Group A Streptococcus in the Gynecologic Patient

Background: Over the past few decades, physicians have been reminded of the potential for serious complications arising from group A streptococcal (GAS) infections. These infections continue to pose a serious threat, primarily because the pathophysiology of these infections is complex. This article reviews some of the features of GAS infections and presents two case reports of GAS pelvic infections in women

Understanding the magnetic polarizability tensor

The aim of this paper is to provide new insights into the properties of the rank 2 polarizability tensor M̆ proposed by Ledger and Lionheart for describing the perturbation in the magnetic field caused by the presence of a conducting object in the eddy-current regime. In particular, we explore its connection with the magnetic polarizability tensor and the Pólya-Szegö tensor and how, by introducing new splittings of M̆, they form a family of rank 2 tensors for describing the response from different categories of conducting (permeable) objects. We include new bounds on the invariants of the Pólya-Szegö tensor and expressions for the low-frequency and high-conductivity limiting coefficients of M̆. We show, for the high-conductivity case (and for frequencies at the limit of the quasi-static approximation), that it is important to consider whether the object is simply or multiply connected but, for the low-frequency case, the coefficients are independent of the connectedness of the object. Furthermore, we explore the frequency response of the coefficients of M̆ for a range of simply and multiply connected objects

The impact of introducing patient co-payments in Germany on the use of IVF and ICSI:a price-elasticity of demand assessment

BACKGROUND: Authorities concerned by rising healthcare costs have a tendency to target reproductive treatments because of the perception that infertility is a low priority. In 2004 German health authorities introduced a 50% co-payment for patients, in an effort to save cost. We explored the impact of this pricing policy on the utilization of reproductive treatments in Germany. METHODS: Using aggregated annual in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycle data in Germany, we evaluated the relationship between changes in the number of cycles in relation to changes in costs faced by consumers following the introduction of a patient co-payment from 'no fees' to (sic)1500-2000 by estimating the short-run price-elasticity of demand. The impact of introducing patient co-payments for IVF/ICSI on the likelihood of switching to other low-cost fertility treatments was evaluated using the cross-price elasticity methodology. RESULTS: The reduction in demand for IVF and ICSI cycles in the year following the introduction of patient co-payments resulted in elasticities of -0.41 and -0.34, respectively. The price-elasticity for the combined reduction of IVF/ICSI in relation to the co-payment was estimated to be -0.36. The cross-price elasticity for clomifene was close to zero (-0.01) suggesting that demand for these interventions are independent of each other and no substitution occurred. CONCLUSIONS: We report price elasticities for IVF and ICSI of -0.41 and -0.34 after introducing a (sic)1500-2000 co-payment. These findings likely represent short-run elasticities that are likely to vary over time as factors that influence the supply and demand for fertility treatments change

Prehistory of Transit Searches

Nowadays the more powerful method to detect extrasolar planets is the transit method. We review the planet transits which were anticipated, searched, and the first ones which were observed all through history. Indeed transits of planets in front of their star were first investigated and studied in the solar system. The first observations of sunspots were sometimes mistaken for transits of unknown planets. The first scientific observation and study of a transit in the solar system was the observation of Mercury transit by Pierre Gassendi in 1631. Because observations of Venus transits could give a way to determine the distance Sun-Earth, transits of Venus were overwhelmingly observed. Some objects which actually do not exist were searched by their hypothetical transits on the Sun, as some examples a Venus satellite and an infra-mercurial planet. We evoke the possibly first use of the hypothesis of an exoplanet transit to explain some periodic variations of the luminosity of a star, namely the star Algol, during the eighteen century. Then we review the predictions of detection of exoplanets by their transits, those predictions being sometimes ancient, and made by astronomers as well as popular science writers. However, these very interesting predictions were never published in peer-reviewed journals specialized in astronomical discoveries and results. A possible transit of the planet beta Pic b was observed in 1981. Shall we see another transit expected for the same planet during 2018? Today, some studies of transits which are connected to hypothetical extraterrestrial civilisations are published in astronomical refereed journals. Some studies which would be classified not long ago as science fiction are now considered as scientific ones.Comment: Submiited to Handbook of Exoplanets (Springer

ELF5 Drives Lung Metastasis in Luminal Breast Cancer through Recruitment of Gr1+ CD11b+ Myeloid-Derived Suppressor Cells.

During pregnancy, the ETS transcription factor ELF5 establishes the milk-secreting alveolar cell lineage by driving a cell fate decision of the mammary luminal progenitor cell. In breast cancer, ELF5 is a key transcriptional determinant of tumor subtype and has been implicated in the development of insensitivity to anti-estrogen therapy. In the mouse mammary tumor virus-Polyoma Middle T (MMTV-PyMT) model of luminal breast cancer, induction of ELF5 levels increased leukocyte infiltration, angiogenesis, and blood vessel permeability in primary tumors and greatly increased the size and number of lung metastasis. Myeloid-derived suppressor cells, a group of immature neutrophils recently identified as mediators of vasculogenesis and metastasis, were recruited to the tumor in response to ELF5. Depletion of these cells using specific Ly6G antibodies prevented ELF5 from driving vasculogenesis and metastasis. Expression signatures in luminal A breast cancers indicated that increased myeloid cell invasion and inflammation were correlated with ELF5 expression, and increased ELF5 immunohistochemical staining predicted much shorter metastasis-free and overall survival of luminal A patients, defining a group who experienced unexpectedly early disease progression. Thus, in the MMTV-PyMT mouse mammary model, increased ELF5 levels drive metastasis by co-opting the innate immune system. As ELF5 has been previously implicated in the development of antiestrogen resistance, this finding implicates ELF5 as a defining factor in the acquisition of the key aspects of the lethal phenotype in luminal A breast cancer

Phenotypic variation of larks along an aridity gradient:Are desert birds more flexible?

We investigated interindividual variation and intra-individual phenotypic flexibility in basal metabolic rate (BMR), total evaporative water loss (TEWL), body temperature (T-b), the minimum dry heat transfer coefficient (h), and organ and muscle size of five species of larks geographically distributed along an aridity gradient. We exposed all species to constant environments of 15degreesC or 35degreesC, and examined to what extent interspecific differences in physiology can be attributed to acclimation. We tested the hypothesis that birds from deserts display larger intra-individual phenotypic flexibility and smaller intern individual variation than species from mesic areas.Larks from arid areas had lower BMR, TEWL, and h, but did not have internal organ, sizes different from birds from mesic habitats. BMR of 15degreesC-acclimated birds was 18.0%, 29.1%, 12.2%, 25.3%, and 4.7% higher than of 35degreesC-acclimated Hoopoe Larks, Dunn's Larks, Spike-heeled Larks, Skylarks, and Woodlarks, respectively. TEWL of 15degreesC-acclimated Hoopoe Larks exceeded values for 35degreesC-acclimated individuals by 23% but did not differ between 15degreesC- and 35degreesC-acclimated individuals in the other species. The dry heat transfer coefficient was increased in 15degreesC-acclimated individuals of Skylarks and Dunn's Larks, but not in the. other species. Body temperature was on average 0.4degreesC +/- 0.15degreesC (mean +/- 1 SEM) lower in 15degreesC-acclimated individuals of all species. Increased food intake in 15degreesC-acclimated birds stimulated enlargement of intestine (26.9-38.6%), kidneys (9.8-24.4%), liver (16.5-27.2%), and. stomach (22.0-31.6%). The pectoral muscle increased in 15degreesC-acclimated Spike-heeled Larks and Skylarks, remained unchanged in Hoopoe Larks, and decreased in 15degreesC-acclimated Woodlarks and Dunn's Larks. We conclude that the degree of intra-individual flexibility varied between physiological traits and among species, but that acclimation does not account for interspecific differences in BMR, TEWL, and h in larks. We found no general support for the hypothesis that species from desert environments display larger intra-individual phenotypic flexibility than those from mesic areas.The coefficient of variation of larks acclimated to their natural environment was smaller in species from and areas than in species from mesic areas for mass-corrected BMR and surface-specific h, but not for mass-corrected TEWL. The high repeatabilities of BMR, TEWL, and h in several species indicated a within-individual consistency on which natural selection could operate.</p

Freshwater Sponges Have Functional, Sealing Epithelia with High Transepithelial Resistance and Negative Transepithelial Potential

Epithelial tissue — the sealed and polarized layer of cells that regulates transport of ions and solutes between the environment and the internal milieu — is a defining characteristic of the Eumetazoa. Sponges, the most ancient metazoan phylum [1], [2], are generally believed to lack true epithelia [3], [4], [5], but their ability to occlude passage of ions has never been tested. Here we show that freshwater sponges (Demospongiae, Haplosclerida) have functional epithelia with high transepithelial electrical resistance (TER), a transepithelial potential (TEP), and low permeability to small-molecule diffusion. Curiously, the Amphimedon queenslandica sponge genome lacks the classical occluding genes [5] considered necessary to regulate sealing and control of ion transport. The fact that freshwater sponge epithelia can seal suggests that either occluding molecules have been lost in some sponge lineages, or demosponges use novel molecular complexes for epithelial occlusion; if the latter, it raises the possibility that mechanisms for occlusion used by sponges may exist in other metazoa. Importantly, our results imply that functional epithelia evolved either several times, or once, in the ancestor of the Metazoa

Diurnal and Circadian Rhythms in the Tomato Transcriptome and Their Modulation by Cryptochrome Photoreceptors

BACKGROUND: Circadian clocks are internal molecular time-keeping mechanisms that provide living organisms with the ability to adjust their growth and physiology and to anticipate diurnal environmental changes. Circadian clocks, without exception, respond to light and, in plants, light is the most potent and best characterized entraining stimulus. The capacity of plants to respond to light is achieved through a number of photo-perceptive proteins including cryptochromes and phytochromes. There is considerable experimental evidence demonstrating the roles of photoreceptors in providing light input to the clock. METHODOLOGY: In order to identify genes regulated by diurnal and circadian rhythms, and to establish possible functional relations between photoreceptors and the circadian clock in tomato, we monitored the temporal transcription pattern in plants entrained to long-day conditions, either by large scale comparative profiling, or using a focused approach over a number of photosensory and clock-related genes by QRT-PCR. In parallel, focused transcription analyses were performed in cry1a- and in CRY2-OX tomato genotypes. CONCLUSIONS: We report a large series of transcript oscillations that shed light on the complex network of interactions among tomato photoreceptors and clock-related genes. Alteration of cryptochrome gene expression induced major changes in the rhythmic oscillations of several other gene transcripts. In particular, over-expression of CRY2 had an impact not only on day/night fluctuations but also on rhythmicity under constant light conditions. Evidence was found for widespread diurnal oscillations of transcripts encoding specific enzyme classes (e.g. carotenoid biosynthesis enzymes) as well as for post-transcriptional diurnal and circadian regulation of the CRY2 transcript