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Biomedical subjects

T Hirai

Publications and source records attributed to T Hirai.

At least 145 records · Page 8Linked to original sources

A polydiagnostic study of depressive disorders according to DSM-IV and 23 classical diagnostic systems.

The classification of mood disorders is one of the most highly debated topics in modern psychiatry. The introduction of DSM-III (and its followers) has set a new standard in this controversy but little empirical evidence is available as to how the various classical diagnostic categories of mood disorders by Kraepelin, Schneider, Leonhard, Hamilton, Kielholz, Winokur and others compare with this new standard. The Intensive Prospective Study arm of the Group for Longitudinal Affective Disorders Study has studied a broad spectrum of mood disorders in 23 participating centres from all over Japan with a polydiagnostic semistructured interview called Comprehensive Assessment List of Affective disorders. In this paper we examined how the various classical diagnostic systems of depressive disorders correspond to the DSM-IV diagnoses, and found the following: (1) The classical 'neurotic' or 'psychogenic' depressions are diagnosed as major depression and not as dysthymia in DSM-IV; although dysthymia was dubbed as 'depressive neurosis' in DSM-III, its criteria were not true to the traditional usage of the term. Viewed from the other side of the coin, DSM-IV can be said to stand in the unitary tradition. (2) Some of the classical diagnostic categories such as Schneider's depressive psychopathy and Klein's acute dysphoria as well as modern ones such as Akiskal's subaffective dysthymia and Angst's recurrent brief depression were rarely seen in traditional psychiatric treatment settings. (3) Comparisons of the unique diagnostic systems such as those by Leonhard, Winokur and Berner warrant further studies on their validity.

Adult↗

p53, p21(Waf1/Cip1) and cyclin D1 protein expression and prognosis in esophageal cancer.

Recently, various cell cycle regulators have been investigated as biological markers of malignant potential. These regulators might influence the survival rate and the effect of adjuvant therapies. In this study, we analyzed p53, p21(Waf1/Cip1) and cyclin D1 expression in 64 esophageal cancer patients and the relationship between clinicopathologic parameters and patient survival. The positive expression rate was 48.4%, 42.2% and 43.8% in the p53, p21 and cyclin D1 groups respectively. Multivariant analysis revealed that tumor depth, chemotherapy, p53, p21 and cyclin D1 expression showed significant values. p53- and cyclin D1-negative patients had a worse prognosis. p21-positive patients had a better prognosis. In stage 0, I and II patients, there was a significant difference between p53-positive and -negative, p21-positive and -negative, and cyclin D1-positive and -negative groups. In stage III and IV patients, there was no significant difference between any two groups. However, a significant difference was seen in the p21 group: among patients who received adjuvant chemotherapy, the p21-positive group had a 5-year survival rate of 50% compared with 13.4% in the p21-negative group (not significant).

Cyclin D1↗

Meningioma followed up for radiological findings before and after radiosurgery: case report.

The present paper reports on serial image changes before and after radiosurgery regarding a falx meningioma incidentally discovered in a 79-year-old female. The tumor doubling time during the 3-year observation period before radiosurgery was 469 days. Following radiosurgery using a gamma knife, tumour volume temporarily increased, but then reduced to 55% in 22 months. No symptoms or signs are observable at present, when the patient is 84 years old. These findings suggest that in treating elderly patients with meningioma diagnosed by imaging, radiosurgery should be the first method considered. Also presented are changes in image findings over time.

Aged↗

Trehalose embedding technique for high-resolution electron crystallography: application to structural study on bacteriorhodopsin.

Trehalose was compared with glucose in its use as an embedding medium for the preparation of two-dimensional crystals for electron crystallographic structure analysis. Purple membranes (two-dimensional crystals of bacteriorhodopsin) embedded in either sugar were studied in a 'partially hydrated' state as well as after 'drying' of the specimen. Diffraction patterns of the four conditions, all showing spots to a resolution better than 3.0 A, were analysed and merged. In the case of glucose embedded specimens, the merging R-factor obtained from the diffraction patterns of dried specimens was significantly better than the one obtained from partially hydrated specimens. In the case of trehalose embedding, the merging R-factor for partially hydrated specimens was significantly better than the dried one. The trehalose embedded, partially hydrated specimens gave the best merging R-factor in all four cases.

Bacteriorhodopsins↗

Time course of the effects of temocapril on cardiovascular structure and function in patients with essential hypertension.

To investigate the time course of cardiovascular structural changes in patients with essential hypertension after angiotensin-converting enzyme (ACE) inhibition, we determined left ventricular structure, minimal vascular resistance in the forearm as an index of resistance vessel structure and stiffness beta of carotid artery in 15 essential hypertensive subjects during a placebo period and after 2, 6, and 12 months of temocapril treatment. Blood pressure decreased within 2 weeks, and the antihypertensive effects were noted throughout the 12-month administration period. Left ventricular mass index decreased significantly after 2 months (120+/-12 to 106+/-9 g/m2; p < 0.01) and was normalized after 12 months (88+/-6 g/m2). Postischemic minimal vascular resistance in the forearm decreased gradually from 2.1+/-0.5 to 1.6+/-0.4 PRU at month 12 of temocapril treatment. In contrast, increased stiffness index beta of carotid artery was not altered during a 1-year treatment period (11.4+/-4.9 to 11.6+/-3.8 at month 12 of treatment). These data indicated that the regression of structural changes of left ventricle and arterioles occurred gradually and progressively for 1-year treatment with ACE inhibition, but large arteries were not affected.

Adult↗

Absence of myocardial ischemia during sudden controlled occlusion of coronary arteries in patients with well-developed collateral vessels.

OBJECTIVE: To determine whether the presence of well-developed collateral vessels (visualized by baseline angiography) prevents myocardial ischemia associated with electrocardiographic ST-segment deviation or anginal pain during subsequent coronary balloon occlusion. METHODS: Study patients with stable effort angina but without complete coronary obstruction were divided into two groups on the basis of whether myocardial ischemia was observed during the first minute of coronary balloon occlusion in order to compare the degrees of collateral development at baseline. Patients in group A (n = 47) had electrocardiographic ischemic ST-segment deviations or angina, or both, during balloon inflation, whereas patients in group B (n = 13) had neither. RESULTS: The incidences both of poor anterograde perfusion with TIMI grade 1 or 2 (77 versus 38%, P < 0.05) and of well-developed collateral vessels (Rentrop grade 3) in the perfusion territory of the target vessel for coronary angioplasty (77 versus 15%, P < 0.01) were higher for patients in group B than they were for those in group A. The incidence of no myocardial ischemia during balloon inflation among the patients with well-developed collateral vessels was higher than that among those without (59 versus 7%, P < 0.01). The prediction of the absence of myocardial ischemia during balloon inflation according to whether well-developed collateral vessels were present had the sensitivity 77% (10 of 13) and the specificity 93% (40 of 43) for the study patients. CONCLUSION: Absence of myocardial ischemia (revealed by electrocardiographic changes or angina during transient coronary balloon occlusion) was associated with presence of well-developed collateral vessels (Rentrop grade 3; visualized by baseline angiography), suggesting that the patients with well-developed collateral vessels have a low risk of developing acute myocardial infarction or hemodynamic instability upon abrupt closure of the culprit coronary artery.

Angioplasty, Balloon, Coronary↗

An evaluation of three-dimensional ultrasonography for the measurement of gallbladder volume.

OBJECTIVE: Various three-dimensional ultrasonography systems have been developed. We estimated the accuracy of a three-dimensional ultrasonography system for measuring gallbladder volume and compared the results to the sum-of-cylinders method. METHODS: In an in vitro study, 10 balloons of various shapes, sized 5-68 mL were scanned by real-time ultrasonography. In an in vivo study, we evaluated the gallbladder emptying of 14 healthy male volunteers after ingestion of two raw egg yolks. In both studies, volume measurement was performed by the three-dimensional ultrasonography method and the sum-of-cylinders method. RESULTS: With the three-dimensional ultrasonography method, the mean difference between the measured volume and the true volume and the limits of agreement were smaller than those of the sum-of-cylinders method. Gallbladder volumes did not differ significantly with both ultrasound methods. CONCLUSION: The three-dimensional ultrasonography method accurately determined gallbladder volumes.

Adult↗

Comparison of low attenuation areas on computed tomographic scans between inner and outer segments of the lung in patients with chronic obstructive pulmonary disease: incidence and contribution to lung function.

BACKGROUND: The low attenuation areas on computed tomographic (CT) scans have been reported to represent emphysematous changes of the lung. However, the regional distribution of emphysema between the inner and outer segments of the lung has not been adequately studied. In this study the regional distribution of low attenuation areas has been compared by quantitative CT analysis and the contribution of the regional distribution to pulmonary function tests evaluated in patients with chronic obstructive pulmonary disease (COPD). METHODS: Chest CT images and the results of pulmonary function tests were obtained from 73 patients with COPD. The lung images were divided into inner and outer segments in the upper (cranial), middle, and lower (caudal) sections. The percentage ratio of low attenuation area to corresponding lung area (LAA%) was then calculated. The LAA% of each segment was also compared with the results of pulmonary function tests. RESULTS: The mean (SD) LAA% of the inner segment was 39.1 (18.5) compared with 28.1 (13.2) for the outer segment (p<0.0001). Linear and multiple regression analyses revealed that airflow limitation is closely correlated with the inner segment LAA% of the lower lung. In contrast, the carbon monoxide transfer factor is closely correlated with the inner segment LAA% of the upper lung. CONCLUSION: Low attenuation areas on CT scans are more often found in the inner segment of the lung than in the outer segment, and the contribution of the inner segment to pulmonary function tests may be greater than the outer segment.

Aged↗

Brain lesions: when should fluid-attenuated inversion-recovery sequences be used in MR evaluation?

PURPOSE: To compare qualitatively and quantitatively the contrast of brain lesions detected with fluid-attenuated inversion-recovery (FLAIR) and intermediate-weighted sequences at magnetic resonance (MR) imaging. MATERIALS AND METHODS: In this prospective study, 47 patients suspected of having a brain lesion underwent MR imaging with FLAIR, intermediate-weighted, and T2-weighted sequences. Qualitative assessment was performed of lesion conspicuity, detection, overall image artifact, and additional clinical information. Contrast and contrast-to-noise ratio (CNR) were calculated between lesions and the normal brain or cerebrospinal fluid (CSF). RESULTS: FLAIR images were equal to intermediate-weighted images for overall lesion conspicuity and detection but were associated more often with image artifacts. Lesion-to-background contrast was significantly higher on FLAIR than on intermediate-weighted images. FLAIR images failed to demonstrate multiple sclerosis (MS) plaques located in the basal ganglia and brain stem. CONCLUSION: Although FLAIR images provided additional information in some cases, they did not have distinct advantages over intermediate-weighted images. When cases of MS are evaluated, intermediate-weighted images are preferable to FLAIR images. Except in cases of MS, either FLAIR or intermediate-weighted sequences should be added to T2-weighted sequences at MR imaging.

Adolescent↗

Effects of lung volume on lung and chest wall mechanics in rats.

To investigate the effect of lung volume on chest wall and lung mechanics in the rats, we measured the impedance (Z) under closed- and open-chest conditions at various positive end-expiratory pressures (0-0.9 kPa) by using a computer-controlled small-animal ventilator (T. F. Schuessler and J. H. T. Bates. IEEE Trans. Biomed. Eng. 42: 860-866, 1995) that we have developed for determining accurately the respiratory Z in small animals. The Z of total respiratory system and lungs was measured with small-volume oscillations between 0.25 and 9.125 Hz. The measured Z was fitted to a model that featured a constant-phase tissue compartment (with dissipation and elastance characterized by constants G and H, respectively) and a constant airway resistance (Z. Hantos, B. Daroczy, B. Suki, S. Nagy, and J. J. Fredberg. J. Appl. Physiol. 72: 168-178, 1992). We matched the lung volume between the closed- and open-chest conditions by using the quasi-static pressure-volume relationship of the lungs to calculate Z as a function of lung volume. Resistance decreased with lung volume and was not significantly different between total respiratory system and lungs. However, G and H of the respiratory system were significantly higher than those of the lungs. We conclude that chest wall in rats has a significant influence on tissue mechanics of the total respiratory system.

Airway Resistance↗

Acute response of the lung mechanics of the rabbit to hypoxia.

We measured the change in total lung resistance (RL) and that in total lung elastance (EL) induced by hypoxia (n = 7) and compared the results with those by intravenous histamine bolus (n = 5) at three different positive end-expiratory pressure (PEEP) levels (2, 5, and 8 hPa) in open-chest and vagotomized rabbits. The percent increase ratio of RL (PIRR) and EL (PIRE) was defined as the change in RL and EL, respectively, induced by hypoxia compared with that in the normoxic condition, expressed as a percentage. PIR values for the change in RL and EL induced by bolus injection of histamine were also calculated. The PIRR and PIRE induced by hypoxia and by histamine were positive by a statistically significant amount at every PEEP level, except for the PIRE value at 8-hPa PEEP in the hypoxic challenge. The PIRE-to-PIRR ratio values in the hypoxic challenge at 2-hPa PEEP were significantly larger than those in the histamine challenge (hypoxia: 0.91 +/- 0.23%; histamine: 0.37 +/- 0. 065%, P < 0.05). The increase in EL induced by histamine in the acute phase has been reported to be mainly derived from tissue distortion secondary to bronchial constriction. Thus our results suggest that a part of the increase in EL by hypoxia was originated in different parenchymal responses from histamine and imply that this hypoxic response of lung parenchyma is sensitive to the increase in parenchymal tethering at high PEEP levels.

Airway Resistance↗

Improvement of regional myocardial and coronary blood flow reserve in a patient treated with enhanced external counterpulsation: evaluation by nitrogen-13 ammonia PET.

Enhanced external counterpulsation (EECP) is a noninvasive treatment for chronic stable angina, which works by recruiting and developing the coronary collateral vessels. Coronary perfusion and coronary flow reserve (CFR) were evaluated by nitrogen-13 (13N) ammonia positron emission tomography (PET) in a patient who had undergone EECP. The patient, who had 3-vessel coronary artery disease, required a percutaneous transluminal coronary angioplasty (PTCA) for the right coronary artery. The PTCA was successful, but 6 months later he again felt chest oppression. The coronary angiography showed re-stenosis at the PTCA site, and other progressive coronary stenosis. The patient was again treated with EECP for 35 h. The 13N-ammonia PET was performed both at baseline and during dipyridamole provocation, before and after EECP treatment. Coronary perfusion of each myocardial wall increased at the baseline (anterior: 0.52-0.75; septal: 0.48-0.66; lateral: 0.61-0.68; inferior: 0.46-0.57 ml min(-1) g(-1), and the CFRs in the septal and inferior walls (septal: 2.07-2.15; inferior: 1.99-2.06) also increased after the treatment. Thus, the EECP treatment improved both coronary perfusion at baseline and CFR, which suggests that it may be one of the choices for treatment of angina.

Ammonia↗

Effects of recombinant bovine granulocyte-macrophage colony-stimulating factor on bovine peripheral blood neutrophil functions in vitro and in vivo.

Effects of recombinant bovine granulocyte-macrophage colony-stimulating factor (rboGM-CSF) on bactericidal activity of bovine peripheral blood neutrophils in vitro and in vivo were studied. In in vitro experiment, bovine blood neutrophils were cultured for 9 hr in media containing 0.005, 0.05 or 0.5 microg/ml of rboGM-CSF. Neutrophils treated with rboGM-CSF showed significantly higher luminol-dependent chemiluminescence (LDCL) than control cells. In in vivo experiment, neutrophils isolated from cows injected 5.0 microg/kg of rboGM-CSF showed significantly higher Nitrobluetetrazolium (NBT) reduction value than that from control cows 24 hr post injection. Total leukocyte counts of cows injected rboGM-CSF sharply decreased 6 hr post injection and recovered to normal level 2 days post injection. Body temperature of these cows rose 6 hr post injection and back to normal level at 24 hr post injection. It was suggested that rboGM-CSF enhanced bactericidal activity of bovine neutrophils both in vitro and in vivo.

Animals↗

Collagen-phagocytosing ability of periodontal osteoblasts at the bone surface.

The collagen-phagocytosing activity of osteoblasts at the alveolar bone-ligament interface of rat mandibular first molars was investigated both histologically and histochemically. Alveolar bones of male Wistar rats (6 months old) were used in this study. Collagen-containing phagosomes appeared in cuboidal osteoblasts aligned on the bone surface. The 5.7% of the osteoblasts exhibiting alkaline phosphatase activity revealed collagen-containing phagosomes, and the collagen fibrils within the phagosomes were at various stages of degradation. In addition, acid phosphatase activity and the immunocytochemical distribution of cathepsin B were found in these collagen-containing phagosomes at similar locations. The presence of both enzymes in the phagosomes suggests that an intracellular degradation of collagen occurs. Therefore, in addition to the osteoblastic functions of synthesizing and secreting bone matrices, osteoblasts are also capable of phagocytosis and the intracellular disintegration of collagen. Our findings suggest that osteoblasts at the alveolar bone-periodontal ligament interface have a collagen-phagocytosing ability and play an important role in the physiological remodeling and metabolic breakdown of collagen fibrils of periodontal ligament without osteoclastic bone remodeling.

Animals↗

Myocardial metabolism of 123I-BMIPP in a canine model with ischemia: implications of perfusion-metabolism mismatch on SPECT images in patients with ischemic heart disease.

UNLABELLED: 123I-(rho-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) is a fatty acid analog for SPECT imaging. This radiopharmaceutical possesses the unique property, that is, perfusion-metabolism mismatch on SPECT images in patients with ischemic heart disease. However, the reason of this mechanism remains unclear. METHODS: Using open-chest dogs under anesthesia, we made a system to release all the blood of the great cardiac vein outside without recirculation, if necessary. Left anterior descending artery (LAD) was occluded for 30 min after reperfusion. After the injection of BMIPP into LAD, blood samplings from the cardiac vein and abdominal aorta (6 dogs) or serial biopsy specimens from the LAD region (5 dogs) were performed, and then compared with the normal control. The catabolites of BMIPP, including backdiffusion of nonmetabolized BMIPP, were evaluated with high-performance liquid chromatography (HPLC) in the efflux study. Thin-layer chromatography (TLC) technique was introduced in the tissue analytical study. RESULTS: Although the rapid extraction of BMIPP from the plasma into the myocardium and the subsequent retention were unchanged, the early washout (8 min) of radioactivity significantly increased (51% +/- 12% to 65% +/- 7%; P < 0.05) with ischemia. The metabolites from the myocardium consisted of backdiffusion of nonmetabolized BMIPP, alpha, intermediate, and full oxidation metabolites. Among these metabolites, backdiffusion of nonmetabolized BMIPP in blood significantly increased (27.9% +/- 7.7% to 42.3% +/- 8.1%; P < 0.05), especially in the early phase with ischemia. In tissue, the radioactivity was concentrated in the triglyceride pool even in the early phase, and in addition, BMIPP and alpha-oxidized metabolite significantly decreased in the early phase with ischemia (t = 1 min after BMIPP injection, 25.9% +/- 8.6% to 14.5% +/- 2.1%, P < 0.01; t = 2 min, 8.9% +/- 5.0% to 4.5% +/- 1.7%, P < 0.05). CONCLUSION: These results show that backdiffusion of nonmetabolized BMIPP from the myocardium increased and BMIPP (long-chain fatty acids) in tissue decreased with ischemia, suggesting backdiffusion of nonmetabolized BMIPP might play an important role in myocardial perfusion-metabolism mismatch on SPECT images in patients with ischemic heart disease.

Animals↗

Respiratory impedance during positive expiratory airway pressure in patients with chronic obstructive pulmonary disease.

The effect of positive airway pressure (5.0 hPa) on airway impedance (Za) and tissue impedance (Zt) during the expiratory phase in chronic obstructive pulmonary disease (COPD) patients was evaluated using random noise oscillation and a body box method. The results were then compared with those obtained from normal subjects. In normal subjects, there was no significant difference between non-expiratory positive pressure (NPEP) and positive expiratory pressure (PEP) for the Zar (real part) and Zai (imaginary part) at 10 Hz (Zar NPEP: 2.14 +/- 0.76, PEP: 1.96 +/- 0.79; Zai NPEP: 1.42 +/- 0.66, PEP: 1.40 +/- 0.70 hPa l-1 s). However, in COPD patients, Zar decreased significantly and the Zai increased significantly during PEP as compared to the values during NPEP (Zar NPEP: 7.10 +/- 1.88, PEP: 5.97 +/- 1.67, P < 0.05; Zai NPEP: -4.10 +/- 2.27, PEP: -2.99 +/- 2.62 hPa l-1 s, P < 0.05). These results suggested that both central and peripheral airway resistance decreased during PEP in COPD patients. Tissue compliance (Ct) calculated from the Zt increased significantly during PEP as compared to during NPEP, in both normal subjects and in COPD patients (normal NPEP: 0.024 +/- 0.004, PEP: 0.021 +/- 0.003, P < 0.05; COPD NPEP: 0.024 +/- 0.004, PEP: 0.014 +/- 0.004 l hPa-1, P < 0.001). This may have been indicative of the stiffened chest wall during PEP.

Adult↗