Ouabain-induced cytoplasmic vesicles and their role in cell volume maintenance

Cellular swelling is controlled by an active mechanism of cell volume regulation driven by a Na+/K+-dependent ATPase and by aquaporins which translocate water along the osmotic gradient. Na+/K+-pump may be blocked by ouabain, a digitalic derivative, by inhibition of ATP, or by drastic ion alterations of extracellular fluid. However, it has been observed that some tissues are still able to control their volume despite the presence of ouabain, suggesting the existence of other mechanisms of cell volume control. In 1977, by correlating electron microscopy observation with ion and water composition of liver slices incubated in differentmetabolic conditions in the presence or absence of ouabain, we observed that hepatocytes were able to control their volume extruding water and recovering ion composition in the presence of ouabain. In particular, hepatocytes were able to sequester ions and water in intracellular vesicles and then secrete themat the bile canaliculus pole.We named this “vesicularmechanismof cell volume control.” Afterward, thismechanism has been confirmed by us and other laboratories in several mammalian tissues.This review summarizes evidences regarding this mechanism, problems that are still pending, and questions that need to be answered. Finally, we shortly review the importance of cell volume control in some human pathological conditions

Milling force model for asymmetric end-mills during high-feed milling on AISI-P20

Manufacturing molds for plastic parts injection are a particular machining domain, where challenging materials, like AISI P20 steel, are forced to satisfy the highest surface quality requirements. Before mirror polishing, milling operation is a common and challenging task due to drilling and milling with the same tool. Thus, special cutting tools, like asymmetric indexable type, are often used. This tool presents two geometrically equal positive inserts – one placed horizontally and the other vertically – for the flexible machining of holes, cavities, floors, and walls. Rough-medium milling operations lead to a complicated relationship between cutting conditions and geometrical tool parameters, making it challenging to balance the tool life of both inserts. The novelty of this work is to propose a model for cutting force prediction with an asymmetric tool to explain the separated behavior of both inserts and determine a better compromise between cutting conditions and tool life. The experimental tests were done for model validation and then wear cutting tests for testing improved cutting conditions. The results predicted by the model proved that by changing the depth of cut from 0.3 mm to 0.8 mm, the wear in both inserts was more balanced, increasing chip volume up to 1.7 times.Peer ReviewedPostprint (author's final draft

Apoptosis: a relevant tool for anticancer therapy.

Apoptosis is a form of cell death that permits the removal of damaged, senescent or unwanted cells in multicellular organisms, without damage to the cellular microenvironment. Defective apoptosis represents a major causative factor in the development and progression of cancer. The majority of chemotherapeutic agents, as well as radiation, utilize the apoptotic pathway to induce cancer cell death. Resistance to standard chemotherapeutic strategies also seems to be due to alterations in the apoptotic pathway of cancer cells. Recent knowledge on apoptosis has provided the basis for novel targeted therapies that exploit apoptosis to treat cancer. These new target include those acting in the extrinsic/intrinsic pathway, proteins that control the apoptosis machinery such as the p53 and proteosome pathway. Most of these forms of therapy are still in preclinical development because of their low specifity and susceptibility to drug resistance, but several of them have shown promising results. In particular, this review specifically aims at providing an update of certain molecular players that are already in use in order to target apoptosis (such as bortezomib) or which are still being clinically evaluated (such ONYX-015, survivin and exisulind/aptosyn) or which, following preclinical studies, might have the necessary requirements for becoming part of the anticancer drug programs (such as TRAIL/Apo2L, apoptin/VP3)

Optical velocimetry based on the spatial correlation of off-axis image speckle patterns

A method is proposed for measuring the linear velocity of a moving rough surface. It is based on maximizing the spatial correlation between two laterally shifted image speckle patterns. Besides, an expression of a spatially variant point-spread function is given, which modifies the spatial distributions of the off-axis image speckle patterns.Facultad de Ingeniería (FI)Centro de Investigaciones Ópticas (CIOp

Male breast cancer.

Male breast cancer (MaleBC) is a rare disease, accounting for <1% of all male tumors. During the last few years, there has been an increase in the incidence of this disease, along with the increase in female breast cancer (FBC). Little is known about the etiology of MaleBC: hormonal, environmental and genetic factors have been reported to be involved in its pathogenesis. Major risk factors include clinical disorders carrying hormonal imbalances, radiation exposure and, in particular, a positive family history (FH) for BC, the latter suggestive of genetic susceptibility. Rare mutations in high-penetrance genes (BRCA1 and BRCA2) confer a high risk of BC development; low-penetrance gene mutations (i.e. CHEK-2) are more common but involve a lower risk increase. About 90% of all male breast tumors have proved to be invasive ductal carcinomas, expressing high levels of hormone receptors with evident therapeutic returns. The most common clinical sign of BC onset in men is a painless palpable retroareolar lump, which should be evaluated by means of mammography, ultrasonography and core biopsy or fine needle aspiration (FNA). To date, there are no published data from prospective randomized trials supporting a specific therapeutic approach in MaleBC. Tumor size together with the number of axillary nodes involved are the main prognostic factors and should guide the treatment choice. Locoregional approaches include surgery and radiotherapy (RT), depending upon the initial clinical presentation. When systemic treatment (adjuvant, neoadjuvant and metastatic) is delivered, the choice between hormonal and or chemotherapy (CT) should depend upon the clinical and biological features, according to the FBC management guidelines. However great caution is required because of high rates of age-related comorbidities

babysitting procedures in proximal nerve trunk injuries two case reports and a review

One of the most important goals in treating proximal nerve injuries is to maintain the function of distal effectors during axonal regeneration. Babysitting, that is, connecting the injured nerve to a healthy trunk provides a bypass for distal neural regeneration or reactivation. It avoids degeneration of sensory and motor terminations, with minimal donor nerve damage. We present a technique where a nerve graft is used between ulnar and median nerve through two end-to-side sutures in the distal third of the forearm, in two different cases of proximal ulnar nerve injury. Both patients were young manual workers, the former suffered a total nerve disruption proximal to the elbow following a car accident and the latter suffered a perineurial scar from a high voltage injury at the proximal third of the forearm. The proximal injury was grafted with a sural nerve in the former and treated by neurolysis in the latter. Results were graded by the Highet-Zachary scale for both sensory and motor recovery. The outcomes of our series were compared to six other case reports in the literature (including median nerves) treated with this technique. Both clinical and experimental data show that babysitting effectively protects distal effectors

Gemcitabine-based doublets versus single-agent therapy for elderly patients with advanced nonsmall cell lung cancer: a Literature-based Meta-analysis.

Although platinum-based combinations are considered the best option of care for patients with advanced nonsmall cell lung cancer (NSCLC), single-agent therapy is the preferred treatment for older patients. Since the late 1990s, various combinations of third-generation agents (gemcitabine [G], vinorel- bine, docetaxel, and paclitaxel) have been tested, yielding contradictory results. The authors of this report performed a literature-based meta-analysis to assess the efficacy and tolerability of G-based doublets compared with single-agent chemotherapy for elderly patients with NSCLC. METHODS: Data from all published, randomized, phase 3 trials that compared a G-based doublet with a third-generation single agent in elderly patients were collected from electronic databases (Medline and the Cochrane Central Register of Controlled Trials), relevant reference lists, and abstract books. Pooled odds ratios (ORs) were calculated for the 1-year survival rate, the overall response rate (ORR), and grade 3 and 4 toxicities. RESULTS: Four eligible trials (1436 patients) were selected from 442 studies that initially were identified. A significant difference in ORR favoring G-based doublets over single agents was observed (OR, 0.65; 95% confidence interval [95% CI], 0.51-0.82 [P<.001]), whereas the trend toward an improved 1-year survival rate was not significant (OR, 0.78; 95% CI, 0.57-1.06 [P¼.169]). Grade 3 and 4 toxicities did not differ significantly except for thrombocytopenia (OR, 1.76; 95% CI, 1.12-2.76 [P¼.014]). CONCLUSIONS: G-based doublets appeared to be effective and feasible compared with single agents in the treatment of elderly patients with advanced NSCLC who were not suitable for full-dose, platinum-based chemotherapy. Further prospective, elderly specific, phase 3 trials will be necessary

The TP53 colorectal cancer international collaborative study on the prognostic and predictive significance of p53 mutation: influence of tumor site, type of mutation, and adjuvant treatment

PURPOSE: The aims of the TP53 Colorectal Cancer (CRC) International Collaborative Study were to evaluate the possible associations between specific TP53 mutations and tumor site, and to evaluate the prognostic and predictive significance of these mutations in different site, stage, and treatment subgroups. PATIENTS AND METHODS: A total of 3,583 CRC patients from 25 different research groups in 17 countries were recruited to the study. Patients were divided into three groups according to site of the primary tumor. TP53 mutational analyses spanned exons 4 to 8. RESULTS: TP53 mutations were found in 34% of the proximal colon tumors and in 45% of the distal colon and rectal tumors. They were associated with lymphatic invasion in proximal tumors. In distal colon tumors, deletions causing loss of amino acids were associated with worse survival. In proximal colon tumors, mutations in exon 5 showed a trend toward statistical significance (P < .05) when overall survival was considered. Dukes' C tumors with wild-type TP53 and those with mutated TP53 (proximal tumors) showed significantly better prognosis when treated with adjuvant chemotherapy. CONCLUSION: Analysis of TP53 mutations from a large cohort of CRC patients has identified tumor site, type of mutation, and adjuvant treatment as important factors in determining the prognostic significance of this genetic alteration

Oral temozolomide in heavily pre-treated brain metastases from non-small cell lung cancer: phase II study

Introduction: The primary tumour type most likely to metastasize to the brain is lung cancer. In heavily pre-treated patients, limited therapeutic option is available and the results of availability therapies reported in literature are disappointing. The present phase II study was designed to assess the efficacy and safety of temozolomide (TMZ) as palliative treatment for brain metastases (BrM) in NSCLC patients pre-treated with WBRT and at least one line of chemotherapy for metastatic brain disease. Material and methods: Temozolomide was administered orally at 150 mg/mq/day for five consecutive days for the first cycle, doses were increased to 200 mg/mq/day for 5 days every 28 days for subsequent cycles if no grade 3/4 haematological toxicity was observed. Eligibility criteria included cytological or histological confirmed NSCLC; BrM, recurrent or progressing after WBRT and at least one line of chemotherapy. A total of 30 consecutive patients entered the study and received the allocated treatment. Results: Three patients (10%) achieved an objective response (OR) of BrM with two complete remission. Stable disease and progressive disease were achieved in 3 (10%) and 24 patients (80%), respectively. A correlation between response to TMZ and sensitivity to the previous first line chemotherapy was reported. Time to progression and overall survival were examined both for responder patients and for all included patients. For long-term survivors, we considered the patients who survived >12 months after the start of TMZ. According to this definition, three patients resulted long-term survivors: 2 with OR and 1 with stable brain disease. No grades 3 or 4 toxicity occurred. The total of treatment-related adverse events were mild or moderate (G1-2) in intensity. No patients discontinued TMZ as a result of treatment-related toxicity. Discussion: The results of the present trial clearly demonstrates that TMZ is active and safe in BrM NSCLC patients previously treated with WBRT and at least one line of chemotherapy. © 2005 Elsevier Ireland Ltd. All rights reserved