Combining an Electrochemical Continuous Glucose Sensor With an Insulin Delivery Cannula: A Feasibility Study

BACKGROUND

Combining a continuous glucose monitor with an insulin delivery cannula (CGM-IS) could benefit clinical outcomes. We evaluated the feasibility of a single-needle insertion electrochemical investigational CGM-IS (Pacific Diabetes Technologies, Portland, Oregon) in type 1 diabetes adults.

METHODS

Following 48 hours run-in using a Medtronic 780G in manual mode with a commercial insulin set, 12 participants commenced insulin delivery using the CGM-IS. A standardized test meal was eaten on the mornings of days 1 and 4. Venous samples were collected every 10 minutes one hour prior to and 15 minutes post-meal for four hours. CGM-IS glucose measurements were post-processed with a single capillary blood calibration during warm-up and benchmarked against YSI. A Dexcom G6 sensor was worn post-consent to study end.

RESULTS

Mean absolute relative difference (MARD) for the CGM-IS glucose measurements was 9.2% (484 paired data points). Consensus error grid revealed 88.6% within zone A and 100% in A + B. Mean (SD) % bias was -3.5 (11.7) %. There were 35 paired YSI readings <100 mg/dL cutoff and 449 ≥100 mg/dL with 81.4% within ±15 mg/dL or ±15%, and 89.9% within ±20 mg/dL or ±20%. Two cannula occlusions required discontinuation of insulin delivery: one at 70 hours post insertion and another during the day 4 meal test. Mean (SD) Dexcom glucose measurements during run-in and between meal tests was respectively 161.3 ± 27.3 mg/dL versus 158.0 ± 25.6 mg/dL; P = .39 and corresponding mean total daily insulin delivered by the pump was 58.0 ± 25.4 Units versus 57.1 ± 28.8 Units; P = .47.

CONCLUSIONS

Insulin delivery and glucose sensing with the investigational CGM-IS was feasible. Longer duration studies are needed.

The influence of ball in/out of play and possession in elite soccer: Towards a more valid measure of physical intensity during competitive match-play

The physical demands of soccer match-play have typically been assessed using a low-resolution whole match approach ignoring whether the ball is in or out of play (BIP/BOP) and during these periods which team has possession. This study investigated the effect of fundamental match structure variables (BIP/BOP, in/out of possession) on the physical demands, and especially intensity, of elite match-play. For 1083 matches from a major European league, whole match duration, and player physical tracking data, were divided into BIP/BOP, and in/out of possession periods throughout the match, using on-ball event data. These distinct phases were used to derive absolute (m) and rate (m·min-1) of distance covered in total and within six speed categories during BIP/BOP and in/out possession. The rate of distance covered, an index of physical intensity, was >2-fold greater during BIP vs BOP. Whole match total distance covered was confounded by BIP time and poorly associated with physical intensity during BIP (r = 0.36). Whole match rates of distance covered substantially underestimated those during BIP, particularly for higher running speeds (∼-62%). Ball possession markedly effected physical intensity, with the rates of distance covered running (+31%), at high-speed (+30%) and in total (+7%) greater out than in possession. Whole match physical metrics underestimated the physical intensity during BIP, and thus the rate(s) of distance covered during BIP are recommended for accurate measurement of physical intensity in elite soccer. The greater demands of being out of possession support a possession-based tactical approach to minimise fatigue and its negative consequences.

[Status quo of screening for hip dysplasia]

Since the first description of the ultrasound examination of the infant hip by Graf in 1980 this technique has impressively demonstrated that it lives up to its promise very well. In the implementation of hip ultrasound in the German pediatric guidelines it was hoped that it would improve the sensitivity and specificity of the early detection of dislocated and dysplastic joints in comparison to a general clinical hip screening. Furthermore, it has been repeatedly shown that general newborn hip ultrasound screening according to Graf can significantly reduce not only the treatment rate but also the invasiveness. Consequentially, the cost of treatment as well as the rate of late presenting developmental dysplasia of the hip (DDH) can also be significantly reduced. Despite those proven merits the meaningfulness of general hip ultrasound screening in infancy is still questioned, especially in the Anglo-American world. This article reviews how this misconception came about.

Over-optimistic evaluation and reporting of novel cluster algorithms: an illustrative study

When researchers publish new cluster algorithms, they usually demonstrate the strengths of their novel approaches by comparing the algorithms’ performance with existing competitors. However, such studies are likely to be optimistically biased towards the new algorithms, as the authors have a vested interest in presenting their method as favorably as possible in order to increase their chances of getting published. Therefore, the superior performance of newly introduced cluster algorithms is over-optimistic and might not be confirmed in independent benchmark studies performed by neutral and unbiased authors. This problem is known among many researchers, but so far, the different mechanisms leading to over-optimism in cluster algorithm evaluation have never been systematically studied and discussed. Researchers are thus often not aware of the full extent of the problem. We present an illustrative study to illuminate the mechanisms by which authors—consciously or unconsciously—paint their cluster algorithm’s performance in an over-optimistic light. Using the recently published cluster algorithm Rock as an example, we demonstrate how optimization of the used datasets or data characteristics, of the algorithm’s parameters and of the choice of the competing cluster algorithms leads to Rock’s performance appearing better than it actually is. Our study is thus a cautionary tale that illustrates how easy it can be for researchers to claim apparent “superiority” of a new cluster algorithm. This illuminates the vital importance of strategies for avoiding the problems of over-optimism (such as, e.g., neutral benchmark studies), which we also discuss in the article.

Assessment of Sprint Parameters in Top Speed Interval in 100 m Sprint-A Pilot Study Under Field Conditions

Improving performances in sprinting requires feedback on sprint parameters such as step length and step time. However, these parameters from the top speed interval (TSI) are difficult to collect in a competition setting. Recent advances in tracking technology allows to provide positional data with high spatio-temporal resolution. This pilot study, therefore, aims to automatically obtain general sprint parameters, parameters characterizing, and derived from TSI from raw speed. In addition, we propose a method for obtaining the intra-cyclic speed amplitude in TSI. We analyzed 32 100 m-sprints of 7 male and 9 female athletes (18.9 ± 2.8 years; 100 m PB 10.55-12.41 s, respectively, 12.18-13.31 s). Spatio-temporal data was collected with a radio-based position detection system (RedFIR, Fraunhofer Institute, Germany). A general velocity curve was fitted to the overall speed curve (vbase), TSI (upper quintile of vbase values) was determined and a cosine term was added to vbase within TSI (vcycle) to capture the cyclic nature of speed. This allowed to derive TSI parameters including TSI amplitude from the fitted parameters of the cosine term. Results showed good approximation for vbase (error: 5.0 ± 1.0%) and for vcycle (2.0 ± 1.0%). For validation we compared spatio-temporal TSI parameters to criterion values from laser measurement (speed) and optoelectric systems (step time and step length) showing acceptable RMSEs for mean speed (0.08 m/s), for step time (0.004 s), and for step length (0.03 m). Top speed interval amplitude showed a significant difference between males (mean: 1.41 m/s) and females (mean: 0.71 m/s) and correlations showed its independence from other sprint parameters. Gender comparisons for validation revealed the expected differences. This pilot study investigated the feasibility of estimating sprint parameters from high-quality tracking data. The proposed method is independent of the data source and allows to automatically obtain general sprint parameters and TSI parameters, including TSI amplitude assessed here for the first time in a competition-like setting.

RPL27A is a target of miR-595 and may contribute to the myelodysplastic phenotype through ribosomal dysgenesis

We investigated the functional consequences following deletion of a microRNA (miR) termed miR-595 which resides on chromosome 7q and is localised within one of the commonly deleted regions identified for Myelodysplasia (MDS) with monosomy 7 (−7)/isolated loss of 7q (7q-). We identified several targets for miR-595, including a large ribosomal subunit protein RPL27A. RPL27A downregulation induced p53 activation, apoptosis and inhibited proliferation. Moreover, p53-independent effects were additionally identified secondary to a reduction in the ribosome subunit 60s. We confirmed that RPL27A plays a pivotal role in the maintenance of nucleolar integrity and ribosomal synthesis/maturation. Of note, RPL27A overexpression, despite showing no significant effects on p53 mRNA levels, did in fact enhance cellular proliferation. In normal CD34+ cells, RPL27A knockdown preferentially blocked erythroid proliferation and differentiation. Lastly, we show that miR-595 expression appears significantly downregulated in the majority of primary samples derived from MDS patients with (−7)/(7q-), in association with RPL27A upregulation. This significant downregulation of miR-595 is also apparent when higher risk MDS cases are compared to lower risk cases. The potential clinical importance of these findings requires further validation.

Deep phenotyping of Tregs identifies an immune signature for idiopathic aplastic anemia and predicts response to treatment

Idiopathic aplastic anemia (AA) is an immune-mediated and serious form of bone marrow failure. Akin to other autoimmune diseases, we have previously shown that in AA regulatory T cells (Tregs) are reduced in number and function. The aim of this study was to further characterize Treg subpopulations in AA and investigate the potential correlation between specific Treg subsets and response to immunosuppressive therapy (IST) as well as their in vitro expandability for potential clinical use. Using mass cytometry and an unbiased multidimensional analytical approach, we identified 2 specific human Treg subpopulations (Treg A and Treg B) with distinct phenotypes, gene expression, expandability, and function. Treg B predominates in IST responder patients, has a memory/activated phenotype (with higher expression of CD95, CCR4, and CD45RO within FOXP3(hi), CD127(lo) Tregs), expresses the interleukin-2 (IL-2)/STAT5 pathway and cell-cycle commitment genes. Furthermore, in vitro-expanded Tregs become functional and take on the characteristics of Treg B. Collectively, this study identifies human Treg subpopulations that can be used as predictive biomarkers for response to IST in AA and potentially other autoimmune diseases. We also show that Tregs from AA patients are IL-2-sensitive and expandable in vitro, suggesting novel therapeutic approaches such as low-dose IL-2 therapy and/or expanded autologous Tregs and meriting further exploration.

Efficient Query Processing in 3D Motion Capture Gesture Databases

One of the most fundamental challenges when accessing gestural patterns in 3D motion capture databases is the definition of spatiotemporal similarity. While distance-based similarity models such as the Gesture Matching Distance on gesture signatures are able to leverage the spatial and temporal characteristics of gestural patterns, their applicability to large 3D motion capture databases is limited due to their high computational complexity. To this end, we present a lower bound approximation of the Gesture Matching Distance that can be utilized in an optimal multi-step query processing architecture in order to support efficient query processing. We investigate the performance in terms of accuracy and efficiency based on 3D motion capture databases and show that our approach is able to achieve an increase in efficiency of more than one order of magnitude with a negligible loss in accuracy. In addition, we discuss different applications in the digital humanities in order to highlight the significance of similarity search approaches in the research field of gestural pattern analysis.

SF3B1 mutant MDS-initiating cells may arise from the haematopoietic stem cell compartment

Despite the recent evidence of the existence of myelodysplastic syndrome (MDS) stem cells in 5q-MDS patients, it is unclear whether haematopoietic stem cells (HSCs) could also be the initiating cells in other MDS subgroups. Here we demonstrate that SF3B1 mutation(s) in our cohort of MDS patients with ring sideroblasts can arise from CD34(+)CD38(-)CD45RA(-)CD90(+)CD49f(+) HSCs and is an initiating event in disease pathogenesis. Xenotransplantation of SF3B1 mutant HSCs leads to persistent long-term engraftment restricted to myeloid lineage. Moreover, genetically diverse evolving subclones of mutant SF3B1 exist in mice, indicating a branching multi-clonal as well as ancestral evolutionary paradigm. Subclonal evolution in mice is also seen in the clinical evolution in patients. Sequential sample analysis shows clonal evolution and selection of the malignant driving clone leading to AML transformation. In conclusion, our data show SF3B1 mutations can propagate from HSCs to myeloid progeny, therefore providing a therapeutic target.

Expansion of myeloid derived suppressor cells correlates with number of T regulatory cells and disease progression in myelodysplastic syndrome

Although the role of CD4⁺ T cells and in particular Tregs and Th17 cells is established in myelodysplastic syndrome(MDS), the contribution of other components of immune system is yet to be elucidated fully. In this study we investigated the number and function of myeloid derived suppressor cells (MDSCs) in fresh peripheral blood and matched bone marrow samples from 42 MDS patients and the potential correlation with risk of disease progression to acute myeloid leukemia (AML). In peripheral blood, very low-/low risk patients had significantly lower median MDSC number (0.16×10⁹/L(0.03-0.40)) compared to intermediate-/high-/very high risk patients, in whom median MDSC counts was 0.52×10⁹/L(0.10-1.78), p < 0.005. When co-cultured with CD4+ effector T-cells (T-effectors), MDSCs suppress Teffector proliferation in both allogeneic and autologous settings. There was a positive correlation between the number of Tregs and MDSCs (Spearman R = 0.825, p < 0.005) in high risk and not low risk patients. We also investigated MDSCs' expression of bone marrow-homing chemokine receptors, and our data shows that MDSCs from MDS patients express both CXCR4 and CX3CR1 which might facilitate migration of MDSCs to bone marrow. Monocytic MDSCs(M-MDSCs) which are more frequent in the peripheral blood express higher levels of CX3CR1 and CXCR4 than the granulocytic subtype (G-MDSCs), and circulating M-MDSCs had significantly higher CX3CR1 expression compared to bone-marrow M-MDSCs in intermediate-/high-/very high risk MDS. Our results suggest that MDSCs contribute significantly to the dysregulation of immune surveillance in MDS, which is different between low and high risk disease. It further points at mechanisms of MDSCs recruitment and contribution to the bone marrow microenvironment.

[Are 55 cents always better value than 90 cents for venous thromboembolism prophylaxis? Comparison of three low-molecular-weight heparins with regard to economics and guideline compliance]

BACKGROUND

Four low-molecular-weight heparins with different dosage regimens are allowed for venous thromboembolism prophylaxis in patients with a high risk of thromboembolism in Germany. If comparison is made purely on the basis of drug costs, multi-dose vials are the favourable solution. We try to answer the question whether the choice of low-molecular-weight heparin influences the compliance with the S2 guideline "Inpatient and outpatient thromboembolism prophylaxis in surgery and perioperative medicine." Beyond that we ask if multi-dose administration is superior to the pre-filled syringe when total costs are calculated on the basis of procedure and technical application.

PATIENTS AND METHODS

After training the nursing and medical staff in guideline-compliant implementation of thromboembolism prophylaxis with pre-filled certoparin safety syringes (03/09-05/09) or nadroparin (06/09-08/09) and enoxaparin (02/10-04/10) from multi-dose vials, we calculated the total costs on the basis of procedure and technical application. Furthermore, the satisfaction of the nursing staff was interrogated and the proportion of non-guideline-compliant prescriptions was determinated prospectively on the basis of a total of 388 patient files.

RESULTS

When total costs are calculated on the basis of procedure and technical application, the costs for nadroparin are 1.16 €/0.3 mL, 1.30 €/0.4 mL and 1.58 €/0.6 mL, for enoxaparin 1.04 €/20 and 1.42 €/40, and for certoparin 1.25 €/pre-filled safety syringe. The pre-filled certoparin safety syringe made a very good overall impression on the nursing staff (versus sufficient for nadroparin and enoxaparin). Guideline-compliance was achieved in 100 % with body weight- and risk-independent certoparin, in 79.4 % with risk-adapted enoxaparin, and in 66.4 % with body weight- and risk-dependent nadroparin.

CONCLUSION

The complexity of the dosage regimen of a low-molecular-weight heparin has a decisive influence on guideline-compliance. By calculating total costs on the basis of procedure and technical application multi-dose vials only offer a price advantage in patients with a low or moderate risk of thromboembolism compared with pre-filled safety syringes in the venous thromboembolism prophylaxis of orthopaedic and trauma surgery patients.

Spliceosome mutations exhibit specific associations with epigenetic modifiers and proto-oncogenes mutated in myelodysplastic syndrome

The recent identification of acquired mutations in key components of the spliceosome machinery strongly implicates abnormalities of mRNA splicing in the pathogenesis of myelodysplastic syndromes. However, questions remain as to how these aberrations functionally combine with the growing list of mutations in genes involved in epigenetic modification and cell signaling/transcription regulation identified in these diseases. In this study, amplicon sequencing was used to perform a mutation screen in 154 myelodysplastic syndrome patients using a 22-gene panel, including commonly mutated spliceosome components (SF3B1, SRSF2, U2AF1, ZRSR2), and a further 18 genes known to be mutated in myeloid cancers. Sequencing of the 22-gene panel revealed that 76% (n=117) of the patients had mutations in at least one of the genes, with 38% (n=59) having splicing gene mutations and 49% (n=75) patients harboring more than one gene mutation. Interestingly, single and specific epigenetic modifier mutations tended to coexist with SF3B1 and SRSF2 mutations (P<0.03). Furthermore, mutations in SF3B1 and SRSF2 were mutually exclusive to TP53 mutations both at diagnosis and at the time of disease transformation. Moreover, mutations in FLT3, NRAS, RUNX1, CCBL and C-KIT were more likely to co-occur with splicing factor mutations generally (P<0.02), and SRSF2 mutants in particular (P<0.003) and were significantly associated with disease transformation (P<0.02). SF3B1 and TP53 mutations had varying impacts on overall survival with hazard ratios of 0.2 (P<0.03, 95% CI, 0.1-0.8) and 2.1 (P<0.04, 95% CI, 1.1-4.4), respectively. Moreover, patients with splicing factor mutations alone had a better overall survival than those with epigenetic modifier mutations, or cell signaling/transcription regulator mutations with and without coexisting mutations of splicing factor genes, with worsening prognosis (P<0.001). These findings suggest that splicing factor mutations are maintained throughout disease evolution with emerging oncogenic mutations adversely affecting patients' outcome, implicating spliceosome mutations as founder mutations in myelodysplastic syndromes.

The effects of 5-azacytidine on the function and number of regulatory T cells and T-effectors in myelodysplastic syndrome

Expansion of regulatory T cells occurs in high-risk myelodysplastic syndrome and correlates with a poor prognosis. DNA methyltransferase inhibitors, particularly 5-azacytidine, have been shown to increase the survival of patients with high-risk myelodysplastic syndrome. It is not entirely clear whether this improvement in patients' survival is related to the effects of DNA methyltransferase inhibitors on the immune system and/or the direct effect of these drugs on the dysplastic clone. In this study we investigated the effect of 5-azacytidine on the function and proliferation capability of regulatory T cells and T-helper cells. The number and function of CD4(+) T-cell subsets in 68 patients with intermediate-2/high-risk myelodysplastic syndrome were serially assessed at diagnosis and following treatment. The in-vitro effects of 5-azacytidine on CD4(+) T-cell subsets isolated from both healthy donors and patients with myelodysplastic syndrome were also investigated. The number of peripheral blood regulatory T cells was significantly higher in myelodysplastic syndrome patients than in healthy donors and responders to treatment (P=0.01). The absolute numbers of T-helper 1 and T-helper 2, but not T-helper 17, cells were significantly reduced following 12 months of treatment (P=0.03, P=0.03). The in vitro addition of 5-azacytidine to CD4(+) T cells reduced the proliferative capacity of regulatory T cells (P=0.03). In addition, the 5-azacytidine-treated regulatory T cells had reduced suppressive function and produced larger amounts of interleukin-17. The FOXP3 expression in 5-azacyti-dine-treated T-effectors was also increased. Interestingly, these FOXP3(+)/interleukin-17(+) cells originated mainly from effector T cells rather than regulatory T cells. Our data suggest that 5-azacytidine has profound effects on CD4(+) T cells, which correlate with disease status after treatment. Furthermore, despite the demethylation of the FOXP3 promoter and increased FOXP3 expression following 5-azacytidine treatment, these phenotypic regulatory T cell-like cells lack the regulatory function and cytokine profile of regulatory T cells. These findings are important in correlating the clinically relevant immunomodulatory effects of 5-azacytidine.

Support vector machine classification based on correlation prototypes applied to bone age assessment

Bone age assessment (BAA) on hand radiographs is a frequent and time consuming task in radiology. We present a method for (semi)automatic BAA which is done in several steps: (i) extract 14 epiphyseal regions from the radiographs, (ii) for each region, retain image features using the IRMA framework, (iii) use these features to build a classifier model (training phase), (iv) evaluate performance on cross validation schemes (testing phase), (v) classify unknown hand images (application phase). In this paper, we combine a support vector machine (SVM) with cross-correlation to a prototype image for each class. These prototypes are obtained choosing one random hand per class. A systematic evaluation is presented comparing nominal- and real-valued SVM with k nearest neighbor (kNN) classification on 1,097 hand radiographs of 30 diagnostic classes (0 19 years). Mean error in age prediction is 1.0 and 0.83 years for 5-NN and SVM, respectively. Accuracy of nominal- and real-valued SVM based on 6 prominent regions (prototypes) is 91.57% and 96.16%, respectively, for accepting about two years age range.

[Do German-speaking paediatric orthopaedic surgeons agree on diagnostics and treatment of the neonatal hip?]

BACKGROUND

Ultrasound examination of the neonatal hip has been an integral part of the German programme for the "early detection of disease in childhood" since 01.01.1996. The aim of this study is to determine if any consensus exists among German-speaking paediatric orthopaedic specialists concerning diagnosis and treatment of the neonatal hip 15 years after legal implementation of hip ultrasound screening by the Graf technique.

MATERIALS AND METHODS

A questionnaire was sent to all members of the German speaking Association of Paediatric Orthopaedic Surgeons (Vereinigung für Kinderorthopädie - VKO). The query included questions concerning education and field of activity of the member as well as information on the diagnostics of neonatal hip with regard to examiner, technical equipment, and type of screening. In addition, four cases were presented with clinical history, clinical findings, and rateable Graf sonogram (case 1: 3 days old ♀, type D; case 2: 2 days old ♀, type IV; case 3: 4 weeks old ♀, type II a; case 4: 4 months old ♀, type III a) and a treatment recommendation was requested for each case.

RESULTS

78 of 179 contactable VKO members participated in this survey. 75.6 % of the participants are specialists with additional qualification in paediatric orthopaedic surgery. 68 % of the participants work in a hospital. As stated by 61.5 % of the participants the ultrasound examination of the neonatal hip is primarily done by orthopaedic surgeons. One participant stated that the examination is performed primarily by medical-technical assistants. The majority of participants use a 7.5-MHz linear transducer for ultrasound examination, a positioning device according to Graf and a foot switch as technical equipment. State-of-the-art equipment as recommended by Graf including in addition to the above mentioned an upright image display and a transducer guiding arm system is available to only 21.8 % of the participating VKO members. 23 of 50 participants stated that a general screening is performed at their institution where all newborns get an ultrasound examination within the first week of life regardless of medical history and clinical findings. Therapeutic recommendations for the first case (type D hip) were in 15.4 % wait and check by some colleagues, supplemented by double diapering. 56.4 % would use a flexion-abduction splint and 26.9 % would perform reduction with consecutive retention. To treat case 2 (type IV hip) 3.8 % of participants suggest a flexion-abduction splint and 88.5 % reduction and retention. Concerning the type of reduction the participants do not agree. Pavlik harness as well as closed reduction under anaesthesia or without anaesthesia is recommended. In case 3 (type II a hip) 67.9 % of the colleagues suggest to wait and check, some with supplementary double diapering. 25.6 % suggest a flexion-abduction splint. One colleague would prescribe a Pavlik harness. In case 4 (type III a hip) 14.1 % of the participants suggest a flexion-abduction splint, 80.8 % reduction and retention as described before with disagreement concerning the preferred type of reduction. On combining the therapeutic suggestions for all four cases, 66 % of the participants recommend a type of treatment that is concordant with Graf's guidelines.

CONCLUSION

Despite the existence of clear recommendations the German-speaking paediatric orthopaedic surgeons are quite discordant concerning diagnostics and treatment of the neonatal hip. Uncertainty particularly concerning the evaluation of sonograms of physiologically immature and dysplastic-unstable hips bears the risk of overtreatment as well as of delayed diagnosis of hip dysplasia.

B-cell agonists up-regulate AID and APOBEC3G deaminases, which induce IgA and IgG class antibodies and anti-viral function

B cells express two critical deaminases in the development of adaptive and innate immunity. Activation-induced cytidine deaminase (AID) functions in class switch recombination, somatic hypermutation and may result in affinity maturation of antibodies. Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G; A3G) is an innate anti-retroviral factor that inhibits HIV replication. We have studied a number of B-cell agonists with the aim of identifying the most effective agents that will up-regulate both deaminases and thereby enhance adaptive and innate immunity. CD40 ligand (CD40L) with interleukin-4 or HLA-class II antibodies significantly up-regulated both AID and A3G in isolated human CD19(+) B cells. The functions of these deaminases were demonstrated by enhancement of B-cell surface expression of IgA and IgG and inducing significantly higher IgA and IgG4 antibodies. An enhanced A3G function was then demonstrated by inhibition of HIV-1 replication in co-culture of CD4(+) T cells with autologous B cells, treated with CD40L and CD4 or HLA antibodies, compared with unstimulated human B cells. The dual B-cell-induced deaminase functions may be critical in IgA and IgG antibodies inhibiting pre-entry and A3G that of post-entry HIV-1 transmission and suggests a novel strategy of immunization, especially relevant to mucosal infections.

Innate immunity and HIV-1 infection

HIV-1 is predominantly transmitted through mucosal tissues, targeting CD4(+)CCR5(+) T cells, 50% of which are destroyed within 2 weeks of infection. Conventional vaccination strategies have so far failed to prevent HIV-1 infection. Neither antibodies nor cytotoxic lymphocytes are capable of mounting a sufficiently rapid immune response to prevent early destruction of these cells. However, innate immunity is an early-response system, largely independent of prior encounter with a pathogen. Innate immunity can be classified into cellular, extracellular, and intracellular components, each of which is exemplified in this review by γδ T cells, CC chemokines, and APOBEC3G, respectively. First, γδ T cells are found predominantly in mucosal tissues and produce cytokines, CC chemokines, and antiviral factors. Second, the CC chemokines CCL-3, CCL-4, and CCL-5 can be upregulated by immunization of macaques with SIVgp120 and gag p27, and these can bind and downmodulate CCR5, thereby inhibiting HIV-1 entry into the host cells. Third, APOBEC3G is generated and maintained following rectal mucosal immunization in rhesus macaques for over 17 weeks, and the innate anti-SIV factor is generated by CD4(+)CD95(+)CCR7(-) effector memory T cells. Thus, innate anti-HIV-1 or SIV immunity can be linked with immune memory, mediated by CD4(+) T cells generating APOBEC3G. The multiple innate functions may mount an early anti-HIV-1 response and either prevent viral transmission or contain the virus until an effective adaptive immune response develops.

[Locking plates for osteosyntheses of corrective osteotomies in paediatric orthopaedic and neuroorthopaedic patients]

BACKGROUND

Modern locking plates are widely used for the treatment of adult orthopaedic and trauma patients. Sporadic descriptions of their advantages now exist for paediatric trauma patients. Publications concerning their implantation in paediatric orthopaedic and neuroorthopaedic patients are still scarce even though it is well known that the compliance of children and adolescents is limited and that rapid mobilisation is essential for patients with disorders of neurological origin or bone metabolism to avoid developmental setbacks and perioperative fractures.

PATIENTS AND METHODS

The principle of the locking plate system also described as internal fixateur is based on the thread bolting of the screwheads within the plate. This results in high initial stability and thus high initial loading capacity. Furthermore, it is possible to preserve soft tissue and periosteum which leads to less impaired biological bone healing. Between February 2008 and March 2010 locking plates were used for osteosynthesis in our department in 16 paediatric patients with 20 corrective osteotomies. All patients suffered from either neurological disorders or diseases with alteration of the bone metabolism. The outcome was analysed concerning safety, complications, practicability, mobilisation, consolidation of the osteotomy, loss of correction, as well as complications with the removal of the implants.

RESULTS

Seven of the treated patients suffered from neurological disorders such as cerebral palsy or spina bifida, 9 patients had diseases with local or systemic alteration of their bone metabolism such as vitamin D deficiency and phosphate diabetes. The average age of the patients at the time of surgery was 11.18 (5-18) years. Implant-associated complications were not seen in this patient group, especially no implant failures. Mobilisation was achieved without cast treatment with at least partial weight-bearing within the first postoperative week in most cases. Loss of correction or problems with implant removal did not occur. 18 of the 20 osteotomy sites were completely healed at the 12 week follow-up.

CONCLUSION

Locking plates are a safe and effective treatment device not only for adult trauma patients but also for the treatment of children and adolescents. When stabilisation of corrective osteotomies is performed with locking plates especially young patients benefit from this technique since mobilisation can be started earlier as compared to the use of non-angle stable plates or wires and cast immobilisation becomes unneccessary. The surgeon needs to know the range of products to pick the best implant regarding the growing skeleton's special anatomy. When choosing implants for patients with reduced bone density or impaired motor abilities as in cerebral palsy, spina bifida, and other systemic disorders, locking plates have to be taken into account to facilitate mobilisation and to avoid setbacks in motor development as well as pressure ulcers from casts. Clinical studies have to evaluate if early mobilisation combined with shorter inpatient treatment and less time and cost consuming postoperative physiotherapy or rehabilitation justify the use of the more expensive locking plates for the treatment of otherwise healthy patients.

The melanocortin receptor agonist NDP-MSH impairs the allostimulatory function of dendritic cells

As alpha-melanocyte-stimulating hormone (alpha-MSH) is released by immunocompetent cells and has potent immunosuppressive properties, it was determined whether human dendritic cells (DCs) express the receptor for this hormone. Reverse transcription-polymerase chain reaction detected messenger RNA specific for all of the known melanocortin receptors in DCs. Mixed lymphocyte reactions also revealed that treatment with [Nle(4), DPhe(7)]-alpha-MSH (NDP-MSH), a potent alpha-MSH analogue, significantly reduced the ability of DCs to stimulate allogeneic T cells. The expression of various cell surface adhesion, maturation and costimulatory molecules on DCs was also investigated. Although treatment with NDP-MSH did not alter the expression of CD83 and major histocompatibility complex class I and II, the surface expression of CD86 (B7.2), intercellular adhesion molecule (ICAM-1/CD54) and CD1a was reduced. In summary, our data indicate that NDP-MSH inhibits the functional activity of DCs, possibly by down-regulating antigen-presenting and adhesion molecules and that these events may be mediated via the extracellular signal-regulated kinase 1 and 2 pathway.

The effect of allogeneic in vitro stimulation and in vivo immunization on memory CD4(+) T-cell APOBEC3G expression and HIV-1 infectivity

Allogeneic immunity is one of the most potent natural immune responses. APOBEC3G (A3G) is an intracellular anti-viral factor that deaminates cytidine to uridine. Allogeneic stimulation of human CD4(+) T cells in vitro upregulated A3G mRNA and a significant correlation was found between the mixed leukocyte reaction and A3G mRNA. The mechanism of upregulation of A3G mRNA involves interaction between HLA on DC and TCR of CD4(+) T cells, which is ZAP70 and downstream ERK phosphokinase signalling dependent and induces CD40L and A3G mRNA expression in CD4(+) T cells. Alloimmune-induced A3G was found to be significantly increased in CD45RA(-), CCR5(+) and CD45RA(-)CCR7(-) subsets of effector memory T cells. In vivo studies of women alloimmunized with their partners' PBMC also showed a significant increase in A3G protein in CD4(+) T cells, CD45RO(+) memory and CCR7(-) effector memory T cells. The functional effect of allostimulation upregulating A3G mRNA was demonstrated by a significant decrease in in vitro infectivity, using GFP-labelled pseudovirus and confirmed by a decrease in HIV-1 (BaL) infection of primary CD4(+) T cells. The results suggest that alloimmunization offers an alternative or complementary strategy in inducing an innate anti-viral factor that inhibits HIV-1 infection.

Mucosal immunization in macaques upregulates the innate APOBEC 3G anti-viral factor in CD4(+) memory T cells

APOBEC3G is an innate intracellular anti-viral factor which deaminates retroviral cytidine to uridine. In vivo studies of APOBEC3G (A3G) were carried out in rhesus macaques, following mucosal immunization with SIV antigens and CCR5 peptides, linked to the 70kDa heat shock protein. A progressive increase in A3G mRNA was elicited in PBMC after each immunization (p<0.0002 to p< or =0.02), which was maintained for at least 17 weeks. Analysis of memory T cells showed a significant increase in A3G mRNA and protein in CD4(+)CCR5(+) memory T cells in circulating (p=0.0001), splenic (p=0.0001), iliac lymph nodes (p=0.002) and rectal (p=0.01) cells of the immunized compared with unimmunized macaques. Mucosal challenge with SIVmac 251 showed a significant increase in A3G mRNA in the CD4(+)CCR5(+) circulating cells (p<0.01) and the draining iliac lymph node cells (p<0.05) in the immunized uninfected macaques, consistent with a protective effect exerted by A3G. The results suggest that mucosal immunization in a non-human primate can induce features of a memory response to an innate anti-viral factor in CCR5(+)CD4(+) memory and CD4(+)CD95(+)CCR7(-) effector memory T cells.

VISA

To gain insight into today's large data resources, data mining extracts interesting patterns. To generate knowledge from patterns and benefit from human cognitive abilities, meaningful visualization of patterns are crucial. Clustering is a data mining technique that aims at grouping data to patterns based on mutual (dis)similarity. For high dimensional data, subspace clustering searches patterns in any subspace of the attributes as patterns are typically obscured by many irrelevant attributes in the full space. For visual analysis of subspace clusters, their comparability has to be ensured. Existing subspace clustering approaches, however, lack interactive visualization and show bias with respect to the dimensionality of subspaces.

In this work, dimensionality unbiased subspace clustering and a novel distance function for subspace clusters are proposed. We suggest two visualization techniques that allow users to browse the entire subspace clustering, to zoom into individual objects, and to analyze subspace cluster characteristics in-depth. Bracketing of different parameter settings enable users to immediately see the effect of parameters on their data and hence to choose the best clustering result for further analysis. Usage of user analysis for feedback to the subspace clustering algorithm directly improves the subspace clustering. We demonstrate our visualization techniques on real world data and confirm results through additional accuracy measurements and comparison with existing subspace clustering algorithms.

Extended query refinement for medical image retrieval

The impact of image pattern recognition on accessing large databases of medical images has recently been explored, and content-based image retrieval (CBIR) in medical applications (IRMA) is researched. At the present, however, the impact of image retrieval on diagnosis is limited, and practical applications are scarce. One reason is the lack of suitable mechanisms for query refinement, in particular, the ability to (1) restore previous session states, (2) combine individual queries by Boolean operators, and (3) provide continuous-valued query refinement. This paper presents a powerful user interface for CBIR that provides all three mechanisms for extended query refinement. The various mechanisms of man-machine interaction during a retrieval session are grouped into four classes: (1) output modules, (2) parameter modules, (3) transaction modules, and (4) process modules, all of which are controlled by a detailed query logging. The query logging is linked to a relational database. Nested loops for interaction provide a maximum of flexibility within a minimum of complexity, as the entire data flow is still controlled within a single Web page. Our approach is implemented to support various modalities, orientations, and body regions using global features that model gray scale, texture, structure, and global shape characteristics. The resulting extended query refinement has a significant impact for medical CBIR applications.

Evidence for reduced B-cell progenitors in early (low-risk) myelodysplastic syndrome

Early, low-risk International Prognostic Scoring System (IPSS) myelodysplastic syndrome (MDS) is a heterogeneous disorder where the molecular and cellular hematopoietic defects are poorly understood. To gain insight into this condition, we analyzed gene expression profiles of marrow CD34+ progenitor cells from normal-karyotype, low-blast-count MDS patients, age-matched controls, and patients with non-MDS anemia. Given the heterogeneity of early MDS, a surprisingly consistent finding was decreased expression of B-cell lineage-affiliated genes in MDS patients compared with healthy controls and 3 of 5 samples with non-MDS anemia. Both patients with non-MDS anemia with reduced B-cell gene expression were on chemotherapy. In 25 of 27 of the original samples and 9 further MDS samples, Taqman real-time polymerase chain reaction (PCR) confirmed these data. Flow cytometry on unfractionated marrow from independent samples also demonstrated reduced B-cell progenitors in MDS patients compared with healthy controls. These novel findings suggest a common perturbation in early MDS hematopoiesis. They also provide the rationale for a larger study to evaluate the diagnostic utility of reduced B-cell progenitor number as a diagnostic biomarker of early low-risk MDS, which can pose a diagnostic challenge.

Molecular signatures of self-renewal, differentiation, and lineage choice in multipotential hemopoietic progenitor cells in vitro

The molecular mechanisms governing self-renewal, differentiation, and lineage specification remain unknown. Transcriptional profiling is likely to provide insight into these processes but, as yet, has been confined to "static" molecular profiles of stem and progenitors cells. We now provide a comprehensive, statistically robust, and "dynamic" analysis of multipotent hemopoietic progenitor cells undergoing self-renewal in response to interleukin-3 (IL-3) and multilineage differentiation in response to lineage-affiliated cytokines. Cells undergoing IL-3-dependent proliferative self-renewal displayed striking complexity, including expression of genes associated with different lineage programs, suggesting a highly responsive compartment poised to rapidly execute intrinsically or extrinsically initiated cell fate decisions. A remarkable general feature of early differentiation was a resolution of complexity through the downregulation of gene expression. Although effector genes characteristic of mature cells were upregulated late, coincident with morphological changes, lineage-specific changes in gene expression were observed prior to this, identifying genes which may provide early harbingers of unilineage commitment. Of particular interest were genes that displayed differential behavior irrespective of the lineage elaborated, many of which were rapidly downregulated within 4 to 8 h after exposure to a differentiation cue. These are likely to include genes important in self-renewal, the maintenance of multipotentiality, or the negative regulation of differentiation per se.