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Biomedical subjects

K Otsuka

Publications and source records attributed to K Otsuka.

At least 91 records · Page 5Linked to original sources
PubMed2001

Impact of circadian amplitude and chronotherapy: relevance to prevention and treatment of stroke.

The long-acting calcium antagonist nifedipine reduces the incidence of stroke in Eastern Asia, as shown by the Shanghai Trial Of Nifedipine in the Elderly (STONE) and the Systolic Hypertension in China (Syst-China) trials. Recent trials in Japan have shown that benidipine may be more efficient than the former drug in preventing strokes in the elderly. Benidipine, commonly prescribed in Japan for a definite depressor effect, reportedly without causing remarkable fluctuations in blood pressure (BP), is investigated herein from a chronobiological viewpoint. Eighteen subjects (nine women and nine men, 39 to 87 years of age) with essential hypertension (office and ambulatory systolic, S/diastolic, D BP values above 160/95 mm Hg and 130/80 mm Hg, respectively) were enrolled in this investigation. Ambulatory BP was monitored at 30-min intervals for at least 24 h (ABPM-630, Colin Medical) before and after 4 weeks of crossover treatment with nifedipine tablets (twice daily, 20 mg/d) and benidipine (once daily, 4 mg/d, in the morning). The results indicate that: 1) benidipine and nifedipine reduce 24-h daytime (10:00-20:00) and nighttime (00:00-06:00) averages of SBP and DBP (P < 0.001); 2) the circadian double amplitude of BP is decreased after treatment with benidipine (from 28.6 to 21.1 mm Hg SBP and from 19.7 to 15.2 mm Hg DBP; P< 0.05), while the day-night difference in SBP is increased after treatment with nifedipine (18.6 vs 27.9 mm Hg, P< 0.01); and 3) the increase in the day-night difference of heart rate (HR) is significant after treatment with benidipine (13.6 vs 18.8 beats per minute, bpm; P< 0.05), but not with nifedipine. We have previously evaluated the usefulness of the circadian amplitude of BP as a prognostic tool of cardiovascular outcome, and found that an excessive circadian SBP or DBP amplitude was associated with an increased risk of vascular disease. The fact that benidipine reduces the circadian BP amplitude may be one reason for the superiority of this treatment over nifedipine in preventing an adverse outcome. A reduced heart rate variability (HRV) also predicts adverse cardiovascular outcomes in patients with overt cardiovascular disease and in hypertensive subjects. The fact that benidipine increases the day-night difference in HR may be another reason for the positive effects of this treatment.

Adult↗
PubMed2001

Intragastric acidity and circadian rhythm.

Most patients with peptic ulcers or gastroesophageal reflex disease develop subjective symptoms of epigastralgia and retrosternal pain during the period of time from the middle of the night to the early dawn (nocturnal pain). Such pain often disappears before breakfast. Disturbed circadian rhythm of gastric acid secretion may have a close relationship with the onset and aggravation of acid-related diseases. On the other hand, Helicobacter pylori has been considered to be an etiological agent of duodenal ulcer, and H. pylori eradication has been conducted in patients with gastritis and peptic ulcers. However, such eradication therapy sometimes results in the onset or deterioration of gastroesophageal reflux diseases. In this context, the question of whether the circadian rhythm of gastric acid secretion varies in accordance with the presence or absence of H. pylori infection is of interest. In the present study, we examined the fluctuation in intragastric acidity via a portable pH meter in 10 H. pylori-positive and 10 H. pylori-negative subjects. As a result, a significant difference in the circadian rhythmicity was observed between the H. pylori-negative and the H. pylori-positive group, with mean values for each parameter of 28.1 and 13.3 for amplitude, 22.7 and 12.4 for the midline-estimating statistic of rhythm (MESOR), and 324.0 and 321.0 for acrophase, respectively (P < 0.001). In both H. pylori-positive and negative groups, a tendency was observed toward an increase in intragastric acidity during the time period from the middle of the night to the early dawn, and toward a decrease in intragastric acidity during the early morning. In the H. pylori-positive group, the values for intragastric acidity over time were lower, and the degree of amplitude was smaller as compared to the H. pylori-negative group. Further, H. pylori-positive individuals were at a more advanced stage of the disease.

Adult↗
PubMed2001

Hepatocyte growth factor secreted by periodontal ligament and gingival fibroblasts is a major chemoattractant for gingival epithelial cells.

To ascertain whether periodontal fibroblasts could be involved in the pathogenesis of periodontal pocket formation, the chemotactic activity of periodontal ligament fibroblast-conditioned medium (PLF-CM) and gingival fibroblast-conditioned medium (GF-CM) for gingival epithelial cells was examined using a modified Boyden chamber assay. Both PLF-CM and GF-CM possessed significant chemotactic activity, which was decreased markedly by treatment with anti-human hepatocyte growth factor (HGF) neutralizing antibody. Furthermore, the chemotactic activity of PLF-CM and GF-CM was well correlated with HGF content. These results show that PLF and GF secrete an HGF-like factor, and suggest that such a factor derived from periodontal fibroblasts might play a role in epithelial apical migration in periodontitis.

Cell Line↗
PubMed2001

Panic disorder cases in Japanese-Brazilians in Japan: their ethnic and cultural confusion.

The comparatively high salaries made in Japan are attractive to many Japanese-Brazilians. The number of individuals from this ethnic group being treated in Japanese mental hospitals has increased. We hypothesized that Japanese-Brazilian patients with panic disorders adjusted better to Japanese society and culture than those with other mental disorders. The subjects in the present study are 40 Japanese-Brazilian patients undergoing treatment at the Department of Psychiatry at Jichi Medical School, Japan, from May 1990 to September 1998. Patients were divided into a panic disorder group, a schizophrenic group, a mood disorder group and a neurosis group. Demographic data (Japanese language ability, duration of residence in Japan etc.) were collected. A comparison was made among the four groups. Patients in the panic disorder group showed a significant tendency to be fluent speakers of Japanese. Patients in the panic disorder group also had been in Japan for a significantly longer period of time than those in the other three groups. Japanese ability and length of residence in Japan rule out exacerbating factors due to a foreign living environment. Panic disorder patients usually have resolved the problems inherent in living and working in a foreign country. In general, Japanese-Brazilians are more comfortable both financially and socially in Japan than other foreign laborers because of their cultural and family background. The emotional conflict experienced by such patients may result from concern over whether to live in Brazil or Japan in the future. Their ethnic and cultural identity may be confused, fluctuating between identifying with Brazil and with Japan, and this may cause vague feelings of anxiety.

Adult↗
PubMed2001

Pitch perception shift: a rare side-effect of carbamazepine.

Carbamazepine-induced pitch perception shifts have rarely been described. Two cases of shifted pitch perception developing during medication with carbamazepine are described. Case 1 possessed absolute pitch. Her pitch perception shift disappeared with the discontinuance of carbamazepine. Case 2 did not have absolute pitch. Even though he experienced a pitch perception shift, he developed a tolerance to the shift. We concluded that carbamazepine was the cause of the pitch perception shift in the first case, while the second case probably became attuned to the change in pitch perception because he did not possess absolute pitch.

Adolescent↗
PubMed2001

Carcinoma of the urinary bladder with a lymphomatous appearance.

We present the first report of bladder carcinoma that demonstrates a mixture of two distinct histological patterns resembling malignant lymphoma. The patient was a 79-year-old man. One of the histological patterns was a diffuse growth of monomorphic carcinoma cells, and the other was a dense lymphoplasmacytic infiltrate, obscuring the carcinoma. The tumor cells showing both patterns expressed cytokeratin and epithelial membrane antigen, but not lymphoid markers. Careful immunohistochemical evaluation should be done when diagnosing urinary bladder carcinomas resembling lymphomas (other than primary lymphomas).

Aged↗
PubMed2001

Near 10-year and longer periods modulate circadians: intersecting anti-aging and chronoastrobiological research.

Biological cycles with relatively long and some unusual periods in the range of the half-week, the half-year, years, or decades are being discovered. Their prior neglect constituted a confounder in aging and much other research, which then"flew blind" concerning the uncertainties associated with these cycles when they are not assessed. The resolution of more about 10-year and other cycles, some reported herein, replaces the admission of complete unpredictability, implied by using the label "secularity." Heretofore unaccounted-for variability becomes predictable insofar as it proves to be rhythmic and is mapped systematically to serve as a battery of useful reference values. About 10-year cycles in urinary 17-ketosteroid excretion and in heart rate and its variability, among others, are aligned with cycles of similar length in mortality from myocardial infarction. Associations accumulate between cycles of natural physical time structures, chronomes such as the 10.5-year (circadecennian) Schwabe and the 21-year (circavigintunennian) Hale cycles of solar activity, and chronomes in biota. There are about 50-year (circasemicentennian) cycles in mortality from stroke in Minnesota and in the Czech Republic and also in human morphology at birth, the latter result reducing the likelihood that these cycles are purely human made. Associations among large populations warrant long-term systematic coordinated sampling of natural physical and biological variables of interest for the design of countermeasures against already documented elevated risks of stroke, myocardial infarction, and other catastrophic diseases, notably in elderly adults. New findings will be introduced against the background of the documented value of mapping rhythms in medicine and gerontology. In both these fields, rhythms promise the seeming paradox of better care for less.

17-Ketosteroids↗
PubMed2001

Salt-loading elevates blood pressure and aggravates insulin resistance in Wistar fatty rats: a possible role for enhanced Na+ -H+ exchanger activity.

OBJECTIVE: Increased Na+-H+ exchanger activity (NHE) has been reported as an intermediate phenotype in hypertensive subjects, particularly those with insulin resistance. To investigate whether NHE abnormality plays a role in hypertension, Wistar fatty rat (WFR) with overt obesity, hyperglycemia and marked hyperinsulinemia was examined. METHODS: WFR and Wistar lean rats (WLR) as a control (n = 12, each) were fed either with normal (0.38%) or high sodium (4% NaCl) diet for 12 weeks and then sacrificed to examine platelets NHE activity. RESULTS: Mean arterial pressure (MAP) was higher in WFR than in WLR (113 +/- 4 versus 96 +/- 7 mmHg, P < 0.05) under a normal chow. Vmax values of NHE activity were significantly higher in WFR than in WLR. WFR fed with a high sodium diet showed higher MAP than those with a normal chow (128 +/- 3 versus 113 +/- 4 mmHg, P < 0.05). Though Km values were not different between WFR and WLR under a normal chow, both maximal transport rate (Vmax) and half maximal transport (Km) values were significantly higher in WFR with a high salt diet than those with a control diet. Vmax showed significant correlation with MAP, whereas Km values correlated with immunoreactive insulin (IRI) levels. Significant interaction between dietary sodium intake and the strain differences was observed both on blood pressure and on IRI levels by two-way analysis of variance (ANOVA). CONCLUSION: WFR presented salt-sensitive blood pressure elevation. NHE activity was enhanced in WFR in correlation with the blood pressure. These results suggest that augmented NHE activity contributes to the development of salt-sensitive blood pressure elevation in WFR.

Animals↗
PubMed2001

Influence of interleukin-10 on the interleukin-1 receptor antagonist/interleukin-1 beta ratio in the colonic mucosa of ulcerative colitis.

A decrease in the ratio of IL-1ra/IL-1 beta produced regionally by the colonic mucosa of patients with ulcerative colitis (UC) is believed to play a role in the pathogenesis of UC. To investigate factors influencing intramucosal IL-1ra/IL-1 beta ratios, we evaluated polymorphism of the IL-1ra gene and the production of mucosal cytokines in Japanese patients with UC. Colonic biopsy specimens of mucosal tissue were placed in organ cultures for 24 h. Then, the supernatant concentrations of IL-1 beta, IL-1ra, IL-8, IL-4, IL-10, and TGF-beta were assayed by ELISA. Genomic DNA was extracted from patient peripheral blood samples, then IL-1ra gene polymorphism was determined using PCR amplification. The mucosa from patients with active stage UC showed a tendency toward a decreased IL-1ra/IL-1 beta ratio. In the resolving stage, IL-1ra/IL-1 beta ratios increased with increasing IL-10 and TGF-beta concentrations. The addition of human recombinant IL-10 to the culture supernatants produced concentration-dependent inhibition of IL-1 beta. In Japanese patients with UC, the IL-1ra allele gene 2 phenotype had no effect on the IL-1ra/IL-1 beta ratio. Our findings suggest that a relative deficiency of IL-10 in patients with UC may contribute to persistent inflammatory changes.

Adult↗
PubMed2001

Attachment of human periodontal ligament cells to enamel matrix-derived protein is mediated via interaction between BSP-like molecules and integrin alpha(v)beta3.

BACKGROUND: Although enamel matrix-derived protein (EMD) can stimulate attachment of human periodontal ligament (HPDL) cells to the root surface, the biological mechanism of this phenomenon is unclear. The purpose of this study was to determine which molecules in EMD are involved in the attachment of HPDL cells, and which types of integrins on the cell surface mediate the interaction between the cells and EMD. METHODS: HPDL explants were obtained from tooth surfaces extracted from 4 individuals, and cells taken from the individual explants were separately harvested and subcultured through as many as 5 passages. Cells were incubated on EMD-coated culture plates with and without neutral antibodies for integrins or RGD-sequence blocking peptides and stained with toluidine blue. Proteins in EMD that were able to induce cell attachment were identified by incubating sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) replicas with HPDL cells; the cell-binding regions were detected by staining the cells with toluidine blue. Characteristics of the cell-binding proteins in the EMD were identified by Western blot analysis. RESULTS: It was shown that anti-alpha(v)beta3 antibody and GRGDSP peptide markedly reduced attachment of HPDL cells to EMD. When the cells were incubated with SDS-PAGE replicas, distinct cell attachment was observed at a molecular mass of approximately 55 kDa. The cell-binding ability of this protein was completely blocked by treatment with anti-alpha(v)beta3 antibody or GRGDSP peptide. In the Western blot analysis, the 55 kDa protein was recognized by anti-bone sialoprotein (BSP) antibody as a single band. CONCLUSIONS: Our study provides the first evidence that the attachment of HPDL cells to EMD can be mediated by interaction between a BSP-like molecule and integrin alpha(v)beta3 on the cell surface.

Amino Acid Sequence↗
PubMed2001

[Nasal CPAP treatment and hypertension and altered cardiovascular variability associated with obstructive sleep apnea (OSA)].

In the past 5 years several epidemiologic studies have demonstrated that sleep-related breathing disorders are an independent risk factor for hypertension, probably resulting from a combination of repetitive episodes of hypoxia, hypercapnea, arousals, and a striking surge in sympathetic excitation, and altered baroreflex control during sleep. Obstructive sleep apnea (OSA) may lead to the cardiac arrhythmias and myocardial ischemia and it is a possible risk factor for stroke. We confirmed that nasal CPAP has been shown to lower blood pressure in some hypertensive OSA patients. Early recognition and treatment of sleep-apnea may improve cardiovascular function.

Baroreflex↗
PubMed2001

[Factors allowing continuous working of female nurses in the People's Republic of China--survey of 15 hospitals in 5 areas].

PURPOSE: Few investigations have been conducted on working, childcare and home education among female nurses (nurses) in the People's Republic of China (P.R. of China). The purpose of this study was to clarify the factors allowing continued working of female nurses. METHODS: The subjects were nurses from 15 hospitals in 3 provinces and 2 autonomous areas. They were surveyed by questionnaire regarding their childcare and home education. In was distributed by the Ministry of Health in the P.R. of China and the data were collected between February and April in 1996. RESULTS: A total of 4,284 (80.0%) questionnaires were collected. 1. About 60% of the nurses began working when they were 15 to 19 years old. The average length of service was 13.9 years. 2. Their professional position correlated directly with their years of service. 3. 4.3% of them had not continued working. 4. The nurses entrust their children to day-care institutions (61.2%) or grandparents (22.3%) during the daytime, and to the father (66.3%) or the grandparents (19.5%) during the night. 5. 17.6% of them have experienced being away from home for more than one month due to their job. 6. 66.8% of the nurses have experienced more than one month official trip, and had children under 14 years old at the time. They entrusted their children to day-care institutions (34.1%), to the father (29.2%) and grandparents (25.3%) during the official trip. CONCLUSIONS: In summary, most nurses are employed when they are young and go on working as nurses. It is possible for them to continue their work after marriage, childbirth, and while they are bringing up their children. The high rate of working woman, sufficient nursery schools and family cooperation in housework can be pointed out as main factors that enable them to continue their work.

Adolescent↗
PubMed2001

[Childcare and home education in families of female nurses in the People's Republic of China--survey of 15 hospitals in 5 areas].

PURPOSE: The purpose of this study was to investigate the actual conditions of childcare and home education among families of female nurses in the P. R. of China. METHODS: The subjects were nurses from 15 hospitals in 3 provinces and 2 autonomous areas. They were surveyed by questionnaire regarding their childcare and home education. It was distributed by the Ministry of Health in the P. R. of China and data were collected between February and April in 1996. RESULTS: A total of 4284 (80.0%) questionnaires were collected. 1. The age of the subjects was between 18 and 62 years old with a mean of 32.9 +/- 9.0 (SD) years 71.4% of them had husbands, whose ages were between 23 and 71 years old, the mean age being 38.3 +/- 8.4 (SD) years. The family types were 63.2% nuclear family and 33.7% extended family, with 3.1% being single. 65.1% of the subjects had children, whose mean number was 1.1 +/- 0.4 (SD). Firstborn children were 49.9% girls and 50.1% boys. 2. The most popular method of infant nutrition was breast-feeding, utilized by 60.1%. The highest rate (67.8%) was in the age group of 25 to 29 years old (P < 0.01). 3. The practice of "swaddling" (wrapping the child so as not to allow movement) was more common in the over 40 year old age group than the under 40 year old group (P < 0.01). Swaddling-practice showed significant differences by area. 4. The rates for children who helped with housework were 50.3% for girls and 46.7% for boys. 5. A number of children between 7 and 18 years old were studying English privately. 6. The greatest expectation of the subjects, for their children aged between 7 and 18 years old, was to study. CONCLUSIONS: 1. Infant nutrition showed significant differences between generations, and swaddling-practice differed with the generation and the area. 2. Although girls help their parents more than boys in Japan, boys and girls equally helped their parents in the P. R. of China. 3. Concerning the topics of private learning and parents expectations, the results were similar to those in Japan.

Adolescent↗
PubMed2001

Chronomics.

Several international meetings have revealed an accumulating body of reference values for well-established about-daily and about-yearly rhythms of photic origin and evidence also for about-7-day, -27-day, -half-yearly, -10.5- and -21-yearly, and even -50-yearly rhythmicities in us as well as around us, as invisible non-photic heliogeophysical signatures possibly built into individuals and/or populations, complementing the biological year and day. In time series (biological or other) that are dense and sufficiently long, the characteristics of rhythms, chaos (deterministic and other) and trends can all be quantified as elements of structures called chronomes. Chronobiological methodology assesses uncertainties in comparisons of endpoints in all elements of chronomes, before and after: 1) changes in lifestyle, such as meal quality, quantity, timing and salting of the food; 2) preventive non-drug interventions to limit the risk of vascular disease; or 3) drug treatments for high-risk subjects as well as for those with actual vascular disease, all on a practicable, individualized and also a general population basis. A collateral hierarchy characterizes molecular to psychosocial aspects of living beings that are exposed to their socio-ecological environs and thus are synchronizable and/or otherwise manipulable by society, meals, lighting, heating, and non-photic, non-thermic environmental variations that become predictable to the extent that they appear to constitute cycles, yet adhere only to a statistical, rather than a deterministic causality. With this qualification, chronome mapping with outcomes could eventually serve an individualized optimization of lifestyle, for chronoprevention and chronotherapy as well as for inquiries into the evolution and future of life, a budding chronoastrobiology, in keeping with the original title of the conference.

Animals↗