Machine learning assisted 5-part tooth segmentation method for CBCT-based dental age estimation in adults

BACKGROUND

The utilization of segmentation method using volumetric data in adults dental age estimation (DAE) from cone-beam computed tomography (CBCT) was further expanded by using current 5-Part Tooth Segmentation (SG) method. Additionally, supervised machine learning modelling -namely support vector regression (SVR) with linear and polynomial kernel, and regression tree - was tested and compared with the multiple linear regression model.

MATERIAL AND METHODS

CBCT scans from 99 patients aged between 20 to 59.99 was collected. Eighty eligible teeth including maxillary canine, lateral incisor, and central incisor were used in this study. Enamel to dentine volume ratio, pulp to dentine volume ratio, lower tooth volume ratio, and sex was utilized as independent variable to predict chronological age.

RESULTS

No multicollinearity was detected in the models. The best performing model comes from maxillary lateral incisor using SVR with polynomial kernel ( = 0.73). The lowest error rate achieved by the model was given also by maxillary lateral incisor, with 4.86 years of mean average error and 6.05 years of root means squared error. However, demands a complex approach to segment the enamel volume in the crown section and a lengthier labour time of 45 minutes per tooth.

Traffic Control: Subversion of Plant Membrane Trafficking by Pathogens

Membrane trafficking pathways play a prominent role in plant immunity. The endomembrane transport system coordinates membrane-bound cellular organelles to ensure that immunological components are utilized effectively during pathogen resistance. Adapted pathogens and pests have evolved to interfere with aspects of membrane transport systems to subvert plant immunity. To do this, they secrete virulence factors known as effectors, many of which converge on host membrane trafficking routes. The emerging paradigm is that effectors redundantly target every step of membrane trafficking from vesicle budding to trafficking and membrane fusion. In this review, we focus on the mechanisms adopted by plant pathogens to reprogram host plant vesicle trafficking, providing examples of effector-targeted transport pathways and highlighting key questions for the field to answer moving forward.

The wheels of destruction: Plant NLR immune receptors are mobile and structurally dynamic disease resistance proteins

Nucleotide-binding leucine-rich repeat (NLR) proteins are intracellular immune receptors that restrict plant invasion by pathogens. Most NLRs operate in intricate networks to detect pathogen effectors in a robust and efficient manner. NLRs are not static sensors; rather, they exhibit remarkable mobility and structural plasticity during the innate immune response. Inactive NLRs localize to diverse subcellular compartments where they are poised to sense pathogen effectors. During pathogen attack, some NLRs relocate toward the plant-pathogen interface, possibly to ensure their timely activation. Activated NLRs reorganize into wheel-shaped oligomers, some of which then form plasma membrane pores that promote calcium influx and programmed cell death. The emerging paradigm is that this variable and dynamic nature underpins effective NLR-mediated immunity.

Multi-Attribute Monitoring Method for Process Development of Engineered Antibody for Site-Specific Conjugation

Antibody drug conjugates, a class of biotherapeutic proteins, have been extensively developed in recent years, resulting in new approvals and improved standard of care for cancer patients. Among the numerous strategies of conjugating cytotoxic payloads to monoclonal antibodies, insertion of a cysteine residue achieves a tightly controlled, site-specific drug to antibody ratio. Tailored analytical tools are required to direct the development of processes capable of manufacturing novel antibody scaffolds with the desired product quality. Here, we describe the development of a 12 min, mass-spectrometry-based method capable of monitoring four distinct quality attributes simultaneously: variations in the thiol state of the inserted cysteines, N-linked glycosylation, reduction of interchain disulfide bonds, and polypeptide fragmentation. This method provides new insight into the properties of the antibody intermediate and associated manufacturing processes. Oxidized thiol states are formed within the bioreactor, of which a variant containing an additional disulfide bond was produced and remained relatively constant throughout the fed-batch process; reduced thiol variants were introduced upon harvest. Nearly 20 percent of N-linked glycans contained sialic acid, substantially higher than anticipated for wildtype IgG1. Lastly, previously unreported polypeptide fragmentation sites were identified in the C239i constant domain, and the relationship between fragmentation and glycoform were explored. This work illustrates the utility of applying a high-throughput liquid chromatography-mass spectrometry multi-attribute monitoring method to support the development of engineered antibody scaffolds.

An automated, low volume, and high-throughput analytical platform for aggregate quantitation from cell culture media

High throughput screening methods have driven a paradigm shift in biopharmaceutical development by reducing the costs of good manufactured (COGM) and accelerate the launch to market of novel drug products. Scale-down cell culture systems such as shaken 24- and 96-deep-well plates (DWPs) are used for initial screening of hundreds of recombinant mammalian clonal cell lines to quickly and efficiently select the best producing strains expressing product quality attributes that fit to industry platform. A common modification monitored from early-stage product development is protein aggregation due to its impact on safety and efficacy. This study aims to integrate high-throughput analysis of aggregation-prone therapeutic proteins with 96-deep well plate screening to rank clones based on the aggregation levels of the expressed proteins. Here we present an automated, small-scale analytical platform workflow combining the purification and subsequent aggregation analysis of protein biopharmaceuticals expressed in 96-DWP cell cultures. Product purification was achieved by small-scale solid-phase extraction using dual flow chromatography (DFC) automated on a robotic liquid handler for the parallel processing of up to 96 samples at a time. At-line coupling of size-exclusion chromatography (SEC) using a 2.1 mm ID column enabled the detection of aggregates with sub-2 µg sensitivity and a 3.5 min run time. The entire workflow was designed as an application to aggregation-prone mAbs and "mAb-like" next generation biopharmaceuticals, such as bispecific antibodies (BsAbs). Application of the high-throughput analytical workflow to a shake plate overgrow (SPOG) screen, enabled the screening of 384 different clonal cell lines in 32 h, requiring < 2 μg of protein per sample. Aggregation levels expressed by the clones varied between 9 and 76%. This high-throughput analytical workflow allowed for the early elimination of clonal cell lines with high aggregation, demonstrating the advantage of integrating analytical testing for critical quality attributes (CQAs) earlier in product development to drive better decision making.

Observer Agreement of Vertebral Fracture Grading Using Dual Energy Absorptiometry Vertebral Fracture Assessment in Duchenne Muscular Dystrophy

Routine screening of the spine for vertebral fracture is recommended in the recent international standards of care for boys with Duchenne muscular dystrophy (DMD). Recent international consensus endorses the use of dual energy absorptiometry vertebral fracture assessment for identification of vertebral fractures in children, which could be used instead of spine radiographs. This study aims to evaluate the inter-observer agreement for vertebral fracture classification in boys with DMD, and the impact on clinical management. Dual energy absorptiometry vertebral fracture assessment and morphometric analysis in 39 boys was performed by a reader with no prior experience (R1) and 2 readers with experience (R2 and R3). Inter-observer concordance of vertebral fracture grading comparing R1 with R2 and R3 was substantial (Kappa 0.66, 95% CI 0.56, 0.76). Concordance between R2 and R3 was almost perfect (Kappa 0.93, 95% CI 0.89, 0.97) which did not lead to differences in clinical management. Grading by R1 in comparison to R2 and R3 would have led to change in management of 5/39 boys (13%), according to recent standards of care guidance. Structured education programme on identification of vertebral fractures should be explored to ensure consistency of reporting of this important health outcome measure in DMD.

Feasibility of Dual Energy X-Ray Absorptiometry Based Images for Measurement of Height, Sitting Height, and Leg Length in Children

BACKGROUND

Interpretation of pediatric bone mineral density by dual energy absorptiometry (DXA) requires adjustment for height (Ht). This is often not easily obtainable in nonambulant subjects.

AIMS

To investigate the feasibility of using DXA images to evaluate measurements of Ht, sitting height (SH), and leg length (LL).

METHODOLOGY

A total of 2 observers performed measurements of Ht, SH, and LL on 3 separate occasion using DXA digital images in 125 children. Intraclass correlation and relative technical error of measurement (rTEM) were performed to assess reliability of repeated measurements. In 25 children, Ht and SH were measured in clinic on the same day and Bland-Altman analysis was performed to compare DXA measured Ht, SH, LL with clinic measurements for these 25 children.

RESULTS

Intraclass correlation for DXA based Ht, SH, and LL measurements ranged from 0.996 to 0.998 (p < 0.0001). rTEM of Ht, SH, and LL for observer 1 was 0.0016%, 0.002%, and 0.0034%, respectively. rTEM of Ht, SH, and LL between observer 1 and 2 was 0.0047%, 0.0049%, and 0.0087%, respectively. Mean difference between clinic and DXA measurements from Bland-Altman plots were +0.57 cm (95% confidence interval [CI] -0.54 to +1.68) for Ht, +1.33cm (-1.60 to +4.24) for SH, and -0.76cm (-3.88 to +2.37) for LL.

CONCLUSIONS

Our study demonstrated for the first time that Ht, SH, and LL in children can be measured very precisely using DXA images. Ht can be measured accurately. We believe this may be a convenient method to obtain Ht measurements to allow size adjustment of DXA bone mineral density in immobile children with chronic conditions.

Alternative Lengthening of Telomeres in Pediatric Cancer: Mechanisms to Therapies

Achieving replicative immortality is a crucial step in tumorigenesis and requires both bypassing cell cycle checkpoints and the extension of telomeres, sequences that protect the distal ends of chromosomes during replication. In the majority of cancers this is achieved through the enzyme telomerase, however a subset of cancers instead utilize a telomerase-independent mechanism of telomere elongation-the Alternative Lengthening of Telomeres (ALT) pathway. Recent work has aimed to decipher the exact mechanism that underlies this pathway. To this end, this pathway has now been shown to extend telomeres through exploitation of DNA repair machinery in a unique process that may present a number of druggable targets. The identification of such targets, and the subsequent development or repurposing of therapies to these targets may be crucial to improving the prognosis for many ALT-positive cancers, wherein mean survival is lower than non-ALT counterparts and the cancers themselves are particularly unresponsive to standard of care therapies. In this review we summarize the recent identification of many aspects of the ALT pathway, and the therapies that may be employed to exploit these new targets.

FM2-1 A smartphone camera can detect functional tremor

Objectives

Functional neurological disorders are common, but there is a lack of objective tests for these conditions. Although accelerometry can distinguish functional from other tremor types, it is not routinely used at the bedside. Computer vision describes the processing of camera images by computer. It requires only ubiquitous hardware (e.g. smartphone, laptop) and standard clinical assessment, i.e. simple observation. We investigated computer vision to detect tremor distraction/entrainment in functional tremor.

Design

Early results comparing computer analysis of video from a functional tremor and an essential tremor.

Methods

30 s (60 fps) video of extended forearm was recorded using a smartphone, for a functional tremor and an essential tremor patient. From 15 s, each participant tapped in time with a 3 Hz metronome using the contralateral hand (outside the video frame). Computing algorithms amplified the magnitude of video pixel movement and then measured the direction and size of pixel movement over time.

Results

After the metronome onset, there was a marked change in video pixel movement for the functional tremor patient, with the frequency concentrating at 3 Hz, and this was statistically significant by linear discriminant analysis. There was no significant change in pixel movement after the metronome for the essential tremor patient (frequency remained 8–12 Hz).

Conclusions

Smartphone video pixel movement can detect functional tremor entrainment, suggesting a possible new objective, bedside test.

Abstract P1-15-08: Pathologic complete response rates following neoadjuvant systemic therapy in 794 patients with early breast cancer: The Royal Marsden experience

Background

The presence and extent of residual invasive cancer after neoadjuvant treatment (NACT) is a strong prognostic factor for risk of recurrence, especially in triple-negative (TN) and human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC). Recent advances in the standard-of-care NACT improved pathological complete response (pCR) rates in published clinical trials.

We evaluated the pCR rates, defined as ypT0-is ypN0, in our real-world BC population and in estrogen receptor-positive [ER+] HER2-, HER2+ and TN subgroups and their association with tumour, patients' characteristics and disease-free survival (DFS).

Methods

We retrospectively identified early BC patients receiving NACT between January 2013 and December 2017. Demographics, patient and disease characteristics, pathological responses, toxicities, dose delays and reductions were recorded. Simple statistics, Fisher's exact test, chi-squared method and Cox regression were used as appropriate.

Results

794 patients identified had median age of 50 years (range 24-87) and 93.9% (745 patients) ECOG performance status (PS) 0. 3.0% (24) had clinical stage I disease, 68.0% (540) stage II and 29.0% (230) stage III. 71.0% (564) had grade 3 disease and 91.8% (729) ductal histology. 33.7% (257) had ER+/HER2-, 25.8% (205) had TN and 38.0% (301) HER2+ disease. Overall, 6.8% (54) patients received platinum. 36.6% (291) patients had dose reductions and 24.3% (193) dose delays. Along with NACT, 51.6% (147) of the HER2+ patients received Trastuzumab and Pertuzumab and 48.4% (138) Trastuzumab alone.

pCR rate was 33.1% in the overall population and significantly different in ER+/HER2-, HER2+ and TN subgroups (12.84% versus 52.0% versus 28.43% respectively, p&lt;0.001). pCR was influenced by grade (1: 0%; 2: 24.3%; 3: 36.1%, p 0.005) and histology (ductal: 34.2%; lobular: 10.0%; mixed 25.0%; p 0.01). In the HER2+ subgroup, there was a trend for improved pCR rates for patients receiving Pertuzumab and Trastuzumab (57.0%) versus Trastuzumab alone (51.0%). No statistically significant differences were seen based on patients' characteristics including age and PS or in case of treatment dose reductions and delays. Early discontinuation of NACT was associated with lower pCR rates (20.5% vs 36.29%, p &lt;0.001).

Of interest, pCR rates remained consistent across the period 2013-2017 in the overall population. We observed a trend for improved pCR in the HER2+ (2013: 47.5%; 2014: 44.4%; 2015: 66.7%; 2016: 51.0%; 2017: 51.4%) and TN cohorts (2013: 23.5%; 2014: 25.0%; 2015: 25.0%; 2016: 33.3%; 2017: 34.1%) but not in the ER+/HER2- group.

Median DFS was 83.8 months (95% CI 62.0-NR) in the overall population. Although not reached in the TN cohort, median DFS was different according to disease subgroups (HER2+: 83.78 months; TN: NR; ER+/HER2-: 62.0 months, p &lt;0.0001).

Conclusions

In our analysis pCR rates are consistent with data published in literature and higher in HER2+ and TN disease. The impact of new agents had a relatively low impact on pCR rates in our overall population over the last 5 years, although they produced gradual improvements in the HER2+ and TN subgroups.

Citation Format: Battisti NML, True V, Chaabouni N, Chopra N, Lee K, Shepherd S, Shapira-Rotenberg T, Joshi R, Mohammed K, Allen M, Ring A. Pathologic complete response rates following neoadjuvant systemic therapy in 794 patients with early breast cancer: The Royal Marsden experience [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-15-08.

Polymer encapsulation of anticancer silver–N-heterocyclic carbene complexes

Amphiphilic block copolymers have been developed for the encapsulation of organometallic drugs. silver–N-heterocyclic carbene complexes have shown significant promise as anticancer and antibacterial compounds, and have been studied as the payload in these carriers. Simple modification of the N-heterocyclic carbene ligand structure enables solubility properties and interaction with the polymer to be tuned.

Amphiphilic block copolymers have been developed for the encapsulation of silver anticancer drugs.

A national follow-up survey of UK graduates opinion of undergraduate oral surgery teaching

INTRODUCTION

A national follow-up survey was undertaken to determine whether dental graduates from 2009 perceived that their undergraduate oral surgery education had equipped them for general dental practice 4 years after graduating.

MATERIALS AND METHODS

Graduates from the same 13 United Kingdom dental schools who had taken part in the original survey were invited to take part in this follow-up online survey. Their contact details were identified via the general dental council register, social media and alumni groups.

RESULTS

In total, 161 responded (2009b) which represents 16% of the graduates of the original survey in 2009a. A similar percentage of these respondents perceived that the teaching in oral surgery had given them sufficient knowledge to undertake independent practice (83% and 79% in 2009a and 2009b, respectively). Most respondents (99% in both years) reported confidence in undertaking simple forceps exodontia. Confidence in surgical exodontia was poor in both surveys, but one area that appeared improved in the follow-up related to the sectioning of teeth (84% in 2009b compared with 49% in 2009a). Areas of weakness identified in 2009 were reported to be improved in the follow-up.

CONCLUSION

This follow-up survey supports the findings of the original survey. Future longitudinal studies would allow institutions to identify possible weaknesses in their curriculum and to track the career development of their graduates and facilitate robust data collection.

MRI-based abnormalities in young adults at risk of adverse bone health due to childhood-onset metabolic & endocrine conditions

OBJECTIVE

Traditional methods of bone densitometry may not provide a comprehensive assessment of bone health. We aimed to assess bone micro-architecture and bone marrow adiposity (BMA) by MRI in adults with osteogenesis imperfecta (OI) and endocrinopathy including GH deficiency and/or hypogonadism.

MEASUREMENTS

High-resolution micro-MRI images were acquired at the tibia using 3T MRI to calculate parameters of bone micro-architecture in seven adults with OI and 10 adults with endocrinopathies. MR Spectroscopy was performed in participants to calculate vertebral BMA, which was expressed as percentage fat fraction (%FF). Lumbar spine DXA was performed to assess bone mineral density. The MRI data were compared with a group of 22 healthy adults who were divided into two age-matched control groups.

RESULTS

Intra-operator repeatability was high, with an average CoV of 1% for micro-MRI and 2·5% for MRS. The ratio of apparent bone volume to total volume (appBV/TV) in the endocrinopathy and OI groups was lower than in age-matched control groups (P = 0·003 and P = 0·008 respectively). A weak association between DXA BMD and appBV/TV was also observed (r = 0·5, P = 0·045). %FF was higher in the endocrinopathy group than in the age-matched control group (P = 0·005), but no difference in %FF was observed between the OI group and their age-matched control group (P = 0·26).

CONCLUSIONS

MRI provides valuable detailed information on the micro-architecture and adiposity of bones and is capable of showing clear differences in bone parameters in a range of clinical conditions associated with abnormal bone health.

Fear of falling, fracture history, and comorbidities are associated with health-related quality of life among European and US women with osteoporosis in a large international study

We studied 7,897 women with postmenopausal osteoporosis to assess factors that influence health-related quality of life (HRQoL). An increased number of comorbidities, fear of falling, and previous vertebral fracture were associated with significant reductions in HRQoL. Understanding the factors that affect HRQoL may improve management of these patients.

INTRODUCTION

HRQoL is impaired in women treated for postmenopausal osteoporosis (PMO). The objective of this study was to examine the relationship between clinical characteristics, comorbidities, medical history, patient demographics, and HRQoL in women with PMO.

METHODS

Baseline data were obtained and combined from two large and similar multinational observational studies: Prospective Observational Scientific Study Investigating Bone Loss Experience in Europe (POSSIBLE EU®) and in the US (POSSIBLE US™) including postmenopausal women in primary care settings initiating or switching bone loss treatment, or who had been on bone loss treatment for some time. HRQoL measured by health utility scores (EQ-5D™) were available for 7,897 women (94 % of study participants). The relationship between HRQoL and baseline clinical characteristics, medical history and patient demographics was assessed using parsimonious, multivariable, mixed-model analyses.

RESULTS

Median health utility score was 0.80 (interquartile range 0.69-1.00). In multivariable analyses, young age, low body mass index, previous vertebral fracture, increased number of comorbidities, high fear of falling, and depression were associated with reduced HRQoL. Regression-based model estimates showed that previous vertebral fracture was associated with lower health utility scores by 0.08 (10.3 %) and demonstrated the impact of multiple comorbidities and of fear of falling on HRQoL.

CONCLUSIONS

In this large observational study of women with PMO, there was substantial interindividual variability in HRQoL. An increased number of comorbidities, fear of falling, and previous vertebral fracture were associated with significant reductions in HRQoL.

Cerebral venous outflow resistance and interpretation of cervical plethysmography data with respect to the diagnosis of chronic cerebrospinal venous insufficiency

OBJECTIVE

While chronic cerebrospinal venous insufficiency (CCSVI) can be characterized using cervical plethysmography, much remains unknown about the haemodynamics associated with this procedure. The aim of the study was therefore to gain a deeper understanding of the observed haemodynamics.

METHOD

Forty healthy controls and 44 CCSVI patients underwent cervical plethysmography, which involved placing a strain-gauge collar around their necks and tipping them from the upright (90(o)) to supine position (0(o)) in a chair. Once stabilized, they were returned to the upright position, allowing blood to drain from the neck. A mathematical model was used to calculate the hydraulic resistance of the extracranial venous system for each subject in the study.

RESULTS

The mean hydraulic resistance of the extracranial venous system was 10.28 (standard deviation [SD] 5.14) mmHg.s/mL in the healthy controls and 16.81 (SD 9.22) in the CCSVI patients (P < 0.001).

CONCLUSIONS

The haemodynamics of the extracranial venous system are greatly altered in CCSVI patients.

Results of indirect and mixed treatment comparison of fracture efficacy for osteoporosis treatments: a meta-analysis

Network meta-analysis techniques (meta-analysis, adjusted indirect comparison, and mixed treatment comparison [MTC]) allow for treatment comparisons in the absence of head-to-head trials. In this study, conditional estimates of relative treatment efficacy derived through these techniques show important differences in the fracture risk reduction profiles of marketed pharmacologic therapies for postmenopausal osteoporosis.

INTRODUCTION

This study illustrates how network meta-analysis techniques (meta-analysis, adjusted indirect comparison, and MTC) can provide comparisons of the relative efficacy of postmenopausal osteoporosis therapies in the absence of comprehensive head-to-head trials.

METHODS

Source articles were identified in MEDLINE; EMBASE; Cochrane Central Register of Controlled Trials (CENTRAL) via Wiley Interscience; and Cumulative Index to Nursing and Allied Health Literature (CINAHL) between April 28, 2009 and November 4, 2009. Two reviewers identified English-language articles reporting randomized controlled trials (RCTs) with on-label dosing of marketed osteoporosis agents and fracture endpoints. Trial design, population characteristics, intervention and comparator, fracture outcomes, and adverse events were abstracted for analysis. Primary analyses included data from RCTs with fracture endpoints. Sensitivity analyses also included studies with fractures reported through adverse event reports. Meta-analysis compared fracture outcomes for pharmacological therapies vs. placebo (fixed and random effects models); adjusted indirect comparisons and MTC assessed fracture risk in postmenopausal women treated with denosumab vs. other agents.

RESULTS

Using data from 34 studies, random effects meta-analysis showed that all agents except etidronate significantly reduced the risk of new vertebral fractures compared with placebo; denosumab, risedronate, and zoledronic acid significantly reduced the risk for nonvertebral and hip fracture, while alendronate, strontium ranelate, and teriparatide significantly reduced the risk for nonvertebral fractures. MTC showed denosumab to be more effective than strontium ranelate, raloxifene, alendronate, and risedronate in preventing new vertebral fractures.

CONCLUSIONS

The conditional estimates of relative treatment efficacy indicate that there are important differences in fracture risk reduction profiles for marketed pharmacological therapies for postmenopausal osteoporosis.

OP deference--Libyan crisis 2011. Non combatant evacuation operations (NEO) --role one medical experience

It is the author's belief that Role 1 GDMO led medical care continues to be a potent and adaptable force, capable of operating efficiently and with a high degree of autonomy in potentially high threat environments. The medical team was able to adapt to the operational demand and retained the full confidence of the command chain, however the MO felt acutely aware of gaps in his New Entry Medical Officer clinical training. Short duration courses such as Advanced Paediatric Life Support, Basic Surgical Skills and MIMMS provide excellent added value for medical officers and increase self confidence. NEMO training in the future may benefit from the inclusion of these. Despite the challenges faced during the NEOs the Role 1 medical team in CUMBERLAND found the experience very rewarding and an example of what they joined the Royal Navy to do.

Prevalence of osteoporosis and fractures among women prescribed osteoporosis medication in five European countries: the POSSIBLE EU study

European observational 1-year study assessed osteoporosis and fracture patterns in 3,402 postmenopausal women prescribed osteoporosis medication. Almost 40% of patients had a previous fracture, while 25% had neither fracture nor dual energy X-ray absorptiometry (DXA) diagnosis and were prescribed medication, probably due to other risk factors.

INTRODUCTION

This analysis assessed osteoporosis and fracture prevalence in postmenopausal women prescribed osteoporosis treatment in the Prospective Observational Study Investigating Bone Loss Experience in Europe(POSSIBLE EU).

METHODS

Women in this observational, multicenter 1-year study were categorized by fracture history and location at baseline. Baseline characteristics were analyzed according to no DXA and DXA diagnosis (osteoporosis or osteopenia). Fractures occurring during the 1-year follow-up period were recorded.

RESULTS

Of the 3,402 women enrolled, 39% had a previous fracture, of whom 30% had ≥ 2 fractures. One thousand seven hundred and eighty-four (52%) patients had a DXA diagnosis (osteoporosis 68%, osteopenia 31%, and unknown 1%). Among the osteoporosis patients, 37% had a previous fracture (hip 2.9%, vertebral 8.8%, and non-hip, non-vertebral 25%) and 35% had fractures associated with major trauma. Of the 3,402 women, 1,476 (43%) had no DXA diagnosis; of these, 57% had no fracture (25% of all women). Risk factors varied across patients with and without DXA diagnosis. During the 1-year follow-up period, the fracture incidence in patients with or without a previous fracture at baseline was 4.7% and 1.6%, respectively.

CONCLUSION

Almost 40% of patients prescribed osteoporosis medication had a previous fracture, highlighting a population with advanced disease. In contrast, 25% of patients had neither a previous fracture nor DXA diagnosis and were prescribed treatment, probably due to other risk factors. There is a need for continued improvement of disease management in European women.

Reducing silica and dust exposures in construction during use of powered concrete-cutting hand tools: efficacy of local exhaust ventilation on hammer drills

Concrete cutting in construction is a major source of exposure to respirable crystalline silica. To reduce exposures, local exhaust ventilation (LEV) may be integrated into the hand tools used in concrete cutting. Volunteers from the New England Laborers Training Center participated in a field study focused on the use of LEV on concrete-cutting hammer drills. A randomized block design field experiment employing four workers measured the efficacy of four hood-vacuum source combinations compared with no LEV in reducing dust and silica exposures. Using four-stage personal cascade impactors (Marple 294) to measure dust exposure, a total of 18 personal samples were collected. Reductions of over 80% in all three biologically relevant size fractions of dust (inhalable, thoracic, and respirable) were obtained by using any combination of hood and vacuum source. This study found that respirable dust concentrations were reduced from 3.77 mg/m(3) to a range of 0.242 to 0.370 mg/m(3); thoracic dust concentrations from 12.5 mg/m(3) to a range of 0.774 to 1.23 mg/m(3); and inhalable dust concentration from 47.2 mg/m(3) to a range of 2.13 to 6.09 mg/m(3). Silica concentrations were reduced from 0.308 mg/m(3) to a range of 0.006 to 0.028 mg/m(3) in the respirable size fraction, from 0.821 mg/m(3) to a range of 0.043 to 0.090 mg/m(3) in the thoracic size fraction, and from 2.71 mg/m(3) to a range of 0.124 to 0.403 mg/m(3) in the inhalable size fraction. Reductions in dust concentrations while using the four LEV systems were not statistically significantly different from each other.

Minimization in crossover trials with non-prognostic strata: theory and practical application

To obtain meaningful results in any clinical trial, patients need to be allocated to treatments in such a way that valid analysis can be carried out. Balancing treatment groups before analysis is carried out is more desirable than trying to compensate for incomparability at a later date. Therefore, the development of allocation procedures to produce comparable groups in which prognostic factors are equally represented is important. Minimization, a deterministic allocation method, aims to ensure balance on such factors, particularly in small trials when traditional randomization methods are likely to fail. However, views on the use of conventional analysis following minimization are divided. The use of minimization in two randomised crossover trials is described where, in addition to the comparisons between randomised treatments, it was desired to have balance between groups based on differential trial procedures. Theoretical concerns about the use of minimization are not applicable in this setting, and therefore minimization is shown to be a useful technique for obtaining balance.

Production of antibodies to Staphylococcus aureus serotypes 5, 8, and 336 using poly(DL-lactide-co-glycolide) microspheres

Staphylococcus aureus is responsible for a major portion of the economic losses due to mastitis. Attempts to produce a vaccine to prevent S. aureus mastitis have been hampered by the low immunogenicity of the polysaccharide, which forms on the surface of the organism when it enters the mammary gland. The polysaccharide inhibits phagocytosis and destruction of the organism by neutrophils. This study was conducted to determine if S. aureus polysaccharide serotypes 5, 8, and 336 conjugated to a protein and incorporated in poly(DL-lactide-co-glycolide) microspheres would enhance the production of opsonizing antibodies to the polysaccharide. Cows were immunized with either polysaccharide conjugates emulsified in Freund's incomplete adjuvant or polysaccharide conjugates encapsulated in poly (DL-lactide-co-glycolide) microspheres emulsified in Freund's incomplete adjuvant. All cows produced sustained antibody titers to the three polysaccharide serotypes. Cows immunized with microspheres had higher antibody titers. Cows in both groups produced increased concentrations of IgG1 and IgG2 antibodies; neither group produced an increase in IgM. Immune sera from cows immunized with conjugates alone increased phagocytosis, which decreased at the end of the study. Sera from cows immunized with conjugates in microspheres increased phagocytosis, which was sustained at the end of the study. Immune sera from both groups decreased bacterial adherence to bovine mammary epithelial cells. These data showed that a single injection of antigen in microspheres produced higher titers and more sustained enhancement of phagocytosis, which could aid in the defense of the cow against S. aureus infections.

Mutants of the lactose carrier of Escherichia coli which show altered sugar recognition plus a severe defect in sugar accumulation

Lactose and melibiose are actively accumulated by the wild-type Escherichia coli lactose carrier, which is an integral membrane protein energized by the proton motive force. Mutants of the E. coli lactose carrier were isolated by their ability to grow on minimal plates with succinate plus IPTG in the presence of the toxic lactose analog beta-thio-o-nitrophenylgalactoside (TONPG). TONPG-resistant mutants were streaked on melibiose MacConkey indicator plates, and red clones were picked. These melibiose positive mutants were then streaked on lactose MacConkey plates, and white clones were picked. Transport assays indicated that the mutants had altered sugar recognition and a defect in sugar accumulation. The mutants had a poor apparent K(m) for both lactose and melibiose in transport. One mutant had almost no ability to take up lactose, but melibiose downhill transport was 58% (V(max)) of normal. All of the mutants accumulated methyl-alpha-d-galactopyranoside (TMG) to only 8% or less of normal, and two failed to accumulate. Immunoblot analysis of the mutant lactose carrier proteins indicated that loss of sugar transport activity was not due to loss of expression in the membrane. Nucleotide sequencing of the lacY gene from the mutants revealed changes in the following amino acids of the lactose carrier: M23I, W151L, G257D, A295D and G377V. Two of the mutants (G257D and G377V) are novel in that they represent the first amino acids in periplasmic loops to be implicated with changes in sugar recognition. We conclude that the amino acids M23, W151, G257, A295 and G377 of the E. coli lactose carrier play either a direct or an indirect role in sugar recognition and accumulation.