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Biomedical subjects

N Hashimoto

Publications and source records attributed to N Hashimoto.

At least 775 records · Page 43Linked to original sources
PubMedDate not supplied

Differentiation of suprasellar nonneoplastic cysts from cystic neoplasms by Gd-DTPA MRI.

Magnetic resonance imaging in 9 cases of surgically confirmed nonneoplastic intra- and/or suprasellar cysts was analyzed and compared with that from 17 cases of craniopharyngioma and 12 of cystic pituitary adenoma. Signal intensity did not help in distinguishing nonneoplastic cysts from cystic neoplasms. No postcontrast (Gd-DTPA) cyst wall enhancement was observed among the nonneoplastic cysts, although all 6 craniopharyngiomas and 12 cystic pituitary adenomas that underwent postcontrast study did enhance. Three nonneoplastic cysts were surrounded by the pituitary gland, thus mimicking wall enhancement in the postcontrast studies. Rapid enhancement in the early postcontrast-administration phase (dynamic studies) helped avoid confusion between the normal pituitary tissue and cyst wall enhancement. Magnetic resonance studies with contrast enhancement play an essential role in differentiating nonneoplastic cysts from cystic neoplasms in the sella region.

Adenoma↗
PubMedDate not supplied

An animal model of cerebral aneurysms.

Cerebral aneurysms were induced experimentally in rats by ligating the common carotid artery on one side, making the animals hypertensive, and feeding them the lathyrogen beta-aminopropionitrile. On analysis of this experimental model, haemodynamic stress, hypertension and metabolic disorder of the connective tissue proved to be of primary importance as aetiological factors in the development of cerebral aneurysms. The experimentally induced cerebral aneurysms resemble those in man both in location and in microscopic structure; they can thus be regarded as a good model for the study of the pathogenesis of cerebral aneurysms. The initial changes leading to the formation of aneurysms occurred on the distal side of major artery branches adjacent to the apex, but distal to the intimal pad. It is proposed that degenerative changes in the internal elastic lamina and muscle cells of the media, caused by haemodynamic stress at vessel branches and intimal pads, are the basis for aneurysm formation.

Animals↗
PubMedDate not supplied

Analysis of secretion and expression of platelet-derived growth factor in cultured endothelial cells from stroke-prone spontaneously hypertensive rat.

1. We characterized the endothelial cell-derived growth factors of SHRSP and Wistar Kyoto rats (WKY), respectively and found that platelet-derived growth factor (PDGF)-B chain related growth factor constituted a major portion of the mitogenic activity of the conditioned media of endothelial cells from both animals. There were no remarkable qualitative differences between the endothelial cell-derived growth factors of SHRSP and WKY. 2. Northern analysis revealed that the expression of PDGF-B chain was 2-4-fold enhanced in cultured aortic endothelial cells of SHRSP. This enhanced expression of PDGF-B chain, which may be induced under chronic hypertensive conditions, is suggested to contribute to the increase in endothelial cell-derived growth factors reported in this animal.

3T3 Cells↗
PubMedDate not supplied

PCR amplification of Tetrahymena rDNA segments starting with individual cells.

To facilitate studies of rDNA molecular genetics in Tetrahymena thermophila, we attempted the detection of polymorphisms in the nontranscribed spacers (NTSs) using polymerase chain reaction (PCR), starting with minute amounts of DNA. The targeted polymorphic regions are 85% adenine-thymine (AT). We found conditions of efficient and specific in vitro amplification of targeted segments in the replication domain of the 5'NTS and in the subtelomeric segment of the 3'NTS. The identity of the amplified segments was confirmed by restriction enzyme digestion and DNA sequence analysis. Digestion of the template DNA at restriction sites upstream and downstream of the targeted region increased the efficiency of amplification, presumably because the targeted segments are in a palindromic molecule. Starting from total cell DNA corresponding to as little as 0.03 picogram (equivalent to the DNA content of 0.003 cells or about 30 rDNA molecules), we observed the amplified band after agarose gel electrophoresis and ethidium bromide staining. The yield indicated more than 10-billion-fold amplification. Amplification of the subtelomeric fragment yielded homogeneous product of minimum possible length even though the telomeric-specific primer can bind, at least initially, at a multiplicity of GGGGTT repeats. Amplified 5'NTS product also was detected in an ethidium-bromide-stained gel when PCR was started with a single cell.

Animals↗
PubMedDate not supplied

Great earthquakes and medical information systems, with special reference to telecommunications.

The Hanshin-Awaji earthquake in January 1995 caused the greatest number of deaths and injuries in Japan since World War II. Various weaknesses of modern information systems were exposed during and after the earthquake. The authors carried out a questionnaire survey to investigate the current state of hospital information and to examine the kinds of information needed immediately after an earthquake. The survey results show that information about the ability to admit new patients and the availability of medical supplies is necessary immediately after such a disaster. These results will be useful for planning countermeasures against this kind of disaster.

Communication↗
PubMedDate not supplied

Early changes of experimentally induced cerebral aneurysms in rats: scanning electron microscopic study.

To obtain information about the early changes of experimentally induced cerebral aneurysms in rats, the luminal surface of branching areas of their cerebral arteries was examined with a scanning electron microscope. At the branching sites of major cerebral arteries in the control animals, the intima just distal to the apex markedly protruded into the lumen forming a linear bank-like intimal pad. Along and distal to this pad, there was a shallow long groove (juxta-apical groove). Such grooves were much deeper and wider in experimental animals than those in the control rats. By studying various stages of early aneurysmal changes, cerebral aneurysms were proven to develop from such grooves. In deep juxta-apical grooves and small aneurysms, round regenerated endothelial cells with a large number of microvilli were diffusely present. Degenerated cells with balloons and craters were observed intermingled with such regenerated cells. Interendothelial gaps were also seen. The present study showed the complex structure of the apex of arterial bifurcation in rats, including bank-like intimal pads. Such complex structures of the branching sites were considered to be responsible for the initiation of cerebral aneurysms due to endothelial injury possibly caused by turbulent flow there.

Animals↗
PubMedDate not supplied

An autopsy case with clinically and molecular genetically diagnosed Huntington's disease with only minimal non-specific neuropathological findings.

An autopsy case with clinically and molecular genetically diagnosed Huntington's disease (HD) accompanied with minimal non-specific neuropathological features was reported. When the patient was 45 years old, he had faulty memory, mood swing, personality change and agitation. Neurological and psychiatric examinations revealed choreoathetoid movements in limbs and trunk, generalized hyperreflexia and mental deterioration. However, cerebellar ataxia and muscle rigidity were not disclosed. Neuroimaging study did not show a definite atrophy of heads of caudate nuclei. Neuroacanthocytosis and Wilson's disease were ruled out by the peripheral blood examination and serum Cu and ceruloplasmin examination. At the age of 55 he died of pneumonia. Post-mortem examination revealed minimal non-specific neuropathological features for HD (Vonsattel's grade 0), that is, no visible fibrillary gliosis in the striatum, and few neuronal loss and only proliferation of astrocytes (astrocytosis) in the striatum. Molecular-genetic study the patient's brain tissues and his youngest son's blood was performed. These studies revealed 40 CAG repeats in the patient, 56 CAG repeats in his youngest son. These results suggest they may be HD. Vonsattel et al. [ 1998] insist that grade 0 comprises 1% of all HD brains, and grade 1 comprises 4% of all HD brains. But we could not find any reports in which the clinical and neuropathological features were described in detail on the cases with clinically and molecular genetically diagnosed HD without specific pathological findings. Therefore, we present in detail the clinical and neuropathological features of such case.

Brain↗
PubMedDate not supplied

In vivo evaluation of long-term patency of pancreaticoenterostomy after Whipple operation.

BACKGROUND/AIMS: The aim of this study was to examine the long-term patency of pancreaticoenterostomy in vivo. METHODOLOGY: Evaluation of the patency of the pancreaticoenterostomy was conducted in 12 patients who had undergone the Whipple procedure. After intravenous infusion of secretin (1 microgram/kg), the diameter of the pancreatic duct was taken at 1, 3, 5, 15, 20 and 25 min by means of ultrasonography. We estimated the degree of anastomotic stricture by the maximal dilatation ratio [MDR: Maximal value (Dmax)/basal value (D0)]. The patients underwent pancreatic exocrine function tests before and 1-2 years after surgery. RESULTS: Maximal ductal dilatation was noted from 3 min of 15 min after secretin infusion, thereafter ductal diameter gradually diminished and returned to its basal value at 25 min. Maximal dilatation ratio ranged from 1.3-2.5, 1.7 +/- 0.12. There was a good negative relationship between the maximal dilatation ratio and pancreatic exocrine function. Based on the result of chi 2 analysis, we judged anastomotic stricture to be present in 2 patients with maximal dilatation ratio above 2.0. In these 2 patients, preoperative pancreatic exocrine function recoveries were 69 and 48%, while postoperative pancreatic exocrine function recoveries were 13.8 and 18%, respectively. In the other 10 patients, there was no difference between preoperative and postoperative value of pancreatic exocrine function. CONCLUSIONS: The present method permits safe and non-invasive evaluation of the patency of pancreaticoenterostomy.

4-Aminobenzoic Acid↗
PubMedDate not supplied

Hepatobiliary scintigraphy after biliary reconstruction--a comparative study on Roux-Y and ESCD.

BACKGROUND/AIMS: Reconstruction of extrahepatic biliary tract with benign lesion still has some unsettled problems, such as postoperative cholangitis. This study was conducted to compare bile through the remnant alimentary tract in patients undergoing end-to-side choledochoduodenostomy, and those undergoing Roux-Y choledochojejunostomy, using hepatobiliary scintigraphy. METHODOLOGY: Five normal human volunteers and 13 patients underwent end-to-side choledochoduodenostomy (n = 5), Roux-Y choledochojejunostomy (n = 8), using hepatobiliary scintigraphy. RESULTS: Postoperative acute cholangitis developed in 1 patient (12%) with Roux-Y choledochojejunostomy and none with end-to-side choledochoduodenostomy. Hepatobiliary scintigraphy showed prominent stasis of 99mTc in the proximal jejunum loop of the patients who underwent the Roux-Y choledochojejunostomy procedure, which was not found in the upper jejunum of the patients with end-to-side choledochoduodenostomy. The time taken before visualization of 99mTC at the upper jejunum in the patient who underwent Roux-Y choledochojejunostomy (66.5 +/- 5 min) was significantly longer than that in the healthy controls (40 +/- 5 min). On the other hand, the time taken before visualization of 99mTc at the upper jejunum in end-to-side choledochoduodenostomy (35 +/- 5 min) was similar to that of healthy controls. CONCLUSIONS: This data suggested that end-to-side choledochoduodenostomy procedure for reconstructing the extrahepatic biliary tract was more physiological with less postoperative complication than Roux-Y choledochojejunostomy procedure.

Anastomosis, Roux-en-Y↗
PubMedDate not supplied

IGF-1 stimulates mucosal growth in ileal Thiry-Vella fistulas.

BACKGROUND/AIMS: We determined whether the trophic effects of IGF-1 (Insulin-like growth factor-1) on the small bowel mucosa are mediated by either nonluminal factors or endogenous luminal secretion. The gut hormone IGF-1 stimulates growth of small bowel mucosa. The mechanisms responsible for this trophic effect are not known. METHODOLOGY: Rats underwent construction of a Thiry-Vella fistula of ileum. On postoperative day 10, the two groups were subdivided to receive either saline (control) or IGF-1. After 7 days, rats were killed and the Thiry-Vella fistula was removed. The mucosa was scraped and weighed, and protein content and alkaline phosphatase activity was determined. RESULTS: IGF-1 significantly increased mucosal weight and alkaline phosphatase activity and protein content of ileal Thiry-Vella fistula compared with the control rats. CONCLUSIONS: IGF-1 mediated stimulation of small bowel mucosal growth is mediated by factors that are independent of luminal contents and pancreaticobiliary secretion. IGF-1 may prove to be an important enterotrophic factor for gut mucosal proliferation.

Alkaline Phosphatase↗
PubMedDate not supplied

Analysis of postoperative pancreatitis in DSRS with SPD.

BACKGROUND/AIMS: Distal splenorenal shunt with splenopancreatic disconnection (DSRS + SPD) evolved to prevent the development of a pancreatic siphon, to improve maintenance as well as quality of portal perfusion and to achieve better long-term survival. We report several cases of postoperative pancreatitis in DSRS + SPD. Recently, oxygen-derived free radicals have been reported to play an important role in pathogenesis of acute pancreatitis. METHODOLOGY: In this study, ten cases of DSRS + SPD were examined intraoperatively. The local changes in oxygen-derived free radicals were obtained by measuring lipid peroxide and an endogenous scavenger (SOD) in the development of DSRS + SPD-induced pancreatitis. RESULTS: Lipid peroxide activity as the offense system was not changed before or after SPD. However, SOD activity as a defense system was significantly lowered after SPD compared to before SPD. CONCLUSIONS: These results indicate that an imbalance of both systems might be the cause of postoperative pancreatitis.

Acute Disease↗
PubMedDate not supplied

[RNA-interference, induced by transient and continuous expression of hairpin RNA in cells from Drosophila and mammals].

RNA interference (RNAi) may be induced by a plasmid with an inverted repeat (IR) sequence directing transcription of hairpin-type double-stranded RNA (dsRNA). This study examines the effects of changing various parameters of IR constructs on Drosophila and mammalian RNAi, using the dual luciferase system, RNAi activity was found to vary depending on IR length ass well as the length and sequence of the internal loop separating sense and antisense sequences. Both transient and stable RNAi occurred in Drosophila cultured cells. Although transient DNA-mediated RNAi was noted in most mammalian cells, no mammalian cells stably possessing IR sequences and hence RNAi activity could be obtained. In Drosophila, DNA-mediated RNAi was considerably weaker than long-dsRNA-mediated RNAi. The cytological data indicated that this was most probably caused by abortive processing of hairpin RNA produced within cells. DNA-mediated RNAi was examined at the level of Drosophila individuals using extramacrochaetae as a model gene, and the presence of an intron sequence in the single-stranded loop region was shown to be essential for effective RNAi.

Animals↗
PubMedDate not supplied

Cerebellar glioblastoma genetically defined as a secondary one.

We report here the case of a 29-year-old woman with cerebellar glioblastma. In the present case, tumor lesions were observed in each cerebellar hemisphere. The left-side lesion was diagnosed as glioblastoma, and the right-side lesion as malignant astrocytoma by histopathology. Immunohistochemistry revealed that the tumor cells of the left-side lesion was positive for p53, whereas epidermal growth factor receptors (EGFR) were negative in tumor cells from both sides. Genetic alterations were investigated using a genome DNA microarray (GenoSensor Array 300), which has led us to define this tumor as a secondary glioblastoma. The clinical presentation and genetic findings of this relatively rare entity are discussed.

Adult↗
PubMedDate not supplied

A huge gastric leiomyosarcoma diagnosed preoperatively through diagnostic imaging.

The authors were able to diagnose a huge gastric leiomyosarcoma prior to surgery using various diagnostic imaging techniques. The patient was a 68-year-old woman who presented with a large gas-filled mass the size of a child's head in the center of her abdomen. Based on characteristic findings from a gastric barium study, CT, MRI, and angiography, the patient was diagnosed as having a gastric leiomyosarcoma displaying extramural growth. Upon operation an extramural tumor (20 x 19 x 12 cm) originating from the gastric antrum was confirmed.

Aged↗
PubMedDate not supplied

Shedding and transmission of Chlamydia psittaci in experimentally infected chickens.

Three avian strains of Chlamydia psittaci were inoculated into 8-day-old chickens by the intra-air-sac or peroral route. Uninoculated chickens were kept as cagemates with the air-sac-inoculated birds. The air-sac-inoculated birds had systemic infection, and chlamydiae were detected frequently in the livers, lungs, jejunums, and colo-rectums at high titers (greater than or equal to 10(5.0) ELD50). All three groups of birds had intermittent and persistent shedding of chlamydiae into feces during the 28-day observation period. In the cagemates, organisms were detected first in the colo-rectum 3 days postexposure and later in the liver, but not in the lung. Limited infection was seen particularly in the colo-rectum of the cagemates and perorally inoculated birds. Antibody response was markedly higher in the air-sac-inoculated chickens than in their cagemates and the perorally inoculated birds. These findings suggest that the colorectum is an important target organ for C. psittaci infection in chickens and that it may be the main site from which the organisms are shed into feces of chickens.

Air Sacs↗