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Biomedical subjects

S Nishimura

Publications and source records attributed to S Nishimura.

At least 1,153 records · Page 64Linked to original sources
PubMedDate not supplied

The usefulness and limits of magnetic resonance imaging in the differential diagnosis of pelvic tumors.

Three cases of benign pelvic tumors are presented (2 leiomyomas and 1 fibroma). All three tumors were suspected of being malignant neoplasms because they were visualized as heterogeneous high signal intensity on T2-weighted images, and thus they were difficult to diagnose preoperatively. One of the leiomyomas was located in the retroperitoneum and had been misdiagnosed as an ovarian tumor. All three tumors exhibited secondary myxoid changes, these changes may have been responsible for the high signal intensity on the T2-weighted MR images. Since benign tumors sometimes mimic malignant tumors on MR images, exploratory laparotomy is essential to make a definitive diagnosis.

Female↗
PubMedDate not supplied

A randomized study comparing oral and standard regimens for metastatic breast cancer.

We conducted a randomized controlled trial comparing oral regimen [doxifluridine, an intermediate metabolite of capecitabine, + medroxyprogesterone acetate (MPA) + cyclophosphamide (CPA)] (Method A) with a standard regimen (5-fluorouracil + adriamycin + CPA) plus MPA (Method B) as first line chemotherapy for metastatic breast cancer. Overall response rate was 55.8% for Method A, 46.3% for Method B. The total ratio of responder and long stable disease was significantly higher with Method A (p=0.006). Median time to progression and survival were not differences between Methods. Incidence of toxicity was 56.3% with Method A and 80.0% with Method B (p=0.014). Oral regimen is more useful than standard therapy.

Administration, Oral↗
PubMedDate not supplied

Primary peritoneal clear cell carcinoma: excellent results from paclitaxel and carboplatin combination chemotherapy.

While papillary serous adenocarcinomas are histocytologically common in primary peritoneal carcinomas, clear cell carcinomas are rare. We report a new regimen for the treatment of recurrent clear cell carcinomas of the peritoneum. A 45-year-old woman was referred to our hospital and underwent optimal debulking surgery. Thirty-two months after the operation, lymph node swelling and elevation of serum CA19-9 were detected and recurrence was diagnosed. Paclitaxel (175 mg/m(2)) in a 3-hour and carboplatin (300 mg/m(2)) in a 1-hour infusion were repeated at three-week intervals. After completion of four courses, abdominal CT and serum CA19-9 were undertaken and results compared. Lymph node swelling was significantly decreased and the serum CA19-9 level was decreased to within a normal range. Paclitaxel and carboplatin combination chemotherapy may be effective in preventing the recurrence of peritoneal carcinomas.

Adenocarcinoma, Clear Cell↗
PubMedDate not supplied

Probucol decreases total body fat loss in VX2-carcinoma-induced cachectic rabbits.

We previously reported the continuous decrease of total body fat in VX2-carcinoma-bearing rabbits after tumor implantation, as well as changes in the serum lipid profile. Probucol, an antioxidant drug, has a cholesterol lowering effect against hyperlipidemic subjects. VX2-carcinoma-bearing rabbits fed with a diet containing 1% probucol did not show any difference in serum lipid compositions as compared with rabbits fed with a control diet. Similarly serum lipolytic activity showed no differences, whether probucol was administered or not, while the decrease in total body fat was significantly less when probucol was administered.

Adipose Tissue↗
PubMedDate not supplied

Case report of 14-year survival after radiotherapy for clinical T3 esophageal carcinoma, with local recurrence finally rescued by surgery.

A 51-year-old man with increasing dysphasia was admitted to our hospital on March 18, 1985. Several examinations revealed thoracic esophageal squamous cell carcinoma 11 cm in length staged T3N0M0 (stage IIA) by UICC 1987. As he rejected our proposal of surgery, definitive radiotherapy (60 Gy) was delivered, and complete response was obtained. The patient had been doing well for 5 years after radiotherapy until superficial local recurrence was discovered at a periodic endoscopic examination. High-dose-rate intraluminal brachytherapy (10 Gy/2 Fr) was administered. After a 3-year disease-free interval, superficial recurrence developed in the same location, and early gastric cancer was detected as a secondary cancer. Radical salvage surgery was performed. The patient was alive and disease free 5 years and 5 months after surgery. We present this rare case of a patient who survived 14 years after the initial radiotherapy. The present case demonstrated the importance of long-term follow-up after radiotherapy, long-term local controllability of relatively low doses of intraluminal brachytherapy after superficial recurrence, and the feasibility of salvage surgery as long as local recurrence is limited to within the mucosal layer.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Effects of cyclic plasma perfusion on adipocyte apoptosis and lipolytic activity in VX2 carcinoma-bearing rabbits.

BACKGROUND: In an animal model we found that total body fat (TBF) decreased with progression of tumors, but that it rebounded after cyclic plasma perfusion (CPP). In this study, we investigated changes in adipocyte apoptosis and serum lipolytic activity (LA) after CPP. MATERIALS AND METHODS: TBF, LA, and adipocyte apoptotic index (AAI) in VX2 carcinoma-bearing rabbits were measured every ten days after implantation. CPP was performed every 5 days from post-implantation day (PID) 14. RESULTS: TBF decreased as the days passed and reached 43.2 +/- 10.0% on PID 50 in the non-CPP group, while it decreased 22.7 +/- 8.8% in the CPP group. LA on PID 50 was 17.8 +/- 14.0, 33.2 +/- 6.3 mumol glycerol/10(5) adipocytes in the non-CPP group, while LA did not increase in the CPP group. AAI was 28.8 +/- 16.4, 27.8 +/- 17.7, 10.3 +/- 9.9 and 0.4 +/- 1.1 on PID 10, 20, 30, and 40, respectively, in the non-CPP group. No change was noted in AAI after CPP. CONCLUSIONS: CPP removed a humoral factor that possesses TBF-decreasing LA, but it did not suppress adipocyte apoptosis.

Adipocytes↗
PubMedDate not supplied

The mesh plug technique for adult inguinal herniation.

We studied 112 adult patients who underwent the mesh plug method for inguinal hernia at our clinical division from August 1996 to September 1998. We compared the mesh plug method with conventional sutured repair, such as the Bassini method, the ileopubic tract repair method and the McVay method, according to the duration of operation, postoperative white blood cell count, postoperative CRP, the frequency of analgesics after surgery, and the recurrence rate. The duration of operation in patients with the mesh plug method was significantly short. According to postoperative white blood cell count and CRP, there was no significant difference between the two groups. Frequency of analgesics after surgery was 0.8 times in a patient with conventional sutured repair and 0.4 times in a patient with the mesh plug method, suggesting that it was significantly low in patients with the mesh plug method. The recurrence rate in patients with the mesh plug method was 3.57% (4 cases). All the recurrences had developed within 1 year after surgery, and all of the cases were repaired with the mesh plug method. We conclude that the mesh plug method for adult inguinal hernia was a useful operative procedure with shorter duration of operation, less postoperative wound pain, and almost the same recurrence rate compared with conventional sutured repair.

Adolescent↗
PubMedDate not supplied

Breast conservation for huge-sized locally advanced breast cancer: a case report.

A 35-year-old woman with locally advanced stage IIIB breast cancer (medullary carcinoma) 12 cm in diameter underwent neoadjuvant chemotherapy consisting of three courses of intraarterial infusion [adriamycin (ADR), mitomycin (MMC), cisplatin (CDDP), 5-fluorouracil (5FU)] and four cycles of systemic chemotherapy (ADR, epirubicin, cyclophosphamide, MMC, CDDP) for three months. The tumor markedly diminished after the first course of intraarterial infusion chemotherapy, with a 3-cm tumor remaining after the completion of preoperative administration. Pathologically complete response was noted in specimens resected following breast conservation surgery. Postoperative radiotherapy was added and adjuvant chemohormonal therapy was continued for two years. The patient is alive without recurrence and has been able to conserve the breast for the past eight years, neoadjuvant chemotherapy including intraarterial infusion enabled breast conservation treatment even for huge-sized locally advanced breast cancer.

Adult↗
PubMedDate not supplied

Pathways for activation of the ras-oncogene-encoded p21 protein.

The ras-oncogene-encoded p21 protein is known to cause a large number of human tumors. This protein differs from its normal counterpart protein, which is present in all eukaryotic cells, in that it contains a single amino acid substitution at critical positions in the polypeptide chain, such as at Gly 12, Gly 13, Ala 59, and Gln 61. Using computer-based molecular modeling, it has been found that one region of this protein that is a candidate for interacting with other intracellular proteins is the region from residues 35 to 47. In oocyte microinjection experiments, it was found that this peptide strongly inhibits the mitogenic effects of oncogenic (Val 12-containing)p21 but does not inhibit the cellular effects of activation of normal p21 protein. Furthermore, it has been shown that the cellular effects of oncogenic p21 protein can be completely inhibited by selectively blocking protein kinase C (PKC) with a highly specific inhibitor of this protein, CGP 41 251, a staurosporine derivative. This inhibitor, however, only weakly inhibits the effects of normal cellular ras-p21 protein. In addition, a photoaffinity-labeled p21 protein has been microinjected into NIH 3T3 fibroblasts and have isolated intracellular proteins of MW 35, 43 and 61 kda covalently bound to it. The 43 kda protein is the major one and appears to be critical to the functioning of the p21 protein. Our results suggest that oncogenic and normal p21 proteins utilize overlapping but distinct pathways; the oncogenic pathway can be blocked selectively and requires the activation of PKC and the presence of the 43 kda protein.

Amino Acid Sequence↗
PubMedDate not supplied

A peptide from the GAP-binding domain of the ras-p21 protein and azatyrosine block ras-induced maturation of Xenopus oocytes.

The ras-oncogene-encoded p21 protein causes malignant transformation of NIH 3T3 cells and maturation of Xenopus oocytes when microinjected into these cells. P21 is known to interact with GTPase activating protein (GAP) intracellularly. Residues 32-45 of p21 have been implicated in interacting with GAP. In a previous study, we demonstrated that a synthetic peptide containing residues 35-47 from the GAP-binding region of p21 could block in vivo the effects of oncogenic p21 protein. It has also been found that an antibiotic, azatyrosine, blocks ras-initiated cell transformation. We now demonstrate that both of these agents inhibit the ras-p21 protein-induced maturation of Xenopus oocytes in a dose-related manner when microinjected into oocytes. The effects of each of these agents is specific. Both agents block insulin-induced maturation of oocytes, a process which is known to involve activation of endogenous normal p21 protein. On the other hand, neither agent inhibited oocyte maturation induced by progesterone, which is known to initiate oocyte maturation by ras-independent pathways. The inhibitory effects of the peptide were not mimicked by a control peptide from the CD4 receptor protein. Furthermore, the effect of azatyrosine was not mimicked by L-tyrosine. These results suggest that both the peptide and azatyrosine have potent anti-ras effects intracellularly.

3T3 Cells↗
PubMedDate not supplied

MR imaging: possibility of tissue characterization of brain tumors using T1 and T2 values.

To evaluate the usefulness of T1 and T2 values for tissue characterization of brain tumors, 37 histologically confirmed brain tumors were examined with a 0.5-T superconductive MR system. With spin-echo and inversion-recovery imaging sequences, computed T1 and T2 images were reconstructed, and T1 and T2 values of the tumors were calculated. Relaxation rates (1/T1 and 1/T2), T1/T2 ratios, and malignancy indexes, which were originally designed for gastrointestinal tumors, were also calculated. Values of all these parameters were so wide-ranged that it was impossible to characterize the tumor tissue types.

Adenoma↗
PubMedDate not supplied

MR imaging of brainstem hemorrhage.

To determine the chronologic changes in the MR appearance of brainstem hemorrhage and to evaluate the clinical efficacy of MR imaging, 15 patients were examined with a 0.5-T MR scanner with inversion-recovery (IR) and T2-weighted spin-echo (SE) images. In the acute stage (up to the sixth day), hematomas were hypo- or isointense on IR images and isointense and then hypointense on SE images. In the subacute stages (the seventh day to 2 months), hematomas changed from hypo- or isointensity to hyperintensity centripetally on IR images and to hyperintensity on SE images. Parenchymal reactions were hypointense first on SE images and then on IR images. In the chronic stage (over 2 months), hematomas "disappeared" and the parenchyma was hypointense on both IR and SE images. The superior clinical efficacy of MR imaging relative to CT for the detection of hemorrhage was obvious except in the acute stage, when hematomas had an intensity similar to that of the adjacent brainstem, and the patients usually were in serious condition.

Adult↗
PubMedDate not supplied

MR imaging of blood flows in the cavernous sinus.

To evaluate blood flows in the cavernous sinus (CS), seven normal CSs and a postmortem CS were evaluated using T1-weighted spin echo sequences. After the noncontrast study, contrast study with Gd-DTPA was performed in all cases except the postmortem one. In the normal CSs, arterial flows of the intracavernous carotid artery (ICA) were disclosed as no-signal areas in the noncontrast study and were not enhanced with Gd-DTPA. Most venous flows in the CS were seen as low-intensity areas in the noncontrast study and were markedly enhanced with Gd-DTPA. However, these low-intensity areas were heterogeneous in intensity and several were higher and lower in intensity compared with most venous spaces. In the postmortem case, the CS showed homogeneous low intensity due to the stasis of blood flow. It was thought that the heterogeneous appearance of venous spaces in the normal CSs was due to flow-related phenomena. This heterogeneous pattern of signal intensity suggested the distribution of flow velocities. MR demonstrated both arterial and venous flows, and this was facilitated by Gd-DTPA. MR is a promising modality for the demonstration of blood flows in the CS.

Adult↗
PubMedDate not supplied

Antihypertensive activity of cadralazine in experimental hypertensive rats.

Antihypertensive and tachycardic activities of cadralazine were examined in experimental hypertensive rats (spontaneous, renal and deoxycorticosterone acetate-salt hypertension) after single or repeated oral administration, and compared with those of hydralazine. In single oral administration, cadralazine (0.3-5 mg/kg) produced a dose-related hypotensive effect and its maximum activity was equipotent to or more potent than that of hydralazine (1-5 mg/kg) in these hypertensive rats. The hypotensive effect of cadralazine appeared gradually and reached a maximum at 5-7 hr, while the maximum effect of hydralazine was observed at 1 hr after dosing. In SHR, the significant hypotensive effect of cadralazine persisted for 9-24 hr, but that of hydralazine lasted for only 1-12 hr. Therefore, there were marked differences in onset and duration of the hypotensive effect between cadralazine and hydralazine. Both drugs produced a dose-related tachycardic effect concomitant with the hypotensive effect. The separation ratios of cadralazine on these effects were equivalent to those of hydralazine. In repeated oral administration for 7 days, cadralazine (3 mg/kg/once a day) significantly reduced the daily starting blood pressure. The same response was obtained by 3 times daily repeated administration of hydralazine (3 mg/kg). Tolerance to the hypotensive and tachycardic effects was not observed during successive dosings of cadralazine or hydralazine. The potent and long lasting hypotensive effect of cadralazine might be useful for the treatment of arterial hypertension.

Animals↗
PubMedDate not supplied

Cardiac function after orthotopic heart transplantation: response to postural changes, exercise, and beta-adrenergic blockade.

To prospectively assess the response of orthotopic heart transplant recipients to exercise before and after beta-adrenergic blockade, we investigated 35 orthotopic heart recipients, all with clinically stable conditions and without rejection, and five control, healthy subjects. Radionuclide angiography was performed at rest and during supine bicycle exercise, before and after beta-blockade. At rest, heart rate, systolic and diastolic pressures, and end-systolic volume were higher, whereas the end-diastolic volume and stroke volume indexes, cardiac index, and ejection fraction were significantly lower in the transplant recipients than in healthy control subjects. During exercise, before beta-blockade, transplant recipients attained a lower maximal heart rate and smaller increments in heart rate than did the control subjects. The cardiac index increased during exercise because of an increase in stroke volume (43%) and heart rate (32%) in the transplant recipients and nearly exclusively (93%) because of an increase in heart rate in the normal subjects. After beta-blockade, the ejection fraction, the stroke volume, and the cardiac index fell significantly at rest in both groups. The fall in ejection fraction was greater in the transplant recipients than in the control subjects (-16% +/- 12.6% versus -5.4% +/- 2.6%, respectively; p = 0.0002). After beta-blockade, lower maximal heart rate, ejection fraction, and cardiac index were achieved during exercise in both groups. The peak exercise cardiac index was 42% lower in transplant recipients than in control subjects after beta-blockade. Thus, cardiac performance during exercise is impaired in orthotopic heart transplant recipients. Acute beta-adrenergic blockade accentuates the impairment in ventricular performance and appears to be detrimental in these patients.

Adolescent↗