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Biomedical subjects

N Aoki

Publications and source records attributed to N Aoki.

At least 325 records · Page 18Linked to original sources
PubMed1992

[Lymphomatoid granulomatosis (LYG) occurring in a patient with follicular lymphoma during remission].

A 49 years-old man presented with dry cough, low grade fever, and abnormal shadow on a chest X-ray. He had suffered from follicular lymphoma of the liver 5 years previously. He received irradiation therapy in combination with chemotherapy for approximately three years and had been in complete remission. Physical and radiological examination revealed pleural effusion and softly dense masses in the right lung. The laboratory data were within normal limits. He was diagnosed as having lymphomatoid granulomatosis (LYG) by open lung biopsy. The lung lesion was mainly infiltrated with T cells. The patient received prednisolone and the lung lesions disappeared. However, when a lung mass was noted two months later, he started to receive combination chemotherapy consisting of cyclophosphamide, adriamycin, vincristine, and prednisolone every three months. He has not shown relapse of LYG so far. To investigate the association between the preceding follicular lymphoma and subsequent LYG at this time, DNA analysis using the PCR technique was carried out. The LYG lesion did not show a rearranged band for the JH probe, while the paraffin-embedded specimen of the preceding follicular lymphoma had shown rearranged band for the JH band. Southern blot analysis of the LYG lesion, showed no rearrangement for TCR beta, gamma or JH probe. These findings indicate that the LYG was different from the preceding follicular lymphoma in terms of origin. LYG is considered to be induced in the immunosuppressive state due to lymphoma.

Combined Modality Therapy↗
PubMed1991

Establishment of an interleukin-3-dependent leukemic cell line from a patient with chronic lymphocytic leukemia in the acute phase.

A novel human leukemic cell line, TMD2, which proliferates dependently on interleukin-3 (IL-3), was established from the peripheral blood (PB) of a patient with chronic lymphocytic leukemia (CLL) in the acute phase. After 8 years of the chronic phase of CLL, lymphoblastoid cells appeared and became dominant in the PB. After repeated subcultures of the patient's PB cells in the acute phase, lymphoblastoid cells have proliferated actively in the presence of recombinant human IL-3, and the TMD2 cell line has been established. The lymphoblastoid cells in acute phase and TMD2 cells proliferated dependently on IL-3, whereas growth of the small lymphocytes in chronic phase was not supported by IL-3. Other ILs (IL-1, 2, and 4 through 6) or CSF did not support the growth or survival of TMD2 cells. The existence of high-affinity receptors for IL-3 was shown on TMD2 cells (binding sites 88 per cell, Kd = 76.9 pmol/L). DNA extracted from the small lymphocytes in the chronic phase, the lymphoblastoid cells in the acute phase, and TMD2 cells showed the same rearrangement pattern of the immunoglobulin heavy-chain gene. Therefore, these cells were considered to have originated from the same clone. These results imply that a genetic event that caused the responsiveness to IL-3 in the cell of the chronic phase caused the acute transformation of CLL in this patient. We consider that TMD2 cell line is valuable as a model of cells of CLL in the acute phase and as a tool for studying the signal transduction system of IL-3.

Aged↗
PubMed1991

Antiproliferative and differentiative effects of recombinant interleukin-4 on a granulocyte colony-stimulating factor-dependent myeloblastic leukemic cell line.

The effect of recombinant human interleukin-4 (IL-4) on a granulocyte colony-stimulating factor (G-CSF)-dependent human myeloblastic leukemic cell line, OCI-AML1a, was investigated. IL-4 suppressed the clonogenic cell growth in methylcellulose culture, inhibited the uptake of 3H thymidine in a dose-dependent manner at 5 to 100 U/mL, and consequently suppressed the growth of clonogenic cells in short- and long-term suspension cultures. In addition, IL-4 markedly increased the number of adherent cells. These adherent cells were alpha-naphthyl-butyrate (alpha-NB) esterase-positive and showed macrophage-like appearance, increased expression of CD14, CD11b, CD23, and Ia, and significantly decreased clonogenicity. On the other hand, nonadherent cells growing in suspension showed only slight increase in proportion of alpha-NB esterase-positive or monocyte/macrophage-like cells and increased CD23 expression by an addition of IL-4. The clonogenicity of the nonadherent cells was not significantly influenced by IL-4. By addition of the media conditioned by OCI-AML1a cells in the presence of IL-4, the clonogenic cells growth of OCIAML1a cells was suppressed and adherent cells were markedly increased. The suppressive and differentiative effects on OCI/AML1a cells of the conditioned media and IL-4 itself were almost completely abolished by anti-IL-4 antibody. Furthermore, the neutralizing antibodies against transforming growth factor-beta 2 (TGF-beta 2), tumor necrosis factor-alpha (TNF-alpha), or IL-6 did not influence the effect of recombinant IL-4. Taken together, IL-4 was shown to suppress the growth and induce differentiation toward adherent macrophage-like cells of the G-CSF-dependent myeloblastic cell line. The effect of IL-4 may be direct, and not secondary via inducing production of other cytokines such as TGF-beta, TNF-alpha, or IL-6 by leukemic cells.

Cell Adhesion↗
PubMed1991

Pentoxifylline prevents tumor necrosis factor-induced suppression of endothelial cell surface thrombomodulin.

Thrombomodulin (TM) expression has been reported to be down-regulated by cytokines (endotoxin, interleukin-1, and tumor necrosis factor). We report, in the present study, up-regulation of surface TM antigen of human umbilical vein endothelial cells (HUVECs) by pentoxifylline (PTX) which is one of the agents that can increase intracellular cyclic AMP in HUVECs at therapeutic concentrations. Surface TM antigen was measured by an enzyme immunoassay. PTX increased surface TM antigen and intracellular cAMP in HUVECs in a dose dependent manner. Upregulation of TM by PTX was due to de novo synthesis of TM protein resulting from increased TM mRNA levels. PTX counterbalanced the TNF-induced suppression of TM expression. These results suggest that protein kinase A may be involved in cellular regulatory mechanism for TM expression and PTX may protect partially against TNF-induced endothelial cell injury and restore anticoagulant state of endothelium.

Antibodies↗
PubMed1991

Up-regulation of thrombomodulin by activation of histamine H1-receptors in human umbilical-vein endothelial cells in vitro.

Previous reports demonstrated that the expression of thrombomodulin (TM) in endothelial cells was modulated by various agents. Although TM was down-regulated by endotoxin or cytokines, up-regulation of TM was accomplished when endothelial cells were stimulated with unphysiologically high concentrations of cyclic AMP derivatives or tumour-promoting phorbol esters. We investigated the expression of TM in human umbilical-vein endothelial cells (HUVECs) by physiological substances that can be released into the bloodstream. Histamine (0.1-10 microM, 1-48 h) increased TM activity, TM antigen in cell lysates and TM mRNA levels, but 5-hydroxytryptamine and bradykinin had no effect. Enhancement of TM activity by histamine was completely blocked by the H1-selective antagonist pyrilamine, whereas the H2-antagonist cimetidine had no effect, showing that histamine up-regulates TM activity via H1-receptors on HUVECs. Enhanced TM activity by histamine and the resultant increase in protein C activation might play a role in a feedback regulation for prevention of vascular thrombosis.

Antigens↗
PubMed1991

Regulatory mechanisms for thrombomodulin expression in human umbilical vein endothelial cells in vitro.

It has been reported that thrombomodulin (TM) expression in endothelial cells is modulated by various agents. We investigated cellular regulatory mechanisms for TM expression in human umbilical vein endothelial cells (HUVECs), incubated with agents, by measuring the time course changes in surface TM activity, total TM antigen in cell lysates, and TM mRNA levels. While dibutyryl cAMP (3 mM) increased TM mRNA levels in HUVECs and was followed by increased TM activity, dibutyryl cGMP had no effect on TM activity. Phorbol myristate acetate (PMA) induced rapid loss of surface TM activity (approximately 8 h) and later increased TM mRNA levels between 4 h and 40 h (maximum at 24 h), resulting in biphasic effects on TM activity. Tumor necrosis factor or interleukin-1 beta suppressed surface TM activity and TM mRNA levels. Internalization/degradation of TM in HUVECs incubated with PMA or cytokines was suggested by co-culture with chloroquine. The decrease in surface TM activity observed was not caused by the release of TM molecules from the cells into the conditioned media. These results suggest that TM activity in HUVECs is modulated by independent mechanisms involving cytoplasmic TM mRNA levels and internalization/degradation of TM molecules. These regulatory mechanisms may involve protein kinase A and protein kinase C-dependent mechanisms but are independent of protein kinase G.

Blotting, Northern↗
PubMed1991

Acute subdural haematoma successfully treated by percutaneous subdural tapping in an elderly patient.

An elderly patient suffering acute subdural haematoma associated with cerebral contusion was treated by percutaneous subdural tapping while preparing for craniotomy. Most of the subdural haematoma, though of high density on computed tomography scanning, proved to be semiliquid. Drainage of the haematoma yielded resolution of the mass effect, and was followed by a rapid improvement of consciousness. This observation suggests the significance of trial subdural tapping for the treatment of acute traumatic subdural haematoma prior to craniotomy.

Acute Disease↗
PubMed1991

Rapid bedside technique for percutaneous ventricular drainage in patients with severe subarachnoid haemorrhage. Technical note.

Using immediate ventricular drainage and aggressive postoperative therapy, poor-grade patients suffering ruptured cerebral aneurysms could have a greater opportunity for meaningful recovery. This treatment protocol is facilitated by percutaneous ventricular drainage at the bedside. A simple and less invasive technique reported here is particularly useful for neurosurgeons responsible for the treatment of severe subarachnoid haemorrhage on an emergency basis.

Cerebrospinal Fluid Shunts↗
PubMed1991

Do intracranial arteriovenous malformations cause subarachnoid haemorrhage? Review of computed tomography features of ruptured arteriovenous malformations in the acute stage.

Computed tomography features of ruptured arteriovenous malformations in the acute stage were reviewed. Intracerebral or intraventricular haemorrhage was the major finding, and primary subarachnoid haemorrhage was disclosed to be rare. This observation supports the concept that arteriovenous malformations should not be included in the main pathological conditions causing subarachnoid haemorrhage. This information is of value in identifying the source of intracranial haemorrhage in patients with the coexistence of an arteriovenous malformation and an aneurysm, and provides a significant guideline for treatment.

Acute Disease↗
PubMed1991

Mechanism of feminization in male patients with non-alcoholic liver cirrhosis: role of sex hormone-binding globulin.

We measured serum sex hormone-binding globulin (SHBG) using a radioimmunoassay developed by us, testosterone (T), estradiol (E2), free T and free E2 in 50 male patients with non-alcoholic liver cirrhosis (compensated: 30, decompensated; 20) and age-matched healthy male subjects, SHBG was significantly increased in patients with liver cirrhosis compared with healthy subjects. The high serum SHBG level in male compensated cirrhotic patients tended to decrease with progression to the decompensated state. Serum cholinesterase showed a positive correlation with SHBG in liver cirrhosis. Serum free T and the T/SHBG ratio decreased, while serum E2, free E2, and the E2/T and the free E2/free T ratios increased in liver cirrhosis, resulting in estrogen predominance and feminization of male patients. These changes were more marked in decompensated than compensated liver cirrhosis. An increased free E2/free T ratio was observed in patients with gynecomastia, palmar erythema or vascular spider. The T/SHBG ratio showed a positive correlation with serum free T, suggesting that it can be used as a free T index in liver cirrhosis. From these observations, it is suggested that serum SHBG plays an important role, by regulating the serum free T level in the occurrence of feminization in male patients with non-alcoholic liver cirrhosis.

Adult↗
PubMed1991

Syringomyelia secondary to congenital intraspinal lipoma.

Preoperative evaluation using serial magnetic resonance imaging was performed on an infant with lumbosacral lipoma. Syrinx formation arising just above the lipoma was observed in conjunction with rapid growth of the lipoma. Definite shrinkage of syringomyelia was obtained after radical excision of the lipoma. The syrinx formation was possibly caused by compression from the extramedullary lipoma.

Humans↗
PubMed1991

Does the siphon effect of cerebrospinal fluid shunting develop in vivo? Report of a case casting doubt on the presence of this phenomenon.

A 52-year-old male underwent lumboperitoneal shunting after external decompressive craniectomy. His postoperative course was accompanied by remarkable displacement of the intracranial structures to the opposite side of craniectomy. This phenomenon, probably caused by the siphon effect of cerebrospinal fluid shunting, resolved after cranioplasty. This observation provides the evidence casting doubt on the presence of the siphon effect due to atmospheric pressure in patients without the association of skull defect or open cranial sutures.

Cerebrospinal Fluid Pressure↗
PubMed1991

Syncytium formation of human and non-human cells by recombinant vaccinia viruses carrying the HIV env gene and human CD4 gene.

We examined the ability of the various human and non-human cell lines to form syncytia upon coinfection with recombinant vaccinia viruses each carrying the HIV env and the human CD4 gene. We found that three human cell lines and one of three monkey cell lines exhibited syncytium formation, but that one human cell line, two monkey cell lines and all the rabbit and mouse cell lines examined did not. This indicated that factors other than HIV env and CD4 were participating in syncytium formation and that distribution of these factors was restricted by species and by the cell type in a species.

Animals↗
PubMed1991

Intracranial arteriovenous fistula manifesting as progressive neurological deterioration in an infant: case report.

This 1-year-old male infant had been diagnosed with cerebral degenerative disease because he developed psychomotor regression, and brain atrophy was demonstrated on computed tomography. He underwent magnetic resonance imaging, which suggested a cerebrovascular malformation. Cerebral angiography disclosed an arteriovenous fistula, fed by an anterior cerebral artery and directly draining into a cortical vein. The occlusion of the feeding artery was followed by a satisfactory recovery. The mechanism of the neurological symptoms in this patient is thought to be caused by a steal phenomenon and compression of the brain stem by venous engorgement in the posterior fossa.

Arteriovenous Fistula↗
PubMed1991

Immune response of mice infected with recombinant vaccinia viruses carrying the HIV gag gene.

We examined mouse immune response to 4 kinds of recombinant vaccinia viruses carrying the HIV gag gene, including vac-gag/pol, which produces HIV-like particles with processed gag proteins; vac-gag, which also produces HIV-like particles but with unprocessed gag protein; and vac-gag-pol-fuse and vac-es-gag/pol, neither of which produces such particles but releases reverse transcriptase and gag protein, respectively, from infected cells. Although infection of mice with recombinant vaccinia viruses induced production of the anti-p24 antibody in all mice, vac-gag/pol and vac-es-pol induced higher production than the other two recombinants. Increase in [3H]thymidine uptake by splenic lymphocytes following p24 antigen stimulation was most evident in mice infected with vac-gag/pol. Thus, the highest immune reaction, both humoral and cellular, was elicited by vac-gag/pol, indicating that among those tested, this recombinant vaccinia virus is the best candidate for a vaccine that induces anti-HIV gag immunity.

Animals↗