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K Ando

Publications and source records attributed to K Ando.

At least 433 records · Page 24Linked to original sources
PubMed1991

Effect of partial hepatectomy on glucose-stimulated insulin release from perfused rat pancreas.

To investigate the functional reserve of the endocrine pancreas both in the early and in the recovering stage after partial hepatectomy, we evaluated the changes in the secretion of insulin in response to a glucose load in isolated perfused rat pancreas 4 and 7 d after about 70% hepatectomy in rats. Insulin responses to a high glucose load (16.7 mM) were significantly higher in the first stimulation phase (first 10 min (p less than 0.01 at 4 and 7 d), and the second stimulation phase (second 20 min) (p less than 0.01 at 4 and 7 d), after hepatectomy. These results indicate that in the regenerating stage after hepatectomy, the sensitivity of islet B-cells to a glucose load is increased to support the increased glucose metabolism in this stage. Thus, this insulin hypersecretion from B-cells seems to be among the adaptations of the endocrine pancreas after hepatectomy.

Animals↗
PubMed1991

Recovery functions of fast frequency potentials in the initial negative wave of median SEP.

Following far-field potential of P14 after median nerve stimulation, we identified several small wavelets, designated here as fast frequency potentials or FFP, over the ascending and descending phases of the major negative wave of 'N20.' In 10 normal subjects who had well defined FFP, namely N16, N17, N18 and N19, we studied recovery functions of FFP by applying paired (condition and test) stimuli of various interstimulus intervals (ISIs) ranging from 3 to 150 msec. Recovery of FFP was determined by the difference wave forms, i.e., subtracting the response of conditioning stimuli from the response to paired stimuli. Measuring latencies and amplitude of FFP and also of the far-field potential of P14, we found recoveries of P14 and each FFP to be different; P14 recovered with the shortest ISI while progressively longer ISIs were required for full recovery of the later FFP. This finding suggests the existence of progressively increased number of interspersed synapses from the early to late FFP. It is unlikely that FFP represents passage of the afferent volley from one anatomical site to the next, but rather that they are cortically generated via a closely situated polysynaptic network. The polysynaptic nature of FFP is consistent with the observation that they disappear in sleep and also during anesthesia. The study indicates that FFPs represent different physioanatomical systems from the primary negative wave of 'N20' that results from specific sensory input to the primary sensory cortex.

Adolescent↗
PubMed1991

Atrial natriuretic peptide in the dog with mitral regurgitation.

The concentration and molecular form of the plasma atrial natriuretic peptide (ANP) in dogs with mitral regurgitation was investigated. Plasma ANP concentration in dogs with mitral regurgitation was significantly increased (29.4 +/- 1.88 pmol litre-1, n = 40) compared to that in the controls (14.5 +/- 0.62 pmol litre-1, n = 20, P less than 0.01). Molecular forms of plasma ANP were determined by the gel permeation chromatogram. A single peak corresponding to alpha-ANP was detected in the plasma from the controls. However, a peak corresponding to beta-ANP and, or, gamma-ANP was detected in the plasma of the dogs with mitral regurgitation in addition to alpha-ANP. These results suggest that the process of ANP synthesis was altered and excretion of ANP from the heart was enhanced in dogs with mitral regurgitation.

Animals↗
PubMed1991

Involucrin in well-differentiated adenocarcinoma of the lung. Comparison with adenocarcinomas of different organs.

Using immunoperoxidase stain for involucrin, 50 well-differentiated adenocarcinomas of the lung were compared with similarly well-differentiated adenocarcinomas of other organs, 30 from the stomach, 30 from the colon, 12 from the pancreas and 12 from the prostate. Thirty (60%) adenocarcinomas of the lung were positive for involucrin; in 24 of 30 cases from 10% to more than 60% of tumor cells were positive and in the remaining 6 cases a few cells were positive. The positive cells included columnar or cuboidal tumor cells as well as some squamoid tumor cells. In contrast, only 4 (4.8%) of 84 tumors in the other organs were involucrin positive. Most of the involucrin positive foci of these four cases seemed to show squamous differentiation. These findings suggest that pulmonary adenocarcinoma is more prone to show squamous differentiation, compared with gastric, colonic, pancreatic and prostatic adenocarcinomas. The result may be applied for the differential diagnosis between primary and metastatic well-differentiated adenocarcinomas in the lung.

Adenocarcinoma↗
PubMed1991

Response of plasma atrial natriuretic factor to experimentally induced aortic and mitral regurgitation in dogs.

STUDY OBJECTIVE: The correlations between the plasma concentration of atrial natriuretic factor and right atrial or left atrial pressure were studied in experimentally induced aortic regurgitation and mitral regurgitation in dogs. DESIGN: Aortic regurgitation was created by opening the tip of a basket wire catheter placed at the aortic annulus via the left ventricular wall, and terminated by pulling back the catheter. To create mitral regurgitation a basket catheter was inserted into the mitral annular position via a pulmonary vein. Regurgitation was induced by opening the tip of the catheter, and terminated promptly by closing it. EXPERIMENTAL MATERIAL: Seven beagle dogs were prepared for the aortic regurgitation model and six for the mitral regurgitation model (weights 11.5 to 14.5 kg). MEASUREMENTS AND MAIN RESULTS: The plasma concentration of atrial natriuretic factor was highly correlated with right atrial pressure (r = 0.78, SD = 0.07, n = 7) and left atrial pressure (r = 0.82, SD = 0.05, n = 7) in aortic regurgitation; and with right atrial pressure (r = 0.82, SD = 0.05, n = 6) and left atrial pressure (r = 0.84, SD = 0.05, n = 6) in mitral regurgitation. Further evaluation of the molecular forms of plasma atrial natriuretic factor revealed the alpha form in all 13 dogs and the gamma form in two (one with aortic and the other with mitral regurgitation); no evidence of the beta form was seen. CONCLUSIONS: Atrial natriuretic factor secretion responds rapidly to the circulatory changes caused by valvular incompetence.

Animals↗
PubMed1991

Stimulation of vitellogenesis by pyrethroids in mated and virgin female adults, male adults, and fourth instar females of Ornithodoros moubata (Acari: Argasidae).

The effects of several pyrethroids on vitellogenesis, i.e., vitellogenin (Vg) synthesis and ovarian development in unfed mated female adults of Ornithodoros moubata were investigated. Survival of ticks treated with pyrethrin, resmethrin, and etophenprox was very low. Ticks treated with cypermethrin (CyM), fenvalerate (Fev), and flucythrinate (Flu) survived even when high concentrations were used. Vg titer in the hemolymph of unfed mated females was the same level on day 5 and about three times higher on day 10 after treatment with CyM, Fev, and Flu, as that of engorged adult females. CyM was the most effective in inducing vitellogenesis and was further evaluated in unfed virgin females, males, and fourth instars. CyM was shown to stimulate vitellogenesis in unfed virgin females adults. Oviposition did not occur but ovaries were well developed. CyM also was shown to stimulate Vg in the hemolymph of unfed and fed adult males; however, the Vg levels were very low compared to that of engorged adult females. Extremely high concentrations of Vg were observed in the hemolymph of female nymphs (fourth instar), particularly engorged nymphs, treated with CyM (10 micrograms). No ovarian development was observed in these nymphs. Vg stimulated by CyM was shown to be immunologically and electrophoretically the same as that of normal engorged females.

Animals↗
PubMed1991

Effects of juvenile hormone and its analogs on vitellogenin synthesis and ovarian development in Ornithodoros moubata (Acari: Argasidae).

Effects of juvenile hormones (JH) and JH analogs on the release of vitellogenin (Vg) into the hemolymph and ovarian development in unfed adult female ticks, Ornithodoros moubata (Murray), were investigated. Topical application of acetone solvent and injection of acetone or oils showed some increase in Vg titer in the hemolymph. Topical application of JH (JH I, JH II, JH III) and JH analogs (methoprene, S21149, S21150, and S31183) dissolved in acetone to unengorged adult females elevated Vg titer in the hemolymph but only to the same level as the acetone controls. These effects were independent of dose. Injection of JH (JH I, JH II, JH III) and methoprene dissolved in mineral oil also did not significantly increase the Vg titer in the hemolymph compared with the controls (mineral oil injection). Electrophoretic analysis of hemolymph from females 5 d after treatment topically or by injection with JH and JH analogs showed faint Vg bands which comigrated with Vg's (Vg-1 and Vg-2) of normal, engorged female hemolymph, but Vg bands were detected more clearly in the hemolymph samples that were collected greater than 2 wk after treatment. However, the same level of Vg also was detected in the hemolymph of females treated with acetone or mineral oil. Vg synthesis in females treated with JH and JH analogs was analyzed by in vivo labeling and fluorography, which showed that Vg synthesis was not induced by application of JH to unengorged females.

Animals↗
PubMed1991

Pure apocrine nevus. A study of light-microscopic and immunohistochemical features of a rare tumor.

The pure apocrine nevus is a rare tumor. A new case of pure apocrine nevi of the bilateral axillary regions in a 48-year-old man is herein reported. The patient had two soft masses of both axillae. The time of onset of the masses was unknown. They were not accompanied by problems of sweating. Histologically, these lesions comprised numerous apocrine glands extending from the reticular layer of the dermis to the subcutaneous tissue. In addition, sections from both of the lesions were stained by immunoperoxidase techniques for the presence of epithelial membrane antigen, carcinoembryonic antigen, and the alpha and beta subunits of S100 protein. Immunohistochemical features of the tumor stained by these antibodies are consistent with a pure proliferation of mature, well-differentiated apocrine glands. The tumor of the present case seems to have developed spontaneously. It is believed, therefore, that the tumor seen in this patient is best categorized as a pure apocrine nevus.

Antigens, Neoplasm↗
PubMed1991

Endothelin-1- and endothelin-3-like immunoreactivity in human cerebrospinal fluid.

Using highly specific and sensitive radioimmunoassays (RIAs) for endothelin-1 (ET-1) and endothelin-3 (ET-3), we have determined the concentrations of ET-1- and ET-3-like immunoreactivities (LI) in human cerebrospinal fluid (CSF). The concentration of ET-3-LI (82.5 +/- 4.8 pg/ml) was about 1.5-fold greater than that of ET-1-LI (34.3 +/- 1.3 pg/ml). There was no significant correlation between ET-1-LI and ET-3-LI concentrations in human CSF (r = 0.44). Reverse-phase high-performance liquid chromatography (HPLC) revealed a single major component of ET-1-LI and ET-3-LI coeluting with authentic ET-1 and ET-3, respectively. It is suggested that ET-1 and ET-3 play a neuropeptide-like role in the central nervous system.

Chromatography, High Pressure Liquid↗
PubMed1991

Effect of salt loading on aldosterone response to long-term infusion of angiotensin II in rats.

We examined changes in plasma aldosterone level and blood pressure (BP) after long-term (12 days) intravenous infusion of angiotensin II (Ang II; 15 and 60 ng/min) with two different sodium intakes (0.66% and 8% salt-containing diet) in Wistar rats. Without salt loading, 15 ng/min of Ang II did not increase mean BP (112 +/- 1 vs. 112 +/- 2 mm Hg), but 60 ng/min of Ang II increased mean BP (144 +/- 3 mm Hg, p less than 0.01). However, the 8% salt diet not only enhanced the pressor effect of 60 ng/min Ang II (168 +/- 9 mm Hg, p less than 0.05), but also elevated mean BP with 15 ng/min of Ang II (159 +/- 3 mm Hg, p less than 0.01). On a normal-salt diet (0.66%), plasma aldosterone was increased by Ang II infusion from 11.3 +/- 0.3 ng/dl to 12.7 +/- 0.5 ng/dl (NS) at a rate of 15 ng/min Ang II, and to 15.7 +/- 0.4 ng/dl (p less than 0.01) at 60 ng/min Ang II. However, salt loading reduced Ang II-induced elevation of aldosterone: 11.3 +/- 0.5 ng/dl (less than 0.01) at a rate of 60 ng/min Ang II. Thus, salt loading diminished aldosterone response to Ang II, which might compensate salt-induced enhancement of the pressor effect of Ang II.

Aldosterone↗
PubMed1991

Prolongation of the kidney preservation period by simple cold storage up to 72 hours by human atrial natriuretic peptide.

To prolong the preservation period of donor kidneys, we tried to evaluate the effect of human atrial natriuretic peptide (hANP), which has vasodilator, natriuretic, and GFR-increasing effects. Autotransplantations were successful in 6 of 8 hANP-treated cases, but only one of 7 untreated cases (P less than 0.05) was successful. When removed kidneys were perfused prior to preservation, the gravity perfusion time was shorter in hANP-treated kidneys, resulting in rapid cooling. Renal biopsy 1 hr after transplantation revealed normal histology in the hANP-treated kidneys while a remarkable capillary collapse occurred in controls. A hANP-like immunoreactivity contents of biopsied tissue in the hANP-treated kidneys showed a higher value than in the controls, and cyclic GMP contents were also higher in the hANP-treated kidneys. Microangiography showed complete clarity, down to the peripheral vessels, in the hANP-treated kidneys, but not in the controls. Thus, the present study suggests that hANP is useful for prolonging the preservation time of donor kidneys.

Animals↗
PubMed1991

Human gnathostomiasis.

Two patients became infested with Gnathostoma nipponicum after eating raw loach-fish they had caught in a rice field in central Japan. A fragment of Gnathostoma was found in a biopsy from one of them. The sera of both patients reacted with Gnathostoma antigen using indirect immunofluorescence. Scanning electron microscopy was performed on blocks of the paraffin-embedded parasite sample and the viscera of a fish from the same rice field. The risk of eating raw freshwater fish is discussed.

Animals↗
PubMed1991

Exophthalmos in myelodysplastic syndrome.

A case of myelodysplastic syndrome (MDS) who suffered alternating proptosis was reported. A 57-year-old Japanese man with MDS developed acute painful left proptosis with eyelid edema, conjunctival injection, visual disturbance, and restriction of eye movements. This lasted for 3 weeks. Computerized tomography (CT) showed swelling of the lateral and medial rectus muscles and the optic nerve, as well as a retrobulbar mass. Later, a similar painful right proptosis with severe conjunctival chemosis developed. CT showed only bilateral mild optic nerve swelling. The visual acuity of the right eye decreased to null even after remission of the proptosis. The patient died due to myocardial infarction and underwent autopsy. The right optic nerve stroma was found to be increased over that of the left. Cellular infiltration was noted in the left optic nerve and the retrobulbar connective tissue. This self-limiting and relapsing proptosis was apparently related to MDS. This is only the second MDS case with such severe ophthalmological symptoms reported in the literature.

Exophthalmos↗
PubMed1991

Atypical lipoma of the lung.

An unusual endobronchial lipoma characterised by pleomorphic, multinucleated giant cells admixed with mature adipose cells developed in a 52 year old woman, arising from the right middle lobe bronchus. Lobectomy was performed and the postoperative course was uneventful.

Bronchi↗
PubMed1991

High-potassium diet attenuates salt-induced acceleration of hypertension in SHR.

We studied the effects of K supplementation (8% KCl) for 4 wk on blood pressure (BP), Na space, and renal hemodynamics in 5-wk-old, spontaneously hypertensive rats (SHR) or age-matched Wistar-Kyoto rats (WKY) eating normal-NaCl (0.66%) or high-NaCl (8%) diet. In WKY, high-Na and/or high-K diets had no effects on BP. In SHR, Na load accelerated the development of hypertension, whereas K supplementation did not affect BP of normal-Na SHR but attenuated the increase in BP with Na load. Correspondingly, Na load in SHR significantly increased renal vascular resistance (RVR), and K supplementation attenuated the increased RVR of Na-loaded SHR. Moreover, Na space of SHR was increased compared with that of WKY, and although Na load did not affect Na space, K supplementation tended to decrease Na space in SHR. These results indicate that 9-wk-old SHR is relatively volume-expanded compared with age-matched WKY, and K supplementation could improve the lowered slope of the pressure-Na excretion relationship in SHR, resulting in maintenance of Na balance. Thus the data suggest that changes in RVR, which might be intimately related to renal function for Na excretion, contribute to both salt sensitivity of SHR and antihypertensive action of K supplementation in Na-loaded SHR.

Animals↗
PubMed1991

High potassium intake attenuates antinatriuretic response to air stress in DOCA-salt rats.

We studied the effects of potassium supplementation (2 wk of 0.5% KCl to drink) on responses of renal function to a stressful environmental stimulus (air stress) in deoxycorticosterone acetate (DOCA)-salt rats. In conscious DOCA-salt rats, air stress decreased urine flow rate and urinary sodium excretion without changes in effective renal plasma flow and glomerular filtration rate, whereas in normotensive vehicle-treated rats air stress had no effect on these measures. Renal denervation abolished the antidiuretic and antinatriuretic responses to air stress in DOCA-salt rats. Correspondingly potassium supplementation in DOCA-salt rats could not only reduce basal blood pressure significantly but also attenuate the antidiuretic and antinatriuretic responses to air stress without renal denervation. Evidence suggests that the attenuation by potassium supplementation of air stress-induced decrease in urine flow and sodium excretion in DOCA-salt rats may be partly involved in the natriuretic and the resultant antihypertensive actions of potassium in DOCA-salt hypertensive rats, but the mechanisms could not be clarified by the present study.

Air↗
PubMed1991

Antihypertensive effect of dietary calcium loading in angiotensin II-salt rats.

To clarify the hypotensive effect of high dietary Ca intake on salt-sensitive hypertension, 7-wk-old Sprague-Dawley rats, 3.15% Na and/or 4.07% Ca diet loaded, were administered 125 ng/ml of angiotensin II (ANG II) intraperitoneally for 12 days. Compared with control rats (mean blood pressure 108 +/- 2 mmHg), ANG II administration caused hypertension (131 +/- 4 mmHg, P less than 0.05). Na loading enhanced the hypertensive effect of ANG II (161 +/- 4 mmHg, P less than 0.01). Dietary Ca loading did not significantly inhibit the pressor effect of ANG II alone (119 +/- 4 mmHg). However, Ca loading suppressed hypertension in ANG II-salt rats (126 +/- 4 mmHg, P less than 0.01). Plasma total catecholamine (norepinephrine + epinephrine) was increased in ANG II-salt rats (176 +/- 14 vs. 290 +/- 23 pg/ml, P less than 0.05), but Ca loading decreased plasma catecholamine (182 +/- 13 pg/ml, P less than 0.05). In contrast, plasma catecholamine was not significantly different between ANG II-treated rats with and without Ca loading. Ca loading increased serum Ca in ANG II rats (10.9 +/- 0.1 vs. 11.7 +/- 0.1 mg/dl, P less than 0.05) but did not do so significantly in ANG II-salt rats (10.8 +/- 0.2 vs. 10.9 +/- 0.1 mg/dl). Thus Ca loading exclusively ameliorated salt-sensitive hypertension, which was induced with ANG II administration and Na loading in rats, probably through suppression of the increased sympathetic activity. In addition, these effects of Ca loading were not mediated through an increased blood level of Ca.

Angiotensin II↗