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Biomedical subjects

H Niimi

Publications and source records attributed to H Niimi.

At least 253 records · Page 14Linked to original sources

Efficacy and complications of the Gianturco-Z tracheobronchial stent for malignant airway stenosis.

PURPOSE: To describe our experience using the Gianturco Z-stent (G-Z stent) for the management of malignant tracheobronchial stenosis, with special reference to complications. METHODS: Thirty-six stents were used in 22 patients with 28 lesions. Thirteen patients were grade 5 according to the Hugh-Jones classification. The technical success rates, follow-up results, and complications were reviewed on the basis of the patients' charts and radiographs. RESULTS: All stents were successfully placed in the ideal position without procedure-related complications. After the procedure, respiratory status improved in 95% (21/22) of patients, and performance status improved in 77% (17/22). Mean survival after stent placement was 15 weeks. Four patients suffered from increased thick secretions requiring multiple suctioning and aspiration by bronchoscopy. One of these patients died from asphyxiation 2 weeks after placement. Stent disruption and/or migration was observed in six patients. Of these six, four experienced life-threatening hemoptysis; all four had received aggressive anticancer treatment. CONCLUSION: G-Z stents are useful for palliation of malignant tracheobronchial obstruction. However, complications of stent strut fracture and migration give cause for concern.

Aged↗

Clinical and MRI findings in a case of D-2-hydroxyglutaric aciduria.

We report the 3rd case in the literature of a 3-year-old boy with D-2-hydroxyglutaric (D-2-HG) aciduria, who presented primarily generalized hypotonia and feeding difficulty during the neonatal period, with eventual development of generalized myoclonic seizures. Gas chromatographic analysis of urinary organic acids showed persistent excretion of D-2-HG. The clinical manifestations are quite similar to those of the 2nd reported case with D-2-HG aciduria. Serial MRI performed 1 year and 2 1/2 years after birth demonstrated bilateral symmetrical periventricular lesions in the parieto-occipital white matter, which might reflect the cortical blindness in our patient.

Amino Acid Metabolism, Inborn Errors↗

Intradural spinal meningioma in a 5-year-old female.

The case of a 5-year-old female with an intradural spinal meningioma is presented. She showed slowly progressive muscle weakness of the lower extremities commencing at 3 years. Spinal magnetic resonance imaging (MRI) demonstrated an intradural mass extending from the eleventh thoracic vertebra to the fifth lumbar vertebra, which was excised totally by means of laminoplasty. The surgical procedure brought a gradual improvement in her gait. This case is unusual because of the tumor's location (lumbar) and origin (cauda equina), and because of the onset at a relatively young age.

Child, Preschool↗

Comparison of MRI white matter changes with neuropsychologic impairment in Cockayne syndrome.

The neuropsychologic function and white matter changes observed on magnetic resonance imaging (MRI) in Cockayne syndrome were studied. MRI with T2-weighted sequences revealed periventricular hyperintensity and white matter hyperintensity in all 3 Cockayne syndrome patients examined; in contrast, 8 age-matched controls had no periventricular or white matter hyperintensity. MRI scans were graded according to the severity of periventricular or white matter hyperintensity using a scale applied to an elderly patient population. There was no difference in the severity of MRI white matter changes in these 3 Cockayne syndrome patients, 2 of whom had severe neuropsychologic functions and one a relatively milder one. There was no correlation between neuropsychologic impairment and MRI white matter changes.

Adolescent↗

Moyamoya syndrome in a patient with Down syndrome presenting with chorea.

An 11-year-old girl with Down syndrome is reported with moyamoya syndrome; she presented with chorea and mental regression, but had no hemiplegia or convulsions. Magnetic resonance imaging and magnetic resonance angiography were valuable for diagnosis of moyamoya syndrome. It is suggested that moyamoya syndrome be considered as a possible cause of involuntary movements in Down syndrome patients.

Child↗

CT of chronic infiltrative lung disease: prevalence of mediastinal lymphadenopathy.

OBJECTIVE: Our goal was to determine the prevalence of mediastinal lymph node enlargement at CT in patients with diffuse infiltrative lung disease. MATERIALS AND METHODS: The study was retrospective and included 175 consecutive patients with diffuse infiltrative lung diseases. Diagnoses included idiopathic pulmonary fibrosis (IPF) (n = 61), usual interstitial pneumonia associated with collagen vascular disease (CVD) (n = 20), idiopathic bronchiolitis obliterans organizing pneumonia (BOOP) (n = 22), extrinsic allergic alveolitis (EAA) (n = 17), and sarcoidosis (n = 55). Fifty-eight age-matched patients with CT of the chest performed for unrelated conditions served as controls. The presence, number, and sites of enlarged nodes (short axis > or = 10 mm in diameter) were recorded. RESULTS: Enlarged mediastinal nodes were present in 118 of 175 patients (67%) with infiltrative lung disease and 3 of 58 controls (5%) (p <0.001). The prevalence of enlarged nodes was 84% (46 of 55) in sarcoidosis, 67% (41 of 61) in IPF, 70% (14 of 20) in CVD, 53% (9 of 17) in EAA, and 36% (8 of 22) in BOOP. The mean number of enlarged nodes was higher in sarcoidosis (mean 3.2) than in the other infiltrative diseases (mean 1.2) (p <0.001). Enlarged nodes were most commonly present in station 10R, followed by 7, 4R, and 5. CONCLUSION: Patients with infiltrative lung disease frequently have enlarged mediastinal lymph nodes. However, in diseases other than sarcoid, usually only one or two nodes are enlarged and their maximal short axis diameter is <15 mm.

Adult↗

A discordant movement in urine calcium excretion in relation to serum calcium and parathyroid function occurring immediately after birth.

We studied the relationship between serum calcium and urinary calcium excretion in association with the parathyroid function in 28 neonates at birth and at five days of age. At birth, the urine calcium was low in spite of high cord serum calcium and a low parathyroid hormone level. On the fifth day of birth, urinary calcium excretion increased despite the reduction in serum calcium and an increase in the parathyroid hormone. These results suggest that the large increase in renal blood flow and the consequent increase in calcium load on the immature renal tubule occurring after birth may be the main cause for the change in this serum calcium-urinary calcium relationship. This finding can in part explain the temporary hypocalcemia during this period.

Calcium↗

Studies on intranuclear inclusions and nuclear grooves in papillary thyroid cancer by light, scanning electron and transmission electron microscopy.

OBJECTIVE: To successively examine intranuclear inclusions and nuclear grooves in the same papillary thyroid cancer specimens using a light microscope (LM), scanning electron microscope (SEM) and transmission electron microscope (TEM). STUDY DESIGN: We stained cells by the Papanicolaou method after fixation in 1.25% glutaraldehyde for LM and then attempted to observe them successively by SEM-TEM after fixation in 2% paraformaldehyde and 2% osmium tetroxide. RESULTS: On SEM, intranuclear inclusions were observed as elevated parts, like hills, and nuclear grooves were observed as deep fissures or shallow cracks, sometimes with a few in one cell. On TEM, both intranuclear inclusions and nuclear grooves seemed formed by the nuclear membranes. Intranuclear inclusions also possessed cytoplasm and/or cytoplasmic organelles within some expanded areas in the nuclear grooves. CONCLUSION: It was evident from our three-step technique that intranuclear inclusions and nuclear grooves were essentially the same structures.

Biopsy, Needle↗

Cell-free plasma layer in cerebral microvessels.

Two diameters of vessel and red cell column in cerebral microvessels (> 29.8 microns in diameter) of cat were measured together with red cell velocity, using a two fluorescent tracer method. A fluorescein isothiocyanate (FITC)-labeled red cell was adopted as a flow tracer to measure the cell velocity with a dual window technique. Based on the fluorescence image, the red cell column diameter was measured. Plasma was stained with rhodamine-B isothiocyanate (RITC)-labeled dextran to measure the vessel diameter. The thickness of the cell-free plasma layer could be determined from the difference of the two diameters. The obtained thickness of the cell-free layer was not described by a simple function of vessel diameter or red cell velocity; it was dependent on the pseudo shear rate defined by the ratio of cell velocity to vessel radius. The layer thickness increased with a decrease in the pseudo shear rate.

Animals↗

Moyamoya syndrome in young children: MR comparison with adult onset.

PURPOSE: To clarify whether there were any differences in MR appearance between the childhood and the adult moyamoya syndromes. METHOD: We compared the cranial MR findings in four children under the age of 6 who had moyamoya syndrome with previously documented adult cases. RESULTS: Moyamoya syndrome in younger children exhibited a significant increase in cortical and subcortical infarction, and a decreased incidence of deep white matter infarction in the centrum semiovale and basal ganglia, in contrast to adult cases. There were no remarkable differences between these two groups of moyamoya cases with regard to the occlusive changes of the internal carotid and middle cerebral arteries, or to the flow void sign on MR. CONCLUSION: These differences in the sites and frequencies of infarctions between the childhood and the adult moyamoya syndromes observed on MR might reflect differences in the cerebral circulation.

Adult↗