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Biomedical subjects

K Sugiyama

Publications and source records attributed to K Sugiyama.

At least 19 recordsLinked to original sources
PubMed2006

Investigation of the stability of one-piece acrylic intraocular lenses in cataract surgery and in combined vitrectomy surgery.

BACKGROUND: To compare the degrees of intraocular lens (IOL) movement between eyes that received a one-piece acrylic IOL and those that received a three-piece acrylic IOL after cataract surgery, and also among eyes that received a one-piece acrylic IOL after a combined vitrectomy surgery for cataract. METHODS: In the first study, we report on 50 patients who were implanted with a one-piece acrylic IOL in one eye and a three-piece acrylic IOL in the contralateral eye for senile cataract. In the second study, we report on 50 patients who were implanted with a one-piece acrylic IOL in combined vitrectomy surgery for cataract and retinal diseases. The degree of IOL decentration and tilt, and anterior chamber depth (ACD) were measured using Scheimpflug video photography at 1 week, 1 month, 3 months and 6 months after surgery in both the studies. The postoperative refractive status was also examined. RESULTS: The mean decentration and tilt showed no marked changes during the follow-up in eyes with either IOL implanted, and no marked differences were noted in either study throughout the follow-up. The ACD did not change after surgery with one-piece IOL implantation, for either the cataract surgery group or the combined surgery group, except for 1 week after surgery in eyes requiring gas tamponade. In contrast, marked shallowing in ACD was observed in the three-piece group after cataract surgery. The spherical equivalent did not change markedly in either study. CONCLUSIONS: The one-piece acrylic IOL was stable in the capsular bag, both horizontally and vertically, after cataract surgery, and also after combined surgery.

Acrylic Resins↗
PubMed2006

Regulation of STAT3-mediated signaling by LMW-DSP2.

Signal transducer and activator of transcription 3 (STAT3), which mediates biological actions in many physiological processes, is activated by cytokines and growth factors, and has been reported to be constitutively activated in numerous cancer cells. In this study, we examined whether low molecular weight-dual specificity phosphatase two (LMW-DSP2) is involved in the regulation of the interleukin 6 (IL-6)/leukemia inhibitory factor (LIF)/STAT3-mediated signaling pathway. IL-6/LIF-induced LMW-DSP2 expression in murine testicular or hepatoma cell lines, while LMW-DSP2 overexpression in 293T cells suppressed IL-6-induced phosphorylation and activation of STAT3. Furthermore, LMW-DSP2 suppressed the expression of IL-6-induced endogenous genes. In contrast, small-interfering RNA-mediated reduction of LMW-DSP2 expression enhanced IL-6-induced STAT3-dependent transcription. In fact, LMW-DSP2 interacted with STAT3 in vivo and endogenous LMW-DSP2 bound to STAT3 in murine testicular GC-1 cells. These results strongly suggest that LMW-DSP2 acts as a negative regulator of the IL-6/LIF/STAT3-mediated signaling pathway.

Animals↗
PubMed2006

Physical and functional interactions between Daxx and STAT3.

Signal transducer and activator of transcription 3 (STAT3) play key roles in the intracellular signaling pathways of the interleukin (IL)-6 family of cytokines, which exhibit a diverse set of cellular responses, including cell proliferation and differentiation. Dysregulated IL-6/STAT3 signaling is involved in the pathogenesis of several diseases, for example autoimmune diseases and tumors. Type I interferon (IFN) induces the expression of proapoptotic genes and has been used in the clinical treatment of several tumors. In the present study, we found that type I IFN suppressed IL-6/STAT3-mediated transcription and gene expression. Furthermore, a type I IFN-induced protein, Daxx, also suppressed STAT3-mediated transcriptional activation, while overexpression of Daxx inhibited IL-6/STAT3-mediated gene expression. Importantly, small-interfering RNA-mediated reduction of Daxx expression enhanced IL-6/leukemia inhibitory factor (LIF)-induced STAT3-dependent transcription. Co-immunoprecipitation studies revealed a physical interaction between Daxx and STAT3 in transiently transfected 293T cells. We further found that Daxx and STAT3 were co-localized in the nucleus. These results indicate that Daxx may serve as a transcriptional regulator of type I IFN-mediated suppression of the IL-6/STAT3 signaling pathway.

Adaptor Proteins, Signal Transducing↗
PubMed2005

Reversibility from delayed hyperacute rejection in ABO-incompatible renal transplantation: histopathological findings of renal allograft biopsy.

ABO-incompatible renal transplantation (ABOIRTx) tend to lead to blood type antibody-mediated rejection, the so-called delayed hyperacute rejection (DHAR), which results in short-term graft loss. To clarify the accurate incidence and prognostic value of DHAR among ABOIRTx, we reviewed biopsy specimens obtained from ABOKTx allografts with abrupt dysfunction during the early period after transplantation. Among 74 ABOIRTx patients, 34 patients displayed allograft dysfunction within 14 days following transplantation. The biopsy specimens were classified based on the Banff schema. The pathological diagnosis of ABO blood type antibody-mediated humoral rejection (ABO-AMHR) was made by the following 3 findings: Specimens with all of above-mentioned findings were categorized as severe ABO-AMHR; those with at least one findings, were categorized as mild ABO-AMHR. All patients were treated with steroid pulse therapy and/or modification of other immunosuppressants. Group 1 consisted of severe ABO-AMHR (n = 6); group 2 consisted of mild ABO-AMHR (n = 5); group 3 consisted of acute cellular rejection (n = 3); group 4 consisted of recovery phase of ATN (n = 11); group 5 consisted of calcineurin inhibitor toxicity (n = 2); and group 6 consisted of normal histology (n = 5). One of 6 patients (16%) in group 1 lost the graft because of DHAR irreversible by antirejection and anticoagulation therapy. However, there has been no clear definition of histpathological criteria for DHAR after ABO-incompatible kidney transplantation. The definition must prognosticate whether the rejection process is reversible.

ABO Blood-Group System↗
PubMed2005

The pathologic impact of tacrolimus on protocol biopsy in renal transplant patients with basiliximab-based immunosuppression.

Forty-two ESRD patients underwent renal transplantation using basiliximab (mean age: 30.6 +/- 18.6 years at transplantation; male: 50%; ESRD duration: 51.6 +/- 13.0 months) between February, 2000 and July, 2003. All patients had a protocol biopsy on the day of transplant, on discharge from the hospital (35.5 +/- 13.2 days), and at 1 year after transplant. The immunosuppression included a calcineurin inhibitor, basiliximab, mycophenolate mofetil (MMF), and methylprednisolone. While 16 patients used tacrolimus (FK group: 29.4 +/- 16.6 years old), 26 patients used cyclosporine (CsA group: 31.4 +/- 20.1 years old). Protocol biopsies were graded according to the Banff 97 classification. The incidence of acute rejection episodes within 1 year was greater in the CsA (15%) than the FK group (6%). Serum creatinine at hospital discharge was similar (CsA: 1.01 +/- 0.59 mg/dL, FK: 0.97 +/- 0.49, p = .18); however creatinine at 1 year differed significantly (CyA: 1.22 +/- 0.88 mg/dL, FK: 0.92 +/- 0.39, P = .03). There was a trend toward an increase in the score of interstitial inflammations in the CsA group, while it remained constant in the FK cohort (P = .05 at 1 year between the two groups). Other pathologic scores (t, ci, ct, cv, ah) did not differ between the groups at 1 year. Although there were no differences in the demographics between the two groups, there were several trends toward better renal function in the FK group.

Antibodies, Monoclonal↗
PubMed2005

First living related kidney transplantation results in excellent outcomes for small children.

OBJECTIVE: The aim of this study was to evaluated the outcomes of living related kidney transplantation in small children. MATERIALS AND METHODS: Ten pediatric patients with body weights less than 10 kg received parental kidney transplants (five mothers and five fathers). An intra-abdominal approach was used in nine children and a retroperitoneal approach in one child. Bilateral, left, or right nephrectomy was performed in seven, two, and one child, respectively. Immunosuppression consisted of either cyclosporine (n = 7) or tacrolimus (n = 3) with either mizoribine (n = 4) or mycophenolate mofetil (MMF) (n = 5) or azathioprine (n = 1), and methylprednisolone (n = 10). Antilymphocyte globulin was used in the first series of four children; basiliximab in the most recent five children. RESULTS: All renal allografts functioned immediately after transplantation despite the mismatched size of the large renal allografts. Nine of 10 children were alive with a functional allograft at 6 to 196 months posttransplantation. One child died of intra-abdominal bleeding 5 days posttransplantation. One child has suffered chronic allograft nephropathy 11 years posttransplantation (serum creatinine 3.3 mg/dL). The remaining eight children display good renal function (serum creatinine = 0.2 to 1.43 mg/dL). Steroids were withdrawn in eight of nine children; one child continues on alternative-day therapy. One child (LD55) exceeded the mean standard height. The most recent height standard deviation (SD) scores were superior (-1.75 +/- 1.39 [-3.83 to 0.54]; P < .0082) to those at transplantation (-2.91 +/- 0.79 [-2.00 to -4.14]). CONCLUSIONS: The outcomes of living related kidney transplantation in small children were excellent despite the operative risks and the difficulty of cardiovascular and fluid management. Transplantation for small children appears to result in much better quality of life and growth than dialysis.

Antibodies, Monoclonal↗
PubMed2005

Possible link between glycolysis and apoptosis induced by sodium fluoride.

Fluoride has been used to prevent caries in the dentition, but the possible underlying mechanisms of cytotoxicity induction by this compound are still unclear. Since fluoride is known as an inhibitor of glycolytic enzymes, we investigated the possible connection between NaF-induced apoptosis and glycolysis in human promyelocytic leukemia HL-60 cells. NaF-induced apoptotic cell death is characterized by caspase activation, internucleosomal DNA fragmentation, loss of mitochondrial membrane potential, and production of apoptotic bodies. Higher activation of caspases-3 and -9, as compared with that of caspase-8, suggested the involvement of an extrinsic pathway. Utilization of glucose was nearly halted by NaF, whereas that of glutamine was rather enhanced. NaF enhanced the expression of Bad protein, but not that of Bcl-2 and Bax proteins, and reduced HIF-1alpha mRNA expression. Analysis of these data suggests a possible link between glycolysis and apoptosis.

Apoptosis↗
PubMed2004

Heterologous expression of metabotropic glutamate receptor subtype 1 in Saccharomyces cerevisiae.

The upstream region of the isocitrate lyase gene (UPR-ICL) from the n-alkane-utilizing yeast Candida tropicalis serves as a useful promoter of gene expression in the yeast Saccharomyces cerevisiae. The production of rat metabotropic glutamate receptor 1alpha (mGluR1alpha), which belongs to the G-protein-coupled receptor (GPCR) family, was tested under the control of UPR-ICL. Expression of mGluR1alpha was found in recombinant clones and enhanced by replacing the signal sequence of mGluR1alpha with the corresponding region of the alpha-factor receptor (Ste2), which is a GPCR found in S. cerevisiae. Moreover, the membrane fraction from a recombinant clone associated with Vesl-1S/Homer-1a protein binds the mGluR1alpha in rat cerebellum. These results suggest that the UPR-ICL-controlled gene expression system is useful for heterologous GPCRs in S. cerevisiae.

Animals↗
PubMed2003

Differential relationship between changes in tumour size and microcirculatory functions induced by therapy with an antivascular drug and with cytotoxic drugs. implications for the evaluation of therapeutic efficacy of AC7700 (AVE8062).

A novel combretastatin A-4 derivative, AC7700, which is now in Phase I clinical trials under a new code, AVE8062, has shown strong antitumour effects against solid tumours in rodents because of its powerful and continued stanching of the tumour blood flow (TBF). Despite the strong tumour-suppressing qualities of AC7700, it does not produce an immediate reduction in tumour size. To elucidate the reason for this effect, we investigated the relationship between the change in tumour size in Sato lung carcinoma (SLC) and circulatory functions after therapy with AC7700, doxorubicin (Adriamycin [ADR]), or mitomycin C (MMC). To measure time-lapse changes in TBF with the hydrogen clearance method at the same site after drug administration, we developed a new apparatus for keeping electrodes within a tumour. AC7700 led to the destruction of both cancer cells and tumour vessels by interrupting the supply of nutrients. Intravenous (i.v.) administration of fluorescent dyes after AC7700 treatment revealed no fluorescence within the tumour vessels, which confirmed that the tumour microcirculation had been completely blocked. In contrast, ADR led to the destruction of SLC tumour cells, but did not have the same effect on tumour vessels. Intravenously administered fluorescent dyes immediately reached the tumour, which indicated that the tumour vasculature remained intact, and the TBF remained at the preadministration level, even 6 days after ADR treatment. In addition, although the size of the tumour increased slightly for 2 days with ADR treatment, possibly because of swelling of the cancer cells, thereafter it continued to decrease. MMC had virtually no effect on SLC tumour cells, tumour size or tumour vessels. We conclude that changes in tumour size brought about by cancer chemotherapy depend not only on the sensitivity of the cancer cells to the drug in question, but also on the nature of changes in the microcirculatory functions of the tumour brought about by the therapy. When both tumour cells and the tumour vasculature are destroyed, the effectiveness of therapy can not be determined from changes in tumour size alone.

Animals↗
PubMed2002

Detection of a pineoblastoma with large central cyst in a young child.

THE PATIENT: We present the very rare case of a pineoblastoma with large central cyst in a 7-year-old boy who presented with a short history of gradually worsening headache and upward gaze palsy. IMAGING INVESTIGATIONS: On CT and MRI studies, it was seen as a peripherally calcified, irregularly shaped mass with heterogeneous low signal intensity on T1-weighted images and ringed enhancement after gadolinium administration; there was homogeneous high signal intensity on T1-weighted images. DISCUSSION: We discuss differential diagnosis for several types of cystic tumors in the pineal region, including pineoblastomas.

Brain Diseases↗
PubMed2002

Neural activity of the globus pallidus interna and its anatomical relations to the optic tract in Parkinson's disease.

BACKGROUND: To reveal landmarks for placing the globus pallidus interna (GPi) target on MR images, visual evoked potentials (VEPs) of the optic tract (OT) and neural activities of the GPi were studied retrospectively. METHODS: The dorsal and lateral border of the OT were determined by VEPs of the OT, and neural activity in the pallidal region was recorded with a semimicro-electrode in 20 patients. The Unified Parkinson's Disease Rating Scale (UPDRS) was used to assess the condition of each patient before and 6 months and 12 months after surgery. FINDINGS: The location of trajectories relative to the lateral border of the OT were 3 mm medial (-3) in 6, 2 mm medial (-2) in 7, 1 mm medial (-1) in 8, at the lateral border (0) in 6, 1 mm lateral (+1) in 5, 2 mm lateral (+2) in 6, and 3 mm lateral (+3) in 5. The mean amplitudes along trajectories -3 and -2 mm were significantly higher than the others (post-hoc, p<0.01). In dorsoventral relations, the amplitudes from 5.1 mm to 6.8 mm of the medial trajectories (-3 to 0 mm) were significantly higher than others (post-hoc, p<0.01). The lesions placed medial to the lateral border of the OT located just above the lateral border of the OT on postoperative MR images (n=12) and brought better surgical benefits of total motor score, rigidity and bradykinesia than those placed lateral to the OT (n=8). INTERPRETATION: Our data indicate that hyperactive cells of the GPi are located medial to the lateral border of the OT and at least 5.1 mm above its dorsal surface, and this corresponds to the area just above the lateral border of the OT on MR images.

Aged↗
PubMed2002

Activation of the alternative complement pathway by Agaricus blazei Murill.

Components of Agaricus blazei Murill have been demonstrated to have a wide range of immunopotentiating activities. The present study was designed to evaluate the effect of A. blazei Murill upon activation of the complement system in human serum in vitro. Additional studies were performed to determine the cytotoxic effect of complement-opsonized particles of A. blazei Murill against human tumor cells in culture. A fine particle of A. blazei Murill (ABP), prepared by mechanical disruption, was used throughout the experiments. ABP activated the human complement system via the alternative pathway in human serum. Activation of the alternative pathway was both time- and dose-dependent. When the particles from fruiting bodies of A. blazei Murill (ABP-F) were reacted with human serum, the formation of complement-opsonized ABP, iC3b-ABP-F complexes, and binding of the complexes to human peripheral blood monocytes, were demonstrated in vitro by immunofluorescence. Further, the resident human peripheral nucleated cells incubated in the presence of iC3b-ABP-F complexes inhibited the proliferation of human tumor cell line TPC-1 in vitro.

Adult↗
PubMed2001

Radiation-inducible hSNK gene is transcriptionally regulated by p53 binding homology element in human thyroid cells.

We identified a species relevant to polo-like kinase family, a human homologue of mouse serum-inducible kinase, hSNK gene, whose mRNA expression was rapidly increased in cultured human thyroid cells after X-ray irradiation. The cDNA cloning and genomic analysis of the hSNK gene showed the presence of 14 exons spanning over 6 kb of genomic DNA that encodes a 2.9-kb mRNA product. Promoter analysis demonstrated possible existence of a radiation-responsive element in the p53 binding homology element (p53RE) localized to near upstream of basal promoter of the hSNK gene. Nuclear protein extracts from HeLa and various human thyroid carcinoma cell lines bound selectively to p53RE. Anti-p53 or anti-p73 antibodies, however, failed to recognize the p53RE-protein complex formed in the presence of such nuclear extracts. These results suggest that radiation-responsive transcription factor(s) directly participates in the regulation of hSNK gene expression via the binding to p53RE in promoter region.

Base Sequence↗
PubMed2001

A pediatric patient with classical citrullinemia who underwent living-related partial liver transplantation.

Patients with inborn errors of metabolism undergo liver transplantation, but the effect of transplanting the liver of healthy carriers of these conditions has not been fully clarified. A 6-year-old girl with classical citrullinemia, who repeatedly suffered from hyperammonemia, underwent living-related liver transplantation by using a segment of the liver of her mother, who was a heterozygote carrier for classical citrullinemia. Hyperammonemia alleviated in the patient after the transplantation, thereby dramatically improving her quality of life. Although the levels of plasma and urinary citrulline remained high postoperatively, there was no marked difference in the level of plasma citrulline up to 1 month after surgery when compared with that of previously reported orthotopic liver transplantation cases with classical citrullinemia.

Child↗
PubMed2001

Cutting edge: eotaxin elicits rapid vesicular transport-mediated release of preformed IL-4 from human eosinophils.

IL-4 release is important in promoting Th2-mediated allergic and parasitic immune responses. Although human eosinophils are potential sources of IL-4, physiologic mechanisms to elicit its release have not been established. By flow cytometry and microscopy, eosinophils from normal donors uniformly contained preformed IL-4. In contrast to cytolytic IL-4 release from calcium ionophore-activated eosinophils, eotaxin and RANTES, but not IFN-gamma, elicited IL-4 release by noncytotoxic mechanisms. With a dual Ab capture and detection immunofluorescent microscopic assay, IL-4 was released at discrete cell surface sites. IL-5 enhanced eotaxin-induced IL-4 release, which was mediated by G protein-coupled CCR3 receptors, detectable as early as 5 min and maximum within 1 h. IL-4 release was not diminished by transcription or protein synthesis inhibitors, but was suppressed by brefeldin A, an inhibitor of vesicle formation. Thus, CCR3-mediated signaling can rapidly mobilize IL-4 stored preformed in human eosinophils for release by vesicular transport to contribute to immune responses.

Chemokine CCL11↗
PubMed2001

Occurrence of gangliosides in the common squid and pacific octopus among protostomia.

Acidic lipids from tissues of the common squid Todarodes pacificus and the pacific octopus Octopus vulgaris were characterized. Hepatopancreatic tissues of both animals had complex compositions of resorcinol-positive acidic lipids, many of which became reactive with cholera toxin B subunit and anti-G(M1) antibody after in situ treatment with sialidase on TLC. One of the major acidic lipids in squid tissue was isolated and examined for its structure. This acidic lipid was identified to be the ganglioside G(D1a) based upon the susceptibility to sialidases of different substrate specificity, characterization of reaction products, and electrospray ionization-mass spectrometry of the lipid. Hepatopancreatic tissues of squid and octopus also contained acidic lipids that reacted with A2B5, a monoclonal antibody specific to c-series gangliosides. Cerebral ganglia of both animals expressed resorcinol-positive acidic lipids, though their compositional patterns differed from the hepatopancreatic tissues. N-Acetylneuraminic acid was identified as the main species in lipid-bound sialic acid in both tissues. The contents of lipid-bound sialic acid in cerebral ganglia were significantly lower than those of hepatopancreatic tissues in both animals. The present study presents the first evidence for the occurrence of gangliosides in protostomia.

Animals↗
PubMed2001

XAFS studies of Tb or Eu cored dendrimer complexes with various properties of luminescence.

We studied the extended X-ray absorption fine structure (EXAFS) of Tb or Eu L3-edge of Tb(III) or Eu(III)-cored complexes of different luminescence to which different poly(benzyl ether) dendrons coordinated. The complexes were prepared via a ligand exchange reaction of dendritic carboxylic acid and acetate. Results show that (a) the Eu complex of the first generation of the 3,4- or 3,5-dibenzyloxyphenyl type had a coordination structure different from that of the 2,4-dibenzyloxyphenyl type; (b) the Eu complex of the first generation of 3,5-dinaphthylmethoxyphenyl type had a Eu-O coordination number higher than the total number of oxygen atoms in the carboxylate groups; (c) the Tb complex of the bulky fourth generation had a Th-O coordination number higher than that of the first generation. These results show that the different poly(benzyl ether) dendrons cause the different coordination, which might differently influence the luminescence properties of the complexes.

Biological Assay↗