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Biomedical subjects

Y Murai

Publications and source records attributed to Y Murai.

At least 37 records · Page 2Linked to original sources

Changes of the thromboxane A2/prostacyclin balance in the urine of patients with renal diseases analyzed by gas chromatography/selected ion monitoring.

The thromboxane A2/prostacyclin (TX/PGI) ratios were measured in patients with renal diseases to elucidate the relationship between the ratios and the pathological changes of the diseases. Urinary stable metabolites of thromboxane A2 and prostacyclin, 11-dehydro-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin F1alpha, respectively, were converted to 1-methyl ester-propylamide-9,12,15-tris-dimethylisopropylsilyl ether derivative and 1-methyl ester-6-methoxime-9,12,15-tris-dimethylisopropylsilyl ether derivative, respectively, and applied to a gas chromatography/selected ion monitoring. The TX/PGI ratios of 10 outpatients and 6 inpatients with chronic glomerulonephritis were higher than those of 13 healthy volunteers. In an inpatient with systemic lupus erythematoides, the TX/PGI ratios were gradually lowered to the normal level with the therapies. Furthermore, the ratios seemed to change in advance of the changes of the levels of urinary protein and hematuria. These observations suggested that the TX/PGI ratio was a useful index to assess the pathological condition of renal diseases and the effects of treatment.

Adult↗

Spontaneous regression of a germinoma in the pineal body after placement of a ventriculoperitoneal shunt.

The authors report a case in which a germinoma in the pineal body displayed spontaneous regression after placement of a ventriculoperitoneal (VP) shunt. Spontaneous regression of malignant tumors is extremely rare, occurring in only one of 60,000 to 100,000 patients. Although in rare cases spontaneous regression is known to occur in patients with testicular seminomas, only one case of spontaneous regression of a primary pineal germinoma has so far been reported. In the present case a 17-year-old man presented with headache. A tumor in the pineal body and acute hydrocephalus were revealed by head computerized tomography (CT) and magnetic resonance (MR) imaging, and VP shunt placement was performed. Computerized tomography scanning of the head was performed four times during a 2-week period following the operation, and the patient was temporarily discharged to return to school. At the time of discharge, CT scanning demonstrated no change in the size of the tumor. Two months later, the patient was readmitted to the hospital to undergo surgery. At that time, head MR imaging revealed regression of the tumor. The pathological diagnosis of the lesion was germinoma. The patient underwent three courses of chemotherapy, during which carboplatin and etoposide were administered, in addition to a 24-Gy dose of radiotherapy. No manifestations of nerve impairment were noticed, and the patient was observed on an outpatient basis. The authors think that the factors involved in tumor regression included the effects of the VP shunt, the effects of radiation absorbed during head CT scanning, and the role of the patient's own immune response. However, no conclusion has been reached concerning the actual cause.

Adolescent↗

[Outcomes and predictors of mortality in elderly patients requiring artificial ventilation].

We retrospectively examined the outcomes and the predictors of mortality in 97 patients aged 70 years and over (mean: 79.3 years) who required artificial ventilation for more than 3 hours. The median duration of artificial ventilation was 16 days (range: 1-85). Of these patients, 61% survived ventilator weaning and 37% were discharged from hospital alive. We performed univariate and logistic regression analysis to determine the predictors of dying before weaning and hospital discharge using severity of illness data. The predictors of hospital mortality were examined in 86 patients, excluding those who had malignant disease, all of whom died in hospital. Activities of daily living (ADL) were ranked as "bedridden", "in wheelchair", or "independent". In the three age groups-up to 70 years, 75 to 84 years and 85 years and over-the respective survival rates were 63% (weaned) and 67% (discharged), 69% (weaned) and 39% (discharged), and 33% (weaned) and 12% (discharged); the overall p values being 0.026 (weaned) and 0.003 (discharged). The predictors of dying before weaning according to univariate analysis were as follows: age (p = 0.026), respiratory or cardiac arrest on admission (p = 0.003), acute physiology score (APS) of 25 or more on admission (p = 0.000), systolic blood pressure below 90 mmHg on admission (p = 0.001), hemoglobin less than 11 g/dl (p = 0.044), and total protein less than 6 g/dl (p = 0.007). The predictors of hospital mortality by univariate analysis were as follows: age (p = 0.003), limited ADL (p = 0.001), respiratory or cardiac arrest on admission (p = 0.011), APS 25 or more on admission (p = 0.049), systolic blood pressure less than 90 mmHg on admission (p = 0.002), hemoglobin less than 11 g/dl (p = 0.028), and GOT or GPT more than 50 IU (p = 0.038). The relative risk of dying before weaning decreased in the order: respiratory or cardiac arrest on admission, systolic blood pressure less than 90 mmHg on admission, total protein less than 6 g/dl (Odds ratios: 6.04, 3.90, 3.51, respectively), or, respiratory or cardiac arrest on admission, APS more than 25 in admission, total protein less than 6 g/dl (Odds ratio: 6.94, 3.99, 3.76, respectively). The relative risk of hospital mortality decreased in the order: "bedridden", systolic blood pressure less than 90 mmHg on admission, "with wheel chair" (Odds ratios: 11.76, 6.44, 3.57, respectively). In the older patients, successful ventilator weaning was not indicative of hospital discharge. Ventilator weaning depended mainly on acute health status on admission, but hospital discharge depended also on the presence of limited ADL and preexisting malignant disease.

Activities of Daily Living↗

Simultaneous measurement of volatile sulfur compounds using ascorbic acid for oxidant removal and gas chromatography-flame photometric detection.

A method for the simultaneous measurement of volatile sulfur compounds (COS, H2S, CS2, CH3SH, DMS) is established with preconcentration and GC-flame photometric detection (FPD). Prior to preconcentration of ambient air, it was necessary to remove SO2, water vapor and atmospheric oxidant. SO2 and water vapor were removed using a glass fiber filter and a cooled PTFE water trap loop, respectively. In order to remove atmospheric oxidant, the efficiency of an ascorbic acid scrubber was examined. It was found that an ascorbic acid scrubber enabled measurement of volatile sulfur compounds without adsorption and reaction loss. The detection limits for COS, H2S, CS2, CH3SH and DMS were 20, 34, 35, 263 and 44 pg of S, respectively.

Air↗

Production of functional human alpha 1-antitrypsin by plant cell culture.

Recombinant human alpha 1-antitrypsin (rAAT) was expressed and secreted from transgenic rice cell suspension cultures in its biologically active form. This was accomplished by transforming rice callus tissues with an expression vector, p3D-AAT, containing the cDNA for mature human AAT protein. Regulated expression and secretion of rAAT from this vector was achieved using the promoter, signal peptide, and terminator from a rice alpha-amylase gene Amy3D. The Amy3D gene of rice is tightly controlled by simple sugars such as sucrose. It was possible, therefore, to induce the expression of the rAAT by removing sucrose from the cultured media or by allowing the rice suspension cells to deplete sucrose catabolically. Although transgenic rice cell produced a heterogeneous population of the rAAT molecules, they had the same N-terminal amino acids as those found in serum-derived (native) AAT from humans. This result indicates that the rice signal peptidase recognizes and cleaves the novel sequence between the Amy3D signal peptide and the first amino acid of the mature human AAT. The highest molecular weight band seen on Western blots (AAT top band) was found to have the correct C-terminal amino acid sequence and normal elastase binding activity. Staining with biotin-concanavalin A and avidin horseradish peroxidase confirmed the glycosylation of the rAAT, albeit to a lesser extent than that observed with native AAT. The rAAT, purified by immunoaffinity chromatography, had the same association rate constant for porcine pancreatic elastase as the native AAT. Thermostability studies revealed that the rAAT and native AAT decayed at the same rate, suggesting that the rAAT is correctly folded. The productivity of rice suspension cells expressing rAAT was 4.6-5.7 mg/g dry cell. Taken together, these results support the use of rice cell culture as a promising new expression system for production of biologically active recombinant proteins.

Amino Acid Sequence↗

Urinary thromboxane A2/prostacyclin balance reflects the pathological state of a diabetic.

Levels of the stable urinary metabolites of thromboxane A2 and prostacyclin, 11-dehydro-thromboxane B2 (11-dehydro-TXB2) and 2,3-dinor-6-keto-prostaglandin F1alpha (2,3-dinor-6-keto-PGF1alpha) were measured in diabetics to elucidate the relation between the thromboxane A2/prostacyclin (TX/PGI) balance and pathological states of diabetes mellitus. 11-Dehydro-TXB2 and 2,3-dinor-6-keto-PGF1alpha were derivatized to methyl ester-propylamide-dimethylisopropylsilyl ether and methyl ester-methoxime-dimethylisopropylsilyl ether derivatives, respectively, and applied to a gas chromatography/selected ion monitoring. The TX/PGI ratios of diabetics were higher than those of healthy volunteers, suggesting the hypercoagulative states of this disease. The ratios showed positive correlations with the levels of blood glucose. The levels of hemoglobin A1c and triglyceride were correlated weakly with the ratio. Some of the patients who had relatively low levels of blood glucose also showed high TX/PGI ratios. Furthermore, the ratio increased in the order of the groups 1, 2, and 3; group 1 contained patients who did not take medicine for diabetes, group 2 contained those who took oral hypoglycemic agents, and group 3 contained those who received insulin therapy. These observations indicate that the TX/PGI ratio reflects the pathological conditions of diabetes and is a useful marker, having few different features from other markers that are presently used.

6-Ketoprostaglandin F1 alpha↗

Monitoring of the thromboxane A2/prostacyclin ratio in the urine of patients with retinal vascular occlusion through the low-dose-aspirin therapy using the gas chromatography/selected ion monitoring method.

We determined the levels of the stable urinary metabolites of thromboxane A2 and prostacyclin, 11-dehydro-thromboxane B2 (11-dehydro-TXB2) and 2,3-dinor-6-keto-prostaglandin F1alpha (2,3-dinor-6-keto-PGF1alpha) in patients with retinal vascular occlusion (RVO) to elucidate the change of the thromboxane A2/prostacyclin (TX/PGI) ratio with this disease and the effect of low-dose-aspirin therapy. 11-Dehydro-TXB2 and 2,3-dinor-6-keto-PGF1alpha were converted to 1-methyl ester-propylamide-9,12,15-tris-dimethylisopropylsilyl ether derivative and 1-methyl ester-6-methoxime-9,12,15-tris-dimethylisopropylsilyl ether derivative, respectively, and applied to a gas chromatography/selected ion monitoring. The average level of 11-dehydro-TXB2 in 30 patients with RVO was 1038 +/- 958 pg/mg creatinine. It was significantly higher than that of 27 healthy volunteers, which was 616 +/- 294 pg/mg creatinine (p < 0.05 with unpaired t-test). However, 2,3-dinor-6-keto-PGF1alpha levels were not significantly different between these two groups. The average ratio of TX/PGI in the RVO patients was 32 +/- 26 and it was significantly higher than that of healthy volunteers, 17 +/- 10 (p < 0.01). Patients with central retinal artery occlusion or branch retinal artery occlusion showed greatly high 11-dehydro-TXB2 levels and TX/PGI ratios, although the number of patients was limited in the current study. After the administration of low-dose aspirin (40 mg/day) for about 1 month, the TX/PGI ratio decreased to around the normal level. Following the levels for up to 10 months, they also remained at the normal level. These observations suggested that the 11-dehydro-TXB2 levels and the TX/PGI ratio reflect the pathological conditions of RVO and are useful markers of the treatment.

6-Ketoprostaglandin F1 alpha↗

A micromechanical model of the cochlea with radial movement of the tectorial membrane.

The function of the tectorial membrane in the cochlear micromechanics is uncertain. In modeling approaches some models have assumed it to be a resonator that participates in the sharp tuning mechanisms of the cochlea with its mass coupled to the ciliary stiffness of outer hair cells, being driven by the shear force between the reticular lamina and itself. This paper presents a different type of micromechanical model which assumes that the tectorial membrane is driven by a lymphatic fluid flow that can be shown to have a substantial radial component. It also assumes that the reticular lamina is relatively stiff and thereby restrains the top end of outer hair cells that exert a force to the basilar membrane via Deiters cells. When combined with a three-dimensional block model, it can simulate the sharp tuning mechanisms of the cochlea well.

Acoustic Stimulation↗

Ruptured aneurysm of the orbitofrontal artery associated with dural arteriovenous malformation in the anterior cranial fossa--case report.

A 27-year-old male presented with a rare association of a ruptured orbitofrontal artery aneurysm and a dural arteriovenous malformation (DAVM) fed by both ethmoidal arteries, manifestation as severe headache, nausea, and vomiting. Computed tomography revealed a hematoma within the right frontal lobe and diffuse subarachnoid hemorrhage. The aneurysm was clipped successfully and the hematoma was evacuated. After an uneventful postoperative course, the patient was referred for gamma knife radiosurgery to treat the DAVM. In this case, the DAVM was asymptomatic and pathogenetically unrelated to the aneurysm, which demanded urgent treatment.

Adult↗

Three-dimensional computerized tomography angiography in patients with hyperacute intracerebral hemorrhage.

OBJECT: The authors confirm the usefulness of extravasation detected on three-dimensional computerized tomography (3D-CT) angiography in the diagnosis of continued hemorrhage and establishment of its cause in patients with acute intracerebral hemorrhage (ICH). METHODS: Thirty-one patients with acute ICH in whom noncontrast and 3D-CT angiography had been performed within 12 hours of the onset of hemorrhage and in whom conventional cerebral angiographic studies were obtained during the chronic stage were prospectively studied. Noncontrast CT scanning was repeated within 24 hours of the onset of ICH to evaluate hematoma enlargement. Findings indicating extravasation on 3D-CT angiography, including any abnormal area of high density on helical CT scanning, were observed in five patients; three of these demonstrated hematoma enlargement on follow-up CT studies. Thus, specificity was 60% (three correct predictions among five positives) and sensitivity was 100% (19 correct predictions among 19 negatives). Evidence of extravasation on 3D-CT angiography indicates that there is persistent hemorrhage and correlates with enlargement of the hematoma. Regarding the cause of hemorrhage, five cerebral aneurysms were visualized in four patients, and two diagnoses of moyamoya disease and one of unilateral moyamoya phenomenon were made with the aid of 3D-CT angiography. Emergency surgery was performed without conventional angiography in one patient who had an aneurysm, and it was clipped successfully. CONCLUSIONS: Overall, 3D-CT angiography was found to be valuable in the diagnosis of the cause of hemorrhage and in the detection of persistent hemorrhage in patients with acute ICH.

Acute Disease↗

[The clinical usefulness of high-dose intravenous immunoglobulin therapy for chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy].

To explore the optimum dose of intravenous immunoglobulin (i.v.Ig) for treating patients with chronic inflammatory demyelinating polyrneuropathy and multifocal motor neuropathy, we compared the usefulness of i.v.Ig among 3 treatment doses. Fifty-nine patients were randomly divided into three treatment dosage groups: 20 patients for Group I using 50 mg/kg/day x 5 days, 19 patients Group II using 200 mg/kg/day x 5 days, and 20 patients Group III using 400 mg/kg/day x 5 days. We assessed clinically and electrophysiologically the effectiveness of the treatment at 5 weeks after the initial infusion. For patients in Group I and II who had not improved (or worsened) with the first treatment, we gave a one-step larger dose in the second treatment (i.e. 200 mg/kg/day x 5 days for those who had been given 50 mg/kg/day x 5 days, 400 mg/kg/day x 5 days for those who had been given 200 mg/kg/day x 5 days) after more than 9 weeks. We found that 15% of the patients in Group I, 21% in Group II and 60% in Group III improved dose-dependently with the first intravenous immunoglobulin treatment. Seven (47%) of 16 patients in Group I and 4 (40%) of 11 patients in Group II improved after the second treatment with larger doses. Adverse reactions including chill sensation, fever, skin eruption and increase in blood GOT and GPT levels were transient and mild. One patient in Group III developed left hemiparesis showing the small infarction in the right thalamus during the course of the treatment, but the symptom was mild. In conclusion, the high-dose intravenous immunoglobulin therapy (400 mg/kg/day x 5 days) is useful for treating patients with CIDP and MMN, although care must be taken of the risk of causing cerebral infarctions.

Adolescent↗

[Study of optimal CHOP dose ranges for elderly patients with non-Hodgkin's lymphoma].

Two groups of intermediate-to high-grade non-Hodgkin's lymphoma patients aged 65 years and over were enrolled in a dose-range study of CHOP therapy utilizing 5 doses (1/2, 7/12, 2/3, 5/6, full CHOP): 11 patients 65-79 years of age (group A) and 9 patients 80 years or older (group B). The patients were enrolled consecutively; the study was designed so that if 3 patients completed 3 cycles of CHOP on schedule without major problems, the next highest dose was administered. If 2 patients experienced any major problems during 6 cycles at a given dose, treatment was discontinued and the dose prior to that particular dose was regarded as the optimal dose. The 6 treatment cycles were completed by 3 of 3 (2/3 CHOP), 3 of 4 (5/6 CHOP), and 1 of 4 (full CHOP) group A patients; and by 3 of 3 (1/2 CHOP), 2 of 3 (7/12 CHOP) and 1 of 3 (2/3 CHOP) group B patients. The results indicated that the optimal doses for group A and B were five-sixths and seven-twelfths of the standard CHOP dose, respectively.

Aged↗

Effect of nilvadipine on the voltage-dependent Ca2+ channels in rat hippocampal CA1 pyramidal neurons.

Effects of nilvadipine on the low- and high-voltage activated Ca2+ currents (LVA and HVA ICa, respectively) were compared with other organic Ca2+ antagonists in acutely dissociated rat hippocampal CA1 pyramidal neurons. The inhibitory effects of nilvadipine, amlodipine and flunarizine on LVA ICa were concentration- and use-dependent. The apparent half-maximum inhibitory concentrations (IC50s) at every 1- and 30-s stimulation were 6.3x10-7 M and 1.8x10-6 M for flunarizine, 1.9x10-6 M and 7.6x10-6 M for nilvadipine, and 4.0x10-6 M and 8.0x10-6 M for amlodipine, respectively. Thus, the strength of the use-dependence was in the sequence of nilvadipine>flunarizine>amlodipine. Nilvadipine also inhibited the HVA ICa in a concentration-dependent manner with an IC50 of 1.5x10-7 M. The hippocampal CA1 neurons were observed to have five pharmacologically distinct HVA Ca2+ channel subtypes consisting of L-, N-, P-, Q- and R-types. Nilvadipine selectively inhibited the L-type Ca2+ channel current which comprised 34% of the total HVA ICa. On the other hand, amlodipine non-selectively inhibited the HVA Ca2+ channel subtypes. These results suggest that the inhibitory effect of nilvadipine on the neuronal Ca2+ influx through both LVA and HVA L-type Ca2+ channels, in combination with the cerebral vasodilatory action, may prevent neuronal damage during ischemia.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

Nuclear pore changes and absence of apoptosis in lumbar dorsal root ganglion neurons of doxorubicin-intoxicated rats.

Doxorubicin (DXR) produces degeneration of neurons in the lumbar dorsal root ganglion (DRG) in rats. Light microscopic studies, which included the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling method, and electron microscopic observation revealed that the moderate nuclear and remarkable cytoplasmic degeneration of DRG neurons of Sprague-Dawley rats after intravenous administration of 8 mg/kg of DXR was cell necrosis, not apoptosis. In some neurons, mostly dark and usually with moderate degrees of nuclear degenerative changes, the nuclear pores were decreased in number and obscure 14 and 20 days after DXR administration. DXR enters presumably the nucleus and is partly removed through the nuclear pores. However, the diameters of nuclear pores were similar in DXR-intoxicated and control rats. The changes in nuclear pores of neurons in DXR intoxication, which to our knowledge has not been previously studied, are considered to be part of the degenerative or necrotic changes of DRG neurons.

Animals↗

Different effect of oxytocin on membrane potential of supraoptic oxytocin neurons in virgin female and male rats in vitro.

The effects of oxytocin on membrane potential were investigated in the supraoptic nucleus (SON) neurons of rats using whole-cell patch-clamp technique. SON neurons were electrophysiologically identified as oxytocin (OT) or vasopressin (VP) neurons. Application of OT (1 x 10[-7] M) hyperpolarized membrane potentials of OT neurons in virgin female rats but depolarized membrane potentials of putative OT neurons in male rats. The membrane conductance of SON neurons were increased by treatment of OT in both sexes, suggesting that OT increased the opening of channels on SON neurons. The reversal potential of OT neurons in virgin female rats and putative OT neurons in male rats under OT effective conditions were -66 +/- 1 mV (n = 4) and -46 +/- 2 mV (n = 5), respectively. These data suggest that OT released within the SON suppresses the activity of OT neurons in virgin female rats while it excites putative OT neurons in male rats.

Animals↗

Sympathetic skin responses recorded from non-palmar and non-plantar skin sites: their role in the evaluation of thermal sweating.

OBJECTIVE: To characterize the sympathetic skin responses (SSRs) recorded from non-palmar and non-plantar (non-Pa/P1) skin sites and to evaluate their clinical usefulness. METHODS: SSRs were recorded from 6 non-Pa/P1 sites as well as palmar and plantar (Pa/P1) sites using magnetic neck stimulation in 33 normal subjects, 17 neurological patients with dysautonomia and one patient with lumbar sympathectomy. A conventional thermoregulatory sweat test (TST) was also carried out in 3 patients. RESULTS: Clear and reproducible SSRs were obtained from all recording sites in all of the normal subjects when the skin temperatures of the subjects were maintained above 34 degrees C and the subjects drank 100-200 ml of hot water. The distribution of absent SSRs was closely correlated with that of anhidrosis or a sweating delay shown by the TST in the patients. Nine of the 17 neurological patients (53%) showed normal responses at Pa/P1 sites, and abnormal responses at non-Pa/P1 sites. CONCLUSIONS: Recording SSRs from multiple skin sites including non-Pa/P1 sites after magnetic stimulation is more sensitive in detecting sudomotor dysfunction than is the conventional method of recording SSRs from only Pa/P1 sites. In addition, this new method is very useful for the objective clinical evaluation of thermal sweating.

Adrenoleukodystrophy↗