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Biomedical subjects

H Yasuda

Publications and source records attributed to H Yasuda.

At least 145 records · Page 8Linked to original sources
PubMed2000

Malignant insulinoma which expressed a unique creatine kinase isoenzyme: clinical value of arterial embolization as a palliative therapy.

A 76-year-old man with hypoglycemic coma was diagnosed as malignant insulinoma with multiple hepatic metastases. Embolization was done for two-thirds of the hepatic mass and it rapidly lowered the serum immunoreactive insulin. He was discharged without medication and has been free from hypoglycemia. After the embolization, the serum creatine kinase (CK) level increased transiently although there was no evidence of myocardial infarction. On electrophoresis, the CK activity showed an abnormal peak, suggesting mitochondrial CK. CK release after embolization has been reported in only a few cases with endocrine tumors, which might indicate some relationship between active energy metabolism and mitochondrial CK.

Aged↗
PubMed2000

Evaluation of a new care system provided to diabetic patients in the outpatient clinic.

OBJECTIVE: Evaluation of metabolic states and chronic complications is essential for maintaining a high quality of care for diabetic patients. We have assessed the quality of care in routine outpatient clinics for diabetic subjects in our university hospital, and compared with those in a newly introduced standardized clinic to evaluate the new care system. METHODS: The quality of care was assessed by the chart review in 1995, and compared with those from 1996-1997 in the "Diabetes Follow-up Clinic" which is systematically designed for the standardized care. PATIENTS: The subjects were recruited among 860 patients who visited the outpatient clinic in July and August of 1995 with a diagnosis of diabetes or glucose intolerance. Six hundred seventy-two patients whose follow-up period had been more than 6 months with clinically diagnosed diabetes were used for the analysis. RESULTS: Laboratory tests such as determination of HbA1c, and serum levels of lipids and creatinine were performed in more than 90% of the patients in the routine outpatient clinics. However, ophthalmology referral, 24-hour urine collection for the determination of creatinine clearance and albumin excretion, and electrocardiograms were not well performed and were incompletely documented (40-60% of the patients within a previous year and 70-80% in the last 2 years). In the standardized "Diabetes Follow-up Clinic", only four out of 555 diabetic patients failed to collect their 24-hour urine, and all participants had ankle blood pressure measurements, nerve conduction study, and nylon monofilament tests, etc. Furthermore, more than 95% of the patients had funduscopic examinations by ophthalmologists as well as records of electrocardiogram. CONCLUSION: Introduction of the standardized "Diabetes Follow-up Clinic" may be one of the choices for increasing the quality of outpatient care and for the prevention of chronic diabetic complications.

Adult↗
PubMed2000

Suppression and acceleration of autoimmune diabetes by neutralization of endogenous interleukin-12 in NOD mice.

A corpus of evidence suggests that T-helper type 1 (Th1)-dependent cellular immunity plays a pivotal role in the pathogenesis of autoimmune diabetes. This study was intended to find ways to prevent the development of NOD diabetes using a neutralizing anti-interleukin (IL)-12 antibody (C17.8) that inhibits Thl cell differentiation. When C17.8 was administered from 5 to 30 weeks of age, NOD mice exhibited suppression of both insulitis and diabetes. However, when C17.8 administration ceased at 15 weeks of age, 8 of 13 recipients showed diabetes at 30 weeks of age. These results suggest that IL-12 plays an important role not only in the development of effector cells but also in their activation. In contrast, when C17.8 was injected into 2-week-old female NOD mice for 6 consecutive days, all 16 recipients showed diabetes at 30 weeks of age, whereas 12 of 20 control mice became diabetic. This result suggests that depletion of endogenous IL-12 at a young age results in the enhancement of diabetes. Flow cytometric analysis indicated that activated memory T-cells were present in higher numbers after C17.8 treatment. Transfer of spleen cells from 15-week-old C17.8-treated NOD mice to NOD-scid mice resulted in an earlier onset and a higher incidence of diabetes. Furthermore, administration of C17.8 to 2-week-old NOD mice also resulted in a much earlier onset of diabetes. These results suggest that short-term treatment with anti-IL-12 antibody prohibits IL-2 production at a young age, which may influence the expansion and apoptosis of pathogenic T-cells, resulting in the acceleration of autoimmune diabetes.

Animals↗
PubMed2000

[Effect of epilepsy surgery based on magnetic resonance imaging (MRI) classification].

We prospectively analyzed the effect of surgical procedures in epilepsy patients, except for those with mesial temporal lobe epilepsy. Twenty patients with a mean age of 26 years (range 3 to 58 years, 10 male and 10 female) underwent the surgical procedures. These patients were divided into 3 groups according to MRI findings, as follows; group A (localized type): localized lesions such as angiomas or benign tumors, group B (widespread type): widespread lesions such as regional encephalitis or stroke, visible on anatomical neuroimaging, and group C (cryptic type): no lesion visible on anatomical neuroimaging. Following surgery, 11 (85%) of the 13 patients in group A were seizure-free, one showed worthwhile improvement, and one, whose lesion was not removed totally, was unchanged. In group B, two patients (50%) were seizure-free and 2 (50%) showed worthwhile improvement. All the patients in group C showed worthwhile improvement. Lesionectomy, cortical excision, multiple subpial transection (MST) or a combination of these procedures were effective in groups A and B. Patients in group C had a chance to obtain worthwhile improvement by corpus callosotomy or cortical excision. Intracranial EEG recording provides useful information for epilepsy surgery in intractable cases.

Adolescent↗
PubMed2000

[An elderly case of ruptured aortic arch aneurysm with hemorrhagic cardiac tamponade].

We reported a case of successful aortic arch replacement using selective cerebral perfusion for ruptured distal aortic arch aneurysm (DAAA) with cardiac tamponade. A 80-year-old man who had preoperative episode of severe chest pain. Computed tomography showed saccular DAAA and pericardial effusion. He was diagnosed as ruptured DAAA with hemorrhagic cardiac tamponade. We performed urgent graft replacement of the aortic arch using selective cerebral perfusion. Postoperatively he had no complication. Thirty days after the operation he was discharged from the hospital and he is now leading a normal life.

Aged↗
PubMed2000

[Proposal of a new lymph node mapping system for pancreatic head cancer].

The Japanese Pancreatic Society published the 4th edition of the general guidelines for the study of pancreatic cancer (JPS guidelines) in 1993. The current JPS guidelines differ from the UICC classification of lymph nodes. Thirty-five lymph node stations are divided into three groups in the JPS guidelines. Group 1 (n1) corresponds closely with the regional lymph nodes in the UICC classification. Group 2 (n2) and group 3 (n3) are distant metastases in the UICC classification. To clarify practical lymph node mapping, 2,449 resected tubular adenocarcinomas of the pancreas head registered with the JPS were analyzed. Lymph node involvement was observed most frequently in posterior pancreatoduodenal (PPD) and anterior pancreatoduodenal (APD) and then in paraaortic (n2) nodes. Fifty-six patients who achieved 5-year survival were registered, of whom 19 had lymph node involvement. The sites of lymph node involvement were limited to the PPD and/or APD nodes in 14 cases. PPD and APD nodes differ from the other n1 in terms of high incidence of metastasis and fair prognosis. In conclusion, we propose a new practical lymph node mapping system in which PPD and APD nodes are the first station and the other n1 are the second station.

Humans↗
PubMed2000

[Clinical application of portable near infrared oximetry (HEO-200) to neurosurgical monitoring].

Near infrared spectroscopy (NIRS) have been accepted as a useful modality for non-invasive monitoring of brain oxygenation state. Using a newly developed NIRS apparatus, HEO-200, the authors continuously monitored the changes in the oxygenation state of brain hemoglobin during carotid endarterectomy (CEA) or carotid balloon occlusion tests (BOT) in 21 patients. Somatosensory evoked potentials (SEP), regional cerebral blood flow (rCBF) or transcranial Doppler sonography (TCD) were also employed to compare with the NIRS-responses. In 7 of 21 patients, the carotid artery occlusion caused a continuous deoxygenation of brain hemoglobin as well as a decrease in total hemoglobin. These findings correlated well with temporary neurological deficits and a marked reduction of rCBF in the ipsilateral hemisphere in patients who underwent carotid BOT under local anesthesia. The patients also showed a marked decrease in the N20 amplitude of SEP during CEA under general anesthesia. Restoration of blood flow immediately resolved these findings. The other 14 patients demonstrated no or only transient changes on NIRS as well as on SEP and rCBF study. HEO-200 could non-invasively monitor the relative changes of cerebral oxygenation state with good time resolution, and detect critical ischemia during CEA and carotid BOT.

Aged↗
PubMed2000

[A case of bone metastases from carcinoma of the lung demonstrating increased uptake of 99mTc-ECD].

A 48-year-old man with carcinoma of the lung had loss of consciousness during radiation therapy and underwent 99mTc-ethyl cysteinate dimer (99mTc-ECD) SPECT to evaluate brain tumor seen on CT scan. Incidentally 99mTc-ECD SPECT imaging showed intense accumulation in the frontal and occipital bone. The tumor in the occipital bone had been histologically proven to be a metastasis from carcinoma of the lung. We presented a very rare case of bone metastasis demonstrating increased uptake of 99mTc-ECD.

Brain Neoplasms↗
PubMed1999

(-)-Epigallocatechin gallate inhibits mos activation-mediated xenopus oocyte maturation induced by progesterone.

(-)-Epigallocatechin gallate (EGCG), one of the constituents of green tea known to have a tumor preventing effect, inhibited maturation of Xenopus laevis oocytes induced by progesterone when this polyphenol was microinjected into oocytes at a final concentration of about 1 mM. Western blot and activity measurement analyses showed that Mos translation and the subsequent activations of mitogen-activated protein kinase and p90(rsk), probably by protein phosphorylation, seemed to have been inhibited by the microinjection of EGCG. These results suggest that EGCG may have the ability to control Xenopus oocyte maturation at least during the stage of Mos activation.

Animals↗
PubMed1999

Expression of a dominant negative SHP-2 in transgenic mice induces insulin resistance.

To elucidate the roles of SHP-2, we generated transgenic (Tg) mice expressing a dominant negative mutant lacking protein tyrosine phosphatase domain (DeltaPTP). On examining two lines of Tg mice identified by Southern blot, the transgene product was expressed in skeletal muscle, liver, and adipose tissues, and insulin-induced association of insulin receptor substrate 1 with endogenous SHP-2 was inhibited, confirming that DeltaPTP has a dominant negative property. The intraperitoneal glucose loading test demonstrated an increase in blood glucose levels in Tg mice. Plasma insulin levels in Tg mice after 4 h fasting were 3 times greater with comparable blood glucose levels. To estimate insulin sensitivity by a constant glucose, insulin, and somatostatin infusion, steady state blood glucose levels were higher, suggesting the presence of insulin resistance. Furthermore, we observed the impairment of insulin-stimulated glucose uptake in muscle and adipocytes in the presence of physiological concentrations of insulin. Moreover, tyrosine phosphorylation of insulin receptor substrate-1 and stimulation of phosphatidylinositol 3-kinase and Akt kinase activities by insulin were attenuated in muscle and liver. These results indicate that the inhibition of endogenous SHP-2 function by the overexpression of a dominant negative mutant may lead to impaired insulin sensitivity of glucose metabolism, and thus SHP-2 may function to modulate insulin signaling in target tissues.

Animals↗
PubMed1999

Hydrogenation of 1-Hexene and Hexadienes by Ultrafine Pd Particles Supported on the Surface of PrPO(4) Hollow Particles.

Novel fine polymer particles containing ultrafine Pd particles dispersed on the surface of core shell [core, poly(styrene-co-acrylic acid); shell, PrPO(4)]-type microspheres were prepared by the emulsifier-free emulsion polymerization of styrene with acrylic acid followed by the addition of PdCl(2) and a mixture of Pr(NO(3))(3) and NaH(2)PO(2). Pyrolysis of the resulting polymer particles at 900 degrees C provides organic polymer-free hollow particles (diameter, 473-586 nm) composed of Pd metal and PrPO(4). Hydrogenation of 1-hexene, trans-1,3-hexadiene, trans-1,4-hexadiene, and 1,5-hexadiene using the resulting Pd/PrPO(4) particles (reactant/Pd = 500 mol/mol) as catalyst revealed very high activity, especially for hydrogenations of 1-hexene and 1,5-hexadiene as compared with conventional Pd particles/Al(2)O(3) and Pd particles on powdered PrPO(4). Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

IL-10 inhibits Porphyromonas gingivalis LPS-stimulated human gingival fibroblasts production of IL-6.

Lipopolysaccharides (LPS) of Porphyromonas gingivalis have been implicated in the initiation and development of periodontal diseases. In a previous study, we investigated the signal transduction pathway of P. gingivalis and demonstrated that LPS stimulates the production of interleukin (IL)-6 in human gingival fibroblasts (HGFs), which in turn activates osteoclasts in vitro. The cytokine, IL-10, was initially described as cytokine synthesis inhibitory factor. In this study, we examined that effect of IL-10 on P. gingivalis LPS-induced human gingival fibroblast production of IL-6. LPS-induced IL-6 production was inhibited by IL-10 in a dose-dependent manner. Flow cytometric analysis showed that HGFs bind to fluorescein-isothiocyanate (FITC) labeled IL-10. Western blotting analysis demonstrated the expression of IL-10 receptor on the cell surface of these cells. Engagement of LPS initiated the protein tyrosine phosphorylation of several intracellular proteins including extracellular signal-regulated kinase 2 (ERK2), and these events were suppressed by IL-10. These results suggest that IL-10 inhibits the inflammatory response via the IL-10 receptor in P. gingivalis LPS-initiated periodontal diseases.

Fibroblasts↗
PubMed1999

Therapeutic effect of topical calcium gluconate for hydrofluoric acid burn--time limit for the start of the treatment.

BACKGROUND: There are few studies regarding the time-dependent effectiveness of topical calcium gluconate treatment for the experimental hydrofluoric acid (HF) burn. METHODS: For producing a HF-burn, a drop of 46% or 23% HF solution was put on the back of rats for 3 minutes followed by washing with tap water. Calcium gluconate jelly or ointment was then applied to the burn area at various time intervals. The ointment was applied once a day thereafter. RESULTS: The topical calcium gluconate treatment was much more effective if the application was started within 3 hours. On the other hand, if the application was started after 6 hours or more, there was no difference between the groups and the non-treatment groups. CONCLUSIONS: It is suggested that practitioners should be ready to prepare quickly the calcium gluconate ointment to treat a HF burn, since the calcium gluconate ointment is not commercially available in Japan.

Administration, Topical↗
PubMed1999

Regulation of APC activity by phosphorylation and regulatory factors.

Ubiquitin-dependent proteolysis of Cut2/Pds1 and Cyclin B is required for sister chromatid separation and exit from mitosis, respectively. Anaphase-promoting complex/cyclosome (APC) specifically ubiquitinates Cut2/Pds1 at metaphase-anaphase transition, and ubiquitinates Cyclin B in late mitosis and G1 phase. However, the exact regulatory mechanism of substrate-specific activation of mammalian APC with the right timing remains to be elucidated. We found that not only the binding of the activators Cdc20 and Cdh1 and the inhibitor Mad2 to APC, but also the phosphorylation of Cdc20 and Cdh1 by Cdc2-Cyclin B and that of APC by Polo-like kinase and cAMP-dependent protein kinase, regulate APC activity. The cooperation of the phosphorylation/dephosphorylation and the regulatory factors in regulation of APC activity may thus control the precise progression of mitosis.

3T3 Cells↗
PubMed1999

Impaired regeneration and no amelioration with aldose reductase inhibitor in crushed unmyelinated nerve fibers of diabetic rats.

The regenerative ability of unmyelinated nerve fibers (UNFs) in diabetes and the effect of aldose reductase inhibitor (ARI) on it were ultrastructurally evaluated after sciatic nerve crush in control and untreated and tolrestat-treated streptozocin-induced diabetic rats. The density and number of UNFs were significantly increased in all groups at 5 weeks after the injury. The increase returned to the baseline level in control rats, but not in diabetic rats at 24 weeks. Although the axon size showed a marked decrease at 5 weeks and an incomplete recovery at 24 weeks in all groups, the recovery was significantly worse in diabetic than in control groups. Tolrestat did not have any effect on regeneration of UNFs in diabetes. These results suggest impaired regeneration of UNFs after nerve crush injury in diabetes and less therapeutic effect of ARI on it.

Aldehyde Reductase↗
PubMed1999

Role of isoprenoid lipids on the heterotrimeric G protein gamma subunit in determining effector activation.

Post-translational prenylation of heterotrimeric G protein gamma subunits is essential for high affinity alpha-beta gamma and alpha-beta gamma-receptor interactions, suggesting that the prenyl group is an important domain in the beta gamma dimer. To determine the role of the prenyl modification in the interaction of beta gamma dimers with effectors, the CAAX (where A indicates alipathic amino acid) motifs in the gamma1, gamma2, and gamma11 subunits were altered to direct modification with different prenyl groups. Six recombinant beta gamma dimers were overexpressed in baculovirus-infected Sf9 insect cells, purified, and examined for their ability to stimulate three phospholipase C-beta isozymes and type II adenylyl cyclase. The native beta1 gamma2 dimer (gamma subunit modified with geranylgeranyl) is more potent and effective in activating phospholipase C-beta than either the beta1 gamma1 (farnesyl) or the beta1 gamma11 (farnesyl) dimers. However, farnesyl modification of the gamma subunit in the beta1 gamma2 dimer (beta1 gamma2-L71S) caused a decrement in its ability to activate phospholipase C-beta. In contrast, both the beta1 gamma1-S74L (geranylgeranyl) and the beta1 gamma11-S73L (geranylgeranyl) dimers were more active than the native forms. The beta1 gamma2 dimer activates type II adenylyl cyclase about 12-fold; however, neither the beta1 gamma1 nor the beta1 gamma11 dimers activate the enzyme. As was the case with phospholipase C-beta, the beta1gamma2-L71S dimer was less able to activate adenylyl cyclase than the native beta1 gamma2 dimer. Interestingly, neither the beta1 gamma1-S74L nor the beta1 gamma11-S73L dimers stimulated adenylyl cyclase. The results suggest that both the amino acid sequence of the gamma subunit and its prenyl group play a role in determining the activity of the beta gamma-effector complex.

Adenylyl Cyclases↗