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Biomedical subjects

M Obuchi

Publications and source records attributed to M Obuchi.

At least 37 records · Page 2Linked to original sources
PubMed1997

Fulminant hepatic failure: observation with serial CT.

PURPOSE: To determine the imaging characteristics of fulminant hepatic failure at serial computed tomography (CT) and to assess if any CT findings have prognostic value. MATERIALS AND METHODS: In 40 patients, 207 CT scans were analyzed retrospectively. Thirty-four patients had fulminant hepatic failure (acute in seven and subacute in 27), and six had late-onset hepatic failure. Twenty-one patients died of hepatic failure. CT was performed soon after the onset of coma and repeated weekly. Liver volume was measured by tracing the hepatic contour and summing the areas to estimate whole-liver volume. RESULTS: Liver volumes in survivors (n = 19) and nonsurvivors (n = 21), respectively, were 1,090 cm3 +/- 300 and 830 cm3 +/- 240 at initial CT and 1,130 cm3 +/- 310 and 700 cm3 +/- 280 at last CT (P = .0001). III-defined hypoattenuating areas were noted in 20 patients and were distributed in a solitary (n = 13), multiple (n = 6), or diffuse (n = 1) pattern. At follow-up CT, the area of hypoattenuation increased in six patients (five nonsurvivors) and disappeared or markedly decreased in four survivors. An increase in or late occurrence of ascites was noted in 15 patients (14 nonsurvivors, P = .0001). CONCLUSION: Liver volumes at the initial and last CT examinations and an increase in or late occurrence of ascites are useful prognostic findings.

Adolescent↗
PubMed1997

[Examination of scanning technique for lung cancer screening with helical CT].

As a new application of helical CT scanning we evaluated the parameters for lung cancer screening with an extremely low doses and large helical pitch. On the phantom studies, the image quality obtained with the low dose parameter was not inferior to that of the usual screening technique but artifacts were increased with the large helical pitch. A scanning technique using 120 kv, 40-60mA, 10mmth, 20mm/ sec, and a reconstruction pitch of 2 was used for lung cancer screening (screening parameters) (50 cases), and comparison was made between the detectability of the screening parameters and the routine parameters (120 kv, 200mA, 10mmth, 10-13mm/sec, and a reconstruction pitch of 1-1.3). Detectability with the screening parameters was as follows: nodular lesions (< 5mm in size: 76%. 5-10mm: 90-93% 10mm < 100%), linear lesions: 94-95%, infiltrations: 93-100%. There were no false negative lesions, when the reconstruction pitch of the screening parameters was changed from 1 to 0.25. In conclusion, reconstruction pitch had the most influence on lesion detectability.

Adult↗
PubMed1997

[Significant findings on CT performed before presence of post-surgical bowel obstruction].

We evaluated whether CT performed before the presence of bowel obstruction (pre-CT) is useful in predicting the presence of post-surgical bowel obstruction. Thirty-three patients with post-surgical bowel obstructions who had pre-CT were reviewed. The pre-CT findings were compared with the findings of CT performed after the presence of bowel obstruction (post-CT) in 16 patients, and with the intraoperative findings in 18 patients. Pre-CT demonstrated many interesting findings, such as a discrepancy in the caliber of the bowel, the presence of two adjacent collapsed loops, a beak-like appearance of the bowel, focal distention and/or wall thickness of bowel loops, and twisted mesentery. Twenty-three (70%) of 33 patients had one or more of these findings on pre-CT. All patients with a surgically proved closed loop obstruction had two adjacent collapsed loops on both pre- and post-CT. In six (86%) of seven patients who had focal dilated bowel loops and twelve (71%) of seventeen patients who had twisted mesentery on pre-CT, conservative management was proved ineffective. Pre-CT showed many significant findings. Attention should be paid to these findings, because they can predict the presence of post-surgical bowel obstruction. In particular, we stress that two adjacent collapsed loops on pre-CT is a sign of the presence of post-surgical closed loop obstruction.

Adult↗
PubMed1997

[Proposal on new formulas for renal depth in the technetium-99m-mercaptoacetyltriglycine (MAG3) scintigraphy].

UNLABELLED: Recently, camera-based techniques to measure effective renal plasma flow (ERPF) have become more popular than single plasma sample techniques because camera-based measurements avoid the necessity of delayed plasma samples and in vitro techniques. The measurements of ERPF are used to estimate the clearance of technetium-99m-mercaptoacetyltriglycine (MAG3). However, camera-based techniques are dependent on an accurate estimate of renal depth to correct for soft-tissue attenuation. Then, new formulas for renal depth correction of technetium-99m-MAG3 clearance in place of Tønnesen's, M. Ito's, K. Itoh's, and Taylor's methods were tried to establish in this paper. PATIENTS AND METHODS: Eleven hundred and seventy patients without any renal disease were objected. The data from measurement of renal depth using X-ray CT in supine position were analyzed statistically. RESULTS: The depths of right kidney (Dr) and left kidney (Dl) were 7.33 +/- 1.27 and 7.07 +/- 1.27 cm. The correlation coefficients between Dr and height (H) body weight (W), body surface area (BSA: W0.425 x H0.725 x 0.007184 m2), age, and abdominal thickness (Ta) were 0.275, 0.709, 0.615, 0.087, and 0.743. The correlation coefficients between Dl and H, W, BSA, age, and Ta were 0.269, 0.732, 0.629, 0.029, and 0.812. Ta had best correlation with both Dr and Dl. The calculation formulas for Dr and Dl using Ta were as follows: Dr = 0.32 x Ta + 0.87 cm, and Dl = 0.36 x Ta - 0.08 cm. On the other hand, the multiplex calculation formulas of Dr or Dl with H, W, and Ta were as follows: Dr = 0.18Ta + 8.54 x (W/H) + 0.75 (r = 0.768), and Dl = 0.26Ta + 5.90 x (W/H)-0.16 (r = 0.823). CONCLUSION: The new regression equations provide superior estimates of renal depth compared to conventional equations. Application of these new formulas into camera-based protocols to determine renal clearances may lead to more accurate measurements of ERPF using technetium-99m-MAG3 scintigraphy.

Adolescent↗
PubMed1997

Combined therapy with external beam irradiation and hepatic arterial epirubicin infusion through an implanted port for advanced hepatocellular carcinoma.

Nineteen patients with advanced stage IV hepatocellular carcinoma for which transcatheter arterial embolization and percutaneous ethanol injection were not indicated have been treated by combined therapy with external beam irradiation and repeated hepatic arterial epirubicin infusion through an implanted port. The response rate was 47%, and the median survival was 11.6 months (range, 4.0 to 27.1 months). Eighteen of the 19 patients were able to undergo the infusion therapy on an outpatient basis 3 to 7 weeks after initiation of therapy. This combined therapy was effective in improving tumor-bearing survival and less stressful for the patients because of the minimal therapy-related toxicity and brief hospitalization.

Antibiotics, Antineoplastic↗
PubMed1997

alpha-Galactosylceramide (AGL-517) treatment protects mice from lethal irradiation.

AGL-517 (AGL) has an alpha-galactosylceramide structure and is a derivative of agelasphin-9b, which in turn is isolated from Agelas mauritianus and has immunomodulating activity. When administered before irradiation, AGL has been found to increase survival rates in lethally irradiated mice. In this study, we found that a single injection of AGL administered within 2 hours of lethal irradiation resulted in the long-term survival of mice without bone marrow transplantation. Peripheral blood hematology showed that AGL administration accelerated the recovery of hematopoietic parameters, including reticulocytes and red and white blood cells. Recovery of platelets was moderate. In addition, AGL significantly increased the number of endogenous colony forming units-spleen (E-CFU-S). AGL itself displayed no colony-stimulating activity, but AGL-stimulated spleen cell-conditioned medium (AGL-SCM) promoted the proliferation and differentiation of bone marrow mononuclear cells from normal mice and Lin marrow cells from 5-fluorouracil (5-FU)-treated mice. Using suitable assay systems, we analyzed cytokines in AGL-SCM and found significant increases in stem cell factor (SCF), interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-6 levels compared with control SCM. Additionally, using immunoenzymetric assays, we assessed serum levels of these factors in AGL-treated mice after lethal irradiation. The serum concentrations of IL-3, GM-CSF, and IL-6 were substantially elevated, the maximum levels being reached within 2 hours of injection. Despite inducing the in vitro increase in SCF, AGL did not elevate serum SCF levels. However, certain levels of SCF (approximately 5 ng/mL) were detected in mouse serum regardless of irradiation or AGL treatment. When irradiated mice were given a cytokine cocktail composed of recombinant murine (rm) IL-3, rmGM-CSF, and recombinant human (rh) IL-6 three times a day for 6 days (1 microg of each factor per mouse per day) starting 2 hours after irradiation, 60% of the mice achieved 50-day survival. The radioprotective effect of AGL can be attributed, in part, to the cooperative effect of the cytokines induced by AGL in vivo. These findings suggest that AGL may be a useful in treating radiation-induced hematopoietic damage.

Animals↗
PubMed1997

[Arterial infusion chemotherapy with SMAN CS-Lipiodol for hepatocellular carcinoma evaluation of infusion method].

Forty-four patients with hepatocellular carcinoma were treated with oily anticancer agent SMANCS dissolved in Lipiodol (SMANCS-LPD). The local response rate after the first arterial infusion in all patients was 39%, against 63% in 27 patients with Lipiodol accumulation occupying more than two third of tumor areas. Repeated arterial infusion of SMANCS-LPD did not enhance the therapeutic effect. An infusion of 4mg of SMANCS was ineffective for patients with tumors distributing in bilateral lobes of liver, and 6 mg was recommended for such cases.

Aged↗
PubMed1996

Effects of recombinant human granulocyte colony-stimulating factor on the growth potential of two murine myeloid leukemias.

We investigated the in vitro and in vivo effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the proliferation of two murine leukemic cell lines. The rhG-CSF stimulated leukemic colony formation of the promyelocytic leukemic cell line L-8801 in methylcellulose culture and increased the number of L-8801 cells in liquid culture. However, rhG-CSF treatment prolonged the median survival period of mice implanted with L-8801 cells and the emergence of the leukemic blast cells in peripheral blood. Meanwhile, rhG-CSF had no influence on that of the megakaryoblastic leukemic cells L-8057 and failed to prolong the median survival period of L-8057 leukemic mice. Receptor binding analysis revealed that L-8801 cells expressed a G-CSF receptor (Kd=125 pM, 479 binding sites/cell) and L-8057 cells had no G-CSF receptors. Then, we examined the growth potential of these cells. The median survival period was longer for mice implanted with L-8801 cells cultured with rhG-CSF for 72 h in vitro than for cells grown without rhG-CSF. Furthermore, the median survival period of mice implanted with spleen cells from L-8801 leukemic mice treated with rhG-CSF was prolonged compared with those from leukemic mice without rhG-CSF. In contrast, there was no effect of rhG-CSF on the growth potential of the spleen from L-8057 leukemic mice. The results of our present study demonstrate that rhG-CSF reduced the growth of L-8801 leukemic cells in vitro and in vivo mediated through G-CSF receptors, thereby suppressing the development of leukemia.

Animals↗
PubMed1996

Effect of recombinant human thrombopoietin in nonhuman primates with chemotherapy-induced thrombocytopenia.

We examined the effects of recombinant human thrombopoietin (rhTPO) on myelosuppressive chemotherapy-induced thrombocytopenia in cynomolgus monkeys. After treatment with nimustine (ACNU) on day 0, the monkeys intravenously received rhTPO at a dose of 0.04, 0.2 or 1 microgram/kg/d or monkey's serum once each day from day 1 to day 28. Administration of rhTPO reduced the severity of thrombocytopenia and accelerated the rate of platelet recovery in a dose-dependent fashion. Treatment with the highest rhTPO dose completely prevented thrombocytopenia and stimulated a marked increase in platelet counts over the normal values. Animals treated with ACNU also became neutropenic and slightly anaemic. Administration of rhTPO following ACNU treatment significantly improved neutropenia with increasing doses of rhTPO, but had no effect on anaemia. Compared to the control animals, rhTPO-treated animals exhibited no significant changes in several serum parameters. C-reactive protein concentration and some blood coagulation profiles within the study period. These results suggest a therapeutic efficacy of rhTPO in improving chemotherapy-induced thrombocytopenia.

Animals↗
PubMed1996

Increase in hepatic tissue blood flow by teprenone.

The major objective of the present study was to evaluate mechanisms by which teprenone, a gastric mucosal protecting agent, increases hepatic mucosal blood flow using male Sprague-Dawley rats. Hepatic and gastric blood flow was measured using a laser blood flow meter after administration of teprenone, dissolved in Tween 80, into the inferior vena cava. Teprenone itself increased hepatic and gastric blood flow. It also increased hepatic and gastric blood flow in rats with acute hepatic disorders due to carbon tetrachloride (CCL4) and improved histological changes, such as inflammatory cell infiltration and fatty changes in the liver. The fact that blood endothelin (ET) concentrations increased after administration of teprenone suggest that teprenone has great affinity for ET beta receptors and shows ET beta-receptor antagonist-like effects. Hepatic blood flow decreased after administration of N-nitro-L-arginine methyl ester, a nitric oxide (NO) synthetase inhibitor, suggesting that teprenone increase NO activity. Teprenone was thought to increase hepatic and gastric blood flow by different mechanisms, because it increased gastric mucosal prostaglandin E2 concentrations.

Animals↗
PubMed1996

[Fast two-compartment model analysis with 99mTc-GSA liver scintigraphy].

The use of numerical integration method (N. INT) was evaluated in determining parameters by two-compartment model analysis from liver scintigraphy. Among the 15 subjects, 14 had liver cirrhosis or chronic hepatitis, and one was normal. When using N.INT, the sum of two exponential functions on heart regression curve following intravenous injection of 99mTc-galactosyl human serum albumin (99mTc-GSA) was promptly calculated. The parameters obtained from N.INT, including transfer rate of 99mTc-GSA from extrahepatic blood to liver (k1), dissociation rate from liver to extrahepatic blood (k2), and excretion rate from liver to gallblader (k3), were significantly correlated with those obtained by the nonlinear least square method (NLS). k1/k2 was related with the maximum removal rate of 99mTc-GSA obtained from nonlinear five compartment model analysis (r2 = 0.705, n = 15) and also with the severity score of liver disease as classified by the First Department of Surgery, Mie University Medical School (r2 = 0.686, n = 13). In terms of the time required to obtain these parameters, including the blood retention rate of 99mTc-GSA at 15 min after injection (%ID15), N.INT was faster than the traditional method (NLS).

Aged↗
PubMed1996

[Quantitative analysis of 99mTc-GSA liver scintigraphy with graphical plot method].

99mTc-galactosyl human serum albumin (99mTc-GSA) is a newly developed receptor-binding agent, specific for the asialoglycoprotein receptor, which resides exclusively on the plasma membrane of mammalian hepatocytes. Liver scintigraphy using 99mTc-GSA was performed on 65 patients with liver diseases. Dynamic data were obtained by gamma camera during 20 minutes after the intravenous injection of 3 mg (185 MBq) of 99mTc-GSA. The maximum removal rate of 99mTc-GSA (denoted as P(2)) was measured by two methods: nonlinear five-compartment model analysis adopting the Michaelis-Menten constant for the transfer of 99mTc-GSA from hepatic blood to receptor, and a graphical plot using compartmental dose curves. The graphical plot could estimate easily the maximum removal rate in terms of two data points of 0 and 1 minutes without nonlinear least squares and numerical integration. The results indicated that the maximum removal rate was decided immediately after the intravenous injection of 99mTc-GSA. Although 99mTc-GSA is recognized to accumulate nonlinearly on the liver, the rate constant P(2)*(1/min) of transfer from hepatic blood to the receptor was estimated by graphical plot, assuming a linear five-compartment model. P(2)*Km, which was given by the product of the rate constant P(2)* and the Michaelis constant Km, was well correlated with P(2). Next, for 99mTc-GSA liver scintigraphy, we applied a Patlak plot that was applicable to the linear system, and the rate constant Ku of transfer from extrahepatic blood to the liver was estimated. From the results of graphical plot, it was theoretically shown that Ku represented P(2). This was confirmed by clinical data.

Adult↗
PubMed1995

Experimental study on safety for granulopoiesis in simultaneous therapy with recombinant human granulocyte colony-stimulating factor and chemotherapy.

Since recombinant human granulocyte colony-stimulating factor (rhG-CSF) recruits hematopoietic progenitor cells into the cell cycle, the possibility remains that simultaneous injection of rhG-CSF and chemotherapeutic agents may aggravate the chemotherapy-induced neutropenia by sensitizing normal progenitor cells to the cytotoxic effects of chemotherapeutic agents. Therefore, the use of rhG-CSF is usually restricted from the day after chemotherapy. In the present study, we investigated whether concurrent treatment with rhG-CSF and chemotherapeutic agents aggravated granulopoietic failure, using murine neutropenic models. Neutropenia induced by a single injection of cyclophosphamide, mitomycin C, adriamycin, vincristine, combination of mitomycin C+vincristine, or combination of cyclophosphamide+vincristine+adriamycin (CHOP) was not aggravated by simultaneous injection of rhG-CSF (30 micrograms/kg, SC). In contrast, a single concurrent injection of rhG-CSF and 5-fluorouracil aggravated the neutropenia and the decrease in marrow colony-forming unit-granulocyte/macrophage counts, but simultaneous and following injections of rhG-CSF enhanced the recovery of neutrophils. Moreover, neutropenia induced by successive treatment with cisplatin was prevented by concurrent treatment with rhG-CSF during the period of the chemotherapy. From these results, concurrent treatment with rhG-CSF and chemotherapeutic agents with the exception of 5-fluorouracil may be feasible and well-tolerated in clinical use.

Animals↗
PubMed1994

Enhancement human cytomegalovirus replication in a human lung fibroblast cell line by interleukin-8.

We examined the effects of interleukin-8 (IL-8) on cytomegalovirus (CMV) replication in human fibroblasts. Exposure of fibroblasts to IL-8 augmented both infectious virus production and replication of CMV, with concomitant increases in the levels of both the transcript of the CMV pp71 genome and the synthesis of the CMV late antigen. We also found that CMV selectively induced transcripts of the IL-8 type 1 receptor in fibroblasts. These results suggest that IL-8 also contributes to inflammatory diseases by enhancing CMV replication and that CMV regulates its production through induction of IL-8 receptor.

Cell Line↗
PubMed1990

Müllerian duct cyst: ultrasonographic and computed tomographic spectrum.

A Müllerian duct cyst (MDC) is the persistent remnant of the Müllerian duct. Reports of symptomatic cases are rare, signs and symptoms include perineal pain, dysuria, infertility, hematuria and genital inflammation. The prevalence of MDC has been previously reported as 4% of newborns and 1% in adult males. Herein we report six cases encountered in the past year. Our detection percentage was 1% and is compatible with the reported values. The imaging evaluation of symptomatic and asymptomatic patients with MDC is discussed as well as the apparent discrepancy between the number of previously reported cases and the reported prevalence.

Adolescent↗
PubMed1990

Improved kinetic rate assay of urinary N-acetyl-beta-D-glucosaminidase with 2-chloro-4-nitrophenyl-N-acetyl-beta-D-glucosaminide as substrate.

We have improved the kinetic rate assay method for determining N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30; NAG) activity in urine with use of the synthetic substrate, 2-chloro-4-nitrophenyl-N-acetyl-beta-D-glucosaminide (CNP-NAG), reported previously (Clin Chem 1988;34:2140-2). To increase the solubility of this substrate, we used crown ether (15-crown-5-ether) and ethylene glycol. In addition, we used for the standard solution NAG from human placenta, with specificity corresponding to that of human urine, so that values obtained with the CNP-NAG method and a p-nitrophenyl-NAG method ("MEI Assay NAG") correlated almost completely (r = 0.995, n = 29). Reference values for urinary NAG activity determined by the CNP-NAG method were established for untimed urine specimens from 674 healthy volunteers. The normal reference interval (mean +/- 2 SD) for NAG: 1.6-15.0 (mean 4.9) U per gram of creatinine.

Acetylglucosamine↗
PubMed1989

[A case of myelolipoma originating from bilateral adrenal glands; a comparison of CT and pathological findings].

We experienced a case of bilateral retroperitoneal tumor incidentally on CT which was carried out on suspicion of either cholelithiasis or choledocholithiasis. In company with other radiologic studies, US, angiography etc. we were able to make a correct diagnosis of adrenal myelolipoma preoperatively. Among these studies, CT coincided well with the structure of pathological findings and is thus the most powerful method for the diagnosis of myelolipoma. The case was discussed in addition to the studies of other literatures.

Adrenal Gland Neoplasms↗