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Biomedical subjects

T Sakaguchi

Publications and source records attributed to T Sakaguchi.

At least 325 records · Page 18Linked to original sources

Effects of D-glucose anomers on sweetness, taste and gastric acid secretion in man.

Gastric acid outputs were examined in human subjects after lingual applications of d-glucose and its anomers. A dose-dependent increase in the acid output was noted following the application of equilibrated D-glucose consisting of 36% alpha- and 64% beta-anomer. The response was not reproduced after administration of atropin. The magnitude of acid output produced by alpha-anomer was different from that induced by beta-anomer in men who could not differentiate between sweetness of the two anomers. Results indicate that recognition of sweetness in the cortex is unrelated to the gastric response, and suggest that a subcortical mechanism may detect qualitative differences in taste and produce the oral phase of gastric acid secretion via vagus action in humans.

Adult↗

Increased adrenergic projection from the locus coeruleus to the lateral geniculate nucleus of rats following one-eye-removal at birth.

Electrophysiological studies were made on plastic changes in the projection from the locus coeruleus (LC) to the lateral geniculate nucleus (LGN). In adult rats with one eye removed at birth it was found that the chance for encountering LC neurons activated antidromically from the LGN was significantly larger in the side of eye removal than in control. This was thought to indicate that the amount of projection from the LC to the LGN had increased in response to eye removal at birth.

Adrenergic Fibers↗

Inhibition of gastric motility induced by hepatic portal injections of D-glucose and its anomers.

Intragastric pressures were recorded in bilaterally adrenalectomized male rats with insulin hypoglycaemia. A significant depression in intragastric pressure was noted following the administration of D-glucose injected into the hepatic portal vein but not after the administration of L-glucose, D-mannose, D-fructose, D-galactose, D-xylose or D-arabinose. The reduction in intragastric pressure induced by the portal administration of D-glucose was not reproduced following selective division of the hepatic branch of the vagus nerve. Of the three anomeric forms of D-glucose used (alpha-D-glucose, equilibrated D-glucose and beta-D-glucose), beta-D-glucose was most potent in reducing the intragastric pressure. These results suggest that the vagal afferents may convey information concerning glucose concentration in the portal vein to the central nervous system, and that the activation of such afferents may modulate gastric motility which is dependent on the anomeric stereospecificity of D-glucose.

Animals↗

[An autopsy case of squamous cell carcinoma of the lung presenting with small and large bowel metastasis].

A 81-year-old male with primary squamous cell carcinoma of the lung was admitted because of melena. Upon autopsy, bleeding sites were found in the small and large bowel; they were lesions from the lung carcinoma. Gastrointestinal metastases from primary lung carcinoma are clinically rare, although they are seen in autopsy cases. Review of autopsy data on 1181 cases of primary lung carcinoma showed that 218 (18.5%) manifested gastrointestinal metastases.

Aged↗

[Pancreatic cancer in father and daughter].

A 77-year-old male patient was admitted because of jaundice and general malaise. Exploratory laparotomy disclosed pancreatic head cancer with invasion to the intrapancreatic bile duct. Three months later, his daughter, aged 51, was admitted for evaluation because of body weight loss and back pain. CT scan disclosed 3 low-density areas in the pancreas with irregular margins and multiple low-density areas in the liver. Pancreatic cancer with liver metastasis was confirmed by autopsy. In familial pancreatic cancer, it is essential that genetic in addition to environmental factors be examined in pancreatic carcinogenesis.

Adenocarcinoma↗

[Effects of beryllium chloride on cultured cells].

The effects of beryllium on cultured cells were investigated. Three cell-lines (HeLa-S3, Vero, HEL-R66) were used in these experiments and they were cultured in Eagle's MEM plus 5 or 10% FBS (Fetal Bovine Serum) containing beryllium in various concentrations. HeLa cells or Vero cells were able to grow in the medium with 10 micrograms Be/ml (1.1 mM). On the other hand, the growth of HEL cells were strongly inhibited, even when cultured in the medium with 1 microgram Be/ml (1.1 X 10(-1) mM) and the number of living cells showed markedly low level as compared to that of the control samples cultured in the medium without beryllium. The cytotoxic effects of beryllium on these cells, which were cultured for three days in the medium with beryllium, were observed. None of cytotoxic effects were found on HeLa cells cultured with 0.5 micrograms/ml (5.5 X 10(-2) mM) and on Vero cells cultured with 0.05 micrograms Be/ml (5.5 X 10(-3) mM), while HEL cells received cytotoxic effects even when cultured in the medium containing 0.05 micrograms Be/ml (5.5 X 10(-3) mM), and these effects on the cells appeared strong when cultured in the medium without FBS. It was revealed from these experiments that HEL cells are very sensitive in terms of toxic effects of beryllium. Therefore, there cells can be used for the toxicological study on low level concentrations of the metal.

Animals↗

Characteristics of a new hairless mutation (bald) in rats.

Hereditarily hairless rats have been maintained by sibmatings since 1973. These animals were termed "bald rats", and examined for their characteristics on genetics, physiological, hematological and clinical chemistry values and histology. The bald rats began to lose their hair at approximately three weeks of age. At five weeks of age, the skin was devoid of all general body hair except for the vibrissae, and the skin became wrinkled at two months of age. Histologically, follicular cysts were observed in a large number, from three months of age onward. The bald condition was a simple recessive character (ba); homozygous animals lost hair and heterozygous ones did not. The bald females attained sexual maturity around eight weeks of age and littered normally, but failed to nurse their young. The incapability of supplying sufficient milk supposedly resulted from the mammary glands that involuted after delivery. The bald animals consumed more food but showed lower values for body weights, plasma triglyceride, and epididymal adipose tissue amount than the haired animals. In addition, the bald males had brown adipose tissue in the interscapulum which was histologically activated as in newborn animals. Aged bald animals showed spontaneous tumors of the thymus, pituitary, testis, uterus, mammary gland, and skin. The incidence of skin tumors was much higher than those of tumors of other origins.

Adipose Tissue↗

Morphologic characteristics of the skin of bald mutant rats.

The skin of a new hairless mutation in the rat termed "bald" was examined histologically and enzyme histochemically with animals from three weeks to 18 months of age. The loss of hair in homozygous (bald) rats proved to occur as follows: a club hair rising within the hair follicle in the first catagen phase was not anchored and fell out due to dilatation of the follicular lumen. In the skin of bald rats from two to three months of age on, two types of cyst developed, one from the infundibulum of the hair follicle and the other from a lower follicular portion left in the dermis. Each had histologic patterns different from each other. The wall of the former cyst contained various-sized keratohyaline granules in a large number, while the latter was keratinized without granules. In addition to cyst formation, foreign-body granulomas frequently appeared from three months of age on, originating from degenerated follicular portions in the dermis. In advanced cases after 12 months of age, the granulomatous lesions were sharply demarcated from the other tissue. Histochemically, acid phosphatase activity was observed in the skin of bald rats, in the wall of the dilated hair follicles and the cystic wall where progressive keratinization with age occurred. This enzymatic activity tended to heighten as keratinization proceeded.

Acid Phosphatase↗

[A case of hyperthyroidism combined with thyroid carcinoma].

A 33-year-old woman, with hyperthyroidism combined with thyroid carcinoma is presented. She was given antithyroid medication before the operation, and sub-total thyroidectomy was performed under local anesthesia. Her postoperative course was smooth. Histologically, the resected thyroid was shown to have two small nodular lesions of papillary carcinoma in the diffuse goiter. The current classification, statistics, diagnosis and therapy of this disease are discussed.

Adenocarcinoma, Papillary↗

High-performance liquid chromatographic determination of phenytoin and hydroxyphenytoin in human urine.

Simple and rapid quantitative analysis utilizing high-performance liquid chromatography was performed to determine the concentration of the antiepileptic agent phenytoin, and its main metabolite hydroxyphenytoin, in human urine. For the purposes of simple and rapid determination, the commercially available Extrelut columns were used with diethyl ether and chloroform as extraction solvents. High-performance liquid chromatography was performed on a LiChrosorb RP-8 column, with a mobile phase of methanol-0.02% ammonium acetate (1:1). The internal standard was 5-(4-methylphenyl)-5-phenylhydantoin. The method was applied to patients' urine, to examine the influence of concomitant drugs. Also, the results obtained using the commercially available enzymatic immunoassay method were compared with those from the present method, and it was concluded that a simple and rapid microanalysis is possible with a high extraction ratio.

Adult↗

High-performance liquid chromatographic determination of free fatty acids with 1-naphthylamine.

A 1% benzene solution of oxalyl chloride was added to saturated and unsaturated fatty acids and the mixture was allowed to react at 70 degrees C for 30 min; by this procedure, each fatty acid was converted into its acid chloride in a considerably quantitative manner. By reacting this acid chloride with 1-naphthylamine at 30 degrees C for 15 min, naphtylamine derivatives were produced, which showed strong ultraviolet absorption around 280-290 nm. Experiments were made on the recovery of the fatty acids added to 0.5 ml of human serum, and the recovery was found to fall in the range of 94-106% (coefficient of variation = 0.5-4.1%) when the following amounts of six fatty acids were added: C14:0, 2 micrograms; C16:0, 20 micrograms; C16:1, 5 micrograms; C18:0, 4 micrograms; C18:1, 20 micrograms; C18:2, 10 micrograms.

1-Naphthylamine↗

[Studies on the cell-mediated immunity caused by beryllium compounds].

In order to examine the sensitizing ability of beryllium (Be), a footpad reaction test and a macrophage migration inhibition test were carried out using mice treated with beryllium compounds. The findings of the experiments are summarized as follows: 1) The footpad reaction test of the mice injected with BeCl2 once a week subcutaneously at their dorsal area showed the positive results after four injections. The macrophage migration inhibition test was also performed by an agarose plate method using peritoneal cells and spleen cells obtained from these mice. The ratio of the number of positive mice showed more than 50% after five injections when peritoneal cells were used and after six injections when spleen cells were used. 2) The footpad reaction test of mice injected with one of various Be-compounds six times once a week showed a cross positive reaction against these compounds, and the macrophage migration of these mice was inhibited by these Be-compounds, but not by other metals. 3) When mice were once injected with 7BeCl2, about a half dose of the injected metal was discharged from the body within 7 days after the injection, and about a half dose of the residual metal was still found in the injected site. Further investigations may be required to solve the point that the persistent remaining of this metal in situ may raise the Be sensitizing ability.

Animals↗

Different effects of D-glucose anomers on enhanced motility of the stomach.

The injection of alpha, beta, or equilibrated (alpha: 36%, beta: 64%) D-glucose solution into the cranial side of carotid artery decreased gastric pressure caused by insulin in rats with bilateral adrenalectomy. This effect was not reproduced after vagotomy at the cervical level. The effect of beta-D-glucose was more rapid and potent than that of alpha-D-glucose. The injection of isotonic NaCl solution, however, produced no change in pressure.

Adrenalectomy↗

Renal effects of piretanide in dogs.

Effects of 4-phenoxy-3-(1-pyrrolidinyl)-5-sulfamoyl benzoic acid (piretanide, Arelix) on renal function and hemodynamics were investigated in anesthetized dogs by clearance, stop-flow and radioactive microsphere methods. Marked diuresis occurred within 10 min after intravenous injection of piretanide (0.01, 0.05 and 0.25 mg/kg) and it was accompanied b natriuresis. Piretanide (0.25 mg/kg) clearly inhibited the reabsorption of solute-free water during saline diuresis, suggesting that the drug acts in the ascending limb of Henle's loop. Stop-flow experiments revealed that sodium reabsorption was reduced by piretanide (0.25 mg/kg) at the distal tubule including the ascending limb of Henle's loop. Piretanide (0.25 mg/kg) caused a maximum increase of about 30% in renal blood flow at 10-15 min after the injection; within the renal cortex the increase in blood flow was greater in the juxtamedullary area than in the superficial area. The increased blood flow in the inner cortex conceivably resulted in a washout of the osmotic substances in the medulla and inhibited the concentrating mechanisms of the kidney. The effect of piretanide on intrarenal hemodynamics may also contribute to its diuretic action.

Animals↗