Evaluation of various patient-, lesion-, and procedure-related factors on the occurrence of pneumothorax as a complication of CT-guided percutaneous transthoracic needle biopsy

Purpose: To assess the influence of various patient-, lesion-, and procedure-related variables on the occurrence of pneumothorax as a complication of CT-guided percutaneous transthoracic needle biopsy. Material and methods: In a total of 208 patients, 215 lung/mediastinal lesions (seven patients were biopsied twice) were sampled under CT guidance using coaxial biopsy set via percutaneous transthoracic approach. Incidence of post procedure pneumothorax was seen and the influence of various patient-, lesion-, and procedure-related variables on the frequency of pneumothorax with special emphasis on procedural factors like dwell time and needle-pleural angle was analysed. Results: Pneumothorax occurred in 25.12% (54/215) of patients. Increased incidence of pneumothorax had a statistically significant correlation with age of the patient (p = 0.0020), size (p = 0.0044) and depth (p = 0.0001) of the lesion, and needle-pleural angle (p = 0.0200). Gender of the patient (p = 0.7761), emphysema (p = 0.2724), site of the lesion (p = 0.9320), needle gauge (p = 0.7250), patient position (p = 0.9839), and dwell time (p = 0.9330) had no significant impact on the pneumothorax rate. Conclusions: This study demonstrated a significant effect of the age of the patient, size and depth of the lesion, and needle-pleural angle on the incidence of post-procedural pneumothorax. Emphysema as such had no effect on pneumothorax rate, but once pneumothorax occurred, emphysematous patients were more likely to be symptomatic, necessitating chest tube placement. Gender of the patient, site of the lesion, patient position during the procedure, and dwell time had no statistically significant relation with the frequency of post-procedural pneumothorax. Surprisingly, needle gauge had no significant effect on pneumothorax frequency, but due to the small sample size, non-randomisation, and bias in needle size selection as per lesion size, further studies are required to fully elucidate the causal relationship between needle size and post-procedural pneumothorax rate. The needle should be as perpendicular as possible to the pleura (needle-pleural angle close to 90°), to minimise the possibility of pneumothorax after percutaneous transthoracic needle biopsy

Determination of subcarinal angle of trachea using computed tomography

Background: Change in tracheal bifurcation angle (subcarinal angle) is an indirect marker of various cardiac, pulmonary and mediastinal pathologies. Helical computed tomography (CT) allows acquisition of volumetric set of data of the chest and can be used for accurate measurements of subcarinal angle using reconstructed images on a workstation using minimum intensity projection (MinIP).The objective of this study was to estimate normal subcarinal angle (SCA) of trachea by computed tomography and to assess its relationship with gender.Methods: This was an observational study comprising a study cohort of 552 patients comprising of 312 males and 240 females who were subjected to CT chest for various indications in our department. Patients with no underlying cardiac, mediastinal or pulmonary disease were included in the study. Spiral CT scan of chest was performed on 64-slice seimens CT SOMATOM and images were reconstructed with thickness of 1.5mm and the images were viewed in coronal reformatted minimum intensity projection (MinIP) for determination of subcarinal angle using the angle measuring tool provided in the workstationResults: The mean subcarinal angle (SCA) in males was (67.60±14.55). The mean subcarinal angle (SCA) in females was (78.90±11.04). Females had a higher mean SCA compared to males with a statistically significant difference (p-value <0.05).Conclusions: The mean SCA in females was higher compared to males with a statistically significant difference between the two. This study holds practical relevance with regard to the performance of invasive trachea-bronchial procedures like bronchoscopy and tracheal/bronchial intubation

Late widespread skeletal metastases from myxoid liposarcoma detected by MRI only

Background Myxoid liposarcoma is the second most commonly occurring sub-type of liposarcomas. In contrast to other soft tissue sarcomas, it is known to have a tendency to spread toward extrapulmonary sites, such as soft tissues, retroperitoneum, and the peritoneal surface. Bony spread, however, is not as common. Case presentation We report an unusual case of diffuse skeletal metastases from myxoid liposarcoma occurring 13 years after treatment of the primary tumour in the left lower limb. The skeletal spread of the disease was demonstrated on MRI only after other imaging modalities (plain radiography, CT and TC99 bone scans) had failed to detect these metastases. Conclusion MRI is an extremely sensitive and specific screening tool in the detection of skeletal involvement in these types of sarcomas, and therefore, should be a part of the staging proces

Structure and microstructure evolution of Al-Mg-Si alloy processed by equal-channel angular pressing

An ultrafine grained Al–Mg–Si alloy was prepared by severe plastic deformation using the equal-channel angular pressing (ECAP) method. Samples were ECAPed through a die with an inner angle of F = 90° and outer arc of curvature of ¿ = 37° from 1 to 12 ECAP passes at room temperature following route Bc. To analyze the evolution of the microstructure at increasing ECAP passes, X-ray diffraction and electron backscatter diffraction analyses were carried out. The results revealed two distinct processing regimes, namely (i) from 1 to 5 passes, the microstructure evolved from elongated grains and sub-grains to a rather equiaxed array of ultrafine grains and (ii) from 5 to 12 passes where no change in the morphology and average grain size was noticed. In the overall behavior, the boundary misorientation angle and the fraction of high-angle boundaries increase rapidly up to 5 passes and at a lower rate from 5 to 12 passes. The crystallite size decreased down to about 45 nm with the increase in deformation. The influence of deformation on precipitate evolution in the Al–Mg–Si alloy was also studied by differential scanning calorimetry. A significant decrease in the peak temperature associated to the 50% of recrystallization was observed at increasing ECAP passes.Peer ReviewedPreprin

Conjugation to a SMAC mimetic potentiates sigma-2 ligand induced tumor cell death in ovarian cancer

BACKGROUND: Drug resistance is a significant problem in the treatment of ovarian cancer and can be caused by multiple mechanisms. Inhibition of apoptosis by the inhibitor of apoptosis proteins (IAPs) represents one such mechanism, and can be overcome by a mitochondrial protein called second mitochondria-derived activator of caspases (SMAC). We have previously shown that the ligands of sigma-2 receptors effectively induce tumor cell death. Additionally, because sigma-2 receptors are preferentially expressed in tumor cells, their ligands provide an effective mechanism for selective anti-cancer therapy. METHODS: In the current work, we have improved upon the previously described sigma-2 ligand SW43 by conjugating it to a pro-apoptotic small molecule SMAC mimetic SW IV-52, thus generating the novel cancer therapeutic SW IV-134. The new cancer drug was tested for receptor selectivity and tumor cell killing activity in vitro and in vivo. RESULTS: We have shown that SW IV-134 retained adequate sigma-2 receptor binding affinity in the context of the conjugate and potently induced cell death in ovarian cancer cells. The cell death induced by SW IV-134 was significantly greater than that observed with either SW43 or SW IV-52 alone and in combination. Furthermore, the intraperitoneal administration of SW IV-134 significantly reduced tumor burden and improved overall survival in a mouse xenograft model of ovarian cancer without causing significant adverse effects to normal tissues. Mechanistically, SW IV-134 induced degradation of cIAP-1 and cIAP-2 leading to NF-қB activation and TNFα-dependent cell death. CONCLUSIONS: Our findings suggest that coupling sigma-2 ligands to SMAC peptidomimetics enhances their effectiveness while maintaining the cancer selectivity. This encouraging proof-of-principle preclinical study supports further development of tumor-targeted small peptide mimetics via ligands to the sigma-2 receptor for future clinical applications

Linear and nonlinear optical properties of the conjugated polymers PPV and MEH-PPV

We have used absorption and electroabsorption spectroscopy to investigate the electronic structure of poly(para-phenylene vinylene) (PPV) and poly (2-methoxy, 5-(2'-(ethyl)hexyloxy)-p-phenylene vinylene) (MEH-PPV). In particular we examine the often used assumption that the electronic structure of PPV and its dialkoxy substituted derivatives are essentially the same. The absorption spectrum of PPV consists of three peaks, while that of MEH-PPV has four peaks. We discuss the controversial origin of the extra peak as well as evidence for Davydov splitting effects in the absorption spectrum of PPV. The analysis of the nonlinear spectra shows further differences between the two materials. First, the binding energy of the 1B(u) exciton for PPV is some 0.1 eV higher than for MEH-PPV. Second, the peak value of Im{chi((3))(-omega;0,0,omega)} for PPV is approximately 40 times higher than that of MEH-PPV. We also found that the sum-over-states modeling of the electroabsorption spectra indicates that the transition dipole moment between the mA(g) and nB(u) states is of opposite sign in the two polymers. [S0163-1829(99)02523-0]

Préparation et activité électrocatalytique d’électrodes de poly(thiophène) modifiées par électrodéposition de particules métalliques

Des électrodes de poly(3-méthyl-thiophène) (PMeT) modifiées par inclusion de particules de palladium ont été préparées et caractérisées par différentes techniques S.E.M., T.E.M., E.D.X., diffraction X. L’électrodéposition des particules de palladium a été réalisée à l’aide d’impulsions de potentiel. Nous montrons que les conditions électriques d’inclusion déterminent la taille et la répartition 3D des particules de Pd et que ces paramètres contrôlent l’activité électrocatalytique de ces électrodes