1,721,026 research outputs found
Male Genital Tract Chlamydial Infection: Implications for Pathology and Infertility
No full textChlamydia trachomatis infections are prevalent worldwide, but current research, screening and treatment is focussed on females, with the burden of disease and infertility sequelae considered predominantly a female problem. However, the prevalence of chlamydial infection is similar in males and females. Furthermore, a role for this pathogen in the development of male urethritis, epididymitis and orchitis is widely accepted. While the role of Chlamydia in the development of prostatitis is controversial, we suggest that Chlamydia is an aetiological agent, with incidences of up to 39.5% reported in prostatitis patients. Infection of the testis and prostate is implicated in a deterioration of sperm, possibly affecting fertility. Chlamydia infections may also affect male fertility by directly damaging the sperm, as sperm parameters, proportion of DNA fragmentation, and acrosome reaction capacity are impaired with chlamydial infection. Furthermore, the proportion of male partners of infertile couples with evidence of a Chlamydia infection is greater than documented in the general population. An effect of male chlamydial infection on the fertility of the female partner has also been reported. Thus the need for a vaccine to protect both males and females is proposed. The difficulty arises because the male reproductive tract is an immune privileged site which can be disrupted, potentially affecting spermatogenesis, if inappropriate inflammatory responses are provoked. Examination of responses to infection in humans and in experimental animal models suggest that an IgA-inducing vaccine will be able to effectively target the male reproductive tract, while avoiding harmful inflammatory responses that may impair fertility
Transcutaneous immunization with novel lipid-based adjuvants induces protection against gastric Helicobacter pylori infection
No full textThe development of vaccines to combat pathogens that infect across mucosal surfaces has been a major goal of vaccine research. Successful mucosal vaccination requires the co-administration of adjuvants that can overcome the state of immune tolerance normally associated with mucosal application of proteins. In the case of oral immunization, delivery systems are also required to protect vaccine antigens against destruction by gastric pH and digestive enzymes. Furthermore, adjuvants used for mucosal delivery must be free of neurotoxic effects like those induced by the commonly used experimental mucosal adjuvant cholera toxin. Maintenance of the "cold chain" is also essential for the effectiveness of any vaccine and adjuvants/delivery systems that enhance the stability of a vaccine would offer a significant advantage. Needle-free methods of vaccination that induce protective immunity at multiple mucosal surfaces are also desirable for rapid vaccination of large populations. In the present study we show that transcutaneous immunization (TCI) using Lipid C, a novel lipid-based matrix originally developed for oral immunization, containing soluble Helicobacter sonicate significantly reduces the gastric bacterial burden in mice following gastric challenge with live Helicobacter pylori. Protection is associated with the production of splenic gamma interferon and gastric IgA and was achieved without the co-administration of potent and potentially toxic adjuvants, although protection was further enhanced by inclusion of CpG-ODN and cholera toxin in the lipid delivery system
Ovarian steroid hormones: effects on immune responses and Chlamydia trachomatis infections of the female genital tract
No full textFemale sex hormones are known to regulate the adaptive and innate immune functions of the female reproductive tract. This review aims to update our current knowledge of the effects of the sex hormones estradiol and progesterone in the female reproductive tract on innate immunity, antigen presentation, specific immune responses, antibody secretion, genital tract infections caused by Chlamydia trachomatis, and vaccine-induced immunity
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Chlamydial infection of immune cells : altered function and implications for disease
No full textChlamydia trachomatis is an obligate intracellular bacterial pathogen that infects the genital and\ud
ocular mucosa of humans, causing infections that can lead to pelvic inflammatory disease, infertility, and blinding\ud
trachoma. C. pneumoniae is a respiratory pathogen that is the cause of 12–15% of community-acquired pneumonia.\ud
Both chlamydial species were believed to be restricted to the epithelia of the genital, ocular, and respiratory\ud
mucosa; however, increasing evidence suggests that both these pathogens can be isolated from peripheral blood of\ud
both healthy individuals and patients with inflammatory conditions such as coronary artery disease and asthma.\ud
Chlamydia can also be isolated from brain tissues of patients with degenerative neurological disorders such as\ud
Alzheimer’s disease and multiple sclerosis, and also from certain lymphomas. An increasing number of in vitro\ud
studies suggest that some chlamydial species can infect immune cells, at least at low levels. These infections may\ud
alter immune cell function in a way that promotes chlamydial persistence in the host and contributes to the\ud
progression of several chronic inflammatory diseases. In this paper, we review the evidence for the growth of\ud
Chlamydia in immune cells, particularly monocytes/macrophages and dendritic cells, and describe how infection\ud
may affect the function of these cells
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Chlamydia trachomatis infection: Host immune responses and potential vaccines
No full textChlamydia trachomatis causes genital tract infections that affect men, women, and children on a global scale. This review focuses on innate and adaptive immune responses in the female reproductive tract (FRT) to genital tract infections with C. trachomatis. It covers C. trachomatis infections and highlights our current knowledge of genital tract infections, serovar distribution, infectious load, and clinical manifestations of these infections in women. The unique features of the immune system of the FRT will be discussed and will include a review of our current knowledge of innate and adaptive immunity to chlamydial infections at this mucosal site. The use of animal models to study the pathogenesis of, and immunity to, Chlamydia infection of the female genital tract will also be discussed and a review of recent immunization and challenge experiments in the murine model of chlamydial FRT infection will be presented
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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