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Biomedical subjects

H Miyake

Publications and source records attributed to H Miyake.

At least 397 records · Page 22Linked to original sources
PubMed1991

Common bile duct cancer with massive necrosis mimicking choledochal dilatation on CT. Case report.

Carcinomas of the common bile duct are usually seen as dilatation of the bile duct proximal to a solid mass on CT. In the case reported here, the common bile duct cancer itself mimicked dilated common bile duct on CT because of massive necrosis. In a case of simulating dilated common bile duct on CT, and discrepancy between CT and ultrasonography or endoscopic retrograde cholangiopancreatography, a common bile duct cancer with massive necrosis should be included in the differential diagnosis.

Aged↗
PubMed1991

Postinjection L-phenylalanine increases basal ganglia contrast in PET scans of 6-18F-DOPA.

The sensitivity of 18F-DOPA positron emission tomography for imaging presynaptic dopamine systems is limited by the amount of specific-to-nonspecific accumulation of radioactivity in brain. In rhesus monkeys, we have been able to increase this ratio by taking advantage of the lag time between 18F-DOPA injection and the formation of its main metabolite, the amino acid 18F-fluoromethoxydopa, the entrance of which into brain is responsible for most of the brain's nonspecific radioactivity. By infusing an unlabeled amino acid, L-phenylalanine, starting 15 min after 18F-DOPA administration, we preferentially blocked the accumulation of 18F-fluoromethoxydopa by preventing its entrance into brain through competition at the large neutral amino acid transport system of the blood-brain barrier. This method appears as reliable as the original and more sensitive, as demonstrated by the comparison of normal and MPTP-treated animals under both conditions.

Animals↗
PubMed1991

[The studies of melatonin values in the cerebrospinal fluid of hydrocephalic patients].

The changes in daytime levels of melatonin (MLT) in the cerebrospinal fluid (CSF) of twenty seven hydrocephalic patients were studied by the high-performance liquid chromatography (HPLC) method. Patients comprised three with congenital hydrocephalus (spina bifida 1, Chiari type II malformation 2), four post-meningitic hydrocephalus, fifteen brain tumors (chiasmal germinoma 3; malignant glioma of frontal 3, and temporal lobes 1; germinoma 1, teratoma 2, yolk sac tumor 1, epidermoid 1 in pineal region) and five cases of normal pressure hydrocephalus. CSF was collected between 0930 and 1030 h through puncture of the flushing device of shunt system or the lateral ventricle. The lowest value of MLT detected by HPLC was 15 pg/ml. Melatonin values were higher in patients aged under 10 years than over 20 years in the absence of meningitis or tumor in the pineal region. Even at ages over 15 years, higher CSF MLT values were obtained in the patients with meningitis or tumors in the pineal region. These results suggest that the inflammation or invasion of tumor into the pineal gland may stimulate the secretion of MLT by the pineal gland. However, lower MLT values were obtained in all patients over 40 years old. For these reasons, if one may use the changes of MLT values in CSF as a tumor marker or for determination of the treatment modality, time of CSF collection, age of patient, location or character of the tumor and presence of meningitis should be given due consideration. Also, the presence or absence of the rhythmical changes of melatonin values in a day following circadian rhythm are very important in determination of the treatment modality.

Adolescent↗
PubMed1991

[Changes in CSF pressure induced by acetazolamide administration test--as an indicator of shunt operation for so-called normal pressure hydrocephalus].

Lumber subarachnoid pressure was monitored via intrathecally introduced catheter in 9 patients, who showed ventricular dilatation on brain CT and were suspected of normal pressure hydrocephalus. During the pressure measurement, 500 mg of acetazolamide was rapidly injected intravenously and changes of CSF pressure were recorded. The results of the study were compared to clinical signs, brain CT findings and results of continuous pressure monitoring. The types of response of CSF pressure induced by acetazolamide administration were classified into 2 groups. In 5 cases (Group A), more than 50 percent increase of CSF pressure compared to the resting value was noted. On the contrary, in the remaining 4 cases (Group B), CSF pressure showed only slight increase (less than 25 percent or none). VP shunt was performed in 4 cases in Group A. Definite improvement of clinical symptoms was observed in all of these surgically treated cases. Correlation was found between the response to Acetazolamide administration and the appearance of B wave in the continuous spinal pressure monitoring. This study suggests that Acetazolamide test may be useful diagnostic test to select the patients for shunt operation.

Acetazolamide↗
PubMed1990

[CT and sonographic diagnosis of retained surgical sponge].

Seven cases of pathologically proven retained surgical sponge were reviewed and classified into four types, depending on CT and US findings. Type I: CT shows a mass with tiny gas bubbles, and sonogram shows an echogenic area with strong posterior shadow. Type II: CT shows an irregular high density mass with no gas bubble, and sonogram shows an echogenic area with strong posterior shadow. Type III: CT shows a low density mass with irregular internal high density areas, and sonogram shows a cystic mass with zigzag internal components. Type IV: CT shows an elliptic high density mass with low density area internally. Judging from the experiment and operative findings, these patterns were decided by the number and status of the gauze, volume of the exudate and hematoma, and status of the granulation. The author concludes that these characteristic CT and US findings, together with a history of surgery, permit the correct diagnosis of retained surgical sponge.

Adult↗
PubMed1990

[Differential diagnosis between nonhyperfunctioning adenoma and adrenal metastasis on adrenocortical scintigraphy].

Adrenocortical scintigraphy using I-131-adosterol was performed in six cases of nonhyperfunctioning adenoma incidentally discovered on CT scans and four cases of adrenal metastasis. In all six cases of nonhyperfunctioning adenoma, there was increased uptake of of the I-131-adosterol on the side of the adrenal mass discovered at CT. In three of four cases of adrenal metastasis, there was no uptake of the I-131-adosterol on the side of the mass detected at CT. Uptake was symmetrical in one case of adrenal metastasis. Adrenocortical scintigraphy is able to differentiate nonhyperfunctioning adenoma from adrenal metastasis in recognition of increased uptake of I-131-adosterol on the side of the adrenal mass discovered on CT scans.

Adenoma↗
PubMed1990

Syntheses, antiinflammatory, and analgesic activities of arylbiurets.

A number of arylbiurets were prepared and evaluated as antiinflammatory and analgesic agents by using the carrageenan paw edema and acetic acid stretching tests. Among them, the antiinflammatory activity of 1,3-dimethyl-5-phenylbiuret (7), 1-ethyl-3-methyl-5-phenylbiuret (11), and 1,1,3-trimethyl-5-phenylbiuret (13) were found to be more potent than phenylbutazone. The analgesic activity of 7 and of 5-(4-chlorophenyl)-1,1,3-trimethylphenylbiuret (16) is higher than that of aminopyrine.

Animals↗
PubMed1990

Fluctuation in the concentrations of vanillylmandelic acid and homovanillic acid in mass screening for neuroblastoma.

Fluctuations in the amount of vanillylmandelic acid (VMA) and homovanillic acid (HVA) were studied in random urine samples from 13 infants with neuroblastoma. In patients with a small tumour, many samples contained amounts below the cut off values, suggesting that detection of a patient with neuroblastoma depended on mathematical probability. Using high performance liquid chromatography a patient with a tumour of about 10 g may well be overlooked, whereas a patient whose tumour weighs over 30 g would probably be detected. With qualitative screening, although more likely to miss a patient with low VMA excretion, a patient with a tumour weighing over 50 g would be detected. In a thorough hospital examination care should be exercised in interpreting borderline values of VMA and HVA; excretion information suggesting the existence of a tumour may aid localization by radiological imaging procedures.

Adrenal Gland Neoplasms↗
PubMed1990

Antagonistic effect of physostigmine on ketamine-induced anesthesia.

Effects of physostigmine on ketamine-induced anesthesia and analgesia were studied in male Sprague-Dawley rats using behavioral tests. Rats were divided into six groups. Immediately after loss of the righting reflex following an intraperitoneal injection of ketamine 75 mg/kg, each group of rats was given an intraperitoneal injection of either physostigmine 0.05, 0.1, 0.2, 0.4, 0.6 mg/kg or saline as the control, respectively. Physostigmine 0.1 mg/kg caused the greatest antagonistic effect on ketamine anesthesia as indicated by sleeping time, duration of ataxia and motor coordination. The antagonistic effects of physostigmine were reduced by a dose of physostigmine of greater than 0.1 mg/kg. However, at no dose did physostigmine antagonize ketamine analgesia as indicated by the tail-flick latency. Physostigmine (0.4 and 0.6 mg/kg) itself had analgesic and motor-suppressive actions. It can therefore be presumed that there is a limited threshold of the dose of physostigmine which develops an antagonistic effect on ketamine anesthesia due to the motor-suppressive action. It is also confirmed that physostigmine itself produces analgesia, and does not antagonize ketamine-induced analgesia.

Anesthesia↗
PubMed1990

Incidence of neuroblastoma in Sapporo city.

The incidence of neuroblastoma in Sapporo City for the period before the enforcement of the mass screening of neuroblastoma (1974 to 1980) was compared with the period after it (1981 to 1987). No large difference was found in incidence between them. In 1981 to 1987 the occurrence cluster at 2 to 4 years of age found in the prescreening period disappeared and an accumulation of patients at 0 year of age was noted. The sensitivity of the mass screening was almost stable (76.9% to 80.0%) throughout the 7 years. By the mass screening system of Sapporo City, early detection will be expected in 60% to 70% of all the neuroblastoma patients, the deficiency of which is due to the patients who neglected the mass screening.

Adolescent↗
PubMed1990

N-terminal propeptide of type-III procollagen concentrations in the cord blood: an index of newborn maturity.

Cord serum concentrations of the N-terminal propeptide of type-III procollagen(PIIIP), insulin-like growth factor I (IGF-I), thyroid-stimulating hormone (TSH) and free thyroxine were measured in 149 neonates, consisting of 22 small for gestational age, 95 appropriate for gestational age, 21 large for gestational age and 11 neonates of less than 24 weeks of gestation. Their gestational ages (GAs) ranged from 20 to 41 weeks. A significant negative correlation was found between PIIIP levels and GA (r = -0.83, p less than 0.001). No significant difference was found in PIIIP levels between SGA and LGA neonates, when there were no difference in their GAs, in spite of a significant difference in their birth body weights (p less than 0.01). The high concentrations of the cord serum PIIIP did not appear to be influenced by either IGF-I or thyroid hormones, nor was there any relationship between PIIIP and the birth body weight, but only with GA, suggesting that determining cord levels of PIIIP seems to provide a useful parameter for the assessment of newborn maturity.

Biomarkers↗
PubMed1990

Vaccination of children in Japan.

The coverage rates of six vaccines (BCG, polio, DPT, measles, mumps and varicella) and the prevalence of these diseases in Japan were investigated. It was found that 82.2% of children had been inoculated with BCG before their first birthday, and 85.4% were given two doses of polio vaccine before their second birthday. The high acceptance rates of these vaccines seem to be attributable to mass inoculations at health centers. On the other hand, the median age when the first dose of DPT vaccine was given was as late as 22 months. Mass administration of this vaccine during infancy should be performed since about one-quarter of the patients with diphtheria, pertussis or tetanus were less than one year old. The cumulative percentage for measles inoculation failed to reach 60% by the second birthday. Considering that the incidence of measles has not yet been satisfactory lowered and that infants under 23 months of age account for about one-half of this incidence, more children less than 18 months old should be immunized. The ineffective rate of varicella vaccine was found to be 18.2%, although reestimation of its effectiveness may be necessary.

BCG Vaccine↗
PubMed1990

[Pharmacological profile of mofezolac, a new non-steroidal analgesic anti-inflammatory drug].

Pharmacological activities of mofezolac were investigated in experimental animal models and compared with those of indomethacin, ibuprofen, mefenamic acid, aspirin and aminopyrine. Mofezolac showed a potent suppression of various writhing models in mice or rats; and its potency was slightly lower than that of indomethacin, but was higher than those of the other reference drugs. Thus, mofezolac was especially active against chemically induced writhing and also in the phenylquinone induced intraperitoneal dye leakage reaction in mice. Mofezolac also has a potent inhibitory activity on the algesic responses induced by the mechanical stimulus of the inflammed tissue. Mofezolac exhibited a therapeutic effect comparable to indomethacin in the urate synovitis in dogs. Considering the anti-inflammatory and antipyretic actions, mofezolac was obviously less effective than indomethacin, and its potency was similar to that of ibuprofen. The ulcerogenic effect of mofezolac on the gastric mucosa was far weaker than that of indomethacin. In in vitro studies, the prostaglandin biosynthesis and platelet aggregation were inhibited to the same extent by both mofezolac and indomethacin. Accordingly, it may be considered that the actions of mofezolac are due to the inhibition of cyclooxygenase. Our result suggest that mofezolac can be a useful drug that shows a rapid pain-relieving activity in acute inflammations.

Analgesics↗
PubMed1990

[Acute and chronic effects of organic solvents on the central nervous system. Use of psychobehavioral performance tests in the assessment of toxicity].

Neurotoxicity of organic solvents is one of the most important emerging issues in the field of occupational health. Psychological testing has been proven useful not only in clinical diagnosis but also in experimental and epidemiological studies. Although various psychobehavioral performance test batteries have been applied in the study of neurotoxicity of organic solvents during these last two decades among European countries and America, only few studies have been made on these in Japan. It is therefore considered very important to review the major papers published to date, clarify the issues being currently discussed, and propose important studies for future. The present paper provides a review of the results obtained by the application of behavioral performance tests in the study of solvent toxicity. The studies reviewed are classified into the following five parts: 1. psychological test batteries developed to date, 2. human experimental studies and experimental field studies on the acute toxicity of organic solvents, 3. epidemiological studies on industrial workers, 4. characteristics of the central nervous system dysfunction caused by organic solvents, and 5. prognosis of workers diagnosed as chronic organic solvent intoxication. The paper also discusses the applicability of psychobehavioral techniques and addresses issues in data collection in the study of the effects of solvent exposure on the nervous system.

Behavior↗