Biomedical subjects

N Nakashima

Publications and source records attributed to N Nakashima.

At least 145 records · Page 8Linked to original sources

PubMed1995

[Detection of lupus anticoagulant using a modified diluted Russell's viper venom time test].

Lupus anticoagulants (LA) are considered to be a significant risk factor in patients with unexplained thrombosis and are often present in women who have recurrent miscarriages. According to Petri et al, LA detectable using a diluted Russell's Viper Venom time (dRVVT) test are more closely linked with thrombosis in patients with systemic lupus erythematosus than are anticardiolipin antibodies. We evaluated a new simplified dRVVT test, that is, a combination of LUPO-TESTII and LUCOR, and found that the ratio of LUPO-TESTII/LUCOR values is a good indicator for detection of LA. The cut-off point of the ratio based on receiver-operating characteristic (ROC) analysis was set at 1.07. The sensitivity and specificity were 92.3% and 96.8%, respectively. The ratio of LUPO-TESTII/LUCOR values of 24 (92.3%) of 26 LA-positive patients was significantly higher than those of warfarin-treated patients, patients with hereditary clotting-factor deficiency and patients positive for specific clotting-factor inhibitors (p < 0.01). It was shown that the result was not influenced by warfarin and/or heparin treatment and the presence of specific clotting-factor inhibitors. The ratio of LUPO-TESTII/LUCOR values is regarded as a more useful indicator for the detection of LA than the platelet neutralization procedure test.

Female↗

PubMed1994

[Maximum-intensity-projection CT angiography for evaluating head and neck tumors: usefulness of helical CT and auto bone masking method].

Angiographic images of 10 adult patients with head and neck tumors were obtained by helical computed tomography (CT) using maximum intensity projection (MIP). In all cases, the vasculature of the head and neck region was clearly visualized, and hypervascular lesions were directly demonstrated. In the head and neck, bone masking is a more important problem than in other regions. We developed an effective automatic bone masking method (ABM) using 2D/3D connectivity. Helical CT angiography with MIP and ABM provided accurate anatomic depiction, and was considered to be helpful in preoperative evaluation of head and neck tumors.

Adult↗

PubMed1994

Hac1: a novel yeast bZIP protein binding to the CRE motif is a multicopy suppressor for cdc10 mutant of Schizosaccharomyces pombe.

We cloned by phenotypic complementation a novel Saccharomyces cerevisiae's multicopy suppressor of the Schizosaccharomyces pombe cdc10-129 mutant which we call HAC1, an acronym of 'homologous to ATF/CREB 1'. It encodes a bZIP (basic-leucine zipper) protein of 230 amino acids with close homology to the mammalian ATF/CREB transcription factor and gel-retardation assays showed that it binds specifically to the CRE motif. HAC1 is not essential for viability. However, the hac1 disruptant becomes caffeine sensitive, which is suppressed by multicopy expression of the yeast PDE2 (Phosphodiesterase 2) gene. Although the mRNA level of HAC1 is almost constitutive throughout the cell cycle, it fluctuates during meiosis. The upstream region of the HAC1 gene contains a T4C site, a URS (upstream repression sequence) and a TR (T-rich) box-like sequence, which reside upstream of many meiotic genes. These results suggest that HAC1 may also be one of the meiotic genes.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed1994

Differential diagnosis of ovarian tumors by transvaginal color-pulse Doppler sonography.

To investigate the clinical significance of transvaginal color-pulse Doppler sonography in ovarian tumors, 109 patients were examined at Nagoya University Hospital. Ultrasonographic patterns were classified and the levels of three circulating tumor markers, CA125, CA72-4, and CA19-9, were simultaneously evaluated. In differentiating benign and malignant ovarian tumors, transvaginal color-pulse Doppler and ultrasonographic pattern classification were superior to the tumor markers. Of 49 cases with benign pattern, 45 were benign (91.8%). Of 60 cases with malignant pattern, 24 (40%) were benign and 36 (60%) were malignant or borderline malignant. In this group color-pulse Doppler sonography was the most useful procedure, and sensitivity, specificity, and accuracy were 75.0, 79.2, and 76.7%, respectively. Menopausal status and site of the arterial wave form in the tumor were also important. Transvaginal color-pulse Doppler sonography was a reliable diagnostic method for differentiating ovarian tumors.

Adenocarcinoma↗

PubMed1994

Cloning of the Nilaparvata lugens reovirus genome: conserved terminal nucleotide sequences and nucleotide sequence of genome segment S10.

The segmented double-stranded RNA genome of Nilaparvata lugens reovirus (NLRV) was cloned, and the nucleotide sequence of genome segment S10 and terminal nucleotide sequences of the rest of the segments were determined. Genome segment S10 of NLRV consisted of 1430 nucleotides with a single open reading frame extending for 1293 nucleotides from nucleotide 46. It encoded a polypeptide of 431 amino acids with an M(r) of 49.4K, which was a non-structural protein. The plus-strand RNA of all genome segments had the same conserved trinucleotide 5' AGU- and hexanucleotide-GUUGUC 3' in the 5'- and 3'-terminal regions, respectively. These conserved terminal sequences resembled those found in the segments of the members of the genus Fijivirus.

Amino Acid Sequence↗

PubMed1994

Nucleotide sequence of Nilaparvata lugens reovirus genome segment S8 coding for the major outer capsid protein.

The complete nucleotide sequence of genome segment 8 (S8) of Nilaparvata lugens reovirus (NLRV) was determined. It consisted of 1802 nucleotides containing a long open reading frame (562 amino acids), which was expressed in Escherichia coli as a fusion protein. The expressed S8 product, a 62K protein, was detected by Western blotting using IgG directed against intact NLRV particles. This result indicates that S8 encodes the major outer capsid protein of NLRV. The protein exhibited 18.6% amino acid sequence identity with the predicted translation product of S10 of rice black-streaked dwarf virus.

Amino Acid Sequence↗

PubMed1994

Induction of multinucleated giant cells from rheumatoid arthritis (RA) synovial adherent cells by anti-DR antibody.

To determine the effects of signalling through the DR molecule on synoviocytes from RA patients, the synovial adherent cells were incubated with anti-DR antibodies. After 24 h incubation, we found the formation of multinucleated giant cells in that culture. These multinucleated giant cells showed characteristics of monocyte-macrophage lineage cells and precursor of osteoclasts. Cyclohexamide inhibited the formation of multinucleated giant cells, but not the aggregation of synovial cells, suggesting that newly synthesized proteins are associated with the cell fusion. These results revealed a new mechanism in multinucleated giant cell formation.

Antibodies, Monoclonal↗

PubMed1994

Immunohistochemical characterization of extracellular matrix components of granulosa cell tumor of ovary.

In order to clarify the characteristics of granulosa cell tumors of the ovary, extracellular matrix components were investigated by immunohistochemical techniques. Twenty-three granulosa cell tumors (GCT; eight juvenile and 15 adult type) were studied in comparison with non-neoplastic granulosa cells of human ovaries. In all 23 cases of GCT, chondroitin 6-sulfate proteoglycan revealed with antibody 3B3 was characteristically observed in the extracellular matrix in the solid nest, as well as in microfollicles. In the juvenile cases, the extracellular matrix also contained large proteoglycan (PG) revealed with antibody 2B1. Macrofollicles as well as microfollicles contained PG chondroitin 6-sulfate side chains with a significant amount of chondroitin 4-sulfate. By biochemical analysis using high pressure liquid chromatography, it was also found that disaccharide composition of glycosaminoglycan fractions extracted from granulosa cell tumor tissues consisted mainly of 2-acetamide-2-deoxyl-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-6-O-sulfo-D-galactose (delta Di-6S). The characteristic feature of granulosa cell tumors is the accumulation of chondroitin sulfate PG, especially chondroitin 6-sulfate PG, which may be synthesized by the tumor cells themselves. Immunohistochemical characterization of the extracellular matrix components (collagen, laminin, heparan sulfate PG, chondroitin 4-sulfate PG) was also studied in relation to chondroitin 6-sulfate PG localization.

Adolescent↗

PubMed1994

Dependence of cholecystokinin-8-stimulated insulin release on high glucose levels is evidenced by pseudo-alpha-D-glucose in rat pancreas and islets.

The glucose-dependency of cholecystokinin-8 (CCK-8)-stimulated insulin release was investigated at high (11.1 and 16.7 mM) glucose concentrations in rat pancreas perfusion and islet perifusion using glucose analogues, pseudo-alpha-D-glucose and 2-deoxy-D-glucose. In perfused pancreas, both glucose analogues (22.4 mM) inhibited high glucose (16.7 mM)-induced insulin release, but not normal glucose (5.6 mM)-induced insulin release, with or without CCK-8 (1 nM). In perifused islets, the same level of either of the glucose analogues inhibited high glucose (11.1 mM)-induced insulin release, with or without CCK-8 (100 nM). These results demonstrate that CCK-8-stimulated insulin release only at high glucose level is glucose-dependent.

Animals↗

PubMed1994

Clinical and epidemiologic investigations of nosocomial pulmonary infections caused by methicillin-resistant Staphylococcus aureus.

We evaluated the clinical features of 32 patients with pulmonary infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Most of the patients were elderly, postoperative, and had severe underlying diseases. Chest radiograph typically showed bilateral and multilobar involvement. Empyema was not common and no abscess was identified. Mortality rate was 38 percent. We also performed an epidemiologic study of MRSA infections by chromosomal DNA analysis using pulsed-field gel electrophoresis. Thirty-two strains were classified into 20 different types by chromosomal DNA pattern, and 5 epidemic strains were observed. These strains were considered to be transmitted among patients by hospital personnel.

Cross Infection↗

PubMed1994

[Early detection of hepatocellular carcinoma with lectin reactive alpha-fetoprotein].

Lens culimaris agglutinin A-reactive alpha-fetoprotein (AFP L3) and erythroagglutinating phytohemagglutin-reactive alpha-fetoprotein (AFP P4 + P5) were determined by a sensitive method using lectin-affinity electrophoresis coupled with antibody-affinity blotting, and the usefulness of this method for early detection of hepatocellular carcinoma (HCC) was examined. For 72 operated cases of the HCC group including 28 cases of small liver cancer, the AFP value was 124 +/- 198ng/ml (Mean +/- SD); the lectin fraction values for L3 and P4 + P5 were 12.2 +/- 17.9 and 17.9 +/- 17.9%, respectively, which were significantly higher compared with the chronic hepatitis (CH).cirrhosis (LC) group and showed an increasing tendency with an increase in tumor diameter. The cut-off values for distinguishing HCC from CH.LC, determined with the receiver-operating characteristic (ROC) plots, were 10.0 and 15.0% for the L3 and P4 + P5 fractions, respectively, and the positive rates in the patient with HCC were 33.3 and 48.6% for AFP L3 and AFP P4 + P5, respectively, and 59.7% with a combination assay. For small liver cancer, the positive rate was 17.9% with protein induced by vitamin K absence-II (PIVKA-II) and 46.4% with combination assay of AFP L3 and AFP P4 + P5. Also, for HCC below AFP 50ng/ml, a positive rate of 45.0% was obtained. In the CH.LC group, all cases were negative for AFP L3 and 2 of 44 cases (4.5%) were false-positive for AFP P4 + P5.

Carcinoma, Hepatocellular↗

PubMed1994

Utility of Albusure test in screening for early stage of diabetic nephropathy.

All diabetic patients should be screened for the early stage of diabetic nephropathy, because microalbuminuria has a great prognostic significance. The albusure test (AT), alatex agglutination nephelometric immunoassay, is a rapid and low cost test for the detection of microalbuminuria of 30 mg/L or more. We compared the results of AT and of radioimmunoassay (RIA) for urinary albumin to evaluate the clinical utility of AT using fresh urine samples from 74 diabetic patients without persistent proteinuria and from 11 healthy subjects. Urinary albumin levels measured by RIA were 6.0 +/- 2.3 mg/L in the healthy subjects, 11.0 +/- 8.7 mg/L in the AT-negative group (n = 61), and 38.1 +/- 10.2 mg/L in the AT-positive group (n = 13). Using a cut-off value of 30 mg/L by RIA, the rate of coincidence between AT and RIA was 89.2%, although five subjects were false-positive by AT, and three were false-negative. These results show that AT may provide a useful monitor microalbuminuria, a reliable early mark of diabetic nephropathy.

Adult↗

PubMed1994

[Etiology and molecular biology of hyperproinsulinemia].

Clinical hyperproinsulinemia occurs not only in familial hyperproinsulinemia, but also in insulinoma, renal failure, and even in non-insulin-dependent diabetes mellitus (NIDDM). The etiology of hyperproinsulinemia is divided into (1) abnormality of pro-insulin molecules, (2) abnormality of pancreatic beta-cells other than proinsulin molecules, (3) retardation of proinsulin clearance. Hyperproinsulinemia is now thought to be both a result of the above-mentioned diseases and a cause of atherosclerosis in patients with NIDDM. Recent developments in molecular biology have deepened our knowledge of the biosynthesis and role of proinsulin, especially the prohormone sorting mechanism into secretory granules in pancreatic beta-cells.

Animals↗

PubMed1994

A point mutation in the bile acid biosynthetic enzyme sterol 27-hydroxylase in a family with cerebrotendinous xanthomatosis.

Cerebrotendinous xanthomatosis (CTX) is a rare familial disorder characterized by progressive neurological dysfunction, atherosclerosis, and xanthomas with sterol storage in the nervous system, vessels, and tendons. Increased serum cholestanol, derived from intermediates of cholesterol catabolism, may possibly be a major cause of the disease. An examination was made of the cDNA encoding cytochrome P450 sterol 27-hydroxylase (CYP27) in hepatic mitochondria, considered a defective enzyme inducing CTX, in a Japanese housewife afflicted with CTX and her family. The proposita and one of her brothers, who also had CTX symptoms and hypercholestanolemia, were found to be homozygotic, carrying a point mutation in the CYP27 gene at Arg104 (CGG) to Trp104 (TGG). The mutant position has a 100% conserved positive charge in all known vertebrate cytochrome P450s and even in bacterial cytochrome P450cam. The mother of the proposita and another brother were both free of CTX symptoms and were heterozygotic for the mutation, although their plasma cholesterol increased moderately. An increase in plasma cholestanol alone would, thus, not appear to be a direct cause of sterol storage in CTX, while CTX is strongly suggested to be caused by defects in both alleles of the CYP27 gene.

Aged↗

PubMed1994

Oncogenicity studies of the cognition-enhancing agent nefiracetam in mice and rats.

Oncogenicity studies of nefiracetam (N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide, DM-9384, CAS 77191-36-7), a new cognition-enhancing agent, were carried out in male and female mice and rats. The compound was administered in diet for 104 weeks at dosage levels of 30, 90 and 270 mg/kg/d for mice and of 200, 600 and 1800 ppm for rats. The administration of nefiracetam produced no effects on survival, appearance or behavior. Body weights of the high dose male mice and rats were occasionally significantly decreased when compared to the controls. When calculated on a g/animal/d basis, food consumption was sometimes decreased for these male groups. At necropsy, there was no evidence of treatment related changes, nor were these seen on histopathological examination. All microscopic changes seen in mice and rats were of the usual type commonly occurring in untreated aged B6C3F1 mice and F344 rats. In conclusion, the administration of nefiracetam for 24 months to B6C3F1 mice and F344/DuCrj rats produced only slight effects on body weight in the high dose males with a no-effect level of 90 mg/kg/d for mice or 600 ppm for rats. There was no evidence of an oncogenic effect of nefiracetam.

Animals↗

PubMed1994

[Diagnosis of the pancreatic diseases by intraductal ultrasound of the pancreas--with special reference to clinical cases difficult to diagnose differentially pancreatic diseases by the endoscopic retrograde pancreatography].

We examined the usefulness of the intraductal ultrasound (IDUS) examinations by comparing the IDUS images with the endoscopic retrograde (ER) pancreatograms. We inserted an IDUS probe with 30 MHz at frequency transpapillary into the main pancreatic duct (MPD) in 105 cases with pancreatic diseases (30 cancers, 30 mucin-producing tumor, 3 islet cell tumor, 1 pancreatic serous cyst adenoma, 1 pancreatic teratoma, 1 pancreatic solid and cystic tumor and 39 chronic pancreatitis). All 105 cases were performed ER pancreatography. Sixty-four of 105 cases (22 cancers, 20 mucin-producing tumor, 3 islet cell tumor, 1 pancreatic serous cyst adenoma, 1 pancreatic teratoma, 1 pancreatic solid and cystic tumor and 16 chronic pancreatitis) were operated and the IDUS images were compared with the corresponding histopathological sections. The usefulness of the IDUS examinations of the pancreatic diseases were the following cases; differential diagnosis between benign and malignant cases with localized stenosis of the MPD, differential diagnosis of the cases with displacement of the MPD, and the diagnosis of the intraductal extent and of invasion of the tumor in the mucin-producing tumor of the pancreas with the dilation of the MPD. IDUS examinations are performed by the IDUS probe with high frequency, so the indications of the IDUS examinations are to detect the small lesions in the pancreas.

Cholangiopancreatography, Endoscopic Retrograde↗

PubMed1993

Modification of 1 alpha,25-dihydroxyvitamin D3 metabolism by introduction of 26,26,26,27,27,27-hexafluoro atoms in human promyelocytic leukaemia (HL-60) cells: isolation and identification of a novel bioactive metabolite, 26,26,26,27,27,27-hexafluoro-1 alpha,23(S),25-trihydroxyvitamin D3.

To study whether the introduction of fluoro atoms into C-26 and C-27 positions on the 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3] molecule could affect metabolism in human promyelocytic leukaemia (HL-60) cells, we compared the metabolism of 26,26,26,27,27,27-hexafluoro-1 alpha,25-dihydroxyvitamin D3 [26,27-F6-1 alpha,25(OH)2D3] and 1 alpha,25(OH)2D3 in HL-60 cells. 26,27-F6-1 alpha,25(OH)2D3 was mainly converted into a new bioactive metabolite, 26,26,26,27,27,27-hexafluoro-1 alpha,23(S),25- trihydroxyvitamin D3 [26,27-F6-1 alpha,23(S),25(OH)3D3], but not into 26,26,26,27,27,27-hexafluoro-1 alpha,24(R),25-trihydroxyvitamin D3 [26,27-F6-1 alpha,24(R),25(OH)3D3] in HL-60 cells. 26,27-F6-1 alpha,23(S),25(OH)3D3 was identified by combinations of h.p.l.c., u.v. spectroscopy and g.c.-mass spectrometry. Evidence is presented that 26,27-F6-1 alpha,25(OH)2D2 was metabolized to 26,27-F6-1 alpha,23(S),25(OH)3D3 by C-23 hydroxylation as a first step of the metabolism, and the 23-hydroxylated bioactive metabolite was accumulated in the cells, whereas 1 alpha,25(OH)2D3 was initially deactivated and metabolized to 1 alpha,24(R),25(OH)3D3 by C-24 hydroxylation through a side-chain oxidation pathway resulting in C23-C24 cleavage, yielding 24,25,26,27-tetranor-1 alpha,23(OH)2D3 in HL-60 cells. These results show that 26,27-F6-1 alpha,25(OH)2D3 and 1 alpha,25(OH)2D3 are metabolized by different metabolic pathways in HL-60 cells.

Calcitriol↗

PubMed1993

Detection of human papillomaviruses from histologically normal lymph nodes of Japanese cervical cancer patients by nested polymerase chain-reaction assay.

To determine the prognostic significance of human papilloma virus (HPV) DNA in histologically normal lymph nodes, we developed a nested polymerase chain-reaction (PCR) method on HPV16,18 and 33 DNAs for formalin-fixed, paraffin-embedded tissues. We investigated 370 histologically normal lymph nodes from 15 patients treated for stage-IB/IIB (FIGO) invasive cervical cancer. HPV16 DNA was detected in 7 (47%) and HPV18 DNA in 3 (20%) of the cervical cancers. Examination of histologically normal lymph nodes from these 10 patients by nested PCR revealed HPV DNA in 5 (50%) of them; in all cases HPV type in lymph nodes and tumor was the same. Two of these 5 patients had a recurrence (pelvic cavity or lung) and died of cancer, although all 5 had had pelvic radiotherapy after radical hysterectomy and lymphadenectomy. These findings indicate that nested PCR is useful for evaluating early lymph-node involvement retrospectively in HPV-positive cases.

Adult↗