67 research outputs found
Loss of Sexual Reproduction and Dwarfing in a Small Metazoan
Asexuality has major theoretical advantages over sexual reproduction, yet newly formed asexual lineages rarely endure. The success, or failure, of such lineages is affected by their mechanism of origin, because it determines their initial genetic makeup and variability. Most previously described mechanisms imply that asexual lineages are randomly frozen subsamples of a sexual population.We found that transitions to obligate parthenogenesis (OP) in the rotifer Brachionus calyciflorus, a small freshwater invertebrate which normally reproduces by cyclical parthenogenesis, were controlled by a simple Mendelian inheritance. Pedigree analysis suggested that obligate parthenogens were homozygous for a recessive allele, which caused inability to respond to the chemical signals that normally induce sexual reproduction in this species. Alternative mechanisms, such as ploidy changes, could be ruled out on the basis of flow cytometric measurements and genetic marker analysis. Interestingly, obligate parthenogens were also dwarfs (approximately 50% smaller than cyclical parthenogens), indicating pleiotropy or linkage with genes that strongly affect body size. We found no adverse effects of OP on survival or fecundity.This mechanism of inheritance implies that genes causing OP may evolve within sexual populations and remain undetected in the heterozygous state long before they get frequent enough to actually cause a transition to asexual reproduction. In this process, genetic variation at other loci might become linked to OP genes, leading to non-random associations between asexuality and other phenotypic traits
Granulomatous hepatitis due to Bartonella henselae infection in an immunocompetent patient
<p>Abstract</p> <p>Background</p> <p><it>Bartonella henselae </it>(<it>B. henselae</it>) is considered a rare cause of granulomatous hepatitis. Due to the fastidious growth characteristics of the bacteria, the limited sensitivity of histopathological stains, and the non-specific histological findings on liver biopsy, the diagnosis of hepatic bartonellosis can be difficult to establish. Furthermore, the optimal treatment of established hepatic bartonellosis remains controversial.</p> <p>Case presentation</p> <p>We present a case of hepatic bartonellosis in an immunocompetent woman who presented with right upper quadrant pain and a five cm right hepatic lobe mass on CT scan. The patient underwent a right hepatic lobectomy. Surgical pathology revealed florid necrotizing granulomatous hepatitis, favoring an infectious etiology. Despite extensive histological and serological evaluation a definitive diagnosis was not established initially. Thirteen months after initial presentation, hepatic bartonellosis was diagnosed by PCR studies from surgically excised liver tissue. Interestingly, the hepatic granulomas persisted and <it>Bartonella henselae </it>was isolated from the patient's enriched blood culture after several courses of antibiotic therapy.</p> <p>Conclusion</p> <p>The diagnosis of hepatic bartonellosis is exceedingly difficult to establish and requires a high degree of clinical suspicion. Recently developed, PCR-based approaches may be required in select patients to make the diagnosis. The optimal antimicrobial therapy for hepatic bartonellosis has not been established, and close follow-up is needed to ensure successful eradication of the infection.</p
Breast imaging technology: Application of magnetic resonance imaging to early detection of breast cancer
Since its first introduction approximately 10 years ago, there has been extensive progress in the application of magnetic resonance imaging (MRI) to the detection and diagnosis of breast cancer. Contrast-enhanced MRI has been shown to have value in the diagnostic work-up of women who present with mammogram or clinical abnormalities. In addition, it has been demonstrated that MRI can detect mammogram occult multifocal cancer in patients who present with unifocal disease. Advances in risk stratification and limitations in mammography have stimulated interest in the use of MRI to screen high-risk women for cancer. Several studies of MRI high-risk screening are ongoing. Preliminary results are encouraging
Hypofractionated radiotherapy for prostate cancer
In the last few years, hypofractionated external beam radiotherapy has gained increasing popularity for prostate cancer treatment, since sufficient evidence exists that prostate cancer has a low alpha/beta ratio, lower than the one of the surrounding organs at risk and thus there is a potential therapeutic benefit of using larger fractionated single doses. Apart from the therapeutic rationale there are advantages such as saving treatment time and medical resources and thereby improving patient's convenience. While older trials showed unsatisfactory results in both standard and hypofractionated arm due to insufficient radiation doses and non-standard contouring of target volumes, contemporary randomized studies have reported on encouraging results of tumor control mostly without an increase of relevant side effects, especially late toxicity. Aim of this review is to give a detailed analysis of relevant, recently published clinical trials with special focus on rationale for hypofractionation and different therapy settings
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Synbiotic approach restores intestinal homeostasis and prolongs survival in leukaemia mice with cachexia
Cancer cachexia is a multifactorial syndrome that includes muscle wasting and inflammation. As gut microbes influence host immunity and metabolism, we investigated the role of the gut microbiota in the therapeutic management of cancer and associated cachexia. A community-wide analysis of the caecal microbiome in two mouse models of cancer cachexia (acute leukaemia or subcutaneous transplantation of colon cancer cells) identified common microbial signatures, including decreased Lactobacillus spp. and increased Enterobacteriaceae and Parabacteroides goldsteinii/ASF 519. Building on this information, we administered a synbiotic containing inulin-type fructans and live Lactobacillus reuteri 100-23 to leukaemic mice. This treatment restored the Lactobacillus population and reduced the Enterobacteriaceae levels. It also reduced hepatic cancer cell proliferation, muscle wasting and morbidity, and prolonged survival. Administration of the synbiotic was associated with restoration of the expression of antimicrobial proteins controlling intestinal barrier function and gut immunity markers, but did not impact the portal metabolomics imprinting of energy demand. In summary, this study provided evidence that the development of cancer outside the gut can impact intestinal homeostasis and the gut microbial ecosystem and that a synbiotic intervention, by targeting some alterations of the gut microbiota, confers benefits to the host, prolonging survival and reducing cancer proliferation and cachexia
Polar Invasion and Translocation of Neisseria meningitidis and Streptococcus suis in a Novel Human Model of the Blood-Cerebrospinal Fluid Barrier
Acute bacterial meningitis is a life-threatening disease in humans. Discussed as entry sites for pathogens into the brain are the blood-brain and the blood-cerebrospinal fluid barrier (BCSFB). Although human brain microvascular endothelial cells (HBMEC) constitute a well established human in vitro model for the blood-brain barrier, until now no reliable human system presenting the BCSFB has been developed. Here, we describe for the first time a functional human BCSFB model based on human choroid plexus papilloma cells (HIBCPP), which display typical hallmarks of a BCSFB as the expression of junctional proteins and formation of tight junctions, a high electrical resistance and minimal levels of macromolecular flux when grown on transwell filters. Importantly, when challenged with the zoonotic pathogen Streptococcus suis or the human pathogenic bacterium Neisseria meningitidis the HIBCPP show polar bacterial invasion only from the physiologically relevant basolateral side. Meningococcal invasion is attenuated by the presence of a capsule and translocated N. meningitidis form microcolonies on the apical side of HIBCPP opposite of sites of entry. As a functionally relevant human model of the BCSFB the HIBCPP offer a wide range of options for analysis of disease-related mechanisms at the choroid plexus epithelium, especially involving human pathogens
Patient considerations in the management of gout and role of combination treatment with lesinurad
Liza W Claus, Joseph J Saseen Department of Clinical Pharmacy, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, USA Abstract: Gouty arthritis is one of the most common rheumatic diseases, and the prevalence continues to rise, which is likely related to increased incidence of comorbidities, lifestyle factors, and suboptimal utilization of urate-lowering therapy. In recent years, multiple new guidelines have been published along with the approval of novel drug therapies. Still, gout remains a poorly controlled disease state that is accompanied by a reduced health-related quality of life, increased health care utilization, and overall negative socioeconomic effects, all of which have a negative impact on patient-related health outcomes. The key to success in gout management is utilization of urate-lowering therapy to prevent recurrence of acute gouty arthritis and to resolve tophi, if present. Xanthine oxidase inhibitors are first-line medications for the prevention of recurrent gout followed by uricosurics, including lesinurad (a uric acid reabsorption inhibitor) as an add-on option. The recent US Food and Drug Administration Safety Communication related to cardiovascular risk with febuxostat may result in increased use of allopurinol in combination therapy with a uricosuric agent such as lesinurad. In this review, we discuss gout management, clinical end points, and patient-related outcomes for consideration, summarize the evidence for combination therapy to achieve serum urate targets, and focus on lesinurad as a novel newer medication for the prevention of gout. Keywords: gouty arthritis, patient-centered, treatment, lesinura
Time to Legislate: A Database to Analyse the Temporal Dynamics
Part 3: Policy Modeling and Policy InformaticsInternational audienceWhat are the temporal features of the German legislature? How quickly do lawmakers act and how fast is the acceleration of policy-making processes? To this day political science has not succeeded in analysing these time-related questions concerning the legislature and the time-strategic actions of political actors comprehensively and quantitatively. So far a vast, ample database comprising said information does not exist. Such a lack seems surprising as time as a resource in policy-making is extraordinarily relevant and the collection of necessary information on the German legislature is at least technologically possible today.This paper therefore puts its scientific focus on above-mentioned methodological challenges. It points out how important temporality is to the research on decision-making processes and it presents a database which will list every single procedural step within any given legislative process. The foundation for all raw data is formed by the entire body of indexes of legislative material, issued and published by the Parliamentary Archives of the German Bundestag for every law respectively. All requested pieces of information are obtained by the means of a computer-assisted read-out. Thereby and for the first time, research on the temporal dimensions of policy-making – its duration, pace and acceleration – will become adequately accessible to analysis
Plasma Protein and Soy Fiber Content Effect on Bologna Sausage Properties as Influenced by Fat Level
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