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Biomedical subjects

M Yanase

Publications and source records attributed to M Yanase.

At least 73 records · Page 4Linked to original sources
PubMed1991

Transitional cell carcinoma of the bladder or renal pelvis in children.

Transitional cell carcinoma (TCC) of the bladder or renal pelvis is rare in children. We report 2 children with TCC of the bladder and 1 with TCC of the renal pelvis. One of the two children with bladder carcinoma experienced frequent intravesical recurrences, which is in contrast to the usual clinical course of bladder carcinoma in children. In the 3rd child, renal pelvic carcinoma was found incidentally in a renal pelvis specimen removed during pyeloplasty.

Adolescent↗
PubMed1991

[Studies on pulmonary metastasis of renal cell carcinoma--pulmonary embolism revealed by lung-perfusion imaging and metastasis].

Invasion of renal cell carcinoma to veins is known to have a close relation with pulmonary metastasis. We speculated that a tumor thrombus would lodge in the pulmonary artery before establishment of a clinically apparent pulmonary metastasis. This may be particularly true in patients with renal vein or vena cava involvement of renal cell carcinoma. In this instance, it is crucial to know the clinical consequence of tumor thrombi in the pulmonary artery. Thus, we investigated these issues with the aid of lung-perfusion imaging in 22 renal cell carcinoma patients with and without vein involvement. The lung-perfusion imaging revealed positive in 8 of the patients examined prior to treatment. The incidence of positive finding was well correlated with an extensive vein invasion. Patients with positive imaging prior to treatment were associated with pulmonary metastasis at a higher rate than those with negative findings. These findings have indicated that vein invasion should be related with tumor thrombus formation in the pulmonary artery, and such a status in the lung would, in part, result in pulmonary metastasis. Two different clinical courses were found by an analysis of patients with the positive imaging prior to treatment. One is the clinical course in which positive findings were correlated with a newly developed metastasis in the lung. Thus, care should be taken in development of the metastasis during the follow-up when patients show the positive lung-perfusion imaging prior to treatment. On the other hand, we found two patients in whom the positive findings disappeared during the follow-up.

Adult↗
PubMed1991

[Clinical efficacy of modified M-VAC chemotherapy for advanced urothelial carcinoma and influence of squamous cell carcinoma-associated antigen on efficacy of the chemotherapy].

The efficacy of modified M-VAC chemotherapy was evaluated in twenty-two patients with advanced urothelial carcinoma (18 cases of transitional cell carcinoma, 3 of transitional cell associated with squamous cell carcinoma and 1 of squamous cell carcinoma). Among the 22 patients, 14 underwent two or more courses of modified M-VAC chemotherapy and had lesions suitable for the evaluation. Three of the 14 patients achieved complete response and 6 partial response, resulting in a 64.3% response rate. With regard to the direct effect according to the site of the lesion, the response rate was 75% for the urinary bladder, 100% for lung, 100% for subcutaneous tissues, and 75% for lymph nodes metastasis, whereas the chemotherapy was ineffective for metastasis in the bone and muscle. With this neoadjuvant chemotherapy the primary tumor of the urinary bladder was downstaged from T2 to T0 in one patient who showed complete response. In 4 of 5 patients achieving partial response, the primary tumors were downstaged from T2 to T1. Of 9 patients given this chemotherapy for metastatic lesions, 2 achieved complete response and are alive, whereas all 3 without response died of cancer within the 1 year following the chemotherapy. Since most of the cases associated with the squamous cells carcinoma component showed no response to the therapy, it seems that the level of serum squamous cell carcinoma-associated antigen may be helpful for predicting the efficacy of modified M-VAC chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Modes of action of local hypothalamic and skin thermal stimulation on salivary secretion in rats.

1. In urethane or ketamine-anaesthetized rats, salivary secretion was observed when local brain sites or trunk skin were stimulated thermally or electrically. 2. Salivary secretion was facilitated by bilateral local brain warming. Sensitive sites were restricted to the preoptic area and anterior hypothalamus, but in a region distinct from a previously reported sensitive site for producing saliva-spreading behaviour. 3. Unilateral warming of the preoptic area produced greater salivary secretion from the ipsilateral submandibular/sublingual salivary glands than from the contralateral glands. Electrical stimulation of the same sites elicited salivation only from the ipsilateral glands. 4. Trunk skin, not including the scrotum, was unilaterally cooled when spontaneous salivary secretion was observed in a hot environment. Salivary secretion from both sides was equally suppressed in response to the unilateral skin cooling. 5. We conclude that efferent signals from the anterior part of the hypothalamus project dominantly to the ipsilateral salivary gland for thermally induced salivary secretion. Thermal signals from the skin of either side of the trunk, on the other hand, appear to be integrated and to affect salivary secretion bilaterally.

Animals↗
PubMed1990

Circadian variation of thermoregulatory responses during exercise in rats.

Rats exercised on a treadmill at daytime lows and nighttime highs of circadian change in body temperature at two different work intensities [40 and 60% of maximal oxygen uptake (VO2max)] with the ambient temperature (Ta) at 24 degrees C. Immediately before exercise at 60% VO2max, rectal temperature (Tre) was 0.7 degrees C higher at night than during the day. During the exercise, Tre rose more during the day than at night, and Tre at the end of exercise was the same in the day as at night. Threshold Tre for tail vasodilation did not differ between day and night. Similar tendencies of Tre change and tail vasomotor response were observed at a work intensity of 40% VO2max, except that the rise in Tre was smaller than at the higher work intensity. On the other hand, threshold Tre for tail vasodilation spontaneously occurring in resting rats in a warm environment (Ta of 28 degrees C) was 0.7 degrees C higher at night than during the day. In conclusion, exercise in rats attenuates the differences in deep body temperature and threshold Tre for tail vasodilation seen between day and night.

Animals↗
PubMed1990

Effects of pyrogen administration on temperature regulation in exercising rats.

To study the mechanism of rise in body temperature during exercise, endogenous pyrogen was administered to exercising rats. At rest and at a neutral ambient temperature (Ta) of 24 degrees C, intravenous injection of recombinant human interleukin 1 (IL-1, 40 micrograms/kg) produced a 0.5 degree C rise in rectal temperature (Tre) from 37.4 degrees C. At Ta of 34 degrees C, at which Tre was 38.6 degrees C, Tre rise in response to IL-1 was only 0.2 degree C greater than when saline was used. In the first series of exercise experiments, rats ran on a treadmill after IL-1 or saline injection at two different work intensities (estimated at 40 and 60% of maximal oxygen uptake) at 24 degrees C Ta. At either work intensity, the magnitude of Tre rise after IL-1 injection was approximately 0.5 degree C higher than after saline injection. Threshold Tre for tail vasodilation increased when IL-1 was injected. The difference in the threshold Tre between the IL-1 and saline conditions was 0.5 degree C at either work intensity. Evaporative heat loss was also suppressed and metabolic heat production facilitated when IL-1 was injected. In a second series of experiments, IL-1 was injected after Tre reached a steady state (38.5 degrees C) during exercise. After IL-1 injection Tre increased another 0.5 degrees C, but after saline injection Tre did not change. These results suggest that body temperature rise during exercise is not induced merely by an insufficient capability of dissipating heat and that the thermoregulatory set point is reset during exercise.

Animals↗
PubMed1989

Decrease in the fluidity of brush-border membrane vesicles induced by gentamicin. A spin-labeling study.

In our previous paper (Horio et al., Biochim Biophys Acta 858: 153-160, 1986), we reported that the addition of gentamicin in vitro to rabbit renal brush-border membrane vesicles decreases the apparent Vmax of Na+-dependent D-glucose transport without affecting the apparent Km. In the present study, we investigated the effects of gentamicin on the physical state of spin-labeled rabbit renal brush-border membranes, using electron spin resonance spectrometry. Brush-border membrane vesicles were prepared from outer cortex (mainly contains early proximal tubule) and outer medulla (containing primarily late proximal tubule), and the gentamicin toxicities in both preparations were compared. Significant decreases were observed in the membrane fluidity of 5 mM gentamicin-treated brush-border membranes. The fluidity of outer cortical brush-border membranes was affected at both 25 degrees and 35 degrees, whereas that of outer medullary membranes was affected only at 35 degrees. Two different stearic acid spin labels revealed that gentamicin affected the fluidity only in the superficial region of the membranes. We also demonstrated that the gentamicin-induced decreases in Na+-dependent D-glucose transport and in the membrane fluidity were recovered by washing gentamicin-treated brush-border membranes. We suggest that gentamicin binds to the superficial region of brush-border membranes and inhibits Na+-dependent D-glucose transport across brush-border membranes through the decrease in the membrane fluidity.

Animals↗
PubMed1989

Effects of estrus cycle on thermoregulatory responses during exercise in rats.

In female rats, rectal temperature (Tre), tail vasomotor response, oxygen uptake (VO2), and carbon dioxide production (VCO2) were measured in proestrus and estrus stages during treadmill running at two different speeds at an ambient temperature (Ta) of 24 degrees C. Experiments were performed at 2.00-6.00 a.m., when the difference in Tre was greatest between the two stages; Tre at rest in the estrus stage was 0.54 degrees C higher than in the proestrus stage. In a mild warm environment, threshold Tre for a rise in tail skin temperature (Ttail) was also higher in the estrus stage than in the proestrus stage. In contrast, no difference was seen in the threshold Tre and steady state Tre at the end of exercise between proestrus and estrus stages. These values were higher at the higher work intensity. VO2 was also similar between the two stages, except in the second 5 min after the beginning of exercise, when VO2 was greater and Tre rose more steeply in the proestrus stage. These data indicate that deep body temperature during exercise is regulated at a certain level depending on the work intensity and is not influenced by the estrus cycle.

Animals↗
PubMed1989

Involvement of the hippocampus in central nervous system-mediated glucoregulation in rats.

To find out whether the hippocampus is involved in central nervous system-mediated glucoregulation, we injected saline, neostigmine, dopamine, norepinephrine, bombesin, beta-endorphin, somatostatin, and prostaglandin F2 alpha into the dorsal hippocampus in anesthetized fed rats. After injection of dopamine, norepinephrine, bombesin, beta-endorphin, somatostatin, or prostaglandin F2 alpha, the level of hepatic venous plasma glucose did not differ from that in saline-treated control rats. However, neostigmine, an inhibitor of acetylcholine esterase, caused a dose-dependent increase in the hepatic venous plasma glucose concentration. This neostigmine-induced hyperglycemia was dose-dependently suppressed by coadministration of atropine, but not by hexamethonium. Injection of neostigmine (5 X 10(-8) mol) resulted in an increase not only in glucose but also in glucagon, epinephrine, and norepinephrine in hepatic venous plasma. In bilateral adrenalectomized rats, neostigmine-induced hyperglycemia was suppressed, but the hepatic venous plasma glucose concentration still increased significantly. These results indicate that the hippocampus is involved in central nervous system-mediated glucoregulation through cholinergic muscarinic activation, partly via epinephrine secretion.

Adrenalectomy↗
PubMed1988

Nerve growth factor-mediated sexual differentiation of the rat hypothalamus.

Injection of antibody to nerve growth factor into the cerebral lateral ventricle blocked testosterone-induced behavioral defeminization of neonatal female rats. When tested as adults following ovariectomy and combined estrogen-progesterone treatment, the injected animals showed a significantly higher lordosis quotient than the testosterone-treated, normal rabbit serum-infused controls. Failure of vaginal opening and clitoral enlargement manifested the well-documented masculinizing effect of testosterone on the genitalia in the experimental as well as the control animals. Estrogen sensitivity of hypothalamic neurons which are responsible for the induction of lordosis was retained in the experimental animals. Recordings of the antidromic action potentials from neurons in the ventromedial nucleus of the hypothalamus following stimulation of the midbrain central gray revealed that estrogen decreased the antidromic activation threshold and shortened the absolute refractory period of the hypothalamic efferents along with the estrogen-induced behavioral activation in the experimental animals. In the control group, the estrogen-induced neuronal activation was lost altogether with the behavioral activation.

Action Potentials↗
PubMed1988

Quantitative evaluation of vascular permeability in the gerbil brain after transient ischemia using Evans blue fluorescence.

Mongolian gerbils were used to evaluate brain edema during restoration of flow following bilateral carotid occlusion for 1 h. We have modified the method for fluorometric measurement of Evans blue to monitor vascular protein leakage (vasogenic edema). The extraction of extravasated Evans blue was performed by homogenizing the whole brain in 50% trichloroacetic acid. The supernatant was diluted fourfold with ethanol and the Evans blue fluorescence was measured. The tissue blank was negligible. Evans blue content of the plasma was similarly determined and the ratio of tissue to plasma Evans blue content was calculated. Furthermore, Evans blue fluorescence was used for microscopic investigation. It is suggested that Evans blue fluorescence can be applied for quantification of protein leakage with much more sensitivity and accuracy than the colorimetric absorbance method, as well as for tissue localization of protein leakage.

Animals↗
PubMed1988

Relative contributions of the nervous system and hormones to CNS-mediated hyperglycemia.

We quantitatively determined the relative contributions of hormonal factors and the nervous system to the total glucose response after stimulation of the cholinergic neurons in the central nervous system of fed rats. Hepatic venous plasma glucose, glucagon, insulin, epinephrine, and norepinephrine were measured during 120 min after injection of neostigmine (5 X 10(-8) mol) into the third cerebral ventricle in rats subjected to bilateral adrenodemedullation (ADMX) to prevent epinephrine secretion (observed insulin secretion), with and without intravenous infusion of somatostatin to prevent glucagon and insulin secretion. Injection of neostigmine in intact rats resulted in increases in glucose, glucagon, epinephrine, and norepinephrine. Comparison of glucose areas suggests that 22% of the hyperglycemic response is due to the glucagon effect, that 29% is due to the epinephrine effect, and that an unknown factor other than epinephrine or glucagon, which may include activation through direct neural innervation of the liver via alpha-adrenergic receptor, contributes 49%. The suppressive effect of epinephrine on insulin secretion, which is potentially stimulated by direct neural activation of the pancreas, contributes 18% of the net hyperglycemia.

Adrenal Medulla↗
PubMed1988

Pharmacokinetic and pharmacodynamic interactions between furosemide and hydrochlorothiazide in nephrotic patients.

We examined the response of 8 patients with nephrotic syndrome (creatinine clearance 70.4 +/- 16.0 ml/min) to oral furosemide (F; 40 mg) in the absence (control) and in the presence of oral hydrochlorothiazide (HCT; 100 mg). In the 24-hour period after oral F, HCT was shown to increase urine volume and urinary sodium and chloride excretion. Increment was most significant during the 12- to 24-hour period. Enhancement of the diuresis with HCT was associated neither with a significant increase in the area under the curve of plasma F concentration nor an increase in urinary F excretion. Urinary excretion of glucuronidated F, one of the main metabolites of F, however, was decreased with HCT. In summary, HCT significantly enhanced the response to F in nephrotic patients.

Drug Interactions↗
PubMed1988

The roles of glucagon and adrenal epinephrine in mediating hyperglycemia induced by third cerebroventricular injection of bombesin.

The roles of glucagon and adrenal epinephrine in mediating bombesin-induced central hyperglycemia were further studied in anesthetized rats. Bombesin (10(-9) mol) injected into the third cerebral ventricle produced an increase in plasma concentrations of glucose, glucagon, and epinephrine. Prior bilateral adrenalectomy completely prevented the hyperglucagonemic and hyperglycemic responses to third cerebral ventricle injection of bombesin. These results support the view that bombesin-induced increases in plasma glucose and glucagon are fully dependent on adrenal epinephrine secretion. Furthermore, during constant intravenous infusion of somatostatin, the hyperglycemic response to third cerebral ventricle injection of bombesin was not significantly influenced despite complete inhibition of the increase in plasma glucagon. Therefore, it is suggested that bombesin-induced central hyperglycemia is mainly mediated by epinephrine itself rather than via epinephrine-stimulated glucagon secretion.

Animals↗
PubMed1988

Body temperature regulation in rats during exercise of various intensities at different ambient temperatures.

We examined the relationship between body temperature, tail vasomotor response, and work intensity at different ambient temperatures in rats, using a treadmill and continuously measuring oxygen uptake during exercise. At an ambient temperature (Ta) of 24 degrees C, rectal temperature (Tre) at the beginning of tail vasodilation during exercise increased in proportion to work intensity. After tail vasodilation Tre remained steady, and at the end of 30 min exercise Tre level was proportional to work intensity. At Ta of 14 degrees C, Tre at the end of exercise was slightly higher than at 24 degrees C, and was higher at higher work intensities. At Ta of 4 degrees C, Tre rose slower during exercise than at higher Tas and even dropped at relatively low work intensities. Tail vasodilation did not occur in most cases. At Ta of 34 degrees C, Tre rose continuously during exercise. These data indicate that body temperature of rats during exercise rises in proportion to work intensity, but the extent of body temperature rises differs according to Ta.

Animals↗
PubMed1988

[Clinical evaluation of immunoglobulin-E radioimmunoassay kit].

An IgE RIA kit (Sandwich method; Dainabott), is used to obtain the following results. (1) Standard curve: Since the range of reproduction rate show 3.16-7.07% (C.V.), the curve become steep. (2) Incubations under controlled situation: Both of the incubations are controlled at 15-30 degrees C for 2 h. (3) Reproducibility test: Coefficients of variation (C.V.) of intra-assay and inter-assay variation are 2.32-3.94% and 2.92-3.92% respectively. (4) Recovery test: A result of the recovery test range between 100.1-101.7%. (5) Dilution test: Multiple dilution effects are observed. (6) Average counts of the serum IgE for the controlled and diseased groups: The average counts of the serum IgE for the controlled group, atopic diseased group, allergic rhinitis group and allergic bronchial asthma are 144.9 +/- 183.2 IU/ml, 1,099.0 +/- 2,782.4 IU/ml, 1,150.9 +/- 2,063.3 IU/ml and 600.7 +/- 686.4 IU/ml respectively. The value of the diseased groups have tendency to show higher averages than the controlled group. Since the controlled and diseased groups show wide distributions of the serum IgE level, there is no significant difference of two variations. However the diseased groups have tendency to show higher ratio of the serum IgE level in blood than the controlled groups. These basic researches are quite meaningful, because they are able to apply for a supplemental diagnosis of the atopic and parasitic disease.

Asthma↗
PubMed1988

[Clinical usefulness of a trypsin radioimmunoassay kit].

From the clinical use of RIA-gnost trypsin kit, the following results were obtained. 1. Standard curve showed a steep and good curve was shown. 2. Incubation: The condition for the first incubation was set at the room temperature for 10-24 hours and that for the second incubation at the room temperature for 3-5 hours. With these settings, satisfactory results were obtained. 3. Reproducibility and recovery: The C.V. of the reproducibility and the recovery were considered superior, and the values were below 10% and +/- 3%, respectively. 4. Correlation between trypsin and serum elestase-1: An excellent positive correlation (coefficient of correlation r = 0.889) was shown. 5. Serum trypsin concentration of normal and pancreatic diseases: The normal range was from 100 to 500 ng/ml. Acute pancreatitis rose obviously. Diabetes mellitus and chronic pancreatitis was below 500 ng/ml and the pancreatic cancer showed a tendency to scatter in the range of 50-1,250 ng/ml. The above results indicated that serum trypsin can be easily measured with high precision by using this method. Thus the method is considered useful for the diagnosis of pancreatic diseases.

Humans↗