Biomedical subjects
Publications and source records attributed to A Yamada.
Preliminary screening of antiviral AIDS drugs has been carried out using three different in vitro assay systems. Among 138 samples tested, two were found to inhibit the growth of HIV in vitro. Neither of the positive samples has hopeful signs, as the ranges of effective doses of the samples are very narrow.
Preliminary screening of antiviral AIDS drugs has been carried out using three different in vitro assay systems. Among 246 samples of different origin tested, six were shown to inhibit the growth of HIV in vitro. Two of the positive samples have hopeful signs, as the ranges of effective doses are wider than those of most of positive samples which had been found by us.
MAGE genes encoding tumor-rejection antigens recognized by cytotoxic T lymphocytes are expressed at the mRNA level in various malignant tumors. We have investigated the expression of genes MAGE-1, -2, -3/-6 and -4a/-4b at the mRNA level in malignant and non-malignant ovarian tumors as well as in normal ovaries by reverse transcription-polymerase chain reaction. MAGE-1, -2, -3/-6 and -4a/-4b were expressed in 12, 5, 11 and 4 of 58 malignant tumors, respectively. The majority of these MAGE-mRNA-positive tumors were histologically surface-epithelial-stromal tumors, in particular serous adenocarcinomas. They mostly consisted of either advanced-stage or recurrent tumors. In contrast, neither benign tumors nor normal ovaries expressed any of the MAGE genes investigated. A 46-kDa MAGE-1 protein was identified in MAGE-1-mRNA-positive serous adenocarcinomas by immunoblot analysis with polyclonal anti-MAGE-1 antibody. These results provide important information for specific immunotherapy of ovarian serous adenocarcinomas with MAGE gene products.
BACKGROUND: Right-side circulatory failure (RSCF), a common complication of heart transplant and left ventricular assist device recipients, results in decreased cardiac output because of diminished flow across the pulmonary circuit. We hypothesized that creation of a controlled venoarterial shunt would result in decompression of the right ventricle and improved systemic cardiac output at tolerable oxygen saturations. METHODS AND RESULTS: A venoarterial shunt was created in a large-animal model (calf, n = 6). RSCF was induced by banding the pulmonary artery. Hemodynamic measures and blood gas determinations were obtained during nonshunted and shunted states. Pulmonary artery banding increased mean right ventricular systolic pressure from 44.9 +/- 2.1 mm Hg (mean +/- SEM) to 85.9 +/- 6.9 mm Hg (P < .05, paired t test) and decreased mean aortic flow from 7.8 +/- 1.0 to 4.2 +/- 1.1 L/min (P < .05). Flow through a venoarterial shunt at approximately 40% of cardiac output resulted in a decrease in right ventricular end-systolic pressure from 85.9 +/- 6.9 to 72.1 +/- 5.6 mm Hg (P < .01, ANOVA), a decrease in mean pulmonary artery pressure from 42.9 +/- 5.0 to 37.2 +/- 3.8 mm Hg (P < .01), and an increase in aortic flow from 4.2 +/- .05 to 5.1 L/min (P < .01). Left ventricular stroke work decreased from 2.22 +/- 0.28 to 1.55 +/- 0.88 (P < .05). Carotid artery oxygen saturation did not change significantly (99.9 +/- .02 to 97.6 +/- 1.7) during shunting. CONCLUSIONS: A controlled venoarterial shunt improved hemodynamics and cardiac output in a large animal model with RSCF. This strategy may be useful in the management of transplant and left ventricular assist device recipients with perioperative RSCF.
We examined the induction of cytochrome P450-dependent mixed-function monooxygenase (MFO) in the human hepatoma cell line Hep G2 by means of several factors. The MFO activities induced in the cells cultured in medium containing five commercial sera varied significantly, and the activity in the cells cultured in the absence of serum was about twice as high as that in cells supplemented with serum. The activity of ethoxycoumarin O-deethylase was highest 12 hr after adding 3-methylcholanthrene, and it was induced by several polycyclic aromatic hydrocarbons such as benzo(a)anthracene and benzo(a)pyrene, which are usually found in urban air as environmental contaminants. Furthermore, an extract from the total suspended particles collected using a high volume air sampler, which was mutagenic in the Ames assay using Salmonella typhimurium TA98, induced the same enzyme activities in Hep G2 cells. These findings suggest that serum-free culture allows the stable and highly sensitive measurement of induced MFO activity, and that studies of MFO induction by environmental samples using human hepatoma Hep G2 cells should provide helpful information regarding the risk associated with environmental contaminants.
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Four aspartic acid residues (Asp126, Asp156, Asp233 and Asp295) of Bacillus cereus sphingomyelinase (SMase) in the conservative regions were changed to glycine by in vitro mutagenesis, and the mutant SMases [D126G (Asp126-->Gly etc.), D156G, D233G and D295G] were produced in Bacillus brevis 47, a protein-producing strain. The sphingomyelin (SM)-hydrolysing activity of D295G was completely abolished and those of D126G and D156G were reduced by more than 80%, whereas that of D233G was not so profoundly affected. Two mutant enzymes (D126G and D156G) were purified and characterized further. The hydrolytic activities of D126G and D156G toward four phosphocholine-containing substrates with different hydrophobicities, SM, 2-hexadecanoylamino-4-nitrophenylphosphocholine(HNP), lysophosphatidylcholine (lysoPC) and p-nitro-phenylphosphocholine (p-NPPC), were compared with those of the wild-type. The activity of D126G toward water-soluble p-NPPC was comparable with that of the wild-type. On the other hand, D156G catalysed the hydrolysis of hydrophilic substrates such as HNP and p-NPPC more efficiently (> 4-fold) than the wild-type. These results suggested that Asp126 and Asp156, located in the highly conserved region, may well be involved in a substrate recognition process rather than catalytic action. Haemolytic activities of the mutant enzymes were found to be parallel with their SM-hydrolysing activities. Two regions, including the C-terminal region containing Asp295, were found to show considerable sequence identity with the corresponding regions of bovine pancreatic DNase I. Structural predictions indicated structural similarity between SMase and DNase I. An evolutionary relationship based on the catalytic function was suggested between the structures of these two phosphodiesterases.
The MAGE multigene family, which includes the MAGE-1 and -3 genes that encode tumor-rejection antigens on HLA-A1 recognized by cytotoxic T-lymphocytes (CTL), is preferentially expressed at the mRNA level on human malignant cells, but not on normal cells. However, little is known about the MAGE-4, -41 and -6 genes. In this study, we have amplified 1040 bp (MAGE-1), 1061 bp (MAGE-3 and -6) and 1064 bp (MAGE-4 and -41) cDNA fragments, including the entire coding sequences (927-951 bp), using the reverse transcription-polymerase chain reaction (RT-PCR) method followed by nucleotide (nt) sequencing. One member had greater than 80 or 66% homology with the other members at the nt or deduced amino acid (aa) levels, respectively. Higher homology was found between MAGE-3 and -6 (98% at the nt level) and also between MAGE-4 and -41 (98%). The results of this investigation demonstrated high homology, as well as the clear differences between the members of the MAGE family at the coding sequence level.
Chloramine-T (CAT) is commonly used in the radiolabeling of bioactive molecules by halogenation. CAT may be used either as a solution or in an immobilized form (Iodobeads) to release radioactive elemental iodine or other halogens by oxidation of their salts. CAT has a very high chlorine potential, and it causes oxidative damage to sensitive substrate molecules, such as peptides and proteins. In some cases, the substrates are completely destroyed. To reduce the chlorine potential of CAT, morpholine was mixed with CAT prior to exposure to the substrates. This formed N-chloromorpholine, in situ, which readily reacted with KI to form I2. The kinetics of the formation of N-chloromorpholine from CAT and morpholine were studied spectrophotometrically by following the disappearance of CAT at 250 nm. The reaction was found to be rapid at all pH's from 5 to 11. 1-Aminocyclohexanecarboxylic acid (a model amino acid) decomposed rapidly in the presence of CAT, but there was no decomposition in the presence of N-chloromorpholine. N-Chloromorpholine was compared to CAT solution and Iodobeads for the iodination of L-tyrosine. The formation of mono- and diiodotyrosine were followed by HPLC. On an equimolar basis (0.55 microM), N-chloromorpholine produced a much greater yield of the mono- and diiodinated tyrosine than Iodobeads. Furthermore, decomposition products were observed when tyrosine was exposed to Iodobeads for 15 min. When a CAT solution was used at a higher concentration (5.5 microM), a substantial amount of decomposition occurred, and the yields of the two iodinated species were very small.(ABSTRACT TRUNCATED AT 250 WORDS)
We previously reported that the immunohistochemically defined LFA-1 antigen (LFA-1-like antigen) was expressed on various exocrine tissues uninvolved with tumors in patients with malignant diseases using LFA-1 alpha-specific monoclonal antibodies (mAb) 2F12 and HVS6B6. In this study we investigated differences at the molecular level between LFA-1 on leukocytes and LFA-1-like antigen on MKN45.16, a subline derived from an adenocarcinoma line MKN45 that expresses a high amount of LFA-1-like antigen. LFA-1-like antigen was reactive to mAb 2F12 or HVS6B6, but not to any of the other five different LFA-1 alpha (CD11a)-specific or four LFA-1 beta (CD18)-specific mAb. mAb 2F12 immunoprecipitated a 200-kDa membrane protein (LFA-1-like antigen) from MKN45.16 cells, whereas it precipitated 180-kDa (LFA-1 alpha) and 95-kDa (LFA-1 beta) proteins from a monocytic cell line (THP-1) under both nonreducing and reducing conditions. The molecular difference was confirmed further by N-glycanase treatment of the immunoprecipitates. The isoelectric point of LFA-1-like antigen was 6.0, whereas those of LFA-1 alpha and LFA-1 beta were 6.0 and 4.7, respectively, by two-dimensional gel electrophoresis. Expression of LFA-1 alpha gene on MKN45.16 cells was not detected at the mRNA level by six different sets of LFA-1 alpha-specific oligonucleotides and reverse transcription-polymerase chain reaction. These results indicated that LFA-1-like antigen on an adenocarcinoma cell line was a distinct molecule from LFA-1 on leukocytes.
Autoantibodies in systemic lupus erythematosus (SLE) are believed to be produced through an antigen-driven mechanism, i.e., autosensitization with autoantigens. If this is the case, it is conceivable that antigenic determinants reactive with SLE autoantibodies and induced antibodies raised by immunization are quite similar. To examine this issue, rabbits were immunized with purified histone H1 or chromatin. Although immunization with purified histone H1 did not produce detectable amounts of anti-histone H1 antibodies, immunization with chromatin mounted relatively good antibody responses against not only all histone subunits but also ssDNA. Epitopes on a histone H1 molecule reactive with SLE autoantibodies and rabbit antisera were determined using deletion mutants of a histone H1 molecule. At least two epitopes reactive with induced antibodies were found on a histone H1 and these were closely related to or the same as major autoepitopes in SLE. These data might indicate that B cells producing anti-histone H1 autoantibodies are quite similar to those induced by immunization and provide additional evidence that autosensitization with an autoantigen might be operative and a particulate antigen chromatin could be one of the immunogens for the production of anti-nuclear antibodies of various kinds in SLE.
A hemicoronal or coronal incision is required in combination with a buccal incision to expose the zygoma, including zygomatic process of the temporal bone, and lateral orbital rim under direct visualization. An endoscope was used to expose zygoma in selected cases to reduce the length of the incision. The zygomatic bone and arch were exposed and corrected using an endoscope in eight cases of zygomatic fracture and one case of zygomatic reduction through a small incision just behind the temporal hairline together with a buccal incision. The results obtained were satisfactory with no complications. Clear, magnified endoscopic visualization made it possible to correct some deformities located in this area without using a coronal incision. Endoscopic procedures result not only in dramatically less postoperative scarring because of the small access incisions, but they also cause less damage to vascular and lymphatic circulation and, therefore, are associated with less postoperative edema. However, the fixation of the zygomatic arch using the percutaneous method with an endoscope is a complicated procedure that requires more time than conventional procedures.
The functional recovery of gracilis muscles grafted for treatment of facial paralysis in combination with a cross-face nerve graft was evaluated on the basis of electromyography in 98 cases. Initial action potentials were recorded, on average, 8 months after transplantation. There was a tendency for such potentials to appear earlier in the case of patients who finally attained good muscle activity. Action potentials were polyphasic in the early stage and of short duration and low amplitude. An increase in the amplitude and duration of potentials and a shortening of the distal latency were observed with increase in the numbers of reinnervated muscle fibers. Thereafter, there was a tendency toward decreases in the duration and number of spikes due to the increasing similarity in the distal latency of each neuromuscular unit. The grafted gracilis muscles attained a stable state about 1 year after the initial recording of action potentials. It was expected that spontaneous action potentials during rest might serve to indicate the condition of reinnervation. Their absence during the first few months after transplantation may suggest necrosis of the grafted muscle, while those of long duration and high amplitude observed after 1 postoperative year may be suggestive of disturbance in the reinnervation process. In this study, we could not find any significant difference in the reinnervation process between that of a gracilis muscle grafted following a cross-face nerve graft and a muscle reinnervated following nerve transection and repair. We therefore believe that free gracilis muscle transplantation combining a cross-face nerve graft is appropriate for the reconstruction of muscle function.
A cross-leg free rectus abdominis flap, anastomosing to utilized "carrier" vessels of the contralateral noninjured leg, was used for reconstruction in six cases of extensive traumatic defects and deformities of a lower extremity. This method provides great advantages in free-flap reconstruction of complicated and unfavorable cases in which utilization of what would be suitable recipient vessels in the injured leg is most difficult, but there is good blood circulation of the leg.
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We investigated surface antigens and spontaneous cytokine production of T cells from bronchoalveolar lavage fluid (BALF) and aqueous humor (AH) from pulmonary sarcoidosis patients for a better understanding of the role of T cells in granuloma formation. The levels of CD3, CD11b, and CD28 antigen expression on freshly isolated T cells in the BALF of patients were significantly lower than those in peripheral blood lymphocytes (PBL) of either sarcoidosis patients or healthy donors (HD). In contrast, the levels of CD80 (B7/B7-1) and CD86 (B70/B7-2) antigen expression were significantly higher on these T cells and alveolar macrophages in the BALF of patients. Fifty-three T cell clones (TCC) established from the BALF and AH of the three sarcoidosis patients displayed primarily either CD4+ CD11b+ CD28+ or CD4+ CD11b- CD28- phenotypes. Most (61-90%) of these TCC spontaneously produced greater amounts of IL-1 alpha, IL-10, tumour necrosis factor (TNF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) than did TCC from the PBL from sarcoidosis patients or HD (P < 0.05). Interferon-gamma (IFN-gamma), IL-6, and IL-2, but not IL-4, were also produced by 40-48% of these TCC. These results suggest that CD4+ T cells of the affected organs of sarcoidosis patients are activated and involved in the immunopathogenesis of sarcoidosis through production of various cytokines.
We determined the anti-human immunodeficiency virus type 1 (anti-HIV-1) activities of various dideoxy-nucleoside analogs by using phytohemagglutinin-activated peripheral blood mononuclear cells (PHA-PBMs) and resting PBMs (R-PBMs) as target cells. The comparative order of anti-HIV-1 activity in PHA-PBMs was azidothymidine (AZT) > dideoxycytidine (ddC) > dideoxythymidinene (d4T) > dideoxyinosine (ddI) and 9-(2-phosphonylmethoxyethyl)adenine (PMEA) > 2'-beta-fluoro-dideoxyadenosine (F-ara-ddA), while that in R-PBMs was ddC > ddI, PMEA, and F-ara-ddA, >> AZT and d4T. A pronucleotide, bis-(S-acetylthioethanol)phosphotriester-ddAMP, which bypasses the anabolic monophosphorylation step for the intracellular delivery of ddAMP, was highly active both in PHA-PBMs and R-PBMs. These data may have basic and clinical relevance in the design of anti-HIV chemotherapy, particularly combination chemotherapy with dideoxynucleosides, and in the development of active pronucleotides.