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Biomedical subjects

H Shimazu

Publications and source records attributed to H Shimazu.

At least 181 records · Page 10Linked to original sources
PubMed1979

G-cell population in antral mucosa of the dog.

The gastrin-cell (G-cell) population in the pyloric antrum of 8 dogs was studied quantitatively by immunofluorescence. The G-cell population was dense in the pyloric antrum and very few cells were seen in the antrocorporal junction. The estimated total number of G cells was (1.66 +/- 0.12) X 10(7) in the pyloric antrum and the greatest number of G cells per unit mucosal surface area was along the greater curvature of the pyloric antrum. Except along the greater curvature, G cells per unit musocal volume were significantly greater in number (P less than 0.05) in the proximal antrum adjacent to the antrocorporal junction that in any other regions distal to it. Differences in mucosal thickness were considered as a causative factor for these differences.

Animals↗
PubMed1979

Indirect measurement of instantaneous arterial blood pressure in the rat.

We devised a hydraulic servo-control system for indirect blood pressure measurement in the rat's tail, by which beat-to-beat systolic and diastolic blood pressure can be obtained. In this method the principle of "unloading vascular wall" proposed by Shirer (1962) is employed. The proposed system is composed of a transmittance photoelectric plethysmograph with an occluding cuff, a small diaphragm actuator for compressing and decompressing the segment by the hydraulic pressure, and an electromagnetic shaker driven by a volume servo circuit in accordance with the signal from the photoelectric plethysmograph. The plethysmographic signal is clamped at a proper value corresponding to the unload vascular volume by the instantaneous hydraulic servo control. The cuff pressure thus automatically controlled follows the intra-arterial pressure in the tail segment. The accuracy of this method was evaluated in comparison with direct measurement of blood pressure recorded simultaneously from 16 unanesthetized spontaneously hypertensive and normotensive rats. Close agreement between the simultaneous data from these two methods were observed.

Animals↗
PubMed1979

[Chronic toxicity test of 4-ethoxy-2-methyl-5-morpholino-3(2H)-pyridazinone (M73101) in beagle dogs (author's transl)].

Male and female dogs, aged 17--21 months, were administered orall M 73101 (0, 60, 120 and 240 mg/kg/day), a new analgesic and antiinflammatory drug, for 27 weeks, and following recovery test was carried out for 5 weeks. Dead animals were not found throughout the experimental period. Body weight gain, and food and water consumption were not affected due to M 73101 administration. Except for a slight increase of vomitting in the highest dose, there were no abnormal symptoms. Biochemical examination showed the slight increase in serum alkaline phosphatase activity and free cholesterol level. Pathological examination revealed a dose-dependent increase of liver weight and hypertrophy of hepatocytes due to proliferation of smooth endoplasmic reticulum. In addition, mitochondria became irregularly large in the highest dose. There were no abnormal findings in the gastro-intestinal tracts except for an erosion of gastric mucosa, which was noted in a female dog treated 240 mg/kg/day of M 73101. From these results, it was suggested that the maximum non-toxic dose was 60 mg/kg/day or less, and the greatest safety dose was 120 mg/kg/day in beagle dogs.

Animals↗
PubMed1979

[Studies of intrarenal distribution by macroautoradiogram and tissue distribution of 99mTc-gluconate (author's transl)].

1) The experimental studies have demonstrated that 99mTc-gluconate reaches a high concentration in the kidneys within 1-2 hours after injection and its concentration in organs adjacent to the kidney is low. 2) The initial images of serial macroautoradiograms visualized the inner medulla as well as the cortex and outex medulla, whereas the delayed images revealed only the outer cortex and outer stripes in the outer medulla. These findings suggest that this renal agent consists of two components and the delayed component deposits in the convoluted and straight segments of proximal tuble. 3) This renal agent visualizes the calyceal system and excretory pathways in the initial study and the renal morphology in the delayed study. Therefore, using this renal agent, it may be possible to evaluate a variety of renal diseases, including obstructive uropathy, space-occupying lesions, congenital deformities, etc,.

Animals↗
PubMed1979

Admittance plethysmographic evaluation of undulatory massage for the edematous limb.

A new apparatus, called Hadomer has been developed for the treatment of peripheral lymphedema and venous disorder. It has cuffs with 5 rooms, through which the air pressure moves from periphery to proximal point, just like surging waves. The peripheral stagnant lymph and venous blood are displaced toward the heart by this pneumatic massage. Hadomer has been applied to more than 400 patients with the edematous limbs, with satisfactory results, such as decrease of swelling, pain and induration. These clinical results have been also confirmed by electrical admittance plethysmography which is useful to measure noninvasively the edematous volume and the blood flow. The admittance of the edematous limbs is high and after massaging with Hadomer it approaches normal range. The blood flow in the diseased limbs is less than the healthy one and it is observed better after pneumatically massaging.

Edema↗
PubMed1978

Direct inhibitory synaptic linkage of pontomedullary reticular burst neurons with abducens motoneurons in the cat.

1. Unit spikes of burst neurons were extracellularly recorded in the pontomedullary reticular formation of the cat. These neurons were identified by their burst activity coincident with the quick inhibitory phase of the contralateral abducens nerve during vestibular nystagmus and their antidromic activation from the contralateral abducens nucleus. 2. When the extracellular field potentials in and near the abducens nucleus were triggered by spikes of a contralateral burs neuron, the averaged potential consisted of an early di- or triphasic spike and a late slow positive wave. The early spike was an action current caused by impulses conducting along the axon of the burst neuron. 3. The action potentials of a contralateral burst neuron. 3. The action potentials of a contralateral burst neuron were employed to trigger a post-spike average of the membrane potential of abducens motoneurons. Then unitary IPSPs with monosynaptic latencies were revealed. This provided direct evidence that the burst neurons are inhibitory in nature. The amplitudes of unitary IPSPs ranged from 18 to 220 mu V. Each inhibitory burst neuron branched widely in the abducens nucleus and was estimated to make inhibitory connections with approximately 60% of the motoneuron pool. 4. The post-spike average of compound potentials of the abducens nerve triggered by action potentials of contralateral single inhibitory burst neurons revealed inhibition of spike activity with latencies and time courses compatible with those of unitary IPSPs in motoneurons. The inhibition was observed with all inhibitory burst neurons tested.

Abducens Nerve↗
PubMed1978

Gastric response to meat extract stimulation in patients with gastroduodenal ulcer and patients after vagotomy or antrectomy.

Gastric acid secretion basally and in response to intragastric meat extract instillation or to tetragastrin, and circulating gastrin concentration basally and after meat extract stimulation were studied in 67 patients with gastroduodenal ulcer, 30 patients after highly selective vagotomy or selective vagotomy for duodenal ulcer, 12 patients after antrectomy for or gastric ulcer and 10 control subjects. Circulating gastrin concentration increased significantly after meat extract stimulation in control subjects, patients with ulceration and patients after highly selective vagotomy, and acid secretion in each group was increased significantly above basal level. In patients after selective vagotomy, significant increase of circulating gastrin concentration was observed, but it was not associated with significant increase of acid secretion. After antrectomy, neither gastrin nor acid secretion increased significantly after meat extract stimulation. In conclusion, present study suggested that (1) gastric acid secretion in response to intragastric meat extract is chiefly affected by the responsiveness of oxyntic cells and release of antral gastrin and that (2) the presence of the antrum is almost essential for acid secretion after a test meal, and release of duodenal gastrin after antrectomy would not be so potent biologically as to result in an acid secretion.

Adult↗
PubMed1978

Inhibition of gastric secretion by intraduodenal hypertonic glucose in patients with duodenal ulcer.

Intraduodenal instillation of hypertonic glucose significantly inhibited tetragastrin-induced gastric acid and pepsin outputs in man. The secretory volume of gastric juice was markedly decreased, whereas, acid concentration remained unchanged. Pepsin concentration, on the contrary, was reduced significantly. The degree of inhibition of pepsin output, therefore, was greater than that of acid output. No significant difference in the extent of inhibition of acid or pepsin output was observed between control subjects and patients with duodenal ulcer.

Adult↗