Biomedical subjects

S Onodera

Publications and source records attributed to S Onodera.

At least 37 records · Page 2Linked to original sources

PubMed2000

Blood glucose and insulin concentrations are reduced in humans administered sucrose with inosine or adenosine.

Recently we found that some nucleosides such as inosine or adenosine inhibited alpha-glucosidase from rat intestine. The aim of this study was to determine whether these nucleosides are sucrase inhibitors in humans as well as rats. Blood glucose and insulin responses were examined in 23 healthy volunteers (18 males and 5 females) administered sucrose with inosine and 8 (males) administered sucrose with adenosine. The initial increase in plasma glucose and serum insulin concentrations at 30 min after loading sucrose (50 g) alone were significantly reduced by co-administration of inosine (2.5 and 1.0 g) or adenosine (2.5 g). The total increases in the areas under the plasma glucose and serum insulin concentration curves for 3 h after administration of the same amount of sucrose with inosine were also significantly less than those when the volunteers were administered sucrose alone. These results in humans agree with the findings obtained in our previous studies in rats. These nucleosides may be used as one of the components of artificial sweeteners when mixed with sucrose and may be useful as food additives to suppress increases in blood glucose and insulin.

Adenosine↗

PubMed2000

Controlled study of circadian rhythm of blood pressure in patients with aldosterone-producing adenoma compared with those with essential hypertension.

OBJECTIVE: The circadian rhythm of blood pressure in patients with aldosterone-producing adenoma (APA) is not well understood. We evaluated the circadian blood pressure rhythm in such patients by comparison with that in patients with essential hypertension (EHT). The latter are characterized by a nocturnal blood pressure decline, the so called 'dipping' blood pressure pattern. DESIGN AND METHODS: A total of 12 patients with APA and 36 patients with EHT who were matched by age and sex, and who had no severe organic disorders, were hospitalized to control their diet (low sodium) and activities. Ambulatory blood pressure monitoring was conducted for 24 h. The 24-h blood pressure was divided into waking blood pressure (0600-2130 h) and sleeping blood pressure (2200-0530 h). RESULTS: The two groups showed no significant differences in age, sex, serum creatinine, plasma glucose, daily urinary sodium excretion, and left ventricular mass index. Although the 24-h mean blood pressure was higher in APA (112 +/- 8 mmHg) than EHT (102 +/- 12 mmHg), the dipping mean blood pressure ratio (%), which was calculated from the sleeping and waking blood pressures, did not differ significantly between the two groups (93.2 +/- 5.4 versus 92.8 +/- 5.9). CONCLUSION: The dipping ratio of blood pressure in patients with APA resembled that of patients with EHT. Variables that would influence the circadian rhythm of blood pressure were controlled during study. The results suggest that a circadian blood pressure in patients with APA is of the dipping type, characterized by a nocturnal blood pressure decline, when a low sodium diet is ingested.

Adenoma↗

PubMed2000

Serum glucose and insulin response in rats administered with sucrose or starch containing adenosine, inosine or cytosine.

Blood glucose and insulin responses and gastric emptying were examined in rats intubated with sucrose or soluble starch that contained adenosine, inosine and cytosine. The increase in serum glucose and insulin levels in the rats following loading with sucrose (2.5 g/kg of body weight) or soluble starch (1.875 g/kg of body weight) was significantly reduced by the administration of adenosine, inosine and cytosine (0.0625-0.125 g/kg of body weight). The gastric emptying rates were only marginally affected by the nucleoside administration. The activities of sucrase, maltase, isomaltase and glucoamylase in a crude preparation from the small intestinal mucosa of rats were mildly inhibited by the nucleosides. The decrease in blood glucose and insulin levels may have been in response to a decrease in glucose absorption caused by the inhibiting effect of the nucleosides on the mucosal enzymes that digest sucrose, maltose, and malto- and isomalto-oligosaccharides.

Adenosine↗

PubMed2000

[A case of patent urachus in an adult male].

A 31-year-old man was referred to our hospital for evaluation of urachal rest. The history of his present illness dated back to birth, when the umbilicus was projected and urinary discharge was noted. At that time, the symptom of discharge had spontaneously subsided. At the age of 22, however, the patient again experienced discharge from the umbilicus. Although he did not seek treatment, after six years this symptom disappeared. Around this time, however, pyuria was revealed during medical examination, and abdominal ultrasonography (US) suggested the presence of urachal rest. At the time of hospitalization, physical examination revealed that the patient's right testis was not palpable. He was diagnosed with patent urachus with hemilateral aplasia and monorchism by US, computed tomography, magnetic resonance imaging and cystoscopy. The patient subsequently underwent radical operation. Patent urachus in adults is very rare, and only a few cases have been reported. To our knowledge, only one previously reported case involved a recurrence after spontaneous healing. Further, this is the first report of a patient with patent urachus with hemilateral aplasia and monorchism. Radical operation is generally recommended, based on the fact that very few cases heal conservatively.

Adult↗

PubMed2000

[Clinical statistics on patients and operations during a 20-year period (1978-1997) at Department of Urology, Jikei University School of Medicine].

A statistical analysis was made of diseases, patients, and operations at our department in the four affiliated hospitals of Jikei University School of Medicine from 1978 through 1997. Our findings were as follows. Newly diagnosed urogenital malignancies, except testicular tumors, have been increasing in the last two decades among both outpatients and inpatients. Urogenital infections, including tuberculosis, have gradually been decreasing in the last two decades. The treatment of urinary stone diseases was markedly altered by the induction of extracorponeal shock wave lithotripsy.

Female Urogenital Diseases↗

PubMed2000

[A case of primary renal carcinoid tumor].

The patient was a 44-year-old woman in whom a mass of the right kidney was found when she underwent abdominal ultrasonography in a physical checkup. The computed tomography of abdomen and the magnetic resonance imaging of abdomen revealed a 3 x 3 cm solid mass at the right kidney. Excretory urograms showed a deformity of the right collecting system due to a mass lesion. The specimen of the resected tumor showed a cellular arrangement specific to carcinoid tumor and positive reaction of Grimelius stain. Electron microscopy confirmed the presence of dense-core granules in the tumor cells. Gastrointestinal investigation after the operation revealed no particular findings suggesting a carcinoid syndrome. No evidence of metastasis or recurrence was noted for 5 months after the operation. This was a very rare case of primary renal carcinoid tumor, representing the 12th case in the literature in Japan.

Adult↗

PubMed2000

Effects of supine floating on heart rate, blood pressure and cardiac autonomic nervous system activity.

It is known that heart rate, oxygen uptake and body temperature during exercise in water are affected by water temperature, buoyancy and so on. Relaxation in water (supine floating) has been performed in hydrotherapy and aqua exercise. But there were few reports about supine floating (Schulz and Kaspar 1994). The purpose of this study was to make clear the effects of supine floating on heart rate, blood pressure and cardiac autonomic nervous system activity in males.

Adult↗

PubMed2000

[Relaxative effects of supine floating on heart rate, blood pressure and cardiac autonomic nervous [correction of nerveous] system activity].

The purpose of this study was to make clear the relaxative effects of supine floating (SF) on heart rate, blood pressure and cardiac autonomic nervous activity in males. Ten males served as subjects (n=10, mean age: 22.4 yrs). All subjects gave informed consent before participating. Water and room temperature were 30 degrees C. Heart rate and blood pressure were measured during SF or control (C) conditions. Cardiac autonomic nerve activity was estimated with the power spectrum analysis of heart rate variability (HRV) by using the Fast Fourier Transformation (FFT). High frequency (HF; 0.15-0.40 Hz) and the ratio of low frequency (LF; 0.04-0.15 Hz) to HF (LF/HF) were used as an indicator of cardiac vagal activity and sympatho-vagal balance, respectively. Those values were showed logarithmically (LogHF and LogLF/LogHF). LogHF during SF condition was significantly increased, LogLF/LogHF, heart rate and blood pressure were significantly decreased. These data indicate that cardiac vagal activity is enhanced and sympathetic nervous activity is suppressed by reciprocal response.

Adult↗

PubMed1999

High expression of macrophage migration inhibitory factor in the synovial tissues of rheumatoid joints.

Macrophage migration inhibitory factor (MIF) plays an important role in inflammation and immunity via autocrine/paracrine and endocrine routes. We examined the presence of MIF in the synovial fluids of rheumatoid arthritis (RA) patients. The content of MIF in the synovial fluid was quantitated by enzyme-linked immunosorbent assay which revealed that the concentration of MIF for RA patients was 85. 7+/-35.2 ng/ml (mean+/-SD) (n=25). In comparison, the concentrations for osteoarthritis patients and normal volunteers were 19.5+/-5.3 ng/ml (n=12) and 10.4+/-1.1 ng/ml (n=5), respectively. The expression of MIF mRNA and presence of MIF protein in the synovial tissues of RA were demonstrated by Northern blot and Western blot analyses, respectively. Immunohistochemical analysis revealed that positive staining was largely observed in the cytoplasm of infiltrating T lymphocytes, which might be the major source of MIF detected in the synovial fluids. The pathophysiological role of MIF in RA remains to be elucidated; however, the present results for the first time suggest the possibility that MIF is involved in the potentiation of inflammatory and immunological responses in rheumatoid joints.

Arthritis, Rheumatoid↗

PubMed1999

Gastroprotective mechanism of lafutidine, a novel anti-ulcer drug with histamine H2-receptor antagonistic activity.

Lafutidine (CAS 118288-08-7, FRG-8813) is a novel histamine H2-receptor antagonist with gastroprotective activity. The aim of this study was to investigate the property of the gastro-protective activity of lafutidine by examining the effect on ammonia-induced change in transmucosal potential difference (PD), basal gastric mucosal blood flow (GMBF) and noxious agent-induced cell damage. Intragastrical application of lafutidine accelerated the recovery of the PD reduction after exposure of the mucosa to 0.25% ammonia solution and the accelerating effect was abolished by chemical deafferentation, but not with indometacin, a cyclooxygenase inhibitor. The application of capsaicin, as a reference compound, significantly promoted the recovery of the ammonia-induced PD reduction and this effect was not altered with indometacin. Lafutidine given intragastrically caused a sustained increase in GMBF in a dose-dependent fashion, which was also completely inhibited in the deafferentated rats. In vitro studies revealed that, in contrast to 16,16-dimethyl prostaglandin E2, lafutidine did not protect isolated gastric superficial epithelial cells from ethanol- or ammonia-induced damage. In conclusion, the gastroprotection of lafutidine is induced by promoting the restitution of the damaged mucosa after a noxious agent, not by directly protecting the epithelial cells and this effect may be caused through the mechanism of capsaicin-sensitive afferent nerves.

16,16-Dimethylprostaglandin E2↗

PubMed1999

Growth factor-induced expression of macrophage migration inhibitory factor in osteoblasts: relevance to the plasminogen activator system.

Macrophage migration inhibitory factor (MIF) is a cytokine that mediates inflammatory processes in a variety of tissues. In this study, we examined the expression of MIF mRNA in the mouse osteoblastic cell line MC3T3-E1, whose proliferation is promoted by various growth factors. In the subconfluent state, transforming growth factor-beta, basic fibroblast growth factor, insulin-like growth factor-II, and fetal calf serum markedly upregulated MIF mRNA expression. The upregulation of MIF mRNA was less extensive when the cells were stimulated by the same growth factors in the overconfluent state. We also investigated the expression of MIF mRNA through a whole cell cycle from G0 phase when the osteoblastic cells were synchronized by serum starvation. The MIF mRNA expression, which gradually increased from the G0 and reached its maximum at the S phase, was nonperiodic. Moreover, human recombinant MIF upregulated the expression of urokinase plasminogen activator inhibitor-1 (PAI-1) precursor mRNA in human osteoblastic Saos-2 cells. Plasminogen activator (PA) is known to play an important role in bone metabolism, for example, in activation of procollagenase or growth factors indirectly via the formation of plasmin, and in mitogenic activity for osteoblastic cells. Our results suggest that MIF modulates the proliferation of osteoblasts and, moreover, bone tissue remodeling through the PA and plasmin system.

Animals↗

PubMed1999

Isolation of additional bacteriophages with genomes of segmented double-stranded RNA.

Eight different bacteriophages were isolated from leaves of Pisum sativum, Phaseolus vulgaris, Lycopersicon esculentum, Daucus carota sativum, Raphanus sativum, and Ocimum basilicum. All contain three segments of double-stranded RNA and have genomic-segment sizes that are similar but not identical to those of previously described bacteriophage phi6. All appear to have lipid-containing membranes. The base sequences of some of the viruses are very similar but not identical to those of phi6. Three of the viruses have little or no base sequence identity to phi6. Two of the viruses, phi8 and phi12, contain proteins with a size distribution very different from that of phi6 and do not package genomic segments of phi6. Whereas phi6 attaches to host cells by means of a pilus, several of the new isolates attach directly to the outer membrane. Although the normal hosts of these viruses seem to be pseudomonads, those viruses that attach directly to the outer membrane can establish carrier states in Escherichia coli or Salmonella typhimurium. One of the isolates, phi8, can form plaques on heptoseless strains of S. typhimurium.

Bacteriophages↗

PubMed1999

Antiulcer effect of lafutidine on indomethacin-induced gastric antral ulcers in refed rats.

Lafutidine is a new type antiulcer agent with antisecretory and gastroprotective activities. We investigated the effect of lafutidine on indomethacin-induced antral ulcer in refed rats. Subcutaneous indomethacin injection resulted in the formation of gastric antral ulcer. Lafutidine (1-10 mg/kg, p.o.) reduced the area of ulcer in a dose-dependent manner when administered immediately after the indomethacin injection. Capsaicin at 3 mg/kg, p.o. and 16,16-dimethyl prostaglandin E2 at 3 microg/kg, p.o. also reduced the ulcer area. Chemical deafferentation of capsaicin-sensitive neurons or N(G)-nitro-L-arginine treatment aggravated the ulcer formation and abolished the preventive effect of lafutidine and capsaicin. After the induction of gastric ulcer, lafutidine given twice daily for 2.5 days reduced the area of ulcer in a dose-dependent manner with a significant effect at 10 mg/kg, p.o., as compared with that of the control group. In chemically-deafferentated rats, lafutidine did not show any healing effect. Cimetidine (30 mg/kg, p.o.) and famotidine (1 mg/kg, p.o.) had no significant effect on indomethacin-induced antral ulcer. These results may suggest that lafutidine, unlike cimetidine and famotidine, can prevent the indomethacin-induced antral ulcer formation and accelerate the healing of the ulcer in refed rats through mechanisms involving the capsaicin-sensitive afferent neurons and nitric oxide.

16,16-Dimethylprostaglandin E2↗

PubMed1999

[Clinical studies on inverted papilloma of the urinary tract].

BACKGROUND: Inverted papilloma of the urinary tract is believed to be a benign neoplasm based on its histologic morphology and clinical behavior. In recent years, however, several investigators have warned against too optimistic an approach, emphasizing the possibility of malignant cellular transformation within the lesion, or its eventual association with other urothelial tumors such as transitional cell carcinoma or carcinoma in situ. We here report on 35 clinicopathologically diagnosed cases of inverted papilloma, and present the clinical significance attributed to these lesions in view of the current literature. PATIENTS AND METHODS: From 1976 to 1997, 35 cases of inverted papilloma of the urinary tract were treated at our hospital. This report presents the clinical features of these cases, the results of prognosis research, an investigation of the cases in which inverted papilloma and transitional cell carcinoma were found to co-exist, and a discussion of the recurrent cases of inverted papilloma found in previous literature. RESULTS: The patients ranged from 24 to 77 years of age, with a mean of 54 years, and included 4 women and 31 men. The most frequently occurring symptom was grosshematuria, and more than 90% of the 35 cases occurred in the bladder. In 2 of the 35 cases, transitional cell carcinoma coexisted with the inverted papilloma, at a different location in the bladder in one case and within the same neoplasm in the ureter in the other case. Clinical courses after treatment were followed in 29 of the 35 cases, with a follow-up period of from 8 months to 19 years (mean follow-up, 5 years and 4 months). Of these 29 cases, 2 showed recurrence, one at 16 and one at 30 months after the initial resection. Many previous reports show that the association of inverted papilloma and transitional cell carcinoma is stronger in the upper urinary tract and recurrence of inverted papilloma almost always happens with 2 years. CONCLUSION: This study suggests that some cases of urinary inverted papilloma show recurrence or malignant potential. Our results indicate that all cases of urinary inverted papilloma should be treated and followed as cases of low-grade transitional cell carcinomas. Consequently, all cases must be followed for two years or more after the initial operation.

Adult↗

PubMed1998

Isolation of a mutant that changes genomic packaging specificity in phi6.

Bacteriophage phi6 has a genome of three segments of double-stranded RNA enclosed in a polyhedral procapsid. Plus strand transcripts of the segments are packaged in a serially dependent fashion in which S can package alone, M depends on S, and L depends on S and M. We have isolated a mutant form of the virus in the carrier state that has lost segment S. This finding presented an apparent anomaly with respect to the packaging program. Sequencing of gene 1 of segment L in this virus showed a translational change of arginine to glycine at the 14th position. Procapsids prepared from cDNA containing this mutation show behavior in in vitro packaging that is consistent with the phenotype of the mutant virus. The procapsids are able to package segment S alone, but this RNA is present in reduced amounts when the other segments are present. Segments M and L package without dependence on segment S. The mutant virus appears to produce procapsids that are at the second stage of the packaging program.

Bacteriophage phi 6↗

PubMed1998

Projections from substantia nigra and zona incerta to the cat's nucleus of Darkschewitsch.

The goal of the present experiments was to examine the relationships of the nucleus of Darkschewitsch (ND) with the substantia nigra pars reticulata (SNr), the zona incerta (ZI), and the oculomotor nuclei by using wheat germ agglutinin-horseradish peroxidase (WGA-HRP) as a retrograde and anterograde neuronal tracer injected into various sites of the cat's brain. To eliminate the possibility that fibres of passage from the motor cortex passing through the SNr and ZI were responsible for the ND label, WGA-HRP also was injected into the SNr or the ZI after a large area of the frontal cortex, including the motor area, was destroyed. Retrograde axonal transport demonstrated that many cells of the rostromedial part of the ZI project to the ND, with the ipsilateral projections being dominant. Some cells of the caudomedial part of the SNr project to the ND, again, with the ipsilateral projection being dominant. A few small cells in the ND project bilaterally to the oculomotor nucleus. Anterograde tracer demonstrated that the SNr-ND terminal fields are less dense than the ZI-ND terminal fields. A few fine terminal fibres were observed bilaterally in the oculomotor, trochlear, and abducens nuclei. Electron microscopic examination demonstrated that these fine, labelled terminals contain pleomorphic vesicles and have symmetrical synaptic contacts with dendrites. These results indicate that the ND, a structure that is known to be important for the control of axial muscles (i.e., eye, head, and body muscles), is the target of projections from restricted areas of the SNr and ZI: areas that, during saccadic eye movement, may lead to disinhibition of the ND-oculomotor projection. Accordingly, the ND may function to inhibit the activity of extraocular muscles during saccades.

Animals↗

PubMed1998

Directed changes in the number of double-stranded RNA genomic segments in bacteriophage phi6.

Bacteriophage Phi6 has a genome of three segments of double-stranded RNA. The segments are designated S, M, and L. Each segment has a unique packaging site, pac, near the 5' end of the plus strand. The plus strands of the segments are normally packaged in the order S, M, L. Chimeras of segment M and S in which segment M is at the 5' end of the plus strand can be stably incorporated into the virion; however, an independent segment S must be included along with normal segment L, even if it contains no active genes. A chimera of segment M and S in which segment S is at the 5' end of the plus strand can be stably incorporated into the virion along with normal segment L to form a two-segment genome. A chimera of segments S, M, and L in which the packaging sequence is that of S can also form a stable nonsegmented genome. These findings are consistent with a model that we have proposed for the packaging of the Phi6 genome.

Bacteriophage phi 6↗

PubMed1998

Effects of endurance training on the size and blood flow of the arterial conductance vessels in humans.

The aim of the present study was to determine non-invasively the effects of endurance training on both the size and blood flow of the arterial conductance vessels during exercise by men. Twelve healthy male subjects were assigned to either an exercise-trained group (ET, n = 7) or a sedentary control group (S, n = 5). The ET group underwent cycle-endurance training for 8 weeks (80% VO2max, 40 min day-1, 5 days week-1). The S group led normal lives during the 8-week period. Before and after the training period, cross-sectional areas (CSA) of the ascending and abdominal aorta were measured by echography. Measurements were taken in the semisupine position on a cycle ergometer fitted with a backrest, at rest and during 40, 60 and 80% VO2max of exercise. In addition, Doppler ultrasonographic velocity and flow in the ascending aorta were simultaneously measured. The CSA of the ascending and abdominal aorta after training were significantly larger than those before training in the ET group. Although there were no significant differences in the peak and mean velocities in the ascending aorta before and after the training in the ET group, the blood flow in the ascending aorta during exercise after training was significantly larger than that found before training at each relative intensity. There were no significant differences in any of the Doppler echographic parameters in the S group. These findings suggest that the arterial conductance vessels can be morphologically altered in an adaptive response to the endurance training. Furthermore, the dilation of the conductance vessels with endurance training contributes to an increase in blood flow to the exercising muscles without a rise in blood velocity. In other words, the arterial conductance vessels adapt to maintain adequate blood velocity and shear stress.

Adaptation, Physiological↗