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Y Chiba

Publications and source records attributed to Y Chiba.

At least 55 records · Page 3Linked to original sources
PubMed2001

Pregnancy outcome in nephrotic syndrome with mixed connective tissue disease.

We describe two pregnancies of a young woman with mixed connective tissue disease. In June 1983, she was diagnosed as having Raynaud's phenomenon, arthralgia, and proteinuria. She then developed nephrotic syndrome. Methylprednisolone was initially prescribed at a large dose of 1 g/day which was slowly tapered to 5 mg/day. The proteinuria disappeared. During both pregnancies (the first beginning in December 1988 and the second in May 1992), the patient was placed on a prednisolone maintenance dose (5 mg/day). Both neonates were born healthy at term with no complications. Continuing prednisolone may be useful in pregnant women, and aggressive treatment to prevent mixed connective tissue disease exacerbation may be appropriate during pregnancy.

Adult↗
PubMed2001

Involvement of cytochrome P450 metabolites in the vascular action of angiotensin II on the afferent arterioles.

Recent studies have demonstrated that cytochrome P450-dependent metabolites of arachidonic acid (CYP450-AA) play important roles in the control of renal vascular resistance (RVR). In the present study, we examined the possible involvement of CYP450-AA in the vasoconstrictor action of angiotensin II (Ang II) on the afferent arterioles (Af-Arts), a vascular segment crucial to the control of RVR. Rabbit Af-Arts were microperfused at 60 mmHg in vitro, and the vasoconstrictor action of Ang II (10(-11)-10(-8) M, added to both the bath and lumen) was examined with or without blocking the activity of CYP450 epoxygenase or hydroxylase. Ang II decreased the luminal diameter of Af-Arts in a dose-dependent manner (34+/-2% of control diameter at 10(-8) M, n=9, p<0.0001). Pretreatment with miconazole, an inhibitor of CYP450 epoxygenase, at 10(-6) M decreased the basal diameter by 14+/-1% (n=6, p<0.01) and augmented the vasoconstrictor action of Ang II (7+/-3% of control diameter at 10(-8) M, p<0.001 vs. without miconazole). This augmentation was abolished by blocking the Ang II type 2 (AT2) receptor with PD 123319 at 10(-7) M. In contrast, pretreatment with 17-octadecynoic acid (17-ODYA, 10(-6) M), which inhibits both epoxygenase and hydroxylase activity, had no effect on the basal diameter but attenuated the vasoconstrictor action of Ang 11(46+/-2% of control diameter at 10(-8) M, p<0.01 vs. without 17-ODYA). Our results demonstrate that in the Af-Art, endogenous CYP450-AA are involved not only in the control of basal tone but also in the action of Ang II. Further, it appears that the CYP450 epoxygenase pathway attenuates Ang II action via AT2 receptors.

Angiotensin II↗
PubMed2001

Insulin resistance with enhanced insulin signaling in high-salt diet-fed rats.

Previous clinical studies showed an apparent correlation between hypertension and insulin resistance, and patients with diabetes are known to have increased blood pressure responsiveness to salt loading. To investigate the effect of high salt intake on insulin sensitivity and the insulin signaling pathway, a high-salt diet (8% NaCl) or a normal diet was given to 7-week-old SD rats for 2 weeks. High salt-fed rats developed slightly but significantly higher systolic blood pressure than controls (133 +/- 2 vs. 117 +/- 2 mmHg, P < 0.001), with no change in food intake or body weight. High salt-fed rats were slightly hyperglycemic (108.5 +/- 2.8 vs. 97.8 +/- 2.5 mg/dl, P = 0.01) and slightly hyperinsulinemic (0.86 +/- 0.07 vs. 0.61 +/- 0.06 ng/ml, P = 0.026) in the fasting condition, as compared with controls. Hyperinsulinemic-euglycemic clamp study revealed a 52.7% decrease in the glucose infusion rate and a 196% increase in hepatic glucose production in high salt-fed rats, which also showed a 66.4% decrease in 2-deoxyglucose uptake into isolated skeletal muscle and a 44.5% decrease in insulin-induced glycogen synthase activation in liver, as compared with controls. Interestingly, despite the presence of insulin resistance, high salt-fed rats showed enhanced insulin-induced tyrosine phosphorylation of insulin receptor substrate (IRS)-1, IRS-2 (liver and muscle), and IRS-3 (liver only). Phosphatidylinositol (PI) 3-kinase activities associated with IRS and phosphotyrosine in the insulin-stimulated condition increased 2.1- to 4.1-fold, as compared with controls. Insulin-induced phosphorylation of Ser-473 of Akt and Ser-21 of glycogen synthase kinase-3 also increased 2.9- and 2-fold, respectively, in the liver of the high salt-fed rats. Therefore, in both the liver and muscle of high salt-fed rats, intracellular insulin signaling leading to PI 3-kinase activation is enhanced and insulin action is attenuated. The hyperinsulinemic-euglycemic clamp study showed that decreased insulin sensitivity induced with a high-salt diet was not reversed by administration of pioglitazone. The following can be concluded: 1) a high-salt diet may be a factor promoting insulin resistance, 2) the insulin-signaling step impaired by high salt intake is likely to be downstream from PI 3-kinase or Akt activation, and 3) this unique insulin resistance mechanism may contribute to the development of diabetes in patients with hypertension.

Animals↗
PubMed2001

Effect of platinum coordination complex (PtCx) on citrate uptake by rat renal brush border membrane vesicles (BBMV): cisplatin-intoxicated rats.

Platinosis with severe dermatitis and/or asthma is broadly defined as the effects of soluble platinum salts on people exposed to them occupationally. Platinum coordination complexes are widely used in the treatment of a variety of solid tumors. However, the clinical use of cisplatin, the most useful agent, is limited by the development of nephrotoxicity. Thus, an accidental exposure to soluble platinum at a high dose in platinum refineries and pharmaceutical factories could induce occupational nephrotoxicity. Urinary citrate is freely filtered at the glomerulus, and its reabsorption in the proximal tubule is the major determinant of the rate of renal excretion. In our previous studies, we found that the preincubation of rat renal brush border membrane vesicles (BBMV) with cisplatin and carboplatin, a second-generation platinum coordination complex, significantly inhibited the citrate uptake compared with that of the control BBMV. In this study, we performed in vivo experiments in cisplatin-intoxicated rats to elucidate the toxic mechanism of cisplatin. And our results showed that the citrate uptake was significantly inhibited in cisplatin-intoxicated rats at 1 min compared with that of control rats.

Animals↗
PubMed2001

Active surveillance for acute flaccid paralysis in poliomyelitis high-risk areas in southern China.

OBJECTIVE: On 29 October 2000 poliomyelitis was officially declared to have been eradicated from the Western Pacific Region. This article describes the results of surveillance for cases of acute flaccid paralysis (AFP) in China during the final phase of the eradication effort. METHODS: We conducted hospital-based active surveillance in high-risk areas for poliomyelitis in 5 provinces of southern-China (Sichuan, Yunnan, Guizhou, Guangxi and Jiangxi) between 1995 and 1997 to determine the adequacy of reporting and laboratory diagnosis of cases of AFP. FINDINGS: A total of 1069 AFP cases occurring since 1993 were identified in 311 hospital visits. Less than 50% of AFP cases occurring in 1993 and 1994 had been reported by AFP surveillance, and laboratory diagnosis had been carried out on only a small proportion of these. However, improved cooperation between hospital sectors increased the rate of case reporting and laboratory diagnosis to 85% and 78%, respectively, in 1997. Despite this overall improvement, these two indicators were approximately 10-20% lower in Yunnan Province. Epidemiological analysis revealed that cases of clinical poliomyelitis accounted for as much as one-third of all AFP in 1993 and that some of these cases were clustered. Clusters were rarely observed after 1994. Active surveillance in the China-Myanmar border areas of Yunnan over 1995-96 detected 9 cross-border cases of clinical poliomyelitis, including 2 of wild poliomyelitis. Import of poliomyelitis was thus considered to have occurred frequently until 1996 in this border area of Yunnan. These data were important for the outbreak response immunization carried out in 1996 in the border prefectures of Yunnan. CONCLUSION: Our investigation confirmed a high level of AFP surveillance in poliomyelitis high-risk areas of the five provinces and provided valuable information on the interruption of wild poliovirus circulation in southern China that will be of use to countries in other regions that have yet to eradicate poliomyelitis.

Adolescent↗
PubMed2001

Subclavicular trans-sternal approach to treat subclavian artery aneurysm. Case report.

Subclavian artery aneurysms are relatively rare, and the surgical approach depends on the location (intrathoracic or extrathoracic) and size of the aneurysm. Right subclavian artery aneurysms are usually operated upon using a supraclavicular approach or median sternotomy incision with right supraclavicular extension. We treated a right intrathoracic subclavian artery aneurysm by subclavicular trans-sternal approach. This surgical approach is recommended for treatment of right intrathoracic subclavian artery aneurysms for its easy access and excellent cosmetic results.

Aneurysm↗
PubMed2001

[Aortic dissection in aged siblings without Marfan's syndrome].

Aortic dissection rarely occurs in 2 or more family members without Marfan's syndrome. This report describes two aged siblings who underwent emergency operations for aortic dissection. Case 1: A 71-year-old female (sister), who had Stanford type B aortic dissection, underwent replacement of the descending aorta with a Hemashield graft. Case 2: A 72-year-old male (brother of case 1), who had Stanford type A aortic dissection, underwent replacement of the ascending aorta with a UBE graft following the closure of the entry located in the proximal arch. Neither of 2 siblings nor other family members had any features of the Marfan's syndrome. It is proposed that two aortic dissections occurred coincidentally in one family without Marfan's syndrome.

Aged↗
PubMed2000

Laparoscopically assisted pylorus-preserving gastrectomy.

BACKGROUND: The aim of this study was to describe the procedure of laparoscopically assisted pylorus-preserving gastrectomy (LAPPG), and to evaluate intra- and postoperative conditions of the patients. METHODS: We performed pylorus-preserving gastrectomy under laparoscopic observation, including regional lymph node dissection in early gastric cancer of the lower body. Seven patients were treated (two women and five men) using this procedure between April 1996 and April 1999. RESULTS: All the patients showed good postoperative recovery, and no signs of recurrence were recognized. There were no intraoperative or postoperative complications. Less pain, a rapid recovery, and good cosmetic results were noted. The patients exhibited little weight loss after surgery, and none demonstrated the dumping syndrome. Endoscopic examinations performed postoperatively did not indicate the presence of reflux gastritis or esophagitis. CONCLUSIONS: Our procedure of LAPPG may be useful for early gastric cancer, especially intramucosal cancer.

Aged↗
PubMed2000

The dose-related hypoglycemic effects of insulin emulsions incorporating highly purified EPA and DHA.

The dose-related pharmacological effects of insulin emulsion incorporating highly purified eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were investigated. Water-in-oil-in-water multiple emulsions (insulin dose, 0, 10, 25 and 50 IU/kg) incorporating 2% DHA or EPA were administered directly into the colonic and rectal loops in situ. Serum insulin levels rose and serum glucose levels decreased in an insulin dose-related fashion. The relationship of insulin dose and C(max) or AUC(insulin) was linear at the rectum, but a non-linear relationship was observed at the colon. The trend was more predominant in DHA. In the in vivo rectal absorption experiment using emulsions incorporating 2% DHA, 5 IU/kg of insulin emulsion produced a rapid, transitory increase in serum insulin levels and strong reduction of serum glucose levels. The pharmacological availability determined from the dose-response curve by s.c. administration of insulin reached 43.2+/-26.3% (mean+/-S.D.). Mucosal irritation caused by administration of emulsions incorporating 2% EPA or DHA was evaluated by a lactate dehydrogenase (LDH) release study, and compared with those of the emulsion incorporating 2% oleic or linolenic acid. Only when emulsion incorporating 2% oleic acid was applied in the intestine did significant LDH release into the mesenteric veins occur. Our results indicate that emulsion incorporating highly purified long-chain polyunsaturated fatty acid, especially DHA, has the potential of becoming the formulation for enteral delivery of insulin.

Animals↗
PubMed2000

Characterization of Yeast Yea4p, a uridine diphosphate-N-acetylglucosamine transporter localized in the endoplasmic reticulum and required for chitin synthesis.

Chitin is an essential cell wall component, synthesis of which is regulated throughout the cell cycle in the yeast Saccharomyces cerevisiae. We cloned an S. cerevisiae gene, YEA4, whose product is homologous to the Kluyveromyces lactis uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) transporter. An epitope-tagged Yea4p localized mainly in the 10,000 x g pellet (P2), suggesting endoplasmic reticulum (ER) localization. Membrane vesicles from the P2 fraction showed an 8-fold higher UDP-GlcNAc transport activity in cells harboring a multicopy YEA4 plasmid than in cells harboring vector alone. The activity distribution is identical with the protein distribution in P2, whether the gene is overexpressed or not, suggesting its native localization in P2. Immunolocalization of epitope-tagged Yea4p further revealed ER localization. The increase in transport activity due to the YEA4 overexpression is specific for UDP-GlcNAc, but not for UDP-galactose and GDP-mannose. Deltayea4-disrupted cells showed a reduced rate of UDP-GlcNAc transport, contained less chitin, and were larger and rounder in shape than the wild type cells. Our results indicate that YEA4 encodes an ER-localized UDP-GlcNAc transporter that is required for cell wall chitin synthesis in S. cerevisiae.

Amino Acid Sequence↗
PubMed2000

In vivo effects of highly purified docosahexaenoic acid on rectal insulin absorption.

The purpose of this study was to evaluate the effectiveness and the toxicity of polyunsaturated fatty acid, such as oleic acid, eicosapentaenoic acid (DHA), as potential absorption enhancer for rectal delivery of insulin, using a water-in-oil-in water (W/O/W) multiple emulsion. In a single administration study, rectal insulin absorption was enhanced markedly, and marked hypoglycemia was induced by the emulsion incorporating various fatty acids in an insulin dose-related fashion. The pharmacological availability of the emulsion incorporating 2% oleic acid, EPA and DHA was approximately 7.7, 11.0 and 25.4%, respectively. The insulin absorption enhancement effect was not increased in proportion to the amount of DHA in the emulsion, the mean T(max) value of the serum glucose-time curve could be extended to twice that of the emulsion without PF 127. In a multiple administration study, the mean AUC(glucose) values of the emulsion incorporating DHA showed almost the same value on the first and the tenth day. From the morphological appearance of the mucosal surface, the emulsion incorporating DHA induced no or little mucosal damage. Our findings demonstrated that DHA has a strong insulin permeability enhancement effect and little toxicity. Thus, DHA is an attractive candidate as an absorption enhancer for intestinal delivery of insulin.

Animals↗
PubMed2000

Enhanced enteral bioavailability of vancomycin using water-in-oil-in-water multiple emulsion incorporating highly purified unsaturated fatty acid.

The aim of this study was to evaluate the potential of an emulsion incorporating unsaturated fatty acids to improve the mucosal absorption of poorly absorbed drugs from rat intestinal loops in situ, using a water-in-oil-in-water (W/O/W) multiple emulsion. Vancomycin hydrochloride (VCM) was used as a model drug with low oral bioavailability. The entrapment efficiency of VCM in the emulsion was approximately 60% and remained constant over storage for 1 month at 4 degrees C. The emulsion incorporating C18 unsaturated fatty acids or docosahexaenoic acid (DHA) markedly enhanced VCM absorption after colonic and rectal dosing. The effectiveness of DHA on VCM colonic absorption improvement was the same as that of oleic acid, and less than that of linoleic and linolenic acids. For rectal dosing, bioavailability was similar among various emulsions, in the range 40-50%. The effect of the emulsion incorporating oleic acid or DHA on improving VCM enteral bioavailability was not increased proportional to the incorporated amount. The electrical resistance of membranes was not changed by the incorporation of various fatty acids in emulsions. Our results indicated that W/O/W emulsions incorporating C18 unsaturated fatty acid or DHA were useful carriers for improving the absorption of poorly absorbable drugs via the intestinal tract without gross changes to tight junction function.

Administration, Rectal↗
PubMed2000

Gq protein level increases concurrently with antigen-induced airway hyperresponsiveness in rats.

In the present study, bronchial Gq protein level of the airway hyperresponsive rats was determined by using immunoblot analysis. In the airway hyperresponsive rats that were sensitized and repeatedly antigen challenged, the in vitro bronchial responsiveness to acetylcholine was significantly enhanced as compared with that in the sensitized control group. Moreover, the bronchial contraction induced by 10 microM AlF(4)(-) (generated by 10 microM AlCl(3) plus 10 mM NaF) was significantly elevated after repeated antigen challenge (0.44+/-0.13 and 1.09+/-0.09 g tension in the control and airway hyperresponsive groups, respectively; P<0.01). In both groups, immunoblotting with the antibody against G alpha q gave a single 42 kD band. The G alpha q protein levels in the airway hyperresponsive group (0.58+/-0.12) estimated by G alpha q/beta-actin ratio was significantly greater than those in the control group (0.30+/-0.10; P<0.05). These findings suggest that the increase in G alpha q protein level may be involved in the pathogenesis of antigen-induced airway hyperresponsiveness in rats.

Animals↗
PubMed2000

Complications of laparoscopic and retroperitoneoscopic adrenalectomies in 370 cases in Japan: a multi-institutional study.

A total of 370 laparoscopic adrenalectomies, including 311 transperitoneal (TP) and 59 retroperitoneal (RP) approaches, were performed in nine urologic centers, where the laparoscopic adrenalectomy was first begun independently in Japan, and their affiliated hospitals between January 1992 and September 1996. The clinical diagnoses of those 370 adrenal diseases were primary aldosteronism in 155 patients, Cushing's syndrome in 61. preclinical Cushing's syndrome in 21. pheochromocytoma in 16, nonfunctioning adenoma in 87, complicated cyst in ten, myelolipoma in nine, adrenal cancer in four and other diagnoses in eight (table 1). There was no mortality in this series. Intraoperative complication rate was 33/370 (9%) in total: 26/311(8%) in the TP procedures and 7/59 (12%) in the RP procedures (table 11). Postoperative complication rate was 24/370 (6%) in total: 22/311 (7%) in the TP procedures and 2/59 (3%) in the RP ones (table 111). Conversion rates to open surgery in total, in the TP and in the RP procedures were 13/370 (3.5%), 10/311 (3.2%) and 3/59 (5.1 %). respectively (table IV). Although the RP procedure has a lower morbidity rate compared to the TP procedure, more skill is required to overcome the drawback of the narrow working space and fewer anatomical landmarks.

Adenoma↗
PubMed2000

Endoscopic neodymium:yttrium aluminium garnet (Nd:YAG) laser irradiation of a bladder hemangioma associated with Klippel-Weber syndrome.

A case of endoscopic neodymium:yttrium aluminium garnet (Nd:YAG) laser coagulation of a bladder hemangioma associated with Klippel-Weber syndrome is presented. The patient presented with extensive nevus and swelling of the left lower limb since birth. She was diagnosed with Klippel-Weber syndrome by angiography at the age of 1 year. Gross hematuria had been observed since she was 1 year old and, in addition, endoscopic examination revealed diffuse bladder hemangiomas. At 8 years of age, gross hematuria became worse and gait disturbance also appeared. She was referred to the Department of Urology at Tohoku University School of Medicine for endoscopic treatment in June 1998. Under general anesthesia, the bladder was inflated with CO2 gas and the hemangiomas were coagulated by Nd:YAG laser photonic irradiation endoscopically. Gross hematuria was markedly improved immediately following this treatment. Klippel-Weber syndrome is a rather uncommon disease which shows various types of vascular anomaly and hypertrophy of the lower extremities. Three to 6% of the patients have associated bladder hemangiomas. Although Nd:YAG laser irradiation provides results superior to alternative therapy and is the preferred treatment for most patients with bladder hemangioma, in this case, hemangiomas are multiple and present the possibility of re-bleeding, therefore long-term and close follow up is important.

Child↗
PubMed2000

Retroperitoneoscopic excision of a mesenteric cyst.

Mesenteric cysts are rare intra-abdominal lesions. We present a case of a mesenteric cyst that was discovered by abdominal computed tomography (CT) and excised by retroperitoneoscopic surgery. There have been 10 reports of excision of mesenteric cysts by laparoscopy in the literature, but retroperitoneoscopic resection of such cysts has not been reported. This case suggests that when a mesenteric cyst arises from the ascending or descending colon, the retroperitoneal approach has a lower risk of traumatizing the bowel than does the laparoscopic intra-abdominal approach, and it does not have to compress other intra-abdominal organs.

Adult↗
PubMed2000

Acetylcholine-induced smooth muscle contraction of intrapulmonary small bronchi is augmented in antigen-induced airway hyperresponsive rats.

Smooth muscle responsiveness of intrapulmonary small bronchi obtained from repeatedly antigen-challenged rats was compared with that from control animals to determine whether smooth muscle contractility of peripheral airways is augmented by such repeated challenge. In intact (non-permeabilized) smooth muscles of intrapulmonary bronchi, the acetylcholine (ACh)-induced contractile response was significantly augmented in the repeated challenge group, although 60-mM K+-induced contraction was within the normal level. In beta-escin-permeabilized muscles, no significant difference between groups was observed in the Ca2+-induced contractile responses. Thus, augmented ACh-induced contraction of intact intrapulmonary small bronchial smooth muscle might be, at least in part, due to an enhanced ACh-mediated Ca2+-sensitizing signal.

Acetylcholine↗