The existence of Ca2+-activated, phospholipid-dependent protein kinase (protein kinase C), the effect of gastrin on phospholipid metabolism and guanylate cyclase activity were investigated to elucidate the cellular mechanism of action of gastrin on the corporal mucosa of the canine stomach. Protein kinase activity was determined by measuring the incorporation of [32P] into calf thymus H1-histone from [32P]-ATP. One unit of protein kinase was defined as the amount of enzyme which incorporated 1 pmol of phosphate from ATP into H1-histone. Protein kinase C was found in 100,000xg supernatant of homogenate fractionated by a DEAE-cellulose column chromatography. Characteristics of further purified protein kinase C, such as dependency on divalent cations and phospholipids, were in agreement with those of previously reported protein kinase C in other tissues. Furthermore, the gastric corporal mucosa was found to contain protein kinase C in large quantities. The specific activity of protein kinase C was 26,000 units/mg protein. The phospholipid metabolism was evaluated by the incorporation of [14C]-glycerol-3-phosphate and the change of the radioactivity of [32P] in individual phospholipids. Each phospholipid was extracted from the gastric corporal mucosa and isolated by thin layer chromatography. Guanylate cyclase activity was determined by measuring the cGMP produced, using radioimmunoassay. Gastrin significantly increased the incorporation of [14C]-glycerol-3-phosphate into phosphatidylethanolamine in the presence of acetylcholine (Ach). Ach increased the uptake of the tracer into phosphatidylinositol significantly, and the increase was enhanced by the simultaneous addition of gastrin. In the experiments with [32P]-labeled phospholipids, gastrin increased the incorporation of [32P] into phosphatidylethanolamine significantly. The significant increase of the radioactivity in phosphatidylinositol by Ach failed to be enhanced by gastrin, but that of phosphatidylethanolamine by Ach was enhanced by gastrin. No stimulation of guanylate cyclase activity by gastrin was detected in the dispersed gastric corporal mucosal cells. These results indicate that gastric corporal mucosa was one of the most abundant tissues in which protein kinase C was contained, when compared with various mammalian tissues previously reported by Minakuchi, Nishizuka, et al. Nishizuka et al, recently proposed the novel hypothesis that phosphatidylinositol turnover activated by cAMP-independent agonists will be essentially required to activate protein kinase C. Our results suggest that gastrin can provoke phospholipids turnover including phosphatidylinositol turnover in gastric corporal mucosa. Therefore, our data indicate the possibility that the protein kinase C system plays an important role in the cellular mechanism of action of gastrin on gastric corporal mucosa.

Animals↗

PubMed1983

Krypton-81m single photon emission tomography and the collateral circulation in carotid occlusion: the role of the circle of Willis and leptomeningeal anastomosis.

Cerebral perfusion images were investigated in patients with carotid artery occlusion, using single photon emission computed tomography with the infusion of krypton-81m into the internal, common carotid and vertebral arteries. The contribution of the circle of Willis and cerebral cortical anastomoses to the maintenance of adequate blood supply into the involved hemisphere was analysed. It was concluded that the cerebral perfusion image is superior to angiography in evaluating collateral circulation, and in the case of carotid occlusion, the circle of Willis is important in preventing infarction in the territory of the perforating arteries, while the cerebral cortex mainly receives its blood supply through the cortical leptomeningeal anastomoses, illustrating the major role of the leptomeningeal anastomosis as a collateral channel.

Adult↗

PubMed1983

Preoperative and postoperative cortical function of the kidney with staghorn calculi assessed by 99mtechnetium-dimercaptosuccinic acid renal scintigraphy.

99mTechnetium dimercaptosuccinic acid renal scintigraphy, consisting of the cortical image and dimercaptosuccinic acid renal uptake rate, was used to assess preoperative and postoperative renal function in 55 patients with staghorn calculi. In 14 of 20 patients who had undergone extended pyelolithotomy and in 4 of 22 who had undergone nephrolithotomy there was an increase or no change in the postoperative dimercaptosuccinic acid renal uptake in the surgically treated kidney. However, there was no increase in the postoperative dimercaptosuccinic acid renal uptake in the patients who had undergone pyelolithotomy combined with nephrotomy or partial nephrectomy. Eight per cent of the preoperative dimercaptosuccinic acid renal uptake rate in the diseased kidney seems to be the absolute level for predicting the postoperative recovery of renal function. Dimercaptosuccinic acid renal images provide evidence of morphological changes in the cortex of the kidney with stones and the dimercaptosuccinic acid uptake rate is a useful adjunct for quantitative assessments of preoperative and postoperative residual cortical function.

Adult↗

PubMed1983

Evaluation of gray-scale ultrasonography in the investigation of oral and neck mass lesions.

The clinical applicability of gray-scale ultrasonography to oral and neck mass lesions was investigated. Ultrasonographic findings of pattern, boundary echo, internal echo, and posterior wall echo were correlated with pathologic findings in 22 surgically treated cases. Using this method, the solid or cystic nature, the size, the shape, and the location of the lesions could be determined preoperatively. Because it lacks radiation hazard, ultrasonography appears to be the diagnostic method of choice for patients with enlarged oral and neck tumors.

Adolescent↗

PubMed1983

Superimposition of Krypton-81m single photon emission CT and X-ray CT images for cerebral blood flow evaluation.

Selective arteriographic infusion of krypton-81m was used to obtain cerebral single photon emission computed tomograms. These were then superimposed on X-ray computed tomograms to assess topographically the perfusion of the entire brain. This method enhances the detecting capability for abnormal perfusion areas and has been used in 21 patients with various brain diseases.

Carotid Artery Thrombosis↗

PubMed1983

Multiaxial tomography of heart chambers by gated blood-pool emission computed tomography using a rotating gamma camera.

Fifteen patients and three volunteers underwent radionuclide blood-pool cardiac studies with electrocardiographic gating. Following conventional planar-gated imaging (anterior and left anterior oblique projections), emission computed tomography (ECT), using a rotating gamma camera, was performed. A series of transaxial tomograms of the cardiac chambers was obtained. The left ventricular short-axis plane, long-axis plane, and four-chamber-view plane were then reorganized; each chamber was visualized separately. Compared to gated planar imaging, this technique showed regional asynergy more clearly in patients with myocardial infarction and demonstrated dilatation of the atria and ventricles more accurately in patients with an atrial septal defect and valvular heart diseases. In addition, when a section of the heart is obtained at any angle with gated blood-pool ECT, three-dimensional assessment of cardiac chambers in motion is more precise; mutual superimposition becomes unnecessary.

Adult↗

PubMed1983

Thyroid CT number and its relationship to iodine concentration.

Sixty-seven patients with thyroid disease and 24 normal controls were examined with computed tomography (CT). The mean CT number (Hounsfield units +/- SD) in the normal controls (118.1 +/- 12.2) was significantly higher (p less than 0.001) than the mean CT number in patients with diseased thyroids, except for 2 cases of simple goiter (CT numbers 113, 132). The mean CT numbers in the patients with Graves disease (69.5 +/- 17.6) and Hashimoto thyroiditis (61.4 +/- 9.1) were significantly higher than those in patients with adenoma (41.7 +/- 10.6, p less than 0.001), cyst (33.1 +/- 14.8, p less than 0.001), or cancer (48.7 +/- 13.0, p less than 0.01). In 14 patients studied, a significant correlation was observed between thyroid CT numbers and the iodine concentration of the tissue (r = 0.889; p less than 0.001).

Adolescent↗

PubMed1983

Pulmonary blood flow distribution measured by radionuclide-computed tomography.

Distributions of pulmonary blood flow per unit lung volume were measured with subjects in the prone, supine, and sitting positions by means of radionuclide-computed tomography of intravenously administered 99mTc-labeled macroaggregates of human serum albumin. The blood flow was greater in the direction of gravity in all 31 subjects except one with severe mitral valve stenosis. With the subject in a sitting position, four different types of distribution were distinguished. One type had a three-zonal blood flow distribution as previously reported by West and co-workers (J. Appl. Physiol. 19: 713-724, 1964). Pulmonary arterial pressure and venous pressure estimated from this model showed reasonable agreement with pulmonary arterial pressure and capillary wedge pressure measured by Swan-Ganz catheter in 17 supine patients and in 2 sitting patients. The method makes possible noninvasive assessment of pulmonary vascular pressures.

Adult↗

PubMed1983

Inhibition of thyrotropin-induced adenosine 3'5'-monophosphate increase by immunoglobulins from patients with primary myxedema.

Immunoglobulin G (IgG) fractions prepared from the serum of 18 patients with primary myxedema, 9 patients with goitrous Hashimoto's thyroiditis, and 14 normal controls were tested for their ability to alter TSH stimulation of cAMP production in cultured human thyroid cells and the binding of TSH to its receptor. When compared with the cAMP increase induced by 0.1 mU/ml bovine TSH in the presence of normal IgG, cAMP accumulation was significantly inhibited (P less than 0.005) by the addition of IgG from patients with primary myxedema. TSH-induced cAMP accumulation was not affected by IgG from patients with goitrous thyroiditis. IgG from patients with primary myxedema also inhibited the cAMP increase induced by thyroid-stimulating immunoglobulins, but not against the increase induced by prostaglandin E1. None of the IgG tested affected the basal level of cAMP. Two potent inhibitory IgG were strongly positive for TSH-binding inhibitor immunoglobulins. Excluding these, no significant correlation was found between the thyroid stimulation-blocking activity and the TSH-binding inhibitory activity. These data suggest the presence of at least two different types of antibodies in primary myxedema which block adenylate cyclase stimulation by TSH and might be responsible for thyroid dysfunction and atrophy.

Adenylyl Cyclase Inhibitors↗