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Biomedical subjects

M Yoshida

Publications and source records attributed to M Yoshida.

At least 379 records · Page 21Linked to original sources
PubMed2000

Induction and maintenance of immune effector cells in the gastric tissue of mice orally immunized to Helicobacter pylori requires salivary glands.

BACKGROUND & AIMS: Helicobactor pylori mostly colonizes the gastric mucus that contains salivary antibodies. We studied the role of saliva in the induction and maintenance of gastric immunity conferred by oral vaccination against H. pylori. METHODS: C57BL/6 mice underwent a sialoadenectomy before and after intragastric immunization using whole-cell sonicates of H. pylori and cholera toxin as an adjuvant. At 1 and 6 months after oral inoculation, we assessed the density of the H. pylori colonizing the stomach, specific antibodies in gastric secretion and sera, and the constituents of cellular infiltrates in the tissue. RESULTS: A sialoadenectomy before, but not after, immunization abrogated protection by the vaccination at 1 month after inoculation. Protected mice had more neutrophils, plasma cells, and lymphocytes, but fewer eosinophils, in the gastric tissue than nonprotected mice. Protected mice had a greater increase of immunoglobulin (Ig) G1 specific to H. pylori than IgG2a in sera. At 6 months after inoculation, oral immunization was less effective in mice who had a sialoadenectomy than in control immunized mice. The antibody titers in both gastric secretion and in sera did not correlate with the density of bacteria colonizing the stomach. CONCLUSIONS: It is suggested that, in intragastric immunization against H. pylori, saliva is necessary for both the induction and maintenance of optimal immunity in the stomach. Effective immunity was associated with an increased number of neutrophils and lymphocytes in gastric tissue.

Administration, Oral↗
PubMed2000

Manganese deposits in patients with biliary atresia after hepatic porto-enterostomy.

PURPOSE: The aim of this study was to determine if there is latent manganese toxicity in patients with biliary atresia. METHODS: Fifteen children with biliary atresia were examined postoperatively with regard to whole-blood manganese levels using brain magnetic resonance imaging (MRI) and I-123 iodoamphetamine (IMP) per rectal portal scintigraphy. RESULTS: Nine (60%) of the 15 had high whole-blood manganese levels (mean, 4.1 microg/dL; range, 1.2 to 9.6; normal, 0.5 to 2.5), and these 9 had hyperintense globus pallidus on T1-weighted images, with no corresponding signal change in T2 sequences. I-123 IMP per rectal portal scintigraphy was done for 13 patients to evaluate portosystemic shunt flow. 12 (92%) of these patients had an increased flow. Mean shunt ratio was estimated to be 41% (range, 0.6 to 98; normal, <5%). Encephalopathy was evident in only 1 patient. CONCLUSIONS: Some patients with biliary atresia in the postoperative period have manganese deposits in globus pallidus on T1-weighted images and high whole-blood manganese levels, possibly caused by increased portsystemic shunt, and a latent or subclinical encephalopathy is also present.

Adolescent↗
PubMed2000

Immediate maxillary denture base extension for posterior palatal seal.

A procedure for extension of the maxillary denture base for development of a posterior palatal seal is described. The technique involves provisional extension with paraffin wax and adding direct relining resin supported by a silicone putty core. This simple, quick procedure achieves immediate recovery of retention for underextended maxillary dentures without additional laboratory procedures.

Dental Polishing↗
PubMed2000

Nocturia in the adult: classification on the basis of largest voided volume and nocturnal urine production.

PURPOSE: We propose a criterion to clarify the underlying etiologies of nocturia. MATERIALS AND METHODS: Frequency-volume charts were recorded for 24 hours by 35 men and 32 women who were subjectively free of lower urinary tract symptoms and had no evidence of voiding disorders. At least 5 subjects were included in each of 5 age groups of 20 to 49, 50 to 59, 60 to 69, 70 to 79, 80 to 89 years for both genders. The charts were used to make a tentative criterion, which was validated in 39 elderly individuals with nocturnal frequency. RESULTS: Correlation and regression analyses indicated that the quotients of nocturnal urine output divided by body weight (U(N)/BW) and largest voided volume divided by body weight (V(L)/BW) were useful classification factors. Cutoffs, which were set close to worst quartiles, were 10 ml./kg. for U(N)/BW and 4 ml./kg. for V(L)/BW, respectively. Correction by body weight made the same criterion applicable irrespective of weight. Symptomatic elderly patients were classified into 3 mutually exclusive groups of nocturnal polyuria (U(N)/BW greater than 10 ml./kg.), low bladder capacity (V(L)/BW less than 4 ml./kg.) and combined nocturia. Of 20 subjects who voided 2 times a night 11 (55%) were classified as having nocturnal polyuria and 15 of 19 who voided 3 or 4 times (79%) were classified as having low bladder capacity or combined nocturia. CONCLUSIONS: The criterion provides a reasonable distinction of etiologies of nocturia, and may be usefulness in examination and treatment.

Adult↗
PubMed2000

The distributions of apoptotic cells in the medial preoptic areas of male and female neonatal rats.

The medial preoptic area (MPA) of the hypothalamus of the rat contains two sexually dimorphic nuclei, the periventricular preoptic nucleus (PVpo) and the medial preoptic nucleus (MPN). To examine the relationship between sexual dimorphism and neuronal death, we examined the number of apoptotic cells in the subdivisions of the MPA in neonatal rats of postnatal days 1 (P1), 4 (P4), 7 (P7) and 14 (P14). Apoptotic cells in these areas were classified according to their progression into three stages. P1 and P4 rats contained many apoptotic cells in the subfield along the third ventricle, including the PVpo, and their number was significantly larger in P1 males: in particular, the number of early-stage cells was larger in males than females. The number of apoptotic cells in the MPN was increased in P4 and P7 rats, although no significant sexual differences were seen in the total number or in the number of each progressive stage of apoptotic cells. In P14 rats, very few apoptotic cells were seen in the MPA. Our data revealed that the distribution of apoptotic cells in the MPA of developing rats depends on the sexuality, subdivision of the area and postnatal period.

Animals↗
PubMed2000

Regional distribution and plasma concentration of peptide YY in sheep.

Peptide YY (PYY)-positive cells are distributed in the mucosa of the ileum, cecum, colon, and rectum of sheep, but not in other layers of these regions. By radioimmunoassay, mucosal content of PYY in the ovine large intestine was much less than that in the rat intestine. The plasma concentration of immunoreactive PYY did not significantly fluctuate over a 48-h period in conscious sheep, even after ingestion of roughage and concentrate. Intraluminal nutrients into the ileum and i.v. CCK8 also did not raise the plasma level of PYY. Therefore, PYY seems unlikely to play a role as "ileal brake" in sheep.

Animals↗
PubMed2000

Obstacles to bystander cardiopulmonary resuscitation in Japan.

OBJECTIVE: bystander cardiopulmonary resuscitation (CPR) is performed infrequently in Japan. We conducted this study to identify Japanese attitudes toward the performance of bystander CPR. METHODS: participants were asked about their willingness to perform CPR with varying scenarios and CPR techniques (mouth-to-mouth ventilation plus chest compression (MMV plus CC) versus chest compression alone (CC)). RESULTS: a total of 1302/1355 individuals completed the questionnaire, including high school students, teachers, emergency medical technicians, medical nurses, and medical students. About 2% of high school students, 3% of teachers, 26% of emergency medical technicians, 3% of medical nurses and 16% of medical students claimed they would 'definitely' perform MMV plus CC on a stranger. However, 21-72% claimed they would prefer the alternative of performing CC alone. Respondents claimed their unwillingness to perform MMV is not due to the fear of contracting a communicable disease, but the lack of confidence in their ability to perform CPR properly. CONCLUSION: in all categories of respondents, willingness to perform MMV plus CC for a stranger was disappointingly low. Better training in MMV together with teaching awareness that CC alone can be given should be instituted to maximize the number of potential providers of CPR in the community, even in communities where the incidence of HIV is very low.

Attitude to Health↗
PubMed2000

Whole-body metabolism of the organophosphorus pesticide, fenthion, in goldfish, Carassius auratus.

The in vivo metabolism of fenthion, an organophosphorus pesticide, and its sulfoxide (fenthion sulfoxide) was examined in goldfish (Carassius auratus). When goldfish were administered fenthion i.p. at a dose of 100 mg/kg, two metabolites were isolated from the tank water. They were identified as fenthion sulfoxide and fenthion oxon, in which > P = S of fenthion is transformed to > P = O, by comparing their mass and UV spectra, and their behavior in HPLC and TLC, with those of authentic standards. However, fenthion sulfone was not detected as a metabolite. The amounts of fenthion, fenthion sulfoxide and fenthion oxon excreted within 4 days were 2.7, 3.4 and 2.5%, of the initial dose of fenthion, respectively. Unchanged fenthion was detected in the body of the fish to the extent of 42-50% of the dose after 10 days, but fenthion sulfoxide and fenthion oxon showed very low concentrations. When fenthion sulfoxide was administered to the fish, about 70% of the dose was excreted unchanged into the tank water within 24 h, but little of the reduced compound, fenthion, was found. In contrast, fenthion was detected at 2.1% of dose in the body of goldfish as a metabolite of fenthion sulfoxide. The fact that fenthion is metabolized to the toxic oxon form in fish presumably has environmental and health implication for its use as a pesticide.

Animals↗
PubMed2000

Lack of substantial effect of the H(3)-antagonist thioperamide and of the non-selective mixed H(3)-antagonist/H(1)-agonist betahistine on amygdaloid kindled seizures.

We investigated whether some histamine H(3)-antagonists would attenuate amygdaloid kindled seizures in rats. Thioperamide, a standard H(3)-antagonist, did not significantly reduce either seizure ranks or afterdischarge duration (ADD). Betahistine which has both H(3)-antagonistic activity and H(1)-agonistic activity significantly reduced ADD, albeit mild at a toxic dose, though seizure ranks were not affected. In addition, L-histidine, the precursor of histamine, affected neither seizure ranks, nor ADD. It was shown that H(3)-antagonists have no significant inhibitory action against amygdaloid kindled seizures, probably because released histamine was unable to inhibit those seizures.

Amygdala↗
PubMed2000

Asymptomatic shedding of herpes simplex virus into the oral cavity of patients with atopic dermatitis.

BACKGROUND: Asymptomatic shedding of herpes simplex virus (HSV) into the oral cavity is one of the important sources of the infection. OBJECTIVES: We anticipated that the oral cavity is one of the possible sites of initial recurrence in patients with recurrent-type eczema herpeticum. MATERIALS AND METHODS: Oral swabs were collected from 24 patients with atopic dermatitis aged from 13 to 29 years, and as a control population, from seven patients with skin diseases other than atopic dermatitis aged from 16 to 29 years. We tried to detect HSV DNA by the polymerase chain reaction method. RESULTS: HSV DNA was detected in eight out of 31 specimens from 15 patients with facial lesions of atopic dermatitis, and in one of 15 specimens from nine patients without facial atopic dermatitis, and in two of ten specimens from seven patients with other skin diseases. However, these differences are not statistically significant. Moreover, no patients developed eczema herpeticum during the period of this study. CONCLUSIONS: These results suggest that facial atopic dermatitis may not lead to oral HSV shedding, and there may be little opportunity for the virus in the oral cavity to contaminate other skin sites in adolescents and adults.

Adolescent↗
PubMed2000

Changes in pulmonary histology and exfoliated bronchoalveolar cells induced by in vivo introduction of the tumor necrosis factor-alpha gene.

An inflammatory cytokine, tumor necrosis factor (TNF)-alpha, has been implicated in the pathogenesis of inflammatory lung diseases such as interstitial pneumonia (IP). To clarify the role of the inflammatory cytokine in the pathogenesis of lung inflammation, we introduced a murine TNF-alpha gene into murine lungs by the hemagglutinating virus of Japan (HVJ)-liposome method. Seven days after the TNF-alpha gene introduction resulted in marked cellular infiltration of alveoli, and mild histological change was observed 28 days after the gene introduction. Electron microscopic analysis revealed minimal deposition of collagen fibrils. Analysis of the BAL revealed that the total cell number was markedly increased 3 and 7 days after the gene introduction, and more than 90% of the cells were macrophages. The increase in the cell number was returned to below the normal level 28 days after the gene introduction. During the development of IP, TNF-alpha may regulate pathologic change of the pulmonary interstitium and alveolar cells.

Animals↗
PubMed2000

Increased defecation during stress or after 5-hydroxytryptophan: selective inhibition by the 5-HT(4) receptor antagonist, SB-207266.

5-HT(4) receptor antagonism prevents the ability of exogenous 5-HT or 5-HTP to sensitize the intestinal peristaltic reflex and increase the rate of defecation, generally without affecting non-stimulated intestinal function. In this study we confirmed the ability of the selective 5-HT(4) receptor antagonist SB-207266 1 - 1000 microg kg(-1) p.o., to prevent the increase in defecation evoked over a 60 min period by 5-HTP 10 mg kg(-1) s.c. in conscious mice, in the absence of an apparent constipating action. The role of endogenous 5-HT in the mechanisms of increased defecation and/or diarrhoea was then investigated in conscious, fed rats. This was evoked by 180 min exposure to restraint stress, which increased both the number and mean weight of formed, faecal pellets excreted over the entire time period. SB-207266 1 - 1000 microg kg(-1) p.o. (dosed 30 min before restraint) did not affect the increase in defecation evoked during the first 60 min of restraint stress, but significantly and dose-dependently reduced or prevented the increased defecation during the remaining 120 min of the experiment; this action occurred in the absence of an apparent constipating action of SB-207266. In fasted rats exposed to restraint stress, watery diarrhoea developed and although there was a tendency for SB-207266 1 - 1000 microg kg(-1) p.o. (dosed 30 min before restraint) to reduce the incidence of diarrhoea, this inhibition was not complete. We conclude that selective 5-HT(4) receptor antagonism prevents disruptions in defecation behaviours caused by exogenous or endogenous enteric 5-HT and that this activity is not accompanied by a concomitant suppression of activity (constipation-like) within the intestine itself.

5-Hydroxytryptophan↗
PubMed2000

Antihypertensive effect of valyl-tyrosine, a short chain peptide derived from sardine muscle hydrolyzate, on mild hypertensive subjects.

The present study was conducted to determine whether Valyl-Tyrosine (VY) has an antihypertensive effect on high-normal blood pressure and mild essential hypertension, as well as spontaneous hypertensive rats (SHR). A randomised double-blind placebo-controlled study was carried out on 29 volunteers. A 100-ml drink containing 3 mg of VY and a 100-ml placebo drink were prepared. The subjects were grouped as VY(16M/1F, 45.5 +/- 3.2 years, 146.4 +/- 2.3/90.5 +/- 1.8 mm Hg) and the placebo (P) (11 M/1F, 48.8 +/- 3.0 years, 145.5 +/- 2.4/92.3 +/- 1.8 mm Hg). At 3 weeks of the control (C) period, a VY- or P-drink was administered twice a day for 4 weeks in the experimental (E) period and during the 4-week recovery period, neither drink was given to either group. Blood pressure (BP) was measured every week in the morning in the sitting position. Blood specimens were taken on the last day of the C and E periods. In the VY-group, reduction in systolic (S) and diastolic (D) BP was 9.7 and 5.3 mm Hg (P < 0. 001) at 1 week, and 9.3 and 5.2 mm Hg (P < 0.001) at 4 weeks, following the start of the E period, respectively. Neither SBP nor DBP changed in the P-group. BP in the VY-group increased gradually by the end of the recovery period. Plasma angiotensin (Ang) I and VY concentrations significantly increased while Ang II and aldosterone significantly decreased after VY administration in the VY-group. VY appeared to have a significant antihypertensive effect on mild hypertensive subjects via Ang I-converting enzyme inhibition, as well as SHR, but no adverse effects could be detected at all.

Adult↗
PubMed2000

Review article: transcription factors and growth factors in ulcer healing.

This review is focused on recent investigations demonstrating a pharmacological and pathophysiologic role in gastroduodenal ulceration for growth factors such as basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF), as well as for transcription factors. Our experiments revealed accelerated healing, without decreased gastric acid secretion, of chronic cysteamine-induced duodenal ulcers in rats treated daily for 3 weeks with intragastric administration of bFGF, PDGF or VEGF. Our recent studies also indicate a pathophysiological role of endogenous growth factors in the natural history of experimental duodenal ulcer development and healing. More recently, we investigated the genetic regulation of these growth factors in experimental duodenal ulceration. Since gene expression is most effectively controlled by transcription factors, proteins that bind to cis-acting elements of DNA and guide the binding of polymerase II to start the transcription of specific mRNA, we tested the hypothesis that the expression of IEGs and their transcription factor products, such as Egr-1 and Sp1, might precede the increased synthesis of bFGF, PDGF and VEGF in duodenal ulcer healing. Indeed, the duodenal ulcerogen cysteamine, but not its nonulcerogen and toxic analogue ethanolamine, rapidly increased duodenal (but not gastric) mucosal levels of ET-1, which was followed by enhanced expression of Egr-1 and a decrease in Sp1 in the preulcerogenic stage of duodenal ulceration. These changes in levels of ET-1 and expression of transcription factors were also accompanied by increased expression of the CDK inhibitor p21. Thus, not only growth factors such as bFGF, PDGF and VEGF, but also transcription factors such as Egr-1 and Sp1 and the cell cycle regulator p21, may play a role in the natural history of experimental duodenal ulceration.

Animals↗
PubMed2000

Enrichment of lineage-CD34- cells using a newly developed filter system.

Recent studies have demonstrated the presence of human lineage- (lin-)CD34- cells that are capable of differentiating into CD34+ cells in xenogeneic transplantation systems. We developed a new filter system that can enrich lin-CD34- cells, a precursor cell population of CD34+ cells. The filter consists of polyethylene terephthalate non-woven fabrics coated with hydrophilic polymer. The frequency of lin-CD34- cells in the cell population after filtration was 7.45 +/- 4.41%, a 16.8 +/- 8.81-fold enrichment compared with 0. 49 +/- 0.31% in the cell population before filtration. The mean recovery of lin-CD34- cells was 48.57 +/- 13.59% (n = 15). Purified lin-CD34- cells, obtained by sorting the filtrated cell population, acquired CD34 expression and colony-forming activity after 7 d of culture. Our results indicate that this filter system is useful for isolating lin-CD34- cells, including precursors of CD34+ cells, and will help further the study of lin-CD34- cells.

Antigens, CD34↗
PubMed2000

Formation of sarcoglycan complex with differentiation in cultured myocytes.

The sarcoglycan complex consists of four transmembrane protein subunits. Mutation of any one of the genes encoding these four subunits causes complete loss or marked decrease in expression of the whole complex, resulting in the phenotype of Duchenne-like autosomal recessive muscular dystrophy, termed sarcoglycanopathy. As the basis for understanding this process, we examined how the sarcoglycan complex is formed and associates with other proteins during myogenic differentiation, using a myogenic cell line. Accumulation of the sarcoglycan subunits and formation of the sarcoglycan complex were accomplished with myotube formation. In protein transport inhibition experiments with blefeldin A, we found that the sarcoglycan complex is formed in the endoplasmic reticulum and then associates with the dystroglycan complex and sarcospan en route from the Golgi apparatus to the cell surface. In early myotubes, limited kinds of incomplete sarcoglycan complexes were observed. Their analyses would provide information on the possible patterns of formation of the sarcoglycan complex.

Animals↗