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Biomedical subjects

A Yamada

Publications and source records attributed to A Yamada.

At least 271 records · Page 15Linked to original sources
PubMed1996

Induction of MAGE genes in lymphoid cells by the demethylating agent 5-aza-2'-deoxycytidine.

MAGE genes encoding tumor antigens recognized by cytotoxic T lymphocytes are appropriate target molecules for specific immunotherapy of cancer. We have investigated whether the demethylating agent 5-aza-2'-deoxycytidine (DAC) induces MAGE-1, -2, -3, and -6 in normal and malignant lymphoid cells. DAC induced these MAGE genes in both PHA/interleukin-2 (IL-2)-activated T cells from healthy donors and MAGE-negative T and B cell leukemias in most cases. It also induced MAGE-1 in IL-2-dependent T cell clones and all MAGE genes tested in Epstein-Barr virus-transformed B cell lines. Expression of MAGE-1 protein in the cells was confirmed by western blot analysis with anti-MAGE-1 polyclonal antibody. Therefore, demethylation is a potent stimulus to induce MAGE genes in both normal and malignant lymphoid cells.

Amino Acid Sequence↗
PubMed1996

A novel monoclonal antibody mNI-58A against the alpha-chain of leukocyte function-associated antigen-1 (LFA-1) blocks the homotypic cell aggregation and actively regulates morphological changes in the phorbol myristate acetate (PMA)-activated human monocyte-like cell line, U937.

A monoclonal antibody (mAb), designated mNI-58A, was produced by immunizing mice with the lipopolysaccharide (LPS)-stimulated monocyte-like cell line, U937. The antigen defined by mNI-58A was widely expressed on various lymphoid cells and all cell lines examined except the erythroid cell line, K562. When the reactive patterns between mNI-58A and the mAbs to various human differentiation antigens (CD11a, CD11b, CD11c, CD14, CD16, CD18, CD23, CD28, CD29, CD31, CD43, CD44, CD45RA, CD50, CD54, CD58, CD80, CD102, CD106, HLA-class I and-class II antigen) were compared, that of mNI-58A was found to be similar to those of the leukocyte function-associated antigen-1 (LFA-1) mAbs. Using a competitive immunofluorescence binding assay it was found that the preincubation with one of the CD11a mAbs, 2F12 completely blocked the subsequent binding of mNI-58A. mNI-58A prevented the homotypic cell aggregation of the phorbol myristate acetate (PMA)-activated U937 cells (referred to as PMA-U937) and PMA-activated Epstein-Barr virus (EBV)-transformed B cell lines, B-85 and Mann. mNI-58A markedly induced the spread formation of the PMA-U937 cells following this blocking of the homotypic cell aggregation, whereas 2F12 did not under the same condition. The spread formation induced by mNI-58A was completely blocked by cytochalasin B (CyB), cytochalasin D (CyD), cycloheximide (CHX) or protein kinase C inhibitors, sphingosine and H-7. The U937 cells markedly adhered to the tumor necrosis factor-alpha (TNF-alpha)-stimulated human umbilical vein endothelial cells (HUVECs) and also to the extracellular matrix protein, fibronectin, but mNI-58A did not enhance or block these adhesion process. mNI-58A precipitated two glycoproteins with molecular weight 180 kDa and 95 kDa as determined by SDS-PAGE analysis, which were identical to the LFA-alpha (CD11a) and beta (CD18) chains of leukocyte integrin precipitated by the CD11a mAbs, respectively. Sequential immunoprecipitation studies using the CD11a mAb (2F12) also indicate that mNI-58A recognizes an epitope on the alpha-chain of the LFA-1 molecule. The ability of mNI-58A to block the PMA-U937 cells and to induce the spread formation of these cells suggests that mNI-58A is a novel mAb reacting with an epitope on the alpha-chain of LFA-1 different from those recognized with the existing CD11a mAbs.

Antibodies, Blocking↗
PubMed1996

Adverse events associated with MMR vaccines in Japan.

The largest nationwide active surveillance of four Measles-Mumps-Rubella (MMR) vaccines was conducted in Japan. A total of 1255 pediatricians actively participated in the study, which comprised 8.6% of all members of the Japanese Pediatric Society. The total number of registered recipients of MMR vaccines was 38 203. They were arbitrarily given one of the MMR vaccines produced by three makers (Takeda, Osaka city, Kitasato Minato-ku. Tokyo and Biken Suita city, Japan) or the standard MMR vaccine made of designated strains (Kitasato's measles-AIK-C, Biken's mumps-Urabe Am9 and Takeda's rubella-To336) produced by Takeda, Kitasato and Biken and were observed for 35 days. The rates of virologically confirmed aseptic meningitis per 10,000 recipients were 16.6, 11.6, 3.2 and 0 for the standard MMR, Takeda MMR, Kitasato MMR and Biken MMR vaccines, respectively. The incidence of convulsions between 15 and 35 days was the highest with the standard MMR vaccine and the incidence of fever associated with vomiting occurring between 15 and 35 days (symptoms relevant to aseptic meningitis) were also the highest with the standard MMR vaccine. The incidence of parotid swelling was the lowest with Takeda MMR vaccine. This surveillance revealed that incidences of aseptic meningitis after administration of the standard MMR vaccine and of Biken MMR vaccine were different. This posed questions about the manufacturing consistency of the Urabe Am9 mumps virus vaccines. On the other hand, the National Institute of Health found that the biological characteristics of the Urabe Am9 mumps virus contained in the standard MMR vaccine and in the Biken MMR vaccine were different. The Biken Company reported that the mumps vaccine in the standard MMR vaccine was a mixture of two Urabe Am9 mumps vaccine bulks; one identical to that contained in the Biken MMR vaccine and the other produced by a different manufacturing process.

Child↗
PubMed1996

Distribution of human herpesvirus 6 and varicella-zoster virus in organs of a fatal case with exanthem subitum and varicella.

The distribution of human herpesvirus 6 (HHV-6) and varicella-zoster virus (VZV) was examined in autopsy samples from a fatal case with both virus infections. A 9-month-old boy developed convulsive seizures followed by macular skin rashes, rapidly progressed to brain death, and died 15 days after the onset, when signs of varicella were noted. An isolation of HHV-6 from blood and evaluation of antibody activities to various viral agents including HHV-6 were performed before his death. Postmortem examinations included: (i) isolation of HHV-6 and VZV from tissues or organs; (ii) detection of both virus antigens in tissues or organs by an indirect immunofluorescent assay using monoclonal antibodies to both viruses; (iii) amplification of both viruses and human herpesvirus 7 DNA sequences by a nested polymerase chain reaction assay; and (iv) endonuclease digestion of amplified products of HHV-6 DNA for differentation of variants A and B. Human herpesvirus 6 DNA was detected in peripheral blood mononuclear cells (PBMC) and plasma obtained at the eruptive stage but present only in PBMC 15 days after, indicating the primary infection with HHV-6, although the virus was not isolated from the same blood sample and a significant rise in the antibody titers to HHV-6 was not observed. Both virus antigens and DNA were detected in various tissues or organs obtained at autopsy, but only VZV was isolated from these samples, suggesting disseminated infection with both viruses in an infant. All the amplified products of HHV-6 DNA were variant B. Among the findings for the distribution of virus antigens, it was noteworthy that HHV-6 antigen was demonstrated in the endothelial cells of small vessels in the frontal lobe of the brain. There was no evidence of HHV-7 infection. These data indicate that the primary HHV-6 infection closely followed by the primary VZV infection had the potential hazard of an unexpected and apparently life-threatening event, in which disseminated infections with both viruses were noted in multiple tissues or organs including the brain.

Antibodies, Viral↗
PubMed1996

Hyperammonemia in a patient with short bowel syndrome and chronic renal failure.

A patient with short bowel syndrome (SBS) and renal failure developed a disturbance of consciousness with hyperammonemia. Abnormally low concentrations of ornithine, citrulline, and arginine were observed on the plasma aminogram. These results suggested that the activities of amino acid synthetase localized in the small intestinal flora were lost. The small intestine is required for arginine synthesis; thus, infusion limited to the essential amino acids to SBS patients will cause a deficiency of the urea cycle intermediates, ornithine, citrulline, and arginine and may lead to hyperammonemia. In addition, the renal insufficiency may have caused decreased excretion of ammonia. In this patient, supplemental arginine improved the symptoms.

Aged↗
PubMed1996

A case of nephrotic syndrome developing during postoperative gamma interferon therapy for renal cell carcinoma.

A 70-year-old man developed minimal-change nephrotic syndrome and acute interstitial nephritis while undergoing gamma interferon therapy following right nephrectomy for renal cell carcinoma. It appears that gamma interferon as well as renal cell carcinoma may have played a role as etiologic factors in this nephropathy. We report this extremely rare case of renal cell carcinoma complicated by minimal-change nephrotic syndrome and acute interstitial nephritis, and present a review of the literature.

Acute Disease↗
PubMed1996

Identification of low molecular weight probes on perforin- and Fas-based killing mediated by cytotoxic T lymphocytes.

Perforin- and Fas-based killing pathways are two major mechanisms of cytotoxic T lymphocytes (CTL)-mediated cytotoxicity. In this paper, we have reported the identification of low molecular weight probes on CTL-mediated cytolysis. In addition to inhibitors of acidification so far reported, three other groups of compounds have been identified to block perforin-based cytolysis by the CD8+ CTL clone: (1) an inhibitor of actin polymerization (cytochalasin D), (2) respiratory inhibitors (antimycin A and oligomycin A), and (3) protein kinase inhibitors (calphostin C, herbimycin A, K252a, and staurosporine). Since Fas-based cytolysis by CD4+ CTL clone was inhibitable or rather increased by these agents, only vacuolar type H(+)-ATPase inhibitors such as concanamycin A have been shown to be highly specific probes to block perforin-based CTL-mediated cytotoxicity.

Anti-Bacterial Agents↗
PubMed1996

Surgical treatment of mandibular osteoradionecrosis: versatility of the scapular osteocutaneous flap.

Osteoradionecrosis of the mandible is a serious complication of radiotherapy for head and neck cancer and no single treatment has to date met with consistent success. A free scapular osteocutaneous flap was successfully transferred in nine patients with mandibular osteoradionecrosis who before this had not responded to conservative treatment. All but one of the patients had good bone union and there was no evidence of recurrence during a mean follow up period of four years and one month. This flap not only provides a well-vascularised segment of the bone but also multiple, large skin paddles, each with an abundant and reliable blood supply. In addition, well-vascularised fascia and overlying subcutaneous tissue can be used to fill dead spaces and cover the bony segment and fixation plates. This reduces postoperative infection and promotes primary wound healing. This flap has proved useful for reconstruction of mandibular osteoradionecrosis, particularly when there is a large soft tissue defect.

Adult↗
PubMed1996

Establishment of cell lines stably expressing mumps virus glycoproteins.

We established two cell lines that stably express hemagglutinin-neuraminidase (HeLa-HN) and fusion proteins (HeLa-F) of a fusogenic strain of mumps virus. Infection of HeLa-F cells with a nonfusogenic strain resulted in induction of extensive cell fusion. On the other hand, HeLa-HN cells appeared resistant to cell fusion induced by mumps virus infection.

Animals↗
PubMed1996

[A case of middle cranial fossa meningioma extending into the infratemporal fossa: an approach to the pterygoid extension of the sphenoid sinus via the infratemporal fossa].

A case of middle cranial fossa meningioma extending into infratemporal fossa and the pterygoid process is presented. The patient had a sphenoid sinus extending inferolaterally into the pterygoid process, which is known as pterygoid extension of the sphenoid sinus. This type of variation of the sphenoid sinus allowed a safe and well-oriented approach to the pterygoid process via the infratemporal fossa. The tumor extending into the pterygoid process was removed successfully without damaging any surrounding structures, e.g. maxillary nerve or Vidian nerve. However, pterygoid extension of the sinus is seen in only 40% of cases. Therefore, close preoperative examination with bone window CT scan is mandatory before employing this approach.

Cranial Fossa, Posterior↗
PubMed1996

[Computed tomographical evaluation of diabetic nephropathy].

Diabetic nephropathy can be regarded mainly as a type of microangiopathy, but is a disease that may also include aspects of macroangiopathy. This is especially true of renal disease in non-insulin dependent diabetes mellitus (NIDDM), which is characterized not only by diabetic glomerulosclerosis, but also by atherosclerosis. We performed morphological studies on the kidney, using computed tomography (CT), focusing on such points as: (1) abdominal aortic calcifications at the level of kidney, (2) calcifications in the renal artery, and (3) wedge-shaped defects on the renal surface. We noted that these findings became more prominent in NIDDM patients during end-stage renal failure than during normal renal function, and were significantly more common in those two NIDDM groups than in age-matched nondiabetic patients without hypertension, hyperlipidemia or gout. NIDDM patients exhibited these features more frequently than IDDM patients.

Aged↗
PubMed1996

[A case of Aicardi syndrome: neurophysiological investigation].

A Japanese girl developed tonic spasms in series at two months after birth. When she was admitted at 4 months, she had generalized muscle hypotonia and could not control her head. She had atotal agenesis of the corpus callosum on MRI, reticulo-lacunitis revealed by ophthalmologic examination, and hypsarrhythmia in EEG. Brain stem auditory evoked potentials and flash-visual evoked potentials exhibited abnormally asymmetrical findings. The cortical components of somatosensory evoked potentials were not elicited on admission, but some components became to be recognized on median nerve stimulation in accordance with improvement of EEG findings after various therapeutic trials. We concluded that these neurophysiological examinations were useful to investigate the abnormal lesions of the central nervous system in patients with Aicardi syndrome.

Agenesis of Corpus Callosum↗
PubMed1996

[A new three-dimensional CT reconstruction method for cerebral arteriovenous malformation: development and clinical evaluation of see-through view method].

The authors developed a new three-dimensional reconstruction method called "See-Through View (STV)" using a spiral CT in evaluating of cerebral arteriovenous malformation (AVM). Spiral CT was performed in eight patients with AVM. STV was obtained by reconstructing with a voxel transmission projection using a double threshold method. In all eight patients, STV images enable us to depict the nidus of AVM from all angles by see-throughing skull bone, evaluating the relationship of the vascular lesions adjacent to other cerebrovascular or skeletal structures. In conclusion, STV will provide us further spatial recognition, and will be greatly helpful for surgical planning.

Adult↗
PubMed1996

TCR gamma delta + T cells in peripheral blood of patients with adult Still's disease.

OBJECTIVE: Adult Still's disease, a systemic inflammatory disorder of unknown etiology, shows few specific laboratory markers and histological features. We investigated T cell subsets in peripheral blood lymphocytes (PBL) of patients with adult Still's disease to elucidate immunological features of the disease. METHODS: We studied T cell subsets in PBL of 12 patients with adult Still's disease by flow cytometric analysis. T cell subsets were also investigated for more than 6 months in PBL of 3 patients with adult Still's disease. RESULTS: Both the percentage and absolute number of T cell receptor gamma delta positive (TCR gamma delta +) T cells in active adult Still's disease (n = 6) were significantly (p < 0.05) higher than those in inactive adult Still's disease (n = 6), inactive rheumatoid arthritis (n = 8), or healthy controls (n = 20). An increase of TCR gamma delta + T cells was observed in 5 of 6 patients with adult Still's disease at the active phase. TCR gamma delta + T cells also increased for a considerable period in all the patients tested. In contrast, there were no significant differences in the other T cell subsets (CD3, CD4, CD8, TCR alpha beta) between all the patients and healthy donors. Levels of TCR gamma delta + T cells in PBL correlated well with those of serum ferritin and C-reactive protein in one of the 3 patients whose PBL could be serially investigated. These increased TCR gamma delta + T cells mostly consisted of a V gamma 9/V delta 2 subset. CONCLUSION: TCR gamma delta + T cells in PBL are significantly increased in the active phase in patients with adult Still's disease.

Adult↗
PubMed1996

[Clinical usefulness of trans-brachial angiography for abdominal diseases].

Trans-brachial angiography for abdominal disease has several advantages for the patient. For example, the patient can walk immediately following angiography and can return home or eat in the sitting position after examination. We performed trans-brachial angiography on 451 cases of abdominal disease from June 1992 to March 1995. The purpose of performing angiography in 215 of these cases was examination only, while that in the remaining 236 cases was embolization of liver tumor. Four hundred and five cases were used for the study of safety and accuracy, and the remaining 46 cases as well as another 51 cases of trans-femoral angiography were used for the study of technical difficulty. Based on these experience, we have concluded that trans-brachial angiography for abdominal disease is highly useful, safe and accurate, and can provide significant advantages for patients requiring abdominal angiography.

Adult↗