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Biomedical subjects

M Miyake

Publications and source records attributed to M Miyake.

At least 163 records · Page 9Linked to original sources
PubMed1997

The contribution of endogenous mono-ADP-ribosylation to kindling-induced epileptogenesis.

We examined the alteration of endogenous mono ADP-ribosylation in the hippocampus of amygdaloid kindled rats to clarify the neurochemical basis of epilepsy. A significant increase of the ADP-ribosylation on the 38 kDa protein was observed in the hippocampal membrane of the kindled rat. Several antiepileptics (phenytoin, phenobarbital, carbamazepine, sodium valproate) significantly decreased the ADP-ribosylation on the 38 kDa protein and effaced the increase in the kindled group. The ADP-ribosylation was largely increased by sodium nitroprusside, a nitric oxide generating compound, in both the kindled and control groups. Carbamazepine could not affect the ADP-ribosylation in the presence of sodium nitroprusside. Twenty amino acids from the N-terminus of the ADP-ribosylated 38 kDa protein were determined by sequential analysis. The sequence was completely identical to that of glyceraldehyde-3-phosphate dehydrogenase. These results indicate that the endogenous mono-ADP-ribosylation which increased in the kindled group and decreased by the antiepileptics might be a specific reaction associated with the mechanisms of epileptogenesis.

Adenosine Diphosphate Ribose↗
PubMed1997

Age-related changes in vertebral height ratios and vertebral fracture.

Because no gold standard for the definition of vertebral fracture exists, there has been controversy about whether mild vertebral deformities are truly fractures or simply normal variation in vertebral size and shape. The aim of this study was to assess the associations of mild variations of vertebral height ratios to definite vertebral fractures. In 479 Japanese women (aged 53.9 +/- 9.1 years) who visited our institute for a medical checkup, we performed lateral lumbar radiographs and morphometric parameters were derived by measuring the anterior (Ha), middle (Hm) and posterior (Hp) height of each vertebral body from T12 to L4. Vertebral height ratios, Ha/Hp, Hm/Hp or Hp/Hp' of adjacent vertebrae that were more than 3 SD different from vertebra-specific means of normative data were considered to indicate fractures. Forty-five women were diagnosed with at least one fracture. After excluding the subjects with vertebral fracture, we examined the associations of the variations in vertebral height ratios with age, anthropometric parameters and lumbar bone mineral density (BMD) measured by dual-energy X-ray absorptiometry. Vertebral height ratios, especially Hm/Hp in postmenopausal women, tended to decrease with age and were positively associated with BMD. No significant correlation was observed between anthropometric parameters and vertebral height ratios. Aged-related decrease in vertebral height ratios (Ha/Hp and Hm/Hp, each averaged from T12 to L4) was significant even after the correction for BMD. Mean values of height ratios of non-fractured vertebrae adjusted for age and BMD were significantly lower in postmenopausal women with vertebral fracture than in those without vertebral fracture. Logistic regression analysis showed that BMD and height ratios of non-fractured vertebrae were independent predictors of vertebral fracture risk. The results suggest that older women, and women with at least one obvious (3 SD) fracture, tend to have mild deformities which do not qualify using the 3 SD definition. These mild deformities may represent real consequences of osteoporosis, because they are more pronounced among women with obvious fracture.

Adult↗
PubMed1997

Performance study of a miniature gamma ray scintillation vivo probe for tumor localization.

UNLABELLED: We have developed a miniature gamma-ray endoscopic probe consisting of dual BGO detector probes for tumor detection inside the body cavities. The dual detector system was coupled with random coincidence to decrease the distant background radiation and to improve its spatial resolution for tumor localization. METHOD: The performance of the probe was investigated with a point source and a water phantom. A solution of positron emitting 18F isotope was used as the source. Clinical trials of the probe were done to localize tumors on the skin surface of four subjects carrying tumors close to the body surfaces, into whom 67Ga-citrate and 18F-FDG radiopharmaceuticals were injected. RESULTS: Measurements indicated that the spatial resolution of the dual detector probes is around 1.5 times better than the single detector probe, and both single and dual detector endoscopic probe systems are capable of localizing a tumor on a large photon background. CONCLUSION: The endoscopic probe may be easier to insert inside body cavities due to the small crystal size and the flexible light guides. A single detector probe with higher sensitivity may be useful in searching for tumors over a wide intracavity area but a dual detector probe can be used for precise tumor localization. The detector probe may also be suitable for intraoperative observation.

Adult↗
PubMed1997

Performance evaluation of a large axial field-of-view PET scanner: SET-2400W.

The SET-2400W is a newly designed whole-body PET scanner with a large axial field of view (20 cm). Its physical performance was investigated and evaluated. The scanner consists of four rings of 112 BGO detector units (22.8 mm in-plane x 50 mm axial x 30 mm depth). Each detector unit has a 6 (in-plane) x 8 (axial) matrix of BGO crystals coupled to two dual photomultiplier tubes. They are arranged in 32 rings giving 63 two-dimensional image planes. Sensitivity for a 20-cm cylindrical phantom was 6.1 kcps/kBq/ml (224 kcps/microCi/ml) in the 2D clinical mode, and to 48.6 kcps/kBq/ml (1.8 Mcps/microCi/ml) in the 3D mode after scatter correction. In-plane spatial resolution was 3.9 mm FWHM at the center of the field-of-view, and 4.4 mm FWHM tangentially, and 5.4 mm FWHM radially at 100 mm from the center. Average axial resolution was 4.5 mm FWHM at the center and 5.8 mm FWHM at a radial position 100 mm from the center. Average scatter fraction was 8% for the 2D mode and 40% for the 3D mode. The maximum count rate was 230 kcps in the 2D mode and 350 kcps in the 3D mode. Clinical images demonstrate the utility of an enlarged axial field-of-view scanner in brain study and whole-body PET imaging.

Bone Neoplasms↗
PubMed1997

Fertilization of bovine oocytes grown in vitro.

Early antral follicles 0.5-0.7 mm in diameter were dissected from bovine ovaries, and oocyte-cumulus complexes with pieces of parietal granulosa (OCCGs) were then collected from the follicles. The OCCGs containing oocytes of 90-99 microm diameter (94.7+/-2.8 microm, n = 196) were selected and embedded in collagen gels and cultured for 14 days in TCM199 containing 10% fetal calf serum and 4 mM hypoxanthine. From cultured OCCGs, 144 surviving oocytes were recovered, of which 53 were granulosa cell-enclosed oocytes and 91 were denuded oocytes. The mean diameter of the surviving oocytes was 114.2+/-8.4 microm, significantly larger than that measured before culture (P < 0.05). The granulosa cell-enclosed oocytes and denuded oocytes were further cultured for maturation for 24 h. After culture, 72% (38/53) of the granulosa cell-enclosed oocytes and 59% (54/91) of the denuded oocytes showed normal morphology. These oocytes were then inseminated with bovine spermatozoa. After 29 h of insemination, all of the denuded oocytes had degenerated, while 32% (12/38) of the granulosa cell-enclosed oocytes showed normal morphology. Of the 12 oocytes, 5 were penetrated by spermatozoa, and 2 formed both male and female pronuclei. These results demonstrate for the first time that bovine oocytes grown in vitro acquire meiotic competence and can be penetrated by spermatozoa.

Animals↗
PubMed1997

Up-regulation of oxytocin receptors in porcine endometrium by adenosine 3',5'-monophosphate.

Porcine endometrial cells (a mixture of epithelial, stromal, and glandular cells) were examined for the presence of oxytocin (OT) receptors using a cell culture system and a 125I-labeled OT antagonist. Binding specificity was tested in displacement studies with various related peptides. Scatchard analyses revealed the presence of a binding site with a dissociation constant (Kd) = 0.9 nM and a capacity of 1.9 fmol/10(5) cells. These cells, which were obtained from prepubertal gilts and thus had not been exposed to endogenous ovarian steroids, were used as a model to evaluate the possible action of ovarian steroids and intracellular cAMP on OT receptors. Although ovarian steroids showed no effect on OT receptors, forskolin (an adenylate cyclase activator) and dibutyryl cAMP caused 1.5- to 1.6-fold increases in specific binding of OT without changing the binding affinity. When the endometrial cells were exposed to OT (0.1-1000 nM) in combination with arachidonic acid (10 microM), OT stimulated prostaglandin F2 alpha secretion in a dose-dependent manner. These results indicate the presence of functional OT receptors in prepubertal porcine endometrial cells and suggest that the concentration of OT receptors may be regulated by one or more substances that raise intracellular cAMP levels.

Animals↗
PubMed1997

Genetic identification of members of the genus Corynebacterium at genus and species levels with 16S rDNA-targeted probes.

16S rRNA gene-targeted probes were designed for the identification of corynebacteria at the genus and species levels. The genus-specific probe hybridized all clinically important members of the genus Corynebacterium and could distinguish them from other coryneform bacteria and phylogenetically related high G+C% gram-positive bacteria, including Actinomyces, Rhodococcus, Gordona, Nocardia, Streptomyces, Brevibacterium and Mycobacterium. The species-specific probes for C. jeikeium and C. diphtheriae could differentiated these two species from other members of this genus. The probes were used to select corynebacteria among gram-positive clinical isolates which had been tentatively identified as corynebacteria by biochemical tests. We screened 59 strains with the genus-specific probe; 51 strains hybridized to the genus-specific probe, 8 did not. Of the 51 strains that hybridized to the genus-specific probe, 1 hybridized to the C. diphtheriae species probe and 13 hybridized to the C. jeikeium species probe. The 8 strains that did not hybridize to the genus probe were further characterized by analyzing cell wall diaminopimelic acid and partial 16S rRNA sequencing. The results indicated that these strains were distributed in the genera Arthrobacter and Brevibacterium.

Amino Acids↗
PubMed1997

Amplification of rfbE and fliC genes by polymerase chain reaction for identification and detection of Salmonella serovar Enteritidis, Dublin and Gallinarum-Pullorum.

Polymerase chain reaction (PCR) primers for O9 antigen (rfbE) and phase 1 flagellin antigen (fliC) were designed for the rapid identification and detection of Salmonella serovar Enteritidis and Dublin. The rfbE primer pairs selectively amplified the rfbE region of group O9 Salmonella serovars. The fliC primer pairs amplified the DNAs of g,m and g,p-type flagellar antigen; Salmonella serovar Enteritidis, Dublin, and Essen. However, DNA from flagellar-negative Salmonella serovar Gallinarum-Pullorum was also amplified. The sensitivity of PCR primer pairs was 10(4) CFU/assay by boiled DNA preparation and 10(2) CFU/assay by proteinase K-treated DNA preparation.

Carbohydrate Epimerases↗
PubMed1997

Control of poly-beta-hydroxybutyrate synthase mediated by acetyl phosphate in cyanobacteria.

Poly-beta-hydroxybutyrate (PHB) synthesis in a cyanobacterium, Synechococcus sp. strain MA19, is controlled at the enzyme level and is dependent on the C/N balance in the culture medium. The control involves at least two enzymes. The first enzyme is PHB synthase. Little PHB synthase activity was detected in crude extracts from cells grown under nitrogen-sufficient conditions (MA19(+N)). The activity was detected exclusively in membrane fractions from nitrogen-deprived cells (MA19(-N)) under light but not dark conditions. The shift in the enzyme activity was insensitive to chloramphenicol, which suggests posttranslational activation. Acetyl phosphate activated PHB synthase in membrane fractions from MA19(+N). In vitro, the activation level of PHB synthase changed, depending on the concentration of acetyl phosphate. The second enzyme was phosphotransacetylase (EC 2.3.1.8), which catalyzes the conversion of acetyl coenzyme A (acetyl-CoA) to acetyl phosphate. The activity was detected in crude extracts from MA19(-N) but not in those from MA19(+N). The results suggested that intracellular acetyl phosphate concentration could be controlled, depending on C/N balance and intracellular acetyl-CoA concentration. Acetyl phosphate probably acts as a signal of C/N balance affecting PHB metabolism in MA19.

Acetyl Coenzyme A↗
PubMed1997

Surgical extraction of traumatic orbital mercury.

Initial clinical observation of a 2-year-old boy whose right eyelid had been pierced by a glass thermometer 3 days earlier showed a scab-covered cicatrix and slight swelling in the eyelid. X-ray examination showed the broken thermometer tip, fine glass fragments, and mercury droplets beneath the eyelid and extending along the superior orbital margin. On surgical incision, glass fragments and the thermometer tip were found and extracted from the eyelid and orbital fatty tissue with forceps, and 70.3 mg of mercury droplets were readily removed from the same regions by suction via an elastic needle connected to an injection syringe. Blood mercury gradually rose from the normal range to a peak of 28.4 microg/dl 3 months after surgery, then declined during the following 7 months to a level of 15.1 microg/dl. No abnormality has been found in liver or renal function to present.

Child, Preschool↗
PubMed1997

Multiple gastric carcinoids and pituitary adenoma in type A gastritis.

A 48-year-old male with type A atrophic gastritis developed multiple gastric carcinoids and a pituitary adenoma. Laboratory tests revealed high levels of serum gastrin and growth hormone (GH). He underwent subtotal gastrectomy, resulting in a return of the previously elevated gastrin level to normal. Serum GH concentration remained high. Three months after the surgery, the pituitary tumor, composed greatly of GH-immunoreactive cells, was partially removed. Since hypergastrinemia plays a pivotal role in gastric carcinoid formation and induces GH-releasing factor (GHRH) release resulting in GH-producing pituitary tumor formation, GH-producing pituitary adenoma might be a clinical manifestation in type A gastritis.

Adenoma↗
PubMed1997

[Endoscopic reconstruction after traumatic disruption of the urethra].

Endoscopic reconstruction was performed in 5 patients after complete traumatic disruption of the urethra. A prostatic urethra was disrupted in 1 patient, prostatic and membranous urethrae in 1 and bulbous urethra in 3. After endoscopic reconstruction, all patients required additional internal urethrotomy and urethral bougienage, but became able to void by themselves. Four patients had maximum flow rates between 13.8 and 41.9 ml/s. However, the other patient with an obliterated urethral segment of 4.6 cm had traumatic impotence preoperatively and a poor voiding status after reconstruction. None of the patients developed urinary incontinence or impotence associated with the operation. In conclusion, endoscopic reconstruction is recommended as the initial procedure for patients with obliterated segments smaller than 3 cm.

Accidents, Occupational↗
PubMed1997

[Evaluation by MR imaging of the velocity and volume of pre- and postprandial portal blood flow in the presence or absence of liver cirrhosis].

PURPOSE: We measured pre- and postprandial changes in the portal flow of normal volunteers and patients with liver cirrhosis using MR imaging and examined how to quantify portal flow to evaluate liver function. MATERIALS AND METHODS: Three groups were selected: middle aged normal volunteers (mean age 37.2 yrs., 5 persons), aged normal volunteers (mean age 61.5 yrs., 6 persons), and patients (mean age 67.6 yrs., 7 persons). We used cine-PC and the spin-echo method to measure portal flow velocity (PV) and vertical sectional area (PA), respectively. We repeated measurements of PV and PA in turn for about 60 minutes after a meal. RESULT: There were no significant differences in PV between the three groups before the meal. Study after the meal also indicated no significant difference between the two normal groups. In the normal group, PV and portal flow volume (Pvol.) increased by about 77% and 127%, respectively. In the cirrhotic liver group, PV and Pvol. increased by about 14% and 32%, respectively. A significant difference was seen between the normal and patient groups after the meal. We, therefore considered that the changing rate of Pvol. might be a sensitive parameter for evaluating liver function, including reserve.

Adult↗
PubMed1997

[Prognostic implication of DNA contents on long-term outcome of childhood acute lymphoblastic leukemia].

Prognostic value of cellular DNA content was evaluated in 189 children with acute lymphoblastic leukemia. Treatment outcome of the three different DNA index (DI) groups (Group A, DI = 1.0 vs. Group B, DI 1.01-1.15 vs. Group C, DI > or = 1.16) was compared between the two treatment risk groups (standard-risk and high-risk groups) stratified by the initial leukocyte count and age. In the standard-risk group, these groups had 10-year event free survival (EFS) rate (SE) of 62% (6%), 40% (21%) and 87% (6%), respectively (p < 0.05). In the high risk group, they had 10-year EFS rate of 30% (5%), 33% (27%) and 60% (19%), respectively (p < 0.01). Use of the DI, leukocyte count and age may be sufficient to distinguish the patients with an extremely low risk of failing to the standard ALL therapy from the patients with a relatively high-risk of treatment failure.

Child↗
PubMed1997

[Pharmacokinetic studies of all-trans retinoic acid (ATRA) and pilot study of intermittent schedule of ATRA and chemotherapy in childhood acute promyelocytic leukemia. Children's Cancer and Leukemia Study Group].

A pharmacokinetic study of all-trans retinoic acid (ATRA) was performed in 8 patients with various types of leukemia and MDS. After oral administration at a dose of 30 mg/m2, the mean peak plasma concentration was 430 ng/ml and was reached at 150 min. In one patient who failed to respond a very low plasma ATRA level was seen. Though the plasma ATRA exposure decreased significantly with daily drug administration, an intermittent schedule of ATRA administration would yield higher plasma drug concentrations. We treated 2 patients with refractory acute promyelocytic leukemia (APL) in a pilot study of ATRA followed by intensive chemotherapy (APL-ATRA protocol). Two patients successfully achieved complete remission with ATRA after failing under conventional chemotherapy. Based on the pharmacokinetic study of ATRA, an intermittent schedule of ATRA in addition to chemotherapy suggests an effective regimen for children with APL. Phase II trials to evaluate the role of intermittent schedules of ATRA are planned in Children's Cancer and Leukemia Study Group.

Administration, Oral↗
PubMed1997

[Treatment results of intermittent and cyclic regimen with ATRA and chemotherapy in childhood acute promyelocytic leukemia. Children's Cancer and Leukemia Study Group].

An intermittent and cyclic regimen with All-Trans Retinoic Acid (ATRA) and intensive chemotherapy was conducted due to pharmacokinetic studies on ATRA for acute promyelocytic leukemia (APL) in children. We have treated 17 children with APL using ATRA for remission induction followed by an intermittent schedule of ATRA plus intensive chemotherapy (APL-ATRA protocol). There were 10 males and 7 females. The median age was 9.0 years old. The median baseline white blood cell count was 12.1 x 10(3)/microliter, hemoglobin 7.8 g/dl, platelet 4.5 x 10(4) microliters at diagnosis. Sixteen patients showed t(15; 17) translocation. RT-PCR analysis was available in 15 patients and showed PML/RAR alpha rearrangement in all patients. Overall, 13 or 17 newly diagnosed patients (88%) achieved complete remission and EFS was 67%. Compared to the control (same chemotherapy without ATRA regimen), remission induction and EFS were significantly increased. The toxicity of ATRA consisted of retinoic acid syndrome in 1 and pseudotumor cerebli in another. Other toxicities included headache, chelitis, gastrointestinal trouble and bone pain. These results suggest that intermittent and cyclic regimen with ATRA and intensive chemotherapy (APL-ATRA protocol) is highly effective for APL patients.

Aclarubicin↗