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Biomedical subjects

N Wei

Publications and source records attributed to N Wei.

71 records · Page 4Linked to original sources
PubMed1991

Synthesis and secretion of human atrial natriuretic peptide in Saccharomyces cerevisiae.

A chemically synthesized alpha-hANP gene was inserted into plasmid YFD18, which was an expression-secretion vector of yeast. The recombinant then transformed in the yeast Y33. The expression level of yeast transformants was about 700 micrograms ANP/L detected by RIA. More than 99% of expression products were secreted in the culture medium. N-terminal analysis of purified product showed that the first 4 amino acid residues of alpha-hANP were deleted.

Amino Acid Sequence↗
PubMed1990

Structure and assembly of turnip crinkle virus. VI. Identification of coat protein binding sites on the RNA.

Structural studies of turnip crinkle virus have been extended to include the identification of high-affinity coat protein binding sites on the RNA genome. Virus was dissociated at elevated pH and ionic strength, and a ribonucleoprotein complex (rp-complex) was isolated by chromatography on Sephacryl S-200. Genomic RNA fragments in the rp-complex, resistant to RNase A and RNase T1 digestion and associated with tightly bound coat protein subunits, were isolated using coat-protein-specific antibodies. The identity of the protected fragments was determined by direct RNA sequencing. These approaches allowed us to study the specific RNA-protein interactions in the rp-complex obtained from dissociated virus particles. The location of one protected fragment downstream from the amber terminator codon in the first and largest of the three viral open reading frames suggests that the coat protein may play a role in the regulation of the expression of the polymerase gene. We have also identified an additional cluster of T1-protected fragments in the region of the coat protein gene that may represent further high-affinity sites involved in assembly recognition.

Base Sequence↗
PubMed1990

[An application of oligonucleotide-directed mutagenesis on making deletion mutation].

By the method of oligonucleotide-directed mutagenesis, we made 27bp and 18bp deletion at junction region between alpha-factor signal sequence and alpha-hANP gene, alpha-factor signal sequence and alpha-IFN gene, respectively. Since the deleted region contains one HindIII site, the mutants without this site were selected. The result of DNA sequence analysis showed that the sequences of the mutants were the same as designed.

Atrial Natriuretic Factor↗
PubMed1989

Infectious barley stripe mosaic virus RNA transcribed in vitro from full-length genomic cDNA clones.

Full-length genomic cDNA clones of the Type and ND18 strains of barley stripe mosaic virus (BSMV) were transcribed in vitro using T7 RNA polymerase. The combination of RNAs alpha, beta, and gamma synthesized in the presence of 5' cap analogs was infectious after inoculation onto barley plants, conclusively demonstrating the tripartite nature of the BSMV genome. Transcripts synthesized in the absence of cap analogs were not infectious. A gamma-specific subgenomic RNA which is normally present in BSMV virions was not required to establish a systemic infection. In vitro transcripts of variant cDNA clones which were isolated from the ND18 strain, containing either a simple nucleotide substitution or a 372-nucleotide duplication similar to one found in the genome of the Type strain, were also found to be biologically active. Two dicotyledonous hosts which have a differential response to infection with the Type and ND18 strains of BSMV were identified and these phenotypes were shown to be faithfully reproduced by inoculation with in vitro transcripts derived from the appropriate full-length cDNA clones.

Blotting, Western↗
PubMed1987

Rapidly fatal pneumococcal septicemia in systemic lupus erythematosus.

Streptococcal pneumoniae septicemia was responsible for the deaths of 3 patients with chronic systemic lupus erythematosus. The absence of a spleen likely contributed to sepsis in 2 patients. One patient had been immunized with 14-valent pneumococcal vaccine with a doubling of serum antibody concentrations at one month to all vaccine capsular polysaccharide types except for Types 1 and 12. The patient died 74 months after immunization of pneumococcal Type 1 sepsis.

Adult↗
PubMed1985

Sclerodactyly in a patient with mycosis fungoides.

A 44-year-old man had mycosis fungoides and generalized plaque disease involving 80% of his skin surface with diffuse lymphadenopathy and alopecia of the scalp and groin. In addition, distal to the wrist, there were sclerodermatous changes involving the skin of the hands with associated sclerodactyly of all digits with loss of normal palmar creases. There were no subungual telangiectasis or digital ulcers. The changes in the hand that occurred in this case, no doubt arose as a result of the patient's neoplasm. Abnormalities of collagen biosynthesis and degradation probably occur with mycosis fungoides as a result of the extensive infiltration of the epidermis and dermis with malignant cells. To our knowledge, the association of sclerodactyly with mycosis fungoides has not been previously reported.

Adult↗
PubMed1983

Randomised trial of plasma exchange in mild systemic lupus erythematosus.

The effects of intensive plasma exchange on the serological and clinical manifestations of mildly active systemic lupus erythematosus were evaluated in a controlled, double-blind trial. Twenty patients were randomised to receive either six 4-litre plasma exchanges or a seemingly identical control procedure over a 2-week period. Plasma exchange produced significant reductions in serum levels of IgG, IgM, IgA, and circulating immune complexes measured by an 125I-Clq binding assay. These serological measures returned to baseline 4 weeks after plasma exchange without a rebound above baseline values. Antibodies to DNA were reduced immediately after plasma exchange; however, they often returned to pre-treatment levels before the next procedure. No changes in any of the serological measures were observed in the control group. In sixteen of the eighteen patients who completed the clinical trial activity had either remained stable or improved; the frequency and degree of clinical improvement was the same in both plasma exchange and control groups.

Adolescent↗
PubMed1982

Effect of plasmapheresis on T anc B lymphocyte functions in patients with systemic lupus erythematosus: a double blind study.

Nine patients with active systemic lupus erythematosus entered a double-blind randomized trial to study the therapeutic effect of vigorous versus sham reinfusion plasmapheresis. Four of them received real plasmapheresis while five received sham reinfusion plasmapheresis. In the present communication we report the effects of these procedures on T lymphocytes in peripheral mononuclear cells, proliferative response to mitogens, allogeneic mixed lymphocyte reaction and cell-mediated lympholysis, as well as the effect of plasmapheresis on the spontaneous and pokeweed mitogen induced immunoglobulin secreting cells in peripheral blood. Several mononuclear cell functions were abnormal at the beginning of the study but no significant changes related to plasmaphersis occurred in any of the parameters studied.

B-Lymphocytes↗
PubMedDate not supplied

Vesnarinone is a selective inhibitor of macrophage TNF(alpha) release.

Vesnarinone is an experimental drug that has been used successfully in the treatment of congestive heart failure patients. In this report we investigate the effect of vesnarinone on the cytokine secretory products of mononuclear phagocytes. In a concentration-dependent manner, the drug inhibits the endotoxin(LPS)-stimulated release of tumor necrosis factor (TNF) alpha and suppresses interleukin(IL)-6 release, but does not affect the release of IL-1 alpha, IL-10 and leukemia inhibitory factor (LIF) by mouse peritoneal macrophages. Using competitive polymerase chain reaction (PCR) analyses, we find that vesnarinone significantly reduces TNF(alpha), but not IL-10 mRNA. In addition to LPS, the drug inhibits TNF(alpha) release induced by several other stimuli. The inhibitory effect of the drug on the TNF(alpha) biosynthesis can be observed in differentiated human monocytes, in macrophage cell lines, and in synovial adherent cells from rheumatoid arthritis patients. Although the precise mode of action of vesnarinone in the signal transduction pathway leading to the selective inhibition of TNF(alpha) is not known, the drug might be useful in the treatment of diseases involving that cytokine.

Adjuvants, Immunologic↗
PubMedDate not supplied

The COP9 complex is conserved between plants and mammals and is related to the 26S proteasome regulatory complex.

The COP9 complex, genetically identified in Arabidopsis as a repressor of photomorphogenesis, is composed of multiple subunits including COP9, FUS6 (also known as COP11) and the Arabidopsis JAB1 homolog 1 (AJH1) ([1-3]; unpublished observations). We have previously demonstrated the existence of the mammalian counterpart of the COP9 complex and purified the complex by conventional biochemical and immunoaffinity procedures [4]. Here, we report the molecular identities of all eight subunits of the mammalian COP9 complex. We show that the COP9 complex is highly conserved between mammals and higher plants, and probably among most multicellular eukaryotes. It is not present in the single-cell eukaryote Saccharomyces cerevisiae, however. All of the subunits of the COP9 complex contain structural features that are also present in the components of the proteasome regulatory complex and the translation initiation factor eIF3 complex. Six subunits of the COP9 complex have overall similarity with six distinct non-ATPase regulatory subunits of the 26S proteasome, suggesting that the COP9 complex and the proteasome regulatory complex are closely related in their evolutionary origin. Subunits of the COP9 complex include regulators of the Jun N-terminal kinase (JNK) and c-Jun, a nuclear hormone receptor binding protein and a cell-cycle regulator. This suggests that the COP9 complex is an important cellular regulator modulating multiple signaling pathways.

Adenosine Triphosphatases↗
PubMedDate not supplied

A magnetic bearing system for a continuous ventricular assist device.

This article describes a prototype continuous flow ventricular assist device (CFVAD3) supported in magnetic bearings. The VAD is a small centrifugal four bladed pump. The pump's geometry is explained. The CFVAD3 is the first compact VAD completely supported in magnetic bearings. The magnetic bearings are composed of an inlet side actuator divided into eight pole sets, and an outlet side actuator, also divided into eight pole sets. The pump operating performance was tested and found to be within the design flow rate of up to 9 L/min, and head up to 170 mm Hg for human circulatory support. Magnetic bearing operation out of center positions under various operating orientations were measured and found to be < 1/6 of the bearing clearance, well within specifications. The expected magnetic bearing power loss has been calculated at approximately 6.5 watts.

Heart-Assist Devices↗
PubMedDate not supplied

Colonoscopic evaluation of immunochemical fecal occult blood test for detection of colorectal neoplasia.

BACKGROUND/AIMS: This study was carried out to assess the validity of three testing methods of immunochemical occult blood according to the number of collection times as a means for colorectal cancer screening. METHODOLOGY: Four thousand six hundred and eleven asymptomatic individuals, who received both an immunochemical occult blood test with a three-day method and colonoscopy during a medical checkup, served as subjects for this study. For evaluation of the desirable number of sampling times, we used the results of the first day for the 1-day method, the results of the first and second days for the 2-day method, and the results of three-consecutive days for the 3-day method. Sensitivities and specificities of these three testing methods were evaluated. RESULTS: Sensitivities and specificities for colorectal cancer were calculated to be 56% and 97% for the 1-day method, 83% and 96% for the 2-day method, and 89% and 94% for the 3-day method, respectively, showing a significant difference in sensitivity between the 1-day and the 2-day methods, as well as the 3-day method (p < 0.01), and in specificity between the 1-day as well as the 2-day and 3-day methods (p < 0.05). CONCLUSIONS: These findings indicate that the immunochemical fecal occult blood test is useful for the diagnosis of colorectal cancer, and that 2-day testing is recommended as a means of screening for colorectal cancer.

Adenoma↗
PubMedDate not supplied

False positive pregnancy tests in systemic lupus erythematosus.

False positive, 'atypical ring' pregnancy tests were identified in 14 patients with systemic lupus erythematosus. The abnormality was associated with heavy proteinuria in 8 patients, menopause or drug-induced amenorrhea in 4 patients, and actual pregnancy in one patient. Serum levels of human chorionic gonadotropin were normal in 13 patients and elevated in the single patient with a true pregnancy.

False Positive Reactions↗
PubMedDate not supplied

Clinical significance of low creatine phosphokinase values in patients with connective tissue diseases.

We have noted that values for serum creatine phosphokinase (CPK) are frequently low in patients with connective tissue diseases. Geometric mean values were 96.0 units/L among 121 disease-free males and 50.2 units/L among 63 disease-free females. The geometric mean values were 31.7 units/L in 11 males and 35.2 units/L in 49 females with systemic lupus erythematosus; 15.1 units/L in three males and 13.0 units/L in ten females with rheumatoid arthritis; and 41.6 units/L in 19 females with Sjögren's syndrome. Values within the normal range may occur in the face of active myositis in these illnesses. Findings of a low serum CPK values may occur in the absence of steroid treatment. Thus, a low serum CPK value is frequently found in patients with connective tissue diseases and a normal value should not dissuade one from the diagnosis of myositis.

Adult↗