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Biomedical subjects

Y Tazawa

Publications and source records attributed to Y Tazawa.

At least 91 records · Page 5Linked to original sources
PubMed1986

Significance of serum lipoprotein-X and gammaglutamyltranspeptidase in the diagnosis of biliary atresia. A preliminary study in 27 cholestatic young infants.

As simple and nonsurgical means of differentiating biliary atresia (BA) from intrahepatic cholestasis of unknown origin (IC), liver function tests including serum lipoprotein-X (LP-X) and gamma-glutamyltranspeptidase (GGTP) were done and evaluated for their usefulness in the diagnosis of 27 cholestatic Japanese young infants. Except for LP-X and GGTP levels (P less than 0.01, P less than 0.001), there were no significant differences between the BA (n = 11) and IC (n = 13) groups. When values of mean plus 4 standard deviations were used to differentiate BA from IC (89 mg/100 ml for LP-X and 194 IU/l for GGTP), all BA patients gave positive results for either the critical LP-X of GGTP values. On the other hand, all IC patients gave negative results for both levels, although patients with a paucity of intrahepatic biliary ducts (n = 3) were also positive for either the critical LP-X or GGTP values. The combination test with serum LP-X and GGTP is recommended for helping to differentiate BA from IC in cholestatic young infants.

Bile Ducts↗
PubMed1986

ERG c-wave and pigment granule distribution in isolated chick retina: effects of osmotic pressure variation in vitreal perfusing solution.

The relation between osmotic gradient variation and change in the ERG c-wave was investigated. The vitreous side of the isolated chick retina was perfused with various solutions having osmotic pressures (pi v) ranging between 310 and 600 mOsm, while the choroidal side was maintained at 480 mOsm (pi c). When the osmotic difference (delta pi), (ie, pi v-pi c), was larger than -10 mOsm, normal c-waves with slow rise-times (cs-wave) were obtained; however, when the delta pi was smaller than -30 mOsm, c-waves with fast rise-times (cF-wave) were recorded. The peak time of the cS-waves ranged from 4-6 seconds, while that of the cF-waves was approximately 2 seconds. In addition, changes in the pigment granule distribution were also investigated histologically and photometrically. At delta pi of +10 mOsm, the distribution of pigment granules was similar to that in the dark-adapted chick retina. However, when the delta pi was -30 mOsm, the distribution of pigment granules was similar to that in the light-adapted chick retina. Under the control condition at delta pi of +10 mOsm, the pigment granules were distributed mainly within the cell body of the pigment epithelium, ie, in a direction opposite to the passive flow determined by the artificial osmotic gradient. However, after treatment by ouabain, the granules were spread toward the neural retina in the same direction as the passive flow, suggesting passive movement of these granules. These results suggest that a steep osmotic gradient is present within the normal retina and that the gradient is maintained by an ATPase-dependent mechanism. Moreover, the above results suggest that the cS-wave is scotopic and the cF-wave is photopic.

Animals↗
PubMed1985

Osmotic pressure of the interstitial fluid obtained from neonatal chick eyes and its variation under light and dark adaptation.

In experiments by Yoneyama et al. (1985) a hypertonic perfusing solution was used to record the c-wave from the isolated chick retina. We investigated whether the chick retina was surrounded by such hypertonic liquids. The following results were found: the osmolarity of the subchoroidal humor was markedly higher than that of fluids from other areas of the eye; the relative difference in osmolarity between both sides of the retina was 110-170 mOsmol in the light-adapted condition, whereas it was about 270 mOsmol in the dark-adapted condition; and in the dark-adapted state the volume of the subchoroidal humor decreased about 40% but increased in osmolarity about 30-40%, whereas osmolarity of the subvitreous humor decreased about 15-20 mOsmol. Results suggest the presence of an inward-directed pump mechanism for water-soluble components in the retina in addition to the proposed outward-directed pump mechanism of the pigment epithelium. The inward-directed pump may be more active in the dark-adapted state.

Adaptation, Physiological↗
PubMed1985

Serum bile acids and their conjugates in breast-fed infants with prolonged jaundice.

Serum bile acids and their conjugates were analysed in 20 breast-fed infants with prolonged jaundice. The mean total bile acid levels in serum were increased in the breast-fed infants with jaundice, as compared with those in either breast- or bottle-fed infants without jaundice. However, there were no significant differences between the groups. All the breast-fed infants examined, regardless of association with jaundice, had a bile acid pattern dominated by taurine conjugates (the ratio of glycine- to taurine-conjugated bile acid, G/T ratio, less than 1.00). In contrast, the bottle-fed infants without jaundice had a pattern dominated by glycine conjugates (G/T ratio, more than 1.00). Among the breast-fed infants with jaundice, the mean G/T ratio in those who had serum bilirubin levels over 10 mg/100 ml was significantly lower than that in those who had serum bilirubin levels of less than 10 mg/100 ml. The altered bile acid metabolism might be associated with the pathology of breast milk jaundice.

Bile Acids and Salts↗
PubMed1985

Alterations of serum bile acid profile in breast-fed infants with prolonged jaundice.

Serum bile acid conjugates in breast-fed infants with prolonged jaundice were analyzed by a newly developed procedure using high-performance liquid chromatography with fluorescence labeling. Major bile acids were cholate and chenodeoxycholate conjugates. Some of the breast-fed jaundiced infants had high levels of serum bile acid conjugates (greater than 25 mumol/L), but the mean levels of individual bile acid conjugates found in jaundiced breastfed infants were not significantly different from those in breast-fed infants without jaundice. The glycine- to taurine-conjugated bile acid ratio in breast-fed jaundiced infants was significantly lower than in breast-fed nonjaundiced infants or bottle-fed nonjaundiced infants. In breast-fed infants, the portion of taurine-conjugated bile acids increased in proportion to serum bilirubin levels. These findings suggest that alteration in conjugated bile acid patterns of breast milk jaundice is related to an increased enterohepatic circulation of bile acids as well as bilirubin in infants fed on breast milk that contains high amounts of taurine.

Bile Acids and Salts↗
PubMed1984

Serum vitamin E levels in children with corrected biliary atresia.

In 37 children with long-standing cholestasis who had undergone a Kasai's procedure (double Roux-en-Y hepatic portoenterostomy), serum vitamin E levels were determined. In addition, serum bile acid levels were simultaneously tested as a marker of cholestasis. Eighteen of 37 children had vitamin E levels of less than 0.50 mg/100 ml, and two showed neurological abnormalities including hypoactive deep tendon reflexes and ataxia. Serum vitamin E levels were inversely correlated with serum bile acid levels (p less than 0.01). Older patients have mild cholestasis and high serum vitamin E levels in comparison with younger ones. Improvement in bile excretion into the intestinal tract with age seemed to be responsible for an increase of serum vitamin E levels. Oral supplements of alpha-tocopherol in doses of 5 to 10 mg/kg/day were needed to maintain the normal serum vitamin E levels in postoperative infants.

Ataxia↗
PubMed1984

Fecal and biliary bile acid patterns in children with bile acid malabsorption.

Bile acid metabolism was examined in two children with bile acid malabsorption, who were being treated with intravenous hyperalimentation. Fecal bile acid excretion was 1,261 mumol/m2/day in a child with bile acid malabsorption of unknown origin, and 1,877 mumol/m2/day in a child with secondary bile acid malabsorption after an operation for long-segment aganglionosis. These values were approximately 10 times higher than those in diarrheal or nondiarrheal children without apparent abnormalities in bile acid metabolism. Fecal bile acids in these patients with bile acid malabsorption were almost completely conjugated, with little unconjugated bile acid present. It is possible that the disturbed bile acid deconjugation in the intestine might be caused by a rapid intestinal transit time, which was found in our patients with bile acid malabsorption. In the analysis of biliary lipid composition, children with bile acid malabsorption were shown to have a chenodeoxycholate-dominant pattern, an increased glycine- to taurine-conjugated bile acid ratio, and markedly supersaturated cholesterol. Such profiles may be related not only to bile acid malabsorption but also to cholestasis, presumably due to intravenous hyperalimentation.

Bile↗
PubMed1984

Familial intrahepatic cholestasis associated with progressive neuromuscular disease and vitamin E deficiency.

Three Japanese patients with familial progressive intrahepatic cholestasis developed complications involving neurologic abnormalities characterized by ataxia and pigmentary retinopathy. Serum vitamin E concentrations were extremely low in all patients, suggesting a long-term vitamin E deficiency. High dose oral supplementation of alpha-tocopherol produced normal serum vitamin E levels in two patients. Parenteral administration of vitamin E resulted in no clinical improvement in one patient who first received the treatment at 14 years of age. In the other two patients, the progression of neurological abnormalities was slowed by vitamin E supplementation. Cholestyramine treatment resulted in an apparent decrease in serum vitamin E levels despite oral alpha-tocopherol supplementation.

Adolescent↗
PubMed1984

Serum bile acid patterns determined by an enzymatic method and high-performance liquid chromatography in young infants with cholestasis.

Serum unconjugated and conjugated bile acids in young infants with intrahepatic cholestasis (idiopathic neonatal hepatitis syndrome, n = 8) or extra-hepatic cholestasis (preoperative extrahepatic biliary atresia, n = 8) were examined by an enzymatic procedure and high-performance liquid chromatography. In comparison with the mean level of total serum bile acid of controls having no liver or gastrointestinal diseases, those of each group markedly increased (15.6 +/- 5.1 vs. 120.9 +/- 64.0 and 161.8 +/- 54.2 nmol/ml), but those of unconjugated bile acid were almost unchanged (1.4 +/- 0.5 vs. 1.0 +/- 0.6 and 0.6 +/- 0.2 nmol/ml). The ratios of cholate to chenodeoxycholate and glycine- to taurine-conjugated bile acids (G/T) were not significantly different between the groups of intrahepatic and extrahepatic cholestasis. However, in the patients with intrahepatic cholestasis, the G/T ratio varied greatly and the quantitative determination of individual conjugated bile acids in serum revealed that a half of the patients examined had very low levels of taurine-conjugated cholate and chenodeoxycholate, suggesting a bile acid metabolism alternation specific for underlying intrahepatic cholestasis.

3-Hydroxysteroid Dehydrogenases↗
PubMed1984

Unconjugated, glycine-conjugated, taurine-conjugated bile acid nonsulfates and sulfates in urine of young infants with cholestasis.

A direct assay system for conjugated bile acids using an enzymatic procedure and high-performance liquid chromatography was used for the analysis of urinary bile acid profiles in young infants with intrahepatic cholestasis (idiopathic neonatal hepatitis syndrome) or extra-hepatic biliary atresia. The major urinary bile acids were cholate and chenodeoxycholate conjugates, but a small amount of deoxycholate and 3 beta-hydroxy-5-cholenate conjugates were detected. Although there was no significant difference in total bile acid excretion between patients with intrahepatic cholestasis and extrahepatic biliary atresia, mean ratios of cholate to chenodeoxycholate and sulfated to total urinary bile acids were different between the two groups examined (5.63 +/- 2.83 vs. 2.50 +/- 1.25, p less than 0.05, 15.8 +/- 9.9 vs. 34.5 +/- 9.9%, p less than 0.005). The proportion of taurine-conjugated chenodeoxycholate in the sulfate fraction to the total bile acid was lower in intrahepatic cholestasis, compared with that in biliary atresia (7.7 +/- 7.5 vs 22.7% +/- 7.8%, p less than 0.005). The greater ratio of cholate to chenodeoxycholate and the reduced excretion of sulfated urinary bile acids in intrahepatic cholestasis was due to decreased taurine-conjugated chenodeoxycholate sulfate excretion.

Bile Acids and Salts↗
PubMed1984

Ultrastructural changes in skeletal muscle of a patient with familial intrahepatic cholestasis associated with vitamin E deficiency.

The skeletal muscle from a patient with familial intrahepatic cholestasis associated with vitamin E deficiency was studied by electron microscopy. The muscle fibers showed a variety of pathologic features including degenerative, necrotic and regenerative changes. Granule-like inclusions found in our biopsy specimens were similar in structure to those observed in vitamin E deficient animals. These inclusions were noted not only in the skeletal muscle fibers but also in endothelial cells of the intramuscular capillaries, Schwann cells and perineural cells. Disruption and disappearance of the plasma membrane, separation, disruption and pleats formation of the external lamina, and multilayered external laminae were observed in muscle fibers most frequently. The nerves among muscle fibers also showed degenerative features. These severely degenerative alterations of the muscle fiber have not so far been reported in vitamin E deficient patients. We discuss the process of cell damages caused by vitamin E deficiency.

Child, Preschool↗
PubMed1984

Direct measurement of urinary bile acids of infants by high-performance liquid chromatography connected with an enzyme immobilized column.

An accurate and sensitive method by high-performance liquid chromatography connected with 3 alpha-hydroxysteroid dehydrogenase immobilized column for the measurement of urinary bile acids of noncholestatic and cholestatic infants was performed in this study. The purification and group separation of urinary bile acids were done through a piperidinohydroxypropyl Sephadex LH-20 column. By ultraviolet spectromonitor, non 3 alpha-hydroxy bile acids such as 3 beta-hydroxy-5-cholenate were determined, and 3 alpha-hydroxy bile acids by fluorescence spectromonitor. Urinary bile acids in the specimens obtained from noncholestatic and cholestatic infants were determined by this procedure. Major bile acids were cholate, chenodeoxycholate conjugates and cholate unconjugate in healthy infants. In cholestatic infants, total and individual bile acids were extremely increased, and 3 beta-hydroxy-5-cholenate conjugates appeared in the sulfated fraction.

3-Hydroxysteroid Dehydrogenases↗
PubMed1983

Monosynaptic and disynaptic activation of pyriform cortex neurons by synchronous lateral olfactory tract volleys in the rabbit.

To elucidate the organization of synaptic inputs to pyriform cortex neurons, intracellular and extracellular responses of single units were analyzed in urethane-anesthetized rabbits. The lateral olfactory tract (LOT) or the olfactory bulb (OB) was electrically stimulated. Intracellular recordings revealed two types of cells (type I and type II cells), according to the types of EPSP evoked by the LOT or OB shock. The EPSP in the type I cells had shorter latencies (0.0 to 0.9 ms) from the onset of the component 2 (C2) wave of the field potential (which signals the onset of the synaptic depolarization of the apical dendrites of the pyramidal cells in the PC), and that in the type II cells had longer latencies (1.0 to 6.0 ms). A conditioning LOT or OB shock did not suppress the testing EPSP in the type I cells, whereas the conditioning stimulation greatly suppressed the testing EPSP in most of the type II cells. Extracellular recordings from units responding synaptically to the LOT or OB shock revealed a group of units which had short latencies (0.7 to 1.9 ms) of spike discharges. Those units, which were likely to be the same cells as the type I cells, are believed to mediate excitatory synaptic inputs to the type II cells. On the basis of these results, we concluded that type I cells are monosynaptically activated by LOT volleys, whereas type II cells are activated di- or polysynaptically by way of a relay from type I cells. The type I cells were recorded in both the superficial and the deep parts of the pyriform cortex, although they were recorded more frequently in the superficial part. On the other hand, most of the type II cells were recorded in the deep part of the PC. These results support and extend the previous model, in which the monosynaptically activated superficial pyramidal cells give rise to excitatory inputs to other pyramidal cells and neurons in deep layers.

Animals↗