bluuebunny/crossref_metadata_2025 huggingface dataset:
Ambulatory measurement of knee motion and physical activity: preliminary evaluation of a smart activity monitor
Authors: Huddleston James , Alaiti Amer , Goldvasser Dov , Scarborough Donna , Freiberg Andrew , Rubash Harry , Malchau Henrik , Harris William , Krebs David
Published: September 2006

Background

There is currently a paucity of devices available for continuous, long-term monitoring of human joint motion. Non-invasive, inexpensive devices capable of recording human activity and joint motion have many applications for medical research. Such a device could be used to quantify range of motion outside the gait laboratory. The purpose of this study was to test the accuracy of the modified Intelligent Device for Energy Expenditure and Activity (IDEEA) in measuring knee flexion angles, to detect different physical activities, and to quantify how often healthy subjects use deep knee flexion in the ambulatory setting.

Methods

We compared Biomotion Laboratory (BML) "gold standard" data to simultaneous IDEEA measures of knee motion and gait, step up/down, and stair descent in 5 healthy subjects. In addition, we used a series of choreographed physical activities outside the BML to confirm the IDEEA's ability to accurately measure 7 commonly-performed physical activities. Subjects then continued data collection during ordinary activities outside the gait laboratory.

Results

Pooled correlations between the BML and IDEEA knee flexion angles were .97 +/- .03 for step up/down, .98 +/- .02 for stair descent, and .98 +/- .01 for gait. In the BML protocol, the IDEEA accurately identified gait, but was less accurate in identifying step up/down and stair descent. During sampling outside the BML, the IDEEA accurately detected walking, running, stair ascent, stair descent, standing, lying, and sitting. On average, subjects flexed their knees >120° for 0.17% of their data collection periods outside the BML.

Conclusion

The modified IDEEA system is a useful clinical tool for evaluating knee motion and multiple physical activities in the ambulatory setting. These five healthy subjects rarely flexed their knees >120°.
Grid technology in tissue-based diagnosis: fundamentals and potential developments
Authors: Görtler Jürgen , Berghoff Martin , Kayser Gian , Kayser Klaus
Published: September 2006

Tissue-based diagnosis still remains the most reliable and specific diagnostic medical procedure. It is involved in all technological developments in medicine and biology and incorporates tools of quite different applications. These range from molecular genetics to image acquisition and recognition algorithms (for image analysis), or from tissue culture to electronic communication services.

Grid technology seems to possess all features to efficiently target specific constellations of an individual patient in order to obtain a detailed and accurate diagnosis in providing all relevant information and references.

Grid technology can be briefly explained by so-called nodes that are linked together and share certain communication rules in using open standards. The number of nodes can vary as well as their functionality, depending on the needs of a specific user at a given point in time. In the beginning of grid technology, the nodes were used as supercomputers in combining and enhancing the computation power. At present, at least five different Grid functions can be distinguished, that comprise 1) computation services, 2) data services, 3) application services, 4) information services, and 5) knowledge services.

The general structures and functions of a Grid are described, and their potential implementation into virtual tissue-based diagnosis is analyzed. As a result Grid technology offers a new dimension to access distributed information and knowledge and to improving the quality in tissue-based diagnosis and therefore improving the medical quality.
Intravenous nitroglycerin does not preserve gastric microcirculation during gastric tube reconstruction: a randomized controlled trial
Authors: Buise Marc , van Bommel Jasper , Jahn Alexander , Tran Khe , Tilanus Huug , Gommers Diederik
Published: September 2006

Introduction

Complications of oesophagectomy and gastric tube reconstruction include leakage and stenosis, which may be due to compromised microvascular blood flow (MBF) in gastric tissue. We recently demonstrated that decreased MBF could be improved perioperatively by topical administration of nitroglycerin. The aim of the present study was to investigate whether nitroglycerin, administered intravenously during gastric tube reconstruction, could preserve tissue blood flow and oxygenation in the gastric fundus, and reduce the incidence of postoperative leakage.

Methods

In this single-centre, prospective, double-blinded study, we randomized 32 patients scheduled for oesophagectomy into two groups. The intervention group received intravenous nitroglycerin during gastric tube reconstruction, and the control group received normal saline. Baseline values for MBF, microvascular haemoglobin oxygen saturation and microvascular haemoglobin concentration were determined at the gastric fundus before and after gastric tube construction and after pulling up the gastric tube to the neck.

Results

MBF and microvascular haemoglobin oxygen saturation decreased similarly in both groups during gastric tube reconstruction and were comparable. The oesophageal anastomosis was controlled by contrast radiography before discharge from the hospital; leakage was observed in two patients (13%) in the nitroglycerin group and five patients (31 %) in the control group (not significant).

Conclusion

Under stable systemic haemodynamic conditions, continuous intravenous administration of nitroglycerin could not prevent deterioration in gastric microvascular perfusion and microvascular haemoglobin saturation during gastric tube reconstruction. (Trial registration number NCT 00335010.)
Cytolytic cells induce HMGB1 release from melanoma cell lines
Authors: Ito Norimasa , DeMarco Richard A , Mailliard Robbie B , Han Jie , Rabinowich Hannah , Kalinski Pawel , Stolz Donna Beer , Zeh Herbert J , Lotze Michael T
Published: September 2006

High mobility group box 1 (HMGB1) is one of the recently defined damage-associated molecular pattern molecules, passively released from necrotic cells and secreted by activated macrophage/monocytes. Whether cytolytic cells induce HMGB1 release from tumor cells is not known. We developed a highly sensitive method for detecting intracellular HMGB1 in tumor cells, allowing analysis of the type of cell death and in particular, necrosis. We induced melanoma cell death with cytolytic lymphokine-activated killing (LAK) cells, tumor-specific cytolytic T lymphocytes, TRAIL, or granzyme B delivery and assessed intracellular HMGB1 retention or release to investigate the mechanism of HMGB1 release by cytolytic cells. HMGB1 release from melanoma cells (451Lu, WM9) was detected within 4 h and 24 h following incubation with IL-2-activated PBMC (LAK activity). HLA-A2 and MART1 or gp100-specific cytolytic T lymphocytes induced HMGB1 release from HLA-A2-positive and MART1-positive melanoma cells (FEM X) or T2 cell-loaded, gp100-specific peptides. TRAIL treatment, however, induced HMGB1 release, and it is interesting that this extrinsic pathway-mediated cell death was blocked with the pancaspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone. Conversely, granzyme B delivery did not induce HMGB1 release. HMGB1, along with other intracellular factors released from tumor cells induced by cytolysis, may be important components of the disordered tumor microenvironment. This has important implications for the immunotherapy of patients with cancer. Specifically, HMGB1 may promote healing or immune reactivity, depending on the nature of the local inflammatory response and the presence (or absence) of immune effectors.
Identification and Functional Analysis of the Novel S179R POU1F1 Mutation Associated with Combined Pituitary Hormone Deficiency
Authors: Miyata Ichiro , Vallette-Kasic Sophie , Saveanu Alexandru , Takeuchi Mizuho , Yoshikawa Hideki , Tajima Asako , Tojo Katsuyoshi , Reynaud Rachel , Gueydan Magali , Enjalbert Alain , Tajima Naoko , Eto Yoshikatsu , Brue Thierry
Published: September 2006

Context: The pituitary-specific transcription factor 1 plays a key role in the development and differentiation of three pituitary cell types: somatotrophs, lactotrophs, and thyrotrophs. Several mutations of the human gene (called POU1F1) have been shown to be responsible for a phenotype of combined pituitary hormone deficiency involving GH, prolactin (PRL), and TSH.

Objective: We have identified a novel homozygous C to G mutation in exon 4 of the POU1F1 gene (S179R) in a patient with this rare phenotype. We analyzed the functional consequences of this S179R mutation associated with a single-amino acid change in the POU-specific domain.

Methods: Consequences of this mutation on transcriptional activities by transfection studies in αT3 cells, DNA binding ability by EMSA, structural properties, and nuclear accumulation of POU1F1 were investigated.

Results: The transactivation capacity of this mutant was markedly decreased on the GH1, PRL, TSHβ, and POU1F1 genes. Interestingly, this mutation abolished the functional interaction of POU1F1 on the PRL promoter with the coactivator cAMP response element-binding protein-binding protein but not with the transcription factor LIM homeodomain transcription factor 3. The S179R mutant displayed normal nuclear accumulation but a markedly decreased binding to a DNA response element in keeping with crystallographic data, suggesting that the S179R mutation might interfere with DNA binding.

Conclusions: Together with previous data, our study indicates that both DNA binding and interaction with cofactors like cAMP response element-binding protein-binding protein are critical for POU1F1 function and that functional and structural properties of abnormal POU1F1 proteins are variously influenced by the type of mutations.
Hook Needle-Guided Excision of Recurrent Differentiated Thyroid Cancer in Previously Operated Neck Compartments: A Safe Technique for Small, Nonpalpable Recurrent Disease
Authors: Triponez Frederic , Poder Liina , Zarnegar Rasa , Goldstein Ruth , Roayaie Kayvan , Feldstein Vickie , Lee James , Kebebew Electron , Duh Quan-Yang , Clark Orlo H.
Published: September 2006

Context: As a result of more sensitive techniques to detect recurrent thyroid cancer, the number of patients presenting with small, nonpalpable recurrent thyroid cancer in cervical lymph nodes is increasing. Surgical excision of nonpalpable recurrent thyroid cancer can be difficult, particularly in a previously operated area.

Objective: The objective of this study was to investigate whether preoperative insertion of a hook needle under ultrasound guidance is useful in neck reoperations for recurrent thyroid cancer.

Patients: Ten consecutive patients presenting over a 4-month period with nonpalpable, ultrasound-visible, fine needle biopsy-proven recurrent thyroid cancer in previously operated neck compartment(s) were studied.

Main Outcome Measures: We measured whether it was technically possible to insert a hook needle preoperatively, rate of negative neck exploration, and complication rate.

Results: The hook needle was inserted in seven patients. In three patients, the hook needle was not inserted; one patient had palpable disease 4 months after the preoperative clinic visit, one patient had a tumor too close to the carotid artery, and one patient had multiple bilateral foci of recurrent disease in the central neck. One patient had bleeding after insertion of the needle due to a penetration of an anterior jugular vein that was easily managed at neck reexploration. No other complication occurred during the hook needle insertion, and the only surgical complication was a transient recurrent nerve palsy. All pathology reports showed malignant disease.

Conclusion: Hook needle-guided excision of recurrent thyroid cancer is feasible and appears to be a promising tool for safe and successful reoperation of patients with small recurrent thyroid cancer in cervical lymph nodes.
Salivary α-Amylase Levels after Yohimbine Challenge in Healthy Men
Authors: Ehlert Ulrike , Erni Katja , Hebisch Gundula , Nater Urs
Published: September 2006

Context: We and others have previously shown that standardized psychosocial stress significantly increases salivary α-amylase (sAA), but it remains unclear whether sAA reflects autonomic nervous system activation.

Objective: The aim of this study was to assess cardiovascular effects and sAA and catecholamine secretion after iv injection of yohimbine.

Design and Setting: We conducted a randomized double-blind placebo-controlled study at an academic research unit.

Participants: Thirteen healthy males (aged 20–28 yr) were examined.

Intervention: Participants received iv injection of yohimbine (0.4 μg/kg) or placebo (0.9% NaCl).

Main Outcome Measures: Eight saliva and blood samples were taken before and after injection for the assessment of salivary flow rate and sAA and catecholamine concentrations. In addition, blood pressure, mood, and anxiety were assessed repeatedly.

Results: Yohimbine induced increases of sAA activity and output in comparison to placebo (P = 0.034). Blood pressure (P < 0.001), salivary flow rate (P = 0.007), and catecholamines (P < 0.001) were also significantly increased. No significant correlations between α-amylase parameters and catecholamines were observed.

Conclusions: The results indicate that yohimbine administration activates not only autonomic parameters but also sAA via adrenergic mechanisms, suggesting that sAA might be an indirect indicator of the central sympathetic system.
Impaired Caspase-3 Expression by Peripheral T Cells in Chronic Autoimmune Thyroiditis and in Autoimmune Polyendocrine Syndrome-2
Authors: Vendrame Francesco , Segni Maria , Grassetti Daniele , Tellone Valeria , Augello Giovanni , Trischitta Vincenzo , Torlontano Massimo , Dotta Francesco
Published: September 2006

Context: Activation-induced cell death (AICD) is a major mechanism in the regulation of peripheral tolerance, and caspase-3 represents its major executioner. AICD impairment contributes to the persistence of autoreactive T cells, and defective AICD has been reported in autoimmune thyroiditis as well as in type 1 diabetes mellitus.

Objective: The objective of this study was to evaluate the involvement of caspase-3 in the regulation of AICD resistance in thyroid and polyendocrine autoimmunity.

Design/Settings/Patients/Intervention: Caspase-3 expression was analyzed in peripheral blood lymphocytes from 26 adults (A-AT) and 25 children (Y-AT) affected by autoimmune thyroiditis and 13 individuals affected by chronic autoimmune thyroiditis plus Addison’s disease [autoimmune polyendocrine syndrome-2 (APS-2)] in comparison with 32 age-matched normal control subjects (NC).

Outcome Measures: Caspase-3 mRNA expression in peripheral T cells was evaluated by quantitative real-time PCR; protein expression of both procaspase-3 and activated caspase-3 by Western blot analysis was followed by scanning densitometry.

Results: Caspase-3 mRNA expression was significantly reduced in resting lymphocytes from both A-AT (P = 0.001) and Y-AT (P = 0.016) compared with NC. After lymphocyte activation, protein levels of caspase-3 active form were significantly reduced in A-AT (P = 0.023) and Y-AT (P = 0.001) compared with NC. The APS-2 group displayed characteristics similar to the A-AT group because both caspase-3 mRNA and protein active form levels were significantly reduced compared with NC (P = 0.004 and 0.002, respectively).

Conclusion: Our data show that peripheral lymphocytes of subjects affected by thyroid autoimmunity or APS-2 show defective expression of the major executioner of AICD, thus potentially contributing to AICD resistance and to the development of autoimmunity.
Influences of Age, Gender, Smoking, and Family History on Autoimmune Thyroid Disease Phenotype
Authors: Manji N. , Carr-Smith J. D. , Boelaert K. , Allahabadia A. , Armitage M. , Chatterjee V. K. , Lazarus J. H. , Pearce S. H. S. , Vaidya B. , Gough S. C. , Franklyn J. A.
Published: September 2006

Context: Both genetic and environmental factors contribute to susceptibility to Graves’ disease (GD) and Hashimoto’s thyroiditis (HT), as well as disease manifestations.

Objective: The objective of the study was to define how endogenous/environmental factors contribute to variation in phenotype.

Design/Setting: This was a multicenter cohort study.

Patients/Outcome Measures: We prospectively collected clinical/biochemical data as part of the protocol for a United Kingdom DNA collection for GD and HT. We investigated, in 2805 Caucasian subjects, whether age at diagnosis, gender, family history (FH), smoking history, and presence of goiter influenced disease manifestations.

Results: For 2405 subjects with GD, the presence of goiter was independently associated with disease severity (serum free T4 at diagnosis) (P < 0.001). Free T4 (P < 0.05) and current smoking (P < 0.001) were both independent predictors of the presence of ophthalmopathy. Approximately half of those with GD (47.4% of females, 40.0% of males) and HT (n = 400) (56.4% of females, 51.7% of males) reported a FH of thyroid dysfunction. In GD, a FH of hyperthyroidism in any relative was more frequent than hypothyroidism (30.1 vs. 24.4% in affected females, P < 0.001). In HT, a FH of hypothyroidism was more common than hyperthyroidism (42.1 vs. 22.8% in affected females, P < 0.001). For GD (P < 0.001) and HT (P < 0.05), a FH was more common in maternal than paternal relatives. The reporting of a parent with thyroid dysfunction (hyper or hypo) was associated with lower median age at diagnosis of both GD (mother with hyperthyroidism, P < 0.001) and HT (father with hypothyroidism, P < 0.05). In GD and HT, there was an inverse relationship between the number of relatives with thyroid dysfunction and age at diagnosis (P < 0.01).

Conclusions: Marked associations among age at diagnosis, disease severity, goiter, ophthalmopathy, smoking, and FH provide evidence for interactions between genetic and environmental/endogenous factors; understanding these may allow preventive measures or better tailoring of therapies.
High Prevalence of Pituitary Adenomas: A Cross-Sectional Study in the Province of Liège, Belgium
Authors: Daly Adrian F. , Rixhon Martine , Adam Christelle , Dempegioti Anastasia , Tichomirowa Maria A. , Beckers Albert
Published: September 2006

Context: Prevalence data are important for assessing the burden of disease on the health care system; data on pituitary adenoma prevalence are very scarce.

Objective: The objective of the study was to measure the prevalence of clinically relevant pituitary adenomas in a well-defined population.

Design: This was a cross-sectional, intensive, case-finding study performed in three regions of the province of Liège, Belgium, to measure pituitary adenoma prevalence as of September 30, 2005.

Setting: The study was conducted in specialist and general medical practitioner patient populations, referral hospitals, and investigational centers.

Methods: Three demographically and geographically distinct districts of the province of Liège were delineated precisely using postal codes. Medical practitioners in these districts were recruited, and patients with pituitary adenomas under their care were identified. Diagnoses were confirmed after retrieval of clinical, hormonal, radiological, and pathological data; full demographic and therapeutic follow-up data were collected in all cases.

Results: Sixty-eight patients with clinically relevant pituitary adenomas were identified in a population of 71,972 individuals; the mean (± sd) prevalence was 94 ± 19.3 cases per 100,000 population (95% confidence interval, 72.2 to 115.8). The group was 67.6% female and had a mean age at diagnosis of 40.3 yr; 42.6% had macroadenomas and 55.9% underwent surgery. Prolactinomas comprised 66% of the group, with the rest having nonsecreting tumors (14.7%), somatotropinomas (13.2%), or Cushing’s disease (5.9%); 20.6% had hypopituitarism.

Conclusion: The prevalence of pituitary adenomas in the study population (one case in 1064 individuals) was more than 3.5–5 times that previously reported. This increased prevalence may have important implications when prioritizing funding for research and treatment of pituitary adenomas.
Whose Deaths Matter? Mortality, Advocacy, and Attention to Disease in the Mass Media
Authors: Armstrong Elizabeth M. , Carpenter Daniel P. , Hojnacki Marie
Published: September 2006

Diseases capture public attention in varied ways and to varying degrees. In this essay, we use a unique data set that we have collected about print and broadcast media attention to seven diseases across nineteen years in order to address two questions. First, how (if at all) is mortality related to attention? Second, how (if at all) is advocacy, in the form of organized interest group activity, related to media attention? Our analysis of the cross-disease and cross-temporal variation in media attention suggests that who suffers from a disease as well as how many suffer are critical factors in explaining why some diseases get more attention than others. In particular, our data reveal that both the print and the broadcast media tend to be much less attentive to diseases that disproportionately burden blacks relative to whites. We also find a positive link between the size of organizational communities that take an interest in disease and media attention, though this finding depends on the characteristics of those communities. Finally, this study also reveals the limitations of relying on single-disease case studies—and particularly HIV/AIDS—to understand how and why disease captures public attention. Many previous inferences about media attention that have been drawn from the case of AIDS are not reflective of the attention allocated to other diseases.
Estrogen-receptor-α exchange and chromatin dynamics are ligand- and domain-dependent
Authors: Sharp Z. Dave , Mancini Maureen G. , Hinojos Cruz A. , Dai Fangyan , Berno Valeria , Szafran Adam T. , Smith Kelly P. , Lele Tanmay T. , Ingber Donald E. , Mancini Michael A.
Published: September 2006

We report a mammalian-based promoter chromosomal array system developed for single-cell studies of transcription-factor function. Designed after the prolactin promoter-enhancer, it allows for the direct visualization of estrogen receptor α (ERα) and/or Pit-1 interactions at a physiologically regulated transcription locus. ERα- and ligand-dependent cofactor recruitment, large-scale chromatin modifications and transcriptional activity identified a distinct fingerprint of responses for each condition. Ligand-dependent transcription (more than threefold activation compared with vehicle, or complete repression by mRNA fluorescent in situ hybridization) at the array correlated with its state of condensation, which was assayed using a novel high throughput microscopy approach. In support of the nuclear receptor hit-and-run model, photobleaching studies provided direct evidence of very transient ER-array interactions, and revealed ligand-dependent changes in koff. ERα-truncation mutants indicated that helix-12 and interactions with co-regulators influenced both large-scale chromatin modeling and photobleaching recovery times. These data also showed that the ERα DNA-binding domain was insufficient for array targeting. Collectively, quantitative observations from this physiologically relevant biosensor suggest stochastic-based dynamics influence gene regulation at the promoter level.
Silencing profilin-1 inhibits endothelial cell proliferation, migration and cord morphogenesis
Authors: Ding Zhijie , Lambrechts Anja , Parepally Mayur , Roy Partha
Published: September 2006

Expression of several actin-binding proteins including profilin-1 is up-regulated during capillary morphogenesis of endothelial cells, the biological significance of which remains unknown. Specifically, we hypothesized that profilin-1 is important for endothelial migration and proliferation. In this study, we suppressed profilin-1 expression in human umbilical vein endothelial cells by RNA-interference. Gene silencing of profilin-1 led to significant reduction in the formation of actin filaments and focal adhesions. Loss of profilin-1 expression was also associated with reduced dynamics of cell-cell adhesion. Data from both wound-healing experiments and time-lapse imaging of individual cells showed inhibition of cell migration when profilin-1 expression was suppressed. Cells lacking profilin-1 exhibited defects in membrane protrusion, both in terms of its magnitude and directional persistence. Furthermore, loss of profilin-1 expression inhibited cell growth without compromising cell survival, at least in the short-term, thus suggesting that profilin-1 also plays an important role in endothelial proliferation as hypothesized. Finally, silencing profilin-1 expression suppressed matrigel-induced early cord morphogenesis of endothelial cells. Taken together, our data suggest that profilin-1 may play important role in biological events that involve endothelial proliferation, migration and morphogenesis.
Characterization of a novel meiosis-specific protein within the central element of the synaptonemal complex
Authors: Hamer Geert , Gell Katarina , Kouznetsova Anna , Novak Ivana , Benavente Ricardo , Höög Christer
Published: September 2006

During the first meiotic prophase, alignment and synapsis of the homologous chromosomes are mediated by the synaptonemal complex. Incorrect assembly of this complex results in cell death, impaired meiotic recombination and formation of aneuploid germ cells. We have identified a novel mouse meiosis-specific protein, TEX12, and shown it to be a component of the central element structure of the synaptonemal complex at synapsed homologous chromosomes. Only two other central element proteins, SYCE1 and SYCE2, have been identified to date and, using several mouse knockout models, we show that these proteins and TEX12 specifically depend on the synaptonemal transverse filament protein SYCP1 for localization to the meiotic chromosomes. Additionally, we show that TEX12 exactly co-localized with SYCE2, having the same, often punctate, localization pattern. SYCE1, on the other hand, co-localized with SYCP1 and these proteins displayed the same more continuous expression pattern. These co-localization studies were confirmed by co-immunoprecipitation experiments that showed that TEX12 specifically co-precipitated with SYCE2. Our results suggest a molecular network within the central elements, in which TEX12 and SYCE2 form a complex that interacts with SYCE1. SYCE1 interacts more directly with SYCP1 and could thus anchor the central element proteins to the transverse filaments.
IFTA-2 is a conserved cilia protein involved in pathways regulating longevity and dauer formation inCaenorhabditis elegans
Authors: Schafer Jenny C. , Winkelbauer Marlene E. , Williams Corey L. , Haycraft Courtney J. , Desmond Renee A. , Yoder Bradley K.
Published: September 2006

Defects in cilia are associated with diseases and developmental abnormalities. Proper cilia function is required for sonic hedgehog and PDGFRα signaling in mammals and for insulin-like growth factor (IGF) signaling in Caenorhabditis elegans. However, the role of cilia in these pathways remains unknown. To begin addressing this issue, we are characterizing putative cilia proteins in C. elegans that are predicted to have regulatory rather than structural functions. In this report, we characterized the novel cilia protein T28F3.6 (IFTA-2, intraflagellar transport associated protein 2), which is homologous to the mammalian Rab-like 5 protein. We found that, unlike the intraflagellar transport (IFT) genes, disruption of ifta-2 does not result in overt cilia assembly abnormalities, nor did it cause chemotaxis or osmotic avoidance defects typical of cilia mutants. Rather, ifta-2 null mutants have an extended lifespan phenotype and are defective in dauer formation. Our analysis indicates that these phenotypes result from defects in the DAF-2 (insulin-IGF-1-like) receptor signaling pathway in ciliated sensory neurons. We conclude that IFTA-2 is not a ciliogenic protein but rather is a regulator of specific cilia signaling activities. Interestingly, a mammalian IFTA-2 homolog is also found in cilia, raising the possibility that its function has been conserved during evolution.
Selective membrane exclusion in phagocytic and macropinocytic cups
Authors: Mercanti Valentina , Charette Steve J. , Bennett Nelly , Ryckewaert Jean-Jeacques , Letourneur François , Cosson Pierre
Published: September 2006

Specialized eukaryotic cells can ingest large particles and sequester them within membrane-delimited phagosomes. Many studies have described the delivery of lysosomal proteins to the phagosome, but little is known about membrane sorting during the early stages of phagosome formation. Here we used Dictyostelium discoideum amoebae to analyze the membrane composition of newly formed phagosomes. The membrane delimiting the closing phagocytic cup was essentially derived from the plasma membrane, but a subgroup of proteins was specifically excluded. Interestingly the same phenomenon was observed during the formation of macropinosomes, suggesting that the same sorting mechanisms are at play during phagocytosis and macropinocytosis. Analysis of mutant strains revealed that clathrin-associated adaptor complexes AP-1, -2 and -3 were not necessary for this selective exclusion and, accordingly, ultrastructural analysis revealed no evidence for vesicular transport around phagocytic cups. Our results suggest the existence of a new, as yet uncharacterized, sorting mechanism in phagocytic and macropinocytic cups.
Concurrent Use of Metered-Dose and Dry Powder Inhalers by Children with Persistent Asthma Does Not Adversely Affect Spacer/Inhaler Technique
Authors: Chan Debora S , Callahan Charles W , Hatch-Pigott Virginia B , Lawless Annette , Proffitt H Lorraine , Manning Nola E , Schweikert Mary P
Published: September 2006

Background:

Studies conducted in adults have suggested that patients who use a metered-dose inhaler/holding chamber spacer (MDI/S) and dry powder inhaler (DPI) concurrently will have poorer MDI/S technique than that of patients who use MDI/S exclusively. To our knowledge, as of August 31, 2006, no studies have been performed in pediatric patients.

Objective:

To compare MDI/S technique scores of children using only MDI/S with scores of those using both MDI/S and DPIs.

Methods:

The MDI/S technique of children aged 6–17 years, with persistent asthma, recruited from a general pediatric practice population for an asthma intervention study project was scored using a standardized checklist. MDI/S scores of children who were being treated with maintenance and rescue medication delivered only by MDI/S were compared with those treated with both MDI/S (rescue) and DPI (maintenance). Scores lower than 70% were considered to be inadequate.

Results:

A total of 117 patients (73 male, 44 female), aged 9.70 ± 3.1 years (mean ± SD), with persistent asthma, participated in the study. There were 83 children (54 male, 29 female, age 9.4 ± 3.2 y) in the MDI/S only group and 34 (19 male, 15 female, age 10.3 ± 2.9 y) in the MDI/S + DPI group. In the MDI/S + DPI group, Diskus was the DPI used for 32 patients, and Turbuhaler was used by 2 children. Sixteen patients had severe persistent asthma, 80 had moderate persistent asthma, and 21 had mild persistent asthma as classified by National Heart Lung and Blood Institute guidelines. No difference in sex and age demographics existed; however, there was a difference in the distribution of asthma severity between groups (ie, no patients with mild persistent asthma in the MDI/S + DPI group; p ≤ 0.01). Mean score for the MDI/S only group was 86 ± 17% and, for the MDI/S + DPI group, 90.1 ± 12% (p = 0.15). More patients in the MDI/S group had inadequate scores (18%) compared with those in the MDI/S + DPI group (3%; p < 0.05).

Conclusions:

While DPI and MDI/S techniques are markedly different in several significant ways, concurrent use of these inhalers did not adversely affect MDI/S technique scores of pediatric patients with persistent asthma, compared with those using MDI/S alone. Patients in the MDI/S only group had an inadequate MDI/S score (<70%) more often than did patients in the MDI/S + DPI group.
Consumption of Dietary Supplements Containing Citrus aurantium (Bitter Orange)—2004 California Behavioral Risk Factor Surveillance Survey (BRFSS)
Authors: Klontz Karl C , Timbo Babgaleh B , Street Debra
Published: September 2006

Background:

Following the marketing ban of ephedra-containing supplements in April 2004, many manufacturers substituted the herb Citrus aurantium for ephedra and marketed the products as “ephedra-free” supplements. Extracts of C. aurantium contain synephrine, a sympathomimetic alkaloid.

Objective:

To determine the prevalence of consumption of dietary supplements containing C. aurantium in California during 2004.

Methods:

We used the 2004 California Behavioral Risk Factor Surveillance Survey to determine the prevalence of consumption of dietary supplements containing C. aurantium in California during 2004.

Results:

Two percent (n = 70) of the 4140 survey respondents reported taking a dietary supplement containing C. aurantium in the previous year. Reasons stated included energy enhancement, weight loss, and appetite suppression. Compared with nonusers, users were more likely to report being single, aged 18–34 years, and Hispanic; consuming 3 or more alcoholic drinks on days that they imbibed; and having a heavier body mass index. Among the 5 users who reported experiencing an adverse event that they attributed to the supplement, 3 indicated that the severity was mild.

Conclusions:

Given that supplements containing ephedra were banned in April 2004, the results from this study may serve as a baseline estimate against which future studies of the use of C. aurantium products may be compared.
Effect of Pressure on the Sorption of Yb by Montmorillonite
Authors: Miller Steven E. , Ross Heath G. , Gonzalez Richard D.
Published: September 2006

X-ray diffraction, infrared, and cation-exchange capacity measurements of the reaction products of montmorillonites with YbCl3.6H2O show that at 1 atm irreversible sorption of Yb3+ increases with increasing temperature in the range 20° to 280°C, whereas at 110 atm it decreases with increasing temperature. Above 100°C, less irreversible sorption occurs at 110 atm than at 1 atm. The decreased sorption at high pressure is attributed to reduced cation hydrolytic fixation and to rapid expulsion of interlayer Yb3+ by interlayer water at higher temperatures, with a concomitant decrease in Yb3+ migration to octahedral sites. At 110 atm, 160° and 200°C treatments cause changes in infrared absorption bands (884 cm-1, 848 cm-1) suggesting that sorbed Yb3+ is charge compensated by the deprotonation of Fe3+- and Mg2+-hydroxyl groups. At 290°C deprotonation is restricted to Fe3+-hydroxyl groups.
Charge Heterogeneity in Smectites
Authors: Talibudeen Oscar , Goulding Keith W. T.
Published: September 2006

The heterogeneity of sites for Ca→K exchange was examined by microcalorimetry in the <0.2-μm fractions of some selected smectites. Six groups of sites, ranging in exothermic exchange enthalpy (-d(ΔHx)/dx) from 5.7 to 10.9 kJ/eq were identified. In Wyoming bentonites, only three groups with enthalpies of 5.7 to 7.5 kJ/eq were distinguished, although in the 0.2-1.0-μm fraction, a 10.7-kJ/eq group was also observed. Redhill and Camp Berteau smectites contained, in addition, groups with enthalpies of 8.7-10.9 kJ/eq, but a New Mexico sample only had groups with the higher values. Thus, the exchange enthalpies of four main groups of sites (reclassified from those observed) appear to be inversely related to the extents of interlayer expansion in the samples by the adsorption of polar molecules. Consequently, a 'true mont-morillonite,’ such as a <0.2-μm Wyoming bentonite, contains only fully expanding layers with -d(ΔHx)/ dx values between 5.7 and 7.5 kJ/eq. As such, it is less heterogeneous and should have a much greater swelling capability than Camp Berteau montmorillonite which has, in addition, groups with exchange enthalpies of 8.7 and 10.3 kJ/eq.
Potassium Fixation by Clay Minerals during Hydrothermal Treatment
Authors: Inoue Atsuyuki
Published: September 2006

The amount of K fixed in K- and Ca-saturated montmorillonite, vermiculite (trioctahedral), rectorite-type and IMII-ordered mica/montmorillonites was measured as a function of time (1–64 days), temperature (25o-300°C), pH (6.0, 9.7, and 10.7), and K-concentration (0.02 and 1.0 M) in solution. The amount of K fixed by the clays generally increased with increasing temperature, pH, and K-concentration and reached saturation in response to each experimental condition in 5 or 6 days. The K-montmorillonite and K-vermiculite fixed considerable amounts of K even at 25°C. Fixed K in montmorillonite increased with an increase of the layer charge which is also influenced significantly by the interlayer cation. In detail, the behavior in K-fixation was specific to each clay.

The type of structural transformation with K-fixation was different for each clay. In montmorillonite, especially, the type of transformation was related to the cationic composition of the system; in K homoionic system, montmorillonite transformed rapidly into illite/montmorillonite with about 40% expandable layers at 300°C and in a mixed cation system with Ca and K, it reacted gradually to random illite/montmorillonites with increasing temperature. These data indicate that the cation-exchange process of a natural pore solution plays an important role in the gradual transformation of detrital montmorillonite to illite.
Interlayer Cations as Reaction Directors in the Transformation of Limonene on Montmorillonite
Authors: Frenkel M. , Heller-Kallai L.
Published: September 2006

Clays may catalyze chemical reactions by acting as Brönsted acids, Lewis acids, and/or Lewis bases. The changes occurring when limonene (p-menthadiene) is heated in the presence of montmorillonite illustrate how Brönsted and Lewis acidity may operate competitively, the nature of the interlayer cations determining which reaction dominates. The rate at which the starting material disappears increases with the acidity of the clay, which depends upon the interlayer cations (Na < Mg < Al < H). The concentration of disproportionation and isomerization products reaches a maximum after reaction times which decrease with increasing surface acidity of the clay, p-cymene is produced by oxidation in concentrations inversely related to the surface acidity of the clay. The course of the chemical reaction can thus be steered in the preferred direction by an appropriate choice of interlayer cations.
Crystal Structure of Cronstedtite-2H2
Authors: Geiger Charles A. , Henry Diane L. , Bailey S. W. , Maj Joseph J.
Published: September 2006

The crystal structure of a magnesian cronstedtite-2H2 from Pribram, Czechoslovakia, was refined in space group C1 to a residual of 5.4% with 1832 independent reflections. Tetrahedral ordering between Fe3+ and Si is judged to be complete on the basis of electron density maps, the first confirmation of such ordering in a layer silicate. Octahedral cations are disordered on the M sites. Mean T-O bond lengths do not confirm the tetrahedral ordering, perhaps due to tetrahedral distortion in order to relieve the extreme corrugation of the sheet that would arise from ordering of such different size cations.

In the initial stages of refinement the structure of the crystal under study could not be described adequately on the basis of a single 2H2 polytype. The structure contains two kinds of 2H2 domains that appear shifted by b/3 relative to one another due to a mistake in the interlayer stacking sequence. This mistake of zero shift (the normal 2H2 polytype consists of alternating —b/3 and +b/3 shifts) affects only the tetrahedral sheets. It creates adjacent enantiomorphic domains of 2H2 packets such that domains with small Si tetrahedra sit above larger Fe3+-rich tetrahedra and vice versa. This mechanism to relieve strain may indeed be the cause of the stacking mistakes. A third kind of domain contains regions in which the sense of tetrahedral rotation is reversed, giving rise to split basal oxygens on electron density maps. This multiple domain model best explains extra atomic positions observed on Fourier maps, lack of streaking of k ≠ 3n reflections, and possible nonintegral “satellitic” reflections observed on Weissenberg films.
Role of Ferric Iron in the Oxidation of Hydrocortisone by Sepiolite and Palygorskite
Authors: Cornejo J. , Hermosin M. C. , White J. L. , Barnes J. R. , Hem S. L.
Published: September 2006

The role of adsorbed and structural Fe3+ in palygorskite and sepiolite with respect to the oxidation of hydrocortisone in aqueous suspension has been evaluated using electron spin resonance and UV-visible spectroscopy. Natural surface-adsorbed Fe3+ showed an important activity in the oxidation process, although smaller than octahedral Fe3+. The kinetics of oxidative degradation of hydrocortisone by palygorskite appear to be composed of two apparent first order reactions which may be associated with two kinds of sites for Fe in palygorskite. The lower oxidizing power of sepiolite for hydrocortisone degradation is due to its very low Fe3+ content.
Hydrothermal Reactions of Strontium and Transuranic Simulator Elements with Clay Minerals, Zeolites, and Shales
Authors: Komarneni Sridhar , White William B.
Published: September 2006

Reactions of Sr, La, and Nd (the latter two elements simulating Am and Cm) with potential backfill minerals for radioactive waste storage and with repository wall rocks, such as shale, were investigated under simulated repository conditions of 200° and 300°C for 12 weeks under a confining pressure of 30 MPa. The solid and solution reaction products were characterized to determine the nature and extent of reaction. Chlorite, illite, kaolinite, montmorillonite, mordenite, and clinoptilolite and four shales removed as much as 61.2 and 98.5% of the added SrCl2 and Sr(OH)2 from solution, respectively, by ion exchange and/or by forming new strontium compounds such as SrAl2Si2O8, Sr2MgSi2O7, SrCO3 (strontianite), and SrAl2Si4O12·2H2O (Sr-wairakite). The formation of these sparingly soluble Sr phases by the reaction of the soluble Sr compounds with such backfill materials indicates that the backfill may serve as a barrier during the thermal period of the waste in the life of a repository. These same minerals and shales removed as much as 99.99% of the added La or Nd from solution at 300°C by forming new phases such as LaOHCO3, NdOHCO3, and possibly La or Nd oxides and hydroxides. Zeolites reacted with La and Nd to form smectite. Thus, if La and Nd truly simulate the reactivity of Am and Cm, properly designed backfills can serve as a barrier to the migration of transuranic elements of nuclear wastes.
Clays, Cations, and Geophysical Log Response of Gas-Producing and Nonproducing Zones in the Gammon Shale (Cretaceous), Southwestern North Dakota
Authors: Gautier Donald L. , Starkey Harry C. , Takahashi Kenneth I.
Published: September 2006

The Upper Cretaceous Gammon Shale has served as both source bed and reservoir rock for accumulations of natural gas. Gas-producing and nonproducing zones in the Gammon Shale are differentiated on the basis of geophysical log interpretation. To determine the physical basis of the log responses, mineralogical, cation-exchange, textural, and chemical analyses were conducted on core samples from both producing and nonproducing portions of a well in the Gammon Shale from southwestern North Dakota. Statistical treatment (2 sample t-test and discriminant function analysis) of the laboratory data indicate that the producing and nonproducing zones differ significantly in mixed-layer clay content (7 vs. 12%), weight proportion of the clay-size (0.5-1.0 μm) fraction (5.3 vs. 6.3%) ratio of Ca2+ to Na+ extracted during ion exchange (1.4 vs. 1.0), and abundance of dolomite (10 vs. 8%). The geophysical logs apparently record subtle differences in composition and texture which probably reflect variations in the original detrital constituents of the Gammon sediments. Successfully combining log interpretation and clay petrology aids in understanding the physical basis of log response in clay-rich rocks and enhances the effectiveness of logs as predictive geologic tools.
Reactions of Alcohols with Alkenes over an Aluminum-Exchanged Montmorillonite
Authors: Adams J. M. , Clement D. E. , Graham S. H.
Published: September 2006

The reaction of 2-methyl pent-2-ene with primary alcohols (C1-C18) at 95°C over an Al-montmorillonite gave yields of 20–90% of ethers of the type R-O-C(CH3)2C3H7. Lower yields were produced if secondary alcohols were employed, and tertiary alcohols gave only a trace of this ether. When a variety of alkenes was reacted with butan-1-ol at 95°C over a similar catalyst, no reaction occurred unless the alkene was capable of forming a tertiary carbonium ion immediately upon protonation. In this case the product was the tertiary ether t-R-O-nC4H9. However, at a reaction temperature of 150°C a variety of products were formed including (1) ether by the attack of butanol on the carbonium ions produced either directly from protonation of the alkenes or by hydride shift from such an ion, (2) alkenes by the attack of n-C4H9+ ions (derived from protonation and dehydration of butanol) on the alkene, (3) di-(but-1-yl) ether by dehydration of the butanol, and (4) small amounts of alcohol by hydration of the alkene. The differences in reactivity below and above 100°C are related directly to the amount of water present in the interlayer space of the clay and the degree of acidity found there. Although the clay behaves as an acid catalyst, the reactions are far cleaner (more selective) than comparable reactions catalyzed by sulfuric acid.
Intergradient Vermiculite-Kaolin Mineral in a Korean Ultisol
Authors: Wada Koij , Kakuto Yasuko
Published: September 2006

A 14-Å mineral coexisting with kaolin minerals, mica, and gibbsite in a Korean Ultisol and showing X-ray powder diffraction features of “chloritized” vermiculite was studied by a combination of methods. The 14-Å mineral collapsed on saturation with K+ after extraction with hot 1/3 M sodium citrate, but the Si/Al ratio of the extracted material was close to 1.0 and kaolin minerals dissolved, as indicated by difference infrared spectroscopy. The 14-Å mineral was also collapsed by heating at or above 350°C. The difference infrared spectra and the X-ray powder diffraction patterns indicated that two forms of kaolin mineral are present that differ in thermal stability; one decomposed by heating at or below 375°C and the other by heating above 375°C. The former kaolin mineral is probably associated with vermiculite and the latter is present as a discrete form. The 14-Å mineral was inferred to be an intergradient vermiculite-kaolin mineral, in which most vermiculite layers each partially transform into double kaolin layers, and to represent an intermediate phase during the transformation of 2:1 to 1:1 layer silicates in acid soils.