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Biomedical subjects

T Morikawa

Publications and source records attributed to T Morikawa.

At least 19 recordsLinked to original sources
PubMed2006

Decrease in tetrahydrobiopterin as a possible cause of nephropathy in type II diabetic rats.

A decrease in renal synthesis of nitric oxide (NO) in the progression of diabetic nephropathy has been documented. As (6R)-5,6,7,8-tetrahydrobiopterin (BH4) is an essential cofactor of NO synthase, we investigated whether BH4 deficiency is involved in the pathogenesis of nephropathy. Ten-week-old Otsuka Long-Evans Tokushima Fatty (OLETF) rats were used as a type II diabetic model, and Long-Evans Tokushima Otsuka (LETO) rats as the healthy controls. OLETF rats were orally treated with BH4 (10 mg/kg daily) or with water from 10 to 61 weeks of age. In another experiment, OLETF rats were treated orally with a calcium channel blocker, benidipine (5 mg/kg daily), or with 0.3% carboxymethyl cellulose (nontreated) from 10 to 52 weeks of age. Proteinuria was observed periodically, and at the end of the study, BH4 level and GTP cyclohydrolase I (GTPCH) activity in the kidney were measured. Proteinuria was observed at 13 weeks of age in the OLETF rats, and deteriorated until 61 weeks of age. Supplemental BH4 reduced the proteinuria. At 52 weeks of age, GTPCH activity and the BH4 level were decreased in the plasma and kidneys of OLETF rats, whereas they were significantly higher in the benidipine group than in the nontreated group. Proteinuria was milder in the benidipine group than in the nontreated group, without a concomitant decrease in blood pressure. Histologically observed glomerulosclerosis was mild in the BH4 and benidipine groups. In type II diabetic rats, renal BH4 is considered to play a crucial role in the pathogenesis of diabetic nephropathy. Benidipine was found to preserve BH4 levels, suggesting therapeutic renoprotective effects.

Animals↗
PubMed2006

Cytochrome P450 subfamily CYP710A genes encode sterol C-22 desaturase in plants.

Sterols are isoprenoid-derived lipids that are produced via the mevalonate pathway and are involved in various cellular functions in eukaryotes such as maintenance of membrane integrity and biosynthetic precursors of steroid hormones. Among cellular sterols, Delta(22)-sterols containing a double bond at C-22 in the sterol side chain specifically occur in fungi (ergosterol) and plants (stigmasterol and brassicasterol), and several lines of experimental evidence have suggested specific physiological roles of Delta(22)-sterols in plants. Fungal cytochrome P450 (P450), CYP61, has been established as the sterol C-22 desaturase functioning at the penultimate step in the ergosterol biosynthetic pathway. On the other hand, no particular sequence has been assigned as to the enzyme responsible for the introduction of the double bond into the sterol side chain in plants. In this review, we summarize our recent findings demonstrating that CYP710A P450 family genes encode the plant sterol C-22 desaturases to produce stigmasterol and brassicasterol/crinosterol from beta-sitosterol and 24-epi-campesterol respectively.

Arabidopsis↗
PubMed2006

Salvage of a massive esophago-tracheal fistula resulting from a stenting treatment.

We report the successful surgical resolution of a case of massive esophago-tracheal fistula (ETF) caused by a stenting treatment for stricture of an esophago-gastric anastomosis. A 54-year-old man was admitted to our hospital due to serious pneumonia secondary to ETF. He had previously received esophagectomy and post-operative chemo-radiation therapy for esophageal cancer, followed by stenting treatments for a benign stricture of the esophago-gastric anastomosis. For surgical treatment of the resulting ETF, serial operations were required. The first operation, performed under percutaneous cardiopulmonary support, included removal of the stents followed by tracheotomy, were with the coverage of the tracheal defect achieved using both major pectoral muscle flaps. A salivary fistula was also generated and an enteral nutrition tube was placed. Six months after the first operation, a pedicled ileocolic interposition was performed in order to effect reconstruction of the digestive tube, with an additional microvascular anastomosis of the ileocolic and internal thoracic artery and vein. After the second operation, the patient's ability to ingest food was restored, and he was discharged from the hospital. Thus, ETF was successfully treated by successive surgical operations with delicate intra- and post-operative respiratory management.

Anastomosis, Surgical↗
PubMed2006

Immunohistochemical analysis of nuclear survivin expression in esophageal squamous cell carcinoma.

Despite advances in the treatment of esophageal carcinoma, the prognosis for this disease remains poor. Therefore, it is important to obtain a better understanding of the molecular basis of esophageal carcinogenesis. The purpose of this study was to clarify the roles of survivin in esophageal squamous cell carcinoma (ESCC). One hundred 22 ESCC surgical specimens resected from 1989 to 1999 were examined. Survivin expression was assessed by immunohistochemistry. Tumor cells were considered survivin-positive if the immunoreactivity was confined to the nucleus, and a scoring method was applied. Survivin-positive immunostaining was detected in 68 patients (56%). There was a significant association between survivin expression and pN (P = 0.0472). Moreover, the overall survival rate was worse in patients with survivin-positive tumors than in patients with survivin-negative tumors (P = 0.0189). The overexpression of survivin was associated with the overall survival rate and poor prognosis in patients with ESCC. Survivin may be targeted during cancer therapy because of its selective expression in malignant tissue.

Aged↗
PubMed2005

A role of mast cells for hepatic fibrosis in primary sclerosing cholangitis.

We encountered four patients with overt primary sclerosing cholangitis (PSC) which were histologically classified into stage 2 or 3. We examined the expression of stem cell factor (SCF), a ligand of c-kit, in injured bile ducts by immunohistochemistry, and mast cells were identified by immunohistochemistry using anti-HMCT (human mast cell tryptase) and anti-c-kit antibodies to clarify their relation with portal fibrosis coincident with destroyed bile ducts. SCF was detected in the epithelia of most bile ducts in PSC, and many HMCT- and c-kit-positive mast cells were found in portal tracts. Image analysis showed more significant numbers of c-kit-positive mast cells per area of portal tract in PSC than in chronic hepatitis C, and they might increase from stage 2 to 3. c-Kit-positive cells infiltrated into the portal tracts with SCF-positive destroyed bile ducts, and c-kit mast cells should be investigated in detail to make a role for portal fibrosis in PSC.

Journal Article↗
PubMed2005

Cyclin D1, E2F1 expression levels are associated with characteristics and prognosis of esophageal squamous cell carcinoma.

SUMMARY. We performed a multi-institutional analysis of E2F1 and cyclin D1 expression in cases of esophageal squamous cell carcinoma (ESCC). Cyclin D1 and E2F1 are involved in the transition of cell cycle phases and associated with tumor progression. However, no previous studies have concurrently analyzed combined E2F1 and cyclin D1 expression. The purpose of this study was to clarify the relationship of E2F1 and cyclin D1 in ESCC. We studied 122 patients with primary ESCC who underwent surgical tumor resection. Immunohistochemical analyses were performed for E2F1 and cyclin D1. A statistical analysis of immunohistochemistry results, clinicopathological features, and prognosis was performed. E2F1/cyclin D1 (-/-) tumors were present in 31 patients (25.4%) and correlated with reduced tumor progression. In these patients, pT (P=0.0001), pN (P<0.0001), p-Stage (P=0.0019), and survival rates were better than in patients who were positive for either E2F1 or cyclin D1 (P=0.0232). The expression of E2F1 and cyclin D1 is an indicator of tumor progression and prognosis in patients with ESCC. Combined analysis of E2F1 and cyclin D1 expression helps to determine the characteristics and prognosis of ESCC.

Adult↗
PubMed2005

Esophageal pemphigus vulgaris with carcinoma: postoperative steroid therapy based on pemphigus-related antibodies.

A 71-year-old man had been treated as an outpatient for pemphigus vulgaris. Endoscopic examination disclosed an ulcerated lesion in the middle of the esophagus. A biopsy specimen was diagnosed pathologically as squamous cell carcinoma. At surgery, the esophageal mucosa beyond the resection margin appeared edematous and blistered. We carried out anastomosis with sutures rather than staples at the site where the epithelium was least damaged, to minimize likelihood of anastomotic breakdown from poor blood flow. Histopathologic examination of the resected specimen additionally showed blisters and acantholytic cells throughout the esophageal mucosa, so esophageal pemphigus was diagnosed in addition to carcinoma. The patient's general condition deteriorated from worsening of pemphigus. We initiated steroid therapy, making adjustments according to changes in titers of anti-intercellular bridge antibody and antibodies to the cell adhesion molecules (desmoglein 1 and 3). Fever and extensive blistering subsided dramatically, and the patient was discharged in good condition on hospital day 103. When performing esophagectomy in the presence of esophageal pemphigus, the anastomosis must be fashioned cautiously because any mechanical stress can abrade the friable edematous esophageal mucosa. While steroid therapy is known to be effective for pemphigus vulgaris, our findings indicate that in patients with postoperative deterioration of their general condition, marked improvement can be obtained by using antibody titers to guide timing and dose in steroid administration.

Aged↗
PubMed2003

Caveolin-I overexpression is a favourable prognostic factor for patients with extrahepatic bile duct carcinoma.

Extrahepatic bile duct carcinoma (EBDC) is a malignancy well known for its poor prognosis. Some clinicopathological prognostic markers have been proposed, but genetic factors have not been well investigated. We have examined expression patterns of caveolin-1, which has been shown to function as a tumour suppressor in vitro, in EBDC using immunohistochemistry. Normal tissues adjacent to the tumour cells did not show immunoreactivity for caveolin-1. A total of 22 of the 60-carcinoma tissue samples (36.7%) studied were positive for caveolin-1. Caveolin-1 immunostaining negatively correlated with the patient's age and pathological T factor (pT) in a statistically significant manner. Multivariate analysis using Cox's proportional hazards model identified caveolin-1 expression as an independent positive prognostic factor. Thus, our study suggests that caveolin-1 expression may be a useful prognostic marker for EBDC.

Adult↗
PubMed2003

Video-assisted anatomic mediobasal segmentectomy of lung.

Although video-assisted thoracic surgery (VATS) is now widely accepted, pulmonary segmentectomy is rarely performed. We present a case series of patients undergoing this procedure. The first patient had multiple arteriovenous malformations of the right mediobasal segment and a leiomyoma in the bronchus of the mediobasal segment. The second patient had multiple pulmonary metastases from colon cancer, including one in the right mediobasal segment. The third patient had metastases in the right ventrobasal and mediobasal segments from a solitary fibrous tumor that originated in the contralateral diaphragm. In the first two patients, a solitary mediobasal segmentectomy was done. In the third patient, a combined ventrobasal and mediobasal bisegmentectomy was performed. There were no complications, and visualization was excellent. Because VATS provides such excellent exposure, mediobasal segmentectomy of the lung is feasible, even though this operation is not done as an open procedure.

Aged↗
PubMed2003

An extrapleural approach to the anterior mediastinum using video-assisted thoracic surgery (VATS).

A lateral extrapleural approach via video-assisted thoracic surgery (VATS) was used in a patient suspected of having a benign tumor of right lobe of the thymus. The patient previously had undergone lung resection for pulmonary tuberculosis, and the ipsilateral thorax had contracted and dense pleural adhesions were likely to exist. Lateral extrapleural approach by VATS was performed successfully and is an alternative to open surgery in highly selected patients with anterior mediastinal lesions.

Aged↗
PubMed2002

Bilateral adrenal hemorrhage in essential thrombocythemia.

A 67-year-old woman with previously untreated essential thrombocythemia developed bilateral adrenal hemorrhage. She had no known vascular risk factors including smoking, diabetes mellitus, hypertension, and hypercholesterolemia. Her platelet count was 921 x 10(9)/l. She received preemptive steroid therapy to prevent the occurrence of adrenal crisis, but 5 weeks later the replacement therapy was discontinued because the patient fully recovered with a normal adrenocorticotropic hormone stimulation test. Thereafter, she remained well for more than 4 years with a platelet count ranging from 600 to 800 x 10(9)/l. Although adrenal hemorrhage is very rare, it can occur as a hemorrhagic complication of essential thrombocythemia.

Adrenal Gland Diseases↗
PubMed2002

Investigation of parenchymal cell differentiation in organotypic slice culture of mouse fetal liver under administration of sodium butyrate.

The fetal mouse liver tissues in our organotypic slice culture were spread and flattened for at least 3 weeks; small, round cells were distributed in the center and polygonal cells were seen in the periphery. Ultrastructurally, polygonal cells showed abundant rough endoplasmic reticulum and mitochondria. They expressed albumin (ALB) and alpha-fetoprotein (AFP) for at least 3 weeks, and Cx32-immunoreactivity was also seen in a plaque on the cells. Many proliferating cell nuclear antigen (PCNA)-positive cells were observed at the periphery, and there were scattered CK-19-positive cells. The spreading of the fetal liver tissue in organotypic slice culture was reduced in medium containing sodium butyrate (SB). The expression of ALB was well maintained in polyglonal cells of the SB(+) group 3 weeks after culture and AFP-immunoreactivity was decreased in the SB(+) group. The concentration of ALB in the medium was significantly higher in the SB(+) than in the SB(-) group. CK-19-positive cells in the SB(+) group were increased in number more than those in the SB(-) group. PCNA-positive cells were less numerous in the SB(+) group, and Cx32-positive plaques were increased. SB can help immature hepatocytes to differentiate into the mature type and the cholangiocytic lineage, reducing their proliferation. These findings suggest that parenchymal cells in our organotypic slice culture of the fetal mouse liver can maintain structure and function as in vivo for the long term, and SB is shown to be a differentiation inducer of parenchymal cells in the slice culture.

Albumins↗
PubMed2001

Availability of lobe-selective bronchial blockade for video-assisted thoracic surgery: an initial experience with three cases.

BACKGROUND: Stable oxygenation and sufficient collapse of the lung are essential for video-assisted thoracic surgery (VATS). We performed the lobe-selective lung collapse technique with VATS for patients who had deteriorated lung function. METHODS AND RESULTS: CASE 1: A 75-year-old man who had undergone thoracoplasty showed spontaneous pneumothoraces in the contralateral side. Bullae were stapled successfully under complete isolation and collapse of diseased lobe. CASE 2: A 57-year-old woman who had undergone left lower lobectomy for lung cancer presented with another lung cancer in the right lower lobe. The right lower lobe bronchus was closed selectively, and basal segmentectomy was performed. CASE 3: A 60-year-old woman who had lost left lung function presented with right-side spontaneous pneumothoraces. The right upper lobe was collapsed selectively, and bullectomy was performed. CONCLUSION: Lobe-selective bronchial blockade may be beneficial when VATS is performed for selected patients with deteriorated lung function.

Adenocarcinoma↗
PubMed2001

Absolute stereostructures of novel norcadinane- and trinoreudesmane-type sesquiterpenes with nitric oxide production inhibitory activity from Alpinia oxyphylla.

Novel 14-norcadinane-type sesquiterpenes, oxyphyllenodiols A and B, and 11,12,13-trinoreudesmane-type sesquiterpenes, oxyphyllenones A and B, were isolated from the methanolic extract of kernels of Alpinia oxyphylla. The absolute stereostructures of these norsesquiterpenes were determined on the basis of physicochemical and chemical evidence. In addition, oxyphyllenodiol A and oxyphyllenone A were found to inhibit the NO production in lipopolysaccharide-activated macrophages.

Animals↗
PubMed2001

Phytoestrogens from the roots of Polygonum cuspidatum (Polygonaceae): structure-requirement of hydroxyanthraquinones for estrogenic activity.

The methanolic extract from the roots of Polygonum (P.) cuspidatum was found to enhance cell proliferation at 30 or 100 microg/mL in MCF-7, an estrogen-sensitive cell line. By bioassay-guided separation from P. cuspidatum with the most potent activity, emodin and emodin 8-O-beta-D-glucopyranoside were isolated as active principles. The methanolic extracts from Polygonum, Cassia, Aloe, and Rheum species, which were known to contain anthraquinones, also showed the MCF-7 proliferation. As a result of the evaluation of various anthraquinones from plant sources and synthetic anthraquinones, aloe-emodin, chrysophanol, chrysophanol 8-O-beta-D-glucopyranoside, and 1,8-dihydroxyanthraquinone showed weak activity. On the other hand, alizalin and 2,6-dihydroxyanthraquinone as well as emodin having the 2- and/or 6-hydroxyl groups showed potent activity. These results show that the unchelated hydroxyl group is essential for strong activity. Emodin and 2,6-dihydroxyanthraquinone also inhibited 17beta-estradiol binding to human estrogen receptors (ERs) with K(i) values of 0.77 and 0.31microM for ERalpha and 1.5 and 0.69 microM for ERbeta. These findings indicate that hydroxyanthraquinones such as emodin are phytoestrogens with an affinity to human estrogen receptors.

Anthraquinones↗
PubMed2001

Visible-light photocatalysis in nitrogen-doped titanium oxides.

To use solar irradiation or interior lighting efficiently, we sought a photocatalyst with high reactivity under visible light. Films and powders of TiO(2-x)N(x) have revealed an improvement over titanium dioxide (TiO2) under visible light (wavelength < 500 nanometers) in optical absorption and photocatalytic activity such as photodegradations of methylene blue and gaseous acetaldehyde and hydrophilicity of the film surface. Nitrogen doped into substitutional sites of TiO2 has proven to be indispensable for band-gap narrowing and photocatalytic activity, as assessed by first-principles calculations and x-ray photoemission spectroscopy.

Journal Article↗
PubMed2001

Do mammalian cells synthesize lipoic acid? Identification of a mouse cDNA encoding a lipoic acid synthase located in mitochondria.

Lipoic acid is a coenzyme essential to the activity of enzymes such as pyruvate dehydrogenase, which play important roles in central metabolism. However, neither the enzymes responsible for biosynthesis nor the biosynthetic event of lipoic acid has been reported in mammalian cells. In this study, a mouse mLIP1 cDNA for lipoic acid synthase has been identified. We have shown that the cDNA encodes a lipoic acid synthase by its ability to complement a mutant of Escherichia coli defective in lipoic acid synthase and that mLIP1 is targeted into the mitochondria. These findings suggest that mammalian cells are able to synthesize lipoic acid in mitochondria.

Amino Acid Sequence↗