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T Tokunaga

Publications and source records attributed to T Tokunaga.

At least 145 records · Page 8Linked to original sources
PubMed1992

Synthetic oligonucleotides with particular base sequences from the cDNA encoding proteins of Mycobacterium bovis BCG induce interferons and activate natural killer cells.

Thirteen kinds of 45-mer single-stranded oligonucleotide, having sequence randomly selected from the known cDNA encoding BCG proteins, were tested for their capability to augment natural killer (NK) cell activity of mouse spleen cells in vitro. Six out of the 13 oligonucleotides showed the activity, while the others did not. In order to know the minimal and essential sequence(s) responsible for the biological activity, 2 kinds of 30-mer and 5 kinds of 15-mer oligonucleotide fragments of an active 45-mer nucleotide were tested for their activity. One of the 30-mer oligonucleotides, designated BCG-A4a, was active, but the other 30-mer was inactive. All of the 15-mer oligonucleotide fragments were inactive. The BCG-A4a also stimulated the spleen cells to produce interferon (IFN)-alpha and -gamma. An experiment using anti-IFN antisera showed that the NK cell activation by the oligonucleotide was ascribed to the IFN-alpha produced. It was noticed that all of the biologically active oligonucleotides possessed one or more palindrome sequence(s), and the inactive ones did not, with an exception of a 45-mer inactive oligonucleotide containing overlapping palindrome sequences (GGGCCCGGG). These findings strongly suggest that certain palindrome sequences, like GACGTC, GGCGCC and TGCGCA, are essential for 30-mer oligonucleotides, like BCG-A4a, to induce IFNs.

Animals↗
PubMed1992

DNA from bacteria, but not from vertebrates, induces interferons, activates natural killer cells and inhibits tumor growth.

The nucleic acid fraction from cells of 6 species of bacterium and 2 kinds of vertebrate, calf and salmon, was extracted and purified by the same procedures as described previously. When the spleen cells from BALB/c mice were incubated with the nucleic acid fraction from either of the bacteria, natural killer (NK) activity of the cells was remarkably elevated and the cells produced factors to activate macrophages and to inhibit viral growth. It was shown that the factor to activate macrophages was interferon (IFN)-gamma and that to inhibit viral growth was IFN-alpha/beta. On the other hand, the nucleic acid fraction from either of the vertebrate cells did not show such activities. Pretreatment of the bacterial nucleic acid fraction with DNase, but not with RNase, abrogated completely the biological activities. The activities of the bacterial nucleic acid were not influenced by the presence of polymyxin B, an inhibitor of lipopolysaccharide (LPS), and the spleen cells from not only BALB/c mice but also LPS-insensitive C3H/HeJ mice were activated, indicating that the activities of the fraction were not ascribed to LPS contaminated possibly into the fraction, but to DNA itself. Intralesional injection with the bacterial DNA fraction caused regression of mouse IMC tumors, but the injection with the vertebrate DNA fraction did not. These findings prompted us to examine the biological activities of DNA samples from a variety of animals and plants, which were provided from other laboratories or purchased from manufacturers. All of the DNA samples from cells of 5 kinds of bacterium, 2 of virus and 4 of invertebrate augmented NK activity and induced IFN, more or less, in mouse spleen calls, while the DNA from 10 kinds of vertebrate, including 3 of fish and 5 of mammal, showed no such activities. The DNA from 2 species of plants, were also inactive. Possible mechanisms to explain the different biological activities of DNA from different cell sources were discussed based on our previous finding that the particular palindromic sequences with a G-C motif(s) are required for induction of IFNs and activation of NK cells with synthetic 30-mer oligonucleotides.

Adjuvants, Immunologic↗
PubMed1992

Antitumor activity of synthetic oligonucleotides with sequences from cDNA encoding proteins of Mycobacterium bovis BCG.

Thirteen kinds of 45-mer or 30-mer synthetic oligonucleotides with sequences randomly selected from the cDNA encoding three kinds of protein of Mycobacterium bovis BCG were tested for their antitumor activity in a murine tumor system. Six out of the 13 single-stranded oligonucleotides which contained one or more hexameric palindromic sequences showed strong antitumor activity while the others without palindromic structure did not. Namely, repeated intralesional injections of 100 micrograms of the 6 oligonucleotides caused regression of the established tumor but the other 7 were ineffective. When tumor cells were mixed with 100 micrograms of an effective oligonucleotide and injected into mice, tumor growth was markedly suppressed. These results suggested that palindromic structure is essential for the antitumor activity of the synthetic oligonucleotides.

Animals↗
PubMed1992

Soluble interleukin-6 receptor is released from receptor-bearing cell lines in vitro.

Soluble interleukin-6 receptor (sIL-6R) was found to be spontaneously released from human myeloma cell line U266 cells into culture supernatant, and was quantitatively measured with a fluorescence sandwich enzyme-linked immunosorbent assay employing antibodies specific to IL-6R. The supernatant IL-6R was generated only from IL-6R-positive cell lines; myeloma cell lines RPMI8226 and PRMI1788, and myelomonocytic cell lines U937, THP-1, and HL-60. In contrast, it was not released from the IL-6R-negative cells; T cell line Molt-4 and Burkitt lymphoma cell line Raji. SDS-PAGE analysis of the soluble IL-6R from U266 cells suggested a molecular weight of approximately 50-55 kDa, 25-30 kDa smaller than the mature cell surface receptor. These results suggest that the generation of soluble IL-6R may be a maker of myeloma cells and myelomonocytic cells.

Cell Line↗
PubMed1992

Oligonucleotide sequences required for natural killer cell activation.

Based on the previous finding that certain 30-mer single-stranded oligodeoxyribonucleotides (oligonucleotides) having particular 6-mer palindromic sequences could induce interferon-alpha and -gamma, and enhance natural killer activity, the present study was carried out to clarify the entire relationship between the activity and the sequence of 30-mer oligonucleotides. The results indicated that the activity depended critically on the presence of particular palindromic sequences including the 5'-CG-3' motif(s). The size and the number of palindromes as well as the extra-palindromic sequences also influenced the activity. An oligonucleotide with a 10-mer palindrome and extra-palindromic oligoguanylate sequences showed the strongest activity among the oligonucleotides tested.

Animals↗
PubMed1992

Contralateral development of acute subdural hematoma following surgery for chronic subdural hematoma--case report.

An unusual case of acute subdural hematoma developed after drainage of chronic subdural hematoma in a 71-year-old male. The acute subdural hematoma was located over a membranous layer in the subdural space similar to the outer membrane of the chronic subdural hematoma. Intraoperatively, bleeding from the bridging vein and oozing from the superior sagittal sinus were observed. The membranous layer probably separated from the dura mater following decompression after drainage of the contralateral hematoma, and this separation then damaged the bridging vein and superior sagittal sinus, resulting in the acute subdural hematoma.

Acute Disease↗
PubMed1992

[Brain metastasis of lung cancer with Eaton-Lambert syndrome--case report].

A case of brain metastasis of lung cancer with Eaton-Lambert syndrome (ELS) is reported. A 45-year-old male was admitted to the Department of Surgery in Kurume University Hospital on November 13, 1985, complaining of general fatigue. On admission, neurological examination revealed diplopia and fatigue of the extremities. The electromyogram (EMG) showed the waning phenomenon in low frequency repetitive stimulation (2Hz) and the waxing phenomenon in high frequency repetitive stimulation (10Hz, 20Hz). His clinical symptoms, radiological findings and EMG findings demonstrated lung cancer with ELS. Left pulmonary lobectomy with lymphnode dissection of the anterior mediastinum and pulmonary hilus was performed on December 4. Intraoperatively, the tumor was strongly adherent to a medium lymphnode. The patient experienced complete relief symptoms due to ELS. Histological examination disclosed a small cell carcinoma without lymphnode metastasis. He was discharged without any neurological deficits following chemotherapy on February 27, 1986. He was readmitted to the Department of Neurosurgery on August 29, 1986, because of the development of nausea and vomiting. Neurological examination demonstrated no abnormalities except for choked disc in the bilateral ocular fundi. The computed tomography scan revealed a metastatic brain tumor with a mural nodule and cyst. The tumor was totally removed on September 2. Histological examination revealed a typical appearance of small cell carcinoma. He followed a satisfactory postoperative course. He was discharged following radiation therapy on November 2, 1986, and was followed as an outpatient. He has no problem in daily life since then. Though the patient had an expanding metastatic brain tumor from lung cancer after the first operation, he experienced no symptoms due to ELS.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗
PubMed1992

Evidence for postjunctional release of ATP evoked by stimulation of muscarinic receptors in ileal longitudinal muscles of guinea pig.

The origin of the ATP release evoked by muscarinic agonists and veratridine from longitudinal muscles of the guinea pig was assessed with muscarinic antagonists. Acetylcholine (ACh) (1 microM) and bethanechol (10 microM) produced an immediate and marked ATP release, which was almost completely blocked by atropine (0.3 microM) and by the M3 muscarinic antagonist 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) (1 microM); release was only slightly affected by tetrodotoxin (0.6 microM). The bethanechol-evoked release of ATP was partly, but not significantly, inhibited by pirenzepine, a M1 muscarinic antagonist. Veratridine, an ACh releaser, also elicited a delayed ATP release, in a concentration-related manner. This ATP release was greatly antagonized by atropine and by Ca++ removal from the medium, implying mediation by endogenous ACh released after depolarization. In contrast, electrically evoked ACh release was enhanced by atropine and 4-DAMP. Bethanechol, unlike veratridine, failed to elicit measurable ACh release from the tissue. The contraction evoked by bethanechol was notably inhibited by atropine and 4-DAMP, but not by pirenzepine and AFDX-116, a M2 muscarinic antagonist, at a concentration of 0.3 microM. These findings suggest strongly that ATP is postjunctionally released from the ileal smooth muscles after stimulation of postsynaptic muscarinic receptors, presumably M3 receptors.

Acetylcholine↗
PubMed1992

[Emergency manual aspiration for severe hypertensive cerebellar hemorrhage].

We treated 16 patients with hypertensive cerebellar hemorrhage and coma, or deep coma. Their ages ranged from 44 to 79 years (mean age: 66.3 years). Manual aspiration was performed in 9 patients and suboccipital craniectomy was performed in 7 patients. The difference in outcome between the manual aspiration group and the suboccipital craniectomy group with severe hypertensive cerebellar hemorrhage was then evaluated. Manual aspiration was performed for 4 patients in coma, and 5 in deep coma, with a mean age of 69.0 years. The average size of the hematoma was 48.7mm and the mean volume was 31. 7ml on CT scan. The mean interval from admission to operation was about 60 minutes. The mean aspiration rate was 79.6% and 7 patients (77.8%) had a good response to drainage. The suboccipital craniectomy patients included 5 in coma, and 2 in deep coma, with a mean age of 63.4 years. The average size of the hematoma was 51.1 mm and the mean volume was 33.1 ml on CT scan. The mean interval from admission to operation was about 112 minutes and the mean evacuation rate was 86.4%. The results were as follows: 1) After manual aspiration, 5 patients (55.6%) had a good outcome and 2 patients (40%) with deep coma showed good recovery. In contrast, after suboccipital craniectomy only 2 patients (28.6%) had a good outcome and all of the deep coma patients showed poor recovery. 2) The outcome may be most strongly influenced by the duration from admission to operation. 3) All patients with a hematoma volume of over 30 ml had a poor outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[MRI findings of closed head injury in children; with special reference to the effect of central shearing force].

It is considered that shearing effect as introduced by Holbourn may produce central concussion, diffuse brain swelling and diffuse axonal injury according to its grade of force. MRI was performed in 38 children who had been admitted to our hospital during the previous 1 year for the treatment of closed head injury of varying severity. In 8 out of 38 cases, abnormal high signal intensity was observed in the medial and para-medial brain parenchyma on MRI. All of these 8 cases suffered from head trauma caused by motor vehicle accidents. They included 2 cases of cerebral concussion, 1 of diffuse brain swelling, and 5 cases of diffuse axonal injury. In 2 cases of cerebral concussion, MRI (T2 weighted) revealed only localized high intensity in the corpus callosum, while CT showed normal and subarachnoid hemorrhage only at the interposium. These two children had been unconscious for periods of 20 to 30 minutes. In one case of diffuse brain swelling, MRI (T2W) showed a slightly obscure border between gray and white matter due to generally increased intensity. In 5 cases of diffuse axonal injury, most of these cases manifested lesions at the corpus callosum, deep white matter, periventricular gray matter, pons, midbrain and the cerebellum as demonstrated by high signal intensity on MRI (T2W) while CT in the acute stage showed small hemorrhage at the corpus callosum, corticomedullary junction and mid-brain and in the ventricles. Among these, two cases also demonstrated subdural hematoma and cortical contusional hemorrhage. At 3-4 weeks after injury, the area of high intensity previously demonstrated in the deep white matter and the corpus callosum on MRI (T2W) was reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Axons↗
PubMed1992

[Multiple intracranial aneurysms following radiation therapy for pituitary adenoma; a case report].

A report is made here on a rare case in which occurrence of multiple cerebral aneurysm was observed after radiotherapy. The case was that of a female aged 51 who was hospitalized with the chief complaint of consciousness disorder. The patient was discharged from the hospital 1 year before, after undergoing subtotal extirpation of a tumor through the transsphenoidal sinus in a case of pituitary adenoma, and post-operative radiotherapy (topical 50 Gy). Mild hyperlipidemia associated with hypothyroidism was observed by blood biochemical test during the patient's hospitalization, and multiple cerebral infarction was also observed by CT scanning and MR imaging. Therefore, conservative treatments including intensified endocrine-supplementing treatment, centering on thyroid hormone, were attempted. The patient's thyroid gland function and hyperlipidemia improved but the consciousness disorder persisted. Exacerbation of the consciousness disorder occurred suddenly 6 weeks after the patient's hospitalization. Subarachnoid hemorrhage and hydrocephalus were observed by CT scanning. Cerebral angiography detected a saccular aneurysm in the trifurcation of the right middle cerebral artery, 3 fusiform aneurysms in the periphery of the right middle cerebral artery, 2 fusiform aneurysms in the posterior cerebral artery and irregularity of wall width in the central artery including the terminal region of the internal carotid artery. These findings were not observed at the initial hospitalization and were considered to have been formed newly afterwards. Further, these findings were observed unexceptionally in all the radiated fields. The patient died 8 weeks after hospitalization, and no autopsy finding was obtained. From the above, we presumed that radiation vasculopathy caused by the radiation therapy made one year previously, had led to the formation of multiple cerebral aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1991

Development of a new host vector system in mycobacteria.

The hybrid plasmid pYT72/pYT92 constructed from an Escherichia coli plasmid pACYC177 and mycobacterial plasmid pMSC262 isolated from Mycobacterium scroflaceum strain W262 transformed both E. coli and BCG. Phage-sensitive mutants S-10 and S-20 isolated from BCG Tokyo strain showed higher frequency of transformation than the wild-type strain. Frequency of transformation was dependent on age of the culture and the electroporation condition used. Several deletion mutants were generated from pYT72/92 to determine the minimum region for the replication in the mycobacteria. A 2.3-kb fragment of pMSC262 was found to contain an essential region. Using this fragment and pACYC177, a small shuttle vector pYT937 containing two drug-resistance markers, kanamycin- and ampicillin-resistance, was constructed. pYT937 contains AatII, BamHI, BbvII, GsuI, HincII, PstI, ScaI and XbaI cloning sites.

Cloning, Molecular↗
PubMed1991

Granulocyte-macrophage colony-stimulating factor promotes the proliferation of human alveolar macrophages in vitro.

The effects of granulocyte-macrophage (GM-CSF) or macrophage-CSF on in vitro proliferation of human alveolar macrophages (AM) were evaluated. AM of healthy volunteers incubated with recombinant human GM-CSF revealed incorporation of [3H]thymidine in vitro. The maximum incorporation was observed at 20 U/ml of GM-CSF on day 3. The proportion of proliferating cells incubated with 20 U/ml of GM-CSF from day 3 to day 4 was 8 to 11% of the total, whereas 3 to 5% of cells proliferated without GM-CSF. The number of cell nuclei increased 1.30- to 1.68-fold in the initial 7 days during incubation with 20 U/ml of GM-CSF, whereas there was a 1.07- to 1.13-fold increase without GM-CSF. Conditioned media obtained by the incubation with human lung tissue exhibited similar effects as recombinant human GM-CSF on macrophages. The effects were completely abrogated by antibody against human GM-CSF. Immunohistochemically, GM-CSF was detected in lung cells including AM, alveolar epithelium, alveolar interstitial cells, and endothelial cells. In contrast, recombinant macrophage-CSF did not induce the proliferation of human AM, although it has been known to promote the proliferation of murine AM. These observations suggest that GM-CSF plays an important role among the regulatory factors that locally support the population of AM in human lungs.

Adult↗
PubMed1991

Preexposure of macrophages to low doses of lipopolysaccharide inhibits the expression of tumor necrosis factor-alpha mRNA but not of IL-1 beta mRNA.

LPS is known to be a potent activator of macrophages and induces the production of TNF-alpha and IL-1. However, the signaling events and regulatory mechanisms required for the activation of macrophages by LPS have not been resolved precisely. We show that LPS modulates its own response in macrophages. Proteose peptone-induced murine peritoneal macrophages (P-PEM) produce significant amount of TNF-alpha and IL-1 after stimulation with LPS. However, preexposure of macrophages to low doses (less than 1 ng/ml) of LPS renders them refractory to stimulation by a second round of LPS, as evaluated by production of TNF-alpha. The loss of sensitivity to a second round of LPS was selective for TNF-alpha production as the LPS-primed macrophages retained the ability to produce IL-1. Northern blot analysis was performed with total RNA obtained from control and LPS- (1 ng/ml) primed P-PEM after 3-h stimulation with a second round of LPS. The expression of TNF-alpha mRNA was inhibited in LPS-primed P-PEM, whereas the expression of IL-1 beta mRNA was the same in control and LPS-primed P-PEM, consistent with the data of biologic activities of these two cytokines. Zymosan-induced TNF-alpha production was the same in control and LPS-primed macrophages, indicating that not all of the pathways required for TNF-alpha production were affected by LPS priming. Monokines such as human (h) rIL-1 alpha, hrTNF-alpha, hrIL-6, and murine rIFN-beta could not substitute for the action of low doses of LPS, and addition of indomethacin could not restore TNF-alpha production. These results suggest that exposure of macrophages to low doses of LPS suppresses the production of TNF-alpha, but not of IL-1, by inhibiting the expression of mRNA through a noncyclooxygenase-dependent mechanism. Thus, LPS-induced production of TNF-alpha and IL-1 in macrophages are differently regulated.

Animals↗
PubMed1991

Effect of a synthetic adjuvant for inducing anti-tumour immunity.

An acylated derivative of muramyl dipeptide (MDP), 6-O-(2-tetradecyl-hexadecanoyl)-muramyl-dipeptide (B30-MDP) is a strong adjuvant effective in inducing cell-mediated immunity. We used B30-MDP as an adjuvant for induction of anti-tumour immunity. Guinea-pigs which were injected repeatedly with a mixture of X-ray-treated leukaemic cells and B30-MDP dissolved in phosphate buffered saline resisted a challenge of leukaemia cells and showed no sign of leukocytosis. The immunity induced was tumour-specific and retained for more than 100 days. These results suggest that B30-MDP is useful as a simple but potent immunotherapeutic tool.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1991

Multiple primary brain tumors of different histological types--report of two cases.

Simultaneous development of histologically different primary brain tumors aside from phacomatoses or previous irradiation is rare, and its preoperative diagnosis is still difficult. We report two such cases, a 49-year-old male with an acoustic neurinoma and a cerebellar hemangioblastoma and a 69-year-old female with a parietal convexity meningioma and an ipsilateral frontal lobe astrocytoma. The tumors in the first case developed closely, so some local stimulation probably acted as a developmental factor. However, the tumors in the second case developed in distant areas and were considered coincidental.

Brain Neoplasms↗
PubMed1991

Multiple brain tumors of different cell types with an unruptured cerebral aneurysm--case report.

A rare case of coexistent Burkitt-type lymphoma and meningioma associated with an unruptured cerebral aneurysm is presented. A 49-year-old male complaining of headache and right hemiparesis was admitted to our hospital. Neuroradiological examination revealed a multinodular mass in the left frontal convexity and an unruptured cerebral aneurysm at the M1 portion of the left middle cerebral artery. He underwent an operation for tumor removal and aneurysm clipping. Histological examination revealed the tumor to be a typical meningotheliomatous meningioma without malignancy. However, a second operation was necessary for another tumor invading into the left frontal lobe, which proved to be a Burkitt-type lymphoma. The second tumor may have been resulted from irritative effect of the first tumor, but the aneurysm was considered purely coincidental.

Brain Neoplasms↗