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Biomedical subjects

K Kaneko

Publications and source records attributed to K Kaneko.

At least 199 records · Page 11Linked to original sources
PubMed1999

Embryogenesis of pancreaticobiliary maljunction inferred from development of duodenal atresia.

The embryogenesis of pancreaticobiliary maljunction is inferred from the embryogenesis of duodenal atresia. The epithelial cells of the duodenum begin to proliferate and completely plug the lumen, but a process of vacuolation recanalizes the duodenum. Recanalization of the common duct frequently appears with two lumina and openings into the duodenum with two orifices. These two major canals create a narrow segment of the duodenum and this narrow zone is the area in the duodenum that is most prone to faulty recanalization and atresia formation. A bifid biliary system inserts at blind upper and lower pouches of the duodenum, and the common bile duct inserts in a Y fashion. The common bile duct inserts at the stenotic segment, and the end result is a T-shaped formation in patients with duodenal stenosis. During the development of the bile duct, abnormal fusion may occur between the bile duct and branches of the right ventral pancreatic duct. The site in the bile duct where a branch of the pancreatic duct joins is likely to develop atresia due to disturbance of the recanalization process, as seen in duodenal atresia. Severe impairment of vacuolation causes divided atretic bile duct at the site where the pancreatic duct inserts in a Y-fashion into the upper and lower bile duct. Moderate impairment of vacuolation causes a stenosis at the site where the pancreatic duct inserts in a T-shape, with a moderate dilatation of the bile duct.

Choledochal Cyst↗
PubMed1999

Ventral pancreatitis defined on MRI.

Ventral pancreatitis, pancreatitis localized in the embryologic ventral pancreas, is rare. To date, only three well documented reports of ventral pancreatitis have been reported in the English-language literature. All three were associated with pancreas divisum. This report presents a patient suspected to have ventral pancreatitis on endoscopic retrograde cholangiopancreatography, confirmed by magnetic resonance imaging.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1999

Changes in fecal fat excretion from allo-intestine transplanted rats after discontinuance of immunosuppressive agents.

We have previously shown in a rat model of segmental small bowel transplantation, that an ileal graft was more favorable for lipid absorption than a jejunal graft. In the present study, we investigated changes in the lipid absorption of allo-ileal grafts after the withdrawal of an immunosuppressant (methyldeoxyspergualin; given for 1 or 2 weeks at 2.5mg/kg per day) and compared the findings with the results of histological examinations. Heterotopic segmental small bowel transplantation (SBT) was performed using cuff anastomoses in the inbred rat strain combination DA (RT1a) and LEW (RT1). Orthotopic SBT was performed as reconstruction SBT. Reconstruction after resection of the original intestinal tract of the recipient was performed on the seventh day after heterotopic segmental ileal grafting. For the histological evaluation of graft rejection, we performed biopsies in the heterotopic model and autopsies in the orthotopic model. Fecal fat excretion from the orthotopically reconstructed recipients was measured by Folch's method. One- and 2-week use of methyldeoxyspergualin allowed the heterotopic allografts to remain intact histologically for 16.8+/-5.6 and 25.3+/-3.3 (mean+/-SD) days, respectively, whereas the grafts were rejected at 7.3+/-1.1 days when the immunosuppressive drug was not used. All the recipients in the orthotopic group had died by 19 days after reconstruction. After discontinuance of the immunosuppressive agent, fat excretion in feces in the surviving orthotopic grafted rats had increased markedly prior to histologically assessed heterotopic graft rejection. Evaluation of fecal lipid excretion may be a useful parameter for detecting graft rejection in rats.

Animals↗
PubMed1999

Operative management of displaced fractures of the sacrum.

Displaced fractures of the sacrum are often associated with mechanical instability and neurologic deficits that cause late musculoskeletal problems and pain. We describe the radiologic and neurologic characteristics of 12 displaced fractures of the sacrum, (in 5 men and 7 women; age at injury, 17-61 years) as well as the management and results. Seven patients had unilateral longitudinal fractures (ULF), and 5 had bilateral longitudinal fractures (BLF) with a transverse fracture. All patients had mechanical instability (rotational and/or vertical). Seven (58%) had neurologic deficits. ULFs were stabilized with iliosacral screws. BLFs were stabilized with transiliac screws (for the longitudinal fractures), and with plates (for the transverse fractures). If neurologic deficits were present, a laminectomy was performed to explore and decompress nerve roots. The duration of follow-up ranged from 23 to 82 months (mean, 47 months). Eleven patients had no pain. Ten of the 12 patients were able to walk without any aids, while 2 patients needed foot apparatuses to walk. All patients showed union of the sacral fracture and a stable pelvis. Two patients did not recover neurologically; 1 patient with ULF had undergone late decompression for chronic radiculopathy and the other, with BLF, had had complete paralysis pre-operatively. Five patients with incomplete paralysis recovered both sensory and motor function. If a patient with a sacral fracture has instability, operative treatment with anatomical reduction is preferred.

Adolescent↗
PubMed1999

Simultaneous determination of RRR- and SRR-alpha-tocopherols and their quinones in rat plasma and tissues by using chiral high-performance liquid chromatography.

We established a method to simultaneously determine RRR- and SRR-alpha-tocopherol (alpha-Toc) and their quinones in biological samples by chiral-phase high-performance liquid chromatography (HPLC). Alpha-Toc had a shorter retention time than alpha-tocopherylquinones (alpha-TQ), and 2-ambo-alpha-Toc was completely separated into two peaks; the first peak was RRR-alpha-Toc and the second SRR-isomer by chiral HPLC connected Chiralcel OD-H column and Sumichiral OA4100 column. In contrast, of the two peaks of alpha-TQ, the first was the SRR-isomer. We also investigated differences in the distribution of RRR- and SRR-alpha-TQ in rat tissues after oral administration of 2-ambo-alpha-Toc by the above HPLC method. Rats deficient in vitamin E were divided into two groups, control and experimental, and tissues were collected at 3, 6, and 24 h after oral 2-ambo-alpha-Toc administration. The concentrations of RRR- and SRR-alpha-Toc and their quinones in plasma and each tissue were determined. The concentration of SRR-alpha-TQ in plasma and adrenal glands was not significantly different from RRR-alpha-TQ. However, the concentration of SRR-alpha-TQ in liver up to 6 h after oral administration was higher than that of RRR-alpha-TQ, and SRR- and RRR-alpha-TQ levels were similar at 24 h after oral administration. Therefore, we may assume that the formation of alpha-TQ in vivo was not different between RRR- and SRR-isomer and that it was not affected by the presence of alpha-Toc stereoisomers.

Animals↗
PubMed1999

Inhibition of experimental bone resorption and osteoclast formation and survival by 2-aminoethanesulphonic acid.

It is known that bone resorption is mediated by osteoclasts, and lipopolysaccharide (LPS) and inflammatory mediators such as interleukin-1 (IL-1) and prostaglandin E2 (PGE2) induce osteoclast differentiation from haemopoietic cells, 2-aminoethanesulphonic acid, which is known as taurine, is an important nutrient and is added to most synthetic human infant milk formulas. In this study, it was found that 2-aminoethanesulphonic acid inhibits the stimulation of bone resorption mediated by LPS of the periodontopathic microorganism Actinobacillus actinomycetemcomitans Y4 in organ cultures of newborn mouse calvaria. The effect of 2-aminoethanesulphonic acid on the development and survival of osteoclast-like multinucleated cells produced in a mouse bone-marrow culture system was also examined. 2-aminoethanesulphonic acid (100 microg/ml) suppressed the formation of these osteoclast-like cells in the presence of LPS of A. actinomycetemcomitans Y4, IL-1alpha or PGE2 in mouse marrow cultures. On the other hand, 2-aminoethanesulphonic acid did not inhibit 1alpha, 25-dihydroxyvitamin D3-mediated osteoclast differentiation. Although IL-1alpha elongated the survival of the osteoclast-like cells, 2-aminoethanesulphonic acid blocked the supportive effect of IL-1alpha on osteoclast survival. 2-aminoethanesulphonic acid showed no effect on the growth of mouse osteoblasts. Finally, it was found that 2-aminoethanesulphonic acid inhibited alveolar bone resorption in experimental periodontitis in hamsters. These results suggest that 2-aminoethanesulphonic acid is an effective agent in preventing inflammatory bone resorption in periodontal diseases.

Aggregatibacter actinomycetemcomitans↗
PubMed1999

Gastric duplication communicating with the left hepatic duct: a rare case of recurrent hemobilia in a child.

Gastric duplication is a rare anomaly, usually manifested as an abdominal mass or gastric outlet obstruction mimicking congenital hypertrophic pyloric stenosis during the first year of life. Occasionally, it communicates with the pancreatic duct and causes pancreatitis. However, communication with the intrahepatic bile duct has not been described. The authors report a rare case of gastric duplication that communicated with the left hepatic duct and caused recurrent hemobilia in a 2-year-old girl. Left hepatectomy and excision of the duplication were curative.

Bile Ducts, Extrahepatic↗
PubMed1999

Morphological investigation of the enteric nervous system in Hirschsprung's disease and hypoganglionosis using whole-mount colon preparation.

BACKGROUND/PURPOSE: A suction rectal mucosal biopsy with positive staining for acetylcholinesterase is a useful test for diagnosis of Hirschsprung's disease (HD). However, hypoganglionosis has not been diagnosed by a rectal mucosal biopsy. The authors morphologically examined the enteric nervous systems in HD and hypoganglionosis patients using whole-mount preparations. METHODS: Six HD patients, two hypoganglionosis patients, and 10 with normally innervated colons were examined. Colonic specimens were incubated with the primary antibodies against protein gene product 9.5 (PGP 9.5) mixed with S-100b protein, tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP), substance P (SP), and neurofilament protein 200 kDa (NFH). They were observed by histochemical technique using light-microscopy in whole-mount preparations. RESULTS: The aganglionic distal colon had thick nerve strands stained with PGP 9.5 mixed with S100 or NFH located in the layer between the longitudinal muscle and the circular one, and the submucosal layer. The nerve strands in the myenteric layer contained few CGRP- and SP-positive fibers and ran along the long axis of the intestine. Ganglion cells appeared along with those thick nerve strands in the transitional zone of HD. In hypoganglionosis, we found small myenteric ganglia with no thick nerve strands. CONCLUSIONS: The enteric nervous system in oligoganglionic segments of HD morphologically differed from the one in hypoganglionosis. A suction rectal mucosal biopsy would be of no use in the diagnosis of hypoganglionosis.

Child, Preschool↗
PubMed1999

Acute respiratory failure associated with intrathoracic masses in neonates.

BACKGROUND: Intrathoracic masses are uncommon in children. Occasionally, they present with acute respiratory failure in the neonatal period. Although emergency resection usually is the treatment of choice, other modalities are sometimes necessary to stabilize the patient. METHODS: Seven neonates with intrathoracic masses were treated. Five had congenital cystic adenomatoid malformations (CCAM), 1 had a mediastinal teratoma, and 1 had a pneumatocele. These cases were reviewed retrospectively. RESULTS: Four of the 7 infants had respiratory failure in the neonatal period. A patient with a large mediastinal teratoma and 1 with a CCAM that increased rapidly after presentation underwent emergency operation, relieving respiratory distress. The other 2 large CCAMs presented with severe respiratory distress immediately after birth because of pulmonary hypoplasia. One neonate with a Stocker-I CCAM died after emergency resection. One more recent patient with a Stocker-III CCAM survived after successful treatment with delayed resection, performed 3 days after birth. Nitric oxide (NO), and extracorporeal membrane oxygenation (ECMO) were instituted as supportive care because of profound persistent fetal circulation (PFC). CONCLUSIONS: Acute respiratory failure associated with intrathoracic masses in neonates may be managed in 1 of 2 ways. A small mass that increases rapidly should be resected soon after presentation. In neonates with large masses with associated PFC, surgery can be delayed until the patient is stable. ECMO, NO, and high-frequency oscillation (HFO) can be used aggressively for stabilizing such neonates.

Extracorporeal Membrane Oxygenation↗
PubMed1999

In vivo imaging of spontaneous ultraweak photon emission from a rat's brain correlated with cerebral energy metabolism and oxidative stress.

Living cells spontaneously emit ultraweak light during the process of metabolic reactions associated with the physiological state. The first demonstration of two-dimensional in vivo imaging of ultraweak photon emission from a rat's brain, using a highly sensitive photon counting apparatus, is reported in this paper. It was found that the emission intensity correlates with the electroencephalographic activity that was measured on the cortical surface and this intensity is associated with the cerebral blood flow and hyperoxia. To clarify the mechanism of photon emission, intensity changes from whole brain slices were examined under various conditions. The removal of glucose from the incubation medium suppressed the photon emission, and adding 50 mM potassium ions led to temporal enhancement of emission and subsequent depression. Rotenone (20 microM), an inhibitor of the mitochondrial electron transport chain, increased photon emission, indicating electron leakage from the respiratory chain. These results suggest that the photon emission from the brain slices originates from the energy metabolism of the inner mitochondrial respiratory chain through the production of reactive oxygen. Imaging of ultraweak photon emission from a brain constitutes a novel method, with the potential to extract pathophysiological information associated with neural metabolism and oxidative dysfunction of the neural cells.

Animals↗
PubMed1999

Insulin inhibits glucagon secretion by the activation of PI3-kinase in In-R1-G9 cells.

Intracellular mechanisms through which insulin inhibits glucagon secretion remain to be elucidated in glucagon secreting cells. In this study, we confirmed that, in In-R1-G9 cells, a pancreatic alpha cell line, insulin stimulated phosphorylation of insulin receptor substrate-1 (IRS-1) and activated phosphatidylinositol 3-kinase (PI3-kinase). We further studied, using wortmannin, an inhibitor of PI3-kinase, whether the inhibitory effect of insulin on glucagon secretion was mediated through PI3-kinase pathway in these cells. In static incubation studies, insulin significantly inhibited glucagon secretion at 2, 6 and 12 h, which was completely abolished by pretreatment with wortmannin. In perifusion studies, insulin significantly suppressed glucagon secretion after 10 min, which was also blocked by wortmannin. Insulin also reduced glucagon mRNA at 6 and 12 h but not at 2 h. Wortmannin also abolished insulin-induced reduction of glucagon mRNA. Insulin increased the amount of 85 kDa subunit of PI3-kinase in plasma membrane fraction (PM), with a reciprocal decrease of the kinase in cytosol fraction (CY). Insulin also increased PI3-kinase activity in PM, but not in CY. Our results suggest that insulin suppressed glucagon secretion by inhibiting glucagon release and gene expression. Both actions were mediated by activation of PI3-kinase. Recruitment and activation of PI3-kinase in plasma membrane might be relevant at least in part to insulin-induced inhibition of glucagon release.

Androstadienes↗
PubMed1999

Successful treatment of Kimura's disease with cyclosporine.

We report the case of a 29-year-old Japanese woman presenting with recurring Kimura's disease. We began treatment with cyclosporine within 7 days, the nodular lesion had almost cleared. The cyclosporine dose was then gradually reduced and discontinued after 6 months. The patient was reassessed 18 months after the cessation of treatment and there was no evidence of recurrence of the disease. We speculate that the effects of cyclosporine on T helper-2 cells improves Kimura's disease.

Adult↗
PubMed1999

Thoracoscopic surgery and pleurodesis for pleuroperitoneal communication in patients on continuous ambulatory peritoneal dialysis.

Two patients on continuous ambulatory peritoneal dialysis (CAPD) developed right massive hydrothorax and were diagnosed as having pleuroperitoneal communication. Thoracoscopic surgery and pleurodesis were performed. It showed that one was caused by multiple flaws in the diaphragm and that the other was attributable to multiple blebs in the diaphragmatic dome. After the procedure, both of them had no recurrence of hydrothorax and underwent CAPD safely. We recommend thoracoscopic surgery and pleurodesis as the first choice of therapeutic methods for pleuroperitoneal communication.

Endoscopy↗
PubMed1999

Cochlear implant in patients with residual hearing.

OBJECTIVE: The postoperative speech perception abilities of severely hearing-impaired patients with multi-channel cochlear implant were compared with preoperative speech perception performance with conventional hearing aids. METHODS: Cochlear implantation was performed in six severely to profoundly hearing-impaired patients. They had unaided pure-tone thresholds of 70-100-dB HL and aided thresholds of 35-90-dB HL in the better ear, but were not able to perceive speech sounds well with hearing aids. RESULTS: Postoperatively, all the patients had significantly improved speech perception performance, exceeded the average skills of profoundly deaf cochlear implant users, and were able to communicate without writing. CONCLUSION: These results imply that cochlear implant may be indicated for severely to profoundly deaf subjects, if they receive little or no benefit from conventional hearing aids.

Adult↗
PubMed1999

Changes of liver-enriched nuclear transcription factors for albumin gene in starvation in rats.

The regulatory mechanism of albumin gene transcription was examined using male Donryu rats (7 wk old) starved for 1 or 3 d. At the designated times, the rats were sacrificed to harvest the liver and to measure the serum albumin level. Neither the serum albumin nor the albumin messenger RNA (mRNA) level showed a significant change for these starvation periods. Among nuclear factors binding to the D site of albumin gene promoter, the CCAAT/enhancer binding protein alpha (C/EBP alpha) mRNA level showed a decrease and the D site binding protein (DBP) mRNA level tended to decrease after 3 d of starvation. In contrast, the C/EBP beta mRNA level showed a significant increase at day 1. As a B site binding nuclear factor, the hepatocyte nuclear factor 1 (HNF-1) mRNA level significantly increased at day 1. Gel mobility-shift analysis combined with Western immunoblotting confirmed the presence of D site binding proteins composed of DBP and C/EBP alpha and beta in both groups subjected to oral feeding and to 3-d starvation, though quantitative analysis could not be done. In conclusion, the nuclear transcription factors binding to the albumin gene promoter undergo regulatory changes during 3 d of starvation, whereas there is no significant decrease in the albumin mRNA level.

Albumins↗
PubMed1999

Weight and shape concerns and dieting behaviours among pre-adolescents and adolescents in Japan.

The attitudes towards body weight and shape, desire for thinness and dieting behaviours were investigated in pre-adolescent and adolescent girls and boys (547 elementary school students, 615 junior high school students, and 470 senior high school students) aged 10-17 years in Osaka Prefecture, Japan, by a self-report questionnaire. Forty-eight per cent of 10-year-old females and 84% of 17-year-old females categorized themselves as 'fat' or 'too fat'. The fear of weight gain and desire for thinness was reported in 35% and 51% of 10-year-old girls, respectively, and increased progressively with ageing to 79% and 87% of 17-year-old girls. In contrast, these were reported by 20-30% of boys in the corresponding age groups. Some practices to be slim were found in 22% of the 10-year-old girls, and increased to 37% among the 17-year-old girls, whereas they were found in around 20% of the boys at each age. The practices to be slim were found in 32% of the girls who were 85-90% of the standard body weight (SBW) and in 14% of the girls less than 85% of the SBW. These results suggest that significant concerns about weight and shape and dieting behaviours are present in young Japanese girls and increase progressively with age. These results are compatible with those in Western society.

Adolescent↗