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Biomedical subjects

H Yabuuchi

Publications and source records attributed to H Yabuuchi.

At least 37 records · Page 2Linked to original sources

Initial hepatic metabolic function in canine liver and pancreas cluster transplantation.

In this study, initial hepatic metabolic function was evaluated by determining the arterial ketone body ratio (AKBR) and plasma amino acid concentrations in an experimental orthotopic combined hepatopancreatic transplantation (OHPT), and comparing the same values in orthotopic liver transplantation (OLT). In OHPT, AKBR decreased in the anhepatic phase and recovered to the preoperative value just 1 h after reperfusion. On the other hand, in OLT, the recovery of AKBR took 3 h after reperfusion with a significant difference compared to OHPT (P less than 0.05). Plasma amino acid levels, especially alanine and total free plasma amino acids increased in the anhepatic phase and recovered within 1 h of reperfusion in OHPT. However, they did not recover until 3 h after reperfusion in OLT. This rapid recovery of hepatic metabolic function in OHPT should be attributed to the order of reperfusion in which the reconstruction of arterial blood flow precedes that of portal blood flow. This model is useful for assessing the best way by which the grafted liver can for assessing the best way by which the grafted liver can control the timing, order, rate, and volume of blood that should be released.

Amino Acids↗

Focal nodular hyperplasia of the liver.

We present herein two successfully treated cases of focal nodular hyperplasia (FNH) of the liver, a relatively rare disease. Case 1 was a 3 year old child in whom typical FNH developed in the left lateral segment of the liver, whereas Case 2 was a 22 year old man in whom characteristic findings were lacking on preoperative diagnostic imaging. Scintigraphy was not performed in either case, however, postoperative histological examination confirmed FNH. Thus, in patients with a hypervascular tumor and normal liver function, FNH should be strongly suspected and a series of scintigraphy proposed. Both cases showed a negative association with oral contraceptive intake but no other obvious etiology was suggested.

Adult↗

Antibody response to the immediate early protein of cytomegalovirus in renal transplant recipients.

The antibody response to the immediate early protein (IEP) of cytomegalovirus (CMV) was examined in seven renal transplant recipients during CMV reactivation and associated clinical abnormalities. Three cases with antibody increase to the IEP in the week after CMV isolation had no CMV-induced disease. The four patients without antibody increase exhibited laboratory abnormalities and three of them had renal dysfunction. In this small number of patients, the antibody response to the IEP in the week after isolation of CMV was associated with absence of abnormal clinical laboratory findings including renal function, and the prognosis was good for graft function in renal transplant recipients with CMV reactivation.

Antibodies, Viral↗

Uptake and metabolism of radiolabelled GM1-ganglioside in skin fibroblasts from controls and patients with GM1-gangliosidosis.

The uptake and metabolism of [3-3H-sphingosine]GM1-ganglioside was measured in cultured skin fibroblasts from controls and patients with infantile, juvenile and adult GM1-gangliosidosis. When dissolved in medium with phosphatidylserine, GM1-ganglioside was efficiently taken up by cultured skin fibroblasts and transferred into lysosomes. A linear increase in GM1-ganglioside endocytosis was shown with phosphatidylserine concentrations of up to 40 micrograms/ml. A pulse-chase study revealed that [3H]GM1-ganglioside was metabolized to GM2-ganglioside, GM3-ganglioside, ceramide dihexoside, ceramide monohexoside, ceramide and sphingosine. Sphingosine was recycled to sphingomyelin. In a 20-h pulse study, cell lines from patients with GM1-gangliosidosis of infantile, juvenile and adult types hydrolysed 2-5%, 20-44% and 54-58% of the total endocytosed GM1-ganglioside respectively. These values were lower than in control cells (64.17 +/- 5.43% (n = 10]. The hydrolysis rates of exogenous [3H]GM1-ganglioside in cultured fibroblasts from patients with various types of GM1-gangliosidosis closely reflected the clinical severity.

Cells, Cultured↗

The immunosuppressive effect of hepatocytes in rats--assessment by heart allograft survival and delayed-type-hypersensitivity reactions.

The immunosuppressive effect of hepatocytes was examined experimentally by heart allograft and delayed-type-hypersensitivity (DTH) reactions. The hepatocyte inoculation (1 X 10(7) of BDE (of the major histocompatibility complex haplotype RT1u), LEW (RT1l), and DA (RT1a) into the spleens of LEW rats significantly prolonged the survival of BDE heart allografts to 14.3 +/- 2.7 (mean +/- SD), 9.2 +/- 0.8, and 10.8 +/- 2.3 days respectively, compared with 6.7 +/- 0.8 days in controls (p less than 0.01). Moreover, the BDE hepatocytes had a significantly prolonged survival compared to the LEW (p less than 0.01) and DA (0.02 less than p less than 0.05) groups. BDE hepatocyte (donor specific) inoculation 4 and 7 days before priming with the spleen cells reduced DTH responses in the LEW rats to 44.6 +/- 4.8 per cent, and 74.2 +/- 8.0 per cent, respectively. DA hepatocyte inoculation (third party) 4 and 7 days prior to priming reduced DTH responses to 72.5 +/- 11.5 per cent, and 76.5 +/- 11.9 per cent, respectively. All DTH responses were significantly suppressed after hepatocyte inoculation compared to 100 per cent in the controls (p less than 0.01). Moreover, the inoculation of BDE hepatocytes (donor specific) 4 days prior to the priming significantly reduced DTH responses compared to the group primed 7 days before (p less than 0.01). From these results we concluded that hepatocytes produced not only non-specific but also donor specific immunosuppressive effects through T cell immune reaction. Moreover, donor specific immunosuppressive effects were induced at least 4 to 7 days after hepatocyte inoculation.

Animals↗

Evaluation of initial hepatic allograft function with changes of free plasma amino acids in canine orthotopic liver transplantation.

We investigated the correlation between amino acid level and hepatic graft function. Plasma amino acid levels were measured at three time periods during canine orthotopic liver transplantation. During the anhepatic phase, plasma amino acid levels rose except for tryptophan. Cystine and alanine (Ala) increased significantly to 210 +/- 28% (n = 20, mean +/- SEM) and 203 +/- 11% from preoperative values (100%), respectively. In animals successfully surviving without hepatic insufficiency after transplantation of fresh livers (n = 7), plasma amino acid levels were restored to preoperative values within 3 hr following reperfusion. On the other hand, in animals that died from hepatic insufficiency within 5 days after grafting of warm ischemically damaged livers (n = 8), plasma amino acids, especially Ala, phenylalanine, total free plasma amino acids, and aromatic amino acids progressively increased to 216 +/- 25, 274 +/- 36, 152 +/- 15, and 152 +/- 15% at 3 hr after reperfusion. These were significantly higher compared to those of the group of animals transplanted with fresh livers (P less than 0.01-0.05). Furthermore, higher values were found in those dogs transplanted with warm ischemically damaged livers surviving for shorter periods. Also in dogs that died from hepatic insufficiency within 8 hr after grafting of livers preserved for 24 hr (n = 5), amino acid levels were at high values at 3 hr. These results suggest that in animals having good graft function, plasma amino acid levels are restored to preoperative values by 3 hr after reperfusion. In other cases, primary nonfunction should be strongly suspected after liver transplantation.

Amino Acids↗

Induced microseizures in West syndrome.

Induced microseizures (IMS) were observed in a 5-month-old girl with symptomatic West syndrome. The seizures occurred following the suppression of infantile spasms with adrenocorticotropic hormone therapy and disappeared following the cessation of clonazepam administration. The ictal manifestations consisted of periods of irregular respiration, and respiratory arrest lasting for several seconds which often involved opening of the eyes and mild extension of the neck corresponding with the diffuse fast wave bursts in EEG activity observed during sleep. These seizures were thought to be equivalent to the IMS in Lennox-Gastaut syndrome, which have never been reported before in patients with West syndrome.

Adrenocorticotropic Hormone↗

[Facilitation and recovery of the H-reflex in children].

Facilitation and recovery of the H-reflex were studied in 63 children with cerebral palsy, and the results were compared with those obtained for 60 normal children. H waves were recorded from the gastrocnemius with surface electrodes, after applying paired stimulations to the tibial nerve in the midpopliteal crease. In normal children, both the facilitation and the recovery showed a tendency to decrease with their development, while those for children with cerebral palsy were more marked than normal children in all age groups. The present study indicated that the excitability of spinal alpha motoneurons and the subliminal fringe in the motoneuron pool might change due to the maturation of and the damage to the central nervous system in children. We consider that H-reflex examination provides useful information for the supraspinal control to the spinal mechanism to regulate muscle contraction in children as well as in adults.

Adolescent↗

Study of pathogenesis in twitcher mouse, an enzymatically authentic model of Krabbe's disease.

The twitcher mouse was investigated by examining in vivo synthesis of galactosylceramide (Galcer) and galactosylsphingosine (Galsph) in a sciatic nerve culture, and in vitro enzymic activities for synthesis of Galcer and Galsph in the spinal cord from normal and affected mice. For the in vivo study, the sciatic nerve was incubated for 24 h in medium containing [3H]galactose, or [3H]-sphingosine-labeled Galcer or Galsph. With [3H]galactose, reduced synthesis of Galcer was found as early as 1 week of age and synthesis decreased to about 15% of normal value at 4 weeks. Increased Galsph was detected after 7 days of feeding with galactose. In a study of [3H]sphingosine-labeled Galcer and Galsph feeding, Galcer did not induce Galsph synthesis in either normal or affected mice, and synthesis of Galcer from Galsph was found only in normal mice, suggesting that Galcer was synthesized from sphingosine after hydrolysis of Galsph. In vitro, the activities of UDP-galactose: ceramide galactosyltransferase and UDP-galactose: sphingosine galactosyltransferase were reduced to less than 50% of control after 2 weeks of age in affected mice. We conclude that (1) decreased Galcer was due to impaired synthesis of Galcer, (2) Galsph was synthesized from galactose and not from deacylation of Galcer, and (3) Galsph accumulation was due not to increased synthesis but to decreased hydrolysis.

Age Factors↗

Interaction of zonisamide with benzodiazepine and GABA receptors in rat brain.

The effects of zonisamide on [3H]flunitrazepam binding and [3H]muscimol binding were studied in Sprague-Dawley rat brain. Specific [3H]flunitrazepam bound was decreased to 64.6 +/- 5.6% (mean +/- SD, n = 5, p < 0.002) and 91.9 +/- 4.0% (p < 0.005) by the addition of 10(-3) M and 10(-4) M zonisamide, respectively. Scatchard plot analysis of [3H]flunitrazepam binding with 10(-3) M of zonisamide revealed an increased Kd value with no change in Bmax. No inhibitory effect of zonisamide was seen on the enhancement of specific [3H]flunitrazepam binding by GABA. As for the effects on GABA receptors, specific [3H]muscimol bound was decreased to 27.7 +/- 10.4% (mean +/- SD, n = 4, p < 0.005) and 68.3 +/- 3.7% (mean +/- SD, n = 4, p < 0.005) by the addition of 10(-3) M and 10(-4) M zonisamide, respectively. Since therapeutic serum level of zonisamide are around 10(-4) M, these results suggest that zonisamide neuropharmacologically interacts with the GABA/benzodiazepine receptor ionophore complex in a manner similar to phenytoin.

Animals↗

[3H]zonisamide binding in rat brain.

We previously reported that zonisamide inhibits both [3H]flunitrazepam and [3H]muscimol binding in rat brain. In the present study, [3H]zonisamide was found to bind in a saturable fashion to the crude synaptosomal fraction of whole rat brain. Linear regression analysis of the binding data in the Scatchard plot indicated a Kd of 90 nM, and a maximal binding capacity of 1.40 x 10(3) fmol/mg protein. Displacement studies revealed an inhibitory effect of clonazepam and an enhancement effect of GABA on specific [3H]zonisamide binding. These results suggest that specific [3H]zonisamide binding sites may have a tight correlationship with benzodiazepine receptors in rat brain.

Animals↗

[Perinatal brain injuries and subsequent epilepsy: a study on intraventricular hemorrhage in preterm infants and hypoxic-ischemic encephalopathy in full-term infants].

The clinical course of symptomatic epilepsy caused by intraventricular hemorrhage (IVH) in 7 preterm infants and hypoxic-ischemic encephalopathy (HIE) in 9 full-term infants were followed up for more than 2 years and 6 months. West syndrome was the first manifestation of epilepsy in 10 cases (IVH: 4, HIE: 6), and all 16 patients had severe neuropsychiatric deficits. Comparing with children without epilepsy, IVH grades III and IV, mechanical ventilation for more than 6 days and neonatal convulsions in the patients with IVH, and mechanical ventilation and neonatal convulsions in the patients with HIE, were significantly related to the risk of subsequent epilepsy. These findings suggest that the degree of brain injuries may be predictive of the development of epilepsy during infancy and early childhood in the patients with IVH or HIE.

Brain Ischemia↗

[Chronological change of EEG findings in a case of pyridoxine dependency seizures].

A patient of pyridoxine dependent seizures was reported. He was born at 34 weeks' gestation and weighted 2,760 g. Apgar scores were 6 and 9 at 1 and 5 minutes, respectively. He showed the first seizure 2 hours after his birth. Phenobarbital, phenytoin, sodium valproate, diazepam and clonazepam were not effective. Pyridoxal phosphate (50 mg) was given intravenously, resulting in suppression of convulsions. However, muscle tonus was severely depressed. In EEG, a discontinuous pattern was found in quiet and indeterminate sleep on the 2nd day of life. At 5th week multifocal spikes were found, and the discontinuous pattern persisted. Ictal discharges at 13th week showed generalized, continuous, irregular and high voltage slow waves with multifocal spikes. At 27th week of life, high voltage slow waves disappeared and multifocal spike discharges decreased. At 2 years and 10 months of age, the patient was suffering from athetotic cerebral palsy and severe mental retardation. Pyridoxal phosphate at the doses of 35-40 mg/kg/day had been administered. Irritability sometimes occurred and additional 50 mg of pyridoxal phosphate controlled this irritability effectively.

Administration, Oral↗

[Clinical study of imipenem/cilastatin sodium in children with severe infections].

Clinical studies of imipenem/cilastatin sodium (IPM/CS) were conducted in 40 pediatric patients. 29 out of the 40 patients were treated for infections and 11 for prophylaxis. The following results were obtained. 1. The response rate in 29 patients with infections was 79.3%. Among the 29 patients, 16 patients who presented with malignant diseases showed the response rate of 68.8%. The response rate was lower in patients with severe infections than in those with mild or moderate infections, and a lower response rate was associated with severe neutropenia. However, there were no differences in the response rates between patients who had previously been treated and those who had been untreated with other antibiotics. The response rate in 6 patients from whom causative organisms were isolated was 83.3% and that in the remaining 23 patients was 78.3%. 2. The response rate in 11 patients to whom IPM/CS was administered prophylactically was 63.6%. 3. As for side effects, a rash was observed in 1 patient and hematuria in another, and the abnormal laboratory test results observed were elevations of GOT and GPT in 1 patient. However, they were not clinically significant. From the above results, it appears that IPM/CS may be used as a drug of the first choice for the treatment of patients with severe infections in which the causative organisms are unknown, and for the prophylaxis of infection in patients with neutropenia.

Bacterial Infections↗