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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 919 records · Page 51Linked to original sources
PubMed1990

Human T lymphotrophic virus type I may not be associated with multiple sclerosis in Japan.

To study the possible involvement of human T lymphotrophic virus type I (HTLV-I) or a related retrovirus in Japanese cases of multiple sclerosis (MS), we first performed a Western blot analysis with purified Ag of HTLV-I. Ten out of 31 MS patients (32.2%), 19 of 66 patients (28.8%) with other neurologic diseases, and 2 of 64 healthy blood donors (3.1%) had antibodies reactive with Ag corresponding to the group-specific Ag (gag) proteins (p15, p19, p24) on their sera. There were no significant differences between MS and other neurologic diseases concerning the patterns and the frequency. Second, we tried to establish T cell lines from PBMC of 22 MS patients with crude IL-2 without accessory cells, because HTLV-I-infected T cells can be immortalized in a high ratio under those conditions. Only one T cell line (MS-14C), however, could be maintained in long term culture. MS-14C and cultured T cells for 3 to 5 wk derived from MS patients were examined by Southern blot analysis under both stringent and low stringent conditions with HTLV-I as a probe. No HTLV-I related bands could be detected. By polymerase chain reaction examination, we also could not detect HTLV-I provirus genome in the fresh PBMC from 20 MS patients, although some of them had gag-reactive antibodies. Our data do not favor the hypothesis of HTLV-I or an HTLV-I-related human retrovirus in the etiology of MS.

Antigens, Viral↗
PubMed1990

[Effects of experimental hepatic artery embolization with lipiodol and gelatin sponge on liver tissue].

The effect of hepatic artery embolization with Lipiodol (Lp) and Gelatin sponge particles (GSP) on liver tissue was evaluated in 17 dogs embolized with GSP, 12 dogs with Lp and 19 dogs with Lp + GSP. Survival rate and extent of liver damage were used as evaluation criteria. None of the dogs with GSP died during the 4 week period, two exhibited small liver infarctions. Of the dogs with 0.2 to 5 ml/kg Lp, two dogs with 4 ml/kg or 5 ml/kg Lp died of cardiac failure. Gross liver examination did not show any liver infarction. Eight of the 19 dogs with Lp + GSP died of liver failure. Gross examination of the surviving dogs demonstrated infarction in 9 of the 11 livers with 100% incidence in those with 0.2 ml/kg or 0.5 ml/kg Lp. Liver infarction increased in size with the increase of Lp volume. In combination with Lp + GSP, the Lp volume should be less than 0.1 ml/kg.

Animals↗
PubMed1990

[Prophylactic therapy for liver metastasis of gastrointestinal carcinomas using biological response modifiers (BRM): fundamental studies on the inhibition of experimental liver metastasis by intraportal administration of OK-432].

For prophylactic therapy to inhibit hepatic metastatic recurrence after surgical treatment of gastro-intestinal carcinomas, the effects of OK-432, a biological response modifier (BRM), were examined with inoculation of tumor cells and administration of OK-432 via portal vein. Experiments with the inhibition of liver metastasis were performed as follows. The animals were divided into five groups. Group 1: 1.0 KE of OK-432 was given intraportally 5 minutes after injection of 5.0 X 10(6) tumor cells per rat via the portal vein. Group 2: Non-medicated group, only 5.0 X 10(6) tumor cells per rat were injected into portal vein, as the control for group 1. Group 3: 0.5 KE of OK-432 and 2.5 X 10(6) tumor cells per rat were used. Group 4: 1.0 KE of OK-432 and 2.5 X 10(6) tumor cells were used. Group 5: Non-medicated group, injected with 2.5 X 10(6) tumor cells as the control group for groups 3 and 4. Colonies of metastases in the liver of each group were examined by autopsy on the 30th day after treatment. Metastases were observed in 75% of group 1, 100% of group 2, 58.8% of group 3, 64.3% of group 4 and in 90% of group 5. For the investigation of the mechanisms to inhibit these liver metastases, 51Cr labeled AH60C tumor cells were injected into the portal vein, and the remained of radioactivity in rat liver was examined. The result showed that OK-432 injected into the portal vein did not directly kill the lodging tumor cells. To prove the morphological evidence of inhibition of hepatic metastasis, the changes of tumor cells were microscopically observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

A minimally invasive technique for multiple measurement of regional blood flow of the rat brain using radiolabeled microspheres.

To observe the rat brain blood flow with microspheres, a left ventricular catheter for sphere introduction was threaded into position via the right brachial artery. Cross-circulation with a donor rat was employed to prevent any mismatch between the infused and sampled blood volumes. Multiple measurements yielded stable flow data, and the responsiveness to hypercapnia was well preserved, irrespective of the dose of injected spheres (48 x 10(3) and 130 x 10(3)).

Animals↗
PubMed1990

Chemiluminescence high performance liquid chromatography of corticosteroids using lucigenin as post-column reagent.

A chemiluminescence high performance liquid chromatographic method for the determination of corticosteroids and tetrahydrocorticosteroids has been developed. Corticosteroids and their metabolites extracted from urine samples were separated using an ODS column and a mixture of methanol + water + 0.01 M sodium acetate solution (70:30:5) as eluent. The eluent from the column was mixed with the chemiluminescent solution containing lucigenin and Triton X-100 and a 0.28 M KOH solution by pumps and monitored by a chemiluminescence detector. No interference was encountered and the method is both precise and reproducible.

Acridines↗
PubMed1990

Sodium-23 MR imaging of the kidney in guinea pig at 2.1 T, following arterial, venous, and ureteral ligation.

In vivo 23Na magnetic resonance images of guinea pig kidney were obtained at 2.1 T using a spin-echo sequence with an echo time of 19 ms. The intact kidney showed a very strong signal intensity in the sodium image. The signal intensity of the kidney decreased to 55% after ligation of the renal artery together with the vein and the ureter. The total sodium content in the excised kidney after arterial occlusion, measured by flame photometry, was 24% higher than that in the intact kidney. The transverse relaxation time (T2) of the extracellular sodium in the isolated kidney decreased to one-third of that in the intact kidney. This shortening of T2 may be partly responsible for the decrease in the 23Na signal intensity from the kidney after arterial occlusion.

Animals↗
PubMed1990

Effects of zinc oxide-eugenol on leucocyte number and lipoxygenase products in artificially inflamed rat dental pulp.

The number of leucocytes and level of endogenous LTC4 in the pulp tissue were measured by a histological method and radioimmunoassay, respectively. When the mandibular incisor pulp was irritated by drilling a hole in the dentine without using any coolant, the number of polymorphonuclear leucocytes and lymphocytes and the concentration of LTC4 increased to 3.2, 1.9 and 1.8 times their respective levels in normal pulp 6 h after the injury. The total leucocyte number in blood collected from these rats was also increased significantly. In contrast, when the cavities cut in dentine were filled with a zinc oxide-eugenol mixture (powder: liquid 100 mg/25 microliters), the increase in the number of cells was significantly curtailed, and the LTC4 level fell to 50% of that in normal pulp within 1 h after the filling. No decrease in the LTC4 level was observed after filling with a zinc oxide-water mixture, but the level decreased in response to an increase in eugenol content in the zinc oxide-eugenol placed in the cavity. Biosynthesis of [14C]-HETE and HPETE from [14C]-arachidonic acid was inhibited by the addition of 10 microM eugenol to the pulp homogenate. Thus eugenol released from zinc oxide-eugenol inhibited the biosynthesis of lipoxygenase products and the early chemotactic accumulation of leucocytes.

Animals↗
PubMed1990

A simple and rapid method for HLA-DP genotyping by digestion of PCR-amplified DNA with allele-specific restriction endonucleases.

We previously reported a simple and rapid method for HLA-DQA genotyping by digestion of polymerase chain reaction-amplified DQA genes with allele-specific restriction endonucleases. Here we report the application of this method to DP genotyping. The second exon of the HLA-DPB genes was selectively amplified from genomic DNAs of 72 HLA-D homozygous B-cell lines by the polymerase chain reaction method. Amplified DNAs were digested with ApaI, SacI, BstUI, FokI, and RsaI, which can recognize allelic sequence variations in the polymorphic segments of the DPB second exon and then subjected to electrophoresis in polyacrylamide gels. Sixteen different polymorphic patterns of the restriction fragments were found, and twelve were identical to patterns predicted from the known DNA sequences correlating with each HLA-DPw specificity defined by cellular typing. The other four patterns were distinct from those of the known DPw specificities, suggesting the presence of novel DP alleles. This polymerase chain reaction-restriction fragment length polymorphism method provides a simple and rapid technique for accurate definition of HLA-DP types at the nucleotide level, replacing the technically demanding method of primed lymphocyte typing.

Alleles↗
PubMed1990

Reconstruction of the triangular fibrocartilage complex after surgery for treatment of synovial osteochondromatosis of the distal radioulnar joint.

Synovial osteochondromatosis of the hand is uncommon, except for tenosynovial chondromatosis of the digits. It is even more rare in the wrist joint. A patient with synovial osteochondromatosis of the distal radioulnar joint that involved the triangular fibrocartilage complex is described. At operation, synovectomy, excision of osteochondral bodies, and removal of the entire triangular fibrocartilage complex was done. The triangular fibrocartilage complex was reconstructed using part of the extensor carpi ulnaris tendon. One year after operation, the patient had regained almost full range of motion and is without pain.

Cartilage, Articular↗
PubMed1990

[11C]octopamine synthesis using [11C]cyanide: chemical and enzymatic approaches for the [11C]cyanohydrin synthesis.

[11C]-p- and m-octopamine hydrochloride were synthesized from [11C]HCN in a two-step sequence. Chemical and enzymatic approaches were used for the formation of the [11C]cyanohydrin intermediates as the key step. Isolated radiochemical yields of 0.7-2.3% at the end-of-synthesis were obtained with an overall preparation time of 40-60 min. The enantiomeric purity of the [11C]-p-octopamine obtained through the enzymatic process was 92% e.e. in the (S)-enantiomer, whereas that of the [11C]-m-octopamine was 42% e.e. in the (R)-enantiomer, as determined by HPLC without any derivatization.

Carbon Radioisotopes↗
PubMed1990

Arteriovenous shunt in digit replantation.

From May 1958 to May 1987, 331 digits were replanted successfully with an overall survival rate of 86.2%. Complete success in replantation of amputated fingers requires an accurate anastomoses of both arteries and veins. However, anastomosis between arteries may not be possible in some patients. Since reports that a thumb amputated at the interphalangeal joint area could be successfully replanted by an arteriovenous shunt on the palmar side, we did arteriovenous shunts in four such cases. Two replantations were successful; necrosis developed in the other two patients.

Adult↗
PubMed1990

An experimental study of the venous flap: investigation of the recipient vein.

In previous studies using rabbit ears, total venous perfusion flaps (TVPF) were used that did not contain in the experimental model any chosen arteries truly representative of clinical venous flaps. We discovered that the TVPF could survive even under conditions of poor blood circulation. In the present study, conditions of the recipient veins were investigated using flow-through veins in TVPFs of rabbit ears and human dorsal digital veins. The research suggested that conditions for TVPF survival are a high density of the venous network in the flap and the presence of venous oscillation, high oxygen tension, and effective blood flow in the recipient vein.

Adolescent↗
PubMed1990

Continuous local intraarterial infusion of antithrombotic agents for epigastric flap transfer in rabbit.

In free tissue transfer, the recipient arteries and veins are often damaged by injury, and their lumens are often narrowed due to thickening of the intima. These factors are considered paramount in the poor success rate of free tissue transfers. In the reported study, the authors examined the effects of continuous intraarterial infusion with heparin and urokinase in experimental epigastric flap transfer. By intraarterial infusion, the drug concentration at the target site could be significantly increased. The viability of an epigastric flap transferred to a recipient site with thickened arterial intima was significantly improved in a rabbit model by a seven-day continuous local intraarterial infusion of heparin at 10 U/kg/hr and urokinase at 100 IU/kg/hr, compared with control or intravenous infusion. Use of an anticoagulant with a fibrinolytic enzyme is considered to be the best choice for a successful outcome in flap transfer.

Abdomen↗
PubMed1990

Adult T-cell leukemia-derived factor/thioredoxin, produced by both human T-lymphotropic virus type I- and Epstein-Barr virus-transformed lymphocytes, acts as an autocrine growth factor and synergizes with interleukin 1 and interleukin 2.

Interleukin 1 (IL-1) has been obtained from the Epstein-Barr virus-infected B-lymphoblastoid cell line 3B6 and shown to be involved in autocrine growth of 3B6 B cells. Independently, adult T-cell leukemia-derived factor (ADF) was purified from human T-lymphotropic virus I-infected leukemic T-cell line (ATL-2) and reported as an interleukin 2 (IL-2) receptor-inducing factor. We have previously reported the same molecular mass, pI, and NH2-terminal amino acid sequence for both 3B6-derived IL-1 and ADF. cDNA cloning of ADF demonstrated high homology with the prokaryotic disulfide reducing enzyme thioredoxin. We show here that ADF and 3B6-derived IL-1 are identical. By RNA blot, 3B6 and ATL-2 cells were shown to contain high levels of 0.6-kilobase mRNA corresponding to ADF. Such message was not detected in resting peripheral blood lymphocytes but could be weakly induced by lymphocyte activation. Antibodies have been raised against synthetic peptides corresponding to the NH2 terminus and the COOH terminus of ADF. Immunoblotting and sequential immunoprecipitation with these antibodies revealed the same 13-kDa protein in 3B6 and ATL-2 cells. Recombinant ADF could sustain growth of 3B6 and ATL-2 cells at low cellular concentration without fetal calf serum; ADF, thus, appears involved in their autocrine growth. Similarly, recombinant ADF could enhance growth of other B-cell lines, including the Epstein-Barr virus-negative Burkitt lymphoma line BL41 and the lymphoblastoid cell lines CRAG8, CRB95, and 1G8. Finally, recombinant ADF exhibits marked synergism with other cytokines, such as IL-1 and IL-2, allowing virally infected lymphocytes to respond to suboptimal amounts of a variety of growth factors.

B-Lymphocytes↗
PubMed1990

Adenosine triphosphate compartmentation in the rat heart: a 31P spin-lattice relaxation study.

Longitudinal relaxation times (T1) of phosphorus compounds in the perfused rat heart and erythrocytes were measured using the 31P Driven-Equilibrium Single-Pulse Observation of T1 relaxation (DESPOT) method at 33 degrees C. Both creatine phosphate in the heart and the three phosphate groups of adenosine triphosphate (ATP) in erythrocytes showed single-exponential relaxation. The three phosphate groups of ATP in the heart, however, had two T1 components. The T1 values of the short and the long T1 components of the beta-phosphate of ATP were ca. 0.4 and 14 s, respectively. The fraction with the long T1 represented ca. 30% of the total ATP content. These results suggested that there were two major pools of intracellular ATP in the rat heart which could be determined by 31P NMR spectroscopy.

Adenosine Triphosphate↗
PubMed1990

Energy coupling of L-glutamate transport and vacuolar H(+)-ATPase in brain synaptic vesicles.

Energy coupling of L-glutamate transport in brain synaptic vesicles has been studied. ATP-dependent acidification of the bovine brain synaptic vesicles was shown to require CI-, to be accelerated by valinomycin and to be abolished by ammonium sulfate, nigericin or CCCP plus valinomycin, and K+. On the other hand, ATP-driven formation of a membrane potential (positive inside) was found to be stimulated by ammonium sulfate, not to be affected by nigericin and to be abolished by CCCP plus valinomycin and K+. Like formation of a membrane potential, ATP-dependent L-[3H]glutamate uptake into vesicles was stimulated by ammonium sulfate, not affected by nigericin and abolished by CCCP plus valinomycin and K+. The L-[3H]glutamate uptake differed in specificity from the transport system in synaptic plasma membranes. Both ATP-dependent H+ pump activity and L-glutamate uptake were inhibited by bafilomycin and cold treatment (common properties of vacuolar H(+)-ATPase). ATP-dependent acidification in the presence of L-glutamate was also observed, suggesting that L-glutamate uptake lowered the membrane potential to drive further entry of H+. These results were consistent with the notion that the vacuolar H(+)-ATPase of synpatic vesicles formed a membrane potential to drive L-glutamate uptake. ATPase activity of the vesicles was not affected by the addition of Cl-, glutamate or nigericin, indicating that an electrochemical H+ gradient had no effect on the ATPase activity.

Adenosine Triphosphate↗
PubMed1990

A simple and rapid method for HLA-DRB and -DQB typing by digestion of PCR-amplified DNA with allele specific restriction endonucleases.

The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, which we previously reported as an efficient and convenient typing technique for accurate definition of the HLA-DQA1 and -DPB1 alleles, is now extended and applied to HLA-DRB and -DQB typing. The second exon of the HLA-DRB (B1 and B3 or B4) and DQB (B1 and B2) genes was selectively amplified from genomic DNAs of 70 HLA-homozygous B cell lines by PCR. Amplified DNAs were digested with the restriction endonucleases, which can recognize allelic variations specific for HLA-DR, -DQ, and -Dw allospecificities and then subjected to electrophoresis in polyacrylamide gel. Of DRB genes, FokI, HinfI, HhaI, HphI, KpnI and SacII were selected and the 20 different polymorphic patterns of the restriction fragments thus obtained were found to correlate with each HLA-DR and -Dw type defined by serological and cellular typing. Of the DQB genes, FokI, HaeIII, HhaI, RsaI and Sau3AI produced nine different polymorphic patterns of the restriction fragments, correlating with the HLA-DQ and -Dw types. This PCR-RFLP method provides a simple and rapid technique for accurate definition of the HLA-DR, -DQ and -Dw types at the nucleotide level, eliminating the need for radioisotope as well as allele specific oligonucleotide probes.

Alleles↗