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Biomedical subjects

Y Kondo

Publications and source records attributed to Y Kondo.

At least 523 records · Page 29Linked to original sources
PubMed1993

Rapid response of striatal muscarinic M1-receptor mRNA to muscarinic cholinergic agents in rat brain.

The effects of a single administration of muscarinic cholinergic agents on the level of muscarinic M1-receptor messenger RNA (M1-R mRNA) in the rat striatum were studied. Carbachol increased the M1-R mRNA expression rapidly and transiently, while trihexyphenidyl decreased it. These results suggest that muscarinic cholinergic agents participate in the positive regulation of muscarinic receptor mRNA in the early stage after treatment, contrary to the negative regulation in the chronic stage.

Animals↗
PubMed1993

Functional relationships between mesencephalic central gray and septum in regulating lordosis in female rats: effect of dual lesions.

In order to clarify the functional relationships between the lateral septum (LS) and the mesencephalic central gray (MCG) in regulating lordosis behavior, ovariectomized female rats received dual lesions in these two areas. In the first experiment, females with unilateral (right or left, R-MCGL or L-MCGL) or bilateral MCG (B-MCG) lesions were subjected to behavioral tests after the implantation of a Silastic tube containing estradiol. Lordosis was observed in only one B-MCGL female. In the R-MCGL and L-MCGL groups, most females displayed lordosis, but lordosis quotients (LQ) were significantly lower than that of the control group. These results suggest the importance of the MCG in lordosis regulation, and that there is no functional laterality in the MCG. In the second experiment, B-MCGL or R-MCGL females received bilateral LS lesions (LSL). The lordotic activity in the LSL + B-MCGL group was extremely low, being comparable to that of B-MCGL alone. On the other hand, in the LSL + R-MCGL females, the LQ was significantly higher than that of females with R-MCGL alone and was comparable to that of controls. Thus, the lateral septum plays an inhibitory role in regulating lordosis, but the influence of the lateral septum is not stronger than the facilitatory influence of the mesencephalic central gray, because the LSL could not recover the suppressive effect of the MCGL.

Animals↗
PubMed1993

Long-term indwelling bilateral ureteral stents for bilateral hydronephrosis of unknown etiology.

We describe a rare case of long-term indwelling bilateral ureteral stents that were replaced yearly for 7 years because of azotemia associated with bilateral hydronephrosis of undetermined etiology on radiological examinations. During year 5 the patient had an uneventful gestation with delivery of a normal neonate by cesarean section. Hydronephrosis remained improved for 2 years after withdrawal of the stents.

Adult↗
PubMed1993

Microtubule-associated proteins, MAP 1A and MAP 1B, interact with F-actin in vitro.

Microtubule-associated protein (MAP) 1 consisting of MAP 1A and 1B was purified from rat brain by the poly-L-aspartic acid (PLAA) method. We found that MAP 1 bound to F-actin in vitro up to a molar ratio of MAP 1 to actin monomers of 1:10. The apparent binding constant was about 2.7 x 10(7) M-1. In contrast to the binding of MAP 2 or tau to F-actin, the binding of MAP 1 to F-actin did not affect the low-shear viscosity of actin filaments. Binding experiments performed using fragments of MAP 1, obtained by chymotrypsin digestion, indicated that MAP 1 included binding domains to F-actin that were different from those in microtubules and also two light chains (31 and 29 kDa) that were cosedimented with F-actin as well as with microtubules.

Actins↗
PubMed1993

P-chlorophenylalanine facilitates copulatory behavior in septal lesioned but not in preoptic lesioned male rats.

Effects of p-chlorophenylalanine (pCPA), synthesis-inhibitor of serotonin, on copulatory behavior were examined in testosterone (T) treated castrated male rats with lesions in the lateral septum (LSL) or in the medial preoptic area (MPOL). Three weeks after the operation, all animals were chronically treated with T using silastic capsules. Behavioral tests were carried out at 10 and 20 days after the implantation of T. In half of the males in each group, 100 mg/Kg pCPA was injected daily for 4 days before each test. The other half of the group was injected with saline instead of pCPA. In saline-treated groups, the males with LSL or MPOL showed extremely lower frequencies of mount and intromission than control males without brain surgery. pCPA-treated control males showed higher copulatory activities than saline-treated control males. In contrast, even after the treatment with pCPA, severe impairment of sexual behavior was observed in males with MPOL. On the other hand, pCPA-treated LSL males displayed copulatory behavior more frequently than saline-treated LSL males. These results agreed with previous reports that both the medial preoptic area and the lateral septum play an excitatory role in regulating male sexual behavior. Furthermore, these results suggest that the inhibitory function of serotonergic neurons govern dependently on the function of the medial preoptic area, but independently on the function of the lateral septum.

Animals↗
PubMed1993

Carcinosarcoma of the prostate.

A unique case of carcinosarcoma of the prostate occurring in a 32 year old man is presented. This is the youngest case reported to date among nine well-documented examples. The patient underwent a total prostatectomy under the diagnosis of prostatic sarcoma. Despite adjuvant chemotherapy and full-dose radiotherapy being undertaken, the patient died from multiple lung metastases about 8 months after the operation. The surgically resected primary tumor was composed of two histologically distinct elements, these being an undifferentiated carcinoma and a sarcoma with various mesodermal components. These elements were intimately intermingled and transitional forms were often noticed. The sarcomatous portion contained myxoid areas, spindle cell sarcomas with nuclear palisading, areas of osteoid formation and small islands of chondromatous differentiation. The pathogenesis of this complex neoplasm is discussed, and it is suggested that vestigial embryologic Müllerian mesodermal tissue may be capable of diverse differentiation.

Adult↗
PubMed1993

Morphometric analysis of gastric adenoma and well-differentiated adenocarcinoma as a basis for microscopic discrimination.

Morphometric analyses were performed on 11 cases of well-differentiated gastric adenocarcinoma and six cases of gastric adenoma. The values for the mean nuclear area (AN), the index for roundness of the nucleus (FX), and the nucleus/cytoplasm ratio (N/C) were larger in the carcinoma group than in the adenoma group (P < 0.01; t-test). The value of nuclear numerical density (NA) was larger in the adenoma group than in the carcinoma group (P < 0.01; t-test). There was an overlap between the N/C ratio in the carcinoma and adenoma groups. It was concluded that roundness and enlargement of the nucleus, and a low nuclear density are important prerequisites for distinguishing the common type of adenocarcinomas from adenomas. An additional morphometric analysis was performed on seven cases of mucosal carcinoma. A three-dimensional discriminant analysis using AN, FX and NA revealed that of these seven cases, three were consistent with the carcinoma group while one case was consistent with the adenoma group. The remaining three cases were judged as borderline.

Adenocarcinoma↗
PubMed1993

Morphological alterations of glomerulus induced by infusion of cationized ferritin.

Morphological alterations of the glomerulus were induced by infusion of cationized ferritin. After a direct injection of highly cationized ferritin (CF) into the left kidney of rats, endothelial injuries were followed by activation of platelets and the coagulation system after 1-2 h, which occluded capillary loops. In most glomeruli, resolving processes occurred from 2 h onward, leaving a mild thickening of the mesangial region at 7 days. On the other hand, in severely involved glomeruli, capillary loops were still obstructed even at 24 h by hypertrophic and proliferated endothelial cells as well as mesangial cells, instead of platelets and fibrin strands. After this period, exfoliation of podocytes and endothelial cells occurred over a wide area, which resulted in glomerular obsolescence at 7 days. These progressive glomerular injuries were assumed to be closely related to the persistence of CF in glomeruli, which might be caused by disturbances of glomerular clearing systems. Mild proteinuria was only noticed in severely involved cases. It is concluded that an assault on glomerular endothelial cells by cationic macro-molecules can cause thrombotic complications leading to glomerular obsolescence.

Animals↗
PubMed1993

Papillo-choledochectomy in the operative management of mucosal neoplasms of the periampullary region.

Two patients with mucosal cancer of the periampullary region were treated with papillo-choledochectomy, which entails removal of the papilla of Vater and the whole length of the common bile duct. The neoplasm is dissected out through the plane between the duodenal circular and longitudinal muscles, deep to the sphincter of Oddi and the fibromuscular layer of the bile duct. Pathological examination showed that cancer was confined to the mucosal layer without stromal invasion, and that the operation achieved radical cure. For mucosal cancer, papillo-choledochectomy is an alternative to pancreatoduodenectomy, provided that repeated frozen-section studies confirm the completeness of excision.

Adenocarcinoma↗
PubMed1993

Direct evidence for the absence of active Na+ reabsorption in hamster ascending thin limb of Henle's loop.

The mechanisms of Na+ transport across cell membranes were investigated in the in vitro microperfused hamster ascending thin limb (ATL) of Henle's loop using a fluorescent Na+ indicator sodium-binding benzofuran isophthalate. The intracellular Na+ concentration ([Na+]i) of the ATL cells was 17.1 +/- 1.7 mM (n = 22) when the ATL was microperfused in vitro with Hepes-buffered solution containing 204 mM Na+. Elimination of metabolites such as glucose and alanine from the basolateral solution increased [Na+]i. Applying either 5 mM cyanide or 5 mM iodoacetic acid to the bath also increased [Na+]i. The elimination of K+ and the addition of 10(-4) M ouabain in the bath increased [Na+]i by 25.0 +/- 5.0 mM (n = 5) in 3 min and by 10.7 +/- 2.4 mM (n = 4), respectively. The elimination of luminal and basolateral Na+ resulted in a decrease in [Na+]i, indicating Na+ permeability of both the luminal and basolateral cell membranes. The luminal Na+ permeability was not affected by furosemide. The presence of luminal Na+ permeability and the basolateral Na+/K+ ATPase suggests the presence of net active reabsorption of Na+, which is not a physiologically important amount, in our estimation.

Alanine↗
PubMed1993

Graves' immunoglobulin G stimulates iodide efflux in FRTL-5 thyroid cells.

TSH induced I- efflux in FRTL-5 cells, a cell line derived from normal rat thyroid cells, is not mediated by cAMP but intracellular Ca2+ signaling. Graves' patient immunoglobulin G is known to activate the thyroidal cAMP pathway, but little is known about the activation of Ca2+ signaling. We report here that, similarly to TSH, the polyethylenglycol-precipitated serum fraction of Graves' patients induces I- efflux in FRTL-5 cells. The cells grown in the presence of TSH were incubated for 3 weeks in a Ham's 10 medium containing 1% CS, insulin, and hydrocortison for TSH depletion. After preincubating with 125I-iodide for 50 min to label intracellular iodide, the cells were challenged by serum samples for 1 min. The addition of normal pooled-serum hardly affected the I- efflux. The Graves' immunoglobulin G fractions dose-dependently stimulated I- efflux. The averaged potency of 12 patients' sera relative to the values of the pooled serum as 100% was 217 +/- 56.4%. This value was significantly higher (P < 0.001) than that for eight normal subjects (110 +/- 16.1%). The present study is the demonstration suggesting that Graves' thyrotoxicosis is mediated not only by an adenylate cyclase-cAMP system but also by a phospholipid-Ca2+ system.

Animals↗
PubMed1993

Receptor cross-talk can optimize assays for autoantibodies to the thyrotropin receptor: effect of phenylisopropyladenosine on adenosine 3',5'-monophosphate and inositol phosphate levels in rat FRTL-5 thyroid cells.

Immunoglobulins (IgG) from patients with Graves' disease increase inositol phosphate (IP) as well as cAMP production in rat thyroid FRTL-5 cells; IgGs from normal control subjects do not. Graves' IgG-and TSH-induced IP formation is inhibited by blocking TSH receptor (TSHR) antibodies from hypothyroid patients with primary myxedema, as is the cAMP response; this suggests that the Graves' IgG are acting through the TSHR to induce both the cAMP and phosphatidyl-inositol 4,5-biphosphate signal cascades in FRTL-5 thyroid cells as in cells with recombinant TSHR. Optimal conditions for measuring the Graves' IgG-induced IP increase include a NaCl-free Hanks' Balanced Salt Solution (HBSS) buffer system and a P1 purinergic receptor agonist; the action of each is additive. Optimization by NaCl-free HBSS is similar to that observed in cAMP assays and is specific for TSH or Graves' IgG; thus, NaCl-free HBSS did not affect ATP-induced, and actually inhibited norepinephrine-induced, IP production in FRTL-5 cells. The P1 purinergic receptor agonist acts via receptor cross-talk, which also allows further optimization of cAMP assays. Thus, adenosine deaminase improves Graves' IgG-induced cAMP production by removing adenosine from the medium. Although NaCl-free HBSS improved TSH- or Graves' IgG-induced IP and cAMP production in cells with recombinant TSHR; the modulatory action of phenylisopropyladenosine was lost.

Animals↗
PubMed1993

Interaction of a protein-bound polysaccharide (PSK) with chicken gizzard caldesmon.

The interaction of a protein-bound polysaccharide (PSK) with caldesmon was studied in detail using sedimentation, low-shear viscometry, electron microscopy and affinity chromatography. The binding of caldesmon to F-actin was concentration-dependently inhibited by PSK. Bundle formation of actin filaments owing to caldesmon was also inhibited by PSK. Caldesmon bound to a PSK-Sepharose 4B column at low ionic strength was released at about 400 mM NaCl, whereas G-actin was not retained by the column. Treatment of caldesmon with chymotrypsin produced major fragments near 100, 80, 60, 38 and 25 kDa. In contrast, 60 and 25 kDa fragments were rarely formed by this treatment in the presence of PSK. Fragments of 80 and 38 kDa, major products produced by chymotrypsin, bound individually to a PSK-Sepharose column, indicating that caldesmon has at least two binding sites for PSK. Addition of calcium and calmodulin partially released caldesmon from actin filaments. PSK-dependent release of caldesmon was also observed in the presence of calcium and calmodulin.

Actins↗
PubMed1993

Genetic polymorphisms of salivary proteins in the rat.

Two genetic polymorphisms of salivary proteins were found by polyacrylamide gel electrophoresis among inbred strains of rats. Both proteins (RSP-1 and RSP-2) were inherited as a single autosomal trait. The loci were designated as Rsp-1 (rat salivary protein-1) and Rsp-2. Rsp-1 had two codominant alleles (Rsp-1a, Rsp-1b), and Rsp-2 had two alleles (Rsp-2a, and Rsp-2b); Rsp-2a was dominant over Rsp-2b. The Rsp-1 locus is not linked with the linkage groups (LGs) I, II, IV, V and the LGs containing Acp-2 and Pg-1. The Rsp-2 is not linked with the LGs I, II, V, X and the LGs containing Amy-1, Es-6 and Pg-1.

Alleles↗
PubMed1993

Lack of direct action of atriopeptidase inhibitor on cellular pH regulation in rabbit S2 proximal straight tubules.

While the in vivo diuretic and antihypertensive effects of the newly-developed drug Candoxatril (UK-79300), a prodrug of a selective atriopeptidase inhibitor UK-73967 (API) are well established, the mechanism of its diuretic action is not yet fully understood due to the lack of information about its direct effects on proximal tubules. To elucidate whether this atriopeptidase inhibitor has any direct effects on proximal tubules, we examined the effect of API on intracellular pH (pHi) of the in vitro microperfused proximal S2 segment of rabbit kidney, using the pH-sensitive fluorescent dye, (2',7')-bis(carboxyethyl)-(5,6)-carboxyfluorescein (BCECF). In the steady-state condition, pHi was 7.13 +/- 0.02 (n = 19). Atriopeptidase inhibitor (API) at 100 microM added to the bath changed pHi by only 0.02 +/- 0.07 unit (n = 7, p > 0.05) in 10 min. The same concentration of API in the lumen changed pHi by 0.03 +/- 0.02 unit (n = 6, p > 0.05). To test whether the synergistic effects of API on the luminal and basolateral transport systems prevented the apparent change in pHi, we also examined the effect of API in the presence of amiloride in the lumen. The inhibition of Na+/H+ antiporter by the addition of 1 mM of amiloride to the lumen caused no change in pHi response to basolateral API application. API was without effect on pHi also in the presence of atrial natriuretic polypeptide (ANP). These results suggest that API per se has no significant effect on the process of proximal acidification over a short time period.

Animals↗
PubMed1993

New double-barreled, ion-sensitive microelectrodes for measuring intracellular Cl- activities in rabbit renal collecting ducts.

The use of the conventional ion-sensitive double-barreled microelectrodes has been unsuccessful for studying small epithelial cells such as those of the collecting duct because of the difficulty in obtaining the ideal electrodes for impaling cells. We developed a new type of ion-sensitive, double-barreled microelectrode of a size and tip configuration ideal for use in impaling small cells such as the principal cells (PCs) of the cortical collecting ducts, and remaining therein, for more than 30 min. The electrodes were pulled in two steps. The first includes the reciprocal twisting of two parallel glass capillaries, without pulling, to form a round, nontortuous fused glass capillary in the puller. In the second step, the round, fused straight capillaries are pulled so as to form the tip. This resulting procedure enabled us to impale the PCs without altering their cell membrane potentials. The basolateral membrane voltage (Vb) in PCs of the cortical collecting ducts was -69.1 +/- 1.6 mV (n = 8) and intracellular Cl- activity ([Cl]i) in PCs of the cortical collecting duct was 11.8 +/- 0.9 mmol/liter (n = 5). Changing the concentration of Cl- in the ambient solution showed that the basolateral cell membrane of the PCs was highly permeable to Cl-. This new electrode will help to obtain new information on intracellular ion handling, with the electrodes applied to the collecting duct cells.

Animals↗
PubMed1993

The development of sleep-wakefulness rhythm in normal infants and young children.

The development of circadian sleep-wakefulness rhythm was investigated by a longitudinal study of two normal newborns for two and a half years and by a transversal study of 182 normal infants and young children living in three different areas of Japan. The circadian rhythm became established before 4 months of age, and daytime sleep became concentrated within two time periods from 7 months of age, and then within a single peak from 14 months of age. The time period 00:00-04:00 developed into the "absolute sleep period" from 3 months of age, and the "absolute wakefulness period" appeared first in the time period 08:00-11:00 from 14 months of age, and then in the time period 16:00-21:00 from one and a half years of age. Establishment of circadian rhythm as indicated by the numbers of sleep epochs in daytime and in nighttime, and the longest continuous sleep or wakefulness periods reflect the development of the nervous system and were influenced by the change of light-dark in the environment. These parameters showed critical ages, but not sexual or regional differences. However, regional differences were found in the times of waking up in morning and falling asleep at night. This indicated the phase of the circadian rhythm was also influenced by natural and social environmental factors.

Aging↗