Biomedical subjects

H Kawamoto

Publications and source records attributed to H Kawamoto.

At least 91 records · Page 5Linked to original sources

PubMed1999

[Significance of area under the flow volume curve--useful index of bronchial asthma].

Some studies have reported that area under the flow volume curve (AUFVC) can be an index of pulmonary function. However, the significance of AUFVC remains to be clarified. We have clarified that AUFVC reflects the momentum of expired air. Size of flow volume curve (= AUFVC) has been commonly recognized to be changeable visually in patients with asthma. To clarify whether size of flow volume curve (= AUFVC) is a useful index of the course of bronchial asthma, we compared the rate of improvement forced expiratory volume in 1 second (FEV1.0), peak expiratory flow rate (PEFR) or forced vital capacity (FVC) to the rate of improvement in AUFVC after admission in 20 patients with bronchial asthma. The rate of improvement in AUFVC positively correlated with the rate of improvement in FEV1.0, PEFR or FVC. AUFVC demonstrated more marked improvement than other indices. Since AUFVC reflects the momentum of expired air, bronchial asthma's patients could understand visually that the momentum of expired air decreased due to airway stenosis by presenting flow volume curve. Therefore, visual size of flow volume curve helped patients with asthma to understand the condition of asthma. Size of flow volume curve (AUFVC) may be useful index of the course of bronchial asthma.

Adult↗

PubMed1999

[Expired nitric oxide concentration derived from nasal cavity and that derived from airway and lung in Japanese cedar pollinosis].

AIM: Japanese cedar pollinosis (Type I allergy to Japanese cedar pollen) shows a high incidence in spring in Japan, demonstrating symptoms such as pituita, rhinostenosis, lacrimation and sometimes pharyngeal pain. The following study investigated whether expired nitric oxide (NO) concentration is increased in Japanese cedar pollinosis, and whether expired NO concentration can be used to discriminate from cold syndrome which symptoms are similar to Japanese cedar pollinosis. SUBJECTS AND METHODS: In 20 healthy subjects, 20 patients with Japanese cedar pollinosis and 20 patients with cold syndrome, expired NO concentrations derived from nasal cavity and those derived from airway and lung were measured. Expired NO concentrations derived from nasal cavity and those derived from airway and lung were compared among the groups. RESULTS: In patients with Japanese cedar pollinosis expired NO concentrations derived from nasal cavity and those derived from airway and lung markedly increased. In patients with cold syndrome there were no significant increases in these concentrations. DISCUSSION: It is considered that expired NO concentration is useful for discriminating Japanese cedar pollinosis from cold syndrome. It seems interesting that not only expired NO concentrations derived from nasal cavity but also those derived from airway and lung were clevated. Generalized airway inflammation may be present, even without clinical asthma, in patients with Japanese cedar pollinosis.

Adult↗

PubMed1998

Presence of progenitors restricted to T, B, or myeloid lineage, but absence of multipotent stem cells, in the murine fetal thymus.

The most immature population of fetal thymus (FT) cells has been shown to generate not only T but also B and myeloid cells. The present study was undertaken to clarify whether such a multipotent activity of the earliest population of FT cells is attributed to multipotent hemopoietic progenitors or to a mixture of lineage-restricted progenitors. Examination of individual FT progenitors by a recently established clonal assay system, which is able to determine the developmental potential of each progenitor toward T, B, and myeloid lineages, elucidated that a large majority of progenitors in FT were restricted to the T cell lineage. Presence of a small number of B or myeloid lineage-restricted progenitors was also disclosed. No multipotent progenitors, however, were detected in FT. These results are consistent with our recent finding that restriction of hemopoietic stem cells to T, B, and myeloid lineages takes place in the fetal liver.

Animals↗

PubMed1998

Structural basis for chemical inhibition of human blood coagulation factor Xa.

Factor Xa, the converting enzyme of prothrombin to thrombin, has emerged as an alternative (to thrombin) target for drug discovery for thromboembolic diseases. An inhibitor has been synthesized and the crystal structure of the complex between Des[1-44] factor Xa and the inhibitor has been determined by crystallographic methods in two different crystal forms to 2.3- and 2.4-A resolution. The racemic mixture of inhibitor FX-2212, (2RS)-(3'-amidino-3-biphenylyl)-5-(4-pyridylamino)pentanoic acid, inhibits factor Xa activity by 50% at 272 nM in vitro. The S-isomer of FX-2212 (FX-2212a) was found to bind to the active site of factor Xa in both crystal forms. The biphenylamidine of FX-2212a occupies the S1-pocket, and the pyridine ring makes hydrophobic interactions with the factor Xa aryl-binding site. Several water molecules meditate inhibitor binding to residues in the active site. In contrast to the earlier crystal structures of factor Xa, such as those of apo-Des[1-45] factor Xa and Des[1-44] factor Xa in complex with a naphthyl inhibitor DX-9065a, two epidermal growth factor-like domains of factor Xa are well ordered in both our crystal forms as well as the region between the two domains, which recently was found to be the binding site of the effector cell protease receptor-1. This structure provides a basis for designing next generation inhibitors of factor Xa.

Binding Sites↗

PubMed1998

Changing trends and prognoses for patients with papillary thyroid cancer.

OBJECTIVE: To analyze differences in the demographic backgrounds, and in treatments, prognosis, and risk factors of patients with papillary thyroid cancer operated on from 1965 to 1990, by dividing them into 3 chronological groups. DESIGN: Retrospective cohort study of 2423 patients with papillary thyroid cancer (tumor size, > or = 10 mm) who underwent curative surgery at the Noguchi Thyroid Clinic, Oita, Japan. SETTING: A center for the treatment of thyroid disease, at which about 1400 thyroid operations are performed per year. PATIENTS: There were 596 patients treated during from January 1, 1965, to December 31, 1973; 964 patients treated from January 1, 1974, to December 31, 1982; and 959 patients treated from January 1, 1983, to December 31, 1990. RESULTS: Of the 2519 patients treated, 96 were excluded from the study because they had undergone noncurative surgery. Therefore, the analyses are based on data for 2423 patients who underwent curative surgery. Three groups were defined as follows: group 1, underwent surgery during the period 1965-1973 (n = 577); group 2, underwent surgery during the period 1974-1982 (n = 924); and group 3, underwent surgery during the period 1983-1990 (n = 922). The mean age of the patients in group 1 was 42.4 years, in group 2, 45.0 years, and in group 3, 47.8 years. The mean tumor size was 30.4 mm, 26.5 mm, and 24.6 mm, respectively, for groups 1, 2, and 3. The 10- and 20-year disease-specific survival rates were significantly improved from group 1 (95.5% and 90.3%, respectively) to group 2 (97.8% and 93.9%, respectively), and the 10-year rate was significantly improved for group 3 (98.2%). In the multivariate analysis, age, sex, tumor size, and gross nodal metastasis were significant predictors of survival for group 1; however, only age and gross nodal metastasis were significant for group 3. CONCLUSIONS: Over time, papillary thyroid cancer has become diagnosed at an earlier stage, but the age of the patients at diagnosis is older. The disease-specific survival rate was significantly improved, mainly owing to earlier treatment, and the change in the risk factor profile for cancer mortality may be due to the changes in the demographic backgrounds and diagnostic and therapeutic modalities. These considerations derived from risk factor analysis should be considered for treating the patient and for the prediction of patient survival.

Adolescent↗

PubMed1998

Papillary thyroid carcinoma: modified radical neck dissection improves prognosis.

OBJECTIVE: To ascertain whether modified radical neck dissection offers a survival advantage for some subsets of patients with papillary cancer of the thyroid. DESIGN: A retrospective cohort study of 2966 patients curatively treated at the Noguchi Thyroid Clinic and Hospital Foundation, Oita, Japan, between 1946 and 1991. SETTING: A center for the treatment of thyroid disease, where about 1400 thyroid operations are performed per year. PATIENTS: Between 1946 and 1991, patients with papillary cancer whose primary tumor was 1 cm or larger and who were curatively treated were studied. Of the 2859 patients, 72.1% underwent modified radical neck dissection, 8.5% underwent partial node excision, and 19.4% underwent no node excision. RESULTS: A univariate analysis revealed a subset of patients who benefited from modified radical neck dissection. A multivariate analysis revealed that sex (P<.001), age at the time of the operation (P<.001), size of the primary tumor (P<.001), extrathyroidal invasion (P<.001), and the presence of nodal metastasis (P<.01) are significant risk factors. CONCLUSION: Patients with nodal metastasis, patients in whom the primary tumor invades beyond the thyroid capsule, and women older than 60 years can benefit from modified radical neck dissection.

Adult↗

PubMed1998

Acute hepatic failure due to hepatosplenic B-cell non-Hodgkin's lymphoma in a patient infected with hepatitis C virus.

We report a 75-year-old Japanese man infected with hepatitis C virus (HCV) who died of acute hepatic failure due to the hepatic infiltration of B-cell non-Hodgkin's lymphoma (NHL) cells. He suddenly developed jaundice, fatigue, fever, and hepatosplenomegaly during the course of chronic infection with HCV. Postmortem liver necropsy revealed extensive infiltration of lymphoma cells into the liver. Although the association between HCV infection and NHL has recently become a matter of concern, we believe this to be the first reported case of acute hepatic failure caused by hepatic involvement of non-Hodgkin's lymphoma in an HCV-infected patient.

Aged↗

PubMed1998

In vitro generation of lymphohematopoietic cells from endothelial cells purified from murine embryos.

We have investigated the lymphohematopoietic potentials of endothelial cells (EC) and hematopoietic cells (HPC) sorted from embryos. Expression of VE-cadherin, CD45, and Ter119 was used to distinguish EC (VE-cadherin+CD45-Ter119-) from HPC (VE-cadherin-CD45+). Thus defined, EC population takes up acetylated LDL and coexpresses CD31, Flk1, and CD34. In E9.5 embryos, EC from yolk sac (YS) and the embryo proper generate blood cells, including lymphocytes. Thus, lymphohematopoietic EC do exist in the embryo, and they are generated both in YS and the embryo proper. On the other hand, HPC with lymphopoietic potency appear first in the embryo proper. These findings implicate involvement of multiple environmental cues for acquiring lymphopoietic competency during differentiation of HPC.

Animals↗

PubMed1998

Localization of nitric oxide synthase in human nasal mucosa with nasal allergy.

Nitric oxide (NO) plays an important role in the regulation of upper respiratory function. In the nasal cavity, the concentration of NO in the air in patients with untreated allergic rhinitis is higher than that in normal individuals. NO is produced by the action of NO synthase (NOS) using L-arginine as a substrate. To investigate the expression of NOS in human nasal mucosa, histochemical staining for NADPH diaphorase and immunohistochemical staining for NOS isoforms were carried out in nasal inferior turbinate mucosa from patients with nasal allergy. Those without nasal allergy served as controls. NADPH diaphorase histochemical study revealed that NOS was expressed in the nasal epithelium, submucosal glands, nerve fibres and the endothelium in specimens of both allergic and control groups. Immunoreactivity to endothelial NOS (eNOS) was localized to epithelial and endothelial cells in both allergic and control groups. In some specimens in both groups, nerve fibres around submucosal glands stained positively for eNOS. Immunoreactivity to eNOS, however, was slightly stronger in the epithelia of the allergic group than in those of the controls. Immunoreactivity to inducible NOS (iNOS) was localized to epithelial cells, endothelial cells, nasal glands and inflammatory cells. The staining of epithelial cells and inflammatory cells was more marked in the allergic group than the controls. These findings may suggest that the greater amounts of NO in the nasal air of patients with allergic rhinitis are mainly induced by iNOS activity.

Case-Control Studies↗

PubMed1998

Trans-sellar color Doppler ultrasonography during transsphenoidal surgery.

OBJECTIVE: To improve the safety and efficacy of transsphenoidal pituitary adenoma surgery, we investigated transsphenoidal intraoperative color Doppler ultrasonography using a biplane transducer system. METHODS: We studied 23 patients with pituitary adenomas (18 patients with macroadenomas and 5 patients with microadenomas) who underwent transsphenoidal surgery. The Hitachi EUB555 color Doppler ultrasound system (Hitachi Medical, Tokyo, Japan) was used with a pediatric biplane transesophageal echo cardiography probe (EUP-ES533, 7.5 MHz, biplane phased array sector probe, 9.8-mm tip). The probe was inserted into the saline-filled sphenoid sinus after the sellar floor was opened. Intra- and suprasellar images were obtained just before dural incision and after the tumor removal was thought to have been accomplished. RESULTS: In all patients, the tumor was depicted as a slightly hyperechoic mass, as compared with the cerebrum. Using color Doppler imaging, major cerebral arteries were depicted clearly in 74% of patients. The pituitary glands, pituitary stalks, and optic chiasms were observed in patients with small adenomas, but not when large adenomas were present. Cavernous sinus invasion, concomitant aneurysm, and residual tumor were clearly visualized. In patients with large adenomas, the end point of surgery was decided when there was an ultrasonographically demonstrated collapsed tumor capsule, subcapsular total vacancy, and reappearance of the optic chiasm. CONCLUSION: Trans-sellar color Doppler ultrasonography seems to be a useful intraoperative guiding system that may improve the safety and efficacy of transsphenoidal surgery.

Adenoma↗

PubMed1998

Survey of human group C rotaviruses in Japan during the winter of 1992 to 1993.

Fecal specimens from patients with acute diarrhea were collected from 10 prefectures in Japan over a 6-month period (November 1992 to April 1993), and the specimens that were negative for human group A rotaviruses were screened for the presence of human group C rotaviruses (CHRVs) by the reverse passive hemagglutination test. Of 784 specimens examined, 53 samples (6.8%) that were collected in 7 of 10 prefectures were positive for CHRV, indicating that CHRVs are widely distributed across Japan. Most of the CHRV isolates were detected in March and April, and CHRVs mainly prevailed in children ages 3 to 8 years. The genome electropherotypes of eight strains isolated in five individual prefectures were surprisingly similar to each other and were different from those of CHRV strains isolated to date. The outer capsid glycoprotein (VP7) gene homologies of the isolates retrieved in 1993 were subsequently analyzed by the dot blot hybridization method. As a result, the VP7 genes of the isolates revealed very high levels of homology not only with each other but also with the VP7 gene of the OK118 strain isolated in 1988. These results suggest that a large-scale outbreak of CHRV occurred during the winter of 1992 and 1993 in Japan.

Adolescent↗

PubMed1998

Cold exposure enhances nitroxidergic nerve-mediated vasodilatation in canine nasal mucosa.

We have previously reported that there is non-adrenergic, non-cholinergic (NANC) innervation in canine nasal mucosa and that the relaxation response to electrical stimulation of the NANC nerve is mainly mediated by nitric oxide (NO). In the present study, we examined the effect of cold exposure (24 degrees C) on nitroxidergic nerve-mediated vasodilatation in isolated canine nasal mucosa. Nasal mucosa strips, prepared from canine nasal septum and moderately precontracted with methoxamine in the presence of atropine and guanethidine, relaxed in response to transmural electrical stimulation (square pulses of 0.5-msec duration, at 5 Hz and 25 V). The degree of relaxation at 24 degrees C (55.4+/-13.2% of methoxamine-induced contraction, mean+/-S.D., n=6) was significantly greater than that at 34 degrees C (33.8+/-8.6%, n=6). This phenomenon was reversible. In contrast, the magnitude of relaxation responses to an NO donor (sodium nitroprusside of 0.1 and 1 microM) remained unchanged by cold exposure. These results suggest that the release of NO from the nitroxidergic nerve endings is augmented by cold exposure and, thus, vasodilatation of the nasal blood vessel is enhanced, thereby contributing to the swelling of the nasal mucosa in cold conditions.

Animals↗

PubMed1998

Effects of successful adenomectomy on body composition in acromegaly.

The purpose of the present study was to investigate postsurgical change in body composition in patients who have undergone surgery for acromegaly. Eight patients with acromegaly had determination of serum GH, insulin-like growth factor-I (IGF-I), height, body weight, and bioelectric impedance before surgery and at 2 weeks, 1 month, 3 months, and 6 months after surgery. Body composition was analyzed by bioelectric impedance analysis (BIA). We analyzed body fat (BF), body lean mass (BLM), body cell mass (BCM), total body water (TBW), intracellular water (ICW) and extracellular water (ECW). The serum GH concentration and IGF-I had decreased significantly 2 weeks after surgery. Body weight had decreased significantly 1 month after surgery and recovered 3 months after surgery. BIA showed that TBW and BCM had decreased significantly 2 weeks after surgery. BF gradually increased up to 1 month after surgery and was increased significantly at 3 months after surgery. The percent ratio of TBW/body weight decreased and the percent ratio of BF/body weight increased during the 6 months after surgery. The percent ratio of ECW/TBW did not change during the 6 months following surgery. In conclusion, the rapid body weight loss which occurred within 2 weeks after surgery was caused by decreases in TBW and BCM. The recovery of body weight, which was seen later than 1 month after surgery, was caused by an increase in BF. The postoperative change in body composition in acromegaly ceased 3 months after surgery.

Acromegaly↗

PubMed1998

Post-operative thyroid status of patients with Graves' disease is determined by the responsiveness of thyrocyte to TSH under the present thyroid gland remnant.

In order to determine whether thyrocyte responsiveness to TSH is correlated with post-operative thyroid status, thyrocytes obtained from 51 patients with Graves' disease were cultured for 3 days. This was followed by culture with 10 mU/mL of TSH (TSH group) or without TSH (control group) for 3 additional days. On the 8th culture day, the amount of thyroglobulin (Tg) secreted into the culture medium was assayed and the Tg ratio (amount of Tg from the stimulated group/amount of TG from the control group) was calculated. Log10 (the Tg ratio) was used for the statistic study. The post-operative status of the patient was determined based mainly on the serum concentration values of free T3 and T4 obtained between 5 and 16 months after surgery. Multivariate analysis revealed that among age, gender, TSH-binding inhibitory immunoglobulin (TBII) obtained before the surgery, estimated weight of the thyroid gland remnant, and Log10 (Tg ratio), only Log10 (Tg ratio) was statistically significant (P=0.008). When the Log10 (Tg ratio) value was small, most patients showed signs of as post-operative hypothyroidism, and as the value became larger as the number of euthyroid and/or hyperthyroid patients increased.

Adult↗

PubMed1998

[Decongesting effect of tramazoline on nasal airway patency and nasal symptoms as evaluated by acoustic rhinometry: an objective study in 30 allergic and six non-allergic subjects].

In this prospective clinical study, we investigated the effect of the nasal decongestant tramazoline on nasal airway patency in 30 subjects with perennial nasal allergy to housedust mites and in six non-allergic volunteers who served as controls. The allergic subjects were further subdivided into groups, the severe group and the moderate group, according to the level of specific IgE. We used acoustic rhinometry as an objective method, and the nasal cavity volume (NCV) and the minimum cross-sectional area (MCA) were measured before and 10 minutes after nasal spraying. Before mucosal decongestion, the average NCV in the severe group was 5.94 cm3, which was significantly lower than those in the other two groups: 7 cm3 in the control group and 8.13 cm3 in the moderate group, respectively (P = 0.02). A more significant difference was found when the first 3-cm area of the NCV was evaluated (P = 0.009). Pharmacologic decongestion caused an increase in nasal patency by 54% from the baseline NCV values in the control group, 38% in the moderate group and 48% in the severe group. There was no significant difference among the three groups. Changes in nasal symptoms were also determined by questionnaire. The degree of improvement in subjective nasal congestion was more pronounced in the allergic groups than in the control group.

Acoustics↗

PubMed1998

Transcranial Doppler ultrasonography to evaluate need for cerebrospinal fluid drainage in hydrocephalic children.

The aim of this study was to determine whether the resistive index in the anterior cerebral artery, as measured by transcranial Doppler ultrasonography without and with pressure provocation, predicts the need for cerebrospinal fluid drainage in hydrocephalic children. Both without and with pressure provocation, the resistive index was significantly higher (P > 0.05) in patients with raised intracranial pressure compared with control group patients and dropped significantly after drainage. With receiver operating characteristic analysis, the optimal cutoff point between normal and abnormal resistive index values was determined at 0.71 without pressure provocation and at 0.90 with pressure provocation. The addition of the pressure provocation test improved accuracy from 81 to 91%, mainly by improving specificity. In conclusion, transcranial Doppler ultrasonography with pressure provocation accurately identifies hydrocephalic children who require cerebrospinal fluid drainage procedures.

Cerebrospinal Fluid Shunts↗

PubMed1998

[A case of cervical-mediastinal lymph node tuberculosis progressed to pulmonary lesion through a bronchial fistula].

The patient was a 25-year-old man who had been admitted to a local hospital due to fever and trachelophyma. Tubercle bacillus was detected in pus culture obtained by biopsy of the trachelophyma, but not in sputum culture. Because combined therapy with 3 antituberculous drugs (RFP, INH and SM) failed to reduce the fever or drainage from the biopsy region, the patient was transferred to our hospital. Chest X-ray films taken on admission revealed dilatation of the superior mediastinal shadow; chest CT images revealed cervical and mediastinal lymphadenopathy and an anterior mediastinal abscess, but no pulmonary lesion. About 2 months after admission, cough developed and Gaffky type 2 was detected in the patients sputum. Bronchoscopy and bronchography revealed a bronchomediastinal fistula. Forty days after the onset of cough, reticulogranular shadows were observed in the right upper lobe on chest X-ray films, and a diffuse centrilobular lesion was observed in the right upper lobe on chest CT images. From these clinical observations, the patient was given a diagnosis of cervical-mediastinal lymph node tuberculosis, which had progressed to pulmonary lesion through a bronchial fistula due to lymphadenitis.

Adult↗

PubMed1998

[Measurement of expired nitric oxide concentration].

UNLABELLED: Much interest has been focused on standardization of measurement of expired nitric oxide (NO) concentration. The aim of this study was establish a simple measurement of expired NO concentration. SUBJECTS AND METHODS: This study included 5 healthy male adults. To clarify whether NO is excreted in expired air constantly, its concentrations were measured while changing the flow rate. To examine the influence of NO derived from the nasal cavity, we compared expired No concentrations sampled from the month with those sampled from the endotracheal tube inserted to the trachea at a constant flow rate serially. RESULTS: Expired NO concentrations decreased in inverse with the flow rate. No may be serially excreted in expired air. When serial changes of expired No concentrations sampled from the mouth were examined, its NO concentration initially reached a peak, then showed a plateau. Serial changes of those sampled from the endotracheal tube showed only a plateau. Plateau levels were not different between the two kinds. Therefore the peak values may have been influenced by NO derived from the nose that fell in the trachea by inspiration. Plateau values appeared to represent airway and lung-derived NO. CONCLUSIONS: A simple measurement of expired NO concentration should be sampled from the mouth at a constant flow rate serially. Evaluating plateau values is appropriate for expired NO concentration.

Adult↗