Biomedical subjects

Y Mori

Publications and source records attributed to Y Mori.

At least 109 records · Page 6Linked to original sources

PubMed2001

Immunohistological study of interferon-gamma- and interleukin-4-bearing cells in human periodontitis gingiva.

The purpose was to investigate the balance between interferon (IFN)-gamma- and interleukin (IL)-4-bearing cells in various human inflamed gingiva by immunohistochemistry. Gingival tissues obtained from patients with gingivitis or periodontitis were divided into three groups based on the degree of histopathological inflammation, mild, moderate and severe. The tissues were also divided into four groups according to the clinical probing depth (PD). IFN-gamma- and IL-4-bearing cells in gingival tissues were stained immunohistologically and counted. The ratio of IL-4-bearing cells to IFN-gamma-bearing cells was calculated for each section. IFN-gamma-bearing cells were widespread in the connective tissue and their number increased significantly with the severity of inflammation and an increase of PD. IL-4-bearing cells were located beneath the pocket epithelium and their number showed no significant differences among the inflammation or PD groups. The ratios of IL-4-bearing cells to IFN-gamma-bearing cells in the severe inflammation or deep PD groups were significantly lower than those in the moderate inflammation or shallow PD groups. These results suggest that a low ratio of IL-4-bearing cells to IFN-gamma-bearing cells might be involved in the destruction of periodontal tissue.

Adult↗

PubMed2001

Risk stratification using serum concentrations of cardiac troponin T in patients with end-stage renal disease on chronic maintenance dialysis.

BACKGROUND: It has been recently suggested that cardiac troponin T (cTnT) may be more sensitive than troponin I (cTnI) for subclinical myocardial cell injury in patients on chronic dialysis. METHODS: We prospectively compared the predictive value of cTnT with cTnI, atrial (ANP) and brain natriuretic peptide (BNP) in 100 consecutive outpatients on chronic dialysis without acute coronary syndromes over a period of 3 months, and assessed whether the combination of cTnT with clinical information including age, duration of dialysis, and medical histories was useful for risk stratification of these patients. During the 2-year follow-up period, 19 patients died, mostly due to cardiac causes (53%). RESULTS: The area under the receiver operator characteristic (ROC) curve for the cTnT as predictor of both overall and cardiac death was significantly greater than the area under the cTnI curve (p < 0.0001 and p = 0.01), the BNP curve (p < 0.001 and p < 0.01) or the ANP curve (p < 0.0001 and p < 0.005). In a stepwise multivariate Cox regression analysis, only cTnT (p < 0.05 and p < 0.01) and a history of heart failure requiring hospitalization (p < 0.05 and p < 0.005) were independent predictors of both all cause and cardiac mortality. Using parameters of cTnT > or =0.1 microg/l and/or history of heart failure, the overall and cardiac mortality rate for the low risk group (n=66) were 4.5% and 1.5%, respectively, 40% and 16% for the intermediate risk group (n=25), and 67% and 56% for the high risk group (n=9). CONCLUSION: cTnT concentrations offer a higher prognostic accuracy than cTnI, ANP and BNP in patients on chronic dialysis. The combination of elevated cTnT and a history of heart failure may be a highly effective means of risk stratification of these patients.

Adult↗

PubMed2001

TCV-116 stimulates eNOS and caveolin-1 expression and improves coronary microvascular remodeling in normotensive and angiotensin II-induced hypertensive rats.

Angiotensin II (Ang II) plays an important role as a modulator of vascular structure and function in arterial hypertension. This study investigated the effects of an Ang II type 1 receptor antagonist, TCV-116, on endothelial nitric oxide synthase (eNOS) mRNA and protein expression, and NOS activity and eNOS regulatory protein caveolin-1 protein expression in the left ventricle of Wistar-Kyoto rats treated for 2 weeks with Ang II (200 ng/kg/min) and evaluated these relations to myocardial remodeling. Rats given Ang II alone (ANGII) were compared with rats also receiving TCV-116 (ANGII-TCV). The eNOS mRNA and protein levels, and NOS activity and caveolin-1 protein expression in the left ventricle were significantly decreased in ANGII compared with control rats (CON), and were significantly increased in ANGII-TCV compared with ANGII. Moreover, compared with CON, the eNOS and caveolin-1 expression was significantly greater in CON treated with TCV-116. ANGII showed a significant increase of the wall-to-lumen ratio, perivascular and myocardial fibrosis, and type I collagen mRNA expression, with all these parameters being significantly improved by TCV-116. Thus, coronary microvascular and myocardial remodeling in normotensive and Ang II-induced hypertensive rats was significantly ameliorated by a subdepressor dose of TCV-116, which may be at least in part mediated by an increase in local eNOS mRNA and protein expression, and NOS activity in the left ventricle.

Angiotensin II↗

PubMed2001

Alarm pheromone enhances stress-induced hyperthermia in rats.

Behavioral and physiological effects of alarm pheromones emanating from stressed conspecific animals were investigated. Experimentally naive male Wistar rats were exposed to the test chambers containing alarm pheromones, which had been released by other rats receiving foot shocks in the same chamber beforehand. Along with behavioral analysis, the heart rate (HR) and core body temperature (cBT) were measured simultaneously using a biotelemetory system. Exposure to the alarm pheromones increased freezing, sniffing and walking and decreased resting as compared with rats exposed to control odors. In addition, these pheromone-exposed animals showed consistent increases in body temperature, i.e., stress-induced hyperthermia. After exposure to the alarm substances, immunoreactivity to nuclear Fos protein in the mitral cell layer in the accessory olfactory bulb (AOB) also increased compared with the reaction to control odors. These results suggest that an alarm pheromone enhances stress responses of conspecific animals both behaviorally and physiologically, and that these effects are mediated via activation of the AOB.

Animals↗

PubMed2001

Analysis of microcystins in sediments using MMPB method.

During the course of study on the detoxification of microcystins, the adsorption on sediments in the natural environment was investigated. Because it was very difficult to extract microcystins from sediments using conventional techniques, a physicochemical screening method, the MMPB (2-methyl-3-methoxy-4-phenylbutyric acid) method, including ozonolysis and mass spectrometric detection was developed. This method consisted of the following operations: lyophilized sediments were suspended in methanol and MMPB-d(3) as an internal standard was added to this suspension, which was cooled at -78 degrees C with vigorous stirring and then treated with a stream of ozone/oxygen. After centrifugation, an aliquot of the reaction solution was subjected to EI (electron ionization)-GC/MS analysis after methylation with 14% BF(3)-methanol and liquid-liquid extraction. The established method had a potential for the analysis of microcystins in sediments that are difficult to analyze using conventional methods. Finally, this method was applied to sediment samples collected in Japanese lakes and six of the eleven samples showed positive results. The obtained results clearly indicated that the adsorption on sediments contributes to the detoxification of microcystins under natural conditions.

Adsorption↗

PubMed2001

Long-term results of stereotactic gamma radiosurgery of meningiomas.

BACKGROUND: The early effects at a mean of 30 months and long-term results at 7 years after gamma radiosurgery for meningiomas were evaluated. METHODS: Changes in tumor size were evaluated every 3 to 6 months after treatment using a five-point grading system, as well as changes in neurological signs and general status. RESULTS: Early effects in 87 cases of benign meningioma showed a minimal size reduction of 16.1% and a response rate of 8.0%, but a higher control rate of 93%. The cavernous sinus meningioma showed a size reduction of 23.2%, a response rate of 11.1%, and control of 100%. A greater size reduction of 24.8% and response rate of 33.3%, but a lower control rate of 75% were obtained in 12 cases of malignant meningioma. Side effects were found in 12 cases (13.8%): radiation-induced edema in 9, hearing disturbance in 2, and visual deterioration in 1. Long-term results for 54 of 87 patients with benign tumors showed that response increased from 8% to 42.6% but control decreased slightly due to increased disease progression. CONCLUSION: Gamma radiosurgery is effective and safe for meningiomas to control residual or recurrent tumors after surgery and initial tumors, with acceptable side effects and rate of tumor progression.

Adult↗

PubMed2001

Radiosurgery of cavernous hemangiomas in the cavernous sinus.

BACKGROUND: Cavernous hemangiomas in the cavernous sinus are rare and demonstrate unique clinical courses. Although they rarely cause spontaneous bleeding, serious bleeding is not uncommon during operations. Total eradication of such tumors is very difficult because of the location and intraoperative bleeding. Consequently, alternatives to operative resection have been examined. METHODS: Three cases of cavernous hemangiomas in the cavernous sinus, presenting chiefly with ocular signs and facial pain, were treated by radiosurgery using a gamma knife. Two of the patients had been operated on before radiosurgery, while the third patient was diagnosed on the basis of neurological signs as well as radiological findings. RESULTS: MRI scans at the time of radiosurgery showed tumors in the cavernous sinus with low or iso-intensity on T1-weighted images and high signal intensity on T2-weighted images. All of the tumors intensely enhanced with gadolinium-DTPA. The tumors had diameters of 14 to 28 mm and were treated with a marginal dose of 14 to 17 Gy (mean 15.7 Gy). In the mean follow-up period of 27 months after radiosurgery, all of the tumors decreased in size (PR). Neurologically, none of the patients showed any deterioration, and one demonstrated an obvious improvement in ocular movement. CONCLUSIONS: Radiosurgery for cavernous hemangioma in the cavernous sinus is apparently safe and effective with consistent tumor shrinkage. Therefore, radiosurgery is an excellent alternative to operative intervention and may even replace operative procedures if the tumors are small in diameter or when they recur.

Adult↗

PubMed2001

Morphological changes of the anterior spinal artery during aortic cross-clamping and effect of prostaglandin E1 with perfusion.

This investigation was designed to evaluate the morphological changes of anterior spinal artery (ASA) and its reaction to prostaglandinE1 (PGE1) during aortic cross-clamping. ASA during 30 min cross-clamping was observed with charge-coupled device (CCD) and ASA diameter (ASAD) was measured. Group A: Infrarenal aorta was cross-clamped. Group B: Infrarenal aorta was cross-clamped and aorta above the bifurcation was snared. The aortic segment between clamp and snare was perfused with blood. Group C: PGE1 of 100 ng/kg/min was added to perfusate of Group B. The aortic segmental pressures in group B and C were about 30% of the proximal systolic arterial pressure and were significantly higher than distal pressure of group A. After cross-clamping, ASAD decreased about 80% of before cross-clamping in group A. By segmental perfusion of which pressure was about 30% of proximal systolic arterial pressure, ASAD remained almost 90% in group B. By administration of PGE1, ASAD was significantly increased in group C. The changes of ASAD were significantly different between group A and C, and between group B and C.

Alprostadil↗

PubMed2001

Complete nucleotide sequence of a group A avian rotavirus genome and a comparison with its counterparts of mammalian rotaviruses.

The nucleotide sequences encoding four structural proteins (VP1-4) and six nonstructural proteins (NSP1-6) of avian rotavirus PO-13 were determined. Based on the results of earlier sequencing studies [Ito et al., 1995, Sequence analysis of cDNA for the VP6 protein of group A avian rota viruses. Arch. Vriol. 140, 605-612; Rohwedder et al., 1997, Chicken rotavirus Ch-1 shows a second type of avian VP6 gene, Virus Genes 15, 65-71; Rohwedder et al., 1997, Bovine rotavirus 993/83 shows a third subtype of avian VP7 protein, Virus Genes 14, 147-151], determination of PO-13 genome sequence has been completed. The PO-13 genome is 18845 nucleotides in length. It is 290 nucleotides longer than the genome of SA11. The amino acid sequence homology between PO-13 and mammalian rotaviruses ranged from 76-77% (VP1) to 16-18% (NSP1). The features of gene and amino acid sequence were compared with those of the corresponding protein of mammalian rotaviruses. Based on results of the phylogenetic analyses of NSP1, we speculate that an ancestral rotavirus could have separated into groups A, B and C rotaviruses at an early evolutionary stage and that group A rotavirus separated into mammalian and avian rotaviruses with host evolution.

Amino Acid Sequence↗

PubMed2001

Effect of gravity field on the nonequilibrium/nonlinear chemical oscillation reactions.

Biological systems have evolved for a long time under the normal gravity. The Belousov-Zhabotinsky (BZ) reaction is a nonlinear chemical system far from the equilibrium that may be considered as a simplified chemical model of the biological systems so as to study the effect of gravity. The reaction solution is comprised of bromate in sulfuric acid as an oxidizing agent, 1,4-cyclohexanedione as an organic substrate, and ferroin as a metal catalyst. Chemical waves in the BZ reaction-diffusion system are visualized as blue and red patterns of ferriin and ferroin, respectively. After an improvement to the tubular reaction vessels in the experimental setup, the traveling velocity of chemical waves in aqueous solutions was measured in time series under normal gravity, microgravity, hyper-gravity, and normal gravity using the free-fall facility of JAMIC (Japan Microgravity Center), Hokkaido, Japan. Chemical patterns were collected as image data via CCD camera and analyzed by the software of NIH image after digitization. The estimated traveling velocity increased with increasing gravity as expected. It was clear experimentally that the traveling velocity of target patterns in reaction diffusion system was influenced by the effect of convection and correlated closely with the gravity field.

Bromates↗

PubMed2001

Validation of a digital color Doppler flow measurement method for pulmonary regurgitant volumes and regurgitant fractions in an in vitro model and in a chronic animal model of postoperative repaired tetralogy of Fallot.

OBJECTIVES: The purpose of this study was to validate a digital color Doppler (DCD) automated cardiac flow measurement method for quantifying pulmonary regurgitation (PR) in an in vitro and a chronic animal model of the right ventricular outflow tract of postoperative tetralogy of Fallot (TOF). BACKGROUND: There has been no reliable ultrasound method that can accurately quantitate PR. METHODS: We developed an in vitro model of mild pulmonary stenosis and wide-open PR that mimics the patterns of flow seen in patients with postoperative TOF. Thirteen different forward and regurgitant stroke volumes (RSVs) across the noncircular shaped cross-sectional outflow tract flow area were estimated using the DCD method in two orthogonal planes. In six sheep with surgically created PR, 24 different hemodynamic states with PR strictly quantified by electromagnetic probes were also studied. RESULTS: The RSVs and regurgitant fractions (RFs) obtained by the DCD method using average values from two orthogonal planes correlated well with reference values (RSV: r = 0.99, mean difference = 0.02 +/- 0.39 ml/beat for in vitro model; r = 0.97, mean differences = 1.79 +/- 1.84 ml/beat for animal model, RF: r = 0.98, mean difference = -1.10 +/- 4.34% for in vitro model; r = 0.94, mean difference = 2.73 +/- 6.75% for animal model). However, the DCD method using a single plane had limited accuracy for estimating pulmonary RFs and RSVs. CONCLUSIONS: The DCD method using average values from two orthogonal planes provides accurate estimation of RSVs and RFs and should have clinical importance for serially quantifying PR in patients with postoperative TOF.

Animals↗

PubMed2001

Insulin resistance induced in dairy steers by tumor necrosis factor alpha is partially reversed by 2,4-thiazolidinedione.

The aim of this study was to determine whether 2,4-thiazolidinedione (2,4-TZD) influences the effects of peripheral insulin action in steers given recombinant bovine tumor necrosis factor (TNF) alpha (rbTNF). Steers were treated once daily for 9 d (d0 - d8) with either s.c. injection of rbTNF (2.5 microg/kg), rbTNF + i.v. injection of 2,4-TZD (2.0 mg/kg), or s.c. injection of saline (control). The plasma glucose, NEFA, and insulin concentrations in the rbTNF-treated group increased compared to those in the control and rbTNF + 2,4-TZD groups, whereas glucagon concentration decreased. A single i.v. injection of insulin (0.2 U/kg), glucose (112.5 mg/kg), or growth hormone (GH)-releasing hormone (GHRH) (0.25 microg/kg) was performed on d4, d6, and d8, respectively. In the insulin challenge, the net area under the glucose curve (AUC) was smaller in the rbTNF group than in the control and rbTNF + 2,4-TZD groups. In the glucose challenge, the net insulin AUC was smaller in rbTNF + 2,4-TZD group than in rbTNF group. In the GHRH challenge, there was no difference in GH responses to GHRH between the rbTNF and rbTNF + 2,4-TZD groups, respectively. We conclude that 2,4-TZD treatment partially reverses the impairment of peripheral insulin action caused by rbTNF injection in steers.

Animals↗

PubMed2001

Stereotactic gamma radiosurgery for pineal and related tumors.

The role of gamma knife radiosurgery as an additional therapy after conventional treatments for pineal and related tumors was studied in 30 of 33 tumors with a mean follow-up of 23.3 months. Overall results showed that a complete response was obtained in 8 cases (26.7%) and the response rate was 73.3%. However, tumor progression was found in 8 cases (26.7%), of whom 7 (23.3%) died as a consequence. Germinoma and pineocytoma showed higher response and control rates (100%), and neither progression nor death occurred after gamma knife treatment. Germinoma with syncytiotrophoblastic giant cells (STGC) has been thought to have an intermediate prognosis. Two of our cases showed a partial response and another progression. Malignant germ cell tumor and pineoblastoma showed unfavorable responses and prognosis, with the response and progression rates both being 50%. Gamma knife radiosurgery was the initial treatment in three pineal tumor cases without a histological diagnosis, and one complete and two partial responses were obtained. Gamma knife radiosurgery is expected to be an effective and novel approach to pineal and related tumors, not only as an adjuvant but also as an initial treatment.

Adolescent↗

PubMed2001

The fat-derived hormone adiponectin reverses insulin resistance associated with both lipoatrophy and obesity.

Adiponectin is an adipocyte-derived hormone. Recent genome-wide scans have mapped a susceptibility locus for type 2 diabetes and metabolic syndrome to chromosome 3q27, where the gene encoding adiponectin is located. Here we show that decreased expression of adiponectin correlates with insulin resistance in mouse models of altered insulin sensitivity. Adiponectin decreases insulin resistance by decreasing triglyceride content in muscle and liver in obese mice. This effect results from increased expression of molecules involved in both fatty-acid combustion and energy dissipation in muscle. Moreover, insulin resistance in lipoatrophic mice was completely reversed by the combination of physiological doses of adiponectin and leptin, but only partially by either adiponectin or leptin alone. We conclude that decreased adiponectin is implicated in the development of insulin resistance in mouse models of both obesity and lipoatrophy. These data also indicate that the replenishment of adiponectin might provide a novel treatment modality for insulin resistance and type 2 diabetes.

Adiponectin↗

PubMed2001

Distinct properties and differential beta subunit regulation of two C-terminal isoforms of the P/Q-type Ca(2+)-channel alpha(1A) subunit.

Two C-terminal splice variants (BI-1 and BI-2, now termed Ca(v)2.1a and Ca(v)2.1b) of the neuronal voltage-gated P/Q-type Ca(2+) channel alpha(1A) pore-forming subunit have been cloned (Mori et al., 1991, Nature, 350, 398-402). BI-1 and BI-2 code for proteins of 2273 and 2424 amino acids, respectively, and differ only by their extreme carboxyl-termini sequences. Here, we show that, in Xenopus oocytes, the two isoforms direct the expression of channels with different properties. Electrophysiological analysis showed that BI-1 and BI-2 have peak Ba(2+) currents (I(Ba)) at a potential of +30 and +20 mV, respectively. The different C-terminal sequence (amino acids 2229-2273) of BI-1 caused a shift in steady-state inactivation by +10 mV and decreased the proportion of fast component of current inactivation twofold. Likewise, the biophysical changes in I(Ba) caused by coexpression of the beta(4) auxiliary subunit were substantially different in BI-1- and BI-2-containing channels in comparison to those induced by beta(3). Several of these differences in beta regulation were abolished by deleting the carboxyl-terminal splicing region. By creating a series of GST fusion proteins, we identified two locations in the C-terminal (Leu2090-Gly2229 for BI-1 and BI-2, and Arg2230-Pro2424 for BI-2 only) that determine the differential interaction of beta(4) with the distinct alpha(1A) isoforms. These interactions appear to favour the binding of beta(4) to the AID site, and also the plasma membrane expression of BI-2. These results demonstrate that the final segment of the C-terminal affects alpha(1A) channel gating, interaction and regulation with/by the beta subunits. The data will have several implications for the understanding of the biophysical effects of many channelopathies in which the carboxyl-termini of alpha(1A) and beta(4) are affected.

Animals↗

PubMed2001

Hypothalamically induced emotional behavior and immunological changes in the cat.

Numerous animal studies on the correlation between stress and immunity have been performed but few such studies have been made concerning the relationship between various kinds of stress-related emotional behavior and immunological changes. Electrical stimulation of the hypothalamus in cats elicits various emotional behaviors such as restlessness, defensive attack, defensive retreat and quiet biting attack. We examined changes in the lymphocyte proliferative responses and plasma cortisol level which accompanied such emotional behavior. A significant increase in plasma cortisol was observed in the restlessness, defensive attack and defensive retreat groups, but not in the quiet biting attack or non-response (control) groups. A significant increase in the lymphocyte proliferative responses to phytohemagglutinin (PHA) was observed in the restlessness and defensive attack groups but not in the defensive retreat, quiet biting attack or non-response groups. These results suggest that various kinds of emotional behavior appear to be differentially correlated with the lymphocyte proliferative responses, while also being differentially correlated with the plasma cortisol concentration. Because the changes in lymphocyte responses and plasma cortisol did not always completely correlate with one another, the changes in the lymphocyte responses are not considered to be influenced by plasma cortisol alone.

Animals↗

PubMed2001

Successful treatment of low-flow priapism associated with phenothiazine therapy.

We present a case of low-flow priapism that was successfully treated. A 21-year-old man with a history of schizophrenia was admitted with a painful complete erection. He had taken propericiazine, phenothiazine derivatives, before hospitalization and was treated with a glandular-cavernosal shunt (El-Ghorab's procedure). Currently, he is able to have erections without any changes in his quality of life.

Adult↗

PubMed2001

Angiotensin II signaling and HB-EGF shedding via metalloproteinase in glomerular mesangial cells.

BACKGROUND: Angiotensin II (Ang II) has been implicated in the development of glomerulosclerosis by stimulating fibronectin (FN) synthesis. The processing and release of heparin binding-endothelin growth factor (HB-EGF) are activated by protein kinase C (PKC) and Ca2+ signaling. We studied the roles of HB-EGF and endothelial growth factor (EGF) receptor (EGFR) in Ang II-induced FN expression using mesangial cells. METHODS: Mesangial cells were prepared from mouse kidneys by the explant method and cells were used at passages 4 and 5. RESULTS: Ang II stimulated FN mRNA levels dose-dependently with a maximal increase (3.4-fold) after 12 hours of incubation. This action was completely inhibited by PKC inhibitors and slightly blocked by Ca2+ chelating agents. FN mRNA accumulation by Ang II was abolished by tyrosine kinase inhibitors, a specific inhibitor for EGFR (AG1478) and extracellular signal-regulated kinase (ERK) inactivation. Addition of neutralizing anti-HB-EGF antibody, as well as pretreatment with heparin or the metalloproteinase inhibitor batimastat abolished induction of FN expression by Ang II. In mesangial cells stably transfected with a chimeric construct containing HB-EGF and alkaline phosphatase (ALP) genes, ALP activity in incubation medium was rapidly increased by Ang II (1.7-fold at 0.5 min) and reached a 4.1-fold increase at two minutes. Ang II phosphorylated EGFR (maximal at 2 min) and ERK (maximal at 8 min) in a PKC- and metalloproteinase-dependent manner. Ang II stimulated the expression and release of transforming growth factor-beta (TGF-beta) via EGFR-mediated signaling, and the released TGF-beta also contributed to Ang II-mediated FN expression via EGFR transactivation. CONCLUSIONS: Ang II-mediated FN expression was regulated by autocrine effects of HB-EGF and TGF-beta, suggesting a novel paradigm for cross-talk between Ang II and growth factor receptor signaling pathways.

Angiotensin II↗