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Biomedical subjects

K Arita

Publications and source records attributed to K Arita.

212 records · Page 12Linked to original sources
PubMed1977

Effect of 1alphaOH-vitamin D3 in a case of pseudohypoparathyroidism.

A 37-year-old woman with typical features of pseudohypoparathyroidism (chronic tetany, paresthesia, persistent hypocalcemia, round face, short stature, short metacarpals and metatarsals, cucutaneous calcification and lack of response to exogenous and endogenous parathyroid hormone as regards urinary phosphate and cyclic AMP excretion) was treated with oral administration of 2 microgram/day of 1alphaOH-vitamin D3. Serum calcium started to rise within 3 days returning to the normal level with disappearance of symptoms referrable to hypocalcemia. Such a favorable effect of a small dose of 1alphaOH-vitamin D3 in a patient with typical hypoparathyroidism suggests an important role of disturbance of 1alpha-hydroxylation of vitamin D3 by the kidney in the pathogenesis of calcium and phosphorus abnormality in this disease. Forty-four cases of pseudohypoparathyroidism in the Japanese literature were briefly reviewed.

Administration, Oral↗
PubMedDate not supplied

Prenatal diagnosis of open spina bifida by MRI and ultrasonography.

A case that was diagnosed prenatally as having open spina bifida by magnetic resonance imaging (MRI) and ultrasound (US) examination is reported. At the time of the third US examination, the spina bifida cystica was detected, but it could not be determined by US whether it was open or closed spina bifida. A lumbosacral skin defect was detected on MRI, which permitted prenatal diagnosis of open spina bifida. Surgical repair was performed immediately after delivery. Prenatal intrauterine evaluation of the fetal CNS morphology and malformation has advanced with the improvement of diagnostic tools. Each diagnostic tool, however, has its own advantages and disadvantages. In prenatal intrauterine evaluation, it is important that observation be made through the combined use of multiple diagnostic tools.

Adult↗
PubMedDate not supplied

Lethal effects of the combination of hyperthermia and bromocriptine or a somatostatin analogue on normal pituitary cells and pituitary tumour cells.

Effects of hyperthermia alone and combined with bromocriptine (BC) or a somatostatin analogue (SMS 201-995) were studied in vitro on normal pituitary and pituitary tumour cells (GH3 cells). GH3 cells were more sensitive to heat than normal pituitary cells and a maximal difference in survival was obtained with hyperthermia at 42.5 degrees C for 6 h. BC had cytotoxic and antiproliferative effects on GH3 cells, whereas SMS 201-995 was not effective. Hyperthermia at 42.5 degrees C for 3 h in combination with BC enhanced selective cytotoxicity for GH3 cells. In contrast, combined treatment with hyperthermia and SMS 201-995 failed to enhance cytotoxicity for GH3 cells. The combination of hyperthermia and BC could provide improved therapeutic efficacy in patients with pituitary adenomas.

Animals↗
PubMedDate not supplied

Cystic lymphangioma: its orofacial manifestations.

A patient age five years, nine months with cystic lymphangioma was studied to determine the causes of malocclusion and the optimum time for its treatment. The main findings were unilateral anterior and posterior crossbite and displacement of the mandibular midline due to maxillary deformity and mandibular rotation. The force of the cystic lymphangioma mass caused deformity of the maxilla and rotation of the mandible. The patient had no functional impairment of speech or mastication. A decision was made to defer treatment of malocclusion until complete surgical excision of the cystic lymphangioma can be undertaken, thereby minimizing the chance of malocclusion re-occurrence.

Cephalometry↗
PubMedDate not supplied

Absence of mutations in the NBS1 gene in B-cell malignant lymphoma patients.

BACKGROUND: Nijmegen breakage syndrome (NBS), also known as ataxia-telangiectasia (AT) variant, is an autosomal recessive disorder characterized by microcephaly, growth retardation, severe combined immunodeficiency and a high incidence of lymphoid carcinoma, the majority of which are B-cell lymphomas. To determine whether the NBS1 gene is a tumor suppressor gene in B-cell lymphoma, we screened B-cell malignant lymphoma (ML) for any evidence of NBS1 mutation. MATERIALS AND METHODS: Sequence analysis of the NBS1 gene was performed from PCR products amplified from the DNA of 12 extracranial ML or RT-PCR products amplified from cDNA of 8 primary central nervous system lymphoma. RESULTS: Direct sequence analysis revealed that no NBS1 mutations were present in any of these patients. CONCLUSION: The present results suggested that the contribution of NBS1 mutations to B-cell ML was minimal, despite the fact that the NBS1 gene was causative factor in these cases.

Adolescent↗
PubMedDate not supplied

Quantitative MR evaluation of intracranial epidermoid tumors by fast fluid-attenuated inversion recovery imaging and echo-planar diffusion-weighted imaging.

BACKGROUND AND PURPOSE: Quantification of MR can provide objective, accurate criteria for evaluation of a given MR sequence. We quantitatively compared conventional MR sequences with fast fluid-attenuated inversion recovery (fast-FLAIR) and echo-planar diffusion-weighted (DW) MR imaging in the examination of intracranial epidermoid tumors. METHODS: Eight patients with surgically confirmed intracranial epidermoid tumors were examined with T1-weighted MR sequences, fast T2- and proton density-weighted dual-echo sequences, fast-FLAIR sequences, and DW echo-planar sequences. We measured the MR signal intensity and apparent diffusion coefficient (ADC) of epidermoid tumors, normal brain tissue, and CSF and calculated the tumor-to-brain and tumor-to-CSF contrast ratios and contrast-to-noise ratios (CNR). Results were compared among the five MR methods. RESULTS: On fast-FLAIR imaging, the mean signal intensity of epidermoid tumors was significantly higher than that of CSF but significantly lower than that of the brain; the contrast ratio and CNR of tumor-to-CSF were 4.71 and 9.17, respectively, significantly greater than the values with conventional MR imaging. On echo-planar DW imaging, epidermoid tumors showed a remarkably hyperintense signal relative to those of the brain and CSF; the mean contrast ratio and CNR of tumor-to-CSF were 13.25 and 19.34, respectively, significantly greater than those on fast-FLAIR or conventional MR imaging. The mean ADC of epidermoid tumors was 1.197 x 10(-3) mm(2)/s, significantly lower than that of CSF but higher than that of brain tissues. CONCLUSION: Fast-FLAIR imaging is superior to conventional MR imaging in depicting intracranial epidermoid tumors. Echo-planar DW imaging provides the best lesion conspicuity among the five MR methods. The hyperintensity of epidermoid tumors on echo-planar DW imaging is not caused by the diffusion restriction but by the T2 shine-through effect.

Aged↗
PubMedDate not supplied

Subtracted 3D CT angiography for evaluation of internal carotid artery aneurysms: comparison with conventional digital subtraction angiography.

BACKGROUND AND PURPOSE: 3D computed tomographic angiography (3DCTA) has been used recently for the evaluation of intracerebral aneurysms, but it is difficult to use this technique to visualize aneurysms near the base of the skull because of the presence of bone. Subtracted 3DCTA could replace digital subtraction angiography (DSA) for evaluation of aneurysms near the base of the skull if the 2 methods were to give similar results. The aim of this study was to compare the evaluation of aneurysms of the internal carotid artery (ICA) near the base of the skull by subtracted 3DCTA and DSA. METHODS: CTA and DSA were obtained in 25 patients with unruptured aneurysms of the ICA. To create subtracted 3DCTA images, we used a volume subtraction (VS) method, wherein nonenhanced volume data are subtracted from enhanced volume data. CTA and DSA were reviewed by 2 neuroradiologists who performed the detection and characterization of aneurysms of the ICA by using 2D multiplanar reformatted (MPR) and VS- and nonsubtracted (NS)-3DCTA images with volume rendering techniques. RESULTS: DSA detected 29 aneurysms in the 25 patients. VS-3DCTA detected all 29 aneurysms in the 25 patients and was equivalent to DSA for evaluating their characteristics (location, size, and direction). NS-3DCTA detected 19 (1 cavernous, 4 ophthalmic, 1 superior hypophyseal, 7 posterior communicating, and 6 anterior choroidal artery) of these 29 aneurysms, but it could not characterize ophthalmic and superior hypophyseal artery aneurysms because they were only partly visible on NS-3DCTA because of bony structures. 2D-MPR images detected all but the small aneurysms (24 of 29 detected). VS-3DCTA and 2D-MPR could visualize all branching arteries (ophthalmic, posterior communicating, and anterior choroidal) detected by DSA, but NS-3DCTA could not visualize ophthalmic arteries because of the presence of bony structures. CONCLUSION: VS-3DCTA can be used as an alternative to DSA for preoperative examination of aneurysms near the skull base, where it provides equivalent identification and characterization.

Adult↗