Direct Transition from Hospital to Home Dialysis: Revolutionizing Home Dialysis Training.

A large portion of new patients with end stage kidney disease initiates dialysis in the acute setting and continue with outpatient dialysis at in-center facilities. To increase home dialysis adoption, programs have successfully operationalized Urgent Start peritoneal dialysis to have patients avoid in-center dialysis and move straight to home. However, Urgent Start home hemodialysis (HHD) has not been a realistic option for providers or patients due to complex machines and long training times (greater than four weeks). The landscape of dialysis treatment is evolving, and innovative approaches are being explored to improve patient outcomes and optimize health care resources. This article delves into the concept of directly transitioning incident patients from hospital admission to HHD, bypassing traditional in-center dialysis training. This forward-thinking approach aims to empower patients, enhance their treatment experience, maximize efficiency, and streamline health care operations. A large hospital organization in the Northeast was able to successfully transition three patients from hospital "crash" starts on hemodialysis directly to HHD.

Complete remission with romidepsin in a patient with T-cell acute lymphoblastic leukemia refractory to induction hyper-CVAD.

T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL) are neoplasms that originate from T-cell precursors. Outcomes in adult patients with T-ALL/LBL remain unsatisfactory; early relapse following intensive induction chemotherapy is a concern, and patients with relapsed or refractory disease have a poor prognosis. Romidepsin is a potent, class 1 selective histone deacetylase inhibitor approved for the treatment of patients with peripheral T-cell lymphoma who have had ≥1 prior therapy and patients with cutaneous T-cell lymphoma who have had ≥1 prior systemic therapy. Here, we report the case of an adult patient with T-ALL refractory to induction hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD). Treatment with romidepsin was initiated, and romidepsin in combination with hyper-CVAD resulted in complete remission, with mild tumor lysis syndrome as the only detectable additional toxicity. The patient eventually underwent allogeneic stem cell transplant while in first complete remission. Prior studies have shown that romidepsin is capable of inducing durable responses with manageable toxicities in patients with mature T-cell lymphomas. This case study describes the successful use of romidepsin in combination with hyper-CVAD in an adult patient with refractory T-ALL and highlights the activity of romidepsin in the T-cell lineage. The potential of romidepsin-containing regimens in patients with T-ALL/LBL deserves further study.

Fibrillary glomerulonephritis in an HIV patient without concurrent hepatitis C infection: Case report and review of the literature
.

The most common renal disease associated with human immunodeficiency virus infection (HIV) is HIV-associated nephropathy (HIVAN), especially in the African American patient population. However, various patterns of glomerulonephritis (GN) are not uncommon, collectively accounting for nearly half of the renal biopsies performed in HIV patients. Most GNs that occur in HIV patients are immune complex mediated, often with concurrent infections such as hepatitis B or C. Fibrillary glomerulonephritis (FGN), a rare primary glomerular disease, has only been reported in 2 HIV patients, and both patients had concurrent hepatitis C (HCV) infection. Here we report a unique case of FGN with unusual ultrastructural morphology in an HIV-positive African American patient without concurrent HCV infection. The patient presented with nephrotic range proteinuria and renal insufficiency. A percutaneous kidney biopsy showed mesangial and segmental endocapillary proliferative GN with crescent formation. Immunofluorescence studies revealed IgG-, κ-, and C3-positive deposits in the mesangium and capillary loops. Electron microscopy demonstrated diagnostic features of FGN: randomly-arranged fibrillary deposits with a diameter of 15 - 30 nm. The deposits had an unusual distribution pattern of hump-like large deposits on the subepithelial aspect. Additionally, smaller deposits were also present in the mesangium. To our knowledge, this is the first reported case of FGN in an HIV patient without concurrent HCV infection.
.

Reclaiming Autologous Amputated Tissue for Limb Salvage of a Diabetic Foot Burn with Underlying Critical Limb Ischemia.

BACKGROUND: Diabetes mellitus is a worldwide pandemic that impacts more than 387 million people, with 29 million individuals affected in the United States alone. Diabetic patients have a 25% lifetime risk of developing a diabetic foot ulcer (DFU). Having a DFU is associated with a risk of recurrence approaching 70%. In addition, 1 in 6 patients with DFU will have a lower-limb amputation, with an associated increase in mortality ranging from 47% to 70%. Therefore, limb salvage is critical in patients with DFU. CASE STUDY: This article describes the case of a 70-year-old man with diabetes mellitus, end-stage renal disease, and peripheral arterial occlusive disease who presented with a 1.5% total-body-surface-area, third-degree burn to the left hallux with dry gangrene extending to the midfoot. Ankle brachial indexes were 0.66 on the left and 0.64 on the right. Toe pressures on the left were absent because of extensive dry gangrene. His right foot had a prior transmetatarsal amputation. Using a retrograde pedal approach, a chronic total occlusion of the left posterior tibial artery was recanalized with balloon angioplasty. He then underwent a transmetatarsal amputation with closure, except that the plantar medial side could not be closed without tension. Therefore, an autologous full-thickness skin graft, from the amputation specimen, was used to bridge the defect. DISCUSSION: At 32-week follow-up, the wound was healed, the graft had fully incorporated, and the patient was ambulating well using custom orthotic footwear. The creative use of amputated tissue to assist with wound coverage has not been well described in the literature.

Multivalent Molecules as Modulators of RNA Granule Size and Composition.

RNA granules are ensembles of specific RNA and protein molecules that mediate localized translation in eukaryotic cells. The mechanisms for formation and selectivity of RNA granules are unknown. Here we present a model for assembly of one type of RNA granule based on experimentally measured binding interactions among three core multivalent molecular components necessary for such assembly: specific RNA molecules that contain a cis-acting sequence called the A2 response element (A2RE), hnRNP A2 proteins that bind specifically (with high affinity) to A2RE sequences or nonspecifically (with lower affinity) to other RNA sequences, and heptavalent protein cytoskeleton-associated protein 5 (CKAP5, an alternative name for TOG protein) that binds both hnRNP A2 molecules and RNA. Non-A2RE RNA molecules (RNA without the A2RE sequence) that may be recruited to the granules through nonspecific interactions are also considered in the model. Modeling multivalent molecular interactions in granules is challenging because of combinatorial complexity in the number of potential molecular complexes among these core components and dynamic changes in granule composition and structure in response to changes in local intracellular environment. We use a hybrid modeling approach (deterministic-stochastic-statistical) that is appropriate when the overall compositions of multimolecular ensembles are of greater importance than the specific interactions among individual molecular components. Modeling studies titrating the concentrations of various granule components and varying effective site pair affinities and RNA valency demonstrate that interactions between multivalent components (TOG and RNA) are modulated by a bivalent adaptor molecule (hnRNP A2). Formation and disruption of granules, as well as RNA selectivity in granule composition are regulated by distinct concentration regimes of A2. Our results suggest that granule assembly is tightly controlled by multivalent molecular interactions among RNA molecules, adaptor proteins, and scaffold proteins.

Young female vascular surgeons more likely to enter academia.

OBJECTIVE: In the last decade, there has been a dramatic increase in the number of women entering vascular surgery. Our goal was to evaluate the differences in career paths based on gender and to determine some of the factors that influence career decisions among young vascular surgeons. METHODS: A 17-item web-based survey focusing on current employment status, reasons for choosing academic vs nonacademic positions, and career satisfaction was distributed to 900 members of the Society for Vascular Surgery who completed vascular surgery training in the past 10 years. RESULTS: A total of 199 individuals responded to the survey (22.1%). The cohort included 49 (24.6%) women and 149 (74.9%) men. The majority of the respondents were non-Hispanic white (66.3%). Sixty-four percent of all respondents were younger than 40 years. Overall, 72.9% of women had applied to academic positions after their training compared with 58.8% of men. Women were more likely to apply for and to work in an academic setting (P = .0266 and P = .0198, respectively) and cited mentorship more frequently (P = .0474) as the reason for choosing an academic practice. Women respondents were less likely to have a spouse or children (P = .0269 and P < .001, respectively). More than 87.4% of all respondents were very satisfied or somewhat satisfied with their careers. However, men were more likely to be very satisfied compared with women (P = .0345). CONCLUSIONS: Career satisfaction remains high among young vascular surgeons. In this cohort of vascular surgery graduates, we found that women were more likely to pursue academic positions than men, with mentorship, ability to teach, and complexity of cases commonly cited as reasons for this career choice. However, whether young women stay in academia and what factors affect academic retention will need further evaluation.

Environmental impact of geometric earthwork construction in pre-Columbian Amazonia.

There is considerable controversy over whether pre-Columbian (pre-A.D. 1492) Amazonia was largely "pristine" and sparsely populated by slash-and-burn agriculturists, or instead a densely populated, domesticated landscape, heavily altered by extensive deforestation and anthropogenic burning. The discovery of hundreds of large geometric earthworks beneath intact rainforest across southern Amazonia challenges its status as a pristine landscape, and has been assumed to indicate extensive pre-Columbian deforestation by large populations. We tested these assumptions using coupled local- and regional-scale paleoecological records to reconstruct land use on an earthwork site in northeast Bolivia within the context of regional, climate-driven biome changes. This approach revealed evidence for an alternative scenario of Amazonian land use, which did not necessitate labor-intensive rainforest clearance for earthwork construction. Instead, we show that the inhabitants exploited a naturally open savanna landscape that they maintained around their settlement despite the climatically driven rainforest expansion that began ∼2,000 y ago across the region. Earthwork construction and agriculture on terra firme landscapes currently occupied by the seasonal rainforests of southern Amazonia may therefore not have necessitated large-scale deforestation using stone tools. This finding implies far less labor--and potentially lower population density--than previously supposed. Our findings demonstrate that current debates over the magnitude and nature of pre-Columbian Amazonian land use, and its impact on global biogeochemical cycling, are potentially flawed because they do not consider this land use in the context of climate-driven forest-savanna biome shifts through the mid-to-late Holocene.

IMPROVING PREDICTIVE MODELS OF IN-STREAM PHOSPHORUS CONCENTRATION BASED ON NATIONALLY-AVAILABLE SPATIAL DATA COVERAGES.

Spatial data are playing an increasingly important role in watershed science and management. Large investments have been made by government agencies to provide nationally-available spatial databases; however, their relevance and suitability for local watershed applications is largely unscrutinized. We investigated how goodness of fit and predictive accuracy of total phosphorus (TP) concentration models developed from nationally-available spatial data could be improved by including local watershed-specific data in the East Fork of the Little Miami River, Ohio, a 1290 km2 watershed. We also determined whether a spatial stream network (SSN) modeling approach improved on multiple linear regression (nonspatial) models. Goodness of fit and predictive accuracy were highest for the SSN model that included local covariates, and lowest for the nonspatial model developed from national data. Septic systems and point source TP loads were significant covariates in the local models. These local data not only improved the models but enabled a more explicit interpretation of the processes affecting TP concentrations than more generic national covariates. The results suggest that SSN modeling greatly improves prediction and should be applied when using national covariates. Including local covariates further increases the accuracy of TP predictions throughout the studied watershed; such variables should be included in future national databases, particularly the locations of septic systems.

The Suicide Prevention, Depression Awareness, and Clinical Engagement Program for Faculty and Residents at the University of California, Davis Health System.

OBJECTIVE: The authors replicated a program developed by UC San Diego, identified medical staff at risk for depression and suicide using a confidential online survey, and studied aspects of that program for 1 year. METHODS: The authors used a 35-item, online assessment of stress and depression depression developed and licensed by the American Foundation for Suicide Prevention that aims to identify and suicide risk and facilitate access to mental health services. RESULTS: During 2013/2014, all 1864 UC Davis residents/fellows and faculty physicians received an invitation to take the survey and 158 responded (8% response rate). Most respondents were classified at either moderate (86 [59%]) or high risk for depression or suicide (54 [37%]). Seventeen individuals (11%) were referred for further evaluation or mental health treatment. Ten respondents consented to participate in the follow-up portion of the program. Five of the six who completed follow-up surveys reported symptom improvement and indicated the program should continue. CONCLUSIONS: This program has led to continued funding and a plan to repeat the Wellness Survey annually. Medical staff will be regularly reminded of its existence through educational interventions, as the institutional and professional culture gradually changes to promptly recognize and seek help for physicians' psychological distress.

A fluorescent bisboronic acid compound that selectively labels cells expressing oligosaccharide Lewis X.

Two fluorescent diboronic acid compounds (6a and 6b) with a dipeptide linker were synthesized as potential sensors for cell surface saccharide Lewis X (Le(X)). Compound 6a with a dipeptide (H-Asp-Ala-) as the linker was found to selectively label CHOFUT4 cells, which express Le(x), at micromolar concentrations, while non-Le(x)-expressing control cells were not labeled.

Management of mixed arterial venous lower extremity ulceration: A review.

Mixed arterial venous disease is estimated to affect up to 26% of patients with lower extremity ulcerations. However, its clinical significance and pathophysiology are incompletely understood. Furthermore, there is no consensus on the optimal treatment modality, whether conservative or operative. In this review paper, we describe the current understanding of the pathophysiology of mixed arterial venous lower extremity ulcers. Guidelines for diagnostic tests for patients with mixed arterial venous diseases are discussed. We review some of the newer biological skin substitutes for conservative wound care. Finally, we propose a treatment algorithm based on current available data.

Racial disparities in outcomes of endovascular procedures for peripheral arterial disease: an evaluation of California hospitals, 2005-2009.

BACKGROUND: Racial/ethnic disparities in treatment outcomes of peripheral arterial disease (PAD) are well documented. Compared with non-Hispanic (NH) whites, blacks and Hispanics are more likely to undergo amputation and less likely to undergo bypass surgery for limb salvage. Endovascular procedures are being increasingly performed as first line of therapy for PAD. In this study, we examined the outcomes of endovascular PAD treatments based on race/ethnicity in a contemporary large population-based study. METHODS: We used Patient Discharge Data from California's Office of Statewide Health Planning and Development to identify all patients over the age of 35 who underwent a lower extremity arterial intervention from 2005 to 2009. A look-back period of 5 years was used to exclude all patients with prior lower extremity arterial revascularization procedures or major amputation. Cox proportional hazards regression was used to compare amputation-free survival and time to death within 365 days. Logistic regression was used for comparison of 1-month myocardial infarction, 1-month major amputation, 1-month all-cause mortality, 12-month major amputation, 12-month reintervention, and 12-month all-cause mortality rates among NH white, black, and Hispanic patients. These analyses were adjusted for age, gender, insurance status, severity of PAD, comorbidities, history of coronary artery angioplasty or bypass surgery, or history of carotid endarterectomy. RESULTS: Between 2005 and 2009, a total of 41,507 individuals underwent PAD interventions, 25,635 (61.7%) of whom underwent endovascular procedures. There were 17,433 (68%) NH whites, 4,417 (17.2%) Hispanics, 1,979 (7.7%) blacks, 1,163 (4.5%) Asian/Native Hawaiians, and 643 (2.5%) others in this group. There was a statistically significant difference in the amputation-free survival within 365 days among the NH white, Hispanic, and black groups (P < 0.0001); the hazard ratio for amputation within 365 days was 1.69 in Hispanics (95% confidence interval [CI] 1.51-1.90, P < 0.0001) and 1.68 in blacks (95% CI 1.44-1.96, P < 0.001) compared with NH whites following endovascular procedures after adjusting for age, gender, insurance status, comorbidities, severity of PAD, history of coronary artery angioplasty or bypass surgery, or history of carotid endarterectomy. After adjusting for the aforementioned confounders, the first reintervention within 12 months was also significantly associated with race/ethnicity (P = 0.002). Odds ratio for reintervention was 1.17 in blacks (95% CI 1.06-1.30, P = 0.002) and 1.084 in Hispanics (95% CI 1.00-1.16, P = 0.04) compared with NH whites. CONCLUSIONS: In this contemporary large population-based study, we demonstrated that even among matched cohorts Hispanics and blacks have worse amputation-free survival than NH whites following endovascular therapy. Our study also found that Hispanics and blacks are more likely to undergo lower extremity arterial reinterventions than NH whites. Further research is crucial in understanding if higher reintervention rates in Hispanics and blacks are because of more severe disease and/or poor access to proper follow-up care and optimal medical management.

Risk factors associated with the diagnosis of abdominal aortic aneurysm in patients screened at a regional Veterans Affairs health care system.

BACKGROUND: An active abdominal aortic aneurysm (AAA) screening program at a regional Veterans Affairs (VA) health system identifies patients at risk for AAA. The purpose of this study is to evaluate unique risk factors associated with the AAA diagnosis upon AAA screening examination to identify the most at risk patients for AAA. METHODS: Data were extracted from a regional VA health care system to identify patients who underwent AAA screening within a 3-year period. An aortic diameter ≥3.0 cm was defined as an AAA. Patient risk factors included age, body mass index, total cholesterol, estimated glomerular filtration rate (eGFR), statin use, and active smoking status; the presence of hypertension, diabetes, coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), or peripheral vascular disease (PVD) was also evaluated. Risk factors were compared in a multivariate analysis between patients with AAA and patients with a normal aorta. RESULTS: A total of 6,142 patients (mean ± SD age: 72.7 ± 5.3 years) were screened for AAA between January 2007 and December 2009. A total of 469 patients (7.6%) with AAA were identified. The following risk factors were significantly associated with a diagnosis of AAA: age >75 years (39.6% vs. 28.9%; P < 0.001), prevalence of CAD (43.1% vs. 28.5%; P < 0.001), COPD (26% vs. 11.4%; P < 0.001), PVD (37.3% vs. 7.7%; P < 0.001), eGFR <60 mL/min (36.7% vs. 24.3%; P < 0.001), and current smoking (23.2% vs. 15.3%; P < 0.001). The risk factors significantly associated with normal aortic size were the presence of diabetes (18.6% vs. 27.4%; P < 0.001) and total cholesterol ≥200 mg/dL (10.4% vs. 15%; P = 0.04). CONCLUSIONS: The diagnosis of AAA in a large screening study is typically identified in patients who are at high risk for cardiovascular disease. The presence of diabetes is a major cardiovascular risk factor that is more associated with normal aorta when compared to patients with the AAA diagnosis. Total cholesterol ≥200 mg/dL was associated with decreased AAA risk, and renal insufficiency was associated with increased AAA risk.

FMRP and myelin protein expression in oligodendrocytes.

Fragile X syndrome (FXS) is caused by lack of expression of fragile X mental retardation protein (FMRP), the product of the Fmr1 gene. In many cases FXS is associated with abnormalities in CNS myelination. Although FMRP is expressed in oligodendrocyte progenitor cells and immature oligodendrocytes (OLGs) previous studies have not detected it in mature, myelin-producing OLGs. FMRP represses translation of myelin basic protein (MBP) RNA in vitro and is believed to prevent premature MBP expression in immature OLGs. Lack of FMRP in FXS could lead to premature myelination and/or myelin abnormalities. Here we show that FMRP is expressed in mature, MBP-positive OLGs of rodents and in MBP-positive human OLGs. We confirm that FMRP is a translational repressor of MBP mRNA in vitro, but at concentrations likely too high to be physiologically relevant in vivo. We find MBP expression in cultured Fmr1 KO OLGs to be similar to wild type, and expression of MBP and other myelin proteins in brain homogenates of the Fmr1 KO mouse to be similar to wild type before, during, and after the period of active myelination. These results suggest that while FMRP is expressed in mature OLGs, myelin abnormalities caused by lack of FMRP expression in FXS are not recapitulated in rodents.

Mental testing in the early twentieth century: internationalizing the mental testing story.

This article suggests a possible approach to analyzing the global history of intelligence testing in light of some recent work in the history of science and science studies. In particular, it uses work in metrology and subaltern studies to develop possible models for the dissemination, appropriation, and transformation of mental testing in the early 20th century. It draws on the accounts presented in the other articles in this collection to substantiate its claims. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Primary ciliary dyskinesia-causing mutations in Amish and Mennonite communities.

OBJECTIVE: To determine whether individuals with primary ciliary dyskinesia (PCD) from unrelated Amish and Mennonite families harbor a single and unique founder mutation. STUDY DESIGN: Subjects from Amish and Mennonite communities in several states were enrolled in the study. All subjects were clinically characterized, and nasal nitric oxide levels were measured. Nasal epithelial scrapings were collected from several subjects for ciliary ultrastructural analyses. DNA was isolated from patients with PCD and their unaffected first- and second-degree relatives. Genome-wide homozygosity mapping, linkage analyses, targeted mutation analyses, and exome sequencing were performed. RESULTS: All subjects from Old-Order Amish communities from Pennsylvania were homozygous for a nonsense mutant DNAH5 allele, c.4348C>T (p.Q1450X). Two affected siblings from an unrelated Mennonite family in Arkansas were homozygous for the same nonsense DNAH5 mutation. Children with PCD from an Amish family from Wisconsin had biallelic DNAH5 mutations, c.4348C>T (p.Q1450X) and c.10815delT (p.P3606HfsX23), and mutations in other genes associated with PCD were also identified in this community. CONCLUSION: The Amish and Mennonite subjects from geographically dispersed and socially isolated communities had the same founder DNAH5 mutation, owing to the common heritage of these populations. However, disease-causing mutations in other PCD-associated genes were also found in affected individuals in these communities, illustrating the genetic heterogeneity in this consanguineous population.

Outcomes of an abdominal aortic aneurysm screening program.

OBJECTIVE: In 2007, Medicare guidelines were established to identify persons at risk for the presence of an abdominal aortic aneurysm (AAA). The purpose of this study is to evaluate the 5-year outcomes of an AAA screening program in a regional Veterans Affairs (VA) health care system. METHODS: Data were extracted from a regional VA health care network identifying all veteran males 65 to 75 years of age who smoked at least 100 cigarettes during their lifetime. In 2007, an AAA screening mandate was implemented allowing patients meeting screening criteria to be evaluated for AAA as part of the patient's health maintenance. AAA is identified as an aortic diameter size of 3.0 cm or greater. Clinician adherence to screening protocols and referral to a vascular surgeon for aneurysms >5.5 cm were also evaluated. RESULTS: A total of 9751 patients (71.5 ± 5.6 standard deviation years of age) were screened for an AAA over a 5-year period from January 1, 2007 to December 31, 2011. A total of 698 aneurysms (7.1%) were found. Referrals to a vascular surgeon were made on 45 patients with aneurysms >5.5 cm. Over a 5-year period, a total of 2754 patients (28.2%) were inappropriately screened: 416 patients were under 65 years old, 2243 patients were over 75 years old, 36 patients were women, and 123 patients without aneurysms had multiple screenings. In 2007, during the first year of implementation, 39.2% of patients were inappropriately screened. Over the next 4 years, inappropriate screenings decreased with 33.7% in 2008, 28.6% in 2009, 17.7% in 2010, and 14.3% in 2011. CONCLUSIONS: A large AAA screening program at the VA detects more aneurysms, but at smaller diameters than that published in clinical trials. Over time, the number of inappropriate AAA screenings has continued to decrease, demonstrating greater awareness and application of the AAA screening guidelines by primary care providers. Developing surveillance guidelines for small and medium aneurysms is a potential area for future research.

Natural history of carotid artery occlusion.

Carotid artery occlusion (CAO) is a risk factor for stroke ipsilateral to the occlusion and puts patients in a high-risk category when contralateral endarterectomy is performed. The purpose of this study was to evaluate the long-term outcomes of patients with internal CAO and to determine risk factors predictive of subsequent neurological event, contralateral carotid intervention, or death. Patients with internal CAO shown by duplex ultrasonography were retrospectively identified and followed between January 2002 and June 2010 (follow-up: 1-101 months, mean: 52 months) at a tertiary care hospital. All had multiple duplex examinations available for review. Chi-square analysis was used to determine risk factors for neurologic event, contralateral intervention, or all-cause morality. Multivariate Cox proportional hazard analysis was conducted using univariate risk factors with P values <0.1. Survival was estimated using the Kaplan-Meier method (P < 0.05 significant). Eighty patients with internal CAO were identified and available for analysis. On initial encounter, 30 (38%) were symptomatic, with 26 (87%) having symptoms referable to the side of the occluded internal carotid artery. During follow-up, seven (9%) had a neurologic event, of which six (86%) were referable to the occluded side; 14 (18%) patients underwent a contralateral operation. Nineteen (24%) patients died during the period of study. Although numerous variables of multivessel disease were significant with χ(2) analysis, there was no significant risk factor associated with neurologic event on multivariate analysis. However, the development of a hemodynamically significant stenosis (>50%) or occlusion of the external carotid artery (ECA) ipsilateral to the occlusion on follow-up (P < 0.027) was associated with increased risk of death. Kaplan-Meier analysis showed 7-year survival for patients with ECA disease at follow-up was significantly worse (16.2% ± 10.3% [n = 21] vs. 79% ± 8.7% [n = 59]; P < 0.00001). Frequently, patients present with neurological symptoms referable to the side of the internal CAO. Eighty-six percent of neurologic events that occur in follow-up are attributable to the side of the occluded carotid, indicating that the occluded side continues to contribute to neurologic morbidity over time. Multivariate analysis revealed no single factor to be predictive of subsequent neurologic events. With significant risk of death in patients found to have ipsilateral ECA stenosis during follow-up, it seems reasonable to continue surveillance of the occluded carotid.

Differential subcellular distributions and trafficking functions of hnRNP A2/B1 spliceoforms.

Trafficking of mRNA molecules from the nucleus to distal processes in neural cells is mediated by heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 trans-acting factors. Although hnRNP A2/B1 is alternatively spliced to generate four isoforms, most functional studies have not distinguished between these isoforms. Here, we show, using isoform-specific antibodies and isoform-specific green fluorescent protein (GFP)-fusion expression constructs, that A2b is the predominant cytoplasmic isoform in neural cells, suggesting that it may play a key role in mRNA trafficking. The differential subcellular distribution patterns of the individual isoforms are determined by the presence or absence of alternative exons that also affect their dynamic behavior in different cellular compartments, as measured by fluorescence correlation spectroscopy. Expression of A2b is also differentially regulated with age, species and cellular development. Furthermore, coinjection of isoform-specific antibodies and labeled RNA into live oligodendrocytes shows that the assembly of RNA granules is impaired by blockade of A2b function. These findings suggest that neural cells modulate mRNA trafficking by regulating alternative splicing of hnRNP A2/B1 and controlling expression levels of A2b, which may be the predominant mediator of cytoplasmic-trafficking functions. These findings highlight the importance of considering isoform-specific functions for alternatively spliced proteins.

Herpes simplex virus type 1 helicase-primase: DNA binding and consequent protein oligomerization and primase activation.

The heterotrimeric helicase-primase complex of herpes simplex virus type I (HSV-1), consisting of UL5, UL8, and UL52, possesses 5' to 3' helicase, single-stranded DNA (ssDNA)-dependent ATPase, primase, and DNA binding activities. In this study we confirm that the UL5-UL8-UL52 complex has higher affinity for forked DNA than for ssDNA and fails to bind to fully annealed double-stranded DNA substrates. In addition, we show that a single-stranded overhang of greater than 6 nucleotides is required for efficient enzyme loading and unwinding. Electrophoretic mobility shift assays and surface plasmon resonance analysis provide additional quantitative information about how the UL5-UL8-UL52 complex associates with the replication fork. Although it has previously been reported that in the absence of DNA and nucleoside triphosphates the UL5-UL8-UL52 complex exists as a monomer in solution, we now present evidence that in the presence of forked DNA and AMP-PNP, higher-order complexes can form. Electrophoretic mobility shift assays reveal two discrete complexes with different mobilities only when helicase-primase is bound to DNA containing a single-stranded region, and surface plasmon resonance analysis confirms larger amounts of the complex bound to forked substrates than to single-overhang substrates. Furthermore, we show that primase activity exhibits a cooperative dependence on protein concentration while ATPase and helicase activities do not. Taken together, these data suggest that the primase activity of the helicase-primase requires formation of a dimer or higher-order structure while ATPase activity does not. Importantly, this provides a simple mechanism for generating a two-polymerase replisome at the replication fork.