Biomedical subjects
Publications and source records attributed to H Sakai.
A benign tumour of osseous and cartilaginous origins, osteochondroma generally develops in osseous tissue and is frequently found near the end of long bones. It is relatively rare in the oral and maxillofacial region but is common in the mandibular condyle and coronoid process in the pediculate form. This is a report on a rare case of osteochondroma in soft tissue near the mandibular angle without pedicle to the bone.
We report the results of the first-time test of the local hidden variable theories (Bell-Clauser-Horne-Shimony-Holt) involving strongly interacting pairs of massive spin 1/2 hadrons from the decay of short-lived (tau<10;-21sec) 2He spin-singlet state, populated in the nuclear reaction 2H+;1H-->;2He+n. The novel features of this experiment are (a) the use of an 'event-ready' [corrected] detector of nearly 100% efficiency to prepare an unbiased sample and (b) a focal-plane polarimeter of full 2pi sr acceptance with a random "post selection" of the reference axes. The spin-correlation function is deduced to be S[exp](pi/4)=2.83+/-0.24stat+/-0.07sys. This result is in agreement with nonlocal quantum mechanical prediction and it violates the Bell-CHSH inequality of |S|<or=2 at a confidence level of 99.3%.
Using two new X-chromosome short tandem repeats (X-STR) multiplex (quadruplex) systems, we investigated Japanese population data (drawn from 401 individuals) for eight X-STR loci (DXS10011, DXS9898, DXS8377, HPRTB, DXS7132, DXS6797, GATA172D05, and DXS6807). Allele typing with the systems was successful for all loci. The combined powers of discrimination of the eight loci in men and women were 0.999997 and 0.9999999996, respectively. We conclude that combined analyses of the eight X-STR loci using these two quadruplex polymerase chain reaction systems represent a powerful tool for Japanese forensic practice.
We studied the mean hemoglobin (Hb) concentration in elite male and female long track junior and senior speed skaters from 2000 to 2005. In addition, the number of abnormal hematological findings observed over this period of time was investigated. We also studied whether there were differences in Hb concentration between top ranked and lower ranked skaters, and whether a relationship between Hb concentration and competitive results could be observed. The present study shows that the mean Hb level in male and female junior and senior long track speed skaters remained fairly stable and did not change from 2000 through 2005. The number and percentage of abnormal hematological findings were found to vary between 0 and 2 %, and failed to show a clear pattern or trend over the years. There was no difference in mean Hb levels between top ranked and lower ranked skaters, and no meaningful relationship between Hb concentration and ranking could be found.
Dimensionality is one of the most important parameters of physical phenomena. Only two things determine the universality class of a phase transition: the dimensionality of a given system and the symmetry of the order parameter. In most cases, the dimensionality of a substance is predetermined by its crystal structure. Examples in which the effective dimensionality is reduced are quite rare. Here we show that the three-dimensional cubic system of Tl(2)Ru(2)O(7) most probably evolves into a one-dimensional spin-one Haldane system with a spin gap below 120 K, accompanied by anomalies in the structure, resistivity and susceptibility. We argue that these anomalies are due to an orbital ordering of Ru 4d electrons, with a strong coupling among three degrees of freedom: orbital, spin and lattice. Our work provides a unique example of the spontaneous formation of Haldane system with an insight into the intriguing interplay of different degrees of freedom.
Human cytochrome P450 (CYP) 2A6 metabolizes nicotine to cotinine. Genetic polymorphisms of CYP2A6 contribute to the interindividual variability of nicotine metabolism. We encountered some subjects possessing two copies of the CYP2A6 gene, although they were genotyped as heterozygotes of the CYP2A6*4A allele (entire CYP2A6 gene deleted allele). From the subjects, we found CYP2A7 polymorphic alleles (CYP2A7*1B, CYP2A7*1C, and CYP2A7*1D) in which the sequences in the 3'-flanking region were converted to the corresponding CYP2A6 sequences, being confused with the CYP2A6*4A. These allele frequencies in European-Americans (n=187) were 1.3, 2.1, 0.3%, respectively, but these were very rare in African-Americans (n=176), Japanese (n=184), and Koreans (n=209). By an improved genotyping method, the allele frequency of CYP2A6*4A of 3.7% in European-Americans was corrected to 0%. The comprehensible and reliable genotyping method developed in this study would be useful to evaluate associations between the genotype and phenotype.
Infections of human papillomavirus (HPV) induce a variety of benign tumors, such as warts and condylomas. During the process of aberrant cell proliferation, genetic mutations are accumulated in the cells, from which malignant tumor cells arise. The viral oncoproteins E6 and E7 are known to help disrupt the cell cycle checkpoint machinery and accelerate chromosomal instability, events which are critical in malignant conversion. However, the mechanisms involved in the hyperplasia caused by HPV infection have remained unknown. We analysed the effects of regulatory genes of HPV18, a typical high-risk-type HPV, on the formation of the epithelial organ by using an organotypic culture system, and found that E7 had potent activity to induce hyperplasia, to which the disruption of the pRb pathway was well correlated. However, analysis with the E7 variants indicated that other pocket proteins are also involved in the activity.
We sought to evaluate a more effective system for analyzing X-chromosomal short tandem repeats (X-STRs) in highly degraded DNA. To generate smaller amplicon lengths, we designed new polymerase chain reaction (PCR) primers for DXS7423, DXS6789, DXS101, GATA31E08, DXS8378, DXS7133, DXS7424, and GATA165B12 at X-linked short tandem repeat (STR) loci, devising two miniX-multiplex PCR systems. Among 333 Japanese individuals, these X-linked loci were detected in amplification products ranging in length from 76 to 169 bp, and statistical analyses of the eight loci indicated a high usefulness for the Japanese forensic practice. Results of tests on highly degraded DNA indicated the miniX-STR multiplex strategies to be an effective system for analyzing degraded DNA. We conclude that analysis by the current miniX-STR multiplex systems offers high effectiveness for personal identification from degraded DNA samples.
Living-donor lobar lung transplantation (LDLLT) has been applied to patients with various end-stage lung diseases. The recurrence of pulmonary lymphangioleiomyomatosis (LAM) after lung transplantation has been rarely reported. Herein, we report a case of recurrent pulmonary LAM after LDLLT. A 24-year-old woman presented with pneumothorax and infiltrates in the left lung 1 year after bilateral LDLLT for LAM. These symptoms and radiologic findings occurred repeatedly and then improved quickly. Thereafter, computed tomography of the chest revealed a tiny emphysematous change of the subpleural region in the left lung, which was exacerbated gradually and was finally diagnosed as LAM recurrence by transbronchial lung biopsy. In previous reports of LAM recurrence, the diagnosis was made at the time of autopsy. This is also the first reported case diagnosed early, that is, when the patient was alive and her allograft had not deteriorated badly.
AIMS: To determine the prevalence of hepatitis C virus (HCV) infection in B-cell lymphoma in Japan. HCV infection and type II (monoclonal IgM) cryoglobulinaemia (CG) may be involved in the pathogenesis of low-grade B-cell lymphoma (ML) in southern Europe. METHODS AND RESULTS: Forty-five (11.3%) of 400 B-cell ML cases were HCV antibody (Ab) positive, which was significantly (P < 0.01) higher than the blood donors (2.5%). Among them, 28 diffuse large B-cell lymphoma (DLBCL) cases were included. In the primary sites, 10 (47.6%) of 21 splenic DLBCL and seven (23.3%) of 30 gastric DLBCL were HCV Ab positive, which were significantly (P < 0.05) higher than the myeloma cases (4.9%). HCV infection was rarely (4.2%) detected in 24 lymphoplasmacytic and salivary gland low-grade B-cell ML cases. Type II CG was detected in one myeloma case (3.5%) of 29 HCV+ B-cell ML. By real-time polymerase chain reaction, HCV RNA was detected in fresh tumour tissues of all 11 B-cell ML cases examined. Lymphoma cells were positive for the envelope HCV non-structural (NS)3 and envelope (E2) proteins in six of eight examined B-cell ML cases. CONCLUSIONS: The rare incidence of type II CG is characteristic of Japanese HCV+ ML patients and may influence the low incidence of low-grade B-cell ML. HCV infection may play a role in lymphomagenesis of splenic and gastric DLBCL.
Increasing our understanding of the factors regulating seasonal changes in rice canopy carbon gain (C(gain): daily net photosynthesis -- night respiration) under elevated CO(2) concentrations ([CO(2)]) will reduce our uncertainty in predicting future rice yields and assist in the development of adaptation strategies. In this study we measured CO(2) exchange from rice (Oryza sativa) canopies grown at c. 360 and 690 micromol mol(-1)[CO(2)] in growth chambers continuously over three growing seasons. Stimulation of C(gain) by elevated [CO(2)] was 22-79% during vegetative growth, but decreased to between -12 and 5% after the grain-filling stage, resulting in a 7-22% net enhancement for the whole season. The decreased stimulation of C(gain) resulted mainly from decreased canopy net photosynthesis and partially from increased respiration. A decrease in canopy photosynthetic capacity was noted where leaf nitrogen (N) decreased. The effect of elevated [CO(2)] on leaf area was generally small, but most dramatic under ample N conditions; this increased the stimulation of whole-season C(gain). These results suggest that a decrease in C(gain) enhancement following elevated CO(2) levels is difficult to avoid, but that careful management of nitrogen levels can alter the whole-season C(gain) enhancement.
Light and electron microscopic features and immunohistochemical features of Cryptosporidium andersoni (C. andersoni) and host reaction in the mucosa were studied. Although the affected cattle demonstrated no apparent clinical signs, a severe infection of C. andersoni was observed in the abomasum. C. andersoni were round in shape, measured 6-8 microm in size and were mainly observed to be freely located in the gastric pits, being attached in occasional cases to the surface of the abomasum epithelium. Frequent inflammatory cells had infiltrated the lamina propria of the affected mucosa, and frequent mitotic figures were observed in epithelial cells at the dilated isthmus. To access the cell kinetics, the number of epithelial cells infected with C. andersoni were counted and compared with noninfected cattle. The number of gastric pit cells in infected cattle was significantly higher than that in the controls. The number of proliferative cells determined by the Ki-67 antigen in C. andersoni infected cattle was also significantly higher than that in the controls. Transmission electron microscopy and scanning electron microscopy revealed that the morphology of the C. andersoni organism was common to those of other Cryptosporidium spp. Immunohistochemically, several commercial antibodies against Cryptosporidium spp. showed positive reactions at the wall of these oocysts or parasitophorous vacuoles. This report is possibly the first to discuss the prominent hyperplasia of the abomasum mucosa, as well as morphologic features of C. andersoni in cattle.
Expression of vascular endothelial growth factor (VEGF), its receptors (flt-1 and flk-1), and basic fibroblast growth factor (bFGF) in canine hemangiosarcoma (HSA) and hemangiomas was investigated by immunohistochemical analysis. In addition, expression of the mRNAs of VEGF, flt-1, flk-1, and flg-1 (a receptor for bFGF), was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and in situ hybridization (ISH) with cRNA probes. VEGF, bFGF, flt-1, and flk-1 were immunohistochemically detected in the neoplastic cells in HSAs; the staining intensity was stronger in HSAs than in hemangiomas. On the other hand, the neoplastic cells in hemangiomas exhibited very weak or no expression of VEGF, although they showed moderate expression of flt-1 and flk-1. The mRNAs of VEGF, flt-1, flk-1, and flg-1 were detected in the neoplastic cells in HSAs by ISH and RT-PCR. However, VEGF mRNA was not detectable in the neoplastic cells in hemangiomas by ISH, although it was detected in the inflammatory cells in the tumors by RT-PCR. Moreover, the HSAs that showed intense staining for flk-1 had a high proliferative activity, which was reflected as a high Ki-67 positive index. These results suggest that the expression of the growth factors and their receptors, especially flk-1, might be associated with the malignant proliferation of HSAs.
Three precise measurements for elastic pd scattering at 135 MeV/A have been performed with the three different experimental setups. The cross sections are described well by the theoretical predictions based on modern nucleon-nucleon forces combined with three-nucleon forces. Relativistic Faddeev calculations show that relativistic effects are restricted to backward angles. This result supports the two measurements recently reported by RIKEN and contradicts the KVI data.
The entrapment of kojic acid and its newly synthesized ester (kojic oleate) has been evaluated. Kojic oleate was synthesized by DCC (N,N'-dicyclohexylcarbodiimide, DCC)/(4-(N,N-dimethylamino)pyridine, DMAP) esterification method and identified by FAB-MS and 1H NMR. The synthesized product was mainly 7-O-kojic oleate with more than 80% yield. It was entrapped in vesicular membrane prepared from 9.5:9.5:1.0 molar ratio of amphiphiles (Span 60, Tween 61 or DPPC), cholesterol and dicetyl phosphate. Kojic acid was encapsulated in the water compartment of these vesicles in order to confirm the vesicle formation. The morphology and particle size of the vesicles were characterized by an optical microscope and transmission electron microscope (TEM). The entrapment efficiencies of kojic acid and kojic oleate in the vesicles were investigated by dialysis and column chromatography, respectively. The contents of the entrapped kojic acid and kojic oleate were assayed by HPLC. The entrapment efficiency of kojic acid was 0.01-0.04 mol, whereas kojic oleate gave higher entrapment efficiency of 0.25-0.35 mol/mol of the total compositions of amphiphile/cholesterol/dicetyl phosphate. Structural modification of kojic acid improved its entrapment in the vesicles. Tween 61 vesicles could entrap kojic oleate more than did Span 60 vesicles. The pi-A isotherms revealed the lower area per molecule of Span 60, which formed a more rigid pack of its molecule on air/water interface than that of Tween 61. This implied the high rigidity of vesicular membrane prepared with Span 60 led to the lower amount of kojic oleate entrapped in the vesicles. From the release study of kojic acid through the dialysis membrane, it indicated that the intercalation of kojic oleate in the vesicular membranes did not significantly affect the release of kojic acid from the vesicles.
In order to elucidate the nature of the exotic ordered phase of NpO2 below T(0)=26 K, we have initiated the first 17O-NMR measurements on this system. From the 17O-NMR spectrum, the occurrence of two inequivalent oxygen sites has been confirmed below T0. It has also been shown that the characteristic features of the hyperfine interaction at the oxygen sites are well explained by invoking a hyperfine interaction with field-induced antiferromagnetic moments which appear as a result of the triple-q antiferroquadrupolar order. The NMR findings strongly support the occurrence of the longitudinal triple-q multipole structure in NpO2.
We performed emergency living-donor lobar lung transplantation (LLTx) successfully in a 24-year-old woman with end-stage pulmonary and massive abdominopelvic lymphangioleiomyomatosis (LAM). Preoperatively, her respiratory condition was critical, but abdominopelvic lesions had been well controlled with medication. No LAM patients with massive abdominopelvic lesions as in the present case have been reportedly treated by LLTx previously. The present case demonstrates that LLTx can be a therapeutic option for end-stage pulmonary LAM with massive abdominopelvic involvement.
AIMS: To examine histopathological and immunohistochemical changes in lenticules and host of corneal buttons from patients who previously underwent epikeratoplasty for keratoconus. METHODS: 12 penetrating keratoplasty specimens from patients with keratoconus who had previously undergone epikeratoplasty, eight keratoconus, and seven normal corneas were examined. Immunostaining for Sp1, alpha1-proteinase inhibitor (alpha1-PI), and alpha2-macroglobulin (alpha2M) were performed. RESULTS: In nine of the 12 lenticules, the keratoconus-like disruptions were found in Bowman's layer. Peripheral and posterior keratocyte repopulation of the lenticules was observed in all cases. Keratocyte repopulation in the anterior and mid-stromal regions of the lenticules appeared related to the time since epikeratoplasty. Sp1 nuclear staining of the basal and wing epithelial cells was more intense in lenticules and keratoconus corneas than in normal corneas. Lenticular, host, and keratoconus keratocytes showed positive Sp1 staining, whereas staining was absent in normal corneas. Compared to normal corneas, alpha1-PI and alpha2M immunostaining was lower in the lenticules, host, and keratoconus specimens. CONCLUSIONS: The epithelial cells and keratocytes repopulated in the lenticules retain keratoconus-like biochemical abnormalities such as upregulation of Sp1 and downregulation of alpha1-PI and alpha2M. The authors speculate that both keratocytes and the corneal epithelium may participate in the development of keratoconus.