Identifying priority sites for whale shark ship collision management globally

The expansion of the world's merchant fleet poses a great threat to the ocean's biodiversity. Collisions between ships and marine megafauna can have population-level consequences for vulnerable species. The Endangered whale shark (Rhincodon typus), shares a circumglobal distribution with this expanding fleet and tracking of movement pathways has shown that large vessel collisions pose a major threat to the species. However, it is not yet known whether they are also at risk within aggregation sites, where up to 400 individuals can gather to feed on seasonal bursts of planktonic productivity. These "constellation" sites are of significant ecological, socio-economic and cultural value. Here, through expert elicitation, we gathered information from most known constellation sites for this species across the world (>50 constellations and >13,000 individual whale sharks). We defined the spatial boundaries of these sites and their overlap with shipping traffic. Sites were then ranked based on relative levels of potential collision danger posed to whale sharks in the area. Our results showed that researchers and resource managers may underestimate the threat posed by large ship collisions due to a lack of direct evidence, such as injuries or witness accounts, which are available for other, sub-lethal threat categories. We found that constellations in the Arabian Sea and adjacent waters, the Gulf of Mexico, the Gulf of California, and Southeast and East Asia, had the greatest level of vessel collision threat. We also identified 39 sites where peaks in shipping activity coincided with peak seasonal occurrences of whale sharks, sometimes across several months. Simulated potential collision mitigation options estimated a minimal impact to industry, as most whale shark core habitat areas were relatively small. Given the threat posed by vessel collisions, a coordinated, multi-national approach to collision mitigation is needed within priority whale shark habitats to ensure collision protection for the species.

Species associated with whale sharks Rhincodontypus (Orectolobiformes, Rhincodontidae) in the Galapagos Archipelago

Whale sharks Rhincodontypus frequently appear to interact or associate with other species, which vary depending on the community structure and the demographic of the whale sharks at each location globally. Here, we present the species sighted frequently around whale sharks in the Galapagos Archipelago and reported by dive guides and scientists and also in earlier publications. These associated species include cetacean species: bottlenose dolphins Tursiopstruncatus, other shark species: silky sharks Carcharhinusfalciformis, Galapagos sharks Carcharhinusgalapagensis, scalloped hammerhead sharks Sphyrnalewini, tiger sharks Galeocerdocuvier and teleost fish species: remoras Remora remora, yellowfin tuna Thunnusalbacares, almaco jacks Seriolarivoliana and black jacks Caranxlugubris. The recording of interspecies associations and interactions may lead to better understanding of the natural history of whale sharks and can show important symbiotic relationships or interdependence between different species.

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements.

Preliminary Laboratory Vibration Testing of a Complete Neonatal Patient Transport System

Premature infants or neonates in need of advanced clinical care must be transported to specialized hospitals. Past studies have examined vibrations experienced by patients during transport; however, multiple confounding factors limit the utility of on-road data. Hence, the development of a standardized test environment is warranted. The overall purpose of this project is to characterize vibrations during neonatal patient transport and develop mitigation strategies to reduce exposure. This paper focusses on the development of a laboratory test environment and procedure that enables studying the equipment vibration in a comprehensive and repeatable manner. For the first time, a complete neonatal patient transport system, including a stretcher, has been mounted on an industrial shaker. Results largely validate the system's ability to simulate on-road vibrations with high repeatability.

Zoledronate

Zoledronate is the most potent and most long-acting bisphosphonate in clinical use, and is administered as an intravenous infusion. Its major uses are in osteoporosis, Paget's disease, and in myeloma and cancers to reduce adverse skeletal related events (SREs). In benign disease, it is a first- or second-line treatment for osteoporosis, achieving anti-fracture efficacy comparable to that of the RANKL blocker, denosumab, over 3 years, and it reduces fracture risk in osteopenic older women. It is the preferred treatment for Paget's disease, achieving higher rates of remissions which are much more prolonged than with any other agent. Some trials have suggested that it reduces mortality, cardiovascular disease and cancer, but these findings are not consistent across all studies. It is nephrotoxic, so should not be given to those with significant renal impairment, and, like other potent anti-resorptive agents, can cause hypocalcemia in patients with severe vitamin D deficiency, which should be corrected before administration. Its most common adverse effect is the acute phase response, seen in 30-40% of patients after their first dose, and much less commonly subsequently. Clinical trials in osteoporosis have not demonstrated increases in osteonecrosis of the jaw or in atypical femoral fractures. Observational databases are currently inadequate to determine whether these problems are increased in zoledronate users. Now available as a generic, zoledronate is a cost-effective agent for fracture prevention and for management of Paget's disease, but wider provision of infusion facilities is important to increase patient access. There is a need to further explore its potential for reducing cancer, cardiovascular disease and mortality, since these effects could be substantially more important than its skeletal actions.

Whole-body vibration in neonatal transport: a review of current knowledge and future research challenges

Interfacility transport to tertiary care for high-risk neonates has become an integral part of equitable access to optimal perinatal healthcare. Excellence in clinical care requires expertise in transport medicine and the coordination of safe transport processes. However, concerns remain regarding environmental stressors involved in the transportation of sick high-risk neonates, including noise and vibration. In order to mitigate the potential deleterious effects of these physical stressors during transport, further knowledge of the burden of exposure, injury mechanisms and engineering interventions/modifications as adjuncts during transport would be beneficial. We reviewed the current literature with a focus on the contribution of new and emerging technologies in the transport environment with particular reference to whole-body vibration. This review intends to highlight what is known about vibration as a physical stressor in neonates and areas for further research; with the goal to making recommendations for minimizing these stressors during transport.

miPIE: NGS-based Prediction of miRNA Using Integrated Evidence

Methods for the de novo identification of microRNA (miRNA) have been developed using a range of sequence-based features. With the increasing availability of next generation sequencing (NGS) transcriptome data, there is a need for miRNA identification that integrates both NGS transcript expression-based patterns as well as advanced genomic sequence-based methods. While miRDeep2 does examine the predicted secondary structure of putative miRNA sequences, it does not leverage many of the sequence-based features used in state-of-the-art de novo methods. Meanwhile, other NGS-based methods, such as miRanalyzer, place an emphasis on sequence-based features without leveraging advanced expression-based features reflecting miRNA biosynthesis. This represents an opportunity to combine the strengths of NGS-based analysis with recent advances in de novo sequence-based miRNA prediction. We here develop a method, microRNA Prediction using Integrated Evidence (miPIE), which integrates both expression-based and sequence-based features to achieve significantly improved miRNA prediction performance. Feature selection identifies the 20 most discriminative features, 3 of which reflect strictly expression-based information. Evaluation using precision-recall curves, for six NGS data sets representing six diverse species, demonstrates substantial improvements in prediction performance compared to three methods: miRDeep2, miRanalyzer, and mirnovo. The individual contributions of expression-based and sequence-based features are also examined and we demonstrate that their combination is more effective than either alone.

Association of whale sharks (Rhincodon typus) with thermo-biological frontal systems of the eastern tropical Pacific

Satellite tracking of 27 whale sharks in the eastern tropical Pacific, examined in relation to environmental data, indicates preferential occupancy of thermo-biological frontal systems. In these systems, thermal gradients are caused by wind-forced circulation and mixing, and biological gradients are caused by associated nutrient enrichment and enhanced primary productivity. Two of the frontal systems result from upwelling, driven by divergence in the current systems along the equator and the west coast of South America; the third results from wind jet dynamics off Central America. All whale sharks were tagged near Darwin Island, Galápagos, within the equatorial Pacific upwelling system. Occupancy of frontal habitat is pronounced in synoptic patterns of shark locations in relation to serpentine, temporally varying thermal fronts across a zonal expanse > 4000 km. 80% of shark positions in northern equatorial upwelling habitat and 100% of positions in eastern boundary upwelling habitat were located within the upwelling front. Analysis of equatorial shark locations relative to thermal gradients reveals occupancy of a transition point in environmental stability. Equatorial subsurface tag data show residence in shallow, warm (>22°C) water 94% of the time. Surface zonal current speeds for all equatorial tracking explain only 16% of the variance in shark zonal movement speeds, indicating that passive drifting is not a primary determinant of movement patterns. Movement from equatorial to eastern boundary frontal zones occurred during boreal winter, when equatorial upwelling weakens seasonally. Off Peru sharks tracked upwelling frontal positions within ~100–350 km from the coast. Off Central America, the largest tagged shark (12.8 m TL) occupied an oceanic front along the periphery of the Panama wind jet. Seasonal movement from waning equatorial upwelling to productive eastern boundary habitat is consistent with underlying trophic dynamics. Persistent shallow residence in thermo-biological frontal zones suggests the role of physical-biological interactions that concentrate food resources.

A General Strategy for Targeting Drugs to Bone

Targeting drugs to their desired site of action can increase their safety and efficacy. Bisphosphonates are prototypical examples of drugs targeted to bone. However, bisphosphonate bone affinity is often considered too strong and cannot be significantly modulated without losing activity on the enzymatic target, farnesyl pyrophosphate synthase (FPPS). Furthermore, bisphosphonate bone affinity comes at the expense of very low and variable oral bioavailability. FPPS inhibitors were developed with a monophosphonate as a bone-affinity tag that confers moderate affinity to bone, which can furthermore be tuned to the desired level, and the relationship between structure and bone affinity was evaluated by using an NMR-based bone-binding assay. The concept of targeting drugs to bone with moderate affinity, while retaining oral bioavailability, has broad application to a variety of other bone-targeted drugs.

The role of candidate-gene CNTNAP2 in childhood apraxia of speech and specific language impairment

Childhood apraxia of speech (CAS) is a debilitating pediatric speech disorder characterized by varying symptom profiles, comorbid deficits, and limited response to intervention. Specific Language Impairment (SLI) is an inherited pediatric language disorder characterized by delayed and/or disordered oral language skills including impaired semantics, syntax, and discourse. To date, the genes associated with CAS and SLI are not fully characterized. In the current study, we evaluated behavioral and genetic profiles of seven children with CAS and eight children with SLI, while ensuring all children were free of comorbid impairments. Deletions within CNTNAP2 were found in two children with CAS but not in any of the children with SLI. These children exhibited average to high performance on language and word reading assessments in spite of poor articulation scores. These findings suggest that genetic variation within CNTNAP2 may be related to speech production deficits.

Whale shark (Rhincodon typus) seasonal presence, residence time and habitat use at darwin island, galapagos marine reserve

The life history of the whale shark (Rhincodon typus), including its reproductive ecology, still remains largely unknown. Here, we present results from the first whale shark population study around Darwin Island, Galapagos Marine Reserve. Following a diversified approach we characterized seasonal occurrence, population structure and size, and described habitat use of whale sharks based on fine scale movements around the island. Whale shark presence at Darwin Island was negatively correlated with Sea Surface Temperature (SST), with highest abundance corresponding to a cool season between July and December over six years of monitoring. From 2011 to 2013 we photo-identified 82 whale sharks ranging from 4 to 13.1 m Total Length (TL). Size distribution was bimodal, with a great majority (91.5%) of adult female individuals averaging 11.35 m±0.12 m (TL±SE), all but one showing signs of a potential pregnancy. Population dynamics models for apparently pregnant sharks estimated the presence of 3.76±0.90 (mean ± SE) sharks in the study area per day with an individual residence time of 2.09±0.51 (mean ± SE) days. Movement patterns analysis of four apparently pregnant individuals tracked with acoustic tags at Darwin Island revealed an intense use of Darwin's Arch, where no feeding or specific behavior has been recorded, together with periodic excursions around the island's vicinity. Sharks showed a preference for intermediate depths (20-30 m) with occasional dives mostly to mid-water, remaining the majority of their time at water temperatures between 24-25°C. All of our results point to Darwin Island as an important stopover in a migration, possibly with reproductive purposes, rather than an aggregation site. Current studies carried out in this area to investigate regional scale movement patterns may provide essential information about possible pupping grounds for this enigmatic species.

CleanEMG--power line interference estimation in sEMG using an adaptive least squares algorithm

This paper presents an adaptive least squares algorithm for estimating the power line interference in surface electromyography (sEMG) signals. The algorithm estimates the power line interference, without the need for a reference input. Power line interference can be removed by subtracting the estimate from the original sEMG signal. The algorithm is evaluated with simulated sEMG based on its ability to accurately estimate power line interference at different frequencies and at various signal-to-noise ratios. Power line estimates produced by the algorithm are accurate for signal-to-noise ratios below 15 dB (SNR estimation error at 15 dB is 14.7995 dB + 1.6547 dB).

A health equity methodology for auditing oral health and NHS General Dental Services in Sheffield, England

OBJECTIVES

To describe a method used in a health equity audit (HEA) of oral health and National Health Service (NHS) General Dental Services.

METHODS

Need, demand and provision of NHS General Dental Services were estimated by electoral ward using readily available data. Need was estimated using five-year-old dmft data. Scheduled and unscheduled demand were differentiated; scheduled demand was estimated using NHS dental registration data and unscheduled demand using emergency clinic and NHS Direct call activity data. Provision was estimated using self-declared dentist NHS hours and NHS Units of Dental Activity practice allocations. All variables were correlated with socioeconomic deprivation in each electoral ward, estimated by rates of receipt of Income Support.

SETTING

Sheffield, England.

RESULTS

Estimated need in electoral wards varied and correlated positively with increasing socio-economic deprivation. Scheduled demand tended to be lower and unscheduled demand higher in more deprived wards. Estimates of NHS General Dental Service provision indicated marginally higher provision in more deprived wards, though the correlation was weak. A synthesis of the findings estimated where need was least well met by provision.

CONCLUSION

A HEA of oral health and NHS General Dental Services can be undertaken using readily available data. However, data used to estimate need, demand or provision may have to change for future audits as the data routinely collected changes.

The bisphosphonate zoledronic acid has antimyeloma activity in vivo by inhibition of protein prenylation

Nitrogen-containing bisphosphonates (N-BPs) are effective antiosteolytic agents in patients with multiple myeloma. Preclinical studies have also demonstrated that these agents have direct antitumor effects in vitro and can reduce tumor burden in a variety of animal models, although it is not clear whether such effects are caused by direct actions on tumor cells or by inhibition of bone resorption. N-BPs prevent bone destruction in myeloma by inhibiting the enzyme farnesyl pyrophosphate synthase in osteoclasts, thereby preventing the prenylation of small GTPase signaling proteins. In this study, utilizing a plasmacytoma xenograft model without complicating skeletal lesions, treatment with zoledronic acid (ZOL) led to significant prolongation of survival in severe combined immunodeficiency mice inoculated with human INA-6 plasma cells. Following treatment with a clinically relevant dose of ZOL, histological analysis of INA-6 tumors from the peritoneal cavity revealed extensive areas of apoptosis associated with poly (ADP-ribose) polymerase cleavage. Furthermore, Western blot analysis of tumor homogenates demonstrated the accumulation of unprenylated Rap1A, indicative of the uptake of ZOL by nonskeletal tumors and inhibition of farnesyl pyrophosphate synthase. These studies provide, for the first time, clear evidence that N-BPs have direct antitumor effects in plasma cell tumors in vivo and this is executed by a molecular mechanism similar to that observed in osteoclasts.

Skeletal complications of prostate cancer: pathophysiology and therapeutic potential of bisphosphonates

Patients with prostate cancer are at risk for skeletal complications resulting from treatment-induced bone loss and for bone metastases. The therapeutic potential of zoledronic acid for the treatment of prostate cancer has been demonstrated in both preclinical and clinical studies. In patients receiving androgen-deprivation therapy, zoledronic acid increases bone mineral density, and, in patients with bone metastases, it reduces the incidence of skeletal complications. Preclinical studies have also demonstrated the antitumor potential of bisphosphonates. Specifically, zoledronic acid inhibits proliferation and induces apoptosis of human prostate cancer cell lines in vitro and has enhanced antitumor activity when combined with taxanes. Animal models have further shown that bisphosphonates decrease tumor-induced osteolysis and reduce skeletal tumor burden. In a model of prostate cancer, zoledronic acid significantly inhibited growth of both osteolytic and osteoblastic tumors and reduced circulating levels of prostate-specific antigen. These studies suggest that zoledronic acid has the potential to inhibit bone metastasis and bone lesion progression in patients with prostate cancer.

Ox erythrocyte agglutinability. 4. The effect of neuraminidase treatment on the agglutinability of cells and ghosts

1. The inherited differential agglutinability of cattle erythrocytes is shown to be similarly expressed on ghosts and intact cells. 2. Removal of virtually all sialic acid by prolonged neuraminidase treatment does not alter the agglutinability status of ghosts prepared from either high or low agglutinable cells. Hence the differing sialic acid content of the two cell types is not responsible for the differential agglutinability. 3. The significance of these findings with respect to other well defined agglutination systems and current theories of membrane structure is discussed.

Global investigation of protein-protein interactions in yeast Saccharomyces cerevisiae using re-occurring short polypeptide sequences

Protein–protein interaction (PPI) maps provide insight into cellular biology and have received considerable attention in the post-genomic era. While large-scale experimental approaches have generated large collections of experimentally determined PPIs, technical limitations preclude certain PPIs from detection. Recently, we demonstrated that yeast PPIs can be computationally predicted using re-occurring short polypeptide sequences between known interacting protein pairs. However, the computational requirements and low specificity made this method unsuitable for large-scale investigations. Here, we report an improved approach, which exhibits a specificity of ∼99.95% and executes 16 000 times faster. Importantly, we report the first all-to-all sequence-based computational screen of PPIs in yeast, Saccharomyces cerevisiae in which we identify 29 589 high confidence interactions of ∼2 × 10⁷ possible pairs. Of these, 14 438 PPIs have not been previously reported and may represent novel interactions. In particular, these results reveal a richer set of membrane protein interactions, not readily amenable to experimental investigations. From the novel PPIs, a novel putative protein complex comprised largely of membrane proteins was revealed. In addition, two novel gene functions were predicted and experimentally confirmed to affect the efficiency of non-homologous end-joining, providing further support for the usefulness of the identified PPIs in biological investigations.

Regional volumetric change of the tongue during mastication in pigs

Structure and movement of the tongue have been studied extensively, but little study has been carried on its 3D deformation and ensuing volumetric changes during various functions. The purpose of this study is to investigate the volumetric changes of a regional section of the tongue during feeding. Four 12-week-old Yucatan miniature pigs were used. During natural mastication and water drinking, the width, length, thickness and volumetric changes were measured using six implanted ultrasonic crystals, which circumscribed a wedge-shaped volume in the region of the tongue body. Jaw movements were videotaped and digitized. Signals from these two sources were synchronized to allow real-time analyses. Significant volumetric changes (P < 0.001) were found in chewing, ingestion and drinking, and these changes were stereotypical in relation to rhythmic jaw movements. Volumetric change during chewing was not only more regular, but significantly larger (45.6%, P < 0.001) than that during ingestion (31.4%). The volumetric changes were less regular in drinking and the changing range (30.4%) was close to that during ingestion. Real-time analysis indicated that the volume began increasing at late jaw closing and reached the peak at late power stroke. The increase in duration of volume only took up 33.4% of the total chewing cycle length; significantly shorter than that of volume decrease. Correlation analysis revealed that the change in posterior dorsal and ventral widths had the greatest positive association with volumetric change (r = 0.43) in direction. The covariance calculations further indicated that dimensional changes in length and thickness coupled negatively with volumetric changes in amplitude. These results revealed that regional volumetric change of the tongue occurs during feeding and chewing requires larger volumetric changes than do ingestion and drinking. Volumetric expansion occurs in the phase of power stroke during chewing and is coupled with increases in widths in the direction and with decreases of thickness and length in the amplitude. The results further suggested that the regional volumetric expansion may play the determinant role in functional load production on its surrounding tissues, and may also imply that neuromuscular control of the tongue is region-specific, a notion incompatible with traditional scheme of categorizing muscle function in the tongue.

Rapid adhesion of Stagonospora nodorum spores to a hydrophobic surface requires pre-formed cell surface glycoproteins

Adhesion of fungal pathogens to leaf surfaces is an important first step in the infection process. Previous work on Stagonospora nodorum, a major necrotrophic pathogen of wheat and other cereals, has shown that conidia attach rapidly to a hydrophobic surface and this is followed by the active secretion of extracellular matrix material to consolidate adhesion. In this paper the role of pre-formed spore surface glycoproteins in the rapid adhesion of S. nodorum conidia to an artificial surface, polystyrene, has been investigated. Sodium dodecyl sulphate (SDS) and the enzymes chitinase and lyticase have been used to release cell wall glycoproteins from spores and these have been identified using SDS polyacrylamide gel electrophoresis (PAGE) and Western blotting. Labelling with fluorescently tagged lectins has also been used to study the spore surface. The results show that there are a small number of glycoproteins non-covalently and covalently attached to other components in the spore wall, which is not a uniform structure. The effects of proteases, lectins, and other treatments of spores in an adhesion assay have been used to show that pre-formed glycoproteins are involved in rapid adhesion to a hydrophobic surface. There is also evidence for a rapid release of glycoproteins by spores that is also involved in adhesion and this is not an active process.

Structural basis for the exceptional in vivo efficacy of bisphosphonate drugs

To understand the structural basis for bisphosphonate therapy of bone diseases, we solved the crystal structures of human farnesyl pyrophosphate synthase (FPPS) in its unliganded state, in complex with the nitrogen-containing bisphosphonate (N-BP) drugs zoledronate, pamidronate, alendronate, and ibandronate, and in the ternary complex with zoledronate and the substrate isopentenyl pyrophosphate (IPP). By revealing three structural snapshots of the enzyme catalytic cycle, each associated with a distinct conformational state, and details about the interactions with N-BPs, these structures provide a novel understanding of the mechanism of FPPS catalysis and inhibition. In particular, the accumulating substrate, IPP, was found to bind to and stabilize the FPPS-N-BP complexes rather than to compete with and displace the N-BP inhibitor. Stabilization of the FPPS-N-BP complex through IPP binding is supported by differential scanning calorimetry analyses of a set of representative N-BPs. Among other factors such as high binding affinity for bone mineral, this particular mode of FPPS inhibition contributes to the exceptional in vivo efficacy of N-BP drugs. Moreover, our data form the basis for structure-guided design of optimized N-BPs with improved pharmacological properties.

Dietary determinants of post-menopausal bone loss at the lumbar spine: a possible beneficial effect of iron

INTRODUCTION

Previous studies suggesting different effects of diet on post-menopausal bone loss may have given conflicting results because they sometimes failed to exclude confounding conditions or used imprecise methodology.

DESIGN

To identify dietary determinants of bone loss from the lumbar spine after menopause in women not taking hormone replacement who developed no evidence of spondylotic or sclerotic degenerative disease, forty-three women were followed with repeated (mean = 12) measurements of bone mineral density (BMD) at L2-4 for 11-14 years. Eleven developed evidence suggestive of degenerative disease and were excluded. Diet was assessed at the beginning of the study and 2.5 years later using 3-day and 7-day periods of weighed intakes. Nutrients estimated were: carbohydrate, fat, protein, fibre, calcium, magnesium, iron, phosphorus, copper, zinc and six vitamins. We tested the ability of diet to predict post-menopausal bone loss using stepwise regression.

RESULTS

Each woman's BMD change was described by a single coefficient after log transformation of the BMD data. The best model for BMD loss including dietary factors alone had two significant determinants: daily energy or protein (p=0.0003) intake was adverse, while dietary iron (p=0.002) was predictive of bone maintenance, an effect that persisted if iron was expressed as a ratio to energy intake. Adding body mass index to the model increased the goodness of fit (R (2)adj rose from 0.33 to 0.42) without affecting the statistical significance of the dietary determinants.

CONCLUSIONS

Diet may influence bone loss after menopause, with dietary iron (or an associated factor) possibly having a protective effect on bone at the spine.

Bisphosphonates: preclinical review

Bisphosphonates effectively inhibit osteoclast-mediated bone resorption and are integral in the treatment of benign and malignant bone diseases. The evolution of bisphosphonates over the past 30 years has led to the development of nitrogen-containing bisphosphonates (N-BPs), which have a mechanism of action different from that of the nonnitrogen-containing bisphosphonates. Studies conducted over the past decade have elucidated the mechanism of action and pharmacologic properties of the N-BPs. N-BPs exert their effects on osteoclasts and tumor cells by inhibiting a key enzyme in the mevalonate pathway, farnesyl diphosphate synthase, thus preventing protein prenylation and activation of intracellular signaling proteins such as Ras. Recent evidence suggests that N-BPs also induce production of a unique adenosine triphosphate analogue (Apppi) that can directly induce apoptosis. Our increased understanding of the pharmacologic effects of bisphosphonates is shedding light on the mechanisms by which they exert antitumor effects. As a result of their biochemical effects on protein prenylation, N-BPs induce caspase-dependent apoptosis, inhibit matrix metalloproteinase activity, and downregulate alpha(v)beta(3) and alpha(v)beta(5) integrins. In addition, zoledronic acid (Zometa; Novartis Pharmaceuticals Corp.; East Hanover, NJ and Basel, Switzerland) exerts synergistic antitumor activity when combined with other anticancer agents. Zoledronic acid also inhibits tumor cell adhesion to the extracellular matrix and invasion through Matrigel trade mark and has antiangiogenic activity. A growing body of evidence from animal models demonstrates that zoledronic acid and other bisphosphonates can reduce skeletal tumor burden and prevent metastasis to bone. Further studies are needed to fully elucidate these biochemical mechanisms and to determine if the antitumor potential of bisphosphonates translates to the clinical setting.

Use of REMI andAgrobacterium-mediated transformation to identify pathogenicity mutants of the biocontrol fungus,Coniothyrium minitans

Restriction enzyme mediated integration (REMI) and Agrobacterium-mediated transformation (ATMT) were used to transform protoplasts or germinated conidia of the mycoparasite Coniothyrium minitans to hygromycin resistance. Using REMI, up to 32 transformants mug DNA(-1) were obtained, while 37.8 transformants 5 x 10(5) germlings(-1) were obtained using ATMT. Single-copy integrations occurred in 8% and 40% of REMI and ATMT transformants, respectively. A novel microtitre plate-based test was developed to expedite screening of 4000 REMI and ATMT C. minitans transformants. Nine pathogenicity mutants that displayed reduced or no pathogenicity on sclerotia of Sclerotinia sclerotiorum were identified.

Loss of vertebral bone and mechanical strength in estrogen-deficient rats is prevented by long-term administration of zoledronic acid

This study investigated the protective effect of long-term treatment with the bisphosphonate zoledronic acid on bone mass, structure, and strength in adult, estrogen-deficient rats. Rats were ovariectomized (OVX) at the age of 4 months and divided into four groups of 20 rats: one group of saline-treated OVX controls, and three groups of OVX rats treated with 0.3, 1.5, or 7.5 microg/kg/week s.c. zoledronic acid (ZOL). An additional group of sham-operated, saline-treated rats served as normal controls. Biochemical assays were performed after 16 and 51 weeks, respectively, and bone mineral density (BMD) determinations after 17 and 52 weeks, respectively. Before the end of the experiment animals were injected with tetracyclines for the determination of dynamic bone indexes. Finally, animals were sacrificed after 52 weeks, and vertebral bones (LV5) were subjected to mechanical compression testing. LV4 were used for histology and LV2 for microcomputed tomography. ZOL treatment abolished the rise of osteocalcin and reduced urinary deoxypyridinoline excretion. BMD was reduced in the OVX group in comparison to sham controls, and the decline was dose-dependently prevented by ZOL treatment. Tetracycline labeling showed a significant increase in bone formation rate (BFR) in OVX rats which was abolished by ZOL treatment. The same was observed for osteoid perimeter (Os.Pm) suggesting that ZOL diminished the high bone turnover associated with estrogen deficiency. Architectural parameters (BV/TV, Tb.Th*, Tb.N*, Tb.Sp*, SMI, CD) underwent the expected changes toward structural deterioration which was completely prevented by ZOL administration at doses of 1.5 and 7.5 microg/kg/week s.c. Similar results were obtained in compression testing: maximum stress fell significantly after OVX, and this effect was effectively prevented by ZOL treatment. Regression analysis suggests that in this rat model, SMI and Tb.Th* significantly contribute to compressive strength, albeit to a smaller degree than total cross-sectional area. The data further suggest that in the aged OVX rat, SMI and TB.Th* change in an interdependent way. ZOL prevents this process by inhibiting plate thinning and the transition into rod-shaped trabeculae.

Targeting osteoclasts with zoledronic acid prevents bone destruction in collagen-induced arthritis

OBJECTIVE

To study the effect of zoledronic acid (ZA) on synovial inflammation, structural joint damage, and bone metabolism in rats during the effector phase of collagen-induced arthritis (CIA).

METHODS

CIA was induced in female dark agouti rats. At the clinical onset of CIA, rats were assigned to treatment with vehicle or single subcutaneous doses of ZA (1.0, 10, 50, or 100 microg/kg). Clinical signs in all 4 paws were scored on a daily basis. After 2 weeks, the joints in the hind paws were assessed using plain radiographs, microfocal computed tomography (micro-CT), histologic scoring, and histomorphometry, and the serum levels of type I collagen crosslinks were measured by enzyme-linked immunosorbent assay.

RESULTS

Although ZA mildly exacerbated synovitis, it effectively suppressed structural joint damage. At doses of >/=10 microg/kg, ZA significantly reduced radiographic bone erosions, Larsen scores, and juxtaarticular trabecular bone loss as quantified by micro-CT. ZA prevented increased type I collagen (bone) breakdown in CIA and diminished histologic scores of focal bone erosion by up to 80%. Increases in the percentage of eroded surface, osteoclast surface, and osteoclast numbers associated with CIA were prevented by ZA, even though synovitis scores were unchanged.

CONCLUSION

Single doses (>/=10 microg/kg) of ZA strikingly reduced focal bone erosions and juxtaarticular trabecular bone loss, although synovitis was mildly exacerbated. Targeting osteoclasts with ZA may therefore be an effective strategy for preventing structural joint damage in rheumatoid arthritis.

Bisphosphonates: new therapeutic agents for the treatment of bone tumors

Bisphosphonates (BPs) have been used successfully for many years to reduce the skeletal complications associated with the benign and malignant bone diseases that are characterized by enhanced osteoclastic bone resorption. Until recently, it was thought that the clinical efficacy of BPs in the treatment of cancer patients with bone metastases was purely a result of the inhibition of osteoclast-mediated bone resorption. However, recent studies have demonstrated that BPs inhibit the growth, attachment and invasion of cancer cells in culture and promote their apoptosis. These results suggest that BPs are also anti-cancer agents, raising the possibility that BPs could inhibit cancer-cell colonization in visceral organs. However, results from clinical trials are conflicting, and whether BPs possess anti-cancer effects or not remains controversial.

Time series analysis of jaw muscle contraction and tissue deformation during mastication in miniature pigs

Masticatory muscle contraction causes both jaw movement and tissue deformation during function. Natural chewing data from 25 adult miniature pigs were studied by means of time series analysis. The data set included simultaneous recordings of electromyography (EMG) from bilateral masseter (MA), zygomaticomandibularis (ZM) and lateral pterygoid muscles, bone surface strains from the left squamosal bone (SQ), condylar neck (CD) and mandibular corpus (MD), and linear deformation of the capsule of the jaw joint measured bilaterally using differential variable reluctance transducers. Pairwise comparisons were examined by calculating the cross-correlation functions. Jaw-adductor muscle activity of MA and ZM was found to be highly cross-correlated with CD and SQ strains and weakly with MD strain. No muscle's activity was strongly linked to capsular deformation of the jaw joint, nor were bone strains and capsular deformation tightly linked. Homologous muscle pairs showed the greatest synchronization of signals, but the signals themselves were not significantly more correlated than those of non-homologous muscle pairs. These results suggested that bone strains and capsular deformation are driven by different mechanical regimes. Muscle contraction and ensuing reaction forces are probably responsible for bone strains, whereas capsular deformation is more likely a product of movement.

A biomechanical evaluation of the role of labrum on anterior/posterior translation of shoulders at different degrees of abduction

The objective of the study was to investigate the effects of anterior and posterior labrums on the anterior/posterior translations of shoulders. Thirteen cadaver shoulders were arthroscopically evaluated and nine were selected based on the absence of any pathological findings. These shoulders were tested intact, vented and after sequential arthroscpoic incision of the anterior and posterior labrums. The anterior/posterior translations were measured in a specially designed apparatus. The loads vs. displacement curves were obtained. The loads vs. displacement curves of the shoulders before and after labrum incision did not show any appreciable differences. Moreover the measured loads at 6 mm displacement did not show any statistically significant differences due to labrum incision. It was concluded that both anterior and posterior labrum incisions of the shoulders did not show any appreciable differences in anterior/posterior laxity. An arthroscopic technique was successfully developed to isolate the effect of labrum on the shoulder laxity.

Long-term zoledronic acid treatment increases bone structure and mechanical strength of long bones of ovariectomized adult rats

Zoledronic acid (ZOL) is a highly potent heterocyclic bisphosphonate which has been shown to inhibit bone resorption in short-term experiments in young growing animals. In this investigation we have evaluated the effects of a 1-year administration to mature, ovariectomized (OVX) rats as a model for postmenopausal osteoporosis in order to elucidate (1) the temporal changes in urinary biochemical markers of bone turnover and femoral bone mineral density (BMD), (2) to measure changes of static and dynamic histomorphometric parameters and mechanical strength, and (3) to assess the preventive effects of chronic treatment with ZOL on these parameters. In urine, deoxypyridinoline increased after OVX and was significantly reduced by ZOL administration, indicative of a reduced bone collagen turnover. These changes were accompanied by alterations of tibial cancellous bone: trabecular bone volume and parameters of bone architecture were significantly augmented by ZOL and bone formation rates fell as a consequence of suppressed bone turnover, but were still measurable. No signs of "frozen bone" or osteomalacia could be detected. BMD of the whole femurs rose in sham-operated control animals (SHAM) during the entire experimental period, whereas in OVX animals, BMD plateaued after 32 weeks at a lower level. ZOL at a low dose (0.3 mg/kg/week s.c.) did not alter whole femur BMD, but at higher doses (1.5 and 7.5 mg/kg/week s.c.) BMD increased to the level of the SHAM group. A distinct pattern was noted for the distal quarter of the femur, a region rich in cancellous bone: BMD initially increased in all treatment groups except the OVX group, and at a later stage fell again at a comparable rate irrespective of treatment. Mechanical stability, as assessed by a 3-point bending test, was significantly increased by all doses of ZOL and exceeded OVX and sham-operated controls. The effects on mechanical properties were observed at a low dose which did not measurably increase femoral BMD after 1-year treatment. Multiregression analysis revealed a significant positive correlation between maximum load and BMD, and a significant negative correlation of maximum load with labeled perimeter, a marker of bone formation and turnover. No significant correlation was found with urinary deoxypyridinoline, a marker of bone resorption. The data show that mechanical testing detects improvements of functional bone quality following low dose bisphosphonate treatment which are not identified by standard DXA measurements of BMD.

Antitumor effects of bisphosphonates

BACKGROUND

Bisphosphonates are widely used to treat skeletal complications of malignancy. These drugs accumulate in bone where they inhibit osteoclastic bone resorption and reduce the local release of factors that stimulate tumor growth. The mechanism of action of bisphosphonates is dependent on chemical structure: Nonnitrogen-containing compounds (e.g., etidronate, clodronate) are metabolized into cytotoxic analogues of ATP, whereas the more potent nitrogen-containing compounds (N-BPs; e.g., pamidronate, ibandronate, zoledronic acid) inhibit protein prenylation, thus affecting cell function and survival. Because protein prenylation is required by all cells, not just osteoclasts, the possibility arises that N-BPs could also affect the viability of tumor cells.

METHODS

Several groups have investigated the in vitro effects of bisphosphonates, either alone or in combination with other antineoplastic agents, on the viability and metastatic properties of many tumor cell types. Similarly, the effect of bisphosphonate treatment on osteolysis and tumor burden has been studied in a variety of animal tumor models.

RESULTS

In vitro, submicromolar concentrations of N-BPs inhibited tumor cell adhesion and reduced invasion through extracellular matrix. At higher concentrations, antiproliferative and proapoptotic effects have been reported. In animal models of bone metastases, bisphosphonate treatment markedly reduced osteolytic lesions. There is also evidence of a reduction in tumor burden in bone and occasionally in other organs. Survival may be prolonged, but bisphosphonates do not appear to inhibit the growth of primary soft tissue tumors or orthotopic xenografts.

CONCLUSIONS

The cell culture data clearly demonstrated that N-BPs exert antitumor properties and interact synergistically with other antineoplastic agents. As bisphosphonates accumulate in bone, they can also exert cytostatic effects on tumor cells in bone metastases, either directly or indirectly via osteoclast inhibition and alterations in the bone microenvironment. Further in vivo research is now required to optimize the dosing regimen of N-BPs to exploit fully their antitumor potential.

Mechanisms of bisphosphonate effects on osteoclasts, tumor cell growth, and metastasis

Bisphosphonates are potent inhibitors of osteoclast-mediated bone resorption that also exhibit antitumor activity. There is now extensive in vitro evidence that bisphosphonates inhibit proliferation and induce apoptosis of tumor cell lines. In addition, they appear to inhibit tumor cell adhesion and invasion of the extracellular matrix. These data are supported by a growing body of evidence from animal models demonstrating that bisphosphonates can reduce skeletal tumor burden. This may reflect direct antitumor effects or indirect effects via osteoclast inhibition and alteration of the bone microenvironment. Research has begun to shed light on the complex mechanisms by which bisphosphonates inhibit bone resorption and interfere with the formation and growth of bone lesions. Nitrogen-containing bisphosphonates inhibit protein prenylation and thereby short-circuit intracellular signaling via small guanine triphosphatases, such as Ras, which require membrane localization. As a result of these biochemical effects on the mevalonate pathway, bisphosphonates appear to modulate the expression of bcl-2 leading to caspase-dependent apoptosis, inhibit matrix metalloproteinases, downregulate alphavbeta3 and alphavbeta5 integrins, and increase expression of osteoprotegerin, thereby antagonizing osteoclastogenesis. Further preclinical studies are ongoing to fully elucidate these biochemical mechanisms, and well-designed clinical trials are necessary to investigate whether the antitumor potential of bisphosphonates can be realized in the clinical setting.

Preclinical pharmacology of zoledronic acid

The evolution of bisphosphonates over the past 30 years has led to the development of nitrogen-containing bisphosphonates with ever-increasing potency. Recent studies have begun to shed light on the unique mechanism of action and pharmacologic properties of these compounds. On the basis of in vitro studies and animal models of osteoclast-mediated bone resorption, zoledronic acid is the most potent bisphosphonate among a large number of compounds tested, including pamidronate and most other commercially available bisphosphonates. Zoledronic acid maintains bone mass in estrogen-deficient animals without adversely affecting bone mineralization. Moreover, the high potency of zoledronic acid translates into dramatic suppression of bone resorption markers at very low doses in patients with bone metastases, and zoledronic acid has shown efficacy across a broad range of tumor types. Preclinical studies have also shown the potential of bisphosphonates to inhibit tumor cell growth and colonization of the bone and to reduce skeletal tumor burden in animal models. A variety of mechanisms have been proposed to explain these observations and continue to be investigated in animal models. Studies are ongoing to determine if the antitumor potential of bisphosphonates can be exploited in the clinical setting.

Bisphosphonates in cancer therapy

Bisphosphonates inhibit osteoclast-mediated bone resorption in metastatic bone disease. A wealth of preclinical data have begun to shed light on the complex mechanisms by which bisphosphonates inhibit bone resorption and interfere with the formation and growth of bone metastases. Nitrogen-containing bisphosphonates inhibit the mevalonate pathway, which results in the inhibition of osteoclast function and the induction of apoptosis in osteoclasts and tumor cells alike. There is now extensive evidence that bisphosphonates have cytostatic activity against tumor cell lines and inhibit tumor cell adhesion and invasion of the extracellular matrix. These data are supported by a growing body of evidence from animal models demonstrating that bisphosphonates can reduce skeletal tumor burden. However, it remains unclear whether this reduction reflects a direct antitumor effect or an indirect effect via osteoclast inhibition and alteration of the bone microenvironment. Further preclinical studies are needed to elucidate these biochemical mechanisms fully; ultimately, well-controlled clinical trials will be required to investigate whether the antitumor potential of bisphosphonates translates into a significant clinical benefit for patients with cancer.

Novel antiangiogenic effects of the bisphosphonate compound zoledronic acid

Bisphosphonate drugs inhibit osteoclastic bone resorption and are widely used to treat skeletal complications in patients with tumor-induced osteolysis. We now show that zoledronic acid, a new generation bisphosphonate with a heterocyclic imidazole substituent, is also a potent inhibitor of angiogenesis. In vitro, zoledronic acid inhibits proliferation of human endothelial cells stimulated with fetal calf serum, basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (IC(50) values 4.1, 4.2, and 6.9 microM, respectively), and modulates endothelial cell adhesion and migration. In cultured aortic rings and in the chicken egg chorioallantoic membrane assay, zoledronic acid reduces vessel sprouting. When administered systemically to mice, zoledronic acid potently inhibits the angiogenesis induced by subcutaneous implants impregnated with bFGF [ED(50), 3 microg/kg (7.5 nmol/kg) s.c.]. These findings indicate that zoledronic acid has marked antiangiogenic properties that could augment its efficacy in the treatment of malignant bone disease and extend its potential clinical use to other diseases with an angiogenic component.

Highly potent geminal bisphosphonates. From pamidronate disodium (Aredia) to zoledronic acid (Zometa)

Bisphosphonates (BPs) are pyrophosphate analogues in which the oxygen in P-O-P has been replaced by a carbon, resulting in a metabolically stable P-C-P structure. Pamidronate (1b, Novartis), a second-generation BP, was the starting point for extensive SAR studies. Small changes of the structure of pamidronate lead to marked improvements of the inhibition of osteoclastic resorption potency. Alendronate (1c, MSD), with an extra methylene group in the N-alkyl chain, and olpadronate (1h, Gador), the N,N-dimethyl analogue, are about 10 times more potent than pamidronate. Extending one of the N-methyl groups of olpadronate to a pentyl substituent leads to ibandronate (1k, Roche, Boehringer-Mannheim), which is the most potent close analogue of pamidronate. Even slightly better antiresorptive potency is achieved with derivatives having a phenyl group linked via a short aliphatic tether of three to four atoms to nitrogen, the second substituent being preferentially a methyl group (e.g., 4g, 4j, 5d, or 5r). The most potent BPs are found in the series containing a heteroaromatic moiety (with at least one nitrogen atom), which is linked via a single methylene group to the geminal bisphosphonate unit. Zoledronic acid (6i), the most potent derivative, has an ED(50) of 0.07 mg/kg in the TPTX in vivo assay after sc administration. It not only shows by far the highest therapeutic ratio when comparing resorption inhibition with undesired inhibition of bone mineralization but also exhibits superior renal tolerability. Zoledronic acid (6i) has thus been selected for clinical development under the registered trade name Zometa. The results of the clinical trials indicate that low doses are both efficacious and safe for the treatment of tumor-induced hypercalcemia, Paget's disease of bone, osteolytic metastases, and postmenopausal osteoporosis.

Maintenance of Crohn's disease over 12 months: fixed versus flexible dosing regimen using budesonide controlled ileal release capsules

BACKGROUND

It may be possible to achieve more effective management of Crohn's Disease by introducing a flexible dosage regimen sensitive to patients' needs.

AIM

Comparison of the efficacy and tolerability of a fixed vs. flexible budesonide controlled ileal release treatment regimen for the prevention and management of relapse in Crohn's disease patients. Budesonide controlled ileal release is an oral formulation which delivers drug directly to disease sites in the ileum and ascending colon, by preventing more proximal release and absorption.

METHODS

A randomized, double-blind comparison of a fixed dose of budesonide controlled ileal release (6 mg o.m.) and a flexible dose of budesonide controlled ileal release (3, 6 or 9 mg o.m.) for 12 months, in 143 patients in remission from ileal or ileo-caecal Crohn's Disease.

RESULTS

Very low rates of clinical relapse in Crohn's disease were achieved with budesonide controlled ileal release 6 mg o.m. There was no significant difference between the treatment groups with respect to the survival estimate of percentage of treatment failures (flexible group 15%, fixed group 19%; P=0.61). The average consumed dose of budesonide was comparable in both groups (5.8 mg flexible, 6.0 mg fixed). Similar proportions of patients reported adverse events (flexible 100%, fixed 97%). There were 33 serious adverse events (flexible 19, fixed 14) and 13 withdrawals due to significant adverse events (flexible 9, fixed 4).

CONCLUSION

Maintenance treatment with budesonide controlled ileal release 6 mg o.m. is well-tolerated and is associated with low rates of clinical relapse in stable Crohn's disease over 12 months. Flexible dosing remains an option for individual patients, but this study has shown no advantage over a standard fixed dosing regimen.

Tolerability of aminosalicylates in inflammatory bowel disease

Since its synthesis in the 1930s and subsequent introduction, sulfasalazine has been an effective treatment for inflammatory bowel disease. However, up to one-third of patients are unable to take the drug because of severe intolerance. The finding in 1977 that the anticolitic effect of sulfasalazine lay in its 5-aminosalicylic [(5-ASA); mesalazine] moiety led to the development of new generations of 5-ASA agents. These new agents include a slow continuous release formulation, pH-dependent release formulations, formulations using alternative carrier molecules and rectally administered formulations. Newer 5-ASA formulations are more effective than placebo in maintaining remission of ulcerative colitis. They have also been used for the treatment of active Crohn's disease as well as maintenance treatment of ileocolonic Crohn's disease, although their role in isolated small bowel disease is controversial. In general terms, all of the newer 5-ASA preparations are much better tolerated than sulfasalazine. The use of standard dosages of mesalazine in pregnancy appears to be tolerated; however, continuing surveillance of pregnancy outcome is recommended. While there is evidence that mesalazine can cause nephrotoxic reactions, these reactions can occur with all 5-ASA-containing preparations, particularly in individuals with existing renal disease. Blood dyscrasias can also occur with all aminosalicylates.