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Shigeru Sato

Publications and source records attributed to Shigeru Sato.

At least 37 records · Page 2Linked to original sources
PubMed2005

Occurrence of hyaline droplets in renal biopsy specimens: an ultrastructural study.

Hyaline droplets are apical cytoplasmic vesicles containing an accumulation of electron-dense amorphous materials surrounded by a unit membrane. Hyaline droplets may originate from apical vesicles after conversion to osmotic vesicles and loss of internally lined glycocalyx. They are found in the proximal tubular epithelium in biopsies from patients with renal diseases; however, their biological importance is not well understood. We reviewed ultrastructural pathology records of 140 renal biopsy patients to determine the occurrence and relevance of hyaline droplets. Of the cases, 14 (10%) showed the presence of hyaline droplets in proximal tubular epithelium. The distribution of cases were 8 of the 19 (42%) with minimal change nephritic syndrome, 2 of the 37 (5%) with IgA nephropathy, 2 of the 4 (50%) with membranous glomerulonephropathy, 1 of the 4 (25%) with tubulointerstitial nephritis, and 1 of the 1 (100%) with acute renal failure. The droplets were frequently found in male patients (86%), never in children, and were mostly associated with tubular necrosis (8 of 14 cases; 56%). Many hyaline droplets were observed in the cytoplasm of necrotic proximal tubular epithelial cells, and even when tubular necrosis was not evident, the proximal tubular epithelial cells containing hyaline droplets showed degenerated microvilli and decreased basal interdigitations. These results suggest that hyaline droplets could be one marker of renal tubular necrosis and a sign of functional disorder of protein reabsorption by degenerating proximal tubular epithelium.

Adult↗
PubMed2005

Cortical activation during reading of ancient versus modern Japanese texts: fMRI study.

The purpose of this study was to investigate human brain activity during the reading of ancient Japanese texts using functional magnetic resonance imaging. Thirty right-handed normal Japanese subjects performed two reading tasks: covert reading of (1) ancient and (2) modern Japanese text. Common areas are activated during both tasks. Activity in the left inferior frontal cortices increased during the reading of ancient Japanese text compared with the reading of modern Japanese text, whereas occipital activity increased during the reading of modern Japanese text. Our results indicate that ancient Japanese language may be processed as a foreign language.

Adolescent↗
PubMed2005

Slc12a2 is a direct target of two closely related homeobox proteins, Six1 and Six4.

Six genes are homologs of Drosophila sine oculis and encode transcription factors that are characterized by a conserved Six domain and homeodomain. Of the six family members (Six1-Six6) in mice, Six1 and Six4 show similar expression patterns during embryogenesis. Six1-/- mice show defective formation of various organs such as inner ear, nose, skeletal muscle, kidney and thymus, whereas Six4-/- mice show little anomaly in organogenesis. To understand the molecular basis for the differential function of Six1 and Six4 in vivo, we screened target genes of Six1 and Six4 and found that Six1 and Six4 differentially regulated a set of target genes. Gel-retardation assays indicated that the promoter region of one of the targets, sodium-potassium-chloride cotransporter 1 (Slc12a2), contains multiple Six1-binding sites and one common binding site of Six1 and Six4, suggesting that the DNA-binding specificity of Six1 is distinct from that of Six4. This underlies the differential regulation of common target genes by Six1 and Six4. Furthermore, in situ hybridization demonstrated that the expression of Slc12a2 was reduced in the developing dorsal root ganglia of Six1-/-/Six4-/- mice, suggesting that Six1 and Six4 regulate Slc12a2 in vivo.

Animals↗
PubMed2005

[A case of gastric cancer with multiple liver metastases effectively treated by hepatic arterial infusion of MMC, TS-1/CDDP therapy, and thermotherapy].

A 62-year-old man was revealed to have type 2 gastric cancer with synchronous liver metastasis. We considered liver metastasis to be a prognostic factor, and performed two courses of combination thermochemotherapy consisting of hepatic arterial infusion of MMC and TS-1 and thermotherapy. Partial response was observed in the liver metastases,but the primary lesion showed no changes; therefore, we performed four courses of combination thermochemotherapy consisting of TS-1/CDDP therapy and thermotherapy. By the end of three courses of this therapy,the primary lesion had cicatrized,and endoscopic biopsy revealed no cancer cells. These results suggest that gastric cancer,in which liver metastasis is considered to be a prognostic factor,can be effectively treated by combination therapy with hepatic arterial infusion therapy, followed by thermochemotherapy for the primary lesion.

Adenocarcinoma↗
PubMed2004

CSF-chemokines in HTLV-I-associated myelopathy: CXCL10 up-regulation and therapeutic effect of interferon-alpha.

We measured four chemokines in the cerebrospinal fluid (CSF) in human T-lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) with ELISA. CXCL10/IP-10, a T cell type 1 (Th1)-associated chemokine, was significantly elevated in HAM/TSP compared with controls, and the values were even significantly higher in HAM/TSP than in multiple sclerosis (MS) in which CXCL10/IP-10 up-regulation was previously reported. Among Th2-associated chemokines, CCL17/TARC and CCL11/Eotaxin in HAM/TSP were not different from those in controls. As shown in MS, CCL2/MCP-1 was significantly lower in HAM/TSP than in control. Following interferon (IFN)-alpha therapy in HAM/TSP, CCL2/MCP-1 became significantly higher than that before therapy, which may reflect a Th2 induction, while CXCL10/IP-10 remained elevated.

Adult↗
PubMed2004

Oligoclonal IgG bands in Japanese patients with multiple sclerosis. A comparative study between isoelectric focusing with IgG immunofixation and high-resolution agarose gel electrophoresis.

A low prevalence of oligoclonal IgG bands (OB) has been reported as a unique feature of Japanese multiple sclerosis (MS) as compared with Western MS. We compared the frequency of OB between isoelectric focusing (IEF) and agarose gel electrophoresis (AGE) in 59 Japanese patients with clinically definite MS [39 with conventional form of MS (CMS) and 20 with optic-spinal form of MS (OSMS)]. The frequency of IEF-OB in total MS was 54%, whereas that of AGE-OB was only 17%. When OSMS was excluded, the frequency increased to 77% by IEF, whereas it remained 23% by AGE. Our study strongly suggests that IEF is highly effective for detecting OB in Japanese MS patients.

Adult↗
PubMed2004

Pigment cell lineage-specific expression activity of the ascidian tyrosinase-related gene.

Solitary ascidian tadpole larvae develop two types of black pigment cells in the major sensory organs of the brain. Such pigment cells have been demonstrated to express the melanogenic genes, tyrosinase and Tyrp/TRP (tyrosinase-related protein). To understand the genetic and developmental mechanisms underlying the differentiation of chordate pigment cells, we examined the function of the promoter region of Tyrp/TRP gene, an ascidian (Halocynthia roretzi) tyrosinase family gene. The expression of the gene in pigment cell lineage starts at the early-mid gastrula stages. To identify the transcriptional regulatory region of the gene allowing cell-type-specific expression, a deletion series of the HrTyrp 5' flanking region fused to a lacZ reporter gene was constructed and microinjected into ascidian fertilized eggs. The region of 73 bp in HrTyrp was identified as sufficient for expression in pigment cell-precursors of tailbud stage embryos. It is noteworthy that there is no M-box element highly conserved in the promoters for vertebrate tyrosinase family genes such as tyrosinase, Tyrp1/TRP-1 and Tyrp2/TRP-2 (Dct). Although the regulatory system of ascidian pigment-cell development is likely to contain most factors critical to vertebrate pigment-cell development, there might be critical differences in the mode of regulation, such as the developmental timing of interactions of factors, proteins and genes, involved in pigment cell differentiation and pigmentation.

5' Flanking Region↗
PubMed2004

Isolation and developmental expression of Mitf in Xenopus laevis.

Mitf (gene for microphthalmia-associated transcription factor) encodes a transcription factor of the basic/helix-loop-helix/leucine-zipper family and is a key regulator during the development of two different types of melanin-producing cell lineages, namely neural crest-derived melanocytes/melanophores, and the retinal pigment epithelium (RPE) differentiated from the outer layer of the eye cup. Mitf-deficient mice show a lack of melanocytes and small eyes caused by abnormal RPE development. An interesting feature of Mitf is the existence of multiple isoforms with different amino termini and their functions in the development of these melanin-producing pigment cells. In this study, we isolated two Mitf homologues (XlMitfalpha and XlMitfbeta) and their isoforms from Xenopus laevis. Alignment analysis of the amino acid sequences of the N-termini suggests that these isoforms are homologues of mouse Mitf-M (expressed specifically in the melanocyte lineage) and Mitf-A (strongly expressed in the RPE, although this expression is ubiquitous). In Xenopus, XlMitfalpha is strongly expressed in the melanophore lineage (especially in premigratory melanoblasts) and the presumptive RPE and the epiphysis, in which melanin-producing cells differentiate in some vertebrates. Conservation of the Mitf isoforms expected to possess specific functions in the development of melanin-producing cells and of the expressions in such cell types in Xenopus suggest that XlMitf plays a central role in the development of melanin-producing cell lineages, and that, as in mice and humans, most of the signaling molecules or transcription factors implicated genetically in the development of melanin-producing cell lineages affect either Mitf expression or its function (Goding [2000] Genes Dev. 14:1712-1728).

Amino Acid Sequence↗
PubMed2004

CSF chemokine levels in relapsing neuromyelitis optica and multiple sclerosis.

The pathogenesis of relapsing neuromyelitis optica (RNMO) remains unknown. We, for the first time, studied the levels of four chemokines in the cerebrospinal fluid in RNMO with ELISA and compared the data with those in multiple sclerosis (MS) and control. CXCL10/IP-10 and CCL17/TARC were significantly elevated in both RNMO and MS. Conversely, CCL2/MCP-1 was significantly lower in MS, but not in RNMO, than in control. CCL11/Eotaxin was not different between groups. None of the four chemokines studied was significantly different between RNMO and MS.

Age of Onset↗
PubMed2004

Th1/Th2 balance and HTLV-I proviral load in HAM/TSP patients treated with interferon-alpha.

We studied the immunological and virological effects of interferon-alpha (IFN-alpha) therapy in nine patients with HTLV-I-associated myelopathy (HAM/TSP). After therapy, the percentages of CCR5+ cells in CD4+ cells significantly decreased in the cerebrospinal fluid as well as blood. The therapy also significantly lowered the intracellular IFN-gamma+/interleukin-4+ T-cell ratio in blood. Those helper T-cell type 1 (Th1)-related responses tended to be higher and reduce more evidently following therapy in three patients who clinically improved. Also, all the three patients had one or more HTLV-I copies in five blood mononuclear cells. These results suggest that IFN-alpha suppresses Th1 responses in HAM/TSP and that the patients with higher Th1 immunity and proviral loads may be responders of the therapy. Larger-scale studies are needed to confirm the findings.

Aged↗
PubMed2004

Ultrastructural changes during in situ early postmortem autolysis in kidney, pancreas, liver, heart and skeletal muscle of rats.

Many morphological studies of the postmortem interval were carried out under conditions in which the tissue was incubated in vitro after extirpation. However, the extirpation affects cell viability. We examined the ultrastructural changes in the kidney, pancreas, liver, heart and skeletal muscle of male Wistar rats occurring postmortem in situ. In each organ, cell edema (cell swelling), appearance of amorphous dense deposits in the mitochondria, loss of glycogen granules, dilation of the endoplasmic reticulum, clumping and margination of nuclear chromatin, and/or condensation of nuclear chromatin were observed, but the duration of the period of ultrastructural change was organ specific. Most of the ultrastructural changes occurred earlier in kidney. In hepatocytes, the morphological degeneration occurred later than in the renal tubule epithelium and earlier than that in the myocardium. Of the five organs we examined, skeletal muscle showed the greatest delay in postmortem change. In the distal tubule epithelium and pancreatic acinar cells, two forms of nuclear change were seen: one resembled necrotic change and the other resembled apoptotic change. The effect of lysosomes and hydrolytic enzymes was not as great as previous findings.

Animals↗
PubMed2004

Colonoscopy in the diagnosis of intestinal tuberculosis in asymptomatic patients.

BACKGROUND: Colonoscopy with terminal ileoscopy is crucial for the diagnosis of intestinal tuberculosis. This report describes characteristic endoscopic findings in patients with intestinal tuberculosis with few or no clinical symptoms. METHODS: Data for 11 consecutive patients in whom a diagnosis of intestinal tuberculosis was made during the last 15 years in one facility were reviewed. Clinical findings and the frequency of endoscopic findings were evaluated. Mucosal lesions were classified into 4 types: type 1, circumferential ulceration with nodules; type 2, round or irregularly shaped small ulcers, arranged circumferentially, without nodules; type 3, multiple erosions restricted to the large intestine; and type 4, small ulcers or erosions restricted to the ileum. The gross endoscopic appearance of healed lesions included patulous ileocecal valve, pseudodiverticular deformity, and atrophic mucosal areas with aggregated ulcer scars. RESULTS: Only one patient had remarkable clinical symptoms (anorexia and weight loss), whereas, the other 10 had few or no symptoms. The frequency of type 1, 2, 3, and 4 endoscopic findings was, respectively, 36%, 36%, 9%, and 18%. The frequencies for patulous ileocecal valve, pseudodiverticular deformity, and atrophic mucosal area were, respectively, 45%, 45%, and 91%. CONCLUSIONS: When colonoscopy is performed in asymptomatic patients, it is important to be aware of subtle endoscopic findings that are characteristic for intestinal tuberculosis. Recognition of such findings may lead to a correct diagnosis of early stage intestinal tuberculosis.

Adult↗
PubMed2004

420 nm intense continuous light therapy for acne.

BACKGROUND: Topical antibiotics, isotretinoin or systemic antibiotics are usually used for acne therapy. However, isotretinoin cannot be used during pregnancy because it can cause significant birth defects while systemic antibiotics can have adverse side effects such as gastrointestinal irritation, photosensitivity and tetracycline sensitivity. Describe here is a high-intensity, narrow-band, blue light (ClearLight) system, and its therapeutic clinical effect is investigated on acne using cutaneous measurements, bacterial observations and ultrastructural changes. MATERIALS AND METHODS: A total of 28 adult healthy volunteers with facial acne (mean age 28.1 years, range 16-56 years) were recruited for this study. They were treated with a total of eight serial biweekly 15-minute treatment sessions. Clinical counts of acne, as well as moisture, sebum and pH measurements were taken between each session. Nine of the 28 patients were followed for 2-3 months after the last treatment. Detection of bacteria in acne pustules was analyzed by culture and by polymerase chain reaction (PCR). Ultrastructural changes were examined in eight patients after four sessions of the light therapy. RESULTS: All patients completed the study. Overall, there was a 64.7% improvement in acne lesions. There were no bacterial changes before or after the therapy, although damaged Propionibacterium acnes were observed at the ultrastructural level. CONCLUSIONS: ClearLight performed eight times over 4 weeks can be useful in the treatment of acne. Further investigation will be needed to elucidate the mechanism of action of ClearLight.

Acne Vulgaris↗
PubMed2004

Simultaneous determination of the main metabolites in rice leaves using capillary electrophoresis mass spectrometry and capillary electrophoresis diode array detection.

The study of the metabolomics of primary metabolites using conventional chemical analyses requires a high-throughput method. Chemical derivatizations are a prerequisite for gas-chromatographic separation, and a large sample quantity is needed for liquid-chromatographic separation and nuclear magnetic resonance detection systems. Recently, we have developed a capillary electrophoresis-mass spectrometry (CE-MS) technology that can simultaneously quantify a large number of primary metabolites, using only a small quantity of samples, and without any chemical derivatizations. Parallel use of a capillary electrophoresis-diode array detector (CE-DAD) system further enables almost all water-soluble intracellular metabolites to be analyzed. We demonstrate, with rice leaves, a simple and rapid method of sample preparation for CE analysis; using this method, we have successfully measured the levels of 88 main metabolites involved in glycolysis, the tricarboxylic acid cycle, the pentose phosphate pathway, photorespiration, and amino acid biosynthesis.

Electrophoresis, Capillary↗
PubMed2004

Effects of exercise training after open heart surgery on quality of life and exercise tolerance in patients with mitral regurgitation or aortic regurgitation.

We conducted a questionnaire survey regarding quality of life (QOL) to evaluate the effects of exercise training on the QOL in patients with valvular heart disease after surgery. This study included 64 consecutive patients who underwent heart surgery. They were divided into two groups: exercise training could (EX(+) group, n = 31) and could not be performed (EX(-) group, n = 33) until 6 months after surgery. To evaluate the QOL and exercise tolerance, we employed "a questionnaire regarding disease and quality of life" developed for Japanese people and cardiopulmonary exercise testing. In our questionnaire survey, the improvement rating (Delta subjective/social index), which was calculated from the difference between the pre-and postoperative values, was greater in the EX(+) group than that in the EX(-) group (4.9 +/- 3.1 versus 1.1 +/- 4.0, P < 0.05). In the changes in exercise tolerance, Delta anaerobic threshold was greater in the EX(+) group (0.79 +/- 0.17 versus -0.02 +/- 0.28, P < 0.01). Moreover, there was a positive correlation between Delta subjective/social index and Delta peak VO(2) (r = 0.62, P < 0.05). We concluded that exercise training for patients after cardiac surgery improves the QOL and exercise tolerance. It is suggested that changes in subjective and social parameters contribute to an exercise training-related improvement in the QOL.

Aged↗
PubMed2003

Better success of retinal reattachment with long-standing gas tamponade in highly myopic eyes.

BACKGROUND: To evaluate the efficacy of long-term gas tamponade after pars plana vitrectomy (PPV) for retinal detachment (RD) due to a macular hole (MH) in highly myopic eyes. METHODS: A retrospective study was conducted at two institutions. The study included 25 highly myopic eyes with RD resulting from a MH. C3F8 gas tamponade was used in 13 eyes (C3F8 gas group), and SF6 gas tamponade was used in 12 eyes (SF6 gas group) following PPV. C3F8 gas has a longer half-life time in the vitreous cavity than SF6 gas. The main outcome measures were the anatomic reattachment rate and the visual acuity (VA). Follow-up periods were at least 24 months. RESULTS: The anatomic reattachment rate and MH closure following the initial surgery were significantly higher in the C3F8 gas group (100%) than in the SF6 gas group (66.7%; P=0.039). The differences in the postoperative VAs were not significant both for all eyes and only for eyes with initial anatomic success. (P=0.42 and P=0.54, respectively). In addition, no significant difference was found in the improvement of VA both for all eyes and for the initial success eyes (P=0.66 and P=0.56, respectively). CONCLUSION: We conclude that the longer duration of tamponade with C3F8 gas results in a higher rate of successful closure and that C3F8 gas tamponade is an effective treatment for MH with RD in highly myopic eyes.

Aged↗