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1.
J Phys Chem A ; 127(10): 2322-2335, 2023 Mar 16.
Article in English | MEDLINE | ID: mdl-36790472

ABSTRACT

The formation of molecular cocrystals in condensed aerosol particles has been recently proposed as an efficient pathway for generation of complex organics in Titan's atmosphere. It follows that cocrystal precipitation may facilitate the transport of biologically important precursors to the surface to be sequestered in an organic karstic and sand environment. Recent laboratory studies on these planetary minerals have predominantly synthesized cocrystals by the controlled freezing of binary mixtures from the liquid phase, allowing for their structural and spectroscopic characterization. However, these techniques are perhaps not best representative of aerosol nucleation and growth microphysics in planetary atmospheres. Herein, we report the first synthesis of the known 1:1 C6H6:C2H2 cocrystal using vapor deposition methods onto a cryogenically cooled substrate. Subsequent transmission FTIR spectroscopy has confirmed the formation of the empirical C6H6:C2H2 cocrystal structure via the observation of diagnostic infrared spectral features. Predicted by periodic-DFT calculations, altered vibrational profiles depict a changing site symmetry of the C6H6 and C2H2 components after transition to the cocrystal unit cell geometry. The 80 K temperature of the cocrystal phase transition overlaps with the condensation curves obtained for both species in Titan's lower stratosphere, revealing that the cocrystal may act as an important environment for photo- and radio-lytic processes leading to the formation of higher order organics in Titan's atmosphere. Such solid-state astrochemistry can now be pursued in oxygen-free laboratory settings under (ultra)high vacuum using standard surface science setups.

2.
Support Care Cancer ; 31(8): 459, 2023 Jul 11.
Article in English | MEDLINE | ID: mdl-37432501

ABSTRACT

PURPOSE: To determine the experiences, information, support needs and quality of life of women in the UK living with metastatic breast cancer (MBC) to provide content for educational materials. METHODS: An online survey, hosted for 3 months on a UK MBC charity website, comprised sections covering issues such as communication about MBC treatment and management, helpful and less helpful things that healthcare professionals, family and friends did or said and completion of the Patient Roles and Responsibilities Scale (PRRS). RESULTS: A total of 143 patients participated; 48/143(33%) presented de novo; 54/143(38%) had been living with MBC > 2 years. PRRS analysis revealed that MBC imposed a serious impact upon most respondents' own caring abilities and social lives. A majority 98/139 (71%) wished they had known more about MBC before their diagnosis; 63/134(47%) indicated that they still did not fully understand their illness; merely 78/139(56%) had access to a specialist nurse and only 69/135(51%) had been offered any additional support. Respondents reported little consideration given to their lifestyle/culture during consultations and inconsistent information, support services, continuity of care or access to clinical trials. They commented upon things health care professionals/friends and family did or said that were useful and cited other behaviours that were especially unhelpful. CONCLUSIONS: MBC exerted a deleterious impact upon patients' activities of daily living which were exacerbated in part by significant gaps in support, communication and information. IMPLICATIONS FOR CANCER SURVIVORS: LIMBER results are informing the content of educational materials currently being developed for patients' formal and informal carers.


Subject(s)
Breast Neoplasms , Porcine Reproductive and Respiratory Syndrome , Swine , Animals , Humans , Female , Quality of Life , Activities of Daily Living , Breast Neoplasms/therapy , United Kingdom
3.
Pharmazie ; 74(3): 131-135, 2019 03 01.
Article in English | MEDLINE | ID: mdl-30961676

ABSTRACT

Propranolol is a popular ß adrenergic antagonists that, together with pindolol, binds also to serotoninergic receptors, namely 5-HT1A/B. In this work the rigidification of the propranolol structure by locking its hydroxyl group within a 1,3-dioxolane ring was investigated. Constrained derivatives of propranolol were synthesized, fully characterized and tested for their affinity at ß-adrenoreceptors and 5-HT1A/B/C receptors using radioligand binding assay. The constrained derivatives were inactive, as expected, at ß1/2/3 adrenergic receptors. Although less expected, these derivatives failed to bind also to 5-HT1A/B/C receptors. The rigidification of propranolol is detrimental for 5-HT1AR activity.


Subject(s)
Adrenergic beta-Antagonists/chemistry , Adrenergic beta-Antagonists/pharmacology , Propranolol/analogs & derivatives , Propranolol/pharmacology , Serotonin 5-HT1 Receptor Antagonists/chemistry , Serotonin 5-HT1 Receptor Antagonists/pharmacology , Adrenergic beta-Antagonists/chemical synthesis , Cell Line , Dioxolanes/chemistry , Humans , Propranolol/chemical synthesis , Propranolol/chemistry , Serotonin 5-HT1 Receptor Antagonists/chemical synthesis , Structure-Activity Relationship
5.
Appl Opt ; 54(11): 3218-24, 2015 Apr 10.
Article in English | MEDLINE | ID: mdl-25967306

ABSTRACT

We demonstrate for the first time, to the best of our knowledge, that a Sagnac interferometer can threshold the energies of pulses. Pulses below a given threshold T are suppressed, while those above this threshold are normalized. The device contains an in-loop tunable isolator and 10.4 m of a highly doped silica fiber. We derive an analytical model of the nonlinear optical loop mirror's pulse energy transfer function and show that its energy transfer function approximates a step function for very high phase shifts (>π). We reveal some limitations of this approach, showing that a step-function transfer function necessarily results in pulse distortion in fast, nonresonant all-optical devices.

6.
Vet Parasitol Reg Stud Reports ; 49: 101005, 2024 04.
Article in English | MEDLINE | ID: mdl-38462306

ABSTRACT

Flystrike remains an important animal health issue on New Zealand sheep farms. To date no useful predictive tool to assist farmers to develop control options has been available. The aim of this study was to use National Institute of Water and Atmospheric Research (NIWA) virtual climate station data in New Zealand to develop a weather-based model to accurately predict the presence of Lucilia spp. on sheep farms throughout New Zealand. Three LuciTrap® baited fly traps were positioned on each of eight sheep farms throughout New Zealand (5 in the North Island and 3 in the South Island). The traps were put out for both the 2018-2019 and 2019-2020 seasons. They were emptied each week and the flies morphologically identified; with the counts of Lucilia cuprina and L. sericata combined as Lucilia spp. The count data for Lucilia spp. for each week of trapping was transformed into a binary outcome and a generalised linear mixed effects models fitted to the data, with farm as a random effect. The dependent variable was Lucilia spp. flies caught, yes or no, and the independent variables were mean weekly climate variables from the nearest NIWA virtual climate station to that farm. The model was trained on the 2018-2019 catch data and tested on the 2019-2020 catch data. A cut point was identified which maximised the model's ability to correctly predict whether Lucilia spp. were present or not for the 2019-2020 catch data, and the sensitivity, specificity, accuracy, and area under the curve (AUC) of the model calculated. The final model included just 3 significant variables, mean weekly 10 cm soil temperature, mean weekly soil moisture index, and mean weekly wind speed at 10 m. Mean weekly 10 cm soil temperature accounted for 64.7% of the variance explained by the model, mean weekly soil moisture index 34.7% and mean weekly wind speed at 10 m only 0.6%. The results showed that the predictive model had a sensitivity of 0.93 (95% CI = 0.80-0.98) and a specificity of 0.75 (95% CI = 0.62-0.85), using a cut point for the probability of Lucilia spp. being present on farm = 0.383. This model provides New Zealand farmers with a tool which will allow them to know when Lucilia spp. flies will likely be present and thus more accurately plan their interventions to prevent flystrike.


Subject(s)
Diptera , Myiasis , Animals , Sheep , Farms , New Zealand/epidemiology , Weather , Myiasis/veterinary , Calliphoridae , Soil
7.
Biotechnol Bioeng ; 109(4): 971-82, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22124969

ABSTRACT

The characterization of host cell protein (HCP) content during the production of therapeutic recombinant proteins is an important aspect in the drug development process. Despite this, key components of the HCP profile and how this changes with processing has not been fully investigated. Here we have investigated the supernatant HCP profile at different times throughout culture of a null and model GS-CHO monoclonal antibody producing mammalian cell line grown in fed-batch mode. Using 2D-PAGE and LC-MS/MS we identify a number of intracellular proteins (e.g., protein disulfide isomerise; elongation factor 2; calreticulin) that show a significant change in abundance relative to the general increase in HCP concentration observed with progression of culture. Those HCPs that showed a significant change in abundance across the culture above the general increase were dependent on the cell line examined. Further, our data suggests that the majority of HCPs in the supernatant of the cell lines investigated here arise through lysis or breakage of cells, associated with loss in viability, and are not present due to the secretion of protein material from within the cell. SELDI-TOF and principal components analysis were also investigated to enable rapid monitoring of changes in the HCP profile. SELDI-TOF analysis showed the same trends in the HCP profile as observed by 2D-PAGE analysis and highlighted biomarkers that could be used for process monitoring. These data further our understanding of the relationship between the HCP profile and cell viability and may ultimately enable a more directed development of purification strategies and the development of cell lines based upon their HCP profile.


Subject(s)
Antibodies, Monoclonal/biosynthesis , CHO Cells/metabolism , Culture Media, Conditioned/analysis , Immunoglobulin G/biosynthesis , Proteins/analysis , Proteomics , Animals , Antibodies, Monoclonal/genetics , Batch Cell Culture Techniques/methods , Biomarkers , Bioreactors , CHO Cells/cytology , Cell Survival , Chromatography, High Pressure Liquid , Cricetinae , Cricetulus , Electrophoresis, Gel, Two-Dimensional , Glutamate-Ammonia Ligase/biosynthesis , Glutamate-Ammonia Ligase/genetics , Immunoglobulin G/genetics , Isoelectric Focusing , Particle Size , Proteins/metabolism , Recombinant Fusion Proteins/biosynthesis , Recombinant Fusion Proteins/isolation & purification , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Time Factors
8.
Mol Pharm ; 9(4): 874-82, 2012 Apr 02.
Article in English | MEDLINE | ID: mdl-22380593

ABSTRACT

Advancements toward an improved vaccine against Bacillus anthracis, the causative agent of anthrax, have focused on formulations composed of the protective antigen (PA) adsorbed to aluminum hydroxide. However, due to the labile nature of PA, antigen stability is a primary concern for vaccine development. Thus, there is a need for a delivery system capable of preserving the immunogenicity of PA through all the steps of vaccine fabrication, storage, and administration. In this work, we demonstrate that biodegradable amphiphilic polyanhydride nanoparticles, which have previously been shown to provide controlled antigen delivery, antigen stability, immune modulation, and protection in a single dose against a pathogenic challenge, can stabilize and release functional PA. These nanoparticles demonstrated polymer hydrophobicity-dependent preservation of the biological function of PA upon encapsulation, storage (over extended times and elevated temperatures), and release. Specifically, fabrication of amphiphilic polyanhydride nanoparticles composed of 1,6-bis(p-carboxyphenoxy)hexane and 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane best preserved PA functionality. These studies demonstrate the versatility and superiority of amphiphilic nanoparticles as vaccine delivery vehicles suitable for long-term storage.


Subject(s)
Antigens, Bacterial/chemistry , Bacillus anthracis/immunology , Nanoparticles/chemistry , Polyanhydrides/chemistry , Protein Stability
9.
Br J Anaesth ; 106(3): 352-8, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21258074

ABSTRACT

BACKGROUND: This study evaluated whether an objective tool would provide a more reliable and valid assessment of perioperative risk compared with the ASA-physical status (ASA-PS) in children. METHODS: A system-based risk assessment tool was developed using these categories: Neurological, Airway, Respiratory, Cardiovascular, and Other (NARCO) with a subcomponent grading surgical severity (SS). Anaesthesiologists reviewed the preoperative assessments and assigned NARCO, SS, and ASA-PS scores independently. Perioperative outcomes were recorded by trained observers. Validity and reliability of the tools were evaluated. RESULTS: NARCO correlated with ASA-PS (ρ=0.664; P<0.01) supporting its criterion validity. Inter-rater reliability of the measures was supported (intraclass correlation coefficients 0.71-0.96; κ 0.43-0.87) except for the Airway category. Measures of exact agreement were slightly better for NARCO compared with ASA-PS. NARCO, SS, and ASA-PS scores correlated significantly with perioperative escalation of care, adverse events (AE), hospital length of stay, and admission status. Correlations between NARCO and ASA-PS and outcomes improved when SS was factored into their coding. There were significant, but low, correlations between all measures and mortality. The odds of having escalation of care, AE, and mortality were 5-47 times greater among children with higher risk scores. CONCLUSIONS: Findings suggest that all measures of outcome have acceptable to excellent reliability with a slight improvement in agreement for the NARCO compared with the ASA-PS. This study supports the validity of both the NARCO and the ASA-PS in predicting perioperative risk in children with a slight improvement in correlations when combined with the SS score.


Subject(s)
Health Status Indicators , Preoperative Care/methods , Adolescent , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Intraoperative Complications , Perioperative Care/methods , Postoperative Complications , Prognosis , Psychometrics , Risk Assessment/methods
10.
Eukaryot Cell ; 9(2): 336-43, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19966032

ABSTRACT

The P2 aminopurine transporter, encoded by TbAT1 in African trypanosomes in the Trypanosoma brucei group, carries melaminophenyl arsenical and diamidine drugs into these parasites. Loss of this transporter contributes to drug resistance. We identified the genomic location of TbAT1 to be in the subtelomeric region of chromosome 5 and determined the status of the TbAT1 gene in two trypanosome lines selected for resistance to the melaminophenyl arsenical, melarsamine hydrochloride (Cymelarsan), and in a Trypanosoma equiperdum clone selected for resistance to the diamidine, diminazene aceturate. In the Trypanosoma brucei gambiense STIB 386 melarsamine hydrochloride-resistant line, TbAT1 is deleted, while in the Trypanosoma brucei brucei STIB 247 melarsamine hydrochloride-resistant and T. equiperdum diminazene-resistant lines, TbAT1 is present, but expression at the RNA level is no longer detectable. Further characterization of TbAT1 in T. equiperdum revealed that a loss of heterozygosity at the TbAT1 locus accompanied loss of expression and that P2-mediated uptake of [(3)H]diminazene is lost in drug-resistant T. equiperdum. Adenine-inhibitable adenosine uptake is still detectable in a DeltaTbat1 T. b. brucei mutant, although at a greatly reduced capacity compared to that of the wild type, indicating that an additional adenine-inhibitable adenosine permease, distinct from P2, is present in these cells.


Subject(s)
Membrane Transport Proteins/genetics , Protozoan Proteins/genetics , Trypanocidal Agents/pharmacology , Trypanosoma brucei brucei/drug effects , 3' Untranslated Regions , DNA, Protozoan/metabolism , Diminazene/analogs & derivatives , Diminazene/pharmacology , Drug Resistance/genetics , Membrane Transport Proteins/metabolism , Open Reading Frames , Protozoan Proteins/metabolism , Trypanosoma brucei brucei/genetics , Trypanosoma brucei brucei/metabolism
11.
Biotechnol Bioeng ; 107(1): 85-95, 2010 Sep 01.
Article in English | MEDLINE | ID: mdl-20506289

ABSTRACT

With the trend towards the generation and production of increasing numbers of complex biopharmaceutical (protein based) products, there is an increased need and requirement to characterize both the product and production process in terms of robustness and reproducibility. This is of particular importance for products from mammalian cell culture which have large molecular structures and more often than not complex post-translational modifications (PTMs) that can impact the efficacy, stability and ultimately the safety of the final product. It is therefore vital to understand how the operating conditions of a bioprocess affect the distribution and make up of these PTMs to ensure a consistent quality and activity in the final product. Here we have characterized a typical bioprocess and determined (a) how the time of harvest from a mammalian cell culture and, (b) through the use of an ultra scale-down mimic how the nature of the primary recovery stages, affect the distribution and make up of the PTMs observed on a recombinant IgG(4) monoclonal antibody. In particular we describe the use of rapid whole antibody analysis by mass spectrometry to analyze simultaneously the changes that occur to the cleavage of heavy chain C-terminal lysine residues and the glycosylation pattern, as well as the presence of HL dimers. The time of harvest was found to have a large impact upon the range of glycosylation patterns observed, but not upon C-terminal lysine cleavage. The culture age had a profound impact on the ratio of different glycan moieties found on antibody molecules. The proportion of short glycans increased (e.g., (G0F)(2) 20-35%), with an associated decrease in the proportion of long glycans with culture age (e.g., (G2F)(2) 7-4%, and G1F/G2F from 15.2% to 7.8%). Ultra scale-down mimics showed that subsequent processing of these cultures did not change the post-translational modifications investigated, but did increase the proportion of half antibodies present in the process stream. The combination of ultra scale-down methodology and whole antibody analysis by mass spectrometry has demonstrated that the effects of processing on the detailed molecular structure of a monoclonal antibody can be rapidly determined early in the development process. In this study we have demonstrated this analysis to be applicable to critical process design decisions (e.g., time of harvest) in terms of achieving a desired molecular structure, but this approach could also be applied as a selection criterion as to the suitability of a platform process for the preparation of a new drug candidate. Also the methodology provides means for bioprocess engineers to predict at the discovery phase how a bioprocess will impact upon the quality of the final product.


Subject(s)
Antibodies, Monoclonal/analysis , Centrifugation/methods , Mass Spectrometry/methods , Peptide Mapping/methods , Protein Processing, Post-Translational , Recombinant Proteins/analysis , Animals , CHO Cells , Cricetinae , Cricetulus
12.
J Cell Biol ; 73(1): 139-48, 1977 Apr.
Article in English | MEDLINE | ID: mdl-856828

ABSTRACT

The ribosomes extracted from the mitochondria of the ciliate, Paramecium aurelia, have been shown to sediment at 80S in sucrose gradients. The cytoplasmic ribosomes also sediment at 80S but can be distinguished from their mitochondrial counterparts by a number of criteria. Lowering of the Mg++ concentration, addition of EDTA, or high KCl concentrations results in the dissociation of the cytoplasmic ribosomes into 60S and 40S subunits, whereas the mitochondrial ribosomes dissociate into a single sedimentation class at 55S. Furthermore, the relative sensitivity of the two types of ribosome to dissociating conditions can be distinguished. Electron microscopy of negatively stained 80S particles from both sources has also shown that the two types can be differentiated. The cytoplasmic particles show dimensions of 270 X 220 A whereas the mitochondrial particles are larger (330 X 240 A). In addition, there are several distinctive morphological features. The incorporation of [14C]leucine into nascent polypeptides associated with both mitochondrial and cytoplasmic ribosomes has been shown: the incorporation into cytoplasmic 80S particles is resistant to erythromycin and chloramphenicol but sensitive to cycloheximide, whereas incorporation into the mitochondrial particles is sensitive to erythromycin and chloramphenicol but resistant to cycloheximide.


Subject(s)
Mitochondria/ultrastructure , Paramecium/ultrastructure , Ribosomes/ultrastructure , Animals , Centrifugation, Density Gradient , Chloramphenicol/pharmacology , Cycloheximide/pharmacology , Cytoplasm/ultrastructure , Erythromycin/pharmacology , Leucine/metabolism , Paramecium/metabolism , Peptide Biosynthesis , Ribosomes/metabolism
13.
Biotechnol Bioeng ; 104(2): 321-31, 2009 Oct 01.
Article in English | MEDLINE | ID: mdl-19507199

ABSTRACT

This article describes how a combination of an ultra scale-down (USD) shear device feeding a microwell centrifugation plate may be used to provide a prediction of how mammalian cell broth will clarify at scale. In particular a method is described that is inherently adaptable to a robotic platform and may be used to predict how the flow rate and capacity (equivalent settling area) of a centrifuge and the choice of feed zone configuration may affect the solids carry over in the supernatant. This is an important consideration as the extent of solids carry over will determine the required size and lifetime of a subsequent filtration stage or the passage of fine particulates and colloidal material affecting the performance and lifetime of chromatography stages. The extent of solids removal observed in individual wells of a microwell plate during centrifugation is shown to correlate with the vertical and horizontal location of the well on the plate. Geometric adjustments to the evaluation of the equivalent settling area of individual wells (Sigma(M)) results in an improved prediction of solids removal as a function of centrifuge capacity. The USD centrifuge settling characteristics need to be as for a range of equivalent flow rates as may be experienced at an industrial scale for a machine of different shear characteristics in the entry feed zone. This was shown to be achievable with two microwell-plate based measurements and the use of varying fill volumes in the microwells to allow the rapid study of a fivefold range of equivalent flow rates (i.e., at full scale for a particular industrial centrifuge) and the effect of a range of feed configurations. The microwell based USD method was used to examine the recovery of CHO-S cells, prepared in a 5 L reactor, at different points of growth and for different levels of exposure to shear post reactor. The combination of particle size distribution measurements of the cells before and after shear and the effect of shear on the solids remaining after centrifugation rate provide insight into the state of the cells throughout the fermentation and the ease with which they and accumulated debris may be removed by continuous centrifugation. Hence bioprocess data are more readily available to help better integrate cell culture and cell removal stages and resolve key bioprocess design issues such as choice of time of harvesting and the impact on product yield and contaminant carry over. Operation at microwell scale allows data acquisition and bioprocess understanding over a wide range of operating conditions that might not normally be achieved during bioprocess development.


Subject(s)
Biotechnology/methods , Centrifugation/methods , Culture Media/chemistry , Cell Culture Techniques/methods , Particle Size , Particulate Matter
14.
Science ; 210(4472): 899-901, 1980 Nov 21.
Article in English | MEDLINE | ID: mdl-7434002

ABSTRACT

Exposure of pregnant rats to the anesthetic nitrous oxide on the ninth day of gestation causes fetal resorption, skeletal anomalies, and macroscopic lesions including encephalocele, anophthalmia, microphthalmia, and gastroschisis. The inert gas xenon, which has anesthetic properties similar to those of nitrous oxide, does not cause teratogenic effects under the same experimental conditions.


Subject(s)
Anesthetics/adverse effects , Nitrous Oxide/toxicity , Teratogens , Xenon/toxicity , Animals , Female , Pregnancy , Rats , Structure-Activity Relationship
15.
Parasitology ; 136(12): 1491-500, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19555522

ABSTRACT

Human sleeping sickness in Africa, caused by Trypanosoma brucei spp. raises a number of questions. Despite the widespread distribution of the tsetse vectors and animal trypanosomiasis, human disease is only found in discrete foci which periodically give rise to epidemics followed by periods of endemicity A key to unravelling this puzzle is a detailed knowledge of the aetiological agents responsible for different patterns of disease--knowledge that is difficult to achieve using traditional microscopy. The science of molecular epidemiology has developed a range of tools which have enabled us to accurately identify taxonomic groups at all levels (species, subspecies, populations, strains and isolates). Using these tools, we can now investigate the genetic interactions within and between populations of Trypanosoma brucei and gain an understanding of the distinction between human- and nonhuman-infective subspecies. In this review, we discuss the development of these tools, their advantages and disadvantages and describe how they have been used to understand parasite genetic diversity, the origin of epidemics, the role of reservoir hosts and the population structure. Using the specific case of T.b. rhodesiense in Uganda, we illustrate how molecular epidemiology has enabled us to construct a more detailed understanding of the origins, generation and dynamics of sleeping sickness epidemics.


Subject(s)
Molecular Epidemiology , Trypanosoma brucei brucei/genetics , Trypanosomiasis, African/epidemiology , Animals , Disease Outbreaks , Genetic Techniques , Humans , Polymerase Chain Reaction/methods , Trypanosoma brucei brucei/classification , Trypanosomiasis, African/parasitology
16.
J Leukoc Biol ; 84(4): 924-31, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18664528

ABSTRACT

A bidirectional communication exists between the CNS and the immune system. The autonomic nervous system, through neurotransmitters and neuropeptides, works in parallel with the hypothalamic-pituitary-adrenal axis through the actions of glucocorticoids to modulate inflammatory events. The immune system, through the action of cytokines and other factors, in turn, activates the CNS to orchestrate negative-feedback mechanisms that keep the immune response in check. Disruption of these interactions has been associated with a number of syndromes including inflammatory, autoimmune, and cardiovascular diseases, metabolic and psychiatric disorders, and the development of shock. The hypothalamic-pituitary-gonadal axis also plays an important part in regulating immunity through the secretion of sex hormones. Although numerous studies have established a role for immunomodulation by estrogen and testosterone, the role of progesterone is less well understood. Progesterone is crucial for reproductive organ development and maintenance of pregnancy, and more recent studies have clearly shown its role as an important immune regulator. The main focus of this review will be about the role of steroid hormones, specifically glucocorticoids and progesterone, in inflammatory responses and infectious diseases and how dysregulation of their actions may contribute to development of autoimmune and inflammatory disease.


Subject(s)
Autoimmune Diseases/physiopathology , Glucocorticoids/physiology , Infections/physiopathology , Inflammation/physiopathology , Progestins/physiology , Disease Progression , Disease Susceptibility , Glucocorticoids/immunology , Humans , Infections/immunology , Inflammation/immunology , Lupus Erythematosus, Systemic/immunology , Lupus Erythematosus, Systemic/physiopathology , Polymorphism, Genetic , Progestins/immunology , Receptors, Glucocorticoid/genetics , Receptors, Glucocorticoid/immunology , Receptors, Glucocorticoid/physiology
17.
Nat Electron ; 2(10)2019.
Article in English | MEDLINE | ID: mdl-32118196

ABSTRACT

A number of current approaches to quantum and neuromorphic computing use superconductors as the basis of their platform or as a measurement component, and will need to operate at cryogenic temperatures. Semiconductor systems are typically proposed as a top-level control in these architectures, with low-temperature passive components and intermediary superconducting electronics acting as the direct interface to the lowest-temperature stages. The architectures, therefore, require a low-power superconductor-semiconductor interface, which is not currently available. Here we report a superconducting switch that is capable of translating low-voltage superconducting inputs directly into semiconductor-compatible (above 1,000 mV) outputs at kelvin-scale temperatures (1K or 4 K). To illustrate the capabilities in interfacing superconductors and semiconductors, we use it to drive a light-emitting diode (LED) in a photonic integrated circuit, generating photons at 1K from a low-voltage input and detecting them with an on-chip superconducting single-photon detector. We also characterize our device's timing response (less than 300 ps turn-on, 15 ns turn-off), output impedance (greater than 1MΩ), and energy requirements (0.18fJ/µm2,3.24mV/nW).

18.
Trends Genet ; 6(10): 317-22, 1990 Oct.
Article in English | MEDLINE | ID: mdl-2281527

ABSTRACT

African trypanosomes are important pathogens of humans and domestic animals, but little was known, until recently, of the genetic system of these parasites. Recent results demonstrate the existence of nonobligatory genetic exchange between different stocks of T. brucei. A number of models have been put forward for the mechanism of genetic exchange, including a fusion model with subsequent random loss of chromosomes and a more conventional mendelian system.


Subject(s)
Recombination, Genetic , Trypanosoma brucei brucei/genetics , Animals , Chromosomes , Crosses, Genetic , DNA, Protozoan/genetics , Mice , Models, Genetic , Reproduction , Trypanosoma brucei brucei/physiology
19.
J Neurosurg ; 106(2): 338-50, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17410721

ABSTRACT

OBJECT: The hypoxia-inducible pleiotropic hormone, erythropoietin (EPO), has recently been found to promote the development and survival of neurons and astrocytes. Since hypoxia has been implicated in the malignant progression of some human cancers, the authors investigated whether EPO signaling influenced the malignant properties of human astrocytoma cells. METHODS: Reverse transcriptase-polymerase chain reaction, Western blot analysis, and immunohistochemical studies were used to measure EPO and its receptor (EPOR). Cell viability, Matrigel invasion assays, metalloprotease assays, EPO neutralizing antibodies, and EPOR overexpression were used to study the biological actions of EPO. Expression of both EPO and EPOR was observed in the hypoxic regions and invasive margins of glioma specimens obtained at biopsy, and expression of EPOR correlated with the stage of the tumor. The EPOR was also functionally upregulated by hypoxia in cultured glioblastoma multiforme (GBM) cells. Both hypoxia and EPO protected cultured GBM cells from cisplatin cytotoxicity and promoted the invasiveness of GBM cells through Matrigel by potentiating metalloprotease activity. Hypoxia-enhanced cell invasion was attenuated in cells that overexpressed a nonfunctional EPOR. CONCLUSIONS: Hypoxia-inducible autocrine and paracrine EPO signaling participates in the malignant progression of GBMs.


Subject(s)
Brain Neoplasms/pathology , Erythropoietin/physiology , Glioma/pathology , Animals , Antineoplastic Agents/therapeutic use , Brain Neoplasms/drug therapy , Brain Neoplasms/metabolism , Cell Hypoxia/physiology , Cell Line, Tumor , Cisplatin/therapeutic use , Epoetin Alfa , Erythropoietin/therapeutic use , Glioma/drug therapy , Glioma/metabolism , Hematinics/therapeutic use , Humans , Neoplasm Invasiveness , Rats , Rats, Wistar , Receptors, Erythropoietin/metabolism , Recombinant Proteins , Signal Transduction/physiology
20.
Vet Parasitol ; 149(1-2): 29-40, 2007 Oct 21.
Article in English | MEDLINE | ID: mdl-17728067

ABSTRACT

Cryptosporidium and Giardia are major causes of diarrhoeal disease in humans, worldwide and are major causes of protozoan waterborne diseases. Both Cryptosporidium and Giardia have life cycles which are suited to waterborne and foodborne transmission. There are 16 'valid'Cryptosporidium species and a further 33+ genotypes described. Parasites which infect humans belong to the Giardia duodenalis "type", and at least seven G. duodenalis assemblages are recognised. Cryptosporidium parvum is the major zoonotic Cryptosporidium species, while G. duodenalis assemblages A and B have been found in humans and most mammalian orders. In depth studies to determine the role of non-human hosts in the transmission of Cryptosporidium and Giardia to humans are required. The use of harmonised methodology and standardised and validated molecular markers, together with sampling strategies that provide sufficient information about all contributors to the environmental (oo)cyst pool that cause contamination of food and water, are recommended. Standardised methods for detecting (oo)cysts in water are available, as are optimised, validated methods for detecting Cryptosporidium in soft fruit and salad vegetables. These provide valuable data on (oo)cyst occurrence, and can be used for species and subspecies typing using appropriate molecular tools. Given the zoonotic potential of these organisms, epidemiological, source and disease tracking investigations involve multidisciplinary teams. Here, the role of the veterinarian is paramount, particularly in understanding the requirement for adopting comprehensive sampling strategies for analysing both sporadic and outbreak samples from all potential non-human contributors. Comprehensive sampling strategies increase our understanding of parasite population biology and structure and this knowledge can be used to determine what level of discrimination is required between isolates. Genetic exchange is frequent in C. parvum populations, leading to recombination between alleles at different loci, the generation of a very large number of different genotypes and a high level of resolution between isolates. In contrast, genetic exchange appears rare in Cryptosporidium hominis and populations are essentially clonal with far fewer combinations of alleles at different loci, resulting in a much lower resolution between isolates with many being of the same genotype. Clearly, more markers provide more resolution and high throughput sequencing of a variety of genes, as in multilocus sequence typing, is a way forward. Sub-genotyping tools offer increased discrimination, specificity and sensitivity, which can be exploited for investigating the epidemiology of disease, the role of asymptomatic carriers and contaminated fomites and for source and disease tracking for food and water contaminated with small numbers of (oo)cysts.


Subject(s)
Cryptosporidiosis/transmission , Cryptosporidium/physiology , Giardia/physiology , Giardiasis/transmission , Zoonoses , Animals , Cryptosporidiosis/epidemiology , Cryptosporidiosis/prevention & control , Disease Outbreaks , Food Contamination , Food Parasitology , Giardiasis/epidemiology , Giardiasis/prevention & control , Humans , Public Health , Water/parasitology , Zoonoses/epidemiology , Zoonoses/parasitology , Zoonoses/transmission
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