Biomedical subjects
Publications and source records attributed to Y Yamashiro.
In a patient with Shwachman syndrome, a high incidence of chromosome breakage was found. Chromosome studies done on three occasions on the patient's PHA-stimulated peripheral blood lymphocytes showed elevated frequencies of spontaneous chromosome aberrations compared with those in normal individuals. The patient's lymphocytes did not show increased sensitivity to mitomycin C.
An abnormal pancreatico-choledocho-ductal junction, in which free communication between the pancreatic duct and the common bile duct was present, was observed in 17 out of 120 cases (14.2%) of biliary tract carcinoma and in all of four cases of congenital biliary dilatation, but in noe of about 200 control patients without biliary tract disease. Outstanding findings in the pancreas, such as degeneration of the ductal epithelium and interlobular fibrosis, were found in 6 of 21 cases of abnormal junction. In an experimental study using 63 puppies given choledocho-pancreatic end-to-side ductal anastomosis, dilatation of the bile duct of varying degree occurred and mucosal hyperplasia of the biliary tract was observed in 12 of 25 anastomosed dogs for a duration of more than one month. Cell kinetics in biliary tract mucosa observed by the use of monoclonal antibody against bromodeoxyuridine (BrdU) was obviously elevated in dogs subject to long-term follow-up. As for pancreatic lesions, the incidence and histologic findings were similar to those of human studies, as follows: chronic pancreatitis in only a few animals, mild periductal parenchymatous change in 15 puppies and no significant change in 44 puppies. Therefore, an abnormal pancreatico-choledocho-ductal junction may be one of the significant factors producing biliary dilatation, biliary tract carcinoma and pancreatitis.
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Supplementation of lipid intake by infusion of solutions of essential fatty acid (EFA)-rich powder through Suruga II enterostomy was carried out for the treatment of EFA deficiency in nine children with postoperative congenital biliary atresia (CBA). Infusion of EFA-rich powder dissolved in excreted bile was effective in six patients except for a case who had a total bile acid concentration in the excreted bile that was less than critical micellar level. Administration of EFA-rich powder dissolved in a mixture of the patient's own bile and 1 to 2 mmol/L taurocholate (TC) solution corrected EFA deficiency in three children with total bile acid concentration lower than the critical level. Our results therefore show that infusion of EEA-rich lipid through Suruga II enterostomy after dissolving in the excreted bile is an effective treatment for EFA deficiency in postoperative patients with CBA, and that 1 to 2 mmol/L TC solution used as artificial bile facilitates lipid absorption in cases with total bile acid in the bile less than the critical micellar level.
The in-vitro interactions of four antimicrobial agents (piperacillin, dibekacin, minocycline, norfloxacin) and four antineoplastic agents (mitomycin C, bleomycin, doxorubicin, 5-fluorouracil) were examined by the chequerboard dilution method using 108 clinical isolates of four species of Gram-negative bacilli. Among the antimicrobial agents, piperacillin showed the greatest degree of synergism and norfloxacin the least. The frequency of synergism was essentially similar among the antineoplastic agents, although 5-fluorouracil was more frequently synergistic than other antineoplastic agents against Pseudomonas aeruginosa. Among the four species, synergism was most frequently shown against Proteus vulgaris and least against Escherichia coli. Antagonism was rarely seen.
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The antibacterial activity of 5-fluorouracil, an antineoplastic agent, was found to be enhanced by piperacillin, a beta-lactam antibiotic, resulting in a synergism. It was considered that the synergism was caused by an increase of 5-fluorouracil uptake into the bacterial cell. On the other hand, amount of piperacillin bound to penicillin binding protein (PBP) did not change when 5-fluorouracil was added. The morphological change of the cell was due to the 5-fluorouracil when synergism appeared between 5-fluorouracil and piperacillin.
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Serum and renal tissue concentrations of ceftizoxime (CZX) after intravenous dosing with 1 g were determined in 15 patients with renal disease. The highest serum concentration of CZX was 105 micrograms/ml 6 minutes after dosing and the lowest concentration was 10.5 micrograms/ml at 170 minutes. The highest renal tissue concentration was 155 micrograms/g and the lowest concentration was 7.46 micrograms/g. There were no correlation between the tissue concentrations and sampling time. Tissue to serum concentration ratios ranged from 0.28 to 5.73. These patients were divided into 3 groups; hydronephrosis, normal kidneys and renal atrophy according to pyelographic findings. Their renal tissue concentrations were compared with serum concentrations in each group. The tissue concentrations were lower than the serum concentrations in the first group, and were almost the same or higher in the other groups. CZX concentrations in the medulla and the cortex were determined in 5 patients; and were higher in the medulla in 4 of these patients. Urinary tract infection due to E. coli, K. pneumoniae, P. mirabilis, S. pyogenes or S. epidermidis was present in 5 of the 25 patients. Intravenous injection of 1 g of CZX provided therapeutically effective concentrations against these urinary tract infections.
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Clinical features of ten Japanese children with cerebrovascular Moyamoya disease are reported and non-Japanese paediatric cases of the disease are reviewed from the world literature. The most common initial manifestations were headache in four cases (40%), motor deficit and convulsion in three cases (30%). As their recurrent and/or residual symptoms, eight children (80%) developed motor deficit consisting of hemiplegia in five cases and paresis or weakness of the extremities in three cases, and four (40%) had headaches. The mode of presentation in our cases was similar to that of non-Japanese cases, in addition to a female preponderance. Electroencephalographic findings of prominent high voltage delta bursts following hyperventilation and slowness of returning to the normal pattern, seen in all hyperventilated cases, is one of the features. Of 15 carotid arteries visualised in ten patients, sites of occlusion or stenosis were seen between the bifurcation of the posterior communicating artery and that of the anterior cerebral artery or the middle cerebral artery in 13 arteries, with a vascular network in the basal ganglia. This study suggests that if hyperventilation procedures produce prominent high voltage delta bursts during electroencephalography in children with headache and/or motor deficit, cerebrovascular disease, especially Moyamoya disease, should be suspected.
A choledochopancreatic end-to-side ductal anastomosis was successfully performed in 40 puppies as an experimental animal model of choledochopancreatic elongated common channel disorders. Follow-up periods were up to 1 year after surgery. Fusiform dilatation was developed in all puppies. The dilatation was completed within 1 week after surgery and did not increase its size after that. Also, all puppies developed pancreatic juice reflux into the bile duct. As for the etiology of the dilatation of the bile duct, temporary stricture of anastomosis was a more important factor than the pancreatic juice reflux in our models. In the biliopancreatic juice, we found no significant change of bile acid analysis between the control and our operated puppies, but almost all pancreatic enzyme activities were elevated. Bile acid was considered to play an important role in the activation of pancreatic enzymes. Epithelial hyperplasia was the only significant pathological change in the bile duct wall. Definite chronic pancreatitis developed in one puppy 16 months after surgery and was considered to be caused by the reflux of bile into the pancreatic duct. The action of biliopancreatic juice to both the bile duct and to the pancreas was mild and chronic.
Exocrine pancreatic function was evaluated in 19 diabetic children on the basis of a pancreozymin-secretin test, a p-aminobenzoic acid (PABA) test, and a determination of fasting plasma trypsin and elastase-1 levels. In the pancreozymin-secretin test, the diabetics exhibited lower mean values in all the parameters measured, significant differences being seen in the volume of duodenal fluid and the output of bicarbonate and amylase. Compared to the controls, the diabetics also had lower levels in the PABA test and in the trypsin and elastase-1 measurements. No significant correlation was seen between exocrine pancreatic dysfunction and the duration of diabetes. However, the duration of diabetes in children who showed extremely low levels (below the mean +/- 2 SD for the control subjects) in the PABA test and low plasma trypsin and elastase-1 values was more than 1 year. This study revealed that diabetic children had reduced exocrine pancreatic function, some in an early stage of the disease. Therefore, the reduction may be due to a functional disturbance rather than to an anatomical loss of exocrine pancreatic tissue.
To investigate the mechanisms initiating pancreatic enzyme activation followed by the development of a choledochal cyst and/or pancreatitis under anomalous choledocho-pancreatic ductal junction (ACPDJ), choledocho-pancreatic end-to-side ductal anastomosis was successfully performed in 40 puppies as an experimental model of ACPDJ. As a result, reflux of pancreatic juice into the common bile duct readily and continuously occurred, and all pancreatic enzymes in bile obtained from the common bile duct were activated. Total bile acids increased about 2 months after surgery, and the ratio of taurodeoxycholic acid to total bile acids increased within the first months after surgery. Various degrees of common bile duct dilatation developed in all puppies within 7 to 10 days after the surgery, and no further dilatation occurred in the subsequent period. Histological change in the pancreatic duct was less prominent than that in the common bile duct, but histologically proved chronic pancreatitis was found in three of 23 sacrificed dogs, in which there was strong evidence of free and massive regurgitation of the bile-pancreatic juice mixture between the bile and the pancreatic duct systems. These findings in this experimental study constitute the first step to prove that ACPDJ, which is often found in patients with choledochal cyst, is an important etiologic factor not only for choledochal cyst but also for pancreatitis, and bile acids play an important role in the mechanism of pancreatic enzyme activation under the condition of ACPDJ.