Validation of a Simplified Model for Subarachnoid Hemorrhage in Mice

BACKGROUND

Subarachnoid hemorrhage (SAH) represents a severe injury to the brain and is associated with a high mortality (40%). Several experimental SAH models are described in the literature requiring specialized equipment and a high degree of surgical expertise. Our goal was to validate a simplified, cost-effective model to permit future studies of SAH.

METHODS

SAH was induced by injection of homologous blood into the cisterna magna. Perfusion-fixation then perfusion of gelatinous India ink was performed. Brains and brainstems were collected and imaged for analysis of cerebral vasospasm. Triphenyl tetrazolium chloride (TTC) staining was used to analyze brain tissue cell death 24 hours following stroke. A composite neuroscore was utilized to assess SAH-related neurologic deficits.

RESULTS

Anterior cerebral artery and basilary artery diameters were significantly reduced at 24 hours post SAH induction. Middle cerebral artery diameter was also reduced; however, the results were not significant. TTC staining showed no infarcted tissue. Neuroscores were significantly lower in the SAH mice, indicating the presence of functional deficits.

CONCLUSIONS

This simplified model of SAH elicits pathological changes consistent with those described for more complex models in the literature. Therefore, it can be used in future preclinical studies examining the pathophysiology of SAH and novel treatment options.

Neuroprotection and Beyond: The Central Role of CB1 and CB2 Receptors in Stroke Recovery

The endocannabinoid system, with its intricate presence in numerous cells, tissues, and organs, offers a compelling avenue for therapeutic interventions. Central to this system are the cannabinoid receptors 1 and 2 (CB1R and CB2R), whose ubiquity can introduce complexities in targeted treatments due to their wide-ranging physiological influence. Injuries to the central nervous system (CNS), including strokes and traumatic brain injuries, induce localized pro-inflammatory immune responses, termed neuroinflammation. Research has shown that compensatory immunodepression usually follows, and these mechanisms might influence immunity, potentially affecting infection risks in patients. As traditional preventive treatments like antibiotics face challenges, the exploration of immunomodulatory therapies offers a promising alternative. This review delves into the potential neuroprotective roles of the cannabinoid receptors: CB1R's involvement in mitigating excitotoxicity and CB2R's dual role in promoting cell survival and anti-inflammatory responses. However, the potential of cannabinoids to reduce neuroinflammation must be weighed against the risk of exacerbating immunodepression. Though the endocannabinoid system promises numerous therapeutic benefits, understanding its multifaceted signaling mechanisms and outcomes remains a challenge.

THU0522 DIFFERENCES IN MUSCLE PROPERTIES IN GCA PATIENTS COMPARED TO HEALTHY CONTROLS AS ASSESSED BY QUANTITATIVE MRI

Background:

Giant cell arteritis (GCA) is a systemic inflammatory vasculitis that often presents with headaches and visual symptoms. It is a medical emergency as it can lead to permanent sight loss. Prompt treatment with high doses of glucocorticoid therapy are often required. However, it has been shown that GCA patients on glucocorticoid therapy develop muscle weakness, known as glucocorticoid induced myopathy (1).

Quantitative MRI may be sensitive to detect the differences in muscle parameters between newly diagnosed GCA patients compared to healthy controls. MRI T2 is sensitive to fluid related to physiological changes at the molecular level, and is regarded as an indirect measure of muscle inflammation (2). MRI muscle fat fraction (FF) is useful for identifying myosteatosis (3). Diffusion tensor imaging (DTI) is sensitive to changes in muscle microstructure and may be useful in identifying changes to muscle fibres (4).

Objectives:

To obtain preliminary estimates of the extent to which quantitative MRI-based measurements of muscle T2, FF, DTI and volume differ between newly diagnosed GCA patients and healthy controls (HC) and how the muscle changes over 3- and 6-month intervals following glucocorticoid therapy.

Methods:

MRI of the mid-thigh were acquired using Dixon imaging to assess FF, Stimulated Echo Acquisition Mode echo planar imaging (STEAM-EPI) to measure diffusion, and a fat-suppressed multi-echo spin-echo to measure T2. Regions of interest were drawn around the quadriceps and hamstrings. All participants had knee extension and flexion torque measured on an isokinetic dynamometer, and isometric dynamometer to measure grip strength.

Results:

20 GCA patients (68.2±8.3 years, 14/20 female, mean ESR 26.9mm/h, mean CRP 39.6mg/L) were enrolled within 14 days of starting glucocorticoids: 15 returned at 3 months (mean ESR 17mm/h, mean CRP 5.7mg/L); 8 returned at 6 months (mean ESR 18 mm/h, mean CRP 6mg/L). 20 directly age- and gender-matched HC also were recruited. T2 and FF were higher and muscle volume lower in the GCA patients at baseline compared to HC (fig. 1 and 2). Within the hamstrings, the mean differences between GCA patients and HC for T2, FF and muscle volume were 2.2ms (95% CI 1, 4; p=0.09), 3.8% (95% 2, 5; p<0.001), and -166cm3 (95% CI 110, 210; p<0.001) respectively. There was no substantive difference in mean diffusivity or fractional anisotropy. Results in the quadriceps followed a similar trend. Following glucocorticoid treatment, there were no substantive changes in MRI measurements. Knee flexion/extension and handgrip strength were lower in the GCA patients at baseline compared to HC, with differences of -5.3Nm (95% CI -32.6, -7.4; p=0.003) and -4.4Nm (95% CI -56.7, -1.3; p=0.04) for flexion and extension respectively. Muscle strength did not change following glucocorticoid treatment.

Figure 1.

Quantitative MRI measurements of GCA patients and healthy controls in the hamstrings.

Conclusion:

This pilot study suggests for the first time that muscle health may be affected in newly diagnosed GCA patients compared to age and gender matched HC, as demonstrated by higher T2 and FF, and lower muscle volume and muscle strength. These preliminary results show that muscle changes may occur in the early stages of GCA and persist throughout the disease duration. If these findings are confirmed, it will be important to consider interventions to improve muscle health in the treatment pathway for GCA.

References:

[1]Proven A, et al. Arthritis and rheumatism. 2003;49(5):703-8.

[2]Maillard SM, et al. 2004;43(5):603-8.

[3]Grimm A, et al. The Journal of Frailty & Aging. 2018.

[4]Ran J, et al. 2016;263(7):1296-302.

Figure 2.

Quantitative muscle volume and muscle strength measurements of GCA patients and healthy controls.

Disclosure of Interests:

Matt Farrow: None declared, John Biglands: None declared, Steven Tanner: None declared, Elizabeth Hensor: None declared, Sarah Mackie Grant/research support from: Roche (attendance of EULAR 2019; co-applicant on research grant), Consultant of: Sanofi, Roche/Chugai (monies paid to my institution not to me), Paul Emery Grant/research support from: AbbVie, Bristol-Myers Squibb, Merck Sharp & Dohme, Pfizer, Roche (all paid to employer), Consultant of: AbbVie (consultant, clinical trials, advisor), Bristol-Myers Squibb (consultant, clinical trials, advisor), Lilly (clinical trials, advisor), Merck Sharp & Dohme (consultant, clinical trials, advisor), Novartis (consultant, clinical trials, advisor), Pfizer (consultant, clinical trials, advisor), Roche (consultant, clinical trials, advisor), Samsung (clinical trials, advisor), Sandoz (clinical trials, advisor), UCB (consultant, clinical trials, advisor), Ai Lyn Tan: None declared

OP0332 MUSCLE DETERIORATION DUE TO RHEUMATOID ARTHRITIS: ASSESSMENT BY QUANTITATIVE MRI AND STRENGTH TESTING

Background:

As well as joint damage, rheumatoid arthritis (RA) is also associated with altered body composition known as rheumatoid cachexia (RC). RC is characterised by reduced skeletal muscle and increased (white) fat mass and decreased strength. RC is associated with increased disease severity and disability (1). It is unknown at what stage muscle involvement begins in RA, and if the muscle damage is modifiable when patients achieve disease control.

Quantitative MRI (qMRI) can measure the biomarkers associated with RC. MRI T2 is sensitive to fluid related to physiological changes at the molecular level, and is regarded as an indirect measure of muscle inflammation (2). MRI muscle fat fraction (FF) measurements are useful for identifying myosteatosis (3).

Objectives:

To obtain preliminary estimates of the extent to which muscle imaging phenotype differs between RA and healthy controls (HC); and to describe the RA phenotype at different levels of disease activity.

Methods:

39 RA patients (comprising three groups) and 13 age and gender directly matched HC had a MRI scan of their dominant thigh. The RA groups were:

[1]13 ‘New RA’ - newly diagnosed, treatment naïve

[2]13 ‘Active RA’ - diagnosed >1 year, persistent DAS28 >3.2 for >1 year

[3]13 ‘Remission RA’ - diagnosed >1 year, persistent DAS28 <2.6 for >1 year

MR images of the mid-thigh were acquired using Dixon imaging to assess FF and a fat-suppressed multi-echo spin-echo to measure T2. Regions of interest were drawn around the quadriceps and hamstrings. All participants had knee extension and flexion torque measured on an isokinetic dynamometer, and isometric dynamometer to measure grip strength. One-Way ANOVA with Dunnett’s post-hoc analysis provided preliminary indication of potential differences between T2, FF, muscle volume and strength measurements between the disease stages.

Results:

39 RA patients were recruited: 13 new RA (mean age [years] 63 ± 15, DAS28 5.2 ± 3), 13 active RA (mean age [years] 65 ± 10, DAS28 4.8 ± 3), 13 remission RA (mean age [years] 67 ± 19, DAS28 1.7 ± 0.7) and also 13 HC. T2 and FF were higher in RA patients compared to HC (fig. 1). Within the hamstrings for T2, the mean differences between HC versus new, active and remission patients were 4.5ms (95% CI 2.5, 6.4; p<0.001), 3ms (95% CI 1.1, 4.9; p=0.001), and 5.0ms (95% CI 3.0, 6.4; p<0.001) respectively. Quadriceps results were similar. For muscle volume, the mean differences between HC versus new, active and remission patients were -517.3cm3(95% CI -751, -283; p<0.001), -370.5cm3(95% CI -605, -136; p=0.001), and -312.3cm3(95% CI -546. -77; p=0.006) respectively (fig. 2). Knee flexion/extension and handgrip strength were lower in all 3 groups of RA patients compared to HC. For knee flexion, the mean differences between HC versus new, active and remission patients were 18.4Nm (95% CI -35, -1; p=0.03), 10.1Nm (95% CI -27, 7; p=0.3), and 13.3Nm (95% CI -33, 0; p=0.1) respectively.

Figure 1.

Quantitative T2 and FF MRI of RA patients and healthy controls

Conclusion:

This pilot study suggests muscle health may be adversely affected in RA patients compared to matched HC. Our results suggest that muscle changes occur in the earliest stages of RA and persist throughout the disease duration, even in clinical remission. If confirmed, these data imply the need for adjunctive muscle intervention to current RA treatment strategies in order to improve patient outcomes.

References:

[1]Giles JT, et al. Arthritis Care & Research. 2008

[2]Maillard SM, et al. Rheumatology (Oxford, England). 2004

[3]Grimm A, et al. The Journal of Frailty & Aging. 2018.

Figure 2.

MRI muscle volume in RA patients and healthy controls

Disclosure of Interests:

Matt Farrow: None declared, John Biglands: None declared, Steven Tanner: None declared, Elizabeth Hensor: None declared, Maya H Buch Grant/research support from: Pfizer, Roche, and UCB, Consultant of: Pfizer; AbbVie; Eli Lilly; Gilead Sciences, Inc.; Merck-Serono; Sandoz; and Sanofi, Paul Emery Grant/research support from: AbbVie, Bristol-Myers Squibb, Merck Sharp & Dohme, Pfizer, Roche (all paid to employer), Consultant of: AbbVie (consultant, clinical trials, advisor), Bristol-Myers Squibb (consultant, clinical trials, advisor), Lilly (clinical trials, advisor), Merck Sharp & Dohme (consultant, clinical trials, advisor), Novartis (consultant, clinical trials, advisor), Pfizer (consultant, clinical trials, advisor), Roche (consultant, clinical trials, advisor), Samsung (clinical trials, advisor), Sandoz (clinical trials, advisor), UCB (consultant, clinical trials, advisor), Ai Lyn Tan: None declared

Primary cemented bipolar radial head prostheses for acute elbow injuries with comminuted radial head fractures: mid-term results of 37 patients

BACKGROUND

Radial head arthroplasty represents a widely accepted treatment for elbow injuries with non-reconstructible radial head fractures. The aim of this retrospective multicenter study was to assess mid-term results of patients with clearly defined elbow injuries including type III fractures of the radial head according to Mason's classification type III after primary arthroplasty using a cemented bipolar design.

MATERIALS AND METHODS

In 45 cases a primary cemented bipolar arthroplasty of the radial head was implanted for elbow injuries combined with an acute Mason type III radial head fracture. In all patients associated fractures were detected with preoperative CT scans and ligamentous injuries were evaluated and both were addressed intraoperatively based on a standardized algorithm. Patients with associated injuries other than coronoid fractures and collateral ligament tears were excluded from this study to obtain a more homogenous sample. Clinical and radiological assessment was performed on thirty-seven patients at an average of 5.6 years postoperatively.

RESULTS

DASH Score, functional rating index of Broberg and Morrey, Mayo Elbow Performance Score, and Mayo Modified Wrist Score confirmed good-to-excellent results in most of the patients. Compared to the unaffected arm range of motion and grip strength were slightly reduced. No elbow instability or loosening of the prosthesis, and minor degenerative changes were detected in a few cases.

CONCLUSION

Primary cemented bipolar arthroplasty for type III fractures according to Mason's classification in an elbow injury pattern only including associated coronoid fractures and/or ligamentous tears resulted in good-to-excellent mid-term results. These results suggest that primary bipolar radial head arthroplasty combined with distinct treatment of all associated injuries provides good functional outcomes concerning range of motion, elbow stability, and strength in this cohort. However, the associated injuries may influence clinical and radiological outcome and need to be detected, classified, and treated carefully.

Peri-implantitis and the prosthodontist

Peri-implantitis has been described as progressive crestal bone loss around a dental implant. The condition is poorly understood, and is challenging to manage; it is commonly and widely attributed to issues with the implant, the implant surface, surgical technique and oral hygiene. The effect of prosthodontic stages of treatment on the postoperatively established state has not been adequately investigated. It is the authors' contention that the manner in which the implant is restored contributes significantly to prognosis and peri-implant disease experience, and that the role of prosthodontic aspects of treatment in the causation of peri-implantitis may be seriously underestimated. The prosthodontist has a clear role and responsibility in the avoidance of future peri-implant problems by ensuring that implants are restored in an entirely biologically and biomechanically sound manner. The number of implant treatments carried out year-on-year is rising apace, with more and more implants being restored in general dental practice. With the rapid emergence of lower cost dental implant systems and a broadening range of generic restorative options and components for well-established systems, there is an increasing need to consider and understand how the implant restorative process may have a negative impact upon the peri-implant tissues, and how this effect may be minimised and peri-implant health promoted and maintained by paying attention to detail throughout the entire process.

The challenge of Monteggia-like lesions of the elbow

Aims

The aim of this retrospective multicentre study was to evaluate mid-term results of the operative treatment of Monteggia-like lesions and to determine the prognostic factors that influence the clinical and radiological outcome.

Patients and Methods

A total of 46 patients (27 women and 19 men), with a mean age of 57.7 years (18 to 84) who had sustained a Monteggia-like lesion were followed up clinically and radiologically after surgical treatment. The Mayo Modified Wrist Score (MMWS), Mayo Elbow Performance Score (MEPS), Broberg and Morrey Score, and Disabilities of the Arm, Shoulder and Hand (DASH) score were used for evaluation at a mean of 65 months (27 to 111) postoperatively. All ulnar fractures were stabilized using a proximally contoured or precontoured locking compression plate. Mason type I fractures of the radial head were treated conservatively, type II fractures were treated with reconstruction, and type III fractures with arthroplasty. All Morrey type II and III fractures of the coronoid process was stabilized using lag screws.

Results

Good results were found for the MMWS, with a mean of 88.4 (40 to 100). There were 29 excellent results (63%), nine good (20%), seven satisfactory (15%), and one poor (2%). Excellent results were obtained for the MEPS, with a mean of 90.7 (70 to 100): 31 excellent results (68%), 13 good (28%), and two fair (4%). Good results were also found for the functional rating index of Broberg and Morrey, with a mean score of 86.6 (57 to 100). There were 16 excellent results (35%), 22 good (48%), six fair (13%), and two poor (4%). The mean DASH score was 15.1 (0 to 55.8). Two patients had delayed wound healing; four patients had nonunion requiring bone grafting. One patient had asymptomatic loosening of the radial head prosthesis.

Conclusion

Monteggia-like lesions are rare. With correct identification, classification, and understanding using CT scans followed by appropriate surgical treatment that addresses all components of the injury, good to excellent mid-term results can be achieved. Cite this article: Bone Joint J 2018;100-B:212–18.

Caregiver parenting and gender attitudes: Associations with violence against adolescent girls in South Kivu, Democratic Republic of Congo

Violence against adolescent girls occurs at alarmingly high rates in conflict-affected settings, in part due to their increased vulnerability from their age and gender. However, humanitarian programming efforts have historically focused either on child abuse prevention or intimate partner violence prevention and have not fully addressed the specific needs of adolescent girls, including engagement of caregivers to reduce risk of violence against adolescent girls. Thus, the objectives of this analysis are to examine the whether gendered and parental attitudes of caregivers in South Kivu, Democratic Republic of Congo (DRC) were associated with their adolescent girls' experiences of violence and girls' attitudes towards IPV. Cross-sectional data from 869 girls (10-14 years) and their caregivers (n=764) were drawn from a baseline assessment of a violence prevention evaluation conducted in 2015. Findings suggest that female caregiver's gender equitable attitudes for adults may be associated with reduced odds of sexual abuse and less acceptance of IPV for adolescent girl children. Parenting attitudes and beliefs and gender equity for girl children were not associated with violence risk for girls, while increased accepting attitudes of negative discipline were only associated with lowered odds of sexual abuse. Understanding of caregivers' attitudes may provide potential insight into how to more effectively engage and develop programming for caregivers to promote the safety and well-being of adolescent girls.

Disclosure bias for group versus individual reporting of violence amongst conflict-affected adolescent girls in DRC and Ethiopia

Methodologies to measure gender-based violence (GBV) have received inadequate attention, especially in humanitarian contexts where vulnerabilities to violence are exacerbated. This paper compares the results from individual audio computer-assisted self-administered (ACASI) survey interviews with results from participatory social mapping activities, employed with the same sample in two different post-conflict contexts. Eighty-seven internally displaced adolescent girls from the Democratic Republic of the Congo and 78 Sudanese girls living in Ethiopian refugee camps were interviewed using the two methodologies. Results revealed that the group-based qualitative method elicited narratives of violence focusing on events perpetrated by strangers or members of the community more distantly connected to girls. In contrast, ACASI interviews revealed violence predominantly perpetrated by family members and intimate partners. These findings suggest that group-based methods of information gathering frequently used in the field may be more susceptible to socially accepted narratives. Specifically, our findings suggest group-based methods may produce results showing that sexual violence perpetrated by strangers (e.g., from armed groups in the conflict) is more prevalent than violence perpetrated by family and intimate partners. To the extent this finding is true, it may lead to a skewed perception that adolescent GBV involving strangers is a more pressing issue than intimate partner and family-based sexual violence, when in fact, both are of great concern.

Creating opportunities through mentorship, parental involvement, and safe spaces (COMPASS) program: multi-country study protocol to protect girls from violence in humanitarian settings

Background

Violence against adolescent girls in humanitarian settings is of urgent concern given their additional vulnerabilities to violence and unique health and well-being needs that have largely been overlooked by the humanitarian community. In order to understand what works to prevent violence against adolescent girls, a multi-component curriculum-based safe spaces program (Creating Opportunities through Mentorship, Parental involvement and Safe Spaces – COMPASS) will be implemented and evaluated. The objectives of this multi-country study are to understand the feasibility, acceptability and effectiveness of COMPASS programming to prevent violence against adolescent girls in diverse humanitarian settings.

Methods/design

Two wait-listed cluster-randomized controlled trials are being implemented in conflict-affected communities in eastern Democratic Republic of Congo (N = 886 girls aged 10–14 years) and in refugee camps in western Ethiopia (N = 919 girls aged 13–19 years). The intervention consists of structured facilitated sessions delivered in safe spaces by young female mentors, caregiver discussion groups, capacity-building activities with service providers, and community engagement. In Ethiopia, the research centers on the overall impact of COMPASS compared to a wait-list group. In DRC, the research objective is to understand the incremental effectiveness of the caregiver component in addition to the other COMPASS activities as compared to a wait-list group. The primary outcome is change in sexual violence. Secondary outcomes include decreased physical and emotional abuse, reduced early marriage, improved gender norms, and positive interpersonal relationships, among others. Qualitative methodologies seek to understand girls’ perceptions of safety within their communities, key challenges they face, and to identify potential pathways of change.

Discussion

These trials will add much needed evidence for the humanitarian community to meet the unique needs of adolescent girls and to promote their safety and well-being, as well as contributing to how multi-component empowerment programming for adolescent girls could be adapted across humanitarian settings.

Trial registration

Clinical Trials NCT02384642 (Registered: 2/24/15) & NCT02506543 (Registered: 7/19/15).

Peroxisome proliferator-activated receptor γ agonist effect on rheumatoid arthritis: a randomized controlled trial

Introduction

Rheumatoid arthritis (RA), a chronic inflammatory disease, is associated with insulin resistance. Experimental evidence indicates that the relationship between insulin resistance and inflammation is bidirectional: Inflammation promotes insulin resistance, and insulin resistance promotes inflammation. Therefore, we examined the hypothesis that pioglitazone, a thiazolidinedione peroxisome proliferator-activated receptor γ agonist, would decrease inflammation and disease activity and improve insulin resistance in patients with RA.

Methods

In a single-center, randomized, double-blind, placebo-controlled crossover study patients with RA (N = 34) receiving stable therapy were randomized to also receive either pioglitazone 45 mg daily (n = 17) or matching placebo (n = 17) for eight weeks. This was followed by a four-week washout period and alternative treatment for eight weeks. Outcomes included change in Disease Activity Score in 28 joints (DAS28) score, individual components of the DAS28 score and homeostatic model assessment for insulin resistance (HOMA). Intention-to-treat analysis and linear mixed-effects models were used.

Results

Patients had a mean (±SD) age of 51 (±14.2) years, 82.4% were female and baseline DAS28 high-sensitivity C-reactive protein (DAS28-CRP) was 4.58 (±1.1) units. Addition of pioglitazone was associated with a 9.3% reduction (95% confidence interval (CI) = 0.17% to 17.6%) in DAS28-CRP (P = 0.046), but no significant change in DAS28 erythrocyte sedimentation rate (DAS28-ESR) (P = 0.92). There was a 10.7mm (95% CI = 0.4 to 20.9 mm) improvement in patient-reported global health (P = 0.042), a 48.6% decrease (95% CI = 27.6% to 63.5%) in CRP (P < 0.001) and a 26.4% decrease (95% CI = 3.7% to 43.8%) in insulin resistance as measured by HOMA (P = 0.025), but no significant reduction in swollen or tender joint count or in ESR (all P > 0.05). Lower-extremity edema was more common during pioglitazone treatment (16%) than placebo (0%).

Conclusion

Addition of pioglitazone to RA therapy improves insulin resistance and modestly reduces RA disease activity measured by DAS28-CRP and two of its components, including patient-reported global health and CRP, but not DAS28-ESR or ESR.

Trial registration

NCT00763139

Health and adult productivity: the relation between adult nutrition, helminths, and agricultural, hunting, and fishing yields in the Bolivian Amazon

OBJECTIVES

Infectious disease and nutritional stress have both been associated with reductions in adult work productivity and work capacity in the context of wage labor, but less research has investigated their effects among groups relying on more traditional subsistence practices of horticulture and foraging. In this article, we examine the relations among measures of adult nutritional status (BMI, skinfold measurements, and fat-free mass) and infection (presence of soil transmitted helminth infections) and measures of adult work productivity.

METHODS

As part of a larger panel study among Tsimane', a foraging-horticulturalist group in the Bolivian Amazon, health surveys, anthropometric information, and the quantity of products (both crops and game) brought into the household were collected for 320 Tsimane' adults over a four-month period in 2003. In addition, a single fecal sample was collected for a sub-sample of 86 adults.

RESULTS

Our analysis shows mixed associations between either BMI or the presence of parasitism and reported adult productivity. Muscularity was not clearly related to adult productivity. In contrast, body fatness (Skinfold z-score) was inversely associated with the average quantity of fish and game brought into the household, especially for men.

CONCLUSIONS

These findings suggest that the effects of adult infection and nutritional stress may be less clearly identified outside of the context of wage labor. Further research linking adult physical activity levels and metabolic rates to productivity in diverse contexts is needed.

Microtechnologies in implant and restorative dentistry: A stroll through a digital dental landscape

This is an explanatory article introducing the combination of various technologies used in implant and restorative dentistry. The aim of the article is to provide an overview of some of the techniques supporting the restorative treatment plan at various stages to provide contemporary, state-of-the-art bridgework based on dental implants. It is a discussion of the way existing technologies used in fields of engineering and medicine are brought together to form a complete process.

Short-term changes in magnetic resonance imaging and disease activity in response to infliximab

Objectives:

To characterise and quantify short-term changes in local inflammation using magnetic resonance imaging (MRI), and to correlate the findings with clinical disease activity in response to infliximab in patients with spondyloarthritis.

Methods:

28 consecutive patients with established spondyloarthritis under successful long-term treatment with infliximab underwent MRI immediately before and one week after re-administration of the TNF blocker. C-reactive protein and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) were assessed at both time points. The MRI protocol included coronal and sagittal turbo-short T1 inversion recovery (STIR) images as well as contrast-enhanced sagittal T1-weighted, fat-suppressed images. Images were assessed in independent sessions using the ASspiMRI-a score, the signal-difference-to-noise ratios (SDNR) and volumetry to assess oedematous and inflamed tissues.

Results:

BASDAI values were expectedly low at study entry (3.3, SD 2.3). One week after administration of infliximab, 46% of patients reached a BASDAI 20, 39% a BASDAI 50. Kappa values for qualitative assessments and all measurements were excellent (range between 0.83 and 1.0) The ASspiMRI-a dropped most in the thoracic (3.3 points), less in the lumbar (1.21 points) and least in the cervical spine (0.38 points). The decrease of the ASspiMRI-a, the SDNR and the inflamed volumes in response to infliximab re-treatment was significant (p<0.01). The BASDAI showed a weak correlation with the ASspiMRI-a (r  =  0.41).

Conclusions:

MRI proves to be a valid method to assess and quantify short-term effects of therapy in spondyloarthritis. Comparison between MRI and BASDAI changes show that the BASDAI may underestimate local inflammation. It suggests an explanation for the structural disease progression despite clinical remission.

Maintenance versus growth: investigating the costs of immune activation among children in lowland Bolivia

Immune function is a central component of maintenance effort, and it provides critical protection against the potentially life threatening effects of pathogens. However, immune defenses are energetically expensive, and the resources they consume are not available to support other activities related to growth and/or reproduction. In our study we use a life history theory framework to investigate tradeoffs between maintenance effort and growth among children in a remote area of Amazonian Bolivia. Baseline concentrations of C-reactive protein (CRP) were measured in 309 2- to 10-year olds as an indicator of immune activation, and height was measured at baseline and three months later. Elevated CRP at baseline predicts smaller gains in height over the subsequent three months, with the costs to growth particularly high for 2- to 4-year olds and for those with low energy reserves (in the form of body fat) at the time of immunostimulation. These results provide evidence for a significant tradeoff between investment in immunity and growth in humans, and highlight an important physiological mechanism through which maintenance effort may have lasting effects on child growth and development.

Rain, temperature, and child-adolescent height among Native Amazonians in Bolivia

BACKGROUND

Global climate change and recent studies on early-life origins of well-being suggest that climate events early in life might affect health later in life.

AIM

The study tested hypotheses about the association between the level and variability of rain and temperature early in life on the height of children and adolescents in a foraging-farming society of native Amazonians in Bolivia (Tsimane').

SUBJECT AND METHODS

Measurements were taken for 525 children aged 2-12 and 218 adolescents aged 13-23 in 13 villages in 2005. Log of standing height was regressed on mean annual level and mean intra-annual monthly coefficient of variation (CV) of rain and mean annual level of temperature during gestation, birth year, and ages 2-4. Controls include age, quinquennium and season of birth, parent's attributes, and dummy variables for surveyors and villages.

RESULTS

Climate variables were only related with the height of boys age 2-12. The level and CV of rain during birth year and the CV of rain and level of temperature during ages 2-4 were associated with taller stature. There were no secular changes in temperature (1973-2005) or rain (1943-2005).

CONCLUSION

The height of young females and males is well protected from climate events, but protection works less well for boys ages 2-12.

A massive phytoplankton bloom induced by an ecosystem-scale iron fertilization experiment in the equatorial Pacific Ocean

The seeding of an expanse of surface waters in the equatorial Pacific Ocean with low concentrations of dissolved iron triggered a massive phytoplankton bloom which consumed large quantities of carbon dioxide and nitrate that these microscopic plants cannot fully utilize under natural conditions. These and other observations provide unequivocal support for the hypothesis that phytoplankton growth in this oceanic region is limited by iron bioavailability.

MR imaging of erosions in interphalangeal joint osteoarthritis: is all osteoarthritis erosive?

OBJECTIVE

Erosive osteoarthritis is usually considered as an inflammatory subset of osteoarthritis (OA). However, an inflammatory component is now recognised in all subsets of OA, so this subgroup of erosive or inflammatory OA is more difficult to conceptualise. The aim of this study was to compare routine CR and MRI to investigate erosion numbers and morphology to determine whether hand OA in general is a more erosive disease than previously recognised.

DESIGN AND METHODS

Fifteen patients with clinical (OA) of the small joints of the hand underwent MRI of one of the affected proximal interphalangeal (PIP) or distal interphalangeal (DIP) joints. Conventional radiographs (CR) of the hand were also obtained. The MR images were reviewed by two observers for the presence of central and marginal erosions. The site and morphology of any erosions was recorded. CR images of the same hand joint were scored independently for central and marginal erosions by the same observers.

RESULTS

There was 100% agreement between the observers for scoring erosions on CR. Agreement for the MRI scores was also excellent (kappa = 0.84). MRI detected 37 erosions, of which only 9 were seen on CR. The increase in sensitivity using MRI was much greater for marginal erosions (1 detected on CR, 19 on MRI) than for central erosions (8 on CR, 18 on MRI). Using MRI 80% of joints examined showed 1 or more erosions compared with 40% using CR. If only marginal erosions were considered 80% of joints were still considered erosive by MRI criteria, but only 1 showed evidence of erosion on CR. Morphologically central erosions appeared to represent areas of subchondral collapse and pressure atrophy. In contrast, marginal erosions resembled those seen in inflammatory arthritides.

CONCLUSION

Erosions, and particularly marginal erosions typical of those seen in inflammatory arthritis, are a more common feature of small joint OA than conventional radiographs have previously indicated.

Ethnobotanical knowledge is associated with indices of child health in the Bolivian Amazon

Culture is a critical determinant of human behavior and health, and the intergenerational transmission of knowledge regarding the use of available plant resources has historically been an essential function of culture. Local ethnobotanical knowledge is important for health and nutrition, particularly in rural low-resource settings, but cultural and economic transitions associated with globalization threaten such knowledge. This prospective study investigates the association between parental ethnobotanical knowledge and child health among the Tsimane', a horticulturalist and foraging society in Amazonian Bolivia. Anthropometric data and capillary blood samples were collected from 330 Tsimane' 2- to 10-year-olds, and mothers and fathers were interviewed to assess ethnobotanical knowledge and skills. Comprehensive measures of parental schooling, acculturation, and economic activities were also collected. Dependent variables included three measures of child health: (i) C-reactive protein, assayed in whole-blood spots as an indicator of immunostimulation; (ii) skinfold thickness, to estimate subcutaneous fat stores necessary to fuel growth and immune function; and (iii) height-for-age, to assess growth stunting. Each child health measure was associated with maternal ethnobotanical knowledge, independent of a wide range of potentially confounding variables. Each standard deviation of maternal ethnobotanical knowledge increased the likelihood of good child health by a factor of >1.5. Like many populations around the world, the Tsimane' are increasingly facing the challenges and opportunities of globalization. These results underscore the importance of local cultural factors to child health and document a potential cost if ethnobotanical knowledge is lost.

High-resolution microscopy coil MR-Eye

The eye is involved in several pathologies where precise identification of the underlying condition is essential for the optimal patient care. This preliminary report presents the potential of high-resolution microscopy coil magnetic resonance imaging (HR-MRI) to undertake this task being actively used in the clinical setting. We used a commercially available MRI scanner and a microscopy surface coil. Exquisite anatomic detail of the eye and orbit with depiction of previously unobserved structures and clear demonstration of the underlying pathology was achieved. This report supports the idea that orbital imaging can be revolutionized with the introduction of HR-MRI with broad clinical implications.

Age-related changes in human crystallins determined from comparative analysis of post-translational modifications in young and aged lens: does deamidation contribute to crystallin insolubility?

We have employed recently developed blind modification search techniques to generate the most comprehensive map of post-translational modifications (PTMs) in human lens constructed to date. Three aged lenses, two of which had moderate cataract, and one young control lens were analyzed using multidimensional liquid chromatography mass spectrometry. In total, 491 modification sites in lens proteins were identified. There were 155 in vivo PTM sites in crystallins: 77 previously reported sites and 78 newly detected PTM sites. Several of these sites had modifications previously undetected by mass spectrometry in lens including carboxymethyl lysine (+58 Da), carboxyethyl lysine (+72 Da), and an arginine modification of +55 Da with yet unknown chemical structure. These new modifications were observed in all three aged lenses but were not found in the young lens. Several new sites of cysteine methylation were identified indicating this modification is more extensive in lens than previously thought. The results were used to estimate the extent of modification at specific sites by spectral counting. We tested the long-standing hypothesis that PTMs contribute to age-related loss of crystallin solubility by comparing spectral counts between the water-soluble and water-insoluble fractions of the aged lenses and found that the extent of deamidation was significantly increased in the water-insoluble fractions. On the basis of spectral counting, the most abundant PTMs in aged lenses were deamidations and methylated cysteines with other PTMs present at lower levels.

Prevalence of transportation safety measures portrayed in primetime US television programs and commercials

OBJECTIVE

To determine the prevalence of transportation related safety behaviors, such as seatbelt and helmet use, in primetime US television programs and commercials.

DESIGN

Cross sectional study.

SETTING

Top rated television programs and associated commercials from four major US television networks were reviewed for the prevalence of transportation safety related behaviors during a one month period in 2005. Programs were categorized according to the time and network of airing, program type, program rating, and--for commercials--type of product being advertised

SUBJECTS

Occupants of automobiles, motorcycles, or bicycles in 507 instances in which a transportation scene was aired.

RESULTS

Seatbelt use was depicted in 62% and 86% of individuals in television program and commercial automobile scenes, respectively. The prevalence of motorcycle helmet use was 47% in television programs and 100% in commercials. Bicycle helmets were used in 9% of television programs and 84% of commercials. The frequency of seatbelt use in programs and commercials varied by television rating and genre but did not differ by network, time of airing, or age of character portrayed.

CONCLUSIONS

The prevalence of safety related behaviors aired on major US networks during primetime slots is higher than previous reports but still much lower than national averages. Commercials, in contrast, portray transportation safety measures with a frequency that exceeds that of US television programs or most national surveys.

Physical growth and nutritional status of Tsimane' Amerindian children of lowland Bolivia

This study examines patterns of growth and nutritional status of indigenous Tsimane' children under 9 years of age (n = 199 boys and 210 girls), based on a cross-sectional sample from 58 villages from the Beni Deparment of lowland Bolivia. Compared with US children, Tsimane' children are quite short, with linear growth tracking at or below the US 5th centile in both sexes. The prevalence of low height-for-age ("stunting;" HA Z-scores </=-2) is 52% in boys and 43% in girls. In contrast, weight-for-height in Tsimane' children approximates the US median, with the prevalence of low weight-for-height ("wasting"; WH Z-scores </=-2) being only 4% and 6% in boys and girls, respectively. Tsimane' boys and girls are leaner than their US peers, but their levels of body fatness are not so low as to indicate severe energy stress. Arm muscularity of Tsimane' children is similar to that of their US age peers, and this suggests that they are not experiencing acute protein malnutrition. Variation in measures of nutritional status of Tsimane' children is modestly correlated with village-level differences. Degree of isolation, as measured by distance to urban centers or to primary forest, was not a strong predictor of children's anthropometric status. Rather, in both boys and girls, nutritional status was most strongly associated with number of teachers in the village, a measure of access to education. Comparative analyses indicate that high levels of statural growth stunting are common among indigenous populations throughout lowland South America. This problem appears to be largely attributable to poor dietary quality (diets low in key micronutrients) and high disease loads. Further research is needed to identify the specific causes and potential interventions for the high rates of childhood growth stunting in this region.

Anorexia nervosa (restrictive subtype) is associated with a polymorphism in the novel norepinephrine transporter gene promoter polymorphic region

Long-term weight-restored patients with anorexia nervosa (AN) have lower norepinephrine levels than controls. Since this may reflect altered reuptake by the norepinephrine transporter (NET), we hypothesised that the NET gene was involved in the genetic component of AN. PCR-amplification of an AAGG repeat island (AAGG1) in the NET gene promoter region revealed a novel 343-bp sequence with five additional AAGG repeat islands (AAGG2-AAGG6). We named the sequence from AAGG1 to AAGG6 inclusive, the NET gene promoter polymorphic region (NETpPR). A 4-bp deletion (S4) or insertion (L4) in AAGG4 resulted in the net loss or gain, respectively, of a putative Elk-1 transcription factor site. The transmission disequilibrium test(TDT) with 87 Australian trios (patient plus parents) demonstrated significant preferential transmission of L4 (McNemar's chi(2) = 7.806, df = 1, P = 0.0052, odds ratio: 2.1) from parent to child with restricting AN (AN-R), suggesting that L4 or a DNA variant in linkage disequilibrium with it, doubles the risk for developing AN-R.

Variability of deoxynivalenol measurements in barley

Deoxynivalenol (DON), a toxin produced by Fusarium fungi, can occur in many cereal grains. If wet climatic conditions coincide with the flowering period of plant development, circumstances are favorable for the fungi infection. Because the presence of DON in barley can have significant economic consequences to barley producers, commercially available test kits are used to measure DON in shipments throughout marketing channels. The quantity of barley sampled from a lot and used to measure DON can vary widely, depending on where the test is conducted. The Grain Inspection, Packers and Stockyards Administration of the U.S. Department of Agriculture specifies that a minimum of 100 g of grain must be processed to measure DON. Other laboratories may use more or less grain. A study undertaken to measure the variability among measurements of different sample sizes found no detectable differences in variability attributable to sample size. It was concluded that the variability among DON concentrations in samples from the lot was small relative to that introduced by the measurement process (combined sample preparation and analysis). A separate experiment investigated variation among samples taken from a lot, variation among subsamples taken from ground samples, and variation among multiple replicated measurements of an extract. On 10 lots, all 3 sources were significant contributors to variation. Stratification of DON within lots was hypothesized as a source of variation of DON measurements. Tests indicated that some stratification may exist.

A study of Wilson disease mutations in Britain

Wilson disease (WD) is an autosomal recessive disease of copper transport. The disease is caused by a large number of mutations in the ATP7B gene, some of which appear to be population specific, whereas others are found in probands from a variety of different ethnic backgrounds. This study presents the results of screening the ATP7B gene by SSCP and sequencing in order to define the spectrum of mutations seen in British referrals for WD. The 52 patients screened included 10 with a non-British mixed ethnicity origin. This study identified 19 novel mutations and 18 mutations that had been previously described. The novel mutations included seven nonconservative missense mutations, eight small insertions, or deletions causing frameshift, two nonsense mutations, and two splice-site mutations. Seven of the 10 mixed ethnicity patients harboured homozygous mutations, whereas only four of the larger British group were homozygotes. The detection rate by SSCP analysis in the British group of 42 consecutive unrelated WD probands was 70%. However, SSCP screening of just three exons (exons 8, 14, and 18) is predicted to identify 60% of mutations present in WD referrals.

A study of Wilson disease mutations in Britain

Wilson disease (WD) is an autosomal recessive disease of copper transport. The disease is caused by a large number of mutations in the ATP7B gene, some of which appear to be population specific, whereas others are found in probands from a variety of different ethnic backgrounds. This study presents the results of screening the ATP7B gene by SSCP and sequencing in order to define the spectrum of mutations seen in British referrals for WD. The 52 patients screened included 10 with a non-British mixed ethnicity origin. This study identified 19 novel mutations and 18 mutations that had been previously described. The novel mutations included seven nonconservative missense mutations, eight small insertions, or deletions causing frameshift, two nonsense mutations, and two splice-site mutations. Seven of the 10 mixed ethnicity patients harboured homozygous mutations, whereas only four of the larger British group were homozygotes. The detection rate by SSCP analysis in the British group of 42 consecutive unrelated WD probands was 70%. However, SSCP screening of just three exons (exons 8, 14, and 18) is predicted to identify 60% of mutations present in WD referrals.

Control of myelination by specific patterns of neural impulses

A cell culture preparation equipped with stimulating electrodes was used to investigate whether action potential activity can influence myelination of mouse dorsal root ganglia axons by Schwann cells. Myelination was reduced to one-third of normal by low-frequency impulse activity (0.1 Hz), but higher-frequency stimulation (1 Hz) had no effect. The number of Schwann cells and the ultrastructure of compact myelin were not affected. The frequency of stimulation that inhibited myelination decreased expression of the cell adhesion molecule L1, and stimulation under conditions that prevented the reduction in L1 blocked the effects on myelination. This link between myelination and functional activity in the axon at specific frequencies that change axonal expression of L1 could have important consequences for the structural and functional relationship of myelinating axons.

Magnetic resonance of the neonatal brain

We discuss the advantages of magnetic resonance (MR) technique in the study of the neonatal brain. Major results have been obtained concerning the understanding of the normal appearance of the developing brain. Bands of cells migrating to the cortex have been identified in the frontal periventricular white matter up to late gestation. MR can also identify the disappearance of the subependymal germinal matrix with increasing gestational age. With respect to the lesions of prematurity, subependymal germinal matrix hemorrhages were for the first time identified by MR underneath the posterior horns of the lateral ventricles. Subtle ischemic lesions of the periventricular white matter, not detected by brain ultrasound scan, are also described. Analysis of the lesions of the term neonates showed the role of MR in defining a more precise prognosis of infants who have sustained "birth asphyxia". The lesions can affect the basal ganglia, watershed areas of the white matter, and cortex. MR scans performed in the second week of life seem to show a stronger association with the outcome. Brain ischemic areas of the term neonates presenting with focal or multifocal seizures can also be detected by MR. These infarcted zones are usually located in the perfusion territory of the middle cerebral artery, more often in the left hemisphere. The timing of the scan is an important factor as the conventional MR can be negative in the first two-three days after the seizures. The diffusion-weighted imaging (DWI) is a new MR technique very sensitive to acute ischemic injury, and it may solve the problem of the scan timing.

MR features of developing periventricular white matter in preterm infants: evidence of glial cell migration

PURPOSE

MR imaging of the brain is increasingly used in the investigation of the newborn, but little information is available on the normal appearance of the developing brain. We scanned a series of newborn infants in an attempt to define the normal appearance of developing periventricular white matter and to assess how pathologic conditions may modify this appearance.

METHODS

Sixty-eight newborn infants, median postmenstrual age (PMA) 34 weeks (range, 24 to 42 weeks), were subdivided into two groups: group A (n = 33), which included those with normal clinical and sonographic examinations, and group B (n = 35), which contained those with evidence of neuroabnormality detected prior to the MR study, either clinically or by cerebral sonography. Images were acquired in two planes on a 1.5-T imager using turbo spin-echo pulse sequences.

RESULTS

Symmetric periventricular bands of reduced signal intensity were noted in the frontal periventricular white matter on T2-weighted images in 98% of group A infants and in 97% of group B infants. The number of bands was inversely related to PMA. The reduction in number of bands with increasing PMA was delayed in group B infants.

CONCLUSION

The uniform appearance of periventricular bands in a population of healthy infants and their relationship to the infants' maturity is consistent with the results of previous histologic studies. These studies demonstrate the presence of migrating glial cells within the periventricular white matter of infants beyond 20 weeks' gestation, when neuronal migration to the cortex is complete. We postulate that the bands seen on T2-weighted images represent groups of migrating glial cells, providing a further marker of cerebral maturation.

Frontal-striatal cognitive deficits in patients with chronic schizophrenia

Spatial working memory and planning abilities were assessed in 36 hospitalized patients with chronic schizophrenia, using the computerized Cambridge Neuropsychological Test Automated Battery (CANTAB), and compared with those of normal subjects and patients with neurological disorders (frontal lobe lesions; temporal lobe and amygdalohippocampal lesions; Parkinson's disease), matched for age, sex and National Adult Reading Test IQ. The patients in the group with temporal lobe lesions were unimpaired in their performance on these tasks. Patients with schizophrenia were impaired on visuo-spatial memory span compared with all the other groups, while severity of Parkinson's disease was correlated with the degree of impairment on this task. The patients with schizophrenia and those with frontal lobe lesions were impaired on a 'spatial working memory' task, with increased 'between-search errors'. Patients with Parkinson's disease performed this task poorly compared with the younger control subjects. Patients with schizophrenia were unable to develop a systematic strategy to complete this task, relying instead on a limited visuo-spatial memory span. Higher level planning ability was investigated using the CANTAB 'Tower of London'. All groups were equally able to complete the task. However, the groups of patients with schizophrenia and frontal lobe lesions made fewer perfect solutions and required more moves for completion. Movement times were significantly slower in the schizophrenia group, suggesting impairment in the sensorimotor requirements of the task. The patients with schizophrenia were not impaired in their 'initial thinking' (planning) latencies, but had significantly prolonged 'subsequent thinking' (execution) latencies. This pattern resembled that of the group with frontal lobe lesions and contrasted with the prolonged 'initial thinking' time seen in Parkinson's disease. The results of this study are indicative of an overall deficit of executive functioning in schizophrenia, even greater than that seen in patients with frontal lobe lesions. However, the pattern of results in schizophrenia resembled that seen in patients with lesions of the frontal lobe or with basal ganglia dysfunction, providing support for the notion of a disturbance of frontostriatal circuits in schizophrenia. Our findings also indicate that there is a loss of the normal relationships between different domains of executive function in schizophrenia, with implications for impaired functional connectivity between different regions of the neocortex.

Mandibular fractures following third molar extraction. A retrospective clinical and radiological study

Twelve patients with 13 mandibular fractures following third molar extraction were treated in our Department between 1980 and 1995. Clinical and radiographic data relating to these patients were analysed retrospectively to determine complication characteristics. Only one fracture occurred during surgery. The first week after the operation was found to be most critical for fracture occurrence. A "cracking" sound from the jaw while eating frequently indicated that a fracture had occurred, but repeated radiographic examination may be necessary for definitive diagnosis. Most teeth removed belonged to Groups II/III according to PELL & GREGORY's classification, indicating partial or total impaction of the tooth and a narrow space in the retromolar triangle. In all cases, tooth roots were superimposed on or adjacent to the inferior alveolar canal. Clinically, the age of the patient seemed to be a common predisposing factor, and patients older than 30 to 40 years were considered to be a risk group. Regardless of the degree of impaction and tooth position, the fracture type seen was uniform, i.e. preangular location and a typical course of the fracture line. After adequate fracture treatment, no further complications were noted.

Regional responsiveness of the tibia to intermittent administration of parathyroid hormone as affected by skeletal unloading

To determine whether the acute inhibition of bone formation and deficit in bone mineral induced by skeletal unloading can be prevented, we studied the effects of intermittent parathyroid hormone (PTH) administration (8 micrograms/100 g/day) on growing rats submitted to 8 days of skeletal unloading. Loss of weight bearing decreased periosteal bone formation by 34 and 51% at the tibiofibular junction and tibial midshaft, respectively, and reduced the normal gain in tibial mass by 35%. Treatment with PTH of normally loaded and unloaded animals increased mRNA for osteocalcin (+58 and +148%, respectively), cancellous bone volume in the proximal tibia (+41 and +42%, respectively), and bone formation at the tibiofibular junction (+27 and +27%, respectively). Formation was also stimulated at the midshaft in unloaded (+47%, p < 0.05), but not loaded animals (-3%, NS). Although cancellous bone volume was preserved in PTH-treated, unloaded animals, PTH did not restore periosteal bone formation to normal nor prevent the deficit in overall tibial mass induced by unloading. We conclude that the effects of PTH on bone formation are region specific and load dependent. PTH can prevent the decrease in cancellous bone volume and reduce the decrement in cortical bone formation induced by loss of weight bearing.

A novel SR-related protein specifically interacts with the carboxy-terminal domain (CTD) of RNA polymerase II through a conserved interaction domain

The largest subunit of the RNA polymerase II (pol II) contains at the carboxy-terminus a peculiar repetitive sequence that consists of 52 tandem repeats of the consensus motif Tyr-Ser-Pro-Thr-Ser-Pro-Ser, referred to as the C-terminal domain (CTD). Upon transcriptional initiation/promoter clearance, the CTD becomes extensively phosphorylated and apparently remains so during elongation. While the underphosphorylated CTD plays a role in transcriptional initiation, recent evidence couples the highly phosphorylated CTD to RNA processing, namely polyadenylation and splicing. Using a yeast two-hybrid screen, we have selected for human proteins that interact with the CTD of RNA polymerase II. The CTD-GAL fusion protein used as a bait is highly phosphorylated in yeast and, accordingly, we did not isolate proteins implicated in transcriptional regulation but rather proteins with possible roles in RNA splicing. One major cDNA clone isolated this way encodes SRrp129/CASP11, a protein that contains a conserved CTD-interaction domain at the C-terminus and an internal serine-arginine rich domain (SR domain). Proteins of the SR family have been implicated in RNA splicing, notably in the regulation of alternative splicing. Thus we consider it likely that SRrp129 is an auxiliary splice factor. We also improved our method to quickly map domains involved in protein-protein interaction (Stagljar et al., 1996, BioTechniques 21, 430-432). Instead of using sonication for the production of a random DNA fragment library, we took advantage of the fact that DNAse I in the presence of manganese (II) produces double strand rather than single strand DNA breaks. The DNA fragment library of the SRrp129 clone was then used in the yeast two-hybrid system to identify the 100-amino acid domain that interacts with the CTD of RNA polymerase II.