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Biomedical subjects

K Otsuka

Publications and source records attributed to K Otsuka.

At least 181 records · Page 10Linked to original sources
PubMed1996

Clinical relevance of about-yearly changes in blood pressure and the environment.

Changes identified by inferential statistics from summer to winter of high to low arterial blood pressures (BP) have been quantified as a large predictable about-yearly BP swing. This condition of a large annual BP amplitude (LABPA) raises concern about hypotension as well as hypertension and raises new questions regarding appropriate guidelines for diagnosis and treatment. Recommendations made in the fall on the basis of data collected in the summer may be totally inadequate in dealing with the patient's condition in the winter. In order to avoid such mistakes, it is imperative to implement a systematic surveillance of BP in the light of current chronobiological limits. Patients with a large circannual BP amplitude are particularly suited for a study of the underlying hormonal mechanisms. The longitudinal monitoring of their BP is also amenable to the study of environmental influences from near and far.

Aldosterone↗
PubMed1996

Epidural dumbbell-shaped chordoma mimicking a neurinoma.

The authors present a case of cervical chordoma which manifested in a 5-year-old boy as a dumbbell-shaped epidural tumor without bone destruction. Both CT and MRI demonstrated tumor features suggesting this diagnosis, which was confirmed by histology.

Child, Preschool↗
PubMed1996

Nature and distribution of chondroitin sulphate and dermatan sulphate proteoglycans in rabbit alveolar bone.

The type and distribution of mineral binding and collagenous matrix-associated chondroitin sulphate and dermatan sulphate proteoglycans in rabbit alveolar bone were studied biochemically and immunocytochemically, using three monoclonal antibodies (mAb 2B6, 3B3, and 1B5). The antibodies specifically recognize oligosaccharide stubs that remain attached to the core protein after enzymatic digestion of proteoglycans and identify epitopes in chondroitin 4-sulphate and dermatan sulphate; chondroitin 6-sulphate and unsulphated chondroitin; and unsulphated chondroitin, respectively. In addition, mAb 2B6 detects chondroitin 4-sulphate with chondroitinase ACII pre-treatment, and dermatan sulphate with chondroitinase B pre-treatment. Bone proteins were extracted from fresh specimens with a three-step extraction procedure: 4 M guanidine HCl (G-1 extract), 0.4 M EDTA (E-extract), followed by guanidine HCl (G-2 extract), to characterize mineral binding and collagenous matrix associated proteoglycans in E- and G2-extracts, respectively. Biochemical results using Western blot analysis of SDS-polyacrylamide gel electrophoresis of E- and G2-extracts demonstrated that mineral binding proteoglycans contain chondroitin 4-sulphate, chondroitin 6-sulphate, and dermatan sulphate, whereas collagenous matrix associated proteoglycans showed a predominance of dermatan sulphate with a trace of chondroitin 4-sulphate and no detectable chondroitin 6-sulphate or unsulphated chondroitin. Immunocytochemistry showed that staining associated with the mineral phase was limited to the walls of osteocytic lacunae and bone canaliculi, whereas staining associated with the matrix phase was seen on and between collagen fibrils in the remainder of the bone matrix. These results indicate that mineral binding proteoglycans having chondroitin 4-sulphate, dermatan sulphate, and chondroitin 6-sulphate were localized preferentially in the walls of the lacunocanalicular system, whereas collagenous associated dermatan sulphate proteoglycans were distributed over the remainder of the bone matrix.

Animals↗
PubMed1996

Adsorption of saliva-coated and plain streptococcal cells to the surfaces of hydroxyapatite beads.

This study was conducted to observe the differences between the adsorption of Streptococcus sanguis by saliva-coated and non-saliva-coated cells (plain cells) to the surfaces of saliva-coated, bovine serum albumin-coated or buffer-washed hydroxyapatite beads. Saliva treatment of bacterial cells altered the manner of saturation due to changes of affinity and/or the maximal number of adsorption sites on the hydroxyapatite beads. This result indicates that saliva treatment of bacterial cells might be a necessary step in testing bacterial adsorption to saliva-coated hydroxyapatite beads or saliva-coated teeth.

Adsorption↗
PubMed1996

Blood pressure "dipping" and "non-dipping" in obstructive sleep apnea syndrome patients.

Obstructive sleep apnea syndrome (OSAS) has been associated with a higher than normal cardiovascular morbidity and mortality. Some OSAS patients lack the sleep-related, nocturnal decrease, or "dip," in blood pressure which is seen in normal individuals. These subjects, called "non-dippers," may be at greater risk for cardiovascular problems. We studied 40 OSAS patients (including 3 women) and 6 control subjects, all identified by polysomnography, for nocturnal blood pressure "dipping." We performed a second nocturnal polysomnogram to determine their apnea and hypopnea indices, (A + H)I, and oxygen saturation levels at the beginning of the study and then initiated 48 hours of ambulatory blood pressure monitoring, with data points collected every 30 minutes. Controls, which included one hypertensive subject, were all dippers. Nineteen OSAS subjects (48% of OSAS individuals) were systolic non-dippers and only 9 of them (22.5%) were diastolic non-dippers. We considered the following clinical variables as potential predictors of non-dipping: age, body mass index, respiratory disturbance index, years of reported loud snoring by bed partners, lowest oxygen saturation during nocturnal sleep, and percentage of sleep time spent with oxygen saturation below 90%. Multiple regression analyses indicated respiratory disturbance index as the only significant variable for systolic (p = 0.04) and diastolic (p = 0.03) blood pressure non-dipping. When we forced the following two nonsignificant variables into the model, they showed a very meager impact: number of years with reported loud snoring (p = 0.4 and p = 0.5, respectively for systolic and diastolic blood pressure non-dipping) and age (p = 0.5 and p = 0.6). The calculated model explained only a low percentage of the variance with an r2 of 0.25 and 0.26 for systolic and diastolic blood pressure non-dipping, respectively. Analysis of hypertension/normotension and dipping/non-dipping failed to show a significant relationship in the studied population. Fifty percent of the normotensive OSAS subjects were non-dippers and 43% of the hypertensive OSAS subjects were also non-dippers. We found a relationship between increasing respiratory disturbance index and increasing average 24-hour systolic blood pressure only when OSAS subjects were non-dippers and hypertensive.

Adult↗
PubMed1996

Blunted pressure natriuresis in ovariectomized Dahl-Iwai salt-sensitive rats.

Our objective was to determine whether increased salt sensitivity after menopause precedes the development of overt hypertension. We investigated the effect of ovariectomy on pressure natriuresis in Dahl-Iwai salt-sensitive (DS) and salt-resistant (DR) rats by in vivo perfusion studies. Differences in the neural and hormonal backgrounds of the kidney were minimized by renal denervation and by holding plasma vasopressin, aldosterone, corticosterone, and norepinephrine levels constant by intravenous infusion. The pressure-natriuresis relationship was blunted in DS rats compared with DR rats (slope, 0.30 versus 0.63 mumol.min-1.g kidney wt-1.mm Hg-1, P < .01). The impaired pressure-natriuresis response of DS rats was further blunted by ovariectomy (from 0.30 to 0.14 mumol.min-1.g kidney wt-1.mm Hg-1, P < .05), and that of DR rats was not. The ovariectomized DS rats developed hypertension earlier than sham-operated DS rats by salt loading. These results show that ovariectomy enhances genetic salt sensitivity by blunting the pressure-natriuresis relationship, which precedes the development of overt hypertension in female DS rats.

Animals↗
PubMed1996

Chronobiometric assessment of autogenic training effects upon blood pressure and heart rate.

Autogenic training, a method of self-hypnosis, lowers the extent of within-day variation of systolic blood pressure assessed by the circadian double amplitude. The blood pressure and heart rate of ten patients, conventionally diagnosed as having hypertension or white-coat hypertension, were automatically monitored at 30-min intervals for 7 days before autogenic training and again for 7 days, at 1 or 2 months after the start of autogenic training (practiced three times daily). The circadian double amplitude of systolic blood pressure of the patients investigated was 3 to 17 mm Hg lower on autogenic training. In 5 patients, reductions by 7 to 17 mm Hg were statistically significant. These results are regarded as provisional statistics, the utility of which depends on replication. By contrast, the over-all group reduction of the circadian double amplitude of systolic blood pressure by 8 mm Hg on the average can be taken at face value. Autogenic training also lowered the circadian double amplitude of diastolic blood pressure, but the effect was small as was the effect of autogenic training upon the MESOR (a rhythm adjusted mean) and acrophase (a measure of the timing of over-all high values recurring each day). The effect of autogenic training upon the circadian double amplitude of systolic blood pressure suggests its trial as first-line treatment of patients with an excessive circadian blood pressure amplitude, a condition which, even in the absence of an elevated 24-hr, average of blood pressure, is associated with a large increase in the risk of developing ischemic stroke or nephropathy.

Aged↗
PubMed1996

[Expression of decay-accelerating factor on CD8-positive lymphocytes as an index of aging and of host defense function].

Decay-accelerating factor (DAF) is a membrane glycoprotein that prevents complement activation on blood cells. Among CD8+ T cells, DAF-negative cells can be distinguished from DAF-positive cells. We computed the proportion of DAF-negative CD8+ T cells in the peripheral blood of 59 normal healthy subjects, 27 to 93 years old, and analyzed the differences between subjects of different ages. The proportion of CD8+ T cells that were DAF-negative correlated significantly and positively with age. We also studied these lymphocytes in patients with cerebrovascular dementia, Alzheimer's dementia, cancer, rheumatoid arthritis and systemic lupus erythematosus. The proportion of CD8+ T cells that were DAF-negative did not correlate significantly with age in patients with cerebrovascular dementia, Alzheimer's dementia or cancer, but it correlated significantly and positively with age in patients with rheumatoid arthritis and in those with systemic lupus erythematosus. Therefore, healthy subjects and patients with various diseases can be classified according to age and to the proportion of CD8+ T cells that are DAF-negative. This proportion can then be used as an index of aging and of host defense function.

Adult↗
PubMed1996

[Surgical treatment of infective endocarditis : an analysis of the risk factor for operative mortality].

From January 1980, through December 1995, 60 patients underwent surgical treatment of infective endocarditis (IE) at Sakakibara Hospital. Of 60 patients, 40 showed active endocarditis and 20 healed endocarditis at the time of operation. The over-all hospital mortality was 10% (6/60). The complication of cerebral accident (embolism and bleeding) was related to a higher incidence of operative mortality. The reconstructions of destruction and disruption of ventricular-aortic or mitral-aortic continity in the presence of acute infection of the annular tissue were in need of radical and complex surgical techniques. It is recommended to follow up these patients thoughtfully and to perform reoperation or re-reoperation before a patient develops severe heart failure or multiple organ failure.

Adult↗
PubMed1996

Sodium balance and hypertension in obese and fatty rats.

To investigate the role of sodium in obesity induced hypertension, Wistar fatty rats (WFR) were employed. This rat has the following characteristics: (1) hyperglycemia, (2) hyperinsulinemia, and (3) hypertriglycemia. Four percent sodium chloride with constant amount of food intake was administered to these rats from 8 to 16 weeks. During this period, body wt, food intake, water consumption, urine volume, systolic blood pressure, urinary excretion of sodium and potassium, urinary albumin excretion, plasma sodium and potassium, and plasma glucose and immunoreactive insulin (IRI) were measured before, and twice more during eight weeks. No remarkable changes were observed in plasma glucose level during these periods between the two groups. On the other hand, in group 1 IRI significantly increased compared with group 2. Mean blood pressure was increased from 110 +/- 5 to 130 +/- 8 mm Hg (P < 0.01). To ascertain whether this salt sensitivity relates to the abnormalities in pressure-natriuresis responses, the pressure-natriuresis (P-N) was characterized. The P-N curve in WFR was shifted to the right and its slope was flattened compared to its control Wistar lean rats. In conclusion, an excess of dietary sodium intake may contribute to an elevation of blood pressure in Wistar fatty rat with hyperglycemia and hyperinsulinemia. This salt sensitivity may change the abnormal pressure-natriuresis responses.

Animals↗
PubMed1995

Effect of compression temperature on the consolidation mechanism of chlorpropamide polymorphs.

The effect of environmental temperature on the compression mechanism of chlorpropamide (CPM) polymorph, forms A and C, was investigated with an eccentric type tabletting machine with two load cells and a noncontact displacement transducer. The temperature of the die was controlled at 0 and 45 degrees C by a thermocontroller. Sample powders (200 mg), which were also controlled at 0 and 45 degrees C by a thermocontroller, were compressed at almost 230 MPa. The tabletting dynamic processes of CPM forms A and C at 0 and 45 degrees C were evaluated by Cooper and modified Heckel analyses. The results suggest that particle brittleness or plasticity was affected by compression at different temperatures. The higher tablet hardness of form A at 45 degrees C was thought to be caused by the increased plasticity of primary particles, whereas that of form C at 45 degrees C was ascribed to the decreased size of the secondary particles.

Chemistry, Pharmaceutical↗
PubMed1995

Stimulation of human periodontal ligament fibroblast collagenase production by a gingival epithelial cell-derived factor.

To examine whether cell-to-cell interactions between human gingival epithelial cells (HGE) and periodontal ligament fibroblasts (PLF) or gingival fibroblasts (GF) take place in the periodontium, the effects on collagenase production by PLF and GF were analyzed after adding several concentrations of HGE-conditioned medium (HGE-CM) to PLF or GF culture. Collagenase production by both cell populations was stimulated by adding HGE-CM, which stimulated collagenase production by PLF to a greater extent than that by GF. The HGE-derived stimulatory factor had a molecular mass of approximately 20 kDa, and its stimulant effect was inhibited markedly in the presence of an anti-human interleukin-1 alpha (IL-1 alpha) neutralizing antibody, indicating that the factor was identical to, or antigenically cross-reactive with, IL-1 alpha. These results suggest that epithelial apical migration in the periodontium may occur after interstitial resident cells have released tissue-degrading enzymes, such as collagenase, and damaged the extracellular matrix, once a sufficient amount of IL-1 alpha-like factor for stimulating the production of proteolytic enzyme has been released by HGE in periodontal lesions.

Cells, Cultured↗
PubMed1995

[Detection of the exoskeleton of Sarcoptes scabiei in histological sections using Fungiflora Y].

Fungiflora Y was applied to a deparaffinized section of a biopsied skin with scabies, a section of a brain infected with Cysticercus cellulosae, a section of a lung infected with Pneumocystis carinii and a section of a cockroach. The exoskeleton of the mite and the cockroach were stained with Fungiflora Y and were visualized as a greenish-blue fluorescence under incident illumination with ultraviolet light, whereas the Cysticercus cellulosae and the Pneumocystis carinii were not visualized at all. Fungiflora Y, which has been reported to stain fungi, is likely to detect arthropods exoskeleton in histological sections.

Animals↗
PubMed1995

[A case of traumatic diaphragmatic hernia accompanied with rupture of pericardium].

We experienced a case of left traumatic diaphragamatic hernia accompanied with rupture of pericardium after blunt trauma by traffic accident. A 55-year-old man who had suffered blunt chest and upper abdominal trauma because of smash of two cars when he had been turning to right in the corner was admitted to our hospital. On arrival at the hospital, the patient complained severe dyspnea that reduced by lying on his right. Another position couldn't be taken because of deterioration of dyspnea. Chest X-ray showed disappeared left diaphragmatic line and abnormal transparent mass that suggest alimentary canal in the left intrapleural space. Cardiac ultrasonography showed abnormal tubular mass close to the left side of mediastinum that deviated to right. The patient was diagnosed as traumatic diaphragmatic hernia and emergency operation was performed. Left diaphragma was lacerated sagitally toward its top for about 12 cm in length. Left pleuropericardium was seen to be lacerated longitudinally for about 8 cm in length in front of the phrenic nerve intraoperatively. Both lacerations were closed by direct suture. The patient discharged on the 37th postoperative day without phrenic nerve palsy. At making diagnosis of patient with chest and abdominal trauma, injure of diaphragma and/or pericardium also must be considered. If it is possible, operation must be performed without hesitation in order to get good prognosis.

Accidents, Traffic↗