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Biomedical subjects

H Endoh

Publications and source records attributed to H Endoh.

At least 73 records · Page 4Linked to original sources
PubMed1995

Scanning electron microscopic observation of pancreatic ducts in WBN/Kob rats.

To elucidate changes of pancreatic ducts in chronic pancreatitis, we observed pancreatic tissues with light microscopy and scanning electron microscopy, and corrosion casts of pancreatic ducts with scanning electron microscopy, in male WBN/Kob rats, considered a spontaneously occurring chronic pancreatitis model. At 3 months of age, hemorrhage and increased fibrosis were found in part of the pancreatic tail. After 3 months of age, pancreatic ductal lumina exhibited a winding form and inner surfaces showed long cilia and crater-like depressions. Fibrous tissues gradually extended into exocrine tissues and islets after 6 months of age. Most pancreatic ductal lumina developed a helical form with many deep depression at 14 months of age. It is suggested that increased pancreatic ductal pressure causes these findings.

Animals↗
PubMed1994

Hairpin and dimer structures of linear plasmid-like DNAs in mitochondria of Paramecium caudatum.

The molecular structure of plasmid-like DNAs (designated type-II) which were isolated from mitochondria in the ciliated protozoan Paramecium caudatum was characterized. These type-II DNAs are always detected as a set of four kinds with sizes of 8.2, 4.1, 2.8 and 1.4 kb. The DNAs of 8.2 and 2.8 kb exist as dimers consisting of 4.1- and 1.4-kb monomer molecules, respectively. Electron microscopic observations indicated configurations of a hairpin structure that had a protruding end of single-stranded DNA in one terminus and a loop in the other terminus. The monomers stick together with base-pairing in opposite directions at the protruding end to form the dimers, suggesting the presence of inverted repeats. These unusual dimers may have a role in replication of the DNAs in which the monomers can serve as a primer for each other.

Animals↗
PubMed1994

Left ventricular contractile state in preterm infants: relation between wall stress and velocity of circumferential fiber shortening.

Fetal and newborn lambs' hearts have limited capacity to adapt to increased afterload. In human preterm infants, however, this limited left ventricular pump function has not been investigated. To determine the normal left ventricular resting contractile state in preterm infants, we studied the relation of end-systolic wall stress to the rate-corrected velocity of circumferential fiber shortening (VCF) in 11 preterm infants of gestational ages 28 to 36 weeks. We performed the first (7 to 14 days of postnatal age) and the second (29 to 39 days of postnatal age) examinations. There was a significant inverse linear correlation between wall stress and VCF in the first and the second examinations (r = -0.616 and r = -0.715, respectively). Both regression lines had slopes that were steeper than those previously reported for older age groups. The preterm infants had high VCF values (mean 1.05 and 1.09 cir/sec, respectively) and low-wall stress values (mean 36.0 and 36.9 gm/cm2, respectively) in the first and the second examinations. We therefore suggest that the preterm infants have a high resting contractile state, but left ventricular performance may deteriorate in the face of increased afterload.

Analysis of Variance↗
PubMed1994

Possible involvement of central cholinergic system in ameliorating effects of indeloxazine, a cerebral activator, on disturbance of learning behavior in rats.

Effects of indeloxazine, a cerebral activator, on passive avoidance learning by disruption of cholinergic transmission were studied in rats. The shortened latency was prolonged when indeloxazine was administered before training in rats subjected to scopolamine-injection, ethylcholine aziridinium ion (AF64A)-treatment and nucleus basalis magnocellularis (NBM) lesion. Indeloxazine administered immediately after training also showed ameliorating effects on passive avoidance in NBM-lesioned rats. Indeloxazine increased extracellular acetylcholine concentration in the frontal cortex of rats. Indeloxazine possesses facilitatory effects on cerebral function in part due to activation of the central cholinergic system.

Acetylcholine↗
PubMed1994

Changes in blood flow velocity in the middle cerebral artery during nonpulsatile hypothermic cardiopulmonary bypass.

BACKGROUND AND PURPOSE: We evaluated the utility of blood flow velocity measurements by transcranial Doppler ultrasonography as a tool to indirectly measure cerebral perfusion during cardiopulmonary bypass. METHODS: We simultaneously measured blood flow velocity in the middle cerebral artery and physiological variables in 18 patients undergoing cardiac surgery under hypothermic cardiopulmonary bypass in which pH and PaCO2 were managed with the alpha-stat acid-base strategy. We expressed blood flow velocity as a relative value of control obtained under normothermia and normocarbia before bypass. We also developed an original index, modified cerebral metabolic rate for oxygen, to estimate cerebral metabolic rate for oxygen. RESULTS: Relative velocity was significantly (P < .01) reduced during stable aortic cross-clamp compared with before bypass and was significantly (P < .01) increased during rewarming compared with at aortic cross-clamp. Modified cerebral metabolic rate for oxygen significantly correlated with nasopharyngeal temperature during cooling, aortic cross-clamp, and rewarming (r = .756, P < .0001; r = .4, P < .01; r = .725, P < .0005, respectively). Calculated temperature coefficient for modified cerebral metabolic rate of oxygen was 2.7 +/- 1.4 (mean +/- SD, n = 10) during cooling. Only nasopharyngeal temperature and PaCO2 were significant determinants of relative velocity during aortic cross-clamp. CONCLUSIONS: We can monitor cerebral perfusion and metabolism by measurements of relative velocity and modified cerebral metabolic rate for oxygen during hypothermic cardiopulmonary bypass.

Adolescent↗
PubMed1993

Transcription in vitro promoted by the Agrobacterium VirG protein.

Expression of the virulence genes (vir) on the hairy-root-inducing plasmid pRiA4 is induced by plant signals in Agrobacterium cells through a two-component regulatory system, the VirA-VirG system. We constructed an in vitro transcription system that consisted of the purified VirG protein and the Agrobacterium RNA polymerase holoenzyme. Both versions of VirG, the non-phosphorylated form and the VirA-phosphorylated form, were active but showed different patterns of the pH-dependency for transcriptional activation.

Bacterial Proteins↗
PubMed1993

Intracranial calcifications associated with nephrogenic diabetes insipidus.

A 6-year-old boy with nephrogenic diabetes insipidus (NDI) and intracranial calcification is reported. The calcifications were symmetrical and located in the basal ganglia and in the subcortical regions of the frontal, temporal, parietal and occipital lobes. Episodes of hyperosmolality during infancy are considered to be one of the causes of intracranial calcification in NDI. However, other unknown factors may be involved, because up to now there have been no reports of intracranial calcification in patients with central diabetes insipidus.

Brain Diseases↗
PubMed1993

Evidence that cyclosporine causes both intracellular migration and inappropriate urinary excretion of magnesium in rats.

We determined the effects of cyclosporine on calcium, magnesium, and potassium metabolism in rats. Thirty Sprague-Dawley rats were randomized into three groups of ten animals each--control rats given olive oil, rats given cyclosporine at a dosage of 5 mg/kg daily, and rats given 15 mg/kg daily for four weeks. Urinary excretion of calcium, magnesium, and potassium was determined before and after 2 and 4 weeks of cyclosporine therapy. All rats were sacrificed after 4 weeks of therapy, and calcium, magnesium, and potassium concentrations in serum and tissues were determined. Serum magnesium levels were significantly lower in the cyclosporine-treated groups than in the control group, but there was no significant difference between the control and either of the cyclosporine-treated groups with regard to total urinary excretion of magnesium after four weeks of treatment. Magnesium content in the kidney, muscle, and liver was significantly higher in the 15 mg/kg group than in the control group. Calcium content in the kidney and liver was significantly higher as well. Potassium content in any type of tissue was similar in the three groups. We conclude that the intracellular migration of magnesium plays an important role--as does impaired renal conservation of magnesium--in the pathogenesis of cyclosporine-induced hypomagnesemia and that there is a discrepancy between magnesium and potassium metabolism in cyclosporine-treated rats.

Animals↗
PubMed1993

Management of intractable pain with percutaneous epidural spinal cord stimulation: differences in pain-relieving effects among diseases and sites of pain.

This study is a survey of the overall clinical results achieved with our pain treatment method, percutaneous epidural low-frequency (1.6-8.0 Hz) spinal cord stimulation. It examines the relationship between the effectiveness of epidural spinal cord stimulation (ESCS) and diseases or sites of pain. Continuous indwelling of the catheter electrodes in the posterior epidural space ranged from 3 to 67 days, and the duration of percutaneous ESCS varied from less than 1 wk to more than 1 yr. Complete pain relief (100%) was achieved during stimulation in 11.5% of the patients (52 of 454). Complete (100%) to partial (more than 30%) pain relief occurred in 71.1% of the patients. In six (1.3%) patients pain was aggravated by stimulation. Analgesics and/or sedatives were discontinued completely after treatment in 52 patients (11.5%) and reduced in 263 patients (57.9%). The number of patients who rated pain relief better than 50% was significantly more in carcinoma/sarcoma and causalgia (P < 0.001), and significantly less in postherpetic neuralgia and thromboangitis obliterans/arterial sclerosis obliterans (P < 0.001) than the average in all diseases. There was a significantly high responsiveness to ESCS in female patients in comparison to male patients (P < 0.05). Pain in the head/face, neck/upper extremities, and trunk responded more to ESCS than pain in the lower extremities. Alleviation of pain by ESCS was lower when the verbal pain score was high. There were no major complications in percutaneous ESCS. Thus, we have demonstrated that pain-alleviating effects of ESCS varies significantly by disease and site of pain, and that this simple percutaneous method can be used for a relatively long period.

Aged↗
PubMed1993

[The effects of hemodilution on cerebral hemodynamics and oxygen consumption during nonpulsatile hypothermic cardiopulmonary bypass].

The effects of hemodilution on cerebral hemodynamics and oxygen consumption during nonpulsatile hypothermic cardiopulmonary bypass (CPB) were investigated in 16 patients undergoing elective open heart surgery under CPB. They were divided into 2 groups; high (25%) (H) and low hematocrit (15%) (L) groups according to the hematocrit values during CPB. Simultaneous measurements of blood flow velocity in the middle cerebral artery (VMCA) and oxygen tension in the jugular venous bulb (PjvbO2) were performed at prebypass, bypass, and post bypass periods. There were no significant differences in nasopharyngeal temperature (NPT), cerebral perfusion pressure, pump flow rate, and PaCO2 between the two groups at any period. VMCA changed in correlation with NPT in both groups, and VMCA in the L group was faster than that in the H group at any period. PjvbO2 increased during aortic cross clamp, and decreased on rewarming in both groups. However, there were no significant differences in VMCA and PjvbO2 between the two groups at any period. These findings suggest that increased cerebral blood flow may compensate the decreased oxygen content due to the hemodilution during CPB. Therefore, the profound hemodilution up to 15% of hematocrit is considered to be a safe technique during CPB.

Adult↗
PubMed1992

Exon-intron organization of the Arabidopsis thaliana protein kinase genes CDC2a and CDC2b.

We have previously shown by cDNA cloning that a higher plant, Arabidopsis thaliana, possesses at least two CDC2 genes (CDC2a and CDC2b) similar to the cell-cycle-controlling cdc2 gene of Schizosaccharomyces pombe. To understand the exon-intron organization of these genes, genomic clones were isolated and their nucleotide sequences determined. The coding and 5'-untranslated regions of CDC2a were interrupted by seven and one introns, respectively, whilst CDC2b contained three introns within the coding portion. These intron positions partly overlapped with each other and with those of the yeast cdc2 gene, nevertheless the lengths and sequences of the corresponding introns were diverse.

Amino Acid Sequence↗
PubMed1992

Changes in intracellular pH of mouse hippocampal slices responding to hypoxia and/or glucose depletion.

Effects of hypoxia and/or glucose depletion on apparent intracellular pH, (pHi)app, were studied in hippocampal slices of mouse brain using the fluorescence pH indicator BCECF (2',7'-bis(carboxyethyl)carboxyfluorescein). In the presence of glucose (11 mM), (pHi)app of the CA1 pyramidal cell layer decreased with hypoxia but rapidly recovered with reoxygenation. The response in (pHi)app to hypoxia was consistent with changes in lactate content. By superfusion with a hypoxic and glucose-devoid solution, (pHi)app decreased in the first 5 min, but then increased in two phases: during a 5- to 7-min period and again during the latter period of superfusion. BCECF fluorescence rapidly diminished in this latter period. These changes in (pHi)app could not be explained only by the lactate content in the slices. Some other mechanisms may also regulate the (pHi)app in the slices during and after hypoxia and glucose depletion.

Animals↗
PubMed1992

Control of drug release with a combination of prodrug and polymer matrix: antitumor activity and release profiles of 2',3'-diacyl-5-fluoro-2'-deoxyuridine from poly(3-hydroxybutyrate) microspheres.

Drug release was controlled by a combination of prodrug and polymer matrix. Prodrugs of 5-fluoro-2'-deoxyuridine with different physicochemical properties were synthesized by esterification with aliphatic acids (propionate, n-butyrate, and n-pentanoate). Microspheres containing these ester prodrugs were prepared with poly(3-hydroxybutyrate) of three molecular weights (65,000, 135,000, and 450,000). The release rates from the spheres depended on both the lipophilicity of the prodrug and the molecular weight of the polymer. Regardless of the polymer, the relative release rates were propionate greater than butyrate greater than pentanoate. The release of butyrate and pentanoate from the spheres consisting of low-molecular-weight polymer (M(r), 65,000) was faster than that from the spheres of higher molecular weight (M(r), 135,000 or 450,000). A single intraperitoneal injection of spheres of the highest molecular weight polymer containing butyrate or pentanoate resulted in higher antitumor effects against P388 leukemia in mice than did free prodrugs given over a period of five consecutive days. The polymer sphere itself showed low toxicity to and good biocompatibility with mice and rats.

Animals↗
PubMed1992

Effects of dorsal root entry zone lesions on CSF and plasma neuropeptides and catecholamines.

Effects of dorsal root entry zone lesions (DREZLs) on cerebrospinal fluid (CSF) and plasma concentrations of neuropeptides, catecholamines, and cyclic nucleotides were studied in 9 patients with intractable chronic pain. Contents of beta-endorphin-like-material in CSF decreased in all patients 12-17 days following DREZLs during which complete to good pain relief was achieved. Contents of beta-endorphin-like-material in CSF increased again about one month after DREZLs in two and remained unchanged in one of three patients tested, who complained of partial reappearance of pain. Contents of beta-endorphin-like-materials in plasma showed no significant changes after DREZLs. Substance P, noradrenaline, adrenaline, and cyclic nucleotide levels in both CSF and plasma were variable among the subjects and did not change significantly following the operations. Thus, the results suggest that production of beta-endorphin-like-material in the central nervous system is decreased by DREZL, though the increase in its turn-over might not be neglected. The mechanisms of the decrease in contents of beta-endorphin-like-material in CSF after DREZLs were discussed in terms of our current knowledge of pain and pain inhibitory systems.

Adult↗
PubMed1992

Pathogenesis of cyclosporine-induced hypomagnesemia.

We studied the pathogenesis of cyclosporine-induced hypomagnesemia in five patients with nephrosis. Serum magnesium concentrations and urinary excretion of magnesium were reduced by the therapy. In contrast, the magnesium concentrations in mononuclear blood cells were increased. We conclude that short-term use of cyclosporine induces an intracellular shift of magnesium and causes hypomagnesemia.

Adolescent↗
PubMed1992

Effects of biological response modifiers with different modes of action used separately and together on immune responses in mice with syngeneic tumours.

The effect of a protein-bound polysaccharide (PSK) obtained from cultured mycelia of the Basidiomycetes Coriolus versicolor on activities involved in the host defence mechanism of C57BL/6 mice bearing adenocarcinoma 755 was compared with that of live bacille Calmette-Guérin (BCG). Delayed footpad reaction, the activity of splenic natural killer cells and interferon production induced by concanavalin A in splenic cells of healthy mice were little affected by PSK, but in mice bearing tumours PSK prevented the tumour-induced reduction in these activities. Live BCG augmented these activities in healthy mice but had little effect on the reduction of activities induced by a tumour. The immunosuppressive activity of the serum of tumour-bearing mice was reduced by PSK administration; live BCG did not have this effect. The combined use of live BCG and PSK improved these activities in the host, with synergistic increases in the antitumour effect. These results suggest that the combined use of live BCG and PSK, which have different modes of action, may be useful in the treatment of cancer.

Adjuvants, Immunologic↗