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H Kawamoto

Publications and source records attributed to H Kawamoto.

At least 55 records · Page 3Linked to original sources
PubMed2001

Stepwise lineage restriction of progenitors in lympho-myelopoiesis.

It has long been controversial whether hematopoiesis progresses through ordered stages of determination as in embryonic development. This is due to the absence of a methodology capable of exactly determining the developmental potential of hematopoietic stem/progenitor cells. The multilineage progenitor (MLP) assay enabled us to discriminate among seven types of hematopoietic progenitors, which are multipotent progenitor p-MTB (capable of generating myeloid, T and B cells), bipotent progenitors p-MT, p-MB and p-TB, and unipotent progenitors p-M, p-T and p-B. Among these seven types, the p-TB type progenitor was found to be absent. These findings indicate that the process of lineage commitment proceeds through an ordered but not random process. By extending the area of investigation to include the erythroid lineage, more convincing evidence for the ordered process was obtained. Detailed and exact illustration of the process of hematopoiesis will provide an opportunity to revive hematopoiesis as one of the most fascinating targets of research in developmental biology.

Animals↗
PubMed2001

[Topics of clinical physiological tests--pulmonary function--proposal of physio-chemical tests].

Pulmonary functions are classified as respiratory and non-respiratory. Although the mechanisms of non-respiratory pulmonary function have already been established, no new tests of respiratory pulmonary function have been developed for a long time. Thus, we report here a new analytic test of respiratory pulmonary functions. The new analytic method is physio-chemical analysis, in which the chemical factors of lungs are estimated from the physiological characteristics of lung during respiration. As examples, this report shows the method of exchanging mechanical energy to chemical energy in a comparison of lung ventilatory work between smokers and non-smokers. This report discusses the relationship between chemical energy and ATP in the blood of pneumoconiosis patients.

Aged↗
PubMed2001

Functional role of nitric oxide in the nasal mucosa of the guinea pig after instillation with lipopolysaccharide.

Nitric oxide (NO) has been found to have various actions in the body. Recently, considerable attention has been focused on the intimate relationship between the intracellular production of NO and morphological or functional changes in ciliated cells. The aim of this study was to clarify the functional significance of NO in the nasal mucosa. Healthy, adult, pigmented guinea pigs were randomly divided into one control and three experimental groups. The animals were instilled with either lipopolysaccharide (LPS) only or LPS plus dexamethasone or NG-nitro L-arginine methyl ester (L-NAME). The effect of NO on the nasal epithelium was analyzed morphologically by scanning electron microscopy and physiologically by ciliary beat frequency (CBF) measurement. The origin of NO was also investigated using a fluorescent indicator for NO, namely 4,5-diaminofluorescein diacetate. LPS induced damage of cilia 3 days after the first instillation, while dexamethasone or L-NAME seemed to attenuate the effect of LPS. NO production was localized in ciliated cells and the main source of NO in ciliated cells is suggested to be inducible NO synthase. The greater number of ciliated cells of LPS-treated animals produced a larger amount of NO compared with normal animals. LPS also induced a decrease in CBF, which was inhibited by dexamethasone or L-NAME. It is suggested that NO may play an important role in pathological changes in the nasal mucosa.

Animals↗
PubMed2001

[Relationship between flow volume curve and CT findings in non-smoking patients with long histories of bronchial asthma].

AIM: This study was conducted to verify whether bronchial asthma (BA) alone causes pulmonary emphysema (PE), and to examine the computed tomography (CT) findings in non-smokers with BA demonstrating the flow volume curve (FV curve) characteristic of PE. SUBJECTS AND METHODS: Non-smoking patients with a history of BA for more than 20 years were divided into 2 groups: the dogleg pattern group (n = 5), with an FV curve characteristic of PE, and the concave pattern group (n = 16) with an FV curve characteristic of BA. CT scans was performed using CT values (level, 900 H.U.; width, 400 H.U.) that facilitate detection of a low attenuation area (LAA), and using conventional CT values (level, 700 H.U.; width, 1,300 H.U.). LAA (including air trapping), thickness of the bronchial wall, and partial atelectasis were compared between the 2 groups. RESULTS: PE was not detected, although air trapping was found in all subjects. The thickness of the airway was greater in the dogleg pattern than in the concave pattern. The incidences of air trapping and partial atelectasis were higher in the former than in the latter. DISCUSSION: BA alone may not cause PE. Some BA patients without PE show the FV curve characteristic of PE, reflecting an increase in the thickness of the airway wall and a decrease in the pulmonary ventilation probably due to the air trapping and the partial atelectasis.

Aged↗
PubMed2001

[Dissecting aneurysm of the anterior cerebral artery with persistent pearl & string sign on cerebral angiograms over a period of eight years].

We present a rare case of a dissecting aneurysm of the left anterior cerebral artery (ACA) with persistent pearl & string sign on cerebral angiograms over a period of 8 years. A 43-year-old woman with disturbance of consciousness and right sided hemiparesis was conservatively treated. Computed tomographic (CT) scan revealed a low-density area in the left frontal lobe. Initial angiography, which was performed at 6 months after the onset, showed a pearl & string sign at the A2 portion of the left ACA. After 8 years, repeat angiography again showed persistent pearl & string sign at the same portion of the left ACA. We discussed the changes in findings usually obtained in cerebral angiography concerning dissecting aneurysms in ACA.

Adult↗
PubMed2001

[Pulmonary function tests and their clinical significances on outside of textbooks].

Pulmonary functions are classified two kinds of functions which are respiratory and non-respiratory. We explained new clinical significant results by looking at the usual respiratory pulmonary function tests and devices in this paper. We found two new indexes on uneveness of ventilation by analyzed compartments of forced expiratory curves(Tiffneu curves) and at improvement of CO single breathing method on diffusing capacity test. We found new index on bronchial anaphylaxis for bronchial asthma by time constant measured from forced expiratory curves, also. We found new index on ventilatory efficiency at developing the automatic respiratory resistance meter by the forced oscillation method of Du Bois, too.

Adolescent↗
PubMed2000

In vitro and in vivo pharmacological characterization of J-113397, a potent and selective non-peptidyl ORL1 receptor antagonist.

1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl -1, 3-dihydro-2H-benzimidazol-2-one (J-113397) was found to be the first potent nonpeptidyl ORL1 receptor antagonist (K(i): cloned human ORL1=1.8 nM) with high selectivity over other opioid receptors (K(i): 1000 nM for human mu-opioid receptor, >10,000 nM for human delta-opioid receptor, and 640 nM for human kappa-opioid receptor). In vitro, J-113397 inhibited nociceptin/orphanin FQ-stimulated [35S]guanosine 5'-O-(gamma-thio)triphosphate (GTP gamma S) binding to Chinese Hamster Ovary (CHO) cells expressing ORL1 (CHO-ORL1) with an IC(50) value of 5.3 nM but had no effect on [35S]GTP gamma S binding by itself. Schild plot analysis of the [35S]GTP gamma S binding assay and cAMP assay using CHO-ORL1 indicated competitive antagonism of J-113397 on the ORL1 receptor. In CHO cells expressing mu-, delta- or kappa-opioid receptors, J-113397 had no effects on [35S]GTP gamma S binding up to a concentration of 100 nM, indicating selective antagonism of the compound on the ORL1 receptor. In vivo, J-113397, when administered subcutaneously (s.c.), dose-dependently inhibited hyperalgesia elicited by intracerebroventricular (i.c.v.) administration of nociceptin/orphanin FQ in a tail-flick test with mice. An in vitro binding study using mouse brains indicated that J-113397 possesses high affinity for the mouse ORL1 receptor (K(i): 1.1 nM) as well as the human receptor. In summary, J-113397 is the first potent, selective ORL1 receptor antagonist that may be useful in elucidating the physiological roles of nociceptin/orphanin FQ.

Analgesics, Opioid↗
PubMed2000

A potent and highly selective nonpeptidyl nociceptin/orphanin FQ receptor (ORL1) antagonist: J-113397.

We discovered a potent nociceptin/orphanin FQ receptor (ORL1) receptor antagonist, J-113397 (1-[(3R, 4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1, 3-dihydro-2H-benzimidazol-2-one). J-113397 inhibited [125I][Tyr(14)]nociceptin binding to Chinese hamster ovary (CHO) cells expressing ORL1 receptor in a dose-dependent manner (IC(50); 2. 3 nM), but showed 600-fold or less affinity for mu-, delta- and kappa-opioid receptors. Nociceptin/orphanin FQ-induced suppression of cyclic AMP accumulation elicited by forskolin was completely inhibited by J-113397 with an IC(50) value of 26 nM. These results indicate that J-113397 is a potent and selective nonpeptidyl antagonist of the ORL1 receptor.

Animals↗
PubMed2000

Delayed cerebral radiation necrosis occurring twice at different regions and times in a patient with a metastatic brain tumour.

No case of histopathologically confirmed delayed cerebral radiation necrosis (DCRN) that occurred twice at different regions and times in the same patient has been previously reported. We present a patient with such a rare clinical course and who is surviving long-term (over 13 years) with a history of a distant metastasis of a malignant tumour. To diagnose DCRN preoperatively was very difficult. However, surgical extirpation seemed to be effective for DCRN. The patient is still in a good performance status after surgery.

Brain↗
PubMed2000

T cell progenitors emerge earlier than B cell progenitors in the murine fetal liver.

The developmental potential of individual cells in the Lin-c-kit+CD45+IL-7R+ (IL-7R+) population from murine fetal liver was investigated using a clonal assay capable of determining the potential of a progenitor to give rise to myeloid, T, and B cells. Unipotent progenitors generating T cells (p-T) or B cells (p-B) but not other types of progenitors were found in the IL-7R+ population. A large proportion of progenitors at day 12 of gestation are p-T, whereas the frequency of p-T dramatically decreases with gestational age. In marked contrast, p-B are very rare by day 12, but they rapidly increase thereafter. These findings strongly suggest that the commitment of multipotent progenitors to T and B cell lineages occurs independently.

Animals↗
PubMed2000

Seasonal changes in calcium homeostasis affect the incidence of postoperative tetany in patients with Graves' disease.

BACKGROUND: We have found that postoperative tetany occurs in patients with Graves' disease who have secondary hyperparathyroidism caused by a deficiency in calcium and vitamin D concomitant with transient hypoparathyroidism after surgery. There are seasonal variations in serum 25-hydroxyvitamin D (25[OH]D) concentrations. The purpose of this study was to investigate the effects of seasonal changes in calcium homeostasis on the incidence of postoperative tetany in patients with Graves' disease who undergo subtotal thyroidectomy. PATIENTS AND METHODS: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25(OH)D, and 1,25-dihydroxyvitamin D (1,25[OH]2D) in female patients with Graves' disease who underwent subtotal thyroidectomy during the summer (n = 89) and during the winter (n = 89). RESULTS: The serum levels of calcium, magnesium, and 25(OH)D were significantly higher, but iPTH levels and 1,25(OH)2D levels were lower in summer than in winter. The percentage of vitamin D deficiency (25(OH)D < 25 nmol/L) was 23% in summer and 62% in winter (P < .001). iPTH was below the detection limit on the first postoperative day in 15 patients (13.8%) in summer and in 13 patients (11.4%) in winter. In summery, tetany developed in only 4 of 15 patients and in one patient whose iPTH level was below normal (incidence of tetany, 5.6%). In winter, however, tetany developed in 6 of 13 patients and in 4 patients whose iPTH level was below normal (incidence of tetany, 11.2%). CONCLUSIONS: Patients with Graves' disease are more susceptible to calcium and vitamin D deficiency during the winter than during the summer, resulting in the tendency toward a higher incidence of postoperative tetany in winter.

Adult↗
PubMed2000

Calcium and its regulating hormones in patients with graves disease: sex differences and relation to postoperative tetany.

OBJECTIVE: To find out why female sex is the most important risk factor for tetany, as calcium and bone metabolism may differ between the sexes. DESIGN: Prospective study. SETTING: Thyroid centre, Japan. PATIENTS AND METHODS: 45 men (mean age 35 years, SD 13) and 178 women (mean age 33 years, SD 12) with Graves disease treated by subtotal thyroidectomy. INTERVENTIONS: Measurement of serum concentrations of intact parathyroid hormone (iPTH), calcium, electrolytes, 25-hydroxyvitamin D (25 (OH) D), and 1,25-dihydroxyvitamin D (1,25 (OH) 2D). MAIN OUTCOME MEASURES: Mean values of these substances, together with reductions in serum calcium concentration, relative youth, increased alkaline phosphatase activity, large goitre, and increased serum TSH binding inhibitory globulin concentration. RESULTS: Women had significantly lower calcium concentrations than men (mean (SD) 2.37 (0.13) compared with 2.43 (0.07), p = 0.003). Serum calcium concentrations correlated significantly with concentrations of 25 (OH) D (p < 0.001). 121 of the women (68%) compared with 13 (29%) of men had vitamin D deficiency as defined as 25 (OH) D < 25 nmol/l (p < 0.05). 15 patients (8%) developed tetany postoperatively compared with I man (2%, p = 0.2). CONCLUSION: Women with Graves disease are more susceptible to calcium and vitamin D deficiency than men, which may account for the higher incidence of postoperative tetany among women with the disease.

25-Hydroxyvitamin D 2↗
PubMed2000

Correlation between deposition of immuno-components and infiltration pattern of polymorphonuclear leukocytes in the lesions of chronic urticaria.

Urticaria is often associated with perivascular infiltration of leukocytes into the lesions. Although mast cell-derived chemical mediators are considered to play crucial roles in the infiltration of leukocytes as well as in the dermal edema, other mechanisms for the leukocyte infiltration have not been well defined. This study revealed that approximately 25% of the cases of chronic idiopathic urticaria in whom wheals had continued for more than 12 h had deposition of immuno-components in the lesions, although histological examination of the lesions did not show leukocytoclastic vasculitis. In these lesions with deposition of immuno-components, both neutrophils and eosinophils had infiltrated at a constant ratio (approximately 2:1), whereas, in the lesions without deposition, a variable population of leukocytes was seen. This result suggests that activation of complements occurs in the lesions of a considerable percentage of patients with chronic idiopathic urticaria and that the complement fragments influence the infiltration patterns of polymorphonuclear leukocytes.

Adult↗
PubMed2000

[Genetic characterization of Norwalk-like viruses (NLVs) detected in Japan from 1989 to 1998 and establishment of consensus primers].

By means of reverse transcription-polymerase chain reaction using various pairs of primers, 902 strains of Norwalk-like viruses (NLVs) were detected during 10 years from 1989 to 1998 in the nationwide area of Japan including Hokkaido and Okinawa. Nucleotide sequencing was done on 177 strains, and we found that 153 strains (86%) of them belonged to geno-group II (GII). GII could be classified into five subgroups (G2A, G2B, G2C, G2D and G2E) based on the amino acid sequences showing a similarity of more than 91%. Among them G2C and G2D (named JP1) as well as G2E (named JP2), which were occasionally identified in Japan (detection rate of 17%) but rarely detected in the other countries, revealed to form new subgroups. From the above analysis, three pairs of new primers were established as consensus primers for NLVs. All the three sets of primers, P1/P2,P1/P3 and Y1/Y2, amplified both GI and GII equally and efficiently.

Consensus Sequence↗
PubMed2000

A modified burr-hole method 'galeoduroencephalosynangiosis' in a young child with moyamoya disease. A preliminary report and surgical technique.

We performed combined indirect surgical procedures using encephaloduroarteriomyosynangiosis and a burr-hole method according to descriptions by Suzuki et al. and Kawaguchi et al. with some modifications in a 4-year-old child with moyamoya disease. Transient ischemic attacks on both sides completely disappeared within 1 month and never occurred during 2.5 years follow-up period. This surgical procedure may have enough value as the first operation to prevent ischemic damage in the territories of both the anterior cerebral artery and middle cerebral artery in children with moyamoya disease.

Anterior Cerebral Artery↗