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Biomedical subjects

Y Tazawa

Publications and source records attributed to Y Tazawa.

At least 109 records · Page 6Linked to original sources
PubMed1983

Biliary lipid compositions in cholestatic diseases of infancy.

Biliary lipid compositions in infants with cholestasis were analysed. Bile acid and phospholipid values were appreciably lower in infants with idiopathic neonatal hepatitis syndrome or corrected biliary atresia than in control infants. Cholesterol values were not, however, notably lower in infants with cholestasis. When biliary lipid components were determined in terms of molar percent, bile acid values were considerably lower in infants with cholestasis than in controls, and cholesterol and phospholipids were appreciably higher, as was the lithogenic index.

Age Factors↗
PubMed1983

Neuronal pathways for activation of inhibitory interneurons in pyriform cortex of the rabbit.

The neuronal pathways responsible for the fast inhibitory postsynaptic potentials (IPSPs) elicited in principal cells in the pyriform cortex (PC) by volleys from the olfactory bulb (OB), the lateral olfactory tract (LOT), the anterior commissure (AC), and the deep-lying structures of the PC (DPC) were studied in the rabbit. The central latencies of the fast IPSPs (measured from the onset of the monosynaptic excitatory postsynaptic potential (EPSP) elicited by volleys through the LOT) ranged between 3.0 and 9.3 ms (5.5 +/- 1.3 (SD) ms; n = 54) in the case of OB shocks and between 4.5 and 6.5 ms (5.1 +/- 0.7 (SD) ms; n = 7) in the case of LOT shocks. The onset latencies of the fast IPSPs were between 2.5 and 11.8 ms (5.1 +/- 1.8 (SD) ms; n = 66) in the case of DPC shocks and between 3.5 and 10.1 ms (5.8 +/- 1.5 (SD) ms; n = 61) in the case of AC shocks. The conditioning OB or LOT shocks almost completely eliminated the LOT-evoked fast IPSP when the testing shock was applied at the peak period of the conditioning slow IPSP. The conditioning OB shocks also eliminated the initial part of the OB-evoked fast IPSP, leaving the later part of the fast IPSP almost unchanged. Thus, the onset latency of the OB-evoked fast IPSP was lengthened by 7.1 +/- 2.9 (SD) ms (n = 35) by the conditioning OB shock. The conditioning OB or DPC shocks left the peak amplitude of the DPC-evoked fast IPSP almost unaffected. Similarly, the conditioning OB or AC shocks left the peak amplitude of the AC-evoked fast IPSP almost unaffected. The conditioning OB, DPC, or AC shocks had only a slight influence on the onset latency of the DPC- or AC-evoked fast IPSPs. Rhythmical steps at intervals of 3-5 ms were observed in the rising phase of the OB-evoked fast IPSP. This was interpreted as a result of a repetitive impingement of interneuronal discharges on the impaled cells. Spatial facilitation was observed among the fast IPSPs evoked by volleys from the OB, DPC, and AC when shocks were applied at suitable intervals. A slight facilitation was also seen between the LOT-evoked fast IPSP and the DPC- or AC-evoked fast IPSP. These results were interpreted as a result of the convergence of excitatory synaptic inputs onto the presumed inhibitory interneurons from the four structures of the brain. A temporal facilitation of the fast IPSPs was observed when the OB, DPC, or AC shocks were applied repetitively at short intervals. This suggests a temporal facilitation of the spike discharges of the presumed inhibitory interneurons under similar conditions. From these results, criteria were determined for identifying the inhibitory interneurons.

Animals↗
PubMed1983

Interneurons mediating fast postsynaptic inhibition in pyriform cortex of the rabbit.

Interneurons mediating the fast IPSPs in principal cells in the pyriform cortex (PC) of the rabbit were searched for using criteria derived from the analysis of the properties of the fast inhibitory postsynaptic potentials (IPSPs). Thirty units were identified as inhibitory interneurons. The interneurons were activated synaptically by volleys from the olfactory bulb (OB), the lateral olfactory tract (LOT), the anterior commissure (AC), and deep-lying structures of the PC (DPC). The interneurons showed a tendency to discharge repetitively in response to shocks applied to these structures of the basal forebrain (OB, LOT, AC, and DPC). The conditioning OB shocks eliminated the testing LOT-evoked discharges of the interneurons. The conditioning OB shocks eliminated the initial part of the testing OB-evoked discharges, leaving the later part relatively unchanged. On the other hand, the conditioning OB shocks did not completely eliminate the testing DPC- or AC-evoked discharges. A temporal facilitation of discharges in the interneurons was observed in response to volleys from the OB, DPC, or AC. A spatial facilitation of discharges in the interneurons was observed in response to a combination of shocks applied to the OB, DPC, and AC. The interneurons were recorded at depths 525-2,755 microns deep to the turnover point of the component 2 wave of field potentials evoked by volleys through the LOT fibers. They were located mostly in the deeper part of layer III of the PC. Intracellular recordings from the presumed inhibitory interneurons showed that OB stimulation elicited two successive excitatory postsynaptic potentials (EPSPs) on which the bursting discharges were superimposed. These EPSPs were followed by a long-lasting hyperpolarizing potential. A comparison of the latencies of the antidromic activation of the principal cells and the synaptic activation of the inhibitory interneurons following OB or DPC stimulation suggested that the inhibitory interneurons are activated at least partly through the axon collaterals of the principal cells, which project their main axons to the OB or DPC. A circuit diagram was proposed for the neuronal pathways responsible for the fast IPSPs of principal cells in the PC.

Animals↗
PubMed1983

Dietary therapy in a girl with propionic acidemia: supplement with leucine resulted in catch up growth.

A 15-month-old girl with propionic acidemia presented a failure to thrive and muscular hypotonia, who had been treated with diets low in leucine, valine, isoleucine, threonine and methionine. Supplementation with leucine gave her a catch up growth and brought about an improvement in muscular hypotonia in parallel with restoration of plasma leucine which had been below normal range during the treatment with the above diets. Oral loading test of leucine produced no ketoacidosis. These findings indicate that the restriction of leucine is not necessary in the dietary management of propionic acidemia.

Amino Acid Metabolism, Inborn Errors↗
PubMed1982

Urinary monohydroxy bile acids in young infants with obstructive jaundice.

Using an aluminum oxide column, we fractionated and quantitatively determined urinary monohydroxy bile acids in young infants. For comparison purposes, monohydroxy bile acids were also measured in urine from older children and adults with obstructive jaundice. Lithocholic acid was not found in any specimens of the young infants examined, while 3 beta-hydroxy-5-cholenoic acid was detected in all. In the biliary atresia group, 3 beta-hydroxy-5-cholenoic acid excreted was 0.45+/-0.28 mumol per day (n=7), and in the neonatal hepatitis group, 0.48+/-0.44 mumol per day (n=9). The mean rate of 3 beta-hydroxy-5-cholenoic acid to total urinary bile acids in the biliary atresia group was 2.1%, and 1.3% in the neonatal hepatitis group. In the older children and adults with obstructive jaundice (n=6), 3 beta-hydroxy-5-cholenoic acid was excreted at a mean rate of 3.9% of total urinary bile acids, ranging from 0.63 to 14.81 mol per day. The excretion rate of 3 beta-hydroxy-5-cholenoic acid was related to that of chenodeoxycholic acid (p less than 0.05) in infants, while it was related to that of both chenodeoxycholic acid (p less than 0.01) and cholic acid (p less than 0.05) in older children and adults.

Adult↗
PubMed1982

Familial cholestasis with gallstone, ataxia and visual disturbance.

Two siblings with progressive intrahepatic cholestasis were reported. The brother died at 4 years of age because of hepatic failure followed by persistent obstructive jaundice starting at 4 months of age. The sister had unique clinical features, including recurrent obstructive jaundice since early infancy, radiopaque gallstone and neurological abnormalities which were cerebellar ataxia, bilateral ptosis, hyporeflexia and visual disturbance involving retinal degeneration and optic atrophy. She had a coarse facial appearance, camptodactyly and sclerotic skin with many scratch marks. Persistent high levels of serum bile acids were found while the patient was icteric and even anicteric, though serum cholesterol levels were approximately within normal limits. The serum lipoprotein-X was negative whenever examined. Cholestyramine treatment gave incomplete relief from pruritus but resulted in no improvement in her clinical course.

Cerebellar Ataxia↗
PubMed1980

Demonstration of IgG EA (early antigen) and IgM MA (membrane antigen) antibodies in CMV infection of healthy infants and in those with liver disease.

The sequence of antibody production to various virus-specific antigens in CMV infection in infancy was studied. In healthy infants, IgG EA antibody was demonstrated in 18% of cord sera, and disappeared within two months after birth in all cases not shedding virus. The nonmaternal EA antibody was produced following virus excretion and decreased rapidly following cessation of virus excretion. Thus, demonstration of EA antibody in infants after 2 months of age was found to indicate acquired CMV infection, even when CMV could not be isolated. IgM MA antibody did not persist as long as EA antibody, disappearing before cessation of virus excretion. Both IgG EA and IgM MA antibodies were more frequently demonstrated in infants with hepatitis than in healthy infants. These findings suggest the possible association of CMV with hepatitis in infants.

Antibodies, Viral↗
PubMed1980

Effect of tiopronin on senile cataracts. A double-blind clinical study.

The therapeutic effect of tiopronin on incipient senile cataracts was evaluated in 150 cases (275 eyes) by a double-blind study using nonactive placebo. A more favorable tendency to visual acuity was noted in the tiopronin than in the placebo group. The slit-lamp microscopic findings showed a statistically significant difference between the tiopronin and the placebo groups. Integrated judgement revealed tiopronin to be significantly effective as compared with the placebo. A side effect of fever with systemic eruption was observed in 1 case in the tiopronin group but disappeared completely when administration of the drug was discontinued.

Age Factors↗