Primary pleural leiomyosarcoma with rapid progression and fatal outcome: a case report

Introduction

Leiomyosarcomas are neoplasms of smooth muscles that most commonly arise from the uterus, gastrointestinal tract, or soft tissue. Primary pleural leiomyosarcoma is extremely rare. To the best of our knowledge, only nine cases have been published to date. Because of the rarity of pleural leiomyosarcoma and its similarity (clinical and histological) to other pleural neoplasms, particularly sarcomatous mesothelioma, diagnosis is often difficult.

Case presentation

A 58-year-old North African man was admitted with complaints of dyspnea and chest pain to our hospital. Chest computed tomography revealed right pleural effusion and pleural thickening. A transthoracic needle biopsy yielded a diagnosis of leiomyosarcoma, and tumor cells were strongly and uniformly positive for vimentin, a smooth muscle actin at immunohistochemical analysis. A general examination did not show any metastatic lesions in other areas. One month after diagnosis, the tumor grew rapidly, with pulmonary invasion, and therefore he was treated only by palliative care. He died from respiratory failure one month later. Because no organ of origin of the leiomyosarcoma, other than the pleura, was detected, this case was diagnosed as a primary pleural leiomyosarcoma.

Conclusions

Although leiomyosarcoma originating from the pleura is rare, this entity is increasingly described. The purpose of presenting this case report is to raise awareness among clinicians to consider this clinical entity as a differential diagnosis when a pleural mass is identified.     

A new susceptibility locus for hypospadias on chromosome 7q32.2-q36.1

Hypospadias is a common malformation (1/300 boys) where the urethra opens on the ventral side of the penis. It is considered a complex disorder with both genetic and environmental factors involved in the pathogenesis. To identify the chromosomal loci involved in the pathogenesis of hypospadias, we performed a genome-wide linkage analysis in a three-generational family showing autosomal dominant inheritance of hypospadias. Fifteen individuals, whereof seven affected, were genotyped within a total of 426 microsatellite markers and the genotyping results were analyzed using parametric and non-parametric linkage analyses. The genome-wide linkage analysis and subsequent fine mapping gave a maximum linkage in both parametric (LOD score 2.71) and non-parametric (NPL score 5.01) single-point analyses for marker D7S640. A susceptibility haplotype shared by all affected boys was identified with the centromeric and telomeric boundaries defined by markers D7S2519 and D7S2442, respectively. This suggests a novel hypospadias locus at chromosome 7q32.2-q36.1 that encompasses 18.2 Mb (25 cM) and harbors hundreds of genes. Mutation analysis of two genes within the region, the AKR1D1 (aldo-keto reductase family 1, member D1) gene involved in the androgen pathway and the PTN gene coding for pleiotrophin, an embryonic differentiation and growth factor, was performed but without putative findings.     

Latitudinal patterns of magnitude and interannual variability in net ecosystem exchange regulated by biological and environmental variables

Over the last two and half decades, strong evidence showed that the terrestrial ecosystems are acting as a net sink for atmospheric carbon. However the spatial and temporal patterns of variation in the sink are not well known. In this study, we examined latitudinal patterns of interannual variability (IAV) in net ecosystem exchange (NEE) of CO₂ based on 163 site-years of eddy covariance data, from 39 northern-hemisphere research sites located at latitudes ranging from ∼29°N to ∼64°N. We computed the standard deviation of annual NEE integrals at individual sites to represent absolute interannual variability (AIAV), and the corresponding coefficient of variation as a measure of relative interannual variability (RIAV). Our results showed decreased trends of annual NEE with increasing latitude for both deciduous broadleaf forests and evergreen needleleaf forests. Gross primary production (GPP) explained a significant proportion of the spatial variation of NEE across evergreen needleleaf forests, whereas, across deciduous broadleaf forests, it is ecosystem respiration (Re). In addition, AIAV in GPP and Re increased significantly with latitude in deciduous broadleaf forests, but AIAV in GPP decreased significantly with latitude in evergreen needleleaf forests. Furthermore, RIAV in NEE, GPP, and Re appeared to increase significantly with latitude in deciduous broadleaf forests, but not in evergreen needleleaf forests. Correlation analyses showed air temperature was the primary environmental factor that determined RIAV of NEE in deciduous broadleaf forest across the North American sites, and none of the chosen climatic factors could explain RIAV of NEE in evergreen needleleaf forests. Mean annual NEE significantly increased with latitude in grasslands. Precipitation was dominant environmental factor for the spatial variation of magnitude and IAV in GPP and Re in grasslands.     

Coexistence of at least three distinct beta-adrenoceptors in human internal mammary artery.

The internal mammary artery (IMA) is currently the preferred conduit for myocardial revascularization. However, perioperative vasospasm and a hypoperfusion state during maximal exercise may limit its use as a bypass graft. The mechanism of spasm has not been clearly defined. Since beta-adrenoceptor activation plays a major role in vasorelaxation, the present study was carried out to investigate the beta-adrenoceptor responsiveness of human IMA smooth muscle. Isoproterenol produced a concentration-dependent relaxation in endothelium-denuded IMA segments, precontracted with phenylephrine (maximal relaxation 46.33+/-5.45%). Atenolol (10(-6)M) and propranolol (2x10(-7)M) inhibited isoproterenol-induced relaxation. While atenolol produced partial inhibition, propranolol caused a complete inhibition in a majority of the segments and a partial inhibition in a minority. BRL 37344, a selective beta 3-adrenoceptor agonist, produced a concentration-dependent relaxation in phenylephrine-precontracted rings of endothelium-denuded IMA (maximal relaxation 40.35+/-4.07%). Cyanopindolol, a beta-adrenoceptor partial agonist, produced a marked relaxation (58.65+/-6.2%) in endothelium-denuded IMA rings, precontracted with phenylephrine. Cyanopindolol-induced relaxation was resistant to blockade by propranolol (2x10(-7)M). Spontaneous contractions of IMA rings were also observed in some cases that were inhibited by isoproterenol and BRL 37344. This observation implies the important role of beta-adrenoceptor activation in prevention of human IMA spasm. The results obtained in present study indicate that human IMA smooth muscle possesses an atypical beta-adrenoceptor together with beta1- and beta2-adrenoceptors. Regarding the relaxation induced in IMA rings by adding BRL 37344, the possible identical entities of IMA atypical beta-adrenoceptors and beta 3-adrenoceptors are suggested.     

Expression analysis of selected miR-206 targets from the transforming growth factor-β signaling pathway in breast cancer

Breast cancer as a molecularly heterogeneous malignancy is associated with dysregulation of several signaling pathways, including transforming growth factor-β (TGF-β) signaling. On the other hand, several recent studies have demonstrated the role of microRNAs (miRNAs) in breast cancer pathogenesis. In the current study, we performed a computerized search to find miR-206 target genes that are functionally linked to the TGF-β signaling pathway. We selected LEF1, Smad2, and Snail2 genes to assess their expression in 65 breast cancer samples and their adjacent noncancerous tissues (ANCTs) in correlation with expression levels of miR-206 as well as clinicopathological characteristics of patients. miR-206 was significantly downregulated in (Estrogen receptor) ER-positive breast cancer samples compared with their corresponding ANCTs. Association analysis between expression levels of genes and demographic features of patients showed significant association between expressions of SMAD2 and LEF1 genes and body mass index ( P values of 0.03 and 0.02, respectively). miR-206 low-expression levels were associated with TNM stage, mitotic rate, and lymph node involvement ( P values of 0.02, 0.01, and 0.01 respectively). In addition, SMAD2 high-expression levels were associated with HER2 status ( P = 0.02). Consequently, our data highlight the role of TGF-β signaling dysregulation in the pathogenesis of breast cancer and warrant further evaluation of miRNAs and messenger RNA coding genes in this pathway to facilitate detection of cancer biomarkers and therapeutic targets.     

Molecular and morphological variation of rare endemic oncocyclus irises (Iridaceae) of Lebanon

Oncocyclus irises endemic to Lebanon form a complex of three closely related taxa replacing each other over short geographical distances in a linear habitat. In order to characterize the appropriate taxonomic levels and to assess their conservation status, we investigated patterns of phenotypic variability and the partitioning of genetic variation within and among populations using random amplified polymorphic DNA (RAPD) markers. Multivariate analysis (principal components analysis and multiple correspondence analysis), based on 16 quantitative and six qualitative characters, revealed no separation between populations or taxa. Moreover, no morphological character could be used to define clear boundaries between populations/taxa. The genetic characterization revealed high levels of polymorphism and diversity (H_s). Principal components analysis showed population delimitations, but no groupings reflecting the currently defined taxa could be identified. Both morphological and genetic data showed that Lebanese oncocyclus irises could not be fitted into clear taxonomic boundaries. Consequences for conservation are discussed. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 123–135.     

Independent coding of movement duration in a repetitive non-visually guided movement

Temporal information is an embedded feature of our sensory and motor experiences. How is temporal information encoded in the brain? In the two-stage theory of timing, an explicit representation of timing is responsible for the movement initiation while movement duration is coded implicitly. We investigated the correlation of movement duration and amplitude in a repetitive one-dimensional non-visually guided movement to find out if temporal information could be coded independently from movement. Subjects were asked to learn the distance between two points by moving their hands repeatedly along the distance between two sticks, while they could not see their hands and hand path. After a training phase, a delay of either 2 or 20 s was imposed and the subjects were asked to reproduce the learned distance. There was no correlation between distance difference and time difference in either delay condition. In the 20 s delay experiment, in comparison to the 2 s delay experiment, there was a significant increase in distance reproduction error. However, there was no significant change in time differences in either of the experiments. In addition, the time difference between the training and test trials was independent from the direction of the distance difference (i.e., overshot, undershot, or accurate). In conclusion, time may be coded as an independent measure after the delay period, so it should be a kind of explicitly coded information.