Outcome and technical consideration of conversion total hip arthroplasty after failed fixation of intracapsular and extracapsular hip fractures: Are they really that different?

INTRODUCTION

Conversion Total Hip Arthroplasty (cTHA) is a rescue strategy for proximal femur osteosynthesis failures. However, it is unclear whether cTHAs performed for extra-capsular fracture fixation failures (ECF) or for intra-capsular fracture fixation failures (ICF) share the same complexity and efficacy. The purpose of our study was to compare cTHAs performed on pre-existing ICFs and pre-existing ECFs, focusing on surgical complications and functional outcomes in both groups.

METHODS

An observational retrospective study was conducted on cTHA patients, treated between 2014 and 2018, divided into 2 groups: ICF-group and ECF-group. The main outcomes were: type of implant used, duration of surgery, need for transfusions, incidence of complications, functional outcomes.

RESULTS

28 patients were included (15 in the ECF group and 13 in the ICF group); the average follow-up was of 31 ± 17.3 months. No significant differences were identified in terms of the type of implant used and duration of surgery. The number of transfused patients was 4 in the ICF group and 12 in the ECF group (p = 0.02); the average transfused units were 0.4 ± 0.7 in the ICF group and 1.3 ± 0.9 in the ECF group (p = 0.01). The incidence of complications - an infection and a dislocation, both of which occurred in the ICF group - and functional outcomes did not present significant differences.

CONCLUSION

The conversion surgery on ECFs patients is technically more difficult for the surgeon and prone to greater blood loss. The outcomes are satisfactory and overlap between the two groups.

Assessment and therapeutic choice in septic arthritis of the hip in an intravenous drug abuser: case report at 14 years follow-up and review of literature

INTRODUCTION

Osteoarticular infections are found frequently in drug addicted individuals, representing one of the main reasons for their hospitalization. Through inoculation, the pathogenic agents can enter the individual's system directly through the skin or parenterally, transmitted, that is, through syringes and other objects used during such practice. In these particular conditions, or when the medical history is vague, a warranted suspicion and the execution of targeted research can help in the diagnosis of high-risk patients such as addicts.

DISCUSSION

With this paper, the Authors are presenting a case of septic arthritis in the hip joint, in a drug addicted patient with the habit of injecting narcotics into the femoral vein, in correspondence of the anatomical region known as the triangle of Scarpa. Following an examination of the bacterial culture samples taken by arthrocentesis, the S. Aureus infection was identified and a targeted antibiotic therapy (coxacillin and aminoglycosides) was prescribed. After one year, with clinical examination and medical scans resulting negative for infection, there was a remaining deformity of the femoral head and, therefore, a total hip arthroplasty (THA) was performed. The 14 year post-operative clinical examination and medical scan check-up showed a complete articular functionality and recovery of normal daily and work related activities.

Survey of laboratory-acquired infections around the world in biosafety level 3 and 4 laboratories

Laboratory-acquired infections due to a variety of bacteria, viruses, parasites, and fungi have been described over the last century, and laboratory workers are at risk of exposure to these infectious agents. However, reporting laboratory-associated infections has been largely voluntary, and there is no way to determine the real number of people involved or to know the precise risks for workers. In this study, an international survey based on volunteering was conducted in biosafety level 3 and 4 laboratories to determine the number of laboratory-acquired infections and the possible underlying causes of these contaminations. The analysis of the survey reveals that laboratory-acquired infections have been infrequent and even rare in recent years, and human errors represent a very high percentage of the cases. Today, most risks from biological hazards can be reduced through the use of appropriate procedures and techniques, containment devices and facilities, and the training of personnel.

Functional Interaction Between the ESCRT-I Component TSG101 and the HSV-1 Tegument Ubiquitin Specific Protease

Similar to phosphorylation, transient conjugation of ubiquitin to target proteins (ubiquitination) mediated by the concerted action of ubiquitin ligases and de-ubiquitinating enzymes (DUBs) can affect substrate function. As obligate intracellular parasites, viruses rely on different cellular pathways for their own replication and the well conserved ubiquitin conjugating/de-conjugating system is not an exception. Viruses not only usurp the host proteins involved in the ubiquitination/de-ubiquitination process, but they also encode their own ubiquitin ligases and DUBs. Here we report that an N-terminal variant of the herpes simplex virus (HSV) type-1 large tegument protein VP1/2 (VP1/2(1-767)), encompassing an active DUB domain (herpesvirus tegument ubiquitin specific protease, htUSP), and TSG101, a component of the endosomal sorting complex required for transport (ESCRT)-I, functionally interact. In particular, VP1/2(1-767) modulates TSG101 ubiquitination and influences its intracellular distribution. Given the role played by the ESCRT machinery in crucial steps of both cellular pathways and viral life cycle, the identification of TSG101 as a cellular target for the HSV-1 specific de-ubiquitinating enzyme contributes to the clarification of the still under debate function of viral encoded DUBs highly conserved throughout the Herpesviridae family.

Autochthonous Hookworm-Related Cutaneous Larva Migrans Disease in Northeastern Italy: A Case Report

Here we report the case of a 42-yr-old patient who presented himself to us with a serpiginous erythematous lesion from the wrist of the right forearm up the arm to the right shoulder A similar lesion of a smaller size was also present in the left forearm. On the basis of clinical manifestations and progression of the lesion, combined with previous treatments and different diagnostic investigations, hookworm-related cutaneous larva migrans (HrCLM) disease was hypothesized. Albendazole was employed as treatment and the resolution of the symptoms confirmed the diagnosis. The relevance of the reported case relies on 3 main aspects: the acquisition of the disease in Italy, the initial treatment with topical corticosteroids that sped up the progression of the cutaneous trail, and the uncommon location of the lesions. Furthermore, the anamnestic data and the laboratory/clinical investigations strongly suggested an occupational exposure to the etiological agent. As illustrated here, HrCLM might represent a challenge for Western physicians in terms of diagnosis, treatment, and ways of acquisition. Describing the clinical presentation and the treatment of cases of cutaneous larva migrans might contribute to early and correct diagnosis, to an increase of our knowledge on this disease, and to an update on its epidemiology.

Metal ion levels from well-functioning Birmingham Hip Resurfacings decline significantly at ten years

A retrospective study was conducted to investigate the changes in metal ion levels in a consecutive series of Birmingham Hip Resurfacings (BHRs) at a minimum ten-year follow-up. We reviewed 250 BHRs implanted in 232 patients between 1998 and 2001. Implant survival, clinical outcome (Harris hip score), radiographs and serum chromium (Cr) and cobalt (Co) ion levels were assessed. Of 232 patients, 18 were dead (five bilateral BHRs), 15 lost to follow-up and ten had been revised. The remaining 202 BHRs in 190 patients (136 men and 54 women; mean age at surgery 50.5 years (17 to 76)) were evaluated at a minimum follow-up of ten years (mean 10.8 years (10 to 13.6)). The overall implant survival at 13.2 years was 92.4% (95% confidence interval 90.8 to 94.0). The mean Harris hip score was 97.7 (median 100; 65 to 100). Median and mean ion levels were low for unilateral resurfacings (Cr: median 1.3 µg/l, mean 1.95 µg/l (< 0.5 to 16.2); Co: median 1.0 µg/l, mean 1.62 µg/l (< 0.5 to 17.3)) and bilateral resurfacings (Cr: median 3.2 µg/l, mean 3.46 µg/l (< 0.5 to 10.0); Co: median 2.3 µg/l, mean 2.66 µg/l (< 0.5 to 9.5)). In 80 unilateral BHRs with sequential ion measurements, Cr and Co levels were found to decrease significantly (p < 0.001) from the initial assessment at a median of six years (4 to 8) to the last assessment at a median of 11 years (9 to 13), with a mean reduction of 1.24 µg/l for Cr and 0.88 µg/l for Co. Three female patients had a > 2.5 µg/l increase of Co ions, associated with head sizes ≤ 50 mm, clinical symptoms and osteolysis. Overall, there was no significant difference in change of ion levels between genders (Cr, p = 0.845; Co, p = 0.310) or component sizes (Cr, p = 0.505; Co, p = 0.370). Higher acetabular component inclination angles correlated with greater change in ion levels (Cr, p = 0.013; Co, p = 0.002). Patients with increased ion levels had lower Harris hip scores (p = 0.038). In conclusion, in well-functioning BHRs the metal ion levels decreased significantly at ten years. An increase > 2.5 µg/l was associated with poor function.

HIV-1-mediated delivery of a short hairpin RNA targeting vascular endothelial growth factor in human retinal pigment epithelium cells

BACKGROUND

Vascular endothelial growth factor (VEGF) has been shown to play a major role in the pathological neovascularisation that occurs in degenerative retinal diseases like age-related macular degeneration (AMD). Although several approaches to attenuate VEGF show significant promise, repeated treatments are required to achieve therapeutic benefits. As lentiviruses efficiently and stably infect resting cells, a human immunodeficiency virus type 1 (HIV-1)-based vector was used for the delivery and long-term endogenous expression of a short hairpin RNA (shRNA) specific for VEGF in postmitotic human retinal pigment epithelium (RPE) cells.

METHODS

An HIV-1 vector expressing a shRNA targeting VEGF was developed and adopted to transduce RPE cell cultures, in both normoxic and hypoxic conditions in vitro. Intracellular VEGF expression was analysed by western blotting, and the release of VEGF in culture supernatants was determined by ELISA.

RESULTS

At least 90% of RPE cells were successfully transduced by HIV-1 virions. Inhibition of VEGF expression and reduction by 95% of VEGF release in transduced cells were achieved. Moreover, shRNA-VEGF effectively and specifically prevented hypoxia-induced VEGF upregulation.

CONCLUSION

HIV-1-mediated delivery of a shRNA-VEGF leading to gene expression knockdown could represent a novel therapeutic strategy against neovascularisation-related eye diseases.

Role of multivesicular bodies and their components in the egress of enveloped RNA viruses

As an enveloped virus buds, the nascent viral capsid becomes wrapped in a plasma membrane-derived lipid envelope, and a membrane fission event is thus necessary to separate the virion from the host cell. This membrane fission event is well characterised in the case of enveloped RNA viruses, where it is promoted by late assembly domains (L-domains) present at the level of specific viral structural proteins. Research conducted over the past 10 years has demonstrated that L-domains represent docking sites for cellular proteins essential for the biogenesis of a cellular organelle, the multivesicular body (MVB). In this way, enveloped RNA viruses hijack the MVB components to the cellular site where the budding is executed. This review will focus on the cellular machinery exploited by enveloped RNA viruses in order to be released from infected cells. The role of ubiquitin and lipids in viral budding will also be discussed.

Analysis of human immunodeficiency virus type 1 vector cis- and trans-acting elements production by means of Semliki Forest virus

Recombinant Semliki Forest virus (SFV) is an attractive viral vector system owing to its ability to allow high efficiency of viral protein expression. To produce recombinant pseudotyped human immunodeficiency virus type 1 (HIV-1) virions, we designed a chimeric SFV/HIV vector system that contains both the HIV-1 cis- and trans-acting elements under the transcriptional control of the SFV replicase and investigated the ability of the hybrid SFV/HIV system to produce lentiviral particles capable of transducing target cells. Co-transfection of target cells with the two helper SFV packaging system RNAs along with each SFV/Gag-Pol, SFV/VSV(G) as well as SFV/HIV-1 vector unit replicon led to the generation of efficient transducing competent recombinant SFV/HIV particles. In contrast, co-transduction of target cells with the SFV/HIV chimeric virions produced recombinant particles with low transducing ability. Our data suggest that both the genomic and the subgenomic RNAs containing the HIV-1 vector unit were negatively selected for incorporation into recombinant particles, despite the fact that the SFV-driven HIV-1 vector replicon was the only one containing a lentiviral packaging sequence. The results of this study provide insights relevant to the design of chimeric lentiviral vectors.

Oncolysis of pancreatic tumour cells by a γ34.5-deleted HSV-1 does not rely upon Ras-activation, but on the PI 3-kinase pathway

The ability of viruses to selectively target, replicate within, and destroy tumour cells without deleterious effects in normal cells (oncolysis), makes the use of viruses as an attractive tool for cancer treatment. Pancreatic adenocarcinoma, being insensitive to traditional therapy and having a rather poor prognosis, represents a suitable target to evaluate viral oncolysis as a novel therapeutic approach. Herpes simplex virus (HSV) has been reported to produce an oncolytic effect in cells overexpressing Ras. As Ras signalling is frequently aberrant in pancreatic cancer, we compared four pancreatic cell lines (which differ in the presence of mutated or wild-type ras) for their ability to support growth of gamma34.5-replication attenuated HSV-1 (R3616). Our data show that permissiveness to viral replication is neither associated with enhanced Ras signalling nor with defective PKR activity. By contrast, we provide evidence that disregulation of the PI 3-kinase signalling pathway allows conditionally replication-defective R3616 virus to overcome the cellular antiviral activity.

Back pain in pregnancy: 1-year follow-up of untreated cases

Back Pain (BP) is one of the most frequent symptoms during the last period of pregnancy, and high incidence has been described in several studies. Until now no wide, multicenter and prospective clinical studies on the natural course of BP after pregnancy have been available. We performed a multicenter follow-up study in a sample of pregnant women using the Italian validated version of the Roland questionnaire to assess the evolution of BP after pregnancy and identify prognostic factors. Each center had to re-evaluate at least 75% of the initially enrolled women, with latency of 1 year after delivery. At the follow-up, we acquired substantial clinical data concerning the post-delivery period. The evaluation of symptom evolution was based on the Roland questionnaire. At follow-up, 53% of re-evaluated women had no BP symptoms. Moreover, there was a significant improvement of patient-oriented assessment in women who suffered BP after delivery. With regard to the predictive factors, the presence of BP before pregnancy implied a 3.1-fold higher probability of improvement after delivery. In conclusion, women without history of BP before pregnancy and who complain of these symptoms during pregnancy require greater attention, because they have a lower possibility for improvement. Conversely, in women with a history of BP, pregnancy represents a transient period of worsening symptoms, probably due to the temporary para-physiological mechanical condition.

Brain resistance to HSV-1 encephalitis in a mouse model

Brain resistance to intracerebral superinfections develops after a peripheral inoculation of neurovirulent viruses. Superinfection resistance combines specificity, toward the virus used for the peripheral inoculum, and short-term duration after the inoculum. In order to study this unusual combination, neurovirulent superinfections were made on albino Swiss mice previously infected with a nasal inoculum. A herpesvirus strain SC16, or a homologue recombinant virus carrying the reporter lac Z gene or a vesicular stomatitis virus (VSV) (a virus taxonomically unrelated to Herpesviridae) were used. The mice underwent a neurological examination and their survival rate was recorded. The brains superinfected with the reporter virus were stained for the beta-galactosidase reaction to trace the virus spread and the inflammatory infiltrates were characterized immunocytochemically. The results confirm and extend previous observations about virus specificity and short-term duration of superinfection resistance. They show, moreover, an enhanced brain inflammation with T-cells and macrophages infiltrating the tissue around microvessels, at a time when both neurovirulence and the spread of herpesvirus in the brain are reduced. The results suggest that the immune response to superinfection in the nervous tissue is enhanced by blood-brain barrier mechanisms that promote the timely extravasation of immune cells.

Evaluation of a near-patient test and 2 enzyme-linked immunosorbent assay-based assays for detecting anti-herpes simplex virus type-2 antibodies

Several type-specific serologic assays for herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), based on glycoprotein G1 (gG1) and gG2, have recently been developed. These include immunodot (POCkit HSV-2) and enzyme-linked immunosorbent assay (ELISA). The diagnostic value of POCkit HSV-2, a near-patient test, and of 2 immunoenzymatic, type-specific assays was evaluated on 122 patients attending an STD clinic. Western blot was used as the reference test. The sensitivity of POCkit HSV-2 was good but the specificity was poor, so that in a population with low seroprevalence, a positive result is likely to be a false positive. Analysis of 2 currently available HSV type-specific ELISAs yielded results suggesting that the sensitivity of these tests may also be suboptimal.

Molecular basis of the interactions between herpes simplex viruses and HIV-1

Herpes simplex virus types 1 and 2 (HSV-1 and -2) are two of the major opportunistic agents involved in the pathogenesis of AIDS, which is caused by human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2). A body of evidence suggests that they can also act as co-factors by interacting with HIV-1, thereby influencing disease progression. Indeed, the HIV-1 life cycle can be affected by HSV at different levels of interaction, both in vitro and in vivo: (i) transactivation of the HIV-1 long terminal repeat can be mediated, probably through different pathways, by HSV-1-infected cell protein (ICP)0, ICP4, ICP27 and US11 gene products; the HSV-1 transactivator viral protein 16 is not able to transactivate the long terminal repeat; (ii) cytokine release and antigen presentation from HSV-infected cells are both able to stimulate HIV-1 expression; (iii) Pseudotyping of the HIV-1 core particle with HSV-1 envelope glycoproteins can expand HIV-1 tropism to new cell types. Moreover, in vivo studies report that aciclovir treatment can produce a survival benefit in HIV-1-infected patients and that recurrent genital herpes appears to be linked to HIV-1 transmission by both boosting plasma retroviral load and providing a portal of entry and exit for HIV-1.

A role for ubiquitin ligase recruitment in retrovirus release

Retroviral Gag polyproteins have specific regions, commonly referred to as late assembly (L) domains, which are required for the efficient separation of assembled virions from the host cell. The L domain of HIV-1 is in the C-terminal p6(gag) domain and contains an essential P(T/S)AP core motif that is widely conserved among lentiviruses. In contrast, the L domains of oncoretroviruses such as Rous sarcoma virus (RSV) have a more N-terminal location and a PPxY core motif. In the present study, we used chimeric Gag constructs to probe for L domain activity, and observed that the unrelated L domains of RSV and HIV-1 both induced the appearance of Gag-ubiquitin conjugates in virus-like particles (VLP). Furthermore, a single-amino acid substitution that abolished the activity of the RSV L domain in VLP release also abrogated its ability to induce Gag ubiquitination. Particularly robust Gag ubiquitination and enhancement of VLP release were observed in the presence of the candidate L domain of Ebola virus, which contains overlapping P(T/S)AP and PPxY motifs. The release defect of a minimal Gag construct could also be corrected through the attachment of a peptide that serves as a physiological docking site for the ubiquitin ligase Nedd4. Furthermore, VLP formation by a full-length Gag polyprotein was sensitive to lactacystin, which depletes the levels of free ubiquitin through inhibition of the proteasome. Our findings suggest that the engagement of the ubiquitin conjugation machinery by L domains plays a crucial role in the release of a diverse group of enveloped viruses.

6-Aminoquinolones as new potential anti-HIV agents

A series of 6-aminoquinolone compounds were evaluated for their in vitro activity against human immunodeficiency virus type 1 (HIV-1). Compound 12a, bearing a methyl substituent at the N-1 position and a 4-(2-pyridyl)-1-piperazine moiety at the C-7 position, was the most active in inhibiting HIV-1 replication on de novo infected C8166 human lymphoblastoid cell lines. The 12a EC(50) value was 0.1 microM, a 7-20-fold lower concentration relative to that for compounds 8a and 7a containing a cyclopropyl and tert-butyl substituent at the N-1 position, respectively. When the C-6 amino group was replaced with a fluorine atom, a decreased antiviral effect was observed. The observed effects are selective, since potency is substantially reduced when testing the compounds against the herpes simplex virus type 1 (HSV-1). Active quinolone derivatives very efficiently interact with TAR RNA, which suggests a nucleic acid-targeted mechanism of action.

Asymptomatic herpes simplex type 1 virus infection of the mouse brain

An asymptomatic and transitory brain infection takes place in adult Swiss CD-1 mice after intranasal inoculation of HSV-1 strain SC16. Time course and distribution of the infection in the brain are demonstrated, (i) by titration of the nasal tissue and olfactory bulbs for 16 days post-infection (p.i.), showing a maximum production yield on day 7 p.i. and no replicating virus on day 16 p. i.; (ii) expression in the brain of the lac Z reporter gene of HSV-1 strain SC16-DeltaUS5-lac Z consistent with a central spread of the virus through the central olfactory pathways and the trigeminal system as described in acute HSV-1 encephalitis models; (iii) PCR amplifications of a segment of the thymidine kinase gene (HSV-tk) showing the persistence of viral genome in the nasal tissue and olfactory bulbs after clearance of infectious virus. The asymptomatic character of the infection is demonstrated over 2 months p.i. (i) by normal body weight; (ii) a neurological survey which excludes motor, sensory, balance and postural signs; (iii) two behavioral tests, the open-field test for exploratory activity and the cookie-finding test for olfactory search. On the other hand, intracerebral inocula cause encephalitis and death in a few days (LD50 ca. 14 p.f.u.). Intracranial, surgical transection of one olfactory nerve does not prevent infection of the corresponding bulb nor does it modify virus distribution, suggesting multiple entry routes from the nasal cavity to the brain. In conclusion, HSV-1 strain SC16 reaches the brain of CD-1 mice from the nasal cavity and replicates without neurological or behavioral signs.

Herpes simplex virus chronically infected human T lymphocytes are susceptible to HIV-1 superinfection and support HIV-1 pseudotyping

Peripheral blood lymphocytes (PBL) and CEM CD4+ T-cell line can be infected by herpes simplex virus-1 (HSV-1). CEM cells were characterized as a cellular model to study interactions occurring between HSV-1 and HIV-1. Virtually all cells were persistently infected by HSV-1 (CEM(HSV)) and expressed the latency associated transcripts, whereas only a fraction tested positive for HSV-antigens. CD4 and CXCR-4 expression and function were not affected in CEM(HSV) cells and no significant increase of deoxyribonucleotide pools was noticed. Superinfection of CEM(HSV) cells with HIV-1 led to a cell line chronically infected by both viruses (CEM(HSV/HSV)). Evidence was also obtained that this cell line can produce HIV-1 pseudotyped by HSV-1 envelope. These results may have important implications for a better understanding of AIDS pathogenesis.