Biomedical subjects

S Kawashima

Publications and source records attributed to S Kawashima.

At least 271 records · Page 15Linked to original sources

PubMed1993

Isolation of rat GnRH receptor cDNA having different 5'-noncoding sequence.

A rat GnRH receptor cDNA was cloned with 1317 base pairs (bp) from a pituitary cDNA library. This clone had a full amino acid coding region, with 172 and 161 bp noncoding sequences in 5'- and 3'-flanking regions of the coding region, respectively. The nucleotide sequence of amino acid coding region was completely identical to that of previous report by Kaiser et al. (1992), but 5'-noncoding region was much longer than the previously reported one and its sequence was different. This 5'-noncoding region could be divided into two subregions on the basis of similarity between the two sequences. The 32 bp sequence flanking the coding region was completely identical to the previous report, but remaining 5'-end sequence almost totally lacked similarity. In the 3'-flanking region of coding region, 167 bp-long sequence was also newly identified. The new species of GnRH receptor mRNA found in the present study suggests that the presence of various mechanisms of GnRH receptor expression in the rat pituitary.

Amino Acid Sequence↗

PubMed1993

[Spontaneous rupture of left external iliac vein--a case report].

Spontaneous rupture of iliac vein is rare, and only twelve Caucasian cases have been reported. To our knowledge, this is the first reported case in Japan, and the thirteenth in the world. An 80-year-old female complained of sudden pain in the left flank as she passed stools and then collapsed. At the emergency laparotomy, a large retroperitoneal hematoma was encountered and a tear of 2cm length was found in the left external iliac vein with fresh intravenous thrombus. After a complete thrombectomy, the rent was sutured and her postoperative course was uneventful. The surgeon should consider the possibility of spontaneous vein rupture in the differential diagnosis with the patient presenting hypovolemic shock of unknown cause, which is often accompanied by abdominal tenderness, particularly when the patient is a middle age female, and the lesion is on the left side.

Aged↗

PubMed1993

Effects of late reperfusion on infarct expansion and infarct healing in conscious rats.

We examined the effects of late reperfusion on infarct expansion and infarct healing process in conscious rats. Coronary occlusion and reperfusion were carried out in conscious rats 1 week after appropriate surgical preparations. The rats were randomized into the following four groups: sham operated, permanent occlusion, early reperfusion (i.e., reperfusion performed 1 hour after occlusion), and late reperfusion (i.e., reperfusion performed 6 hours after occlusion). Histological examination was performed 7 days after coronary occlusion. In the early reperfusion group, infarct size and expansion were reduced when compared to the permanent occlusion group. In rats subjected to late reperfusion, infarct size and expansion were not different from those in the permanent occlusion group. The extent of unresorbed necrotic myocardium in areas of infarcted scar was reduced in both early and late reperfusion groups. Infiltration by neutrophilic cells into areas of necrotic myocardium 16 hours after myocardial infarction was increased in both reperfusion groups. Infiltration by macrophages 3 days after infarction was also increased in both reperfusion groups. Late reperfusion, therefore, does not affect infarct expansion, but does contribute to the acceleration of the infarct healing process.

Animals↗

PubMed1993

Translocation of human platelet calpain-I.

Intracellular localization of calpain (calcium dependent cysteine proteinase) was studied in resting or activated human platelets. When stimulated with 2 U/ml thrombin, approximately 40% of total cellular calpain activity and 25% of antigen translocated mainly to the intracellular membrane fractions with autolytic activation. Translocation of calpain was completely abolished by the addition of EDTA to the sonication medium. However an endogenous calpain inhibitor (calpastatin) activity was not detected in the membrane fractions both in resting and in thrombin stimulated platelets. Translocation of calpain was also observed in the platelets stimulated with ionomycin, collagen or phorbor myristate acetate (PMA). These data suggest that cytosolic calpain reversibly translocates to the intracellular membranes during platelet activation without an interference by calpastatin.

Blood Platelets↗

PubMed1993

[Multiple mitochondrial DNA deletions in chronic progressive external ophthalmoplegia (CPEO)].

We reviewed familial cases of chronic progressive external ophthalmoplegia (CPEO) associated with multiple mitochondrial DNA (mtDNA) deletions. A new case of familial CPEO with multiple mtDNA deletions, which were detected in the proband's skeletal muscles by Southern blotting and in all the tissues examined by using the polymerase chain reaction is also described. There was an approximate correlation between the clinical severity of the muscle involvement and the amount of mtDNA with deletions. Most of these familial CPEO cases, with multiple mtDNA deletions, exhibited an autosomal dominant mode of transmission. Abnormalities of some nucleus-driven factors, involved in the replication of mtDNA, may result in these multiple mtDNA deletions.

Base Sequence↗

PubMed1993

Measurement of serum levels of macrophage colony-stimulating factor (M-CSF) in patients with uremia.

Serum levels of monokines, including macrophage colony-stimulating factor (M-CSF), tumor necrosis factor-alpha (TNF-alpha), interleukin-1 alpha (IL-1 alpha) and IL-1 beta (IL-1 beta), were measured in patients with chronic renal failure in an attempt to clarify the kinetics of these cytokines in the course of renal anemia. M-CSF was the only monokine detectable in the serum from all patients as well as healthy donors, making this cytokine feasible and reliable for serial evaluations. On all occasions, the level of M-CSF in uremic patients was significantly higher than that in healthy donors (29.4 +/- 12.3 vs. 5.5 +/- 1.1 ng/mL). In patients undergoing hemodialysis, the serum level of M-CSF was greater than that in patients undergoing continuous ambulatory peritoneal dialysis or in uremic patients without dialysis therapy. No difference was observed, however, in the levels of IL-1 alpha, IL-1 beta and TNF-alpha levels in these groups. Patients with severe anemia were subsequently treated with 60 to 80 U/kg per week of human recombinant erythropoietin (rhEpo) for 3 months. After this replacement therapy, hemoglobin levels increased with a variable change ranging from 0 to 3.5 g/dL. The pretherapy M-CSF level, however, was found to predict statistically the response to the therapy (p < 0.05). Patients with a lower pretherapy value responded better to rhEpo therapy; those with a higher level showed a minor degree of response. From these results, we postulate that the elevated M-CSF serum level in uremic patients is in part a consequence of the dialysis procedure and that rhEpo therapy is more effective in patients who are under sophisticated dialysis protocol and have a lower M-CSF level.

Erythropoietin↗

PubMed1993

[Partial anomalous pulmonary venous connection to inferior vena cava (incomplete type of scimitar syndrome) in an elderly patient].

A 71-year-old woman presented with recent onset of dyspnea and fatigue on moderate exertion. She had been well during her entire life and had had three pregnancies and deliveries. Cardiomegaly was noted at the age of 30. On physical examination, systolic murmur was detected at the lower left sternal border. The chest X-ray showed cardiomegaly, increased pulmonary vascular markings and elevated right diaphragm. The electrocardiogram showed left ventricular hypertrophy. The echocardiography showed enlargement of right ventricle and atrium, massive tricuspid regurgitation and anomalous venous flow connected to the inferior vena cava from its right-posterior side. Cardiac catheterization demonstrated mild pulmonary hypertension and O2 step-up at the level of the anomalous venous connection to the inferior vena cava. On pulmonary arteriography, left pulmonary venous flow return to the left atrium and atrial septal defect was not found. Veins from the right lung met to form one vessel, went downward, and connected to the inferior vena cava at the level of Th12. L-R shunt was 45% and Qp/Qs was 1.83. Isolated partial anomalous pulmonary venous connection is a rare finding, and it is thought that the natural prognosis is good. The existence of our case, diagnosed at the age of 71, supported this concept.

Age Factors↗

PubMed1992

Slow axonal transport of soluble proteins and calpain in retinal ganglion cells of aged rabbits.

The rate of slow axonal transport of soluble proteins in retinal ganglion cells of the rabbit decreased with approximately 25% in aged (6 years) compared to previous estimates in adult (2 years) animals. Immunobinding of calpain to microtiter plates coated with a monoclonal antibody to mu-calpain was used to isolate labelled axonally transported mu-calpain from the nerve extracts. It was found that the distribution of labelled mu-calpain in the retrobulbar optic pathway was similar to the distribution profile of the slowly migrating phase of soluble proteins.

Aging↗

PubMed1992

Inhibition of DNA polymerases by tripeptide derivative protease inhibitors.

Benzyloxycarbonyl(Z)-Leu-Leu-Leu-al and dansyl(Dns)-Leu-Leu-Leu-CH2Cl, well known as protease inhibitors, effectively inhibit the activities of DNA polymerases alpha, beta and gamma from rat liver and pol I from Escherichia coli, but the ability of these inhibitors to inhibit terminal deoxynucleotidyl transferase (TdT) is weak. The mode of inhibition by these tripeptide analogues is non-competitive with dNTP. The Ki values for Z-Leu-Leu-Leu-al and Dns-Leu-Leu-Leu-CH2Cl are 6.25 x 10(-5) M and 6.56 x 10(-5) M, respectively.

Amino Acid Sequence↗

PubMed1992

Replacement of m-calpain by mu-calpain during maturation of megakaryocytes and possible involvement in platelet formation.

Localization of calpains in human bone marrow cells was studied immunohistochemically employing monoclonal antibodies against the high-Ca(2+)-requiring form (m-calpain) and the low-Ca(2+)-requiring form (mu-calpain). Most cells were stained with anti-m-calpain more strongly than with anti-mu-calpain, and staining with anti-mu-calpain was prominent only in megakaryocytes. To confirm the result, megakaryoblastic cell line (T-33) cells were subjected to immunoblot analysis. However no immunoreactivity to mu-calpain was seen in T-33 cells. Bone marrow from a patient with idiopathic thrombocytopenic purpura showed immature megakaryocytes (stage II) strongly stained by anti-m-calpain antibody while mature cells (stage III) were strongly stained by anti-mu-calpain antibody. These results suggest that mu-calpain plays a crucial role in mature megakaryocytes, possibly in platelet production.

Antibodies, Monoclonal↗

PubMed1992

Isolation and characterization of possible target proteins responsible for neurite outgrowth induced by a tripeptide aldehyde in PC12H cells.

A tripeptide protease inhibitor, benzyloxycarbonyl-Leu-Leu-Leu-aldehyde (ZLLLal), induces the outgrowth of one or two long neurites from PC12 cells. Since this neurite outgrowth is different from that induced by nerve growth factor (NGF) in some aspects, the existence of a molecule that regulates neurite formation in PC12 cells was expected. To identify a target molecule, Leu-Leu-Leu-aldehyde (LLLal) was immobilized as a ligand for affinity chromatography. Proteins of 33-kDa, 35-kDa, and 180-kDa from the membrane and cytoplasmic fractions of PC12 cells bound specifically to the affinity column. ZLLL-COOH has no ability to induce neurite outgrowth, and the 33-kDa, 35-kDa, and 180-kDa proteins do not bind to an LLL-COOH coupled affinity column. By using the LLLal-affinity column, the 33-kDa/35-kDa proteins were found to be converted to 36-kDa/38-kDa proteins during brain development in rats. These results suggest that LLLal-binding proteins are involved in neuronal differentiation.

Animals↗

PubMed1992

Calpain activation is essential for membrane fusion of erythrocytes in the presence of exogenous Ca2+.

The membrane mobility agent, 2-(methoxyethoxy)ethyl-cis-8-(2-octylcyclopropyl)octanoate (A2C) promotes the fusion of rat, rabbit, and human erythrocytes in the presence of exogenous Ca2+. Under these conditions, the high sensitivity form of calcium-activated neutral protease (mu-calpain) in erythrocytes is activated autolytically. mu-Calpain is activated in accordance with fusion; that is, both erythrocyte fusion and autolytic activation of mu-calpain are induced in rat erythrocytes at 30 min, in rabbit erythrocytes at 150 min, and in human erythrocytes at 240 min after the addition of A2C and Ca2+. When erythrocytes are preincubated with the Ca2+ ionophore A23187, both fusion and autolytic activation start earlier. A leupeptin analogue, Cbz-Leu-Leu-Leu-aldehyde (ZLLLal), inhibits both the autolytic activation of mu-calpain and fusion induced by A2C and Ca2+. These results indicate that treatment of erythrocytes with A2C and Ca2+, results in first an influx of Ca2+ into the cells, followed by autolytic activation of mu-calpain, proteolysis of membrane proteins, exposure of fusion-sites, and, finally, fusion of erythrocytes.

Animals↗

PubMed1992

Calcium-activated neutral protease (CANP) in normal and dysmyelinating mutant paralytic tremor rabbit myelin.

Calcium-activated neutral protease (CANP) in normal and dysmyelinating mutant, paralytic tremor (PT) rabbit myelin and premyelin fractions was studied using immature (4-5 wk) or adult animals. The enzyme was estimated by determination of its catalytic activity as well as by using immunoblot analysis after SDS-PAGE separation. The presence of two forms of CANP--one activated by calcium in the micromolar concentration (mu CANP) range and the other exhibiting low calcium sensitivity in the millimolar concentration range (m-CANP)--was found in the myelin and premyelin fractions. The developmental pattern of the enzyme activity was different for each of these two enzyme isoforms depending on the fraction studied. The higher activity on CANP (both isoforms) found in PT myelin and premyelin could be related to delayed myelination and/or to the higher turnover rate of already formed myelin. These results suggest complex and specific roles for these isoenzymes during myelin formation as is discussed further in this article. Our results confirm the extensive degradation of myelin basic protein (MBP), proteolipid protein (PLP), and, to a lesser extent, the other myelin proteins by endo- and exogenous CANP. This degradation process was significantly elevated in PT rabbit myelin. Moreover as was shown by two-dimensional gel electrophoresis, calcium-controlled proteolysis in nonmutant rabbits affected the net-charge of MBP in a manner similar to that reported for PT myelin, suggesting the possible involvement of CANP in the generation of charge isomers of MBP.

Animals↗

PubMed1992

Specific increase in calcium-activated neutral protease with low calcium sensitivity (m-calpain) in proerythroblastic K562 cell line cells induced to differentiation by phorbol 12-myristate 13-acetate.

Changes in the level of calcium-activated neutral proteases (calpains) in K562 cells induced to differentiate by phorbol 12-myristate 13-acetate (PMA) were examined by an immunohistochemical technique and Western blot analysis. A remarkable increase in m-calpain (high-Ca(2+)-requiring form) level was detected after PMA-treatment, while there was no significant difference in mu-calpain (low-Ca(2+)-requiring form) level between PMA-treated and untreated K562 cells. To confirm whether the increase in m-calpain is specific to PMA-induced differentiation, we examined changes in calpain in K562 cells cultured in serum-free medium and in synchronized cells. The results indicate that the increase has no relation to growth arrest or to cell cycle. PMA-treated cells exhibited increased nonspecific esterase activity, suggesting monocytic differentiation. Immunoelectron microscopic study showed the reactions of dense deposits with monoclonal anti-m-calpain antibody on cell membranes, on membranes of coated vesicles, and on rough endoplasmic reticulum of K562 cells after 26 h of PMA treatment.

Blotting, Western↗

PubMed1992

Annual changes in the binding of follicle-stimulating hormone to gonads and plasma gonadotropin concentrations in Indian weaver birds inhabiting the subtropical zone.

In birds, annual changes in gonadal weight are much more pronounced in the male than in the female. To analyze the mechanism inducing such a sex difference in the gonadal responsiveness to natural environmental conditions, we measured annual changes in the binding of follicle-stimulating hormone (FSH) to the gonads and the plasma gonadotropin concentration in adult Indian weaver birds inhabiting the subtropical zone. The binding of FSH was highly specific for mammalian FSHs and located primarily in the gonad. The testicular weight and FSH binding showed marked changes during the annual breeding cycle. The testicular weight was maximal in the breeding phase (June, 1987) and minimal in the nonbreeding phase (December, 1987). FSH binding per unit testicular weight was greatest in the nonbreeding phase, while the total FSH binding per two testes was maximal in the breeding phase and minimal in the regressive phase (October, 1987). In contrast, the changes in the ovarian weight and FSH binding to the ovary were less pronounced than those in the testis. Although FSH binding per unit ovarian weight showed a peak in the nonbreeding phase, there was no significant change in the total FSH binding per ovary during the year, indicating the presence of a clear sex difference in the total FSH binding. Scatchard plot analyses of the binding suggested that the dissociation constant (Kd) ranged from 0.35 to 1.53 nM regardless of sex and season and that the changes in FSH binding were due to changes in the number of binding sites. Plasma FSH and luteinizing hormone (LH) levels markedly changed during the year in both sexes. Both FSH and LH levels were maximal in the breeding phase and minimal in the nonbreeding phase regardless of sex, although the rate of change in either hormone tended to be greater in the male than in the female.

Animals↗

PubMed1992

An oxidative mechanism is involved in high glucose-induced serum protein modification causing inhibition of endothelial cell proliferation.

In order to investigate the role of hyperglycemia on the development of atherosclerosis in diabetics, the effects of high glucose-induced modification of serum factors on the proliferation of bovine carotid artery endothelial cells were studied. Dialysates of high glucose-treated serum inhibit cell growth in a time- and glucose concentration-dependent manner. With 6 weeks of pretreatment, 16.7 mM glucose causes a 47.2% inhibition in cell growth compared to 5.6 mM glucose (P < 0.001). Pretreatment of serum in the presence of reduced glutathione (0.5-1.0 mM), an antioxidant, significantly prevents the high glucose-induced inhibition without inhibiting the formation of early non-enzymatic glycosylation products. Dithiothreitol (7.5 mM) treatment after preincubation with glucose fully restores the glucose-induced inhibition. When the dialysates are fractionated according to molecular mass, the high glucose-induced inhibition is maximal in the MW fraction above 100 kDa. These data suggest that high glucose conditions facilitate the susceptibility of serum proteins to sulfhydryl oxidation forming disulfide crosslinks and this oxidative process may contribute to the inhibition of endothelial cell proliferation.

Animals↗

PubMed1992

Suppression of the development of uterine adenomyosis by danazol treatment in mice.

Inhibitory effects of danazol, an isoxazol derivative of synthetic steroid 17 alpha-ethinyl-testosterone, on the development of uterine adenomyosis, a pathological disorder of endometrial tissue defined as the presence of endometrial glands and stroma in the myometrium, were investigated in mice of SHN strain. Mice treated with 0.5 microgram danazol for 5 weeks during 4-9 weeks of age and killed at 21 weeks of age showed significantly lower incidence of the spontaneous development of adenomyosis than the age-matched intact control mice. The inhibitory effects of danazol were also evident in mice bearing pituitary isografts which were effective in inducing an early and a high incidence of adenomyosis. Furthermore, the treatment with danazol resulted in the decrease of serum levels of luteinizing hormone (LH) and prolactin (PRL) associated with hypofunction of ovaries and persistent diestrus. These results support the usefulness of danazol for the clinical treatment of gynecological disorders except for hypofunction of ovaries.

Animals↗

PubMed1992

Possible involvement of clathrin in neuritogenesis induced by a protease inhibitor (benzyloxycarbonyl-Leu-Leu-Leu-aldehyde) in PC12 cells.

Our previous reports showed that benzyloxycarbonyl (Z)-Leu-Leu-Leu-al (ZLLLal) induces neurite outgrowth in PC12 cells, and that 33-, 35-, and 180-kDa proteins from PC12 cells elute specifically from a Leu-Leu-Leu-al (LLLal)-coupled affinity column. Several lines of evidence suggest that the 33-, 35-, and 180-kDa proteins are components of clathrin, well-known for its role in endocytosis. Separation of clathrin into its heavy and light chains showed that the clathrin heavy chains have the ability to bind to a LLLal affinity column directly. Furthermore, ZLLLal enhances the rate of polymerization of clathrin triskelion to the coat structure. ZLLL-COOH does not cause neurite outgrowth in PC12 cells, and has no effect on the rate of clathrin polymerization. On immunocytochemical analysis of PC12 cells with an anti-clathrin heavy chain antibody, enhanced staining of the clathrin heavy chain was observed concomitantly with neurite outgrowth initiated by ZLLLal, but not by NGF. This study provides new insights into both the role of the clathrin molecule and the regulatory mechanism of neurite outgrowth.

Amino Acid Sequence↗