Value and limitations of chimney grafts to treat arch lesions.

AIM: The endovascular debranching with chimney stents provides a minimally invasive alternative to open surgery with readily available devices and has extended the option of endoluminal therapy into the realm of the aortic arch. But a critical observation at the use of this technique at the aortic arch is important and necessary because of the lack of long-term results and long term patency of the stents. Our study aims to review the results of chimney grafts to treat arch lesions. METHODS: A systematic health database search was performed in December 2014 according to the Prisma Guidelines. Papers were sought through a meticulous search of the MEDLINE database (National Library of Medicine, Bethesda, MA) using the Pubmed search engine. RESULTS: Twenty-two articles were eligible for detailed analysis and data extraction. A total of 182 patients underwent chimney techniques during TEVAR (Thoracic Endovascular Aneurysm Repair). A total of 217 chimney grafts were implanted: 36 to the IA, 1 to the RCCA, 91 to the LCCA and 89 to the LSA. The type of stent-graft used for TEVAR was described in 132 patients. The type and name of chimney graft was described in 126 patients. In 53 patients information was limited to the type. Primary technical success, defined as a complete chimney procedure was achieved in 171 patients (98%). In 8 patients it was not clearly reported. The overall stroke rate was 5.3%. The overall endoleak rate, in those papers were it was clearly reported, was 18.4% (31 patients); 23(13,6%) patients developed a type IA endoleak, 1 patient (0.6%) developed type IB endoleak and 7 patients (4.1%) developed a type II endoleak CONCLUSION: The total endovascular aortic arch debranching technique represent a good option to treat high-risk patients, because it dramatically reduces the aggressiveness of the procedure in the arch. Many concerns are still present, mainly related to durability and material interaction during time. Long-term follow-up is exceptionally important in light of the interactions of the stents, the thoracic endograft, the aortic arch, and every variation in systolic and diastolic pressure. Actually this technique has acceptable short and mid-term results. Long term data are available just from a very small number of patients and more data from a wider number are needed in order to embrace this method as a safe one.

Automated knot tying for fixation in minimally invasive, robot-assisted cardiac surgery.

Cardiovascular disease (CVD) is perhaps the most significant worldwide health issue. While open-heart surgery remains the predominant treatment, significant advancements have been made in minimally invasive surgery (MIS) and minimally invasive robot-assisted (MIRA) surgery. MIRA techniques offer many advantages over open-heart procedures and have extended the capabilities of MIS. However, these benefits come at the cost of increased operating times due to time spent tying knots. The additional bypass time limits patient access and is the most significant barrier to the adoption of MIRA techniques. This research seeks to overcome this barrier by designing a device for MIRA cardiac procedures that automates the knotting of sutures. If this task can be automated while ensuring the delivery of high-quality knots, great progress can be made in transforming the field. MIRA cardiac procedures can move from novel procedures performed by a select group of surgeons on a limited pool of patients to a viable alternative available to the majority of patients with CVD. In this research we propose a design for a self-contained device that delivers a locking knot. Results suggest that consistent knots can be delivered at a time savings of 12.5% and 26.4% over manual knots for trained and untrained users of a surgical robot, respectively.

A new case of Lazarus phenomenon?

The international medical literature described sporadical cases of an exceptional event called the "Lazarus phenomenon". This is the spontaneous reviviscence of an individual after a long time of asystolia following a cardiac accident depending on different pathogenesis (i.e. arrhythmia, ischaemic stroke, haemorrhage, brainstem death). All of the reported cases concerned patients presenting recovery after discontinuation of cardiopulmonary resuscitation. Different explanations of the physiopathology of the phenomenon can be given, first of all, the latency of catecholamine action in such patients. We report the case of an 81-year-old woman who experienced a cardiac accident on the street. Once the cardiopulmonary resuscitation was interrupted, the patient presented life activities after some minutes.

Cytotoxic synergism of methioninase in combination with 5-fluorouracil and folinic acid.

Potentiation of the cytotoxic activity of 5-fluorouracil (FUra) by folinic acid (5-HCO-H4folate) is due to elevation of the methylene tetrahydrofolate (CH2-H4folate) level, which increases the stability of the ternary complex of thymidylate synthase (TS), fluorodeoxyuridine monophosphate, and CH2-H4folate that inactivates the TS. Methionine deprivation results in the production of tetrahydrofolate (H4folate) and, subsequently, CH2-H4folate from methyl tetrahydrofolate, as a consequence of the induction of methionine synthesis. We hypothesized that the efficacy of FUra could be augmented by the combination of high-concentration 5-HCO-H4folate and recombinant methioninase (rMETase), a methionine-cleaving enzyme. Studies in vitro were performed with the cell line CCRF-CEM. Cytotoxic synergism of FUra + rMETase and FUra + 5-HCO-H4folate + rMETase was demonstrated with the combination index throughout a broad concentration range of FUra and rMETase. A subcytotoxic concentration of rMETase reduced the IC50 of FUra by a factor of 3.6, and by a factor of 7.5, in the absence and in the presence of 5-HCO-H4folate, respectively. 5-HCO-H4folate increased the intracellular concentrations of CH2-H4folate and H4folate from their baseline levels. Concentrations of folates were not changed by exposure to rMETase. Levels of free TS in cells treated with FUra + 5-HCO-H4folate and with FUra + rMETase were lower than those in cells exposed to FUra alone. The decrease of TS was still more pronounced in cells treated with FUra + 5-HCO-H4folate + rMETase. The synergism described in this study will be a basis for further exploration of combinations of fluoropyrimidines, folates, and rMETase.

Evaluation of the cytocentrifuge Gram stain as a screening test for bacteriuria in specimens from specific patient populations.

To assess the usefulness of the cytocentrifuge Gram stain as a urine screening test in the clinical microbiology laboratory for the elimination of culture for screen-negative specimens, we compared the results of the cytocentrifuge Gram stain to the results of culture for 1,171 urine specimens. The data were analyzed separately for specimens from males (inpatients) and females (inpatients and outpatients), as well as for catheterized and voided specimens. Overall, the cytocentrifuge Gram stain had excellent negative predictive value (97.7%) and sensitivity (92.3%) at a culture threshold of 10(5) colony-forming units per milliliter or more. The negative predictive value and sensitivity decreased at lower culture thresholds in all populations. The negative predictive value decreased most markedly for female outpatients. Because of low positive predictive value and specificity, this test is not reliable as a sole indicator for presumptive therapy in many cases with positive results. If its limitations are recognized, the cytocentrifuge Gram stain is a useful screening test for the rapid exclusion of bacteriuria.

Interleukin-13 responsiveness and interleukin-13 receptor expression in non-Hodgkin's lymphoma and reactive lymph node B cells. Modulation by CD40 activation.

Interleukin-13 (IL-13) responsiveness was examined in lymph node B cells from patients with non-Hodgkin's lymphoma (NHL) and patients with benign reactive immune disorders. Proliferation assays showed that NHL B cells from 8 of 21 patients responded to IL-13 in the absence of a co-activation signal. IL-13-unresponsive NHL B cells from 9 of the 13 remaining patients were induced to respond to IL-13 upon antibody-triggered CD40 activation, as did reactive B cells. Binding experiments with radiolabeled IL-13 revealed that the constitutive expression of IL-13 receptors (IL-13R) was associated with IL-13 responsiveness in the absence of CD40 activation. In IL-13-unresponsive cells, IL-13R expression was induced after CD40 activation. This effect was enhanced by IL-10, which was able to potentiate the IL-13 response of CD40-activated cells. Furthermore, IL-13 was found to increase the viability of cultured NHL cells, but not that of non-malignant cells. These results suggest that IL-13, which behaves as a potent co-factor for normal lymph node B cell activation, might provide growth and/or survival advantages to NHL B cells.

New cell lines of human breast cancer origin.

Established human mammary tumor cell lines constitute an important tool in the study of breast cancer. The aim of this work was to isolate and characterize two new mammary tumor cell lines, JCK and GCS, which were obtained from the pleural effusion and ascitic fluid, respectively, from two breast cancer patients. Both cell lines had some properties of transformed cells, namely immortalization and growth in soft agar. The carcinoma cells presented epithelial morphology shown by light and electron microscopy, and antigenic properties shown by different tumor markers such as a cytokeratin cocktail, carcinoembryonic antigen, epithelial membrane antigen, and human milk fat globule membrane antigen. A significant increase was also found (P greater than 0.05) in cell growth and 3H-thymidine incorporation into DNA in the JCK and GCS cell lines in the presence of 17 beta estradiol at concentrations of 10(-9) and 10(-7) M, respectively, after 5 days in culture. These cells presented estradiol receptor levels which were similar in the biopsies and the resulting cell lines. The aromatase activity was also similar in the JCK cell line and the original patient biopsy. However, there was a considerably higher aromatase activity in the GCS cell line than in the biopsy specimen. Southern hybridizations with the neu oncogene showed an additional 12 kb fragment in both cell lines, as also seen in patients with breast cancer. We conclude from these studies that this in vitro system may provide us with a way to study metastatic cells and improve clinical management of breast cancer patients.