate and tropical climates.

Rice ( Oryza sativa L.) plants develop vertically with shoot elongation and horizontally with tillering. The purpose of this study was to identify and characterize genomic regions influencing the rice plant architecture by quantitative trait locus (QTL) analysis for the component traits: culm length (CL), panicle length (PnL), panicle number (PnN) and tiller number (TN). For this QTL analysis, 191 recombinant inbred lines (F(7)) derived from a cross of Milyang 23 (M23) and Akihikari (AK) were grown in 1995, 1996 and 1997 (May-Oct) in Joetsu, Japan (temperate climate), and in the 2000 dry season (Jan-Apr), the 2000 wet season (Jun-Oct) and the 2001 dry season in Los Baños, The Philippines (tropical climate). Results showed that rice plant architecture was influenced by 19 genomic regions categorized into five groups. In Group I, two regions (on chrs. 6 and 11) affected shoot elongation (CL and PnL) and tillering (PnN and TN) in opposite directions more significantly in Los Baños than in Joetsu. In Group II, two regions (chrs. 3 and 12) affected shoot elongation, whereas in Group III, five regions [chrs. 1 (two), 2, 3 and 9] affected only culm length (CL). Expressions of four regions of Group III were influenced by either tropical or temperate environments. In Group IV, seven regions (chrs. 1, 2, 4, 5, 6, 8 and 9) controlled panicle development (PnN or PnL), and in Group V, three regions (chrs. 1, 2 and 3) regulated tillering (PnN or TN). Characterizing these 19 genomic regions provided a detailed analysis of rice plant architecture with emphasis on the multiple effect and environmental responsive regions.

Mapping QTLs influencing rice floral morphology using recombinant inbred lines derived from a cross between Oryza sativa L. and Oryza rufipogon Griff.

To understand the genetic basis of floral traits associated with the mating system in rice, we analyzed pistil, stamen and glume traits using a recombinant inbred line population, derived from a cross between an Asian cultivated rice ( Oryza sativa L.), Pei-kuh, and a wild rice ( Oryza rufipogon Griff.), W1944. Quantitative trait loci (QTLs) affecting floral morphology were detected by composite interval mapping using a linkage map constructed using 147 markers, mostly RFLPs. A total of 7, 4, 14 and 6 QTLs were detected for traits related to pistil, stamen, and size and shape of the glume, respectively. Comparison of 31 QTLs affecting these organs revealed ten QTLs affecting the different organs in four adjacent regions on chromosomes 2, 4, 5 and 10, but most QTLs (68%) were located separately on the whole chromosomes. Although four QTLs for stigma breadth, anther length and thickness of lemma and palea explained more than 25% of the total phenotypic variance, most QTLs (87%) had smaller effects. These results suggest that quantitative variation observed for pistil, stamen and glume traits is controlled by several distinct genes with small effects.

An unusual staining of the tooth roots: a case report with histological and micro-analytical studies.

The discoloration of tooth roots is rare. We report here a 22-year-old Japanese woman with blackish-brown staining of the roots of the upper and lower third molars. Staining was found in the dentin and cementum. Electron probe X-ray microanalysis showed no significant difference in the composing elements between the stained tooth root and control tooth. Fluorescent bands coincided with staining in the dentin of the root and cementum along the incremental lines under confocal laser-scanning microscope.

Simultaneous resection of pancreas and liver metastases from different metachronous primary cancers.

Resection of a pancreatic head tumor and partial resection of the liver for metastatic lesions were carried out simultaneously in a 72-year-old woman. The patient had a history of two previous operations, right nephrectomy for renal cell carcinoma (clear cell type), done 14 years previously, and an Autincloss procedure for cancer of the left breast (solid tubular carcinoma); (T1N0M0; stage I) done 7 years previously. At the current presentation, preoperative radiographic examination showed a hypervascular tumor in each of the pancreatic and hepatic lesions, but with different patterns. On the basis of histological findings in the two resected specimens, it was difficult to establish whether the hepatic tumor originated from the renal cell carcinoma or the breast cancer, but postoperative immunohistochemical studies for carcinoembryonic antigen (CEA), estrogen receptors, and gross cystic disease fluid protein (GCDFP)-15 showed that the pancreatic tumor had metastasized from the renal cell carcinoma, and the liver tumor from the breast cancer. The immunohistochemical investigation of different markers thus proved to be useful in making the final diagnosis of metastatic lesions from different and metachronous cancers.

Histological and analytical studies of a tooth in a patient with cleidocranial dysostosis.

A histopathological and analytical study of a permanent tooth from a patient with cleidocranial dysostosis (CCD) was performed. The patient was a 47-year-old woman, who had 10 erupted permanent teeth and 2 partially erupted and 19 completely impacted teeth, including supernumerary teeth. The erupted right upper premolar was extracted and observed using a light microscope and an electron probe X-ray microanalyzer (EPMA). Findings showed enamel hypoplasia, predominantly irregular globular dentin and Tomes' granular layer, and a complete lack of cellular cementum in the ground section. The incremental von Ebner and counter Owen lines were obscure. Comparative quantitative analysis using the EPMA showed that the quantities of calcium and phosphate were lower in the enamel and dentin than those of the control sample.

Pharmacodynamic analysis of steroid 5alpha-reductase inhibitory actions of Z-350 in rat prostate.

The pharmacodynamics of (S)-4-[3-[4-[1-(4-methylphenyl)-3-[4-(2-methoxyphenyl)piperazine-1-yl]propoxy]benzoyl]indole-1-yl] butyric acid hydrochloride (Z-350), which has alpha(1)-adrenoceptor antagonistic and steroid 5alpha-reductase inhibitory effects, were investigated in rats. The disposition of Z-350 was a function of linear kinetics at doses from 1 to 30 mg/kg; the bioavailability was calculated to be 65.2%. The inhibition of 5alpha-reductase was dependent on the concentration of Z-350 in plasma and in the prostate. Analysis of the relationship between the concentration in the prostate and the inhibition seen after a single oral administration showed that the Hill constant was almost 1.0 and EC(50)(n(H)) was 47.4 ng/g of tissue; these parameters did not change after multiple administration. Z-350 inhibited 5alpha-reductase 1 h after oral administration at a dose of 3 mg/kg; maximum inhibition was observed after 2-4 h, and the inhibition (%) was maintained for 24 h after oral administration.

Hormonal effects of Z-350, possessing steroid 5alpha-reductase inhibitory and alpha1-adrenoceptor antagonistic actions, in the rat.

We examined the hormonal effects of Z-350, (S)-4-[3-(4-[1-(4-methylphenyl)-3-[4-(2-methoxyphenyl)piperazine-1-yl]propoxy]benzoyl)indole-1-yl]butyric acid hydrochloride, which has both alpha1-adrenoceptor blocking activity and steroid 5alpha-reductase inhibitory activity, in male and female rats. Z-350 administered orally for 14 days at a dose of 30 mg/kg to normal male rats significantly reduced the weight of the prostate and seminal vesicles without affecting the weight of the testis, epididymis, adrenals, kidney or liver. Prostatic levels of dihydrotestosterone decreased dose-dependently, with a slight increase in the level of testosterone at a Z-350 dose of 100 mg/kg. We observed no effects on the weight of the prostate in castrated rats or on the weight of the uterus in normal or 17beta-estradiol-treated female rats. These results suggest that Z-350 inhibits prostatic growth via inhibition of steroid 5-reductase without other hormonal effects.

Mapping of QTLs associated with cytosolic glutamine synthetase and NADH-glutamate synthase in rice (Oryza sativa L.).

Ninety-eight backcross inbred lines (BC1F6) developed between Nipponbare, a japonica rice, and Kasalath, an indica rice were employed to detect putative quantitative trait loci (QTLs) associated with the contents of cytosolic glutamine synthetase (GS1; EC 6.3.1.2) and NADH-glutamate synthase (NADH-GOGAT; EC 1.4.1.14) in leaves. Immunoblotting analyses showed transgressive segregations toward lower or greater contents of these enzyme proteins in these backcross inbred lines. Seven chromosomal QTL regions for GS1 protein content and six for NADH-GOGAT protein content were detected. Some of these QTLs were located in QTL regions for various biochemical and physiological traits affected by nitrogen recycling. These findings suggested that the variation in GS1 and NADH-GOGAT protein contents in this population is related to the changes in the rate of nitrogen recycling from senescing organs to developing organs, leading to changes in these physiological traits. Furthermore, a structural gene for GS1 was mapped between two RFLP markers, C560 and C1408, on chromosome 2 and co-located in the QTL region for one-spikelet weight. A QTL region for NADH-GOGAT protein content was detected at the position mapped for the NADH-GOGAT structural gene on chromosome 1. A QTL region for soluble protein content in developing leaves was also detected in this region. Although fine mapping is required to identify individual genes in the future, QTL analysis could be a useful post-genomic tool to study the gene functions for regulation of nitrogen recycling in rice.

HeLa ZIP kinase induces diphosphorylation of myosin II regulatory light chain and reorganization of actin filaments in nonmuscle cells.

Dlk/ZIP kinase is a serine/threonine kinase highly homologous to DAP kinase. We have reported that HeLa ZIP kinase (hZIPK) phosphorylated the regulatory light chain of myosin II (MRLC) at both Ser19 and Thr18 in vitro. In this study, we demonstrate that hZIPK also induces the diphosphorylation of MRLC in nonmuscle cells. Peptide mapping revealed that transient transfection of hZIPK into HeLa cells caused diphosphorylation of MRLC. In contrast, transfection of the kinase inactive mutant of hZIPK did not induce any phosphorylation of MRLC. Using antibodies specific for mono- or diphosphorylated MRLC, we showed that diphosphorylated MRLC induced by the overexpression of hZIPK was concentrated in striking aggregates or bundles of actin filaments in HeLa cells, while monophosphorylated MRLC showed no prominent localization to these aggregates. Overexpression of hZIPK also induced dramatic changes in cell shape and disruption of nuclear morphology reminiscent of changes during apoptosis. These effects of hZIPK were suppressed by the coexpression of a mutant MRLC where both phosphorylation sites were replaced with alanine, indicating that the changes in actin organization were a consequence of MRLC diphosphorylation. These results suggested that hZIPK plays a role in regulating actin organization and cell morphology in non-muscles and at least part of its effects are mediated through the diphosphorylation of MRLC.

Myosin II regulatory light chain as a novel substrate for AIM-1, an aurora/Ipl1p-related kinase from rat.

Previous studies demonstrated that the phosphorylated myosin II regulatory light chain (MRLC) is localized at the cleavage furrow of dividing cells, suggesting that phosphorylation of MRLC plays an important role in cytokinesis. However, it remains unclear which kinase(s) phosphorylate MRLC during cytokinesis. AIM-1, an Aurora/Ipl1p-related kinase from rat, is known as a serine/threonine kinase that is required for cytokinesis. Here we examined the possibility that AIM-1 is a candidate for a kinase that phosphorylates MRLC during cytokinesis. As a result, we showed that AIM-1 monophosphorylated MRLC at Ser19 using two-dimensional phosphopeptide mapping analysis and several MRLC mutants. Furthermore, AIM-1 was colocalized with monophosphorylated MRLC at the cleavage furrow of dividing cells. We propose here that AIM-1 may participate in monophosphorylation of MRLC during cytokinesis.

Intraosseous neurilemmoma of the mandible.

We report a rare case of intraosseous neurilemmoma of the mandible, with an emphasis on radiographic findings. The tumor, located mainly in the premolar region, presented as an expansive, unilocular, well-defined, radiolucent lesion on plain radiography. No dilatation of the mandibular canal was identified. MR imaging helped to identify the solid nature of the tumor. A biopsy was necessary to make the final diagnosis because of the relatively nonspecific nature of the lesion.

Long-term restoration of masticatory function with fixed mandibular implants in cases of oral cancer.

The results of the present study show that the fixed mandibular implant system enables patients who have operations to treat oral cancer to use a stabilized denture continuously over an extended period of time.

Direct intraoperative measurements of aortic and pulmonary blood flows in patients with severe pulmonary artery hypertension.

BACKGROUND: Evaluate the significance of direct intraoperative measurements of aortic and pulmonary blood flows by electromagnetic flowmeter as an absolute decision basis for operability in patients with ventricular septal defect/complete atrioventricular septal defect and severe pulmonary artery hypertension. EXPERIMENTAL DESIGN: Prospective study. SETTING: Institutional practice. PATIENTS: Eight patients with marginal operability based on preoperative Doppler echocardiography and cardiac catheterization (pulmonary-to-systemic flow ratio=1.1-2.3, pulmonary-to-systemic resistance ratio=0.34-0.91, and pulmonary vascular resistance=4.6-18.2 units x m2) underwent direct intraoperative measurements of aortic and pulmonary blood flows by electromagnetic flowmeter. Operation would be performed according to the results of direct intraoperative measurements in every patient. RESULTS: Aortic flow by direct intraoperative measurements ranged from 0.9 to 3.2 L/min/m2, and pulmonary blood flow from 4.1 to 8.4 L/min/m2. Pulmonary-to-aortic flow ratio was calculated at 2.1-6.6. Pulmonary vascular resistance ranged from 2.6 to 7.7 units x m2. We assessed that all patients still had operability, and performed corrective operations. Postoperative courses corresponded with the data from the direct intraoperative measurements. CONCLUSIONS: When some clinical findings, particularly Doppler echocardiographic findings, of these patients are slightly in favor of reversibility of pulmonary vascular disease despite discrepant data of preoperative cardiac catheterization under a tight control of carbon dioxide tension, we recommend that direct intraoperative measurement of aortic and pulmonary blood flows is especially useful in decision making for the operability of patients with severe pulmonary artery hypertension.