bluuebunny/crossref_metadata_2025 huggingface dataset:
The HOPE Project: The UK Experience
Authors: Aizlewood C. , Dimitroulopoulou C.
Published: September 2006

HOPE (Health Optimisation Protocol for Energy-efficient Buildings) was a collaborative European project, which aimed to demonstrate that energy-efficient buildings can be both healthy and comfortable for their occupants. The fieldwork within the HOPE project included a preliminary cross-sectional stage using building checklists and occupant questionnaires, and a more detailed investigation of a small number of home and office buildings. These measurements aimed to evaluate indoor environmental quality (including ventilation). The main problems found in the UK offices were related to ventilation, high temperature and high levels of particulate matter, areas that were also highlighted as concerns in the occupant questionnaires. This means that perceived occupant health may be a preliminary indication for office building evaluation. However, that was not the case in the UK homes, where occupant health and comfort were not consistent with physical environmental measurements, indicating that perceived health and comfort was based on more than the physical parameters and cannot be fully explained by the measurements.
Leiomyosarcoma of the Left Atrium
Authors: Hinton Tonda
Published: September 2006

Leiomyosarcoma of the left atrium is a very rare finding with a poor prognosis. A morbidly obese patient presented to the echocardiography lab with symptoms of acute congestive heart failure. Following admission, the patient received a transthoracic echocardiogram. This echo showed a large mass in the left atrium causing severe mitral regurgitation as well as severe pulmonary hypertension. The patient then received a transesophageal echocardiogram due to his obesity and the ability to better visualize the mass. Based on the echocardiography images, the patient was taken to surgery and the mass was excised. The mass was sent to the pathology lab, where a final diagnosis of sarcoma most consistent with leiomyosarcoma was confirmed. One month postoperative, the patient developed malignant pericardial effusion and was found to be in poor health. Echocardiography played an important and expedient role in the care and treatment of this patient.
Comparative Analysis Using the 80-Lead Body Surface Map and 12-Lead ECG With Exercise Stress Echocardiograms
Authors: Rodriguez, Joleen Duarte , Santos Lynette
Published: September 2006

This retrospective study constituted of 144 patients who were recruited at the University of California Davis Medical Center (UCDMC) Echo and Stress Laboratory during a 10-month period by referrals for standard ESE to assess for CAD. Participation criteria included referral for a standard ESE, age older than 18 years, and the same criteria as standard stress tests. Standard stress test exclusion criteria were applied as well (Table 1).12 All patients gave informed consent. The study group, called the 80-lead BSM group, consisted of 72 participants. Seventy-two random participants comprised the 12lead ECG group (see Table 2). Twenty-two participants in the 80-lead group had poor image quality ESE or incomplete data for exercise cessation and/or image acquisition real time; as a result, these participants were excluded from the study. None of the ESE of the 12-lead ECG group was considered of poor image quality, nor were any data incomplete. STRESS ECHOCARDIOGRAMS
Echocardiographic Features of Postesophagogastrectomy Intrathoracic Stomach Mimicking Intracardiac Mass
Authors: Minderman Daniel , Chhokar Vikramjit , D'Cruz Ivan
Published: September 2006

Under certain abnormal conditions, part or all of the stomach can migrate through the diaphragm into the thorax. These conditions include congenital defects in the diaphragm and traumatic rupture of the diaphragm (commonly resulting from automobile accidents). A more common cause of partial translocation of the stomach into the chest is a sliding hernia through the esophageal hiatus itself. Intrathoracic stomach can also be iatrogenic; in this article, the authors describe the echocardiographic findings of a patient in whom carcinoma of the esophageal-gastric junction was resected and the cut ends of the esophagus and stomach anastomosed by bringing the stomach up into the thorax.
Sonographic Evaluation of the Portal and Hepatic Systems
Authors: Owen Cindy , Meyers Patrick
Published: September 2006

Color and spectral Doppler are used to evaluate flow characteristics in the portal and hepatic vessels. On occasion, suprahepatic pathologies are reflected in the flow characteristics of the hepatic veins and transmitted to the portal venous system across the hepatic sinusoids. Few definitive duplex findings are pathognomic for portal hypertension. Evaluation of the portal venous system is analogous to a puzzle. A picture of the processes can only be attained after many of the pieces are assembled.
Sonographic Evaluation of Frozen Venous Valves
Authors: Kavic Thomas , Kimbrow Lori
Published: September 2006

Deep vein thrombosis can damage venous valves, which results in their becoming adherent to the vessel wall. This condition is referred to as a “stuck” or “frozen” venous valve that is incompetent and allows venous reflux to occur. Sonographers using high-frequency, real-time sonography are becoming more successful at imaging these valves and evaluating their functionality. Color Doppler and spectral analysis are also employed to gain further insight into the severity of reflux flow in the affected vessel. This case study documents the presence of frozen venous valves bilaterally through the use of a sonographic examination. Accurate diagnosis of frozen venous valves can decrease the damaging effects of chronic venous insufficiency by promoting timely treatment. Surgical advancements have allowed repair of these nonfunctioning valves, which increases healing of symptoms related to postthrombotic syndrome.
Regulation of ϵ germline transcription and switch region mutations by IgH locus 3′ enhancers in transgenic mice
Authors: Laurencikiene Jurga , Tamosiunas Vytas , Severinson Eva
Published: September 2006

Germline (GL) transcription is regulated by specific promoters and immunoglobulin heavy chain (IgH) 3′ locus enhancers and is necessary for Ig class-switch recombination (CSR). We have generated different transgenic lines containing the GL ϵ promoter, switch (S) ϵ region, and constant (C) ϵ region with or without the DNase I–sensitive regions (HS) 3A-HS1,2 or HS3B-HS4 3′ IgH enhancer pairs. The enhancerless construct was expressed in B cells activated by interleukin (IL)–4 and CD40, thus resembling regulation of the endogenous gene. Both enhancer-containing transgenes efficiently increased expression in B cells and were strongly up-regulated by stimuli. In addition, Sϵ regions of the transgene containing HS3B-HS4 were mutated in activated, sorted B cells. Such mutations are known to precede CSR and are dependent on activation-induced cytidine deaminase (AID). Our findings show that all elements necessary for recruitment of the recombination machinery are present in the transgene containing HS3 and HS4. These enhancers probably provide something more specific than mere increased accessibility of switch regions. We propose that transcription factors binding the enhancers help to target the recombination machinery to the switch regions.
Oncogenic role of Pax5 in the T-lymphoid lineage upon ectopic expression from the immunoglobulin heavy-chain locus
Authors: Souabni Abdallah , Jochum Wolfram , Busslinger Meinrad
Published: September 2006

Four of 9 PAX transcription factor genes have been associated with chromosomal translocations in human tumors, although their oncogenic potential has not yet been demonstrated in transgenic mouse models. The B-lymphoidPAX5 gene participates in the generation of the t(9;14)(p13;q32) translocation in germinal center B cells, which leads to deregulated PAX5 expression under the control of the immunoglobulin heavy-chain (IgH) locus in a subset of B-cell non-Hodgkin lymphomas. Here we reconstructed a human t(9;14) translocation in a knock-in mouse by inserting a PAX5 minigene into the IgH locus. The IgHP5ki allele, which corresponds to a germline rather than somatic mutation, is activated in multipotent hematopoietic progenitors and is subsequently expressed in dendritic cells (DCs) and in natural killer (NK), T, and B cells. Ectopic Pax5 expression interferes with normal T-cell development and causes immature T-lymphoblastic lymphomas in IgHP5ki/+ and IgHP5ki/P5ki mice. Aggressive T-cell lymphomas develop even faster in IkPax5/+ mice expressing Pax5 from the Ikaros locus. Pax5 expression in thymocytes activates B-cell–specific genes and represses T-lymphoid genes, suggesting that Pax5 contributes to lymphomagenesis by deregulating the T-cell gene-expression program. These data identify Pax5 as a potent oncogene and demonstrate that the T-lymphoid lineage is particularly sensitive to the oncogenic action of Pax5.
Efficiency of T-cell receptor expression in dual-specific T cells is controlled by the intrinsic qualities of the TCR chains within the TCR-CD3 complex
Authors: Heemskerk Mirjam H. M. , Hagedoorn Renate S. , van der Hoorn Menno A. W. G. , van der Veken Lars T. , Hoogeboom Manja , Kester Michel G. D. , Willemze Roel , Falkenburg J. H. Frederik
Published: September 2006

Genetic engineering of T lymphocytes is an attractive strategy to specifically redirect T-cell immunity toward viral infections and malignancies. We previously demonstrated redirected antileukemic reactivity of cytomegalovirus (CMV)–specific T cells by transfer of minor histocompatibility antigen HA-2–specific T-cell receptors (TCRs). HA-2–TCR-transferred CMV-specific T cells were potent effectors against HA-2–expressing leukemic cells, as well as CMV-expressing cells. Functional activity of these T cells correlated with TCR cell-surface expression. In the present study we analyzed which properties of transferred and endogenous TCRs are crucial for efficient cell-surface expression. We demonstrate that expression of the introduced TCR is not a random process but is determined by characteristics of both the introduced and the endogenously expressed TCR. The efficiency of TCR cell-surface expression is controlled by the intrinsic quality of the TCR complex. In addition, we demonstrate that chimeric TCRs can be formed and that efficiency of TCR expression is independent of whether TCRs are retrovirally introduced or naturally expressed. In conclusion, introduced, endogenous, and chimeric TCRs compete for cell-surface expression in favor of the TCR-CD3 complex with best-pairing properties.
Foamy virus–mediated gene transfer to canine repopulating cells
Authors: Kiem Hans-Peter , Allen James , Trobridge Grant , Olson Erik , Keyser Kirsten , Peterson Laura , Russell David W.
Published: September 2006

Foamy virus (FV) vectors are particularly attractive gene-transfer vectors for stem-cell gene therapy because they form a stable transduction intermediate in quiescent cells and can efficiently transduce hematopoietic stem cells. Here, we studied the use of FV vectors to transduce long-term hematopoietic repopulating cells in the dog, a clinically relevant large animal model. Mobilized canine peripheral blood (PB) CD34+ cells were transduced with an enhanced green fluorescent protein (EGFP)–expressing FV vector in an 18-hour transduction protocol. All 3 dogs studied had rapid neutrophil engraftment to greater than 500/μL with a median of 10 days. Transgene expression was detected in all cell lineages (B cells, T cells, granulocytes, red blood cells, and platelets), indicating multilineage engraftment of transduced cells. Up to 19% of blood cells were EGFP+, and this was confirmed at the DNA level by real-time polymerase chain reaction (PCR) and Southern blot analysis. These transduction rates were higher than the best results we obtained previously with lentiviral vectors in a similar transduction protocol. Integration site analysis also demonstrated polyclonal repopulation and the transduction of multipotential hematopoietic repopulating cells. These data suggest that FV vectors should be useful for stem-cell gene therapy, particularly for applications in which short transduction protocols are critical.
A first insight into the genetic diversity of Mycobacterium tuberculosis in Dar es Salaam, Tanzania, assessed by spoligotyping
Authors: Eldholm Vegard , Matee Mecky , Mfinanga Sayoki GM , Heun Manfred , Dahle Ulf R
Published: September 2006

Background

Tanzania has a high tuberculosis incidence, and genotyping studies of Mycobacterium tuberculosis in the country are necessary in order to improve our understanding of the epidemic. Spoligotyping is a potentially powerful genotyping method due to fast generation of genotyping results, high reproducibility and low operation costs. The recently constructed SpolDB4 database and the model-based program 'Spotclust' can be used to assign isolates to families, subfamilies and variants. The results of a study can thus be analyzed in a global context.

Results

One hundred forty-seven pulmonary isolates from consecutive tuberculosis patients in Dar es Salaam were spoligotyped. SpolDB4 and 'Spotclust' were used to assign isolates to families, subfamilies and variants. The CAS (37%), LAM (22%) and EAI (17%) families were the most abundant. Despite the dominance of these three families, diversity was high due to variation within M. tuberculosis families. Of the obtained spoligopatterns, 64% were previously unrecorded.

Conclusion

Spoligotyping is useful to gain an overall understanding of the local TB epidemic. This study demonstrates that the extensive TB epidemic in Dar es Salaam, Tanzania is caused by a few successful M. tuberculosis families, dominated by the CAS family. Import of strains was a minor problem.
Malaria hotspot areas in a highland Kenya site are consistent in epidemic and non-epidemic years and are associated with ecological factors
Authors: Ernst Kacey C , Adoka Samson O , Kowuor Dickens O , Wilson Mark L , John Chandy C
Published: September 2006

Background

Malaria epidemics in highland areas of East Africa have caused considerable morbidity and mortality in the past two decades. Knowledge of "hotspot" areas of high malaria incidence would allow for focused preventive interventions in resource-poor areas, particularly if the hotspot areas can be discerned during non-epidemic periods and predicted by ecological factors.

Methods

To address this issue, spatial distribution of malaria incidence and the relationship of ecological factors to malaria incidence were assessed in the highland area of Kipsamoite, Kenya, from 2001–2004.

Results

Clustering of disease in a single geographic "hotspot" area occurred in epidemic and non-epidemic years, with a 2.6 to 3.2-fold increased risk of malaria inside the hotspot, as compared to outside the area (P < 0.001, all 4 years). Altitude and proximity to the forest were independently associated with increased malaria risk in all years, including epidemic and non-epidemic years.

Conclusion

In this highland area, areas of high malaria risk are consistent in epidemic and non-epidemic years and are associated with specific ecological risk factors. Ongoing interventions in areas of ecological risk factors could be a cost-effective method of significantly reducing malaria incidence and blunting or preventing epidemics, even in the absence of malaria early warning systems. Further studies should be conducted to see if these findings hold true in varied highland settings.
The early responses of VEGF and its receptors during acute lung injury: implication of VEGF in alveolar epithelial cell survival
Authors: Mura Marco , Han Bing , Andrade CristianoF , Seth Rashmi , Hwang David , Waddell Thomas K , Keshavjee Shaf , Liu Mingyao
Published: September 2006

Introduction

The function of the vascular endothelial growth factor (VEGF) system in acute lung injury (ALI) is controversial. We hypothesized that the role of VEGF in ALI may depend upon the stages of pathogenesis of ALI.

Methods

To determine the responses of VEGF and its receptors during the early onset of ALI, C57BL6 mice were subjected to intestinal ischemia or sham operation for 30 minutes followed by intestinal ischemia-reperfusion (IIR) for four hours under low tidal volume ventilation with 100% oxygen. The severity of lung injury, expression of VEGF and its receptors were assessed. To further determine the role of VEGF and its type I receptor in lung epithelial cell survival, human lung epithelial A549 cells were treated with small interference RNA (siRNA) to selectively silence related genes.

Results

IIR-induced ALI featured interstitial inflammation, enhancement of pulmonary vascular permeability, increase of total cells and neutrophils in the bronchoalveolar lavage (BAL), and alveolar epithelial cell death. In the BAL, VEGF was significantly increased in both sham and IIR groups, while the VEGF and VEGF receptor (VEGFR)-1 in the lung tissues were significantly reduced in these two groups. The increase of VEGF in the BAL was correlated with the total protein concentration and cell count. Significant negative correlations were observed between the number of VEGF or VEGFR-1 positive cells, and epithelial cells undergoing cell death. When human lung epithelial A549 cells were pre-treated with 50 nM of siRNA either against VEGF or VEGFR-1 for 24 hours, reduced VEGF and VEGFR-1 levels were associated with reduced cell viability.

Conclusion

These results suggest that VEGF may have dual roles in ALI: early release of VEGF may increase pulmonary vascular permeability; reduced expression of VEGF and VEGFR-1 in lung tissue may contribute to the death of alveolar epithelial cells.
Exposure to Mycobacterium avium can modulate established immunity against Mycobacterium tuberculosis infection generated by Mycobacterium bovis BCG vaccination
Authors: Flaherty David K , Vesosky Bridget , Beamer Gillian L , Stromberg Paul , Turner Joanne
Published: September 2006

Mycobacterium bovis bacille Calmette Guerin (BCG), the current vaccine against infection with Mycobacterium tuberculosis, offers a variable, protective efficacy in man. It has been suggested that exposure to environmental mycobacteria can interfere with the generation of BCG-specific immunity. We hypothesized that exposure to environmental mycobacteria following BCG vaccination would interfere with established BCG immunity and reduce protective efficacy, thus modeling the guidelines for BCG vaccination within the first year of life. Mice were vaccinated with BCG and subsequently given repeated oral doses of live Mycobacterium avium to model exposure to environmental mycobacteria. The protective efficacy of BCG with and without subsequent exposure to M. avium was determined following an aerogenic challenge with M. tuberculosis. Exposure of BCG-vaccinated mice to M. avium led to a persistent increase in the number of activated T cells within the brachial lymph nodes but similar T cell activation profiles in the lungs following infection with M. tuberculosis. The capacity of BCG-vaccinated mice to reduce the bacterial load following infection with M. tuberculosis was impaired in mice that had been exposed to M. avium. Our data suggest that exposure to environmental mycobacteria can negatively impact the protection afforded by BCG. These findings are relevant for the development of a vaccine administered in regions with elevated levels of environmental mycobacteria.
Premature Mortality in Patients with Addison’s Disease: A Population-Based Study
Authors: Bergthorsdottir Ragnhildur , Leonsson-Zachrisson Maria , Odén Anders , Johannsson Gudmundur
Published: September 2006

Background: The survival rate of patients with primary adrenal insufficiency (Addison’s disease) undergoing currently accepted replacement therapy is not known, although well-informed patients are considered to have a normal survival rate. In this study, we evaluated the mortality of patients with Addison’s disease in Sweden.

Methods: A population-based, retrospective, observational study was performed, using the National Swedish Hospital and Cause of Death Registers, covering the period from 1987–2001. After a diagnosis of Addison’s disease, each patient was followed until the end of follow-up or death. Mortality was compared with that of the Swedish background population.

Findings: We identified 1675 patients (995 women and 680 men) diagnosed with primary adrenal insufficiency. The average follow-up from initial diagnosis was 6.5 yr. Five hundred seven patients died during the study period compared with an expected 199. The risk ratio for all-cause mortality was 2.19 (confidence interval 1.91–2.51) for men and 2.86 (confidence interval 2.54–3.20) for women. The excess mortality in both men and women was attributed to cardiovascular, malignant, and infectious diseases. Concomitant diabetes mellitus was observed in 12% of the patients, but only contributed to the increased mortality to a minor extent.

Interpretation: Compared with the background population, we observed that the risk ratio for death was more than 2-fold higher in patients with Addison’s disease. Cardiovascular, malignant, and infectious diseases were responsible for the higher mortality rate.
Dynamic Strength Training Improves Insulin Sensitivity without Altering Plasma Levels and Gene Expression of Adipokines in Subcutaneous Adipose Tissue in Obese Men
Authors: Klimcakova E. , Polak J. , Moro C. , Hejnova J. , Majercik M. , Viguerie N. , Berlan M. , Langin D. , Stich V.
Published: September 2006

Context: Obesity is characterized by a low-grade inflammatory state, which could play a role in insulin resistance. Dynamic strength training improves insulin sensitivity.

Objective: The objective of this study was to investigate, in obese subjects, whether the insulin sensitizing effect of dynamic strength training is associated with changes in plasma levels and gene expression of adipokines potentially involved in the development of insulin resistance.

Design: Twelve obese male subjects were investigated before and at the end of 3 months of dynamic strength training. Insulin sensitivity was evaluated using euglycemic-hyperinsulinemic clamp. Blood samples and needle biopsy samples of sc abdominal adipose tissue were obtained. The plasma levels and adipose tissue mRNA levels of adiponectin, leptin, IL-1β, IL-6, and TNF-α were determined.

Results: The training induced an increase in the whole-body glucose disposal rate by 24% (P = 0.04). The body weight was not altered during the training. Plasma levels of leptin decreased during the training (16.6 ± 6.3 vs. 13.1 ± 5.7 ng/ml) by 21% (P < 0.02), whereas no change in plasma levels of other adipokines and C-reactive protein was observed. Gene expression of the investigated adipokines was not changed in sc adipose tissue during the training.

Conclusions: In obese subjects, the dynamic strength training resulted in an improvement of whole-body insulin sensitivity. The increase in insulin sensitivity was not associated with training-induced modifications of plasma levels or adipose tissue gene expression of adipokines supposedly involved in the development of insulin resistance.
Acromegaly and Somatotroph Hyperplasia with Adenomatous Transformation Due to Pituitary Metastasis of a Growth Hormone-Releasing Hormone-Secreting Pulmonary Endocrine Carcinoma
Authors: Nasr Christian , Mason Alexander , Mayberg Marc , Staugaitis Susan M. , Asa Sylvia L.
Published: September 2006

Context: GHRH excess from extracranial endocrine tumors is known to cause somatotroph hyperplasia and acromegaly. Hypothalamic gangliocytomas producing GHRH are also known to be associated with pituitary adenomas causing acromegaly.

Objectives: The objective of this study was to describe a case of acromegaly due to a pulmonary GHRH-secreting endocrine carcinoma with metastasis to the pituitary gland and to look at the peculiar histological features of this case.

Subject: The patient was a 44-yr-old woman who was diagnosed with a biopsy-proven metastatic pulmonary endocrine tumor during pregnancy. After delivery, she underwent radiation and chemotherapy for pulmonary and skeletal metastases. Her disease was clinically stable for 7 yr until she developed bitemporal hemianopia. She had symptoms and signs of acromegaly.

Methods: Imaging, biochemical, and histological studies were performed.

Results: Magnetic resonance imaging (MRI) of the brain confirmed the presence of a 2.6-cm lesion within the sella turcica extending above the sella and compressing the optic chiasm. Endocrine studies showed elevated serum levels of GH, prolactin, α-subunit of glycoprotein hormones, IGF-I, chromogranin A, and GHRH. The patient underwent uneventful transsphenoidal resection of the sellar tumor. Postoperatively, she noted an improvement in symptoms of acromegaly. Histological examination confirmed metastatic endocrine carcinoma to the pituitary, and immunohistochemistry localized GHRH to the tumor cells. The adjacent pituitary exhibited somatotroph hyperplasia with abundant reactivity for GH and α-subunit. In addition, there was focal neoplastic transformation to a sparsely granulated somatotroph phenotype with fibrous bodies.

Conclusion: This is the first report of a GHRH-producing endocrine tumor metastasizing to the pituitary and causing local hyperstimulation with somatotroph hyperplasia and adenomatous transformation.
Low-Grade Systemic Inflammation Causes Endothelial Dysfunction in Patients with Hashimoto’s Thyroiditis
Authors: Taddei Stefano , Caraccio Nadia , Virdis Agostino , Dardano Angela , Versari Daniele , Ghiadoni Lorenzo , Ferrannini Ele , Salvetti Antonio , Monzani Fabio
Published: September 2006

Objective: The objective of this study was to assess whether low-grade systemic inflammation might contribute to the pathogenesis of endothelial dysfunction in patients with subclinical hypothyroidism (sHT) and autoimmune thyroiditis.

Background: sHT patients are characterized by peripheral endothelial dysfunction and low-grade inflammation.

Methods: In 53 sHT and 45 healthy subjects, we studied the forearm blood flow (strain-gauge plethysmography) response to intrabrachial acetylcholine (Ach) (0.15–15 μg/min·dl) with and without local vascular COX inhibition by intrabrachial indomethacin (50 μg/min·dl) or nitric oxide synthase blockade by N-mono methyl arginine (l-NMMA) (100 μg/min·dl) or the antioxidant vitamin C (8 mg/min·dl). The protocol was repeated 2 h after systemic nonselective COX inhibition (100 mg indomethacin) or selective COX-2 blockade (200 mg celecoxib) oral administrations.

Results: sHT patients showed higher C-reactive protein and IL-6 values. In controls, vasodilation to Ach was blunted by l-NMMA and unchanged by vitamin C. In contrast, in sHT, the response to Ach, reduced in comparison with controls, was resistant to l-NMMA and normalized by vitamin C. In these patients, systemic but not local indomethacin normalized vasodilation to Ach and the inhibition of l-NMMA on Ach. Similar results were obtained with celecoxib. When retested after indomethacin administration, vitamin C no longer succeeded in improving vasodilation to Ach in sHT patients. Response to sodium nitroprusside was unchanged by indomethacin or celecoxib.

Conclusions: In sHT patients, low-grade chronic inflammation causes endothelial dysfunction and impaired nitric oxide availability by a COX-2-dependent pathway leading to increased production of oxidative stress.
Assessment of Iodine Status Using Dried Blood Spot Thyroglobulin: Development of Reference Material and Establishment of an International Reference Range in Iodine-Sufficient Children
Authors: Zimmermann Michael B. , de Benoist Bruno , Corigliano Sandro , Jooste Pieter L. , Molinari Luciano , Moosa Khairya , Pretell Eduardo A. , Al-Dallal Zuhair Salman , Wei Yao , Zu-Pei Chen , Torresani Toni
Published: September 2006

Context: Thyroglobulin (Tg) may be a valuable indicator of improving thyroid function in children after salt iodization. A recently developed Tg assay for use on dried whole blood spots (DBS) makes sampling practical, even in remote areas.

Objective: The study aim was to develop a reference standard for DBS-Tg, establish an international reference range for DBS-Tg in iodine-sufficient children, and test the standardized DBS-Tg assay in an intervention trial.

Design, Participants, and Interventions: Serum Tg reference material of the European Community Bureau of Reference (CRM-457) was adapted for DBS and its stability tested over 1 yr. DBS-Tg was determined in an international sample of 5- to 14-yr-old children (n = 700) who were euthyroid, anti-Tg antibody negative, and residing in areas of long-term iodine sufficiency. In a 10-month trial in iodine-deficient children, DBS-Tg and other indicators of iodine status were measured before and after introduction of iodized salt.

Results: Stability of the CRM-457 Tg reference standard on DBS over 1 yr of storage at −20 and −50 C was acceptable. In the international sample of children, the third and 97th percentiles of DBS-Tg were 4 and 40 μg/liter, respectively. In the intervention, before introduction of iodized salt, median DBS-Tg was 49 μg/liter, and more than two thirds of children had DBS-Tg values greater than 40 μg/liter. After 5 and 10 months of iodized salt use, median DBS-Tg decreased to 13 and 8 μg/liter, respectively, and only 7 and 3% of children, respectively, had values greater than 40 μg/liter. DBS-Tg correlated well at baseline and 5 months with urinary iodine and thyroid volume.

Conclusions: The availability of reference material and an international reference range facilitates the use of DBS-Tg for monitoring of iodine nutrition in school-age children.
The Promise and Limits of Racial/Ethnic Concordance in Physician-Patient Interaction
Authors: Schnittker Jason , Liang Ke
Published: September 2006

Although some scholars suggest that racial/ethnic concordance between physicians and patients will do much to eliminate disparities in medical care, the evidence for concordance effects is mixed. Using nationally representative data with an oversample of blacks and Latinos, this study examines a variety of topics, including beliefs about and preferences for concordance, the effects of concordance on patient experiences, and interactions between expectations and experiences. The results point to the limited effects of concordance in general but illuminate for whom concordance matters most. The results encourage more nuanced and contingent theories. They suggest that racial/ethnic concordance holds little salience in the minds of most black and Latino patients and that discordance has little effect. Nevertheless, there is some evidence that concordance has a positive effect among those who prefer concordance—thus the apparent effects of concordance might reflect the effects of patient choice more than concordance per se. The conclusion sketches policy implications, including the merits of promoting concordance among targeted groups of patients, even in the absence of overall effects on disparities.
Regulation of the polarity kinases PAR-1/MARK by 14-3-3 interaction and phosphorylation
Authors: Göransson Olga , Deak Maria , Wullschleger Stephan , Morrice Nick A. , Prescott Alan R. , Alessi Dario R.
Published: September 2006

Members of the PAR-1/MARK kinase family play critical roles in polarity and cell cycle control and are regulated by 14-3-3 scaffolding proteins, as well as the LKB1 tumour suppressor kinase and atypical protein kinase C (PKC). In this study, we initially investigated the mechanism underlying the interaction of mammalian MARK3 with 14-3-3. We demonstrate that 14-3-3 binding to MARK3 is dependent on phosphorylation, and necessitates the phosphate-binding pocket of 14-3-3. We found that interaction with 14-3-3 was not mediated by the previously characterised MARK3 phosphorylation sites, which led us to identify 15 novel sites of phosphorylation. Single point mutation of these sites, as well as the previously identified LKB1-(T211) and the atypical PKC sites (T564/S619), did not disrupt 14-3-3 binding. However, a mutant in which all 17 phosphorylation sites had been converted to alanine residues (termed 17A-MARK3), was no longer able to bind 14-3-3. Wild-type MARK3 was present in both the cytoplasm and plasma membrane, whereas the 17A-MARK3 mutant was strikingly localised at the plasma membrane. We provide data indicating that the membrane localisation of MARK3 required a highly conserved C-terminal domain, which has been termed kinase-associated domain-1 (KA-1). We also show that dissociation of 14-3-3 from MARK3 did not affect catalytic activity, and that a MARK3 mutant, which could not interact with 14-3-3, was normally active. Finally, we establish that there are significant differences in the subcellular localisation of MARK isoforms, as well as in the impact that atypical PKC overexpression has on 14-3-3 binding and localisation. Collectively, these results indicate that 14-3-3 binding to MARK isoforms is mediated by multiple phosphorylation sites, and serves to anchor MARK isoforms in the cytoplasm.
Dystroglycan loss disrupts polarity and β-casein induction in mammary epithelial cells by perturbing laminin anchoring
Authors: Weir M. Lynn , Oppizzi Maria Luisa , Henry Michael D. , Onishi Akiko , Campbell Kevin P. , Bissell Mina J. , Muschler John L.
Published: September 2006

Precise contact between epithelial cells and their underlying basement membrane is crucial to the maintenance of tissue architecture and function. To understand the role that the laminin receptor dystroglycan (DG) plays in these processes, we assayed cell responses to laminin-111 following conditional ablation of DG gene (Dag1) expression in cultured mammary epithelial cells. Strikingly, DG loss disrupted laminin-111-induced polarity and β-casein production, and abolished laminin assembly at the step of laminin binding to the cell surface. Dystroglycan re-expression restored these deficiencies. Investigations of the mechanism revealed that DG cytoplasmic sequences were not necessary for laminin assembly and signaling, and only when the entire mucin domain of extracellular DG was deleted did laminin assembly not occur. These results demonstrate that DG is essential as a laminin-111 co-receptor in mammary epithelial cells that functions by mediating laminin anchoring to the cell surface, a process that allows laminin polymerization, tissue polarity and β-casein induction. The observed loss of laminin-111 assembly and signaling in Dag1-/- mammary epithelial cells provides insights into the signaling changes occurring in breast carcinomas and other cancers, where the binding function of DG to laminin is frequently defective.
Characterization of erasin (UBXD2): a new ER protein that promotes ER-associated protein degradation
Authors: Liang Jing , Yin Chaobo , Doong Howard , Fang Shengyun , Peterhoff Corrine , Nixon Ralph A. , Monteiro Mervyn J.
Published: September 2006

Ubiquitin regulator-X (UBX) is a discrete protein domain that binds p97/valosin-containing protein (VCP), a molecular chaperone involved in diverse cell processes, including endoplasmic-reticulum-associated protein degradation (ERAD). Here we characterize a human UBX-containing protein, UBXD2, that is highly conserved in mammals, which we have renamed erasin. Biochemical fractionation, immunofluorescence and electron microscopy, and protease protection experiments suggest that erasin is an integral membrane protein of the endoplasmic reticulum and nuclear envelope with both its N- and C-termini facing the cytoplasm or nucleoplasm. Localization of GFP-tagged deletion derivatives of erasin in HeLa cells revealed that a single 21-amino-acid sequence located near the C-terminus is necessary and sufficient for localization of erasin to the endoplasmic reticulum. Immunoprecipitation and GST-pulldown experiments confirmed that erasin binds p97/VCP via its UBX domain. Additional immunoprecipitation assays indicated that erasin exists in a complex with other p97/VCP-associated factors involved in ERAD. Overexpression of erasin enhanced the degradation of the ERAD substrate CD3δ, whereas siRNA-mediated reduction of erasin expression almost completely blocked ERAD. Erasin protein levels were increased by endoplasmic reticulum stress. Immunohistochemical staining of brain tissue from patients with Alzheimer's disease and control subjects revealed that erasin accumulates preferentially in neurons undergoing neurofibrillary degeneration in Alzheimer's disease. These results suggest that erasin may be involved in ERAD and in Alzheimer's disease.
Visualisation of macropinosome maturation by the recruitment of sorting nexins
Authors: Kerr Markus C. , Lindsay Margaret R. , Luetterforst Robert , Hamilton Nicholas , Simpson Fiona , Parton Robert G. , Gleeson Paul A. , Teasdale Rohan D.
Published: September 2006

We report that phosphoinositol-binding sorting nexin 5 (SNX5) associates with newly formed macropinosomes induced by EGF stimulation. We used the recruitment of GFP-SNX5 to macropinosomes to track their maturation. Initially, GFP-SNX5 is sequestered to discrete subdomains of the macropinosome; these subdomains are subsequently incorporated into highly dynamic, often branched, tubular structures. Time-lapse videomicroscopy revealed the highly dynamic extension of SNX5-labelled tubules and their departure from the macropinosome body to follow predefined paths towards the perinuclear region of the cell, before fusing with early endosomal acceptor membranes. The extension and departure of these tubular structures occurs rapidly over 5-10 minutes and is dependent upon intact microtubules. As the tubular structures depart from the macropinosome there is a reduction in the surface area and an increase in tension of the limiting membrane of the macropinosome. In addition to the recruitment of SNX5 to the macropinosome, Rab5, SNX1 and EEA1 are also recruited by newly formed macropinosomes, followed by the accumulation of Rab7. SNX5 forms heterodimers with SNX1 and this interaction is required for endosome association of SNX5. We propose that the departure of SNX5-positive tubules represents a rapid mechanism of recycling components from macropinosomes thereby promoting their maturation into Rab7-positive structures. Collectively these findings provide a detailed real-time characterisation of the maturation process of the macropinocytic endosome.
Nucleo-cytoplasmic shuttling of human Kank protein accompanies intracellular translocation of β-catenin
Authors: Wang Yong , Kakinuma Naoto , Zhu Yun , Kiyama Ryoiti
Published: September 2006

The human Kank protein has a role in controlling the formation of the cytoskeleton by regulating actin polymerization. Besides the cytoplasmic localization as reported before, we observed the nuclear localization of Kank in OS-RC-2 cells. To uncover the mechanism behind this phenomenon, we focused on the nuclear localization signal (NLS) and the nuclear export signal (NES). We found one NLS (NLS1) and two NESs (NES1 and NES2) in the N-terminal region of Kank-L that were absent in Kank-S, and another NLS (NLS2) and NES (NES3) in the common region. These signals were active as mutations introduced into them abolished the nuclear import (for NLS1 and NLS2) or the nuclear export (for NES1 to NES3) of Kank. The localization of Kank in the cells before and after treatment with leptomycin B suggested that the transportation of Kank from the nucleus to the cytoplasm was mediated by a CRM1-dependent mechanism. TOPFLASH reporter assays revealed a positive relationship between the nuclear import of Kank and the activation of β-catenin-dependent transcription. Kank can bind to β-catenin and regulate the subcellular distribution of β-catenin. Based on the findings shown here, we propose that Kank has multiple functions in the cells and plays different roles in the cytoplasm and the nucleus.
Regulation of epidermal homeostasis and repair by phosphoinositide 3-kinase
Authors: Pankow Sandra , Bamberger Casimir , Klippel Anke , Werner Sabine
Published: September 2006

The epidermis undergoes continuous self-renewal to maintain its protective function. Whereas growth factors are known to modulate overall skin homeostasis, the intracellular signaling pathways, which control the delicate balance between proliferation and differentiation in keratinocytes, are largely unknown. Here we show transient upregulation of the phosphoinositide 3-kinase (PI3K) catalytic subunits p110α and p110β in differentiating keratinocytes in vitro, expression of these subunits in the epidermis of normal and wounded skin, and enhanced Akt phosphorylation in the hyperproliferative wound epidermis. Stimulation of PI3K activity in cultured keratinocytes by stable expression of an inducible, constitutively active PI3K mutant promoted cell proliferation and inhibited terminal differentiation in keratinocyte monocultures and induced the formation of a hyperplastic, disorganized and poorly differentiated epithelium in organotypic skin cultures. Activation of PI3K signaling also caused reorganization of the actin cytoskeleton and induced keratinocyte migration in vitro and in skin organ cultures. The identification of 122 genes, which are differentially expressed after induction of PI3K signaling provides insight into the molecular mechanisms underlying the observed effects of active PI3K on keratinocytes and indicates that hyperproliferation may be achieved at the expense of genome integrity. These results identify PI3K as an important intracellular regulator of epidermal homeostasis and repair.
A novel endothelial-specific heat shock protein HspA12B is required in both zebrafish development and endothelial functions in vitro
Authors: Hu Guang , Tang Jian , Zhang Bo , Lin Yanfeng , Hanai Jun-ichi , Galloway Jenna , Bedell Victoria , Bahary Nathan , Han Zhihua , Ramchandran Ramani , Thisse Bernard , Thisse Christine , Zon Leonard I. , Sukhatme Vikas P.
Published: September 2006

A zebrafish transcript dubbed GA2692 was initially identified via a whole-mount in situ hybridization screen for vessel specific transcripts. Its mRNA expression during embryonic development was detected in ventral hematopoietic and vasculogenic mesoderm and later throughout the vasculature up to 48 hours post fertilization. Morpholino-mediated knockdown of GA2692 in embryos resulted in multiple defects in vasculature, particularly, at sites undergoing active capillary sprouting: the intersegmental vessels, sub-intestinal vessels and the capillary sprouts of the pectoral fin vessel. During the course of these studies, a homology search indicated that GA2692 is the zebrafish orthologue of mammalian HspA12B, a distant member of the heat shock protein 70 (Hsp70) family. By a combination of northern blot and real-time PCR analysis, we showed that HspA12B is highly expressed in human endothelial cells in vitro. Knockdown of HspA12B by small interfering RNAs (siRNAs) in human umbilical vein endothelial cells blocked wound healing, migration and tube formation, whereas overexpression of HspA12B enhanced migration and accelerated wound healing - data that are consistent with the in vivo fish phenotype obtained in the morpholino-knockdown studies. Phosphorylation of Akt was consistently reduced by siRNAs against HspA12B. Overexpression of a constitutively active form of Akt rescued the inhibitory effects of knockdown of HspA12B on migration of human umbilical vein endothelial cells. Collectively, our data suggests that HspA12B is a highly endothelial-cell-specific distant member of the Hsp70 family and plays a significant role in endothelial cells during development and angiogenesis in vitro, partially attributable to modulation of Akt phosphorylation.
Trimerisation is important for the function of clathrin at the mitotic spindle
Authors: Royle Stephen J. , Lagnado Leon
Published: September 2006

Clathrin is a triskelion consisting of three heavy chains each with an associated light chain. During mitosis, clathrin contributes to kinetochore fibre stability. As the N-terminal domain at the foot of each leg can bind to the mitotic spindle, we proposed previously a `bridge hypothesis' wherein clathrin acts as a brace between two or three microtubules within a kinetochore fibre to increase fibre stability. Here, we have tested this hypothesis by replacing endogenous clathrin heavy chain in human cells with a panel of clathrin constructs. Mutants designed to abolish trimerisation were unable to rescue the mitotic defects caused by depletion of endogenous clathrin. By contrast, stunted triskelia with contracted legs could partially rescue normal mitosis. These results indicate that the key structural features of clathrin that are necessary for its function in mitosis are a trimeric molecule with a spindle interaction domain at each end, supporting the bridge hypothesis for clathrin function in mitosis.
Bell's Palsy: A Review of Treatment Using Antiviral Agents
Authors: Alberton Dario L , Zed Peter J
Published: September 2006

Objective:

To review the evidence evaluating the efficacy and safety of antiviral agents to reduce morbidity associated with Bell's palsy.

Data Sources:

MEDLINE, EMBASE, and PubMed were searched (all up to April 2006) for English-language, prospective, randomized, controlled clinical trials that evaluated the use of antiviral agents in Bell's palsy. Search terms included Bell's palsy, acyclovir, valacyclovir, famciclovir, and randomized controlled trials.

Study Selection and Data Extraction:

Prospective, randomized, controlled trials that evaluated efficacy and safety endpoints of antiviral agents in the treatment of Bell's palsy were included. Primary efficacy outcomes included facial paralysis recovery profile, facial paralysis recovery index, and the House–Brackmann facial nerve grading scale. Safety outcomes were also identified by each trial.

Data Synthesis:

Two prospective, randomized clinical trials were included in this review, both involving the use of acyclovir for treatment of Bell's palsy. Acyclovir monotherapy was shown to be inferior to prednisone monotherapy; however, the combination of acyclovir and prednisone was found to be superior to prednisone alone. There are limited data describing the safety of acyclovir in Bell's palsy.

Conclusions:

The use of acyclovir in the treatment of Bell's palsy remains controversial. Additional, adequately powered, randomized, placebo-controlled trials are needed to definitively support its use. For the time being, the evidence reviewed in this article would favor the combination of acyclovir and prednisone if commenced within the first 72 hours of symptom onset.