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H Inuzuka

Publications and source records attributed to H Inuzuka.

26 records · Page 2Linked to original sources

R-cadherin: a novel Ca(2+)-dependent cell-cell adhesion molecule expressed in the retina.

cDNAs encoding a novel member of the cadherin cell adhesion receptor family were cloned. This cadherin is expressed in the retina of the chicken and is termed R-cadherin. It is similar to other cadherins in its primary structure, but most resembles N-cadherin, showing 74% amino acid identity. Cells expressing R-cadherin can adhere to those expressing N-cadherin when mixed, but they form homotypic clusters within their chimeric aggregates. In the development of the neural retina, R-cadherin begins to be expressed around embryonic day 8 in both neuronal and glial cells, and this expression continues up to the hatching stage. The pattern of the expression of R-cadherin was different from that of N-cadherin, suggesting distinctive roles in retinal morphogenesis.

Amino Acid Sequence↗

Differential expression of R- and N-cadherin in neural and mesodermal tissues during early chicken development.

R-cadherin is a newly identified member of the cadherin family of cell adhesion receptors. The expression of R-cadherin in early chicken embryos was studied using affinity-purified antibodies to this molecule, comparing it with that of N-cadherin. Immunoblot analysis of various organs of 10.5-day embryos showed that R-cadherin is most abundantly expressed in the retina and brain. Immunostaining of the cervical and thoracic regions of embryos revealed that R- and N-cadherin are expressed in all neural tissues. In the neural tube, R-cadherin appears at around stage 21, although N-cadherin expression begins at a much earlier stage. The distribution of R-cadherin in the neural tube differs from that of N-cadherin; for example, some regions of the tube express only R-cadherin, and other regions only N-cadherin. In the peripheral ganglia, these two cadherins are also expressed in different patterns which change during development. Some mesenchymal tissues including the notochord, the myotome, myotubes and perichondria also express these cadherins, again in different patterns. Thus, R- and N-cadherin are differentially expressed in all the tissues examined, and they may contribute to the spatial segregation of heterogeneous cells in a tissue.

Animals↗

[Coronary artery bypass grafting for ischemic heart disease combined with aortitis].

Coronary artery bypass grafting (CABG) was performed in a 67-year-old woman with aortitis. She had a past history of right radical mastectomy. Preoperative coronary angiogram showed diffuse stenotic lesions in both right and left coronary arteries. The pressure gradient between ascending aorta and peripheral radial artery was 90 mmHg and the cause of coronary stenosis seemed to be hypertension due to stenotic distal aorta. The aortogram showed occluded bilateral internal thoracic arteries (ITA) and stenotic abdominal aorta. The cephalic artery was supplied by a large meandering artery via dilated gastroepiploic artery (GEA). And thus the GEA was not useful for CABG. Quadruple CABG was performed with mild varicose saphenous vein (saphenous vein grafts to left anterior descending artery and third branch, and sequential saphenous vein graft to right posterior descending and atrioventricular branches). It seemed to be important to demonstrate the arterial lesion of ITA and GEA before CABG in patients with aortitis.

Aged↗

Cadherin-mediated cell-cell adhesion and neurogenesis.

Cadherins constitute a molecular family which confers adhesive specificities on cells. Their expression is spatio-temporally regulated in embryos and the multiple types of cadherins are expressed in the nervous system. The inhibition of cadherin action with antibodies resulted in the perturbation of the histogenesis of neural tissues. The sites for determining the binding specificities of cadherins reside in their amino terminal 113 amino acid region. Possible roles of cadherins associated with these properties in neurogenesis are discussed.

Animals↗

Cadherin subclasses: differential expression and their roles in neural morphogenesis.

Cadherins homophilically bind cells. Thus, cells expressing identical cadherins adhere selectively to each other, and they do not randomly intermix with the cells expressing other types of cadherins in vitro. Neural tissues express multiple types of cadherins, and the expression of each cadherin type is spatiotemporally regulated within a tissue during development. This molecular family therefore could operate for the sorting of different cell types in the nervous system. The regulation of N-cadherin expression is also important for the early development of the neural tube. The ectopic expression of N-cadherin in Xenopus embryos, which was induced by mRNA injection, led to the disorganization of neural tube structures or the fusion of the neural tube to the epidermis. These results suggest that the precise regulation of cadherin expression at the quantitative as well as at the qualitative level si crucial for neural morphogenesis.

Animals↗

Ultrastructural alterations of right and left ventricular myocytes in tetralogy of Fallot.

We examined the ultrastructure of right and left ventricular myocardial biopsies obtained prior to cardiopulmonary bypass in fourteen patients undergoing total correction of tetralogy of Fallot (TOF). Twelve patients were undergoing primary one-stage repair and two patients had had a previous Blalock-Taussig shunt operation. The ages of the patients ranged from 3 to 35 years. In left ventricular (LV) myocytes, the sarcolemma often formed pouches filled with mitochondria and the muscle fibers showed a disoriented arrangement. In addition, the myofibrils showed hypercontraction and the Z-bands were thickened; the degree of the myofibril contraction was more severe than that in right ventricular (RV) myocytes. These ultrastructural findings are similar to those observed in myocytes under hypoxic conditions. The number of lysosomes in LV myocytes, but not in RV myocyte increased in the older patients. While we have not established a causal relationship between the ultrastructural findings and clinical features in our cases, our observations are consistent with the possibility that early total correction of TOF may be required to prevent the development of hypoxic changes and degeneration of heart muscle.

Adolescent↗

[Combined operation for renovascular hypertension and ischemic heart disease].

We have experienced two patients of ischemic heart disease associated with renovascular hypertension. Patient 1 (60-year-old man) underwent LV aneurysmectomy and triple aortocoronary bypass grafting (saphenous vein to diagonal branch, left internal mammary artery to obtuse marginal branch, and right gastroepiploic artery to right coronary artery). Seventy five days after the initial cardiac surgery endarterectomy for the left renal artery and bifurcated Dacron graft implantation for the iliac artery obstruction were performed. Patient 2 (62-year-old woman) underwent simultaneous operation of both right nephrectomy and triple aortocoronary bypass grafting (saphenous vein grafts to obtuse marginal branch and right coronary artery, and left internal mammary artery to left anterior descending artery). Their postoperative courses were uneventful except unstable and high blood pressure for four to seven days after the operation. It appears that it should be decided to achieve either simultaneous or two stage approach for ischemic heart disease associated with renovascular hypertension based on the preoperative cardiac function. And both postoperative cardiac function and hypertension should be carefully managed until the blood pressure becomes stable after the surgery.

Coronary Artery Bypass↗