Biomedical subjects

Y Nakano

Publications and source records attributed to Y Nakano.

At least 127 records · Page 7Linked to original sources

PubMed2000

Temporary use of an accuflex stent for unextractable common bile duct stones.

Endoscopic management has become the main therapeutic approach for the extraction of common bile duct (CBD) stones, and successful removal can be achieved in 80-90% patients using conventional balloon and basket techniques. However, if it is difficult to completely fragment a stone, or to clear the CBD, which may occur for a variety of reasons, the therapeutic problem will remain. When bile duct stones can not be removed, a viable management option is to place a biliary stent to ensure drainage. However, recent studies of long-term biliary stenting, with a plastic stent, showed a relatively high rate of morbidity and mortality. We report an alternative, unique treatment for unextractable common bile duct stones, using the temporal placement of an expandable metallic stent (EMS) to facilitate passage of fragments through the papilla.

Aged↗

PubMed2000

Mutation report: complete paternal uniparental isodisomy of chromosome 1: a novel mechanism for Herlitz junctional epidermolysis bullosa.

Uniparental disomy denotes a situation when an individual has inherited two copies of a specific chromosome from a single parent. Uniparental disomy has been demonstrated to be involved in the pathogenesis of recessively inherited diseases in rare cases. Here we report a patient of Japanese origin with Herlitz junctional epidermolysis bullosa (OMIM no. 226700), who died at the age of 8 mo from complications of the disease. The mutation analysis revealed that the proband was homozygous for a nonsense mutation C553X in the LAMC2 gene encoding the gamma2 chain of laminin 5. The father was a heterozygous carrier of this mutation whereas the mother had two normal alleles of this gene. The patient showed homozygosity for 15 known intragenic polymorphisms in the LAMC2 gene. Furthermore, genotype analysis, performed from the parents and the proband, using 16 microsatellite markers spanning the entire chromosome 1, revealed that the patient was homozygous for all markers tested, and that these alleles originated from the father. Among the 16 markers, eight were fully informative for the absence of the maternal chromosome 1 in the proband, suggesting that the patient had complete paternal isodisomy of this chromosome. Thus, the Herlitz junctional epidermolysis bullosa phenotype in this patient is caused by homozygous LAMC2 mutation C553X that is of paternal origin and results from nondisjunction and uniparental disomy involving monosomy rescue. This is a novel mechanism resulting in Herlitz junctional epidermolysis bullosa and has implications for assessment of the risk in subsequent pregnancies.

Base Sequence↗

PubMed2000

Incidence of cleft lip or palate in 303738 Japanese babies born between 1994 and 1995.

To investigate the incidence of cleft lip or palate or both (CLP) in Japan, 303738 babies born in 1532 institutions between 1994 and 1995 were examined and 437 (0.14%) were found to have abnormalities. Of these babies, 32.1% had cleft lip, 43.3% had cleft lip and palate, and 24.8% had cleft palate (Table 2). These results show that the incidence of cleft lip and palate has declined compared with the period from 1981 to 1982.

Cleft Lip↗

PubMed2000

The bronchoconstrictive action of evodiamine, an indoloquinazoline alkaloid isolated from the fruits of Evodia rutaecarpa, on guinea-pig isolated bronchus: possible involvement on vanilloid receptors.

Evodiamine, a constituent of Evodiae Fructus (Evodia rutaecarpa Benth., Rutaceae), produced a bronchial contraction that is resistant to atropine and abolished by pretreatment with a mixture of the NK1 and NK2 receptor antagonists. Contractile responses to evodiamine were examined in guinea-pig isolated bronchus and compared with those to capsaicin. Both compounds evoked bronchial contraction in a concentration-dependent manner. Maximal contractions for evodiamine and capsaicin were observed at concentrations of 3 microM and 1 microM, respectively. Capsazepine (10 microM), an established antagonist of vanilloid receptor (capsaicin receptor), competitively inhibited the bronchial contraction evoked by evodiamine, suggesting that evodiamine activated vanilloid receptors. Evodiamine (3 microM) and capsaicin (1 microM) produced complete crossed tachyphylaxis. Both compounds desensitized tissues to subsequent additions of either evodiamine or capsaicin. These results suggest that the evodiamine-induced contractile response of the bronchus could be attributed to the resultant tachykinin release from sensory neurons by binding of evodiamine to vanilloid receptors. Rutaecarpine, which belongs to the same indoloquinazoline-type alkaloid as evodiamine, showed neither bronchoconstrictive, desensitizing effects nor vanilloid antagonistic effects at all the concentrations examined (up to 200 microM).

Animals↗

PubMed2000

Efficacy of adding multiple doses of oxitropium bromide to salbutamol delivered by means of a metered-dose inhaler with a spacer device in adults with acute severe asthma.

BACKGROUND: The efficacy of combination therapy adding multiple doses of anticholinergics to beta(2)-agonists to improve outcome has not been established in adults with acute severe asthma. OBJECTIVE: This study was undertaken to compare the outcome of adults with acute severe asthma treated with 4 puffs of salbutamol (100 microg/actuation) every 20 minutes for 3 doses plus 4 puffs of oxitropium bromide (100 microg/actuation) with each of the 3 salbutamol doses versus salbutamol alone administered by means of a metered-dose inhaler with a spacer device. METHODS: A randomized, single-blind, placebo-controlled study was performed in 74 patients between 18 and 55 years old presenting to the emergency department (ED) for treatment of acute asthma with a peak expiratory flow (PEF) of 50% or less than the normal predicted value. The primary endpoint was improvement in PEF over the course. The secondary endpoint was the need for additional ED treatment at 120 minutes. RESULTS: The increase in PEF over the course was significantly greater in the oxitropium plus salbutamol treatment group (P <.0001). The mean absolute difference in PEF at 120 minutes for combination therapy compared with salbutamol alone was 37.8 L/min (P =.001). In addition, the proportion of need for additional ED treatment was less in the combination group than the group receiving salbutamol alone (odds ratio, 0.32; 95% confidence interval, 0.11-0.90). CONCLUSION: Adding multiple doses of oxitropium bromide to salbutamol delivered by means of a metered-dose inhaler with a spacer device for acute severe asthma produces a significant improvement in lung function and reduces the need for additional ED treatment.

Acute Disease↗

PubMed2000

EUS changes predictive for recurrence of esophageal varices in patients treated by combined endoscopic ligation and sclerotherapy.

BACKGROUND: Recurrence of varices is still common after endoscopic treatment of esophageal varices. In this study, predictive signs of variceal recurrence were investigated by ultrasonic (US) miniature probe in patients treated by combined endoscopic ligation and sclerotherapy. METHODS: Detectability of vessels by US miniature probe was evaluated first in rats. In 41 patients treated by combined therapy, the esophagus and the cardia region were examined by US miniature probe. In 25 patients examined by percutaneous transhepatic portography, the relationship between US miniature probe and percutaneous transhepatic portography findings was evaluated. RESULTS: The smallest vessel detected by US miniature probe was 0.3 mm in diameter in the study using intra-abdominal vessels of rat. After variceal eradication, US miniature probe showed intramural vessels in the cardia that were classified as follows: grade I, a few vessels (19 patients, 46%); grade II, uniformly scattered vessels (11, 27%); grade III, abundant vessels resembling a honeycomb (11, 27%). As the sonographic grade increased, the rate of variceal recurrence increased. As the venographic grade of staining in the distal esophagus increased, the esophageal wall became thicker and the sonographic grade at the cardia increased. CONCLUSIONS: Endosonographic evaluation of the distal esophagus and cardia is predictive of variceal recurrence.

Adult↗

PubMed2000

CD4(+) v(alpha)14 NKT cells play a crucial role in an early stage of protective immunity against infection with Leishmania major.

The roles of gamma delta T, NK and NKT cells in an early stage of protective immunity against infection with Leishmania major were investigated. Further, the contribution of these innate cells to the expression of 65 kDa heat shock protein (HSP65) in host macrophages was examined, since we found previously that this expression prevents apoptotic death of infected macrophages and is a crucial step in the acquisition of protective immunity against infection with various obligate intracellular protozoa including L. major. C57BL/6 and DBA/2 mice were found to be resistant against the infection on the basis of the parasite burden in their regional lymph nodes, and to strongly express HSP65 in their macrophages, whereas BALB/c mice were susceptible and barely expressed the HSP65. In those resistant mice, CD4(+) NKT cells prominently increased in their regional lymph node and were the main effector cells at least for an early stage of the protective immunity and for the HSP65 expression, whereas this subset did not increase in susceptible BALB/c mice. Further, neither gamma delta T nor NK cells in resistant mice contributed to those protective immune responses. The NKT cell subset bore CD3, CD4, TCR alpha beta, IL-2R beta and NK1.1 but scarcely asialo-GM(1). Moreover, this effector subset was confirmed to be V(alpha)14 NKT cells by using J(alpha)281(-/-) mice.

Animals↗

PubMed2000

Implanted tumor growth is suppressed and survival is prolonged in sixty percent of food-restricted mice.

To examine the effect of food restriction on immune functions in the tumor-bearing state, mice were divided into a control group (fed 5.0 g diet/d; 71 kJ/d) and a 60% food-restricted group (fed 3.0 g diet/d; 43 kJ/d) at 8-wk of age, and 4 wk later, L1210 tumor cells were inoculated intradermally. In the food-restricted mice, tumor growth was significantly suppressed, and mean survival time after the tumor inoculation was prolonged (P < 0.05). The plasma concentrations of two antitumor cytokines, interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), were greater in the food-restricted group before tumor inoculation (P < 0. 05). Furthermore, the food-restricted mice had significantly higher plasma levels of IFN-gamma and TNF-alpha after tumor inoculation, although the treatment significantly increased these cytokine levels in both groups. Splenic natural killer cell cytotoxicity was also higher in the tumor-bearing food-restricted mice than in controls (P < 0.05). Food-restricted mice have strong antitumor immunity, and as a result, tumor growth is suppressed and survival time is prolonged in these mice.

Analysis of Variance↗

PubMed2000

A tobacco NtMET1 cDNA encoding a DNA methyltransferase: molecular characterization and abnormal phenotypes of transgenic tobacco plants.

A cDNA encoding a DNA methyltransferase, with a predicted polypeptide of 1556 amino acid residues containing all motifs conserved in this enzyme family, was isolated from tobacco plants, and the corresponding gene was designated as NtMET1. RNA blot analysis indicated NtMET1 transcripts to accumulate in dividing tissues of tobacco plants, and they could be detected during the S phase in synchronized dividing BY2 cells. In situ hybridization revealed the transcripts to be localized exclusively in actively proliferating tissues around axillary apical meristem. In order to ascertain physiological roles, transgenic tobacco plants that had the antisense construct were made and examined for phenotypes. Methylation levels of genomic DNA from transgenic plants significantly decreased in comparison with wild-type levels, and distinct phenotypic changes including small leaves, short internodes and abnormal flower morphology were noted. Microscopic observation revealed that leaf structure differed between transgenic and wild-type plants. These results suggest that NtMET1 functions during DNA replication, and that DNA methylation plays an important role in plant morphogenesis.

Cell Cycle↗

PubMed2000

Psychosocial factors regulating natural-killer cell activity in recurrent spontaneous abortions.

PROBLEM: The preconceptional natural-killer cell (NK) activity predicts subsequent miscarriage among women with unexplained recurrent spontaneous abortion (RSA). Psycho-neuro-immuno-endocrine network has recently been proposed as a mechanism for abortions. We therefore examined which psychosocial factors influenced the NK activity among women with RSA. METHOD OF STUDY: We measured the preconceptional NK activity of 61 women with a history two consecutive unexplained first-trimester miscarriages and no live births. We also administered semi-structured interviews and a battery of self-report questionnaires to assess their social support, personality, self-esteem and psychiatric symptoms. RESULTS: The preconceptional NK activity was negatively correlated with the women's neuroticism personality trait (r= -0.32, P = 0.01) and current depressive symptoms (r = -0.26, P= 0.05), and positively correlated with their self-esteem (r = 0.34, P = 0.01). CONCLUSIONS: In addition to several substances such as transforming-growth-factor beta and granulocyte-macrophase colony-stimulating factor, we found that low neuroticism, low depression scale score and high self-esteem contributed to high NK activity among women with RSA.

Abortion, Habitual↗

PubMed2000

Formation of methyl mercaptan from L-methionine by Porphyromonas gingivalis.

Methyl mercaptan production by oral bacteria is thought to be one of the main causes of oral malodor. We examined the ability of periodontopathic Porphyromonas gingivalis to produce methyl mercaptan from L-methionine and found that the invasive strains W83 and W50 produced large amounts of methyl mercaptan. We cloned and sequenced the mgl gene encoding L-methionine-alpha-deamino-gamma-mercaptomethane-lyase (METase) from P. gingivalis W83. The structural mgl gene consisted of 1,200 bp and encoded a 43.3-kDa protein. To examine the role of methyl mercaptan in the pathogenesis of P. gingivalis, a METase-deficient mutant of P. gingivalis W83 was constructed. The methionine degradation activity and virulence of the mutant (M1217) and the parent strain (W83) in mice were compared. M1217 showed a marked decrease in the formation of methyl mercaptan from L-methionine and decreased virulence compared with the wild-type strain W83. These results suggest that methyl mercaptan not only is one of the sources of oral malodor, but may also play a role in the pathogenicity of P. gingivalis.

Animals↗

PubMed2000

Role of serotype-specific polysaccharide in the resistance of Streptococcus mutans to phagocytosis by human polymorphonuclear leukocytes.

To clarify the role of cell surface components of Streptococcus mutans in resistance to phagocytosis by human polymorphonuclear leukocytes (PMNs), several isogenic mutants of S. mutans defective in cell surface components were studied with a luminol-enhanced chemiluminescence (CL) assay, a killing assay, and a transmission electron microscope. The CL responses of human PMNs to mutant Xc11 defective in a major cell surface antigen, PAc, and mutant Xc16 defective in two surface glucosyltransferases (GTF-I and GTF-SI) were the same as the response to the wild-type strain, Xc. In contrast, mutant Xc24R, which was defective in serotype c-specific polysaccharide, induced a markedly higher CL response than the other strains. The killing assay showed that human PMNs killed more Xc24R than the parent strain and the other mutants. The transmission electron microscopic observation indicated that Xc24R cells were more internalized by human PMNs than the parental strain Xc. These results may be reflected by the fact that strain Xc24R was more phagocytosed than strain Xc. The CL response of human PMNs to a mutant defective in polysaccharide serotype e or f was similar to the response to Xc24R. Furthermore, mutants defective in serotype-specific polysaccharide were markedly more hydrophobic than the wild-type strains and the other mutants, suggesting that the hydrophilic nature of polysaccharides may protect the bacterium from phagocytosis. We conclude that the serotype-specific polysaccharide, but not the cell surface proteins on the cell surface of S. mutans, may play an important role in the resistance to phagocytosis.

Antigens, Bacterial↗

PubMed2000

Suppression of specific IgE antibody responses by liposome-conjugated ovalbumin in mice sensitized with ovalbumin via the respiratory tract.

BACKGROUND: Previously we have shown that intranasal administration of ovalbumin (OVA) together with cholera toxin (CT) abrogates nasal tolerance to OVA, resulting in the induction of specific IgE antibody (Ab) responses, and that intraperitoneal injection of OVA coupled with liposomes (OVA-liposomes) induces a selective suppression of IgE Ab responses to OVA. Whether OVA-liposomes suppress anti-OVA IgE Ab responses in mice sensitized with CT-combined OVA via the respiratory tract remains to be clarified. METHODS: In some experiments, mice were given OVA, liposomes or OVA-liposomes with or without CT intranasally three times, at 2-week intervals (weeks 0, 2 and 4). In other experiments, mice were given OVA-liposomes intranasally 2 days before or 1 and 3 weeks after CT-combined OVA (week 0), which was administered intranasally three times, at 2-week intervals (weeks 0, 2 and 4). Two weeks after the third administration of CT-combined OVA (week 0), nasal wash and serum IgA, IgG and IgE Ab responses were assayed. RESULTS: Pretreatment with OVA-liposomes suppressed IgE Ab responses to CT-combined OVA, with a significantly high production of both nasal IgA and serum IgG Abs. Moreover, treatment with OVA-liposomes 1 and 3 weeks after CT-combined OVA administration also suppressed IgE Ab responses. The suppression of anti-OVA IgE Ab production by OVA-liposomes was accompanied by a simultaneous enhancement of specific IgA and IgG (IgG1, and especially IgG2a) Ab production. CONCLUSIONS: Postimmunization treatment with OVA-liposomes, as well as preimmunization treatment, suppressed specific IgE Ab responses in mice sensitized intranasally with CT-combined OVA. Allergens conjugated to liposomes may be appropriate for preventing the development of allergies to inhaled or dietary antigens in humans.

Administration, Intranasal↗

PubMed2000

Distorted trachea in patients with chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVES: We evaluated the size and configuration of the trachea in patients with chronic obstructive pulmonary disease (COPD; n = 35) on high-resolution computed tomography (HRCT) images and compared them with those of healthy volunteers (n = 24). METHODS: Using a newly developed computed method for analyzing the digital data of HRCT, the size and configuration of the trachea were automatically evaluated. RESULTS: The size of the trachea of the COPD subjects was the same as that of the control subjects; however, the configuration was more distorted in the COPD patients. There was no difference in the tracheal index (TI), which is the ratio of the coronal to the sagittal length, between these two groups; however, the ratio of the short to the long radius (SR/LR) was significantly smaller in the COPD group than in the control group. There was a significant correlation between SR/LR and airflow limitation as assessed by pulmonary function tests in the COPD group. CONCLUSIONS: The SR/LR is a better index of tracheal deformity than the classical TI. This deformity is not a consequence secondary to hyperinflation or emphysematous change of the lung, because the low attenuation area of the lung was not correlated with SR/LR.

Aged↗

PubMed2000

Computed tomographic measurements of airway dimensions and emphysema in smokers. Correlation with lung function.

Chronic obstructive pulmonary disease (COPD) is characterized by the presence of airflow obstruction caused by emphysema or airway narrowing, or both. Low attenuation areas (LAA) on computed tomography (CT) have been shown to represent macroscopic or microscopic emphysema, or both. However CT has not been used to quantify the airway abnormalities in smokers with or without airflow obstruction. In this study, we used CT to evaluate both emphysema and airway wall thickening in 114 smokers. The CT measurements revealed that a decreased FEV(1) (%predicted) is associated with an increase of airway wall area and an increase of emphysema. Although both airway wall thickening and emphysema (LAA) correlated with measurements of lung function, stepwise multiple regression analysis showed that the combination of airway and emphysema measurements improved the estimate of pulmonary function test abnormalities. We conclude that both CT measurements of airway dimensions and emphysema are useful and complementary in the evaluation of the lung of smokers.

Adult↗

PubMed2000

Airway wall thickness in asthma assessed by computed tomography. Relation to clinical indices.

Postmortem studies have shown that airway wall thickening is present in asthmatic patients and may play a pathophysiologic role. We investigated the presence and characteristics of airway wall thickening in patients with asthma, using helical computed tomography. Eighty-one asthmatic patients and 28 healthy control subjects were studied cross-sectionally. Airway wall thickness was assessed by a validated method on the basis of wall area (WA), WA corrected by body surface area (WA/BSA), and WA%, defined as (WA/total area) x 100 at the apical bronchus of the right upper lobe. Airway luminal area (Ai) and Ai/BSA were also examined. Asthma duration and severity, pulmonary function, and serum eosinophil cationic protein levels were evaluated. Intraobserver and interobserver reproducibility of WA, WA%, and Ai measurements were good. As compared with control, WA, WA/BSA, and WA% were significantly increased in patients with mild (n = 13), moderate (39), and severe persistent (22) asthma but not in patients with intermittent asthma (7). Comparison of the four asthmatic subgroups demonstrated thicker airways in more severe disease, but no difference in Ai or Ai/BSA. When all asthmatic patients were analyzed together, WA and WA/BSA correlated with the duration, although weakly, and severity of asthma. WA and WA/BSA negatively correlated with FEV(1) (percentage of predicted), FEV(1)/FVC (%), and FEF(25-75%) (percentage of predicted), whereas WA% negatively correlated with only FEV(1). We conclude that airway wall thickening occurs in patients with asthma and is not limited to those with severe disease. The degree of airway wall thickening may relate to the duration and severity of disease and the degree of airflow obstruction.

Adult↗

PubMed2000

Effects of ZNC-2381, a new oral compound, on several hepatic injury models and on hepatocellular apoptosis in mice and rats.

The hepatoprotective effect of ZNC-2381 (1-(4-aminophenyl) methyl-3-(3-nitrophenyl)-1,3-dihydroimidazo[4,5-b]pyridine-2-one), a novel 2-one dihydroimidazopyridine derivative, has been evaluated in several experimental models of hepatic injury. In mice, oral ZNC-2381, administered at doses of 3, 10 or 30 mgkg(-1), 1 h before induction of hepatic injury with concanavalin A, dose-dependently inhibited increases in serum alanine aminotransferase (ALT) activity. Apoptosis of liver cells, as indicated by DNA fragmentation (nucleosome assay) and DNA-ladder formation (electrophoresis), was also inhibited dose-dependently. ZNC-2381 dose-dependently inhibited concanavalin A-induced increases in serum tumour necrosis factor (TNF)-alpha levels, and TNF-alpha mRNA expression in the liver. Oral ZNC-2381 also dose-dependently inhibited increases in serum ALT activity in mice with hepatic injury induced by Propionibacterium acnes and a bacterial lipopolysaccharide (LPS) or D-galactosamine-LPS, and in rats with D-galactosamine-induced hepatic injury. These results indicate that oral ZNC-2381 inhibits cytokine (TNF-alpha) production and cytokine-related hepatocellular apoptosis, and might thus prevent different types of hepatic injury.

Alanine Transaminase↗

PubMed2000

Characterization of a vitamin B12 compound in the edible purple laver, Porphyra yezoensis.

The edible purple laver, Porphyra yezoensis, contained 51.49+/-1.51 microg of vitamin B12 compounds per 100 g dry weight of the laver (mean +/- SEM, n = 4). A vitamin B12 compound was purified from the lyophilized purple laver and partially characterized. The silica gel 60 TLC and reversed-phase HPLC patterns of the purified pink-colored compound were identical to those of authentic vitamin B12, but not to those of vitamin B12 analogues inactive for humans.

Biological Availability↗