The Personalized Parkinson Project: examining disease progression through broad biomarkers in early Parkinson's disease

BACKGROUND

Our understanding of the etiology, pathophysiology, phenotypic diversity, and progression of Parkinson's disease has stagnated. Consequently, patients do not receive the best care, leading to unnecessary disability, and to mounting costs for society. The Personalized Parkinson Project (PPP) proposes an unbiased approach to biomarker development with multiple biomarkers measured longitudinally. Our main aims are: (a) to perform a set of hypothesis-driven analyses on the comprehensive dataset, correlating established and novel biomarkers to the rate of disease progression and to treatment response; and (b) to create a widely accessible dataset for discovery of novel biomarkers and new targets for therapeutic interventions in Parkinson's disease.

METHODS/DESIGN

This is a prospective, longitudinal, single-center cohort study. The cohort will comprise 650 persons with Parkinson's disease. The inclusion criteria are purposely broad: age ≥ 18 years; and disease duration ≤5 years. Participants are followed for 2 years, with three annual assessments at the study center. Outcomes include a clinical assessment (including motor and neuro-psychological tests), collection of biospecimens (stool, whole blood, and cerebrospinal fluid), magnetic resonance imaging (both structural and functional), and ECG recordings (both 12-lead and Holter). Additionally, collection of physiological and environmental data in daily life over 2 years will be enabled through the Verily Study Watch. All data are stored with polymorphic encryptions and pseudonyms, to guarantee the participants' privacy on the one hand, and to enable data sharing on the other. The data and biospecimens will become available for scientists to address Parkinson's disease-related research questions.

DISCUSSION

The PPP has several distinguishing elements: all assessments are done in a single center; inclusion of "real life" subjects; deep and repeated multi-dimensional phenotyping; and continuous monitoring with a wearable device for 2 years. Also, the PPP is powered by privacy and security by design, allowing for data sharing with scientists worldwide respecting participants' privacy. The data are expected to open the way for important new insights, including identification of biomarkers to predict differences in prognosis and treatment response between patients. Our long-term aim is to improve existing treatments, develop new therapeutic approaches, and offer Parkinson's disease patients a more personalized disease management approach.

TRIAL REGISTRATION

Clinical Trials NCT03364894 . Registered December 6, 2017 (retrospectively registered).

Rates and predictors of hypoglycaemia in 27 585 people from 24 countries with insulin-treated type 1 and type 2 diabetes: the global HAT study

AIMS

To determine the global extent of hypoglycaemia experienced by patients with diabetes using insulin, as there is a lack of data on the prevalence of hypoglycaemia in developed and developing countries.

METHODS

This non-interventional, multicentre, 6-month retrospective and 4-week prospective study using self-assessment questionnaire and patient diaries included 27 585 patients, aged ≥18 years, with type 1 diabetes (T1D; n = 8022) or type 2 diabetes (T2D; n = 19 563) treated with insulin for >12 months, at 2004 sites in 24 countries worldwide. The primary endpoint was the proportion of patients experiencing at least one hypoglycaemic event during the observational period.

RESULTS

During the prospective period, 83.0% of patients with T1D and 46.5% of patients with T2D reported hypoglycaemia. Rates of any, nocturnal and severe hypoglycaemia were 73.3 [95% confidence interval (CI) 72.6-74.0], 11.3 (95% CI 11.0-11.6) and 4.9 (95% CI 4.7-5.1) events/patient-year for T1D and 19.3 (95% CI 19.1-19.6), 3.7 (95% CI 3.6-3.8) and 2.5 events/patient-year (95% CI 2.4-2.5) for T2D, respectively. The highest rates of any hypoglycaemia were observed in Latin America for T1D and Russia for T2D. Glycated haemoglobin level was not a significant predictor of hypoglycaemia.

CONCLUSIONS

We report hypoglycaemia rates in a global population, including those in countries without previous data. Overall hypoglycaemia rates were high, with large variations between geographical regions. Further investigation into these differences may help to optimize therapy and reduce the risk of hypoglycaemia.

A meta-analysis of rate ratios for nocturnal confirmed hypoglycaemia with insulin degludec vs. insulin glargine using different definitions for hypoglycaemia

AIMS

A prospective meta-analysis of phase 3 trials showed lower rates of nocturnal hypoglycaemia with insulin degludec vs. insulin glargine. We investigated the consistency of the results across different definitions of hypoglycaemia.

METHODS

This post-hoc, patient-level meta-analysis included six randomized, controlled, 26- or 52-week phase 3a trials in insulin-naïve participants with Type 2 diabetes mellitus (Type 2 diabetesinsulin naïve ), participants with Type 2 diabetes mellitus using basal-bolus therapy (Type 2 diabetesBB ) and those with Type 1 diabetes mellitus. We used three definitions of hypoglycaemia and different timescales for the nocturnal period. Rates were analysed for the entire core trial period, the 'maintenance period' only, and the extension trial set population. Analyses utilized a negative binomial regression model.

RESULTS

In Type 2 diabetesinsulin naïve participants, risk of nocturnal hypoglycaemia was significantly lower with insulin degludec vs. insulin glargine for all hypoglycaemia definitions and trial periods. Risk was also lower for the timescale 21.59-05.59, but not 00.01-07.59. For Type 2 diabetesBB , nocturnal hypoglycaemia rates were lower with insulin degludec vs. insulin glargine across all definitions, timescales and trial periods, with one exception. For individuals with Type 1 diabetes mellitus, nocturnal hypoglycaemia risk was significantly lower with insulin degludec during the maintenance period for the original definition (plasma glucose < 3.1 mmol/l, timescale 00.01-05.59) and in the extension trial set population for all hypoglycaemia definitions except for the nocturnal timescale 00.01-07.59.

CONCLUSIONS

Compared with insulin glargine, insulin degludec is associated with lower rates of nocturnal hypoglycaemia in people with Type 2 diabetes mellitus, and similar or lower rates in Type 1 diabetes mellitus, across different definitions.

ID: 95: IL-33/ST2 TRIGGERING OF IL-9–SECRETING T CELLS: FROM PROTEOMICS TO THERAPEUTICS

As one of the most validated immunotherapies to date, allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative option for high-risk hematological malignancies, particularly acute myeloid leukemia (AML). The immunotherapeutic activity of allo-HCT is known as the graft-vs-leukemia (GVL) activity. However, GVL activity is often accompanied by T-cell reactivity to allo-antigens in normal host tissues, which leads to graft-versus-host disease (GVHD), another major cause of death after HCT. Therefore, there is a great unmet need to improve the current process of allo-HCT through increasing the GVL activity and decreasing GVHD. We have shown that an elevated plasma level of soluble (s)ST2 in HCT patients is a risk factor for severe GVHD. ST2 blockade reduces sST2-producing T cells while maintaining protective membrane (m)ST2-expressing T cells such as type 2 T cells and regulatory T cells during aGVHD. A novel IL-9 producing T helper subset, Th9, expresses mST2. Furthermore, Th9 cells and IL-9 producing CD8 cytotoxic (Tc9) cells have higher antitumor activity than Th1 and Tc1 cells in melanoma models. Interestingly, we found that the addition of IL-33 during T9 differentiation (T9IL-33) increased expression of mST2 and PU.1, a transcription factor that promotes IL-9 production in both CD4 and CD8 T cells. Adoptive transfer of T9IL-33 cells with bone marrow cells in a murine model of HCT resulted in less severe GVHD compared to transfer of T9IL-33 cells generated from ST2−/− or IL-9−/− T cells. Furthermore, cytolytic molecules implicated in anti-leukemic activity (granzyme B and perforin) were upregulated in WT T9IL-33 cells while ST2−/− T9IL-33 cells did not. WT T9IL-33 cells also exhibited higher anti-leukemic activity when cultured with a retrovirally transduced MLL-AF9 leukemic cells in comparison to ST2−/− T9IL-33 in in vitro cytolytic assays. In vivo GVL experiments with MLL-AF9 AML and adoptive transfer of T9IL-33 cells resulted in increased survival compared to syngeneic mice, allo-HCT mice transferred with T1 cells, or T9 cells or T9IL-33 cells generated from ST2−/− or IL-9−/− T cells. Human T9 cells are poorly studied. Here we demonstrate that IL-33 has the same impact on human T cells through enhancing IL-9 and Granzyme B production compared to T9 cells as well as demonstrated higher in vitro anti-leukemic cytolytic activity when incubated with MOLM14, an aggressive AML tumor cell line expressing FLT3/ITD mutations. Importantly, CD8α expression was upregulated in WT T9IL-33 (both CD4 and CD8) cells in comparison to ST2−/− T9IL-33 cells, and CD8α blockade with neutralizing antibody during allogeneic specific T9IL-33 differentiation reduced cytotoxicity of both murine T9IL-33, and human T9IL-33 cells as compared to the cell blocked with isotype control, suggesting that CD8α was associated with MHC-restricted cytolytic activity in T9IL-33 cells. Altogether, our observations demonstrated that adoptive transfer of T9IL-33 cells represents a promising cellular therapy following HCT.

ID: 91: ST2 BLOCKADE REDUCES SST2-PRODUCING T CELLS WHILE MAINTAINING PROTECTIVE MST2-EXPRESSING T CELLS DURING GRAFT-VERSUS-HOST DISEASE

Allogeneic hematopoietic stem cell transplantation is an important curative therapy for hematological malignancies and other blood disorders, but graft-versus-host disease (GVHD) remains a devastating complication. We previously identified high plasma soluble suppression of tumorigenicity 2 (ST2) as a biomarker of the development of GVHD and death. ST2, also known as the interleukin (IL)-33 receptor, is one of the newest members of the IL-1 receptor family, and its only known ligand is IL-33. Due to alternative splicing, ST2 has two main isoforms: a membrane-bound form (mST2), expressed on hematopoietic cells that promote type 2 helper T (Th2) cell immune responses, and a soluble form (sST2), secreted by non-hematopoietic cells. sST2 acts as a decoy receptor for IL-33, limiting its availability to mST2-expressing cells. Thus, we hypothesized that blockade of the sST2 will free IL-33 for signaling in mST2-expressing T cells [Th2 cells and ST2+FoxP3+ regulatory T cells (Tregs)], which will attenuate GVHD.

First, we found the onset of GVHD symptoms was correlated with a marked increase of plasma ST2 in multiple clinically relevant GVHD murine models, and blockade of sST2 in the peri-transplant period with a neutralizing monoclonal antibody (anti-ST2 mAb) reduced GVHD clinical and histopathological severity and mortality. We identified intestinal stromal cells and T cells as major sources of sST2 during GVHD. ST2 blockade decreased systemic interferon-γ, IL-17, and IL-23 but increased IL-10 and IL-33 plasma levels. ST2 blockade also reduced sST2 production by IL-17–producing T cells while maintaining protective mST2-expressing Th2 cells and Tregs. In addition, ST2 blockade increased the frequency of intestinal myeloid-derived suppressor cells (MDSCs) and decreased the frequency of intestinal CD103 dendritic cells (DCs). Finally, whole transcriptome analysis of T cells comparing anti-ST2 mAb-treated mice versus IgG control-treated mice showed that anti-ST2 mAb administration up-regulated gene expression of cytokines and cytolytic molecules that have been implicated in antitumoral or graft-vs-leukemia (GVL) activity, such as IL-27, IL-18, IL-9, type I interferons, and granzyme A. We therefore postulated that ST2 blockade would not affect therapeutic GVL activity. To confirm this in a clinically relevant GVL model, we developed primary retrovirally induced MLL-AF9 eGFP+ leukemic cells on the C3H.SW background. The phenotype of the leukemic cells in this model is eGFP+, CD3−, B220− and Mac-1hiGr-1hi. Our results indicated that administration of anti-ST2 mAb or ST2−/− donor T cells preserved substantial GVL activity and resulted in significantly improved leukemia-free survival.

In summary, our findings identify intestinal alloreactive T cells as an important source of the decoy receptor for IL-33 that can be blocked with two doses of anti-ST2 mAb in the peri-transplant period without inhibiting the beneficial mST2 expression on Th2 cells and Tregs or the GVL activity. In addition, ST2 blockade induced expansion of tolerogenic MDSCs while inhibiting immunogenic CD103 DCs during GVHD. This study offers new perspectives on the translation of drug-targetable biomarkers for selectively and safely treating GVHD and other T cell-mediated human disorders.

Diffusion-weighted imaging of malignant ocular masses: initial results and directions for further study

BACKGROUND AND PURPOSE

Ocular masses represent a spectrum of malignant tumors and benign lesions that are sometimes difficult to detect and differentiate by conventional imaging techniques. The aim of this study was to characterize a group of malignant ocular masses with DWI, with the goals of establishing reference data and identifying potential clinical applications for improved noninvasive characterization.

MATERIALS AND METHODS

With institutional review board approval, 26 malignant ocular masses in 22 patients were retrospectively analyzed. Five masses were excluded from further analysis due to nonvisualization. Fifteen retinoblastomas, 5 melanomas, and 1 highly undifferentiated carcinoma were studied. Region-of-interest analysis was performed, and the ADC of each mass was measured and also compared with a normal-appearing thalamus. Lesion thickness was measured, the amount of susceptibility artifact was qualitatively assessed and graded, and the correlation between these factors and retinoblastoma ADC was determined.

RESULTS

Retinoblastomas had an ADC of 0.93 ± 0.3 × 10(-3) mm(2)/s (mean). Melanoma had an ADC of 1.18 ± 0.16 × 10(-3) mm(2)/s. The ADC of retinoblastoma was strongly inversely correlated with lesion thickness, likely representing the effect of partial volume averaging. ADC was not correlated with the amount of subjectively determined susceptibility artifact.

CONCLUSIONS

Malignant ocular tumors were consistently characterized with DWI, though with limitations due to artifact and partial volume averaging. Additional description of DWI of ocular masses and further technical improvements may lead to a clinical role for DWI.

A microfluidics approach for the isolation of nucleated red blood cells (NRBCs) from the peripheral blood of pregnant women

OBJECTIVE

Nucleated red blood cells (NRBCs) have been identified in maternal circulation and potentially provide a resource for the monitoring and diagnosis of maternal, fetal, and neonatal health and disease. Past strategies used to isolate and enrich for NRBCs are limited to complex approaches that result in low recovery and less than optimal cell purity. Here we report the development of a high-throughput and highly efficient microfluidic device for isolating rare NRBCs from maternal blood.

MATERIAL AND METHODS

NRBCs were isolated from the peripheral blood of 58 pregnant women using a microfluidic process that consists of a microfluidic chip for size-based cell separation and a magnetic device for hemoglobin-based cell isolation.

RESULTS

The microfluidic-magnetic combination removes nontarget red blood cells and white blood cells at a very high efficiency (approximately 99.99%). The device successfully identified NRBCs from the peripheral blood of 58/58 pre-termination samples with a mean of 37.44 NRBC/mL (range 0.37-274.36 NRBC/mL). These results were compared with those from previous studies.

CONCLUSION

The microfluidic device results in an approximate 10- to 20-fold enrichment of NRBCs over methods described previously. The reliability of isolation and the purity of the NRBC product have the potential to enable the subsequent application of molecular diagnostic assays.

MR imaging of orbital inflammatory syndrome, orbital cellulitis, and orbital lymphoid lesions: the role of diffusion-weighted imaging

BACKGROUND AND PURPOSE

Orbital inflammatory syndrome (OIS) has clinical features that overlap with orbital lymphoid lesions and orbital cellulitis. Prompt diagnosis is needed in all 3 conditions because the management of each one differs greatly. CT and MR imaging, though useful, do not always distinguish among these conditions. The aim of this study was to identify the role of diffusion-weighted imaging (DWI) in differentiating these 3 diagnoses.

MATERIALS AND METHODS

A retrospective analysis of orbital MR imaging was conducted. T1- and T2-weighted and postcontrast images were analyzed. Region-of-interest analysis was performed by using measurements in areas of abnormality seen on conventional MR imaging sequences and measurements of the ipsilateral thalamus for each patient. The DWI signal intensity of the lesion was expressed as a percentage of average thalamic intensity in each patient. Similarly, lesion apparent diffusion coefficients (ADCs) and lesion-thalamus ADC ratios were calculated. Statistical significance was determined by the Kruskal-Wallis test, and post hoc pairwise comparisons, by the Mann-Whitney U test for DWI-intensity ratio, ADC, and ADC ratio.

RESULTS

A significant difference was noted in DWI intensities, ADC, and ADC ratio between OIS, orbital lymphoid lesions, and orbital cellulitis (P < .05). Lymphoid lesions were significantly brighter than OIS, and OIS lesions were significantly brighter than cellulitis. Lymphoid lesions showed lower ADC than OIS and cellulitis. A trend was seen toward lower ADC in OIS than in cellulitis (P = .17).

CONCLUSIONS

DWI may help differentiate OIS from lymphoid lesions and cellulitis and may allow more rapid management.

Changes in resin-infiltrated dentin stiffness after water storage

Plasticization of polymers by water sorption lowers their mechanical properties in a manner that is predictable by the polarity of their component resins. This study tested the hypothesis that when adhesive resins were used to create resin-infiltrated dentin, the reductions in their flexural moduli after water storage would be lowered proportional to their hydrophilic characteristics. Three increasingly hydrophilic resin blends were used to fabricate polymer beams and macro-hybrid layer models of resin-infiltrated dentin for testing with a miniature three-point flexure device, before and after 1-4 weeks of water storage. Flexural modulus reductions in macro-hybrid layers were related to, and more extensive than, reductions in the corresponding polymer beams. Macro-hybrid layers that were more hydrophilic exhibited higher percent reductions in flexural modulus, with the rate of reduction proportional to the Hoy's solubility parameters for total intermolecular attraction forces (delta(t)) and polar forces (delta(p)) of the macro-hybrid layers.

Hemifacial microsomia: a case report

Hemifacial microsomia is a congenital malformation in which there is a deficiency in the amount of hard and soft tissue on one side of the face. It is primarily a syndrome of the first branchial arch, involving underdevelopment of the temporomandibular joint, mandibular ramus, masticatory muscles and the ear. The affected ear may have an external soft-tissue malformation in addition to being lower set than on the contra lateral side. Hearing loss may result from underdevelopment of the osseous components of the auditory system and a diminished or absent external auditory meatus. Occasionally, second branchial arch defects involving the facial nerve and facial muscles coexist with Hemifacial microsomia. Radiographic examination in case of Hemifacial microsomia is of limited value because of superimposition of normal and abnormal bony structures. The skeletal and soft-tissue findings of a patient with Hemifacial microsomia who underwent three-dimensional computerized tomography is presented here to improve our knowledge and diagnostic skill of this uncommon entity.

Releasing the therapeutic potential of the psychiatric nurse: a human relations perspective of the nurse-patient relationship

In psychiatry mental health nurses form the largest professional discipline providing care on an everyday basis for sustained periods. Mental health nurses therefore are in a pivotal position to establish valued therapeutic alliances. In practice, however, a disproportionate amount of nursing time is taken up by administration, time spent talking to patients is minimal and when interactions do occur they remain notionally therapeutic and often are not theoretically informed. This noted paucity of therapeutic contact is antithetical to the aspirations of service users who increasingly are asking for a more skilled approach to the talking-listening that occurs in the therapeutic encounter. It is hypothesized by the present authors that an object-relations perspective of the nurse-patient relationship could release the largely untapped therapeutic potential of the psychiatric nurse by (1) bridging the gap between theory and practice and (2) providing a professional identity from within which nurses can begin to 'get to know' and understand the predicament of the patient with severe mental illness.

Clinicopathological significance of Borderline Nuclear Change - High Grade Dyskaryosis Not Excluded

During a recent discussion on classification of cervical cytology, the introduction of a 'Borderline Nuclear Change - High Grade Dyskaryosis Not Excluded' (BNCH) category was proposed. BNCH cases diagnosed prospectively were retrieved from laboratory records. Questionnaires were sent to referring practitioners regarding clinicopathological outcome. Cytopathological features resulting in the BNCH classification were recorded on slide review. A total of 103 reports on conventional cervical smears diagnosed as BNCH from 1999 to 2002 were retrieved, comprising 0.096% of 107 634 smears. Of 86/103 cases with clinical follow-up, CIN2 or worse was present in 30 (35%); 15 (17%) showed a borderline/low-grade abnormality and 41 (48%) were negative. No individual cytopathological feature was predictive of high-grade disease on follow-up. The yield of high-grade abnormalities on follow-up of BNCH supports the introduction of this terminology.

Perception of orthodontic treatment need: opinion comparisons of orthodontists, pediatric dentists, and general practitioners

AIM

To determine the relationship between treatment need assessment scores of orthodontists, general practitioners, and pediatric dentists.

STUDY DESIGN

Observational.

SAMPLE

Ten general dental practitioners, 18 orthodontists and 15 pediatric dentists reviewed 137 dental casts and recorded their opinion on whether orthodontic treatment was needed.

RESULTS

We found a high level of agreement between pediatric dentists, orthodontists and general practitioners (Kappa range 0.86-0.95). Between the groups, the amount of agreement was lower.

CONCLUSIONS

Orthodontists, general dental practitioners, and pediatric dentists in this sample exhibit high levels of agreement on orthodontic treatment need.

Topographical and physicochemical modification of material surface to enable patterning of living cells

Precise control of the architecture of multiple cells in culture and in vivo via precise engineering of the material surface properties is described as cell patterning. Substrate patterning by control of the surface physicochemical and topographic features enables selective localization and phenotypic and genotypic control of living cells. In culture, control over spatial and temporal dynamics of cells and heterotypic interactions draws inspiration from in vivo embryogenesis and haptotaxis. Patterned arrays of single or multiple cell types in culture serve as model systems for exploration of cell-cell and cell-matrix interactions. More recently, the patterned arrays and assemblies of tissues have found practical applications in the fields of Biosensors and cell-based assays for Drug Discovery. Although the field of cell patterning has its origins early in this century, an improved understanding of cell-substrate interactions and the use of microfabrication techniques borrowed from the microelectronics industry have enabled significant recent progress. This review presents the important early discoveries and emphasizes results of recent state-of-the-art cell patterning methods. The review concludes by illustrating the growing impact of cell patterning in the areas of bioelectronic devices and cell-based assays for drug discovery.

Signaling by mechanical strain involves transcriptional regulation of proinflammatory genes in human periodontal ligament cells in vitro

Intracellular signals generated by mechanical strain profoundly affect the metabolic function of osteoblast-like periodontal ligament (PDL) cells, which reside between the tooth and alveolar bone. In response to applied mechanical forces, PDL cells synthesize bone-resorptive cytokines to induce bone resorption at sites exposed to compressive forces and deposit bone at sites exposed to tensile forces in an environment primed for catabolic processes. The intracellular mechanisms that regulate this bone remodeling remain unclear. Here, in an in vitro model system, we show that tensile strain is a critical determinant of PDL-cell metabolic functions. Equibiaxial tensile strain (TENS), when applied at low magnitudes, acts as a potent antagonist of interleukin (IL)-1beta actions and suppresses transcriptional regulation of multiple proinflammatory genes. This is evidenced by the fact that TENS at low magnitude: (i) inhibits recombinant human (rh)IL-1beta-dependent induction of cyclooxygenase-2 (COX-2) mRNA expression and production of prostaglandin estradiol (PGE2); (ii) inhibits rhIL-1beta-dependent induction matrix metalloproteinase-1 (MMP-1) and MMP-3 synthesis by suppressing their mRNA expression; (iii) abrogates rhIL-1beta-induced suppression of tissue inhibitor of metalloprotease-II (TIMP-II) expression; and (iv) reverses IL-1beta-dependent suppression of osteocalcin and alkaline phosphatase synthesis. Nevertheless, these actions of TENS were observed only in the presence of IL-1beta, as TENS alone failed to affect any of the aforementioned responses. The present findings are the first to show that intracellular signals generated by low-magnitude mechanical strain interfere with one or more critical step(s) in the signal transduction cascade of rhIL-1beta upstream of mRNA expression, while concurrently promoting the expression of osteogenic proteins in PDL cells.

Cholecystogastric fistula: laparoscopic repair

We describe a patient with a cholecystogastric fistula treated by the laparoscopic approach. The use of intracorporeal suturing allows laparoscopic management of cholecystogastric fistulae without the need for an endoscopic transecting stapler.

Complex proximal humeral fractures in adults--a systematic review of management

We performed a systematic review of the literature to compare the clinical outcomes of the management of three and four part fractures of the proximal humerus by conservative regimes, internal and external fixations and arthroplasty. We identified 147 reports of comparative trials and case series between 1969 and 1999. We selected only studies dealing exclusively with three and four part fractures of the proximal humerus, with at least 15 patients, treated within 48 h of injury by one of the three modalities studied, in which at least one of the outcomes of interest (pain, range of motion, infection and restoration of anatomy) was described. Also, to be included, studies had to have a follow-up period of at least 6 months, in which a minimum of 85% of patients were followed-up. Twenty four reports met our eligibility criteria. Conservatively managed patients had more pain and a poorer range of motion than those managed by either fixation or arthroplasty. Better restoration of anatomy was delivered in the fixation group. There was no significant difference in the functional range of motion between the arthroplasty and fixation groups, but there were very few studies available to compare infection rates in these two management modalities. The results from the present systematic review suggest that the data from the published literature are inadequate for evidence-based decision making with regards to the treatment of complex proximal humeral fractures.

Cross-talk between alpha(4)beta(1)/alpha(5)beta(1) and c-Kit results in opposing effect on growth and survival of hematopoietic cells via the activation of focal adhesion kinase, mitogen-activated protein kinase, and Akt signaling pathways

Erythroid progenitor cells (EPCs) are deficient in mice lacking either the ligand stem cell factor (SCF), its receptor c-Kit, or beta(1)-integrins. In nonhematopoietic cells, integrins and receptor tyrosine kinases can collaborate to modulate cellular functions, providing evidence for cross-talk between signals emerging from these cell surface molecules. Using specific recombinant fibronectin peptides that contain the binding site for the integrin alpha(4)beta(1) (FN-H296) or alpha(5)beta(1) (FN-CH271) or both alpha(4)beta(1) and alpha(5)beta(1) (FN-CH296), this study investigated the effect of adhesion alone, or in combination with activation of c-Kit, on functional and biochemical outcomes in an EPC line, G1E-ER2, and primary EPCs. G1E-ER2 cells and primary EPCs cultured on FN-CH271 in the presence of c-Kit activation led to a significant increase in proliferation in comparison with cells grown on FN-H296 or FN-CH296. G1E-ER2 cells cultured on FN-H296 or FN-CH296 resulted in significant cell death in comparison to cells grown on FN-CH271. Activation of c-Kit enhanced the survival of G1E-ER2 cells grown on FN-H296 or FN-CH296; however, the rescue was only partial. The reduced survival of G1E-ER2 cells on FN-H296 correlated with reduced activation of Akt and expression of Bcl-2 and Bcl-x(L), whereas increase in proliferation on FN-CH271 correlated with significantly enhanced and sustained activation of focal adhesion kinase (FAK) and extracellular-regulated kinase (ERK) pathways. These data demonstrate that adhesion-induced signals emanating from ligation of alpha(4)beta(1) and alpha(5)beta(1) result in distinct biologic outcomes, including death via alpha(4)beta(1) and survival/proliferation via alpha(5)beta(1). (Blood. 2001;97:1975-1981)

A novel mechanism of cooperation between c-Kit and erythropoietin receptor. Stem cell factor induces the expression of Stat5 and erythropoietin receptor, resulting in efficient proliferation and survival by erythropoietin

Optimal production of red cells in vivo requires collaboration between c-Kit, erythropoietin receptor (Epo-R), and GATA-1. However, the mechanism(s) of collaboration remain unclear. Utilizing an embryonic stem cell-derived erythroid progenitor cell line from mice deficient in GATA-1, we have examined the role of c-Kit and Epo-R in erythroid cell proliferation, survival, and differentiation. In the absence of GATA-1, we demonstrate an essential role for c-Kit in survival and proliferation of erythroid progenitors via the regulation of Bcl-2 expression. In addition, we demonstrate that Epo-R and Stat5 are regulated by a second, novel mechanism. We demonstrate that c-Kit stimulation by stem cell factor is essential for the maintenance of Epo-R and Stat5 protein expression, which results in significantly enhanced Bcl-x(L) induction and survival of erythroid progenitors in response to Epo stimulation. Restoration of GATA-1 function results in terminal erythroid maturation and up-regulation of Epo-R and Bcl-x(L) expression, leading also to significantly enhanced survival of terminally differentiating erythroid progenitors in the presence of only Epo. These results demonstrate that c-Kit and Epo-R have unique role(s) during distinct phases of erythroid maturation, and both stem cell factor and Epo contribute to the regulation of the Epo-R-Stat5-Bcl-x(L) pathway to ensure optimal survival, proliferation, and differentiation of erythroid progenitors.

Characterization and targeted disruption of murine Nup50, a p27(Kip1)-interacting component of the nuclear pore complex

p27(Kip1) is a member of the Cip-Kip family of cyclin-dependent kinase (Cdk) inhibitors that binds to cyclin-Cdk complexes and inhibits their catalytic activity in response to antiproliferative stimuli. p27(Kip1) is regulated by several posttranscriptional mechanisms, including subcellular localization. We have identified a component of the nuclear pore complex (NPC), termed Nup50, through its two-hybrid interactions with p27(Kip1). Nup50 is a nucleoplasmically oriented component of the nuclear pore complex with a role in protein export (T. Guan, R. H. Kehlenbach, E. C. Schirmer, A. Kehlenbach, F. Fan, B. E. Clurman, N. Arnheim, and L. Gerace, Mol. Cell. Biol. 20:5619-5630, 2000). We found that murine Nup50 is a widely expressed nucleoporin and that Nup50 expression is highest in the developing neural tube and adult testes. We have also examined interactions between Nup50 and the NPC and found specific two-hybrid interactions between Nup50 and several well-defined components of the NPC, as well as coimmunoprecipitation of Nup50 with the nucleoporin Nup153 from transfected mammalian cells. In order to study Nup50 function in vivo, we cloned the mouse Nup50 genomic locus and created a targeted Nup50 deletion in the mouse germ line. Nup50 disruption resulted in a complex phenotype characterized by late embryonic lethality, neural tube defects, and intrauterine growth retardation. Although Nup50-null mouse embryo fibroblasts exhibited no defects in either cell cycle control or p27(Kip1) regulation, Nup50 deletion was associated with abnormalities in p27(Kip1) expression and cell proliferation in the developing neuroepithelium. We conclude that Nup50 is a nucleoporin with essential functions during mouse development.

Rac2 stimulates Akt activation affecting BAD/Bcl-XL expression while mediating survival and actin function in primary mast cells

Mast cells generated from Rac2-deficient (-/-) mice demonstrated defective actin-based functions, including adhesion, migration, and degranulation. Rac2(-/-) mast cells generated lower numbers and less mast cell colonies in response to growth factors and were deficient in vivo. Rac2(-/-) mast cells demonstrated a significant reduction in growth factor-induced survival, which correlated with the lack of activation of Akt and significant changes in the expression of the Bcl-2 family members BAD and Bcl-XL, in spite of a 3-fold induction of Rac1 protein. These results suggest that Rac2 plays a unique role in multiple cellular functions and describe an essential role for Rac2 in growth factor-dependent survival and expression of BAD/Bcl-XL.

Frictional resistance in orthodontic brackets with repeated use

This study measured and compared the level of frictional resistance generated with a nonrepeated and repeated experimental design to evaluate whether the wear in the bracket slot will influence frictional resistance. Both 0.018 and 0.022 inch slot size edgewise brackets were tested in a specially designed apparatus. The frictional resistance was measured on an Instron Universal Testing Machine. A repeated measures ANOVA was used to determine differences among the 10 individual bracket wire specimens for each combination to study the influence of wear on static and kinetic frictional force. A paired t test (two-tail) procedure was used to compare the static and kinetic frictional forces in the nonrepeated and repeated study for each bracket slot, wire size, and bracket type. The results show that there was a distinct trend for the mean frictional force to be higher with the repeated use of the brackets.

The presence of novel amino acids in the cytoplasmic domain of stem cell factor results in hematopoietic defects in Steel(17H) mice

Stem cell factor (SCF) is expressed as an integral membrane growth factor that may be differentially processed to produce predominantly soluble (S) (SCF(248)) or membrane-associated (MA) (SCF(220)) protein. A critical role for membrane presentation of SCF in the hematopoietic microenvironment (HM) has been suggested from the phenotype of the Steel-dickie (Sl(d)) mice, which lack MA SCF, and by studies performed in our laboratory (and by others) using long-term bone marrow cultures and transgenic mice expressing different SCF isoforms. Steel(17H) (Sl(17H)) is an SCF mutant that demonstrates melanocyte defects and sterility in males but not in females. The Sl(17H) allele contains a intronic mutation resulting in the substitution of 36 amino acids (aa's) in the SCF cytoplasmic domain with 28 novel aa's. This mutation, which affects virtually the entire cytoplasmic domain of SCF, could be expected to alter membrane SCF presentation. To investigate this possibility, we examined the biochemical and biologic properties of the Sl(17H)-encoded protein and its impact in vivo and in vitro on hematopoiesis and on c-Kit signaling. We demonstrate that compound heterozygous Sl/Sl(17H) mice manifest multiple hematopoietic abnormalities in vivo, including red blood cell deficiency, bone marrow hypoplasia, and defective thymopoiesis. In vitro, both S and MA Sl(17H) isoforms of SCF exhibit reduced cell surface expression on stromal cells and diminished biological activity in comparison to wild-type (wt) SCF isoforms. These alterations in presentation and biological activity are associated with a significant reduction in the proliferation of an SCF-responsive erythroid progenitor cell line and in the activation of phosphatidylinositol 3-Kinase/Akt and mitogen-activated protein-Kinase signaling pathways. In vivo, transgene expression of the membrane-restricted (MR) (SCF(X9/D3)) SCF in Sl/Sl(17H) mutants results in a significant improvement in peripheral red blood cell counts in comparison to Sl/Sl(17H) mice.

Comparison of frictional resistance in titanium and stainless steel brackets

This study measures and compares the level of frictional resistance generated between titanium and stainless steel brackets. Both 0.018 and 0.022 inch slot size edgewise brackets were tested with different sized rectangular stainless steel wires in a specially designed apparatus. The frictional resistance was measured on Instron Universal testing machine (Instron Corp, Canton, Mass) with a 10 pound load cell. The specimen population was composed of 180 brackets and 180 wire specimens. A completely randomized design (one way) ANOVA was used to test for significant differences among the three bracket/wire types in the 0.018 and 0.022 inch slot sizes. This was followed by the Student Newman Keuls Multiple Comparison of means ranking at P < .05 to determine differences between the different groups. The titanium brackets showed lower static and kinetic frictional force as the wire size increased, whereas stainless steel brackets showed higher static and kinetic frictional force as the wire size increased.

Comparison of load transmission and bracket deformation between titanium and stainless steel brackets

This study measures the load transmitted and structural integrity of stainless steel and titanium brackets on application of torsional forces. Both 0.018 and 0.022 inch slot size edgewise brackets were tested in a specially designed apparatus that applied a torque value of 45 degrees. The load generated was measured by an Instron Universal Testing Machine at intervals of 15 degrees, 30 degrees, and 45 degrees of torque application. The structural stability of the brackets was evaluated by measuring the bracket slot width with a traveling stereoscopic microscope before and after the brackets were subjected to torsional forces. The specimen population was composed of 80 brackets and 80 wire specimens. An independent sample t test was used for comparison of mean load generated at 45 degrees of torque application. Repeated measures ANOVA (one-way) comparison was used to evaluate changes in load at different torque levels for the stainless steel and titanium brackets. A paired t test (two-tail) was used to determine the difference between initial and final bracket slot width at 45 degrees of torque applied for the two bracket types. The titanium brackets transmitted higher loads at 15 degrees and 30 degrees torque and lower load at 45 degrees torque on application of torsional forces in comparison to stainless steel brackets. The titanium brackets demonstrated superior dimensional stability compared to stainless steel brackets (P < .0001).

Deficiency of the hematopoietic cell-specific Rho family GTPase Rac2 is characterized by abnormalities in neutrophil function and host defense

In mammals, the Rho family GTPase Rac2 is restricted in expression to hematopoietic cells, where it is coexpressed with Rac1. Rac2-deficient mice were created to define the physiological requirement for two near-identical Rac proteins in hematopoietic cells. rac2-/- neutrophils displayed significant defects in chemotaxis, in shear-dependent L-selectin-mediated capture on the endothelial substrate Glycam-1, and in both F-actin generation and p38 and, unexpectedly, p42/p44 MAP kinase activation induced by chemoattractants. Superoxide production by rac2-/- bone marrow neutrophils was significantly reduced compared to wild type, but it was normal in activated peritoneal exudate neutrophils. These defects were reflected in vivo by baseline neutrophilia, reduced inflammatory peritoneal exudate formation, and increased mortality when challenged with Aspergillus fumigatus. Rac2 is an essential regulator of multiple specialized neutrophil functions.

Electrical, chemical, and topological addressing of mammalian cells with microfabricated systems

This communication describes our work in electrical, topological, and chemical micromodification of surfaces to modulate cellular form and function. We have addressed the surface physico-chemico-mechano properties of cell culture substrates that play a role in modulating cellular behavior. Single factorial model systems have been built using techniques adapted from microlithography. The tools and techniques of microfabrication, if harnessed and used correctly, can be enabling in elucidating the underlying principles and fundamental forces driving the cell-substrate interface. Additionally, the long-term practical applications of microfabrication in medicine and biomaterial/tissue engineering lie in enabling "communication" with living cells/tissues at the cellular and subcellular levels.

Cellular and cytoskeleton morphology and strength of adhesion of cells on self-assembled monolayers of organosilanes

The objective of this study was to explore the potential use of self-assembled monolayers (SAMs) of alkylamine and arylalkyamine as well-defined, homogeneous, tailored in vitro model surfaces for exploring the effect of hydrodynamic flow on morphology and strength of adhesion of human umbilical vein endothelial cells. The cell surface area, shape, f-actin distribution, and adhesion strength of human umbilical vein endothelial cells cultured on self-assembled monolayers of organosilanes were found to be dependent on the chemical composition of the organosilane film and the magnitude of wall shear stress. The direct effects of the differences in chemistry between the two silanes, in modulating cellular response, are probably only secondary to the modulation of cellular functions mediated by differential protein adsorption and conformation on the two silanes. For short seeding times (30 min), prior to application of flow, both substrate chemistry and shear stress modulated the cellular morphology and cytoskeletal organization. For longer seeding times (24 h), prior to application of flow, the chemistry of the underlying surface was the dominant variable in modulating cellular morphology, while the hydrodynamic shear stress modulated the cytoskeleton organization. Cells on N-(2-aminoethyl)-3-aminopropyl trimethoxysilane (EDA) were pleomorphic, while cells on ((((aminoethyl)amino)methyl)phenylethyl)trimethoxysilane (PEDA) expressed a rounded morphology. Application of an incrementally loaded flow regime (0.07-1.25 ml/s) resulted in a time- and shear stress-dependent (10-180 dyn/cm2) detachment of cells, with the cells on EDA depicting higher resistance to wall shear stress. Cellular morphology correlated with the strength of adhesion; cells with rounded morphology on a hydrophobic silane, PEDA, were less tightly bound to the silane, while spread cells on a hydrophilic silane, EDA, were more tightly bound. The higher surface free energy of EDA is speculated to influence the increased cell spreading and strength of adhesion observed in these studies. The presence of the phenyl group in PEDA reduces the surface free energy and may account for the reduced spreading and lower strength of adhesion. The use of well-defined systems, such as monolayer organosilanes, with tunable surface physicochemical properties may serve to deconstruct the complex interaction of cells with extracellular matrix components: surface charge, surface hydrophobicity, and other short- and long-range forces can be individually controlled and correlated with cellular functions. The organosilane monolayers could serve as the building blocks for sequential addition of proteins or cell adhesive/cell repulsive cues to stepwise engineering and construction of more complex systems resembling ECM matrices.

Signaling through the interaction of membrane-restricted stem cell factor and c-kit receptor tyrosine kinase: genetic evidence for a differential role in erythropoiesis

Mutations of the receptor tyrosine kinase c-kit or its ligand stem cell factor (SCF), which is encoded as a soluble and membrane-associated protein by the Steel gene in mice, lead to deficiencies of germ cells, melanocytes, and hematopoiesis, including the erythroid lineage. In the present study, we have used genetic methods to study the role of membrane or soluble presentation of SCF in hematopoiesis. Bone marrow-derived stromal cells expressing only a membrane-restricted (MR) isoform of SCF induced an elevated and sustained tyrosine phosphorylation of both c-kit and erythropoietin receptor (EPO-R) and significantly greater proliferation of an erythrocytic progenitor cell line compared with stromal cells expressing soluble SCF. Transgene expression of MR-SCF in Steel-dickie (Sld) mutants resulted in a significant improvement in the production of red blood cells, bone marrow hypoplasia, and runting. In contrast, overexpression of the full-length soluble form of SCF transgene had no effect on either red blood cell production or runting but corrected the myeloid progenitor cell deficiency seen in these mutants. These data provide the first evidence of differential functions of SCF isoforms in vivo and suggest an abnormal signaling mechanism as the cause of the severe anemia seen in mutants of the Sl gene.

Overexpression of human stem cell factor impairs melanocyte, mast cell, and thymocyte development: a role for receptor tyrosine kinase-mediated mitogen activated protein kinase activation in cell differentiation

Stem cell factor (SCF) is synthesized as both soluble (S) and membrane-associated (MA) proteins. Indirect insight into the function of MA and S isoforms of SCF has come from studies performed in Steel (Sl) mutant mice. However, the physiologic role(s) of these two isoforms remain unknown. In an attempt to better understand the in vivo role of c-kit/SCF interactions on various cell lineages, transgenic mice were generated that overexpress MA isoform of human SCF (hSCF). In murine cells, hSCF behaves as an antagonist to normal SCF function, due to interference with the interaction between endogenous murine SCF and its receptor, c-kit, encoded by the dominant white spotting (W) gene. Mice expressing the hSCF transgene display a variety of phenotypic abnormalities, which are accentuated when combined with W alleles. Here we show that mice homozygous for the hSCF transgene demonstrate a coat color deficiency seen in some mice homozygous for mild W alleles. Specifically, homozygous hSCF transgenic mice (hSCF220) display a pronounced forehead blaze, with additional white spots over the cervical region, as well as a very large belly spot. Doubly heterozygous animals that carry both a mutated W allele and the hSCF transgene also display an unusual pigment defect and a dramatic reduction in the number of dermal mast cells. Furthermore, overexpression of MA hSCF in the thymus results in abnormal thymocyte differentiation and proliferation, which is associated with reduced mitogen activated protein (MAP) kinase activation. Thus, MAP kinase activation by a receptor tyrosine kinase, such as c-kit, may be critical for the differentiation of thymocytes in vivo.