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K Sugimura

Publications and source records attributed to K Sugimura.

At least 163 records · Page 9Linked to original sources
PubMed1993

Morphometric analysis of the sural nerve in experimental dorsal rhizotomy in rats.

To investigate the histological changes in the sural nerve by the damage to the centrally projected axon (CPA), we examined light-microscopic findings after dorsal rhizotomy. The L4-6 dorsal roots were cut unilaterally near the entry zone, with minimal laminectomy, in 27 anesthetized 8- to 10-week-old Sprague-Dawley rats. Animals were killed 1, 2, 4 and 8 weeks and 6 months after surgery, and morphometric results from the sural nerves on the side of the rhizotomy were compared with those from the unaffected side. There were no significant differences in total number, density, frequency distribution of diameters, thickness of myelin, and axonal circularity of myelinated fibers. In an analysis of teased fibers, neither demyelinated nor remyelinated fibers were found, and significant axonal degeneration was found in only 1 of 27 sural nerves on the side of the rhizotomy. These results suggest that pathological damage to the sural nerve is not the product of CPA lesions, even if the subject has dorsal root lesions at some distance from the ganglion.

Animals↗
PubMed1993

Analysis of genes within the HLA region affecting susceptibility to ulcerative colitis.

To clarify the molecular relationship between HLA loci and ulcerative colitis (UC) in Japanese patients, we performed HLA-DP genotyping by the PCR-RFLP method and studied tumor necrosis factor beta-chain genetic polymorphism by Southern hybridization, in addition to conventional serologic typing. Significant increase was observed in Bw52, DPw9 (DPB1*0901), and DR2 (DRB1*1502) in Japanese patients with UC. Linkage analysis indicated that A24-Bw52-DR2-DPw9 alleles constitute a common haplotype in Japanese UC patients. Among the patients not carrying Bw52, B13 was significantly increased and B44 was relatively increased. These Bw52, B13, and B44 alleles share the unique amino acids, serine and aspartic acid at positions 67 and 77, respectively. These positions are in the second hypervariable region of the alpha 1-domain of the HLA-B13, B44, Bw52, and B49 antigens (B49 is quite rare in the Japanese population). The inflammatory region in UC patients was found to vary depending on their HLA-B alleles. These results suggest that the HLA-B locus itself plays an important role in the susceptibility to Japanese UC.

Adult↗
PubMed1993

MR imaging of vertebral metastases: evaluation of fat saturation imaging.

OBJECTIVE: To compare conventional T1-weighted imaging (SE-T1) and chemical shift fat-saturation T1-weighted imaging (FS-T1) in the diagnosis of bone metastases. SUBJECTS: Twenty-two patients (101 vertebrae) with non-neoplastic lesions (Group 1) and 21 patients (72 vertebrae) with spinal metastases (Group 2) were evaluated with both images. RESULTS: The signal intensity (SI) distribution of Groups 1 and 2 on SE-T1 showed various patterns, and SI measurement was not significantly different between the two groups. On FS-T1, all non-neoplastic lesions had a low-intensity homogeneous appearance; however, the metastases had mixed to high SI. The SI measurement data of Group 2 was significantly (P < 0.0001) higher than that of Group 1. CONCLUSION: FS-T1 was useful in evaluating vertebral metastases.

Adult↗
PubMed1993

Quantification of occlusive and reperfused myocardial infarct size with Gd-DTPA-enhanced MR imaging.

The potential of Gd-DTPA-enhanced magnetic resonance imaging (MRI) for measuring infarct size was assessed in canine hearts. Twelve dogs underwent pre- and post-contrast MR imaging before and after recanalization. Infarct area was identified by triphenyltetrazolium chloride (TTC) staining of postmortal specimens in each case. Recanalization was complete in 10 dogs. High SI area was seen after reperfusion in nine of them; and it showed low signal intensity before reperfusion in seven of them. Two dogs were killed during reperfusion period: neither of them showed a low SI area before reperfusion. Necrotic regions were confirmed by TTC staining in seven of 12 dogs. Both the visual and quantitative assessment (n = 7) indicated that the extent of the low SI area before reperfusion was approximately the same as that of the necrotic region shown by TTC staining, while the high SI area seen after reperfusion was obviously larger than both the necrotic region and the low SI area on pre-reperfusion images. The correlation coefficient between low SI area and necrotic area was 0.98, and between high SI area and necrotic area was 0.80. These results suggest that Gd-DTPA-enhanced MRI may be useful for quantification of infarct size in occlusive myocardial infarction but it may overestimate in reperfused one.

Animals↗
PubMed1993

Case report: MR imaging of a carcinoid tumour of the liver.

A surgically confirmed solitary primary liver carcinoid tumour is described. MR imaging demonstrated a low signal intensity mass on T1-weighted images, a low signal intensity mass with small area of higher intensity on fat saturation T1-weighted images, and heterogeneous high signal intensity mass on T2-weighted images. The fibrous capsule and septa were demonstrated as low signal intensity bands on both proton- and T2-weighted images.

Carcinoid Tumor↗
PubMed1993

Polymorphism in genes for the enzyme arginine deiminase among Mycoplasma species.

The extent of restriction fragment length polymorphism in genes for the arginine deiminase enzyme among 28 species of mycoplasmas was assessed by Southern blot analysis of DNA digested with EcoRI or TaqI nuclease probed with a 725-bp internal fragment of the arginine deiminase gene from Mycoplasma arginini. The results indicated unexpected heterogeneity among species of a single genus.

Blotting, Southern↗
PubMed1993

Pelvic endometriosis: detection and diagnosis with chemical shift MR imaging.

Fat-saturation magnetic resonance (MR) imaging for detection and characterization of pelvic endometriosis was prospectively investigated in 35 women with a clinical diagnosis of the disease. Large endometrioma was diagnosed when the lesion was larger than 1 cm in diameter and hyperintense on T1- and T2-weighted images. Small endometrioma was diagnosed when a well-demarcated hyperintense lesion less than 1 cm in diameter was seen on T1-weighted or fat-saturated T1-weighted images. Surgery performed after MR imaging revealed a normal pelvis in six patients, endometriosis in 26 (33 large and 19 small endometriomas), and other cystic lesions in three. Conventional T1- and T2-weighted imaging accurately demonstrated 27 of 33 large endometriomas and two of 19 small endometriomas. Fat-saturation T1-weighted imaging in combination with conventional technique accurately demonstrated 30 of 33 large and nine of 19 small endometriomas. Diagnostic accuracy was improved with addition of fat-saturated images, so their use together with conventional images is recommended in assessment of endometriosis.

Adipose Tissue↗
PubMed1993

Characterization of renal aldosterone receptors in genetically hypertensive rats.

To investigate the aldosterone responsiveness of genetically hypertensive rats, we compared characteristics of renal cytosolic aldosterone receptors from the M strain of stroke-prone, spontaneously hypertensive rats (M-SHRSP) with normotensive Wistar-Kyoto rats (WKY). In M-SHRSP, blood pressure was elevated significantly at 6 wk of age, when their plasma aldosterone concentrations were similar to those in WKY. Decreases in urine volume and sodium excretion were also observed in M-SHRSP. At 10 wk of age, M-SHRSP plasma aldosterone concentrations became significantly higher than those in WKY. On the other hand, the concentration of renal cytosolic aldosterone receptors (type I, aldosterone specific) had already increased at 6 wk of age in M-SHRSP, with no difference in affinity, and levels remained increased thereafter. There were no significant differences in molecular weights or ionic charges of either "activated" or "non-activated" aldosterone-receptor complexes between M-SHRSP and WKY, indicating that the molecular properties were similar in both groups. These results suggest that the increased concentration of aldosterone receptors in the kidneys of M-SHRSP might increase their aldosterone responsiveness and contribute to the development of high blood pressure in these animals.

Animals↗
PubMed1993

Evaluating coronary reperfusion during acute myocardial infarction in a canine model by gadolinium-DTPA-enhanced magnetic resonance imaging.

In previous studies, magnetic resonance imaging (MRI) using contrast agents was found to be useful in distinguishing reperfused infarcts from nonreperfused infarcts. However, there have been only a few detailed studies using consecutive MR images for the assessment of myocardial reperfusion during an acute myocardial infarction and also no studies have been performed using a percutaneous transluminal coronary occlusion model (closed chest model). We induced acute myocardial infarction in dogs by occluding and then reperfusing the coronary artery with a balloon catheter. ECG-gated MR images were taken using the spin-echo technique before and after Gd-DTPA injection during both coronary artery occlusion and after reperfusion. We defined the intensity ratio (IR) as the signal intensity at the ischemic area divided by that at the nonischemic area on MR images and compared each image by the IR. Without Gd-DTPA, there was no difference between infarcted and normally perfused myocardium. Infarcted myocardium had a low signal intensity (IR = 0.68 +/- 0.14) soon after Gd-DTPA injection. This difference diminished with time. After reperfusion the infarcted myocardium had a high signal intensity (IR:1.76 +/- 0.34). We conclude that Gd-DTPA- enhanced MRI can distinguish reperfused from nonreperfused infarcts soon after Gd-DTPA administration.

Animals↗
PubMed1993

Ovarian cystic teratomas: value of chemical fat saturation magnetic resonance imaging.

Chemical fat saturation (FS) magnetic resonance imaging (MRI) for the characterization of ovarian cystic teratoma was evaluated in 19 patients with 22 lesions. The tumour was evaluated for signal intensity, location and size; the presence of chemical shift artefact, debris and fat-fluid level. Ovarian cystic teratoma was diagnosed prospectively if the mass contained fat and/or more than one type of internal pattern on (1) SE T1-, T2-, (2) SE T1-, T2-, FS T1-weighted images. A correct diagnosis was reached in 17 of 22 tumours on conventional T1- and T2-weighted images, and in 21 of 22 tumours when fat-saturation images were added. When fat-saturation images were added, four of five tumours misdiagnosed on conventional images were then correctly diagnosed. These tumours contained only small amounts of fat. Fat-saturation images could detect smaller amounts of fat than conventional images. However, one tumour did not show decreased intensity on fat saturation images, and was not diagnosed even when fat-saturation images were added. Fat saturation images have been shown to be of value in diagnosing cystic teratomas.

Adolescent↗
PubMed1993

Production of transgenic rats using pregnant and pseudopregnant rats prepared at a breeding farm.

We used pregnant and pseudopregnant Wistar-Imamichi rats, prepared at a breeding farm, for production of transgenic rats. The donor and recipient rats were transported to our facility for ova manipulation and embryo implantation, respectively. As a foreign gene, 1.9 kb of a hybrid gene was constructed with the rat renin promoter and chloramphenicol acetyltransferase-coding gene. Fertilized oocytes were collected from the donor and the foreign DNA was microinjected into the pronuclei of 539 oocytes by the method of Hochi. The manipulated oocytes were cultured to the 2-cell stage. One hundred seventeen 2-cell embryos were implanted in the recipient rats. Of 67 newborns, 55 rats grew up to be 3-week-old weanlings. Genomic DNA was extracted from the tail of these weanlings and examined by polymerase chain reaction analysis. Six transgenic rats were found to have been generated by the present method. In this way, transgenic rats were produced by an efficient combination of breeding farm utilization and laboratory research.

Animals↗
PubMed1993

The role of MR imaging in determining surgical eligibility for pelvic exenteration.

OBJECTIVE: The purpose of this study was to evaluate the role of MR imaging in the preoperative assessment of candidates for pelvic exenteration. Specifically, we sought to determine if MR imaging was reliable in selecting patients with pelvic cancer for surgical exenteration. MATERIALS AND METHODS: MR images of the pelvis were retrospectively evaluated in 23 patients with proved pelvic cancer. These images were analyzed for (1) presence and location of the primary or recurrent tumor; (2) tumor extension to the bladder, rectum, or pelvic sidewall; and (3) presence and location of lymphadenopathy. On the basis of the MR findings, we determined suitability for pelvic exenteration by using generally accepted contraindications to surgery (involvement of the pelvic sidewall muscles or metastatic lymphadenopathy). In addition, tumor involvement of the bladder or rectum was evaluated to help determine the type of exenteration indicated. Surgical and/or histologic confirmation was available in all 23 cases. RESULTS: The accuracy of MR imaging in selecting patients was 83% (19 of 23), with a positive predictive value of 56% and a negative predictive value of 100%. In evaluating tumor involvement of the pelvic sidewall and lymph nodes, the negative predictive values were 100% and 95%, respectively. Tumor extension into the pelvic sidewall was overestimated in four patients, in three of whom it was not possible to distinguish radiation changes from tumor on MR images. For assessing extension of these pelvic tumors into the bladder and rectum, MR imaging had an accuracy of 81% and 85%, respectively. CONCLUSION: MR imaging may provide an accurate means of selecting patients considered for pelvic exenteration. MR accurately determined which patients should undergo the surgery, by demonstrating absence of sidewall abnormalities or adenopathy. Radiation changes could not be reliably distinguished from tumor involvement in those patients with sidewall abnormalities, however, especially in the first 6 to 12 months after treatment.

Adult↗
PubMed1993

[Clinical study of immunotherapy with interferon alpha and gamma in metastatic renal cell carcinoma].

A clinical study was conducted to evaluate the efficacy of combination therapy with interferon (IFN) alpha and gamma in 16 patients with advanced renal cell carcinoma whom we observed between August 1986 and June 1992. Eight patients had already had stage IV disease when they were seen first and five of them underwent nephrectomy. The other eight patients developed metastases after nephrectomy. The time to occurrence of the metastasis was 4-110 months. The dosage of the regimen was IFN alpha, 3 x 10(6) U, intramuscularly for 7 consecutive days at weeks 1, 3, 5 and 7 and IFN gamma, 6 x 10(6) JRU by intravenous drip on days 2, 4 and 6 of weeks 2, 4, 6 and 8. At and after week 9, the combined use of IFN alpha, 3 x 10(6) U, and IFN gamma, 1-6 x 10(6) JRU, was continued at least on a once-a-week basis as maintenance therapy as long as possible. The effect was evaluated as PR in 2 patients, MR in 2, NC in 3 and PD in 9. The response rate was 12.5% and the efficacy rate including MR was 25%. The time to onset of the effect was 8-24 weeks. Of the four patients showing MR or better responses, three had stage IV disease and one had metastatic disease after the operation. The duration of effect was 2-8 months. Side effects were fever, general malaise, anorexia, leukocytopenia and impaired liver function, and were noted frequently.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Effects of long- and medium-chain triglycerides on amino acid uptake in rat intestinal brush border membrane vesicles.

1. Uptake of L-leucine, L-phenylalanine, L-proline and L-lysine into brush border membrane vesicles from rats fed either a medium-chain triglyceride (MCT) or a long-chain triglyceride (LCT) diet was studied under conditions of the presence of absence of a Na+ gradient. 2. From the results of initial rate, Na(+)-dependent transport in LCT feeding were lower than in feeding MCT. The Na(+)-independent transport did not vary in either group except for L-lysine uptake. 3. For L-leucine, L-phenylalanine and L-proline in Na+ dependence, kinetic analysis revealed 4-6-fold smaller Vmax values in LCT group than in MCT group. L-Lysine in Na(+)-independent transport was 10-fold lower in LCT group than in MCT group. The Km values were not affected by feeding the LCT or MCT diet. 4. It is clear that amino acid transport is regulated by different types of dietary fat. We consider that the alteration of transport activity is attributable to the changes in number of membrane-bound transport carriers but not to their affinity.

Amino Acids↗
PubMed1993

Dependence of angiotensin production in transgenic mice carrying either the human renin or human angiotensinogen genes on species-specific kinetics of the renin-angiotensin system.

In order to study the functional role of the renin-angiotensin system in the control of blood pressure, projects were initiated using transgenic mice carrying either the human renin gene or the human angiotensinogen gene. To extend the usefulness of the transgenic model system of hypertension research, a two-tiered strategy for generation of transgenic mice with high blood pressure has been developed. This unique system allows the establishment of transgenic lines with a strict species specificity of the renin-angiotensinogen reaction exhibited by transgene products that are regulated in a tissue specific manner. In this report, the strategy concerning the "two-tiered method" is presented and evidence is provided the overproduction of angiotensin occurs only in the combined reaction with human renin and human angiotensinogen expressed in transgenic mice.

Amino Acid Sequence↗
PubMed1992

Magnetic resonance imaging of Krukenberg tumor from gastric cancer.

The magnetic resonance imaging (MRI) findings in a 42-year-old woman with a giant Krukenberg tumor from gastric cancer are reported. The macroscopic features of the Krukenberg tumor resulting from gastric cancer were clearly and precisely shown on MRI. Furthermore, MRI was more useful than ultrasonography or CT for determining the origin and further tissue characterization of the tumor. These findings suggest that MRI can be especially useful in the evaluation of giant ovarian tumors as in the present case.

Adenocarcinoma, Mucinous↗