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Biomedical subjects

T Higa

Publications and source records attributed to T Higa.

At least 109 records · Page 6Linked to original sources
PubMed1986

Increase in plasma atrial natriuretic polypeptide (ANP) following sodium load in anesthetized rats.

To investigate the releasing mechanisms of atrial natriuretic polypeptide (ANP), identical amounts of 5% glucose solution, isotonic (0.9%) or hypertonic (5%) saline were infused intravenously for 5 min (2 ml/min) in anesthetized rats. At the same time, plasma immunoreactive ANP (ir-ANP) was measured using a direct radioimmunoassay. Plasma ir-ANP increased after infusion of 5% glucose solution (P less than 0.01) and isotonic saline (P less than 0.05), and returned rapidly to the basal levels in the recovery period. Plasma ir-ANP increased to a greater degree in the group infused with hypertonic saline than in the other two groups. The major immunoreactive component of increased ir-ANP was identified as alpha-rat ANP, a 28 amino acid residue, by using reverse phase high-performance liquid chromatography. These results suggest that sodium ions may be a stimulating factor of ANP release as well as volume expansion.

Animals↗
PubMed1986

Evaluation of radionuclide imaging and echography in the diagnosis of thyroid nodules.

Radionuclide imaging with both Tc-99m sodium pertechnetate and Tl-201 chloride was studied in 152 patients with thyroid nodules. Ultrasonography also was performed in 81 of those patients. Tc-99m sodium pertechnetate scans demonstrated nodules in 69.7% of 78 differentiated thyroid carcinomas (DC) and 72.2% of 54 thyroid adenomas (Ad). Tl-201 chloride was accumulated in 73.7% of DC and 53.6% of Ad. By combining the Tc-99m sodium pertechnetate and Tl-201 chloride scans, the detectability of the nodules was increased to 90.8% for DC and 88.9% for Ad, respectively. The Tc-99m sodium pertechnetate scans showed better visualization of cystic lesions than did the Tl-201 chloride imaging. The Tl-201 chloride images clearly demonstrated intrathoracic tumor invasions in six cases of carcinoma and two cases of Ad. The Tl-201 chloride scan was also of value in detecting regional lymph node involvement and the recurrence and metastasis after thyroidectomy. The detectability of space-occupying lesions by ultrasonography was 96.3% in 81 patients with thyroid nodules. Ultrasonography differentiated well between solid and cystic lesions. The presence and extent of nodular lesions were detected with radionuclide imaging and ultrasonography in 98.8% of patients. Radionuclide imaging combined with ultrasonography provides a rapid, convenient, and useful method for the localization and visualization of thyroid tumors.

Adenocarcinoma↗
PubMed1986

A follow-up study using iodine-131 metaiodobenzylguanidine imaging in a patient with neuroblastoma.

A new radiopharmaceutical, I-131 metaiodobenzylguanidine (I-131 MIBG) was used to determine the location and to follow-up tumors in a 13-month-old girl with neuroblastoma. I-131 MIBG imaging revealed both a primary abdominal tumor and a distant metastatic orbital tumor. Follow-up study with I-131 MIBG imaging demonstrated significant resolution of tumors after external radiotherapy and chemotherapy. I-131 MIBG imaging is a simple, safe, and specific method of determining the location of tumors and also is clinically useful in the evaluation and management of patients with neuroblastoma.

3-Iodobenzylguanidine↗
PubMed1986

SPECT with N-isopropyl-p iodoamphetamine in occlusive cerebrovascular diseases.

The role of SPECT imaging with N-isopropyl-p iodoamphetamine (I-123 IMP) in the detection of angiographically documented occlusive cerebrovascular diseases was evaluated in 24 patients, and the results of regional cerebral blood flow (rCBF) were compared with x-ray CT. Twelve patients had internal carotid occlusion, ten had intracranial occlusion beyond the circle of Willis, one had common carotid occlusion, and one had basilar artery occlusion. SPECT images were obtained with a gamma camera, which was rotated 360 degrees around the patient's head 30 minutes after an intravenous injection of 3 mCi of I-123 IMP. CT images in the transverse plane were obtained, and the regions of reduced attenuation were identified for comparison of topographic extension of the lesion with the regions of decreased rCBF seen on SPECT. In six cases, the lesions seen on the SPECT images were distinctly more extensive than those seen on CT. In the remaining 18 cases, the extent of the lesion was identical on both CT and SPECT images. Radiochemical and radionuclide impurities, the distance of the detector from the head, and the nature of the collimator affected the SPECT results. I-123 IMP SPECT imaging complements CT findings in detecting the ischemic zones beyond the regions identified on CT images, and may have a major rule in the management of patients with occlusive cerebrovascular diseases.

Amphetamines↗
PubMed1985

Hemodynamic and hormonal effects of propranolol on patients with essential hypertension during head-up tilting: a comparison between normal and low cardiac index groups.

Twelve outpatients with essential hypertension who showed a normal cardiac index (CI) (between 2.5 and 3.6 1/min/m2) or low CI (2.5 and less 1/min/m2) were studied. Head-up tilting (70 degrees) was performed for 15 min before and 2 weeks after treatment with propranolol (90 mg/day). Before treatment, the normal CI group showed a fall in systolic blood pressure (SBP) associated with a decrease in CI and an increase in the total peripheral resistance index (TPRI) during tilting. Conversely, the low CI group showed a rise in SBP associated with an increase in CI and a decrease in TPRI. There was a negative correlation (r = -0.69, P less than 0.05) between the basal CI and the change caused by the tilting. During treatment with propranolol, on the other hand, both groups showed decreases in CI. There was a greater increase in plasma renin activity (PRA) in the normal than in the low CI group before treatment with propranolol. The rise in PRA was significantly (P less than 0.05) suppressed by propranolol in the normal CI group only. It was demonstrated that the low CI group showed a different hemodynamic response to the tilting than the normal CI group. The lower rise in PRA may have partially contributed to the lack of increase in TPRI in the low CI group, compared with the normal CI group. Such hemodynamic differences may be abolished by propranolol which has a cardioinhibitory and/or renin-suppressive effect.

Aged↗
PubMed1985

Diagnosis and therapy of necrotizing tracheobronchitis in ventilated neonates.

From January 1983 to September 1984 our neonatal ICU (NICU) treated eight endotracheally intubated infants who had suspected airway obstruction characterized by hypercarbia dissonant with severity of lung disease and difficulty in ventilation with lack of chest movement, both on conventional intermittent mandatory ventilation and high-frequency oscillation. Bronchoscopic removal of necrotic tissue was possible in six infants, two of whom survived. Bronchoscopy showed desquamation of epithelial surfaces, leaving encrusted exudations considered to be characteristic of necrotizing tracheobronchitis (NTB). The four nonsurvivors of bronchoscopy and one of the infants not submitted to bronchoscopy had NTB confirmed at autopsy. NTB was not associated with any specific lung disease, humidifier, or ventilator. The autopsy frequency of NTB during this period was 5 per 160 NICU admissions. A separate chart review of unselected autopsied cases in 1981 and 1982 showed that 12 of 284 neonates admitted to the NICU had NTB. NTB appears to be a rediscovered condition related to endotracheal intubation and mechanical ventilation using high mean airway pressures.

Bronchitis↗
PubMed1985

Cardiac content and plasma concentration of atrial natriuretic polypeptide (ANP) in spontaneously hypertensive rats (SHR).

The cardiac content and plasma concentration of atrial natriuretic polypeptide (ANP) in hypertensive rats were measured by using radioimmunoassay for ANP. The animals used in this study were young (5-week-old) and adult (12- to 14-week-old) spontaneously hypertensive rats (SHR), stroke-prone SHR (SHR-SP) and normotensive control Wistar-Kyoto rats (WKY). Most immunoreactive ANP in the cardiac extract of the hypertensive rats (both SHR and SHR-SP) was found to be predominantly gamma-form as well as that of WKY. Cardiac ANP content in adult SHR and SHR-SP was significantly lower than in adult WKY (p less than 0.01), although there were no differences among three groups in young rats. Similar tendencies were also observed for plasma ANP concentration. The level of plasma in adult hypertensive rats was significantly lower or tended to be lower than in adult normotensive rats. Furthermore, a high negative correlation was present between blood pressure and cardiac ANP content (r = 0.748, p less than 0.01) and between blood pressure and plasma ANP concentration (r = 0.608, p less than 0.01) in all adult rats but there were no such relationships in young rats. The present study suggests that atrial natriuretic polypeptide may contribute to the pathogenesis or maintenance of high blood pressure in the genetic hypertensive rats.

Animals↗