Biomedical subjects

M Sawada

Publications and source records attributed to M Sawada.

At least 163 records · Page 9Linked to original sources

PubMed1998

Dehydroepiandrosterone sulfate deficiency in chronic fatigue syndrome.

The chronic fatigue syndrome (CFS) is a condition of unknown etiology, characterized by a persistent debilitating fatigue, the muscle-related symptoms and the neuropsychiatric symptoms. Recently, it has been reported that the patients with CFS might have impaired activation of the hypothalamic-pituitary-adrenal axis, and suggested that a part of the patho-genesis of CFS might be associated with abnormalities of the endocrine system. Herein, we show that the majority of Japanese patients with CFS had a serum dehydroepiandrosterone sulfate (DHEA-S) deficiency. Serum DHEA-S is one of the most abundantly produced hormones which is secreted from the adrenal glands, and its physiological function is thought to be a precursor of sex steroids. DHEA-S has recently been shown to have physiological properties, such as neurosteroids, which are associated with such psychophysiological phenomena as memory, stress, anxiety, sleep and depression. Therefore, the deficiency of DHEA-S might be related to the neuropsychiatric symptoms in patients with CFS.

17-Hydroxycorticosteroids↗

PubMed1998

[Acute promyelocytic leukemia accompanied by scrotal Fournier's gangrene during ATRA treatment and relapsed as external ear tumor].

A 43-year-old man was admitted because of gingival bleeding. A diagnosis of acute promyelocytic leukemia (APL) was made. He was given combination chemotherapy including all-trans retinoic acid (ATRA). During the myelosuppression stage, the patient developed Fournier's gangrene of the scrotum. He achieved complete remission and underwent a hemicastration procedure. Seven months later, bilateral external ear tumors developed. Biopsy specimens of the tumors revealed infiltration of APL cells. A second remission was obtained by chemotherapy including ATRA. However, bilateral ear tumors developed again 5 months later despite indications of normal marrow without proliferation of leukemic blasts. Irradiation successfully reduced the ear tumors, but the patient died of cerebral hemorrhage from a left frontal extramedullary tumor. This was a rare case of APL accompanied by Fournier's gangrene of the scrotum during ATRA treatment, and by extramedullary tumors of the external ear and brain during leukemic relapse.

Adult↗

PubMed1998

Prospective study of mutant frequencies at the hprt and T-cell receptor gene loci in pediatric cancer patients during chemotherapy.

Mutant frequencies (MFs) at the hypoxanthine phosphoribosyl transferase gene and the T-cell receptor (TCR) gene loci were evaluated in nine pediatric cancer patients before and during anticancer chemotherapy. The study population consisted of three patients with Hodgkin's disease, four patients with neuroblastoma, and two patients with Wilms' tumor. Except for one patient with neuroblastoma and one patient with Wilms' tumor, MFs at the hypoxanthine phosphoribosyl transferase locus tended to increase during the early cycles of treatment. The elevation was most striking and persistent in patients with Hodgkin's disease. The clonal relationship was determined in mutant cells derived from Hodgkin's disease patients by TCR-gamma gene rearrangement pattern and showed that the elevation of MFs resulted from increased mutational events rather than from clonal expansion of mutants. An increase in TCR MF was also found during chemotherapy in most patients, but the time of TCR MF elevation was variable among patients. Among the chemotherapeutic agents used in this study, cyclophosphamide was considered to be the most mutagenic. Our present study clearly demonstrates that anticancer chemotherapy can induce mutagenesis in vivo in various pediatric cancer patients.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1998

[Procainamide-induced lupus in a patient with bilateral pleural effusion].

A 70-year-old physician was admitted to our hospital because of bilateral pleural effusion and left-sided chest pain on deep inspiration. On admission, the APTT was prolonged and was not corrected with a 1:1 mixture of normal plasma. Results of serological examinations included a positive lupus-anticoagulant test and a positive ANA test at a titer of 1:1,280 in a homogeneous pattern. The patient's age, sex, symptoms, signs, and laboratory results all argued against the diagnosis of SLE except for ANA and lupus anticoagulant test. Because procainamide had been prescribed (250 mg every 6 h) for premature ventricular contractions for eight years before admission, procainamide-induced lupus was suspected. Procainamide was discontinued. Chest pain persisted and tests for c-reactive protein were positive. Prednisolone was administered. Procainamide induced lupus was diagnosed, because anti-histone H 2 A-H 2 B complex antibodies were high by enzyme-linked immunosorbent assay, and IgM-class anti-histone antibodies were found in response to H1, H 2 B and H 2 A-H 2 B complex (immunoblotting), which suggested the drug induced lupus. There are only a few reports of drug induced lupus in which the lupus-anticoagulant test was positive and prednisolone was indicated. The measurements of anti-histone antibodies and of expression of anti-histone antibodies were useful in distinguishing drug-induced lupus from SLE.

Aged↗

PubMed1998

Potent sigma1-receptor ligand 4-phenyl-1-(4-phenylbutyl) piperidine modulates basal and N-methyl-D-aspartate-evoked nitric oxide production in vivo.

BACKGROUND AND PURPOSE: final sigma-Receptor ligands ameliorate ischemic neuronal injury and modulate neuronal responses to N-methyl-D-aspartate (NMDA) receptor stimulation. Because NMDA-evoked synthesis of nitric oxide (NO) may play an important role in excitotoxic-mediated injury, we tested the hypothesis that final sigma-receptor ligands attenuate basal and NMDA-evoked NO production in the striatum in vivo. METHODS: Microdialysis probes were placed bilaterally into the striatum of halothane-anesthetized adult Wistar rats. Rats were divided into 7 treatment groups and perfused with artificial cerebrospinal fluid (aCSF) containing 3 micromol/L [14C]L-arginine for 2 to 3 hours followed by NMDA in various combinations with the following drugs: L-nitroarginine (L-NNA); the final sigma1-receptor ligand 4-phenyl-1-(4-phenylbutyl) piperidine (PPBP); the selective final sigma1-receptor antagonist 1-(cyclopropylmethyl)-4-(2'-oxoethyl) piperidine hydrobromide (DuP 734); and the noncompetitive NMDA receptor blocker MK-801 in aCSF. Right-left differences between [14C]L-citrulline in the effluent from rats treated with different drug combinations were assumed to reflect differences in NO production. RESULTS: After a 3-hour loading period with [14C]L-arginine, addition of 1 mmol/L NMDA increased [14C]L-citrulline recovery compared with aCSF alone. This NMDA-evoked increase was inhibited by 1 mmol/L of L-NNA and PPBP. Perfusion of 1 mmol/L of the final sigma1-receptor antagonist DuP 734 with 1 mmol/L PPBP augmented NMDA-evoked [14C]L-citrulline recovery compared with perfusion with PPBP and NMDA. MK-801 attenuated the basal as well as NMDA-evoked [14C]L-citrulline recovery. PPBP did not cause any further attenuation in the basal and NMDA-evoked [14C]L-citrulline recovery in the presence of MK-801. CONCLUSIONS: These data indicate that a final sigma1-receptor ligand attenuates basal as well as NMDA-evoked NO production. Because the attenuated NO production was reversed by DuP 734, PPBP appears to act as an agonist at the final sigma1-receptor. Attenuated NO production by final sigma1-receptor agonists provides one possible mechanism for focal ischemic neuroprotection.

Animals↗

PubMed1998

Comparative study of sialidase activity and G(M3) content in B16 melanoma variants with different metastatic potential.

We previously demonstrated that transfection of a sialidase cDNA into B16-BL6 cells, a highly metastatic and invasive cell line derived from the mouse B16 melanoma, resulted in a marked suppression of metastasis accompanied by decreased cellular content of the GM3 that is one of the target molecules of the sialidase expressed (Tokuyama et al., 1997 Int. J. Cancer, 73, 410-415). To obtain further insight into the involvement of sialidase in metastasis, we made a comparison of the levels of sialidase activity and GM3 content between B16 melanoma cell lines with low (B16-F1) and high (B16-F10 and -BL6) metastatic potential. The cells exhibited sialidase activity towards 4-methylumbelliferyl N-acetylneuraminic acid (4MU-Neu5Ac) and gangliosides at acidic pH in the particulate fractions, but not in the cytosol. The activity toward 4MU-NeuAc was significantly lower in highly metastatic cells. The activity toward gangliosides, on the other hand, varied independently of metastatic potential: B16-F10 cells with a high potential for experimental metastasis showed the lowest level and B16-BL6 cells having high invasiveness had rather a higher level of ganglioside sialidase along with a much greater GM3 synthase activity than the other two cell lines. Flow cytometric analysis with anti-GM3 antibody revealed that highly metastatic cell lines were higher in the binding affinity as compared to B16-F1 cells, B16-BL6 cells containing twice as much cellular GM3 as B16-F1 cells on thin-layer chromatography.

Animals↗

PubMed1998

[Cytarabine-induced pericarditis].

We report two cases of cytarabine (Ara-C) induced pericarditis. The first patient was a 61-year-old man with de novo acute myelogenous leukemia (AML) with trilineage myelodysplasia (M2). Fever and pericardial effusion developed after treatment with low-dose Ara-C and etoposide (VP16) during the patient's second leukemic relapse. The second patient was a 65-year-old man with myelodysplastic syndrome (MDS) transformed into AML (M2). He achieved a complete remission after treatment with low-dose Ara-C and VP16. However, during consolidation chemotherapy consisting of oral cytarabine ocfosfate and VP16, fever and pericardial effusion developed. In both cases, pericardiocentesis revealed exudative effusion with many neutrophils. Neither bacterial nor fungal infection was demonstrated. Chest symptoms and fever were resolved by methylprednisolone pulse therapy and pericardial drainage. Both patients were given a diagnosis of pericarditis caused by allergic reaction to Ara-C. We also report on 6 other patients with Ara-C syndrome who have been encountered by our hospital.

Aged↗

PubMed1998

[Experience of cancer home chemotherapy with cooperation between hospital and clinic].

Cancer home chemotherapy has improved through the cooperation between hospital and clinic. We have experienced cancer home chemotherapy in 90 cases of terminal cancer from August 1990 to May 1998. Patients had received Low-dose infusions of 5-FU and CDDP during 6-7 days using an implanted reservoir and balloon-style continuous infusor. This therapy was continued for about several months to 2 years. We chose one method from among central venous infusion, subselective aortal infusion, selective arterial infusion, and combination of these types of infusion. The role of the hospital includes reduction operations and operations involving implant systems. When these are finished, patients are discharged from hospital and introduced to the clinic as quickly as possible. On the other hand, the clinic should care for implanted infusion system, prevent side effects, and care for patient's general condition. Side effects due to drug overdose must especially be prevented. This time, we have examined the respective roles of the hospital and clinic, some mutual problems, along with medical costs and insurance.

Ambulatory Care Facilities↗

PubMed1997

Expression of Ly-6C on microglia in the developing and adult mouse brain.

Expression of Ly-6C, a murine homolog of human CD59, in the brain was examined immunologically using an ER-MP20 monoclonal antibody both in vitro and in vivo. Ly-6C was expressed both on the isolated microglia and on microglia in the developing and adult cerebellum. The number of cerebellar microglia expressing Ly-6C markedly increased during the first postnatal week in mouse development. The expression of Ly-6C on microglia in the developing and adult brain may be related to the unique role(s) of microglia under normal and/or pathological conditions of the brain.

Animals↗

PubMed1997

NADH dehydrogenase deficiency in an apoptosis-resistant mutant isolated from a human HL-60 leukemia cell line.

An apoptosis-resistant mutant (VC-33) was selected from HL-60 by alternating exposure to camptothecin and etoposide. VC-33 cells demonstrated resistance to apoptosis as induced not only by camptothecin and etoposide but by a variety of other agents as well, including 1-beta-D-arabinofuranosylcytosine, hydroxyurea, calcium ionophore (A23187), cycloheximide, and UV irradiation. In an effort to identify the mechanism of such apoptosis resistance, a mRNA differential display analysis was used. Among a total of 12 bands with reduced expression in VC-33 cells, 1 cDNA clone was isolated that was hybridized to the wild-type transcript but not to the VC-33 transcript on Northern blotting. Partial sequence of this gene revealed 98% homology to mitochondrial NADH dehydrogenase subunit 5. When cell growth and intracellular ATP levels under glucose starvation were measured, VC-33 cells were found to be more sensitive than wild-type cells. Thus, NADH dehydrogenase deficiency may contribute, at least in part, to the mechanism of resistance to apoptosis in VC-33 cells.

Antineoplastic Agents↗

PubMed1997

Migration activity of microglia and macrophages into rat brain.

We examined the entry of intra-arterially injected microglia and macrophages into the brain using a rat muscle graft model to compare their respective abilities to invade the brain parenchyma. Isolated microglia without any activation treatment entered into the brain with or without the muscle graft, while macrophages activated by phorbol 12-myristate-13-acetate (PMA) entered the brain only in the presence of the muscle graft. These results suggest that microglia have a higher affinity for the brain than macrophages.

Animals↗

PubMed1997

Nitric oxide inhibits the dopamine-induced K+ current via guanylate cyclase in Aplysia neurons.

Nitric oxide (NO) is produced by the enzyme nitric oxide synthase (NOS) and has been implicated in inter- and intracellular communication in the nervous system. The present study was undertaken to assess the effects of sodium nitroprusside (SNP) and hydroxylamine (HOA), NO donors, on a dopamine (DA)-induced K+ current in identified Aplysia neurons using voltage-clamp and pressure ejection techniques. Bath-applied SNP (10-25 microM) reduced the DA-induced K+ current without affecting the resting membrane conductance and holding current. The DA-induced K+ current also was inhibited by the focal application of 200 microM HOA to the neuron somata. The DA-induced K+ current suppressing effects of SNP and HOA are completely reversible. Pretreatment with 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 1 microM), a specific inhibitor of NO-stimulated guanylate cyclase, and hemoglobin (50 microM), a nitric oxide scavenger, decreased the SNP-induced inhibition of the DA-induced current. In contrast, intracellular injection of 1 mM guanosine 3',5'-cyclic monophosphate (cGMP) or bath-applied 3-isobutyl-1-methylxanthine (IBMX; 50 microM), a non-specific phosphodiesterase inhibitor, inhibited the DA-induced current, mimicking the effect of the NO donors. These results demonstrate that SNP and HOA inhibit the DA-induced K+ current and that the mechanism of NO inhibition of the DA-induced current involves cGMP-dependent protein kinase.

1-Methyl-3-isobutylxanthine↗

PubMed1997

Apoptosis-resistant phenotype selected by alternating exposure to camptothecin and etoposide.

We selected an apoptosis-resistant subline (VC-33) in a human promyelocytic leukemia cell line, HL-60, by alternating exposure to camptothecin (CPT) and etoposide (VP-16). When wild-type (WT) and VC-33 cells were incubated with various concentrations of either CPT or VP-16 for 4 h, VC-33 showed several-fold resistance to apoptosis induced by these agents in comparison with WT cells. VC-33 cells also exhibited cross-resistance to apoptosis induced by 1-beta-d-arabinofuranosylcytosine, hydroxyurea, a calcium ionophore (A23187), cycloheximide, or UV irradiation. The levels of protein-DNA cross-linking induced by CPT or VP-16, and the amounts of ara-CTP generation, tended to be smaller in VC-33 cells, but the difference was not sufficient to explain the difference in the sensitivity to apoptosis. The initial rise of intracellular calcium ions with A23187 and the expression of P-glycoprotein, Bcl-2, and Bcl-Xl were comparable between WT and VC-33 cells. This mutant may represent a new phenotype of resistance to apoptosis induced by a variety of agents, and may thus be useful in the study of the mechanisms of apoptosis.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1997

Constitutive endonuclease to induce high molecular weight or internucleosomal DNA fragmentation in freshly isolated leukemia cells.

Using an autodigestion method, we investigated endogenous endonuclease(s) in leukemia cells freshly obtained from pediatric patients with various types of leukemia. Endonucleolytic activity was found to cause both high molecular weight and internucleosomal DNA fragmentation at a neutral pH in whole cell lysates of all common acute lymphoblastic leukemia (cALL) blasts, which was Mg2+-dependent and Ca2+-independent. Whole lysates from most acute myeloblastic leukemia (AML) cells possessed similar endonuclease activity, but both Mg2+ and Ca2+ were required for the activity. Our results suggest that leukemia cells of different lineages have distinct constitutive endonucleases, which may play a role in the occurrence of apoptosis in these cells.

Apoptosis↗

PubMed1997

Mouse cytochrome P450 (Cyp3a11): predominant expression in liver and capacity to activate aflatoxin B1.

S1 mapping analysis for the expression of Cyp3a11 and Cyp3a13 indicated that Cyp3a11 mRNA is predominantly expressed in mouse liver, compared with that of Cyp3a13. In addition, all of six inducers, such as dexamethasone, 3-methylcholanthrene, phenobarbital, polychlorinated biphenyl, pregnenolone 16 alpha-carbonitrile, and rifampicin, increased the expression of the Cyp3a11 mRNA more extensively than that of Cyp3a13. The level of mRNAs corresponding to Cyp3a11 and Cyp3a13 reached the maximum level between 4 and 8 weeks after birth. Cyp3a11 enzyme was expressed into CR119 cells which had been established as a cell line stably expressing NADPH-cytochrome P450 reductase cDNA of guinea pigs. These transformants showed aflatoxin B1-dependent cytotoxicity in proportion to the amounts of Cyp3a11 mRNA. This cytotoxicity was enhanced by 7,8-benzoflavone, a known activator of CYP3A protein. Based on these results, we confirm that CYP3A in the mouse, which is an animal species known to be relatively insensitive to aflatoxin B1 genotoxicity, can activate this mycotoxin efficiently.

Aflatoxin B1↗

PubMed1997

Synthesis of methyl 6-O-beta-inulotriosyl-alpha-D-glucopyranoside by intermolecular transglycosylation reaction of cycloinulo-oligosaccharide fructanotransferase.

Incubation of cycloinulohexaose and methyl alpha-D-glucopyranoside in the presence of cycloinulo-oligosaccharide fructanotransferase gave some hetero-oligosaccharides. The main product was a tetrasaccharide whose sugar composition was methyl alpha-D-glucopyranoside-D-fructose in a ratio 1:3. This oligosaccharide was isolated from the reaction mixture by charcoal-column chromatography and was identified as methyl O-beta-D-fructofuranosyl-(2--> 1)-O-beta-D-fructofuranosyl-(2-->1)-O-beta-D-fructofuranosyl-(2-->6)- alpha-D-glucopyranoside (methyl 6-O-beta-inulotriosyl-alpha-D-glucopyranoside), by two-dimensional NMR spectroscopy.

Carbohydrate Conformation↗

PubMed1997

Effectiveness of intra-arterially infused papaverine solutions of various concentrations for the treatment of cerebral vasospasm.

We evaluated the effect of intra-arterially infused papaverine solutions of various concentrations on cerebral vasospasm following subarachnoid haemorrhage. A total of 90 vascular territories in 46 patients with symptomatic cerebral vasospasm after subarachnoid haemorrhage were treated with intra-arterial infusions of papaverine. In all patients, papaverine was infused at the top of the internal carotid artery (ICA). Of the 90 vascular territories, 30 vascular territories in 14 patients were treated with an infusion of 0.1-0.2% (weight/volume) papaverine (Group 1), 30 vascular territories in 16 patients were treated with a 0.4% (w/v) papaverine infusion (Group 2), and 30 vascular territories in 16 patients were treated with an infusion of 0.8-2.0% (w/v) papaverine (Group 3). Among the three groups, we compared the vasodilatory effects of papaverine by assessing the angiographical and clinical improvements following the treatment. When 0.4% (w/v) papaverine was infused, 24 vascular territories (80%) were successfully dilated and 7 patients (44%) showed a marked reversal of neurological deficits due to vasospasm. Therefore, 80 mg/20 ml (0.4% (w/v)) papaverine infused over a 10-minute period proved to be a beneficial concentration. Transient focal neurological deficits due to the infusion of papaverine occurred in 1 Group 1 patient (7%), 1 Group 2 patient (6%), and 7 Group 3 patients (44%). Highly concentrated papaverine had a higher risk of temporary deterioration. In conclusion, the papaverine concentration of 0.4% (w/v) infused at the top of the ICA was a safe and adequate concentration for treating cerebral vasospasm.

Adult↗

PubMed1997

Myelodysplastic syndrome presenting as third malignancy after non-Hodgkin's lymphoma and osteosarcoma.

The patient was initially diagnosed as having non-Hodgkin's lymphoma and was cured following treatment with prednisolone, vincristine, daunorubicin, 1-asparaginase, and cyclophosphamide. Seven years and two months later, he developed osteosarcoma in his right femur. He received chemotherapy consisting of methotrexate, carboplatin, etoposide, and ifosfamide and again obtained remission. After 2 years and 7 months, however, he was found to have pancytopenia with morphological abnormalities in the erythroid and myeloid series. Diagnosis of myelodysplastic syndrome (MDS) was made. Cytogenetic analysis of bone marrow cells revealed -5 and -7, which is typical for secondary MDS. This is a rare case of third malignancy presumably caused by alkylating agents.

Adolescent↗