RESUMO
Assisted reproductive technology is a common procedure which helps millions of couples who suffer fertility problems worldwide every year. Screening for genetic abnormalities prior to such procedure is very important to prevent the transmission of harmful genetic mutations to future generations. Microdeletions within the azoospermia factor (AZF) region of the Y chromosome and the expansion of the CAG trinucleotides in the androgen receptor (AR) gene are among the susceptible causes of male infertility in different ethnic groups. Such association has never been studied in Jordan. In this study, we compared CAG repeat length between azoospermic infertile and normospermic fertile Jordanian males and we also screened the frequency of Y chromosome microdeletions in the same cohort. The study included 142 nonobstructive azoospermic cases and 145 normospermic controls. Results have shown that the median CAG repeat length in the azoospermic group is 19 ± 2 compared to 19 ± 1.5 (p = .6262) in the control group. Deletions within the Y chromosome AZF region were detected in 7 of 142 cases (4.93%) and no deletions were seen in the control group. The results of this study confirm the importance of the AZF region in normal spermatogenesis, whereas it shows no link between the length of CAG repeats in the AR gene and male azoospermia in Jordanian group examined.
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Gossypiboma is a term used to describe a pseudotumor caused by accidental retention of surgical swab or sponge in the body after surgery. The abdominal cavity is the most common site of retained surgical sponge. It is quite an infrequent surgical complication which is usually rarely reported because of the fear of medico-legal consequences. Here, we are reporting a case of a 26-years-old woman referred to our outpatient surgery clinic (OPD) from another hospital with complaint of intermittent abdominal pain, fever, and abdominal lump for 4 months following removal of IUD, which was attempted laparoscopically, and later converted to open laparotomy. She also had a history of cesarean section done one and half year ago in the same hospital. Clinical examination revealed a palpable abdominal mass in the para-umblical region. However, a computed tomography (CT) revealed a huge intra-abdominal mass. A diagnosis of intra-abdominal gossypiboma was suggested and the patient underwent exploratory laparotomy where the diagnosis was confirmed and the mass was excised.
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Near-infrared spectroscopy is a non-invasive neuroimaging method which uses light to measure changes in cerebral blood oxygenation associated with brain activity. In this work, we demonstrate the ability to record and analyze images of brain activity in real-time using a 16-channel continuous wave optical NIRS system. We propose a novel real-time analysis framework using an adaptive Kalman filter and a state-space model based on a canonical general linear model of brain activity. We show that our adaptive model has the ability to estimate single-trial brain activity events as we apply this method to track and classify experimental data acquired during an alternating bilateral self-paced finger tapping task.
Assuntos
Encéfalo/fisiologia , Processamento de Imagem Assistida por Computador/métodos , Modelos Neurológicos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Algoritmos , Circulação Cerebrovascular/fisiologia , Humanos , Processamento de Imagem Assistida por Computador/instrumentação , Desempenho Psicomotor/fisiologia , Software , Espectroscopia de Luz Próxima ao Infravermelho/instrumentaçãoRESUMO
AIMS: Aeromonas hydrophila is recognized as a human pathogen following wound exposure or ingestion of contaminated water and food. For rapid identification of this bacterium, a TaqMan-based real-time PCR assay has been developed. METHODS AND RESULTS: Primers and probes that target specific sequences of the 16S rRNA gene and cytolytic enterotoxin gene (aerA) were combined in a duplex assay. Presence and size of PCR products were confirmed with microchannel fluidics electrophoresis analysis. After validation, using type strain CIP7614T DNA, the PCR assay was tested on 12 positive and negative controls. Twenty-one Aeromonas strains were isolated from environmental samples and were identified with biochemical tests as Aer. sobria, Aer. caviae and Aer. hydrophila. Only Aer. hydrophila strains tested positive by PCR assay. CONCLUSIONS: The PCR developed here was successfully applied for the identification of Aer. hydrophila from reference, clinical and environmental samples and showed a high discrimination between Aer. hydrophila and other Aeromonas species. SIGNIFICANCE AND IMPACT OF THE STUDY: This molecular method is convenient, rapid (2.5 h vs 24 h), specific to identify Aer. hydrophila and usable for diagnosis in medical and veterinary laboratories.
Assuntos
Aeromonas hydrophila/classificação , Aeromonas hydrophila/isolamento & purificação , DNA Bacteriano/genética , Infecções por Bactérias Gram-Negativas/diagnóstico , Reação em Cadeia da Polimerase/métodos , Aeromonas hydrophila/genética , Aeromonas hydrophila/metabolismo , Toxinas Bacterianas/genética , Técnicas de Tipagem Bacteriana , Primers do DNA/genética , Microbiologia Ambiental , Humanos , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Sensibilidade e EspecificidadeRESUMO
We compare the consistency and accuracy of two image binning approaches used in 4D-CT imaging. One approach, phase binning (PB), assigns each breathing cycle 2pi rad, within which the images are grouped. In amplitude binning (AB), the images are assigned bins according to the breathing signal's full amplitude. To quantitate both approaches we used a NEMA NU2-2001 IEC phantom oscillating in the axial direction and at random frequencies and amplitudes, approximately simulating a patient's breathing. 4D-CT images were obtained using a four-slice GE Lightspeed CT scanner operating in cine mode. We define consistency error as a measure of ability to correctly bin over repeated cycles in the same field of view. Average consistency error mue+/-sigmae in PB ranged from 18%+/-20% to 30%+/-35%, while in AB the error ranged from 11%+/-14% to 20%+/-24%. In PB nearly all bins contained sphere slices. AB was more accurate, revealing empty bins where no sphere slices existed. As a proof of principle, we present examples of two non-small cell lung carcinoma patients' 4D-CT lung images binned by both approaches. While AB can lead to gaps in the coronal images, depending on the patient's breathing pattern, PB exhibits no gaps but suffers visible artifacts due to misbinning, yielding images that cover a relatively large amplitude range. AB was more consistent, though often resulted in gaps when no data existed due to patients' breathing pattern. We conclude AB is more accurate than PB. This has important consequences to treatment planning and diagnosis.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Imagens de Fantasmas , Interpretação de Imagem Radiográfica Assistida por Computador , Humanos , Respiração , Tomografia Computadorizada por Raios X/métodosRESUMO
Two patients presenting to the Central Military Hospital of Beirut with symptomatic lingual thyroid are reported. I131 thyroid scanning revealed the lingual thyroid to be the only functional thyroid tissue present in each patient. Subsequent CT scanning demonstrated the large size of these ectopic thyroids causing significant mechanical obstruction. These were excised transorally using a posterior midline tongue-splitting incision and reimplanted in the rectus abdominis muscles. Details of this modified tongue-splitting surgical approach are described. A brief review of the literature concerning lingual thyroid and its surgical treatment is also presented as well as three patients operated on for lingual thyroid at the American University of Beirut Medical Centre between 1975 and 1994 using an external neck incision.
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Coristoma/cirurgia , Glândula Tireoide , Tireoidectomia/métodos , Doenças da Língua/cirurgia , Língua/cirurgia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A retrospective study of 27 cases of umbilical pilonidal sinus (UPNS) was conducted at the Central Military Hospital of Beirut between 1987 and 1991. In this study a simple conservative surgical technique is described by removing the dead hair and the cotton like dirt as an outpatient procedure without need for anaesthesia or hospitalization. There were 26 male and one female, a mean age of 26 years, patients were followed for a period of 2 years (1987-1991). The cure rate was 98% with only four cases which needed more than one session of treatment.
Assuntos
Seio Pilonidal/cirurgia , Umbigo , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Masculino , Seio Pilonidal/diagnóstico , Estudos Retrospectivos , Fatores de TempoRESUMO
Laparoscopic herniorrhaphy is a relatively new and successful surgical technique and follow-up studies are beginning to provide short- and middle-term results. In this article, the authors discuss their experience and technique with the preperitoneal laparoscopic inguinal hernia repair between the years 1993 and 1995 during which they accomplished 30 herniorrhaphies on 25 patients with one recurrence and four postoperative neuralgias.
Assuntos
Hérnia Inguinal/cirurgia , Laparoscopia , Humanos , Complicações Pós-Operatórias , Recidiva , Telas CirúrgicasRESUMO
This Phase III study evaluates an investigational quadrivalent meningococcal CRM(197) conjugate vaccine, MenACWY-CRM (Novartis Vaccines), when administered concomitantly or sequentially with two other recommended adolescent vaccines; combined tetanus, reduced diphtheria and acellular pertussis (Tdap), and human papillomavirus (HPV) vaccine. In this single-centre study, 1620 subjects 11-18 years of age, were randomized to three groups (1:1:1) to receive MenACWY-CRM concomitantly or sequentially with Tdap and HPV. Meningococcal serogroup-specific serum bactericidal assay using human complement (hSBA), and antibodies to Tdap antigens and HPV virus-like particles were determined before and 1 month after study vaccinations. Proportions of subjects with hSBA titres > or =1:8 for all four meningococcal serogroups (A, C, W-135, Y) were non-inferior for both concomitant and sequential administration. Immune responses to Tdap and HPV antigens were comparable when these vaccines were given alone or concomitantly with MenACWY-CRM. All vaccines were well tolerated; concomitant or sequential administration did not increase reactogenicity. MenACWY-CRM was well tolerated and immunogenic in subjects 11-18 years of age, with comparable immune responses to the four serogroups when given alone or concomitantly with Tdap or HPV antigens. This is the first demonstration that these currently recommended adolescent vaccines could be administered concomitantly without causing increased reactogenicity.
Assuntos
Adjuvantes Imunológicos/efeitos adversos , Proteínas de Bactérias/efeitos adversos , Vacinas contra Difteria, Tétano e Coqueluche Acelular/administração & dosagem , Imunização/métodos , Vacinas Meningocócicas/efeitos adversos , Vacinas Meningocócicas/imunologia , Vacinas contra Papillomavirus/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Adolescente , Anticorpos Antibacterianos/sangue , Anticorpos Antivirais/sangue , Proteínas de Bactérias/administração & dosagem , Atividade Bactericida do Sangue , Criança , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Feminino , Humanos , Esquemas de Imunização , Incidência , Masculino , Vacinas Conjugadas/efeitos adversos , Vacinas Conjugadas/imunologiaRESUMO
We have recently described a murine model of Staphylococcus aureus-induced septic arthritis. One of the hallmarks of this disease is a striking hypergammaglobulinemia. In the present study we have used a sensitive ELISPOT technique to assess, at the single cell level, the B-cell differentiation properties of this arthritogenic, toxic shock syndrome toxin-1 (TSST-1)-producing staphylococcal strain. In vivo, inoculation of live S. aureus resulted in lymphoproliferation, early (within 3-4 days) peak of IgM-secreting cells and late (2 weeks after the injection) pronounced increase of IgG-secreting cells. We have documented that this late increase of IgG-secreting cells is a CD4+ T-cell-dependent phenomenon. Furthermore, we have showed that there is a relationship between the hypergammaglobulinemia and the appearance of arthritis, since a nonarthritogenic staphylococcal strain will not give rise to increased frequency of immunoglobulin-secreting cells. To elucidate mechanisms responsible for S. aureus-induced polyclonal B-cell activation, we have assessed in vitro effects of formalin-fixed arthritogenic S. aureus on the release of cytokines. Our results show that the S. aureus LS-1 strain induces in vitro preferentially IgM-secreting cells, many of them displaying autoantibody properties. The magnitude of this response is high and comparable with optimal concentrations of LPS, a potent murine polyclonal B-cell activator. Interleukin-1 alpha (IL-1 alpha), tumor necrosis factor (TNF), and interleukin-6 (IL-6) were all secreted by mouse MNC after in vitro exposure to formalin-killed S. aureus. Inhibition experiments, using neutralizing antibodies to these cytokines, revealed that IL-1 alpha and IL-6 but not TNF-alpha had potent B-cell differentiation properties in S. aureus-stimulated cell cultures.
Assuntos
Artrite Experimental/imunologia , Linfócitos B/imunologia , Ativação Linfocitária , Monocinas/fisiologia , Staphylococcus aureus/imunologia , Linfócitos T/imunologia , Animais , Formação de Anticorpos , Diferenciação Celular/efeitos dos fármacos , Parede Celular/imunologia , Interleucina-1/fisiologia , Interleucina-6/fisiologia , Masculino , Camundongos , Baço/citologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
In a newly developed mouse model of Staphylococcus aureus arthritis the kinetics of joint destruction and serological manifestations as well as the clinical course of arthritis and osteitis were studied. Almost all mice developed histopathological signs of arthritis upon a single intravenous injection of 10(7) S. aureus LS-1 cells. There was rapid joint destruction, with synovial hypertrophy already visible, within 24 h after injection of the bacteria. Cartilage and/or bone erosions were seen in a majority of the mice within 72 h. Extra-articular manifestations, especially signs of bone infection, were also found soon after inoculation of the bacteria. Tail osteitis was frequent (50% of the mice) but appeared later than arthritis. Polymorphonuclear cells prevailed in the early joint lesions and were also common in the extra-articular manifestations. Within 3 days, mononuclear cells were also seen in the inflamed synovium, gaining a dominant position 3 weeks after the start of the disease. Serum interleukin-6 levels were already increased within 6 h after bacterial injection and remained elevated throughout the course of arthritis. Serum tumor necrosis factor levels were increased within 24 h. There was a tremendous induction of immunoglobulin production, especially of the immunoglobulin G1 isotype. This was paralleled by the production of specific antibodies to S. aureus (cell walls and toxin), as well as autoantibodies (rheumatoid factors and anti-single-stranded DNA antibodies), all predominantly of the immunoglobulin G isotype. The type and magnitude of the immunoglobulin G response together with the elevated interleukin-6 levels speak in favor of both antigen-specific and polyclonal B-cell activation during S. aureus arthritis. This study points out important similarities between our new model of S. aureus arthritis and human S. aureus arthritis. This resemblance will enable controlled studies of pathogenetic mechanisms of septic arthritis as well as therapeutic and prophylactic approaches.
Assuntos
Artrite Reativa/imunologia , Artrite Reativa/patologia , Toxinas Bacterianas , Infecções Estafilocócicas , Superantígenos , Animais , Anticorpos Antinucleares/biossíntese , Proteínas da Membrana Bacteriana Externa/biossíntese , DNA de Cadeia Simples/imunologia , Modelos Animais de Doenças , Enterotoxinas/sangue , Ensaio de Imunoadsorção Enzimática , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Interleucina-6/sangue , Masculino , Camundongos , Osteíte/imunologia , Osteíte/patologia , Fator Reumatoide/sangue , Fator de Necrose Tumoral alfa/biossínteseRESUMO
Although enterotoxins have been implicated in disease states such as food poisoning and toxic shock syndrome, their role in infectious arthritis is not known. To study the arthritogenic properties of toxic shock syndrome toxin 1 (TSST-1), two pairs of S. aureus strains isogenic for TSST-1 production were injected intravenously into healthy Swiss mice. Mice injected with TSST-1-secreting staphylococcal strains developed more frequent and more severe arthritis than did mice inoculated with the isogenic TSST-1-deficient counterparts. Immunohistochemical analysis of arthritic joints revealed an equal number of infiltrating phagocytes in both groups; however, mice inoculated with TSST-1-producing staphylococci had significantly more (P < .01) interleukin-2 receptor-expressing cells in the inflamed synovium than did mice that received the isogenic counterpart. Thus, TSST-1 is a virulence determinant in S. aureus arthritis in mice. The precise mechanism by which this toxin contributes to the development and progression of arthritis needs further investigation.
Assuntos
Artrite Infecciosa/microbiologia , Toxinas Bacterianas , Enterotoxinas/fisiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/patogenicidade , Superantígenos , Animais , Linhagem Celular , Imuno-Histoquímica , Masculino , Camundongos , Receptores de Interleucina-2/metabolismo , VirulênciaRESUMO
Erosive arthritis is a common and feared complication of staphylococcal infection. The reason(s) for the progressive course of the arthritis is unknown. It has been recently established that enterotoxins produced by Staphylococcus aureus display superantigen properties leading to stimulation of T cells carrying distinct T cell receptor V beta elements. This finding provides a potential connection between staphylococcal exoproteins and endogenous immune mechanisms participating in the infectious process. We have recently describe successful induction of infections arthritis in mice after intravenous inoculation of a toxic shock syndrome toxin-1 (TSST-1)-producing S. aureus LS-1 strain. Using this model we have now found a clonal expansion of T cells expressing V beta 11+ T cell receptor in the synovial tissue of arthritic mice. The role of TSST-1 as a superantigen inducing oligoclonal expansion was confirmed in an in vitro culture system. The expansion of V beta 11+ T cells proved to be of arthritogenic significance since mice genomically deleted of the V beta 11+ T cells did not develop arthritis and since pretreatment of healthy mice with anti-CD4 or anti-V beta 11 monoclonal antibodies inhibited arthritis. In addition, CD4+ and V beta 11+ T cells showed themselves to be of pathogenic significance in staphylococcal-induced mortality, since mice depleted of such populations showed increased survival. We propose that in hematogenously spread S. aureus-induced arthritis the TSST-1-dependent clonal expansion of CD4+ V beta 11+ T cells is a driving pathogenic force.
Assuntos
Artrite Infecciosa/imunologia , Toxinas Bacterianas , Enterotoxinas/fisiologia , Infecções Estafilocócicas/imunologia , Superantígenos , Subpopulações de Linfócitos T/imunologia , Animais , Bacteriemia/imunologia , Bacteriemia/mortalidade , Células Cultivadas , Técnicas Imunoenzimáticas , Masculino , Camundongos , Receptores de Antígenos de Linfócitos T alfa-beta/fisiologia , Baço/citologia , Infecções Estafilocócicas/mortalidadeRESUMO
We have previously demonstrated that staphylococcal enterotoxins contribute to arthritis and mortality during staphylococcal infection. To further explore the mechanism by which bacterial superantigens contribute to the pathogenesis of Staphylococcus aureus septicemia, T-cell receptor V beta 3 transgenic (TGV beta 3) mice and nontransgenic (non-TG) littermates were inoculated intravenously with S. aureus AB-1, which produces large amounts of staphylococcal enterotoxin A, which specifically reacts with T-cell receptor V beta 3. Within 9 days after inoculation, 85% of the TGV beta mice died, compared with 31% of their non-TG littermates (P < 0.01). The high mortality of TGV beta 3 mice was accompanied by elevated bacterial burdens in the blood, spleen, and kidneys. The in vivo kinetics of cytokine mRNA expression was studied by an in situ hybridization technique. Staphylococcal infection gave rise to increased expression of interleukin 1 beta (IL-1 beta) mRNA and sparsely expressed tumor necrosis factor alpha (TNF-alpha), IL-4, and IL-10 mRNAs in both groups. Gamma interferon mRNA expression increased on day 3 and was maintained at a detectable level in the late phase of infection in TGV beta 3 mice, in contrast to non-TG mice. Impressively, significantly higher expression of TNF-beta mRNA in TGV beta 3 mice was noted throughout the course of infection than in non-TG littermates. These findings suggest that overproduction of TNF-beta and gamma interferon, the Th1 cytokines, may play a crucial role in the pathogenesis of septicemia caused by enterotoxin-secreting staphylococci.
Assuntos
Enterotoxinas/toxicidade , Receptores de Antígenos de Linfócitos T alfa-beta/fisiologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/patogenicidade , Animais , Citocinas/biossíntese , Citocinas/genética , Expressão Gênica , Ativação Linfocitária , Camundongos , Camundongos Transgênicos , RNA Mensageiro/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Baço/imunologia , Infecções Estafilocócicas/mortalidadeRESUMO
To investigate the role of B cells in the development of experimental Staphylococcus aureus-induced arthritis, we used X-linked immunodeficiency (xid) mice that carry a Bruton's tyrosine kinase mutation affecting the function of B cells. NFR/N.xid and congenic NFR/N mice were inoculated i.v. with a toxic syndrome toxin-1 producing S. aureus LS-1 strain. B cell-deficient NFR/N.xid mice developed less frequent (p < 0.01) and less severe (p < 0.01) arthritis than NFR/N mice did. These clinical findings were corroborated by histopathologic evaluation, indicating that NFR/N.xid mice had significantly lower (p < 0.01) erosivity of the disease. Interestingly, infected NFR/N.xid mice showed decreased bacterial burden in blood, joints, and other organs compared with the control mice. Serologic studies displayed poor B cell responses to staphylococcal cell walls, toxic shock syndrome toxin-1, and ssDNA, accompanied by a low level of Igs in infected NFR/N.xid mice. More importantly, xid defect affected cytokine profile. The in vitro experiments showed that the lymphocytes from NFR/N.xid mice had low IL-6, but high IFN-gamma production upon stimulation with staphylococcal cell walls compared with NFR/N mice. Furthermore, the in situ hybridization technique revealed the relative increase of IFN-gamma, but marked decrease of IL-1 beta mRNA expression in spleens of infected NFR/N.xid mice. No significant difference in IL-4, IL-10, and TNF-alpha mRNA expression was found between both strains. Our findings demonstrate that B cells may, directly or indirectly, contribute to the pathogenesis of septic arthritis. The results indicate that increased IFN-gamma production along with low IL-6 and IL-1 beta synthesis found in xid mice may provide a more favorable outcome of S. aureus arthritis.
Assuntos
Artrite Infecciosa/imunologia , Linfócitos B/fisiologia , Síndromes de Imunodeficiência/genética , Infecções Estafilocócicas/imunologia , Animais , Células Cultivadas , Citocinas/biossíntese , Ligação Genética , Interferon gama/fisiologia , Ativação Linfocitária , Camundongos , Cromossomo XRESUMO
We evaluated children (15-months old and older) with recurrent upper respiratory tract infections and normal levels of immunoglobulins in serum for specific polysaccharide immunodeficiency using an enzyme-linked immunosorbent assay method. Results showed that of 12 patients vaccinated with Act-HIB vaccine, one did not develop specific antibodies to Haemophilus influenzae type b, demonstrating that such immunodeficiency is present in Costa Rican children.
Assuntos
Anticorpos Antibacterianos/biossíntese , Infecções por Haemophilus/imunologia , Polissacarídeos Bacterianos/imunologia , Infecções Respiratórias/imunologia , Pré-Escolar , Costa Rica , Ensaio de Imunoadsorção Enzimática , Feminino , Vacinas Anti-Haemophilus/imunologia , Haemophilus influenzae tipo b/imunologia , Humanos , Lactente , Masculino , Recidiva , Infecções Respiratórias/microbiologiaRESUMO
Using a recently developed murine model of haematogenously induced Staphylococcus aureus, the authors have characterized the phenotypes and functional properties of inflammatory cells present in the synovium of arthritic mice. The results show that large numbers of granulocytes and macrophages were observed in the inflamed synovia within 24 h of inoculation of S. aureus strain LS-1. Many of the synovial macrophage-like cells strained for cytoplasmic IL-1 alpha and TNF-alpha. Subsequently (> or = 48 h later), a prominent infiltration of T lymphocytes, predominantly of CD4+ phenotype, was observed. Some of the T lymphocytes stained for IL-2 receptor and intracytoplasmic interferon-gamma (IFN-gamma). Surprisingly, in spite of the severe inflammatory process, very few cells expressed MHC class-II molecules in the arthritic synovia. In addition, in vivo depletion of CD4+ T-cells resulted in a considerably milder course of staphylococcal arthritis. The similarities in the phenotype expression of synovial cells and central role of T-cells in S. aureus arthritis as well as in non-infectious models of arthritis, indicate that the process governing joint destruction is likely to be the same, irrespective of the initial stimulus.
Assuntos
Artrite Infecciosa/etiologia , Infecções Estafilocócicas/etiologia , Linfócitos T/imunologia , Animais , Artrite Infecciosa/imunologia , Artrite Infecciosa/patologia , Modelos Animais de Doenças , Imuno-Histoquímica , Interferon gama/metabolismo , Interleucina-1/metabolismo , Depleção Linfocítica , Masculino , Camundongos , Fenótipo , Receptores de Interleucina-2/metabolismo , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/patologia , Membrana Sinovial/imunologia , Membrana Sinovial/patologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Linfócitos T/patologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The importance of the MHC class II region for the development of septic arthritis was studied in a murine model of haematogenously induced Staphylococcus aureus arthritis. In the first experiment MHC class II deficient mice (A beta-/-) and their heterozygous (A beta+/-) littermates were intravenously inoculated with a single dose of toxic shock syndrome toxin-1 producing S. aureus LS-1 strain. The results demonstrate that the expression of class II MHC molecules increases the prevalence and severity of arthritis. To analyse the impact of MHC class II haplotypes on the disease onset and progression the authors used congenic C3H.NB, C3H.Q and C3H/HeJ mice in the second set of experiments. The results show that C3H/HeJ mice developed the highest frequency and the most severe course of arthritis compared with C3H.NB and C3H.Q animals. Immunohistochemical analysis of arthritic joints revealed equal number of macrophages, CD4+ and CD8+ lymphocytes in the inflamed synovia in all the congenic mice. In contrast, the number of MHC class II expressing cells was higher in the arthritic joints of C3H/HeJ mice compared with the congenic strains (P < 0.001). Furthermore, serum levels of proarthrtitogenic cytokines, such as tumour necrosis factor and interleukin-6 were higher in C3H/HeJ group. This study indicates that MHC class II expression is necessary for the development of S. aureus arthritis in mice and that different MHC class II haplotypes confer varying susceptibility for development of joint inflammation induced by staphylococci.
Assuntos
Artrite Infecciosa/etiologia , Artrite Infecciosa/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Infecções Estafilocócicas/etiologia , Infecções Estafilocócicas/imunologia , Animais , Antígenos/administração & dosagem , Antígenos/farmacologia , Artrite Infecciosa/genética , Citocinas/biossíntese , Suscetibilidade a Doenças , Imuno-Histoquímica , Injeções Intravenosas , Articulação do Joelho , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C3H , Camundongos Mutantes , Mitógenos/administração & dosagem , Mitógenos/farmacologia , Infecções Estafilocócicas/genética , Superantígenos/administração & dosagem , Superantígenos/farmacologiaRESUMO
We have studied the role of the accessory gene regulator (agr) of Staphylococcus aureus as a virulence determinant in the pathogenesis of septic arthritis. At least 15 genes coding for potential virulence factors in Staphylococcus aureus are regulated by a putative multicomponent signal transduction system encoded by the agr/hld locus. agr and hld mutants show a decreased synthesis of extracellular toxins and enzymes, such as alpha-, beta-, and delta-hemolysin, leucocidin, lipase, hyaluronate lyase, and proteases, and at the same time an increased synthesis of coagulase and protein A as compared with the wild-type counterpart. We have used a recently described murine model of S. aureus-induced arthritis to study the virulence of S. aureus 8325-4 and two agr/hld mutants derived from it. Sixty percent of the mice injected with the wild-type strain developed arthritis, whereas agrA and hld mutants displayed joint involvement in only 10 and 30%, respectively. In addition, 40% of the mice inoculated with the wild-type strain displayed an erosive arthropathy; such changes were not detectable at all in mice inoculated with the agrA mutant. Serum levels of interleukin-6, a potent B-cell differentiation factor, were significantly higher (P < 0.001) in the mice inoculated with the wild-type strain than in those inoculated with the agrA mutant counterpart. Overall, our results suggest that the agr system of S. aureus is an important virulence determinant in the induction and progression of septic arthritis in mice.
Assuntos
Artrite Infecciosa/microbiologia , Genes Bacterianos , Genes Reguladores , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/patogenicidade , Animais , Artrite Infecciosa/patologia , Aderência Bacteriana , Modelos Animais de Doenças , Interleucina-6/biossíntese , Camundongos , Staphylococcus aureus/genética , VirulênciaRESUMO
We have recently demonstrated that toxic shock syndrome toxin-1 (TSST-1), a staphylococcal exotoxin with superantigenic properties, is involved in the pathogenesis of septic arthritis. The aim of the current study was to characterize in detail the in vitro properties of TSST-1 with regard to T cell activation patterns. We demonstrate that TSST-1 preferentially expands murine V beta 11+ T lymphocytes and this expansion occurs equally well within CD4 and CD8 compartments. To analyze the functional properties of V beta 11+ T cells expanded in response to TSST-1, we have utilized a combined in situ hybridization and immunocytochemistry method. With this technique we show that TSST-1-stimulated V beta 11+ T cells are an important source of IFN gamma mRNA synthesis, suggesting that this cytokine may participate in superantigen-mediated septic arthritis.