A gamma-herpesvirus immune evasion gene allows tumor cells in vivo to escape attack by cytotoxic T cells specific for a tumor epitope

DNA vaccines induce CTL attack on target tumor epitopes, but tumor elimination in vivo also requires sufficient effector CTL to enter the site, guided by inflammatory chemokines. Many herpesviruses contain genes for chemokine and chemokine receptor-like proteins to protect infected cells from immune attack. To assess if this evasion strategy could protect tumor cells, we used a model where CTL specific for a single epitope were the only effectors. Following DNA vaccination, CTL eliminated tumor cells from a subcutaneous site. However, introducing a viral gene encoding a secreted broad-spectrum chemokine-binding protein (M3) into tumor cells completely blocked CTL attack. Transduced tumor cells also protected neighboring non-transduced tumor. These findings confirm the importance of chemokines for migration of CTL to a non-lymphoid site. They may have relevance for escape of human virus-associated malignancies, and raise the question of whether analogous molecules might contribute to the failure of CTL to eliminate tumors.     

Modification of the Staphylococcus aureus fibronectin binding phenotype by V8 protease.

The amount of cell surface fibronectin (Fn)-binding protein (FnBP) adhesin expressed by Staphylococcus aureus is maximal during exponential growth but disappears rapidly as the culture progresses into stationary phase. To identify factors responsible for the loss of cell surface FnBP, a culture of S. aureus L170, which shows high levels of Fn binding, was supplemented at the time of inoculation with concentrated stationary-phase supernatant from S. aureus L530, a strain which binds Fn poorly. The resulting exponential-phase cells were devoid of FnBP. The factor responsible for this activity was purified from the culture supernatant and identified as V8 protease. When cultured with 375 ng of exogenous V8 protease ml(-1), exponential-phase cells of S. aureus L170 were devoid of cell surface FnBP, and concentrations as low as 23 ng x ml(-1) resulted in reduced amounts of FnBP. Addition of the protease inhibitor alpha2-macroglobulin to the culture medium prevented the growth-phase-dependent loss of cell surface FnBP, whereas growth with exogenous V8 protease resulted in reduced adherence to the solid-phase N-terminal fragment of Fn and to the extracellular matrix synthesized by fetal rabbit lung fibroblasts. Although FnBP was extremely sensitive to V8 protease, exogenous protease did not exert a significant influence on the amount of cell surface protein A. However, a limited number of other high-molecular-weight cell surface proteins were also sensitive to V8 protease. Therefore, both the adhesive phenotype and cell surface protein profile of S. aureus can be modified by V8 protease activity.     

Acceleration of the Menstrual Cycle by Intercourse

Hazard statistics were applied to an extensive set of prospective data to test for an acceleration of the menstrual cycle by intercourse. Intercourse appeared to accelerate both the basal body temperature (BBT) shift and the onset of menses. Menses was accelerated more by a combination of follicular and luteal intercourse than by luteal intercourse alone (using the BBT shift as an ovulation indicator). The accelerator effects of intercourse therefore appear to cumulate across the menstrual cycle.     

Adrenal pseudocysts: Evidence of their posthemorrhagic nature

Hemorrhagic adrenal pseudocysts are uncommon nonneoplastic lesions that have been reported as secondary to intraparenchymal hemorrhage or alternatively related to endothelial (vascular) cysts. Ultrastructural and immunohistochemical evidence in support of the latter has been presented, but the exact nature of hemorrhagic adrenal pseudocysts remains poorly defined. We evaluated six surgical specimens of hemorrhagic adrenal pseudocysts using immunohistochemical staining for CD31 and CD34, as well as conventional histochemistry. All six cases had hemorrhagic contents within a wall of variable thickness possessing focal areas of linear, disrupted elastin, and smooth muscle. Three cases demonstrated extensive thrombosis with organization, including papillary endothelial hyperplasia, simulating angiosarcoma. In these cases, CD31 and CD34 staining decorated areas of papillary endothelial hyperplasia as well as foci of the internal cyst lining, whereas the other cases were negative for both antibodies. Of interest is the history of FNA prior to surgical resection in three cases of hemorrhagic adrenal pseudocysts, two of which showed papillary endothelial hyperplasia. The presence of papillary endothelial hyperplasia and our immunohistochemical findings support, the conclusion that adrenal pseudocysts are posthemorrhagic and derive from vascular disruption. Furthermore, FNA or other interventional studies may be associated with papillary endothelial hyperplasia in hemorrhagic adrenal pseudocysts.     

Measurements of dose distributions in small beams of 6 MV x-rays

Dose distributions produced by small circular beams of 6 MV x-rays have been measured using ionisation chambers of small active volume. Specific quantities measured include tissue maximum ratios (TMR), total scatter correction factors (St), collimator scatter correction factors (Sc) and off-axis ratios (OAR). Field sizes ranged from 12.5 to 30 mm diameter, and were defined by machined auxiliary collimators with the movable jaws set for a 4 cm x 4 cm field size. Due to the lack of complete lateral electronic equilibrium for these small fields, the accuracy of the measurements was also investigated. This was accomplished by studying dose response as a function of detector size. Uncertainties of 2.5% were observed for the central axis dose in the 12.5 mm field when measuring with an ionisation chamber with a diameter of 3.5 mm. The total scatter correction factor exhibits a strong field size dependence for fields below 20 mm diameter, while the collimator scatter correction factor is constant and is defined by the setting of the movable jaws. Off-axis ratio measurements show larger dose gradients at the beam edges than those achieved with conventional collimator systems. Corrected profiles measured with an ionisation chamber are compared with measurements made with photographic film and LiF thermoluminescent dosemeters.     

Inhibition of C5 or absence of C6 protects from sepsis mortality

Inhibiting complement anaphlytoxin C5a during sepsis may prevent sepsis mortality. Although human anti-C5 antibodies exist, their therapeutic use in microbial sepsis has been avoided because of the hypothesis that inhibiting C5b will prevent formation of the bactericidal membrane attack complex (MAC) and worsen clinical outcome. We wished to test the hypothesis that inhibition of C5 would improve outcomes in sepsis. Sepsis was induced in rats by laparotomy and cecal ligation and puncture (CLP) by an IACUC-approved protocol. Sham animals underwent laparotomy without CLP. Following CLP rats were randomized to receive a single IV dose of purified IgG ant-C5 antibody (Ab) or control IgG Ab. Anti-C5 Ab treated rats (n = 20) had significantly lower mortality vs. controls (n = 21), 20% vs. 52% (P = 0.019, log-rank). Analysis of bacterial load by culture of spleen and liver homogenates showed a reduction in colony forming units in anti-C5 Ab treated rats vs. control IgG (P = 0.003 and 0.009, respectively). Anti-C5 treatment reduced lung injury as measured by total MPO content of lung tissue (P = 0.024). Finally, rats genetically deficient in C6 production, unable to form MAC but capable of producing C5a and C5b, were protected from CLP-induced sepsis mortality. Our results show that in anti-C5 antibody therapy prevents CLP sepsis-induced mortality and improves lung injury. Inhibition of the complement MAC does not increase bacterial load or mortality, therefore, the use of anti-C5 therapy may be beneficial rather than detrimental in sepsis.     

Multiple effects of the 72-kDa, adenovirus-specified DNA binding protein on the efficiency of cellular transformation

The early region 2A gene (E2A) of adenovirus types 2 and 5 encodes a 72-kDa DNA binding protein (DBP) which contains two physical domains comprising approximately the amino-terminal one-third and carboxyl-terminal two-thirds of the protein, respectively. Previous work has shown that some Ad5 mutants containing temperature-sensitive (ts) mutations in the carboxyl-terminal domain of DBP, such as Ad5ts125, show a 3- to 8-fold enhanced ability to transform rat cells. We have examined the transformation characteristics of a series of Ad5 E2A deletion mutants, Ad5dl801-5, which encode either no functional DBP or encode truncated, defective DBPs. The E2A deletion mutants transformed rat embryo cells at frequencies similar to wild-type (wt) Ad5. These results suggest that the high transformation phenotype of carboxyl-terminal E2A mutants like Ad5ts125 is not due to the simple inactivation of DBP function, but rather results from an activity possessed by an altered DBP. This hypothesis is supported by the fact that the transformation phenotype of Adsts125 and similar mutants is dominant over the wild-type phenotype. A number of additional Ad2 and Ad5 E2A mutants were examined with respect to their ability to transform primary rat embryo cells. It was found that a carboxyl-terminal E2A mutant, Ad2+ND1ts23, also showed the enhanced transformation phenotype. In contrast, several amino-terminal E2A host-range (hr) mutants, originally isolated on the basis of their ability to replicate in monkey cells, transformed rat embryo cells at a frequency similar to wild-type virus. Ad2ts400, and E2A mutant with alterations in both DBP domains, showed a wild-type frequency of transformation, while two similar mutants, Ad5ts125 X 405 and Ad5ts125 X 404, showed an enhanced frequency. Last, it was found that coinfection of primary rat embryo cells with the hr mutants plus Ad5ts125 or Ad2+ND1ts23 resulted in a wild-type frequency of transformation, demonstrating that the hr mutants are dominant to the ts mutants with regard to transformation phenotype. Thus, DBP can both positively and negatively affect viral transformation in this system.     

Complete nucleotide sequence of the genomic RNA of Sindbis virus

The entire nucleotide sequence of the genomic RNA of the type virus of the alphavirus genus, Sindbis virus, has been determined. The genome is 11,703 nucleotides in length, exclusive of the 5' cap and the 3'-terminal poly(A) tract. After the 5'-terminal cap there are 59 nucleotides of 5' nontranslated nucleic acid followed by a reading frame of 7539 nucleotides that encodes the nonstructural polypeptides and which is open except for a single opal termination codon. Following 48 untranslated bases located in the junction region which separates the nonstructural and structural protein coding sequences, there is an open reading frame 3735 nucleotides long that encodes the structural proteins. Finally, the 3' untranslated region is 322 nucleotides long. The nonstructural proteins are translated from the genomic RNA as two polyprotein precursors. The first is 1896 amino acids in length and terminates at an opal codon at position 1897. This polyprotein is processed to produce three polypeptides called nsP1, nsP2, and nsP3. Sites of post-translational cleavage to produce these three proteins have been tentatively located using available N-terminal amino acid sequence data. In both cases cleavage probably occurs between the two alanine residues in the sequence Gly-Ala-Ala. The fourth nonstructural protein, nsP4, is produced when readthrough of the opal codon produces a second polyprotein precursor of length 2513 amino acids, which is also cleaved posttranslationally. The structural proteins are translated from a subgenomic message which begins at nucleotide 7598, is 4106 nucleotides in length (exclusive of the poly(A) tract), and is coterminal with the 3' end of the genomic RNA. The structural proteins are also translated as a polyprotein precursor which is cleaved to produce a nucleocapsid protein and two integral membrane glycoproteins as well as two small peptides not present in the mature virion. A replication strategy for Sindbis virus based upon the complete nucleotide sequence, as well as prior data, is presented.     

Primary total hip replacement--a survey of current practice and identifying changing trends

Primary total hip replacement (THR) surgery is the most commonly performed and successful reconstructive procedure in orthopaedic surgery. We performed a survey of Irish Orthopaedic consultants to elucidate current practices of primary THR in elderly and young patients and identify changing trends. There was an 83% response rate. Most respondents use a cemented THR in elderly patients. 69% use a different THR in younger patients compared to older patients. 9% refer younger patients to hip replacement specialist consultant colleagues. 70% report changing to a new implant or new technique in younger patients and 45% use a hybrid THR, 15% an uncemented THR, 15% perform hip resurfacing and 47% use different bearing surfaces. Only 17% use the Charnley hip prosthesis in younger patients. Young and active patients will place high demands on a new THR and newer techniques, implants and bearing surfaces are being adopted in the hope of better outcomes.