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Biomedical subjects

K Sugimura

Publications and source records attributed to K Sugimura.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

CT assessment of postirradiation changes in the rectum and perirectal region.

Postirradiation changes in the rectum and perirectal tissue were assessed by computed tomography (CT) in 55 patients (total of 60 examinations) and correlated with radiation dose and time elapsed. Thickening of the perirectal fascia, increased density of the perirectal fat, and swelling of the rectal wall occurred in 48, 60, and 8% of patients, respectively, regardless of radiation dose within 30 Gy. However, widening of the presacral space was seen in 8% of patients receiving a rectal dose of less than 45 Gy, a percentage that increased to 16% for patients receiving 45 Gy or more. Thickening of the perirectal fascia, increased density of the perirectal fat, widening of the presacral space, and muscular changes were seen regardless of the time from the start of therapy. CT does not appear to be reliable enough in detecting residual or recurrent tumor in the rectum. However, knowledge of the CT features of postirradiation changes is helpful for diagnosis in patients with pelvic malignancies.

Adult↗
PubMedDate not supplied

Colorectal carcinoma: evaluation with ultrafast CT.

We investigated the value of ultrafast computed tomography for the preoperative assessment of colorectal carcinoma. Ultrafast CT demonstrated the primary tumor in 25 (89%) of 28 patients. Local tumor extension was detected with a sensitivity of 90%, a specificity of 78%, and an overall accuracy of 82%. Invasion into adjacent organs was detected with a sensitivity of 80%, a specificity of 91%, and an overall accuracy of 89%. Diagnoses of pericolic or perirectal lymph node metastasis were true-positive in ten, true-negative in 12, false-positive in one, and false-negative in two and those for distant lymph node metastasis were true-positive in four, true-negative in 24, and false-negative in one. Ultrafast CT may be more useful than conventional CT in evaluating local extension and pericolic or perirectal lymph node metastases because it avoids motion artifact.

Adult↗
PubMedDate not supplied

Malignant vaginal melanoma. Usefulness of fat-saturation MRI.

We present a case of malignant vaginal melanoma studied by magnetic resonance imaging (MRI). A dark irregular mass was noted in the anterior wall of the vaginal cavity on physical examination. On fat-saturated T1-weighted MRI, the vaginal lesion was demonstrated more clearly than by conventional T1- and T2-weighted images. Furthermore, the fat-saturated image detected the bladder metastasis from the vaginal lesion.

Aged↗
PubMedDate not supplied

Evaluation of biological responses to polymeric biomaterials by RT-PCR analysis III: study of HSP 70, 90 and 47 mRNA expression.

In this study, in order to analyze how cells recognize biomaterials, mRNA was evaluated on various substrates as shown in the attached HeLa S3 cells. The expressed Heat-Shock Protein (HSP) 70A, 70B, 90 and 47 mRNA were isolated and detected using the RT-PCR method. As a result, 70B, 90 and 47 mRNA expressions varied with differences in the hydrophilicity hydrophobicity of the substrates. HSP mRNAs outcome was induced significantly in the HeLa S3 cells that had adhered onto the hydrophilic surfaces. On the other hand, in the cells that had adhered to the hydrophobic surfaces, HSP mRNAs expressions were low. In the non-adhered HeLa S3 cells the tendency found in HSP 70B and HSP 47 mRNA's expressions was the same as that found in adhered cells, while there were no significant differences in the HSP 90 mRNA expression among either of the samples. We have concluded that HSP mRNAs expression is an important marker in the study of cell-polymer interactions.

Biocompatible Materials↗
PubMedDate not supplied

Usefulness of Gd-DTPA contrast-enhanced dynamic MRI and serum determination of LDH and its isozymes in the differential diagnosis of leiomyosarcoma from degenerated leiomyoma of the uterus.

This prospective study was conducted to identify the magnetic resonance imaging (MRI) characteristics of uterine leiomyosarcoma (LMS) and to evaluate the diagnostic accuracy of conventional MRI and dynamic MRI with or without serum measurement of lactate dehydrogenase (LDH) levels. Two hundred ninety-eight consecutive patients were entered in this study. In eligible 227 patients, ten patients with LMS and 130 patients with uterine degenerated leiomyoma (DLM) were included for the present study. Precontrast T1, T2 weighted images were obtained in all patients. Serum LDH and its isozymes were also measured. Dynamic MRI by Gd-DTPA was obtained in all patients with LMS and 32 patients with DLM in whom elevated LDH levels were observed. The contrast enhancement at 60 s after administration of Gd-DTPA was detected in all LMS, but absent in 28 of 32 DLM patients. Concerning serum LDH isozymes, both total LDH and LDH isozyme type 3 were elevated in all 10 patients with LMS. The sensitivity for determination of LMS with MRI alone, dynamic MRI alone, and combined use of MRI (including dynamic MRI) and serum LDH levels was 100% in each group. The specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 93.1%, 52.6%, 100%, and 93.1% with MRI alone, and 93.8%, 83.3%, 100%, and 95.2% with dynamic MRI alone, and 100%, 100%, 100%, 100% with combined use of LDH and MRI, respectively. In conclusion, the combined use of dynamic MRI and serum measurement of LDH (isozymes) seems to be useful in making a differentiated diagnosis of LMS from DLM before treatment.

Biomarkers, Tumor↗
PubMedDate not supplied

Improved reliability of repetitive RF interstitial heating in combination with brachytherapy: the effective use of water.

Interstitial heating and brachytherapy are often combined in the treatment of cancer. In such instances, a needle-type internal electrode is inserted into the RALS (remotely controlled afterloading system) catheter instead of a radioactive source. A problem with this approach, however, is that the temperature distribution pattern generated by the inserted electrode varies at any given target region in each heating treatment, which makes it difficult to accurately replicate the heating treatment protocol. This variation is suspected to be caused by non-uniformity in the small gap between the internal electrode and the inner surface of the surrounding catheter, causing electric currents to flow between the electrode and the heating material, which differs from procedure to procedure. To solve this problem, the gap was filled with water of high permittivity, and the temperature distribution was investigated using phantoms. With this method, a stable and reproducible temperature rise distribution was obtained in the phantom experiment.

Brachytherapy↗
PubMedDate not supplied

Production and activation of hepatocyte growth factor in acute renal failure.

Hepatocyte growth factor (HGF) facilitates the regeneration of injured kidney in acute renal failure (ARF). HGF is produced as a single-chain precursor by cells of mesenchymal origin and is converted to a biologically active, heterodimeric molecule by proteolytic processing. We studied HGF mRNA and protein levels in systemic organs of glycerol-induced ARF rats, a model of crush syndrome. HGF protein concentration of tissue homogenate was measured by ELISA. Both mRNA and protein levels were increased in liver and spleen at 24 hours after the glycerol injection whereas HGF protein level was decreased in the injured kidney. Expression of HGF receptor/c-met mRNA was elevated only in the kidney. These results suggest that HGF supplied in an endocrine manner may play an important role in the regenerating process following ARF. Next, we measured serum HGF concentration by ELISA in 8 ARF patients caused by crush syndrome and the molecular size of serum HGF was determined by immunoblotting. Although serum HGF levels elevated in all patients, the HGF levels did not associate with their prognoses. While a single-chain molecule was predominantly observed in sera from chronic renal failure patients and healthy subjects, the majority of serum HGF was a heterodimeric form in 7 ARF patients. In one patient who developed disseminated intravascular coagulation syndrome and had a poor prognosis, a single-chain molecule was predominant although the serum HGF concentration was equivalent. These data suggest that the activity of proteolytic processing may be also an important factor for the expression of the biological function of HGF.

Acute Kidney Injury↗
PubMedDate not supplied

Amyloid deposition in seminal vesicles mimicking tumor invasion from bladder cancer: MR findings.

Amyloid deposition in the seminal vesicle is a not unusual finding at autopsy. A case of MR findings of amyloid deposition in the seminal vesicles with urinary bladder cancer is reported. Invasion of the seminal vesicle could not be excluded on T2-weighted imaging, but gadopentetate dimeglumine may be useful in its ability to differentiate amyloid deposition from seminal vesicle tumor invasion.

Aged↗
PubMedDate not supplied

MR detection of degenerating uterine leiomyomas.

OBJECTIVE: Gonadotropin-releasing hormone (GnRH) analogues have been advocated for the conservative management of uterine leiomyoma. These drugs induce a hypoestrogenic state and affect undegenerated myoma cells. Therefore, we evaluated the usefulness of MRI for distinguishing undegenerated and degenerated leiomyomas. MATERIALS AND METHODS: Twenty lesions were studied in 16 patients with surgically resected leiomyoma. A 1.5 T unit was used to obtain T1- and T2-weighted images and Gd-DTPA-enhanced T1-weighted images. Signal intensity maps were made for each pulse sequence, and detailed histological maps were also made in the same plane as the MR images. Then the MR maps were compared with the histological maps of the resected specimens. RESULTS: Interstitial edema, the initial sign of degeneration, was detected as a high signal intensity region on T2-weighted images and showed enhancement with Gd-DTPA. Hyaline degeneration could not be distinguished from smooth muscle whorls on T1- and T2-weighted images. However, undegenerated leiomyoma could be distinguished from hyaline degeneration, because the former was slightly enhanced by Gd-DTPA but the latter was not. CONCLUSION: These findings showed that Gd-DTPA-enhanced MRI can distinguish undegenerated leiomyomas from degenerated leiomyomas and suggest that MRI may be useful for predicting the response of this tumor to GnRH analogue therapy.

Adult↗
PubMedDate not supplied

MRI in predicting the response of ovarian endometriomas to hormone therapy.

OBJECTIVE: Our goal was to investigate the usefulness of MRI in predicting the response of endometriomas to hormone therapy. MATERIALS AND METHODS: MRI and laparoscopy at the onset of treatment and follow-up MRI after 6 months of hormone therapy were performed in 21 patients with 49 endometriomas. T1- and T2-weighted images were obtained with a 1.5 T apparatus using a body coil. The lesions were divided into a responder group and a nonresponder group according to whether the lesion size decreased by > or = 50% or not. RESULTS: With MRI, shading was seen in 25 of 27 lesions (93%) from the nonresponder group, but in only 6 of 22 (27%) from the responder group. Low SI rim was seen in 59% of the responders and 89% of the nonresponders. Multiplicity in 68% of the responders and in 85% of the nonresponders and irregularity in 41% of the responders and in 78% of the nonresponders were shown. Multiple logistic analysis revealed shading was the most important factor in prediction of the response to hormone therapy. CONCLUSION: Shading was an important sign in evaluating the response of endometriomas to hormone therapy. MRI may assist in selecting the appropriate therapy for endometriomas.

Adult↗
PubMedDate not supplied

Two-dimensional time-of-flight MR venography: assessment with detection of chronic deep venous thrombosis in combination with magnetization transfer contrast.

PURPOSE: The purpose of this study was to determine the optimum imaging parameters for 2D-TOF MR venography (MRV) of the pelvis and suprapopliteal deep venous system in combination with off-resonance magnetization transfer constant (MTC) and to evaluate the use of MRV in patients suspected of having chronic deep venous thrombosis (DVT) by comparing its accuracy with that of conventional venography (CV). METHOD: MRV was performed in 10 normal subjects to determine the optimum imaging parameters. Systematically varied scan parameters included flip angles ranging from 30 to 120 degrees by 10 degrees increments. Best TR was calculated by using the theoretical relation between the optimal TR and flow velocity. We then evaluated the use of MRV in 26 patients (total 52 deep venous systems) suspected of having chronic DVT by comparing its accuracy in evaluating the intrapelvic and suprapopliteal deep venous system with that of CV. RESULTS: The optimal imaging parameters for intrapelvic and suprapopliteal venous system MRV were found to be a flip angle of 60 degrees and a pulse sequence of 35/6.9 (TR ms/TE ms) combined with an off-resonance MTC technique. All the main veins of the intrapelvic and suprapopliteal venous systems were clearly demonstrated in each subject. The sensitivity of MRV was 100% and its specificity was 100% for diagnosis of pelvic venous stenosis. The collateral vessels were demonstrated with MRV in all patients. CONCLUSION: 2D-TOF off-resonance MTC MRV of the pelvis and the suprapopliteal lower extremities is suitable for evaluation of intrapelvic branches and suprapopliteal deep venous system and chronic DVT.

Chronic Disease↗
PubMedDate not supplied

Inflammatory pseudotumor of the bladder: MR findings.

We report a case of inflammatory pseudotumor of the bladder in a 29-year-old woman with gross hematuria that was considered as embryonal rhabdomyosarcoma on biopsy specimens. MRI demonstrated a polypoid tumor covered by clot, which disrupted the low intensity of the bladder wall. The lesion exhibited an intermediate signal on T1-weighted images and prominent high intensity on T2-weighted images and was markedly enhanced. A pathologic study revealed a tumor of myxoid stroma invading into the deep muscular layer of the bladder wall.

Adult↗
PubMedDate not supplied

Gut-associated lymphoid tissues in ulcerative colitis.

BACKGROUND: The main feature of ulcerative colitis (UC) is numerous infiltration of not only lymphocytes and plasma cells but also neutrophils and macrophages, indicating acute on chronic inflammation. Recent studies show that apoptosis may play an important role in the regulation of gut-associated lymphoid tissues (GALT). Therefore, this study was performed to clarify apoptosis of lymphocytes in the peripheral blood and colonic mucosa of UC. METHODS: Three-color flow cytometry was used to clarify apoptosis of lymphocytes in the peripheral blood and colonic mucosa of patients with active and inactive UC compared with controls using fluorescence-labeled monoclonal and polyclonal antibodies such as Fas (CD95), Fas ligand, CD4, CD8, CD45RO, etc. RESULTS: The ratio of Fas and CD45RO double-positive cells in the peripheral blood of UC patients was significantly increased in CD8 but not CD4 T cells when compared with controls. The ratio of Fas-positive and CD45RO-negative cells was significantly increased in CD4 and CD8 T cells of UC when compared with controls. There was unbalanced immunoregulation between CD4 and CD8 T cells in the colonic mucosa of UC probably due to apoptosis through Fas-Fas ligand system. CONCLUSIONS: Abnormal GALT system was found in UC probably due to dysregulation of T cells through Fas-Fas ligand system.

Antigens, CD↗
PubMedDate not supplied

CT and MR findings of splenic angiosarcoma.

A surgically confirmed primary splenic angiosarcoma is described. Although angiography showed most of the characteristic findings of the present patient, MR imaging provided a useful information as a supplemental tool. The tumor demonstrated low-signal intensity on both T1- and T2-weighted images, which might differ from hemangioma findings. Subacute hemorrhage within the tumor was revealed by MR imaging, suggesting the way in which the tumor grew during a short period of time. This finding was different from reported angiosarcoma MR findings of siderotic nodules within the tumor. After the administration of Gd-DTPA, MR images clearly demonstrated heterogeneous enhancement within the tumor, which corresponded to the pathologic findings of solid parenchyma with necrotic tissues.

Contrast Media↗
PubMedDate not supplied

The 5-HT2 receptor antagonist sarpogrelate reduces urinary and plasma levels of thromboxane A2 and urinary albumin excretion in non-insulin-dependent diabetes mellitus patients.

1. Therapeutic effects of a 5-HT2 receptor antagonist sarpogrelate on microalbuminuria and thromboxane (TX)A2 biosynthesis were examined in non-insulin-dependent diabetes mellitus (NIDDM) patients. 2. In protocol I, the ankle-brachial pressure index (API; an indicator of peripheral blood flow) and urinary albumin excretion (UalbV; an indicator of renal function) were determined in 42 NIDDM patients who had been treated with 300 mg/day sarpogrelate for 8 weeks. In an analysis of the results, the NIDDM patients were divided into four groups based on the severity of either vasculopathy or nephropathy as follows: group A, API < 0.9, UalbV > or = 100 mg/day; group B, API < 0.9, UalbV < 100 mg/day; group CAPI > or = 0.9, UalbV > or = 100 mg/day; and group D, API > or = 0.9, UalbV < 100 mg/day. 3. In protocol II, 10 NIDDM patients with UalbV values > 100 mg/day were divided into two groups to further confirm the effect of sarpogrelate on albuminuria: group E, the sarpogrelate treatment group (n = 5); and group F, the no treatment group (n = 5). 4. In protocol I, the incidence of a cold sensation in the lower extremities was reduced from 45.2 to 21.4% following sarpogrelate treatment. In patients with UalbV > or = 100 mg/day (groups A and C), UalbV was significantly decreased independent of API, while it did not change in patients with UalbV < 100 mg/day (groups B and D). Plasma TXB2 levels were significantly decreased following sarpogrelate treatment, whereas plasma 6-keto-prostaglandin F1 alpha levels were not. 5. In protocol II, in the sarpogrelate treatment group (group E), albuminuria was significantly improved and both plasma levels TXB2 and urinary TXB2 excretion were significantly decreased. In contrast, in the untreated group (group F), neither plasma levels TXB2 nor urinary TXB2 excretion was changed. 6. In conclusion, microalbuminuria was improved by treatment with the 5-HT2 receptor antagonist sarpogrelate independent of latent vasculopathy. Blockade of 5-HT2 receptors is suggested to be beneficial for the treatment of nephropathy in NIDDM patients. It is possible that the inhibition of TXA2 biosynthesis is involved in the therapeutic effect of 5-HT2 receptor antagonists.

Albuminuria↗
PubMedDate not supplied

Markedly high signal intensity lesions in the uterine cervix on T2-weighted imaging: differentiation between mucin-producing carcinomas and nabothian cysts.

PURPOSE: Both mucin-producing carcinomas and nabothian cysts in the cervix show very high signal intensity on T2-weighted images (WI). The purpose of this study was to evaluate the potential of MR imaging in differentiating mucin-producing carcinomas from nabothian cysts. MATERIALS AND METHODS: Forty-six patients who underwent hysterectomy and had very high signal intensity lesions in the uterine cervix on T2-WI were included in this study. The pathological diagnoses were mucin-producing carcinoma in 13 patients, non-mucin-producing carcinoma accompanied with nabothian cyst in four patients, and nabothian cyst in 29 patients. T1-WI, T2-WI, and Gd-T1-WI were obtained in all patients. Malignancies were diagnosed on Gd-T1-WI as follows: (1) an enhanced lesion, (2) an irregular margin, (3) iso-intensity on T1-WI. In contrast, high signal intensity on T1-WI was considered benign. RESULTS: Thirteen of 17 malignant lesions and three of 29 benign lesions were enhanced. Irregular margins were observed in 12 of 17 malignant lesions and four of 29 benign lesions. Nineteen benign lesions and seven malignant lesions demonstrated high signal intensity on supplemental T1-WI. Combining the lesion criteria of enhancement, irregular lesion margin, and iso-intensity on T1-WI, the overall accuracy, sensitivity, and specificity rates of diagnosing malignancy were 89%, 88%, and 90%, respectively (p < 0.01). CONCLUSION: MR imaging accurately differentiated mucin-producing carcinomas from nabothian cysts that showed high signal intensity on T2-WI in the cervical stroma. For diagnosing mucin-producing carcinomas and nabothian cysts when signal intensity was remarkably high on T2-WI, Gd-T1-WI findings provided key information for differentiation, and T1-WI was useful for improving specificity.

Adenocarcinoma, Mucinous↗
PubMedDate not supplied

Evaluation of small internal mammary lymph node metastases in breast cancer by MRI.

PURPOSE: In breast cancer, diagnosis of a small internal mammary lymph node (IMLN) metastasis of less than 10 mm in size has been difficult. Our purpose was to retrospectively evaluate MRI findings of small IMLN metastases in comparison with dissected IMLNs. METHODS: We studied 43 dissected IMLNs (range 2-12 mm, mean 4.512+/-2.763 mm) in 16 women with breast cancer (15 primary, and 1 recurrent). MRI examinations were performed using a 1.5 Tesla scanner (200FX; Toshiba, Tokyo, Japan) to obtain noncontrast T1-weighted SE images (TR/TE; 500/15 or 400/15ms), with a slice thickness of 5 mm on coronal images, 10 mm or 7 mm on sagittal images, FOV 15x15 cm, matrix 256x256, using a surface coil with patients in the supine position. MR images were evaluated regarding the major diameter and shape and margin of each node. RESULTS: Regarding the presence of IMLN metastases, there was a significant difference between nodes with a major diameter of 5 mm or more and those of less than 5 mm (p<0.05). Using the size-based criterion (defining< or =5 mm as positive), MRI had 90.7% accuracy, 93.3% sensitivity, and 89.3% specificity. There were no significant differences in the shape-or margin-based criterion. CONCLUSIONS: MRI was useful in diagnosing small IMLN metastases, using a size-based criterion.

Adult↗