Search PubMed⌕ Search

Biomedical subjects

K Endo

Publications and source records attributed to K Endo.

At least 559 records · Page 31Linked to original sources

Effect of ryanodine on histamine release from rat peritoneal mast cells induced by anti-IgE.

Ryanodine strongly inhibited histamine release from rat peritoneal mast cells induced by anti-IgE. Ryanodine also inhibited Ca(2+)-mobilization from the intracellular Ca(2+)-store as well as histamine release in mast cells activated by anti-IgE. These results suggest that the effect of ryanodine on histamine release from rat mast cells might be due to the inhibition of Ca2+ release from the intracellular Ca2+ store.

Animals↗

Presynaptic inhibitory action of enkephalin on excitatory transmission in superficial dorsal horn of rat spinal cord.

1. Tight-seal whole-cell recordings were made from marginal neurones visually identified in thin slices of 1- to 2-week-old rat lumbar spinal cord. Excitatory postsynaptic currents (EPSCs), either evoked by extracellular stimulation or those arising spontaneously in tetrodotoxin, i.e. miniature EPSCs (mEPSCs), were recorded after blocking inhibitory synaptic inputs with strychnine and bicuculline. 2. The EPSCs were abolished reversibly by kynurenic acid or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) but not affected by (+)-2-amino-5-phosphonovalerate (APV), suggesting that they were mediated by non-NMDA (N-methyl-D-aspartate) glutamate receptors. Micromolar concentrations of methionine [Met5]enkephalin reversibly reduced the magnitude of evoked EPSCs and the frequency of mEPSCs. 3. The enkephalin action on the mEPSC frequency was blocked by naloxone. A specific agonist of mu-opiate receptor, [D-Ala2,N-Me-Phe4, Gly5]enkephalin-ol (DAGO) suppressed the mEPSC frequency. In contrast, neither a delta-opiate receptor agonist, [D-Pen2, L-Pen5]enkephalin (DPLPE) nor a kappa-opiate receptor agonist, (5 alpha, 7 alpha, 8 beta)-(-)-N-methyl-N-[7-(1-pyrrolidinyl)-1- oxaspiro(4,5)-dec-8-yl]benzeneacetamide (U-69,593) significantly affected the mEPSC frequency. 4. The amplitude of mEPSCs or of currents induced by exogenous L-glutamate, was not affected by [Met5]enkephalin. It is suggested that [Met5]enkephalin presynaptically inhibits glutamatergic EPSCs by activating the mu-opiate receptor. 5. The frequency of mEPSC was reduced by about 50% by replacement of external Ca2+ with Mg2+ or by addition of Cd2+. In Ca(2+)-free-Mg2+ solution, [Met5]enkephalin did not reduce the remaining mEPSCs' frequency any further. 6. It is concluded that the opiates may suppress presynaptic Ca2+ entry, thereby inhibiting synaptic transmission.

Animals↗

[Significance of antimicrobial activities testing of antimicrobial agents in human urine].

In order to clarify the in vivo effect of the new quinolones in the urinary tract, we investigated the antimicrobial activities against Escherichia coli in the human urine. Human urine was prepared from a normal volunteer. After cations were removed by chelating resin, human urine was supplemented with 50, 100, or 500 micrograms of Mg2+ per ml using MgCl2 or 10, 50, or 150 micrograms of Ca2+ per ml using CaCl2. The pH of human urine was adjusted to 5.5, 7.0, or 8.0 with HCl or NaOH. Four clinical isolates of E. coli and E. coli NIHJ JC-2 were used. And antimicrobial activities of the new quinolones (norfloxacin, enoxacin, ofloxacin and ciprofloxacin) against these strains were measured using various urines as mediums. Antimicrobial activities of the new quinolones were reduced in the presence of high concentration of magnesium or low pH of urine. However, there was no influence of calcium concentration of urine on antimicrobial activities of the new quinolones. From these results, the component of the urine should be checked in the treatment of the patients with urinary tract infection.

4-Quinolones↗

Connections between utricular nerve and dorsal neck motoneurons of the decerebrate cat.

1. We studied connections between the utricular (UT) nerve and dorsal neck motoneurons in decerebrate cats. Electrodes were fixed in place on the UT nerve under visual observation; the other branches of the vestibular nerve were transected. 2. The N1 field potential evoked by UT nerve stimulation was recorded in the vestibular nuclei at the start of each experiment. The potential typically grew until it reached a plateau. Stimulus spread (if any) to the central ends of other nerve branches was revealed by an additional increase in N1 amplitude after the plateau was reached. 3. We recorded intracellularly from 55 motoneurons in C1-C3. Some were identified as having axons in the dorsal rami, which innervate dorsal neck muscles. Others projected in nerves that were not available for stimulation. 4. UT nerve stimulation evoked synaptic potentials in essentially all motoneurons studied. The predominant pattern consisted of disynaptic excitatory postsynaptic potentials in ipsilateral motoneurons and inhibitory postsynaptic potentials that were at least trisynaptic in contralateral motoneurons. 5. The results demonstrate the presence of short-latency connections between the utricular nerve and dorsal neck motoneurons. The functional role of this pathway remains to be investigated.

Animals↗

A novel chromosomal translocation t(3;17)(q29;q11) in a case with polycythemia vera.

We report a novel chromosomal translocation t(3;17)(q29;q11) in a case with polycythemia vera (PV). The present case (38-year-old male) developed the spent phase of PV after a 10 years' clinical course and showed excessive proliferation of myeloid cells in the bone marrow. The karyotype analysis of the bone marrow cells showed chromosomal translocation t(3;17)(q29;q11), and the same aberration was detected in the granulocyte-colony-stimulating-factor-stimulated peripheral blood cells, suggesting the cells with the t(3;17)(q29;q11) showed myeloid differentiation. It is known as well that the retinoic acid receptor gene, which is related with a myeloid disorder, is located in 17q11. Thus, the novel chromosomal translocation could be associated with the pathogenesis of the disorder in this patient.

Adult↗

A new method for promoting adhesion between precious metal alloys and dental adhesives.

A new, simple method of modifying the adherend metal surface by a liquid Ga-Sn alloy (Adlloy) was applied to dental precious and base-metal alloys for adhesion with 4-META adhesive resin. Adhesions of 4-META resin to three other surface states--as-polished, oxidized at high temperature, and electroplated tin--were also performed for comparison with the adhesion on Adlloy-modified surfaces. Bond strength measurements were made, and the durability against water at the adhering interface was evaluated. The Adlloy-modified gold alloys (Type IV and 14 K) and silver-based alloys (Ag-Pd and Ag-Cu) showed not only high bond strengths but also excellent water durability at the adhesion interface. Surface modification by Adlloy, however, did not affect adhesion to Ag-In-Zn and base-metal (SUS, Co-Cr, and Ni-Cr) alloys. Adhesion to the tin-electroplated specimens was comparable with that to the Adlloy-modified specimens.

Acrylic Resins↗

ESCA study on dental alloy surfaces modified by Ga-Sn alloy.

A new, simple surface modification method for adherend metals has been developed. It gives high bond strength and superior water durability to dental precious-metal alloys bonded with 4-META/MMA-TBB resin. However, there was no effect on the bonding of Ag-In-Zn alloy and base-metal alloys. In the present study, the alloy surfaces modified by the new method were analyzed by ESCA and SEM for determination of details of the modification effect. A new alloying layer containing Ga and Sn was formed on the precious-metal alloys. The main factor for excellent adhesion to be achieved was the formation of a very thin layer of Ga2O3 and SnO2, less than 1-2nm thick, on the alloy surface. A thicker modified layer, as formed on the Ag-In-Zn and Ni-Cr alloys, led to low bonding ability.

Acrylic Resins↗

Epidermal growth factor inhibits follicular response to human chorionic gonadotropin: possible role of cell to cell communication in the response to gonadotropin.

Epidermal growth factor (EGF) affects follicular steroidogenesis and expression of gonadotropin receptors. The effects of EGF on hCG-induced estradiol and progesterone secretion and ovulation were examined in the in vitro perfused rabbit ovary. We also examined the effects of EGF on hCG-induced progesterone secretion by isolated granulosa cells. In addition, distribution of hCG within the follicle was probed by immunohistochemical means 30 min after its administration to the in vitro perfused ovary. EGF significantly (P less than 0.05) reduced hCG-induced secretion of estradiol (control, 117 +/- 12 pg/min.follicle; 10 ng/ml EGF, 55 +/- 10) and progesterone (control, 18.2 +/- 1.2 ng/min.follicle; 10 ng/ml EGF, 11.9 +/- 0.8) by the perfused ovary. In contrast, EGF did not inhibit hCG-induced progesterone secretion by isolated granulosa cells. Ovulatory efficiency (number of ovulated ova per number of mature follicles x 100) when EGF was given 30 min before hCG was reduced dose-dependently from 58.2% with no EGF to 8.3% with 10 ng/ml EGF (P less than 0.001). Ovulation was not inhibited by EGF when it was given 30 min after hCG. Distribution of hCG in the preovulatory follicle was confined to the basement membrane, thecal cell layer, and a small fraction of the outer granulosa cell layer. These observations suggest that gonadotropin stimulates the follicle through the release of a secondary signal(s) from ligand-bound granulosa cells near the follicle wall to unexposed cells of the inner avascular area. EGF may inhibit the follicular response to hCG by attenuation of this cell to cell communication.

Animals↗

A chimeric analog of human and salmon calcitonin eliminates antigenicity and reduces gastrointestinal disturbances.

The minimum region in salmon calcitonin (sCT) which induces antigenicity and gastrointestinal disturbances has been identified by examining the cross-reactivity of several sCT fragments and CT analogs with antisera from sCT-treated patients, and by examining inhibition of gastrointestinal motility of these sCT fragments and CT analogs in conscious dogs. Sixteen residues at the N-terminus of sCT comprised the minimum fragment capable of inducing both activities. Human CT (hCT) showed no antigenicity and a four-order weaker inhibition of gastrointestinal motility than sCT. Based on these data, we synthesized the human and salmon chimeric CT, ACT-15, in which the 16 N-terminal residues were those of hCT and the 16 C-terminal residues were those of sCT. ACT-15 had no cross-reactivity with the antisera and had almost the same weak gastrointestinal inhibition effect as hCT in dog and rat models. Nevertheless, it retained a hypocalcemic activity and an analgesic activity comparable to sCT. These results suggest that the amino acid residues in the N-terminal half of CT are responsible for the formation of antibodies and the induction of gastrointestinal disturbances, but may not influence calcium metabolism or analgesia. Clinical studies of ACT-15 will be needed to confirm this hypothesis.

Amino Acid Sequence↗

Mannan-coated liposome delivery of gadolinium-diethylenetriaminepentaacetic acid, a contrast agent for use in magnetic resonance imaging.

Gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA), a paramagnetic contrast agent for use in magnetic resonance imaging (MRI) was bound to stearylamine and incorporated into the liposomal membranes (Gd-DTPA liposomes). In addition, the Gd-DTPA liposomes were coated with mannan (cholesterol-aminoethylcarbamylmethyl mannan), a polysaccharide, to obtain the mannan-coated liposomes. An in vitro MRI study showed that the Gd-DTPA liposomes produced a greater intensity of contrast than did the Gd-DTPA solution with a reduced T1 relaxation time. Intravenous injection of the Gd-DTPA liposomes containing 153Gd or liposomes containing 153Gd or 14C-DTPA to mice showed an accumulation of Gd-DTPA primarily in the liver and lung. When the mannan-coated liposomes were administered, an increased uptake of Gd-DTPA by these tissues was demonstrated. The mannan-coated liposomes may enhance contrast of the liver in MRI at a lower dose of Gd-DTPA.

Animals↗

The microvasculature of the human bone marrow correlated with the distribution of hematopoietic cells. A computer-assisted three-dimensional reconstruction study.

Surgical specimens of ordinary bone marrow from eight patients were submitted to computer-assisted three-dimensional reconstruction from resin-embedded, semi-thin serial sections. This was undertaken with the aim of contributing to a better understanding of hematopoietic microenvironment by establishing the basic architecture of the bone marrow, particularly the microvasculature and its relation to the hematopoietic cell series. The basic vascular structure was found to consist of mutually intertwining sinuses and hematopoietic cords (or compartments), the latter with an arteriole running along the axis. This allowed to define the unitary structure of the bone marrow as a hematopoietic cord with a central arteriole and surrounded by sinuses. Here granulopoietic cells were distributed mostly along the wall of the central arteriole. Erythropoietic cells, located mainly around the sinus wall, proved to be forming a continuous network of cord instead of separate "islands" as usually assumed, justifying a designation of "erythroblastic cords". Megakaryocytes were positioned in close vicinity to the sinus wall. These findings appear not only to be helpful in analyzing factors involved in the in vivo hematopoiesis of man, but also to visualize the importance of structural studies of bone marrow.

Adult↗

[MR study of the brain stem in elderly subjects].

Findings in patients in whom brain stem lesions were suspected were studied by a high-field-strength (1.5 T) MR imager. MR scans were obtained in 97 patients over a 10-month period. The mean age was 71 years (range, 39-94 years). A high incidence of infarction and lesions showing a high signal on T2-weighted image, but an almost normal signal on the T1-weighted image were observed at the pons in elderly cases. Furthermore, cases in which these two findings were observed, had a high incidence of lesion at other regions than pons. Cases with a past history of hypertension had higher incidence of lesions at the pons than normotensive patients (alpha less than 0.01). These findings suggest that MRI examination in the elderly could detect a high incidence abnormal lesions at the brain stem as well as in basal ganglia.

Aged↗

Effect of dietary fat and fiber on fecal flora, bacterial metabolites, and fecal properties in Japanese volunteers.

The effects of dietary fat and dietary fiber (DF) levels in diet on fecal flora, activities of three fecal enzymes, putrefactive metabolites, fecal mutagenicity and fecal properties were studied in eight healthy volunteers. They were given low fat and low DF diet (LF: fat energy ratio was 13.9%, and DF intake was 9.0 g/day) for 10 days, high fat and low DF diet (HF: fat energy ratio was 52.7%, and DF intake was 7.1 g/day) for 10 days, and high fat and high DF diet (HFF: fat energy ratio was 52.0%, and DF intake was 24.8 g/day) for 10 days. No change of fecal flora at the bacterial group level was observed throughout the experimental period, except that the population of lactobacilli showed a tendency to increase in HF period. Fecal activities of beta-glucuronidase, beta-glucosidase and nitroreductase and some putrefactive products were unchanged between LF and HF, while these values decreased in HFF period. No significant change of fecal properties was observed between LF and HF, while by HFF supplementation fecal weight increased and fecal pH value was lower than that in LF and HF. Excretions of iron, zinc and calcium in feces did not increase by high DF supplementation.

Adult↗

Re-evaluation of skin lesion distribution in atopic dermatitis. Analysis of cases 0 to 9 years of age.

Distribution of skin lesions was studied in 1,012 patients under 10 years of age, with atopic dermatitis. Of these, 812 (80.2%) had an atopic history; 200 did not. Both categories were divided by age into five subgroups (3-5 months, 6-11 months, 1 year, 2-4 years and 5-9 years) and the incidence of lesions in each of 52 skin regions was compared between the positive and negative history groups and between different age groups. The results were as follows. 1. There was a change in predilection site, from the head (the scalp, face and peri-auricular area) to the neck and flexures (cubital and popliteal fossae) between 1 and 2 years of age. 2. The trunk (shoulders, chest, abdomen and back) was the most common predilection site in both infants and children. 3. Only the upper arm was affected more frequently on the external side than the internal side in all age groups. 4. The nose, mamillae, palms and feet were the least affected areas in all age groups. 5. Incidences in the positive history group were no higher than in the negative group.

Age Factors↗

[The assessment of clinical usefulness of 131I-MIBG scintigraphy for localization of tumors of sympathetic and adrenomedullary origin--a report of multicenter phase III clinical trials].

A phase III clinical study of 131I-metaiodobenzylguanidine (131I-MIBG) was performed in 66 patients with tumors of sympathetic and adrenomedullary origin, including 32 patients with suspected pheochromocytoma, 25 with suspected neuroblastoma, 7 pre- or postoperative medullary carcinoma of the thyroid and each with carcinoid and suspected Sipple's syndrome. A total of 150 sites which were confirmed for presence (72 sites) or absence (78 sites) of tumors were examined on 131I-MIBG scintigrams. True positive ratio of the scintigraphy was 84.7% (61/72) and true negative ratio was 94.9% (74/78). Positive scintigraphy was obtained in 86.5% (32/37) of pheochromocytoma, 78.6% (22/28) of neuroblastoma and 100% (6/6) of medullary carcinoma of the thyroid. Accumulation of 131I-MIBG was seen in 16.8% of normal adrenal glands. Neither adverse reactions nor abnormal laboratory findings were noted in relation to 131I-MIBG injections. Our study indicates that 131I-MIBG is a safe and clinically useful radiotracers for the visualization and localization of tumors of sympathetic and adrenomedullary origin.

3-Iodobenzylguanidine↗

Bcl-2 confers growth and survival advantage to interleukin 7-dependent early pre-B cells which become factor independent by a multistep process in culture.

Early pre-B cells derived from mouse lymphoid bone marrow cultures were expanded on a surrogate stromal cell line composed of NIH3T3 fibroblasts engineered to secrete interleukin 7 (IL-7). Three immortal, IL-7-dependent cell lines were generated and infected with recombinant retroviruses to determine the effects of the human follicular B-cell lymphoma gene, bcl-2, on immature stages of B-cell development. Cells expressing bcl-2 grew at rates similar to those of control (vector only) cells when plated on bone marrow stromal lines, but exhibited a c. two-fold net proliferative advantage when grown in liquid medium supplemented with IL-7 alone. Bcl-2 prevented apoptosis when the infected early pre-B-cell lines were deprived of IL-7 and other growth factors provided by stromal cells. Following factor deprivation, a subset of cells expressing bcl-2 survived indefinitely. Two such cultures spontaneously gave rise to factor-independent variants which grew slowly in unsupplemented liquid culture and formed agar colonies, yet still responded positively to IL-7 and kit ligand, and negatively to gamma-interferon. Bcl-2 thus provides a survival capacity and modest growth advantage to early pre-B cells, which may recapitulate its effects in human B cells bearing t(14;18) translocations and ultimately contribute to transformation.

Animals↗