The seeds of invasion: enhanced germination in invasive European populations of black locust (Robinia pseudoacacia L.) compared to native American populations.

Local adaptation and the evolution of phenotypic plasticity may facilitate biological invasions. Both processes can enhance germination and seedling recruitment, which are crucial life-history traits for plants. The rate, timing and speed of germination have recently been documented as playing a major role during the invasion process. Black locust (Robinia pseudoacacia L.) is a North American tree, which has spread widely throughout Europe. A recent study demonstrated that a few populations are the source of European black locust. Thus, invasive populations can be compared to native ones in order to identify genetic-based phenotypic differentiation and the role of phenotypic plasticity can thereby be assessed. A quantitative genetics experiment was performed to evaluate 13 juvenile traits of both native and invasive black locust populations (3000 seeds, 20 populations) subjected to three different thermal treatments (18 °C, 22 °C and 31 °C). The results revealed European populations to have a higher germination rate than the native American populations (88% versus 60%), and even when genetic distance between populations was considered. Moreover, this trait showed lower plasticity to temperature in the invasive range than in the native one. Conversely, other studied traits showed high plasticity to temperature, but they responded in a similar way to temperature increase: the warmer the temperature, the higher the growth rate or germination traits values. The demonstrated genetic differentiation between native and invasive populations testifies to a shift between ranges for the maximum germination percentage. This pattern could be due to human-mediated introduction of black locust.

Targeting CD1c-expressing classical dendritic cells to prevent thymus and activation-regulated chemokine (TARC)-mediated T-cell chemotaxis in rheumatoid arthritis.

OBJECTIVES: Thymus and activation-regulated chemokine (TARC) attracts cells that express the C-C chemokine receptor type 4 (CCR4), including CD4 T cells. As expression of CCR4 is increased on peripheral T cells and intra-articular interleukin (IL)-17-producing cells in patients with rheumatoid arthritis (RA), we investigated whether TARC plays a role in the attraction of T cells to the synovial compartment. In addition, we assessed the role of classical dendritic cells (cDCs) in the production of TARC in RA. METHOD: TARC was measured in synovial fluid (SF) samples from RA and osteoarthritis (OA) patients. Spontaneous and thymic stromal lymphopoietin (TSLP)-induced TARC production by mononuclear cells (MCs) and CD1c cDCs from peripheral blood (PB) and SF was assessed. The role of TARC in CD4 T-cell migration towards cDCs was assessed and the contribution of CD1c-expressing cells to TARC production was studied. RESULTS: TARC concentrations were higher in SF of RA patients compared to OA patients. MCs from SF produced TARC spontaneously and produced more TARC upon stimulation than paired PBMCs. Blocking TARC strongly inhibited CD4 T-cell chemotaxis by TSLP-stimulated cDCs, associated with decreased production of tumour necrosis factor (TNF)-α. Depletion of cDCs from SFMCs strongly reduced TARC production. CONCLUSIONS: TARC levels are increased in RA SF and our data indicate that this results from production by SFMCs and in particular CD1c cDCs. TARC attracts T cells and TARC secretion by MCs is crucially dependent on the presence of CD1c cDCs. Considering the potential of SF cDCs to activate T cells and induce pro-inflammatory cytokine secretion, targeting intra-articular cDCs constitutes a novel therapeutic approach in RA.

The efficacy of abatacept in reducing synovial T cell activation by CD1c myeloid dendritic cells is overruled by the stimulatory effects of T cell-activating cytokines.

OBJECTIVE: To investigate whether the potential of abatacept to inhibit vigorous CD1c myeloid dendritic cell (MDC)-driven activation of naive and memory CD4 T cells is abrogated in the presence of T cell-activating cytokines. METHODS: CD4 T cell subsets (naive [Tn], central memory [Tcm], and effector memory [Tem] T cells) were isolated from the peripheral blood (PB) of healthy controls and the PB and synovial fluid (SF) of rheumatoid arthritis (RA) patients. CD4 T cells were cocultured with autologous, thymic stromal lymphopoietin (TSLP)-primed CD1c MDCs in the presence or absence of abatacept (CTLA-4Ig) and/or interleukin-7 (IL-7) or IL-15. Subsequently, T cell proliferation and cytokine production were measured. RESULTS: The percentages of each CD4 T cell subset from the circulation of healthy controls and RA patients were comparable and mainly consisted of Tn and Tcm cells, whereas the SF of RA patients mainly consisted of Tcm and Tem cells. Activation of CD4 T cell subsets by TSLP-primed MDCs from the RA PB was completely blocked by abatacept. Addition of IL-7 or IL-15 to the cocultures strongly increased CD4 T cell activation and overruled the inhibitory capacity of abatacept. IL-7-induced reversal was associated with robust induction of interferon-γ, tumor necrosis factor α, and IL-17 secretion. Similarly, CD4 T cell proliferation induced by TSLP-primed MDCs from the SF of RA patients was strongly blocked by abatacept, but this inhibitory effect was vigorously overruled in the presence of IL-7. CONCLUSION: These findings indicate that the presence of T cell-activating cytokines such as IL-7 or IL-15 in the joints of RA patients reduces the capacity of abatacept to inhibit MDC-driven CD4 T cell activation. This mechanism may be one explanation for the partial, and sometimes absent, response to abatacept therapy in a subset of patients.

A modified RT-PCR technique to screen for viral RNA in the semen of hepatitis C virus-positive men.

BACKGROUND: Our objective was to use an adapted RT-PCR technique to assess the presence of hepatitis C virus (HCV) in semen and also in different density gradient semen fractions collected from men with chronic viral hepatitis participating in an assisted reproduction programme. METHODS: This study included 50 semen samples from 35 HCV(+) men, with active viral replication assessed by RT-PCR, collected the day of oocyte retrieval and used for assisted reproduction. These samples were subjected to standard assisted reproduction sperm preparation conditions, using density-gradient centrifugation with 45 and 90% layers. Aliquots of semen, 45 and 90% fractions, and embryo culture media were frozen at -80 degrees C for subsequent virological analyses. All aliquots were tested with a commercially available HCV RNA assay, adapted for use with semen after a number of technical changes. This assay yielded a sensitivity of 50-100 HCV RNA copies/ml and strongly diminished the effect of seminal amplification inhibitors. RESULTS: HCV RNA was detected in 7/50 (14%) semen samples tested, 5/35 (14.3%) men. HCV RNA was found in only 1/50 45% fractions but never in the 90% fraction or embryo culture media. Sera from 3/5 men contained 3.19-7.40 x 10(5) IU/ml, while the two others had 4.5 and 11.7 x 10(6) IU/ml. However, HCV RNA was quantified at <600 IU/ml in the HCV(+) semen of these five patients. The ongoing pregnancy rate was of 20% (10/50) with one delivery at the time of the present report. No anti-HCV antibody was found in any of the women or the newborn. CONCLUSIONS: Although HCV is present at low concentrations in the semen of a few HCV(+) patients, no purified sperm fraction (i.e. 90% fraction) used in assisted reproduction was HCV(+) and no seroconversion was observed in the women and the newborn, thereby suggesting a very low risk of virus transmission. Nevertheless, because the presence of HCV in semen implies a possible risk of nosocomial contamination, safety regulations must be strictly applied in assisted reproduction laboratories.

Diagnostic utility of eosinophils in the pleural fluid.

This study was conducted to assess the prevalence of eosinophilia in 358 consecutive samples of pleural fluid (all cases corresponded to first thoracentesis), to review the cause of eosinophilic pleural effusions, and to determine whether the presence of eosinophils increases the likelihood of nonmalignant underlying disorders. Eosinophilic pleural effusions were identified in 45 patients (12.6%): malignant underlying conditions were diagnosed in 11 patients (24.4% with eosinophilic effusions) and benign aetiologies were found in 27 patients. Benign aetiologies included uncomplicated paraneumonic effusion in 10 patients, tuberculosis in seven, complicated paraneumonic in five, liver cirrhosis in three, hydronephrosis in one and pulmonary thromboembolism in one. Seven pleural effusions were idiopathic. There was no difference in the prevalence between eosinophilic and noneosinophilic effusions according to the different diagnoses. With parameters of sensitivity, specificity, pretest and post-test probability and positive and negative predictive values for any prevalence figure using the Bayes' theorem and for any value of eosinophils (both in percentage or absolute numbers) in the pleural fluid (receiver operating characteristic curve) an adequate predictor of benign disease was not found. It is concluded that pleural eosinophilia at the initial thoracentesis cannot be considered as a predictor of an underlying benign disorder.

[Fiber bronchoscopy in lung cancer: relationship between radiology, endoscopy, histology and diagnostic value in a series of 1801 cases]. / Fibrobroncoscopia en el cáncer de pulmón: relación entre radiología, endoscopia, histología y rendimiento diagnóstico en una serie de 1.801 casos.

A retrospective analysis of 1,801 patients with primary pulmonary neoplasm diagnosed by fiber bronchoscopy between 1977 and 1992 was carried out in order to determine the relation between chest X-rays and endoscopic and histological findings, as well as to assess the diagnostic usefulness of the various endoscopic techniques used. Central tumors numbered 1,598 and peripheral ones 203. The largest tissue classification was squamous (39%) and the most common X-ray finding was pulmonary mass (40%). Endoscopy showed neoplastic infiltration in 49% of the cases and endobronchial tumor in 27%. X-rays showing pulmonary mass, hilar involvement and atelectasis were more often associated with infiltration, tumor and necrosis and with a small-cell tissue type. Bronchial biopsy gave the best diagnostic results in these cases. In cases of solitary pulmonary nodule and pleural effusion, on the other hand, normal endoscopic results with non-specific changes or extrapulmonary involvement, predominated, with adenocarcinoma and non-small cell tissue types. Transbronchial biopsy, especially with radioscopic monitoring, was most useful in these cases. We conclude that chest X-rays and endoscopic results can be used to predict the most likely tissue type in lung cancer and that they can serve as guides for the choice of diagnostic technique.

[Tetracycline pleurodesis for treatment of malignant pleural effusions. Retrospective study of 91 cases]. / Pleurodesis con tetraciclinas en el tratamiento del derrame pleural maligno. Estudio retrospectivo de 91 casos.

BACKGROUND: Malignant pleural effusions (MPE) are a common complication in patients with advanced neoplasms. Even though no large series confirming this exist, tetracycline pleurodesis has become the therapy of choice. The aim of this retrospective study was to evaluate its efficacy, adverse effects and possible factors predicting the success of the method. METHODS: Between 1985 through 1991, 91 patients with cytologically or histologically confirmed MPE were treated with 1,000-1,500 mg tetracycline pleurodesis. There were 49 females and 42 males, with a mean age of 59 years. The most common malignancies were lung, breast and unknown primary carcinomas. 85% patients complained of dyspnea and the volume of the effusion was moderate in half the cases. 12 variables were analyzed in relation with the probability of response through chi 2 test; survival and recurrence times were calculated with Kaplan and Meier's method. RESULTS: 73 patients were evaluable, with a 67% response rate (22 complete, 27 partial). Time to relapse was significantly higher for partial responses (mean 112 days) than for failures (mean 33 days). 37 patients presented mild complications (pain and fever). Karnofsky performance status (70% or greater), size of the effusion (small or moderate), chest radiograph (only effusion) and pleural LDH (600 U/l or less) attained favourable prognostic significance. Median survival was reached at 6 months. CONCLUSIONS: Tetracycline pleurodesis is an effective and well-tolerated paliative treatment for MPE. Along with other known parameters (pleural pH and glucose levels), Karnofsky performance status, size of the effusion, chest radiograph and pleural LDH allow to predict its results and optimize its indications.