Case Report: Resolution of high grade anal squamous intraepithelial lesion with antibiotics proposes a new role for syphilitic infection in potentiation of HPV-associated ASCC

Introduction

Human Papillomavirus (HPV) is the primary risk factor for the development of anal intraepithelial neoplasia (AIN) and is a leading risk factor for anogenital squamous cell carcinoma (ASCC). Despite common shared risk factors for both HPV and syphilis, co-infection is not well documented, and the role of syphilitic infection in HPV-associated AIN and ASCC potentiation is not defined.

Case description/methods

A 72-year-old single male presented with complaints of mild rectal pain and intermittent rectal bleeding. A flexible sigmoidoscopy was performed, and a firm 4.5cm x 3cm perianal mass was detected and superficially biopsied. Pathology findings demonstrated evidence of a high grade squamous intraepithelial lesion (HGSIL, AIN II/III/AIS) with viral cytopathic effect, consistent with HPV infection. Much of the biopsied lesion showed acanthotic squamous mucosa with intraepithelial neutrophils and abundant submucosal plasma cells, suggesting possible syphilitic involvement. Subsequent immunohistochemical staining for p16 as a surrogate marker for HPV was positive, as was an immunohistochemical stain for spirochetes, supportive of co-infection with Treponema pallidum pallidum (T. pallidum), the causative agent in venereal syphilis. The patient was referred to an infectious disease specialist for syphilitic infection and was treated with penicillin with surprisingly complete resolution of the lesion. EUAs were performed 2- and 3-months following treatment without lesion recurrence. However, one year following diagnosis, a flexible sigmoidoscopy revealed a 5 mm recurrent HPV-related low-grade AIN 1 lesion at the dentate line.

Discussion

Resolution of the lesion by antibiotic treatment for syphilitic infection suggested that co-infection by T. pallidum may potentiate HPV-associated squamous cell carcinoma based on histological findings. Findings from this case, as well as a review of bacterial involvement and potentiation in various cancers, are reviewed here. Such findings offer new insight regarding the role of STI-associated bacteria and HPV co-infection in the establishment of AIN and may additionally propose new treatment modalities for ASCC.

A new semi-orthotopic bone defect model for cell and biomaterial testing in regenerative medicine

In recent decades, an increasing number of tissue engineered bone grafts have been developed. However, expensive and laborious screenings in vivo are necessary to assess the safety and efficacy of their formulations. Rodents are the first choice for initial in vivo screens but their size limits the dimensions and number of the bone grafts that can be tested in orthotopic locations. Here, we report the development of a refined murine subcutaneous model for semi-orthotopic bone formation that allows the testing of up to four grafts per mouse one order of magnitude greater in volume than currently possible in mice. Crucially, these defects are also "critical size" and unable to heal within the timeframe of the study without intervention. The model is based on four bovine bone implants, ring-shaped, where the bone healing potential of distinct grafts can be evaluated in vivo. In this study we demonstrate that promotion and prevention of ossification can be assessed in our model. For this, we used a semi-automatic algorithm for longitudinal micro-CT image registration followed by histological analyses. Taken together, our data supports that this model is suitable as a platform for the real-time screening of bone formation, and provides the possibility to study bone resorption, osseointegration and vascularisation.

Spatiotemporal distribution of thrombospondin-4 and -5 in cartilage during endochondral bone formation and repair

During skeletal development most bones are first formed as cartilage templates, which are gradually replaced by bone. If later in life those bones break, temporary cartilage structures emerge to bridge the fractured ends, guiding the regenerative process. This bone formation process, known as endochondral ossification (EO), has been widely studied for its potential to reveal factors that might be used to treat patients with large bone defects. The extracellular matrix of cartilage consists of different types of collagens, proteoglycans and a variety of non-collagenous proteins that organise the collagen fibers in complex networks. Thrombospondin-5, also known as cartilage oligomeric matrix protein (TSP-5/COMP) is abundant in cartilage, where it has been described to enhance collagen fibrillogenesis and to interact with a variety of growth factors, matrix proteins and cellular receptors. However, very little is known about the skeletal distribution of its homologue thrombospondin-4 (TSP-4). In our study, we compared the spatiotemporal expression of TSP-5 and TSP-4 during postnatal bone formation and fracture healing. Our results indicate that in both these settings, TSP-5 distributes across all layers of the transient cartilage, while the localisation of TSP-4 is restricted to the population of hypertrophic chondrocytes. Furthermore, in fractured bones we observed TSP-4 sparsely distributed in the periosteum, while TSP-5 was absent. Last, we analysed the chemoattractant effects of the two proteins on endothelial cells and bone marrow stem cells and hypothesised that, of the two thrombospondins, only TSP-4 might promote blood vessel invasion during ossification. We conclude that TSP-4 is a novel factor involved in bone formation. These findings reveal TSP-4 as an attractive candidate to be evaluated for bone tissue engineering purposes.

Immunomodulation of surface biofunctionalized 3D printed porous titanium implants

Additive manufacturing (AM) techniques have provided many opportunities for the rational design of porous metallic biomaterials with complex and precisely controlled topologies that give rise to unprecedented combinations of mechanical, physical, and biological properties. These favorable properties can be enhanced by surface biofunctionalization to enable full tissue regeneration and minimize the risk of implant-associated infections (IAIs). There is, however, an increasing need to investigate the immune responses triggered by surface biofunctionalized AM porous metals. Here, we studied the immunomodulatory effects of AM porous titanium (Ti-6Al-4V) printed using selective laser melting, and of two additional groups consisting of AM implants surface biofunctionalized using plasma electrolytic oxidation (PEO) with/without silver nanoparticles. The responses of human primary macrophages and human mesenchymal stromal cells (hMSCs) were studied in terms of cell viability, cell morphology and biomarkers of macrophage polarization. Non-treated AM porous titanium triggered a strong pro-inflammatory response in macrophages, albeit combined with signs of anti-inflammatory effects. The PEO treatment of AM porous titanium implants showed a higher potential to induce polarization towards a pro-repair macrophage phenotype. We detected no cytotoxicity against hMSCs in any of the groups. However, the incorporation of silver nanoparticles resulted in strong cytotoxicity against attached macrophages. The results of this study indicate the potential immunomodulatory effects of the AM porous titanium enhanced with PEO treatment, and point towards caution and further research when using silver nanoparticles for preventing IAIs.

Cell-surface markers identify tissue resident multipotential stem/stromal cell subsets in synovial intimal and sub-intimal compartments with distinct chondrogenic properties

OBJECTIVE

Synovium contains multipotent progenitor/stromal cells (MPCs) with potential to participate in cartilage repair. Understanding the identity of these MPCs will allow their therapeutic potential to be fully exploited. Hence this study aimed to identify primary synovial MPCs and characterize them in the context of cartilage regeneration.

METHODS

Primary MPC/MPC-subset specific markers in synovium were identified by FACS analysis of uncultured cells. MPC-subsets from human synovium obtained from patients undergoing total knee arthroplasty were FACS sorted, cultured, immunophenotyped and chondrogenically differentiated. The anatomical localization of MPCs in synovium was examined using immunohistochemistry. Finally, the presence of these MPC subsets in healthy synovium obtained from human organ donors was examined.

RESULTS

A combination of CD45, CD31, CD73 and CD90 can isolate two distinct MPC-subsets in synovium. These MPC-subsets, freshly isolated from synovium, did not express CD45 or CD31, but expressed CD73. Additionally, a sub-population of CD73⁺ cells also expressed CD90. CD45^-CD31^-CD73⁺CD90^- cells were significantly more chondrogenic than CD45^-CD31^-CD73⁺CD90⁺ cells in the presence of TGFβ1. Interestingly, reduced chondrogenic ability of CD73⁺CD90⁺ cells could be reversed by the addition of BMP2, showing discrete chondrogenic factor requirements by distinct cell-subsets. In addition, these MPCs had distinct anatomical localization; CD73 was expressed both in intimal and sub-intimal region while CD90 was enriched in the sub-intimal region. We further demonstrated that these subsets are also present in healthy synovium.

CONCLUSIONS

We provide indications that primary MPCs in synovial intima and sub-intima are phenotypically and functionally distinct with different chondrogenic properties.

Allogeneic chondrogenically differentiated human bone marrow stromal cells do not induce dendritic cell maturation

Bone marrow stromal cell (BMSC)‐mediated endochondral bone formation may be a promising alternative to the current gold standards of autologous bone transplantation, in the development of novel methods for bone repair. Implantation of chondrogenically differentiated BMSCs leads to bone formation in vivo via endochondral ossification. The success of this bone formation in an allogeneic system depends upon the interaction between the implanted constructs and the host immune system. The current study investigated the effect of chondrogenically differentiated human bone marrow stromal cell (hBMSC) pellets on the maturation and function of dendritic cells (DCs) by directly coculturing bone forming chondrogenic hBMSC pellets and immature or lipopolysaccharide (LPS)‐matured DCs in vitro. Allogeneic chondrogenic hBMSC pellets did not affect the expression of CD80, CD86, or HLADR on immature or LPS‐matured DCs following 24, 48, or 72 hr of coculture. Furthermore, they did not induce or inhibit antigen uptake or migration of the DCs over time. IL‐6 was secreted by allogeneic chondrogenic hBMSC pellets in response to LPS‐matured DCs. Overall, this study has demonstrated that maturation of immature DCs was not influenced by allogeneic chondrogenic hBMSC pellets. This suggests that allogeneic chondrogenic hBMSC pellets do not stimulate immunogenic responses from DCs in vitro and are not expected to indirectly activate T cells via DCs. For this reason, allogeneic chondrogenic bone marrow stromal cell pellets are promising candidates for future tissue engineering strategies utilising allogeneic cells for bone repair.

Collagen type X is essential for successful mesenchymal stem cell-mediated cartilage formation and subsequent endochondral ossification

in tissue engineering, endochondral ossification (EO) is often replicated by chondrogenically differentiating mesenchymal stromal cells (MSCs) in vitro and achieving bone formation through in vivo implantation. The resulting marrow-containing bone constructs are promising as a treatment for bone defects. However, limited bone formation capacity has prevented them from reaching their full potential. This is further complicated since it is not fully understood how this bone formation is achieved. Acellular grafts derived from chondrogenically differentiated MSCs can initiate bone formation; however, which component within these decellularised matrices contribute to bone formation has yet to be determined. Collagen type X (COLX), a hypertrophy-associated collagen found within these constructs, is involved in matrix organisation, calcium binding and matrix vesicle compartmentalisation. However, the importance of COLX during tissue-engineered chondrogenesis and subsequent bone formation is unknown. The present study investigated the importance of COLX by shRNA-mediated gene silencing in primary MSCs. A significant knock-down of COLX disrupted the production of extracellular matrix key components and the secretion profile of chondrogenically differentiated MSCs. Following in vivo implantation, disrupted bone formation in knock-down constructs was observed. The importance of COLX was confirmed during both chondrogenic differentiation and subsequent EO in this tissue engineered setting.

Understanding tissue-engineered endochondral ossification; towards improved bone formation

Endochondral ossification (EO) is the process by which the long bones of the body form and has proven to be a promising method in tissue engineering for achieving cell-mediated bone formation. The present review centred on state-of-the-art research pertaining to mesenchymal stem cells (MSCs)-mediated endochondral bone formation, focusing on the role of donor cells, extracellular matrix and host immune cells during tissue-engineered bone formation. Possible research avenues to improve graft outcome and bone output were highlighted, as well as emerging research that, when applied to tissue-engineered bone grafts, offers new promise for improving the likelihood of such grafts transition from bench to bedside.

Injectable BMP-2 delivery system based on collagen-derived microspheres and alginate induced bone formation in a time- and dose-dependent manner

The aim of the current study was to reduce the clinically used supra-physiological dose of bone morphogenetic protein-2 (BMP-2) (usually 1.5 mg/mL), which carries the risk of adverse events, by using a more effective release system. A slow release system, based on an injectable hydrogel composed of BMP-2-loaded recombinant collagen-based microspheres and alginate, was previously developed. Time- and dose-dependent subcutaneous ectopic bone formation within this system and bone regeneration capacity in a calvarial defect model were investigated. BMP-2 doses of 10 µg, 3 µg and 1 µg per implant (50 µg/mL, 15 µg/mL and 5 µg/mL, respectively) successfully induced ectopic bone formation subcutaneously in rats in a time- and dose-dependent manner, as shown by micro-computed tomography (µCT) and histology. In addition, the spatio-temporal control of BMP-2 retention was shown for 4 weeks in vivo by imaging of fluorescently-labelled BMP-2. In the subcritical calvarial defect model, µCT revealed a higher bone volume for the 2 µg of BMP-2 per implant condition (50 µg/mL) as compared to the lower dose used (0.2 µg per implant, 5 µg/mL). Complete defect bridging was obtained with 50 µg/mL BMP-2 after 8 weeks. The BMP-2 concentration of 5 µg/mL was not sufficient to heal a calvarial defect faster than the empty defect or biomaterial control without BMP-2. Overall, this injectable BMP-2 delivery system showed promising results with 50 µg/mL BMP-2 in both the ectopic and calvarial rat defect models, underling the potential of this composite hydrogel for bone regeneration therapies.

Mesenchymal stem cell-mediated endochondral ossification utilising micropellets and brief chondrogenic priming

With limited autologous and donor bone graft availability, there is an increasing need for alternative graft substitutes. We have previously shown that chondrogenically priming mesenchymal stem cell (MSC) pellets for 28 d in vitro will reproducibly result in endochondral bone formation after in vivo implantation. However, pellet priming time for clinical applications is quite extensive. A micropellet (μpellet)-fibrin construct was developed and coupled, with a shorter priming period, determined by an in vitro time course experiment. In vitro data showed expression of chondrogenic genes and matrix production after 7 d of chondrogenic priming, indicating that briefer priming could possibly be used to induce bone formation in vivo. 7 and 28 d primed pellet, pellet-fibrin and μpellet-fibrin constructs were cultured for in vitro analysis and implanted subcutaneously for 8 weeks into nude mice. μpellet-fibrin constructs, cultured in vitro for 7 or 28 d, produced comparable bone to standard pellets in vivo. MSC-mediated bone formation was achieved following only 7 d of in vitro priming. Bone formation in vivo appeared to be influenced by overall matrix production pre-implantation. Given this short priming time and the injectable nature of the μpellet-fibrin constructs, this approach might be further developed as an injectable bone substitute, leading to a minimally-invasive treatment option, which would allow for tailored filling of bone defects.

Apparent rate constant mapping using hyperpolarized [1-(13)C]pyruvate

Hyperpolarization of [1-13C]pyruvate in solution allows real-time measurement of uptake and metabolism using MR spectroscopic methods. After injection and perfusion, pyruvate is taken up by the cells and enzymatically metabolized into downstream metabolites such as lactate, alanine, and bicarbonate. In this work, we present comprehensive methods for the quantification and interpretation of hyperpolarized 13C metabolite signals. First, a time-domain spectral fitting method is described for the decomposition of FID signals into their metabolic constituents. For this purpose, the required chemical shift frequencies are automatically estimated using a matching pursuit algorithm. Second, a time-discretized formulation of the two-site exchange kinetic model is used to quantify metabolite signal dynamics by two characteristic rate constants in the form of (i) an apparent build-up rate (quantifying the build-up of downstream metabolites from the pyruvate substrate) and (ii) an effective decay rate (summarizing signal depletion due to repetitive excitation, T1-relaxation and backward conversion). The presented spectral and kinetic quantification were experimentally verified in vitro and in vivo using hyperpolarized [1-13C]pyruvate. Using temporally resolved IDEAL spiral CSI, spatially resolved apparent rate constant maps are also extracted. In comparison to single metabolite images, apparent build-up rate constant maps provide improved contrast by emphasizing metabolically active tissues (e.g. tumors) and suppression of high perfusion regions with low conversion (e.g. blood vessels). Apparent build-up rate constant mapping provides a novel quantitative image contrast for the characterization of metabolic activity. Its possible implementation as a quantitative standard will be subject to further studies.

Human osteoarthritic synovium impacts chondrogenic differentiation of mesenchymal stem cells via macrophage polarisation state

OBJECTIVE

Mesenchymal stem cells (MSCs) are a promising cell type for the repair of damaged cartilage in osteoarthritis (OA). However, OA synovial fluid and factors secreted by synovium impede chondrogenic differentiation of MSCs, and the mechanism responsible for this effect remains unclear. In this study, we sought to investigate whether M1 and M2 synovial macrophages can contribute to the inhibition of MSC chondrogenesis.

DESIGN

The constitution of synovial macrophage subsets was analysed by immunohistochemical staining of human OA synovium sections for CD86 (M1 marker) and CD206 (M2 marker). To assess the effect of synovial macrophages on chondrogenesis, collagen type II (COL2) and aggrecan (ACAN) gene expression were compared between MSCs undergoing chondrogenic differentiation in medium conditioned (CM) by human OA synovial explants, human synovial macrophages and fibroblasts, or peripheral blood derived primary human monocytes differentiated towards an M1 or M2 phenotype.

RESULTS

OA synovium contained both M1 and M2 macrophages. Medium conditioned by synovial macrophages (CD45 + plastic adherent cells) down-regulated chondrogenic gene expression by MSCs. Additionally, CM of M1 polarised monocytes significantly decreased COL2 and ACAN gene expression by MSCs; this effect was not observed for treatment with CM of M2 polarised monocytes.

CONCLUSION

MSC chondrogenesis is inhibited by OA synovium CM through factors secreted by synovial macrophages and our findings suggest that M1 polarised subsets are potential mediators of this anti-chondrogenic effect. Modulation of macrophage phenotype may serve as a beneficial strategy to maximise the potential of MSCs for efficient cartilage repair.

Evaluation of the ability of collagen-glycosaminoglycan scaffolds with or without mesenchymal stem cells to heal bone defects in Wistar rats

PURPOSE

The aim of this experiment was to examine the capacity of collagen-glycosaminoglycan scaffolds, with or without mesenchymal stem cells, to satisfactorily repair a 5-mm rat calvarial defect.

METHODS

Fifty-five Wistar rats were used in the study. The defects were either left empty to serve as controls (n = 7) or filled with cell-free scaffolds (n = 11), cell-seeded scaffolds that were pre-cultured in standard culture medium (n = 13), cell-seeded scaffolds that were pre-cultured in osteoinductive factor-supplemented medium (n = 12) or particulate autogenous bone (n = 12). The animals were sacrificed at 12 weeks after surgery, and specimens were prepared for histomorphometric analysis. The linear bone healing and the bone area within the defect were measured.

RESULTS

Comparable results were obtained using cell-free collagen-glycosaminoglycan scaffolds and autogenous bone both in terms of linear bone healing (P < 0.986) and area of new bone (P < 0.846). While the test groups showed significantly more bone formation compared to the empty defect control group, the linear bone healing and area of new bone within the defect were significantly lower in the cell-seeded scaffolds than in the cell-free scaffolds. The results have demonstrated that a cell-free collagen-glycosaminoglycan scaffold is capable of repairing a 5-mm rat calvarial defect as effectively as autogenous bone and that seeding the scaffold with pre-cultured mesenchymal stem cells prior to implantation offered no beneficial effect and resulted in incomplete healing of the defect.

CONCLUSIONS

The results thus suggest that the scaffold has immense potential for tissue repair showing favorable osteoconductive properties, biocompatibility and degradability.

Ferumoxides-protamine sulfate is more effective than ferucarbotran for cell labeling: implications for clinically applicable cell tracking using MRI

The use of superparamagnetic iron oxide (SPIO) for labeling cells holds great promise for clinically applicable cell tracking using magnetic resonance imaging. For clinical application, an effectively and specifically labeled cell preparation is highly desired (i.e. a large amount of intracellular iron and a negligible amount of extracellular iron). In this study we performed a direct comparison of two SPIO labeling strategies that have both been reported as efficient and clinically translatable approaches. These approaches are cell labeling using ferumoxides-protamine complexes or ferucarabotran particles. Cell labeling was performed on primary human bone marrow stromal cells (hBMSCs) and chondrocytes. For both cell types ferumoxides-protamine resulted in a higher percentage of labeled cells, a higher total iron load, a larger amount of intracellular iron and a lower amount of extracellular iron aggregates, compared with ferucarbotran. Consequently, hBMSC and chondrocyte labeling with ferumoxides-protamine is more effective and results in more specific cell labeling than ferucarbotran.

Endometrial and vaginal effects of low-dose estradiol delivered by vaginal ring or vaginal tablet

AIMS

The major aims of the study were to compare the safety of a continuous low-dose estradiol-releasing vaginal ring (ESTring) to that of a vaginal estradiol tablet (Vagifem) on the endometrium and the relief of subjective symptoms and signs of urogenital estrogen deficiency. Quality of life and acceptability of treatment delivery were also assessed.

STUDY DESIGN

A prospective, randomized study in which women were assigned in a 2:1 ratio to ESTring and Vagifem and followed for 12 months. The primary endpoint was endometrial safety, based on the results of ultrasound measurement of endometrial thickness and a progestogen challenge test at baseline and week 48. Efficacy was determined by subjective assessment of urogenital estrogen deficiency symptoms at baseline and weeks 3, 12, 24, 36 and 48 and assessment of signs of vaginal epithelial atrophy by the clinician at baseline, 12 and 48 weeks. In addition, pelvic floor strength, vaginal cytological evaluation and pH, bacteruria and patient acceptability were assessed. Quality of life was assessed using a menopause-specific quality-of-life questionnaire and a 2-day bladder diary at baseline and 12 and 48 weeks. The comparability of the two groups was assessed using ANOVA, chi2 or Fisher's exact tests.

RESULTS

A total of 126 women were randomized to ESTring and 59 to Vagifem. There was no statistical difference between the groups in the alleviation of symptoms and signs of urogenital estrogen deficiency. Maturation indices increased in both groups, from generally atrophic at baseline to proliferative or highly proliferative at 48 weeks. After 48 weeks of treatment, there was no statistically significant difference in endometrial thickness between the two groups. A statistically smaller proportion of bleeding/spotting occurred in the ESTring group (n = 0) compared to the Vagifem users (n = 4). Estradiol and total estrone serum levels increased during treatment in both groups but remained within the normal postmenopausal range. General health status in both groups was unchanged but the urogenital component of health burden was significantly improved in both groups. Bladder diary variables showed no differences between treatment groups.

CONCLUSION

Equivalent endometrial safety and efficacy in the relief of the symptoms and signs of urogenital estrogen deficiency were demonstrated for the 12 months' use of a low-dose estradiol-releasing vaginal ring and a vaginal estradiol tablet.

Cell labelling with superparamagnetic iron oxide has no effect on chondrocyte behaviour

BACKGROUND

Tissue engineering and regenerative medicine are two rapidly advancing fields of research offering potential for effective treatment of cartilage lesions. Today, chondrocytes are the cell type of choice for use in cartilage repair approaches such as autologous chondrocyte implantation. To verify the safety and efficacy of such approaches it is necessary to determine the fate of these transplanted cells. One way of doing this is prelabelling cells before implantation and tracking them using imaging techniques. The use of superparamagnetic iron oxide (SPIO) for tracking of cells with magnetic resonance imaging (MRI) is ideal for this purpose. It is non-radioactive, does not require viral transfection and is already approved for clinical use as a contrast agent.

OBJECTIVE

The purpose of this study was to assess the effect of SPIO labelling on adult human chondrocyte behaviour.

METHODS

Cells were culture expanded and dedifferentiated for two passages and then labelled with SPIO. Effect on cell proliferation was tested. Furthermore, cells were cultured for 21 days in alginate beads in redifferentiation medium. Following this period, cells were analysed for expression of cartilage-related genes, proteoglycan production and collagen protein expression.

RESULTS

SPIO labelling did not significantly affect any of these parameters relative to unlabelled controls. We also demonstrated SPIO retention within the cells for the full duration of the experiment.

CONCLUSIONS

This paper demonstrates for the first time the effects of SPIO labelling on chondrocyte behaviour, illustrating its potential for in vivo tracking of implanted chondrocytes.

Once-daily amoxicillin versus twice-daily penicillin V in group A beta-haemolytic streptococcal pharyngitis

BACKGROUND

Rheumatic fever is a preventable chronic disease preceded by group A beta-haemolytic streptococcal (GABHS) pharyngitis.

OBJECTIVE

To test the non-inferiority of once-daily (QD) oral amoxicillin to the recommended twice-daily (BID) oral penicillin V in GABHS pharyngitis.

METHODS

This was a randomised non-inferiority trial carried out in a school-based clinic in New Zealand. Children presenting with GABHS pharyngitis were randomised to oral amoxicillin 1500 mg QD (or 750 mg if bodyweight was <or=30 kg) or to oral penicillin V 500 mg BID (or 250 mg if bodyweight was <or=20 kg) for 10 days. Observed medication and weekend diary cards were used to monitor adherence.

OUTCOME

Eradication of GABHS, determined with follow-up throat cultures on days 3-6, 12-16 and 26-36. GABHS isolates were serotyped to distinguish bacteriological treatment failures (and relapses) from new acquisitions. Non-inferiority was defined as an upper 95% confidence limit (CL) for the difference in success of eradication in the amoxicillin and penicillin V treatment groups of <or=10%.

RESULTS

353 children with positive throat swabs for GABHS were randomised to amoxicillin (n = 177) or penicillin V (n = 176). The upper 95% CL for the differences in positive cultures between the antibiotics was 4.9% at days 3-6, 6.5% at days 12-16 and 8.5% at days 26-36. Treatment failures (including relapses) occurred at each visit in 5.8%, 12.7% and 10.7% of amoxicillin recipients and 6.2%, 11.9% and 11.3% of penicillin V recipients, respectively. No significant differences in resolution of symptoms were noted between treatment groups. One case of unsubstantiated acute rheumatic fever occurred after 7 days of amoxicillin.

CONCLUSION

In this adequately powered study, once-daily oral amoxicillin is not inferior to twice-daily penicillin V for the treatment and eradication of GABHS in children with pharyngitis.

Circulating myeloid and plasmacytoid dendritic cells after allergen inhalation in asthmatic subjects

BACKGROUND

Dendritic cells are key contributors to initiation and maintenance of T-cell immunity to inhaled allergen. The purpose of this study was to enumerate the changes in peripheral blood myeloid (mDCs) and plasmacytoid dendritic cells (pDCs), the DCs expressing chemokine receptor 6 (CCR6) and chemokine receptor 7 (CCR7), following diluent and allergen inhalation in asthmatic subjects.

METHODS

Peripheral blood was obtained from 16 allergic asthmatic subjects before and at 0.5, 1, 2, 3, 4, 6, 24, and 48 h after inhaled diluent and allergen challenges. Dendritic cells were enumerated using flow cytometry.

RESULTS

Allergen inhalation significantly reduced mDCs at 6 h (21.3 +/- 2.0 vs 15.0 +/- 1.8/microl blood; P < 0.05) and 24 h (21.5 +/- 3.4 vs 16.4 +/- 2.4/microl blood; P < 0.05) after challenge. Circulating pDCs were significantly lower than baseline up to 24 h after both allergen and diluent challenges. There was a significant efflux of CCR6(+) mDCs from peripheral blood at 6 h and CCR6(+) pDCs at 4 h after allergen challenge, when compared with diluent. There was no difference in the number of circulating CCR7(+) mDCs or pDCs after diluent or allergen challenges.

CONCLUSIONS

Peripheral blood mDCs and CCR6(+) mDCs, but not pDCs, are reduced up to 24 h after allergen inhalation. Thus, allergen inhalation causes trafficking of immature CCR6(+) DCs from blood into the airway, while that of the trafficking of the mature CCR7(+) DCs from the airways into the regional lymph nodes probably occurs through the lymphatic system.

Ideal body weight correlates better with engraftment after PBSC autograft than actual body weight, but is under-estimated in myeloma patients possibly due to disease-related height loss

Stem cell dose is important in determining rate of engraftment following autograft. We show closer correlation with haematopoietic reconstitution when the CD34+ cell dose is calculated using ideal (IBW) rather than actual (ABW) body weight in 218 patients receiving peripheral blood stem cell (PBSC) autograft for haematological malignancy. ABW was 21% greater than IBW thus the median CD34+ dose of 5.0 x 10(6)/kg (ABW) rose to 6.1 x 10(6)/kg when calculated by IBW. Neutrophils reached 0.5 x 10(9)/l in 11 days (range 8-21), while platelets reached 20 x 10(9)/l unsupported in 12 days (range 7-38). For both neutrophil and platelet engraftment, a greater inverse correlation was seen when IBW was used to calculate stem cell dose (r2=0.082 vs r2=0.104 for neutrophils and r2=0.085 vs r2=0.135 for platelets). Those non-myeloma patients who failed to achieve a CD34+ dose of 4 x 10(6) cells/kg by ABW but did so by IBW achieved neutrophil and platelet engraftment not significantly different from those who achieved that stem cell dose by both methods. This was not confirmed in patients treated for myeloma, possibly owing to inaccurate IBW in patients with skeletal height loss. We confirm that calculation of CD34+ cell dose by IBW safely predicts engraftment for patients with haematological malignancies other than myeloma undergoing PBSC autograft.

Loading conditions and bone formation in the GH region of the shoulder

The present study investigates how loading of the shoulder effect the formation of the trabeculae in the subarticular region of the gleno-humeral joint. Bone morphology was determined from scapular cadaveric specimens and finite element (FE) analysis was employed to analyse principal stress trajectories. Boundary conditions corresponded to five functional activities were considered. The results show deviations of the computed trajectories from actual trabecular lines obtained from the bone specimens ranged on average from 10% to 17%. Each activity produced different regional deviation corresponding to the specific loading condition. This study concludes that certain loading conditions are more significant in explaining the formation of the trabecular architecture. The results also suggest that due to the extra sensitivity of the front and the rear aspects of the "lateral region" to the loading conditions, these regions may be more indicative in reflecting shoulder injuries.

A comparison of the osteogenic potential of adult rat mesenchymal stem cells cultured in 2-D and on 3-D collagen glycosaminoglycan scaffolds

Adult mesenchymal stem cells (MSCs) have the capability to differentiate along several lineages including those of bone, cartilage, tendon and muscle, thus offering huge potential for the field of tissue engineering. The purpose of this study was to characterise the differentiation capacity of rat MSCs cultured on standard plastic coverslips in 2 dimensions and on a novel collagen glycosaminoglycan scaffold in the presence of a standard combination of osteoinductive factors. Cells were cultured for 3, 7, 14 and 21 days and several markers of osteogenesis were analysed. While the initial response of the cells in 3-D seemed to be faster than cells cultured in 2-D, as evidenced by collagen type I expression, later markers showed that osteogenic differentiation of MSCs took longer in the 3-D environment of the collagen GAG scaffold compared to standard 2-D culture conditions. Furthermore, it was shown that complete scaffold mineralisation could be evoked within a 6 week timeframe. This study further demonstrates the potential use of MSC-seeded collagen GAG scaffolds for bone tissue engineering applications.

Influence of different hormonal regimens on endometrial microvascular density and VEGF expression in women suffering from breakthrough bleeding

BACKGROUND

The aim of this study was to quantify blood vessel density (BVD) and immunoreactive vascular endothelial growth factor (VEGF) levels in endometrial biopsies taken from women suffering breakthrough bleeding (BTB) under different exogenous hormonal regimes.

METHODS

Endometrial biopsies from women in Melbourne with BTB were divided into four groups: combined-continuous hormone therapy (HT) (estrogen and progestin taken daily), cyclical HT (daily estrogen with progestin for 14 days each cycle), progestin-only, or no HT. Subjects from Barcelona were using the Mirena intrauterine levonorgestrel-releasing system for contraceptive purposes, with menstrual diaries for classification into four groups (amenorrhea, infrequent, regular and prolonged). Control biopsies from Melbourne were included in the study. Endometrial samples were immunostained for VEGF and blood vessel localization using an antibody to CD34.

RESULTS

Results showed that BVD was significantly reduced in the progestin-only treated group compared with the other three treatment groups (P = 0.028). In addition, all four Mirena BTB groups had significantly reduced BVD compared with controls. Considerable heterogeneity was observed in VEGF immunostaining within and between individual samples with no major differences between HT or Mirena.

CONCLUSION

These results provide strong evidence that unopposed progestins reduce endometrial BVD and that there is no link between VEGF immunostaining and BVD or BTB.

Influence of strong static magnetic fields on primary cortical neurons

Intense uniform magnetic fields, such as those used in magnetic resonance imaging (MRI), are thought to exert little influence at the cellular level. Here we report modifications of the signaling cascades in rat cortical neurons cultured for 1 h in magnetic fields of up to 5 Tesla. The activation of c-Jun N-terminal kinase (JNK) increases monotonically with field strength, with a maximal activation of approximately 10% at 5 T, whereas the activation of extra cellular-regulated kinase (ERK) shows a maximum at 0.75 T ( approximately 10%). Since ERK is involved in cellular differentiation, these results indicate a magnetic induction of the signaling events associated with differentiation. However, the cells respond to further increases in field strength by evoking a stress response, since JNK is a stress-activated protein kinase. Three possible mechanisms are discussed and of these, the most plausible is magnetic field induced change in the membrane rest potential, a microscale magnetohydrodynamic effect. This mechanism most likely involves the activation of voltage dependent Ca(2+) channel opening; since intracellular Ca(2+) concentration was also found to be modified by the static magnetic field.

Outcome after primary hemiarthroplasty for fracture of the head of the humerus

We have examined 167 patients who had a hemiarthroplasty for three- and four-part fractures and fracture-dislocations of the head of the humerus in a multicentre study involving 12 Austrian hospitals. All patients were followed for more than a year.

Anatomical healing of the tuberosity significantly influenced the outcome as measured by the Constant score and subjective patient satisfaction. With regard to pain, the outcome was generally satisfactory but only 41.9% of patients were able to flex the shoulder above 90°. The age of the patient and the type of prosthesis significantly influenced the healing of the tuberosity, but bone grafting did not. Achievement of healing of the tuberosity was inferior in institutions at which less than 15 hemiarthroplasties had been performed (Mann-Witney U test, p = 0.0001).

Effect of hormone replacement therapies and selective estrogen receptor modulators in postmenopausal women with uterine leiomyomas: a literature review

This systematic review examines current literature relating to clinical studies of hormone replacement therapy (HRT) and tibolone, including selective estrogen receptor modulators (SERMs) such as tamoxifen and raloxifene, and their usage in postmenopausal women with fibroids. After a MEDLINE search, 28 relevant articles were found in total, of which five concerned randomized controlled trials. The results from class I studies and class II studies are evaluated in the categories of those that involved tibolone only, those that involved HRT only, and those that involved SERMs such as tamoxifen and raloxifene. In conclusion, tibolone has no significant effect on myoma size in postmenopausal women. There is myoma growth in postmenopausal women taking HRT. However, this does not appear to cause clinical symptoms.

Computed tomography and magnetic resonance imaging of the equine head

Horses are frequently presented with clinical conditions warranting diagnostic imaging of the head. Unfortunately, evaluation of the equine head can be difficult using conventional radiography. The anatomic complexity and superimposition of the osseous, dental, and soft tissue structures complicate radiographic interpretation and diagnoses. Multiple radiographic projections may be necessary to image specific regions, and side-to-side comparison is often essential.

The number of CD34+ cells mobilized into the peripheral blood can predict the quality of subsequent collections

PBPC were mobilized using a variety of chemotherapy regimens plus G-CSF in a group of 126 consecutive patients. Data are presented that show a close correlation between the number of CD34+ cells mobilized into the peripheral blood (PB) and the number of CD34+ cells subsequently collected by leukapheresis (R = 0.904). On the basis of this correlation, a regression formula was calculated that could give an estimate of the total number of CD34+ cells likely to be collected by leukapheresis from a given number of CD34+ cells per microliter PB. An easy-to-read table has been compiled to show how this type of analysis can be applied to predict the likely dose of CD34+ cells that will be obtained by leukapheresis over a wide range of patient weights.

Peripheral blood progenitor cell mobilisation in patients with multiple myeloma following oral idarubicin and dexamethasone (Z-Dex) induction therapy

Difficulties associated with current intensive induction regimens for multiple myeloma and uncertainty as to how to achieve optimal peripheral blood progenitor cell mobilisation (PBPC) prompted this study of an oral induction regimen, Z-Dex (oral idarubicin and dexamethasone) followed by PBPC mobilisation using four different regimens. Thirty-patients received Z-Dex (median age 56 years, range 46-66 years) including 24 patients with previously untreated disease. The overall response rate was 75% with a CR rate of 16.7% and PR rate of 75.7% in patients with previously untreated disease. We compared four mobilisation regimens: low-dose (LD) cyclophosphamide, high-dose (HD) cyclophosphamide, cis-platin/VP16 and cis-platin, Ara-C and dexamethasone (DHAP). Failure to mobilise optimal numbers of PBPCs (>1.0 x 10(6) CD34+ cells/kg and >20 x 10(4) CFU-GM/kg) was seen in two patients who received LD cyclophosphamide, in two patients who received HD cyclophosphamide and three patients who received cis-platin/VP16. No patient failed to mobilise adequate numbers of PBPCs following DHAP. In previously untreated patients, DHAP mobilised significantly more PBPC than LD cyclophosphamide (P=0.02), HD cyclophosphamide (P=0.0015) and cis-platin/VP16 (P=0.021). This study demonstrates the efficacy of Z-Dex in inducing tumour responses in patients with multiple myeloma without limiting PBPC mobilisation in subsequent dose-intensive schedules. Furthermore, we also demonstrate that DHAP is superior to cyclophosphamide (low- and high-dose) and cis-platin/VP16 in mobilising PBPCs and demonstrated a degree of tumour control.

CD34+ cells can be selected efficiently from cryopreserved peripheral blood progenitor cells and can retain their proliferative potential

Hematopoietic stem and progenitor cells express the CD34 antigen. Techniques have been developed that enable purified populations of CD34+ cells to be selected from hematopoietic tissues. These selected CD34+ cells have several potential applications, including CD34 selection to obtain a tumor purging effect in autologous transplantation studies and using CD34+ cells as the starting cells for ex vivo expansion studies and as a vehicle for gene transduction protocols. We have investigated the feasibility of using cryopreserved peripheral blood progenitor cells (PBPC) for CD34 selection. Cells could be recovered from cryopreservation with good yields and high viability. After CD34 selection, the final product was, on average, 84% pure, with a recovery of 54%. These cells retained extensive proliferative potential, as demonstrated by ex vivo expansion culture. We believe that cryopreserved PBPC could be thawed, and CD34+ cells could be selected and used for transplantation following high-dose chemotherapy.