Biomedical subjects

E Fujii

Publications and source records attributed to E Fujii.

At least 55 records · Page 3Linked to original sources

PubMed1996

[A study on the maternal plasma C21 steroids concentration during pregnancy].

During pregnancy, C21 steroids such as progesterone (P4), and cortisol (F), have been reported to be closely involved in uterine contraction. To clarify the association between changes in steroid hormones and the onset of delivery, we measured the concentrations of six C21 steroids in maternal blood by high performance liquid chromatography. Changes in each steroid hormone were evaluated by analysis of variance during pregnancy. Pregnenolone, a source of C21 steroids, gradually increased during pregnancy. P4 and 17P4, its metabolite, reached a peak 3 weeks before delivery and noticeably decreased thereafter. Accompanying a decrease in P4 and 17P4, 20P4 and F, its metabolite, were noticeably increased. The association among these steroid hormones was also evaluated. The correlation between P4 and F was reversed after 3 weeks before delivery. These results suggest that steroid hormones in the maternal blood begin to change dynamically about 3 weeks before delivery. In particular, a decrease in P4 and an increase in F seem to be closely related to the onset of delivery.

17-alpha-Hydroxyprogesterone↗

PubMed1996

Treatment protocol for fractures of the odontoid process.

Treatment results in 104 patients with odontoid fractures were reviewed. There were 2 type I, 62 type II, 32 type III fractures and eight epiphysiolyses in children <7 years old. Thirty-seven patients were managed nonoperatively using plaster casts, cervical braces, or halo devices. Sixty-seven patients were treated surgically including anterior screw fixation (ASF), posterior fusion (PF), and transoral anterior fusion (TAF). Plaster casts and cervical braces were effective for type I fractures and epiphysiolyses only. Halo devices provided successful results in stable type III fractures. ASF is the treatment of choice for most type II and unstable III fractures including some old cases. PF also provided successful union, although impaired cervical motion remained. It should be reserved for irreducible fractures, established nonunions, and as a salvage procedure. TAF should be limited to exceptional cases requiring anterior spinal cord decompression.

Adolescent↗

PubMed1995

Endothelin-1, but not endothelin-3, suppresses lipoprotein lipase gene expression in brown adipocytes differentiated in culture.

The effect of endothelins on lipoprotein lipase activity and lipoprotein lipase mRNA levels was studied in brown adipocytes differentiated in culture. Lipoprotein lipase activity was determined in two fractions; lipoprotein lipase released by heparin (10 IU/ml, 1 h) into the medium (heparin-releasable fraction) and lipoprotein lipase activity remaining in cells (extractable fraction). Time-course studies showed that endothelin 1 (10(-7) M) progressively decreased both lipoprotein lipase fractions (heparin-releasable, extractable), until nadir at 24 h. Endothelin-1 reduced both lipoprotein lipase activities (heparin-releasable, extractable) in a concentration-dependent manner, whereas endothelin-3 did not produce any significant changes in either of them. Northern blot analysis revealed that endothelin-1 (10(-7)-10(-11) M) caused a concentration-dependent decrease in lipoprotein lipase mRNA obtained from cells on day 9. Furthermore, pretreatment of brown adipocytes with endothelin ETA receptor antagonist FR139317 antagonized the endothelin-1-induced reduction of lipoprotein lipase activity and lipoprotein lipase mRNA. These results suggest that endothelin-1 decreases lipoprotein lipase activity by inhibiting the lipoprotein lipase gene expression in brown adipocytes differentiated in culture, possibly through endothelin ETA receptors on cell membranes. Because of marked reduction of lipoprotein lipase activity and its mRNA as a marker of adipogenic differentiation, endothelin-1 may have an inhibitory role in the differentiation of brown adipocytes.

Adipocytes↗

PubMed1995

The presence of 2-keto-3-deoxygluconic acid and oxoaldehyde dehydrogenase activity in human erythrocytes.

2-Keto-3-deoxygluconic acid (3-DGA) is produced from 3-deoxyglucosone (3-DG:a highly reactive glycation intermediate) through oxidation by the enzyme oxoaldehyde dehydrogenase (OAD) in animals. We developed a specific assay method for 3-DGA using high-performance liquid chromatography [Fujii, E. et al. (1994) J. Chromatogr. B 660, 265-270] and measured it in the hemolysate and plasma of diabetic patients and healthy subjects. Both human erythrocytes and plasma contained considerable amounts of 3-DGA. However, human erythrocyte contained about 30-50 times higher 3-DGA than human plasma did and also had the same ability to convert 3-DG to 3-DGA as OAD had. Erythrocyte 3-DGA levels of diabetic patients were 990 +/- 370 nmol/gHb (n = 57, Mean +/- SD) and were significantly higher compared with healthy subjects (527 +/- 194 nmol/gHb, n = 7, p < 0.01). In all diabetic patients and healthy subjects (n = 64), there was only one patient who had a very low level of erythrocyte 3-DGA and lacked the ability to convert 3-DG to 3-DGA. When erythrocytes were incubated at 37 degrees C for 8 hours in phosphate buffer containing 0.35 mM 3-DG, 3-DG was easily taken into the erythrocytes and was converted to 3-DGA. Our results suggest the contribution of OAD not only to the prevention of glycation of hemoglobin but also to that of blood vessels by scavenging plasma 3-DG into erythrocytes.

Adult↗

PubMed1995

Developmental changes in response to endothelins and receptor subtypes of isolated rat duodenum.

The response of isolated duodenum to endothelin-1, -3 and IRL 1620 (Suc-[Glu9,Ala11,15]endothelin-1 (8-21)), a selective endothelin ETB receptor agonist, was studied in both neonatal (1-week-old) and adult rats by recording mechanical activity isotonically. Endothelin-1, -3 and IRL 1620 (1-100 nM) elicited sustained contraction of neonatal duodenum, in a concentration-dependent manner, with a potency order of endothelin-1 = endothelin-3 > IRL 1620. The response to endothelin-1 and -3 (10-1000 nM) of adult duodenum was biphasic, i.e., transient relaxation followed by contraction, with a potency order of endothelin-1 > endothelin-3. The contractile response to endothelin-1 of adult but not neonatal duodenum was significantly antagonized by pretreatment with FR139317 (1 microM), an endothelin ETA receptor antagonist. An endothelin ETB receptor antagonist, RES-701-1 (3 microM), weakly antagonized the IRL 1620-induced contraction of neonatal duodenum. However, RES-701-1 (10 microM) did not affect the response to endothelin-1 of either adult or neonatal duodenum. These results indicate that the duodenal response to endothelins changes from a sustained contraction in neonates to a biphasic response in adults. The contractile response to endothelins of neonatal duodenum is suggested to be mediated through endothelin ETB receptors or possibly RES-701-1-resistant ETB receptor subtypes and contraction of adult duodenum through endothelin ETA receptors. The mechanism of the endothelin-induced response of duodenum was also studied.

Aging↗

PubMed1995

Role of eicosanoids but not nitric oxide in the platelet-activating factor-induced increase in vascular permeability in mouse skin.

We investigated the role of endogenous eicosanoids and nitric oxide (NO) in the platelet-activating factor (PAF)-induced increase in vascular permeability in mouse skin. Subcutaneous injection of PAF (45-180 pmol/site) induced a dose-related increase in vascular permeability at the injection site. The vascular permeability induced by PAF (180 pmol/site) was significantly inhibited by pretreatment with an intraperitoneal injection of 1-O-hexadecyl-2-acetyl-sn-glycero-3-phospho (N,N,N-trimethyl) hexanolamine (PAF receptor antagonist) (5 and 25 mg/kg) and indomethacin (cyclooxygenase inhibitor) (10 mg/kg), whereas it was not affected by concurrent intravenous administration of NO synthase inhibitors NG-nitro-L-arginine methyl ester (10 mg/kg) or methylene blue (100 micrograms/kg) nor by topical injection of NG-nitro-L-arginine methyl ester. The inhibitory effect of indomethacin was partially reversed by topical administration of prostaglandin E2. These results suggest that PAF increases venular permeability by activating PAF receptors and that plasma extravasation is potentiated by the release of prostanoids which cause arteriolar dilatation. However, NO is not involved in the effect of PAF in mouse skin.

Amino Acid Oxidoreductases↗

PubMed1995

Developmental brain changes investigated with proton magnetic resonance spectroscopy.

Volume-selective proton magnetic resonance spectroscopy (1H-MRS) of the brain was performed with a 1.5 Tesla magnet in 47 healthy children and in six healthy adults. Peaks of N-acetylaspartate (NAA), choline (Cho) and creatine (Cr) were observed in all cases, but a lactate peak was not observed. In the right parietal region. 1H-MRS revealed increases in the rations of NAAJCho and NAA/Cr and a decrease in Cho/Cr with advancing age. The most rapid changes were noted between one and three years of age. 1H-MRS of the right frontal region also was performed in 21 cases (20 children and one adult). In the right frontal region, there was an increase in the ratio of NAA/Cho and a decrease in Cho/Cr with advancing age, while a developmental change was not observed in the ratio of NAA/Cr. The ratios of both NAA/Cho and NAA/Cr were lower in the right frontal region than in the right parietal region. These results show that developmental changes and regional variation of metabolites are observed in 1H-MRS of the brain, and need to be considered in its application.

Adolescent↗

PubMed1995

[Reproducibility of MTD system for detection of Mycobacterium tuberculosis: a cooperative study among six laboratories].

The Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) is a rapid test for the detection of Mycobacterium tuberculosis, utilizing the rRNA amplification method. For assessing the reliability and reproducibility of the method, a co-operative blind study was conducted among 6 laboratories. Materials for test were sputum and water samples containing known numbers of Mycobacterium bovis BCG or Mycobacterium avium, and samples without bacteria. From three of 6 laboratories, false-positive results were reported for bacteria negative samples, however, the ratio was below 10%; 8.3% (3/36 samples), 5.6% (2/36), and 2.8% (1/36), respectively. It indicates the indispensability of negative controls for sample pretreatment and RNA extraction stages in the routine MTD test. In every laboratory, all the samples with 10(2) BCG in water and 10(4) BCG in sputum were found to be MTD positive. For the sputum samples with 10(2) BCG, positive results with the ratio above 80% were reported from 4 laboratories. These results indicate that the MTD test based on rRNA amplification method is quite useful for the rapid diagnosis of M. tuberculosis infection.

Humans↗

PubMed1995

[Regeneration of the cauda equina after transection and end-to-end anastomosis in the dog].

This study was designed to test surgical techniques for reconstruction of an injured cauda equina. After transection of the intradural lumbar nerve root, end-to-end anastomosis was performed under surgical microscope in the dog. To preserve accurate adaptation of the transected nerve root, the root sheath and the funiculi were carefully sutured with a minimal number of stitches. Regenerated axons in the ventral root appeared distal from the suture at five weeks postoperatively, whereas those in the dorsal root appeared at seven weeks after anastomosis. The histogram and regrowth rate of the ventral root showed regenerative processes similar to those of peripheral nerves, though a little slower. The fact that an evoked potential from the sutured ventral root was recordable after stimulation of the sciatic nerve indicated restoration of nerve conduction. Although further experimental studies are required to develop adequate surgical techniques, microsurgical anastomosis of the transected cauda equina is potentially applicable for appropriate clinical cases of a cauda equina injury.

Anastomosis, Surgical↗

PubMed1995

[Effects of steroid hormones on change in [Ca2+]i and on PI response following oxytocin stimulation in cultured human myometrial cells].

In oxytocin (OT)-induced myometrial contraction, it is considered that Ca2+ release associated with activation of PI response is the main cascade. Steroid hormones such as dehydroepiandrosterone-sulfate (DHAS), progesterone (P), and cortisol (F), which show diverse changes during pregnancy, are considered to be involved in myometrial contraction at the onset of delivery. In this study, we examined changes in the intracellular Ca2+ concentration ([Ca2+]i) and PI response under OT stimulation. (1) After cultured human myometrial cells were incubated for 48 hours in a medium containing 10(-6) M of DHAS, P, or F, [Ca2+]i was measured with an OLYMPUS OSP3 by using the fluorescent Ca2+ indicator Fura2-AM. When the maximum change in [Ca2+]i under stimulation with 10(-8) M OT was regarded as 100% (control), it was increased significantly to 121.1 +/- 9.8% in the cells treated with F, but was reduced to 89.4 +/- 4% in those treated with P. It was increased to 107.5 +/- 6.9% in the cells treated with DHAS, but the difference was not significant. (2) After loading with 5 microCi 3H myo-inositol and various steroid hormones for 24 hours in the cells, the intracellular IP1-3 production under stimulation with 10(-8) M OT was examined. IP1-3 production and IP total production (IPn) were significantly increased in the cells treated with F as compared with the control, but IPn was reduced by about 40% in the cells treated with 10(-6) M P. And in the cells treated with DHAS, IPn was slightly increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium↗

PubMed1995

[The mechanism of beta-receptor desensitization in human myometrial culture cell].

Beta-adrenoceptor desensitization is considered to be primarily due to phosphorylation of receptors by protein kinase A (PKA) and beta-adrenaline receptor kinase (beta-ARK) and sequestration of receptors themselves. But in the human uterine muscle, the desensitization mechanism has been evaluated only as a phenomenon, and there are few studies on its mechanism. We evaluated cAMP production by beta-agonist and changes in the number of beta-receptors in cultured human myometrial cells. Uterine muscle cell were obtained from patients with benign disease before menopause and cultured. 1) At the confluent stage, dl-Isoproterenol Hydrochloride (ISP) was added under various conditions, and the intracellular cAMP concentration was determined by EIA. 2) After the addition of ISP (10(-6) M), plates were incubated at 37 degrees C, and beta-AR on the cell membrane surface (S beta-AR) and total beta-AR (T beta-AR) was measured in a binding assay with 125I-pindolol. The production of cAMP dose-dependently increased 30 minutes after the addition of ISP at 10(-6) M or higher, but rapidly decreased thereafter. T beta-AR was similar in the cells treated with ISP (10(-6) M) and the untreated cells. On the other hand, S beta-AR decreased by about 50% in the ISP treated cells. These result suggest the desensitization of beta-AR in human uterine muscle, and the involvement of the sequestration mechanism as its cause.

Cells, Cultured↗

PubMed1994

Quantitation of the glycation intermediate 3-deoxyglucosone by oxidation with rabbit liver oxoaldehyde dehydrogenase to 2-keto-3-deoxygluconic acid followed by high-performance liquid chromatography.

A simple and sensitive method for the detection of 3-deoxyglucosone was developed using oxidation with crude oxoaldehyde dehydrogenase to 2-keto-3-deoxygluconic acid followed by high-performance liquid chromatography (HPLC). Oxoaldehyde dehydrogenase was prepared from rabbit liver and partially characterized. 2-Keto-3-deoxygluconic acid produced from 3-deoxyglucosone by oxoaldehyde dehydrogenase was derivatized with 1,2-diamino-4,5-methylenedioxybenzene, and the fluorescent products were detected and quantitated by HPLC using a solvent containing borate. In the presence of borate, 2-keto-3-deoxygluconic acid was completely separated from N-acetylneuraminic acid. The detection limit of 3-deoxyglucosone was 2.5 pmol/injection (10 microliters) at a signal-to-noise ratio of 3. This method was used to confirm the inhibitory effect of aminoguanidine on glycation.

Aldehyde Oxidoreductases↗

PubMed1994

Developmental changes in the response of rat isolated duodenum to nicotine.

Developmental changes in the response to ganglionic stimulants, nicotine and dimethylphenylpiperazinium, were investigated in rat isolated duodenum by recording isotonic mechanical activity. The duodenal response to nicotine/dimethylphenylpiperazinium (3 x 10(-7) to 10(-3) M) in neonatal rats was contraction, which was blocked by hexamethonium, tetrodotoxin and hyoscine. The response to nicotine/dimethylphenylpiperazinium (10(-6) to 10(-4) M) in the adult duodenum was relaxation, which was blocked by tetrodotoxin and hexamethonium, but by neither guanethidine nor hyoscine. The transition of the response to nicotine/dimethylphenylpiperazinium from contraction to relaxation occurred at around the 3rd postnatal week. Nicotine-induced relaxation of adult duodenum was significantly inhibited by preincubation with alpha-chymotrypsin, a proteolytic enzyme, and a combination of nucleotide pyrophosphatase and 8-phenyltheophylline, a P1 purinoceptor antagonist. Nicotine-induced relaxation was desensitized by alpha, beta-methylene ATP, a stable P2x purinoceptor agonist. These results suggest that the contractile response of isolated duodenum to nicotine is mediated through cholinergic transmission in neonatal rats and the relaxant response is mediated through non-adrenergic, non-cholinergic transmission, which involves both peptidergic and purinergic transmission, in adult rats.

Adenosine Triphosphate↗

PubMed1994

Possible role of nitric oxide in 5-hydroxytryptamine-induced increase in vascular permeability in mouse skin.

In order to test the hypothesis that a 5-hydroxytryptamine (5-HT)-induced increase in vascular permeability results from a cascade triggered by activation of the synthesis of nitric oxide (NO), the vascular permeability was investigated using the Pontamine sky blue leakage method in male mice. Subcutaneous injection of 5-HT induced a dose-related increase of vascular permeability at the injection site. The vascular permeability induced by 5-HT was inhibited by pretreatment with intraperitoneal injection of ketanserin (5-HT2A antagonist) and methysergide (5-HT1/2A antagonist), less efficiently by 1-(2-methoxyphenyl)-4-[4-(2-phthalimido)butyl] piperazine (NAN-190) (5-HT1A antagonist), but not by granisetron (5-HT3 antagonist). Increase in vascular permeability induced by 5-HT was inhibited by concurrent intravenous administration of NO synthase inhibitors NG-nitro-L-arginine methyl ester (L-NAME) and methylene blue but not by the inactive enantiomer NG-nitro-D-arginine methyl ester (D-NAME). These results suggest that 5-HT increases vascular permeability by activating the 5-HT receptors and that endogenous NO is involved in this effect of 5-HT.

Amino Acid Oxidoreductases↗

PubMed1994

Involvement of endogenous nitric oxide in non-adrenergic, non-cholinergic contraction elicited by [Met5]-enkephalin in rat isolated duodenum.

To investigate the possible neuromodulatory role of nitric oxide (NO) in the gastrointestinal tract, an examination was made of the effects of NG-nitro-L-arginine (L-NOARG), an inhibitor of NO synthase, on the intestinal response to [Met5]-enkephalin (ENK) by recording the mechanical activity of the isolated duodenum from rats. [Met5]-enkephalin elicited a biphasic response of the duodenum, i.e. transient relaxation followed by contraction. The relaxation induced by ENK was blocked by naloxone, an opioid receptor antagonist, but not by tetrodotoxin (TTX). The contractile response of the duodenum to ENK was blocked by TTX but not by naloxone. The contractile response was not affected by hyoscine, a muscarinic antagonist, or guanethidine, an adrenergic neuron blocking agent, indicating mediation by non-adrenergic, non-cholinergic (NANC) nerves. The contractile but not the relaxant response to ENK was blocked by L- but not D-NOARG. The contractile response was also inhibited by methylene blue, an inhibitor of both NO synthase and guanylate cyclase, and by indomethacin, a cyclooxygenase inhibitor. Thus, endogenous NO and prostaglandins are involved in the contractile response to ENK. Endogenous NO may modulate the release of excitatory NANC transmitters via a prejunctional mechanism.

Amino Acid Oxidoreductases↗

PubMed1994

[Infantile spasms with localized cerebral lesion detected by 99mTcHMPAO-SPECT].

We experienced a 6-month-old girl with infantile spasms who had localized cerebral lesion detected by 99mTcHMPAO-SPECT. She was born vaginally after a full term uncomplicated delivery with a birth weight of 3,100 g. She developed emprosthotonic spasms with series formation and EEG showed asymmetric periodic hypsarrhythmia which was predominant in the right hemisphere. While MRI could not detected any focal lesion, 99mTcHMPAO-SPECT disclosed hypoperfusion at the right anterior temporal and frontal areas. Although vitamin B6, clonazepam and sodium valproate were administered with no remarkable benefit, the treatment with ACTH-Z or carbamazepine resulted in cessation of spasms and improvement of the EEG findings. Consequently, the study with 99mTcHMPAO-SPECT was useful to clarify the pathology of infantile spasms, and we concluded that a patient with localized cerebral lesions should be given carbamazepine.

Brain↗

PubMed1994

[Developmental changes in proton MR spectroscopy of the brain].

Volume-selective proton MR spectroscopy (1H-MRS) of the brain was performed on a 1.5 T magnet in 31 healthy children aged from 1 month to 15 years and one healthy adult. Peaks of N-acetylaspartate (NAA), choline (Cho) and creatine (Cr) were observed in all cases on 1H-MRS, but not lactate. On 1H-MRS of the right parietal region, with advancing age, 1H-MRS revealed an increase in the ratios of NAA to Cho and NAA to Cr and a decrease in Cho to Cr. The most rapid change was noted during the first one to three years of life. 1H-MRS of the right frontal region was also performed in eleven cases. The ratio of NAA/Cho was smaller in the right frontal region than in the right parietal region. From this result, it may be suggested that the neuronal maturation in the frontal region delays as compared with the parietal region.

Adolescent↗

PubMed1993

[The effect of oxytocin stimulation on PGE2, 6keto PGF1 alpha production in human myometrial monolayer culture].

In order to clarify the mechanism by which oxytocin induces the generation of prostaglandin (PG) in human myometrial smooth muscle cell, we determined the concentration of PGE2 and 6ketoPGF1 alpha in the culture supernatant of human myometrial monolayer cells stimulated by oxytocin. PGE2 and 6ketoPGF1 alpha demonstrated a biphasic increasing curve when oxytocin was added. The first increase, phase 1, was a transient phenomenon with a peak at 20 seconds whereas the second increase, phase 2, was a continuous phenomenon starting at 120 seconds. Moreover, phase 1 was significantly inhibited by the DG lipase inhibitor, RHC80267. Phase 2 was significantly inhibited by the PLA2 inhibitor, Mepacrine. Phase 1 and 2 were dose dependent in the range 10(-10) to 10(-6) M. PG production at rest during which 6ketoPGF1 alpha was higher than PGE2, was reversed by oxytocin stimulation. These results suggest that oxytocin stimulation would actuate biphasic PG production, and this mechanism would probably regulate the myometrial construction in labor-pain initiation.

Calcium↗