Management of Tibial and Femoral Non-unions and Stress Fractures with Severe Ipsilateral Knee Arthritis with Long Stemmed Modular Total Knee Arthroplasty.

Management of patients with non-unions or stress fractures of the tibia or distal femur with debilitating ipsilateral knee arthritis can be difficult to manage. In these examples of care, we present three illustrations of using long stemmed modular total knee components to successfully manage both tibial and femoral non-unions and stress fractures as well as ipsilateral arthritis with resultant deformity. The average improvement in our knee outcome scores for these three patients via pre-operative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) and one-year post-operative KOOS, JR is 44.37. After treatment with a long stemmed modular total knee prosthesis all three examples of care went on to union and the arthritic deformity was corrected. (Journal of Surgical Orthopaedic Advances 31(3):166-168, 2022).

Utilisation of calcium sulphate beads in one-stage aseptic revision total hip arthroplasty.

INTRODUCTION: Periprosthetic joint infection (PJI) affects many revision total hip arthroplasty (THA) patients, contributing to a concomitant rise in revision costs. Means of decreasing the risk of PJI include the use of antibiotic adjuncts, such as calcium sulphate beads (CSBs). Mixed with antibiotics, the potential benefits of CSBs include dissolvability and antibiotic drug elution. However, information comparing them in aseptic revision is scarce. Therefore, this study investigated CSB utilisation for infection prevention in aseptic revision THA. Specifically, we compared (1) infection rates; (2) lengths of stay; (3) subsequent infection procedures; and (4) final surgical outcome in 1-stage aseptic revision THA patients who did received CSBs to 1-stage aseptic revision THA patients who did not. METHODS: A retrospective chart review was performed to identify all patients who underwent an aseptic revision THA between January 2013 and December 2017. Patients who received CSBs (n = 48) were compared to non-CSB patients (n = 58) on the following outcomes: postoperative infections, lengths of stay (LOS), subsequent irrigation and debridements (I+Ds), and final surgical outcome, classified as successful THA reimplantation, retained antibiotic spacer, or Girdlestone procedure. Chi-square and t-testing were used to analyse the variables. RESULTS: There was no significant differences found between CSB patients and non-CSB patients in postoperative infections (p = 0.082), LOS (p = 0.179), I+Ds (p = 0.068), and final surgical outcome (p = 0.211). CONCLUSION: This study did not find any statistical difference between CSBs and standard of care in infection rates and surgical outcomes. The advantage of these beads for 1-stage aseptic revisions is questionable.

Transferring, translating and transforming knowledge: the role of brokering in healthcare networks.

PURPOSE: This research examines how knowledge and information are managed within two care networks. We develop a conceptual framework drawing on the notion of brokering and the 3T framework, which is used to describe the relative complexity of boundaries (referred to in the framework as syntactic, semantic and pragmatic) as well as capabilities and processes required to exchange information within the network. Previous research on brokering has focused on healthcare managers and professionals, but this research extends to patients and caregivers. Understanding knowledge exchange and brokering practices in healthcare is critical to the delivery of effective services. DESIGN/METHODOLOGY/APPROACH: For this case research, non-participant observation and experienced-based interviews were undertaken with healthcare professionals, patients and caregivers within two care networks. FINDINGS: The findings reveal brokering roles occupied by healthcare professionals, patients and caregivers support the transfer, translation and transformation of knowledge and information across functional and organisational boundaries. Enablers and disablers to brokering and the exchange of knowledge and information are also identified. RESEARCH LIMITATIONS/IMPLICATIONS: The study is limited to two care networks for long-term conditions within the UK. Further research opportunities exist to examine similar care networks that extend across professional and organisational boundaries. PRACTICAL IMPLICATIONS: This research informs healthcare professionals of the brokering capabilities that occur within networks and the enabling and disabling factors to managing knowledge across boundaries. ORIGINALITY/VALUE: This paper provides a conceptual framework that categorises how increased levels of knowledge and information exchange and brokering practices are managed within care networks.

Early induction of autophagy in human fibroblasts after infection with human cytomegalovirus or herpes simplex virus 1.

The infection of human fetal foreskin fibroblasts (HFFF2) with human cytomegalovirus (HCMV) resulted in the induction of autophagy. This was demonstrated by the increased lipidation of microtubule-associated protein 1 light chain 3 (LC3), a hallmark of autophagy, and by the visualization of characteristic vesicles within infected cells. The response was detected first at 2 h postinfection and persisted for at least 3 days. De novo protein synthesis was not required for the effect, since HCMV that was irradiated with UV light also elicited the response, and furthermore the continuous presence of cycloheximide did not prevent induction. Infection with herpes simplex virus type 1 (HSV-1) under conditions that inhibited viral gene expression provoked autophagy, whereas UV-irradiated respiratory syncytial virus did not. The induction of autophagy occurred when cells were infected with HCMV or HSV-1 that was gradient purified, but HCMV dense bodies and HSV-1 light particles, each of which lack nucleocapsids and genomes, were inactive. The depletion of regulatory proteins Atg5 and Atg7, which are required for autophagy, reduced LC3 modification in response to infection but did not result in any detectable difference in viral or cellular gene expression at early times after infection. The electroporation of DNA into HFFF2 cultures induced the lipidation of LC3 but double-stranded RNA did not, even though both agents stimulated an innate immune response. The results show a novel, early cellular response to the presence of the incoming virion and additionally demonstrate that autophagy can be induced by the presence of foreign DNA within cells.

Evidence that maturation of the N-linked glycans of the respiratory syncytial virus (RSV) glycoproteins is required for virus-mediated cell fusion: The effect of alpha-mannosidase inhibitors on RSV infectivity.

Glycan heterogeneity of the respiratory syncytial virus (RSV) fusion (F) protein was demonstrated by proteomics. The effect of maturation of the virus glycoproteins-associated glycans on virus infectivity was therefore examined using the alpha-mannosidase inhibitors deoxymannojirimycin (DMJ) and swainsonine (SW). In the presence of SW the N-linked glycans on the F protein appeared in a partially mature form, whereas in the presence of DMJ no maturation of the glycans was observed. Neither inhibitor had a significant effect on G protein processing or on the formation of progeny virus. Although the level of infectious virus and syncytia formation was not significantly affected by SW-treatment, DMJ-treatment correlated with a one hundred-fold reduction in virus infectivity. Our data suggest that glycan maturation of the RSV glycoproteins, in particular those on the F protein, is an important step in virus maturation and is required for virus infectivity.

Analysis of the interaction between respiratory syncytial virus and lipid-rafts in Hep2 cells during infection.

The assembly of respiratory syncytial virus (RSV) in lipid-rafts was examined in Hep2 cells. Confocal and electron microscopy showed that during RSV assembly, the cellular distribution of the complement regulatory proteins, decay accelerating factor (CD55) and CD59, changes and high levels of these cellular proteins are incorporated into mature virus filaments. The detergent-solubility properties of CD55, CD59, and the RSV fusion (F) protein were found to be consistent with each protein being located predominantly within lipid-raft structures. The levels of these proteins in cell-released virus were examined by immunoelectronmicroscopy and found to account for between 5% and 15% of the virus attachment (G) glycoprotein levels. Collectively, our findings suggest that an intimate association exists between RSV and lipid-raft membranes and that significant levels of these host-derived raft proteins, such as those regulating complement activation, are subsequently incorporated into the envelope of mature virus particles.

The small hydrophobic (SH) protein accumulates within lipid-raft structures of the Golgi complex during respiratory syncytial virus infection.

The cellular distribution of the small hydrophobic (SH) protein in respiratory syncytial virus (RSV)-infected cells was examined. Although the SH protein was distributed throughout the cytoplasm, it appeared to accumulate in the Golgi complex within membrane structures that were enriched in the raft lipid, GM1. The ability of the SH protein to interact with lipid-raft membranes was further confirmed by examining its detergent-solubility properties in Triton X-100 at 4 degrees C. This analysis showed that a large proportion of the SH protein exhibited detergent-solubility characteristics that were consistent with an association with lipid-raft membranes. Analysis of virus-infected cells by immuno-transmission electron microscopy revealed SH protein clusters on the cell surface, but only very low levels of the protein appeared to be associated with mature virus filaments and inclusion bodies. These data suggest that during virus infection, the compartments in the secretory pathway, such as the endoplasmic reticulum (ER) and Golgi complex, are major sites of accumulation of the SH protein. Furthermore, although a significant amount of this protein interacts with lipid-raft membranes within the Golgi complex, its presence within mature virus filaments is minimal.

Does a betaretrovirus infection trigger primary biliary cirrhosis?

Patients with primary biliary cirrhosis develop progressive ductopenia associated with the production of antimitochondrial antibodies that react with a protein aberrantly expressed on biliary epithelial cells and peri-hepatic lymph nodes. Although no specific microbe has been identified, it is thought that an infectious agent triggers this autoimmune liver disease in genetically predisposed individuals. Previous serologic studies have provided evidence to suggest a viral association with primary biliary cirrhosis. Here we describe the identification of viral particles in biliary epithelium by electron microscopy and the cloning of exogenous retroviral nucleotide sequences from patients with primary biliary cirrhosis. The putative agent is referred to as the human betaretrovirus because it shares close homology with the murine mammary tumor virus and a human retrovirus cloned from breast cancer tissue. In vivo, we have found that the majority of patients with primary biliary cirrhosis have both RT-PCR and immunohistochemistry evidence of human betaretrovirus infection in lymph nodes. Moreover, the viral proteins colocalize to cells demonstrating aberrant autoantigen expression. In vitro, we have found that lymph node homogenates from patients with primary biliary cirrhosis can induce autoantigen expression in normal biliary epithelial cells in coculture. Normal biliary epithelial cells also develop the phenotypic manifestation of primary biliary cirrhosis when cocultivated in serial passage with supernatants containing the human betaretrovirus or the murine mammary tumor virus, providing a model to test Koch's postulates in vitro.

Distribution of the attachment (G) glycoprotein and GM1 within the envelope of mature respiratory syncytial virus filaments revealed using field emission scanning electron microscopy.

Field emission scanning electron microscopy (FE SEM) was used to visualize the distribution of virus-associated components, the virus-attachment (G) protein, and the host-cell-derived lipid, GM1, in respiratory syncytial virus (RSV) filaments. RSV-infected cells were labeled in situ with a G protein antibody (MAb30) whose presence was detected using a second antibody conjugated to colloidal gold. No bound MAb30 was detected in mock-infected cells, whereas significant quantities bound to viral filaments revealing G protein clusters throughout the filaments. GM1 was detected using cholera toxin B subunit conjugated to colloidal gold. Mock-infected cells revealed numerous GM1 clusters on the cell surface. In RSV-infected cells, these gold clusters were detected on the filaments in low, but significant, amounts, indicating the incorporation of GM1 within the viral envelope. This report describes the first use of FE SEM to map the distribution of specific structural components within the envelope of a Paramyxovirus.

pH reduction as a trigger for dissociation of herpes simplex virus type 1 scaffolds.

Assembly of the infectious herpes simplex virus type 1 virion is a complex, multistage process that begins with the production of a procapsid, which is formed by the condensation of capsid shell proteins around an internal scaffold fashioned from multiple copies of the scaffolding protein, pre-VP22a. The ability of pre-VP22a to interact with itself is an essential feature of this process. However, this self-interaction must subsequently be reversed to allow the scaffolding proteins to exit from the capsid to make room for the viral genome to be packaged. The nature of the process by which dissociation of the scaffold is accomplished is unknown. Therefore, to investigate this process, the properties of isolated scaffold particles were investigated. Electron microscopy and gradient sedimentation studies showed that the particles could be dissociated by low concentrations of chaotropic agents and by moderate reductions in pH (from 7.2 to 5.5). Fluorescence spectroscopy and circular dichroism analyses revealed that there was relatively little change in tertiary and secondary structures under these conditions, indicating that major structural transformations are not required for the dissociation process. We suggest the possibility that dissociation of the scaffold may be triggered by a reduction in pH brought about by the entry of the viral DNA into the capsid.

The products of human cytomegalovirus genes UL23, UL24, UL43 and US22 are tegument components.

We have investigated the human cytomegalovirus (HCMV) US22 gene family members UL23, UL24, UL43 and US22. Specific antibodies were generated to identify pUL23 (33 kDa), pUL24 (40 kDa) and pUL43 (48 kDa), while pUS22 was identified by monoclonal antibody HWLF1. A C-terminally truncated UL43 product (pUL43t; 21 kDa) produced by a deletion mutant was also investigated. The UL24 and UL43 genes were expressed with early-late (gamma1) and true-late (gamma2) kinetics, respectively. Immunoblot and immuno-EM studies demonstrated that pUL23, pUL24, pUL43 and pUS22 were virion tegument components. Immunofluorescence and immuno-EM studies showed that pUL23, pUL24, pUL43 and pUL43t were located in cytoplasmic protein aggregates, manifesting two forms: complex juxtanuclear structures and smaller, membrane-bound aggregates resembling dense bodies. The complex-type aggregate is a putative site of particle maturation. Because pUL43t was present in protein aggregates, but under-represented in virus particles compared to pUL43, it was concluded that N-terminal sequences target pUL43 to protein aggregates and that C-terminal sequences are important for incorporation into particles. Since three other US22 family products (pUL36, pTRS1 and pIRS1) are documented tegument components, at least seven of the twelve US22 family genes encode tegument proteins, suggesting that the products of the remaining five genes might be similarly located. These findings demonstrate a common biological feature among most, if not all, US22 family proteins and implicate the family in events occurring immediately after virus penetration.

Caveolin-1 is incorporated into mature respiratory syncytial virus particles during virus assembly on the surface of virus-infected cells.

We have employed immunofluorescence microscopy and transmission electron microscopy to examine the assembly and maturation of respiratory syncytial virus (RSV) in the Vero cell line C1008. RSV matures at the apical cell surface in a filamentous form that extends from the plasma membrane. We observed that inclusion bodies containing viral ribonucleoprotein (RNP) cores predominantly appeared immediately below the plasma membrane, from where RSV filaments form during maturation at the cell surface. A comparison of mock-infected and RSV-infected cells by confocal microscopy revealed a significant change in the pattern of caveolin-1 (cav-1) fluorescence staining. Analysis by immuno-electron microscopy showed that RSV filaments formed in close proximity to cav-1 clusters at the cell surface membrane. In addition, immuno-electron microscopy showed that cav-1 was closely associated with early budding RSV. Further analysis by confocal microscopy showed that cav-1 was subsequently incorporated into the envelope of RSV filaments maturing on the host cell membrane, but was not associated with other virus structures such as the viral RNPs. Although cav-1 was incorporated into the mature virus, it was localized in clusters rather than being uniformly distributed along the length of the viral filaments. Furthermore, when RSV particles in the tissue culture medium from infected cells were examined by immuno-negative staining, the presence of cav-1 on the viral envelope was clearly demonstrated. Collectively, these findings show that cav-1 is incorporated into the envelope of mature RSV particles during egress.

Open access endoscopy in rural and remote Western Australia: does it work?

BACKGROUND: Access to diagnostic endoscopy is limited in rural and remote Western Australia. Published reports suggest open access referrals may result in over-servicing, this is reduced by adherence to the American Society for Gastrointestinal Endoscopy (ASGE) guidelines. The aim was to assess whether an outreach surgical service offering open access endoscopy to rural areas was being over utilized. METHODS: Prospective data collection from all patients undergoing upper and lower endoscopy procedures between January 1996 and June 2000 were included in the present study. Indications for referral between the general practitioners and the visiting surgeons were reviewed in patient records and assessed for compliance with the ASGE guidelines. The groups were analysed for appropriateness of referrals and frequency of positive pathology investigations. Records for all patients undergoing colonoscopy were reviewed to determine the reason and number of cancelled procedures. RESULTS: A total of 772 endoscopies were performed and 75% were booked as open access services. The referral rate for procedures was greater for general practitioners (583) compared to the visiting surgeons (189), the overall compliance rate for approved indications using the ASGE guidelines for both groups was 92%. There was no significant difference in pathology found between groups. CONCLUSION: The present study shows that an outreach rural surgical service programme in Western Australia offering open access endoscopy conforms to international guidelines and does not induce unnecessary procedures. Rural patients benefit from a personal cost savings and convenience. There is an associated reduction in government-assisted travel costs to larger centres as well as decreased waiting lists.

Furin cleavage of the respiratory syncytial virus fusion protein is not a requirement for its transport to the surface of virus-infected cells.

The intracellular cleavage of respiratory syncytial virus (RSV) fusion (F) protein by furin was examined. In RSV-infected LoVo cells, which express an inactive form of furin, and in RSV-infected Vero cells treated with the furin inhibitor decanoyl-Arg-Val-Lys-Arg-chloromethyl ketone (dec-RVKR-cmk), the F protein was expressed as a non-cleaved 73 kDa species. In both cases the F protein was initially expressed as an endoglycosidase H (Endo H)-sensitive precursor (F0(EHs)) which was modified approximately 40 min post-synthesis by the addition of complex carbohydrates to produce the Endo H-resistant form (F0(EHr)). The size and glycosylation state of F0(EHr) were identical to a transient intermediate form of non-cleaved F protein which was detected in RSV-infected Vero cells in the absence of inhibitor. Cell surface biotinylation and surface immunofluorescence staining showed that F0(EHr) was present on the surface of RSV-infected cells. RSV filaments have been shown to be the predominant form of the budding virus that is detected during virus replication. Analysis of the RSV-infected cells using scanning electron microscopy (SEM) showed that, in the presence of dec-RVKR-cmk, virus budding was impaired, producing fewer and much smaller viral filaments than in untreated cells. A comparison of immunofluorescence and SEM data showed that F0(EHr) was routed to the surface of virus-infected cells but not located in these smaller structures. Our findings suggest that activation of the F protein is required for the efficient formation of RSV filaments.