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Biomedical subjects

H Miyake

Publications and source records attributed to H Miyake.

At least 703 records · Page 39Linked to original sources

Effect of prenatal exposure to styrene on the neurobehavioral development, activity, motor coordination, and learning behavior of rats.

Maternal Wistar rats were exposed via inhalation to 0, 50, or 300 ppm styrene for 6 h/day during gestation days 7 to 21, and offspring were subsequently evaluated in several neurobehavioral tests. Preliminary results with a small number of litters revealed significant dose-dependent effects in tests performed prior to weaning (surface righting, pivoting locomotion, and bar holding), as well as in tests performed after weaning (motor coordination, open-field behavior, and motor activity). Exposure to low concentrations of styrene (50 ppm) caused disturbances in motor coordination in addition to delaying some motor and reflex developments. Large doses (300 ppm) led to changes in open-field behavior and increases in spontaneous activity in addition to the delay in neurobehavioral developments. Exposure of dams to styrene did not clearly affect the learning behavior of the offspring. It was also observed that age played a role in the differences in styrene's effects on neurobehavioral function. Only subtle effects were found in both open-field behavior and motor-coordination function when compared with control rats at 120 days of age. These results suggest that the functional neurobehavioral development of progeny of dams exposed to styrene (or other solvents) should be further investigated.

Animals↗

Effects of cerivastatin sodium, a new HMG-CoA reductase inhibitor, on biliary lipid metabolism in patients with hypercholesterolemia.

The use of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors has become common in the treatment of hypercholesterolemia. The present uncontrolled study was undertaken to determine the effect of cerivastatin sodium (BAY w 6228), a new HMG-CoA reductase inhibitor, on biliary lipid levels in patients with hypercholesterolemia. Twenty-one hypercholesterolemic patients (World Health Organization type IIa = 16 patients; type IIb = 5 patients) received placebo during a 4- to 6-week observation period, after which they received cerivastatin sodium 0.2 mg/d for 12 weeks. Fasting blood samples were drawn for the measurement of serum lipid levels early in the morning before the start of treatment and once a month for each of the 12 weeks of cerivastatin sodium treatment. Gallbladder bile samples were aspirated with a duodenal tube by cerulein stimulation to assess bile lithogenicity. Serum total cholesterol levels decreased markedly after 12 weeks. However, no significant difference was found in the molar percentage composition of biliary lipids (e.g., cholesterol, phospholipids, and total bile acids) or in individual biliary bile acids. Consequently, no significant change in bile cholesterol saturation index was found. The index values before and after 12 weeks of treatment were 0.81 +/- 0.38 and 0.80 +/- 0.47, respectively, whereas when patients were grouped by type of hypercholesterolemia, there was a tendency toward decreased lithogenicity in patients with type IIb but not type IIa hypercholesterolemia. We concluded that cerivastatin sodium was an effective cholesterol-lowering drug that did not appear to worsen biliary lipid metabolism and that may decrease lithogenicity in patients with type IIb hypercholesterolemia.

Adult↗

Chemosensitization of human renal cell cancer using antisense oligonucleotides targeting the antiapoptotic gene clusterin.

BACKGROUND: Renal cell cancer (RCC) is a chemoresistant disease with no active chemotherapeutic agent achieving objective response rates higher than 15%. Clusterin is a cell survival gene that increases in human renal tubular epithelial cells after various states of injury and disease. Downregulation of clusterin, using antisense oligonucleotides (ASO), has recently been shown to increase chemosensitivity in several prostate cancer models. The objectives in this study were to evaluate clusterin expression levels in human RCC and normal kidney tissue, and to test whether clusterin ASO could also enhance chemosensitivity in human RCC Caki-2 cells both in vitro and in vivo. METHODS: Immunohistochemical staining was used to characterize clusterin expression in 67 RCC and normal kidney tissues obtained from radical nephrectomy specimens. Northern blot analysis was used to assess changes in clusterin mRNA expression after ASO and paclitaxel treatment. The effects of combined clusterin ASO and paclitaxel treatment on Caki-2 cell growth was examined using an MTT assay. Athymic mice bearing Caki-2 tumors were treated with clusterin ASO alone, clusterin ASO plus paclitaxel, and mismatch control oligonucleotides plus paclitaxel, over a period of 28 days with measurement of tumor volumes once weekly over 8 weeks. RESULTS: Immunohistochemistry of normal and malignant kidney tissue sections of 67 patients demonstrated positive clusterin staining for almost all RCC (98%) and an overexpression, compared to normal tissue, in a majority of RCC (69%). Clusterin ASO, but not mismatch control oligonucleotides, decreased clusterin mRNA expression in Caki-2 cells in a dose-dependent and sequence-specific manner. Pretreatment of Caki-2 cells with clusterin ASO significantly enhanced chemosensitivity to paclitaxel in vitro. Characteristic apoptotic DNA laddering was observed after combined treatment with ASO plus paclitaxel, but not with either agent alone. In vivo administration of clusterin ASO plus paclitaxel acted synergistically to increase apoptosis and significantly delay Caki-2 tumor growth, compared to mismatch control oligonucleotide plus paclitaxel. In addition, TUNEL staining revealed increased apoptotic cells in tumors treated with clusterin ASO plus paclitaxel compared to treatment with either clusterin ASO or paclitaxel alone. CONCLUSION: These findings confirm that the use of clusterin ASO may be a feasible strategy to enhance chemosensitivity for patients with advanced RCC.

Adenocarcinoma, Clear Cell↗

Effects of low lead exposure on neuro-behavioral function in the rat.

Small doses (45-180 micrograms/g) of lead acetate were administered to male rats by gavage every day during the first 3 wk of life. A blood concentration of approximately 59 micrograms/100 ml blood produced signs of disturbances in reflex development and some changes in emotional behavior. Larger doses resulted in subtle changes in the neuromotor coordination function. The effect of low levels of lead exposure on the cognitive function in operant conditioning could not clearly be observed. Brain lead concentration tended to be higher than in other tissues examined. At approximately 10 months following cessation of lead acetate administration, the brain lead concentration had decreased to almost the same level found in control rats, and no distinguishable differences were observed between the lead-treated rats and controls in emotional behavior and neuromotor coordination.

Animals↗

Computed tomography in amyloid goiter.

Two cases of amyloid goiter showed diffuse decreased density of enlarged thyroid on CT. The diffuse decreased density of amyloid goiter on CT is thought to represent large amount of adipose tissue often found in amyloid goiter. When diffuse decreased density of the enlarged thyroid is recognized on CT, amyloid goiter should enter into differential diagnosis.

Adult↗

Thickened gastric walls showing diffuse low attenuation on CT.

Thickened gastric walls of diffusely low attenuation were observed on CT of three of eight patients with mucinous adenocarcinoma in a retrospective review of 141 cases of gastric carcinoma. On pathologic examination the low attenuation correlated with large amounts of mucin in the pathologic specimens. Mucinous adenocarcinoma with abundant mucin should be included in the differential diagnosis of thickened gastric walls of diffusely low attenuation.

Adenocarcinoma, Mucinous↗

MRI of cervical masses of thymic origin.

OBJECTIVE: Thymic diseases can arise from remnants of thymic tissues along the path of fetal descent and may simulate thyroid tumors or lymphadenopathy. MATERIALS AND METHODS: We present two patients with a cervical mass arising from the cervical thymus that was caused by incomplete descent of the thymus into the mediastinum. RESULTS: In one patient a cervical mass was surgically confirmed to be a cervical thymoma, which simulated a thyroid cancer on CT and 201Tl-scintigraphy. In another patient, cervical thymic hyperplasia arising from an incompletely descended thymus was surgically confirmed. The isointensity between the cervical mass and an enlarged mediastinal thymus was recognized on MRI. CONCLUSION: If a cervical mass is located in the region of the lower pole of the thyroid or if there is a connection or the same intensity between the cervical mass and the mediastinal thymus on MRI, a diagnosis of a cervical mass of thymic origin should be considered.

Adult↗

Low attenuation intratumoral matrix: CT and pathologic correlation.

Diffuse low attenuation lesions on CT scans are caused by various pathologic conditions, especially differences of the intratumoral matrix. Low attenuation on CT scans was more defined than fat density and less than muscle density, the so-called near water density. We present representative cases of low attenuation lesions in correlation with their pathologic features. Intratumoral matrix showing diffuse low attenuation on CT was classified into eight groups: fatty degeneration/fatty metamorphosis, intracellular high lipid content, large amounts of lipid-laden macrophages, mucin-producing tumor, myxoid degeneration/myxoid matriX, massive necrosis, true cystic growth of the neoplasm, and massive edema. Lesions with fatty degeneration or intracellular high lipid content could be shown as negative CT attenuation. Knowledge of the neoplasms or disease processes that tend to have such pathology will lead to correct interpretation of CT scans of various organs.

Adult↗

Down-regulation of angiotensin II receptors in hypertrophied human myocardium.

1. Specific [125I]-angiotensin II (AngII) binding in normal and hypertrophied human myocardial membranes was saturable and of high affinity. Low concentrations of unlabelled AngII and saralasin competed with [125I]-AngII for the binding sites in these tissues. Thus, saturable [125I]-AngII binding in human myocardium exhibited pharmacological specificity that characterized high affinity receptors for AngII. 2. There was little difference in the apparent dissociation constant (Kd) values for [125I]-AngII binding between normal and hypertrophied human myocardium, whereas the maximal number of binding sites (Bmax) was significantly (51%) lower in the hypertrophied group. Further, PD123177, a selective antagonist of the AT2 receptor subtype, showed three orders of magnitude higher affinity for [125I]-AngII binding sites in both normal and hypertrophied myocardium than losartan, a selective antagonist of the AT1 receptor subtype; the Hill coefficients for these drugs were close to one. 3. A significant decrease in Bmax and Kd values for (-)-[125I]-iodocyanopindolol binding between normal and hypertrophied human myocardium rarely occurred. 4. The present study suggests that both normal and hypertrophied human myocardium predominantly contains the AT2 receptor subtype and that these receptors are down-regulated in hypertrophied tissues.

Aged↗

Mass screening for neuroblastoma and estimation of costs.

On the basis of epidemiological data and medical costs for patients with neuroblastoma, we have calculated the cost of mass screening for neuroblastoma with high performance liquid chromatography (HPLC) compared to the cost when it is not performed. If the sensitivity of the mass screening is 80% and 22,000 infants are screened annually the cost will be 27,809,000 yen ($191,800). If mass is not performed, the cost will be 28,446,000 yen ($196,200). The difference in cost (637,000 yen or $4,400) is fairly small. If the sensitivity is 75% and 16,500 infants are screened, the difference is also small (174,000 yen or $1,200). Therefore, mass screening with the HPLC method will not be an undue financial burden. But re-screening at an older age will be done with less financially favorable results, considering that the sensitivity may not be as high as that of the first screening and that mothers are somewhat reluctant about re-screening. The balance of the cost of mass screening by qualitative methods may also be less favorable, since the detection rate is low.

Chromatography, High Pressure Liquid↗

Klippel-Feil syndrome with conductive deafness and histological findings of removed stapes.

The Klippel-Feil syndrome is usually associated with sensorineural hearing impairment, but rarely is it associated with conductive or mixed deafness. A 22-year-old female presented with fusion of the cervical vertebrae, torticollis, scoliosis, pterygium colli, the Sprengel deformity with an omovertebral bone, concavity of the thorax and conductive hearing impairment of the right ear. Tympanotomy disclosed an atrophic long process of incus and a fixation of the stapes footplate, and stapedectomy was performed with immediate postoperative improvement of hearing. However, she developed a sudden hearing loss with dizziness soon after she had physical exercise on the 15th postoperative day, and revision surgery revealed a perilymph fistula of the oval window. Histological investigations of the removed stapes showed no specific osseous changes but hyperostosis of the posterior edge of the footplate. The literature is reviewed and the etiology of the conductive deafness and the perilymph fistula is discussed.

Adult↗

The administration of medical records in Japanese hospitals: a status report.

We performed the nation-level investigation, the aim of which is to grasp the present status of the administration of medical records in Japanese hospitals. There have been conducted such few investigations as this one yet in Japan. We made a report of the administration of medical records, the use of medical records, and the use of advanced tools like microfilms, computers, broken down by some attributes like establishments and bed sizes. As a result of statistical analysis of 446 hospitals, 10% hospitals showed considerably advanced administration of medical records. The remaining hospitals depend on the manual administration as an initial stage. We would generally say that private hospitals are the most delayed, however the difference is small. With respect to the classification of bed sizes, the degree of advancement in the administration of medical records is parallel to the direction of the more bed sizes.

Hospital Departments↗

The relationship between homovanillic/vanillylmandelic acid ratios and prognosis in neuroblastoma.

A total of 44 cases with neuroblastoma cases (excluding true positive cases detected in mass screenings) who were born from 1979 to 1991, and had data concerning the clinical stage and values of vanillylmandelic acid (VMA) and homovanillic acid (HVA) at diagnosis (microg/mg creatinine) were followed up until the end of 1994. Deaths were confirmed using the record of vital statistics of the Hokkaido Government. The 60-month survival rate of those who had an HVA/VMA ratio of 1-2 was 80.0%. Conversely, those with ratios <1 or >2 had respective survival rates of 24.1% and 5.3%. Most of those with a ratio >2 died within 24 months of diagnosis. Many of the cases with a ratio <1 lived over 12 months but died within about 36 months. Many tumors of those cases with a ratio of 1-2 originated in extra-adrenal glands, and had negative n-myc amplification. Most of the patients with a ratio >2 were diagnosed at 1 year of age or older. The HVA/VMA ratio at diagnosis is useful in estimating both the survival period and the prognosis.

Adrenal Gland Neoplasms↗

Lifestyle and gastric cancer: a case-control study.

In Hokkaido, Japan, in order to investigate the etiological relation between gastric cancer and lifestyle, a case-control study was conducted, employing 242 cases with this cancer and 484 controls matched for sex, age, and place of residence. Eating meals within a short time, eating until full, irregularity in the time for supper, having dentures, and lack of teeth showed high odds ratios. Putting an excess digestive burden on the stomach by insufficient chewing promotes the development of this cancer. Stress, long working time, irregularity in sleeping time, and gray hair in males showed high odds ratios. A stressful life may be promotive for this cancer through depressed immunoresistance. Logistic regression analysis showed that those who ate meals rapidly, had strong stress and had lost many teeth were at high risk. The linear trend of the dose-response relationship between the number of teeth lost and the odds ratio was highly significant. To avoid stress, to chew foods sufficiently, and to maintain the health of the oral cavity can help to prevent gastric cancer.

Adult↗

Mass screening for neuroblastoma by HPLC and by non-HPLC: a review.

There have been a number of contradictory views concerning the efficacy of mass screening for neuroblastoma. Three Japanese and one cohort study from Quebec, and three Japanese cross-sectional studies were reviewed. The four cohort studies revealed that mass screening using high performance liquid chromatography (HPLC) reduced the incidence of this disease by about half in children aged from 1 to 4 years while little reduction was noted in screening utilizing non-HPLC methods. There is a large difference in the efficacy of mass screening depending on the method used. In the three cross-sectional studies, there was no discrimination between screened and unscreened cases, or between subjects screened by HPLC and non-HPLC methods. The percentage of children in the cross-sectional studies screened by HPLC was low. Cross-sectional studies seem inappropriate in assessing the effectiveness of current HPLC mass screening.

Brain Neoplasms↗