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Biomedical subjects

W C Russell

Publications and source records attributed to W C Russell.

At least 37 records · Page 2Linked to original sources
PubMed1999

The use of positive B cell flow cytometry crossmatch in predicting rejection among renal transplant recipients.

We performed retrospective flow cytometry crossmatch (FCXM) on 106 renal graft recipients who were transplanted based on current T cell negative serologic crossmatch. T and B cell FCXMs were performed on current and historical peak reactive post-transplant sera using 1024-channel flow cytometer and the shift in median channel fluorescence (SMCF) over the negative control was calculated. Cut-off values for a positive T and B crossmatch, > 40 and > 80 SMCF, respectively, were determined based on previous retrospective analysis of the data in the context of clinical outcome in our center, and were 1.5 times the standard deviation (SD) above the mean median channel fluorescence (MCF) of normal sera controls. The 1-yr graft survival was 95% for the total group of patients studied, and 87% for the recipients who had a positive T cell FCXM. To focus on the influence of a positive B cell FCXM on the incidence of rejection, primary transplant recipients who had a negative T cell FCXM (n = 81) were studied. Fifteen of 30 (50%) recipients with a positive B cell FCXM experienced at least one rejection episode within the first year. By contrast, only 15 of 51 (29.4%) of patients with a negative B cell FCXM experienced rejection (p = 0.05). The mean B cell SMCF in the group of patients who had no rejections was 45 +/- 59, while that of the group of patients who experienced at least one rejection was 97 +/- 97 (p = 0.012). By comparison, the rejection rate among the retransplant patients was 44.4%, and the mean B cell SMCF in the group with rejection was 94 +/- 75 while it was 5 +/- 7 among retransplant patients who did not have rejection (p = 0.031). Eighty-six percent of sensitized (panel reactivity antibodies (PRA) > 10%) patients who had a B positive/T negative FCXM experienced rejection, compared to 33% (n = 6 out of 16) of the B negative/T negative sensitized patients (p = 0.03). Furthermore, 62% (n = 13 out of 21) of donor-recipient mismatched patients with a B positive/T negative FCXM experienced rejection, compared to 38% (n = 13 out of 35) of patients with T negative/B negative FCXM who were similarly mismatched (p = 0.064). These data demonstrate the value of a positive B cell FCXM for predicting post-transplant rejections particularly when evaluated in the context of prior sensitization and/or DR mismatching. Our results suggest that B cell FCXM may have significant clinical implications, justifying its use in post-transplant management of recipients who have other risk factors of rejection.

Adult↗
PubMed1999

Adenovirus core protein VII displays a linear epitope conserved in a range of human adenoviruses.

A monoclonal antibody (MAb) which recognized a linear epitope on polypeptide VII of human adenovirus (Ad) serotype 4 also interacted with polypeptides VII of Ad serotypes 2, 5, 7 and 10, but not with 12 and 40, in Western blotting. Utilizing a hexapeptide phage display library, the MAb was found to recognize the consensus sequence RXYXPX. A peptide based on a similar sequence from Ad2, viz. VEEARNYTPTPPPV, was synthesized and shown to inhibit binding of the MAb to polypeptide VII. Direct sequencing of the Ad4 polypeptide VII gene validated these observations, the sequence RNYTPA being detected. Comparison with gene sequences from other Ads indicates that this sequence is preserved in polypeptide VII of types 2 and 5 but in types 12 and 40 insertion of another residue disrupts this motif.

Adenoviruses, Human↗
PubMed1998

Analysis of the hexon gene sequence of bovine adenovirus type 4 provides further support for a new adenovirus genus (Atadenovirus).

The putative hexon gene of bovine adenovirus type 4 (BAV-4), encoding 910 amino acid residues, has been identified and sequenced. A characteristic codon usage biased towards the use of AT-rich triplets was observed. Comparative analysis with other hexon sequences detected a high level of amino acid identity in the regions corresponding to the pedestals of the hexon. Substitutions, insertions and deletions were identified mainly in the variable regions forming the loops which are exposed on the outer surface of the virion. In these variable regions, BAV-4 shared similarity only with egg drop syndrome (EDS) virus and ovine adenovirus isolate 287 (OAV287). The close relationship of these viruses was also demonstrated by phylogenetic analysis of the hexon gene. In addition to the two groups of the Mastadenovirus and Aviadenovirus genera, a third cluster appeared comprising BAV-4, OAV287 and EDS virus.

Amino Acid Sequence↗
PubMed1998

Adenovirus core protein V is delivered by the invading virus to the nucleus of the infected cell and later in infection is associated with nucleoli.

A 'west-Western' blotting procedure indicates that adenovirus core protein V is linked to the capsid via protein VI. Double-labelling techniques employing confocal microscopy and immunofluorescence suggest that this linkage is disrupted following infection and penetration of the host cell. Protein V enters the nucleus presumably still in association with the other core proteins attached to the virus genome. Later in infection protein V rapidly accumulates in the nucleus in close association with nucleoli.

Adenoviruses, Human↗
PubMed1998

Adenovirus core protein V interacts with p32--a protein which is associated with both the mitochondria and the nucleus.

Adenovirus protein V is associated with the DNA-containing virus core and functions as a bridge between the capsid and the core. A yeast two-hybrid analysis performed with a human cDNA library using protein V as 'bait' selected a cellular protein, p32 --described previously as associated with the splicing factor ASF/SF2. By expression and purification of p32 and preparation of an antibody we confirmed the binding of p32 to V by a variety of methods including immune precipitation. We demonstrated that p32 was primarily located in the cytoplasm in association with mitochondria but could also be detected in the nucleus as distinct granules and tubules. By examining infected cells using confocal microscopy and immunofluorescence we were able to follow the intracellular locations of protein V and p32 and it is postulated that p32 is part of a system which imports proteins to the nucleus and that adenovirus hijacks this process to deliver its genome to the nucleus.

Adenoviruses, Human↗
PubMed1998

Derivation of an equation to estimate marrow content of bovine cervical vertebrae.

Marrow content of bovine cervical vertebrae from Choice- and Select-grade carcasses weighing 294 to 343 kg was determined so that a method to monitor the amount of marrow in meat from advanced meat/bone separation machinery and recovery (AMR) systems could be developed. The marrow determination requires cleaning and then ashing bones. Because a large difference in ash content of bone and bone marrow exists and because cartilage content of cervical vertebrae in Choice and Select beef is relatively constant, it was possible to derive the following equation: Weight of marrow = [weight of cartilage (% ash in cartilage - % ash in bone) + % ash in bone (total weight) - (total ash)]/[(% ash in bone - % ash in marrow)]. Constants for ash in fresh bone, marrow, and cartilage were 58.51, .57, and 2.14% with SD of 2.23, .15, and .30%, respectively. A cartilage content of 9.5% along with cervical vertebrae weight and total ash weight were also used to calculate 33.9% marrow in cervical vertebrae. Means for marrow pressed or centrifuged from bovine cervical vertebrae were lower than those obtained from the equation. Therefore, pressing and centrifuging left some marrow in spongy bone. Our ashing method for determining the amount of marrow in whole cervical vertebrae should be useful for determining marrow remaining in cervical vertebrae of bone cakes from AMR systems. Percentage ash in pressed bones is higher and the calculated marrow content is lower when pressed bones are compared to cervical vertebrae that are not pressed. The amount of marrow in whole cervical vertebrae minus the amount left in cervical vertebrae from bone cakes equals the amount in meat from AMR systems.

Analysis of Variance↗
PubMed1997

Use of west-western blotting for detection of adenovirus receptors.

A modification of an immunoblotting procedure was developed to detect virus receptors: a nitrocellulose membrane containing electrotransferred cellular proteins separated by polyacrylamide gel electrophoresis in the presence of SDS is treated with the whole virus (viral proteins) and an antiserum against individual viral proteins, followed by the detection of the receptors after their incubation with peroxidase labeled anti-species antibodies by enhanced chemiluminescence. The method detects adenovirus receptors for the capsid proteins including 20- and 80-kD receptors for the fiber, 20- and 40-kD receptors for the penton, and 80- and 200-210-kD receptors for protein IIIa.

Adenoviridae↗
PubMed1997

Naturally occurring cerebral nematodiasis due to Baylisascaris larval migration in two black-and-white ruffed lemurs (Varecia variegata variegata) and suspected cases in three emus (Dromaius novaehollandiae).

During September and October 1992, two black-and-white ruffed lemurs (Varecia variegata variegata) were housed in an outdoor wire enclosure at the Tulsa Zoological Park. The following February and April, both lemurs developed head tilt and ataxia, and they were euthanized. Necropsy revealed multifocal malacia of the white matter of the pons, cerebellum, internal capsule, and cerebral and cerebellar peduncles. Nematode larvae consistent with Baylisascaris spp. were observed in the brain of one lemur. A retrospective study revealed three cases of ataxia in emus (Dromaius novaeholloandiae) that were previously housed in the same enclosure. Archival paraffin-embedded tissue from one emu revealed tractlike foci of malacia within the white matter of the cerebellum. Circumstantial evidence, including the observation of numerous raccoons (Procyon lotor) in the vicinity, and the presence of numerous Baylisascaris. procyonis in the intestine of a single trapped raccoon implicate this roundworm as the pathologic agent in the lemurs.

Animals↗
PubMed1995

Adenovirus protein-protein interactions: molecular parameters governing the binding of protein VI to hexon and the activation of the adenovirus 23K protease.

A variety of recombinant proteins derived from protein pVI of human adenovirus type 2 (Ad2) were analysed for their ability to bind Ad2 hexon in vitro. As pVI is also required for activation of the adenovirus-coded protease, the same pVI derivatives were assessed for their ability to activate recombinant adenovirus-coded 23K protease. Two regions, between amino acid residues 48-74 and 233-239 of pVI, were required for the interaction with hexon. These regions are highly conserved amongst mastadenovirus pVI proteins. Both these regions are capable on their own of binding hexon weakly but must be provided in cis for strong hexon binding. In addition, we found evidence to indicate than conformation as well as sequence was important for good hexon binding in our assays. Authentic processing of the appropriate recombinant pVI derivatives, by the recombinant protease, was obtained without the addition of other cofactors. These findings are discussed in relation to the role of pVI in triggering the adenovirus maturation pathway.

Adenoviruses, Human↗
PubMed1995

Is there a case for a virus aetiology in multiple sclerosis?

Multiple Sclerosis (MS) is a devastating demyelinating disease with a very high prevalence in North-East Scotland and in the Orkney and Shetland Islands. MS appears to be a multifactorial disorder with environmental and genetic elements and it has been proposed that these, in tandem, provoke an autoimmune response giving rise to the disease. Although there is no direct evidence of a specific virus being involved in MS, there are nevertheless grounds for suspecting a viral association. This review discusses these aspects of MS and suggests that a more aggressive approach to unravelling the role of viruses is needed.

Autoimmunity↗
PubMed1995

Selection for lambing rate and clean fleece weight in sheep.

This study was designed to compare the effectiveness of selection for lambing rate (LB) and clean fleece weight (CFW) separately or by a combination of both traits at once. Two flocks of approximately 200 western white faced ewes per flock were maintained at two locations. Each flock was divided into four equal selection groups of similar initial birth type and age. The basis of selection in each flock was as follows: Line I, single trait selection for LB; Line II, single trait selection for CFW; Line III, multiple trait selection for LB and CFW; and Line IV; visual selection based on conformation and general fleece quality. Repeatability and heritability estimates were .18 and .16 +/- .04, respectively, for LB and .66 and .60 +/- .09, respectively, for CFW. The genetic correlation between LB and CFW was .26 +/- .16. Linear regression coefficients (number born/year) of annual response for LB in Lines I to IV were .018 +/- .008, .009 +/- .006, .011 +/- .005, and .009 +/- .005 (P > .05). Linear regression coefficients (kg/year) of annual observed response for CFW in lines I to IV were -.001 +/- .006, .027 +/- .009, .019 +/- .006, and .008 +/- .006. Response in Lines II and III was significant for CFW (P < .05) compared with Lines I and IV. In this study, CFW was increased by selection in white-faced sheep with little effect on lambing rate.

Animals↗
PubMed1994

Adenovirus protein-protein interactions: hexon and protein VI.

A variety of mastadenoviruses were denatured, their polypeptides separated by electrophoresis on SDS-polyacrylamide gels and transferred to nitrocellulose. The immobilized polypeptides were washed, incubated with buffers containing hexons from human adenoviruses (Ad) types 2, 5 and 12 and the location of bound hexons was detected with anti-hexon antibodies. It was found that hexons from any of the three human adenovirus types bound to protein VI from all the mastadenoviruses examined. Furthermore we found that hexon-VI binding was significantly greater than the interaction between hexon and the precursor to VI, pVI. This binding was susceptible to detergents and to changes in pH or salt concentration. A rabbit polyclonal antibody was raised against a recombinant protein derived from the middle third of pVI from Ad2 and was used to quantify the difference in binding and to demonstrate the presence of a single intermediate (designated iVI) in the processing of pVI to VI. The affinity between iVI and hexon was considerably greater in our assay than that of pVI but was less than that between hexon and VI. A complementary binding of recombinant iVI to immobilized hexons was also demonstrated. This latter interaction, however, was only observed when hexon preparations were not boiled prior to electrophoresis, substantiating the proposition that the recognition motif on the hexon was conformation-dependent. These results are discussed in the context of understanding further the molecular basis of protein-protein interactions between the structural proteins of adenoviruses and the factors involved in virion maturation.

Adenoviruses, Human↗