Robot-assisted post-chemotherapy retroperitoneal lymph node dissection in germ cell tumor: is the single-docking with lateral approach relevant?

INTRODUCTION: Surgical treatment of post-chemotherapy residual mass of germ cell tumor (GCT) may be performed in various techniques. We assess the feasibility, safety, and efficacy of single-docking with lateral approach robot-assisted retroperitoneal lymph node dissection (R-RPLND) in residual mass of GCT in our center. MATERIALS AND METHODS: A retrospective review of patients undergoing R-RPLND for residual mass of CGT was performed between January 2014 and April 2017. Patients with residual mass < 3 cm for seminoma or < 1 cm for non-seminoma were eligible. All surgeries were performed with single-docking RPNLD technique in lateral decubitus. We assessed preoperative characteristics (age, testicular pathology, template, chemotherapy regimen, lesion size, and clinical stage), peroperative (operative time, estimated blood loss, intraoperative complication, node count, pathology, and number of positive node), and postoperative outcomes (postoperative complications, hospital length of stay, recurrence-free survival at 2 year, and ejaculation dysfunction). RESULTS: Eleven patients underwent R-RPLND with a median size of the residual mass of 20 mm. Median operative time was 153 min with 120 ml of estimated blood loss, without intraoperative complication. Median nodes count was 7 [1; 24]. Two patients had post-chemotherapy necrotic nodes and one no tumorous node. One patient had postoperative Clavien I complication (chyloperitoneum). We report 72.7% of antegrade ejaculation at 1 month from the surgery. Median clinical recurrence-free survival was 100% after 2 years from the surgery (n = 6). CONCLUSION: Lateral approach with single-docking R-RPLND for residual mass of GCT is feasible and safe, with satisfying functional and oncologic outcomes.

Methodology of phase II clinical trials in metastatic elderly breast cancer: a literature review.

PURPOSE: As the incidence of invasive breast cancer will increase with age, the number of elderly patients with a diagnosis metastatic breast cancer will also rise. But the use of cytotoxic drugs in elderly metastatic breast cancer patients is not systematic and is dreaded by medical oncologists. The need for prospective oncologic data from this population seems increasingly obvious. The main objective of this review is to investigate design and characteristics of phase II trials that assess activity and feasibility of chemotherapies in elderly advanced/metastatic breast cancer patients. METHODS: An electronic search in PUBMED allowed us to retrieve articles published in English language on phase II trials in elderly metastatic breast cancer between January 2002 and May 2016. Sixteen publications were finally included in this review. RESULTS: The primary endpoint was a simple, a composite, and a co-primary endpoints in 11, three, and two studies, respectively. Efficacy was the primary objective in 15 studies: simple (n = 10), composite (n = 3), co-primary endpoints (n = 2). Composite or co-primary endpoints combined efficacy and toxicity. Thirteen studies used multistage designs. CONCLUSIONS: Only five studies evaluated the feasibility, i.e., to jointly assess efficacy and tolerance to treatment (toxicity, quality of life, etc) as primary endpoint. Development of elderly specific phase III clinical trials might be challenging, it therefore seems essential to conduct phase II clinical trials evaluating jointly efficacy and toxicity in a well-defined geriatric population. Use of multistage designs that take into account heterogeneity would allow to identify a subpopulation at interim analysis and to reduce the number of patients exposed to an inefficient or a toxic treatment regimen. It is crucial to evaluate new therapies (targeted therapies, immunotherapies) using adequate methodologies (Study design, endpoint).

Vinflunine-gemcitabine versus vinflunine-carboplatin as first-line chemotherapy in cisplatin-unfit patients with advanced urothelial carcinoma: results of an international randomized phase II trial (JASINT1).

BACKGROUND: There is no standard first-line chemotherapy for advanced urothelial carcinoma (aUC) in cisplatin-ineligible (cisplatin-unfit) patients. The study assessed the efficacy and tolerability profile of two vinflunine-based cytotoxic regimens in this setting. PATIENTS AND METHODS: Patients with aUC a creatinine clearance (CrCl) of <60 but ≥30 ml/min, performance status 0 or 1 and no prior chemotherapy for advanced disease were randomized (1 : 1). They received vinflunine 250 or 280 mg/m(2) (based on baseline CrCl) on day 1, plus either gemcitabine [750 mg/m(2) escalated to 1000 mg/m(2) in cycle 2 if no toxicity grade (G) ≥2 on days 1 and 8 (VG) or plus carboplatin area under the curve 4.5 day 1 (VC) every 21 days]. To detect a 22% improvement in each arm compared with H0 (41%) in the primary end point, disease control rate (DCR = complete response + partial response + stable disease), 31 assessable patients per arm were required (α = 5%, ß = 20%). RESULTS: Sixty-nine patients were enrolled (34 VG, 35 VC). Less G3/4 haematological adverse events (AEs) were reported with VG: neutropaenia was seen in 38% (versus 68% with VC) and febrile neutropaenia in 3% (versus 14% with VC) of patients. No major differences were observed for non-haematological AEs. DCR was 77% in both groups; overall response rate (ORR) was 44.1% versus 28.6%, with a median progression-free survival of 5.9 versus 6.1 months and median OS of 14.0 versus 12.8 months with VG and VC, respectively. CONCLUSION: Both vinflunine-based doublets offer a similar DCR, ORR and OS. The better haematological tolerance favours the VG combination, which warrants further study. CLINICALTRIALS.GOV PROTOCOL IDENTIFIER: NCT 01599013.

Guidelines for the definition of time-to-event end points in renal cell cancer clinical trials: results of the DATECAN project†.

BACKGROUND: In clinical trials, the use of intermediate time-to-event end points (TEEs) is increasingly common, yet their choice and definitions are not standardized. This limits the usefulness for comparing treatment effects between studies. The aim of the DATECAN Kidney project is to clarify and recommend definitions of TEE in renal cell cancer (RCC) through a formal consensus method for end point definitions. MATERIALS AND METHODS: A formal modified Delphi method was used for establishing consensus. From a 2006-2009 literature review, the Steering Committee (SC) selected 9 TEE and 15 events in the nonmetastatic (NM) and metastatic/advanced (MA) RCC disease settings. Events were scored on the range of 1 (totally disagree to include) to 9 (totally agree to include) in the definition of each end point. Rating Committee (RC) experts were contacted for the scoring rounds. From these results, final recommendations were established for selecting pertinent end points and the associated events. RESULTS: Thirty-four experts scored 121 events for 9 end points. Consensus was reached for 31%, 43% and 85% events during the first, second and third rounds, respectively. The expert recommend the use of three and two endpoints in NM and MA setting, respectively. In the NM setting: disease-free survival (contralateral RCC, appearance of metastases, local or regional recurrence, death from RCC or protocol treatment), metastasis-free survival (appearance of metastases, regional recurrence, death from RCC); and local-regional-free survival (local or regional recurrence, death from RCC). In the MA setting: kidney cancer-specific survival (death from RCC or protocol treatment) and progression-free survival (death from RCC, local, regional, or metastatic progression). CONCLUSIONS: The consensus method revealed that intermediate end points have not been well defined, because all of the selected end points had at least one event definition for which no consensus was obtained. These clarified definitions of TEE should become standard practice in all RCC clinical trials, thus facilitating reporting and increasing precision in between trial comparisons.

Gastrointestinal metastases in renal cell carcinoma: A retrospective multicenter GETUG (Groupe d'Étude des Tumeurs Uro-Génitales) study.

BACKGROUND: Among patients with renal cell carcinoma (RCC), bone and visceral metastases have a poor prognosis, while endocrine gland metastases have a more favorable prognosis. Gastrointestinal metastases (GIMs) are rare, and their prognosis is still poorly understood. OBJECTIVES: To report clinical presentations, patient characteristics, therapeutic strategies, and prognosis of GIMs from RCC. METHODS: We retrospectively collected data from RCC patients presenting GIMs, in 10 French GETUG centers, between 2000 and 2021. RESULTS: We identified 74 patients with 87 GIMs, mostly gastric or duodenal. The median age at GIM diagnosis was 69 years and 76% of patients already had other metastases. GIMs occurred after a median duration of 5.4 years (IC95%=[4.2-7.1]) and 1.9 years (IC95%=[1.2-3.8]) from RCC diagnosis and first metastasis, respectively. GIMs were symptomatic in 52 patients (70%), with anemia in 41 patients (55%) and/or gastrointestinal bleeding in 31 patients (42%). Only 22 asymptomatic patients (30%) were fortuitously diagnosed. GIM management consisted of systemic treatment only in 29 GIMs (33%), local treatment only in 23 GIMs (26%), and both local and systemic treatment in 18 GIMs (21%). For 17 GIMs (20%), there was no therapeutic modification. After diagnosis of GIM, median overall survival was 19 months. CONCLUSION: We report the largest retrospective cohort of GIMs in RCC patients. They should be suspected in case of anemia or gastrointestinal bleeding in any patient with a history of RCC. Their management varies widely depending on their location in the digestive tract and whether or not they are symptomatic.

Routine FDG PET-CT in patients with a high-risk localized melanoma has a high predictive positive value for nodal disease and high negative predictive value for the presence of distant metastases.

BACKGROUND: FDG PET-CT is the superior imaging modality for the detection of visceral metastases (M+) in patients with melanoma. Conflicting evidence exists regarding its role for the initial staging of patients with high risk localized melanoma (large Breslow Thickness (BT) and/or ulceration). OBJECTIVE: To assess the role of routine staging with FDG PET-CT in melanoma patients with localized high risk melanoma. METHODS: Forty-eight consecutive patients with 1 < BT < 4 mm with ulceration and with BT ≥ 4 mm were staged with PET-CT. PET-CT procedures were performed on a GE Discovery ST® scanner. PET-CT findings for regional nodal status and presence of distant metastatic disease were collected. The gold standard for nodal assessment was pathological examination. The gold standard for M+ was conventional imaging and clinical follow-up, confirmed by biopsy whenever feasible. RESULTS: No patient had a positive PET-CT for M+. Six patients (13%) had a non-conclusive PET-CT; none of them presented with M+ within 6 months. Forty-three patients (90%) had a negative PET-CT, amongst them only one patient (2.5%) presented with M+ within a year. Six patients had FDG-avid lymph nodes in the drainage territory of the primary melanoma, either SLNB or lymph node dissection confirmed metastatic nodal involvement. The predictive positive value of PET for regional node involvement was 100%. COMMENTS: FDG PET-CT does not seem to be effective at detecting M+ at baseline staging in patients with high risk localized melanoma. However, it has a high negative predictive value for the presence of M+ at 6 months and a high positive predictive value for nodal involvement.

[Mood and cognitive disorders, and androgen deprivation]. / Troubles de l'humeur et cognitifs et suppression androgénique.

Prostate cancer has become a chronic disease. In this context, it is important to take into account the quality of life of patients and their family in the therapeutic approach. Recent studies have demonstrated the importance of depression and the risk of suicide in patients with prostate cancer as well as the repercussions of the disease on the spouse and their relationship. The implication of hormonal treatment in the increase in risk of depression is difficult to affirm. Few studies have investigated this subject and they present methodological biases. Some authors report an increased risk of cognitive decline in patients on androgen deprivation. However, even if certain physiopathological hypotheses have been put forward, the imputability of the treatment on the alteration of cognitive functions has not been clearly established. Urologists are at the forefront of diagnosis and treatment of prostate cancer occurring most often in elderly subjects. Therefore, given the prevalence of depression syndromes and/or the alteration of cognitive functions in this population, the urologist must be aware of these different factors, which are potentially aggravated by the introduction of androgen deprivation. Based on a review of the recent literature, the authors suggest using a simple depression screening tool: confirmation of the diagnosis and management is within the competence of the general practitioner. As for the risk of cognitive decline, it seems difficult to imagine, and not necessarily relevant, to systematically propose a battery of neuropsychometric screening tests. On the other hand, giving the patient the G8 screening test can allow the urologist to assess whether the patient needs a geriatric consultation or not.

No Difference in the Phenotypic Expression of Frailty among Elderly Patients Recently Diagnosed with Cancer Vs Cancer Free Patients.

OBJECTIVES: To examine frailty determinants differences in patients with a recent diagnosis of cancer compared to non-cancer patients among older adult. Revealing those differences will allow us to individualize the exact frailty management in those patients diagnosed with cancer. DESIGN: This is an observational cross-sectional, monocentric study. SETTING: Patients were evaluated at the Geriatric Frailty Clinic (GFC), in the Toulouse University Hospital, France, between October 2011 and February 2016. PARTICIPANTS: 1996 patients aged 65 and older were included (1578 patients without cancer and 418 patients with solid and hematological cancer recently diagnosed). MEASUREMENTS: Frailty was established according to the frailty phenotype. The frailty phenotype measures five components of frailty: weight loss, exhaustion, low physical activity, weakness and slow gait. Frailty phenotype was categorized as robust, pre-frail and frail. RESULTS: In a multinomial logistic regression, cancer, compared to the non-cancer group, is not associated with an increased likelihood of being classified as pre frail (RRR 0.9, 95% CI [0.5 ; 1.6 ], p 0.9) or frail (RRR 1.2, 95% CI [0.7 ; 2.0], p 0.4) rather than robust. When considering each Fried criterion, a significant higher odd of weight loss was observed in older patients with cancer compared to the non-cancer patients (OR 2.3, 95% CI [1.8; 3.0], p <0.001) but no statistically significant differences was found among the four other Fried criteria. Sensitivity analysis on the frailty index showed that cancer was not associated with a higher FI score compared to non-cancer (ß 0.002, 95%CI [-0.009; 0.01], p 0.6). CONCLUSION: In this real-life study evaluating elderly patients with and without cancer, we didn't confirm our hypothesis, in fact we found that cancer was not associated with frailty severity using both a phenotypic model and a deficit accumulation approach. Cancer may contribute, at least additively, to the development of frailty, like any other comorbidity, rather than a global underlying condition of vulnerability.

Multidisciplinary development of the Geriatric Core Dataset for clinical research in older patients with cancer: A French initiative with international survey.

BACKGROUND: To define a core set of geriatric data to be methodically collected in clinical cancer trials of older adults, enabling comparison across trials. PATIENTS AND METHODS: Following a consensus approach, a panel of 14 geriatricians from oncology clinics identified seven domains of importance in geriatric assessment. Based on the international recommendations, geriatricians selected the mostly commonly used tools/items for geriatric assessment by domain (January-October 2015). The Geriatric Core Dataset (G-CODE) was progressively developed according to RAND appropriateness ratings and feedback during three successive Delphi rounds (July-September 2016). The face validity of the G-CODE was assessed with two large panels of health professionals (55 national and 42 international experts) involved both in clinical practice and cancer trials (March-September 2017). RESULTS AND DISCUSSION: After the last Delphi round, the tools/items proposed for the G-CODE were the following: (1) social assessment: living alone or support requested to stay at home; (2) functional autonomy: Activities of Daily Living (ADL) questionnaire and short instrumental ADL questionnaire; (3) mobility: Timed Up and Go test; (4) nutrition: weight loss during the past 6 months and body mass index; (5) cognition: Mini-Cog test; (6) mood: mini-Geriatric Depression Scale and (7) comorbidity: updated Charlson Comorbidity Index. More than 70% of national experts (42 from 20 cities) and international experts (31 from 13 countries) participated. National and international surveys showed good acceptability of the G-CODE. Specific points discussed included age-year cut-off, threshold of each tool/item and information about social support, but no additional item was proposed. CONCLUSION: We achieved formal consensus on a set of geriatric data to be collected in cancer trials of older patients. The dissemination and prospective use of the G-CODE is needed to assess its utility.

Electrostatic analysis of TEM1 beta-lactamase: effect of substrate binding, steep potential gradients and consequences of site-directed mutations.

BACKGROUND: Escherichia coli TEM1 is a penicillinase and belongs to class A beta-lactamases. Its naturally occurring mutants are responsible for bacterial resistance to beta-lactamin-based antibiotics. X-ray structure determinations show that all class A beta-lactamases are similar, but, despite the numerous kinetic investigations, the reaction mechanism of these enzymes is still debated. We address the questions of what the molecular contexts during the acylation and deacylation steps are and how they contribute to the efficiency of these penicillinases. RESULTS: Electrostatic analysis of the 1.8 A resolution refined X-ray structure of the wild-type enzyme, and of its modelled Michaelis and acyl-enzyme complexes, showed that substrate binding induces an upward shift in the pKa of the unprotonated Lys73 by 6.4 pH units. The amine group of Lys73 can then abstract the Ser70 hydroxyl group proton and promote acylation. In the acyl-enzyme complex, the deacylating water is situated between the carboxylate group of Glu166, within the enzyme, and the estercarbonyl carbon of the acyl-enzyme complex, in an electrostatic potential gradient amounting to 30 kTe-1 A-1. Other residues, not directly involved in catalysis, also contribute to the formation of this gradient. The deacylation rate is related to the magnitude of the gradient. The kinetic behavior of site-directed mutants that affect the protonation state of residue 73 cannot be explained on the basis of the wild-type enzyme mechanism. CONCLUSIONS: In the wild-type enzyme, the very high rates of acylation and deacylation of class A beta-lactamases arise from an optimal chemical setup in which the acylation reaction seems triggered by substrate binding that changes the general base property of Lys73. In site-directed mutants where Lys73 is protonated, acylation may proceed through activation of a water molecule by Glu166, and Lys73 contributes as a proton shuffle partner in this pathway.

Conformational changes induced by phosphorylation of the FixJ receiver domain.

BACKGROUND: A variety of bacterial adaptative cellular responses to environmental stimuli are mediated by two-component signal transduction pathways. In these phosphorelay cascades, histidine kinases transphosphorylate a conserved aspartate in the receiver domain, a conserved module in the response regulator superfamily. The main effect of this phosphorylation is to alter the conformation of the response regulator in order to modulate its biological function. The response regulator FixJ displays a typical modular arrangement, with a phosphorylatable N-terminal receiver domain and a C-terminal DNA-binding domain. In the symbiotic bacterium Sinorhizobium meliloti, phosphorylation of this response regulator activates transcription of nitrogen-fixation genes. RESULTS: The crystal structures of the phosphorylated and of the unphosphorylated N-terminal receiver domain of FixJ (FixJN) were solved at 2.3 A and 2.4 A resolution, respectively. They reveal the environment of the phosphoaspartate in the active site and the specific conformational changes leading to activation of the response regulator. Phosphorylation of the conserved aspartate induces major structural changes in the beta 4-alpha 4 loop, and in the signaling surface alpha 4-beta 5 that mediates dimerization of the phosphorylated full-length response regulator. A site-directed mutant at this protein-protein interface decreases the affinity of the phosphorylated response regulator for the fixK promoter tenfold. CONCLUSIONS: The cascade of phosphorylation-induced conformational changes in FixJN illustrates the role of conserved residues in stabilizing the phosphoryl group in the active site, triggering the structural transition and achieving the post-phosphorylation signaling events. We propose that these phosphorylation-induced conformational changes underly the activation of response regulators in general.

Structural transitions in the FixJ receiver domain.

BACKGROUND: Two-component signal transduction pathways are sophisticated phosphorelay cascades widespread in prokaryotes and also found in fungi, molds and plants. FixL/FixJ is a prototypical system responsible for the regulation of nitrogen fixation in the symbiotic bacterium Sinorhizobium meliloti. In microaerobic conditions the membrane-bound kinase FixL uses ATP to transphosphorylate a histidine residue, and the response regulator FixJ transfers the phosphoryl group from the phosphohistidine to one of its own aspartate residues in a Mg(2+)-dependent mechanism. RESULTS: Seven X-ray structures of the unphosphorylated N-terminal receiver domain of FixJ (FixJN) have been solved from two crystal forms soaked in different conditions. Three conformations of the protein were found. In the first case, the protein fold impairs metal binding in the active site and the structure reveals a receiver domain that is self-inhibited for catalysis. In the second conformation, the canonical geometry of the active site is attained, and subsequent metal binding to the protein induces minimal conformational changes. The third conformation illustrates a non-catalytic form of the protein where unwinding of the N terminus of helix alpha 1 has occurred. Interconversion of the canonical and self-inhibited conformations requires a large conformational change of the beta 3-alpha 3 loop region. CONCLUSIONS: These unphosphorylated structures of FixJN stress the importance of flexible peptide segments that delineate the active site. Their movements may act as molecular switches that define the functional status of the protein. Such observations are in line with structural and biochemical results obtained on other response regulator proteins and may illustrate general features that account for the specificity of protein-protein interactions.

The structure of Staphylococcus aureus epidermolytic toxin A, an atypic serine protease, at 1.7 A resolution.

BACKGROUND: Staphylococcal epidermolytic toxins A and B (ETA and ETB) are responsible for the staphylococcal scalded skin syndrome of newborn and young infants; this condition can appear just a few hours after birth. These toxins cause the disorganization and disruption of the region between the stratum spinosum and the stratum granulosum--two of the three cellular layers constituting the epidermis. The physiological substrate of ETA is not known and, consequently, its mode of action in vivo remains an unanswered question. Determination of the structure of ETA and its comparison with other serine proteases may reveal insights into ETA's catalytic mechanism. RESULTS: The crystal structure of staphylococcal ETA has been determined by multiple isomorphous replacement and refined at 1.7 A resolution with a crystallographic R factor of 0.184. The structure of ETA reveals it to be a new and unique member of the trypsin-like serine protease family. In contrast to other serine protease folds, ETA can be characterized by ETA-specific surface loops, a lack of cysteine bridges, an oxyanion hole which is not preformed, an S1 specific pocket designed for a negatively charged amino acid and an ETA-specific specific N-terminal helix which is shown to be crucial for substrate hydrolysis. CONCLUSIONS: Despite very low sequence homology between ETA and other trypsin-like serine proteases, the ETA crystal structure, together with biochemical data and site-directed mutagenesis studies, strongly confirms the classification of ETA in the Glu-endopeptidase family. Direct links can be made between the protease architecture of ETA and its biological activity.

The structure of a Staphylococcus aureus leucocidin component (LukF-PV) reveals the fold of the water-soluble species of a family of transmembrane pore-forming toxins.

BACKGROUND: Leucocidins and gamma-hemolysins are bi-component toxins secreted by Staphylococcus aureus. These toxins activate responses of specific cells and form lethal transmembrane pores. Their leucotoxic and hemolytic activities involve the sequential binding and the synergistic association of a class S and a class F component, which form hetero-oligomeric complexes. The components of each protein class are produced as non-associated, water-soluble proteins that undergo conformational changes and oligomerization after recognition of their cell targets. RESULTS: The crystal structure of the monomeric water-soluble form of the F component of Panton-Valentine leucocidin (LukF-PV) has been solved by the multiwavelength anomalous dispersion (MAD) method and refined at 2.0 A resolution. The core of this three-domain protein is similar to that of alpha-hemolysin, but significant differences occur in regions that may be involved in the mechanism of pore formation. The glycine-rich stem, which undergoes a major rearrangement in this process, forms an additional domain in LukF-PV. The fold of this domain is similar to that of the neurotoxins and cardiotoxins from snake venom. CONCLUSIONS: The structure analysis and a multiple sequence alignment of all toxic components, suggest that LukF-PV represents the fold of any water-soluble secreted protein in this family of transmembrane pore-forming toxins. The comparison of the structures of LukF-PV and alpha-hemolysin provides some insights into the mechanism of transmembrane pore formation for the bi-component toxins, which may diverge from that of the alpha-hemolysin heptamer.

Body Composition and Anti-Neoplastic Treatment in Adult and Older Subjects - A Systematic Review.

BACKGROUND: The estimation of the risk of poor tolerance and overdose of antineoplastic agents protocols represents a major challenge in oncology, particularly in older patients. We hypothesize that age-related modifications of body composition (i.e. increased fat mass and decreased lean mass) may significantly affect tolerance to chemotherapy. METHOD: We conducted a systematic review for the last 25 years (between 1990 and 2015), using US National library of Medicine Medline electronic bibliographic database and Embase database of cohorts or clinical trials exploring (i) the interactions of body composition (assessed by Dual X-ray Absorptiometry, Bioelectrical Impedance Analyses, or Computerized Tomography) with pharmacokinetics parameters, (ii) the tolerance to chemotherapy, and (iii) the consequences of chemotherapies or targeted therapies on body composition. RESULTS: Our search identified 1504 articles. After a selection (using pre-established criteria) on titles and abstract, 24 original articles were selected with 3 domains of interest: impact of body composition on pharmacokinetics (7 articles), relationship between body composition and chemotoxicity (14 articles), and effect of anti-cancer chemotherapy on body composition (11 articles). The selected studies suggested that pharmacokinetic was influenced by lean mass, that lower lean mass could be correlated with toxicity, and that sarcopenic patients experienced more toxicities that non-sarcopenic patients. Regarding fat mass, results were less conclusive. No studies specifically explored the topic of body composition in older cancer patients. CONCLUSIONS: Plausible pathophysiological pathways linking body composition, toxicity, and pharmacokinetics are sustained by the actual review. However, despite the growing number of older cancer patients, our review highlighted the lack of specific studies in the field of anti-neoplastic agents toxicity regarding body composition conducted in elderly.

Crystallization and preliminary crystallographic data for bovine antithrombin III.

Crystals of bovine antithrombin III were obtained in the presence of metal ions with ammonium sulphate as precipitating agent. Crystals belong to space group P4(1)2(1)2 or P4(3)2(1)2 with cell parameters a = b = 91.4 A, c = 383.1 A; there are two molecules per asymmetric unit. Electrophoresis experiments and amino acid sequence analysis of the N-terminal part of redissolved crystals suggest that the protein molecules are cleaved at the active site.

Crystal structure of cleaved bovine antithrombin III at 3.2 A resolution.

The crystal structure of cleaved antithrombin III (ATIII) has been determined to 3.2 A resolution by single isomorphous replacement, real space density modification and phase extension protocols. The heavy-atom sites and the first molecular envelope were determined owing to the molecular replacement solution previously reported and partially refined. Refinement of the two molecules of the asymmetric unit led to a crystallographic R-factor of 0.212 for all reflections between 8.0 and 3.2 A, without inclusion of water molecules. The root-mean-square deviation from ideal values is, respectively, 0.015 A and 3.6 degrees for bond lengths and bond angles. The topology of the molecule closely resembles that of cleaved serpins inhibitors with the two residues forming the reactive bond at opposite ends of the molecule. The most significant difference between ATIII and alpha 1-antitrypsin lies in the 45 residue N-terminal extension in ATIII which contribute to the definition of the heparin binding site. This loop region at the surface of the molecule is held by two disulphide bridges to the protein core and exhibits high temperature factor values. It forms a valley which restrains the possibilities for binding of heparin. Docking of the pentasaccharide unit which represents the minimum fragment of heparin able to bind to ATIII indicates a possible role for arginine 14 in the interaction of heparin and the protein.

Discoupling the Ca(2+)-activation from the pore-forming function of the bi-component Panton-Valentine leucocidin in human PMNs.

The consecutive cell activation, including Ca(2+)-channel opening, and pore formation leading to human neutrophil lysis were the two functions of the staphylococcal Panton-Valentine leucocidin attempted to be discoupled by site-directed mutagenesis. In a first approach consisting in deletions of the cytoplasmic extremity of the transmembranous domain, we produced a LukF-PV DeltaSer125-Leu128 with a slightly reduced Ca(2+) induction but with a significantly lowered lytic activity when combined with its synergistic protein LukS-PV. The second approach consisted in the modification of charges and/or introduction of a steric hindrance inside the pore, which also led to interesting mutated proteins: LukF-PV G131D, G131W and G130D. The latter had an intact Ca(2+) induction ability while the lytic one was 20-fold diminished. Binding properties and intrinsic pore diameters of these discoupled toxins remained comparable to the wild-type protein. The mutated proteins promoted interleukin-8 secretion, but they were rather inactive in an experimental model. New insights are brought concerning the role of the two functions in the virulence of this bi-component leucotoxin.

The molecular puzzle of two-component signaling cascades.

Two-component systems constitute prevalent signaling pathways in bacteria and mediate a large variety of adaptative cellular responses. Signaling proceeds through His-Asp phosphorelay cascades that involve two central partners, the histidine protein kinase and the response regulator protein. Structural studies have provided insights into some design principles and activation mechanisms of these multi-domain proteins implicated in the control of virulence gene expression in several pathogens.