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Biomedical subjects

S Kawamoto

Publications and source records attributed to S Kawamoto.

At least 109 records · Page 6Linked to original sources
PubMed1999

CT of epithelial ovarian tumors.

Ovarian cancer is the second most common gynecologic malignancy in the United States and causes more deaths than any other cancer of the female reproductive system. Approximately two-thirds of patients have tumors that have spread beyond the pelvis at the time of diagnosis. Ovarian tumors arise from the surface epithelium or mesothelium, germ cells, or the gonadal stroma. Epithelial ovarian tumors include serous, mucinous, endometrioid, clear cell, and undifferentiated tumors. In general, the likelihood of malignancy increases with increasing solid-tissue elements and thicker septa. Surgery is central to the management of ovarian cancer. At the initial exploratory laparotomy, surgicopathologic staging and debulking of the tumor are undertaken. Patients with advanced cancer frequently undergo second-look surgery after chemotherapy to detect any residual disease. CT can provide staging information for preoperative planning and determination of surgical resectability, demonstrate tumor response to therapy, and allow detection of persistent or recurrent disease. However, a major limitation of CT is the lack of sensitivity for detection of small tumor implants, especially on the small intestine or mesentery. Dedicated CT of the pelvis is best performed with spiral CT. Ovarian carcinoma can spread by means of intraperitoneal implantation, lymphatic invasion, and hematogenous dissemination.

Adenocarcinoma, Clear Cell↗
PubMed1999

Mesh-and-glue technique to prevent leakage of cerebrospinal fluid after implantation of expanded polytetrafluoroethylene dura substitute--technical note.

Expanded polytetrafluoroethylene (ePTFE) can be used as a dura substitute but is associated with leakage of cerebrospinal fluid (CSF) through the suture line. Fibrin glue alone may not prevent this problem. This new method for sealing the suture line in ePTFE membrane uses an absorbable polyglycoic acid mesh soaked with fibrinogen fluid placed on the suture line. Thrombin fluid is then slowly applied to the wet mesh, forming a large fibrin membrane reinforced by the mesh over the suture line. Only one of 33 patients in whom this technique was used had CSF leakage, whereas 12 of 59 patients in whom a dural defect was closed with ePTFE alone showed postoperative subcutaneous CSF collection (p < 0.05). Our clinical experiences clearly show the efficacy of the mesh-and-glue technique to prevent CSF leakage after artificial dural substitution. Mesh and glue can provide an adequate repair for small dural defect. The mesh-and-glue technique may also be used for arachnoid sealing in spinal surgery.

Biodegradation, Environmental↗
PubMed1999

Primary sclerosing cholangitis: MR imaging findings with pathologic correlation.

OBJECTIVE: The purpose of this study was to evaluate MR imaging findings of primary sclerosing cholangitis, to compare them with histopathologic findings, and to determine if these findings help differentiate primary sclerosing cholangitis from other disorders that result in end-stage liver disease. MATERIALS AND METHODS: MR imaging was performed in 40 patients (27 men, 13 women; age range, 13-72 years; mean, 47 years) with primary sclerosing cholangitis over a 9-year period. In 16 patients who underwent orthotopic hepatic transplantation and in seven patients who underwent needle biopsy, correlation was made between MR imaging and pathologic findings. RESULTS: Focal signal changes in the liver parenchyma were seen on T2-weighted images as peripheral wedge-shaped zones of increased signal intensity in 29 patients (72%), as a reticular pattern in 15 patients (38%), and as periportal edema in 16 patients (40%). Lobar atrophy involved the right lobe in three patients (8%) and the left lobe in 11 patients (28%); hypertrophy of the caudate lobe was seen in nine patients (23%). Features of portal hypertension were seen in 14 patients (35%). Histologic assessment showed zones of segmental atrophy and scarring on the periphery of the liver. CONCLUSION: Peripheral wedge-shaped areas of high T2 signal intensity and dilatation of bile ducts are characteristic MR features of primary sclerosing cholangitis. Pathologic correlation suggests that these features may be related to underlying perfusion changes and bile duct inflammation in patients with primary sclerosing cholangitis.

Adolescent↗
PubMed1999

[New quinolone versus vancomycin/tobramycin for intestinal sterilization in patients who undergo allogeneic bone marrow transplantation].

The frequency of infection in recipients of allogeneic bone marrow transplants (BMT) who received oral new quinolones (NQ) was compared with that in BMT recipients who were given oral vancomycin/tobramycin (V/T). Between 1984 and 1997, our hospital treated 79 patients with V/T and 90 patients with NQ. Number of febrile days, duration of intravenous antibiotics administration, and frequency of documented infections were statistically the same for both groups. However, the frequency of grampositive bacterial infections, especially staphylococcal infections, was slightly higher in patients receiving NQ than in patients receiving V/T (p = 0.12). Of the patients who received NQ, those who underwent unrelated donor BMT procedures were generally febrile for slightly longer periods than those who underwent related donor BMT procedures (p = 0.10). These results suggest that oral NQ is as effective as oral V/T for the prevention of serious gramnegative bacterial infections in patients who undergo BMTs.

Administration, Oral↗
PubMed1999

[Analysis of risk factor for patients and renal survival in anti-myeloperoxidase antibody (MPO-ANCA) associated glomerulonephritis].

We investigated the clinical and histological features and the outcome of 15 patients with antimyeloperoxidase antibody(MPO-ANCA) associated glomerulonephritis. The patients were divided into two groups on the basis of renal functional outcome: Group 1 consisted of 7 patients where an initial deterioration in renal function was improved at the final observation. Group 2 included 8 patients who had a progressive deterioration in renal function leading to end stage renal disease or chronic dialysis, or who died. We compared the clinical and histological features at renal biopsy and the outcome following steroid therapy between the two groups. Group 1 patients had significantly lower levels of serum creatinine and UN, and higher values for creatinine clearance (Ccr) than Group 2 patients(1.9 +/- 0.6 vs. 6.7 +/- 4.7 mg/dl, 29 +/- 7 vs. 73 +/- 39 mg/dl, 30 +/- 9 vs. 10 +/- 5 ml/min, p < 0.05, respectively). Histologically, Group 1 patients had a significantly lower percentage of crescent formation than Group 2 patients(41 +/- 6 vs. 74 +/- 4%, p < 0.05), whereas there was no significant difference in tubulo interstitial damage between the 2 groups. Moreover, in 4 patients of Group 1 where a second renal biopsy was performed two months after steroid therapy, marked attenuation in acute tubulo-interstitial changes was observed in association with a rapid improvement of renal function. These results suggest that diffuse tubulo-interstitial inflammatory changes despite a relatively low frequency of cellular crescent formation may be a prognostically important histological feature showing a good response to steroid therapy.

Adolescent↗
PubMed1999

[Eosinophilic pneumonia without eosinophilia in BALF or peripheral blood and diagnosed by open lung biopsy].

A 47-year-old woman was referred to our hospital because of cough and an abnormal shadow in the left lung field. The infiltrate reduced without therapy and another infiltrate appeared in the right lung field. Bronchiolitis obliterans organizing pneumonia was clinically suspected due to the absence of signs of eosinophilia in peripheral blood and bronchoalveolar lavage fluid (BALF). Open lung biopsy specimens disclosed alveolitis with mononuclear cell infiltration and organization within the air spaces of bronchioli and alveolar ducts. The observation of pronounced eosinophil infiltration in the alveolar spaces of some specimens yielded a diagnosis of eosinophilic pneumonia. After steroid therapy, the abnormal shadows disappeared. BALF lymphocyte surface marker analysis detected no decrease in the CD4/CD8 ratio; activated CD4 and CD8 lymphocytes were notably higher than the corresponding levels in peripheral blood. IL-5, IL-3, and GM-CSF values in BALF were not significantly elevated. This was a case of borderline eosinophilic pneumonia that was difficult to diagnose on the basis of clinical parameters alone.

Anti-Inflammatory Agents↗
PubMed1998

Cloning and developmental expression of the murine homolog of doublecortin.

While analyzing active genes in neonatal mouse hippocampus by quantitative 3'-cDNA collection, we identified a highly conserved murine homolog of doublecortin, the causative gene of X-linked lissencephaly (XLIS) and subcortical laminar heterotopia (SCLH) syndrome. The m-doublecortin cDNA contains nearly 8 kb 3' UTR homologous to hs-doublecortin and it was mapped to the X chromosome. The expression of m-doublecortin is limited to the developing CNS, especially the cortical plate, supporting that XLIS/SCLH syndrome is associated with an arrest of neuronal migration in the cerebral cortex. The m-doublecortin mRNA was absent in the ventricular zone where neuronal precursors proliferate, and interestingly it was found in various brain structures that are not typically affected in patients with this syndrome.

Amino Acid Sequence↗
PubMed1998

A novel sporulation-control gene (spo0M) of Bacillus subtilis with a sigmaH-regulated promoter.

A novel sporulation-control gene (spo0M) of Bacillus subtilis was cloned, sequenced and analyzed. The spo0M gene is located at the end of large tRNA gene clusters including rrnD and codes for a 257-amino-acid protein with a calculated size of 29.6kDa. The protein Spo0M has a strong negative charge (calculated pI=4.3) and shows no significant sequence homology to any known proteins. Gene disruption experiments revealed that spo0M is not essential for cell viability, but its disruption results in considerable impairments (decreasing by 20- to 100-fold) in sporulation. The morphological stage blocked in sporulation was stage 0 as observed by electron microscopy, and expression analysis using spo0Aps-bgaB fusion revealed an impaired gene expression of spo0A in the spo0M mutant. In contrast, spo0M disruption had no effect on antibiotic productivity. Propagation of the spo0M gene in wild-type cells using a high-copy-number plasmid also impaired sporulation, indicating that overproduction of Spo0M exerts certain negative effects on sporulation. spo0M gene expression is controlled by sigmaH, as demonstrated: (1) by monitoring expression of a bgaB transcriptional fusion integrated into the amyE locus on the chromosome of the wild-type or spo0H mutant cells, and (2) by in-vitro transcription of spo0M gene with EsigmaH.

Amino Acid Sequence↗
PubMed1998

A novel SCG10-related gene uniquely expressed in the nervous system.

We have isolated a novel cDNA (HiAT3: hippocampus abundant transcript 3) in the course of screening for genes that are preferentially expressed in neonatal mouse hippocampus using random 3'-directed cDNA sequencing approach. It encodes a 180-aa protein that has high similarity to SCG10, a neuron-specific negative regulator of microtubule dynamics during neurite outgrowth. The expression of HiAT3 is limited to neurons and peaks about 1 week after birth. The identification of HiAT3 suggests that there may be an elaborate destabilizing regulation for microtubule dynamics in neurons in addition to the stabilizing effect of multiple microtubule-associated proteins (MAPs).

Amino Acid Sequence↗
PubMed1998

Induction of entry into the stationary growth phase in Pseudomonas aeruginosa by N-acylhomoserine lactone.

N-acylhomoserine lactone (AHSL, autoinducer) is capable of regulating a set of genes by sensing cell density and developing an intercellular communication in Pseudomonas aeruginosa. Addition of AHSL in the exponential growth phase, regardless of cell density, induces a repression of cell growth of P. aeruginosa, an expression of stationary phase specific factor sigma 8 in vivo and a morphological change into smaller spherical shape indistinguishable from that in the stationary phase. It is demonstrated that AHSL can trigger an entry of bacteria into stationary phase as a growth controlling signal.

4-Butyrolactone↗
PubMed1998

Transcriptional regulation of the human nonmuscle myosin II heavy chain-A gene. Identification of three clustered cis-elements in intron-1 which modulate transcription in a cell type- and differentiation state-dependent manner.

In an attempt to identify cis-acting elements for transcriptional regulation of the human nonmuscle myosin II heavy chain (MHC)-A gene, the region extending 20 kilobases (kb) upstream and 40 kb downstream from the transcription start sites, which includes the entire 37-kb intron 1, was examined. Using transient transfection analysis of luciferase reporter constructs, a 100-base pair (bp) region (N2d) in intron 1, located 23 kb downstream from the transcriptional start sites, has been found to activate transcription in a cell type- and differentiation state-dependent manner. Maximum activity (approximately 20-fold) is seen in NIH 3T3 fibroblasts and intermediate activity (7-fold) in proliferating and undifferentiated C2C12 myoblasts. In contrast, this region is almost inactive in terminally differentiated C2C12 myotubes, in which endogenous nonmuscle MHC-A expression is down-regulated. Gel mobility shift assays and methylation interference analyses were performed using NIH 3T3 nuclear extracts to determine the protein-binding elements for transcription factors. Three binding elements have been identified within the N2d region. Antibody-supershift experiments, as well as competition experiments using consensus binding sequences for specific transcription factors, revealed that the most 5'-element, C (GGGAGGGGCC) is recognized specifically and exclusively by Sp1 and Sp3 transcriptional factors. Element C is immediately followed by a novel element, A (GTGACCC). A third element, F (GTGTCAGGTG), which contains an E-box, is located 50 bp 3' to element A. Element F can be recognized partially by upstream stimulatory factors, USF1 and/or USF2. Transfection studies with luciferase reporter constructs which include mutations in all three elements in various combinations demonstrate that the A and C binding factors cooperatively activate transcriptional activity in NIH 3T3 cells. The F binding factor shows an additive effect on transcription.

3T3 Cells↗
PubMed1998

Additional techniques adopted for major vascular anastomoses during orthotopic liver transplantation.

Of 372 patients who underwent liver transplants between January 1985 and March 1995, 7 required variations in vascular anastomoses due to discrepancies in the size-match of the donor and recipient vessels, the presence of a thrombosed hepatic artery or portal vein, or complete absence of the portal vein. The techniques described herein enabled us to perform successful transplantation in all patients. Although rethrombosis of the portal vein developed in one patient after a third transplant, this patient remains clinically well. The use of an operating microscope and the harvesting of an extended length of donor superior mesenteric vein or vascular grafts of the donor iliac or saphenous vessels, for potentially difficult transplants, are invaluable techniques.

Adult↗
PubMed1998

Melittin, a metabostatic peptide inhibiting Gs activity.

Some basic amphiphilic peptides are known to directly stimulate heterotrimeric GTP-binding proteins (G proteins). Mastoparan and melittin are known to stimulate Gi activities. Here, we found melittin inhibited guanine nucleotide-dependent adenylyl cyclase activity in synaptic membranes of the rat cerebral cortex. However, in insect cell membranes overexpressing specific heterotrimeric G proteins using baculovirus expression system, melittin showed unique effects different from those by mastoparan on G protein activities. This peptide markedly stimulated Gi1 and G11 activities, whereas it did inhibit Gs activities. Kinetic studies revealed that the inhibition of Gs activity by melittin is attributed to the inhibition of GDP release in exchange for added guanine nucleotides (or the association of guanine nucleotides). Thus, melittin may be the first metabostatic peptide inhibiting G protein (Gs) activity, and both mechanisms through the stimulation of Gi and inhibition of Gs might be involved in the melittin-induced inhibition of adenylyl cyclase.

Adenylyl Cyclases↗
PubMed1998

Three-dimensional CT angiography of the thorax: clinical applications.

Spiral CT with three-dimensional (3D) display can provide a rapid noninvasive examination of the vascular system and has been shown to have a wide range of clinical applications in the thorax, including imaging of the aorta, pulmonary vasculature, and venous abnormalities. Three-dimensional images can provide views of the imaging volume from innumerable viewing angles for both the radiologist and referring clinician, and potentially obviate invasive procedures such as angiography. In this article, we will review many of these applications of spiral CT angiography with 3D displays. Emphasis is placed on study design, protocol selection, and display of pathology.

Angiography↗
PubMed1998

Altered antigenicity of M-177, a 177-kDa allergen from the house dust mite Dermatophagoides farinae, in stored extract.

BACKGROUND: A high molecular weight allergen, M-177 (177 kDa) was isolated from Dermatophagoides farinae using a specific antibody raised to an allergenic clone Mag 3, which was obtained by immunoscreening a mite cDNA library. The potent IgE reactivity of M-177 is comparable with that of Der f 2. OBJECTIVE: The aim of this study was to analyse the molecular characteristics and the allergenic activity of M-177 in stored mite extracts. METHODS: Antigens were analysed by immunoblotting and enzyme-linked immunosorbent assay (ELISA; inhibition). Allergenic activity was estimated from IgE reactivity and the results of a histamine release assay. RESULTS: The intact M-177 molecule was present in high concentrations in fresh extract obtained from purified mite bodies, but was only detected in small amounts in stored extracts. Instead of the intact molecule, anti-Mag 3 antibody detected various cross-reactive antigens in the stored preparations. Studies of a stored liquid extract showed that these cross-reactive antigens were produced by the degradation of M-177, and that this change was suppressed by the addition of protease inhibitors. Interestingly, the allergenic activity of the fragmented M-177 (sM-177) isolated from the stored extracts was greater than that of the intact antigen. Specific IgE reacted with sM-177 in 84.2% of 38 sera samples from patients allergic to mites, while 65.8% were positive for M-177-specific IgE. Similarly, the histamine release test showed that sM-177 had greater allergenic activity in vitro. ELISA inhibition indicated that the increased allergenic activity resulted from alteration of the antigenicity with the degradation of M-177. CONCLUSIONS: M-177 is a protease-sensitive allergen. The breakdown products of M-177 provoked higher allergenic activity than the intact allergen.

Animals↗
PubMed1998

Intranasal administration of human immunodeficiency virus type-1 (HIV-1) DNA vaccine with interleukin-2 expression plasmid enhances cell-mediated immunity against HIV-1.

DNA vaccine against human immunodeficiency virus type-1 (HIV-1) can induce substantial levels of HIV-1-specific humoral and cell-mediated immunity. To develop more potent HIV-1 DNA vaccine formulations, we used a murine model to explore the immunomodulatory effects of an interleukin-2 (IL-2) expression plasmid on an HIV-1 DNA vaccine following intranasal administration of the combination. When the vaccine and expression plasmid were incorporated into cationic liposomes and administered to mice, the HIV-1-specific delayed-type hypersensitivity response and cytotoxic T lymphocyte activity were significantly increased. Restimulated immune lymphoid cells showed enhanced production of both IL-2 and interferon-gamma and reduced secretion of IL-4. The level of total antibody to HIV-1 antigen was not greatly changed by coadministration of the DNA vaccine and IL-2 expression plasmid. An analysis of serum HIV-1-specific IgG subclasses showed a significant drop in the IgG1/IgG2a ratio in the group that received the plasmid-vaccine combination. These results demonstrate that the IL-2 expression plasmid strongly enhances the HIV-1-specific immune response via activation of T helper type-1 cells.

Adjuvants, Immunologic↗