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Biomedical subjects

S Morimoto

Publications and source records attributed to S Morimoto.

At least 487 records · Page 27Linked to original sources
PubMed1989

Radiographic type p pneumoconiosis: high-resolution CT.

High-resolution computed tomography (CT) was performed in 90 patients with pneumoconiosis who had small rounded opacities on radiographs. The CT appearances of radiographic type p small rounded opacities in 55 patients were compared with the appearances of type q and r opacities. Radiographic type p pneumoconiosis on high-resolution CT scans was characterized by tiny binary branching structures or a gathering of a few dots. In 21 of the 55 patients, nonperipheral, small areas of low attenuation with a central dot were found. On the basis of CT-pathologic correlation in two postmortem specimens, these tiny opacities and areas of low attenuation corresponded to irregular fibrosis around and along the respiratory bronchioles and to focal-dust emphysema, respectively. Focal emphysema was most commonly found in pneumoconiosis with p-type changes and can be identified with high-resolution CT scanning. The addition of high-resolution CT to chest radiography is useful in achieving more accurate categorization of the lesions.

Humans↗
PubMed1989

Primary thyroid lymphoma: comparison of CT and US assessment.

Sixteen patients with primary thyroid lymphoma were studied with computed tomography (CT) and ultrasonography (US), and findings were compared. In 13 of 16 patients, detection of the primary tumor with US and CT were comparable. US was superior in one case, and CT in another. One tumor was not detected with either technique. Thyroid lymphomas appeared as extremely hypoechoic masses intermingled with echogenic structures. Although echogenicity of unaffected thyroid tissue was also low because of coexisting Hashimoto thyroiditis, thyroid lymphomas were relatively well differentiated as markedly hypoechoic areas. Five tumors showed contiguous spread into both thyroid lobes. US and CT were equally sensitive in detection of superficial lymphomatous nodes (seven of 16 cases). CT was superior to US in the definition of tumor extent in two patients with intrathoracic tumor extension and in one with laryngeal invasion. In patients with suspected thyroid lymphoma, CT should be the primary radiologic technique used for diagnosis and staging; US will be useful in local follow-up.

Aged↗
PubMed1989

Effects of CV-4093, a new dihydropyridine calcium channel blocker, on renal hemodynamics and function in stroke-prone spontaneously hypertensive rats (SHRSP).

Renal effects of CV-4093, a newly developed dihydropyridine calcium channel blocker, were examined using anesthetized stroke-prone spontaneously hypertensive rats, and the findings were compared with those of nicardipine. An intravenous injection of CV-4093 (2 micrograms/kg) produced long-lasting hypotension with a slow-onset accompanied by moderate renal vasodilation. There were no appreciable alterations in glomerular filtration rate (GFR) and urine formation, except that urine flow (UF) increased significantly during the first 10 min after injection. When CV-4093 was administered at 10 micrograms/kg, the hypotensive action was markedly augmented. Eighty minutes after the injection, a decrease in mean arterial pressure of about 45 mmHg was observed. Simultaneously, renal blood flow increased significantly from the control value of 5.76 +/- 0.46 ml/g.min to 6.94 +/- 0.28 ml/g.min. Renal vascular resistance decreased immediately after the injection, and the response lasted for over 3 hr, thereby indicating the marked and sustained renal vasodilating effect of CV-4093. GFR was constant throughout the experiment, but UF and urinary excretion of sodium were increased significantly. Fractional excretion of sodium was also elevated, thereby suggesting an inhibitory action of CV-4093 on renal tubular reabsorption of sodium. Nicardipine at a dose of 10 micrograms/kg, a dose producing an effective hypotensive action, caused no significant increases in RBF and urine formation. The renal vasodilating and diuretic actions of CV-4093 may provide a beneficial effect in the treatment of hypertension.

Animals↗
PubMed1989

Reversible hyporeninemic hypoaldosteronism in a patient with tetraplegia.

A 66-year-old man with tetraplegia developed hyperkalemia. Hyporeninemic hypoaldosteronism was disclosed on the basis of a lack of response of plasma renin activity to furosemide administration or tilting with marked hypotension and a subnormal response of aldosterone to furosemide stimulation, tilting, angiotensin II infusion and ACTH administration, as well as increased vascular responsiveness to angiotensin II infusion. Of interest was the finding that urinary excretion of epinephrine and norepinephrine was markedly reduced, indicating that hyporeninemia may possibly be due to a chronic lack of sympathetic nervous stimuli. The patient was treated with sodium polystyrene sulfonate resin and/or 9-alpha-fluorohydrocortisone, and wheelchair rehabilitation. However, even after stopping 8-month-mineralcorticoid replacement, normokalemia was maintained. Reexamination of the renin-angiotensin-aldosterone system revealed a normalized response to tilting or ACTH administration along with the normal catecholamine excretion. One more point to be noted is that ACTH administration resulted in a rise in the plasma levels of cortisol, corticosterone and 18-OH-corticosterone, but not aldosterone. This may be attributed to ACTH-stimulated 18-OH-corticosterone derived from the zona fasciculata or alternatively to a partial defect of corticosterone methyl oxidase type II (18-dehydrogenase) in the adrenal glomerulosa cells. These results suggested that hyporeninemic hypoaldosteronism may have been attributable to a decrease in systemic nervous stimuli and that such abnormalities were reversible.

Adrenocorticotropic Hormone↗
PubMed1989

Circulating levels of calcitonin gene-related peptide in patients with medullary thyroid carcinoma.

Calcitonin gene-related peptide, originally found in rat medullary thyroid carcinoma cells, was measured by radioimmunoassay in plasma samples with added aprotinin from 17 normal volunteers and 21 patients with medullary thyroid carcinoma. The concentrations were below 75 pmol/l in all 17 normal subjects with a mean of 33 +/- 19 pmol/l plasma. In the patients, the plasma calcitonin gene-related peptide concentrations ranged from below 5 pmol/l to 236 pmol/l, although the mean (36 +/- 48 pmol/l) was not significantly different from the mean normal level. Increase in the plasma calcitonin gene-related peptide level was observed in 2 of 5 patients in response to infusion of 4.3 mg/kg of calcium for 10 minutes and in 3 of 5 patients in response to infusion of 4 micrograms/kg of tetragastrin for 5 minutes. These observations suggest that measurement of calcitonin gene-related peptide level may be helpful in determination of diseases in which the level of calcitonin is of less diagnostic value.

Adolescent↗
PubMed1989

Plasma 18-hydroxycorticosterone and aldosterone responses to angiotensin II and corticotropin in diabetic patients with hyporeninemic and normoreninemic hypoaldosteronism.

To examine the nature of adrenal abnormalities in diabetic patients with hyporeninemic and normoreninemic hypoaldosteronism, responses of plasma 18-hydroxycorticosterone and plasma aldosterone to angiotension II infusions and ACTH injection were investigated in 8 diabetic patients with hyporeninemic hypoaldosteronism and 9 diabetic patients with normoreninemic hypoaldosteronism compared to 11 control subjects. In both the patients with hyporeninemic and normoreninemic hypoaldosteronism, plasma 18-hydroxycorticosterone and plasma aldosterone were low, whereas plasma cortisol and plasma corticosterone were within normal ranges. Percent increments of plasma 18-hydroxycorticosterone and plasma aldosterone above their baseline levels after angiotensin II infusions were low or somewhat low in the patients with hyporeninemic hypoaldosteronism and low in the patients with normoreninemic hypoaldosteronism. Percent increments of plasma 18-hydroxycorticosterone and plasma aldosterone above their baseline levels after ACTH injection were similar in three groups. These results suggest that in diabetic patients with isolated hypoaldosteronism, the adrenal abnormality, regardless of whether it is primary or secondary, is mainly due to impaired adrenal responsiveness to angiotension II and atrophy and the zona glomerulosa.

18-Hydroxycorticosterone↗
PubMed1989

[Optic nerve hemangioblastoma. Case report].

A solitary hemangioblastoma of the optic nerve was found in a 36-year-old male with a distinct family history of intracranial hemangioblastoma. The patient was admitted with complaints of visual loss and exophthalmos of the right eye. X-rays showed enlargement of the right optic canal. Right carotid angiography revealed a hypervascular tumor in the orbital apex, supplied by the ophthalmic artery. Computed tomography disclosed a pear-shaped, isodense mass with moderate contrast enhancement in the orbital apex. The right optic nerve was enlarged along its entire course and was involved with the apical mass. Surgery via the right frontal extradural approach disclosed a solid, vascular tumor involving the optic nerve at the apex of the orbit. Histological examination showed the tumor to be a characteristic hemangioblastoma. Over 90% of intracranial hemangioblastomas are located in the posterior fossa. Supratentorial hemangioblastomas, especially those arising in the optic nerve, are extremely rare. In addition, optic nerve hemangioblastomas are frequently familial and are associated with infratentorial hemangioblastomas, angiomatosis retinae, and cysts of the abdominal viscera.

Adult↗
PubMed1989

Urinary excretion of angiotensin-converting enzyme in NIDDM patients with nephropathy.

Twenty-four-hour urinary excretion of angiotensin-converting enzyme (ACE) was investigated in relation to that of albumin and beta 2-microglobulin (beta 2M) in 25 non-insulin-dependent diabetes mellitus (NIDDM) patients without nephropathy, 13 NIDDM patients with incipient nephropathy, 18 NIDDM patients with overt nephropathy, and 14 nondiabetic subjects. NIDDM patients without nephropathy and nondiabetic subjects were similar in albumin, beta 2M, and ACE excretion. NIDDM patients with incipient nephropathy had elevated albumin excretion (P less than .01) and similar beta 2M and ACE excretion compared with nondiabetic subjects. On the other hand, NIDDM patients with overt nephropathy had elevated albumin, beta 2M, and ACE excretion compared with nondiabetic subjects (P less than .01). In all NIDDM patients studied, a positive correlation was found between ACE excretion and albumin excretion (r = 0.76, P less than .001) or beta 2M excretion (r = 0.52, P less than .01). These data suggest that elevated ACE excretion in NIDDM patients with overt nephropathy may be reflective of renal tubular damage.

Albuminuria↗
PubMed1989

[Comparison of hypotensive effects of acutely administered human parathyroid hormone (1-34) in normal young and elderly subjects].

The effects of acute administration of human parathyroid hormone (1-34) [PTH(1-34)] on the blood pressure of 15 young (mean age +/- SD, 20.9 +/- 1.7 years; 7 males and 8 females) and 11 elderly (78.1 +/- 5.9 years; 4 males and 7 females) normal subjects were compared. The elderly subjects have a slightly, but significantly higher mean basal systolic blood pressure (132.4 +/- 17.7 mmHg) than the young subjects (118.7 +/- 11.4 mmHg), but the basal diastolic and mean blood pressures of the two groups were similar. Intravenous bolus infusion of PTH(1-34) at a dose of 100 U induced transient, but marked hypotension in all subjects. The mean maximal decrease in systolic blood pressure (-delta SBP was significantly more (p less than 0.01) in the elderly subjects (42.5 +/- 13.9 mmHg) than in the young subjects (8.0 +/- 8.9 mmHg), but the maximal decrease in diastolic blood pressure (-delta DBP) was similar in the elderly (25.6 +/- 13.9 mmHg) and young (27.3 +/- 10.9 mmHg) subjects. The maximal decrease in the mean blood pressure (-delta MBP) was also significantly higher (p less than 0.01) in the elderly subjects (31.9 +/- 8.7 mmHg) than in young ones (20.6 +/- 7.6 mmHg). The corrected serum level of calcium (scCa) was significantly (p less than 0.01) lower in the elderly subjects (9.6 +/- 0.2 mg/dl) than in the young ones (10.0 +/- 0.3 mg/dl), and the serum level of C-terminal parathyroid hormone (C-PTH) was significantly higher in the elderly subjects (270 +/- 80 pg/ml) than in the young ones (150 +/- 80 pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Clinical application of Sonolith 2000 on Extracorporeal Shock Wave Lithotripsy for renal and ureteral calculi].

The collaborate studies of clinical application of Extracorporeal Shock Wave Lithotripsy (ESWL) using Sonolith 2000, performed at Departments of Urology of Nara Medical University, the University of Tokai School of Medicine and Wakayama Medical College between March and August 1987, were reported. In total 155 ESWL sessions were carried out on 111 patients suffering from in total 119 upper urinary tract stones. The localization system using ultrasound imaging with a computer assisted multiarticulated arm were evaluated as excellent or effective in 117 cases (98.3%). The stone fragmentations were evaluated as excellent (less than or equal to 3 mm) or effective (less than or equal to 5 mm) in 101 cases (84.9%). On the X-ray film obtained six weeks after the final ESWL treatments, 61 cases (51.3%) were free from stone fragments, 20 cases (16.8%) had sand-like fragments and 18 cases (15.1%) had stone fragments less than 5 mm. 99 cases (83.2%) without stone or with stone fragments less than 5 mm were considered to be with satisfactory results. No serious adverse effect was observed, but petchia on the flanks where shock wave penetrated and mild hematuria were observed in all cases. It is concluded that ESWL treatment using Sonolith 2000 is applicable in the managements of patients with the upper urinary tract stones without serious adverse effects.

Adult↗
PubMed1989

Gravity-dependent atelectasis. Radiologic, physiologic and pathologic correlation in rabbits on high-frequency oscillation ventilation.

The authors identify the radiologic features of progressive atelectasis induced under conditions of reduced lung volume. Control (n = 5) and experimental (n = 7) animals were placed on high-frequency oscillation (HFO) ventilation (mean airway pressure: 3 cm H2O) for 6 hours. In the experimental animals, lung volume was artificially reduced by pneumoperitoneum during HFO ventilation. Computed tomography scans and chest radiographs were obtained every hour, and arterial blood gases analyzed. No changes were detected in the control animals. In the experimental animals, in which hypoxemia developed, homogeneous opacity in the dependent lung was found on CT images, and chest radiographs showed a diffuse homogenous shadow with loss of lung volume. Study of pathologic sections from the lung showed that the roentgenographic findings represented atelectasis. The lung was divided into three zones, from dependent to nondependent regions: severe atelectasis, mild atelectasis, and normal lung. Hyperinflations eliminated atelectasis seen on the CT images and alleviated hypoxemia; however an undesirable effect that causes barotrauma also was observed.

Animals↗
PubMed1989

Low density lipoprotein and apoprotein B induce increases in inositol trisphosphate and cytosolic free Ca2+ via pertussis toxin-sensitive GTP-binding protein in vascular smooth muscle cells.

Low density lipoprotein (LDL), a major cholesterol-carrying lipoprotein in the plasma, binds to its receptor through apoprotein B (Apo-B). The addition of LDL and Apo-B induced rapid (5 s), but transient increase in the inositol 1,4,5-trisphosphate (Ins-1,4,5-P3) level with K0.5 values of 1.1 and 0.07 microgram/ml, accompanied by increases of cytosolic free Ca2+ concentration [( Ca2+]i), in vascular smooth muscle cells (VSMC). The increases by LDL and Apo-B were both reduced by pretreatment of the VSMC with pertussis toxin. The early change in Ins-1,4,5-P3 involving a GTP-binding protein may function as an initial signal for the action of LDL in VSMC.

Animals↗
PubMed1989

[A case of tracheopathia osteoplastica].

A case of tracheopathia osteoplatica in a 43-year-old man, detected incidentally at the upper gastrointestinal examination was reported. The examination showed a long segment esophageal compression from a paraesophageal lesion. CT was effective to demonstrate the typical narrowing and wall thickening of the trachea, and to demonstrate that the esophageal compression was caused by the deformed trachea.

Adult↗
PubMed1989

[Electrocardiograms during acute occlusion of the left circumflex artery as compared with that of the right coronary artery].

To assess the characteristic electrocardiographic (ECG) ST changes during acute occlusion of the left circumflex artery (LCX), we observed ECG changes during percutaneous transluminal coronary angioplasty (PTCA) of the LCX and compared the results with those obtained during right coronary angioplasty. Results were as follows: 1. In the 30 patients who had LCX angioplasty (group LCX), ST-segment elevation occurred most frequently in lead V6 (67.7%) and in lead III (46.7%), but rarely in leads and aVL. ST depression occurred most frequently in lead V3 (80.0%) and in lead V2 (73.3%), but rarely in other leads except for leads I and aVL (23.3%, 33.3%). 2. Four types of ST change in lead combinations were observed. These included: (1) ST elevation in the inferior leads (II, III and aVF), (2) ST elevation in the lateral leads (V5 and V6), (3) ST depression in the anterior leads (V2-V4) and (4) ST depression in the high lateral leads (I and aVL). In group LCX, nine cases (30.0%) manifested all four changes, and six cases (20.0%) revealed only ST depression in the anterior leads without ST changes in other leads. 3. ST depression in the anterior leads and ST elevation in the inferior and lateral leads were observed in nearly equal frequency in patients who received PTCA at the proximal site (Seg. 11) and at the distal site (Seg. 13) in the group LCX. However, ST depression in the high-lateral leads was more frequently observed in the distal than in the proximal cases (66.7% vs 33.3%).(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1989

Psoriasis and vitamin D3. A review of our experience.

Psoriasis is associated with abnormally exaggerated epidermal cellular turnover. Recent studies showed that calcitriol (1,25-dihydroxyvitamin D3) a calcitrophic hormone, regulates terminal differentiation of basal cells of epidermal keratinocytes. We administered active forms of vitamin D3 in both oral and topical ways in an open-design study to patients with psoriasis vulgaris. Significant improvement was observed at the end of the study periods in these patients, especially in those treated with topical application of calcitriol. We also found a significant negative correlation between the severity of psoriasis and the basal serum level of 1 alpha,25-dihydroxyvitamin D but not with those of other calcium-related parameters in psoriatic patients. These data suggest that exogenous active forms of vitamin D3 are effective for treatment of psoriasis and that the endogenous 1,25-dihydroxyvitamin D level also may be involved in the development of this skin disease.

Administration, Oral↗
PubMed1989

Effects of glycyrrhizin and glycyrrhetinic acid on (Na+ + K+)-ATPase of renal basolateral membranes in vitro.

Studies were made on the direct effects of glycyrrhizin and its aglycone, glycyrrhetinic acid on the activities of (Na+ + K+)-ATPase and (Ca2+ + Mg2+)-ATPase, a membrane bound Na+ and Ca2+-extrusion pump enzyme of the basolateral membranes (BLM) of canine kidney. Glycyrrhetinic acid inhibited the activity of the Na+-pump enzyme dose-dependently (IC50 = 1.5 x 10(-4) M), but had no effect on that of the Ca2+-pump enzyme of kidney BLM and homogenates. Glycyrrhizin also inhibited the Na+-pump enzyme activity but had less effect (IC50 = 2 x 10(-3) M). The effects of these compounds were due to competitive inhibition with ATP binding to the enzyme (Ki = 12 microM) and so were different from that of ouabain, which inhibits the Na+-pump by binding to its extracellular K+-binding site. The direct effect of glycyrrhetinic acid on the membrane may be important role in the multiple actions of licorice.

Aldosterone↗