Upper Tract Urothelial Carcinoma (UTUC): Prevalence, Impact and Management Challenge.

Upper tract urothelial carcinoma (UTUC) is an aggressive and difficult malignancy to treat. Owing to its rarity and the lack of specific high-level data, management mirrors that of urothelial cancer of the bladder (UCB). Over the past decade, UTUC has shown minimal improvement in survival rates. Its location makes the diagnosis and staging of UTUC more complex. Moreover, surgery often leads to a decline in renal function, rendering a proportion of patients ineligible for cisplatin. There is debate as to how best manage locally advanced UTUC perioperatively. Although immune checkpoint inhibitors (ICIs) have changed the treatment landscape for UCB, the response to ICIs in UTUC has been variable. With new technologies, our understanding of the molecular biology of UTUC has grown, helping to identify key molecular differences from UCB. This review summarises the evidence available on UTUC as a disease entity, discusses treatment in perioperative and metastatic settings, and considers future directions for the management of patients diagnosed with UTUC.

Exploring associations between social determinants of health and mental health outcomes in families from socioeconomically and racially and ethnically diverse households.

This cross-sectional study investigated the associations between Social Determinants of Health (SDOH) and mental health outcomes of parents and children (n = 1307) from the Latinx, Native American, Somali/Ethiopian, White, Hmong, and African American communities. Logistic regression models were used to estimate the adjusted associations between five parent and child mental health measures and 25 measures of SDOH. False discovery rate q-values were computed to account for multiple comparisons. Families of color reported 5.3-7.8 SDOH barriers while White families reported 1.7 SDOH barriers on average. Adjusted analyses indicated that low family functioning and high perceived discrimination were associated with low resiliency among parents and increased behavioral difficulties among children. Other SDOH that were adversely associated with parent or child mental health included lack of social support, recent stressful life events, and adverse childhood experiences among parents. SDOH in the social and community context were most likely to be associated with mental health problems. Community-engaged evidence-based interventions are needed to improve population mental health.

Acute extracorporeal shockwave lithotripsy for ureteric stones - 7-years' experience from a busy district general hospital.

OBJECTIVES: To demonstrate the efficacy and cost-effectiveness of acute extracorporeal shockwave lithotripsy (ESWL) for ureteric stones we present our experience of ESWL in 530 ureteric stone cases, in the largest UK series we are aware of to date. ESWL is underutilised in ureteric stone management. The Getting It Right First Time (GIRFT) report showed just four units nationally treated >10% of acute ureteric stones with ESWL. Despite guideline recommendations as a first-line treatment option, few large volume studies have been published. PATIENTS AND METHODS: Retrospective review of prospectively collected data between December 2012 and February 2020 was performed. Data relating to patient demographics, stone characteristics, skin-to-stone distance, and treatment failure were collected. Cost analysis was conducted by the Trust's surgical financial manager. Multivariable analyses were performed to assess for predictors of ESWL success. RESULTS: A success rate of 68% (95% confidence interval 64%-72%) at 6 weeks was observed (n = 530). The median (interquartile range) number of treatment sessions was 2 (1, 2). Stone diameter was observed to be a predictor of ESWL success. The small number of stones treated of >13 mm or >1250 HU had an ~50% chance of successful treatment. Acute ureteric ESWL was less costly than acute ureterorenoscopy, consistent with findings from previous NHS studies. CONCLUSION: Acute ESWL is a safe, reliable, and financially viable treatment option for a wider spectrum of patients than reflected in international guidelines based on our large, heterogenous series. In the coronavirus disease 2019 (COVID-19) era, with theatre access reduced and concerns over aerosol generating procedures, acute ESWL remains an attractive first-line treatment option.

Diversity in valuing social contact and risk tolerance leading to the emergence of homophily in populations facing infectious threats.

How self-organization leads to the emergence of structure in social populations remains a fascinating and open question in the study of complex systems. One frequently observed structure that emerges again and again across systems is that of self-similar community, i.e., homophily. We use a game theoretic perspective to explore a case in which individuals choose affiliation partnerships based on only two factors: the value they place on having social contacts, and their risk tolerance for exposure to threat derived from social contact (e.g., infectious disease, threatening ideas, etc.). We show how diversity along just these two influences is sufficient to cause the emergence of self-organizing homophily in the population. We further consider a case in which extrinsic social factors influence the desire to maintain particular social ties, and show the robustness of emergent homophilic patterns to these additional influences. These results demonstrate how observable population-level homophily may arise out of individual behaviors that balance the value of social contacts against the potential risks associated with those contacts. We present and discuss these results in the context of outbreaks of infectious disease in human populations. Complementing the standard narrative about how social division alters epidemiological risk, we here show how epidemiological risk may deepen social divisions in human populations.

Dissemination of Evidence-Based Recommendations for Sickle Cell Disease to Primary Care and Emergency Department Providers in North Carolina: A Cost Benefit Analysis.

Background: Sickle cell disease (SCD) is a genetic condition affecting primarily individuals of African descent, who happen to be disproportionately impacted by poverty and who lack access to health care. Individuals with SCD are at high likelihood of high acute care utilization and chronic pain episodes. The multiple complications seen in SCD contribute to significant morbidity and premature mortality, as well as substantial costs to the healthcare system. Objectives: SCD is a complex chronic disease resulting in the need for primary, specialty and emergency care. Many providers do not feel prepared to care for individuals with SCD, despite the existence of evidence-based guidelines. We report the development of a SCD toolbox and the dissemination process to primary care and emergency department (ED) providers in North Carolina (NC). We report the effect of this dissemination on health-care utilization, cost of care, and overall cost-benefit. Methods: The SCD toolbox was adapted from the National Heart, Lung, and Blood Institute recommendations. Toolbox training was provided to quality improvement specialists who then disseminated the toolbox to primary care providers (PCPs) affiliated with the only NC managed care coordination system and ED providers. Tools were made available in paper, online, and in app formats to participating managed care network practices (n=1 800). Medicaid claims data were analyzed for total costs and benefits of the toolbox dissemination for a 24-month pre- and 18-month post-intervention period. Results: There was no statistically significant shift in the number of outpatient specialty visits, ED visits or hospitalizations. There was a small decrease in the number of PCP visits in the post-implementation period. The dissemination resulted in a net cost-savings of $361 414 ($14.03 per-enrollee per-month on average). However, the estimated financial benefit associated with the dissemination of the SCD toolbox was not statistically significant. Conclusions: Although we did not find the expected shift to increased PCP visits and decreased ED visits and hospitalizations, there were many lessons learned.

Estimation of the impacts of substance use on workplace productivity: a hybrid human capital and prevalence-based approach applied to Canada.

OBJECTIVE: Policy makers require evidence-based estimates of the economic costs of substance use-attributable lost productivity to set strategies aimed at reducing substance use-related harms. Building on a study by Rehm et al. (2006), we provide estimates of workplace costs using updated methods and data sources. METHODS: We estimated substance use-attributable productivity losses due to premature mortality, long-term disability, and presenteeism/absenteeism in Canada between 2007 and 2014. Lost productivity was estimated using a hybrid prevalence and incidence approach. Substance use prevalence data were drawn from three national self-report surveys. Premature mortality data were from the Canadian Vital Statistics Death Database, and long-term disability and workplace interference data were from the Canadian Community Health Survey. RESULTS: In 2014, the total cost of lost productivity due to substance use was $15.7 billion, or approximately $440 per Canadian, an increase of 8% from 2007. Substances responsible for the greatest economic costs were alcohol (38% of per capita costs), tobacco (37%), opioids (12%), other central nervous system (CNS) depressants (4%), other CNS stimulants (3%), cannabis (2%), cocaine (2%), and finally other psychoactive substances (2%). CONCLUSION: In 2014, alcohol and tobacco represent three quarters of substance use-related lost productivity costs in Canada, followed by opioids. These costs provide a valuable baseline that can be used to assess the impact of future substance use policy, practice, and other interventions, especially important given Canada's opioid crisis and recent cannabis legalization.

Examining the functional range of commercially available low-cost airborne particle sensors and consequences for monitoring of indoor air quality in residences.

Low-cost airborne particle sensors are gaining attention for monitoring human exposure to indoor particulate matter. This study aimed to establish the concentrations at which these commercially available sensors can be expected to report accurate concentrations. We exposed five types of commercial integrated devices and three types of "bare" low-cost particle sensors to a range of concentrations generated by three different sources. We propose definitions of upper and lower bounds of functional range based on the relationship between a given sensor's output and that of a reference instrument during a laboratory experiment. Experiments show that the lower bound can range from approximately 3 to 15 µg/m3 . At greater concentrations, sensor output deviates from linearity at approximately 300-3000 µg/m3 . We also conducted a simulation campaign to analyze the effect of this limitation on functional range on the accuracy of exposure readings given by these devices. We estimate that the upper bound results in minimal inaccuracy in exposure quantification, and the lower bound can result in as much as a 50% error in approximately 10% of US homes.

Validity and reliability of a novel 3D scanner for assessment of the shape and volume of amputees' residual limb models.

BACKGROUND: Objective assessment methods to monitor residual limb volume following lower-limb amputation are required to enhance practitioner-led prosthetic fitting. Computer aided systems, including 3D scanners, present numerous advantages and the recent Artec Eva scanner, based on laser free technology, could potentially be an effective solution for monitoring residual limb volumes. PURPOSE: The aim of this study was to assess the validity and reliability of the Artec Eva scanner (practical measurement) against a high precision laser 3D scanner (criterion measurement) for the determination of residual limb model shape and volume. METHODS: Three observers completed three repeat assessments of ten residual limb models, using both the scanners. Validity of the Artec Eva scanner was assessed (mean percentage error <2%) and Bland-Altman statistics were adopted to assess the agreement between the two scanners. Intra and inter-rater reliability (repeatability coefficient <5%) of the Artec Eva scanner was calculated for measuring indices of residual limb model volume and shape (i.e. residual limb cross sectional areas and perimeters). RESULTS: Residual limb model volumes ranged from 885 to 4399 ml. Mean percentage error of the Artec Eva scanner (validity) was 1.4% of the criterion volumes. Correlation coefficients between the Artec Eva and the Romer determined variables were higher than 0.9. Volume intra-rater and inter-rater reliability coefficients were 0.5% and 0.7%, respectively. Shape percentage maximal error was 2% at the distal end of the residual limb, with intra-rater reliability coefficients presenting the lowest errors (0.2%), both for cross sectional areas and perimeters of the residual limb models. CONCLUSION: The Artec Eva scanner is a valid and reliable method for assessing residual limb model shapes and volumes. While the method needs to be tested on human residual limbs and the results compared with the current system used in clinical practice, it has the potential to quantify shape and volume fluctuations with greater resolution.

A systematic review and individual patient data meta-analysis of prognostic factors for foot ulceration in people with diabetes: the international research collaboration for the prediction of diabetic foot ulcerations (PODUS).

BACKGROUND: Annual foot risk assessment of people with diabetes is recommended in national and international clinical guidelines. At present, these are consensus based and use only a proportion of the available evidence. OBJECTIVES: We undertook a systematic review of individual patient data (IPD) to identify the most highly prognostic factors for foot ulceration (i.e. symptoms, signs, diagnostic tests) in people with diabetes. DATA SOURCES: Studies were identified from searches of MEDLINE and EMBASE. REVIEW METHODS: The electronic search strategies for MEDLINE and EMBASE databases created during an aggregate systematic review of predictive factors for foot ulceration in diabetes were updated and rerun to January 2013. One reviewer applied the IPD review eligibility criteria to the full-text articles of the studies identified in our literature search and also to all studies excluded from our aggregate systematic review to ensure that we did not miss eligible IPD. A second reviewer applied the eligibility criteria to a 10% random sample of the abstract search yield to check that no relevant material was missed. This review includes exposure variables (risk factors) only from individuals who were free of foot ulceration at the time of study entry and who had a diagnosis of diabetes mellitus (either type 1 or type 2). The outcome variable was incident ulceration. RESULTS: Our search identified 16 cohort studies and we obtained anonymised IPD for 10. These data were collected from more than 16,000 people with diabetes worldwide and reanalysed by us. One data set was kept for independent validation. The data sets contributing IPD covered a range of temporal, geographical and clinical settings. We therefore selected random-effects meta-analysis, which assumes not that all the estimates from each study are estimates of the same underlying true value, but rather that the estimates belong to the same distribution. We selected candidate variables for meta-analysis using specific criteria. After univariate meta-analyses, the most clinically important predictors were identified by an international steering committee for inclusion in the primary, multivariable meta-analysis. Age, sex, duration of diabetes, monofilaments and pulses were considered most prognostically important. Meta-analyses based on data from the entire IPD population found that an inability to feel a 10-g monofilament [odds ratio (OR) 3.184, 95% confidence interval (CI) 2.654 to 3.82], at least one absent pedal pulse (OR 1.968, 95% CI 1.624 to 2.386), a longer duration of a diagnosis of diabetes (OR 1.024, 95% CI 1.011 to 1.036) and a previous history of ulceration (OR 6.589, 95% CI 2.488 to 17.45) were all predictive of risk. Female sex was protective (OR 0.743, 95% CI 0.598 to 0.922). LIMITATIONS: It was not possible to perform a meta-analysis using a one-step approach because we were unable to procure copies of one of the data sets and instead accessed data via Safe Haven. CONCLUSIONS: The findings from this review identify risk assessment procedures that can reliably inform national and international diabetes clinical guideline foot risk assessment procedures. The evidence from a large sample of patients in worldwide settings show that the use of a 10-g monofilament or one absent pedal pulse will identify those at moderate or intermediate risk of foot ulceration, and a history of foot ulcers or lower-extremity amputation is sufficient to identify those at high risk. We propose the development of a clinical prediction rule (CPR) from our existing model using the following predictor variables: insensitivity to a 10-g monofilament, absent pedal pulses and a history of ulceration or lower-extremities amputations. This CPR could replace the many tests, signs and symptoms that patients currently have measured using equipment that is either costly or difficult to use. STUDY REGISTRATION: This study is registered as PROSPERO CRD42011001841. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Fluoroscopic assessment of lumbar total disc replacement kinematics during walking.

STUDY DESIGN: Descriptive. OBJECTIVE: The purpose of this study was to determine the in vivo kinematics of functional spinal units, during gait, in individuals with a single-level lumbar total disc replacement (TDR). SUMMARY OF BACKGROUND DATA: TDR is a motion preservation technology that offers an alternative to spinal fusion for treatment of degenerative disc disease. The aim of TDRs is to replicate motion of the functional spinal units, which may protect adjacent intervertebral discs against accelerated degeneration. At present, there is limited understanding of the in vivo motion of TDRs, particularly during dynamic activities such as gait. Such information is important for understanding the wear characteristics of TDRs and furthering design rationale of future implants. METHODS: TDR motions were obtained from 24 participants who underwent implantation with single-level L4-L5 or L5-S1 CHARITÉ or In Motion TDRs. Video fluoroscopy was used to obtain measurements in the frontal and sagittal planes during fixed speed treadmill walking. RESULTS: The mean range of motion between the upper and lower lumbar TDR endplates during walking was 1.6° and 2.4° in the frontal and sagittal planes, respectively. These values were significantly different from zero and corresponded to 19% of the maximum static range of motion in each plane. CONCLUSION: Lumbar TDRs provide a degree of motion preservation at the operative level during moderate speed walking. The distribution of lumbar TDR motions during walking presented here will inform relevant standards for conducting standardized tests of lumbar TDRs, particularly wear assessments, and, hence, enable more realistic mechanical and computer-based wear simulations to be performed. LEVEL OF EVIDENCE: N/A.

Price to be paid for two-metal catalysis: magnesium ions that accelerate chemistry unavoidably limit product release from a protein kinase.

Incorporation of divalent metal ions into an active site is a fundamental catalytic tool used by diverse enzymes. Divalent cations are used by protein kinases to both stabilize ATP binding and accelerate chemistry. Kinetic analysis establishes that Cyclin-dependent kinase 2 (CDK2) requires simultaneous binding of two Mg(2+) ions for catalysis of phosphoryl transfer. This tool, however, comes with a price: the rate-acceleration effects are opposed by an unavoidable rate-limiting consequence of the use of two Mg(2+) ions by CDK2. The essential metal ions stabilize ADP product binding and limit the overall rate of the reaction. We demonstrate that product release is rate limiting for activated CDK2 and evaluate the effects of the two catalytically essential Mg(2+) ions on the stability of the ADP product within the active site. We present two new crystal structures of CDK2 bound to ADP showing how the phosphate groups can be coordinated by either one or two Mg(2+) ions, with the occupancy of one site in a weaker equilibrium. Molecular dynamics simulations indicate that ADP phosphate mobility is more restricted when ADP is coordinated by two Mg(2+) ions compared to one. The structural similarity between the rigid ADP·2Mg product and the cooperatively assembled transition state provides a mechanistic rational for the rate-limiting ADP release that is observed. We demonstrate that although the simultaneous binding of two Mg(2+) ions is essential for efficient phosphoryl transfer, the presence of both Mg(2+) ions in the active site also cooperatively increases ADP affinity and opposes its release. Evolution of protein kinases must have involved careful tuning of the affinity for the second Mg(2+) ion in order to balance the needs to stabilize the chemical transition state and allow timely product release. The link between Mg(2+) site affinity and activity presents a chemical handle that may be used by regulatory factors as well as explain some mutational effects.

Cost avoidance using linezolid for methicillin-resistant Staphylococcus aureus infections in a specialist diabetes foot clinic.

OBJECTIVES: An audit was performed to determine whether linezolid (Zyvox, Pharmacia Limited, Sandwich, UK) was being used in accordance with local guidelines and if this had an effect on admissions for diabetes foot ulceration. METHODS: Seven hundred and four patient records from 2005 to 2010 in the Diabetes Foot Clinic, Royal Infirmary of Edinburgh were audited for methicillin-resistant Staphylococcus aureus (MRSA) infections, admissions and antibiotic use. RESULTS: Seventeen percent (n = 119) of patients had proven MRSA infections. Of these, 28% (n = 33) were prescribed linezolid, 94% (n = 31) for up to 14 days and none for >28 days. Eight (24%) had repeated courses. Ninety-one percent (n = 30) either avoided admission or were discharged early with resolution of infection. Four out of 33 patients had reversible blood abnormalities. The total cost for linezolid over this period was £58 000. However, 420 bed days, costing £500/day, were avoided, producing a total saving of £210 000 on inpatient costs. CONCLUSIONS: Linezolid guidelines reduced lengths of stay, inpatient costs and overuse of this expensive but effective treatment.

Health literacy among Spanish-speaking patients in the emergency department.

STUDY OBJECTIVE: Health literacy influences a patient's ability to read and understand labels on medicine containers, appointment slips, informed-consent documents and medical instructions--all of which are considered basic health documents that a patient encounters in healthcare settings. Previous research suggests Spanish-speaking patients have low levels of health literacy. This study compares the functional health literacy (FHL) of Spanish- and English-speaking adult patients in a suburban emergency department (ED). METHODS: Through a prospective, matched cohort design, Spanish-speaking adult patients and pediatric guardians presenting to the ED were matched with English-speaking patients by age, gender and treatment area. Demographic information, including total years of school completed and self-assessed reading ability, was collected. The Test of Functional Health Literacy in Adults (TOFHLA) was administered in the subject's primary language. A score of <60 indicated inadequate FHL, 60-74 marginally adequate FHL, and >74 adequate literacy. RESULTS: Eighty-six matched pairs were enrolled. The median age was 30.5 years, and 56% were male. Spanish speakers averaged a TOFHLA score of 59.72, and English speakers 90.78. Only 7% of English speakers had less-than-adequate FHL compared to 74% of Spanish speakers. The average years of school completed were 10.59 (7.95 Spanish; 13.19 English), and 55% of English speakers reported "excellent" reading ability compared to 13% of Spanish speakers. Last grade completed (p=0.004) and self-assessed reading ability (p=0.0007) are predictors of TOFHLA scores. Those subjects who completed less than the eighth grade had inadequate FHL. CONCLUSIONS: The majority of Spanish-speaking subjects have less-than-adequate FHL. Self-reported reading ability and years of school completed appear to predict FHL and may be clinically useful. Due to the disproportionately low level of health literacy among Spanish-speaking patients demonstrated in this and previous studies, future efforts should focus on developing programs that improve health literacy by providing this population with oral translations and pictorial and video instructions.

Prospective and longitudinal patient self-assessment of health-related quality of life following radical perineal prostatectomy.

PURPOSE: We provide a comprehensive, longitudinal assessment of health related quality of life (HRQOL) following radical perineal prostatectomy (RPP). MATERIALS AND METHODS: We report the results of a prospective cohort study of 109 patients with at least 3 months of followup who underwent RPP between January 2001 and July 2003. A validated patient self-assessment questionnaire, the Expanded Prostate Cancer Index Composite, was administered preoperatively, and 1, 3, 6, 9, 12 and 18 months postoperatively. Mean domain specific HRQOL scores were calculated as well as the proportion of patients achieving an individual baseline by each interval. The Cox proportional hazards model was used to identify predictors of a successful return to baseline of disease specific HRQOL scores. RESULTS: HRQOL scores were lowest 1 month postoperatively and they increased with time. By 6 months a majority of patients had recovered baseline summary scores in urinary (65.1%), bowel (93.6%) and hormonal (91.7%) domains at a median of 5.8 (95% CI 3.6 to 6.2), 1.3 (95% CI 1.1 to 1.5) and 1.3 (95% CI 1.2 to 1.8) months, respectively. One in 4 patients recovered the sexual summary score by 18 months. Significant independent predictors for the recovery of domain summary scores were younger age in urinary (p = 0.001), individual surgeon in bowel (p = 0.022), and older age (p = 0.017) and absent medical comorbidities (p = 0.012) in hormonal domains. CONCLUSIONS: A majority of patients undergoing RRP experience an early recovery of individual urinary, bowel and hormonal HRQOL. Future studies should establish the benefit of bilateral nerve sparing RPP on the recovery of sexual domain HRQOL.

A longitudinal assessment of bowel related symptoms and fecal incontinence following radical perineal prostatectomy.

PURPOSE: Recent studies have suggested an increased incidence of fecal incontinence following radical perineal prostatectomy. We provide a prospective and longitudinal assessment of bowel related symptoms of patients undergoing radical perineal prostatectomy. MATERIALS AND METHODS: A total of 78 patients who underwent radical perineal prostatectomy between January 1 and December 31, 2001 and had a minimal followup of 6 months were included in the analysis. Patient information was obtained from the chart and the bowel domain specific questions of a validated quality of life questionnaire, the Expanded Prostate Cancer Index Composite. The questionnaire was administered to the candidates preoperatively, at 4 weeks following surgery and subsequently at 3-months intervals. A mean bowel function, bother and summary health related quality of life score was calculated at each interval. The duration of new or worsened symptoms with respect to baseline was evaluated using Kaplan-Meier analysis. RESULTS: Symptoms of involuntary stool leakage and rectal urgency were reported by 11.5% (9 of 78) and 19.2% (15) of patients preoperatively. While all bowel related symptoms transiently increased following surgery, rectal urgency was the most persistent symptom, yet normalized in more than 90% of patients within 9 1/2 months. Compared to individual baseline 15.4%, 7.7%, 5.1% and 3.9% of patients reported worsened symptoms of fecal incontinence after 3, 6, 9 and 12 months, respectively. In the subset of 69 patients who denied preoperative fecal incontinence the incidence of involuntary stool leakage was 2.9% by 12 months following radical perineal prostatectomy. Of 10 patients 9 recovered individual health related quality of life score by 6 months after prostatectomy. CONCLUSIONS: Longitudinal assessment of self-reported questionnaire data suggests that fecal incontinence and bowel related symptoms are more prevalent following radical perineal prostatectomy compared to baseline, yet resolve in the majority of patients with time in the early postoperative period.

Assessment of the molecular dynamics structure of DNA in solution based on calculated and observed NMR NOESY volumes and dihedral angles from scalar coupling constants.

To assess the accuracy of the molecular dynamics (MD) models of nucleic acids, a detailed comparison between MD-calculated and NMR-observed indices of the dynamical structure of DNA in solution has been carried out. The specific focus of our comparison is the oligonucleotide duplex, d(CGCGAATTCGCG)(2), for which considerable structural data have been obtained from crystallography and NMR spectroscopy. An MD model for the structure of d(CGCGAATTCGCG)(2) in solution, based on the AMBER force field, has been extended with a 14 ns trajectory. New NMR data for this sequence have been obtained in order to allow a detailed and critical comparison between the calculated and observed parameters. Observable two-dimensional (2D) nuclear Overhauser effect spectroscopy (NOESY) volumes and scalar coupling constants were back-calculated from the MD trajectory and compared with the corresponding NMR data. The comparison of these results indicate that the MD model is in generally good agreement with the NMR data, and shows closer accord with experiment than back-calculations based on the crystal structure of d(CGCGAATTCGCG)(2) or the canonical A or B forms of the sequence. The NMR parameters are not particularly sensitive to the known deficiency in the AMBER MD model, which is a tendency toward undertwisting of the double helix when the parm.94 force field is used. The MD results are also compared with a new determination of the solution structure of d(CGCGAATTCGCG)(2) using NMR dipolar coupling data.