Diversity, equity, and inclusion (DEI) in medical education: DEI at the bedside

BACKGROUND

The ability to recognize and address bias is an important communication skill not typically addressed during training. We describe the design of an educational curriculum that aims to identify and change behavior related to diversity, equity, and inclusion (DEI). "DEI at the Bedside" uses the existing infrastructure of bedside teaching and provides a tool to normalize DEI discussions and develop skills to address bias during a neurology inpatient rotation.

METHODS

As part of traditional clinical rounds, team members on an inpatient service shared experiences with DEI topics, including bias. The team developed potential responses should they encounter a similar situation in the future. We report the results of our needs assessment and curriculum development to evaluate the feasibility of incorporating a DEI educational curriculum in the neurology inpatient setting.

RESULTS

Forty-two DEI experiences were recorded. Medical students were the most frequent discussants (44%). Direction of bias occurred between healthcare team members (33%), against patients (31%), and patients against healthcare team members (28%). Experiences ranged from microaggressions to explicit comments of racism, sexism, and homophobia.

CONCLUSIONS

Based on needs assessment data, we developed a DEI educational curriculum for the inpatient neurology setting aimed to improve knowledge and skills related to DEI topics as well as to normalize conversation of DEI in the clinical setting. Additional study will demonstrate whether this initiative translates into measurable and sustained improvement in knowledge of how bias and disparity show up in the clinical setting and behavioral intent to discuss and address them.

Strokes Averted by Intravenous Thrombolysis: A Secondary Analysis of a Prospective, Multicenter, Controlled Trial of Mobile Stroke Units

OBJECTIVE

This study was undertaken to examine averted stroke in optimized stroke systems.

METHODS

This secondary analysis of a multicenter trial from 2014 to 2020 compared patients treated by mobile stroke unit (MSU) versus standard management. The analytical cohort consisted of participants with suspected stroke treated with intravenous thrombolysis. The main outcome was a tissue-defined averted stroke, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours attributed to thrombolysis and no acute infarction/hemorrhage on imaging. An additional outcome was stroke with early symptom resolution, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours attributed to thrombolysis.

RESULTS

Among 1,009 patients with a median last known well to thrombolysis time of 87 minutes, 159 (16%) had tissue-defined averted stroke and 276 (27%) had stroke with early symptom resolution. Compared with standard management, MSU care was associated with more tissue-defined averted stroke (18% vs 11%, adjusted odds ratio [aOR] = 1.82, 95% confidence interval [CI] = 1.13-2.98) and stroke with early symptom resolution (31% vs 21%, aOR = 1.74, 95% CI = 1.12-2.61). The relationships between thrombolysis treatment time and averted/early recovered stroke appeared nonlinear. Most models indicated increased odds for stroke with early symptom resolution but not tissue-defined averted stroke with earlier treatment. Additionally, younger age, female gender, hyperlipidemia, lower National Institutes of Health Stroke Scale, lower blood pressure, and no large vessel occlusion were associated with both tissue-defined averted stroke and stroke with early symptom resolution.

INTERPRETATION

In optimized stroke systems, 1 in 4 patients treated with thrombolysis recovered within 24 hours and 1 in 6 had no demonstrable brain injury on imaging. ANN NEUROL 2024;95:347-361.

Outcomes of patients with pre-existing disability managed by mobile stroke units: A sub-analysis of the BEST-MSU study

BACKGROUND

Few data exist on acute stroke treatment in patients with pre-existing disability (PD) since they are usually excluded from clinical trials. A recent trial of mobile stroke units (MSUs) demonstrated faster treatment and improved outcomes, and included PD patients.

AIM

To determine outcomes with tissue plasminogen activator (tPA), and benefit of MSU versus management by emergency medical services (EMS), for PD patients.

METHODS

Primary outcomes were utility-weighted modified Rankin Scale (uw-mRS). Linear and logistic regression models compared outcomes in patients with versus without PD, and PD patients treated by MSU versus standard management by EMS. Time metrics, safety, quality of life, and health-care utilization were compared.

RESULTS

Of the 1047 tPA-eligible ischemic stroke patients, 254 were with PD (baseline mRS 2-5) and 793 were without PD (baseline mRS 0-1). Although PD patients had worse 90-day uw-mRS, higher mortality, more health-care utilization, and worse quality of life than non-disabled patients, 53% returned to at least their baseline mRS, those treated faster had better outcome, and there was no increased bleeding risk. Comparing PD patients treated by MSU versus EMS, 90-day uw-mRS was 0.42 versus 0.36 (p = 0.07) and 57% versus 46% returned to at least their baseline mRS. There was no interaction between disability status and MSU versus EMS group assignment (p = 0.67) for 90-day uw-mRS.

CONCLUSION

PD did not prevent the benefit of faster treatment with tPA in the BEST-MSU study. Our data support inclusion of PD patients in the MSU management paradigm.

Rapid Activation of Neuroinflammation in Stroke: Plasma and Extracellular Vesicles Obtained on a Mobile Stroke Unit

BACKGROUND

Neuroinflammation is ubiquitous in acute stroke and worsens outcome. However, the precise timing of the inflammatory response is unknown, hindering the design of acute anti-inflammatory therapeutic interventions. We sought to identify the onset of the neuroinflammatory cascade using a mobile stroke unit.

METHODS

The study is a proof-of-concept, cohort investigation of ultra-early blood- and extracellular vesicle-derived markers of neuroinflammation and outcome in acute stroke. Blood was obtained, prehospital, on an mobile stroke unit. Outcomes were biomarker concentrations, modified Rankin Scale score, and National Institutes of Health Stroke Scale score.

RESULTS

Forty-one adults were analyzed, including 15 patients treated on the mobile stroke unit between August 2021 and April 2022, and 26 healthy controls to establish biomarker reference levels. Median patient age was 74 (range, 36-97) years, 60% were female, and 80% White. Ten (67%) were diagnosed as stroke, with 8 (53%) confirmed and 2 likely transient ischemic attack or stroke averted by thrombolysis; 5 were stroke mimics. For strokes, median initial National Institutes of Health Stroke Scale score was 11 (range, 4-19) and 6 (75%) received tPA (tissue-type plasminogen activator). Blood was obtained a median of 58 (range, 36-133) minutes after symptom onset. Within 36 minutes after stroke, plasma IL-6 (interleukin-6), neurofilament light chain, UCH-L1 (ubiquitin C-terminal hydrolase L1), and GFAP (glial fibrillary acidic protein) were elevated by as much as 10 times normal. In EVs, MMP-9 (matrix metalloproteinase-9), CXCL4 (chemokine (C-X-C motif) ligand 4), CRP (C-reactive protein), IL-6, OPN (osteopontin), and PECAM1 (platelet and endothelial cell adhesion molecule 1) were elevated. Inflammatory markers increased rapidly in the first 2 hours and continued rising for 24 hours.

CONCLUSIONS

The neuroinflammatory cascade was found to be activated within 36 to 133 minutes after stroke and progresses rapidly. This is earlier than observed previously in humans and suggests injury from neuroinflammation occurs faster than had been surmised. These findings could inform development of acute immunomodulatory stroke therapies and lead to new diagnostic tools and improved outcomes.

Golden Hour Treatment With tPA (Tissue-Type Plasminogen Activator) in the BEST-MSU Study

BACKGROUND

Treatment of patients with acute ischemic stroke on mobile stroke units (MSUs) improves outcomes compared with management by standard emergency medical services ambulances and is associated with more patients treated with intravenous tPA (tissue-type plasminogen activator) in the first golden hour after last known normal. We explored the predictors and outcomes of first-hour treatment (FHT) compared with later treatment in an alternating-week cluster-controlled trial of MSUs.

METHODS

We analyzed all patients treated with intravenous tPA in the BEST-MSU Study (Benefits of Stroke Treatment Delivered by a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services). After stratifying by treatment timeframe, we identified factors associated with FHT. We performed adjusted analyses of the association between FHT and clinical outcome and modeled the shape of the relationship between last known normal-to-treatment time and excellent outcome.

RESULTS

Among 941 tPA-treated patients, 206 (21.8%) had lytic started within 60 minutes. Treatment on the MSU, older age, male sex, alert by 911, faster arrival on-scene and imaging, more severe stroke, atrial fibrillation, and absence of heart failure and pretreatment antihypertensive treatment were associated with FHT. Compared with later treatment, FHT was associated with higher adjusted odds ratio for 90-day modified Rankin Scale score of 0 to 1 (odds ratio, 1.87 [95% CI, 1.25-2.84]; P=0.003). Among FHT patients, 68% achieved a 90-day modified Rankin Scale of 0 or 1 or returned to their baseline status. FHT was not associated with higher risk of hemorrhage and was associated with reduced risk of treating neurovascular mimics.

CONCLUSIONS

FHT almost doubles the odds of excellent clinical outcome without increased risk compared with later treatment, which supports the use of MSUs.

Abstract 17: Ultra-early Activation Of Neuroinflammatory Cascade Following Acute Stroke: Plasma And Extracellular Vesicle Biomarkers From A Mobile Stroke Unit

Background: Neuroinflammation is ubiquitous in acute stroke and worsens outcome. However, the precise timing of the inflammatory response is unknown, hindering the design of acute anti-inflammatory therapeutic interventions. We used a mobile stroke unit (MSU) to identify the onset of the neuroinflammatory cascade within minutes of symptom onset.

Methods: The study is a prospective, cohort investigation of ultra-early blood- and extracellular vesicle (EV)-derived markers of neuroinflammation and outcome in acute stroke. Blood was obtained on the MSU with head CT, and from healthy controls. Plasma biomarkers were analyzed with ELISA, SIMOA and ECL. EVs were isolated with HSP pull down. Confirmed strokes, mimics and healthy controls were compared. Variables included demographics, mRS, NIHSS and discharge disposition.

Results: Forty one adults were analyzed, including 15 patients treated on the MSU between August 2021 and April 2022, and 26 controls. For MSU patients, median age was 74 (range 36-97) years, 60% were female, and 80% white. Ten (67%) were diagnosed as stroke, with 8 (53%) confirmed and 2 likely TIA or stroke averted by thrombolysis; 5 were stroke mimics. For strokes, median initial NIHSS score was 11 (range 4-19) and 6 (75%) received tPA. Blood was obtained a median of 58 (range 36-133) minutes after symptom onset. Within 36 minutes after stroke, plasma interleukin-6 (IL-6), neurofilament light chain (NfL), ubiquitin C-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein (GFAP) were elevated by as much as 10 times normal. In EVs, matrix metalloproteinase-9 (MMP-9), chemokine (C-X-C motif) ligand 4 (CXCL4), C-reactive protein (CRP), IL-6, osteopontin (OPN) and platelet and endothelial cell adhesion molecule 1 (PECAM1) were elevated. Inflammatory markers increased rapidly in the first two hours, and continued rising for 24 hours.

Conclusions: This study found the inflammatory cascade is activated as early as 36 minutes after stroke, and progresses rapidly. This is earlier than observed previously in humans, and suggests injury from neuroinflammation may occur faster than had been surmised. The findings may inform development of immunomodulatory therapies for acute stroke, and lead to new diagnostic tools and improved outcomes.

Abstract WMP2: Acute Stroke Treatment In Patients With Pre-exiting Disability: A Secondary Analysis Of The BEST-MSU Trial

Background: Few data exists on acute stroke treatment in patients with pre-existing disability (PD) since they are usually excluded from clinical trials.

Methods: A pre-specified subgroup analysis of tPA-eligible patients with PD enrolled in a prospective multicenter trial of Mobile Stroke Units (MSUs) vs standard management by emergency medical services (EMS). All patients had baseline mRS scores. Co-primary outcomes were mean utility-weighted modified Rankin Scale score (uw-mRS) and return to baseline mRS at 90 days. Linear and logistic regression models compared outcomes in patients with vs without PD, and patients with PD treated by MSU vs EMS. Time metrics, safety, quality of life, and health-care utilization were also compared.

Results: Of 1047 patients, 254 had baseline mRS >= 2 (159 MSU, 95 EMS; 31% mRS 2, 52% mRS 3, 17% mRS 4). Compared to patients without disability, patients with PD were older, had higher NIHSS, more comorbidities, less often lived at home, were treated slower, and had less thrombectomy. Patients with PD had worse 90-day uw-mRS (0.39 vs 0.80), higher mortality, more health-care utilization and worse quality of life than patients without PD. However, rates of symptomatic intracranial hemorrhage and final diagnoses of stroke mimics were similar between groups, and 52% of patients with PD returned to their baseline mRS. Patients with PD treated within the first hour had better 90-day uw-mRS than those treated later (0.48 vs 0.36, p=0.01). Comparing patients with PD treated by MSU vs EMS, time from last-known-well to tPA bolus was shorter (82 vs 111 min), and 24% vs 0% were treated in the first hour. Among patients with PD, MSU patients had non-significantly better 90-day uw-mRS (0.41 vs 0.35, p=0.09) and higher rate of returning to baseline mRS (56% vs 44%, p=0.09) than EMS patients. There was no interaction between either time to treatment (p=0.24) or MSU vs EMS group assignment (p= 0.42), 90-day uw-mRS, and PD vs no disability status.

Conclusion: Although outcomes after stroke are less favorable in patients with vs without PD, in a large, controlled trial, we found no interaction between baseline disability and the benefit of MSU treatment. Our data support the earliest treatment of acute stroke patients regardless of premorbid functional status.

Prospective, Multicenter, Controlled Trial of Mobile Stroke Units

BACKGROUND

Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied.

METHODS

In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients.

RESULTS

We enrolled 1515 patients, of whom 1047 were eligible to receive t-PA; 617 received care by MSU and 430 by EMS. The median time from onset of stroke to administration of t-PA was 72 minutes in the MSU group and 108 minutes in the EMS group. Of patients eligible for t-PA, 97.1% in the MSU group received t-PA, as compared with 79.5% in the EMS group. The mean score on the utility-weighted modified Rankin scale at 90 days in patients eligible for t-PA was 0.72 in the MSU group and 0.66 in the EMS group (adjusted odds ratio for a score of ≥0.91, 2.43; 95% confidence interval [CI], 1.75 to 3.36; P<0.001). Among the patients eligible for t-PA, 55.0% in the MSU group and 44.4% in the EMS group had a score of 0 or 1 on the modified Rankin scale at 90 days. Among all enrolled patients, the mean score on the utility-weighted modified Rankin scale at discharge was 0.57 in the MSU group and 0.51 in the EMS group (adjusted odds ratio for a score of ≥0.91, 1.82; 95% CI, 1.39 to 2.37; P<0.001). Secondary clinical outcomes generally favored MSUs. Mortality at 90 days was 8.9% in the MSU group and 11.9% in the EMS group.

CONCLUSIONS

In patients with acute stroke who were eligible for t-PA, utility-weighted disability outcomes at 90 days were better with MSUs than with EMS. (Funded by the Patient-Centered Outcomes Research Institute; BEST-MSU ClinicalTrials.gov number, NCT02190500.).

Mobile Stroke Unit Reduces Time to Image Acquisition and Reporting

Timely administration of thrombolytic therapy is critical to maximizing the likelihood of favorable outcomes in patients with acute ischemic stroke. Although emergency medical service activation overall improves the timeliness of acute stroke treatment, the time from emergency medical service dispatch to hospital arrival unavoidably decreases the timeliness of thrombolytic administration. Our mobile stroke unit, a new-generation ambulance with on-board CT scanning capability, reduces key imaging time metrics and facilitates in-the-field delivery of IV thrombolytic therapy.

Abstract WP234: Improved Response, Neurologic Evaluation, and Treatment Timing With a Mobile Stroke Unit in a Large Urban Population

Background: The University of Colorado Mobile Stroke Unit (UC MSU) began clinical operation in January 2016, providing ambulance-mounted CT scanning and tele-stroke neurologic assessment in the Denver, CO, metropolitan area. As one of the first U.S. tertiary stroke centers to utilize a mobile stroke protocol we sought to evaluate characteristics of response, neurologic evaluation, and treatment of the MSU.

Methods: The study assessed patient, stroke, ambulance response, neurologic evaluation, and treatment characteristics of the UC MSU for its initial year in service. Variables included time from stroke alert (MSU dispatch) to brain CT in the field, treatment decision, tPA administration, and transport to a hospital stroke center. Time intervals from last seen normal were calculated for all patients. Study variables were compared for patients treated with thrombolysis on the MSU, and those who were not; and with reported times for other MSUs, and hospitals.

Results: Between Jan. 15, 2016 and Jan. 9, 2017, 47 individuals received prehospital management with the UC MSU. Median age was 67 years (IQR 58-77), and 51% were female. Median initial NIH Stroke Scale score was 5 (IQR 2-11), and 36% were moderate to severe (NIHSS ≥8). Thirteen (28%) of patients were treated with IV tPA on the MSU. Median times from stroke alert to MSU arrival on the scene and first CT were 7 minutes (IQR 5-8), and 20 minutes (IQR 18-24), respectively. Median time to tPA administration was 39 minutes (IQR 35-45) from stroke alert, and 52 minutes (IQR 48-77) from the last time the patient was seen normal. Times from stroke alert and last seen normal to arrival at a stroke hospital were a median of 51 minutes (IQR 45-54) and 71 minutes (IQR 56-118), respectively.

Conclusions: In this study of the initial year of an urban MSU’s operation, time intervals from stroke alert to initial brain CT imaging, neurologic evaluation and administration of thrombolysis were found to be substantially reduced compared to conventional, hospital-based stroke protocols, and some earlier MSUs. Intervals from last seen normal to these procedure time points were similarly reduced. These results suggest prehospital management with an MSU has potential to aid the goal of earlier thrombolysis after ischemic stroke symptom onset.

Abstract TMP72: Technological Innovation in a Mobile Stroke Treatment Unit

Background: University of Colorado Hospital, under the UCHealth system, developed a Mobile Stroke Unit (UCHealth MSU) which began clinical operation in January 2016 and added a second operational location in August 2016. As one of the first centers to institute ambulance-mounted brain imaging and neurologic evaluation and treatment in the field for acute stroke in the U.S., it was necessary to design unique, dynamic IT systems for operationalizing the MSU. These include high speed cellular, HIPAA-compliant cloud based environments and remote access to patient electronic medical records (EMR) and a reliable means for rapid image transfer. Here we describe novel technologies engineered and incorporated into the UCHealth MSU.

Methods: Technological data-handling aspects of the UCHealth MSU were reviewed. Functions evaluated included wireless connectivity while in transit, EMR capability in the field, computed tomography (CT) scanning and image transfer, and communications for tele-stroke neurologic assessment.

Results: The UCHealth MSU began clinical operation in January 2016, Wireless communications were designed with redundancy to avoid dropped signals during data transfer. Two IP destinations were assigned for videoconferencing and EMR data transfer, with split-tunnel architecture to direct traffic to each. Placement of the MSU antenna inside the unit reduced interference from home and business Wi-Fi routers encountered. Brain imaging acquired in the ambulance CT scanner is transferred initially to an onboard laptop, then via Citrix Receiver to a hospital-based server and can be visualized by the stroke neurologist, neuroradiologist and all other care providers. Picture Archiving Communications System (PACS) and Radiology Information System (RIS) are two of the XenApps used by CT technologists.

Conclusions: Technological hurdles associated with remote imaging, assessment, and treatment, are critical to overcome if time-saving benefits of mobile stroke protocols are to be recognized. Innovative and unique techniques developed to accommodate wireless communication and image transfer from the field in the UCHealth MSU may aid start-up of similar units elsewhere and serve as a framework to further improve this technology.

Benefits of stroke treatment delivered using a mobile stroke unit trial

Rationale

Mobile stroke units speed treatment for acute ischemic stroke, thereby possibly improving outcomes.

Aim

To compare mobile stroke unit and standard management clinical outcomes, healthcare utilization, and cost-effectiveness in tissue plasminogen activator-eligible acute ischemic stroke patients calling 911.

Sample size

693. Eighty percent power with 0.05 type I error rate to detect a difference of 0.09 in mean utility-weighted modified Rankin scale between groups.

Design

Phase III, multicenter, prospective cluster-randomized (mobile stroke unit versus standard management weeks) comparative effectiveness study in tissue plasminogen activator-eligible patients.

Outcomes

Primary: Ninety-day mean utility-weighted modified Rankin scale. Coprimary: cost-effectiveness based on EQ5D quality of life and one year poststroke costs.

Analysis

Two-sample t-test and linear regression adjusting for covariates; incremental cost-effectiveness ratio and net benefit regression.

Results

As of March 2017, 288 tissue plasminogen activator-eligible patients have been enrolled (173 in the mobile stroke unit arm and 115 in the standard management arm). Two new centers start in early 2017 with target end of recruitment September 2019.

Conclusion

This is the first randomized study to test for disability, healthcare utilization, and cost-effectiveness of a mobile stroke unit. The progress of the study suggests that it is feasible. Management of tissue plasminogen activator eligible acute ischemic stroke patients by a mobile stroke unit could potentially result in less disability and healthcare utilization, and be cost effective. Mobile stroke units are very costly. This trial may determine if the fixed cost can be justified by a reduction in disability and healthcare utilization.

Clinical Trial Registration

NCT02190500.

Ontogenetic variation in epibiont community structure in the deep-sea yeti crab, Kiwa puravida: convergence among crustaceans

Recent investigations have demonstrated that unusually 'hairy' yeti crabs within the family Kiwaidae associate with two predominant filamentous bacterial families, the Epsilon and Gammaproteobacteria. These analyses, however, were based on samples collected from a single body region, the setae of pereopods. To more thoroughly investigate the microbiome associated with Kiwa puravida, a yeti crab species from Costa Rica, we utilized barcoded 16S rRNA amplicon pyrosequencing, as well as microscopy and terminal restriction fragment length polymorphism analysis. Results indicate that, indeed, the bacterial community on the pereopods is far less diverse than on the rest of the body (Shannon indices ranged from 1.30-2.02 and 2.22-2.66, respectively). Similarly, the bacterial communities associated with juveniles and adults were more complex than previously recognized, with as many as 46 bacterial families represented. Ontogenetic differences in the microbial community, from egg to juvenile to adult, included a dramatic under-representation of the Helicobacteraceae and higher abundances of both Thiotrichaceae and Methylococcaceae for the eggs, which paralleled patterns observed in another bacteria-crustacean symbiosis. The degree to which abiotic and biotic feedbacks influence the bacterial community on the crabs is still not known, but predictions suggest that both the local environment and host-derived factors influence the establishment and maintenance of microbes associated with the surfaces of aquatic animals.

Dancing for food in the deep sea: bacterial farming by a new species of Yeti crab

Vent and seep animals harness chemosynthetic energy to thrive far from the sun's energy. While symbiont-derived energy fuels many taxa, vent crustaceans have remained an enigma; these shrimps, crabs, and barnacles possess a phylogenetically distinct group of chemosynthetic bacterial epibionts, yet the role of these bacteria has remained unclear. We test whether a new species of Yeti crab, which we describe as Kiwa puravida n. sp, farms the epibiotic bacteria that it grows on its chelipeds (claws), chelipeds that the crab waves in fluid escaping from a deep-sea methane seep. Lipid and isotope analyses provide evidence that epibiotic bacteria are the crab's main food source and K. puravida n. sp. has highly-modified setae (hairs) on its 3(rd) maxilliped (a mouth appendage) which it uses to harvest these bacteria. The ε- and γ- proteobacteria that this methane-seep species farms are closely related to hydrothermal-vent decapod epibionts. We hypothesize that this species waves its arm in reducing fluid to increase the productivity of its epibionts by removing boundary layers which may otherwise limit carbon fixation. The discovery of this new species, only the second within a family described in 2005, stresses how much remains undiscovered on our continental margins.

Inhibitors of Ketohexokinase: Discovery of Pyrimidinopyrimidines with Specific Substitution that Complements the ATP-Binding Site

Attenuation of fructose metabolism by the inhibition of ketohexokinase (KHK; fructokinase) should reduce body weight, free fatty acids, and triglycerides, thereby offering a novel approach to treat diabetes and obesity in response to modern diets. We have identified potent, selective inhibitors of human hepatic KHK within a series of pyrimidinopyrimidines (1). For example, 8, 38, and 47 exhibited KHK IC50 values of 12, 7, and 8 nM, respectively, and also showed potent cellular KHK inhibition (IC50 < 500 nM), which relates to their intrinsic potency vs KHK and their ability to penetrate cells. X-ray cocrystal structures of KHK complexes of 3, 8, and 47 revealed the important interactions within the enzyme's adenosine 5'-triphosphate (ATP)-binding pocket.

Sensitivity and specificity of stroke symptom questions to detect stroke or transient ischemic attack

BACKGROUND/AIMS

Undiagnosed stroke is a major public health problem. The Questionnaire for Verifying Stroke-Free Status (QVSS) includes eight items and was originally designed to detect stroke-free individuals. Its six symptom-related questions could potentially be used to screen for undiagnosed stroke or transient ischemic attack (TIA), but the sensitivity and specificity of just the six symptom-related questions are unknown.

METHODS

A research assistant administered the QVSS to outpatients from Veterans Administration stroke and general medicine clinics. Neurologists, blinded to QVSS scores, interviewed and examined all subjects to determine stroke status. Responses to the six symptom questions of the QVSS were compared against the neurologist-determined stroke/TIA status.

RESULTS

The sensitivity of the individual symptom questions ranged from 0.22 to 0.60, and the specificity ranged from 0.79 to 0.95. The sensitivity of any of the six symptom questions was 0.82, and the specificity was 0.62.

CONCLUSION

The six symptom-related questions of the QVSS demonstrate a high sensitivity and moderate specificity for the diagnosis of stroke or TIA compared with neurological exam. Though these findings should be validated in a more representative general population, these questions have potential for meeting the public health objective of detecting clinically unrecognized but symptomatic stroke.

Quality of Care for In-Hospital Stroke

Background and Purpose—

Approximately 4% to 17% of all adult strokes have onset in the hospital. Previous research indicates significant in-hospital evaluation delays and lower adherence to some measures of quality care compared to out-of-hospital strokes.

Methods—

Quality of care for in-hospital ischemic strokes compared to stroke with out-of-hospital onset was examined using cohort analysis of a statewide stroke database maintained by the Colorado Stroke Alliance.

Results—

One-hundred sixteen in-hospital strokes were compared to 4946 out-of-hospital strokes. Patients with in-hospital strokes were significantly more likely to have history of coronary artery disease (36.7% vs 26.5%; P =0.02), and in-hospital strokes were more severe (NIHSS score 9.5 vs 7.0; P =0.01). Time to brain imaging was not significantly different (54 minutes vs 43 minutes; P =0.13) between groups. Patients with in-hospital stroke were significantly more likely to have documentation of stroke education (90.4% vs 73.1%; P =0.0002) and assessment for rehabilitation (67.7% vs 45.2%; P <0.0001). Total deficit-free care defined as adherence to all Get With the Guidelines Stroke (GWTG-Stroke) measures was better for in-hospital strokes compared to strokes in the community (52.8% vs 32.3%; P <0.0001).

Conclusions—

Adherence to GWTG-Stroke performance measures was better for in-hospital strokes in this statewide registry. Variability in reporting by participating hospitals suggests in-hospital strokes are under-recognized or under-reported. In-hospital stroke evaluation times remain more than twice the recommended benchmark of 25 minutes, representing an opportunity for process improvement.

Populations of methane-producing bacteria and in vitro methanogenesis in salt marsh and estuarine sediments

Most probable numbers (MPNs) of methanogens in various salt marsh and estuarine sediments were determined with an anaerobic, habitat-simulating culture medium with 80% H(2) plus 20% CO(2) as substrate. Average MPNs for the short Spartina (SS) marsh sediments of Sapelo Island, Ga., were maximal at the 5- to 7-cm depth (1.2 x 10/g of dry sediment). Populations decreased to approximately 880/g of dry sediment at the 34- to 36-cm depth. There was no significant difference between summer and winter populations. In tall Spartina (TS) marsh sediments, average populations were maximal (1.2 x 10/g of dry sediment) in the upper 0- to 2-cm zone; populations from the 5- to 36-cm zones were similar (average of 9 x 10/g of dry sediment). Methanogenic populations for TS sediments of James Island Creek marsh, Charleston, S.C., were similar (average of 3 x 10/g of dry sediment) for all depths tested (0 to 22 cm), which was comparable to the trend observed for TS sediments at Sapelo Island, Ga. Sediment grab samples collected along a transect of James Island Creek and its adjacent Spartina marsh had MPNs that were approximately 20 times greater for the region of Spartina growth (average of 10/g of dry sediment) compared with the channel (approximately 5 x 10 methanogens per g of dry sediment). A similar trend was found at Pawley's Island marsh, S.C., but populations were approximately one order of magnitude lower. In vitro rates of methanogenesis with SS sediments incubated under 80% H(2)-20% CO(2) showed that the 5- to 7-cm region exhibited maximal activity (51 nmol of CH(4) g h), which was greater than rates for sediments above and below this depth. SS sediment samples (5 to 7 cm) incubated under 100% N(2) and supplemented with formate exhibited rates of methanogenesis similar to those generated by samples under 80% H(2)-20% CO(2). Replacing the N(2) atmosphere with H(2) resulted in an eightfold decrease in the rate of methanogenesis. In vitro methanogenic activity by TS salt marsh sediments, incubated under 80% H(2)-20% CO(2), was similar for all depths tested (0 to 22 cm). TS sediment samples (0 to 7 cm) supplemented with formate and incubated under 100% N(2) had greater rates of methanogenesis compared with unsupplemented samples.

Methanogenesis from sucrose by defined immobilized consortia

A bacterial consortium capable of sucrose degradation primarily to CH(4) and CO(2) was constructed, with acetate as the key methanogenic precursor. In addition, the effect of agar immobilization on the activity of the consortium was determined. The primary fermentative organism, Escherichia coli, produced acetate, formate, H(2), and CO(2) (known substrates for methanogens), as well as ethanol and lactate, compounds that are not substrates for methanogens. Oxidation of the nonmethanogenic substrates, lactate and ethanol, to acetate was mediated by the addition of Acetobacterium woodii and Desulfovibrio vulgaris. The methanogenic stage was accomplished by the addition of the acetophilic methanogen Methanosarcina barkeri and the hydrogenophilic methanogen Methanobacterium formicicum. Results of studies with low substrate concentrations (0.05 to 0.2% [wt/vol]), a growth-limiting medium, and the five-component consortium indicated efficient conversion (40%) of sucrose carbon to CH(4). Significant decreases in yields of CH(4) and rates of CH(4) production were observed if any component of the consortium was omitted. Approximately 70% of the CH(4) generated occurred via acetate. Agar-immobilized cells of the consortium exhibited yields of CH(4) and rates of CH(4) production from sucrose similar to those of nonimmobilized cells. The rate of CH(4) production decreased by 25% when cysteine was omitted from reaction conditions and by 40% when the immobilized consortium was stored for 1 week at 4 degrees C.

Stroke alert program improves recognition and evaluation time of in-hospital ischemic stroke

An inpatient stroke alert program is effective in decreasing evaluation time for in-hospital strokes, although response times remain significantly longer than those in the emergency department. It is capable of increasing the percentage of ischemic strokes identified by the hospital's stroke team, at the cost of an increased percentage of false alarms.

A core gut microbiome in obese and lean twins

The human distal gut harbours a vast ensemble of microbes (the microbiota) that provide important metabolic capabilities, including the ability to extract energy from otherwise indigestible dietary polysaccharides. Studies of a few unrelated, healthy adults have revealed substantial diversity in their gut communities, as measured by sequencing 16S rRNA genes, yet how this diversity relates to function and to the rest of the genes in the collective genomes of the microbiota (the gut microbiome) remains obscure. Studies of lean and obese mice suggest that the gut microbiota affects energy balance by influencing the efficiency of calorie harvest from the diet, and how this harvested energy is used and stored. Here we characterize the faecal microbial communities of adult female monozygotic and dizygotic twin pairs concordant for leanness or obesity, and their mothers, to address how host genotype, environmental exposure and host adiposity influence the gut microbiome. Analysis of 154 individuals yielded 9,920 near full-length and 1,937,461 partial bacterial 16S rRNA sequences, plus 2.14 gigabases from their microbiomes. The results reveal that the human gut microbiome is shared among family members, but that each person's gut microbial community varies in the specific bacterial lineages present, with a comparable degree of co-variation between adult monozygotic and dizygotic twin pairs. However, there was a wide array of shared microbial genes among sampled individuals, comprising an extensive, identifiable 'core microbiome' at the gene, rather than at the organismal lineage, level. Obesity is associated with phylum-level changes in the microbiota, reduced bacterial diversity and altered representation of bacterial genes and metabolic pathways. These results demonstrate that a diversity of organismal assemblages can nonetheless yield a core microbiome at a functional level, and that deviations from this core are associated with different physiological states (obese compared with lean).

Marine worms (genus Osedax) colonize cow bones

Bone-eating worms of the genus Osedax colonized and grew on cow bones deployed at depths ranging from 385 to 2893m in Monterey Bay, California. Colonization occurred as rapidly as two months following deployment of the cow bones, similar to the time it takes to colonize exposed whalebones. Some Osedax females found on the cow bones were producing eggs and some hosted dwarf males in their tubes. Morphological and molecular examinations of these worms confirmed the presence of six Osedax species, out of the eight species presently known from Monterey Bay. The ability of Osedax species to colonize, grow and reproduce on cow bones challenges previous notions that these worms are 'whale-fall specialists.'

Acquisition of dwarf male "harems" by recently settled females of Osedax roseus n. sp. (Siboglinidae; Annelida)

After the deployment of several whale carcasses in Monterey Bay, California, a time-series analysis revealed the presence of a new species of Osedax, a genus of bone-eating siboglinid annelids. That species is described here as Osedax roseus n. sp. It is the fifth species described since the erection of this genus and, like its congeners, uses a ramifying network of "roots" to house symbiotic bacteria. In less than 2 months, Osedax roseus n. sp. colonized the exposed bones of a whale carcass deposited at 1018-m depth, and many of the females were fecund in about 3 months post-deployment. As with other Osedax spp., the females have dwarf males in their tube lumens. The males accrue over time until the sex ratio is markedly male-biased. This pattern of initial female settlement followed by gradual male accumulation is consistent with the hypothesis that male sex may be environmentally determined in Osedax. Of the previously described species in this genus, Osedax roseus n. sp. is most similar to O. rubiplumus, but it has several anatomical differences, as well as much smaller females, dwarf males, and eggs. Osedax roseus n. sp. is markedly divergent (minimally 16.6%) for mitochondrial cytochrome oxidase subunit I (mtCOI) sequences from any other Osedax species.

Biotransformation of geldanamycin and 17-allylamino-17-demethoxygeldanamycin by human liver microsomes: reductive versus oxidative metabolism and implications

Comparative metabolite profiling of geldanamycin and 17-allylamino-17-demethoxygeldanamycin (17AAG) using human liver microsomes in normoxia and hypoxia was conducted to understand their differential metabolic fates. Geldanamycin bearing a 17-methoxy group primarily underwent reductive metabolism, generating the corresponding hydroquinone under both conditions. The formed hydroquinone resists further metabolism and serves as a reservoir. On exposure to oxygen, this hydroquinone slowly reverts to geldanamycin. In the presence of glutathione, geldanamycin was rapidly converted to 19-glutathionyl geldanamycin hydroquinone, suggesting its reactive nature. In contrast, the counterpart (17AAG) preferentially remained as its quinone form, which underwent extensive oxidative metabolism on both the 17-allylamino sidechain and the ansa ring. Only a small amount (<1%) of 19-glutathione conjugate of 17AAG was detected in the incubation of 17AAG with glutathione at 37 degrees C for 60 min. To confirm the differential nature of quinone-hydroquinone conversion between the two compounds, hypoxic incubations with human cytochrome P450 reductase at 37 degrees C and direct injection analysis were performed. Approximately 89% of hydroquinone, 5% of quinone, and 6% of 17-O-demethylgeldanamycin were observed after 1-min incubation of geldanamycin, whereas about 1% of hydroquinone and 99% of quinone were found in the 60-min incubation of 17AAG. The results provide direct evidence for understanding the 17-substituent effects of these benzoquinone ansamycins on their phase I metabolism, reactivity with glutathione, and acute hepatotoxicity.

Dihydroquinone ansamycins: toward resolving the conflict between low in vitro affinity and high cellular potency of geldanamycin derivatives

Heat shock protein 90 (Hsp90) is critical for the maturation of numerous client proteins, many of which are involved in cellular transformation and oncogenesis. The ansamycins, geldanamycin (GA) and its derivative, 17-allylaminogeldanamycin (17-AAG), inhibit Hsp90. As such, the prototypical Hsp90 inhibitor, 17-AAG, has advanced into clinical oncology trials. GA and 17-AAG potently inhibit tumor cell proliferation and survival but have been reported to bind weakly to Hsp90 in vitro. Recent studies have suggested that the in vitro potency of ansamycins against Hsp90 may be enhanced in the presence of cochaperones. Here, we present evidence of an alternative explanation. Ansamycins reduced to their dihydroquinones in the presence of common reducing agents in vitro have approximately 40-fold greater affinity than the corresponding oxidized quinones. The dihydroquinone of 17-AAG is not generated in an aqueous environment in the absence of reducing agents but is produced in both tumor and normal quiescent epithelial cells. The reduced form of 17-AAG is differentiated from its oxidized form not only by the higher affinity for Hsp90 but also by a protracted K(off) rate. Therefore, the in vivo accumulation of the high-affinity dihydroquinone ansamycins in tumor cells contributes to the antitumor activity of these compounds and alters our understanding of the active species driving the efficacy of this class of compounds.

Distribution and metabolism of the antipsychotic agent mazapertine succinate in rats

The pharmacokinetics and drug disposition of 14C 1-[3-[[4-[2-(1-methylethoxy)phenyl]-1-piperazinyl]methyl]benzoy]piperidine succinate (RWJ-37796, mazapertine, Mz) have been investigated in male and female Sprague-Dawley rats. Approximately 93% of the orally administered radioactive dose (30 mg/kg) was recovered after 7 days. Fecal elimination accounted for approximately 63% of the dose while urine accounted for 30%. The rate of elimination of 14C Mz was rapid with 81% of the total fecal and 94% of the total urinary radioactivity being excreted within 24 h. There were no significant gender differences in the overall excretion pattern. The maximal plasma concentration of Mz and total radioactivity occurred at 0.5h after dosing and plasma concentrations were consistently higher in female rats. The Mz concentration declined rapidly in plasma with a terminal half-life<2 h. The total radioactive dose in plasma displayed a considerably longer terminal half-life of 9-13 h. Mz and a total of 15 metabolites were isolated and identified in these samples. Unchanged Mz accounted for <5% of the radioactive dose in excreta samples and <8% of the sample in plasma (0-24 h). Metabolites were formed by phenyl hydroxylation, piperidyl oxidation, O-dealkylation, N-dephenylation, oxidative N-debenzylation and glucuronide conjugation.

Migration, isolation, and speciation of hydrothermal vent limpets (Gastropoda; Lepetodrilidae) across the Blanco Transform Fault

The Sovanco Fracture Zone and Blanco Transform Fault separate the Explorer, Juan de Fuca, and Gorda ridge systems of the northeastern Pacific Ocean. To test whether such offsets in the ridge axis create barriers to along-axis dispersal of the endemic hydrothermal vent animals, we examined the genetic structure of limpet populations previously identified as Lepetodrilus fucensis McLean, 1988 (Gastropoda, Lepetodrilidae). Mitochondrial DNA sequences and patterns of allozyme variation revealed no evidence that the 150-km-long Sovanco Fracture Zone impeded gene flow between the Explorer and Juan de Fuca populations. In contrast, the 450-km-long Blanco Transform Fault separates the limpets into highly divergent northern and southern lineages that we recognize as distinct species. We describe southern populations from the Gorda Ridge (Seacliff) and Escanaba Trough as Lepetodrilus gordensis new species and refer northern populations from the Explorer and Juan de Fuca ridge systems to L. fucensis sensu stricto. The species are similar morphologically, but L. gordensis lacks a sensory neck papilla and has a more tightly coiled teleconch. To assess the degree of isolation between these closely related species, we used the Isolation with Migration method to estimate the time of population splitting, effective sizes of the ancestral and derived populations, and rates of migration across the Blanco Transform Fault.

Molecular detection of marine invertebrate larvae

The ecological patterns of many invertebrate larvae remain an ongoing mystery, in large part owing to the difficult task of detecting them in the water column. The development of nucleic-acid-based technology has the potential to resolve this issue by direct identification and monitoring of embryonic and larval forms in situ. We report herein on the successful development and application of nucleic-acid-based sandwich hybridization assays that detect barnacles using rRNA-targeted probes with both group-(order Thoracica) and species-(Balanus glandula) specificity. Primary results include the determination of target 18S rRNA sequences and the construction of "capture" probes for detection of larvae using hybridization techniques. In addition, we modified existing protocols for whole cell hybridization of invertebrate larvae as confirmation of the sandwich hybridization results. We used both hybridization techniques successfully in the laboratory on a plankton time series collected over 3 months, as well as a week-long in situ deployment of the technique in Monterey Bay, CA. The adaptability of this technology promises to be further applicable to various organisms and could be used to enhance our understanding of larval presence in the world's oceans.

N-GLUCURONIDATION OF THE PLATELET-DERIVED GROWTH FACTOR RECEPTOR TYROSINE KINASE INHIBITOR 6,7-(DIMETHOXY-2,4-DIHYDROINDENO[1,2-C]PYRAZOL-3-YL)-(3-FLUORO-PHENYL)-AMINE BY HUMAN UDP-GLUCURONOSYLTRANSFERASES

The potential cancer therapeutic agent, 6,7-(dimethoxy-2, 4-dihydroindeno[1,2-c]pyrazol-3-yl)-(3-fluoro-phenyl)-amine (JNJ-10198409), formed three N-glucuronides that were positively identified by liquid chromatography-tandem mass spectrometry and NMR as N-amine-glucuronide (Glu-A), 1-N-pyrazole-glucuronide (Glu-B), and 2-N-pyrazole-glucuronide (Glu-C). All three N-glucuronides were detected in rat liver microsomes, whereas only Glu-A and -B were found in monkey and human liver microsomes. In contrast to common glucuronides, Glu-B was completely resistant to beta-glucuronidase. Kinetic analyses revealed that glucuronidation of JNJ-10198409 in human liver microsomes exhibited atypical kinetics that may be described by a two-site binding model. For the high affinity binding, K(m) values were 1.2 and 5.0 microM, and V(max) values were 2002 and 2,403 nmol min(-1) mg(-1) for Glu-A and Glu-B, respectively. Kinetic constants of low affinity binding were not determined due to low solubility of the drug. Among the human UDP-glucuronosyltransferases (UGTs) tested, UGT1A9, 1A8, 1A7, and 1A4 were the most active isozymes to produce Glu-A; for the formation of Glu-B, UGT1A9 was the most active enzyme, followed by UGT1A3, 1A7, and 1A4. Glucuronidation of JNJ-10198409 by those UGT1A enzymes followed classic Michaelis-Menten kinetics. In contrast, no glucuronides were formed by all UGT2B isozymes tested, including UGT2B4, 2B7, 2B15, and 2B17. Collectively, these results suggested that glucuronidation of JNJ-10198409 in human liver microsomes is catalyzed by multiple UGT1A enzymes. Since UGT1A enzymes are widely expressed in various tissues, it is anticipated that both hepatic and extrahepatic glucuronidation will likely contribute to the elimination of the drug in humans. Additionally, conjugation at the nitrogens of the pyrazole ring represents a new structural moiety for UGT1A-mediated reactions.

Metabolism and excretion of the antiepileptic/antimigraine drug, topiramate in animals and humans

The metabolism and excretion of 2,3:4,5-bis-O-(1-methylethylidene)-beta-D-fructopyranose sulfamate (TOPAMAX, topiramate, TPM) have been investigated in animals and humans. Radiolabeled [14C] TPM was orally administered to mice, rats, rabbits, dogs and humans. Plasma, urine and fecal samples were collected and analyzed. TPM and a total of 12 metabolites were isolated and identified in these samples. Metabolites were formed by hydroxylation at the 7- or 8-methyl of an isopropylidene of TPM followed by rearrangement, hydroxylation at the 10-methyl of the other isopropylidene, hydrolysis at the 2,3-O-isopropylidene, hydrolysis at the 4,5-O-isopropylidene, cleavage at the sulfamate group, glucuronide conjugation and sulfate conjugation. A large percentage of unchanged TPM was recovered in animal and human urine. The most dominant metabolite of TPM in mice, male rats, rabbits and dogs appeared to be formed by the hydrolysis of the 2,3-O-isopropylidene group.

Outcomes of newly referred neurology outpatients with depression and pain

BACKGROUND

Although depression and pain are common in neurology outpatients, patient factors influencing chronicity are poorly understood. The authors sought to determine the predictors of persistent depression and pain symptoms at 3 and 12 months after an initial outpatient neurology clinic visit.

METHODS

Consecutive new patients (n = 483) at three clinics completed the Patient Health Questionnaire nine-item depression scale and the Brief Pain Inventory at baseline and at 3- and 12-month follow-up. Multivariate analysis was used to model 3- and 12-month depression and pain severity.

RESULTS

The prevalence of depression and pain at baseline/3/12 months was depression 33%/28%/27% and pain 66%/61%/62%. Independent predictors of depression severity at follow-up were more severe depression and pain at baseline and less improvement in pain (model r(2) = 0.53 to 0.56). Independent predictors of pain intensity at follow-up were more severe pain and depression at baseline and less improvement in depression (model r(2) = 0.44 to 0.46). Health care utilization and impairments in health status were greatest in patients with coexisting depression and pain and least in those with neither depression nor pain.

CONCLUSIONS

Depression and pain symptoms in neurology outpatients often persist for at least 12 months and have long-term negative effects on patients' health status. Pain is more likely to persist in patients with depression, and depression is more likely to persist in those with coexistent pain.

Liquid chromatographic and tandem mass spectrometric assay for evaluation of in vivo inhibition of rat brain monoamine oxidases (MAO) A and B following a single dose of MAO inhibitors: application of biomarkers in drug discovery

A simple and selective assay for the evaluation of in vivo inhibition of rat brain monoamine oxidases (MAO) A and B following a single dose of MAO inhibitors was developed through the simultaneous determination of endogenous 5-hydroxy tryptamine, 5-hydroxyindole-3-acetic acid (5-HIAA), tryptophane, and 2-phenethylamine (PEA) in rat brain using liquid chromatography-tandem mass spectrometry (LC/MS/MS). These analytes were separated on a Zorbax SB-C18 column using a gradient elution with acetonitrile and 0.2% formic acid and detected on an electrospray ionization mass spectrometer in positive-ion multiple-reaction-monitoring mode. The susceptibility and variability of these analytes as potential biomarkers in response to MAO inhibition in vivo were evaluated after application to three MAO inhibitors, tranylcypromine, clorgyline, and pargyline. A dramatic increase (about 40-fold) in PEA brain level and a decrease in 5-HIAA by more than 90% were observed after administration of 15 mg/kg of the nonselective MAO inhibitor tranylcypromine. As expected, the brain level of PEA escalated to about 6-fold, while the 5-HIAA level remained unchanged following a dose of the MAO B inhibitor pargyline at 2mg/kg. In contrast, the brain level of 5-HIAA reduced by approximately 53%, but the PEA level was unaffected following the same dose of the MAO A inhibitor clorgyline. The results indicated that 5-HIAA and PEA were susceptible and effective biomarkers in the rat brain in response to MAO A and B inhibition, respectively. The LC/MS/MS method is useful not only for the determination of inhibitory potency but also for the differentiation of the selectivity of a MAO inhibitor against rat brain MAO A and B in vivo.

Prevalence and impact of depression and pain in neurology outpatients

BACKGROUND

We examined the prevalence and health related quality of life (HRQoL) of depression and/or pain in neurology outpatients.

METHODS

Patients at outpatient clinics completed depression, pain, and HRQoL scales. Group comparisons between those with pain alone, depression alone, both conditions, and neither condition were done.

RESULTS

Overall, pain was present in 2/3 and depression in 1/3 of patients. Pain with depression was present in 25%; 75% of depressed patients had pain. These conditions had significant negative impact on mental and physical health status scores. The odds ratio (OR) for having pain was significantly increased in women (OR 2.0), those with depression (OR 2.4), and those with neuropathy/neuromuscular (OR 3.8) or pain syndromes (OR 4.8). The odds of having depression were increased in those with pain (OR 2.4) and with cognitive (OR 4.8) or cerebrovascular (OR 3.3) diagnoses. Neurologists were more likely to recognise and treat pain than depression.

CONCLUSIONS

Depression and pain are common in newly referred neurology outpatients and have substantial negative effects on patients' physical and mental health. Pain is more likely than depression to be recognised and treated by neurologists.

Cone voltage induced in-source dissociation of glucuronides in electrospray and implications in biological analyses

Glucuronidation is a common mechanism in drug metabolism. In-source dissociation of glucuronides in electrospray generates fragment ions identical to those of the precursor ions of the original drugs. The effect of experimental parameters on the process was investigated in the present study using both commercially available compounds and glucuronides generated from microsomal glucuronidation incubations. It was found that cone voltage was the most critical parameter contributing to in-source fragmentation of both O- and N-glucuronides, whereas both the desolvation temperature and the source temperature had little effect. Additionally, the extent of in-source dissociation varied for different glucuronides and could be minimized by lowering cone voltage. As demonstrated in real examples, minimizing in-source dissociation can lead to higher sensitivity in detecting glucuronides in biological samples. In addition, product ions resulting from in-source dissociation of glucuronides potentially interfere with accurate determinations of corresponding drug levels if chromatographic separation is not adequate. For cases in which chromatographic separation of glucuronides from the original drugs is not readily achieved or high-throughput analyses are desired, interference caused by in-source dissociation can usually be eliminated simply by using lower cone voltage. This approach has been proven to be effective in the analysis of more than 100 glucuronides generated from in vitro microsomal incubations.

Analyses of nuclear ldhA gene and mtDNA control region sequences of Atlantic northern bluefin tuna populations

There has been considerable debate about whether the Atlantic northern bluefin tuna exist as a single panmictic unit. We have addressed this issue by examining both mitochondrial DNA control region nucleotide sequences and nuclear gene ldhA allele frequencies in replicate size or year class samples of northern bluefin tuna from the Mediterranean Sea and the northwestern Atlantic Ocean. Pairwise comparisons of multiple year class samples from the 2 regions provided no evidence for population subdivision. Similarly, analyses of molecular variance of both mitochondrial and ldhA data revealed no significant differences among or between samples from the 2 regions. These results demonstrate the importance of analyzing multiple year classes and large sample sizes to obtain accurate estimates when using allele frequencies to characterize a population. It is important to note that the absence of genetic evidence for population substructure does not unilaterally constitute evidence of a single panmictic population, as genetic differentiation can be prevented by large population sizes and by migration.

Host plant effects on activity of the mitosporic fungi Beauveria bassiana and Paecilomyces fumosoroseus against two populations of Bemisia whiteflies (Homoptera: Aleyrodidae)

Laboratory bioassays were conducted to determine the effect of host plant on mycosis in two geographically distinct populations of early 2nd-instar nymphs of Bemisia argentifolii Bellows & Perring from the entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin and Paecilomyces fumosoroseus (Wize) Brown & Smith. Mycosis in B. argentifolii nymphs varied according to the host plant on which the nymphs were reared but not according to the population. Both populations of whiteflies reared on cotton were consistently significantly less susceptible to infection by either fungus than when reared on melon. We hypothesized that the cotton plant produced a fungal inhibitor that may confer protection on whiteflies feeding (and possibly sequestering) upon it. Germination of conidia of both fungi was strongly inhibited (below 12% germination) on the cuticle of nymphs reared on cotton but was over 95% on the cuticle of nymphs reared on melon. We further hypothesized that the terpenoid gossypol, produced by many cultivars of cotton, might have been involved in antibiosis. Gossypol mixed with Noble agar at five concentrations was tested for its effects on germination of conidia of both fungi. P. fumosoroseus was highly tolerant of gossypol, even at the relatively high concentration of 1000 ppm, while B. bassiana tolerated gossypol at concentrations up to 500 ppm and strong inhibition only occurred in presence of gossypol at 1000 ppm. Our in vivo findings on cotton and on the insect's cuticle pointed at a potential host plant-mediated antibiosis. The in vitro tolerance of P. fumosoroseus and partial tolerance of B. bassiana to gossypol disagreed with our in vivo data. Gossypol concentrations higher than 1000 ppm might have increased the sensitivity of the fungi in our in vitro tests. Sequestered gossypol (and/or other cotton plant allelochemicals) by B. argentifolii nymphs would explain, at least partially, the insect's defense against the pathogens.

Hydrogen concentrations in sulfate-reducing estuarine sediments during PCE dehalogenation

Despite recent progress made evaluating the role of hydrogen (H2) as a key electron donor in the anaerobic remediation of chloroethenes, few studies have focused on the evaluation of hydrogen thresholds relative to reductive dehalogenation in sulfidogenic environments. Competition for hydrogen exists among microbial populations in anaerobic sediments, and direct evidence indicates that lower hydrogen thresholds are observed with more energetically favorable electron-accepting processes. This study examined aqueous hydrogen concentrations associated with sulfate reduction and perchloroethylene (PCE) dehalogenation in anoxic estuarine sediment slurry microcosms and evaluated the competition for H2-reducing equivalents within these systems. After an initial lag period of 13 days, PCE was reductively transformed to trichloroethylene (TCE). During the time of continuous PCE dehalogenation, a significantly (P < 0.05) lower hydrogen concentration (0.5 nM) was observed in the sediment slurries amended with PCE as compared to slurries without PCE (0.8 nM). Sulfate reduction to sulfide was observed in all sediment slurries, but in microcosms actively dechlorinating PCE, the amount of reducing equivalents directed to sulfate reduction was approximately half the amount in sediment slurries without PCE. These findings provide evidence that a lower hydrogen threshold exists in anoxic estuarine sediment slurries with PCE as a terminal electron acceptor as compared to sediment slurries in which sulfate reduction was the predominant electron-accepting process. Furthermore, our results utilizing the inhibitor molybdate indicated that H2-utilizing methanogens may have the potential to effectively compete with dechlorinators for hydrogen when sulfate reduction is initially inhibited.

PCR primers for an aldolase-B intron in acanthopterygian fishes

BACKGROUND

Nuclear DNA sequences provide genetic information that complements studies using mitochondrial DNA. Some 'universal' primer sets have been developed that target introns within protein-coding loci, but many simultaneously amplify introns from paralogous loci. Refining existing primer sets to target a single locus could circumvent this problem.

RESULTS

Aldolase intron 'G' was amplified from four fish species using previously described primer sets that target several loci indiscriminately. Phylogenetic analyses were used to group these fragments and other full-length aldolase proteins from teleost fishes into orthologous clades and a primer set was designed to target specifically an intron within the aldolase-B locus in acanthopterygian fishes. DNA amplifications were tried in a variety of acanthopterygian fishes and amplification products, identifiable as aldolase-B intron 'G', were observed in all atherinomorph and percomorph taxa examined. Sequence variation within this locus was found within and among several species examined.

CONCLUSIONS

Using 'universal' primer sets coupled with phylogenetic analyses it was possible to develop a genetic assay to target a specific locus in a variety of fish taxa. Sequence variation was observed within and among species suggesting that this targeted assay might facilitate interspecific and intraspecific comparisons.

Genetics: year zero

Ignorance, denial, and physician centric health care have prevented health systems from adopting new genetics technology into their practices.

Validating the Questionnaire for Verifying Stroke-Free Status (QVSFS) by neurological history and examination

BACKGROUND AND PURPOSE

The Questionnaire for Verifying Stroke-Free Status (QVSFS) is an 8-item structured interview designed to identify stroke-free individuals. Previously, the QVSFS was validated with medical record review in a cohort with a low prevalence (7.1%) of stroke or transient ischemic attack (TIA). The objective of this study was to evaluate the validity of the QVSFS by comparing it with stroke status as determined by neurological history and examination in a population with a higher prevalence of stroke.

METHODS

A research assistant administered the QVSFS to outpatients from Veterans Administration stroke and general medicine clinics. Subjects were defined as QVSFS negative if responses to all 8 questions were negative. Questions requiring rephrasing or clarification were noted. Neurologists, blinded to QVSFS scores, interviewed and examined all subjects to determine stroke-free status, defined as no history or examination findings of previous stroke and/or TIA.

RESULTS

One hundred fifty-five subjects were examined; mean age was 70 years; 98.1% were male. Seventy-eight subjects were determined to be stroke free by the neurologist. The negative predictive value of the QVSFS was 0.96, with positive predictive value of 0.71. No question required rephrasing or clarification >5 times. Twenty-two subjects (14.2%) required rephrasing or clarification of at least 1 question.

CONCLUSIONS

The QVSFS can effectively identify stroke-free individuals with a high degree of accuracy, even in a population with a large proportion of patients with prior stroke or TIA. Accuracy for identifying subjects with stroke and/or TIA is lower, but the QVSFS may still be useful as a screening tool in that regard.

Metabolism of the analgesic drug, tramadol hydrochloride, in rat and dog

1. Metabolism of the analgesic agent, tramadol hydrochloride, was investigated after a single oral administration of 14C-tramadol to four rats (50)mgkg(-1) and two dogs (20)mg kg(-1). 2. Recovery of total radioactivity in rat and dog urine samples over 24 h was 73 and 65% of the radioactive dose, respectively. 3. Unchanged tramadol and a total of 24 metabolites, consisting of 16 Phase I metabolites and eight conjugates (seven glucuromides, one sulphate), were isolated and tentatively identified, which accounted for > 52% of the dose in urine of both species. 4. Of the metabolites, five (M1-5) were previously identified. 5. The metabolites were formed via the following six metabolic pathways: O-demethylation, N-demethylation, cyclohexyl oxidation, oxidative N-dealkylation, dehydration and conjugation. 6. Pathways 1-3 appear to be major steps, forming seven O-desmethyl/N-desmethyl and hydroxy-cyclohexyl metabolites in major quantities. 7. Pathways 1-3 in conjunction with pathway 6 produced four glucuronides along with four minor conjugates. 8. In addition, the in vitro metabolism of tramadol was conducted using rat hepatic S9 fraction in the presence of an NADPH-generating system. Unchanged tramadol (30% of the sample) plus nine metabolites, M1-7, tramadol-N-oxide (M31) and OH-cyclohexyl-M1 (M32), were profiled and tentatively identified based on MS and MS/MS data.

Gene-gene concordance and the phylogenetic relationships among rare and widespread pygmy sunfishes (genus Elassoma)

Pygmy sunfishes (Elassoma) are primarily lowland species with an interesting biogeographic dichotomy: three species have broad geographic distributions, and three are narrowly distributed (and have been recommended for threatened or endangered status). To test phylogenetic predictions derived from the geographic distributions of pygmy sunfishes and possible historical factors contributing to the threatened/endangered status of the rare species, we reconstructed trees for two mitochondrial genes and introns of three nuclear genes. The pattern and rate of nuclear and mitochondrial sequence evolution were heterogeneous within Elassoma, but relationships were generally concordant across gene trees. Elassoma is monophyletic and, as predicted by geographic distributions, E. evergladei, E. okefenokee, and E. zonatum consistently branch from deeper nodes. Phylogeographic structure in mitochondrial and nuclear genes also supports an early origin of E. zonatum. Phylogenetic analyses of the five loci support widely divergent positions for the rare species E. alabamae. Two rare species, E. boehlkei and E. okatie, are sister taxa and are related to a widespread species, E. evergladei.