COL1A1 C-propeptide cleavage site mutation causes high bone mass, bone fragility and jaw lesions: A new cause of gnathodiaphyseal dysplasia?

Gnathodiaphyseal dysplasia (GDD) is a rare autosomal dominant condition characterized by bone fragility, irregular bone mineral density (BMD) and fibro-osseous lesions in the skull and jaw. Mutations in Anoctamin-5 (ANO5) have been identified in some cases. We aimed to identify the causative mutation in a family with features of GDD but no mutation in ANO5, using whole exome capture and massive parallel sequencing (WES). WES of two affected individuals (a mother and son) and the mother's unaffected parents identified a mutation in the C-propeptide cleavage site of COL1A1. Similar mutations have been reported in individuals with osteogenesis imperfecta (OI) and paradoxically increased BMD. C-propeptide cleavage site mutations in COL1A1 may not only cause 'high bone mass OI', but also the clinical features of GDD, specifically irregular sclerotic BMD and fibro-osseous lesions in the skull and jaw. GDD patients negative for ANO5 mutations should be assessed for mutations in type I collagen C-propeptide cleavage sites.

Infection and cellular defense dynamics in a novel 17beta-estradiol murine model of chronic human group B streptococcus genital tract colonization reveal a role for hemolysin in persistence and neutrophil accumulation

Genital tract carriage of group B streptococcus (GBS) is prevalent among adult women; however, the dynamics of chronic GBS genital tract carriage, including how GBS persists in this immunologically active host niche long term, are not well defined. To our knowledge, in this study, we report the first animal model of chronic GBS genital tract colonization using female mice synchronized into estrus by delivery of 17β-estradiol prior to intravaginal challenge with wild-type GBS 874391. Cervicovaginal swabs, which were used to measure bacterial persistence, showed that GBS colonized the vaginal mucosa of mice at high numbers (106–107 CFU/swab) for at least 90 d. Cellular and histological analyses showed that chronic GBS colonization of the murine genital tract caused significant lymphocyte and PMN cell infiltrates, which were localized to the vaginal mucosal surface. Long-term colonization was independent of regular hormone cycling. Immunological analyses of 23 soluble proteins related to chemotaxis and inflammation showed that the host response to GBS in the genital tract comprised markers of innate immune activation including cytokines such as GM-CSF and TNF-α. A nonhemolytic isogenic mutant of GBS 874391, Δcyle9, was impaired for colonization and was associated with amplified local PMN responses. Induction of DNA neutrophil extracellular traps, which was observed in GBS-infected human PMNs in vitro in a hemolysin-dependent manner, appeared to be part of this response. Overall, this study defines key infection dynamics in a novel murine model of chronic GBS genital tract colonization and establishes previously unknown cellular and soluble defense responses to GBS in the female genital tract.

Pathogens penetrating the central nervous system: Infection pathways and the cellular and molecular mechanisms of invasion

The brain is well protected against microbial invasion by cellular barriers, such as the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). In addition, cells within the central nervous system (CNS) are capable of producing an immune response against invading pathogens. Nonetheless, a range of pathogenic microbes make their way to the CNS, and the resulting infections can cause significant morbidity and mortality. Bacteria, amoebae, fungi, and viruses are capable of CNS invasion, with the latter using axonal transport as a common route of infection. In this review, we compare the mechanisms by which bacterial pathogens reach the CNS and infect the brain. In particular, we focus on recent data regarding mechanisms of bacterial translocation from the nasal mucosa to the brain, which represents a little explored pathway of bacterial invasion but has been proposed as being particularly important in explaining how infection with Burkholderia pseudomallei can result in melioidosis encephalomyelitis.

TMIO-pyrimid hybrids are profluorescent, site-directed spin labels for nucleic acids

We report the synthesis of a new class of molecules which are hybrids of long-lived tetramethylisoindolinoxyl (TMIO) radicals and the pyrido[1,2-a]benzimidazole (PyrImid) scaffold. These compounds represent a new lead for noncovalently binding nucleic acid probes, as they interact with nucleic acids with previously unreported C (DNA) and C/U (RNA) complementarity, which can be detected by electron paramagnetic resonance (EPR) techniques. They also have promising properties for fluorimetric analysis, as their fluorescent spin-quenched derivatives exhibit a significant Stokes shift

Tissue requirements for establishing long-term CD4+ T cell-mediated immunity following Leishmania donovani infection

Organ-specific immunity is a feature of many infectious diseases, including visceral leishmaniasis caused by Leishmania donovani. Experimental visceral leishmaniasis in genetically susceptible mice is characterized by an acute, resolving infection in the liver and chronic infection in the spleen. CD4+ T cell responses are critical for the establishment and maintenance of hepatic immunity in this disease model, but their role in chronically infected spleens remains unclear. In this study, we show that dendritic cells are critical for CD4+ T cell activation and expansion in all tissue sites examined. We found that FTY720-mediated blockade of T cell trafficking early in infection prevented Ag-specific CD4+ T cells from appearing in lymph nodes, but not the spleen and liver, suggesting that early CD4+ T cell priming does not occur in liver-draining lymph nodes. Extended treatment with FTY720 over the first month of infection increased parasite burdens, although this associated with blockade of lymphocyte egress from secondary lymphoid tissue, as well as with more generalized splenic lymphopenia. Importantly, we demonstrate that CD4+ T cells are required for the establishment and maintenance of antiparasitic immunity in the liver, as well as for immune surveillance and suppression of parasite outgrowth in chronically infected spleens. Finally, although early CD4+ T cell priming appeared to occur most effectively in the spleen, we unexpectedly revealed that protective CD4+ T cell-mediated hepatic immunity could be generated in the complete absence of all secondary lymphoid tissues.

Probabilistic assessment of herbicide runoff from Japanese rice paddies: The effects of local meteorological conditions and site-specific water management

Uncertainty assessments of herbicide losses from rice paddies in Japan associated with local meteorological conditions and water management practices were performed using a pesticide fate and transport model, PCPF-1, under the Monte Carlo (MC) simulation scheme. First, MC simulations were conducted for five different cities with a prescribed water management scenario and a 10-year meteorological dataset of each city. The effectiveness of water management was observed regarding the reduction of pesticide runoff. However, a greater potential of pesticide runoff remained in Western Japan. Secondly, an extended analysis was attempted to evaluate the effects of local water management and meteorological conditions between the Chikugo River basin and the Sakura River basin using uncertainty inputs processed from observed water management data. The results showed that because of more severe rainfall events, significant pesticide runoff occurred in the Chikugo River basin even when appropriate irrigation practices were implemented. © Pesticide Science Society of Japan.

Transcutaneous bone-anchoring prosthesis with knee replacement: A novel treatment for amputees

Background Over the last two decades, Transcutaneous Bone-Anchored Prosthesis (TCBAP) has proven to be an effective alternative for prosthetic attachment for amputees, particularly for individuals unable to wear a socket. [1-17] However, the load transmitted through a typical TCBAP to the residual tibia and knee joint can be unbearable for transtibial amputees with knee arthritis. Aim A. To describe the surgical procedure combining TKR with TCBAP for the first time; and B. To present preliminary data on potential risks and benefits with assessment of clinical and functional outcomes at follow up Method We used a TCBAP connected to the tibial base plate of a Total Knee Replacement (TKR) prosthesis enabling the tibial residuum and the knee joint to act as weight sharing structures by transferring the load directly to the femur. We performed a standard hinged TKR connected to a custom made TCBAP at the first stage followed by creating a skin implant interface as a second stage. We retrospectively reviewed four cases of trans-tibial amputations presenting with knee joint arthritis. Patients were assessed clinically and functionally including standard measures of health-related quality of life, amputee mobility predictor tool, ambulation tests and actual activity level. Progress was monitored for 6-24 months. Results Clinical outcomes including adverse events show no major complications but one case of superficial infection. Functional outcomes improved for all participants as early as 6 months follow up. Discussion & Conclusion TKR and TCBAP were combined for the first time in this proof-of-concept case series. The preliminary outcomes indicated that this procedure is potentially a safe and effective alternative for this patient group despite the theoretical increase in risk of ascending infection through the skin-implant interface to the external environment. We suggest larger comparative series to further validate these results.

Transcutaneous bone-anchoring prosthesis with hip replacement: A novel treatment for amputees

Background Over the last two decades, Transcutaneous Bone-Anchored Prosthesis (TCBAP) has proven to be an effective alternative for prosthetic attachment for above knee amputees, particularly for individuals suffering from socket interface related complications. [1-17] Amputees with a very short femoral residuum (<15 cm) are at a considerable higher risk for these complications as well as high risk of implant failure, if they underwent a typical TCBAP due to the relatively small bony-implant contact leading to a need of a novel technique. Aim A. To describe the surgical procedure combining THR with TCBAP for the first time; and B. To present preliminary data on potential risks and benefits with assessment of clinical and functional outcomes at follow up Method We used a TCBAP connected to the stem of a Total Hip Replacement (THR) prosthesis enabling the femoral residuum and the hip joint to act as weight sharing structures by transferring the load directly to the pelvis. We performed a tri-polar THR connected to a custom made TCBAP at the first stage followed by creating a skin implant interface as a second stage. We retrospectively reviewed three cases of transfemoral amputations presenting with extremely short femoral residuum. Patients were assessed clinically and functionally including standard measures of health-related quality of life, amputee mobility predictor tool, ambulation tests and actual activity level. Progress was monitored for 6-24 months. Results Clinical outcomes including adverse events show no major complications. Functional outcomes improved for all participants as early as 6 months follow up. All cases were wheelchair bound preoperatively (K0 – AMPRO) improved to walking with One stick (K3 – AMPRO) at 3 months follow up. Discussion & Conclusion THR and TCBAP were combined for the first time in this proof-of-concept case series. The preliminary outcomes indicated that this procedure is potentially a safe and effective alternative despite the theoretical increase in risk of ascending infection through the skin-implant interface to the external environment for this patient group. We suggest larger comparative series to further validate these results.

Bone-anchored prosthesis: Current developments worldwide and challenges

Background Individuals with limb amputation fitted with conventional socket-suspended prostheses often experience socket related discomfort leading to a significant decrease in quality of life. Most of these concerns can be overcome by surgical techniques enabling bone-anchored prostheses. In this case, the prosthesis is attached directly to the residual skeleton through a percutaneous implant (e.g., screw type fixation, press-fit implant).[46, 48, 51, 52, 77, 78] The aim of this study is to present the current advances in these surgical techniques worldwide with a strong focus on the current challenges. Methods The current advances will be extracted from a systematic literature review including approximately 40 articles. The outcomes measured will include the estimation of the population worldwide as well as the complications (e.g., infection, loosening, fractures, and breakage) and the benefits (e.g., functional outcomes, health-related quality of life).[5-19, 51-53, 55, 57, 58, 62, 73, 79] Results The population of individuals fitted with a bone-anchored prosthesis is approximately 550 worldwide. Publications focusing on infection are sparse. However, the rate of superficial infection is estimated at 20%. Deep infection occurs rarely. Loosening and peri-prosthetic fractures are fairly uncommon. Breakage of implant parts occurs regularly mainly due to fall. All studies reported a significant improvement in functional level and overall quality of life. Conclusions Several commercial implants are in developments in Europe and US. The number of procedures is consistently growing worldwide. This technique might be primary way to fit a prosthesis to young and active amputees by 2025.

Prevalence and risk factors for oral HPV infection in young Australians

The prevalence of human papillomavirus (HPV)–associated head and neck cancers is increasing, but the prevalence of oral HPV infection in the wider community remains unknown. We sought to determine the prevalence of, and identify risk factors for, oral HPV infection in a sample of young, healthy Australians. For this study, we recruited 307 Australian university students (18–35 years). Participants reported anonymously about basic characteristics, sexual behaviour, and alcohol, tobacco and illicit drugs use. We collected oral rinse samples from all participants for HPV testing and typing. Seven of 307 (2.3%) students tested positive for oral HPV infection (3 HPV-18, one each of HPV-16, -67, -69, -90), and six of them were males (p = 0.008). Compared to HPV negative students, those with oral HPV infection were more likely to have received oral sex from more partners in their lifetime (p = 0.0004) and in the last year (p = 0.008). We found no statistically significant associations with alcohol consumption, smoking or numbers of partners for passionate kissing or sexual intercourse. In conclusion, oral HPV infection was associated with male gender and receiving oral sex in our sample of young Australians.

Bone-anchored prosthesis: Current developments worldwide and challenges

Background Individuals with limb amputation fitted with conventional socket-suspended prostheses often experience socket related discomfort leading to a significant decrease in quality of life. Most of these concerns can be overcome by surgical techniques enabling bone-anchored prostheses. In this case, the prosthesis is attached directly to the residual skeleton through a percutaneous implant (e.g., screw type fixation, press-fit implant).[46, 48, 51, 52, 77, 78] The aim of this study is to present the current advances in these surgical techniques worldwide with a strong focus on the current challenges. Methods The current advances will be extracted from a systematic literature review including approximately 40 articles. The outcomes measured will include the estimation of the population worldwide as well as the complications (e.g., infection, loosening, fractures, and breakage) and the benefits (e.g., functional outcomes, health-related quality of life).[5-19, 51-53, 55, 57, 58, 62, 73, 79] Results The population of individuals fitted with a bone-anchored prosthesis is approximately 550 worldwide. Publications focusing on infection are sparse. However, the rate of superficial infection is estimated at 20%. Deep infection occurs rarely. Loosening and peri-prosthetic fractures are fairly uncommon. Breakage of implant parts occurs regularly mainly due to fall. All studies reported a significant improvement in functional level and overall quality of life. Conclusions Several commercial implants are in developments in Europe and US. The number of procedures is consistently growing worldwide. This technique might be primary way to fit a prosthesis to young and active amputees by 2025.

Evaluation framework to assess orthopaedic procedures

Introduction & aims The demand for evidence of efficacy of treatments in general and orthopaedic surgical procedures in particular is ever increasing in Australia and worldwide. The aim of this study is to share the key elements of an evaluation framework recently implemented in Australia to determine the efficacy of bone-anchored prostheses. Method The proposed evaluation framework to determine the benefit and harms of bone-anchored prostheses for individuals with limb loss was extracted from a systematic review of the literature including seminal studies focusing on clinical benefits and safety of procedures involving screw-type implant (e.g., OPRA) and press-fit fixations (e.g., EEFT, ILP, OPL). [1-64] Results The literature review highlighted that a standard and replicable evaluation framework should focus on: • The clinical benefits with a systematic recording of health-related quality of life (e.g., SF-26, Q-TFA), mobility predictor (e.g., AMPRO), ambulation abilities (e.g., TUG, 6MWT), walking abilities (e.g., characteristic spatio-temporal) and actual activity level at baseline and follow-up post Stage 2 surgery, • The potential harms with systematic recording of residuum care, infection, implant stability, implant integrity, injuries (e.g., falls) after Stage 1 surgery. There was a general consensus around the instruments to monitor most of the benefits and harms. The benefits could be assessed using a wide spectrum of complementary assessments ranging from subjective patient self-reporting to objective measurements of physical activity. However, this latter was assessed using a broad range of measurements (e.g., pedometer, load cell, energy consumption). More importantly, the lack of consistent grading of infections was sufficiently noticeable to impede cross-fixation comparisons. Clearly, a more universal grading system is needed. Conclusions Investigators are encouraged to implement an evaluation framework featuring the domains and instruments proposed above using a single database to facilitate robust prospective studies about potential benefits and harms of their procedure. This work is also a milestone in the development of national and international clinical outcome registries.

The significance of controlled conditions in lentiviral vector titration and in the use of multiplicity of infection (MOI) for predicting gene transfer events

Background: Although lentiviral vectors have been widely used for in vitro and in vivo gene therapy researches, there have been few studies systematically examining various conditions that may affect the determination of the number of viable vector particles in a vector preparation and the use of Multiplicity of Infection (MOI) as a parameter for the prediction of gene transfer events. Methods: Lentiviral vectors encoding a marker gene were packaged and supernatants concentrated. The number of viable vector particles was determined by in vitro transduction and fluorescent microscopy and FACs analyses. Various factors that may affect the transduction process, such as vector inoculum volume, target cell number and type, vector decay, variable vector - target cell contact and adsorption periods were studied. MOI between 0-32 was assessed on commonly used cell lines as well as a new cell line. Results: We demonstrated that the resulting values of lentiviral vector titre varied with changes of conditions in the transduction process, including inoculum volume of the vector, the type and number of target cells, vector stability and the length of period of the vector adsorption to target cells. Vector inoculum and the number of target cells determine the frequencies of gene transfer event, although not proportionally. Vector exposure time to target cells also influenced transduction results. Varying these parameters resulted in a greater than 50-fold differences in the vector titre from the same vector stock. Commonly used cell lines in vector titration were less sensitive to lentiviral vector-mediated gene transfer than a new cell line, FRL 19. Within 0-32 of MOI used transducing four different cell lines, the higher the MOI applied, the higher the efficiency of gene transfer obtained. Conclusion: Several variables in the transduction process affected in in vitro vector titration and resulted in vastly different values from the same vector stock, thus complicating the use of MOI for predicting gene transfer events. Commonly used target cell lines underestimated vector titre. However, within a certain range of MOI, it is possible that, if strictly controlled conditions are observed in the vector titration process, including the use of a sensitive cell line, such as FRL 19 for vector titration, lentivector-mediated gene transfer events could be predicted. © 2004 Zhang et al; licensee BioMed Central Ltd.

Site and gender specificity of inheritance of bone mineral density

Differences in genetic control of BMD by skeletal sites and genders were examined by complex segregation analysis in 816 members of 147 families with probands with extreme low BMD. Spine BMD correlated more strongly in male-male comparisons and hip BMD in female-female comparisons, consistent with gender- and site-specificity of BMD heritability. Introduction: Evidence from studies in animals and humans suggests that the genetic control of bone mineral density (BMD) may differ at different skeletal sites and between genders. This question has important implications for the design and interpretation of genetic studies of osteoporosis. Methods: We examined the genetic profile of 147 families with 816 individuals recruited through probands with extreme low BMD (T-score < −2.5, Z-score < −2.0). Complex segregation analysis was performed using the Pedigree Analysis Package. BMD was measured by DXA at both lumbar spine (L1-L4) and femoral neck. Results: Complex segregation analysis excluded purely monogenic and environmental models of segregation of lumbar spine and femoral neck BMD in these families. Pure polygenic models were excluded at the lumbar spine when menopausal status was considered as a covariate, but not at the femoral neck. Mendelian models with a residual polygenic component were not excluded. These models were consistent with the presence of a rare Mendelian genotype of prevalence 3–19 %, causing high BMD at the hip and spine in these families, with additional polygenic effects. Total heritability range at the lumbar spine was 61–67 % and at the femoral neck was 44–67 %. Significant differences in correlation of femoral neck and lumbar spine BMD were observed between male and female relative pairs, with male-male comparisons exhibiting stronger lumbar spine BMD correlation than femoral neck, and female-female comparisons having greater femoral neck BMD correlation than lumbar spine. These findings remained true for parent-offspring correlations when menopausal status was taken into account. The recurrence risk ratio for siblings of probands of a Z-score < −2.0 was 5.4 at the lumbar spine and 5.9 at the femoral neck. Conclusions: These findings support gender- and site-specificity of the inheritance of BMD. These results should be considered in the design and interpretation of genetic studies of osteoporosis.