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Biomedical subjects

M Harada

Publications and source records attributed to M Harada.

At least 811 records · Page 45Linked to original sources
PubMed1992

Accuracy of the results measured by in vivo 1H-MRS using model solutions.

In in vivo 1H-MRS of human brain, main three metabolites such as N-acetyl-L-aspartate (NAA), creatine/phosphocreatine (PCr/Cr), and choline (Cho) have been observed. In this paper an accuracy of the results measured by in vivo 1H-MRS using above model solutions was discussed. 1.0 mmol/l choline and 1.5 mmol/l creatine/phosphocreatine saline solutions were measured with STEAM method (echo time 270 msec). The peak area of Cho was larger than that of PCr/Cr against their concentrations and was linearly increased with its concentration in the range of 5.8 and 29 mumol/27 cm3. Although both peak areas of Cho and Cr/PCr were varied with Volume-of-interest (VOI) coordinates, the ratio of Cho to PCr/Cr was approximately 1.6.

Brain↗
PubMed1992

Quantified application of MRI for diagnosis of head and neck tumors.

We evaluated T/M ratios and T2 values of 6 malignant lymphomas and 8 squamous cell carcinomas in the head and neck in order to differentiate these two entities. T/M ratios were calculated by dividing intensity of tumor by that of muscle in same slice images. T2 values were calculated from T2-weighted images and proton-weighted images. Statistical difference of T/M ratios was found between malignant lymphomas and squamous cell carcinomas, but no difference of T2 values was seen between two groups. T/M ratio was considered to be a useful and quantified index for evaluation of head and neck tumor.

Carcinoma, Squamous Cell↗
PubMed1992

Continuous measurement of lactate concentration in skeletal muscle and liver interstitium using a microdialysis method after acute hemorrhage in anesthetized rats.

Interstitial lactate concentration in rat skeletal muscle was continuously measured using a microdialysis method following an acute hemorrhage. For comparison, similar measurements were also performed for liver. Normal lactate levels of skeletal muscle and liver interstitium were 0.58 +/- 0.10 mM and 1.23 +/- 0.04 mM, respectively. After withdrawal of 30% of the estimated total blood volume within 3 min, a constant high blood lactate level was achieved. The lactate concentrations in muscle and liver interstitium also increased to 270 and 210% of the basal levels, respectively, but they did not exceed the blood level. These findings led us to hypothesize that skeletal muscle as well as liver functions as a lactate consumer rather than a producer after acute hemorrhage.

Animals↗
PubMed1992

[Immunophenotypic analysis in acute leukemia].

Acute leukemias have been classified on French-American-British (FAB) criteria depending on the morphocytochemical features of blasts. Immunophenotyping and clonal rearrangement analysis of lineage-associated genes can decide a frozen stage of the hematopoietic differentiation process in blasts from acute leukemias. B-lineage acute lymphoblastic leukemia (ALL) and T-lineage ALL are systematically classified according to the sequential expression of differentiation-associated antigens. In acute myelogenous leukemia (AML), several new entities are proposed: AML-M0 is an AML without cytologic maturation, in which the myeloid commitment should be demonstrated by myeloperoxidase-positive microgranule on immunohistochemical staining or electron-microscopy, or by positive reaction for CD13 or CD33 antigens. CD7-positive AML is considered to be one of immature subtypes of AML, rather than hybrid leukemia. Thus, immunological studies on blasts enable us to discriminate a subgroup of leukemias, which will perhaps contribute to the improvement of treatment approach.

Acute Disease↗
PubMed1992

[A case of ureteral endometriosis; the usefulness of MRI for preoperative diagnosis].

A rare case of ureteral endometriosis is reported. A 46-year-old nulliparous woman was referred to our hospital because of right hydronephrosis which was detected by ultrasonography; Drip infusion pyelography showed right hydroureteronephrosis with the distal obstruction. MRI demonstrated right ovarian endometriosis and resultant ureteral stricture. Based on these findings, we made a preoperative diagnosis of right ureteral endometriosis. Right partial ureterectomy and ureteroureterostomy were performed. Pathological examination of the resected segment showed endometrial tissue around the ureteral lesion. She was administered LH-RH agonist (buserelin); her postoperative course was uneventful. IP showed no abnormalities 6 weeks after the operation. To our knowledge, this case is only the 55th case reported in the literature in Japan.

Endometriosis↗
PubMed1992

In vivo 19F MR spectroscopic study of metabolism of 5-fluorotryptophan in rat liver.

The metabolism of 5-fluorotryptophan in rat liver was examined by in vivo 19F MR spectroscopy. After i.v. injection of 200 mg/kg b.w. of 5-fluorotryptophan the substance was noted immediately as a strong peak, which decreased gradually. Another peak appeared about 40 min after the injection. The chemical shift value of this peak was 1.6 ppm from that of 5-fluorotryptophan. Kynurenine is known to be a major metabolite of tryptophan in the liver. We synthesized 5-fluorokynurenine from 5-fluorotryptophan by ozonolysis. The chemical shift value of 5-fluorokynurenine was confirmed to be coincident with that of the metabolite peak. This strongly suggests that the metabolite peak of 5-fluorotryptophan observed in this study was the 5-fluorokyrurenine signal. We also applied this method for the CCl4-injured liver. In the liver injury group, the metabolite peak appeared slowly and the intensity was low compared to that of the normal group, though the peak of 5-fluorotryptophan decreased similarly as in the normal liver. These results suggest that the decrease of 5-fluorotryptophan is due mainly to the renal excretion, as the injured liver could not metabolize 5-fluorotryptophan.

Animals↗
PubMed1992

[Cavernous hemangioma of the spermatic cord: a case report].

Cavernous hemangioma of the spermatic cord is a very rare disorder. A 26-year-old man was admitted to our hospital with chief complaints of right intrascrotal mass and hematospermia on October 19, 1990. Physical examination revealed a hard, non-transilluminated mass in the right spermatic cord. The mass was resected via the groin. Pathological examination showed cavernous hemangioma. The patient's postoperative course was uneventful. This is only the fourth case of cavernous hemangioma of the spermatic cord to be reported in the literature in Japan.

Adult↗
PubMed1992

[Therapeutic evaluation of imipenem/cilastatin sodium for bacterial infections in patients with hematological diseases].

1. To evaluate the efficacy and tolerance of imipenem/cilastatin sodium (IPM/CS) in severe infections associated with hematopoietic disorders, IPM/CS was administered to a total of 105 patients. 2. Out of 96 patients evaluable for efficacy, clinical responses were excellent in 23 patients, good in 30, fair in 15, poor in 19 and unknown in 9, and the overall response rate was 60.9%. 3. The most common underlying hematopoietic disease was acute non-lymphocytic leukemia and the most common infections were sepsis and suspected sepsis. 4. Daily dose, severity of infection and neutrophil count had effects on the clinical response. 5. The overall eradication rate of bacteria was 83.7%. 6. Side effects were observed in 10 patients (9.5%) and abnormal laboratory test results in 12 (11.4%). From the above findings, we have concluded that IPM/CS is very useful for the treatment of severe infections in compromised patients with hematopoietic diseases.

Adult↗
PubMed1992

[The clinical and pharmacokinetic evaluation of two-route chemotherapy with cisplatin and sodium thiosulfate in combination with angiotensin II].

Thirty-six courses of chemotherapy with cisplatin (CDDP) and sodium thiosulfate (STS) were performed in 31 patients with gynecologic cancer 2 weeks after operation under the hypertensive condition induced by angiotensin II (AT-II). One hundred-fifty mg of CDDP/body was intraperitoneally administered while the usual systolic blood pressure was increased to 130-140% by AT-II. The hypertension was maintained for 15 minutes after finishing CDDP infusion, then 8g of STS was intravenously infused immediately after the cessation of AT-II. The urinary Pt level measured 15 minutes after finishing CDDP infusion was extremely low at 1.37 +/- 0.47 micrograms/ml, in spite of the significantly high levels of plasma total Pt (7.83 +/- 0.85 micrograms/ml) and filtrable Pt (4.02 +/- 0.55 micrograms/ml). This suggests that, during renal vasoconstriction induced by AT-II, the renal blood flow as well as renal uptake of CDDP was decreased. Plasma filtrable Pt levels were measured at 15, 30, 60 and 120 minutes after intraperitoneal administration of CDDP. At 15 and 30 minutes a significantly higher blood concentration was found than in the control group (p less than 0.05). However, CDDP-induced toxicities of the bone marrow, liver, kidney and alimentary tract were not increased. The extreme vasoconstriction in the kidneys and other organs induced by AT-II might have protected these organs from the toxicities of CDDP despite the fact that STS infusion was delayed by 15 minutes after CDDP infusion. STS infused immediately after the cessation of AT-II could neutralize the CDDP preventing the occurrence of toxicities.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1992

[Clinical and pathological study of 152 cases of prostatic cancer].

A total of 152 prostatic cancer patients who underwent mainly hormone therapy was conducted. Our histological grading system combined with structure atypsim--SAT and nuclear anaplasia--NAN allowed for more accurate prognosis of prostatic cancer patients. The prognosis of G3 patients was obviously poor. The over-all 5-year survival rate for prostatic cancer patients with G1, G2 and G3 was 80%, 57% and 17%, respectively. The 5-year reactivation rate for patients with G1, G2 and G3 was 14%, 32% and 87%, respectively. The period for reactivation after initial hormone therapy for prostatic cancer patients with G1, G2 and G3 was 11.4, 10.0 and 3.2 years, respectively. Further improvements in survival for the patients with G3 prostatic cancer will require the development of effective systemic chemotherapy and the re-consideration of appropriate use of hormone therapy.

Aged↗
PubMed1992

[Simple hypothermic retrograde cerebral perfusion for brain protection during aortic arch surgery].

We have recently found that retrograde cerebral perfusion can be performed by simply elevating central venous pressure to 15 mmHg in the Trendelenburg position when the aortic arch is open during aortic arch surgery. During deep hypothermic (15 degrees C) perfusion of the lower half of the body with the descending aorta occluded, and with single cannulation of the right atrium for drainage, oxygen-saturated venous blood perfuses the brain retrogradely, supplying it with oxygen. This method renders clamping of the aortic arch and the arch vessels unnecessary. Eleven cases of aortic arch aneurysm (9 males, 2 females; 5 true aneurysms, 5 dissecting aneurysms, one combined aneurysm; mean age, 63 years) were operated using this technique, whose clinical significance was then evaluated. Median sternotomy was performed in 4 cases, left thoracotomy in 7. Patch replacement was performed in 2 cases and graft replacement in 9 cases (the proximal arch in 2, the whole arch in 2, the distal arch in 5). In two cases coronary artery bypass surgery using the internal thoracic artery was performed simultaneously via lateral thoracotomy. Operation time was 517 +/- 139 min, pump time was 211 +/- 34 min, cardiac arrest time was 84 +/- 34 min and the lowest rectal temperature was 15.7 +/- 1.1 degrees C. In the venous return, PO2 was 188 +/- 136 mmHg, and SO2 97.5 +/- 2.9%, the respective values in the retrogradely perfused blood in the aortic arch being 46 +/- 12 mmHg and 68.8 +/- 18.8%.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Prognostic value of nuclear DNA content and expression of the ras oncogene product in lung cancer.

We evaluated the prognostic significance of nuclear DNA content by flow cytometry and ras oncogene expression in paraffin-embedded sections of tumors obtained surgically from 112 non-small cell lung cancer patients. Sixty-five (77%) of the 84 tumors had DNA aneuploid patterns that were statistically higher in adenocarcinoma than in squamous cell carcinoma. Of the 91 patients analyzed immunohistochemically using anti-ras Mr 21,000 protein (p21) monoclonal antibody rp-35, positive reactions (weak and strong) were observed in 56% of squamous cell carcinomas and 68% of adenocarcinomas. A better 5-yr survival rate was observed in the DNA diploid group (61%) than in the DNA aneuploid group (35%) (P less than 0.01). Patients with p21-negative tumors survived significantly longer (5-yr survival rate of 64%) than did those with p21-weak tumors (38%, P less than 0.05) or those with p21-strong tumors (12%, P less than 0.01). Cox's multivariate analysis showed that DNA ploidy, ras p21 expression, and the stage of the disease were significant prognostic factors for survival. However, the DNA content was not a major independent prognostic factor in adenocarcinoma. The intensity of ras p21 expression was not correlated with nuclear DNA content. These results suggest that DNA content or enhanced ras p21 expression may be different biological markers indicating the malignant potential of lung tumors.

Adenocarcinoma↗
PubMed1991

In vitro uptake of bromodeoxyuridine by human hepatocellular carcinoma and its relation to histopathologic findings and biologic behavior.

The in vitro uptake of bromodeoxyuridine (BrdU) by hepatocellular carcinoma (HCC) cells was studied in 30 hepatectomized patients. Labeling of the nuclei by BrdU expressed as labeling index (LI) was 5.6 +/- 3.2% (mean +/- standard deviation), with a considerable variation from case to case. The mean LI in Grade III to IV cancers (less differentiated, by Edmondson and Steiner's classification, 11.1 +/- 2.1%) was significantly larger (P less than 0.001) than that in Grade I to II cancers (more differentiated, 4.5 +/- 2.0%). Capsule formation was found in all 17 patients except one (94%) with a low DNA synthetic HCC (LI less than 6.0%) compared with seven of 13 (54%) with a high DNA synthetic HCC (LI greater than or equal to 6.0%, P less than 0.02). The 2-year survival rate after surgery was significantly higher (P less than 0.02), and intrahepatic metastasis was significantly less (P less than 0.05) in the former group than in the latter. The BrdU LI of HCC tumors showed a strong correlation with histopathologic findings and the biologic behavior of HCC.

Adult↗
PubMed1991

Photoreversible antigen-antibody reactions.

A monoclonal antibody (Z1H01) for an oligopeptide carrying an azobenzene group, was prepared under conditions where the azobenzene group is in the trans form. The antibody bound the hapten peptide effectively when the hapten peptide is in the trans form (K = 5 x 10(7) M-1), but the antibody released the hapten under irradiation with UV light where the hapten is in the cis form. The antibody bound the hapten again, when the hapten reverted to the trans form after irradiation with visible light.

Animals↗
PubMed1991

Effects of interleukin-4 and interleukin-6 on the proliferation of CD34+ and CD34- blasts from acute myelogenous leukemia.

We studied the effects of interleukin-4 (IL-4) and IL-6 on the growth of leukemic blasts from 40 patients with acute myelogenous leukemia (AML). Patients were selected on the basis of negativity for a series of B-cell antigens including CD10 and CD19. Twenty-one cases were CD34-positive (CD34+) (greater than 15% of blasts) and the remaining 19 were CD34-negative (CD34-) (less than 3% of blasts). IL-4 alone (100 U/ml) could stimulate either DNA synthesis (with greater than 2.0 stimulation index) or leukemic blast colony formation in 24 of 40 AML patients. In the presence of other growth factors, IL-4 showed divergent effects on IL-3-, granulocyte-macrophage colony-stimulating factor-, granulocyte colony-stimulating factor-, or erythropoietin-dependent colony formation. These effects of IL-4 were observed in both CD34+ and CD34- AML cases. IL-6 (100 U/mL) alone could not stimulate DNA synthesis and blast colony formation except for one CD34+ case. On the other hand, IL-6 showed synergistic effects on IL-3- and IL-4-dependent blast colony formation in 10 of 12 and 7 of 9 CD34+ AML cases, respectively. Among CD34- AML cases, such synergism was seen only in 1 of 12 cases for IL-3-dependent colony formation and in 3 of 7 cases for IL-4-dependent colony formation. The divergent effect of IL-4 and the synergistic effect of IL-6 were also observed in purified CD34+ leukemic blast populations, indicating that these phenomena are not mediated by accessory cells. The present study suggests that IL-4, alone or in combination with other growth factors, has divergent effects on the growth of AML progenitors irrespective of the CD34 expression, and that IL-6 acts synergistically with IL-3 or IL-4 on the growth of leukemic progenitors preferentially in CD34+ AML.

Adolescent↗
PubMed1991

Small-angle X-ray scattering studies of Mg.AT(D)P-induced hexamer to dimer dissociation in the reconstituted alpha 3 beta 3 complex of ATP synthase from thermophilic bacterium PS3.

The alpha 3 beta 3 complex of ATP synthase obtained from a thermophilic bacterium PS3 was isolated and found to show the ATPase activity (Kagawa, Y., Ohta, S., and Otawara-Hamamoto, Y. (1989) FEBS Lett. 249, 67-69). The structure and the nucleotide binding effects of the alpha 3 beta 3 complex were investigated by means of small-angle x-ray scattering and high performance liquid chromatography. The scattering profile from the alpha 3 beta 3 complex was explained with a model in which the complex is made of an ellipsoid of revolution with the axes of 121.8, 121.8, and 72.0 A having an elliptical hollow cavity with the axes of 35.4, 35.4, and 72.0 A. By the addition of Mg.AT(D)P, significant changes in the scattering profile were observed, in which the radius of gyration decreased from 44 to 35 A. This change was found by gel filtration to be caused by the dissociation reaction from the alpha 3 beta 3 hexamer to the alpha beta dimer. The dissociation of the alpha 3 beta 3 complex was not induced by unhydrolyzable ATP analogue, nor by Pi, Mg2+, and Pi + Mg2+. The structure of the dimer was well explained by the triaxial ellipsoidal model with the axes of 105.2, 39.4, and 108.2 A. The dissociation into the dimer is considered to be related to the ATPase activity because the AT(D)P-induced dissociation is observed only in the presence of Mg2+ ions.

Adenosine Diphosphate↗
PubMed1991

Physicochemical determinants for the interactions of magainins 1 and 2 with acidic lipid bilayers.

Permeability enhancement of acidic lipid small unilamellar vesicles (dioleoylphosphatidylglycerol, DOPG; dipalmitoylphosphatidylglycerol, DPPG; bovine brain phosphatidylserine, PS) induced by magainins 1 and 2, basic antimicrobial peptides from Xenopus skin, was investigated at 30 degrees C based on leakage of calcein, an entrapped fluorescent marker. Both the peptide concentration and the lipid concentration dependencies of the leakage rate were analyzed to obtain the binding isotherms of the peptides to the membranes and the 'membrane-perturbing activities' of the membrane-bound peptides. For both peptides, the binding affinity was in the order DOPG greater than DPPG greater than PS, which coincided with the zeta potential order (-54, -39, and -9 mV, respectively). An increase in salt concentration of the medium reduced binding and leakage. Electrostatic interactions play a crucial role in the binding process. On the other hand, the membrane-perturbing activity is regulated by membrane fluidity: The fluid membranes (DOPG and PS) were leakier. A circular dichroism study suggested that at least 14 positively charged residues in the N-terminal regions can form amphiphilic helices which interact with the membranes. An even stronger binding of magainin 2 can be explained in terms of more positive charges in its N-terminal region. A tentative model for the magainin-lipid interactions is hypothesized.

Amino Acid Sequence↗