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Biomedical subjects

C E Wang

Publications and source records attributed to C E Wang.

17 recordsLinked to original sources
PubMed2000

ConfMatch: automating electron-density map interpretation by matching conformations.

Building a protein model from the initial three-dimensional electron-density distribution (density map) is an important task in X-ray crystallography. This problem is computationally challenging because proteins are extremely flexible. The algorithm ConfMatch is a global real-space fitting procedure in torsion-angle space. It solves this 'map-interpretation' problem by matching a detailed conformation of the molecule to the density map (conformational matching). This 'best-match' structure is defined as one which maximizes the sum of the density at atom positions. ConfMatch is a practical systematic algorithm based on a branch-and-bound search. The most important idea of ConfMatch is an efficient method for computing accurate bounds. ConfMatch relaxes the conformational matching problem, a problem which can only be solved in exponential time, into one which can be solved in polynomial time. The solution to the relaxed problem is a guaranteed upper bound for the conformational matching problem. In most empirical cases, these bounds are accurate enough to prune the search space dramatically, enabling ConfMatch to solve structures with more than 100 free dihedral angles. Experiments have shown that ConfMatch may be able to automate the interpretation of density maps of small proteins.

Algorithms↗
PubMed2000

Developing a concept of hope from a human science perspective.

This article explores concept development from a human science perspective and uses concept inventing, a method described by Parse, for developing the concept of hope as inspired by the Taiwanese folk song "Mending a Torn Fish Net." The synthesized definition is hope is resolute picturing of the possibilities amid the restrictions-opportunities of communion-aloneness while creatively metamorphosing. This definition is explicitly connected to the three principles of Parse's theory of human becoming. Reflections on research and practice are provided.

Adaptation, Psychological↗
PubMed1999

Human cytomegalovirus infection of caco-2 cells occurs at the basolateral membrane and is differentiation state dependent.

Epithelial cells are known to be a major target for human cytomegalovirus (HCMV) infection; however, the analysis of virus-cell interactions has been difficult to approach due to the lack of in vitro models. In this study, we established a polarized epithelial cell model using a colon epithelial cell-derived cell line (Caco-2) that is susceptible to HCMV infection at early stages of cellular differentiation. Infection of polarized cells was restricted to the basolateral surface whereas virus was released apically, which was consistent with the apical and not basolateral surface localization of two essential viral glycoproteins, gB and gH. HCMV infection resulted in the development of a cytopathology characteristic of HCMV infection of colon epithelium in vivo, and infection did not spread from cell to cell. The inability of HCMV to infect Caco-2 cells at late stages of differentiation was due to a restriction at the level of viral entry and was consistent with the sequestration of a cellular receptor for HCMV. These observations provide the first evidence that restriction of HCMV replication in epithelial cells is due to a receptor-mediated phenomenon.

Caco-2 Cells↗
PubMed1999

Uncv (uncovered): a new mutation causing hairloss on mouse chromosome 11.

A pair of mutant mice with a first sparse coat appeared spontaneously in the production stock of BALB/c mice with a normal coat. After being sib-mated, they produced three phenotypes in their progeny: mice with normal hair, mice with a first sparse coat and then a fuzzy coat, and uncovered mice. Genetic studies revealed the mutants had inherited an autosomal monogene that was semi-dominant. By using 11 biochemical loci--Idh, Car2, Mup1, Pgm1, Hbb, Es1, Es10, Gdc, Ce2, Mod1 and Es3--as genetic markers, two-point linkage tests were made. The results showed the gene was assigned to chromosome 11. The result of a three-point test with Es3 and D11Mit8 (microsatellite DNA) as markers showed that the mutation was linked to Es3 with the recombination fraction 7.89 +/- 2.19%, and linked to D11Mit8 with the recombination fraction 26.30 +/- 3.57%. The recombination fraction between Es3 and D11Mit8 was 32.90 +/- 3.81%. It is suggested that the mutation is a new genetic locus that affected the skin and hair structure of the mouse. The mutation was named uncovered, with the symbol Uncv. Further studies showed the mutation affected not only the histology of skin and hair but also the growth and reproductive performance of the mice. The molecular characterization of the Uncv locus needs to be further studied.

Alopecia↗
PubMed1997

The role of CCR5 and CCR2 polymorphisms in HIV-1 transmission and disease progression.

Entry of human immunodeficiency virus type 1 (HIV-1) into target cells requires both CD4 (ref. 1, 2) and one of a growing number of G-protein-coupled seven-transmembrane receptors. Viruses predominantly use one, or occasionally both, of the major co-receptors CCR5 or CXCR4, although other receptors, including CCR2B and CCR3, function as minor co-receptors. CCR3 appears critical in central nervous system infection. A 32-base pair inactivating deletion in CCR5 (delta 32) common to Northern European populations has been associated with reduced, but not absolute, HIV-1 transmission risk and delayed disease progression. A more commonly distributed transition causing a valine to isoleucine switch in transmembrane domain I of CCR2B (64I) with unknown functional consequences was recently shown to delay disease progression but not reduce infection risk. Although we confirm the lack of association of CCR2B 64I with transmission, we cannot confirm the association with delayed progression. Although subjects with CCR5 delta 32 defects had significantly reduced median viral load at study entry, providing a plausible explanation for the association with delayed progression, this association was not seen with CCR2B 64I. Further studies are needed to define the role of CCR2B64I in HIV pathogenesis.

Acquired Immunodeficiency Syndrome↗
PubMed1995

The Pinwheel Model of Bereavement.

The Pinwheel Model of Bereavement is a process-orientated model of grief which recognizes loss as a unique lived experience. The model and relevant nursing response are described using Margaret Newman's nursing theory of health as expanding consciousness. The model is based on research by Carter (1989) and clinical experience. The contextual theme for the model is "personal history." Six core themes are: being stopped, hurting, missing, holding, seeking, and valuing. Three meta themes are change, expectations, and inexpressibility. Capacities for "being with" the bereaved are identified for the practice of nursing.

Adaptation, Psychological↗
PubMed1994

Structure and function of decay accelerating factor CD55.

Studies of decay-accelerating factor (DAF) function and structure are reviewed. DAF was first recognized as a species restricting factor operating at the level of C3/C5 activation. Cloning of the gene indicates that DAF has four short consensus repeats of the type characteristic of the regulators of complement activation gene cluster family. The third short consensus repeat is responsible for DAF's complement regulatory activity and signaling. DAF, like other glycophosphatidylinositol (GPI) anchored proteins, is associated with tyrosine kinases, and these kinases are probably the signaling devices. The details of how DAF's GPI anchor in the outer leaflet of plasma membrane connects with the tyrosine kinases on the inner leaflet are not known. Although DAF does not have an essential role in controlling hemolysis of erythrocytes, it does have important role in regulating the deposition of C3 on nucleated cells. The therapeutic potential of DAF is discussed.

Animals↗
PubMed1994

Spontaneous rupture of the liver associated with pregnancy: a report of two cases.

Spontaneous rupture of the liver associated with pregnancy is a rare and grave complication, usually occurring in preeclampsia or eclampsia. Two cases of ruptured subcapsular hematoma of the right liver during pregnancy are reported. The first case was a 19-year-old woman who had suffered from epigastralgia and absent fetal heart beat in the 32nd week of gestation. The second case was a 31-year-old female who complained of nausea and right upper quadrant pain in the 35th week of pregnancy. Both had preeclampsia, and developed shock with disseminated intravascular coagulation soon after admission. Both received surgery and were found to have ruptured hematoma over the right liver. Finally, the first patient died of renal failure, but the second survived because preoperative diagnosis had been exact. Greater suspicion, then awareness of diagnosis can lead to better timing of surgery and an improved prognosis for mother and child.

Adult↗