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Biomedical subjects

Y Maeno

Publications and source records attributed to Y Maeno.

At least 109 records · Page 6Linked to original sources
PubMed1997

Expression of occludin, tight-junction-associated protein, in human digestive tract.

The tight junction seals cells together at a subapical location and functionally separates the plasma membrane into an apical and a basolateral domain. This junction is one of the most characteristic structural markers of the polarized epithelial cell. Recently, occludin has been identified as an integral transmembrane protein localizing at the tight junction and directly associated with ZO-1, an undercoat-constitutive cytoplasmic protein. We have investigated occludin expression in conjunction with ZO-1 in normal epithelia and cancers of human digestive tract by immunostaining with a new antibody raised against human occludin. In the normal simple columnar epithelium, occludin was expressed together with ZO-1 as a single line at the apical cell border. However, in the esophagus, which has a stratified squamous epithelium, no occludin expression could be detected, but ZO-1 was expressed in the spinous layer. As for cancers, both occludin and ZO-1 showed the same expression in differentiated adenocarcinoma cells as in normal epithelium, but in poorly differentiated adenocarcinomas, the expression of these two proteins was reduced. There was significant correlation between tumor differentiation and expression of these proteins. These results suggest that occludin, together with ZO-1, is involved in the formation of gland-like structures. In addition, occludin expression can serve as a histopathological indicator for differentiation in gastrointestinal adenocarcinomas.

Adenocarcinoma↗
PubMed1997

[A case of Sairei-to-induced pneumonitis diagnosed by lymphocyte stimulation test of bronchoalveolar lavage fluid].

A 51-year-old woman was admitted with fever, cough and dyspnea. She had been taking Sairei-to, a traditional Chinese medicine, for 2 months. On admission, chest X-ray revealed a ground-glass appearance in the lung fields bilaterally and serum LDH was elevated. A differential cell count of the bronchoalveolar lavage fluid (BALF) showed that lymphocytes were increased, with a decreased ratio of CD4/CD8 cells. A lymphocyte stimulation test (LST) for Sairei-to using the lymphocytes in BALF was a positive, although a test of peripheral blood was negative. Sairei-to-induced pneumonitis was diagnosed based on the clinical course, laboratory findings, BALF cell analysis and LST of BALF. Only 4 cases of pneumonitis due to Sairei-to have been reported. This case suggests that LST of BALF is useful for diagnosing drug-induced pneumonitis.

Bronchoalveolar Lavage Fluid↗
PubMed1996

Long-term consequences of Kawasaki disease. A 10- to 21-year follow-up study of 594 patients.

BACKGROUND: The long-term consequences of the cardiovascular sequelae in Kawasaki disease remain uncertain. METHODS AND RESULTS: We identified 594 consecutive children with acute Kawasaki disease between 1973 and 1983, and this cohort was followed up for 10 to 21 years (mean, 13.6 years). In all patients, we evaluated coronary lesions by coronary angiography just after the acute stage. One hundred and forty-six patients (24.6%) were diagnosed as having coronary aneurysms. A second angiogram was performed 1 to 2 years later in all 146 patients who previously had coronary aneurysms, which demonstrated that 72 (49.3%) of these 146 had regression in the coronary aneurysm. A third angiogram was performed for 62 patients, a fourth for 29, and a fifth for 17. By 10 to 21 years after the onset of the illness, stenosis in the coronary aneurysm had developed in 28 patients. Myocardial infarction occurred in 11 patients, 5 of whom died. In the 26 patients with giant coronary aneurysms, stenotic lesions developed in 12, and no regression occurred. The 448 patients with normal findings at the first angiogram subsequently never developed any abnormal cardiac findings. Systemic artery aneurysms developed in 13 patients (2.2%), and valvular heart disease appeared in 7 (1.2%). CONCLUSIONS: The incidence of coronary aneurysm in acute Kawasaki disease was 25%, 55% of which showed regression. During follow-up, ischemic heart disease developed in 4.7% and myocardial infarction in 1.9%. Death occurred in 0.8%.

Aneurysm↗
PubMed1996

Detection of toluene in an adipoceratous body.

A 24-year-old male was found dead in a car left in a river for about 3 months. The cadaver was almost adipoceratous and autopsy findings revealed that there were neither remarkable injuries nor lethal diseases. Toluene, ethanol, 1-propanol, 2-propanol, 1-butanol, dimethyl sulfide, dimethyl disulfide, isovaleraldehyde and n-butyl n-butyrate were detected in the specimens collected at the autopsy by head space gas chromatography/mass spectrometry (GC/MS). The toluene concentrations (micrograms/g) were 31.0 in brain, 10.6 in liver, 5.4 in kidney, 15.0 in skeletal muscle and 187.1 in adipose tissue. The presence of diatom in lung, liver and kidney suggested that death was caused by drowning. So far as we know, this is the first report of detection of toluene in an adipoceratous body.

Adipose Tissue↗
PubMed1996

Induction of apoptotic cell death in rat thymus and spleen after a bolus injection of methamphetamine.

We examined whether methamphetamine (MAP) induced apoptotic cell death in vivo. Male Wistar rats were injected intraperitoneally with 25 mg MAP/Kg body weight and were sacrifice at 4, 8 and 24 h. As early as 4 h after a single dose of MAP, DNA ladder bands representing DNA fragmentation into multiples of the internucleosomal DNA length of about 180 by were observed by gel electrophoresis in thymic and splenic DNA. DNA from control rats injected with 1 ml physiological saline/Kg body weight showed no ladder band patterns. The proportion of fragmented DNA from the thymus increased in a time-dependent manner up to 8 h and faint ladder band patterns were observed at 24 h, indicating that cell death via apoptosis occurred at an early stage and then apoptotic bodies were scavenged. DNA fragmentation in the thymus and spleen induced with MAP was also confirmed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method in situ. In control thymus samples, stained cells were numerous in the cortex but sparse in the medulla. At the boundary area between the cortex and medulla, stained cells were seen as a layer. In the MAP-treated rats, stained cells were increased and dispersed equally in the cortex and medulla. In control spleen samples, stained cells were numerous in all areas excluding the germinal centers. Cells at the germinal centers were stained intensively in MAP-treated rat spleen. Light microscopical analyses allowed us to identify lymphocytes during the course of apoptotic cell death. Electron microscopic studies showed morphological landmarks for the process of cellular apoptosis in both organs e.g. lymphocytes with chromatin condensed into crescents at the periphery of the nuclei and apoptotic bodies. These result indicate that MAP induced cell death of the thymic and splenic lymphocytes via apoptosis.

Animals↗
PubMed1995

Evaluation of pulmonary artery histopathologic findings in congenital heart disease: an in vitro study using intravascular ultrasound imaging.

OBJECTIVES: This study aimed to 1) compare in vitro intravascular ultrasound images of human pulmonary arteries with corresponding histologic sections, and 2) correlate the relation between intravascular ultrasound findings and Heath-Edwards pathologic grade of pulmonary vascular changes. BACKGROUND: The pathologic assessment of the pulmonary vascular bed is essential for diagnosis and management of congenital heart disease with pulmonary hypertension. METHODS: We evaluated and compared intravascular ultrasound images with histologic findings at identical sites in 40 pulmonary artery segments from 17 autopsy studies: group 1 = 7 patients with pulmonary hypertension (Heath-Edwards grade I to V, 20 segments); group 2 = 10 patients without cardiopulmonary disease (20 segments). RESULTS: In group 2, the pulmonary artery wall echo consisted of a single layer. In group 1, 1) all segments of pulmonary arteries from patients with pulmonary hypertension showed a three-layered appearance; 2) in patients with mild pulmonary hypertension (Heath-Edwards grades I and II), intravascular ultrasound demonstrated increased thickness of the echoluscent zone due to medial hypertrophy with no intimal reaction; 3) patients with severe pulmonary hypertension (Health-Edwards grade III or higher) had intravascular ultrasound findings of increased medial thickness and a bright inner layer from intimal hyperplasia; 4) percent wall thickness derived from intravascular ultrasound showed a significant correlation with that determined by histologic examination (r = 0.89, p = 0.0001, n = 20). CONCLUSIONS: Changes observed with intravascular ultrasound imaging correlate well with histopathologic grade. Thus, intravascular ultrasound may have significant utility in the evaluation of pulmonary vascular morphology in patients with pulmonary hypertension.

Adolescent↗
PubMed1995

Fetal arrhythmias: intrauterine diagnosis, treatment and prognosis.

Fetal echocardiography can provide useful information for the evaluation of fetal arrhythmias. Between 1980 and 1993, 44 fetuses with arrhythmias were diagnosed in utero at 12 and 40 weeks of gestation in Kurume University Hospital. Fetal bradycardia, tachycardia and ectopic beats were revealed in 17, seven and 20 fetuses, respectively, and their clinical features and prognosis were evaluated. In the 17 fetuses with bradycardia, eight were associated with congenital heart defect, and six of these developed to fetal hydrops. Of the 17 fetuses, four died in utero, one was terminated, and six died after birth. The other six cases survived. Three of these had a pacemaker implanted after birth. In the seven fetuses with tachycardia, transplacental anti-arrhythmic drugs were administered in five cases and conversion of the arrhythmia was achieved in four. None of the cases was associated with any congenital heart defect, and none died. Three infants had paroxysmal tachycardia postnatally. In the 20 fetuses with ectopic beats, arrhythmia was observed postnatally in 10, but all of these were resolved within 3 months after birth. Fetal bradycardias carried a poor prognosis in most cases and further studies are required to establish effective treatment. Some cases of fetal tachycardia developed recurrent tachycardia postnatally. Close follow-up of the newborn is therefore necessary.

Arrhythmias, Cardiac↗
PubMed1994

A nonhuman primate model for human cerebral malaria: rhesus monkeys experimentally infected with Plasmodium fragile.

We studied the brains of rhesus monkeys infected with the primate malaria parasite Plasmodium fragile. Electron microscopy showed that, in these animals, erythrocytes infected with P. fragile undergo sequestration and that parasitized red blood cells adhere to endothelial cells in the cerebral microvessels by means of knobs. Cerebral microvessels with sequestered parasitized red blood cells were shown by immunohistochemical analysis to possess the platelet glycoprotein CD36, thrombospondin, and intracellular adhesion molecule-1. The formation of rosettes also was observed in the cerebral microvessels. In a fashion similar to human cerebral malaria, P. fragile produced neurological symptoms in the animals. Thus, rhesus monkeys infected with P. fragile, like those monkeys infected with Plasmodium coatneyi, can be used as a primate model to study human cerebral malaria.

Animals↗
PubMed1994

Ultrastructural localization of CD36 in human hepatic sinusoidal lining cells, hepatocytes, human hepatoma (HepG2-A16) cells, and C32 amelanotic melanoma cells.

Ultrastructural localization of CD36 in human hepatic sinusoidal lining cells, hepatocytes, human hepatoma (HepG2-A16) cells, and C32 amelanotic melanoma cells. Experimental Parasitology 79, 383-390. CD36 is expressed in the endothelial cells of some human organs, but the ultrastructural localization of this molecule in the sinusoidal lining cells of human liver is not well established. We report the ultrastructural localization of CD36 in the liver using a novel murine monoclonal antibody against CD36, namely MO30, as a primary antibody. Immunocytochemistry by the postembedding method showed that CD36 was localized in endothelial cells of sinusoids and in hepatocyte microvilli protruding into the space of Disse. Moreover, in cultured human hepatoma (HepG2-A16) cells and C32 amelanotic melanoma cells, MO30 reacted with microvilli. Hence, CD36 expressed on these cells may be involved in recognition and/or entry of these cells by malaria sporozoites.

Amino Acid Sequence↗
PubMed1994

Malaria-induced increase of splenic gamma delta T cells in humans, monkeys, and mice.

The number and distribution of gamma delta T cells in spleens from patients who died of cerebral malaria and from rhesus monkeys severely infected with Plasmodium coatneyi were examined by immunocytochemistry. gamma delta T cells were significantly increased in these spleens. In a rodent malaria model using Plasmodium chabaudi adami, an avirulent strain of murine malaria parasites, the degree of parasitemia appears to be modulated by the number of gamma delta T cells in the spleen. As parasitemia increases, these T cells increase in number. At some critical point, gamma delta T cells in collaboration with macrophages and alpha beta T cells apparently start to clear parasitized erythrocytes from the blood, leading to an abatement of the parasitemia, which is followed by a reduction in the number of gamma delta T cells. This gamma delta T cell phenomenon may be responsible for the self-limiting infection in mice.

Animals↗
PubMed1994

Intravascular ultrasound of coronary arteries in children. Assessment of the wall morphology and the lumen after Kawasaki disease.

BACKGROUND: The long-term clinical issue in Kawasaki disease (KD) concerns the coronary artery lesion. Two-dimensional echocardiography and coronary angiography are routine examinations to evaluate the coronary lesions; however, these are not adequate to assess the wall morphology of the coronary artery (CA). Intravascular ultrasound imaging (IVUS), a new technology for the evaluation of the coronary artery lumen and wall morphology in vivo, was performed for patients after KD in their long-term follow-up, and we examined the new insights it gave. METHODS AND RESULTS: IVUS was performed during cardiac catheterization in 20 subjects (10 patients after KD who still had coronary aneurysms or regressed coronary aneurysms, 2 after KD who had no coronary abnormal lesion, and 8 control patients with congenital heart disease and normal CA). We evaluated the wall structure at 10 to 15 sites of the CA in each patient. IVUS was performed with a commercially available ultrasound imaging catheter. Four sites of a CA aneurysm in KD demonstrated a markedly dilated lumen without thickened intima. One site of a CA aneurysm with calcification demonstrated an asymmetrical lumen by a dense echo with acoustic shadows. Twenty-two sites of a regressed CA aneurysm demonstrated a marked symmetrical or asymmetrical thickening of the intima with a dense echo, in which the size of the lumen was similar to that at a site near a regressed aneurysm. The sites of angiographically normal CA revealed normal structures and a thin intima in many instances. Nine of 28 sites in KD with a CA abnormal lesion, particularly near a coronary aneurysm or regressed aneurysm, demonstrated a mild thickening of the intima. All the 10 sites in KD without a CA abnormal lesion and all the 25 sites in patients with congenital heart disease with normal CA demonstrated a smooth intima. CONCLUSIONS: This study demonstrated that the site of a regressed coronary aneurysm has a markedly thickened but smooth intima. The sites of angiographically normal CA after KD with or without a coronary lesion demonstrated normal IVUS findings in most instances but in some cases revealed a mild intimal thickening. IVUS is useful to evaluate the CA wall morphology and may contribute to the assessment of long-term CA sequelae and the possible development of arteriosclerotic changes in KD.

Adolescent↗