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Biomedical subjects

H Sumiya

Publications and source records attributed to H Sumiya.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Fertility after orchiopexy for unilateral retention testis].

The testicular function after orchiopexy for unilateral cryptorchism was examined for fertile state with the relation to the age at operation and the testicular size. Sperm concentration decreased with the age at operation, accompanying a rise of gonadotropins and a decrease of the testicular size. The testicular size decreased with the age at operation. sperm deterioration was correlated more with the testicular size in the normally descending side than that of the operated one. The gonadotropin level was inversely correlated with the size of the contralateral normally descending testis. These results indicate that fertility after unilateral orchiopexy is influenced by the age at operation as well as the development of the normally descending contralateral testis.

Adolescent↗
PubMed1991

[Evaluation of brain perfusion SPECT imaging using 99mTc-ECD].

Fundamental and clinical evaluation was performed on 99mTc-ECD, a new agent for brain perfusion SPECT. Radiochemical purity reaches a plateau of approximately 98% at 30 min after reconstitution and remains stable up to 24 hours later. A biodistribution study showed approximately 5% injected dose in the brain, very slow brain washout of 5.6% per hour on the average, and rapid washout from the other organ mainly through the urinary system. Brain ECD distribution was determined within 2 min postinjection and remained stable for up to 1 hour. Three hours later, slight but significant changes in brain distribution were observed, that were relative reduction of cerebral cortical activity and gray to white matter activity ratio, and relative elevation of white matter and thalamic activities. Comparative studies of ECD images with IMP and HMPAO images revealed that radioactivity contrast between affected and unaffected areas was less prominent in ECD than in IMP in cerebral and cerebellar cortical lesions, more prominent in ECD than in IMP in striatal and thalamic lesions, and somewhat more prominent in ECD than in HMPAO in both lesions. Imaging around 1 hour postinjection seems to be more appropriate than immediate postinjection imaging because of the clearance of the extracranial radioactivity and somewhat better radioactivity contrast between affected and unaffected areas.

Adult↗
PubMed1990

Immunohistochemical study of androgen receptor in benign hyperplastic and cancerous human prostates.

Androgen receptor was detected immunohistochemically in benign as well as malignant prostatic tissues by using a monoclonal rat anti-human androgen receptor antibody (AN 1-15). In both benign and malignant cells, the androgen receptor was exclusively localized in nuclei. In hyperplastic prostate, the androgen receptor was stained in the glandular and the stromal cells. In the gland, cells facing the lumen were stained more intensively than those adjacent to the basal membrane. In cancer tissue, receptor-positive and -negative cancer cells were intermingled. The percent of strongly positive cancer cells was correlated inversely with grade. Relapsed cells showed a low population of strongly positive cells irrespective of grade.

Antibodies, Monoclonal↗
PubMed1990

Nonobstructive urinary tract dilatation in nephrogenic diabetes insipidus.

The follow-up study has been performed in 4 male patients with nephrogenic diabetes insipidus lasting for 4 to 15 years. Hydronephrosis or hydroureter appeared to be caused by polyuria with or without urinary tract obstruction. The efficacy of drainage operation is emphasized when polyuria surpasses the transporting ability of urine in the urinary tract.

Adolescent↗
PubMed1990

Plasma concentration of atrial natriuretic factor in idiopathic oedema.

Low level of plasma atrial natriuretic factor (ANF) under altered dietary sodium and its elevation during bigeminy were found in a 40-year-old woman with idiopathic oedema. The natriuretic effect of this peptide and the role of renin-angiotensin-aldosterone system in oedema formation in this disorder are discussed.

Adult↗
PubMed1990

Histochemical examination of expression of ras p21 protein and R 1881-binding protein in human prostatic cancers.

Expression of ras p21 was examined with monoclonal antibody RASK-3 in normal, benign hyperplasic, and cancerous prostates. In patients with stage D2 disease who received endocrine therapy, the relation between ras p21 expression, response to therapy, and prognosis was studied. In these patients, R 1881-binding protein (androgen receptor and progestin-binding protein) was also examined. Non-cancerous cells and most cancer cells from stage A patients did not express ras p21, while expression increased with both higher staging and grading. Staging pelvic lymphadenectomy was done in some stage A2-C cases, and presence of nodal metastasis was correlated with ras p21 expressions in the primary tumours. In stage D2, there was no correlation between ras p21 expression and R 1881-binding protein. Response to therapy and survival did not correlate with expression of ras p21, but was influenced by presence of R 1881-binding protein.

Androgen-Binding Protein↗
PubMed1990

Tc-99m HMPAO brain perfusion tomography atlas using a high resolution SPECT system.

Excellent SPECT images of brain perfusion with Tc-99m HMPAO were obtained by the use of a three-head rotating gamma camera SPECT system with high resolution (FWHM 7mm) in a normal volunteer. These images should be clinically effective for evaluating various neurologic disorders. Transverse, coronal, and sagittal sectional HMPAO-SPECT images are correlated with corresponding brain MRI images of the same normal volunteer in this atlas.

Adult↗
PubMed1990

Measurement of testicular volume by ultrasonography.

To measure testicular volume accurately, an ultrasonographic method was developed and the results obtained from this compared with those obtained by conventional measurements, namely (1) comparison with testis models, (2) an orchidometer, and (3) measurement of testicular volume by calipers through the scrotal skin. Data from these methods were compared with the actual volume measured at operation by slide calipers placed directly on the testis. The volume obtained by comparison with testis models or with an orchidometer tended to over-estimate the actual volume. The volume measured by slide calipers on scrotal skin was also found to be incorrect. On the other hand, the volume measured by ultrasonography proved to be closer to, and to correlate well with, the actual volume, and was considered to be the best method.

Humans↗
PubMed1990

[Adrenal regeneration hypertension--effects of vascular connective tissue protein and plasma corticosterone on hypertension in rats with adrenal regeneration hypertension].

In young rats consuming 1% NaCl drinking solution, unilateral nephrectomy and bilateral adrenal enucleation caused a hypertension. Plasma corticosterone concentration in hypertensive rats was not significantly higher than that of normotensive control rats in early hypertensive or chronic hypertensive stage. At the end of experiment, each rat received an intravenous injection of 0.4 microCi/g of 3H-lysine and was sacrificed 2 hours after the injection. Incorporation of 3H-lysine into collagen or elastin of the mesenteric artery and heart in hypertensive rats was greater than that of normotensive rats. Administration of phenoxybenzamine hydrochloride lower the blood pressure of hypertensive rats and reduced the incorporation of 3H-lysine into collagen and elastin of the mesenteric artery and heart. From these findings, increased protein synthesis of collagen and elastin in hypertensive rats appears to play an important role for the maintenance of adrenal regeneration hypertension.

Adrenal Glands↗
PubMed1990

Investigating the response of prostatic cancer to endocrine therapy.

The presence of androphilic protein identified histochemically with R 1881-CMO-BSA-FITC correlated with response to endocrine therapy and prognosis. Ras P21 was not a useful indicator of the subsequent course of the disease. Conventional X ray assessment of boney metastases still seems of use in monitoring overall progress of the disease.

Bone Neoplasms↗
PubMed1990

[Fundamental study on nuclear medicine imaging of cholinergic innervation in the brain: changes of neurotransmitter and receptor in animal model of Alzheimer's disease].

A fundamental study was performed on the nuclear medicine imaging of cholinergic innervation in the brain. In a cholinergic denervation model prepared by producing an unilateral basal forebrain lesion in the rat, which is reported to be one of animal models of Alzheimer's disease, quantitative determination of acetylcholine in parietal cortices revealed statistically significant 31% decrease on an average in the ipsilateral side relative to the contralateral side to the lesion. In vitro receptor autoradiography showed no significant differences in total, M1 and M2 muscarinic acetylcholine receptors between the ipsilateral and contralateral cortices to the lesion. Simultaneous mapping of presynaptic cholinergic innervation using 3H-2-(4-phenylpiperidino) cyclohexanol (AH5183) demonstrated significant 14% decrease of AH5183 binding on an average in the ipsilateral relative to the contralateral fronto-parieto-temporal cortices to the lesion. These results suggest that AH5183 is a promising ligand for mapping cholinergic innervation in nuclear medicine imaging.

Acetylcholine↗
PubMed1990

Autoradiographic analysis of iodoamphetamine redistribution in experimental brain ischemia.

The pathophysiologic significance of iodoamphetamine (IMP) redistribution was analyzed using a double radionuclide autoradiography technique in experimental brain ischemia in the rat. Within 4 hr after unilateral arterial occlusion, IMP almost completely redistributed at 150 min postinjection in the affected areas. At 2 min postinjection, both a remarkable decrease of IMP accumulation and histopathologic change of diminished staining were observed in these areas. The redistribution amplitude was higher in the affected hemisphere, especially in the regions surrounding the ischemic core than in the unaffected hemisphere. These findings were consistent with computer simulation studies of the time course of brain activity based on the standard diffusible tracer model. The results suggest that IMP redistribution in the ischemic area is due to differences of the temporal changes of the brain activity between the unaffected and affected areas and that it is a "physical" phenomenon (only flow related) rather than a "biologic" one.

Amphetamines↗
PubMed1990

[Brain perfusion SPECT imaging before and during the acetazolamide test using 99mTc-HMPAO].

A new method using brain perfusion 99mTc-HMPAO SPECT imaging was developed for evaluating cerebral perfusion reserve by the acetazolamide test with a short period. The first SPECT study was carried out for 13.5 min to obtain SPECT images at the resting state after 3 min postinjection of 555 MBq (15 mCi) of 99mTc-HMPAO. At the same time as the start of the first SPECT study, 1 g of acetazolamide was intravenously injected. Immediately after the stop of the 1st SPECT study, 925 MBq (25 mCi) of 99mTc-HMPAO from the same vial as in the first study was additionally injected. Three minutes later the second SPECT study was carried out for 10 min. After reconstruction the tomographic images in the first study were subtracted from the images in the second study to obtain those during the acetazolamide test after correction of the time differences in data acquisition between the two studies. This subtraction technique gives independent brain perfusion SPECT images before and during the acetazolamide test. Besides, the regional flow changes during the test were quantitatively analyzed. In conclusion this method seems to be practically useful for evaluating regional brain perfusion before and during drug treatments as a consecutive study with a short period of approximately 30 min.

Acetazolamide↗
PubMed1989

The effect of adrenal surgery on plasma atrial natriuretic factor and sodium escape phenomenon in patients with primary aldosteronism.

Plasma concentrations of atrial natriuretic factor and some vasoactive substances were determined in 8 patients with aldosterone-producing adenoma, 10 with idiopathic adrenal hyperplasia, 10 normotensive subjects and 12 patients with essential hypertension. Plasma atrial natriuretic factor concentration in patients with aldosterone-producing adenoma was the highest among the examined groups. Adrenal surgery reduced plasma concentrations of atrial natriuretic factor and aldosterone concomitant with the elevation in urinary sodium excretion, plasma renin activity and urinary sodium-to-potassium ratio. Withdrawal of trilostane (3 beta-hydroxysteroid dehydrogenase inhibitor) in patients with idiopathic adrenal hyperplasia increased plasma concentrations of atrial natriuretic factor and aldosterone, and decreased the urinary sodium-to-potassium ratio, plasma renin activity and urinary sodium excretion. However, reduced urinary sodium excretion following trilostane treatment returned to the control level successively despite the high levels of plasma atrial natriuretic factor and aldosterone. Acute infusion of saline remarkably increased plasma atrial natriuretic factor concentration in patients with idiopathic adrenal hyperplasia and aldosterone-producing adenoma. These results suggest that a high level of atrial natriuretic factor is a characteristic feature in patients with aldosterone-producing adenoma caused chiefly by the expansion of extracellular fluid volume, and circulating atrial natriuretic factor may contribute to regulation of the sodium escape phenomenon in patients with aldosterone-producing adenoma or idiopathic adrenal hyperplasia.

Adenoma↗
PubMed1989

Double tracer autoradiographic method for sequential evaluation of regional cerebral perfusion.

A new double tracer autoradiographic method for the sequential evaluation of altered regional cerebral perfusion in the same animal is presented. This method is based on the sequential injection of two tracers, 99mTc-hexamethylpropyleneamine oxime and N-isopropyl-(125I)p-iodoamphetamine. This method is validated in the assessment of brovincamine effects on regional cerebral perfusion in an experimental model of chronic brain ischemia in the rat. The drug enhanced perfusion recovery in low-flow areas, selectively in surrounding areas of infarction. The results suggest that this technique is of potential use in the study of neuropharmacological effects applied during the experiment.

Amphetamines↗
PubMed1988

Androphilic protein studied histochemically in stage D2 prostatic cancer.

Androphilic protein in prostatic cancer was histochemically observed with dihydrotestosterone (DHT), R 1881, and mibolerone as ligands. Cancer cells were equally stained with fluorescent R 1881 and mibolerone, and this fluorescence seems to be made up of both the androgen receptor and progestin-binding protein. The staining with fluorescent DHT was weak. Sixty-two Stage D2 prostatic cancer patients were examined with histochemical androphilic protein, and they then received endocrine therapy. The presence of fluorescence of R 1881 was not correlated with grade, but a relationship between the presence of fluorescence and the response to endocrine therapy was noticed 6 months after the start of treatment. Moreover, fluorescence-positive patients showed better survival than fluorescence-negative patients. An examination with fluorescent DHT revealed a similar tendency to that of R 1881, but the frequency of positive fluorescence was lower, indicating that R 1881 is a suitable ligand in this type of study.

Androgen-Binding Protein↗