Formation of high heat resistant coatings by using gas tunnel type plasma spraying.

UNLABELLED: Zirconia sprayed coatings are widely used as thermal barrier coatings (TBC) for high temperature protection of metallic structures. However, their use in diesel engine combustion chamber components has the long run durability problems, such as the spallation at the interface between the coating and substrate due to the interface oxidation. Although zirconia coatings have been used in many applications, the interface spallation problem is still waiting to be solved under the critical conditions such as high temperature and high corrosion environment. The gas tunnel type plasma spraying developed by the author can make high quality ceramic coatings such as Al2O3 and ZrO2 coating compared to other plasma spraying method. A high hardness ceramic coating such as Al2O3 coating by the gas tunnel type plasma spraying, were investigated in the previous study. The Vickers hardness of the zirconia (ZrO2) coating increased with decreasing spraying distance, and a higher Vickers hardness of about Hv = 1200 could be obtained at a shorter spraying distance of L = 30 mm. ZrO2 coating formed has a high hardness layer at the surface side, which shows the graded functionality of hardness. In this study, ZrO2 composite coatings (TBCs) with Al2O3 were deposited on SS304 substrates by gas tunnel type plasma spraying. The performance such as the mechanical properties, thermal behavior and high temperature oxidation resistance of the functionally graded TBCs was investigated and discussed. The resultant coating samples with different spraying powders and thickness are compared in their corrosion resistance with coating thickness as variables. Corrosion potential was measured and analyzed corresponding to the microstructure of the coatings. KEYWORDS: High Heat Resistant Coatings, Gas Tunnel Type Plasma Spraying, Hardness,

Role of alpha2/delta subunit in the development of morphine-induced rewarding effect and behavioral sensitization.

Previous data demonstrate that L-type voltage-gated calcium channel (VGCC) blockers, which bind to alpha(1) subunits of VGCC to suppress Ca(2+) entry into cells, inhibit the development of psychological dependence on drugs of abuse, suggesting the upregulation of L-type VGCC in the development of psychological dependence. However, there are few available data on changes of the auxiliary subunit alpha(2)/delta modifying L-type VGCC under such conditions. We therefore investigated here the role of alpha(2)/delta subunits of VGCCs in the brain of mouse after repeated treatment with morphine. The treatment with morphine increased alpha(2)/delta subunit expression in the frontal cortex and the limbic forebrain of mice showing rewarding effect and sensitization to hyperlocomotion by morphine. The morphine-induced behavioral sensitization and place preference were also suppressed by gabapentin, which binds to an exofacial epitope of the alpha(2)/delta auxiliary subunits of VGCCs. These findings indicate that the upregulation of alpha(2)/delta subunit as well as alpha(1) subunits of VGCC in the frontal cortex and the limbic forebrain plays a critical role in development of morphine-induced rewarding effect and behavioral sensitization following neuronal plasticity.

[Parkinson's disease and depression].

Up to 40% of cases of Parkinson's disease are associated with the occurrence of depression. The symptoms of the patients' depressive state may be factors such as significant weight change, insomnia or hypersomnia, psychomotor retardation, fatigue or loss of energy, feelings of worthlessness or inappropriate guilt, decreased concentration and indecisiveness, and recurrent thoughts of death or suicidal ideation. Given these conditions, drugs prove ineffective in many cases. Electroconvulsive therapy (ECT) has been reported to be beneficial in cases of drug-resistant depression. ECT has also been applied to Parkinsonian patients with depression and found to be effective with both depression and the Parkinsonian symptom. Transcranial magnetic stimulation(TMS) has recently been investigated for application in cases of depression and has become known as a valuable tool for depression therapy. TMS is easily implemented even in outpatient therapy. TMS will make a great contribution to the therapy of depression with Parkinson's disease.

Pentagalloylglucose, an antisecretory component of Paeoniae radix, inhibits gastric H+, K(+)-ATPase.

We purified a compound with strong inhibitory effect on H+, K(+)-ATPase from Paeoniae radix, which has been used in Japan for the treatment of gastritis and peptic ulcers. The compound was identified as 1,2,3,4,6,-penta-o-galloyl-beta-D-glucose by proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, and fast atomic bombardment mass spectrometry. The IC50 of the compound for H+, K(+)-ATPase was 166 nmol/l. Kinetic analyses indicated that the inhibition of the enzyme by pentagalloylglucose was noncompetitive with respect to K+. Pentagalloylglucose had relatively weak inhibitory effects for Mg(+)-ATPase (IC50: > 10 mumol/l) and Na+, K(+)-ATPase (IC50: 2.7 mumol/l). Pentagalloylglucose also inhibited the accumulation of [14C]aminopyrine in parietal cells that had been isolated from guinea pig stomach and stimulated by 10 mumol/l histamine (IC50: 7.8 mumol/l) and 1 mmol/l dbc-AMP (IC50: 10 mumol/l). These results suggest that pentagalloylglucose is a potent inhibitor of H+, K(+)-ATPase and may be responsible for inhibition of acid secretion by Paeoniae radix.

Treatment of obstructive sleep apnea syndrome with a Kampo-formula, San'o-shashin-to: a case report.

The following describes a 76-year-old male with obstructive sleep apnea syndrome successfully treated with a Kampo-formula, San'o-shashin-to (Formula medicamentorum tres ad dispellendi cordis). Polysomnography, performed before and after administration of San'o-shashin-to, revealed that the apnea index decreased from 11.1 events/hour to 4.1 events/hour, and that the apnea plus hypopnea index decreased from 18.4 events/hour to 10.7 events/hour. The patient was normo-weight (body mass index: 20.4 kg/m2), and events of sleep apnea and hypopnea were mostly noted during a non-rapid eye movement sleep. It is possible that San'o-shashin-to has some alleviating effects on the upper airway resistance during sleep.

Successful treatment of radiation cystitis with hyperbaric oxygen therapy: resolution of bleeding event and changes of histopathological findings of the bladder mucosa.

To assess the effect of hyperbaric oxygen (HBO) therapy on radiation cystitis, clinical and histopathological characteristics were examined. Three women with radiation cystitis were treated with HBO therapy. Macrohaematuria was arrested in all patients. Cystoscopy demonstrated abnormal telangiectasia and inflammatory mucosa before treatment. After HBO therapy, the inflammatory mucosae were healed. However, abnormal vessels did not completely disappear. Histopathologically, the epithelium was atrophic and dilated lymph vessels and inflammatory cells were seen in the submucosa. These changes improved after treatment. HBO therapy is effective against radiation cystitis. With improvement of the clinical symptoms also the cystoscopic and histopathological findings changed favourably.

Histochemical studies on endothelin and the endothelin-A receptor in the hypothalamus.

By use of a rabbit polyclonal antibody specific to the endothelin-A (ETA) receptor, we analyzed the distribution of neurons containing ETA receptors in rat brain. Almost all A1-A7 noradrenergic neurons, A8-A16 and retinal amacrine (A17) dopaminergic neurons (except the A15 group), and C3 adrenergic neurons contained ETA receptors. In addition, hypothalamic magnocellular (noncatecholaminergic) neurons also showed immunoreactivity to ETA receptors, whereas the staining intensity was low. These observations were confirmed by analyzing the expression of c-fos in the hypothalamus after central injection of ET isopeptides. We also examined immunohistochemically the distribution of big ETs and mature ETs in the hypothalamus. The paraventricular and supraoptic magnocellular neurons in the hypothalamus were immunopositive for big ET-1 and mature ET-1. However, their nerve fibers were immunostained only with antibody to big ET-1. The observations on big ET-1 were altered by colchicine treatment. Considering all the evidence, mature ET-1 may regulate neurotransmission in the hypothalamic region, whereas big ET-1 is secreted from nerve terminals into the vessels as a neurohormone. It is also concluded that ET, one of the "brain-vascular peptides," has a close relationship with the catecholamine neuron system in the brain.

Functional quantitative analysis of the genome in cultured human mesangial cells. Technical note.

For normal physiological function, each cell tightly regulates gene expression in a specific fashion so that critical proteins are synthesized in a well-coordinated manner. Therefore, it is very important to uncover which genes are expressed in specific cells. Recent technological advances combined with rapid large-scale DNA sequencing and computerized data processing have allowed us to investigate the expression levels of a variety of transcripts in the mesangial cells, a target of injury in many forms of glomerulonephritis. Utilizing a large scale sequencing of a 3'-directed cDNA library, which allows us to avoid variable cloning efficiencies reflecting the size of cDNA, we investigated expression profiles of various molecules in cultured human mesangial cells. Among the 1,193 sequenced clones, 688 (57.7%) appeared more than once (redundant sequence group), representing 203 different species. Thirty-nine of these appeared more than three times. The most abundant mRNA was that of fibronectin, which consisted of 3.9% of the total mRNA population. Except for mitochondrial or ribosomal genes, calcyclin came next (2.5%), followed by two cytoskeletal genes, gamma-actin gene and calpactin 1 light chain gene, in addition to an amyloid precursor protein homolog (0.7%). In conclusion, we performed a molecular biological quantification of transcripts in mesangial cells. Fibronectin was the most abundantly expressed, followed by calcyclin, gamma-actin, calpactin 1 light chain, and an amyloid precursor protein homolog. We also discovered some candidate genes specific for human mesangial cells. The expression profile of the transcripts serves as an important tool in understanding the biological properties of mesangial cells.

Creutzfeldt-Jakob disease associated with autonomic nervous system dysfunction in the early stage.

A 54-year-old man presented with tremor and unusual behavior. He was admitted two months later because of dementia and myoclonus. Periodic synchronous discharges were observed on the electroencephalogram. Based on these findings, we diagnosed the case as Creutzfeldt-Jakob disease. About two weeks after admission, decubitus, bowel dysfunction and hypohidrosis occurred. We observed various autonomic nervous system dysfunctions such as abnormal pupillary response to autonomic drugs, reduced coefficient of variation of R-R interval, and abnormal diurnal blood pressure variation.

[Effects of gosha-jinki-gan on urinary bladder contraction in dogs].

The effects of Gosha-Jinki-Gan on the urinary bladder contraction in anesthetized dogs were studied to elucidate the mode of action. The bladder contraction was induced by electrical stimulation of the left distal end of the pelvic nerve under the bilateral pelvic nerve and hypogastric nerve transections, or by the infusion of acetylcholine (200 micrograms) in to the abdominal aorta. The bladder contraction induced by pelvic nerve stimulation was significantly inhibited by 10 and 100 mg/kg of intravenous Gosha-Jinki-Gan administration. A similar phenomenon was observed by the administration of atropine sulfate (0.1 mg). The acetylcholine-induced contraction was significantly inhibited by administration of 100 mg/kg of Gosha-Jinki-Gan. These findings suggested that Gosha-Jinki-Gan inhibits the urinary bladder contraction induced by the stimulation of cholinergic nerve.

Transurethral balloon laser enhanced thermotherapy in the canine prostate.

BACKGROUND AND OBJECTIVE: Hyperthermia is performed for prostate cancer. We examined the selective induction of coagulonecrotic changes in the objective area of the canine prostate in enhancing the effect of hyperthermia and treating the target area with transurethral balloon laser enhanced thermotherapy (TUBAL-ET) using a light absorbent material. STUDY DESIGN/MATERIALS AND METHODS: The heat exchange of ultrafine carbon particles after laser irradiation was observed in a phantom study using thermography. The carbon solution was injected at the right prostatic lobe in dogs and TUBAL-ET was performed. RESULTS: The charcoal absorbed the Nd:YAG laser energy and apparently converted it into thermal energy in the phantom study by thermographic observation. TUBAL-ET induced coagulonecrotic changes only at the area at which carbon had been injected in the prostate gland. The necrotic tissue was almost absorbed at four weeks after treatment. CONCLUSIONS: TUBAL-ET induces tissue damage at the target area in the prostate gland.

[Effects of Gosha-Jinki-Gan on the function of the urinary bladder in anesthetized dogs].

Gosha-Jinki-Gan is clinically used for the treatment of pollakiuria in patients with benign prostatic hyperplasia. The effect of Gosha-Jinki-Gan on the function of the urinary bladder in anesthetized dogs was examined. Gosha-Jinki-Gan (100 mg/kg) inhibited the rhythmic bladder contractions (RBC). However, the frequency of RBC increased resembling the effect of atropine (0.1 mg/body), and the amplitude decreased. On the cystometrogram, Gosha-Jinki-Gan caused an increase in maximum vesical volume (not significant). These findings indicated that Gosha-Jinki-Gan is a useful drug for the treatment of pollakiuria.

Serial changes in proximal urethral function after transurethral balloon laser hyperthermia of the prostate (TUBAL-H) in a canine model.

We performed transurethral balloon laser hyperthermia of the prostate (TUBAL-H) in 6 mongrel dogs. To evaluate the changes in proximal urethral function after TUBAL-H, the urethral cross sectional area (CSA, cm2) and urethral pressure (Pu, cmH2O) were measured using a balloon probe that allows their simultaneous measurement, and the urethral compliance (Comp, cm3/cmH2O) was calculated from these parameters and serially evaluated. In addition, the changes in Pu, CSA and Comp after administration of an alpha-adrenoceptor antagonist were evaluated before and 16 weeks after TUBAL-H. Before TUBAL-H, the mean Comp was 0.013, and the mean maximum CSA (MCSA) was 0.66. Eight weeks after TUBAL-H, the mean Comp was 0.038, and the mean MCSA was 1.39, showing a significant increase (p < 0.01). Sixteen weeks, after TUBAL-H, the mean Comp was 0.026, and the mean MCSA was 1.21, being lower than those at 8 weeks after TUBAL-H, but significantly higher than those before TUBAL-H (p < 0.05). After administration of the alpha-adrenoceptor antagonist, phentolamine (1 mg/kg), before TUBAL-H, the mean Comp significantly increased to 0.046 (p < 0.05), and the mean MCSA to 1.40 (p < 0.01). The mean Comp was significantly increased to 0.033 (p < 0.05), by phentolamine administration 16 weeks after TUBAL-H, but no other changes were observed. After TUBAL-H, urethral elasticity increased, and this increase persisted for 4 months. The responses of Comp and MCSA to alpha-adrenoceptor antagonist administration before and 16 weeks after TUBAL-H suggested that part of the effects of TUBAL-H is due to damage to alpha-adrenoceptors.

Identification of a cDNA encoding a thiazide-sensitive sodium-chloride cotransporter from the human and its mRNA expression in various tissues.

We report here the identification of a cDNA encoding a human thiazide-sensitive sodium-chloride cotransporter (hTSC) using a PCR-based method. The homology of the hTSC with rat TSC (rTSC) and rat bumetanide-sensitive sodium-potassium-chloride cotransporter (rBSC) was 86% and 64%, respectively, at the nucleotide level, and 92% and 61%, respectively, at the amino acid level. Using fluorescence in situ hybridization (FISH), the hTSC gene has been mapped to chromosome 16q13. Northern blot analysis using polyA+RNA from various human tissues, revealed a major 4.5 kb transcript and a minor 6.5 kb specifically in the kidney, but low level of expression was also observed in small intestine, placenta, prostate, colon, and spleen.

Effect of M-711 on experimental skin reactions induced by chemical mediators in rats.

We investigated the mechanism of anti-allergic action of Moku-boi-to (M-711) and effects on the skin reactions induced by chemical mediators as the model of allergic dermatitis. More than 20 mg/kg BW of M-711 significantly suppressed the enhancement of capillary permeability induced by histamine, LTC4, and anti-serum in the rat skin. Anti-histaminic effect of 40 mg/kg BW of M-711 was equipotent to same as the optimal doses of azelastine and diphenhydramine, respectively. As to anti-LTC4 action, 20 mg of M-711 was compared to the optimal dose of diphenhydramine. Those data showed that M-711 has the suppressive effects on the chemical mediators such as histamine and LTC4 and reduced the skin reaction induced by antigen-antibody response.

Effect of M-711 on experimental asthma in rats.

We experimentally demonstrated the anti-asthmatic effects of M-711, the dry extract of a Chinese herb medicine called Mokuboi-to, using the rat model of allergic asthma. Allergic asthma was induced by the antigen-antibody reaction in the rats and they showed anaphylactic symptoms accompanied with hypotension and depression of respiratory function. More than 20 mg/kg body weight of M-711 was effective in relieving the asthmatic symptoms like methylephedrine. It could lessened the suppress of respiration and provided a good improvement. It also reduced a drop of the blood pressure and improved it quickly. Its ingredients alone were much less effective than M-711 as the total. Those data suggested that M-711 was effective for alleviating allergic asthma in the present study and that its action was provided by interaction of all ingredient raw herbs of M-711.

Transurethral balloon laser thermotherapy: effects of a directionally shielded balloon in canine prostates.

BACKGROUND: Transurethral balloon laser thermotherapy (TUBAL-T) improves objective, but not subjective, symptoms of benign prostatic hyperplasia (BPH). We studied whether or not an Nd:YAG laser beam with a shielded balloon could successfully irradiate the prostate during TUBAL-T in selective manner, to improve the subjective symptoms. METHODS: TUBAL-T was performed on canine prostates using the balloon with a laser probe, which was shielded anteriorly at 90 degrees (from the center of the balloon) and posteriorly at 90 degrees. RESULTS: At 20 watts laser power, the relative power density in the bilateral non-shielded areas was 17.4 and 17.8, and in the shielded area it was 1.0. Observation by thermography revealed that the temperature after laser radiation in a non-shielded area of a fish cake phantom was higher than in a shielded area. Following transurethral thermotherapy using a shielded balloon in dogs, a cavity was formed bilaterally around the urethra, and the tissues at the anteroposterior sides and the urethra were preserved. CONCLUSIONS: TUBAL-T, which has been performed in clinical cases of benign prostatic hyperplasia, might be useful in selective irradiation of adenoma if a shielded balloon is used.

Effect of 22-oxacalcitriol on hyperparathyroidism of dialysis patients: results of a preliminary study.

Intermittent high dose administration of calcitriol or alfacalcidol is effective in suppressing secondary hyperparathyroidism in chronic dialysis patients, however calcaemic action of these vitamin D derivatives is a major obstacle. 22-Oxacalcitriol (OCT) has been reported to have less calcaemic action than calcitriol, while preserving a comparable suppressive effect on parathyroid hormone (PTH) secretion. This preliminary study was conducted to examine the effects of OCT on secondary hyperparathyroidism in chronic dialysis patients. OCT was administrated intravenously immediately after every haemodialysis session three times a week for 12 weeks to three haemodialysis patients with secondary hyperparathyroidism. An initial dose of OCT of 5.5 micrograms/haemodialysis session was increased stepwise by 5.5 micrograms/haemodialysis up to 22 micrograms/haemodialysis according to the suppression of PTH and calcaemic action. OCT was discontinued for at least a week when serum calcium adjusted to albumin concentration measured just before haemodialysis exceeded 11.5 mg/dl. Marked reduction in plasma PTH, alkaline phosphatase and tartrate-resistant acid phosphatase was observed in all three patients. Although the dose of OCT was increased to 22 micrograms/haemodialysis in one patient, the final dose of OCT remained 5.5 micrograms/haemodialysis in the other two patients because of hypercalcaemia. It is concluded that OCT is highly effective in suppressing PTH in dialysis patients with secondary hyperparathyroidism. Hypercalcaemia may be a major factor which limits the use of OCT, though it may occur with higher doses of OCT than those of calcitriol usually given to suppress PTH hypersecretion.

Molecular basis for the management of secondary hyperparathyroidism in chronic renal failure.

Recent clinical and experimental data suggest that the resistance of parathyroid cells to the physiological concentration of calcitriol plays an important role in the pathogenesis and the progression of secondary hyperparathyroidism in chronic renal failure. This resistance is due to the decreased density of the calcitriol receptor in parathyroid cells, which may result from impaired upregulation of calcitriol receptor. Since patients with larger parathyroid glands were more resistance to calcitriol pulse therapy than those with smaller glands and calcitriol receptor density inversely correlated with gland weight, the size of the parathyroid gland may serve as a marker for the degree of resistance to calcitriol. Furthermore, the possible role of phosphorus in the control of parathyroid function has been suggested recently. Thus, it is most important to prevent the progression of parathyroid hyperplasia in chronic renal failure by the early use of active vitamin D, calcitriol pulse therapy, and dietary phosphorus restriction.

Histological and immunohistochemical changes after transurethral balloon laser hyperthermia in the canine prostate.

Transurethral balloon laser hyperthermia (TUBAL-H) for the prostate was performed in a canine model. Eleven normal and hyperplastic prostates were heated at between 40 to 45 degrees C for 30 min. Compared to the pretreatment weight, the prostatic weight significantly increased immediately after treatment and significantly decreased at 4 weeks later, but was not significantly different after 8 weeks. Histologically, shedding of epithelial cells was observed immediately after treatment, although, coagulonecrotic tissue was not seen. After 8 weeks, atrophic changes of epithelial cells were observed at the inner portion of the prostate. By immunohistochemical analysis, epithelial cells expressing apoptosis related antigen (Ley) were observed at the inner portion of the prostate from immediately after treatment until 4 weeks later. The atrophic epithelia and the expression of apoptosis in the prostate gland were pathological changes induced by TUBAL-H. From the present data, it is suggested that TUBAL-H combined with radiation or administration of anti-cancer drugs may be effective for prostate cancer.