Biomedical subjects

M Nakano

Publications and source records attributed to M Nakano.

At least 19 recordsLinked to original sources

PubMed2006

Beneficial effect of interferon-beta treatment in patients with multiple sclerosis is associated with transient increase in serum IL-6 level in response to interferon-beta injection.

In order to predict the clinical benefit of interferon-beta (IFN-beta) to patients with multiple sclerosis (MS), the following markers were investigated; (1) chronological change of cytokines (IFN-gamma, TNF-alpha, IL-6, IL-10, and TGF-beta) after administration of IFN-beta, (2) untoward effects of IFN-beta such as headache and arthralgia, (3) backgrounds of the patients such as age and relapse rate, (4) efficacy of IFN-beta therapy assessed by the change of relapse rate and progression of disability. Chronological blood sampling was performed 0, 10, and 24 h after injection of IFN-beta. The increase of serum IL-6 level in response to IFN-beta administration was associated with headache, arthralgia, relapse rate before treatment, and disability score at the initiation of the therapy. Significant association of change of serum TNF-alpha with age and headache was also observed. The important finding in this study was that patients with a transient increase in IL-6 in response to IFN-beta showed a slow disease progression. This result suggests that this transient increase in the serum IL-6 predicts favorable response to IFN-beta treatment.

Adult↗

PubMed2006

Admission blood glucose levels and early change of neurological grade in poor-grade patients with aneurysmal subarachnoid haemorrhage.

BACKGROUND: The neurological grade of poor-grade subarachnoid haemorrhage (SAH) often changes soon after the patient is admitted to the hospital. It is important to closely monitor for such changes within a short period of time after admission; however, there are other problems that can occur during this time such as rebleeding. The aim of this study was to evaluate the relationship between admission blood glucose levels (ABGL) and early change of neurological grade after admission in patients with poor-grade SAH. METHODS: Forty-six patients with poor-grade SAH (Hunt & Kosnik Grade IV or V), who were admitted within 3 hrs after SAH onset, and who did not have haematomas causing mass effect, or a history of diabetes mellitus, were included in the study. Patients were pretreated to control blood pressure and intracranial pressure, and they were monitored for early change of grade after admission. Blood glucose level was measured at the time of admission. FINDINGS: Spontaneous grade improvement was observed in 9 of 17 Grade IV patients and 9 of 29 Grade V patients. The ABGL of the patients with grade improvement were significantly lower than the ABGL of the patients who did not improve or who got worse. ABGL were lower than 180 mg/dl in 15 of 18 patients who showed grade improvement. CONCLUSIONS: Our results showed that there was a relationship between ABGL and neurological grade changes which were observed after admission in patients with poor-grade SAH. These results suggest that ABGL might be a useful parameter for making therapeutic decisions.

Adult↗

PubMed2006

Development of a rapid strain differentiation method for methicillin-resistant Staphylococcus aureus isolated in Japan by detecting phage-derived open-reading frames.

AIMS: To develop a rapid genotyping method for investigating outbreaks of methicillin-resistant strains of Staphylococcus aureus (MRSA) isolated in Japan. METHODS AND RESULTS: Isolates were genotyped by detecting the keeping pattern of 16 open-reading frames (ORFs), a process we call phage ORF typing (POT). Thirteen of the ORFs were selected from phage genomes and one from a genomic island SaGIm in the genome of strain Mu50. The other two ORFs, one from Tn554 and one from staphylococcal cassette chromosome mec (SCCmec) type II, were used as strain markers. Three hundred and sixty-eight isolates from five hospitals were classified into 133 types by POT, whereas they were classified into 139 types by pulsed-field gel electrophoresis (PFGE) subtyping. The discriminatory power of POT (D=0.989) was equal to that of PFGE subtyping (D=0.986). CONCLUSIONS: MRSA isolates collected in Japan can be genotyped by detecting the keeping pattern of phage-derived ORFs with a discriminatory power equal to that of PFGE subtyping. SIGNIFICANCE AND IMPACT OF THE STUDY: MRSA isolates can be genotyped rapidly by detecting phage-derived ORFs. As particular pandemic clones can be found in a specific region, a typing method localized to a pandemic clone may be effective for the rapid genotyping of MRSA during outbreaks.

Bacterial Typing Techniques↗

PubMed2006

Relationship between occlusal tooth contact patterns and tightness of proximal tooth contact.

The aim of this study was to investigate the relationship between occlusal tooth contact patterns and the tightness of proximal tooth contact (TPTC) during clenching. Twenty young adult volunteers with healthy dentition participated in the study. TPTC between the left second premolar (P2) and the first molar (M1) was measured during clenching at the 50% maximum voluntary contraction level in the intercuspal position (ICP). A silicone impression material was used to make an interocclusal record at the ICP in each subject, and interocclusal records were analysed using an image-processing system. Subjects were classified according to the presence or absence of each type (A, B or C) of occlusal contact. Statistical analysis was performed using the Mann-Whitney U-test. The results of this study exhibited a relationship between B-type contact and the TPTC of maxillary teeth. The experimental group with a lack of B-type contact on maxillary P2 and/or M1 showed a statistically greater TPTC than the group with B-type contact on both of these teeth (P < 0.01). These results suggest that occlusal tooth contact patterns have an influence on TPTC during clenching.

Adult↗

PubMed2005

Redox reaction of iodine in paddy soil investigated by field observation and the I K-Edge XANES fingerprinting method.

In order to elucidate the cause for the leaching of iodine in a flooded paddy field, we investigated the transformation of an iodine species affected by the water management of the paddy field. The increased concentration of iodide (I(-)) in soil solution of a flooded paddy field suggested that I(-) was leached from the soil under anaerobic conditions. The post-edge feature of X-ray absorption near-edge structure (XANES) for iodate (IO(3)(-)) spiked to soil totally disappeared after anaerobic incubation of the soils, and I(-) was dissolved in the solution. On the other hand, I(-) in contact with the soil was not likely to be oxidized to IO(3)(-) under aerobic incubation. Iodine was leached out in soil solution as I(-) under anaerobic conditions, whereas part of the iodine species was retained by soil as I(2) or organoiodine both under anaerobic and aerobic conditions.

Iodine↗

PubMed2005

Rooibos tea (Aspalathus linearis) partially prevents oxidative stress in streptozotocin-induced diabetic rats.

The aim of this study was to investigate the effects of rooibos tea as a natural source of a wide scale of antioxidants on the prevention and treatment of oxidative stress in streptozotocin-induced diabetic rats. Expected significant changes of biochemical parameters characteristic for experimental diabetic state were found in plasma and tissues eight weeks after single dose streptozotocin application. Administration of aqueous and alkaline extracts of rooibos tea (or N-acetyl-L-cysteine for comparison) to diabetic rats did not affect markers of the diabetic status (glucose, glycated hemoglobin and fructosamine). Besides the parameters characterizing hepatotoxic effect of streptozotocin, rooibos tea significantly lowered advanced glycation end-products (AGEs) and malondialdehyde (MDA) in the plasma and in different tissues of diabetic rats, particularly MDA concentration in the lens. From these results we can conclude that antioxidant compounds in rooibos tea partially prevent oxidative stress and they are effective in both hydrophobic and hydrophilic biological systems. Therefore, rooibos tea as a commonly used beverage can be recommended as an excellent adjuvant support for the prevention and therapy of diabetic vascular complications, particularly for protecting ocular membrane systems against their peroxidation by reactive oxygen species.

Acetylcysteine↗

PubMed2005

Venepuncture is preferable to heel lance for blood sampling in term neonates.

BACKGROUND: The analgesic effect of oral sucrose in newborn infants undergoing painful procedures is generally accepted. For blood sampling, some studies have shown that venepuncture (VP) is less painful than heel lance (HL). OBJECTIVE: To determine the least painful and most effective method among blood sampling by VP or HL with or without sucrose. DESIGN: Randomised, double blind, placebo controlled trial. SUBJECTS: A total of 100 healthy, full term newborn infants being screened for inborn errors of metabolism were randomly allocated to one of four experimental groups (25 infants in each). Intervention and OUTCOME MEASURE: Seven specially trained nurses took turns to carry out blood sampling two minutes after administration of oral sucrose or water. Neonatal pain was assessed by the neonatal facial coding system (NFCS), as well as by crying. RESULTS: Without sucrose, the NFCS score was higher in the HL group than the VP group during blood sampling (median 58 v 23, p<0.001). Oral sucrose significantly reduced the score of the HL group (58 v 47, p<0.01) and also tended to reduce the score of the VP group (23 v 2, p<0.1). However, the HL with sucrose group still had a higher score than the VP without sucrose group (47 v 23, p<0.01). Crying and the total procedure time showed the same trends as the NFCS score. CONCLUSIONS: VP is less painful and more effective than HL for blood sampling in newborn infants. Although oral sucrose may have an additive analgesic effect, it is not necessarily required if VP is used for blood sampling.

Analgesics, Non-Narcotic↗

PubMed2005

Participation of the nonreducing terminal beta-galactosyl residues of the neutral N-linked carbohydrate chains of porcine zona pellucida glycoproteins in sperm-egg binding.

The zona pellucida (ZP) surrounding the mammalian oocyte is composed of three glycoprotein components (ZPA, ZPB, and ZPC). Mammalian sperm bind to carbohydrate chains of a ZP glycoprotein in the initial phase of fertilization. Sperm-ligand carbohydrate chains have been characterized in mouse, cow, and pig. In pigs, triantennary/tetraantennary neutral complex-type chains from ZPB/ZPC mixture possess stronger sperm-binding activity than those of biantennary chains (Kudo et al., 1998: Eur J Biochem 252:492-499). Most of these oligosaccharides have beta-galactosyl residues at the nonreducing ends. This study used two in vitro competition assays to investigate the participation of the nonreducing terminal beta-galactosyl residues of the ligand active chains in porcine sperm binding. The removal of the nonreducing terminal beta-galactosyl residues from either the ligand active carbohydrate chains or endo-beta-galactosidase-digested glycoproteins significantly reduced their inhibition of sperm-egg binding, indicating that the beta-galactosyl residues at the nonreducing ends are involved in porcine sperm-egg binding. A correlation between the sperm-binding activity and in vitro fertilization rate is also presented.

Animals↗

PubMed2005

Protein expression of Mdm2 and p53 in hyperplastic and neoplastic lesions of the canine circumanal gland.

Hyperplastic and neoplastic lesions of the circumanal gland in dogs were examined immunohistochemically for nuclear expression of Mdm2 and p53 proteins. Mdm2 nuclear labelling was detected in 64.3% of hyperplastic lesions and 70.7% of adenomas, the immunolabelling being stronger in the latter. Mdm2 reactivity in reserve-like cells in adenomas showed wide variation, the immunoreactive cells ranging from 4 to 80%. No reactivity was shown in 81.9% of adenocarcinomas. In contrast to Mdm2 reactivity, each of 14 hyperplastic lesions and 11 adenocarcinomas, and 60 of 65 adenomas (92.3%) failed to show nuclear p53 reactivity. These results suggest that increased expression of Mdm2 is an early event in circumanal gland tumorigenesis, and may be present in the absence of nuclear p53 protein accumulation.

Adenocarcinoma↗

PubMed2005

Clonally expanded T-cell populations in atomic bomb survivors do not show excess levels of chromosome instability.

Radiation-induced genomic instability has been studied primarily in cultured cells, while in vivo studies have been limited. One major obstacle for in vivo studies is the lack of reliable biomarkers that are capable of distinguishing genetic alterations induced by delayed radiation effects from those that are induced immediately after a radiation exposure. Here we describe a method to estimate cytogenetic instability in vivo using chromosomally marked clonal T-cell populations in atomic bomb survivors. The basic idea is that clonal translocations are derived from single progenitor cells that acquired an aberration, most likely after a radiation exposure, and then multiplied extensively in vivo, resulting in a large number of progeny cells that eventually comprise several percent of the total lymphocyte population. Therefore, if chromosome instability began to operate soon after a radiation exposure, an elevated frequency of additional but solitary chromosome aberrations in clonal cell populations would be expected. In the present study, six additional translocations were found among 936 clonal cells examined with the G-band method (0.6%); the corresponding value with multicolor FISH analysis was 1.2% (4/333). Since these frequencies were no higher than 1.2% (219/17,878 cells), the mean translocation frequency observed in control subjects using the G-band method, it is concluded that chromosome instabilities that could give rise to an increased frequency of persisting, exchange-type aberrations were not commonly generated by radiation exposure.

Breast Neoplasms↗

PubMed2004

An insertional mutation in the rice PAIR2 gene, the ortholog of Arabidopsis ASY1, results in a defect in homologous chromosome pairing during meiosis.

To elucidate the genetic system that establishes homologous chromosome pairing in monocot plants, we have isolated an asynaptic mutant of rice, designated pair2 (homologous pairing aberration in rice meiosis 2), in which 24 completely unpaired univalents are observed at pachytene and diakinesis. The mutation was caused by an insertion of the retrotransposon Tos17, as demonstrated by complementation of the mutation by transformation with the corresponding wild-type gene. The gene in which the element was inserted is orthologous to the ASY1 gene of Arabidopsis thaliana and the HOP1 gene of Saccharomyces cerevisiae. Mature PAIR2 mRNA and several splicing variants were found to be highly expressed in wild-type reproductive tissues, and lower expression was also detected in vegetative tissues. In situ hybridization and BrdU incorporation experiments revealed that PAIR2 expression is specifically enhanced in male and female meiocytes, but not in those at pre-meiotic S phase or in the pollen maturation stages. The results obtained in this study suggest that the PAIR2 gene is essential for homologous chromosome pairing in meiosis, as in the case of the genes ASY1 and HOP1. The study also suggested the possibility that a highly homologous copy of the PAIR2 gene located on a different chromosome is in fact a pseudogene.

Amino Acid Sequence↗

PubMed2004

Clinical evaluation of granulocyte/monocyte apheresis therapy for active ulcerative colitis.

BACKGROUND: Recent evidence suggests that peripheral blood granulocytes and monocytes/macrophages have a major role in the exacerbation of ulcerative colitis. AIMS: Our objective was to investigate if selective granulocyte and monocyte adsorptive apheresis with Adacolumn promotes remission of active ulcerative colitis and spares corticosteroid. SUBJECTS: Sixty patients with active ulcerative colitis were studied, of whom 39 had relapsing-remitting ulcerative colitis, 15 had chronic continuous and 6 had their first episode of ulcerative colitis. METHODS: Granulocytapheresis was done with an Adacolumn filled with cellulose acetate beads as apheresis carriers that adsorb FcgammaR and complement receptors bearing leucocytes (granulocytes, monocytes and a small fraction of lymphocytes). Patients received up to 10 Adacolumn sessions over 12 weeks, one session was 60-90 min at 30 mL/min. No additional medication was given. Efficacy was assessed with Seo's activity index (AI) [Seo M, Okada M, Yao T. An index of disease activity in patients with ulcerative colitis. Am J Gastroenterol 1992;87:971-6]. The mean AL was 197.5 and range 154.4-277.7. AI < 150 was considered significant improvement and AI < 100 was considered clinical remission. RESULTS: Of 60 patients, 50 (83.3 %) improved, 14 achieved remission, granulocytapheresis was most effective in steroid-dependent patients. At entry, the mean dose of prednisolone was 15.3 mg/day per patient and was reduced to 3.6 mg/day after 10 sessions. Granulocytapheresis was well tolerated and no serious side-effects were observed. CONCLUSION: Based on our experience in patients with diverse ulcerative colitis disease expression and long-term exposure to conventional drug therapy, we believe that granulocytapheresis is an effective adjunct to conventional medication for promoting remission and sparing steroids in patients with active ulcerative colitis.

Adolescent↗

PubMed2004

Ice-water interface migration by temperature controlling for stretching of DNA molecules.

This report shows a new DNA stretching method using migration of an ice-water interface. DNA molecules were stretched accompanying the migration of the solid-liquid interface and immobilized in frozen area. This simple method needs no chemical modification to keep DNA in the stretched form. For full stretching of DNA molecules, one terminus of the DNA molecules were anchored on silanized substrate. The anchored DNA molecules were stretched by freezing the DNA solution. The stretched DNA molecules were observed after sublimation of the frozen solution keeping its stretched form on silanized surface which had no attractive interaction with DNA molecules except for the SH-modified terminus in solution. An infrared (IR) laser beam was introduced to a frozen DNA solution through an objective lens for local area melting of the solution. Scanning of the laser irradiation caused stretching and enclosing of DNA molecules in the frozen area followed by migration of the solid-liquid interface.

Biophysical Phenomena↗

PubMed2004

Evaluation of proximal tooth contact tightness at rest and during clenching.

The aims of this study were to develop a device for measuring the tightness of proximal tooth contact and to evaluate the proximal contact tightness using this device at rest and during clenching. Twenty young adult volunteers with healthy dentition participated in this experiment. The tightness of proximal tooth contact between the second premolar and the first molar of both the maxilla and the mandible was measured by pulling a stainless steel strip between them at rest, and at 20 and 50% clenching levels of maximum voluntary contraction of masseter muscles at intercuspal position. Proximal contact tightness increased as the clenching levels of both the maxilla and the mandible increased. At rest, proximal contact tightness was less in the maxilla than in the mandible, whereas during clenching it was less in the mandible. These results indicate that during clenching, the teeth are displaced and they contact appropriately with adjacent teeth, making it possible to exert sufficient occlusal force while maintaining the integrity of dental arches.

Adult↗

PubMed2004

Clinical features, effectiveness of drug-based treatment, and prognosis of new daily persistent headache (NDPH): 30 cases in Japan.

Although new daily persistent headache (NDPH) is considered to be one of the most refractory headaches to pharmacological treatment, the effectiveness of drug-based treatment, and the prognosis of NDPH have not been well studied. The purpose of this study is to evaluate the effectiveness of pharmacological treatment of NDPH. Seventeen men and 13 women who met the IHS diagnostic criteria for NDPH, were treated for five years from November 1997 to October 2002, and whose headache conditions were entirely available for reference as of October 2003 were investigated in Toyonaka Municipal Hospital. Mean age at onset 35.0 years (range 13-73 years). The onset of headache occurred in relation to a stressful life event in six (20%) patients and any precipitating events could not be identified in 24 (80%) patients. For treatment, muscle relaxants were first administered and if no effect was observed, tricyclic antidepressants, selective serotonin reuptake inhibitors, and antiepleptic drugs were subsequently administered. Results of the drug-based treatments in the 30 cases were 'very effective' for eight (27%) cases, 'moderately effective' for one (3%) case, 'mildly effective' for six (20%) cases, and 'not effective' for 15 (50%) cases. According to the survey on the phone for the patients who did not improve to the level of 'mildly effective' or better and did not come back to our institution as of October 2003, there were no cases found to have spontaneously improved to the level of 'mildly effective' or better. These results suggest that NDPH is highly recalcitrant to the treatments with poor prognosis and better treatments are needed.

Adolescent↗

PubMed2004

Human fetuses do not register chromosome damage inflicted by radiation exposure in lymphoid precursor cells except for a small but significant effect at low doses.

Human fetuses are thought to be highly sensitive to radiation exposure because diagnostic low-dose X rays have been suggested to increase the risk of childhood leukemia. However, animal studies generally have not demonstrated a high radiosensitivity of fetuses, and the underlying causes for the discrepancy remain unidentified. We examined atomic bomb survivors exposed in utero for translocation frequencies in blood lymphocytes at 40 years of age. Contrary to our expectation of a greater radiosensitivity in fetuses than in adults, the frequency did not increase with dose except for a small increase (less than 1%) at doses below 0.1 Sv, which was statistically significant. We interpret the results as indicating that fetal lymphoid precursor cells comprise two subpopulations. One is small in number, sensitive to the induction of both translocations and cell killing, but rapidly diminishing above 50 mSv. The other is the major fraction but is insensitive to registering damage expressed as chromosome aberrations. Our results provide a biological basis for resolving the long-standing controversy that a substantial risk of childhood leukemia is implicated in human fetuses exposed to low-dose X rays whereas animal studies involving mainly high-dose exposures generally do not confirm it.

Chromosome Aberrations↗

PubMed2004

Estimating the number of hematopoietic or lymphoid stem cells giving rise to clonal chromosome aberrations in blood T lymphocytes.

Quantifying the proliferative capacity of long-term hematopoietic stem cells in humans is important for bone marrow transplantation and gene therapy. Obtaining appropriate data is difficult, however, because the experimental tools are limited. We hypothesized that tracking clonal descendants originating from hematopoietic stem cells would be possible if we used clonal chromosome aberrations as unique tags of individual hematopoietic stem cells in vivo. Using FISH, we screened 500 blood T lymphocytes from each of 513 atomic bomb survivors and detected 96 clones composed of at least three cells with identical aberrations. The number of clones was inversely related to their population size, which we interpreted to mean that the progenitor cells were heterogeneous in the number of progeny that they could produce. The absolute number of progenitor cells contributing to the formation of the observed clones was estimated as about two in an unexposed individual. Further, scrutiny of ten clones revealed that lymphocyte clones could originate roughly equally from hematopoietic stem cells or from mature T lymphocytes, thereby suggesting that the estimated two progenitor cells are shared as one hematopoietic stem cell and one mature T cell. Our model predicts that one out of ten people bears a non- aberrant clone comprising >10% of the total lymphocytes, which indicates that clonal expansions are common and probably are not health-threatening.

Adolescent↗

PubMed2004

Prediction of clonal chromosome aberration frequency in human blood lymphocytes.

We recently conducted a large-scale screening for clonal aberrations among atomic bomb survivors and proposed a model for the gross clonal composition of blood lymphocytes. Here we show an application of the model indicating that the number, m,of clones detectable by cytogenetic methods in an individual is predictable by the equation m= (1.8 + 6.4FG) x FP x n/500, where FG represents the estimated translocation frequency in the 46 chromosome set, FP is the observed translocation frequency with FISH or other methods, and nis the number of cells examined. Application of the equation to the results of seven other reports gave close agreement between the observed and calculated numbers of clones. Since the model assumes that clonal expansion is ubiquitous, and any translocation can be the constituent of a clone detectable by cytogenetic means, the vast majority of observed clonal expansions of these somatic cells are likely the result of random-hit events that are not detrimental to human health. Furthermore, since our model can predict the majority of clonal aberrations among Chernobyl workers who were examined 5-6 years after irradiation, clonal expansion seems to occur primarily within a few years after exposure to radiation, most likely being coupled with the process of recovery from radiation-induced injury in the lymphoid and hematopoietic systems.

Chromosome Aberrations↗