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Biomedical subjects

H Wu

Publications and source records attributed to H Wu.

At least 847 records · Page 47Linked to original sources
PubMed1984

In vivo evidence for prostaglandin inhibitory activity in New Zealand green-lipped mussel extract.

Prostaglandin synthetase inhibitors (eg, aspirin, indomethacin and naproxen) interfere with ovulation and prolong the gestation period in the rat. These properties could provide a novel test bed for the assessment of agents with prostaglandin biosynthesis inhibitory activity. Rats were fed green-lipped mussel extract and the effects on conception and the subsequent gestation period were determined. Parturition was delayed and fetal development was retarded in the Seatone-fed animals. The observations were consistent with the known effects of nonsteroidal anti-inflammatory drugs, suggesting that Seatone does contain pharmacologically active material inhibiting prostaglandin biosynthesis.

Animals↗
PubMed1984

Effects of compliance alteration on healing of a porous dacron prosthesis in the thoracic aorta of the dog.

In our study, the results reveal that a marked reduction in the compliance of an external-velour, weft-knit Dacron prosthesis did not impair healing of either the graft wall or of the anastomoses when these grafts were implanted in the upper part of the descending thoracic aorta of the dog for 56 days. These observations are clinically relevant, since they are important to the design of noncrimped fabric prostheses which are resistant to kink and compression when used for axillofemoral, femoropopliteal and femorotibial bypass. However, experimental studies of the influence of compliance disparity should be extended to such grafts implanted for several years.

Animals↗
PubMed1984

Scanning electron microscopic observations of the oocyst, sporoblast and sporozoite of Plasmodium yoelii yoelii.

Scanning electron microscopy was used to study the surface characteristics of the oocyst, sporoblast and sporozoite of Plasmodium yoelii yoelii. Observations were made of the sporogonic stages of 6-12 day infections of the malaria parasite in Anopheles stephensi. Oocyst and sporoblast development were not synchronous. The surface of the undifferentiated (early stage) oocyst appeared smooth, whereas that of differentiated (late stage) oocysts were rough or wrinkled. The wall of the differentiated oocysts showed numerous micropores at higher magnification (x15,000-20,000) the biological significance of which is not known. Small, bud-like satellite bodies were seen attached to some oocysts. Various forms of different stages of the sporoblast were described. Sporozoite budding took place on the surface of the sporoblast body. The sporozoite was elongate, curved and with a blunt anterior end.

Animals↗
PubMed1982

On a new gap phenomenon in riemannian geometry.

This note announces some theorems that show that the flat metric of euclidean space has no nearby nonflat complete metric with the property that its curvature keeps a sign and is "uniformly small" in a sense made precise here.

Journal Article↗
PubMed1981

The gene frequency of serum albumin variants in Chinese and the electrophoretic characterization of several serum albumin variants.

By screening a Chinese population of 1025 unrelated persons in Beijing, three serum albumin variants were discovered, and the gene frequency of serum albumin variants of Chinese is estimated as 0.0015. These albumin variants can be distinguished electrophoretically from each other, and were named tentatively as albumin Hanzhong, albumin Changzhi and albumin LXX respectively. A polyacrylamide gel electrophoresis procedure has been developed to characterize albumin variants by determining the relative mobilities (Rm) of albumin variants in a tris-succinate buffer system.

Asian People↗
PubMedDate not supplied

Assisting effects of lithium on hypoglycemic treatment in patients with diabetes.

In this article, we report the assisting effect of lithium on hypoglycemic treatment in patients with diabetes. Thirty-eight diabetic patients, 15 male and 23 female, aged 20-70 yr, 33 noninsulin-dependent diabetes mellitus (NIDDM) patients, and 5 insulin-dependent diabetes mellitus (IDDM) patients, were recruited in this study. Fasting and 1-h postprandial blood glucose (BG) profiles were undertaken from three groups of patients with diabetes before and after short-term of treatment of lithium carbonate. Group I was treated with diet only, Group II with oral hypoglycemic agents (OHA), and Group III with insulin. The fasting blood glucose (FBG) level and 1-h postprandial blood glucose (1-h PBG) level before and after treatment of lithium were: Group I: FBG: 7.67 +/- 0.48 vs 7.13 +/- 0.82; 1-h PBG 15.13 +/- 0.88 vs 10.33 +/- 0.96; Group II: FBG: 8.84 +/- 0.67 vs 6.04 +/- 0.57; 1-h PBG: 12.33 +/- 0.72 vs 9.95 +/- 0.82; Group III: FBG: 10.87 +/- 0.83 vs 6.83 +/- 0.79; 1-h PBG: 12.45 +/- 0.93 vs 9.17 +/- 1.00 mmol/L, respectively. The FBG and PBG of all three groups decreased significantly after lithium treatment, except the FBG in Group I. These data suggest that combined with other therapy, lithium could improve glucose metabolism in most patients with diabetes. Our results suggest that lithium has an assisting hypoglycemic effect on antidiabetic treatment.

Adult↗
PubMedDate not supplied

Association between IgE antibody against soluble egg antigen and resistance to reinfection with Schistosoma japonicum.

There is evidence that immunoglobulin (Ig) E antibody may be a critical component of protective immunity against Schistosoma mansoni and S. haematobium reinfection. In the present study, 555 individuals aged 3-67 years infected with S.japonicum received praziquantel treatment before the transmission season commenced; 45 d later, blood samples from 265 individuals who had no S. japonicum egg in their stool were examined by enzyme-linked immunosorbent assay for specific isotypic antibodies. Single, non-conditional logistic regression analysis showed that exposure intensity, age, soluble egg antigen (SEA)-IgE, SEA-IgM and soluble adult worm antigen-IgG4 were relevant to reinfection; multiple, non-conditional logistic regression analysis showed that exposure intensity was still a significant factor for reinfection while the SEA-IgE antibody level was associated with resistance to reinfection with S. japonicum, with a protective index of 2.00. It is suggested that this population in an area endemic for schistosomiasis japonica exhibits acquired immunity.

Adolescent↗
PubMedDate not supplied

Genomic relatedness of five equine rotavirus strains with different G serotype and P type specificities.

Overall genomic relatedness among five equine rotavirus strains and their relatedness to representative human and animal rotavirus strains were investigated by RNA-RNA hybridization tests. The genomes of strains FI-14, FI-23 and H2 were highly related to one another. Strain L338 had only a low degree of genomic relatedness to the other four equine rotavirus strains. Strain H1 also showed little genetic relatedness to the other equine strains. The genome of the strain H1, however, was highly related to those of porcine rotavirus strains OSU, Gottfried and YM. Genomic relatedness of four equine rotavirus strains (FI-14, FI-23, H2 and L338) to human and other animal rotavirus strains was low, whereas several RNA segments of strain H1 showed a relatedness to those of human strain Wa.

Animals↗
PubMedDate not supplied

Synthesis of uridine phosphoramidite analogs: reagents for site-specific incorporation of photoreactive sites into RNA sequences.

The synthesis of three new photoactive RNA phosphoramidites, 5-bromouridine, 5-iodouridine, and O4-triazolouridine, is reported. The 5' OH of bromouridine and iodouridine were protected as dimethoxytrityl ether using dimethoxytrityl chloride and pyridine. Selective protection of 2' OH was achieved as the corresponding tert-butyldimethylsilyl ether. Protected ribonucleosides were converted to phosphoramidites using 2-cyanoethyl N,N-diisopropylchlorophosphoramidite. O4-Triazolouridine phosphoramidite monomer was prepared in one step from uridine phosphoramidite. These phosphoramidites were used to incorporate photoprobes at any chosen sites in the RNA sequences during chemical syntheses. The modified monomers were incorporated into RNA oligomers with coupling yields > 98%. After chemical synthesis, O4-triazolouridine was converted to 4-thiouridine by the addition of thiolacetic acid during standard deprotection methods. The extent of thiation and incorporation of modified nucleotides into RNA sequences were confirmed by nuclease digest, HPLC, and gel electrophoresis.

Alkaline Phosphatase↗
PubMedDate not supplied

Artificial antibodies for affinity chromatography of homologous proteins: application to blood clotting proteins.

A method to readily isolate antibodies that bind to only one member of a family of homologous proteins is described. A library of different single chain antibody fragments can be displayed on the surface of a bacteriophage vector. Individual antibodies from this library recognizing a particular protein from a family of homologous proteins can be readily isolated by a two-step affinity screening process. In the first step antibodies which bind specifically to the undesired proteins or to homologous regions of the proteins are removed. In the second step, those antibodies specifically recognizing the desired protein are then isolated. Using this procedure and starting with a naive antibody library, a single chain antibody fragment specific to the blood clotting protein, Protein C, which did not recognize either of the homologous proteins, Factor IX or Factor X, was isolated. Similarly an antibody specific to Factor IX, but not Factor X or Protein C, was also isolated. The isolated antibodies can be readily produced, purified, and affixed to sepharose beads for affinity chromatography of the blood clotting factors. One of the key advantages to this procedure over conventional monoclonal antibody isolation is that the antibodies are isolated and produced in vitro so a broad range of related proteins, toxins, viruses, or other products can be targeted.

Chromatography, Affinity↗
PubMedDate not supplied

Homologous human blood protein separation using immobilized metal affinity chromatography: protein C separation from prothrombin with application to the separation of factor IX and prothrombin.

Protein C (PC) is a natural anticoagulant and antithrombotic present in human blood at a concentration of 4 microg/mL. Its deficiency can result in excessive clotting and thrombosis. Protein C can be obtained from human blood plasma; however, there are other coagulant proteins in blood, including prothrombin (factor II), which is present in relatively large amounts and is one of the most active components. Protein C and prothrombin are homologous proteins with similar biochemical features; therefore, immunoaffinity chromatography is used for their separation. However, this technology is very expensive, protein C recovery and activity is low, and contamination problems with mouse antibody are likely. Immobilized metal affinity chromatography (IMAC) utilizes the protein metal-binding properties for protein separation. Protein C has twelve surface-accessible histidines, which are the major metal-binding groups for IMAC separation. After investigating metal ion-binding properties of protein C, we used an IDA-Cu column to separate protein C and prothrombin. Following protein adsorption to the column, prothrombin was washed out using a sodium phosphate buffer containing 2 mM imidazole and protein C was recovered with 15 mM imidazole in the buffer. The mild elution condition allows a high protein C activity and a high recovery. Also, this technology introduces no immunoglobulins, and it is relatively inexpensive. IMAC could replace the immunoaffinity technology for the large-scale separation of protein C from blood plasma Cohn Fraction IV-1. In addition, this work demonstrates a significant application of this technology for the separation of factor IX from prothrombin. Prothrombin has proven to be a harmful contaminant in factor IX cocktails that have been administered to humans in the treatment of hemophilia B.

Blood Proteins↗
PubMedDate not supplied

Developmental differences in the expression and modulation of extracellular matrix proteases and inhibitors in mouse skin fibroblasts.

To investigate developmental differences in the wound repair process between fetal and adult skin fibroblasts, we studied the expression of plasminogen activator, plasminogen activator inhibitor, matrix metalloproteinase, and tissue inhibitor of metalloproteinase in E-15, E-17, newborn and adult mouse skin fibroblasts cultured within three dimensional matrices of either collagen or fibrin. Fibrin overlay and reverse overlay analyses revealed that mouse skin fibroblasts secreted tissue plasminogen activator and type1 plasminogen activator inhibitor. However, only E-15 and E-17 fibroblasts secreted the active form of tissue plasminogen activator, while in newborn and adult fibroblasts tissue plasminogen activator was conjugated to type1 plasminogen activator inhibitor. Only adult fibroblasts expressed a high level of active type1 plasminogen activator inhibitor. Gelatin zymography revealed that the predominant matrix metalloproteinase secreted by all the mouse fibroblasts was gelatinase A (matrix metalloproteinase -2). Matrix metalloproteinase -2 was partially activated in the adult fibroblasts cultured within a collagen matrix. The tissue inhibitor of metalloproteinase-2 was expressed by all fibroblasts, but levels were highest in the newborn and adult fibroblasts. When E-15 fibroblasts were cultured within a fibrin matrix, tissue plasminogen activator was downregulated. Transforming growth factor-betadownregulated tissue plasminogen activator while upregulating type1 plasminogen activator inhibitor, and platelet-derived growth factor enhanced tissue plasminogen activator expression in E-15 fibroblasts. Therefore, plasminogen activator and its inhibitor, and matrix metalloproteinase and its associated tissue inhibitor are differentially expressed in fetal and adult fibroblasts, and their expression is controlled by extracellular matrix components and growth factors present in wounds.

Animals↗
PubMedDate not supplied

Adenine nucleotide N-glycosidase activity of the A-chain of cinnamomin characterized by 1H-nuclear magnetic resonance.

Plant ribosome-inactivating proteins specifically cleave an N-glycosidic bond of a unique adenosine in the largest ribosomal RNA, releasing an adenine from ribosomes of different sources. Here, 1H-nuclear magnetic resonance is used to analyze the enzymatic products of the A-chain of cinnamomin, a type-II ribosome-inactivating protein (RIP) acting on the nucleotides in situ. The enzymatic activities of the RIP on nine nucleotides are compared. Cinnamomin A-chain can cleave the N-glycosidic bond and release an adenine base from adenine nucleotides except 5'-ATP; however, it cannot act on 5'-GMP, 5'-CMP, and 5'-UMP. The A-chain in the mixture of cinnamomin A- and B-chain exhibits higher activity toward adenine nucleotides than the A-chain alone does, suggesting that the B-chain can conformationally stabilize the A-chain. Intact cinnamomin also exhibits lower activity toward adenine nucleotides. However, cinnamomin B-chain and heat-denatured intact cinnamomin cannot hydrolyze all the tested nucleotides. We conclude that hydrolysis of the N-C glycosidic bond of nucleotide compounds by cinnamomin A-chain has a base preference, and the negatively charged phosphate group(s) reduces the recognition ability of the A-chain to adenine nucleotide.

Adenine Nucleotides↗
PubMedDate not supplied

Expression of E-cadherin is associated with squamous differentiation in squamous cell carcinomas.

E-cadherin is a cell surface molecule that mediates cell-cell adhesion in normal epithelium. Disabled or aberrant E-cadherin expression increases cell motility and promotes the transition of well-differentiated adenoma to invasive carcinoma. To evaluate whether E-cadherin could serve as a biomarker of squamous cell differentiation, we analyzed its expression by immunohistochemistry in formalin-fixed, paraffin-embedded tissue sections of 7 head and neck cancer patients, 19 lung cancer patients, 73 esophageal cancer patients, 19 skin cancer patients, and 18 cervical cancer patients. E-cadherin was expressed at very high levels (93%-100%) in adjacent or distant normal squamous epithelia. Likewise, most (75-100%) well-differentiated squamous cell carcinomas (SCCs) also expressed E-cadherin. In contrast, poorly differentiated SCCs expressed less than 40% of E-cadherin. Furthermore, immunohistochemical analysis showed that the differentiation-inducing agent, all-trans retinoic acid, can up-regulate E-cadherin expression in esophageal SCC cells in vitro. Our data demonstrated that E-cadherin expression is associated with SCC differentiation and that may serve as a squamous cell differentiation marker.

Biomarkers, Tumor↗