967 resultados para Abortion, spontaneous
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In a recent vaccination trial assessing the immunogenicity of an NY-ESO-1 (ESO) recombinant protein administered with Montanide and CpG, we have obtained evidence that this vaccine induces specific cytolytic T lymphocytes (CTL) in half of the patients. Most vaccine-induced CTLs were directed against epitopes located in the central part of the protein, between amino acids 81 and 110. This immunodominant region, however, is distinct from another ESO CTL region, 157-165, that is a frequent target of spontaneous CTL responses in A2+ patients bearing ESO tumors. In this study, we have investigated the CTL responses to ESO 157-165 in A2+ patients vaccinated with the recombinant protein. Our data indicate that after vaccination with the protein, CTL responses to ESO 157-165 are induced in some, but not all, A2+ patients. ESO 157-165-specific CTLs induced by vaccination with the ESO protein were functionally heterogeneous in terms of tumor recognition and often displayed decreased tumor reactivity as compared with ESO 157-165-specific CTLs isolated from patients with spontaneous immune responses to ESO. Remarkably, protein-induced CTLs used T-cell receptors similar to those previously isolated from patients vaccinated with synthetic ESO peptides (Vbeta4.1) and distinct from those used by highly tumor-reactive CTLs isolated from patients with spontaneous immune responses (Vbeta1.1, Vbeta8.1, and Vbeta13.1). Together, these results demonstrate that vaccination with the ESO protein elicits a repertoire of ESO 157-165-specific CTLs bearing T-cell receptors that are structurally distinct from those of CTLs found in spontaneous immune responses to the antigen and that are heterogeneous in terms of tumor reactivity, being often poorly tumor reactive.
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OBJECTIVE: High-dose methotrexate (MTX) exposure during pregnancy is associated with embryopathy. The teratogenic potential of MTX at dosages typically used in the treatment of rheumatic diseases remains uncertain. The aim of this study was to evaluate the risk of spontaneous abortion, major birth defects, elective termination of pregnancy, shortened gestational age at delivery, and reduced birth weight in women exposed to MTX. METHODS: Pregnancy outcome in women taking MTX (≤30 mg/week) either after conception or within the 12 weeks before conception was evaluated in a prospective observational multicenter cohort study. Pregnancy outcomes in the MTX group were compared to outcomes in a group of disease-matched women and a group of women without autoimmune diseases (neither group was exposed to MTX). RESULTS: The study sample included 324 MTX-exposed pregnancies (188 exposed post-conception, 136 exposed pre-conception), 459 disease-matched comparison women, and 1,107 comparison women without autoimmune diseases. In the post-conception cohort, the cumulative incidence of spontaneous abortion was 42.5% (95% confidence interval [95% CI] 29.2-58.7), which was significantly higher than the incidence of spontaneous abortion in either comparison group. The risk of major birth defects (7 of 106 [6.6%]) was elevated compared to both the cohort of women without autoimmune diseases (29 of 1,001 [2.9%]) (adjusted odds ratio [OR] 3.1 [95% CI 1.03-9.5]) and the disease-matched cohort (14 of 393 [3.6%]) (adjusted OR 1.8 [95% CI 0.6-5.7]). None of the malformations were clearly consistent with MTX embryopathy. Neither the cumulative incidence of spontaneous abortion (14.4% [95% CI 8.0-25.3]) nor the risk of major birth defects (4 of 114 [3.5%]) was increased in the pre-conception cohort. Elective termination rates were increased in both of the MTX-exposed cohorts. There were no other significant differences among groups in other study end points. CONCLUSION: Post-conception administration of MTX at dosages typically used in the treatment of rheumatic diseases was associated with an increased risk of major birth defects and spontaneous abortion. Such evidence was not found among women in our pre-conception cohort.
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The scaling properties of the rough liquid-air interface formed in the spontaneous imbibition of a viscous liquid by a model porous medium are found to be very sensitive to the magnitude of the pressure difference applied at the liquid inlet. Interface fluctuations change from obeying intrinsic anomalous scaling at large negative pressure differences, to being super-rough with the same dynamic exponent z¿3 at less negative pressure differences, to finally obeying ordinary Family-Vicsek scaling with z¿2 at large positive pressure differences. This rich scenario reflects the relative importance on different length scales of capillary and permeability disorder, and the role of surface tension and viscous pressure in damping interface fluctuations.
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Loss-of-function mutations in human profilaggrin gene have been identified as the cause of ichthyosis vulgaris (IV), and as a major predisposition factor for atopic dermatitis (AD). Similarly, flaky tail (a/a ma ft/ma ft/J) mice were described as a model for IV, and shown to be predisposed to eczema. The aim of this study was to correlate the flaky tail mouse phenotype with human IV and AD, in order to dissect early molecular events leading to atopic dermatitis in mice and men, suffering from filaggrin deficiency. Thus, 5-days old flaky tail pups were analyzed histologically, expression of cytokines was measured in skin and signaling pathways were investigated by protein analysis. Human biopsies of IV and AD patients were analyzed histologically and by real time PCR assays. Our data show acanthosis and hyperproliferation in flaky tail epidermis, associated with increased IL1β and thymic stromal lymphopoietin (TSLP) expression, and Th2-polarization. Consequently, NFκB and Stat pathways were activated, and IL6 mRNA levels were increased. Further, quantitative analysis of late epidermal differentiation markers revealed increased Small proline-rich protein 2A (Sprr2a) synthesis. Th2-polarization and Sprr2a increase may result from high TSLP expression, as shown after analysis of 5-days old K14-TSLP tg mouse skin biopsies. Our findings in the flaky tail mouse correlate with data obtained from patient biopsies of AD, but not IV. We propose that proinflammatory cytokines are responsible for acanthosis in flaky tail epidermis, and together with the Th2-derived cytokines lead to morphological changes. Accordingly, the a/a ma ft/ma ft/J mouse model can be used as an appropriate model to study early AD onset associated with profilaggrin deficiency.
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Concerns have been raised about the use of topical retinoids since the publication of isolated cases of characteristic retinoid embryopathy, originally described after oral use. A collaborative study of the European Network of Teratology Information Services was carried out to evaluate the rate of congenital malformations following first-trimester topical retinoid exposure. A population of 235 exposed pregnant women was compared with 444 controls. No significant differences were observed between groups with regard to the rates of spontaneous abortion (odds ratio [95% confidence interval], 1.5 [0.8-2.7]), minor birth defects (1.3 [0.4-3.7]), and major birth defects (1.8 [0.6-5.4]). No child showed features of retinoid embryopathy. The rate of elective termination in the exposed group was increased 3-fold (3.4 [1.5-7.8]). In conclusion, these results do not suggest an increased risk of retinoid embryopathy. However, according to current knowledge, topical retinoids cannot be advised for use during pregnancy because their risk/benefit ratio remains questionable.
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We show how macroscopic manifestations of P (and T) symmetry breaking can arise in a simple system subject to Aharonov-Bohm interactions. Specifically, we study the conductivity of a gas of charged particles moving through a dilute array of flux tubes. The interaction of the electrons with the flux tubes is taken to be of a purely Aharonov-Bohm type. We find that the system exhibits a nonzero transverse conductivity, i.e., a spontaneous Hall effect. This is in contrast to the fact that the cross sections for both scattering and bremsstrahlung (soft-photon emission) of a single electron from a flux tube are invariant under reflections. We argue that the asymmetry in the conductivity coefficients arises from many-body effects. On the other hand, the transverse conductivity has the same dependence on universal constants that appears in the quantum Hall effect, a result that we relate to the validity of the mean-field approximation.
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Bacterial translocation occurs in ascitic cirrhotic rats, but its association with ascites infection is unknown. The aim of this study was to assess the relation between bacterial translocation and ascites infection in cirrhotic rats. Male Sprague-Dawley rats were induced to cirrhosis with intragastric CCl4. Ascitic fluid, portal and peripheral blood, mesenteric lymph nodes, liver and spleen samples were cultured before death in those cirrhotic rats with less (group A) or more (group B) than 250 polymorphonuclear neutrophils/mm3 in ascitic fluid, as well as in healthy control rats. Histological examination of jejunum, ileum, and caecum was also performed. Bacterial translocation occurred in 45% of ascitic rats (without differences between groups A and B), but in 0% controls (p = 0.01). Bacterial translocation was associated with positive ascitic fluid culture in 60% of the cases. In all of them the same bacterial species was isolated in both mesenteric lymph node and ascitic fluid. Submucosal caecal oedema (100%), ileal lymphangiectasia (41%), and caecal inflammatory infiltrate (41%) occurred in ascitic rats, the last being associated with ascitic fluid positive culture (p = 0.04). These results suggests that bacterial translocation occurs frequently in ascitic cirrhotic rats, and may play a permissive, but not unique, part in a number of ascites infections. Whether histological changes seen in cirrhotic ascitic rats favour bacterial translocation remains to be elucidated.
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The emergence of chirality in enantioselective autocatalysis for compounds unable to transform according to the Frank-like reaction network is discussed with respect to the controversial limited enantioselectivity (LES) model composed of coupled enantioselective and non-enantioselective autocatalyses. The LES model cannot lead to spontaneous mirror symmetry breaking (SMSB) either in closed systems with a homogeneous temperature distribution or in closed systems with a stationary non-uniform temperature distribution. However, simulations of chemical kinetics in a two-compartment model demonstrate that SMSB may occur if both autocatalytic reactions are spatially separated at different temperatures in different compartments but coupled under the action of a continuous internal flow. In such conditions, the system can evolve, for certain reaction and system parameters, toward a chiral stationary state; that is, the system is able to reach a bifurcation point leading to SMSB. Numerical simulations in which reasonable chemical parameters have been used suggest that an ade- quate scenario for such a SMSB would be that of abyssal hydrothermal vents, by virtue of the typical temper- ature gradients found there and the role of inorganic solids mediating chemical reactions in an enzyme-like role. Key Words: Homochirality Prebiotic chemistry.
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Transient high-grade bacteremia following invasive procedures carries a risk of infective endocarditis (IE). This is supported by experimental endocarditis. On the other hand, case-control studies showed that IE could be caused by cumulative exposure to low-grade bacteremia occurring during daily activities. However, no experimental demonstration of this latter possibility exists. This study investigated the infectivity in animals of continuous low-grade bacteremia compared to that of brief high-grade bacteremia. Rats with aortic vegetations were inoculated with Streptococcus intermedius, Streptococcus gordonii or Staphylococcus aureus (strains Newman and P8). Animals were challenged with 10(3) to 10(6) CFU. Identical bacterial numbers were given by bolus (1 ml in 1 min) or continuous infusion (0.0017 ml/min over 10 h). Bacteremia was 50 to 1,000 times greater after bolus than during continuous inoculation. Streptococcal bolus inoculation of 10(5) CFU infected 63 to 100% vegetations compared to 30 to 71% infection after continuous infusion (P > 0.05). When increasing the inoculum to 10(6) CFU, bolus inoculation infected 100% vegetations and continuous infusion 70 to 100% (P > 0.05). S. aureus bolus injection of 10(3) CFU infected 46 to 57% valves. This was similar to the 53 to 57% infection rates produced by continuous infusion (P > 0.05). Inoculation of 10(4) CFU of S. aureus infected 80 to 100% vegetations after bolus and 60 to 75% after continuous infusion (P > 0.05). These results show that high-level bacteremia is not required to induce experimental endocarditis and support the hypothesis that cumulative exposure to low-grade bacteremia represents a genuine risk of IE in humans.
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Two cases of neonatal focal spontaneous colic perforations are reported. The 1st infant, born at 36 3/7 weeks gestational age, presented on day 3 with crying, abdominal distension, and liquid stools. Clinical examination showed a slightly irritable hypothermic (35.7 °C) infant with a distended abdomen and few bowel sounds. Blood tests were normal apart from an elevated C-reactive protein level (59 mg/l). The abdomen x-ray was erroneously considered normal. The infant's condition remained stable for nearly 3 days. After reviewing the initial x-ray, pneumoperitoneum was suspected and confirmed by a cross-table lateral abdominal x-ray. The infant was started on antibiotics and operated. Macroscopically, the entire gut was normal apart from a focal sigmoid perforation, which was stitched. A transmural colic biopsy revealed focal vascular dilation but was negative for necrotising enterocolitis or Hirschsprung disease. The infant recovered quickly. She is now a healthy, normal 3-year-old. The 2nd infant, born at 38 5/7 weeks gestational age, presented between day 1 and 2 with clinical signs of infection associated with slowly progressive ileus. The chest and abdomen x-ray was mistakenly considered normal. Frank septicemia developed. After reviewing the initial x-ray, pneumoperitoneum was suspected and confirmed by a cross-table lateral abdominal x-ray. The infant was operated. Macroscopically, the small intestine was normal, the ascending and transverse colons were dilated, and the descending and sigmoid colons were narrow. Three cecal perforations were discovered and stitched. An ileostomy and multiple colic biopsies were also performed. The postoperative course was complicated by persistent septic ileus due to descending and sigmoid colon leaks, which led to colic resections with end-to-end anastomosis. Rectal aspiration biopsies were also performed. At 1 month of age, the infant was discharged from the hospital. The ileostomy was closed in two steps at 2 and 5 months of age. A normal sweat test excluded cystic fibrosis. All colic and rectal biopsies revealed nonspecific inflammatory signs and excluded necrotizing enterocolitis and Hirschsprung disease. Nonspecific irregular thinning of muscularis mucosae and muscularis propria were observed in the two resected colic segments. The boy is now a healthy 7-year-old. The incidence of neonatal focal spontaneous colic perforations at term or close to term is unknown but probably very rare. Our department is the neonatal referral center for approximately 14,000 annual births. In the last 10 years (2000-2009), out of 5115 neonatal admissions in our unit, only ten cases have presented a neonatal spontaneous intestinal perforation, seven of ten in very-low-birth-weight infants and three of ten in term or near-term neonates (one with Hirschsprung disease and the two cases reported herein). In the same period, 108 infants suffered from necrotizing enterocolitis, seven of 108 were term infants and 6 out of 7 had a congenital heart disease. The medical literature is poor on the subject of focal spontaneous colic perforations at term; no risk factor is described. The most specific clinical sign seems to be the abdominal distension. The presence of pneumoperitoneum on an abdominal x-ray is the most sensitive paraclinical sign. In case of an intestinal perforation, surgery must be performed quickly. The vital prognosis seems to be good. The objective of this study was to draw pediatricians' attention to focal spontaneous colic perforations in term or close to term newborns. In the cases reported, the diagnostic delays could have been prevented if the entity - with its radiological manifestation - had been well known.
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Birt-Hogg-Dube syndrome refers to a dermatologic syndrome, consisting of small papular skins lesion distributed on the scalp, forehead, face and neck, which is autosomal dominantly inherited. Subsequently patients may develop concomitant renal and thoracic pathology. We report the case of a patient with Birt-Hogg-Dube syndrome diagnosed after spontaneous pneumothorax.