Biomedical subjects

E Wang

Publications and source records attributed to E Wang.

At least 253 records · Page 14Linked to original sources

PubMed1995

[PCNA expression and AgNORs image analysis as factors in judging the prognosis of lung cancer].

The expression of PCNA and AgNORs count or AgNORs' area in 86 cases of primary lung cancer and 10 cases of inflammatory pseudotumor were studied by S-P immunostaining of monoclonal antibody (PC-10) and image analysis system. The results showed that the proliferating index (PI) of PCNA positive cells was closely related to AgNORs count and AgNORs' area measured. Both were correlated with the histological type, and the TNM status, decreased with the increasing degree of histological differentiation. Survival analysis showed that the PI and the results of AgNORs image analysis in surgical patients who survived over 5 years were significantly lower than those who survived less than 3 years. The results suggest that immunostaining of PCNA and AgNORs image analysis are useful in judging the malignant degree and the prognosis of primary lung cancer.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed1995

Long-term healing of bone using recombinant human bone morphogenetic protein 2.

A 2.5-cm-long middiaphyseal plate-stabilized segmental defect in the right femora of 5 adult sheep was implanted with 1.5 mg of recombinant human bone morphogenetic protein 2 mixed with inactivated demineralized ovine bone matrix. Bone healing was evaluated for 12 months using clinical, radiographic, gross pathologic, and histologic techniques. Bone formation within the defect was first visible radiographically between Weeks 2 and 4 after surgery; bone union was apparent between Weeks 12 and 16, at which time the plates were removed. Recanalization of the medullary cavity with neocortex formation was near completion at Week 52. Bone mineral content at the defect sites equaled that of the nonsurgically treated intact femora by Week 16. Perifemoral soft tissue mineralization did not occur, and callus size was not greater than that formed with autograft. By Week 52, the sheep were not lame, and at necropsy the surgically treated femora were rigidly healed. Woven and lamellar bone bridged the defect site. An apparently normal sequence of ossification, modeling, and remodeling events had occurred. Recombinant human bone morphogenetic protein 2 mixed with a suitable carrier could provide an alternative to autograft for use in a variety of orthopaedic procedures.

Absorptiometry, Photon↗

PubMed1995

p53 and mdm-2 expression in malignant melanoma: an immunocytochemical study of expression of p53, mdm-2, and markers of cell proliferation in primary versus metastatic tumors.

Alterations in the function of p53, a tumor suppressor gene, have been postulated as a principal underlying mechanism involved in the loss of cell cycle control in human malignancies. Because p53 dysfunction is generally associated with protein overexpression, immunocytochemistry is a valuable technique for the analysis of p53's functional status. We tested the hypothesis that loss of p53 function is a critical event in the early development and progression of human malignant melanoma and can lead to alterations in cell proliferation. We performed an immunocytochemical study in archival fixed, embedded specimens that included 102 melanocytic lesions ranging from benign nevi to metastatic melanoma. In addition to p53, we assessed the p53-associated protein, mdm-2, and markers of cell cycle status (the MIB-1-defined cell proliferation marker; proliferating cell nuclear antigen; and statin, a 57-kDa nuclear protein expressed preferentially by G0 cells). Tumor expression of all nuclear proteins was scored in a semiquantitative fashion related to the fraction of positive tumor nuclei. The overall incidence of significant p53 overexpression was low (8% of primary and 14% of metastatic melanomas). Analysis demonstrated strong correlation between increasing p53 expression in primary versus metastatic lesions (chi 2 analysis, P = 0.001). Correlation was found between increased MIB-1-defined cell proliferation and p53 overexpression in primary melanomas (P = 0.02). Detectable mdm-2 expression was significantly correlated with p53 overexpression (P = 0.02). Comparison of statin and proliferating cell nuclear antigen indices demonstrated inverse correlation (chi 2 , P = 0.03) in the combined groups, but within the metastatic group there was a subset of cases strongly expressing the two markers.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomarkers, Tumor↗

PubMed1995

[Clinical experience with modified method of tubal ligation].

OBJECTIVE: To evaluate the clinical results with modified tubal ligation method. METHODS: From 1983 to 1992, 700 cases of modified tubal ligation operation with tubes cut and overlapped were performed in our hospital, and this was compared with 602 cases of Pomeroy's and 502 cases of modified Uchida's method. Patients were followed at 6 months, 2 and 5 years. Pregnancy rates, menstruation disturbances, lower abdominal or back pain, and leucorrhea were observed. RESULTS: Patients with modified tubal ligation method had a pregnancy rate of 0.43%, which was significantly lower than that of Pomeroy's 1.50% (P < 0.05). The modified method group also had few complications. The occurence rate of menorrhage and prolonged bleeding were apparently lower than that of Pomeroy's too (P < 0.01). CONCLUSION: This modified tubal ligation method is more effective and practicable than Pomeroy's and modified Uchida's method.

Adult↗

PubMed1994

Relationship between cytochrome P450 2E1 and acetone catabolism in rats as studied with diallyl sulfide as an inhibitor.

Previous studies have demonstrated that cytochrome P450 2E1 (P450 2E1) catalyzes the oxidation of acetone in vitro. The present study was designed to determine the importance of P450 2E1 in the catabolism of acetone in rats using diallyl sulfide (DAS) as an inhibitor of this enzyme. After a single intragastric dose of DAS, blood samples were collected from rats at different time points, and blood acetone concentrations were measured by gas chromatography. In a low DAS dose (50 mg/kg body weight) group, the maximum acetone level of 6-fold higher than the normal level was reached at 6 hr; the acetone level returned to normal at 48 hr. In a high dose (200 mg/kg) group, the maximum acetone level of 9-fold higher than the normal level was reached at 12 hr; the acetone level returned to normal at 60 hr. The turnover time and fractional turnover rate of elevated acetone were 15.8 +/- 0.5 hr and 0.054 +/- 0.001 hr-1, respectively, for the low dose, and 19.2 +/- 0.6 hr and 0.046 +/- 0.005 hr-1, respectively, for the high dose. In a chronic experiment, DAS (50 and 200 mg/kg, i.g.) was given to rats daily for 29 days, and elevated blood acetone levels were observed during the entire experimental period: 2.0 to 2.8 micrograms/mL for the low dose and 3.4 to 3.9 micrograms/mL for the high dose at 24 hr after the 1st, 7th, 14th and 28th doses versus 0.8 to 0.9 micrograms/mL for the control. The increase of blood acetone level was closely related to the decreases of N-nitrosodimethylamine (NDMA) demethylase activity and P450 2E1 content in liver microsomes. Consistent with the lack of cumulative effect from the multiple doses of DAS on acetone level, rather stable levels of the DAS metabolites, diallyl sulfoxide (45.0 micrograms/mL, range: 33.8 to 58.6 micrograms/mL) and diallyl sulfone (11.7 micrograms/mL, range: 6.9 to 15.6 micrograms/mL), were observed at 24 hr after the 1st, 7th, 21st and 28th doses with DAS (200 mg/kg) in the chronic experiment. It is likely that the inactivation and inhibition of P450 2E1 by DAS and its metabolites block the oxidation of acetone and cause its elevation in blood. The results strongly suggest an important role of P450 2E1 in acetone catabolism under physiological conditions.

Acetone↗

PubMed1994

Autoantibodies to the alpha/beta T-cell receptors in human immunodeficiency virus infection: dysregulation and mimicry.

Autoimmune reactivity is a consequence of infection with human immunodeficiency virus (HIV). We studied serological cross-reactions of purified pooled IgG from sera of HIV-infected individuals by using nested sets of synthetic overlapping peptides duplicating the covalent structures of T-cell receptors (TCRs) and immunoglobulin light chains and report that two processes of autoantibody production occur. (i) IgG autoantibodies to putative regulatory variable domain CDR1 and FR3 epitopes (where CDR is complementarity-determining region and FR is framework region) are present in pooled IgG from HIV-infected individuals at levels 10-fold greater than that in pooled IgG from healthy humans. (ii) Anti-TCR autoimmunization involves antigenic mimicry between a conserved peptide stretch of the major neutralizing V3 loop determinant of HIV-1 gp120 and the conserved FR4 segment of the TCR V beta. Affinity-purified antibodies to the synthetic V3 loop peptide bound to a recombinant single-chain TCR and to a synthetic TCR joining segment peptide containing the FR4 sequence. Conversely, affinity-purified autoantibodies from pooled IgG from HIV-infected individuals to the TCR peptide bound the V3 loop peptide and a single-chain TCR. Inhibition studies indicated that the cross-reactive immunizing antigen was the V3 loop. These results bear upon the impact of HIV infection on immune regulation and on the selection of peptides for vaccine development.

Amino Acid Sequence↗

PubMed1994

Cloning of human and mouse brain cDNAs coding for S1, the second member of the mammalian elongation factor-1 alpha gene family: analysis of a possible evolutionary pathway.

We previously reported the cloning of a rat S1 cDNA whose deduced amino acid sequence shares high similarity (92%) with that of mammalian elongation factor-1 alpha (EF-1 alpha), a protein involved in the binding of aminoacyl-tRNA to the ribosome during peptide synthesis. We report here the isolation of a full-length cDNA from a mouse brain library and a partial-length cDNA from a human hippocampus library which share extensive sequence similarity to rat S1 cDNA. We show that, as with mammalian EF-1 alpha S, the predicted primary amino acid sequences of rat, mouse, and human S1 are almost identical, except for one conservative substitution. These results indicate that mouse and man contain a second member of the EF-1 alpha gene family, the S1 gene. They also suggest that our result obtained in rat may be extrapolated to mouse and man.

Amino Acid Sequence↗

PubMed1994

Randomised trial of intravenous immunoglobulin G, intravenous anti-D, and oral prednisone in childhood acute immune thrombocytopenic purpura.

The most serious complication of childhood acute immune thrombocytopenic purpura (ITP), intracranial haemorrhage, occurs in about 1% of children with platelet counts below 20 x 10(9)/L. We conducted a randomised study to explore three treatment options in this high-risk group. 146 children (> 6 months and < 18 years old) with typical acute ITP and platelet counts of 20 x 10(9)/L or lower were randomised to receive high-dose intravenous immunoglobulin G (IVIgG) 1 g/kg on 2 consecutive days (n = 34), 0.8 g/kg once (n = 35), intravenous anti-D 25 micrograms/kg on 2 consecutive days (n = 38), or oral prednisone 4 mg/kg per day with tapering and discontinuation of prednisone by day 21 (n = 39). The rate of response as reflected by the number of days with platelet counts at 20 x 10(9)/L or lower and the time taken to achieve a platelet count 50 x 10(9)/L or more was significantly faster for both IVIgG groups than for the anti-D group (p < 0.05); the difference between prednisone and IVIgG was significant (p < 0.05) only for the IVIgG 0.8 g/kg group, and responses to the two IgG groups were similar. These differences in response rates were reflected in the percentages of children with platelet counts of 20 x 10(9)/L or lower at 72 hours following the start of treatment: 3% (IVIgG 0.8 g/kg x 1), 6% (IVIgG 1 g/kg x 2), 18% (anti-D), and 21% (oral prednisone 4 mg/kg/day). Treatment-associated toxicities included a fall in haemoglobin with anti-D (to less than 100 g/L in 24% of cases); weight gain with oral prednisone; and fever, nausea, vomiting, and headache with IVIgG. On the basis of these results, intravenous anti-D cannot be recommended as initial therapy for children with acute ITP and platelet counts of 20 x 10(9)/L or lower. A single dose of 0.8 g/kg IVIgG offers the fastest recovery for the least treatment; additional IgG or oral prednisone can be reserved for the one-third of children who continue to have platelet counts of 20 x 10(9)/L or less at 48-72 hours after the start of treatment.

Adolescent↗

PubMed1994

Mice with duplications and deletions at the Tme locus have altered MnSOD activity.

Superoxide radicals that result from normal cellular metabolism have been implicated as a cause of multiple age-related degenerative diseases (Halliwell, B., and Gutteridge, J. M. (1990) Methods Enzymol. 186, 1-85; Harman, D. (1988) Mol. Cell. Biochem. 84, 155-161; Ames, B. N., Shigenaga, M. K., and Hagen, T. M. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 7915-7922). Manganese superoxide dismutase (MnSOD) is thought to be the sole enzymic scavenger of superoxide in mammalian mitochondria. We have investigated MnSOD activity and gene dose in mice with deletions and a duplication of the Tme (t-associated maternal effect) locus on chromosome 17. We find that MnSOD activity is significantly correlated with gene dose in these animals; animals with heterozygous deletions of Tme have 50% of normal activity, and animals with a heterozygous duplication of Tme have 150% of normal activity. These ratios of activity appear to be systemic, as they were observed in brain, heart, skeletal muscle and liver. The results support the model that basal MnSOD activity is regulated solely by cis elements, in that variation in MnSOD activity caused by altered gene dose on one chromosome is not compensated by gene activity on the other. Since gene knockouts of MnSOD have not yet been generated, the tlub2 and Thp animals may become useful models for those studying the role of mitochondrial superoxide in pathophysiological processes. A model for the maternal-lethal effect of Tme deletions is proposed.

Animals↗

PubMed1994

Reduced thymic maturation but normal effector function of CD8+ T cells in CD8 beta gene-targeted mice.

CD8 is a cell surface glycoprotein on major histocompatibility complex class I-restricted T cells. Thymocytes and most peripheral T cells express CD8 as heterodimers of CD8 alpha and CD8 beta. The intestinal intraepithelial lymphocytes (IEL), which have been suggested to be generated extrathymically, express CD8 predominantly as homodimers of CD8 alpha. We have generated CD8 beta gene-targeted mice. CD8 alpha+ T cell population in the thymus and in most peripheral lymphoid organs was reduced to 20-30% of that in wild-type littermates. CD8 alpha expression on thymocytes and peripheral T cells also decreased to 44 and 53% of the normal levels, respectively. In contrast, neither the population size nor the CD8 alpha expression level of CD8 alpha+ IEL was reduced. This finding indicates that CD8 beta is important only for thymic-derived CD8+ T cells. The lack of CD8 beta reduces but does not completely abolish thymic maturation of CD8+ T cells. Our result also reveals the role of CD8 beta in regulating CD8 alpha expression on thymic derived T cells. Peripheral T cells in these mice were efficient in cytotoxic activity against lymphocytic choriomeningitis virus and vesicular stomatitis virus, suggesting that CD8 beta is not essential for the effector function of CD8+ T cells.

Animals↗

PubMed1994

Terminin (Tp 63/60), a novel cell senescence-related protein, is present in the aging human hippocampus.

We have previously identified a cell senescence-related, detergent-insoluble cytoplasmic protein referred to as terminin, and have presented the development-dependent modification of terminin polypeptides in rat brain. In the present study, we characterize biochemically and immunocytochemically terminin expression in human hippocampus. By immunoblotting with a monoclonal antibody (mab 1.2) against terminin, we identified a 63 kDa polypeptide (Tp63) in the detergent-insoluble fraction of human brain proteins, which can be identified by either one- or two-dimensional electrophoresis. The 63 kDa protein in immunoprecipitates of human hippocampus was found to share a peptide pattern with the 60 kDa terminin (Tp60) previously found in rat brain, as demonstrated by in situ peptide mapping, suggesting that the human 63 kDa protein is a homologue of the rat Tp60. By immunocytochemistry, terminin immunoreactivity was demonstrated throughout the neuronal layers in the human hippocampus. The pyramidal cell layer in hippocampus proper and subiculum, as well as the granule cells in the dentate gyrus, gave rise to immunoreactivity for terminin. It was observed that in the cornu Ammonis, the highest terminin immunoreactivity was present in the pyramidal neurons of CA1. At the cellular level terminin was localized intraneuronally, as demonstrated by confocal microscopy of double staining with both mab 1.2 and an anti-neurofilament antibody. Taken together, the present study establishes that terminin is expressed in abundance in aging human CNS neurons.

Aged↗

PubMed1994

Recognition molecules and immunoglobulin domains in invertebrates.

We have used specific antibody probes to conserved antigenic motifs to identify and characterize immunoglobulin-related molecules in tunicates and a C-type lectin found in lamprey that is related to molecules found in tunicates and mammals. The tunicate immunoglobulin cross-reactive molecule (mu CRM) reacts with antibodies raised to shark IgM heavy chains. Intact tunicate mu CRM is a monomer of Ig light-chain-sized subunits and is oligoclonal by IEF. That this molecule is related to Ig is indicated both by immunochemical data and by peptide sequence homologies. The lamprey lectin is a large polymer (> 500,000 kDa) of 35-kDa and 60-kDa subunits. It appears to be related to C-type lectins as shown by peptide sequence homology and the requirement of Ca2+ for activity. Related molecules appear to be present in tunicates and mammals as shown by cross-reactivity of antibodies in Western blots with single bands from hemolymph and T-cell extracts.

Amino Acid Sequence↗

PubMed1994

Improvements to the differential display method for gene analysis.

Differential display requires two primers to identify discordantly expressed mRNAs. Anchored primers with at least one G residue were superior to those which had one C residue and those ending in A or T were the least efficient. Arbitrary primers with GC pairs at the 5'end were superior to primers with GC pairs at the 3'end. We found that screening of amplified DNA-fixed membranes by a slot blot manifold and hybridization with DNA probes made from sample RNA rapidly re-screened with DNA fragments for differential expression, requires less RNA and is faster than Northern analysis. Similarly, hybridization of DNA fragments to plasmid DNA fixed to membranes and direct PCR sequencing rapidly determine homology to common laboratory plasmids prior to any further manipulation. These modifications permit rapid isolation and characterization of DNA fragments identified by differential display.

Animals↗

PubMed1994

A leukocyte lipid up-regulates the avidity of lymphocyte function-associated antigen-1.

An acidic lipid termed leukocyte adhesion lipid (LAL) was isolated from PMA stimulated lymphoid and myeloid cell lines HL60, Jurkat, K562 and U937 but not from unstimulated cells or PMA treated Cos7 cells. LAL treated peripheral blood leukocytes (PBL) adhered strongly to IL-1 beta activated human umbilical vein endothelial cells (HUVEC), and the interaction could be inhibited by antibodies to intercellular adhesion molecule (ICAM-1) or lymphocyte function-associated antigen-1 (LFA-1). Leukocytes treated with LAL maintained the high avidity state of LFA-1 for at least 1 hr whereas the avidity of LFA-1 in PMA treated cells declined after 30 min. LAL was stable to heat (100 degrees C, 10 min), alkaline phosphatase and proteinase K treatments. Chemical analysis suggested that LAL contained unsaturated lipids. Our findings provide evidence for the involvement of lipids in LFA-1 activation.

Cell Adhesion↗

PubMed1994

A method for analysis of gene expression patterns.

mRNA can be copied into cDNA with the use of reverse transcriptase so that the relative abundance of individual mRNAs is reflected in the cDNA product. With further manipulation a replica of the mRNA expression pattern can be duplicated into a radioactive double-stranded DNA probe. DNA from a series of genes inserted into plasmids can be fixed to a membrane using a slot blot manifold and probed with the RNA-derived DNA probe. The intensity of the hybridization signal for a given gene is a result of its relative abundance in the RNA-derived DNA probe. Quantitation can be achieved through the use of housekeeping genes as baseline monitors. Inclusion of vector sequences can negate any spurious hybridization to vector rather than insert sequences. We have successfully used this method to obtain gene expression patterns for RNA isolated from diverse sources including rodent tissues, various cell lines, and Drosophila and Caenorhabditis elegans samples. Northern blots have verified the results obtained. The pattern of expression of many genes can be determined from as little as 10 micrograms of total RNA, making this method ideally suited for studies in which RNA is rare or in short supply.

Base Sequence↗

PubMed1994

Expression of terminin, a senescence-related cytoplasmic protein, in the aging rat brain.

Terminin is a cytoplasmic protein expressed in irreversibly growth-arrested senescent fibroblast cultures and in terminally differentiated cells of various epithelia. In the present study, terminin was identified by immunohistochemistry in the cytoplasm of neurons and glia of aging rat brain using the monoclonal antibody (Mab) 1.2. Few terminin-positive neurons were observed in 3-month-old brain. At 18 months, terminin immunoreactivity was noted in dentate gyrus granule cells, in hippocampal fibre projections and in neuronal perikarya of deep cerebellar nuclei (but not in cerebellar cortex). In 33-month brain, terminin immunoreactivity in the dentate gyrus was more intense than at 18 months but immunoreactive fibre bundles in the hippocampus were no longer seen. At 33 months, the cerebellar granule cell layer contained terminin-positive horizontal interneurons and received immunoreactive axonal projections not seen in the younger preparations. In addition, ubiquitous low-level terminin expression was noted in neurons of the cerebral cortex, hippocampus and cerebellum of the 33-month-old animals. Thus, in the rat CNS, an increase in terminin appears to be a physiologic marker of neuronal aging. Small numbers of terminin-positive neuroglia were present in gray and white matter of 3-month-old brain and became increasingly more abundant in the 18- and 33-month-old animals. However, even in senescent brains, terminin-positive neuroglia represented a very small fraction of the entire glial pool. Terminin expression in slowly renewing neuroglial populations may identify those cells in which degeneration and death are imminent.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1994

Control of fibroblast senescence and activation of programmed cell death.

We have characterized a nuclear phosphoprotein of 57 kda, statin, found only in nonproliferating cells of both quiescent and senescent natures. Emerging results suggest that statin may function as a sequester to block the early G1 phase phosphorylation for the RB protein. A second protein, terminin, undergoes senescence-specific posttranslational modification from 90 to 60 kda, and further death-specific conversion from 60 to 30 kda. We also found that apoptotic mouse 3T3 fibroblasts express c-fos, c-myc, c-jun, and cdc2, as well as the upregulation of RB phosphorylation and BrdU incorporation, just before final DNA fragmentation and death. It seems that en route to death, cells re-enter the cell-cycle transverse and experience early G1 and part of S Phase; however, this cycling event is an abortive one. In contrast, senescent fibroblasts are resistant to the initiation of the death program, since they are unable to enter cell cycle traverse. Long-term serial passaging of normal human fibroblasts may be inadvertently selecting those, while termed as senescent, are also specialized survivors, and thus a good culture model to study both the control of permanent departure from cell cycle traverse and the mechanism underlying the survival or antideath cellular program.

Animals↗

PubMed1994

Characterization of 57 kDa statin as a true marker for growth arrest in tissue by its disappearance from regenerating liver.

Statin, a 57 kDa nuclear protein, is lost from quiescent fibroblasts in culture when they are induced to enter the cell cycle by feeding with growth factors, or by removal of contact inhibition. In order to investigate changes in statin expression during the transition from a quiescent to a cycling state in situ, we performed 70% partial hepatectomy on rats and analyzed the regenerating liver by immunofluorescence microscopy with antistatin monoclonal antibodies (S44 mAb), and by immunoblotting of liver proteins in cytoplasmic and enriched nuclear/cytoskeletal fractions. Western blot analysis showed that rat hepatocytes in situ contain a nuclear 57 kDa form of statin, as seen in cultured fibroblasts; however additional S44-immunoreactive polypeptides with molecular weights of 53 and 110 kDa are also present in both cytoplasmic and nuclear/cytoskeletal fractions. Immunofluorescence microscopy indicates that the proportion of S44-positive hepatocyte nuclei drops to approximately 60% within 24 hours after hepatectomy, a time period when re-entry of hepatocytes into the cell cycle is first observed. On Western blots of hepatocyte nuclear/cytoskeletal proteins obtained 24 hours after hepatectomy, the 57 kDa form of statin is markedly reduced. These results suggest that, although in liver the S44 antibody recognizes three proteins (53 kDa, 57 kDa, and 110 kDa), the 57 kDa in intact liver, similar to cultured fibroblasts, is the only polypeptide recognized by the statin antibody that disappears when hepatocytes are induced to re-enter the cell cycle from a quiescent state.

Animals↗