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Biomedical subjects

R Nakano

Publications and source records attributed to R Nakano.

At least 163 records · Page 9Linked to original sources
PubMed1991

Antibody to a zinc finger protein in a patient with paraneoplastic cerebellar degeneration.

In some patients with paraneoplastic cerebellar degeneration (PCD), autoantibodies against neural components have been identified. Here, we demonstrate a major 58 kd protein antigen in an immunoblot of human cerebellum by serum from a patient with PCD. Immunohistochemically, the serum recognized neural cells especially Purkinje cells in a human brain. To identify the details of the target antigens for the antibody, we isolated a cDNA clone from a human cerebellar library. Homology searches revealed a similarity with the zinc finger proteins. PCD related proteins reported here may be important to maintain neural cells especially those in the cerebellum, and further studies on this molecule may help us elucidate the causes of degenerative or autoimmune diseases in the cerebellum.

Aged↗
PubMed1991

Structure of mouse myelin-associated glycoprotein gene.

The mouse myelin-associated glycoprotein gene was isolated from a mouse gene library. This gene was split into 13 exons distributed about 15 kb in length. Each extracellular immunoglobulin-related domain was encoded by a single exon, and RNA splicing between those exons occurred between the first and second nucleotides of the junctional codon, the features of which are conserved in most of the genes of the immunoglobulin superfamily. The sequence of the 5'-flanking region appeared to have some regions homologous to other myelin proteins, which suggested that they were possible cis-elements for specific expression of oligodendrocytes.

Animals↗
PubMed1991

Collagenase production by immortalized human aortic endothelial cells infected with simian virus 40.

Human aortic endothelial cells, isolated at autopsy from a 52-year-old male dying from lung cancer, were treated with simian virus 40 (SV40). One colony was isolated from the infected endothelial cell culture 4 weeks after infection. The cells expressed SV40 large T antigen and p53 protein (p53) in their nuclei but lacted the characteristics of a transformed phenotype. The cells grew well in a monolayer over the 97th passage and exhibited Factor VIII-related antigen, Ulex europaeus 1 agglutinin (UEA-1) as endothelial cell markers, and a well-developed fibronectin network. The amount of prostacyclin synthesized by the cells was less than the amount synthesized by normal aortic or umbilical cord vein endothelial cells. The cells produced relatively large amounts of procollagenase, and 12-o-tetradecanoyl-phorbol-13-acetate (TPA) augmented the ability of the cells to produce this enzyme. These immortalized human aortic endothelial cells, which have some characteristics of normal endothelial cells and, like capillary endothelial cells, have the ability to produce collagenase, will probably prove useful for studies of atherosclerosis and angiogenesis.

Animals↗
PubMed1991

Synthesis of biologically active adenovirus preterminal protein in insect cells using a baculovirus vector.

A DNA fragment encoding the polyhedrin promoter of Autographa californica multiple nuclear polyhedrosis virus (AcMNPV strain) was constructed using overlapping oligodeoxyribonucleotides (oligos), which included the 5'-untranslated leader sequence of the polyhedrin-encoding gene. This DNA fragment was cloned into an intermediate transfer vector (pKX105) providing a unique BamHI site for the insertion of foreign genes. The Escherichia coli lacZ gene was first cloned at the BamHI site of pKX105 and the XhoI-KpnI fragment containing the lacZ gene was transferred to another plasmid vector (pEI) consisting of flanking AcMNPV sequences (pEI-lacZ). The E. coli beta-galactosidase that was produced in the infected insect cells using the recombinant virus constituted about 10% of the total cytoplasmic proteins. The pKX105 plasmid was also modified to give rise to pTT-lacZ which consisted of the lacZ gene under the control of the Rous sarcoma virus long terminal repeat promoter to facilitate rapid screening of the baculoviral recombinants in which the gene of interest was cloned under the control of the polyhedrin promoter. The efficiency of these transfer vectors was verified by obtaining high levels of expression of the adenovirus(Ad)-encoded preterminal protein (pTP) which is involved as a protein primer in the initiation of Ad DNA replication. The baculovirus-produced pTP was immunoprecipitable using rabbit polyclonal antibodies raised against a hydrophilic domain of pTP. The pTP protein was localized in the nucleus of the infected insect cells, and was biologically active in the in vitro Ad type 2 (Ad2) replication initiation assay.

Adenoviruses, Human↗
PubMed1991

Immunohistochemical localization of inhibin subunits in human corpora lutea during menstrual cycle and pregnancy.

The cellular localization of the alpha-, beta A-, and beta B-subunits of inhibin was studied in human corpora lutea (CL) during the menstrual cycle and pregnancy. Immunohistochemical techniques using antisera selective for each subunit were used to localize the polypeptide chains. Immunoreactive staining with antisera against the alpha-, beta A-, and beta B-subunits was mainly observed in granulosa luteal cells (luteal cells), whereas thecal luteal cells were faintly stained with antibodies selective for each inhibin subunit. The intensity of immunostaining with alpha-subunit antiserum in luteal cells increased from the early luteal phase to the midluteal phase and subsequently decreased toward the late luteal phase. Inhibin alpha-subunit in the retrogressive CL was not detected. Not only was the immunolocalization of both beta A- and beta B-subunits detected in the luteal cells of the CL of the cycle, but the relative intensity of immunostaining with beta-subunit antiserum changed in a pattern similar to that shown by the alpha-subunit. The luteal cells and thecal luteal cells in the CL of pregnancy exhibited positive staining with antisera directed against each inhibin subunit. The present findings provide further evidence that 1) immunoreactive inhibin subunits are present in luteal cells in the CL of the menstrual cycle; 2) the detectable level of each subunit changes in parallel with the function of the CL over the course of the menstrual cycle; and 3) the CL of pregnancy might be involved in serum inhibin elevation early in gestation.

Adult↗
PubMed1991

Prenatal diagnosis of autosomal recessive polycystic kidney disease by ultrasonography and magnetic resonance imaging.

Autosomal recessive polycystic kidney disease is a relatively rare congenital disease affecting the kidneys and liver. We noticed the kidney abnormality at 22 weeks gestation and observed the patient till the delivery at 36 weeks of gestation. The ultrasonographic features consisted of bilaterally enlarged hyperechogenic kidneys, oligohydramnios, lack of distention and difficulty in identifying the fetal urinary bladder. The serial sonographic features of the kidneys changed as pregnancy progressed. The kidney cysts gradually changed in size, shape and renal texture, but the umbilical velocimetry and the kidney circumference/abdominal circumference ratio did not change. Magnetic resonance imaging also showed similar characteristic features as observed by ultrasonography.

Adult↗
PubMed1991

[Malignant mesenchymoma of the retroperitoneum: a case report].

This is a case report of a malignant mesenchymoma of the retroperitoneum. On December 1988, a 60-year-old man was hospitalized with complaints of painless and increasing swelling in the left side of the abdomen. The tumor was resected on March 1, 1989; tumor weight was 4,780 g. Histologically, the lesion contained liposarcomatous, chondrosarcomatous, fibrohistiocytic and fibrosarcomatous components. After the tumor resection, he received chemotherapy according to the CYVADIC regimen, and he has been doing well without any evidence of recurrence or metastasis.

Humans↗
PubMed1990

High cell density suspension culture of mammalian anchorage independent cells: oxygen transfer by gas sparging and defoaming with a hydrophobic net.

Gas sparging directly into the culture-broth is not done in cell culture, except when the gas flow rate is very small, because much foaming occurs. During screening of defoaming methods, foam was observed to be broken up effectively when it made contact with a net fabricated from hydrophobic materials. Providing a highly efficient oxygen supply to suspension culture was tried using the new defoaming method. In a 5 l reactor equipped with the foam-eliminating net fabricated with polysiloxane, oxygen was transferred at 21 mmole/l.h equivalent to a consumption rate of 1 X 10(8) cells/ml, even at a low oxygen gas flow rate of 0.1 cm/s corresponding to a fourth of the gas flow rate when foam leaked through the net. Perfusion culture of rat ascites hepatoma cell JTC-1 was successfully carried out in the 5 l scale culture system with the net and a hydrophobic membrane for cell filtration. The viable cell concentration reached 2.7 X 10(7) cells/ml after twenty-seven days, in spite of the nutrient-deficient condition of the lower medium exchange rate, that is, a working volume a day, and viability was maintained at more than 90%. In a 1.21 scale culture of mouse-mouse hybridoma cell STK-1, viable cell concentration reached 4 X 10(7) cells/ml. These results showed that oxygen transfer by gas sparging with defoaming was useful for high density suspension culture. A foam-breaking mechanism was proposed.

Animals↗
PubMed1990

Effects of repetitive administration of corticotropin-releasing hormone combined with lysine vasopressin on plasma adrenocorticotropin and cortisol levels in secondary adrenocortical insufficiency.

To examine the functioning of the hypothalamo-pituitary-adrenocortical axis in secondary adrenocortical insufficiency, we administered 100 micrograms synthetic human CRH, iv, plus 10 U lysine-8-vasopressin (LVP), im, three times daily for 3 consecutive days. The changes in plasma ACTH and cortisol levels during the administration and the response to an insulin tolerance test (ITT) conducted before and after the administration were determined. In three patients with isolated ACTH deficiency, basal plasma ACTH and cortisol levels were undetectablly low, and there was no response noted in the ITT or during CRH-LVP administration throughout the observation period. In four patients with adrenocortical insufficiency who had undergone successful transsphenoidal microadenomectomy for Cushing's disease and in six patients who had undergone curative unilateral adrenalectomy for Cushing's syndrome, basal plasma ACTH levels were low, but responded considerably to both stimulation tests. Along with the 3 days of CRH-LVP stimulation, however, neither the peak nor the time-integrated ACTH response was significantly enhanced, because of the variability of the responses among the patients. Compared with the ACTH response on the last day of CRH-LVP stimulation, the subsequent ITT tended to induce a lower ACTH response in the post-Cushing's disease patients and a higher response in the post-Cushing's syndrome patients. Regarding the plasma cortisol levels, the basal, peak, and integrated responses tended to increase daily during CRH-LVP administration. Conversely, the ITT after repetitive CRH-LVP administration induced a higher cortisol response than the test before CRH-LVP administration in the post-Cushing's disease patients. No serious complications were noted in any of the patients during or after the treatment. The present findings indicate that 1) repetitive administration of CRH in combination with LVP is a safe and valuable provocation test to examine the pituitary ACTH reserve and the integrity of the pituitary-adrenocortical axis; 2) isolated ACTH deficiency is usually due to a defect at the pituitary level; 3) with respect to adrenocortical responsiveness, post-Cushing's disease patients show a better accumulation of the provocative effect than do post-Cushing's syndrome patients; and 4) both hypothalamic and pituitary dysfunction are responsible for adrenal hypofunction in patients after hypercortisolemia, but post-Cushing's syndrome patients (especially those with a short period of hypercortisolemia) appeared to have less impairment of hypothalamic ACTH-releasing activity than post-Cushing's disease patients.

Adrenal Cortex↗
PubMed1990

Immunohistochemical localization of pituitary gonadotrophins and gonadal steroids confirms the 'two-cell, two-gonadotrophin' hypothesis of steroidogenesis in the human ovary.

Ovaries from 37 women with normal menstrual cycles were analysed for localization of pituitary gonadotrophins and gonadal steroids using an immunohistochemical method. In the follicular phase, FSH and oestradiol-17 beta localized in the granulosa layer, and LH, progesterone and testosterone localized in the internal thecal layer. In the luteal phase, gonadotrophins and steroids localized in luteal cells. Particularly in the early luteal phase, FSH and oestradiol-17 beta localized in large luteal cells, and LH, progesterone and testosterone localized in small luteal cells. The results of the present immunohistochemical analysis confirm the two-cell, two-gonadotrophin hypothesis of steroidogenesis in the human ovary.

Adult↗
PubMed1990

Ovarian clear-cell carcinoma producing estradiol and human chorionic gonadotropin.

A case of clear-cell carcinoma of the ovary in a 52-year-old woman having an unusual menstrual history is presented. Serum concentrations of human chorionic gonadotropin (hCG) and estradiol were 120 mIU/ml and 86 pg/ml, respectively, while the serum FSH level was 43 mIU/ml. Immunohistochemistry of the tumor revealed positive staining for both hCG and estradiol in the tumor cells.

Adenocarcinoma↗
PubMed1990

Peripheral and ovarian venous concentrations of estradiol and progesterone in postmenopausal women with "non-endocrine" ovarian tumors.

Estradiol (E2) and progesterone (P4) levels in peripheral venous blood were measured in 45 postmenopausal (more than 5 years after menopause) women with ovarian neoplasms. The E2 and P4 concentrations in ovarian venous blood were also measured in 26 of these 45 patients. The steroid levels were compared with the values in 10 postmenopausal women without ovarian tumors. In peripheral venous blood, relatively high E2 concentrations were found in 24 of the 45 (53%) postmenopausal patients with ovarian tumors, and relatively high P4 concentrations were noted 15 of 45 (33%) of the patients. In ovarian venous blood, relatively high values of E2 were found in 18 of 26 (69%) of the postmenopausal patients, and relatively high values of P4 were noted in 11 of these 26 (42%). No differences in the E2 and P4 levels in peripheral and ovarian venous blood were noted between the patients with benign tumors and those with malignant tumors. These results suggest that some of the epithelial ovarian tumors in postmenopausal women have steroid-producing activity.

Estradiol↗
PubMed1990

[Expression of oncogenes by smooth muscle cells in atherosclerotic lesions].

Smooth muscle cells in the thickened intima of the aorta also expressed sis, mye, and c-fos, in addition to collagen types I, III, IV and type V. In the cultures of smooth muscle cells isolated from human aorta, collagen I, III and gelatinase were produced without any other special conditions for the culture. In the presence of PDGF, collagen type V and collagenase production was detected in the culture. Oncogene expression was not detected in the cultured cells when tested by the indirect immunofluorescence technique. Immortalized smooth muscle cells with SV 40 expressed myc, SV 40 large T antigen, and p53 without inhibition of collagen and collagenolytic enzymes production.

Arteriosclerosis↗
PubMed1990

Effect of linoleic acid hydroperoxide on adenovirus DNA replication.

The effect of linoleic acid hydroperoxide on replication of adenovirus type 2 DNA in HeLa cells was examined. The level of the DNA was extremely reduced when the cells immediately after the infection with adenovirus type 2 were incubated for 24 h in the presence of 1 nmol/ml (measured by the thiobarbituric acid reaction and expressed in terms of malondialdehyde) of the hydroperoxide. The levels of the messenger RNA for adenovirus type 2 DNA polymerase and the expressed polymerase were equally reduced. The inhibition of DNA replication by lipid hydroperoxides in animal cells was discussed in relation to degenerative disorders.

Adenoviruses, Human↗
PubMed1989

Localization of gonadotropin binding sites in human ovarian neoplasms.

The binding of human luteinizing hormone and human follicle-stimulating hormone to ovarian tumor biopsy specimens from 29 patients was analyzed. The binding sites for human luteinizing hormone were demonstrated in one tumor of epithelial origin (mucinous cystadenoma) and in one of sex cord-stromal origin (theca cell tumor). The binding sites for human follicle-stimulating hormone were found in three tumors of epithelial origin (serous cystadenoma and mucinous cystadenoma) and in two of sex cord-stromal origin (theca cell tumor and theca-granulosa cell tumor). The surface-binding autoradiographic study revealed that the binding sites for gonadotropins were localized in the stromal tissue. The results suggest that gonadotropic hormones may play a role in the growth and differentiation of a certain type of human ovarian neoplasms.

Adolescent↗
PubMed1989

Estrogen feedback in normal and sulpiride-induced hyperprolactinemic postmenopausal women.

Feedback effect of estrogen on gonadotropin secretion was studied in normal and sulpiride-induced hyperprolactinemic postmenopausal women. Twelve normoprolactinemic postmenopausal women were administered 40 micrograms/day of ethinyl estradiol (EE2) orally throughout the study. On the 4th week of the study, daily doses of 200 micrograms EE2 were also given to each subject for 4 days. Twelve postmenopausal women were given sulpiride orally in a daily dose of 150 mg throughout the study. Serum levels of prolactin were raised in all 12 subjects given sulpiride. In the 12 sulpiride-induced hyperprolactinemic postmenopausal women, EE2 was given in the same manner as in normal postmenopausal women. The negative feedback effect of estrogen with low doses of EE2 (40 micrograms/day for 4 weeks) and the positive feedback effect of estrogen after the subsequent administration of EE2 (200 micrograms/day for 4 days) were demonstrated in both normoprolactinemic and hyperprolactinemic groups. The result of the present study suggests that sulpiride-induced hyperprolactinemia does not affect the negative and positive feedback effect of estrogen in postmenopausal women.

Aged↗
PubMed1989

In vitro membrane desialylation in porcine granulosa cells unmasks functional receptors for follicle-stimulating hormone.

To evaluate the possible existence of masked gonadotropin-binding sites and the functional role of the binding sites in porcine granulosa cells (GCs), we characterized the effects of neuraminidase (NA) pretreatment on [125I]human LH and [125I]human FSH binding to porcine GCs and the functionality of the unmasked receptors exposed by NA pretreatment. NA pretreatment at 37 C for 30 min increased specific FSH binding (P less than 0.01) and had no effect on LH binding to the GCs harvested from follicles of different sizes. Analysis of equilibrium binding experiments revealed that NA increased the number of FSH-binding sites without altering the affinity. In addition, pretreatment with NA resulted in progressive loss of cell membrane-bound sialic acid (P less than 0.01). To evaluate whether the unmasked FSH receptors constitute functional gonadotropin-binding sites, we measured the amounts of cAMP and 17 beta-estradiol produced by cultured GCs pretreated with NA. cAMP formation by GCs pretreated with NA was significantly (P less than 0.02) greater than that by GCs pretreated with medium alone in the presence of ovine FSH. Moreover, 17 beta-estradiol formation significantly increased (P less than 0.05) in GCs pretreated with NA compared with that in GCs pretreated with medium alone. However, there was no difference between medium-treated and NA-treated GCs in cAMP formation stimulated by forskolin. We suggest that porcine GCs contain a population of masked FSH-binding sites exposed by in vitro pretreatment of NA, and the binding sites constitute functional receptors capable of increasing cAMP and 17 beta-estradiol formation with FSH stimulation. Moreover, a possible involvement of plasma membrane-associated sialic acid in the masking/unmasking mechanism of FSH-binding sites was suggested.

Animals↗