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Biomedical subjects

M Miyazaki

Publications and source records attributed to M Miyazaki.

At least 487 records · Page 27Linked to original sources

The effect of the partial pressure of oxygen on blood glucose concentration examined using glucose oxidase with ferricyan ion.

Glucose oxidase with ferricyan ion (GOD-F) is widely applied in clinical settings as a glucose sensor. However, blood oxygen concentration affects this blood glucose value because oxygen, at increased concentrations, consumes blood glucose, which cannot then be measured by this sensor. We investigated the effect of PO2 on blood glucose concentration in 48 patients who were breathing high concentrations of oxygen. Arterial and pulmonary arterial blood glucose values were analyzed using the GOD-F method and, as a control, the hexokinase method. The respective PO2 values were also measured. The blood glucose concentrations measured by the GOD-F method show a significant linear relation with that measured by the hexokinase method in both arterial (y = -24.4 + 1.01x, r = 0.99) and pulmonary arterial blood (y = -3.4 + 1.01x, r = 0.96). The difference of intercepts is statistically significant, but because of the relatively large limits of agreement indicating any hidden extraneous variabilities, the error of the GOD-F method could not be assessed just by the difference. The equation defining the effect of PO2 on the percent change between blood glucose measured by the GOD-F method and that measured by the hexokinase method is -19.8/(1 + 203900/PO2(2.68) (r = 0.62). This formula generally follows our measured materials and introduces the relationship among blood glucose value, PO2, and the error of the GOD-F method. We hesitate to suggest that the arterial blood glucose concentration when measured by the GOD-F method could be underestimated by as much as 20% in patients with high arterial oxygen pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesiology↗

[Hypotensive action of human renin inhibitor KRI-1314 in the common marmoset].

The possibility of using KRI-1314, a new cyclohexylnorstatine derivative, as an antihypertensive drug was examined using common marmosets. KRI-1314 strongly inhibited plasma renin activity (PRA) in both humans and marmosets, with a 50% inhibitory concentration of 4.7 x 10(-9) and 6.9 x 10(-9) M, respectively. In anesthetized marmosets, the increase in both blood pressure and PRA induced by bolus intravenous injection of RH-renin (0.15 microgram/kg) was suppressed by constant intravenous infusion of KRI-1314 (0.01 and 0.1 mg/kg/min) in a dose-dependent manner. In the sustained hypertension induced by continuous intravenous infusion of RH-renin (0.1 microgram/kg/min), a dose-dependent hypotensive response was produced by bolus intravenous injection of KRI-1314 (0.03-3 mg/kg). In the sodium-depleted model, whose PRA was increased by a two-week low-sodium diet coupled with furosemide loading, both intravenous injection (0.1-3 mg/kg) and oral administration (10 and 30 mg/kg) of KRI-1314 to anesthetized and conscious animals, respectively, lowered blood pressure dose-dependently with PRA suppression. The hypotensive activity of orally administered KRI-1314 (30 mg/kg) was almost equal to that of orally administered captopril (1 mg/kg). KRI-1314 did not affect heart rate in any of the experiments. These results indicate that the potent human renin inhibitor KRI-1314 may become an orally effective drug for treating renin-dependent hypertension.

Administration, Oral↗

Erythromycin does not directly affect neutrophil functions.

To determine whether erythromycin could affect neutrophil functions, we measured N-formyl-methionyl-leucyl-phenylalanine (FMLP)-induced chemotaxis and superoxide generation of neutrophils in the presence of erythromycin at various concentrations. Erythromycin had no effect on either of them. We further confirmed that intracellular free calcium concentration ([Ca2+]i) was not influenced by FMLP stimulation in the presence of erythromycin. Our results indicate that erythromycin has no direct effects on neutrophil functions in vitro, although it is reported that erythromycin inhibits the local migration of neutrophils in the small airways of subjects with asthma.

Asthma↗

A sensitive method of non-radioactive in situ hybridization for mRNA localization within human renal biopsy specimens: use of digoxigenin labeled oligonucleotides.

A sensitive method of non-radioactive in situ hybridization using digoxigenin-labeled oligonucleotides is described for the detection of mRNA within human renal biopsy specimens. Although non-radioactive in situ hybridization typically has the drawback of low sensitivity, we increased the sensitivity of this method, providing a practical alternative to the use of radiolabelled probes. The four main points are: 1) assessment of the efficiency of labeling, 2) optimization of the probe concentration for hybridization, 3) requirement of deproteinization of tissues with HCl and proteinase K, and 4) the use of a four-layer immunoperoxidase staining system. This technique was found to clearly localize individual mRNA positive cells within cryostat tissue sections. A variety of controls including sense probes, excess unlabeled anti-sense probes, and RNase-treatment demonstrated the specificity of the technique. This improved method is a powerful technique for detecting mRNA within human renal tissue and will be most useful in the study of gene expression in the pathogenesis of renal diseases.

Actins↗

Partial splenic embolization for the treatment of chronic idiopathic thrombocytopenic purpura.

OBJECTIVE: The purpose of this study was to assess the effectiveness of partial splenic embolization in the treatment of chronic idiopathic thrombocytopenic purpura. SUBJECTS AND METHODS: Twenty-six patients with chronic idiopathic thrombocytopenic purpura underwent partial splenic embolization and were followed up for 6-61 months. The condition was refractory to steroids in 20 of 26 patients. The other six patients, in whom a response to steroids was shown, could not be withdrawn from steroid therapy because their platelet counts decreased with any decrease in steroid dose. Five of 26 patients underwent splenectomy after partial splenic embolization, and the other patients were followed up without medical treatment until platelet counts decreased below 3 x 10(10)/l. The therapeutic effect of partial splenic embolization was defined on the basis of the platelet count at the last follow-up after partial splenic embolization: complete response, greater than 10 x 10(10)/l; partial response, 5 x 10(10)/l to 10 x 10(10)/l; and no response, less than 5 x 10(10)/l without medication. RESULTS: Partial splenic embolization brought a complete response in seven (33%) of 21 patients, a partial response in eight (38%), and no response in six (29%). In four of five patients, who later underwent splenectomy, response to partial splenic embolization was coincident with the response to splenectomy. No serious complications occurred, but minor complications such as abdominal pain, fever, and nausea were observed in most patients. CONCLUSION: This study suggests that partial splenic embolization might be useful as an alternative to splenectomy in the treatment of chronic idiopathic thrombocytopenic purpura.

Adult↗

[Siebold's mydriatic eyedrops].

I discovered two prescriptions of mydriatic eye drops that seemed to be written by Von Siebold. One prescription (prescription 1) belongs to the Siebold Memorial Hall in Nagasaki City, and the other (prescription 2) to the Municipal Museum in Ohzu City in Ehime Prefecture. Prescription 2 does not bear Siebold's signature but can be considered to have been written by him based on handwriting analysis. The major drugs in these prescriptions are Ex Belladonna and Ex Hyoscyamus. However, both prescriptions seem to have been written not only for mydriasis but also for antiphlogistic, analgesic and anticonvulsant effects in patients with eye disease. Based on the notes of the JP III and JP V, the mydriatics used by Siebold in operations such as for cataract were Ex Belladonna and Ex Hyoscyamus at a concentration of about 1%. Prescription 1. For a male with eye disease. Ex Belladonna 0.65 g; Laudanum 20 drops; Barium chloride 1.3 g; Rose water or chamomile water 124.4 g. Administer 3 times/day. Von Siebold (signature). Prescription 2. For Soya's daughter in Narutaki. Ex Hyoscyamus 0.39 g; Rose water 62.2 g. Administer some drops twice/day.

Eye Diseases↗

[Development of the brainstem and cerebellum in autistic children].

Studies of magnetic resonance images have revealed morphological disorders of the brainstem and cerebellum in autistic children and adults. When we studied development of the brainstem and cerebellum in autistic patients, these structures were significantly smaller in autistic patients than in controls. Although the brainstem and cerebellum significantly increased in size with age in both groups, the development of the pons, cerebellar vermis I-V and cerebellar vermis VI-VII was significantly more rapid in autistic patients than in controls. However, the development of the other brain structures in the posterior fossa did not differ between autistic patients and controls. The regression intercepts of the brainstem and cerebellum as well as those of their components were significantly smaller in autistic patients than in controls. These results suggested that significant anatomical changes took place in the posterior fossa brain structures in the prenatal period in autistic children, but were not progressive.

Adolescent↗

Quantitative localization of angiotensin II receptor subtypes in spontaneously hypertensive rats.

Angiotensin II (Ang II) receptors were labelled by in vitro autoradiography using 125I-[Sar1,Ile8]Ang II as a ligand in the kidney, adrenal gland, thoracic aorta, and hindbrain of adult spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Ang II receptors were differentiated into subtypes by susceptibility to subtype 1 (AT1) and subtype 2 (AT2) antagonists. In both rat strains, the adrenal cortex contained predominantly AT1 receptors, while AT2 receptors predominated in the adrenal medulla. The kidney contained exclusively AT1 receptors in glomeruli, proximal tubules, and the outer medulla. AT1 receptors were predominant in the thoracic aorta. The nucleus of the solitary tract (NTS), dorsal motor nucleus of the vagus (DM10), area postrema, and spinal trigeminal nucleus (Sp5) contained exclusively AT1 receptors, whereas the nucleus of the inferior olive contained AT2 receptors predominantly. Significant differences in receptor density were observed between SHR and WKY. The adrenal cortex, renal outer medulla, NTS, DM10, and Sp5 displayed higher AT1 receptor density in SHR than in WKY. These results indicate that expression of AT1 receptors is regulated differently in important targets of Ang II in SHR, and suggest that altered regulation of AT1 receptor expression may be relevant to the pathogenesis of hypertension in SHR.

Adrenal Glands↗

Serum hyaluronate in the assessment of liver endothelial cell function after orthotopic liver transplantation in the rat.

This study was designed to evaluate the use of serum hyaluronate as a marker of liver endothelial cell function after liver transplantation. We performed orthotopic liver transplantation in both isogeneic and allogeneic rejector models. After transplantation, hepatocyte function was assessed on the basis of serum ALT and total bilirubin levels, and liver endothelial cell function was judged on the basis of serum hyaluronate levels. Significant increase of hyaluronate in the rejector model, compared with the isogeneic model, was seen before any significant results could be obtained from conventional liver function tests. The impaired metabolism of hyaluronate in the rejector model was observed after intravenous injection of trace amounts of radioactive material. Serial studies demonstrate that the endothelial cell is a more susceptible target for the immune response than the hepatocyte. Serum hyaluronate concentration may be a better indicator in the early assessment of graft function. We also examined serum hyaluronate levels to evaluate cold ischemia-reperfusion injury to the liver endothelial cells in the isogeneic model. At 2 hr after reperfusion, hyaluronate levels in the 6-hr cold ischemia (nonviable allograft) group were significantly higher than in the 1-hr and 3-hr cold ischemia (viable allograft) groups. However, there was little difference between the viable allograft groups. After an intravenous injection of 1 mg/kg hyaluronate, the hyaluronate elimination rate in the 3-hr group was distinctly slower than that in the 1-hr group. These data indicate that the hyaluronate elimination rate may be a more sensitive marker of liver endothelial cell function in viable liver after a short period of ischemia.

Animals↗

[Omental pedicle flap for chronic empyema].

We have used the omental pedicle flap (OPF) method to treat 10 patients with chronic empyema secondary to pulmonary tuberculosis. Since 1987 they included 9 men and one woman ranging from 48 to 70 years in age. Two patients were required re-operation because of residual bronchopleural fistulas, and the additional procedures (muscle plombage and thoracoplasty) performed in order to close residual dead space produced more severe thoracic deformity and pulmonary dysfunction. In our first successful case, complete thoracoplasty combined with the OPF method also produced pulmonary dysfunction. On the other hand, thoracic deformity was avoided in 3 other patients and 4 patients without thoracoplasty showed better pulmonary function postoperatively. A comparison of the re-operated patients with the successful cases highlighted two important points regarding the OPF method. One is the need for firm fixation of the OPF to a fistula. We usually place a muscular pedicle flap over the OPF, and add limited thoracoplasty as necessary. The other important point is the control of infection. Open window thoracostomy before the OPF method is effective in patients with active infection. The OPF method is an effective radical operation for severe empyema even when residual dead space is present, and it can also be applied to patients with poor pulmonary function.

Aged↗

[Primary spinal intramedullary malignant lymphoma: case report].

We report a case of primary spinal intramedullary malignant lymphoma. A 48-year-old man suffered from numbness and weakness of the left leg for 8 months. He was admitted to the hospital with progressive paraplegia and sudden onset of urinary retention. MRI revealed a low intensity mass on T1-weighted image with diffuse enhancement by Gd-DTPA in the thoracic spinal cord. An intramedullary spinal cord tumor was suspected and an urgent laminectomy (C7-Th5) was performed for decompression and confirmation. In the operation, the spinal cord was seen to be diffusely swollen, but no apparent tumor was identified either in color or consistency, and only biopsy was performed. The pathological diagnosis was malignant lymphoma (diffuse medium size-cell type). Investigations excluded the presence of lymphoma in other sites in the central nervous system and in the extraneural organs. We diagnosed a primary spinal intramedullary malignant lymphoma. Postoperative irradiation and chemotherapy were performed. After the irradiation with 16Gy to the tumor and 30Gy to the whole spinal axis, the tumor disappeared on MRI. One month later MRI demonstrated two markedly enhanced lesions in the right frontal lobe white mantle and the corpus callosum. He died of progressive respiratory disturbance 15 months after the beginning of his illness. Primary involvement of the spinal cord in malignant lymphoma is rare. Only 12 cases have been reported. The number of cases of malignant lymphoma in the central nervous system has gradually increased and it must be taken into consideration when diagnosing spinal cord tumors. We are looking forward to developing curative means including chemotherapy and radiotherapy.

Combined Modality Therapy↗

[Neurophysiologic studies on patients with migration disorder].

Neurophysiologic studies on six patients (five lissencephaly and one schizencephaly) with migration disorder were performed in order to evaluate the CNS function by multimodality evoked potentials. All cases revealed abnormalities in SSEP, four cases lost components below P 3 or had low voltage of P 3 indicating brainstem dysfunction in the somatosensory pathway. Two cases lost component below N 1 indicating sensory cortical dysfunction. Three cases revealed ABR abnormalities including a low amplitude of wave V, and one case revealed a prolonged peak latency of wave I and a low amplitude of all components. Two cases revealed abnormalities of poor cortical components in SEP, two cases in VEP, and three cases in MLR. Five cases had normal findings in P-SEP and three cases in VEP. The result of this study demonstrates that patients with migration disorder are frequently associated with cortical, brainstem and peripheral dysfunctions and has heterogeneity in pathophysiology.

Brain↗

[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↗

Anti-atherosclerotic and plasma lipid lowering effects of the novel calcium blocker with alpha 1-adrenoceptor antagonistic activity, monatepil, in high cholesterol diet-fed Japanese Macaca fuscata monkeys.

1. The preventive effects of atherosclerosis and hyperlipidemia of monatepil ([(+-)-N-(6,11-dihydrodibenzo [b,e]thiepin-11-yl)-4-(4-fluorophenyl)-1-piperazine-butanamide+ + +]monomaleate , AJ-2615, CAS 103377-41-9), a new antihypertensive drug with potent calcium antagonistic and alpha 1-adrenoceptor blocking activities, were investigated in Japanese monkeys (Macaca fuscata) fed with a cholesterol-rich diet (2% cholesterol + 6% corn oil) and compared with those of prazosin. 2. The dose of monatepil selected (30 mg/kg/d, p.o., 6 months) was the plasma concentration dose level of antihypertensive therapy and that of prazosin (2 mg/kg twice daily, p.o., 6 months) was the dose where hypolipidemic effect in cholesterol-fed monkeys has been reported. 3. In the cholesterol diet control group (n = 7), plasma levels of total cholesterol and low-density lipoprotein (LDL) significantly increased and that of high-density lipoprotein-cholesterol (HDL-C) decreased compared with the normal diet group (n = 5). In the monatepil group (n = 5), these changes were significantly suppressed. In the prazosin group (n = 5), these changes were also inhibited but the inhibitory effect was weaker than in the monatepil group. 4. The cholesterol content and sudanophilic area in the aorta indicating atheromatous lesions in the cholesterol-diet fed control group were significantly higher than those in the normal diet control group. In the monatepil group, these changes were significantly suppressed whereas in the prazosin group these changes were partially inhibited. 5. In the histological study, aortic lesions characterized by aggregations of foam cells were observed in the cholesterol-diet control group, while there was little change in the monatepil group. The anti-atherogenic effect of prazosin was weaker than that of monatepil. 6. Coronary atheromatous lesions were found in 4 out of the 7 animals in the cholesterol-diet control group and 3 out of the 5 animals in prazosin group. In contrast, no coronary atheromatous lesion was found in the monatepil group. 7. The treatment with monatepil did not influence food consumption, body weight, physical signs or blood biochemistry. 8. The anti-atherosclerotic and plasma lipid-lowering effects of monatepil may in part be attributable to its calcium antagonistic, alpha 1-adrenoceptor blocking, and anti-lipid peroxidation activities. 9. In conclusion, monatepil is a new class of antihypertensive agent that possesses anti-atherogenic properties and the ability to reduce plasma lipid levels, a main risk factor for atherosclerosis.

Adrenergic alpha-1 Receptor Antagonists↗

[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↗