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Biomedical subjects

Y Hirokawa

Publications and source records attributed to Y Hirokawa.

At least 37 records · Page 2Linked to original sources
PubMed1999

National average for the process of radiation therapy in Japan by Patterns of Care Study.

BACKGROUND: A nationwide effort is in progress to establish the actual state of radiotherapy and its quality assurance (QA) in Japan by using the Patterns of Care Study (PCS). In this study, national averages are calculated with a limited number of patients. A calculation program for national averages was prepared and applied to the radiotherapeutic processes used for esophageal cancer patients entered in the PCS. METHODS: The calculation program for national averages, which were revised on the basis of differences between individual facilities and institutional strata, was developed in accordance with Sedransk's equation for the original PCS in the USA. National averages for several aspects concerning the sampled patients who had esophageal cancer between 1992 and 1994 were calculated with these procedures. Data for facilities and stratification of institution were simulated from a national structure survey of radiation oncology in 1990. RESULTS: Values of the national average by Sedransk's equation were different from those of the simple sample average. There were significant differences in radiotherapeutic processes among stratification of institutions. For esophageal cancer, national averages were 0.129 for applications of endoscopic ultrasound, 0.599 for 'all fields treated each day' and 0.088 for application of brachytherapy. CONCLUSION: National averages for radiotherapy could be calculated. The values obtained in this PCS will be a useful measure for future QA in radiation oncology and in other specialties in Japan.

Esophageal Neoplasms↗
PubMed1999

[Peak inspiratory flow during a diskhaler use in subjects unfamiliar with dry powder devices].

Dry power steroid was firstly introduced in Japan in 1998. We measured peak inspiratory flow (PIF) through a Diskhaler in the following groups: well-trained medical representative (EX group, n = 5), respiratory physicians (RP group, n = 19) and non-medical staffs (NM group, n = 31) who were not familiar with Diskhaler, and asthmatic patients who had been briefly trained by a video movie (TP group, n = 93). When PIF was less than 50 l/m dry powders were frequently remained in the brister. The mean PIF in the EX group was 96.1 +/- 12.6 l/m (mean +/- SD). Since the relationship between the PIF and airway pressure (Paw) during Diskhaler use was expressed as PIF = 16.3 square root of Paw-1.19 (r = 0.97), we calculated PIF from Paw measured by a handy barometer made by ourselves. The mean PIF in RP group was 77.0 +/- 30.1 l/m, and 36.8% of the subjects developed inappropriate PIF (i.e., above 100 l/m or below 50 l/m). In NM group the mean PIF was 53.5 +/- 20.4 l/m which was significantly higher than RP group. In this group 54.8% of the subjects yielded inappropriate PIF. The mean PIF in TP group was 64.9 +/- 24.5 l/m which was significantly lower than that in RP group. Those who developed inappropriate PIF occupied 43.2% of the RP subjects. We concluded that a quantitative presentation of PIF in mandatory to achieve an effective use of Diskhaler.

Adult↗
PubMed1999

[Migratory pneumonitis similar to bronchiolitis obliterans organizing pneumonia after conservative treatment of breast cancer: a case report].

We report the case of a 63-year-old woman who developed cough and fever with migratory lung infiltrates three months after completion of right breast irradiation following conservative surgery. Lung infiltrates were initially localized in the irradiated area, but later spread to unirradiated areas in both lungs. No cause of migratory pneumonitis other than irradiation was found, and we clinically diagnosed this case as radiation-induced migratory pneumonitis similar to BOOP, without lung biopsy. Steroid therapy resulted incomplete resolution of lung infiltrates. The reported case clearly differed from typical radiation pneumonitis. We suggest that lung irradiation might trigger the development of migratory pneumonitis with a clinical pattern similar to that of BOOP.

Anti-Inflammatory Agents↗
PubMed1998

A novel series of 6-methoxy-1H-benzotriazole-5-carboxamide derivatives with dual antiemetic and gastroprokinetic activities.

A novel series of 6-methoxy-1H-benzotriazole-5-carboxamide derivatives with a medium perhydroazacycle ring in the amine moiety were prepared, and their antiemetic and gastroprokinetic activities were evaluated. Among them, N-(1-ethylhexahydroazepin-3-yl)-, N-(1-ethyloctahydroazocin-3-yl)- and N-(1-ethyloctahydroazonin-3-yl)-6-methoxy-1H-benzotriazole-5-carbo xamides (24, 36, 37) showed a potent antiemetic activity (inhibition of apomorphine-induced emesis in dogs) along with gastroprokinetic activity (gastric emptying in rats).

Animals↗
PubMed1998

Synthesis of N-(1-ethyl-4-methylhexahydro-1,4-diazepin-6-yl)nicotinamides and their affinities for 5-HT3 and dopamine D2 receptors.

A series of N-(1-ethyl-4-methylhexahydro-1,4-diazepin-6-yl)nicotinamide derivatives were prepared and evaluated for their binding to 5-HT3 and dopamine D2 receptors. Among them, the 5-bromo-2-methoxy-6-methylaminonicotinamide 16 and its (R)-isomer were found to have potent affinities for both receptors. The affinities of (R)-16 for 5-HT3 and dopamine D2 receptors are approximately 3-fold higher than those of the corresponding benzamide (R)-1 (IC50: 1.1 and 12 nM vs. 2.9 and 35 nM, respectively).

Animals↗
PubMed1998

Contribution of brainstem hypoperfusion to the tracheal and phrenic nerve responses to high-pressure lung inflation in the dog.

Lung inflation to high airway pressure is known to produce tracheal constriction following an initial dilation. This is attributed to stimulation of various pulmonary receptors. In an attempt to find cause of this response, we investigated in 20 decerebrated, tracheostomized and paralyzed dogs changes in the tracheal smooth muscle tension, arterial pressure and the phrenic nerve activity to high-pressure lung inflation. A high-pressure lung inflation evoked a contraction of tracheal smooth muscle following its short-lasting relaxation, and a persistent hypotension. After hilar denervation which eliminated all pulmonary afferents, a high-pressure lung inflation still evoked contraction of tracheal smooth muscle (an increase of 3.7 times) and augmented amplitude and frequency of phrenic bursts. Bilateral transections of sympathetic fibers to the lung, or blockade of arterial perfusion to the carotid sinus and denervation of the carotid sinus bilaterally did not alter the tracheal muscle and phrenic responses to a high-pressure lung inflation. We further found that severe hypotension alone caused similar responses of the tracheal smooth muscle contraction and augmented phrenic activity. Finally, when blood supply to the brainstem was transiently obstructed by clamping both the vertebral and internal carotid arteries bilaterally, the same responses were observed. In contrast, when blood hypoperfusion to the brainstem was prevented by means of extracorporeal circulation, a high-pressure lung inflation failed to evoke such contraction of tracheal smooth muscle and or increased phrenic activity. After transection of the vagus nerves bilaterally at the cervical level the tracheal muscle response to lung inflation was abolished but that of phrenic nerve was preserved. We concluded that the tracheal smooth muscle contraction and phrenic responses induced by high-pressure lung inflation may be in part attributed to brainstem hypoperfusion.

Animals↗
PubMed1998

Wilms' tumor 1 and Dax-1 modulate the orphan nuclear receptor SF-1 in sex-specific gene expression.

Products of steroidogenic factor 1 (SF-1) and Wilms' tumor 1 (WT1) genes are essential for mammalian gonadogenesis prior to sexual differentiation. In males, SF-1 participates in sexual development by regulating expression of the polypeptide hormone Müllerian inhibiting substance (MIS). Here, we show that WT1 -KTS isoforms associate and synergize with SF-1 to promote MIS expression. In contrast, WT1 missense mutations, associated with male pseudohermaphroditism in Denys-Drash syndrome, fail to synergize with SF-1. Additionally, the X-linked, candidate dosage-sensitive sex-reversal gene, Dax-1, antagonizes synergy between SF-1 and WT1, most likely through a direct interaction with SF-1. We propose that WT1 and Dax-1 functionally oppose each other in testis development by modulating SF-1-mediated transactivation.

Animals↗
PubMed1998

A novel series of N-(hexahydro-1,4-diazepin-6-yl) and N-(hexahydroazepin- 3-yl)benzamides with high affinity for 5-HT3 and dopamine D2 receptors.

A novel series of benzamides with a hexahydro-1,4-diazepine or hexahydroazepine ring in the amine moiety were prepared, and their binding affinities for 5-HT3 and dopamine D2 receptors were evaluated. The R isomer of the 1-ethyl-4-methylhexahydro-1,4-diazepinylbenzamide (R)-22 had potent affinity for both receptors. The R-enantiomer of the corresponding 1-ethylhexahydroazepinylbenzamide 28 showed potent affinity for dopamine D2 receptors with reduced affinity for 5-HT3 receptors, while the S isomer was found to be a potent and selective 5-HT3 receptor antagonist.

Animals↗
PubMed1998

Treatment results of stage I and II oral tongue cancer with interstitial brachytherapy: maximum tumor thickness is prognostic of nodal metastasis.

PURPOSE: To evaluate the prognostic importance of T classification and maximum tumor thickness (MTT) on the treatment results of Stage I and II oral tongue cancer treated with interstitial brachytherapy. METHODS AND MATERIALS: Between January 1981 and December 1993, 173 cases were eligible for this retrospective analysis. Of 173 patients, 75 were classified as Stage I and 98 as Stage II: maximum tumor length ranged from 6 to 40 mm. MTT, which ranged from 2 to 38 mm, was measured with ultrasonography and/or palpation. Brachytherapy was performed with iridium hairpins or radium needles following external irradiation in 66 patients, or exclusively in 107 patients. RESULTS: The 5-year local recurrence rates were Stage I, 7%; Stage II, 22%; MTT < 8 mm, 8%; and MTT > or = 8 mm, 28%. The 5-year regional recurrence rates were Stage I, 15%; Stage II, 29%; MTT < 8 mm, 18%; and MTT > or = 8 mm, 31%, respectively. The 5-year local recurrence rates of the patients with Stage I and MTT < 8 mm of the brachytherapy only group were significantly better than those of Stage II and MTT > or = 8 mm (5% and 6% vs. 16% and 24%). The 5-year regional recurrence rates of the patients with Stage I and MTT < 8 mm of the brachytherapy-only group were significantly better than those of Stage II and MTT > or = 8 mm (14% and 16% vs. 34% and 46%). There was no significant difference in the 5-year regional recurrence rates between the two groups of Stage I and Stage II, MTT < 8 mm. However, there was a significant difference in the 5-year regional recurrence rates between the two groups of MTT > or = 8 mm (p < 0.005). CONCLUSIONS: For patients with Stage I and II oral tongue cancer, tumor thickness as well as T classification were prognostic for nodal metastasis and prognosis. Patients with MTT > or = 8 mm are more likely to fail in the neck region. These findings suggest that MTT should be considered along with T stage in determining strategies for Stage I and II oral tongue cancer.

Adult↗
PubMed1998

Myocardial CD36 expression and fatty acid accumulation in patients with type I and II CD36 deficiency.

Long-chain fatty acids (LCFA) are one of the major cardiac energy substrates, so understanding LCFA metabolism may help in elucidating the mechanisms of various heart diseases. CD36 is a multifunctional membrane glycoprotein that acts not only as a receptor for thrombospondin, collagen and oxidized low density lipoprotein but also as a receptor for LCFA. We investigated the relationship between CD36 expression in myocardial capillary endothelial cells and myocardial LCFA uptake in patients with CD36 deficiency. We analyzed CD36 expression in blood cells from 250 patients with heart diseases by means of a flow cytometer. In 218 patients, myocardial LCFA scintigraphy was performed with 123I-beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP). In 5 patients, myocardial capillary endothelial cells were examined immunohistochemically for CD36 expression. Eleven patients (4%) showed signs of type I CD36 deficiency (neither platelets nor monocytes expressed CD36). Twenty patients (8%) had type II CD36 deficiency (monocytes expressed CD36 but platelets did not). In all 11 patients with type I CD36 deficiency, no BMIPP accumulation was observed in the heart, but in 13 patients with type II CD36 deficiency, BMIPP accumulation in the heart was focally reduced, but there were no patients without BMIPP accumulation in the heart. Although the myocardial capillary endothelial cells from two CD36-positive patients expressed CD36, those from two patients with type I CD36 deficiency did not. In a patient with type II CD36 deficiency, some capillary endothelial cells displayed patchy CD36 expression. CD36 deficiency was documented in 31 (12%) patients with heart diseases. Because CD36 was not expressed in the myocardial capillary endothelial cells in patients with type I CD36 deficiency, type I CD36 deficiency is closely related to lack of myocardial LCFA accumulation and metabolism in the myocardium.

Adult↗
PubMed1998

Patterns of care study of radiation therapy for esophageal cancer in Japan: influence of the stratification of institution on the process.

BACKGROUND: To improve the quality of radiation therapy in Japan, Patterns of Care Study (PCS), a widely known QA program in the USA, was introduced in Japan. The feasibility was tested by collecting nationwide data by extramural audit for esophageal cancer. METHODS: From July 1996 through February 1997, PCS audits were performed for 29 institutions. Based on the facility survey by Tsunemoto, 13 institutes were classified as A1 (university hospital/cancer center treating > 300 patients/year), 10 as B1 (other institutes > 120 patients/year) and six as B2 (other institutes < 120 patients/year). Medical charts for 455 patients with thoracic esophageal cancer between 1992 and 1994 were reviewed based on the data format of PCS in the USA. RESULTS: Concerning external beam equipment, linear accelerators of > or = 10 MV were used for 73% of patients in A1, whereas in B1-2, 60Co machines were still used for 13% of patients (P < 0.0001). The median number of full-time equivalent (FTE) radiation oncologists was 2.7 in A1, 0.65 in B1 and 0.2 in B2. Forty-five percent of patients had received surgery in A1 and 34% in B1-2 (P = 0.0068). In the non-surgery group, a higher radiation dose of > 60 Gy was delivered in A1 than in B1-2 (P = 0.0008). Chemotherapy was administered to 51% of the patients in A1 and to 30% in B1-2 (P < 0.0001). Brachytherapy was utilized for 17% in A1 and only for 5% in B1-2 (P = 0.0001). CONCLUSION: Institutional stratification, including equipment and personnel, significantly affected the patterns of care for esophageal cancer. Therefore, to improve the quality of radiation therapy nationwide, improvement of equipment and supply of FTE personnel is extremely important. PCS was found to have great potential for the practical evaluation of how much will be required in Japan.

Adult↗
PubMed1998

[Quality of life assessment in radiation therapy].

Cancer treatment outcome should be evaluated not only with conventional parameters of survival, local control, and response rate, but with quality-of-life (QOL) based parameters. As radiation therapy is a treatment to eradicate cancer without resection of tissues or organs, a better functional or cosmetic result could be obtained compared with surgical treatment. If basically functional or cosmetic results are better, QOL of the patient could be expected to be even more superior. Patient QOL should be assessed from the physical, psychological, and social standpoints. So, adequate instruments or scoring systems are essential to obtain data. In this paper, we introduce an outline of QOL-related research activities in cancer treatment, especially in radiation therapy. We also attempt to assess the functional outcome and late complications, which would affect patient QOL. Finally, the concept of quality adjusted survival time or utility analysis is also mentioned.

Esophageal Neoplasms↗
PubMed1997

3D analysis of human locomotion before and after caloric stimulation.

Human locomotion was analysed in the sagittal and coronal planes using a position detector system composed of 2 infrared video cameras and a data processor. Normal healthy volunteers with 8 marker points on the body were asked to walk in place (WIP) and on a treadmill (WOT). Vertical and medial/lateral (M/L) translational movements were measured. Head angular movements in the sagittal (pitch) and coronal (roll) planes were also analysed. Pitch movements counteracted the vertical head movements. Head movement was remarkably attenuated in the vertical axis compared with that of the trunk. However, head M/L movement showed no difference with that of the lower part of the body. Ice water caloric stimulation was introduced to cause acute unilateral vestibular deficit. The stride length and step cycle became small after caloric stimulation in WOT, but not in WIP. The characteristic change in locomotive pattern was a large lateral sway of the hip joint occurring to the side away from calorization (right) during one foot standing (right foot) (t-test, p = 0.057). Measurement of M/L sway amplitude showed an increase only at the hip joint. As the changes in head and neck movements were not significant after caloric stimulation, it appears that the vestibulo-spinal reflex contributes little to maintaining the dynamic balance of the upper body. The importance of the hip joint for locomotion (hip strategy) was confirmed from the present data.

Adult↗
PubMed1997

[Hypertrophic cardiomyopathy showing no 123I-BMIPP myocardial accumulation with type I CD36 deficiency].

A 57 years old male consulted our hospital in complaining chest oppression and short of breath. Familial and dilated phase hypertrophic cardiomyopathy (HCM) was detected by ECG, echocardiography, left ventriculography and left ventricular endomyocardial biopsy. 201T1 SPECT showed regional increased accumulation in the ventricular septum, however, no myocardial accumulation of 123I-beta-methyl-p-iodophenylpentadecanoic acid (123I-BMIPP) was observed. We analyzed CD36 in this patient, and found he had type 1 CD36 deficiency. Myocardial uptake of long-chain fatty acids occurs via a specific transporter, which is homologous with human CD36. We hypothesize that CD36 deficiency, especially type 1 CD36 deficiency, might be one factor of no myocardial 123I-BMIPP uptake.

CD36 Antigens↗
PubMed1997

[Different patterns of 123I-BMIPP myocardial accumulation in patients with type I and II CD36 deficiency].

The CD36 molecule is a multifunctional membrane type receptor glycoprotein that reacts with thrombospondin, collagen, oxidized LDL and long-chain fatty acids (LCFA). LCFA are one of the major cardiac energy substrates, hence LCFA metabolism may have an important role in cardiac diseases. In this study, we analyzed CD36 expression in 200 patients with heart diseases [44 patients with hypertrophic cardiomyopathy (HCM), 16 with dilated cardiomyopathy (DCM), 26 with old myocardial infarction (OMI), 55 with angina pectoris (AP) and 59 with other miscellaneous heart diseases] using a flow cytometer. 123I-beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) myocardial accumulation was also examined in some patients. Eight patients (2 with HCM, 1 with DCM, 2 with OMI, and 3 with AP) were diagnosed as having type I CD36 deficiency (neither platelets nor monocytes expressed CD36). Sixteen patients (3 with HCM, 1 with DCM, 1 with OMI, 8 with AP, and 3 with other heart diseases) showed type II CD36 deficiency (monocytes expressed CD36 but platelets did not). In all 8 patients with type I CD36 deficiency, there was no BMIPP accumulation in the heart. However, in 13 patients with type II CD36 deficiency, focally reduced BMIPP accumulation was observed, but there were no patients without BMIPP accumulation. CD36 deficiency was observed in a higher proportion (12%) of patients with heart disease in this study than in a reported control study. Type I CD36 deficiency is associated with absence of BMIPP accumulation in the heart, hence it may have an important role in LCFA metabolic disorders and some types of cardiac hypertrophy as well as other heart diseases.

Adult↗
PubMed1996

Response of tracheal smooth muscle tone to lower brain stem hypoxia in dogs.

We examined effects of central hypoxia on tracheal smooth muscle (TSM) tone, phrenic nerve activity (PNA) and blood pressure (BP) in decerebrated, paralysed, and artificially ventilated dogs. Central hypoxia was induced by injection of N2-saturated saline (5 ml; PO, 25-32 torr) through a catheter in the vertebral artery. The effects of central hypoxia were compared with the responses to central chemoreceptors stimulation, namely central hypercapnia induced by intravertebral injection of high CO2 saline (5 ml; PCO2 90-100 torr, PO2 80-120 torr, pH 7.38-7.42) buffered by HCO3-. Central hypoxia caused relaxation of TSM accompanied by depression of PNA and elevation of BP. In contrast, central hypercapnia evoked tracheal constriction along with respiratory excitation and pressor response. The tracheal relaxation in response to central hypoxia occurred with onset and peak latencies similar to those observed in PNA depression and BP elevation. This suggests a common source for the synaptic inputs to three distinct control systems involved in cardiovascular, respiratory and airway functions. Such neuronal substrate is considered to be activated by central hypoxia.

Animals↗
PubMed1996

An analysis of mandibular bone complications in radiotherapy for T1 and T2 carcinoma of the oral tongue.

PURPOSE: To examine the incidence of mandibular bone complication in patients who underwent radiotherapy for T1 and T2 carcinomas of the oral tongue and to analyze the factors contributing to its occurrence. METHODS AND MATERIALS: The clinical records of 148 patients with T1 and T2 carcinoma of the oral tongue treated with radiotherapy alone between 1978 and 1989 were examined retrospectively. Interstitial brachytherapy, used as the major treatment modality, was performed using cobalt needles, radium needles, or iridium hairpins. The prescribed dose at the plane 5 mm from the plane of the radioactive sources was 65-70 Gy in interstitial brachytherapy alone, and 50-60 Gy in the combined treatment with external irradiation. An external irradiation dose of 30 Gy was usually used. RESULTS: Eleven of the patients showed radiation-induced mandibular bone complication. Two (1 T1, 1 T2) had been treated with interstitial brachytherapy alone, and nine (2 T1, 7 T2) with the combination of external irradiation and interstitial brachytherapy. The incidence of radiation complication of bone was significantly higher in the patients with T2 tumors (p = 0.04) and in those who received the combined treatment (p < 0.01). Multivariate analysis revealed that the total dose (p = 0.04) and dose rate of interstitial brachytherapy (p = 0.03) were significant factors contributing to radiation bone complication. A significant difference in the incidence of bone complication was also seen between patients who received a total dose of 90 Gy or more and those who received less than 90 Gy (p < 0.01), as well as between patients who were treated with 0.55 Gy/h or higher and those who were treated with less than 0.55 Gy/h (p = 0.03). CONCLUSION: A significant increase in the incidence of bone complication was found at the total dose of 90 Gy or more and at the dose rate of 0.55 Gy/h or higher. In combined treatment with external irradiation and interstitial brachytherapy, the interstitial brachytherapy dose of 60 Gy appears to be the threshold at which mandibular bone complication is induced when the external irradiation dose is 30 Gy.

Adult↗