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Biomedical subjects

H Iwane

Publications and source records attributed to H Iwane.

7 recordsLinked to original sources
PubMed1992

Collagenous deposits on explanted intraocular lenses.

An immunohistochemical study of type I collagen in deposits on the surface of two intraocular lenses (IOLs) explanted from human eyes was conducted. Type I collagen-immunoreactive proteinaceous deposits with cells were found around the haptics of an iris-supported IOL. A few such deposits and what appeared to be macrophages were observed on the optic. A few cells (presumably macrophages and giant cells) were observed on a posterior chamber IOL, whereas proteinaceous deposits that reacted positively to the antibody were not identified. Type I collagen-immunoreactive deposits on the iris-supported IOL were thought to be the products of fibroblastic cells, originating from iris tissue, that attached directly to the haptics and helped stabilize the implant.

Aged↗
PubMed1991

Immunohistochemical study of deposits on intraocular lenses explanted from human eyes.

Immunohistochemical studies of deposits were carried out on two intraocular lenses (IOLs) explanted from human eyes. One anterior chamber intraocular lens (AC-IOL) was studied using a monoclonal anti-human type I collagen-peptide antibody (C-Ab). One posterior chamber intraocular lens (PC-IOL) was studied using a monoclonal anti-human vimentin antibody (V-Ab). Most of the cells on the AC-IOL contained many melanin granules in the cytoplasm and were thought to be macrophages. They did not show any immunoreactivity to C-Ab. Some spindle-shaped cells and fibrous deposits at the margin of the lens optics showed immunoreactivity to the antibody. These cells were thought to be fibroblasts migrating from the tissue around the IOL, such as the iris. On the PC-IOL, many mononuclear cells and multinucleated giant cells were observed. These cells showed immunoreactivity to vimentin and contained immunostained fibers which were intermediate filaments. They were thought to be either of mesodermal origin or derived from the lens epithelium.

Aged↗
PubMed1990

[Left ventricular function after prolonged exercise].

To determine whether depressed left ventricular (LV) contractile function can occur after exhaustive exercise, echocardiographic studies were performed in eleven athletes before, at the finish (9 minutes) and during recovery (15 hour) after the Biwa Lake Ironman Triathlon (3.2 km Swim, 161 km Bike, 32 km Run). Before racing and during recovery, the studies were performed both at rest and after brief exercise (10-15 minutes). Heart rates after brief exercise were comparable to those attained after racing. Digitized M mode echocardiographic data as to wall thickness, cavity dimension, fractional shortening (FS) and peak circumferential shortening (maxVcf) were obtained. When we compared race finish to pre-race brief exercise, the LV end-diastolic dimension (EDD) was reduced (46 +/- 7 vs 47 +/- 6 mm, less than 0.05) and FS declined (33 +/- 5 vs 39 +/- 6%, p less than 0.05). In spite of reduced wall stress, maxVcf decreased. Individual percent reductions in FS were not correlated with decrease in EDD, but correlated with increases in EDS. Although a persistent reduction in cavity size was observed during recovery, FS and maxVcf returned toward the baseline. The results suggest that prolonged strenuous exercise may result in impaired LV function in part because of a reversible depression in the contractile state.

Adult↗
PubMed1989

Effects of adenosine and pertussis toxin on lipolysis in adipocytes from exercise-trained male rats.

The sensitivity and responsiveness of adipocyte lipolysis to adenosine and pertussis toxin were studied in exercise-trained male rats. Exercise training (9 weeks of treadmill running) significantly increased lipolytic response of adipocytes to noradrenaline (NA). Addition of adenosine deaminase (ADA) to reaction mixture effectively enhanced NA-stimulated lipolysis in adipocytes from both conditioned rats. However, under these conditions, the difference due to exercise training was still evident, although the difference was less pronounced. The inhibition curves of the R-site adenosine analogue N6-phenylisopropyladenosine (PIA) against "basal" (lipolysis in the presence of ADA) and NA-stimulated lipolysis were almost comparable between two groups. Only a small (approx. 2-fold) increase in IC50 of adipocyte lipolysis was observed in each inhibition curve in exercise-trained rats. Within 120 min of addition of pertussis toxin to adipocytes from control rats, "basal" lipolysis was significantly increased as compared to "basal" lipolysis in the absence of toxin at the same point. Similarly, pertussis toxin significantly increased "basal" lipolysis in exercise-trained adipocytes. However these were relatively sensitive to pertussis toxin, since significant effect of toxin was seen within 60 min. An addition of NA (0.1 uM) to the medium in the presence of ADA and toxin significantly increased adipocyte lipolysis in both conditioned rats. Again, under these conditions, we observed that the maximal rate of lipolysis of adipocytes from exercise-trained rats was increased as compared to control rats. These results suggest that the decreased input through the inhibitory pathway in lipolytic cascade may be not rate limiting for the amplified lipolytic responsiveness of adipocytes to hormonal stimuli in exercise-trained rats.

Adenosine↗
PubMed1986

Entrapment of phenylalanine ammonia-lyase in silk fibroin for protection from proteolytic attack.

Phenylalanine ammonia-lyase was entrapped in silk fibroin. The entrapped enzyme showed a similar Km for Phe and pH optimum to the free enzyme. It was resistant against chymotrypsin and trypsin in vitro. To assess the activity in vivo, the free or entrapped enzymes and then Phe were injected into rat duodenum, and cinnamate, a product, in plasma was determined as the most direct evidence of the enzyme activity. The entrapped enzyme but not the free form caused a marked raise of plasma cinnamate. It declined with a half life of about 45 min, which was significantly longer than that (10-15 min) observed upon i.v. administration of cinnamate. These results indicated that the entrapped enzyme was actively degrading Phe in the intestinal tract. Entrapment of phenylalanine ammonia-lyase in fibroin thus provides a new prospect for oral enzyme therapy of phenylketonuria.

Ammonia-Lyases↗
PubMedDate not supplied

Experimental study on enzyme distribution and its relation to myocardial ischemic changes following coronary circulatory disturbances.

Coronary artery ligation of canine heart was performed to investigate the relationship between the lactate dehydrogenase (LDH) pattern in myocardium and the distribution of coronary flow, especially in the early stage of ligation and after reperfusion. In the myocardium of normal dogs, the LDH pattern was similar in the left ventricle, the interventricular septum, and the right ventricle; the average LD5:LD4 ratio was 1.1, 1.2, and 1.2, respectively, and consisted mainly of heart type. In the left and right auricles, however, the ratios were 0.3 and 0.2, respectively, lacking heart type. In the left ventricle, LD5:LD4 ratio in the subendocardium was different from that in the subepicardial layer. Blood flow distribution in canine myocardium was investigated by the fluorescent pattern on the cut surface of heart, in which 10% fluorescein sodium was injected into the cavity. By this method the evolution of the ischemic area from the endocardial layer to the epicardial side following coronary artery ligation and the effect of reperfusion on the ischemic area were clarified. Electron microscopic studies indicated that loss of mitochondrial function may account for the irreversibility of myocardial cell alteration. A new method for studying enzyme localization in tissues was introduced for studying LDH isoenzyme distribution in normal and injured myocardium.

Animals↗