Quasinormal modes of maximally charged black holes.
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Journal Article↗
Biomedical subjects
T Okamura
Publications and source records attributed to T Okamura.
Persistence of multipotent progenitors expressing AML1/ETO transcripts in long-term remission patients with t(8;21) acute myelogenous leukemia.
The leukemia-specific AML1/ETO fusion gene has been shown to be detected by reverse transcriptase polymerase chain reaction (RT-PCR) analysis in patients with t(8;21) acute myelogenous leukemia (AML) in long-term remission. In the present study, the AML1/ETO mRNA could be detected by RT-PCR in bone marrow (BM) and/or peripheral blood (PB) samples from all 18 patients who had been maintaining complete remission for 12 to 150 months (median, 45 months) following chemotherapy or PB stem cell transplantation (PBSCT), whereas it could not be detected in four patients who had been maintaining remission for more than 30 months following allogeneic BM transplantation (BMT). We surveyed the expression of AML1/ETO mRNA in clonogenic progenitors from BM in these cases. Notably, 51 of 2,469 colonies from clonogenic progenitors (2.1%) expressed the AML1/ETO mRNA in 18 cases who were RT-PCR+ in BM and/or PB samples. Expression was observed in various clonogenic progenitors, including granulocyte-macrophage colonies, mixed colonies, erythroid colonies, and megakaryocyte colonies. Furthermore, we analyzed the clonality of these progenitors by X-chromosome inactivation patterns of the phosphoglycerate kinase (PGK) gene in four female patients. The AML1/ETO mRNA+ progenitors showed the PGK allele identical to that detected in the leukemic blasts from the time of initial diagnosis. Normal constitutive hematopoiesis was sustained by polyclonal BM reconstitution in these patients. Accordingly, these committed progenitor cells that express AML1/ETO mRNA during remission likely have arisen from common t(8;21)+ pluripotent progenitor cells with at least trilineage differentiation potential. These data strongly suggest that the origin of the clonogenic leukemic progenitors of t(8;21) AML may be multipotent hematopoietic progenitors that acquired the t(8;21) chromosomal abnormality.
Adult↗
Extreme hyperbilirubinemia induced by endoscopic injection sclerotherapy in a patient with esophageal varices and thalassemia: report of a case.
We describe herein the case of a 57-year-old man with thalassemia who developed acute liver failure after undergoing endoscopic injection sclerotherapy (EIS) to control hemorrhage from a ruptured esophageal varix. The patient, who had been confirmed as having liver cirrhosis due to chronic hepatitis C with thalassemia in 1989, was admitted to our department to undergo EIS for esophageal varices, at which time his serum total bilirubin level was 5.5 mg/dl. As a small amount of hematemesis occurred just after a percutaneous transhepatic portography was performed, emergency EIS was carried out, following which the serum total bilirubin level markedly increased, mainly with a direct fraction, until it reached 70 mg/dl. The patient eventually died from acute liver failure with extreme hyperbilirubinemia on the 27th day after experiencing hematemesis despite all treatment. This unfortunate case demonstrates that sclerotherapy could be an inappropriate method of treatment for patients with hemolytic disease.
Biopsy↗
Granulocyte colony-stimulating factor-induced mobilization of peripheral blood stem cells for autologous and allogeneic transplantation. Fukuoka Bone Marrow Transplantation Group.
Peripheral blood stem and progenitor cells (PBSC and PBPC), which circulate at very low levels during steady-state hematopoiesis, show a transient but marked increase during hematologic recovery from marrow-suppressive chemotherapy. To ensure rapid and sustained hematologic engraftment after autologous PBSC transplantation, sufficient PBSC or PBPC must be infused. To confirm the utility of granulocyte colony-stimulating factor (G-CSF) in chemotherapy-induced PBSC mobilization, we investigated the effect of G-CSF on PBSC mobilization in leukemia and lymphoma patients. The study design was such that PBSC mobilization with and without G-CSF was assessed in the same patients. The results indicate that PBSC mobilization can be enhanced significantly when G-CSF is given during the recovery phase postchemotherapy. Interestingly, progenitor cells of different lineages could be mobilized by G-CSF. We subsequently investigated the effect of increasing G-CSF dose on PBSC mobilization during steady-state hematopoiesis in healthy adult donors. The results indicate that not only committed but also primitive progenitor cells are mobilized into the circulation in a dose-and time-dependent manner when G-CSF at 5, 10, or 15 micrograms/kg was given on each of 5 days and leukapheresis was performed on day 6. From our data we estimate that sufficient PBSC for engraftment after allogeneic PBSC transplantation can be collected on day 5 of administration of G-CSF at 10 micrograms/kg and by 10-1 leukapheresis on days 5 and 6. Furthermore, we found that some G-CSF-mobilized PBSC retained their self-renewal capability. These observations suggest that hematopoietic stem cells for allogeneic PBSC transplantation can be mobilized by short-term administration of relatively high-dose G-CSF.
Animals↗
Neurogenic nitric oxide (NO) in the regulation of cerebroarterial tone.
Sympathetic vasoconstrictor nerves are commonly recognized to mainly control the vascular smooth muscle tone, thus alters regional vascular resistance and blood flow. In contrast to peripheral organs and tissues, regulation by sympathetic nerves of blood flow in the brain is not so evident, and conversely vasodilator innervation is expected to play an important role. The mechanism underlying the neurogenic vasodilation in the cerebral artery has not been determined until recently. This problem was solved by the discovery of nitric oxide (NO) synthase inhibitors. Cerebral arterial dilatation caused by nerve stimulation is abolished by NO synthase inhibition and is restored by L-arginine, a substrate of NO synthase; vasodilator nerve stimulation increases the production of cyclic GMP in the tissue and liberates NOx (nitroxy compounds) from the arterial strip into superfusate. In addition, the presence of neurons containing NO synthase is histochemically demonstrated in the arterial wall. Neurogenic cerebral arterial dilation is thus hypothesized to be mediated by NO liberated as a neurotransmitter from the nerve. Nitroxidergic vasodilator innervation from the pterygopalatine ganglion would be important in the regulation of brain circulation.
Animals↗
Effects of granulocyte colony-stimulating factor on the hemostatic system in healthy volunteers.
We previously identified a receptor for granulocyte colony-stimulating factor (G-CSFR) on platelet membranes, and reported that G-CSF enhanced ADP-induced platelet aggregation. Here, we investigated the priming effect of G-CSF on the hemostatic system in healthy volunteers given G-CSF. Following the administration of rhG-CSF (10 micrograms/kg for 30 min div) to 10 healthy volunteers, we found a significant elevation in the maximum platelet aggregation rate induced by ADP or collagen, thromboxane B2 level and amount of thrombin-antithrombin III complex. The D-D dimer and plasminogen activator inhibitor-1 showed no significant changes. These observations indicate that G-CSF administration may induce hypercoagulability in susceptible subjects. Therefore, patients or donors at risk of thrombosis or hypercoagulable state should be followed carefully after G-CSF administration.
Adenosine Diphosphate↗
A sequence analysis of von Willebrand factor mRNA, gene, and pseudogene in two patients with von Willebrand disease type 2B, and an investigation of gene conversion in its gene.
We identified the point mutations in two unrelated patients with von Willebrand disease (vWD) type 2B using sequence analyses of the gene, pseudogene and messenger RNA of vWF. Both patients were determined to be heterozygotes with amino acid transitions of 1308 Arg-->Cys in Case 1 and 1316 Val-->Met in Case 2. Moreover, we also found single base transitions 7541 A-->G in intron 27 of the active gene, and 7642 A-->G, which thus destroyed the Kpn 1 site, in its pseudogene in both cases. Since these mutations represented changes in the base between the gene and its pseudogene, we studied the presence of gene conversion in exon 28 of vWF gene to clarify its pathological role. Using RT-PCR and an allele-specific restriction enzyme analysis, we identified no gene conversions in this region in four other patients with vWD, 25 normal subjects and one cell line, MEG01. Based on these findings, gene conversion in the vWF gene is not considered to be a frequent phenomenon in either vWD patients or normal subjects.
Adult↗
Gastrointestinal angiodysplasia in congenital platelet dysfunction.
We herein report three cases of repeated massive bleeding from the stomach and small bowel. One patient suffered from both thrombasthenia (type II) and von Willebrand disease (type 1) simultaneously. Two others had Bernard-Soulier's syndrome (BSS). One patient with BSS had bleeding from gastric angiodysplasia and was treated endoscopically by clipping. The other patients had massive bleeding from the small intestine, and had partial resection of the affected small intestine. Histologically, irregular dilatation and proliferation of the blood vessels were demonstrated in the submucosa in bleeding spots from a resected small intestine, and these findings were consistent with the features of acquired angiodysplasia. The development of gastrointestinal angiodysplasia may not only be associated with a dysfunction of von Willebrand factor but also with that of platelets.
Adult↗
Generation of human natural killer cells from peripheral blood CD34+ cells mobilized by granulocyte colony-stimulating factor.
We studied the generation of human natural killer (NK) cells from CD34+ cells that were isolated from peripheral blood stem cells (PBSC) mobilized by granulocyte colony-stimulating factor (g-CSF). The isolated CD34+ cells were cultured in the presence of a combination of interleukin-1 (IL-1alpha), IL-2, and stem cell factor for 5 weeks without marrow stroma. We found that the CD34+ cells isolated from G-CSF-mobilized PBSC (G-CSF/PBSC) could differentiate into a population of NK cells which were CD56+(bright)/CD3- and showed morphologic characteristics of large granular lymphocytes. Immunophenotypic analysis of the NK cells thus generated showed that a small proportion of them expressed CD2, CD8 and CD16 surface markers and approximately half of them coexpressed CD7. This NK population exhibited cytotoxic activity against a NK-sensitive cell line, K562. These observations suggest that CD34+ cells from G-CSF/PBSC contain precursors of NK cells that can differentiate into functional NK cells.
Adult↗
Amyloid goiter: radiological study in a case presenting hypothyroidism.
We report herein a case of amyloid goiter associated with rheumatoid arthritis in which hypothyroidism was observed. A 52-year-old housewife who had suffeed from rheumatoid arthritis for 15 years was referred to our hospital because of general fatigue. On admission, a large goiter was observed. Laboratory data showed primary hypothyroidism. Renal biopsy and gastric mucosa biopsy showed amyloid deposition of AA-type. Thyroid biopsy showed massive amyloid involvement. Although the findings of iodine-123 scintigraphy, technetium-99m pertechnetate scintigraphy, computed tomography and magnetic resonance image studies were similar to those for goiter associated with chronic thyroiditis, tallium-201 chloride scintigraphy gave a differing result, demonstrating absent uptake at 3 hours in this case. Replacement therapy with levothyroxine relieved the symptoms. This case was unusual in that amyloid goiter presented clinically as hypothyroidism. Absence of tallium-201 chloride uptake at 3 hours may be a diagnostic specificity for amyloid goiter in differentiating its hypothyroidism from that caused by chronic thyroiditis.
Amyloid↗
G-CSF-induced mobilization of peripheral blood stem cells from healthy adults for allogeneic transplantation.
We investigated a dose-escalation effect of G-CSF (5, 10, and 15 micrograms/kg) on mobilization of committed and primitive hemopoietic progenitor cells, including CFU-GM, BFU-E, and long-term culture-initiating cells (LTC-IC) in addition to CD34+ cells and yields of progenitor cells in PBSC harvests obtained by leukapheresis of healthy adult donors. Results indicate that the mobilization of these progenitor cells is both dose and time dependent. Despite the very small number of healthy donors studied, it is estimated from our data that a sufficient number of CD34+ cells for allogeneic PBSC transplant (PBSCT) could be collected using a 5 day administration of 10 micrograms/kg of G-CSF to normal adult donors. Adverse effects include general fatigue and bone pain in most of the donors and fever and headache in some. These symptoms were well tolerated in most instances. Laboratory test abnormalities, including transient thrombocytopenia, increased platelet aggregation, and increased serum levels of some liver enzymes, were induced by G-CSF administration, but all were reversible within a short time. These observations suggest that hemopoietic stem cells for allogeneic PBSCT can be mobilized by short-term administration of a relatively high-dose G-CSF.
Adult↗
Angiocentric immunoproliferative lesions of the lymph node.
Clinicopathologic features in 14 cases of lymph node-involved angiocentric immunoproliferative lesions (AILs) are reported. They were selected from 900 cases of lymphoproliferative disorders registered at the Department of Pathology, Fukuoka University. Four cases showed a histologic feature of AIL grade II (AIL-II) and 10 had angiocentric lymphoma (AIL-III). Immunohistologically, transformed B cells were mixed with a large number of small T cells in AIL-II. In AIL-III, there were five cases with B-cell lymphoma, and three had peripheral T-cell lymphoma with no expression of natural-killer (NK)-associated antigens. In the remaining two cases, lymphoma cells expressed both T-cell- and NK-associated antigens. These findings indicate that lymph node-involved AILs are rarely occurring (1.6%) and phenotypically different from sinonasal and cutaneous AILs. Furthermore, NK-associated antigen-positive AILs were found to rarely involve the lymph node. For Epstein-Barr virus (EBV) infection, seven cases of AILs showed many atypical lymphocytes that were positive for EBV-encoded RNA (EBER-1) by using the in situ hybridization analysis. Among them, six cases had latent membrane protein (LMP) positive and EBV nuclear antigen 2 (EBNA-2) negative atypical lymphocytes. The pattern of latent EBV infection was similar to that of Hodgkin's disease, but differed from those of sinonasal T-cell lymphoma and other subtypes of non-Hodgkin's lymphoma. Clinically, 12 patients, including all 4 AIL-II, died within 22 months of the onset of the disease, despite intensive therapy, suggesting that lymph node-involved AILs have a poor prognosis.
Adult↗
Hypercapnia relaxes cerebral arteries and potentiates neurally-induced relaxation.
The present study was designed to determine whether relaxations induced by hypercapnia depend upon nitric oxide (NO) derived from the endothelium, and whether NO-mediated relaxant response to electrical and chemical stimulation of vasodilator nerves is modulated by hypercapnia. In canine and monkey cerebral arterial strips contracted with K+, raising the level of CO2 of the aerating gas in the bathing media from 5 to 10% produced a moderate relaxation, together with an increased Pco2 (from 29.8 to 59.3 mm Hg) and a decreased pH (from 7.43 to 7.15). Relaxation was not influenced by endothelium denudation and treatment with NG-nitro-L-arginine. Contractions elicited by the NO synthase inhibitor were attenuated by the removal of the endothelium. Relaxations, caused by transmural electrical stimulation and nicotine, of canine cerebral arterial strips contracted with prostaglandin F2 alpha, were potentiated only slightly by hypercapnia, but the potentiation of the response to exogenous NO (acidified NaNO2) was clearly greater. It is concluded that as far as the arteries used are concerned, hypercapnia does not seem to liberate NO from the endothelium but does potentiate the effect of NO. The reason for lesser potentiation, by hypercapnia, of the response to nitroxidergic nerve stimulation than to NO action may be associated with an impairment by intracellular acidosis of NO synthase activation.
Animals↗
A case of prostate carcinoma metastasizing to renal cell carcinoma.
Metastasis of one cancer to another cancer is extremely rare. The most frequent metastasizing tumor is a lung carcinoma, and the most common recipient tumor is a renal cell carcinoma. We report herein a case of prostate carcinoma metastasizing to a renal cell carcinoma, which has previously been reported only four times.
Adenocarcinoma↗
[A case of empyema caused by Salmonella enteritidis in a patient with sequela of pulmonary tuberculosis].
A 69-year-old male was admitted to our hospital on Jan. 10, 1995 complaining of bloody sputum, left back pain and fever of 39 degrees C. He had a history of pulmonary tuberculosis 45 years ago. His chest X-ray and CT showed the presence of air-fluid level in the left pleural cavity with thickening and calcification of the pleura. Salmonella Enteritidis was isolated from the sputum, bronchoalveolar lavage fluid and stool. He was diagnosed as suffering from Salmonella-empyema with an internal fistula. Based on the in vitro sensitivity test, sulfamethoxazole/trimethoprim was started. However, the efficacy of the antimicrobia was not sufficient. He then underwent left pleuropneumonectomy. Salmonella was cultured also from the specimen obtained at the operation. His course after operation was uneventful. Thus, although Salmonella Enteritidis is known as a common pathogen of food poisoning, it can cause empyema, especially in a case with an impaired host defence system.
Aged↗
[A case of invasive pulmonary aspergillosis accompanied with Aspergillus meningitis].
A 53-year-old female was admitted to our hospital complaining of chest pain and gait disturbance. Examinations on admission showed that she was immunocompetent except the negative tuberculin test. The chest X-ray showed infiltrative shadows with old tuberculous lesions in the bilateral upper lung fields. In CT, a mass lesion was revealed in the lesion, which destructed the fifth thoracic vertebra and invaded into the epidural space. She died of meningitis on the 18th day after admission. On autopsy, it was made clear that the mass lesion was caused by Aspergillus fumigatus, and that the meningitis was the result of the invasion of the fungus into the epidural space.
Aspergillosis↗
Canine retinal arterial and arteriolar dilatation induced by nipradilol, a possible glaucoma therapeutic.
The effects of nipradilol, an ocular hypotensive drug, on isolated canine retinal central arteries and on retinal arterioles in vivo were investigated. Nipradilol (10(-9) to 10(-5) mol/l) produced a dose-related relaxation of the arterial strips contracted with prostaglandin F2 alpha which was not influenced by timolol or indometacin. The median effective concentration of this drug was five times that of glycerol trinitrate (GTN). The nipradilol-induced relaxation in the endothelium-intact strips was not influenced by NG-nitro-L-arginine, a nitric oxide synthase inhibitor, but was abolished by oxyhemoglobin and methylene blue. Treatment with high concentrations of sodium nitroprusside abolished the response to nipradilol, as observed with that to GTN. Retinal arterial strips responded to isoproterenol with a slight relaxation which was depressed by nipradilol. In anesthetized dogs, intra-arterial injections of nipradilol dilated the retinal arterioles in the ocular fundus; the dilator potency was approximately one fifth that of GTN. It is concluded that nipradilol dilates canine retinal arteries in vitro and arterioles in vivo, possibly due to activation of soluble guanylate cyclase and increased production of cyclic guanosine monophosphate that are associated with nitric oxide liberated from the molecule itself in the tissue but not derived from the endothelium and perivascular nerve. Beta adrenoceptor blocking action was determined in the retinal artery.
Animals↗
Evaluation of the diagnostic value of the measurement of (1-->3)-beta-D-glucan in patients with pulmonary aspergillosis.
The value of the measurement of (1-->3)-beta-D-glucan, a major and common cell wall constituent of fungi, for diagnosing pulmonary aspergillosis was assessed in comparison with that of conventional examinations. The concentrations of (1-->3)-beta-D-glucan in sera was elevated in 7 out of 8 patients with active aspergillosis, but not in cases without active diseases, except for one sample. Further, the concentrations well reflected the activity of the aspergillosis in each case. Regarding conventional examinations, with the immunodiffusion test it was difficult to detect the present activity of the disease. The radioallergosorbent test was useful for diagnosing bronchopulmonary aspergillosis, but not for other types of aspergillosis. The Aspergillus-specific component, galactomannan, was insensitive and the enzyme-linked immunosorbent assay gave highly variable results. Thus, although the assessment of the specificity of the assay is still necessary, compared with other tests, the assay of (1-->3)-beta-D-glucan has the advantage of diagnosing pulmonary aspergillosis and also of assessing the disease activity.
Antibodies, Fungal↗