Biomedical subjects

N Kikuchi

Publications and source records attributed to N Kikuchi.

At least 19 recordsLinked to original sources

PubMed1999

Molecular shape and ATP binding activity of rat p50, a putative mammalian homologue of RuvB DNA helicase.

Based on partial amino acid sequences of p50 purified from a high-salt buffer extract of a rat liver nuclear matrix fraction, p50 cDNA was cloned and sequenced, and its amino acid sequence was predicted. The sequence contained helicase motifs, and showed homology with RuvB DNA helicase of Thermus thermophilus and an open reading frame for an unknown 50.5 k protein of Saccharomyces cerevisiae. p50 was expressed as a GST-fusion protein and antiserum against the protein was generated. p50 was localized to the nuclear matrix by cell fractionation and immunoblotting. p50 bound to ATP-Sepharose beads. Ultracentrifugation and gel filtration analyses showed that p50 in rat liver and Xenopus egg mitotic extracts exists as large complexes corresponding to 697 k and 447 k, respectively. A 50 k protein reactive with p50 antibodies was detected not only in rat liver nuclei, but also in a Xenopus egg cytoplasm fraction and a S. cerevisiae extract. This suggests that this putative DNA helicase is present in a wide variety of species ranging from yeast to mammals.

ATPases Associated with Diverse Cellular Activitie↗

PubMed1998

Home blood pressure measurement has a stronger predictive power for mortality than does screening blood pressure measurement: a population-based observation in Ohasama, Japan.

OBJECTIVE: To compare the predictive powers of self-measurement of blood pressure at home (home blood pressure measurement) and casual (screening) blood pressure measurement for mortality. DESIGN: A prospective cohort study. SUBJECTS AND METHODS: We obtained home and screening blood pressure measurements for 1789 subjects aged > or = 40 years who were followed up for a mean of 6.6 years. The prognostic significance of blood pressure for mortality was determined by the Cox proportional hazards regression model adjusted for age, sex, smoking status, past history of cardiovascular disease, and the use of antihypertensive medication. RESULTS: When the home blood pressure values and the screening blood pressure values were simultaneously incorporated into the Cox model as continuous variables, only the average of multiple (taken more than three times) home systolic blood pressure values was significantly and strongly related to the cardiovascular mortality risk. The average of the two initial home blood pressure values was also better related to the mortality risk than were the screening blood pressure values. CONCLUSIONS: Home blood pressure measurement had a stronger predictive power for mortality than did screening blood pressure measurement for a general population. This appears to be the first study in which the prognostic significances of home and screening blood pressure measurements have been compared.

Adult↗

PubMed1998

Biochemical and serological examination of beta-hemolytic streptococci isolated from slaughtered pigs.

A total of 170 beta-hemolytic streptococci isolated from lesions in slaughtered pigs during 1988 to 1995 were identified by biochemical and serological examinations. Of these, 132 strains (77.6%) were Streptococcus (S.) dysgalactiae and 38 strains (22.4%) were S. porcinus. The largest serological group of streptococci was group C (78 strains, 45.9%), followed by group L (43 strains, 25.3%), group U (14 strains, 8.2%), group G (11 strains, 6.5%), group E (5 strains, 2.9%), and group P (5 strains, 2.9%). Most of isolates from endocarditis (61 strains) and arthritis (25 strains) were group C S. dysgalactiae, but about 33.3% of the isolates from lymphadenitis were group L S. dysgalactiae (28 strains), followed by group C (14 strains, 16.7%), group U S. porcinus (14 strains, 14.3%), and group G (10 strains, 11.9%).

Abattoirs↗

PubMed1998

Two-year experience of the Batista operation for non-ischemic cardiomyopathy.

The Batista operation was performed in 30 patients (25 men and 5 women, mean age 47 years) to treat cardiac failure due to non-ischemic cardiomyopathy, mostly idiopathic dilated cardiomyopathy, from December 1996 to June 1998. Preoperative New York Heart Association (NYHA) class was IV in 21 patients including 17 receiving inotropic support, and class III in 9 patients. Seven patients required emergency surgery because of on-going shock and 23 patients were operated electively. Combined cardiac procedures were; mitral valve reconstruction in 26 patients (19 replacements, 7 repairs), tricuspid annuloplasty in 15, aortic valve replacement in 3 and one each of maze and coronary artery bypass grafting. All patients successfully weaned from cardiopulmonary bypass. Intraaortic balloon pump was used in 6 patients but no left ventricular assist device was used. Two of 23 patients (8.7%) who underwent elective operation died during hospitalization and 3 patients (13.0%) died in the late period. Six of 7 patients (85.7%) with emergency operation died in the hospital and only one survived. Sixteen of 19 survivors returned to NYHA class I-II, and 3 were in class III. Mean ejection fraction increased from 18 +/- 6% to 31 +/- 5%. Diastolic dimension decreased from 79 +/- 8 to 60 +/- 8 mm. End-diastolic and systolic volume indices decreased from 203 +/- 43 to 103 +/- 25 ml/m2 and from 164 +/- 39 to 70 +/- 25 ml/m2, respectively, at the second postoperative week. Six patients had ventriculography at one year after the operation, and no redilation was noted. Increased thickness of left ventricular wall was observed postoperatively. The Batista operation can be performed with relatively low risk and clinical improvement was obvious in elective operation, wheras risk is very high in emergency cases. Therefore, proper guidelines for patient selection and choice of procedure are critically important to achieve a successful outcome in the Batista operation.

Adolescent↗

PubMed1997

A theoretical method for evaluating the relative importance of positive selection and neutral drift from observed base changes.

To evaluate the relative importance of positive selection and neutral drift from the nucleotide base changes observed in the homologous alignment of genes, a theoretical equation of base changes is formulated by including both the influence of selection and the base substitutions due to mutations. Under the assumption that the average rate of base substitutions estimated from synonymous changes is the "true" mutation rate applicable at all positions, this method is applied to the vertebrate globin gene family, and evaluates the departures of base change rates from the "true" mutation rate at the first and second codon positions as a consequence of preferential selection for the conservation of important function. In addition to the strong effect of selection on the amino acid residues in the internal region mostly common to myoglobin and hemoglobin chains, the distinctive directions of selective parameter values are seen at sites on the globin surface, distinguishing the subunit contact residues of hemoglobins from the polar residues on the surface of myoglobins. Moreover, this effect of selection distinguishing between the myoglobin and hemoglobin chain genes becomes weaker in cold-blooded vertebrates, especially in fish, strongly suggesting the possibility that the clear distinction between these globins is a result of selection out of the changes regarded as neutral ones in an ancestor of vertebrates. Thus, the present method may also serve to investigate the homology of many other proteins from the aspect of molecular evolution, mainly focusing on the evolution of their biological functions.

Animals↗

PubMed1997

Relation between nocturnal decline in blood pressure and mortality. The Ohasama Study.

To investigate the relation between nocturnal decline in blood pressure and mortality, we obtained ambulatory blood pressures in 1542 residents aged 40 years or over of a rural Japanese community. Subjects were followed-up for a mean of 5.1 years and were then subdivided into four groups according to the percent decline in nocturnal blood pressure: 1) extreme dippers: percent decline in nocturnal blood pressure > or = 20% of the daytime blood pressure; 2) dippers: decline of > or = 10% but < 20%; 3) nondippers: decline of > or = 0% but < 10%; and 4) inverted dippers: no decline. The relationship between the decline in nocturnal blood pressure and mortality was examined by the Cox proportional hazards regression model adjusted for age, sex, smoking status, previous history of cardiovascular disease, and the use of antihypertensive medication. The mortality risk was highest in inverted dippers, followed by nondippers. There was no difference in mortality between extreme dippers and dippers. This relationship was observed for both treated and untreated subjects, was more pronounced for cardiovascular than for noncardiovascular mortality, and did not change after the data were adjusted for 24-h, daytime, and nighttime blood pressure levels.

Aged↗

PubMed1997

Factors affecting the nocturnal decrease in blood pressure: a community-based study in Ohasama.

OBJECTIVE: To investigate factors affecting the nocturnal decrease in blood pressure. DESIGN: A cross-sectional study of 823 community-based untreated subjects aged > 20 years. Screening and ambulatory blood pressures were measured and the effects of age and the ambulatory blood pressure on the nocturnal decrease were examined. RESULTS: The magnitude of the decrease and the percentage decrease in the nocturnal blood pressure increased with increasing daytime ambulatory blood pressure and decreased with increasing night-time ambulatory blood pressure. Although the magnitude of the nocturnal decrease in blood pressure increased with increasing daytime blood pressure, the nocturnal blood pressure levels in hypertensives were still higher than those in normotensive subjects. The magnitude decreased with increasing age for men but not for women, whereas the percentage decrease decreased with increasing age both for men and for women. The SD of the 24 h blood pressure correlated strongly to the magnitude of the nocturnal decrease (systolic blood pressure r = 0.62, P < 0.0001; diastolic blood pressure r = 0.52, P < 0.0001), suggesting that the SD of the 24 h blood pressure is representative of the nocturnal decrease. A minimal nocturnal decrease was observed frequently in elderly normotensive men but infrequently in hypertensive individuals from the general population. A marked nocturnal decrease was observed frequently in hypertensive women aged > 70 years. CONCLUSION: Although the magnitude of the nocturnal decrease in blood pressure increased with increasing daytime blood pressure, the nocturnal blood pressure levels increased with increasing daytime ambulatory blood pressure. Therefore, the blood pressure in hypertensive subjects should essentially be lowered throughout the 24 h period. A marked nocturnal decrease in blood pressure in some elderly hypertensive women was observed without treatment. The nocturnal blood pressure levels of such subjects should be considered during treatment.

Adult↗

PubMed1997

Phylogenetic positions and assignment of swine and ovine corynebacterial isolates based on the 16S rDNA sequence.

The nucleotide sequences of the 16S ribosomal RNA gene (rDNA) of swine and ovine corynebacterial strains were determined. The sequences of the strains that identified as Corynebacterium pseudotuberculosis by their biochemical characteristics were homologous with each other. The phylogenetic position of C. pseudotuberculosis strains was closet to C. ulcerans and next closet to C. diphtheriae. The nucleotide sequence of another swine isolate, SC8, was similar to that of a recently proposed species, C. seminale, and a non-validated species, "C. glucuronolyticum," with about 0.01 to 0.02 evolutionary distances. Analysis of the predicted secondary structure of the 16S rRNA molecule agreed with the close phylogenetic relationships between C. pseudotuberculosis and C. ulcerans and between C. seminale and strain SC8.

Animals↗

PubMed1997

Phylogenetic analyses of Chlamydia psittaci strains from birds based on 16S rRNA gene sequence.

The nucleotide sequences of 16S ribosomal DNA (rDNA) were determined for 39 strains of Chlamydia psittaci (34 from birds and 5 from mammals) and for 4 Chlamydia pecorum strains. The sequences were compared phylogenetically with the gene sequences of nine Chlamydia strains (covering four species of the genus) retrieved from nucleotide databases. In the neighbor-joining tree, C. psittaci strains were more closely related to each other than to the other Chlamydia species, although a feline pneumonitis strain was distinct (983 to 98.6% similarity to other strains) and appeared to form the deepest subline within the species of C. psittaci (bootstrap value, 99%). The other strains of C. psittaci exhibiting similarity values of more than 99% were branched into several subgroups. Two pigeon strains and one turkey strain formed a distinct clade recovered in 97% of the bootstrapped trees. The other pigeon strains seemed to be distinct from the strains from psittacine birds, with 88% of bootstrap value. In the cluster of psittacine strains, three parakeet strains and an ovine abortion strain exhibited a specific association (level of sequence similarity, 99.9% or more; bootstrap value, 95%). These suggest that at least four groups of strains exist within the species C. psittaci. The 16S rDNA sequence is a valuable phylogenetic marker for the taxonomy of chlamydiae, and its analysis is a reliable tool for identification of the organisms.

Abortion, Veterinary↗

PubMed1997

Mutations within the reactive-site region of human pancreatic secretory trypsin inhibitor confer alpha-thrombin and factor Xa inhibitory activities.

Mutations were introduced into the reactive-site region of human pancreatic secretory trypsin inhibitor (PSTI) to produce thrombin and/or factor Xa inhibitors. All of five mutants showed trypsin inhibitory activity as strong as wild-type PSTI. Moreover, the Arg (P1), Pro-Arg (P2-P1), and Pro-Arg-Ile-Tyr-Asn (P2-P1-P1'-P2'-P3') (bold letters indicated replaced amino acids compared to the wild type) mutants had additional inhibitory activities toward factor Xa, both thrombin and factor Xa, and thrombin, respectively, at 1 x 10(-5) M.

Antithrombins↗

PubMed1997

Bacterial isolation from slaughtered pigs associated with endocarditis, especially the isolation of Streptococcus suis.

Bacterial isolation from slaughtered pigs with endocarditis was carried out from 1985 to 1994. A total of 495 (0.025%) out of 2,006,127 pigs were diagnosed as having endocarditis. Though bacteria were significantly isolated from 399 of the 495 pigs, bacteria could not be isolated in 96 pigs (19.4%). In 11 pigs, 2 bacterial species were isolated from heart lesion. Streptococcus suis was isolated from 127 cases (25.7%), Streptococcus dysgalactiae from 75 (15.2%), Erysipelothrix rhusiopathiae from 63 (12.7%), Actinomyces pyogenes from 39 (7.9%), Pasteurella multocida from 11 (2.2%). Staphylococcus aureus from 10 (2.0%), and Streptococcus porcinus from 8 (1.6%). Among the 99 isolates biochemically identified as S. suis, the major serotype was S. suis type 2 (35.4%). The remainder of the typable isolates were identified as serotypes 1/2 (2.0%) and 9 (1.0%). A total of 61 isolates (61.6%) were untypable.

Abattoirs↗

PubMed1997

Phylogenetic analyses of Staphylococcus based on the 16S rDNA sequence and assignment of clinical isolates from animals.

The nucleotide sequences of the 16S rDNA in 17 strains of 16 taxa of the genus Staphylococcus were determined. The sequences were compared phylogenetically together with the gene sequences of 10 (including 7 other species) Staphylococcus species retrieved from the DNA Data Bank of Japan. Although the primary and secondary structures of most of Staphylococcus species were very similar (homology values 96.4% or more) except for S. caseolyticus MAFF 911387T (homology values 95.4% or less), the 23 staphylococcal species were divided into 10 groups based on similarity, evolutionary distance and phylogenetic tree analysis. Nucleotide stretches in several variable domains in the 16S rDNA sequences appeared to be specific for the bacterial groups or the species. By comparing such characteristics in the sequence and phylogenies of 5 staphylococcal clinical isolates from bovine mastitis, canine and feline pyoderma, and feline urogenital syndrome with the information obtained in this study, the species level of each organism was identified.

Animals↗

PubMed1997

Determinants of circadian blood pressure variation: a community-based study in Ohasama.

We investigated factors affecting the nocturnal decline in blood pressure (BP). A cross sectional study was done in 706 community-based untreated subjects > or = 20 years of age. Screening and ambulatory BPs were measured and the effects of age and the ambulatory BP on the nocturnal decline were examined. Bivariate analysis demonstrated that the magnitude of the decline and the percent decline in the nocturnal BP increased with increase in daytime ambulatory BP and decreased with increase in nighttime ambulatory BP. Although the magnitude of the nocturnal decline in BP increased with increasing daytime BP, the nocturnal BP in hypertensives was still higher than those in normotensives. The magnitude decreased with increasing age in men but not in women, while the percent decline decreased with increasing age in both men and women. Since bivariate analysis demonstrated that the daytime BP, nighttime BP, and standard deviation of the 24-hour BP strongly correlated with the magnitude of the nocturnal decline, these parameters were excluded as independent variables from the multivariate analysis. In the multivariate analysis the nighttime pulse pressure was negatively and daytime pulse pressure was positively associated with the magnitude of the decline and the percent decline in the nocturnal BP. A non-dipping circadian variation was frequently observed in elderly normotensive men but the rate of nondipper was rather low in hypertensive individuals in the general population. A marked dipping pattern was frequently observed in hypertensive women > or = 70 years of age. The nocturnal BP levels in subjects with daytime hypertension are higher than those in subjects with daytime normotension. Therefore, BP must ideally be lowered over 24-hour period in hypertensive subjects. The diminished magnitude of the decline and the decrease in the percent decline in the nocturnal BP in the elderly may be mediated by the disturbed baroreflex function due to the decrease in compliance of large elastic artery. However, in some elderly hypertensive women, excess nocturnal decline in BP is observed. In such subjects, we should take care of the nocturnal BP levels during treatment.

Adult↗

PubMed1997

[Duration of effect of pulmonary rehabilitation in elderly patients with chronic obstructive pulmonary disease].

Pulmonary rehabilitation has been reported to be effective in patients with chronic obstructive pulmonary disease (COPD). To investigate the effect of a moderate period of pulmonary rehabilitation combined with inspiratory muscle training (IMT) in elderly patients with COPD, we instituted pulmonary rehabilitation for 60 weeks in five elderly patients (age: 65.4 +/- 3.7 SE years). IMT was performed for 15 min twice daily using a pressure threshold device. The inspiratory threshold was set at 15% of the maximal inspiratory pressure (PImax) of each individual. Maximal peak flow significantly increased from 3.0 +/- 0.6 (L/s) at baseline to 4.1 +/- 0.7 (L/s) after 12 weeks (p < 0.02) and was maintained at that level for 60 weeks. PImax increased significantly from 49.9 +/- 6.4 cmH2O at baseline to 67.3 +/- 3.0 cmH2O after 12 weeks (p < 0.05) and to 72.8 +/- 3.5 cmH2O (p < 0.02) after 60 weeks of rehabilitation. The 10-minute walking distance increased from 666.6 +/- 55.0 to 764.0 +/- 49.9 m (p < 0.05) after 12 weeks and was maintained at the same level. We conclude that pulmonary rehabilitation combined with IMT improves pulmonary function and inspiratory muscle strength in elderly patients with COPD between for 12 weeks after commencement, but occurs that no significant increase on lung function or 10-minute walking distance from 12 to 60 weeks. Respiratory muscle strength may further increase after 60 weeks.

Age Factors↗

PubMed1997

[The effects of pulmonary rehabilitation combined with inspiratory muscle training on pulmonary function and inspiratory muscle strength in elderly patients with chronic obstructive pulmonary disease].

It has been suggested that pulmonary rehabilitation compined with inspiratory muscle training (IMT) might improve pulmonary function and respiratory muscle strength in elderly patients with chronic obstructive pulmonary disease (COPD). To test this hypothesis, inspiratory muscle strength (PImax), expiratory muscle strength (PEmax) and resting pulmonary function were measured in 13 elderly patients with COPD (aged 70.3 +/- 2.7 years). Inspiratory muscle training (IMT) was performed for 15 min twice a day, using a pressure threshold device, for a total of 12 weeks. The inspiratory threshold was set at 15% of maximal inspiratory pressure (PImax) for each individual. Pulmonary rehabilitation was performed for 12-h sessions over a 12-week period. Patients with COPD were assigned randomly to two groups: pulmonary rehabilitation combined with IMT (group A) (n = 7), and conventional pulmonary rehabilitation only (group B) (n = 6). Functional residual capacity (FRC) decreased significantly from 4.3 +/- 0.4 L at baseline to 3.9 +/- 0.4 L after rehabilitation (p < 0.01), Vp significantly increased from 4.6 +/- 0.8 L/sec at baseline to 5.1 +/- 0.7 L/sec after rehabilitation (p < 0.05) and the PImax increased significantly from 51.5 +/- 5.4 cmH2O at baseline to 80.9 +/- 7.0 cmH2O after rehabilitation (p < 0.02) in group A. However, these variables did not change in group B. There was no improvement in the 10-minutes walking distance of group A, but there was a significant increase in that of group B. It can be concluded that pulmonary rehabilitation combined with IMT improves pulmonary function and inspiratory muscle strength in elderly patients with COPD.

Aged↗

PubMed1997

Cladinose analogues of sixteen-membered macrolide antibiotics. IV. Improved therapeutic effects of 4-O-acyl-L-cladinose analogues of sixteen-membered macrolide antibiotics.

Six derivatives of sixteen-membered macrolides possessing 4-O-acyl-alpha-L-cladinose as a neutral sugar were synthesized via 3"-methylthiomethyl ether intermediates in reasonable yield. Introduction of a methyl group on the 3"-hydroxyl group of midecamycin A1 was effective for enhancing its antibacterial activity. All these derivatives exhibited excellent therapeutic effects in mice, and some of them showed improved pharmacokinetics compared with the natural antibiotics (mycarose type) in mice. Facile synthesis of 9-O-acylated analogues are also described.

Animals↗

PubMed1997

Cladinose analogues of sixteen-membered macrolide antibiotics. III. Efficient synthesis of 4-O-alkyl-L-cladinose analogues: improved antibacterial activities compatible with pharmacokinetics.

The synthesis and biological evaluation of sixteen-membered macrolides possessing a 4-O-alkyl-alpha-L-cladinosyl moiety as a neutral sugar are described. These potent novel derivatives have been efficiently synthesized avoiding glycosylations. Two hydroxyl groups in mycarose of the tri-(tert-butyldimethylsilyl) ether intermediate were successively alkylated. Sequential deprotections of silyl groups afforded 4-O-alkyl-L-cladinose analogues and 3,4-di-O-alkyl-L-mycarose analogues of leucomycin V. Some 4-O-alkyl-L-cladinose analogues exhibited potent antibacterial activities. The most active derivative, 3"-O-methyl-4"-O-(3-methylbutyl)leucomycin V, showed improved metabolic stability in rat plasma in vitro and extremely high concentrations in serum after oral administrations in mice and in hamsters.

Animals↗

PubMed1997

[Electrophysiological evaluation of polyneuropathy in juvenile insulin dependent diabetics].

Thirty patients with juvenile insulin dependent diabetes mellitus (IDDM) were electrophysiologically evaluated. In addition to the conventional motor and sensory nerve conduction studies, intrafascicular microneurography was performed in the median nerve. In this method a tungsten microelectrode was inserted into the median nerve trunk at the elbow, and a compound nerve action potential (CNAP) was recorded with supramaximal electrical stimulation at the wrist. The subjects' age ranged from 8 to 31 years with an average (SD) of 15.4 (6.2) years; the disease duration varied from 1 to 23 years with an average (SD) of 8.3 (5.8) years. Polyneuropathy index (PNI), expressed as a mean percentage of the normal for twelve indices over the four nerves obtained by motor conduction studies, was 93.9% on the average in patients with IDDM. The mean amplitude of CNAP obtained by intrafascicular microneurography was 417 microV. These results indicate that neuropathy in IDDM is milder than that in adult non-insulin dependent diabetes mellitus (NIDDM). The mean value of PNI decreased at a rate of 0.56% per year; the mean glycosylated hemoglobin (A1c) level was as high as 8.2 +/- 0.9%, findings consistent with those of the previous analysis of adult patients with NIDDM. The PNI value had a significant negative correlation with the duration of diabetes mellitus (p < 0.001) and with mean glycosylated hemoglobin (A1c) level (p < 0.01). CNAP amplitude had a tendency to correlate with duration of diabetes mellitus (p < 0.1). In patients with IDDM we can tell exactly when the disease occurred. Progression of neuropathy in juvenile IDDM was identical to that of adult NIDDM. Careful management of diabetes mellitus is of importance to prevent the progression of neuropathy.

Action Potentials↗