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1.
Sci Rep ; 13(1): 22119, 2023 12 13.
Article in English | MEDLINE | ID: mdl-38092830

ABSTRACT

Collagen glue has been used for nearly two centuries to consolidate bone material, although its prevalence in museum collections is only now becoming visible. Identifying and removing collagen glue is crucial before the execution of any geochemical or molecular analyses. Palaeolithic bone objects from old excavations intended for radiocarbon dating were first analysed using ZooMS (Zooarchaeology by Mass Spectrometry) to identify the animal species, however peaks characteristic of both cattle and whale were discovered. Two extraction methods for ZooMS were tested to identify the authentic animal species of these objects, which revealed that these were originally whale bone objects that had been consolidated with cattle collagen glue. This is the first time animal collagen glue has been identified in archaeological remains with ZooMS, illustrating again the incredible versatility of this technique. Another technique, Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance mode (FTIR-ATR), was also tested if it could rapidly identify the presence of collagen glue in archaeological bone material, which was not the case. Two other cleaning methods were tested to remove bone glue contamination prior to radiocarbon dating, along with two modified collagen extraction methods for ZooMS. These methods were applied to bone blank samples (FmC = 0.0031 ± 0.0002, (n = 219), 47 336 ± 277 yr BP) that were experimentally consolidated with collagen glue and to the Palaeolithic bone material (ca. 15 000 and 12 000 yr BP). The experimental bone blanks produced excellent 14C ages, suggesting the cleaning methods were successful, however the 14C ages for some of the Palaeolithic material remained too young considering their contextual age, suggesting that the collagen glue contamination had most likely cross-linked to the authentic collagen molecule. More research is needed in order to gain a deeper understanding of the occurrence and elimination of cross-linked collagen-based glues in material from museum collections.


Subject(s)
Collagen , Radiometric Dating , Animals , Cattle , Radiometric Dating/methods , Carbon Radioisotopes/analysis , Collagen/chemistry , Bone and Bones/chemistry , Archaeology/methods , Whales
2.
Neurology (Chic) ; 2(2): 42-47, 2022.
Article in English | MEDLINE | ID: mdl-36507115

ABSTRACT

Epigenetic changes have been linked to a host of disease states. Besides the physiological function of epigenetic changes in regulating cellular function, recent data indicates that key changes in epigenetic activity also play an important pathophysiologic role following neurotrauma specifically. Such manifestations occur through the activation or silencing of different genes. Histone methylation has emerged as a critical component of this process and can be selectively modulated after injury. Pre-clinical studies have resulted in key discoveries regarding specific methylation sites of interest. This focused review highlights some of these early findings and their relationship to clinical outcomes. These findings suggest areas of future investigation and discovery in the quest to develop ideal biomarkers and methods to utilize them in developing therapeutic interventions.

4.
Radiat Res ; 196(3): 284-296, 2021 09 01.
Article in English | MEDLINE | ID: mdl-34153091

ABSTRACT

Thrombocytopenia is a major complication in hematopoietic-acute radiation syndrome (H-ARS) that increases the risk of mortality from uncontrolled hemorrhage. There is a great demand for new therapies to improve survival and mitigate bleeding in H-ARS. Thrombopoiesis requires interactions between megakaryocytes (MKs) and endothelial cells. 16, 16-dimethyl prostaglandin E2 (dmPGE2), a longer-acting analogue of PGE2, promotes hematopoietic recovery after total-body irradiation (TBI), and various angiotensin-converting enzyme (ACE) inhibitors mitigate endothelial injury after radiation exposure. Here, we tested a combination therapy of dmPGE2 and lisinopril to mitigate thrombocytopenia in murine models of H-ARS following TBI. After 7.75 Gy TBI, dmPGE2 and lisinopril each increased survival relative to vehicle controls. Importantly, combined dmPGE2 and lisinopril therapy enhanced survival greater than either individual agent. Studies performed after 4 Gy TBI revealed reduced numbers of marrow MKs and circulating platelets. In addition, sublethal TBI induced abnormalities both in MK maturation and in in vitro and in vivo platelet function. dmPGE2, alone and in combination with lisinopril, improved recovery of marrow MKs and peripheral platelets. Finally, sublethal TBI transiently reduced the number of marrow Lin-CD45-CD31+Sca-1- sinusoidal endothelial cells, while combined dmPGE2 and lisinopril treatment, but not single-agent treatment, accelerated their recovery. Taken together, these data support the concept that combined dmPGE2 and lisinopril therapy improves thrombocytopenia and survival by promoting recovery of the MK lineage, as well as the MK niche, in the setting of H-ARS.


Subject(s)
16,16-Dimethylprostaglandin E2/therapeutic use , Acute Radiation Syndrome/drug therapy , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Blood Platelets/drug effects , Endothelial Cells/drug effects , Hemorrhagic Disorders/drug therapy , Lisinopril/therapeutic use , Megakaryocytes/drug effects , Thrombocytopenia/drug therapy , Thrombopoiesis/drug effects , Acute Radiation Syndrome/complications , Animals , Blood Platelets/radiation effects , Bone Marrow/drug effects , Bone Marrow/radiation effects , C-Reactive Protein/analysis , Cesium Radioisotopes , Drug Evaluation, Preclinical , Endothelial Cells/radiation effects , Endothelium, Vascular/drug effects , Endothelium, Vascular/radiation effects , Female , Gamma Rays/adverse effects , Hemorrhagic Disorders/etiology , Megakaryocytes/radiation effects , Mice , Mice, Inbred C57BL , P-Selectin/analysis , Platelet Aggregation/drug effects , Platelet Aggregation/radiation effects , Platelet Factor 4/analysis , Radiation Injuries, Experimental/drug therapy , Radiation Injuries, Experimental/etiology , Thrombocytopenia/etiology , Thrombopoiesis/radiation effects , Whole-Body Irradiation , von Willebrand Factor/analysis
5.
Curr Hypertens Rep ; 22(5): 37, 2020 04 14.
Article in English | MEDLINE | ID: mdl-32291521

ABSTRACT

PURPOSE OF REVIEW: Preeclampsia is a dangerous pregnancy condition affecting both the mother and offspring. It is a multifactorial disease with poorly understood pathogenesis, lacking effective treatments. Maternal immune response, inflammation and oxidative stress leading to endothelial dysfunction are the most prominent pathogenic processes implicated in preeclampsia development. Here, we give a detailed overview of the therapeutic applications and mechanisms of mesenchymal stem/stromal cells (MSCs) as a potential new treatment for preeclampsia. RECENT FINDINGS: MSCs have gained growing attention due to low immunogenicity, easy cultivation and expansion in vitro. Accumulating evidence now suggests that MSCs act primarily through their secretomes facilitating paracrine signalling that leads to potent immunomodulatory, pro-angiogenic and regenerative therapeutic effects. MSCs have been studied in different animal models of preeclampsia demonstrating promising result, which support further investigations into the therapeutic effects and mechanisms of MSC-based therapies in preeclampsia, steering these therapies into clinical trials.


Subject(s)
Hypertension , Mesenchymal Stem Cells , Pre-Eclampsia , Animals , Female , Humans , Inflammation , Pre-Eclampsia/therapy , Pregnancy
6.
Clin Exp Pharmacol Physiol ; 45(7): 694-703, 2018 07.
Article in English | MEDLINE | ID: mdl-29381829

ABSTRACT

Sex differences in disease susceptibility due to maternal programming have been reported. We previously observed that maternal smoking induced renal disease and neurological changes are restricted to males, while both male and female offspring develop metabolic disorders. We have also found that maternal L-carnitine supplementation during gestation and lactation can significantly improve glucose intolerance and hyperlipidaemia in male offspring. This study aimed to determine whether such beneficial effects can also occur in female offspring. Balb/c female mice were exposed to cigarette smoke (SE) 6 weeks prior to gestation, during gestation and lactation. A subgroup of the SE dams was given L-carnitine (1.5 mmol/L in drinking water) during gestation and lactation. Female offspring were studied at 20 days (weaning) and 13 weeks (adulthood). Maternal smoking increased liver weight (%) and blood glucose levels at 20 days, as well as glucose intolerance and plasma triglycerides levels at adulthood (P < .05). The hepatic lipid metabolic marker adipose triglyceride lipase was downregulated in the SE offspring at 20 days (P < .05). At 13 weeks, the hepatic pro-inflammatory markers IL-1ß and TNF-α mRNA expression were upregulated, while the anti-inflammatory marker IL-10 mRNA expression was downregulated in the SE offspring (P < .05). Liver fibrosis was apparent at 20 days and 13 weeks. Maternal L-carnitine supplementation either normalised or suppressed the detrimental effects induced by maternal smoke exposure (P < .05). We conclude that maternal L-carnitine supplementation improves metabolic parameters in the female offspring of SE dams.


Subject(s)
Carnitine/pharmacology , Cigarette Smoking/adverse effects , Dietary Supplements , Glucose/metabolism , Lipid Metabolism/drug effects , Maternal Exposure/adverse effects , Animals , Biomarkers/metabolism , Female , Fibrosis , Liver/drug effects , Liver/metabolism , Liver/pathology , Mice , Mice, Inbred BALB C , Pregnancy
7.
Methods ; 112: 68-74, 2017 01 01.
Article in English | MEDLINE | ID: mdl-27582124

ABSTRACT

Adult humans need to make 2.5million red blood cells (RBCs) every second to maintain a steady state level of 25trillion circulating RBCs. Understanding normal erythropoiesis as well as diseases that afflict the erythron, such as genetic anemias, hyperproliferative disorders, and myelodysplastic syndromes, requires a robust method to delineate erythropoietic intermediates. In order to apply the power of flow cytometry to these studies, challenges of limited immunophenotypic markers, incorporation of significant changes in morphology, and maturational changes that occur along a continuum need to be met. Imaging flow cytometry (IFC) provides a solution to address these challenges. Integration of changes in immunophenotype, loss of RNA (ribosomes), and enucleation, with morphological characteristics of cell and nuclear size, can be used to delineate erythroblasts that correlate with classical histological classifications. A protocol is described that demonstrates the basic approaches of staining panel selection, mask generation and selection of features to best sequentially refine erythroid intermediates and remove contaminating cells with overlapping immunophenotype. Ultimately erythroid cells in the murine bone marrow are divided into seven sub-populations using IFC including four erythroblasts (pro-, basophilic, polychromatophilic and orthochromatic), the pyrenocyte, which contains the eliminated nucleus, the enucleated reticulocyte and the mature RBC.


Subject(s)
Bone Marrow Cells/cytology , Cell Lineage/genetics , Erythropoiesis/genetics , Flow Cytometry/methods , Image Cytometry/methods , Animals , Biomarkers/metabolism , Bone Marrow Cells/classification , Bone Marrow Cells/metabolism , Cell Cycle/genetics , Cell Differentiation , Cell Nucleus/ultrastructure , Erythroblasts/cytology , Erythroblasts/metabolism , Erythrocytes/cytology , Erythrocytes/metabolism , Flow Cytometry/instrumentation , Humans , Image Cytometry/instrumentation , Mice , Primary Cell Culture , Reticulocytes/cytology , Reticulocytes/metabolism , Ribosomes/ultrastructure , Staining and Labeling/methods
8.
Seizure ; 38: 68-74, 2016 May.
Article in English | MEDLINE | ID: mdl-27164312

ABSTRACT

PURPOSE: The study aimed to assess whether engagement in a memory training programme and performing internet brain training exercises improve memory function in people with temporal lobe epilepsy (TLE). METHODS: Seventy-seven people with TLE, complaining of memory difficulties, completed the study. Participants ranged in age from 19 to 67 years and 40 had left TLE. Participants were randomised to one of four conditions; Group 1: traditional memory training, Group 2: Lumosity, an on-line cognitive training programme, Group 3: traditional memory training and Lumosity, and Group 4: no training. Memory efficiency and mood were assessed at baseline and three months later. RESULTS: Group analyses indicated improved verbal recall after training (p<0.001) and improved subjective ratings (p<0.007). More participants reported a lessening of the memory burden (p<0.007) after training; differences were significant between Groups 1 and 3 compared to Group 4. Lumosity use was not associated with changes in the memory outcome measures but there was a relationship with depression ratings and the number of memory games played (p<0.01). Conventional memory training, IQ, and post-surgical status were associated with positive memory outcomes. CONCLUSIONS: The study indicates traditional memory rehabilitation techniques can help reduce the burden of memory impairment in TLE. There was no evidence that Lumosity the on-line cognitive training programme had specific advantages. Positive change was not universal and larger studies will be required to explore factors associated with successful outcomes.


Subject(s)
Epilepsy, Temporal Lobe/rehabilitation , Learning , Memory Disorders/rehabilitation , Neurological Rehabilitation/methods , Outcome Assessment, Health Care , Adult , Aged , Epilepsy, Temporal Lobe/complications , Female , Humans , Internet , Male , Memory Disorders/etiology , Middle Aged , Young Adult
10.
Clin Exp Allergy ; 41(1): 46-51, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21105916

ABSTRACT

BACKGROUND: The frequency of adults reporting a history of asthma is rising. However, it is unclear whether this increased prevalence accurately demonstrates a rising trend or if it reflects an overall increase in asthma awareness. OBJECTIVE: To determine the frequency of negative methacholine bronchoprovocation tests in adults who report physician-diagnosed asthma and to explore the clinical characteristics of subjects with negative tests. METHODS: Data from methacholine challenge, spirometry, and physician assessment were analysed from 304 adults who reported physician-diagnosed asthma and responded to community-based advertising for asthma research studies. The clinical characteristics of methacholine-positive and -negative subjects were compared and a predictive model was tested to identify those characteristics associated with a negative test. RESULTS: Of the 304 subjects tested, 83 (27%) had a negative methacholine test. A negative test was positively associated with an adult-onset of symptoms (P<0.001), normal forced expiratory volume in 1 s (P<0.001), and having no history of exacerbation requiring oral steroids (P=0.03). Over half (60%) of those with a negative test reported weekly asthma-like symptoms (cough, dyspnoea, chest tightness, or wheeze), while 39% reported emergency department visits for asthma-like symptoms. CONCLUSIONS AND CLINICAL RELEVANCE: A sizeable percentage of subjects who report physician-diagnosed asthma have a negative methacholine challenge test. These subjects are characterized by diagnosis of asthma as an adult and by normal or near normal spirometry. Caution should be exercised in the assessment and diagnosis of adults presenting with asthma-like symptoms, because they may not have asthma. Further diagnostic studies, including bronchoprovocation testing, are warranted in this patient group, especially if their spirometry is normal.


Subject(s)
Asthma/diagnosis , Bronchial Provocation Tests/methods , Methacholine Chloride , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Physicians , Young Adult
12.
Am J Transplant ; 9(11): 2485-96, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19775318

ABSTRACT

The results of transplantation of human donor islets into the portal vein (PV) in patients with diabetes are encouraging. However, there are complications, for example, hemorrhage, thrombosis and an immediate loss of islets through the 'instant blood-mediated inflammatory reaction' (IBMIR). The gastric submucosal space (GSMS) offers potential advantages. Islets were isolated from adult pigs. Recipient pigs were made diabetic by streptozotocin. Donor islets were injected into the GSMS through a laparotomy (Group 1A, n = 4) or endoscopically (Group 1B, n = 8) or into the PV through a laparotomy (Group 2, n = 3). The pigs were followed for a maximum of 28 days. Monitoring of C-peptide in Group 1 indicated that there was minimal immediate loss of islets whereas in Group 2 there was considerable loss from IBMIR. In Group 1, there were significant reductions in mean blood glucose and mean exogenous insulin requirement between pretransplantation and 20 days posttransplantation. In Group 2, there was no significant reduction in either parameter. Insulin-positive cells were seen in the GSMS in Group 1, but not in the liver in Group 2. Endoscopic gastric submucosal transplantation of islets (ENDO-STI) offers a minimally invasive and quick approach to islet transplantation, avoids IBMIR and warrants further exploration.


Subject(s)
Diabetes Mellitus, Experimental/surgery , Endoscopy/methods , Gastric Mucosa/surgery , Islets of Langerhans Transplantation/methods , Animals , Blood Glucose/metabolism , C-Peptide/blood , Combined Modality Therapy , Diabetes Mellitus, Experimental/drug therapy , Female , Graft Rejection/drug therapy , Graft Rejection/immunology , Graft Rejection/pathology , Graft Survival , Hypoglycemic Agents/pharmacology , Immunosuppressive Agents/pharmacology , Insulin/pharmacology , Islets of Langerhans Transplantation/immunology , Mycophenolic Acid/analogs & derivatives , Mycophenolic Acid/pharmacology , Pancreatectomy , Sus scrofa , Tacrolimus/pharmacology , Transplantation, Homologous
13.
Arterioscler Thromb Vasc Biol ; 29(6): 877-82, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19325144

ABSTRACT

OBJECTIVE: The purpose of this study was to investigate the ability of high-density lipoproteins (HDLs) to upregulate genes with the potential to protect against inflammation in endothelial cells. METHODS AND RESULTS: Human coronary artery endothelial cells (HCAECs) were exposed to reconstituted HDLs (rHDLs) for 16 hours before being activated with tumor necrosis factor-alpha (TNF-alpha) for 5 hours. rHDLs decreased vascular cell adhesion molecule-1 (VCAM-1) promoter activity by 75% (P<0.05), via the nuclear factor-kappa B (NF-kappaB) binding site. rHDLs suppressed the canonical NF-kappaB pathway and decreased many NF-kappaB target genes. Suppression of NF-kappaB and VCAM-1 expression by rHDLs or native HDLs was dependent on an increase in 3beta-hydroxysteroid-Delta 24 reductase (DHCR24) levels (P<0.05). The effect of HDLs on DHCR24 is dependent on SR-BI but not ABCAI or ABCGI. Silencing DHCR24 expression increased NF-kappaB (1.2-fold, P<0.05), VCAM-1 (30-fold, P<0.05), and NF-kappaB p50 (4-fold, P<0.05) and p65 subunits (150-fold, P<0.05). TNF-alpha activation of siDHCR24-treated cells increased expression of VCAM-1 (550-fold, P<0.001) and NF-kappaB (9-fold, P<0.001) that could no longer be suppressed by rHDLs. CONCLUSIONS: Results suggest that antiinflammatory effects of rHDLs are mediated partly through an upregulation of DHCR24. These findings raise the possibility of considering DHCR24 as a target for therapeutic modulation.


Subject(s)
Apolipoprotein A-I/metabolism , Arteritis/prevention & control , Atherosclerosis/prevention & control , Endothelial Cells/enzymology , Lipoproteins, HDL/metabolism , Nerve Tissue Proteins/metabolism , Oxidoreductases Acting on CH-CH Group Donors/metabolism , Animals , Apolipoprotein A-I/administration & dosage , Arteritis/enzymology , Arteritis/etiology , Arteritis/genetics , Atherosclerosis/enzymology , Atherosclerosis/etiology , Atherosclerosis/genetics , Cells, Cultured , Cholesterol, Dietary , Disease Models, Animal , Gene Expression Profiling , Gene Expression Regulation , Humans , I-kappa B Kinase/metabolism , I-kappa B Proteins/metabolism , Infusions, Intravenous , Lipoproteins, HDL/administration & dosage , NF-KappaB Inhibitor alpha , NF-kappa B/metabolism , Nerve Tissue Proteins/genetics , Oxidoreductases Acting on CH-CH Group Donors/genetics , Promoter Regions, Genetic , RNA Interference , RNA, Small Interfering/metabolism , Rabbits , Transfection , Tumor Necrosis Factor-alpha/metabolism , Vascular Cell Adhesion Molecule-1/metabolism
14.
Vasc Health Risk Manag ; 4(1): 11-21, 2008.
Article in English | MEDLINE | ID: mdl-18629352

ABSTRACT

Cardiovascular disease (CVD) remains the leading cause of death in Western society today. There is a striking gender difference in CVD with men predisposed to earlier onset and more severe disease. Following the recent reevaluation and ongoing debate regarding the estrogen protection hypothesis, and given that androgen use and abuse is increasing in our society, the alternate view that androgens may promote CVD in men is assuming increasing importance. Whether androgens adversely affect CVD in either men or women remains a contentious issue within both the cardiovascular and endocrinological fraternities. This review draws from basic science, animal and clinical studies to outline our current understanding regarding androgen effects on atherosclerosis, the major CVD, and asks where future directions of atherosclerosis-related androgen research may lie.


Subject(s)
Androgens/therapeutic use , Arteriosclerosis/complications , Cardiovascular Diseases/drug therapy , Androgens/metabolism , Animals , Arteriosclerosis/physiopathology , Cardiovascular Diseases/etiology , Cardiovascular Diseases/physiopathology , Cardiovascular Diseases/prevention & control , Clinical Trials as Topic , Humans , Risk Factors
15.
Endoscopy ; 40(3): 200-3, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18067066

ABSTRACT

BACKGROUND AND STUDY AIMS: Solid pseudopapillary tumors of the pancreas are rare, low-grade, epithelial neoplasms that are usually discovered incidentally in young women. Distinguishing solid pseudopapillary tumors from other pancreatic tumors, especially pancreatic endocrine tumors, can be challenging. The role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in this context remains unclear. The purpose of this study was to describe the endoscopic ultrasound features of solid pseudopapillary tumors and the role of EUS-FNA in the preoperative diagnosis of these tumors. PATIENTS AND METHODS: Patients from five tertiary referral centers with surgically confirmed solid pseudopapillary tumors who had undergone preoperative EUS-FNA were included. The endoscopic ultrasound findings, cytologic descriptions, immunostaining results, operative records, surgical pathology, and results of the most recent clinical follow-up were reviewed. RESULTS: A total of 28 patients were identified (four men [14 %], 24 women [86 %], mean age +/- standard deviation [SD] 35 +/- 10 years). Solid pseudopapillary tumors had been found as incidental findings on cross-sectional imaging in 50 % of cases. The mean tumor size +/- SD was 42 +/- 19.5 mm and the majority were located in the pancreatic body and tail. The endoscopic ultrasound report described a well-defined, echo-poor mass in 86 %; the tumors were solid in 14 patients (50 %), mixed solid and cystic in 11 patients (39 %), and cystic in three patients (11 %). A preoperative diagnosis of solid pseudopapillary tumor was made in 21 patients (75 %) on the basis of EUS-FNA cytology. Surgical resection was performed in all cases. Laparoscopic resection was performed in eight of these patients (29 %). CONCLUSIONS: A solid pseudopapillary tumor should be included in the differential diagnosis of any well-demarcated, echo-poor, solid or mixed solid/cystic pancreatic lesion seen during endoscopic ultrasound, particularly in young women. The diagnostic accuracy of EUS-FNA for solid pseudopapillary tumors was 75 % in this study. A definitive preoperative diagnosis can guide the surgical approach in selected cases.


Subject(s)
Biopsy, Fine-Needle/methods , Endosonography , Pancreatic Neoplasms/diagnostic imaging , Pancreatic Neoplasms/pathology , Adolescent , Adult , Cohort Studies , Female , Humans , Incidental Findings , Male , Middle Aged , Pancreatic Neoplasms/surgery , Retrospective Studies , Surgery, Computer-Assisted
16.
Phys Rev E Stat Nonlin Soft Matter Phys ; 75(1 Pt 1): 011903, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17358180

ABSTRACT

Dielectric loss spectra are reported for alpha -tocopherol acetate (an isomer of vitamin E) in the supercooled and glassy states. The alpha -relaxation times, tau_{alpha} , measured over a 190 degrees range of temperatures, T , at pressures, P , up to 400MPa can be expressed as a single function of TV3.9 ( V is specific volume, measured herein as a function of T and P ). At ambient pressure, there is no dynamic crossover over eight decades of measured tau_{alpha} . The relaxation spectra above the glass transition temperature T_{g} show ionic conductivity and an excess wing on the high-frequency flank of the alpha -relaxation loss peak. Temperature-pressure superpositioning is valid for the alpha process; moreover, the peak shape is constant (stretch exponent equal to 0.65). However, application of pressure changes the shape of the dielectric spectrum at higher frequencies due to the shift of the excess wing to form a resolved peak. Additionally, another relaxation process, absent at atmospheric pressure, emerges on the high-frequency side of the alpha -process. We propose that this new peak reflects a more compact conformation of the alpha -tocopherol acetate molecule. Drawing on the coupling model, the experimentally determined relaxation times, activation energy, and activation volume for the Johari-Goldstein process are compared to values calculated from the properties of the alpha relaxation. The agreement is generally satisfactory, at least for T

Subject(s)
Biophysics/methods , alpha-Tocopherol/analogs & derivatives , Chemistry, Physical/methods , Electric Conductivity , Ions , Isomerism , Models, Chemical , Molecular Conformation , Pressure , Temperature , Time Factors , Tocopherols , alpha-Tocopherol/chemistry
18.
Endoscopy ; 36(8): 715-9, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15280978

ABSTRACT

BACKGROUND AND STUDY AIMS: It is still difficult to differentiate reliably between benign and malignant biliary tract lesions. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has added to the diagnostic power of EUS for other gastrointestinal tumors. A retrospective analysis of experience with FNA sampling of bile duct lesions was therefore carried out. PATIENTS AND METHODS: All EUS-FNA procedures for bile duct masses or strictures were analyzed at our tertiary referral center from May 2000 through October 2002. Data for EUS findings, the results of EUS-FNA, and tissue sampling at surgery were included. EUS-FNA procedures were carried out using a 22-gauge needle. An experienced cytopathologist was present during FNA in all but three cases. Clinical follow-up details were recorded when available for patients in whom a suitable diagnostic gold standard was not available for comparison. RESULTS: A total of 35 patients underwent EUS-FNA of bile duct lesions during the study period. There were no complications. Data for EUS-FNA of bile duct masses or strictures and tissue obtained at surgery were available for 23 patients. If positive cytology at surgical pathology is taken as the gold standard, EUS-FNA has a diagnostic yield for cancer of 100 % (if atypia/inconclusive findings in the FNA sample are regarded as benign). Eleven patients had a definite malignancy on surgical pathology. Of these 11 patients, five had a finding of malignancy on EUS-FNA, giving a sensitivity of 45 % (if FNA cytology reported as atypia/inconclusive is regarded as benign). Twelve patients had findings of no malignancy from tissue obtained at surgery. Of these 12 patients, nine had benign pathology and three had atypia/inconclusive findings in the EUS-FNA sample (specificity of 100 % if atypia/inconclusive findings are considered benign). A further 12 patients did not have surgical specimens for comparison with EUS-FNA results. Four patients had definite findings of malignancy on EUS-FNA alone, and one patient had FNA findings suspicious for malignancy. Seven patients had negative or equivocal EUS-FNA results. These 12 patients are described but excluded from further analysis, as a gold standard was not available for comparison. However, clinical follow-up data were available for eight of these 12 patients, and in each case the follow-up findings were compatible with previous benign or malignant EUS-FNA findings. CONCLUSIONS: The practice of EUS-FNA has improved the diagnostic yield of EUS. These results suggest that it is a safe and useful procedure for investigating biliary masses or strictures that have hitherto caused considerable diagnostic confusion, especially in patients with negative brush cytology findings. The possibility of false-negative findings remains, but core biopsy needles may improve the situation. The results of further studies are awaited.


Subject(s)
Bile Duct Neoplasms/diagnosis , Biliary Tract Diseases/diagnostic imaging , Biliary Tract Diseases/diagnosis , Endosonography , Aged , Bile Duct Neoplasms/diagnostic imaging , Bile Duct Neoplasms/pathology , Biliary Tract Diseases/pathology , Biopsy, Fine-Needle/methods , Female , Humans , Male , Retrospective Studies , Sensitivity and Specificity
19.
J Chem Phys ; 120(4): 1981-9, 2004 Jan 22.
Article in English | MEDLINE | ID: mdl-15268332

ABSTRACT

This paper describes a new convenient and accurate method of calculating x-ray diffraction integrated intensities from detailed cubic bilayer structures. The method is employed to investigate the structure of a particular surfactant system (didodecyldimethylammonium bromide in a solution of oil and heavy water), for which single-crystal experimental data have recently been collected. The diffracted peak intensities correlate well with theoretical structures based on mathematical minimal surfaces. Optimized electron density profiles of the bilayer are presented, providing new insight into key features of the bilayer structure.

20.
Eur J Cancer Prev ; 12(6): 479-85, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14639125

ABSTRACT

Breast cancer incidence suggests a lifestyle cause. A lifestyle factor used near the breast is the application of antiperspirants/deodorants accompanied by axillary shaving. A previous study did not support a link with breast cancer. If these habits have a role in breast cancer development, women using antiperspirants/deodorants and shaving their underarms frequently would be expected to have an earlier age of diagnosis than those doing so less often. An earlier age of diagnosis would also be expected in those starting to use deodorants and shaving at an earlier age. This is the first study to investigate the intensity of underarm exposure in a cohort of breast cancer survivors. Four hundred and thirty-seven females diagnosed with breast cancer were surveyed. Once grouped by their frequency of underarm hygiene habits, the mean age of diagnosis was the primary end point. Secondary end points included the overall frequency of these habits, and potential usage group confounding variables were evaluated. All statistical tests were two-sided. Frequency and earlier onset of antiperspirant/deodorant usage with underarm shaving were associated with an earlier age of breast cancer diagnosis. Combined habits are likely for this earlier age of diagnosis. In conclusion, underarm shaving with antiperspirant/deodorant use may play a role in breast cancer. It is not clear which of these components are involved. Reviewed literature insinuates absorption of aluminium salts facilitated by dermal barrier disruption. Case-controlled investigations are needed before alternative underarm hygiene habits are suggested.


Subject(s)
Breast Neoplasms/etiology , Deodorants/adverse effects , Environmental Exposure , Hygiene , Adult , Age of Onset , Aged , Aged, 80 and over , Breast Neoplasms/pathology , Cohort Studies , Female , Humans , Life Style , Middle Aged , Retrospective Studies , Risk Factors
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