A cross-sectional multicenter study of osteogenesis imperfecta in North America - results from the linked clinical research centers

Osteogenesis imperfecta (OI) is the most common skeletal dysplasia that predisposes to recurrent fractures and bone deformities. In spite of significant advances in understanding the genetic basis of OI, there have been no large-scale natural history studies. To better understand the natural history and improve the care of patients, a network of Linked Clinical Research Centers (LCRC) was established. Subjects with OI were enrolled in a longitudinal study, and in this report, we present cross-sectional data on the largest cohort of OI subjects (n = 544). OI type III subjects had higher prevalence of dentinogenesis imperfecta, severe scoliosis, and long bone deformities as compared to those with OI types I and IV. Whereas the mean lumbar spine area bone mineral density (LS aBMD) was low across all OI subtypes, those with more severe forms had lower bone mass. Molecular testing may help predict the subtype in type I collagen-related OI. Analysis of such well-collected and unbiased data in OI can not only help answering questions that are relevant to patient care but also foster hypothesis-driven research, especially in the context of 'phenotypic expansion' driven by next-generation sequencing.

Arthroscopic repair of a posterior bony humeral avulsion of the glenohumeral ligament with associated teres minor avulsion

Humeral avulsion of the inferior glenohumeral ligament (HAGL) has recently gained more recognition as a cause of shoulder instability. Posterior HAGL lesions, being much more infrequent than anterior disruptions, have only recently been documented as a notable cause of posterior instability. We detail the treatment of a previously unreported case of a posterior HAGL variant lesion consisting of a bony avulsion with involvement of the teres minor tendon. Arthroscopic fixation was facilitated by use of a "sheathless" arthroscopic approach with a 70° arthroscope and suture anchor.

A novel long-acting glucose-dependent insulinotropic peptide analogue: enhanced efficacy in normal and diabetic rodents

AIM

Glucose-dependent insulinotropic peptide (GIP) is an incretin hormone that is released from intestinal K cells in response to nutrient ingestion. We aimed to investigate the therapeutic potential of the novel N- and C-terminally modified GIP analogue AC163794.

METHODS

AC163794 was synthesized by solid-phase peptide synthesis. Design involved the substitution of the C-terminus tail region of the dipeptidyl peptidase IV (DPP-IV)-resistant GIP analogue [d-Ala(2) ]GIP(1-42) with the unique nine amino acid tail region of exenatide. The functional activity and binding of AC163794 to the GIP receptor were evaluated in RIN-m5F β-cells. In vitro metabolic stability was tested in human plasma and kidney membrane preparations. Acute insulinotropic effects were investigated in isolated mouse islets and during an intravenous glucose tolerance test in normal and diabetic Zucker fatty diabetic (ZDF) rats. The biological actions of AC163794 were comprehensively assessed in normal, ob/ob and high-fat-fed streptozotocin (STZ)-induced diabetic mice. Acute glucoregulatory effects of AC163794 were tested in diet-induced obese mice treated subchronically with AC3174, the exendatide analogue [Leu(14) ] exenatide. Human GIP or [d-Ala(2) ]GIP(1-42) were used for comparison.

RESULTS

AC163794 exhibited nanomolar functional GIP receptor potency in vitro similar to GIP and [d-Ala(2) ]GIP(1-42). AC163794 was metabolically more stable in vitro and displayed longer duration of insulinotropic action in vivo versus GIP and [d-Ala(2) ]GIP(1-42). In diabetic mice, AC163794 improved HbA1c through enhanced insulinotropic action, partial restoration of pancreatic insulin content and improved insulin sensitivity with no adverse effects on fat storage and metabolism. AC163794 provided additional baseline glucose-lowering when injected to mice treated with AC3174.

CONCLUSIONS

These studies support the potential use of a novel GIP analogue AC163794 for the treatment of type 2 diabetes.

Evidence of exotoxin secretion of Piscirickettsia salmonis, the causative agent of piscirickettsiosis

Piscirickettsia salmonis is the aetiological agent of piscirickettsiosis, a disease which affects a variety of teleost species and that is particularly severe in salmonid fish. Bacterial-free supernatants, obtained from cultures of three isolates of Piscirickettsia salmonis, were inoculated in Atlantic salmon, Salmo salar L., and in three continuous cell lines in an effort to determine the presence of secretion of extracellular products (ECPs) by this microorganism. Although steatosis was found in some liver samples, no mortalities or clinical signs occurred in the inoculated fish. Clear cytotoxicity was observed after inoculation in the cell lines CHSE-214 and ASK, derived from salmonid tissues, but not in MDBK, which is of mammalian origin. The degree of cytotoxicity of the ECPs was different among the P. salmonis isolates tested. The isolate that evidenced the highest cytotoxicity in its ECPs exhibited only an intermediate virulence level after challenging fish with bacterial suspensions of the three P. salmonis isolates. Almost complete inhibition of the cytotoxic activity of ECPs was seen after proteinase K treatment, indicating their peptidic nature, and a total preclusion of the cytotoxicity was shown after their incubation at 50 °C for 30 min. Results show that P. salmonis can produce ECPs and at least some of them are thermolabile exotoxins that probably play a role in the pathogenesis of piscirickettsiosis.

Current concepts in clinical research: web-based, automated, arthroscopic surgery prospective database registry

In 2011, postsurgical patient outcome data may be compiled in a research registry, allowing comparative-effectiveness research and cost-effectiveness analysis by use of Health Insurance Portability and Accountability Act-compliant, institutional review board-approved, Food and Drug Administration-approved, remote, Web-based data collection systems. Computerized automation minimizes cost and minimizes surgeon time demand. A research registry can be a powerful tool to observe and understand variations in treatment and outcomes, to examine factors that influence prognosis and quality of life, to describe care patterns, to assess effectiveness, to monitor safety, and to change provider practice through feedback of data. Registry of validated, prospective outcome data is required for arthroscopic and related researchers and the public to advocate with governments and health payers. The goal is to develop evidence-based data to determine the best methods for treating patients.

Glucoregulatory effects and prolonged duration of action of davalintide: a novel amylinomimetic peptide

AIMS

Davalintide is a second-generation amylinomimetic peptide possessing enhanced pharmacological properties over rat amylin to reduce food intake in preclinical models. The current experiments in rats describe additional glucoregulatory actions of davalintide consistent with amylin agonism, and explore the duration of action of these effects.

METHODS

Subcutaneous (SC) injection of davalintide slowed gastric emptying with equal potency to amylin (ED₅₀'s = 2.3 and 4.1 µg/kg). This effect was maintained for 8 h with davalintide, but not amylin. Intraperitoneal injection of davalintide also reduced food intake with a potency similar to amylin (ED₅₀'s = 5.0 and 11.3 µg/kg). Consistent with amylin agonism, davalintide (10 µg/kg, SC) suppressed the plasma glucagon response over 90 min following an intravenous arginine bolus in anaesthetized rats. The elimination t(½) of davalintide (200 µg/kg, SC) was 26 min, similar to the t(½) of amylin, suggesting that pharmacokinetic-independent mechanisms contribute to davalintide's enhanced duration of action. Binding kinetic studies using ¹²⁵I davalintide revealed no appreciable dissociation from the amylin nucleus accumbens receptor after 7 h while ¹²⁵I rat amylin did dissociate from this receptor (K(off) = 0.013/min). Sustained SC infusion of davalintide (275 µg/kg/day) or amylin (300) decreased plasma glucose after an oral glucose challenge at 2 weeks (by 27 and 31%) and suppressed gastric emptying at 3 weeks (by 29 and 47%), demonstrating durable glucoregulatory actions of both peptides.

CONCLUSIONS

These data show glucoregulatory properties of davalintide consistent with amylin agonism and suggest that slowed receptor dissociation plays a role in davalintide's prolonged pharmacodynamic actions.

Alendronate for the treatment of pediatric osteogenesis imperfecta: a randomized placebo-controlled study

CONTEXT

Information on the use of oral bisphosphonate agents to treat pediatric osteogenesis imperfecta (OI) is limited.

OBJECTIVE

The objective of the investigation was to study the efficacy and safety of daily oral alendronate (ALN) in children with OI.

DESIGN AND PARTICIPANTS

We conducted a multicenter, double-blind, randomized, placebo-controlled study. One hundred thirty-nine children (aged 4-19 yr) with type I, III, or IV OI were randomized to either placebo (n = 30) or ALN (n = 109) for 2 yr. ALN doses were 5 mg/d in children less than 40 kg and 10 mg/d for those 40 kg and greater.

MAIN OUTCOME MEASURES

Spine areal bone mineral density (BMD) z-score, urinary N-telopeptide of collagen type I, extremity fracture incidence, vertebral area, iliac cortical width, bone pain, physical activity, and safety parameters were measured.

RESULTS

ALN increased spine areal BMD by 51% vs. a 12% increase with placebo (P < 0.001); the mean spine areal BMD z-score increased significantly from -4.6 to -3.3 (P < 0.001) with ALN, whereas the change in the placebo group (from -4.6 to -4.5) was insignificant. Urinary N-telopeptide of collagen type I decreased by 62% in the ALN-treated group, compared with 32% with placebo (P < 0.001). Long-bone fracture incidence, average midline vertebral height, iliac cortical width, bone pain, and physical activity were similar between groups. The incidences of clinical and laboratory adverse experiences were also similar between the treatment and placebo groups.

CONCLUSIONS

Oral ALN for 2 yr in pediatric patients with OI significantly decreased bone turnover and increased spine areal BMD but was not associated with improved fracture outcomes.

The benefits of on-site cytology with ultrasound-guided fine needle aspiration in a one-stop neck lump clinic

INTRODUCTION

In the National Institute for Health and Clinical Excellence (NICE) guidance on cancer services published in 2004, it was recommended that specialist clinics should be set up for the assessment of patients with neck lumps, structured in a similar way to one-stop breast lump clinics with a cytopathologist present and preferably ultrasound guidance. The aim of this study was to audit the performance of ultrasound-guided fine needle aspiration (FNA) with on-site cytology in a one-stop neck lump clinic at The Royal Liverpool University Hospital.

PATIENTS AND METHODS

Data were collected between November 2008 and May 2009 (7 months). Details of the adequacy rate for the FNA were recorded and whether multiple passes were required. The likely adequacy rate if ultrasound guidance was not available was also calculated.

RESULTS

A total of 274 patients were included in the audit. Of these, 227 (83%) patients required a single pass for adequate diagnostic material. Of the remaining, 45 (16%) required two passes and 2 (1%) required three passes. The overall sample inadequacy rate was 11 of 274 (4%). From these results, it could be predicted that, if immediate cytological evaluation was unavailable, the inadequacy rate would have been 41 of 274 (15%).

CONCLUSIONS

This audit has illustrated the benefits of a one-stop clinic with on-site cytology in providing a rapid diagnostic head and neck cancer service.

The benefits of on-site cytology with ultrasound-guided fine needle aspiration in a one-stop neck lump clinic

INTRODUCTION

In the National Institute for Health and Clinical Excellence (NICE) guidance on cancer services published in 2004, it was recommended that specialist clinics should be set up for the assessment of patients with neck lumps, structured in a similar way to one-stop breast lump clinics with a cytopathologist present and preferably ultrasound guidance. The aim of this study was to audit the performance of ultrasound-guided fine needle aspiration (FNA) with on-site cytology in a one-stop neck lump clinic at The Royal Liverpool University Hospital.

PATIENTS AND METHODS

Data were collected between November 2008 and May 2009 (7 months). Details of the adequacy rate for the FNA were recorded and whether multiple passes were required. The likely adequacy rate if ultrasound guidance was not available was also calculated.

RESULTS

A total of 274 patients were included in the audit. Of these, 227 (83%) patients required a single pass for adequate diagnostic material. Of the remaining, 45 (16%) required two passes and 2 (1%) required three passes. The overall sample inadequacy rate was 11 of 274 (4%). From these results, it could be predicted that, if immediate cytological evaluation was unavailable, the inadequacy rate would have been 41 of 274 (15%).

CONCLUSIONS

This audit has illustrated the benefits of a one-stop clinic with on-site cytology in providing a rapid diagnostic head and neck cancer service.

Lower predation risk for migratory birds at high latitudes

Quantifying the costs and benefits of migration distance is critical to understanding the evolution of long-distance migration. In migratory birds, life history theory predicts that the potential survival costs of migrating longer distances should be balanced by benefits to lifetime reproductive success, yet quantification of these reproductive benefits in a controlled manner along a large geographical gradient is challenging. We measured a controlled effect of predation risk along a 3350-kilometer south-north gradient in the Arctic and found that nest predation risk declined more than twofold along the latitudinal gradient. These results provide evidence that birds migrating farther north may acquire reproductive benefits in the form of lower nest predation risk.

Davalintide (AC2307), a novel amylin-mimetic peptide: enhanced pharmacological properties over native amylin to reduce food intake and body weight

OBJECTIVE

The current set of studies describe the in vivo metabolic actions of the novel amylin-mimetic peptide davalintide (AC2307) in rodents and compares these effects with those of the native peptide.

RESEARCH DESIGN AND METHODS

The anti-obesity effects of davalintide were examined after intraperitoneal injection or sustained peripheral infusion through subcutaneously implanted osmotic pumps. The effect of davalintide on food intake after lesioning of the area postrema (AP) and neuronal activation as measured by c-Fos, were also investigated.

RESULTS

Similar to amylin, davalintide bound with high affinity to amylin, calcitonin and calcitonin gene-related peptide receptors. Acutely, davalintide displayed greater suppression of dark-cycle feeding and an extended duration of action compared with amylin (23 versus 6 h). Davalintide had no effect on locomotor activity or kaolin consumption at doses that decreased food intake. Davalintide-induced weight loss through infusion was dose dependent, durable up to 8 weeks, fat-specific and lean-sparing, and was associated with a shift in food preference away from high-fat (palatable) chow. Metabolic rate was maintained during active weight loss. Both davalintide and amylin failed to suppress food intake after lesioning of the AP and activated similar brain nuclei, with davalintide displaying an extended duration of c-Fos expression compared with amylin (8 versus 2 h).

CONCLUSION

Davalintide displayed enhanced in vivo metabolic activity over amylin while retaining the beneficial properties possessed by the native molecule. In vitro receptor binding, c-Fos expression and AP lesion studies suggest that the metabolic actions of davalintide and amylin occur through activation of similar neuronal pathways.

Long-term effects of brain-derived neurotrophic factor on the frequency of inhibitory synaptic events in the rat superficial dorsal horn

Chronic constriction injury (CCI) of rat sciatic nerve produces a specific pattern of electrophysiological changes in the superficial dorsal horn that lead to central sensitization that is associated with neuropathic pain. These changes can be recapitulated in spinal cord organotypic cultures by long term (5-6 days) exposure to brain-derived neurotrophic factor (BDNF) (200 ng/ml). Certain lines of evidence suggest that both CCI and BDNF increase excitatory synaptic drive to putative excitatory neurons while reducing that to putative inhibitory interneurons. Because BDNF slows the rate of discharge of synaptically-driven action potentials in inhibitory neurons, it should also decrease the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) throughout the superficial dorsal horn. To test this possibility, we characterized superficial dorsal horn neurons in organotypic cultures according to five electrophysiological phenotypes that included tonic, delay and irregular firing neurons. Five to 6 days of treatment with 200 ng/ml BDNF decreased sIPSC frequency in tonic and irregular neurons as might be expected if BDNF selectively decreases excitatory synaptic drive to inhibitory interneurons. The frequency of sIPSCs in delay neurons was however increased. Further analysis of the action of BDNF on tetrodotoxin-resistant miniature inhibitory postsynaptic currents (mIPSC) showed that the frequency was increased in delay neurons, unchanged in tonic neurons and decreased in irregular neurons. BDNF may thus reduce action potential frequency in those inhibitory interneurons that project to tonic and irregular neurons but not in those that project to delay neurons.

Measuring team skills in crime scene investigation: exploring ad hoc teams

The purpose of this study was to measure the team skills of operational crime scene examiners (CSEs). The techniques used were based on established methods and helped to gain a greater understanding of the domain of forensic investigation. The research begins with a hierarchical task analysis and then adapts pre-established methods for measuring the performance of CSEs in four UK Police Forces. The process supports comparison between prescribed methods of 'good practice' and real world practice. This has allowed the identification of the distributed skills and tasks of the CSE. Using Annett et al.'s HTA(T), crime scene examination can be categorised and the communications and coordination structures occurring between teams investigating a burglary considered. This makes it possible to generalise the method to situations involving ad hoc teams.

No tunnel 2-socket technique: all-inside anterior cruciate ligament double-bundle retroconstruction

This report describes an all-inside, double-bundle anterior cruciate ligament retroconstruction (all-inside x2 technique), which is a less invasive technique because of the use of sockets (2 femoral and 2 tibial) instead of complete bone tunnels. When performed with allograft, this may be termed a "no-incision" technique. The femoral sockets are reamed via the anteromedial arthroscopic portal. The tibial sockets are created with the all-inside RetroDrill (Arthrex, Naples, FL) from within the joint. The posterolateral bundle graft is passed first and shuttled through the anteromedial portal and fixed on the femur with a RetroButton (Arthrex), interference screw, or both. It is then fixed on the tibia with a bioabsorbable RetroScrew (Arthrex) near full extension. The anteromedial bundle graft is passed through next, and the process is repeated with tibial fixation performed at 45 degrees of flexion. Posterolateral and anteromedial tibial fixation may be backed up by tying over a cortical button.

Glucuronidation of bioflavonoids by human UGT1A10: structure–function relationships

The extrahepatic human UDP glucuronosyltransferase 1A10 is found throughout the gastrointestinal tract and is thought to participate in the removal of orally ingested lipophilic chemicals. However, its substrate specificity towards these chemicals has not been fully characterized. The structurally diverse bioflavonoids are present in considerable amounts in fruits, vegetables and plant-derived beverages and have been shown to have many biological functions, including antioxidant properties. This study proposes features of the bioflavonoid structure necessary to confer it as a substrate of UGT1A10. The preferred substrates of UGT1A10 contain the hydroxyl group to be glucuronidated at C6 or C7, but not C5 of the A-ring or on C4' of the B-ring. Up to two additional hydroxyl groups on the A-ring enhance activity, whereas the presence of other groups, notably sugar groups, decreases activity. The high glucuronidation efficiency towards many bioflavonoids observed suggests that the contribution of UGT1A10 in the metabolism of these dietary compounds in the gastrointestinal tract may be significant.

Oesophageal stent insertion for palliation of dysphagia in a District General Hospital: experience from a case series of 137 patients

BACKGROUND

Endoscopic oesophageal stent insertion is a widely used procedure to alleviate dysphagia caused by malignant strictures of the oesophagus and gastric cardia. It can, however, be associated with significant complications, mortality and morbidity.

AIM AND METHOD

This retrospective case note study was undertaken to assess success rates, complications and mortality of oesophageal stenting when undertaken in a UK District General Hospital (DGH) setting. Patients who underwent oesophageal stenting for malignant disease from January 2000 to January 2006 were included.

RESULTS

Of the 137 patients studied, oesophageal adenocarcinoma was present in 57% of patients, squamous cell oesophageal carcinoma in 37% and gastric adenocarcinoma in 6%. Indications for stent insertion were: presence of non-resectable tumours (65%), co-morbidities that contraindicated surgery (25%), refusal by patients for surgery for potentially resectable disease (6%) and a need for enhanced oral nutrition prior to surgery (4%). Prior to stenting 86.4% of patients suffered from advanced dysphagia. A significant improvement in symptoms was seen in 94% of patients. Discharge from hospital was within 48 h in 45% of cases. Chest pain was experienced by 13.9% of patients and serious acute stent-related complications (perforation or bleeding) occurred in 5.8% of patients. Overall 41.6% of patients had at least one complication. Mortality was 4.4% at 7 days and 24.8% at 30 days.

CONCLUSION

Oesophageal stent insertion proved to be an effective palliation of dysphagia in group studied. It is a relatively safe procedure with a low rate of serious acute complications (5.8%) and can be done as a short stay in many patients.

Application of a bi-planar postural stability model in children with cerebral palsy

This study presents initial results from a bi-planar model used to investigate the neurological factors affecting balance deficits in children with diplegic cerebral palsy (CP). The model uses an inverted pendulum to describe sway in both the anteroposterior (AP) and mediolateral (ML) planes. The study presents Center of Pressure (COP) data from 17 children diagnosed with spastic diplegic CP using two standard AMTI force plates. Sway metrics in the time and frequency domains in the AP and ML planes were calculated and compared to simulations produced by the model. The proposed bi-planar model successfully reproduced sway signals acquired from experimental (clinical) data.

Yielding and crystallization of colloidal gels under oscillatory shear

We have studied the behavior of a colloidal gel under oscillatory shear. The quiescent gel was an arrested structure formed by a 40% volume fraction hard-sphere suspension in which a "depletion" interparticle attraction was induced by adding nonadsorbing polymer. We applied progressively larger amplitude oscillatory shear to the sample, and observed its behavior using conventional and confocal microscopy as well as dynamic light scattering echo spectroscopy. We find that, to within experimental uncertainties, the point at which irreversible particle rearrangements (or yielding) occur coincides with the observation of crystallization. We summarize our findings in a "shear state diagram." The strain amplitude required for yielding/crystallization increases with decreasing oscillation frequency. We can quantitatively account for our observations by estimating the effect of shear on the probability for a particle to escape from the attractive potential of its neighbor using a Kramers approach.