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Biomedical subjects

N Ono

Publications and source records attributed to N Ono.

At least 91 records · Page 5Linked to original sources
PubMed1997

Surgical management of Mycobacterium avium complex disease.

Between July 1991 and October 1996, eight patients with Mycobacterium avium complex (MAC) underwent pulmonary resection in our department. There was equal distribution of men women. The length of the preoperative period averaged 8.1 months (range: 1 to 30 months). Surgical resection was complete, consisting of lobectomy in 4 patients, lobectomy with partial resection in 2, segmentectomy in 1, and segmentectomy with partial resection in 1. There were no major complications postoperatively. No patients had positive sputum culture with MAC just after operation; however, one patient had positive sputum culture 6 months after operation. Our results show the good outcome of resectional surgery for MAC in properly selected patients, who should be operated as early as possible.

Female↗
PubMed1997

Requirements of DFR1/Heartless, a mesoderm-specific Drosophila FGF-receptor, for the formation of heart, visceral and somatic muscles, and ensheathing of longitudinal axon tracts in CNS.

DFR1 encodes a mesoderm-specific fibroblast growth factor receptor in Drosophila. Here, we identified and characterized a protein-null mutant of DFR1 and examined DFR1 expression in embryos using anti-DFR1 antibody. Mutant phenotypes were completely rescued by a genomic fragment from the DFR1 locus. After invagination, mesodermal cells expressing DFR1 undergo proliferation and spread out dorsally to form a monolayer beneath the ectoderm. In mutant embryos, however, the mesoderm is not capable of extending to the normal dorsal limit and consequently mesodermal cells fail to receive ectodermal signals and thus rendered incapable of differentiating into primordia for the heart, visceral and somatic muscles. DFR1 is also required for normal development of the central nervous system. The absence of DFR1 resulted in the failure of longitudinal glia to enwrap longitudinal axon tracts. DFR1 mutant phenotypes were partially mimicked by the targeted expression of activated Yan, thus demonstrating the MAP kinase pathway to be involved in differentiation of mesoderm.

Abdomen↗
PubMed1997

Three cases of renal angiomyolipoma.

We report three non-typical cases of renal angiomyolipoma including clinical features, imaging examinations (with ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography) and histological findings. Microaneurysms observed by angiography were common to the three cases and were considered to be an important finding in the diagnosis of renal angiomyolipoma. Moreover, the short tau inversion recovery (STIR) method of MRI, which suppresses photon signals of fat, was considered to be useful for the diagnosis. Case 1 was accompanied by spontaneous rupture, Case 2 was difficult to diagnose because of little fat tissue and Case 3 revealed a very small tumor.

Adolescent↗
PubMed1997

Effects of intrathecal nonnarcotic analgesics on chronic tactile allodynia in rats: alpha 2-agonists versus somatostatin analog.

The effects of the intrathecal alpha 2-agonists tizanidine and clonidine and the somatostatin analog octreotide on an experimental rat model of tactile allodynia were investigated to determine the therapeutic potential for treating chronic neuropathic pain. Allodynia was induced by ligating the rat sciatic nerve. The mechanical threshold for paw withdrawal was assessed by applying von Frey hairs to quantify analgesic actions. Mean 50% paw withdrawal thresholds were converted to the percentage of maximum possible effect (%MPE) where %MPE = (postdrug threshold-predrug threshold) divided by (15 g-predrug threshold) x 100. Dose-response curves were plotted for suppression of paw withdrawal 30 minutes after intrathecal injection of various doses of tizanidine, clonidine, and octreotide. Thresholds on the non-lesioned side were greater than 15 g. The lesioned side had baseline thresholds of less than 4.5 g. Dose-response curves were established for the antiallodynia effects of each drug. Tizanidine and clonidine at a 25-micrograms dose increased the threshold to greater than 97% of the MPE, but caused transient hindpaw weakness or sedation. No side effect was observed at a 10-micrograms dose, at which the threshold was 88-96% of MPE. Intrathecal octreotide modestly increased the threshold to only 49-67% of MPE, showing a lesser analgesic effect, although no side effect was observed at a 4-micrograms dose. The antiallodynic effects of intrathecal tizanidine and clonidine were more potent than that of octreotide.

Animals↗
PubMed1997

Inflammatory pseudotumor of the liver--MR imaging findings.

Using retrospective studies, we have investigated the possibility of obtaining characteristic findings of inflammatory pseudotumor of the liver by magnetic resonance (MR) imaging. We examined 8 patients (involving 8 masses) who had been histologically diagnosed as having an inflammatory pseudotumor in the liver. The histological studies were performed on an excised specimen of 1 mass, and on aspiration needle biopsy specimens and the clinical courses of the other 7 masses. T1 weighted images (T1WI) and T2 weighted images (T2WI) were obtained on MR imaging. MR imagings were analyzed for visualized patterns, patterns of internal structure and patterns of contrast enhancement of dynamic MR imaging. The 8 masses were visualized as hypointense on T1WI and hyperintense on T2WI by MR imaging. Dynamic MR imaging revealed that 1 mass was markedly enhanced peripherally while another mass was homogeneously enhanced, and that enhancement was most marked immediately after injection of contrast medium and then gradually disappeared. Vessels were observed in 4 masses (the portal vein in 2 masses, the hepatic vein in 1 mass, and portal and hepatic veins in 1 mass), and these vessels were clearly visualized on T1WI. The MR imaging findings from the early stage of an inflammatory pseudotumor showed a pattern similar to that of hepatic tumors with rich blood flow. The portal vein or hepatic vein was found in the tumor in half the patients, suggesting that this characteristic was useful for diagnosis of an inflammatory pseudotumor in the liver.

Aged↗
PubMed1997

[Significance of rectal contractions during multichannel urodynamic study].

BACKGROUND: The influence of rectal contractions on urination was examined using multichannel urodynamic study. METHODS: We reviewed a total of 246 consecutive urodynamic studies. Each study consisted of a uroflow measurement and multi-channel urodynamic study, evaluating total vesical pressure, abdominal (rectal) pressure, subtracted detrusor pressure and perianal electromyography. Rectal contractions were defined as periodic fluctuations over 5 cmH2O in abdominal pressure detected by a rectal balloon catheter. No relationship of these contractions with cough and breathing was observed. RESULTS: Of the 246 patients, 17 (6.9%) had a positive study for rectal contractions. The patients, who had positive rectal contractions, averaged 70-year-old were older than negative subjects averaged 62-year-old. In multichannel urodynamics, the flow rate was significantly decreased, and electromyographic activity was increased at the moment of each rectal contractions. CONCLUSIONS: The rectal contractions are not artifactual and may be regarded as one of causes responsible for urinary difficulty in the elderly.

Adult↗
PubMed1997

Evaluation of magnetic resonance angiography on portosystemic collaterals in cirrhotic patients.

OBJECTIVE: We examined the usefulness of imaging portosystemic collaterals accompanying liver cirrhosis by magnetic resonance angiography (MRA), which facilitates imaging of the vascular system without contrast medium. METHODS: MRA was performed in 30 patients with liver cirrhosis. Of the 30 patients, percutaneous transhepatic portography (PTP) was performed in 10 patients, and conventional arterial portography (CAP) was performed in 20 patients. The three-dimensional (3D) phase contrast method was used for MRA. Study 1: The ability to image portosystemic collaterals was compared between PTP or CAP and MRA. Study 2: The usefulness of MRA for evaluating the effect of treatment on gastric and esophageal varices was examined. RESULTS: Study 1: In comparing PTP and MRA (n = 10), the left gastric vein (n = 10), splenorenal (gastrorenal) shunt (n = 5), and paraumbilical vein (n = 2) were imaged similarly. However, MRA did not reveal any esophageal varices (n = 10). In comparing CAP and MRA (n = 20), the left gastric vein (n = 17), splenorenal (gastrorenal) shunt (n = 10), and paraumbilical vein (n = 4) were imaged similarly. Whereas CAP revealed esophageal varices (n = 4) in four patients, MRA revealed esophageal varices in only one patient. Study 2: When the effect of treatment for varices was evaluated, MRA 3 wk after embolization therapy for gastric varices (n = 4) confirmed the disappearance of gastrorenal shunt. However, it was impossible to evaluate esophageal varices by MRA. CONCLUSIONS: It was possible to image portosystemic collaterals accompanying liver cirrhosis by MRA. MRA was useful as a routine examination. Furthermore, it was useful for evaluating the effect of embolization therapy on gastric varices.

Adult↗
PubMed1996

CD19 regulates B lymphocyte signaling thresholds critical for the development of B-1 lineage cells and autoimmunity.

CD19 serves as a cell surface response regulator that establishes signaling thresholds critical for B lymphocyte development and activation. B lymphocytes from CD19-deficient mice are hyporesponsive to transmembrane signals, while B lymphocytes from mice that overexpress CD19 to even a small extent (25% increase) become hyperresponsive. The B-1 subpopulation of B lymphocytes is particularly sensitive to CD19 regulation, since their development is severely decreased in CD19-deficient mice. The effect of altered CD19 expression levels on the development of B cells was therefore examined using transgenic mice that express varying levels of cell surface CD19. In this study, immature B cells within the bone marrow of wild-type mice were found to specifically up-regulate CD19 expression levels by twofold as they mature, while CD5+ B cells within the spleen and peritoneum expressed even higher levels of CD19. The development of CD5+ B cells was severely decreased in CD19-deficient mice, while there was a linear correlation between increased CD19 expression levels and the increased frequency of CD5+ B cells within the peritoneum and spleen. In fact, CD5+ B cells became a major B lymphocyte population in mice that overexpressed CD19. Increased expression of CD19 also correlated with increased levels of endogenous anti-DNA Abs and rheumatoid factor. These results indicate that up-regulated expression of CD19 is functionally important for B cell development and that CD19 establishes signaling thresholds that regulate the generation of B-1 lymphocytes as well as the development of autoantibodies.

Animals↗
PubMed1996

Effects of some calcium-related agents on the protoplast transfection of Lactobacillus casei with phage PL-1 DNA.

To clarify the mechanism of Ca2+ involvement in the DNA transfer through cell membrane, we studied the effects of Ca2+-chelator, Ca2+-ionophore, and Ca2+-channel blocker on the protoplast transfection of Lactobacillus casei ATCC 27092 by PL-1 phage DNA in the presence of Ca2+. Ca2+-chelators, citrate, EDTA, and dipicolinic acid, inhibited the transfection probably by compensating the effect of Ca2+. Ca2+-ionophores, A23187 and N,N,N', N'-tetracyclohexyl-3-oxapentanediamide, which were expected to accelerate transfection by introducing Ca2+ into cells, inhibited the transfection. This fact indicated the absence of correlation between the entry of Ca2+ and the transport of DNA into protoplasts. Verapamil, which blocks voltage-dependent Ca2+-channel besides beta-adrenergic receptor, inhibited the transfection with little effect on the survival of the protoplasts. Both flunarizine and vinpocetine, voltage-dependent Ca2+-channel blockers, did not show the selective toxicity. D-alpha-Aminoadipic acid, a glutamate receptor-operated Ca2+-channel blocker, had no effect. Propranolol, which blocks beta-adrenergic receptor as does verapamil, inhibited the transfection without severely damaging the protoplasts. These results suggested that a kind of receptor-operated Ca2+-channel was involved in the transport of PL-1 phage DNA into the cells and that the cell membrane might have a receptor structure somewhat similar to the beta-adrenergic receptor found in mammalian cells.

Adrenergic Antagonists↗
PubMed1996

A comparison of children with suprasellar germ cell tumors and craniopharyngiomas: final height, weight, endocrine, and visual sequelae after treatment.

BACKGROUND: Although treatment results of craniopharyngiomas and germ cell tumors in children have been reported extensively, the relationship between various posttreatment sequelae and the nature of the tumor is not well understood. METHODS: From 1968-94, 47 children with 23 suprasellar germ cell tumors and 24 craniopharyngiomas were treated at Gunma University Hospital, Japan. Forty survivors were assessed with regard to Karnofsky scores, visual scores, final height, final weight, and other endocrine sequelae as long-term functional prognostic indicators. RESULTS: Kaplan-Meier life-table estimates and Karnofsky scores were not significantly different between the two histologic groups. The visual function of survivors did not differ significantly at diagnosis. However, the final visual function following treatment in the germ cell tumor group was better than in the craniopharyngioma group (p < 0.05). Antidiuretic hormone secretion was significantly impaired at diagnosis in the germ cell tumor group (p < 0.0001). However, there was only a marginally significant difference in posttreatment persistent diabetes insipidus. Craniopharyngioma children were shorter and more obese at diagnosis (p < 0.02), and became much more obese than germinoma children with the same hormone therapy (p < 0.003), although the height difference became insignificant following growth hormone treatment. CONCLUSIONS: Children with craniopharyngiomas tended to have more visual disturbances, increased dwarfism and obesity, and less diabetes insipidus than patients with germ cell tumors despite adequate therapy. The method of quantifying visual function may in itself be useful.

Adrenocorticotropic Hormone↗
PubMed1996

Intercostal hemangioma.

Chest wall tumors are uncommon and there have been only a few reports of intercostal hemangioma during the past 20 years. We treated a 33-year-old man who presented with intercostal hemangioma. We resected tumor and surrounding muscles beyond the limits of the lesion without removing any bone or lung tissue. The patient is free of any recurrence 3 years after surgery.

Adult↗
PubMed1996

Intrapleural pirarubicin (4'-O-tetrahydropyranyladriamycin) for treatment of malignant pleural effusion.

Pirarubicin (4'-O-tetrahydropyranyladriamycin), a new anthracyline derivative, was administered as a single agent into the pleural cavity of 42 patients (total 46 courses) with malignant pleural effusion at a dose of 20, 40, 60 or 80 mg/body. All 46 courses were evaluable for non-hematological toxicities. Fever and chest pain (> or = WHO grade 2) were seen in 67.4% and 13.0% of courses, respectively. Patients receiving a dose of 80 mg/body developed fever of > or = 39 degrees C in 45.5%, and chest pain lasting more than three days and requiring pentazocine more than three times in 36.4%. In contrast, patients receiving a dose of < or = 60 mg/body presented these toxicities in only 8.6% and 2.9%, respectively. Nausea-vomiting (> or = WHO grade 2) was observed in only 4.3% of the total 46 courses and alopecia was not observed. Thirty-eight courses (36 patients) were evaluable for hematological toxicities. Myelosuppression (leukocyte nadir count < or = 1900, WHO grade 3 or 4) was seen in four courses (10.5%), and thrombocytopenia (< or = 49,000, WHO grade 3 or 4) in only two (5.3%). Although the mean AUC (0-24) for pirarubicin in plasma during the four courses that produced myelosuppression was significantly higher than that during the 11 courses without myelosuppression, the difference in the mean dose was not significant. Furthermore, no significant correlation was shown between dose (mg/m2) and AUC in plasma. It is considered that myelosuppression is not a dose-related toxicity at a dose of 20-80 mg/body. The dose-limiting toxicity was fever or chest pain, although unexpected myelosuppression was also encountered. The maximum tolerated dose was 80 mg/body. With regard to clinical efficacy, the overall response rate was 73.7% in 38 evaluable courses (38 patients). The mean T(1/2) of pirarubicin concentration in pleural effusion and plasma was 22.1 h and 8.8 h, respectively. We recommend a dose of 40 or 60 mg/body pirarubicin for this pleurodesic treatment.

Adult↗
PubMed1996

Platelet Ca2+ is not increased in stroke-prone spontaneously hypertensive rats: comparative study with spontaneously hypertensive rats.

We have reported that cytosolic Ca2+ concentration ([Ca2+]i) is increased in platelets from spontaneously hypertensive rats (SHR) in both basal and thrombin-stimulated conditions. To determine whether the correlation between blood pressure and cellular Ca2+ metabolism exists in stroke-prone SHR (SHRSP), we investigated Ca2+ handling using fura 2 and aggregation response in platelets of 12- to 13-week-old male SHRSP, SHR, and Wistar-Kyoto rats (WKY). Systolic pressure was highest in SHRSP and lowest in WKY (213 +/- 8, 172 +/- 7, and 135 +/- 5 mm Hg, respectively). Basal [Ca2+]i was significantly higher in SHR than WKY (45.9 +/- 4.5 versus 41.2 +/- 4.8 nmol/L, P<.05), and that in SHRSP (40.2 +/- 2.8 nmol/L) was similar to that in WKY. Thrombin (0.1 IU/mL)-stimulated [Ca2+]i rise was greater in SHR and smaller in SHRSP than in WKY in the presence of extracellular Ca2+ (530 +/- 50 and 408 +/- 52 versus 475 +/- 50 nmol/L, respectively; P<.05). The recovery rate from the peak [Ca2+]i response to thrombin was greatest in SHRSP and least in WKY. Ionomycin (5 micromol/L)-stimulated [Ca2+]i rise was similar in WKY, SHR, and SHRSP (731 +/- 97, 743 +/- 88, and 683 +/- 70 nmol/L, respectively). Thrombin-induced maximum platelet aggregation response was higher in SHR and lower in SHRSP than WKY (82 +/- 4 percent and 61 +/- 15 percent versus 73 +/- 6 percent, respectively; P<.05). In contrast to SHR, basal [Ca2+]i in SHRSP was similar to that in WKY, and thrombin-stimulated [Ca2+]i was attenuated. These result suggest that platelet Ca2+ handling differs between SHR substrains and that an increased [Ca2+]i is not obligatory in genetically hypertensive rats.

Animals↗
PubMed1996

Effects of insulin on calcium metabolism and platelet aggregation.

The influence of insulin on platelets in vitro has not been exhaustively investigated. To clarify whether insulin affects Ca2+ metabolism in platelets directly or through alteration of other systems regulating intracellular Ca2+ homeostasis, we examined the effect of insulin both alone and in combination with prostaglandin E1 on platelet aggregation and Ca2+ metabolism. Incubation of rat platelets with insulin reduced thrombin-induced Ca2+ influx but did not change thrombin-evoked release of Ca2+ from internal stores or the size of internal Ca2+ stores. The interactive effects of insulin with prostaglandin E1 were only additive, and insulin did not augment the effects of prostaglandin E1 on platelet Ca2+ metabolism. In contrast, insulin did not inhibit thrombin-induced platelet aggregation but did augment inhibition of platelet aggregation by prostaglandin E1. Our results suggest that insulin inhibits platelet function by both prostaglandin E1-dependent and -independent mechanisms.

Animals↗
PubMed1996

Effects of tri-, di- and monobutyltin on synaptic parameters of the cholinergic system in the cerebral cortex of mice.

Triorganotin compounds like tributyltin have been reported to be biodegraded to diorganotin, monoorganotin and then inorganic tin in animals after they have been ingested. Effects of tributyltin, dibutyltin and monobutyltin on various cholinergic parameters that are involved in synaptic transmission in the mouse cerebral cortex were investigated in vitro. Tributyltin and dibutyltin, but not monobutyltin, inhibited the activity of choline acetyltransferase, both the high-affinity and low-affinity uptakes of choline into synaptosomes, and the binding of [3H]quinuclidinyl benzilate to muscarinic acetylcholine receptors. Tributyltin and dibutyltin, but not monobutyltin, had a slightly suppressive effect on the K(+)-induced release and synthesis of acetylcholine in slices of the cortex. All three butyltins at concentrations from 10(-6) to 10(-4) M had no effect on the activity of acetylcholinesterase. The extent of the inhibitory effects on the cholinergic parameters, apart from the activity of acetylcholinesterase, was slightly greater in the case of tributyltin than dibutyltin, in particularly at the highest concentration (10(-4) M) tested. Therefore, it is concluded that tributyltin metabolites inhibit various parameters of cholinergic activity with a potency ranking of tributyltin > dibutyltin > monobutyltin.

Acetylcholinesterase↗
PubMed1996

Liver haem metabolism in adjuvant-induced arthritic rats.

1. Adjuvant-induced arthritic (AA) rats show a striking decrease in the level of cytochrome P450, a key microsomal haemoprotein involved in electron transport and drug metabolism in the liver. In the present study, we examined the relationship between the reduction of P450 content and haem metabolism in the liver of AA rats. 2. The activities of many enzymes catalyzing the biosynthesis of haem in the liver were significantly higher in AA rats than in normal rats, whereas only coproporphyrinogen oxidase activity in AA rats was markedly lower than that in normal rats. Furthermore, the activity of haem oxygenase, a key enzyme in the haem degradative pathway, increased significantly in AA rats. In addition, the degree of increase in the activity of this enzyme was clearly higher than that in the activity of 5-aminolevulinate synthase, a key enzyme in the haem synthetic pathway. 3. These results suggest that the reduction of live P450 content in AA rats is based on the lowering of liver haem content due to the combined action of the increased haem oxygenase activity and the decreased coproporphyrinogen oxidase activity. The changes in these enzyme activities were apparently suppressed by the continuous administration of indomethacin, which improved the arthritic states of the animals.

5-Aminolevulinate Synthetase↗