Surgical margin status in relation to surgical approach in the management of early-stage cervical Cancer: A Canadian cervical Cancer collaborative (4C) study

OBJECTIVE

Surgical margin status in women undergoing surgery for early-stage cervical cancer is an important prognostic factor. We sought to determine whether close (<3 mm) and positive surgical margins are associated with surgical approach and survival.

METHODS

This is a national retrospective cohort study of cervical cancer patients treated with radical hysterectomy. Patients with stage IA1/LVSI-Ib2(FIGO 2018) with lesions up to 4 cm at 11 Canadian institutions from 2007 to 2019 were included. Surgical approach included robotic/laparoscopic (LRH), abdominal (ARH) or combined laparoscopic-assisted vaginal/vaginal (LVRH) radical hysterectomy. Recurrence free survival(RFS) and overall survival (OS) were estimated using Kaplan-Meier analysis. Chi-square and log-rank tests were used to compare groups.

RESULTS

956 patients met inclusion criteria. Surgical margins were as follows: negative (87.0%), positive (0.4%) or close <3 mm (6.8%), missing (5.8%). Most patients had squamous histology (46.9%); 34.6% had adenocarcinomas and 11.3% adenosquamous. Most were stage IB (75.1%) and 24.9% were IA. Mode of surgery included: LRH(51.8%), ARH (39.2%), LVRH (8.9%). Predictive factors for close/positive margins included stage, tumour diameter, vaginal involvement and parametrial extension. Surgical approach was not associated with margin status (p = 0.27). Close/positive margins were associated with a higher risk of death on univariate analysis (HR = non calculable for positive and HR = 1.83 for close margins, p = 0.017), but not significant for OS when adjusted for stage, histology, surgical approach and adjuvant treatment. There were 7 recurrences in patients with close margins (10.3%, p = 0.25). 71.5% with positive/close margins received adjuvant treatment. In addition, MIS was associated with a higher risk of death (OR = 2.39, p = 0.029).

CONCLUSION

Surgical approach was not associated to close or positive margins. Close surgical margins were associated with a higher risk of death. MIS was associated with worse survival, suggesting that margin status may not be the driver of worse survival in these cases.

Development of a surgical competency assessment tool for sentinel lymph node dissection by minimally invasive surgery for endometrial cancer

INTRODUCTION

Sentinel lymph node dissection is widely used in the staging of endometrial cancer. Variation in surgical techniques potentially impacts diagnostic accuracy and oncologic outcomes, and poses barriers to the comparison of outcomes across institutions or clinical trial sites. Standardization of surgical technique and surgical quality assessment tools are critical to the conduct of clinical trials. By identifying mandatory and prohibited steps of sentinel lymph node (SLN) dissection in endometrial cancer, the purpose of this study was to develop and validate a competency assessment tool for use in surgical quality assurance.

METHODS

A Delphi methodology was applied, included 35 expert gynecological oncology surgeons from 16 countries. Interviews identified key steps and tasks which were rated mandatory, optional, or prohibited using questionnaires. Using the surgical steps for which consensus was achieved, a competency assessment tool was developed and subjected to assessments of validity and reliability.

RESULTS

Seventy percent consensus agreement standardized the specific mandatory, optional, and prohibited steps of SLN dissection for endometrial cancer and informed the development of a competency assessment tool. Consensus agreement identified 21 mandatory and three prohibited steps to complete a SLN dissection. The competency assessment tool was used to rate surgical quality in three preselected videos, demonstrating clear separation in the rating of the skill level displayed with mean skills summary scores differing significantly between the three videos (F score=89.4; P<0.001). Internal consistency of the items was high (Cronbach α=0.88).

CONCLUSION

Specific mandatory and prohibited steps of SLN dissection in endometrial cancer have been identified and validated based on consensus among a large number of international experts. A competency assessment tool is now available and can be used for surgeon selection in clinical trials and for ongoing, prospective quality assurance in routine clinical care.

Exploring international differences in ovarian cancer treatment: a comparison of clinical practice guidelines and patterns of care

INTRODUCTION

The International Cancer Benchmarking Partnership demonstrated international differences in ovarian cancer survival, particularly for women aged 65-74 with advanced disease. These findings suggest differences in treatment could be contributing to survival disparities.

OBJECTIVE

To compare clinical practice guidelines and patterns of care across seven high-income countries.

METHODS

A comparison of guidelines was performed and validated by a clinical working group. To explore clinical practice, a patterns of care survey was developed. A questionnaire regarding management and potential health system-related barriers to providing treatment was emailed to gynecological specialists. Guideline and survey results were crudely compared with 3-year survival by 'distant' stage using Spearman's rho.

RESULTS

Twenty-seven guidelines were compared, and 119 clinicians completed the survey. Guideline-related measures varied between countries but did not correlate with survival internationally. Guidelines were consistent for surgical recommendations of either primary debulking surgery or neoadjuvant chemotherapy followed by interval debulking surgery with the aim of complete cytoreduction. Reported patterns of surgical care varied internationally, including for rates of primary versus interval debulking, extensive/'ultra-radical' surgery, and perceived barriers to optimal cytoreduction. Comparison showed that willingness to undertake extensive surgery correlated with survival across countries (rs=0.94, p=0.017). For systemic/radiation therapies, guideline differences were more pronounced, particularly for bevacizumab and PARP (poly (ADP-ribose) polymerase) inhibitors. Reported health system-related barriers also varied internationally and included a lack of adequate hospital staffing and treatment monitoring via local and national audits.

DISCUSSION

Findings suggest international variations in ovarian cancer treatment. Characteristics relating to countries with higher stage-specific survival included higher reported rates of primary surgery; willingness to undertake extensive/ultra-radical procedures; greater access to high-cost drugs; and auditing.

Guidelines for Perioperative Care in Cytoreductive Surgery (CRS) with or without hyperthermic IntraPEritoneal chemotherapy (HIPEC): Enhanced recovery after surgery (ERAS®) Society Recommendations - Part I: Preoperative and intraoperative management

BACKGROUND

Enhanced recovery after surgery (ERAS) pathways have been shown to considerably reduce complications, length of stay and costs after most of surgical procedures by standardised application of best evidence-based perioperative care. The aim was to elaborate dedicated recommendations for cytoreductive surgery (CRS) ± hyperthermic intraperitoneal chemotherapy (HIPEC) in a two-part series of guidelines based on expert consensus. The present part I of the guidelines highlights preoperative and intraoperative management.

METHODS

The core group assembled a multidisciplinary panel of 24 experts involved in peritoneal surface malignancy surgery representing the fields of general surgery (n = 12), gynaecological surgery (n = 6), and anaesthesia (n = 6). Experts systematically reviewed and summarized the available evidence on 72 identified perioperative care items, following the GRADE (grading of recommendations, assessment, development, evaluation) system. Final consensus (defined as ≥50%, or ≥70% of weak/strong recommendations combined) was reached by a standardised 2-round Delphi process, regarding the strength of recommendations.

RESULTS

Response rates were 100% for both Delphi rounds. Quality of evidence was evaluated high, moderate low and very low, for 15 (21%), 26 (36%), 29 (40%) and 2 items, respectively. Consensus was reached for 71/72(98.6%) items. Strong recommendations were defined for 37 items, No consensus could be reached regarding the preemptive use of fresh frozen plasma.

CONCLUSION

The present ERAS recommendations for CRS±HIPEC are based on a standardised expert consensus process providing clinicians with valuable guidance. There is an urgent need to produce high quality studies for CRS±HIPEC and to prospectively evaluate recommendations in clinical practice.

Impact of Nutrition on Enhanced Recovery After Surgery (ERAS) in Gynecologic Oncology

Enhanced recovery after surgery (ERAS) pathways aim to improve surgical outcomes by applying evidence-based practices before, during, and after surgery. Patients undergoing surgery for gynecologic malignancies are at high risk of complications due to population, patient, disease, and surgical factors. The nutritional status of the patient provides the foundation for recovery after surgery, and opportunities to optimize outcomes exist from the first patient assessment to the early days after surgery. This review highlights the importance of nutritional assessment and intervention during the pre-operative and post-operative periods in the context of ERAS in gynecologic oncology surgery. The emerging role of immunonutrition, carbohydrate loading, and the importance of individualized care are explored. Evidence from studies in gynecologic oncology is presented, where available, and extrapolated from colorectal and other cancer surgery trials when applicable.

Guidelines for perioperative care in gynecologic/oncology: Enhanced Recovery After Surgery (ERAS) Society recommendations-2019 update

BACKGROUND

This is the first updated Enhanced Recovery After Surgery (ERAS) Society guideline presenting a consensus for optimal perioperative care in gynecologic/oncology surgery.

METHODS

A database search of publications using Embase and PubMed was performed. Studies on each item within the ERAS gynecologic/oncology protocol were selected with emphasis on meta-analyses, randomized controlled trials, and large prospective cohort studies. These studies were then reviewed and graded according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.

RESULTS

All recommendations on ERAS protocol items are based on best available evidence. The level of evidence for each item is presented accordingly.

CONCLUSIONS

The updated evidence base and recommendation for items within the ERAS gynecologic/oncology perioperative care pathway are presented by the ERAS® Society in this consensus review.

Ovarian cancer in Manitoba: trends in incidence and survival, 1992-2011

BACKGROUND

Because the International Cancer Benchmarking Partnership, in a study of diagnosis years between 1995 and 2007, showed lower-than-expected survival for Manitoba's ovarian cancer patients, we undertook an analysis to describe the features of ovarian cancer diagnosed in Manitoba during a 20-year period. We also determined the most recent trends in survival to see if the previous results were sustained.

METHODS

In this retrospective cohort study, ovarian cancer cases diagnosed during 1992-2011 were extracted from the Manitoba Cancer Registry. The incidence of ovarian cancer was calculated for the overall group and for age, morphology, residence, treatment, and stage. Trends over time, with a particular focus on changes that might correlate with poor survival, were analyzed. The 1- and 3-year relative survival rates were also calculated.

RESULTS

The incidence of ovarian cancer did not vary over time (p = 0.640), even when stratified by age or morphology groups. Use of adjuvant chemotherapy decreased (p = 0.005) and use of neoadjuvant chemotherapy increased over time (p = 0.002). Diagnoses of stage iv cancers declined over time (p < 0.020). Trends in incidence did not coincide with previously observed decreases in relative survival.

CONCLUSIONS

A decline in diagnoses of stage iv ovarian cancer could be responsible for a recent increase in relative survival. However, sample size might have limited power in some analyses, and the previously reported decrease in relative survival might have been due to a random fluctuation in the data. Future efforts will focus on continued monitoring of the patterns of ovarian cancer presentation and outcomes in Manitoba.

Superior vena cava syndrome – changing etiology in the third millennium

Superior vena cava syndrome (SVCS), is diagnosed following different degrees of central venous system obstruction, which traditionally was caused by infections, tumors or fibrosing mediastinitis. Recently the role of SVC thrombosis secondary to indwelling central venous devices or pacemaker leads as well as different hypercoagulable states have drawn much attention. In the current review we present a 58-year-old female patient who underwent recurrent pacemaker replacements due to recurrent infections. The patient was hospitalized with superior vena cava syndrome and multiple thrombi in the upper body circulation. Additionally the evaluation was conducted for thrombophilia, which revealed the presence of high titers of antiphospholipid antibodies, suggesting the concurrent diagnosis of the antiphospholipid syndrome (APS). This case reflects the changes in the etiology of SVCS, and the need for a comprehensive evaluation of patients, in the search for additional factors that may complicate a pacemaker insertion, such as the presence of antiphospholipid antibodies. We review the relevant literature and highlight the importance for an interdisciplinary approach in the treatment of SVCS nowadays.

Computational Pool: A New Challenge for Game Theory Pragmatics

Computational pool is a relatively recent entrant into the group of games played by computer agents. It features a unique combination of properties that distinguish it from oth- ers such games, including continuous action and state spaces, uncertainty in execution, a unique turn-taking structure, and of course an adversarial nature. This article discusses some of the work done to date, focusing on the software side of the pool-playing problem. We discuss in some depth CueCard, the program that won the 2008 computational pool tournament. Research questions and ideas spawned by work on this problem are also discussed. We close by announcing the 2011 computational pool tournament, which will take place in conjunction with the Twenty-Fifth AAAI Conference.

Chlorophyll catabolism in senescing plant tissues: In vivo breakdown intermediates suggest different degradative pathways for Citrus fruit and parsley leaves

High-pressure liquid chromatography was used to separate chlorophyll derivatives in acetone extracts from senescing Citrus fruit peel, autumnal Melia azedarach L. leaves, and dark-held detached parsley (Petroselinum sativum L.) leaves. Chlorophyllide a and another polar, dephytylated derivative accumulated in large amounts in senescing Citrus peel, particularly in fruit treated with ethylene. Ethylene also induced a 4-fold increase in the specific activity of Citrus chlorophyllase (chlorophyll chlorophyllidohydrolase, EC 3.1.1.14). Detailed kinetics based on a hexane/acetone solvent partition system showed that the in vivo increase in dephytylated derivatives coincided with the decrease in total chlorophyll. Polar, dephytylated derivatives accumulated also in senescing Melia leaves. Senescing parsley leaves revealed a very different picture. The gradual disappearance of chlorophyll a was accompanied by an increase in pheophytin a and by the transient appearance of several phytylated derivatives. Only pheophytin a and an adjacent peak were left when all the chlorophyll a had disappeared. The pathways for breakdown of chlorophyll in the Citrus and parsley senescence systems are discussed.

Axiomatic Foundations for Ranking Systems

Reasoning about agent preferences on a set of alternatives, and the aggregation of such preferences into some social ranking is a fundamental issue in reasoning about multi-agent systems. When the set of agents and the set of alternatives coincide, we get the ranking systems setting. A famous type of ranking systems are page ranking systems in the context of search engines. In this paper we present an extensive axiomatic study of ranking systems. In particular, we consider two fundamental axioms: Transitivity, and Ranked Independence of Irrelevant Alternatives. Surprisingly, we find that there is no general social ranking rule that satisfies both requirements. Furthermore, we show that our impossibility result holds under various restrictions on the class of ranking problems considered. However, when transitivity is weakened, an interesting possibility result is obtained. In addition, we show a complete axiomatization of approval voting using ranked IIA.

A comparison of overall and cause-specific survival among patients with low- and intermediate-risk prostate cancer treated with brachytherapy, external beam radiotherapy, or radical prostatectomy

5126

Background: The factors thought to influence overall survival (OS) and cause-specific survival (CSS) in patients treated for low and intermediate-risk prostate cancer (CaP) with brachytherapy (PI), external beam radiotherapy (RT), or radical prostatectomy (RP) were evaluated. Methods: From 1996 to 2003, 2285 patients with low or intermediate-risk CaP were treated at the Cleveland Clinic with either PI (n=662), RT (n=570), or RP (n=1053). Factors thought to influence OS and CSS were recorded. These factors included: Charlson score, age, socioeconomic status, race, body mass index (BMI), presence of coronary artery disease (CAD), presence of hypertension (HTN), presence of dyslipidemia (DL), initial prostate-specific antigen (iPSA), biopsy Gleason score (bGS), clinical stage, use of androgen deprivation (AD), AD duration, smoking history including pack-years, alcohol use, and cancer treatment modality (TX). Univariate and multivariate analyses were done using Cox proportional hazards regression. Results: The median follow-up is 59 months (range: 24–119 months). The 5- year OS rate is 96.0%, and the 8-year rate is 89.9%. Multivariate analysis revealed that Charlson score, age, smoking history, and TX were significantly associated with OS. Treatment with RT was independently associated with worse OS relative to PI and RP. CSS was grouped into 4 major categories: CAD, CaP, other cancer, and other. The only significant difference between these CSS categories and the treatment modalities was CaP. The percent of deaths due to CaP in the TX groups were: PI - 3.2%, RP - 9.7%, and RT - 24.5%. Conclusions: Charlson score, age, smoking history, and TX independently affect OS in patients treated for low and intermediate-risk CaP. The cause of the lower OS rate with RT may be related to an increased risk of death due to CaP.

[Table: see text]

No significant financial relationships to disclose.

A role for PKCtheta in outside-in alpha(IIb)beta3 signaling

Fibrinogen binding to platelets triggers alpha(IIb)beta3-dependent outside-in signals that promote actin rearrangements and cell spreading. Studies with chemical inhibitors or activators have implicated protein kinase C (PKC) in alpha(IIb)beta3 function. However, the role of individual PKC isoforms is poorly understood. Biochemical and genetic approaches were used to determine whether PKCtheta is involved in alpha(IIb)beta3 signaling. PKCtheta was constitutively associated with alpha(IIb)beta3 in human and murine platelets. Fibrinogen binding to alpha(IIb)beta3 stimulated the association of PKCtheta with tyrosine kinases Btk and Syk, and tyrosine phosphorylation of PKCtheta, Btk and the actin regulator, Wiskott-Aldrich syndrome protein (WASP). Mouse platelets deficient in PKCtheta or Btk failed to spread on fibrinogen. Furthermore, PKCtheta was required for phosphorylation of WASP-interacting protein on Ser-488, an event that has been linked to WASP activation of the Arp2/3 complex and actin polymerization in lymphocytes. Neither PKCtheta nor Btk were required for agonist-induced inside-out signaling and fibrinogen binding to alpha(IIb)beta3. Thus, PKCtheta is a newly identified, essential member of a dynamic outside-in signaling complex that includes Btk and that couples alpha(IIb)beta3 to the actin cytoskeleton.

The frequency split method for helical cone-beam reconstruction

A new approximate method for the utilization of redundant data in helical cone-beam CT is presented. It is based on the observation that the original WEDGE method provides excellent image quality if only little more than 180 degrees data are used for back-projection, and that significant low-frequency artifacts appear if a larger amount of redundant data are used. This degradation is compensated by the frequency split method: The low-frequency part of the image is reconstructed using little more than 180 degrees of data, while the high frequency part is reconstructed using all data. The resulting algorithm shows no cone-beam artifacts in a simulation of a 64-row scanner. It is further shown that the frequency split method hardly degrades the signal-to-noise ratio of the reconstructed images and that it behaves robustly in the presence of motion.

Distinct Functions of Vav1 in JNK1 Activation in Jurkat T Cells Versus Non-Haematopoietic Cells

Vav1, the 95-kDa protein encoded by the vav1 proto-oncogene, is expressed exclusively in haematopoietic cells, where it becomes phosphorylated on tyrosine residues in response to antigen receptor ligation. Vav1 was found to act as a Rac1-specific guanine nucleotide exchange factor and to activate c-Jun N-terminal kinase (JNK1) in vitro and in ectopic expression systems using non-haematopoietic cells. Here, we studied the role of Vav1 in JNK1 activation in T cells versus non-haematopoietic cells. Vav1 overexpression activated JNK1 in COS7 and 293T cells but not in Jurkat T lymphocytes. In contrast, constitutively activated Rac1 efficiently stimulated JNK1 in both cell types under the same conditions. Vav1 did function in T cells because it clearly stimulated the activity of a nuclear factor of activated T-cell reporter plasmid in the same cells. Moreover, Vav1 induction of JNK1 in T cells required coexpression with calcineurin. This cooperation was cell type specific because it was not observed in COS7 or 293T cells. In contrast, Vav1 did not cooperate with calcineurin to activate either extracellular signal-regulated kinase 2 or p38. These findings demonstrate that Vav1 alone is a poor activator of the JNK1 pathway in T cells and emphasize the importance of studying the physiological functions of Vav1 in haematopoietic cells.

Vav1/Rac-dependent actin cytoskeleton reorganization is required for lipid raft clustering in T cells

Formation of the immunological synapse (IS) in T cells involves large scale molecular movements that are mediated, at least in part, by reorganization of the actin cytoskeleton. Various signaling proteins accumulate at the IS and are localized in specialized membrane microdomains, known as lipid rafts. We have shown previously that lipid rafts cluster and localize at the IS in antigen-stimulated T cells. Here, we provide evidence that lipid raft polarization to the IS depends on an intracellular pathway that involves Vav1, Rac, and actin cytoskeleton reorganization. Thus, lipid rafts did not translocate to the IS in Vav1-deficient (Vav1-/-) T cells upon antigen stimulation. Similarly, T cell receptor transgenic Jurkat T cells also failed to translocate lipid rafts to the IS when transfected with dominant negative Vav1 mutants. Raft polarization induced by membrane-bound cholera toxin cross-linking was also abolished in Jurkat T cells expressing dominant negative Vav1 or Rac mutants and in cells treated with inhibitors of actin polymerization. However, Vav overexpression that induced F-actin polymerization failed to induce lipid rafts clustering. Therefore, Vav is necessary, but not sufficient, to regulate lipid rafts clustering and polarization at the IS, suggesting that additional signals are required.

Antigen-induced translocation of PKC-theta to membrane rafts is required for T cell activation

Protein kinase C-theta (PKC-theta) is essential for mature T cell activation; however, the mechanism by which it is recruited to the TCR signaling machinery is unknown. Here we show that T cell stimulation by antibodies or peptide-major histocompatibility complex (MHC) induces translocation of PKC-theta to membrane lipid rafts, which localize to the immunological synapse. Raft translocation was mediated by the PKC-theta regulatory domain and required Lck but not ZAP-70. In addition, PKC-theta was associated with Lck in the rafts. An isolated PKC-straight theta catalytic fragment did not partition into rafts or activate the transcription factor NF-kappa B, although addition of a Lck-derived raft-localization sequence restored these functions. Thus, physiological T cell activation translocates PKC-theta to rafts, which localize to the T cell synapse; this PKC-theta translocation is important for its function.

Vav2 activates c-fos serum response element and CD69 expression but negatively regulates nuclear factor of activated T cells and interleukin-2 gene activation in T lymphocyte

Vav1 and Vav2 are members of the Dbl family of guanine nucleotide exchange factors for the Rho family of small GTPases. Although the role of Vav1 during lymphocyte development and activation is well characterized, the function of Vav2 is still unclear. In this study, we compared the signaling pathways regulated by Vav1 and Vav2 following engagement of the T cell receptor (TCR). We show that Vav2 is tyrosine-phosphorylated upon TCR stimulation and by co-expressed Src and Syk family kinases. Using glutathione S-transferase fusion proteins, we observed that the Src homology 2 domain of Vav2 binds tyrosine-phosphorylated proteins from TCR-stimulated Jurkat T cell lysates, including c-Cbl and SLP-76. Like Vav1, Vav2 cooperated with TCR stimulation to increase extracellular signal-regulated kinase activation and to promote c-fos serum response element transcriptional activity. Moreover, both proteins displayed a similar action in increasing the expression of the early activation marker CD69 in Jurkat T cells. However, in contrast to Vav1, Vav2 dramatically suppressed TCR signals leading to nuclear factor of activated T cells (NF-AT)-dependent transcription and induction of the interleukin-2 promoter. Vav2 appears to act upstream of the phosphatase calcineurin because a constitutively active form of calcineurin rescued the effect of Vav2 by restoring TCR-induced NF-AT activation. Interestingly, the Dbl homology and Src homology 2 domains of Vav2 were necessary for its inhibitory effect on NF-AT activation and for induction of serum response element transcriptional activity. Taken together, our results indicate that Vav1 and Vav2 exert overlapping but nonidentical functions in T cells. The negative regulatory pathway elicited by Vav2 might play an important role in regulating lymphocyte activation processes.

Protein kinase C-theta mediates a selective T cell survival signal via phosphorylation of BAD

Protein kinase C (PKC)-activating phorbol esters protect T cells from Fas-induced apoptosis. However, the mechanism of this protective effect and the identity of the relevant PKC isoform(s) are poorly understood. Here, we show that PKCtheta plays a selective and important role in this protection. Fas triggering led to a selective caspase-3-dependent cleavage of the enzyme and proteasome-mediated degradation and inactivation of its catalytic fragment. These events preceded the onset of apoptosis. Pharmacological inhibition of PKCtheta promoted Fas-mediated apoptosis in three different types of T cells. Conversely, constitutively active PKCtheta (and, to a lesser degree, PKCepsilon) selectively protected T cells from Fas-induced apoptosis. We provide evidence that the distant Bcl-2 family member, BAD, is a PKCtheta substrate, is phosphorylated by TCR stimulation, and can mediate at least in part the anti-apoptotic effect of PKCtheta.

Vav-Rac1-mediated activation of the c-Jun N-terminal kinase/c-Jun/AP-1 pathway plays a major role in stimulation of the distal NFAT site in the interleukin-2 gene promoter

Vav, a hematopoiesis-specific signaling protein, plays an important role in T-cell development and activation. Vav upregulates the expression of the interleukin-2 (IL-2) gene, primarily via activation of the distal NFAT site in the IL-2 gene promoter (NFAT-IL-2). However, since this site cooperatively binds NFAT and AP-1, the relative contribution of Vav to NFAT versus AP-1 activation has not been determined. Here, we studied the respective roles of the AP-1 and NFAT pathways in the T-cell receptor (TCR)-mediated, Vav-dependent activation of NFAT-IL-2. Although Vav stimulated the transcriptional activity of an NFAT-IL-2 reporter gene, it failed to stimulate the transcriptional or DNA-binding activities of an AP-1-independent NFAT site derived from the human gamma interferon gene promoter. Vav also did not stimulate detectable Ca(2+) mobilization and nuclear translocation of NFATc or NFATp. On the other hand, Vav induced the activation of Rac1 or Cdc42 and c-Jun N-terminal kinase (JNK), enhanced the transcriptional and DNA-binding activities of AP-1, and induced increased phosphorylation of c-Jun. Dominant-negative Vav and/or Rac1 mutants blocked the TCR-mediated stimulation of these events, demonstrating the physiological relevance of these effects. Vav also associated with Rac1 or Cdc42 in T cells, and anti-CD3 antibody stimulation enhanced this association. These findings indicate that a Rac1-dependent JNK/c-Jun/AP-1 pathway, rather than the Ca(2+)/NFAT pathway, plays the predominant role in NFAT-IL-2 activation by Vav.

Spatial dependence of the phase in localized bioelectrical impedance analysis

The variety of phase functions, theta(z) = arctan X(z)/R(z), observed earlier on the thighs of healthy and seriously ill subjects via localized bioelectrical impedance analysis, can be represented by a model which combines realistic thigh shapes with homogeneous, axially symmetric conductivity tensors. While quantitative results depend sensitively on the way current is injected, it appears to be generally true that d theta/d(z) < 0 whenever phi(r) > phi(z) (and vice versa), where phi(r) and phi(z) are the phases of the radial and longitudinal conductivity components.

Membrane lipid microdomains and the role of PKCtheta in T cell activation

Productive T cell activation depends on the assembly of a highly ordered and compartmentalized immunological synapse or supramolecular activation complex (SMAC). Reorganization of the actin cytoskeleton and clustering of specialized membrane microdomains, or lipid rafts, occur early following TCR/CD3 and costimulatory receptor ligation. Many key signaling molecules localize in lipid raft patches during T cell activation. Lipid raft reorganization is required for T cell activation, where it plays an apparently important role in stabilizing the T cell synapse. Here we review recent evidence supporting the role of lipid rafts in T cell activation. Particular emphasis is placed on the coupling of protein kinase C-theta(PKCtheta), which is selectively expressed in T cells and is known to function as an essential signal for T cell activation, and lipid rafts.

Enhanced bud regeneration in aspen (Populus tremula L.) roots cultured in liquid media

 The regeneration potential of excised aspen (Populus tremula L.) roots cultivated in liquid medium, as affected by plant growth regulators and by the position of the isolated root explant on the main root, was investigated. The effect of various levels of benzyladenine (BA) and thidiazuron (TDZ) on bud regeneration in root explants was studied. TDZ in the medium had a marked effect on bud development as compared with BA, inducing a tenfold increase in the number of buds regenerated from various root explants. TDZ enhanced both root and root-borne shoot biomass production but reduced further shoot development and elongation. The position of the isolated root sections on the main root affected regeneration, the proximal sections further away from the root tip producing the highest number of buds per explant in both BA and TDZ treatments. Buds regenerated in close proximity to the site of lateral roots in BA-treated roots, while in TDZ-treated root sections, the buds formed all over the root regardless of the presence of lateral roots. The buds developed from inner cortical and sub-epidermal cell layers, disrupting the epidermis and the inner layers. Root biomass production and growth was greatly enhanced in well-aerated bioreactor culture in the presence of 4.5×10^-2 μM TDZ. A high number of the root-borne shoots could be rooted and converted to plantlets. However, while shoots regenerated in a medium with BA rooted well in a growth regulator-free medium, shoots formed in a medium with TDZ required auxin for rooting. Roots cultured in the presence of ancymidol, a gibberellin biosynthesis inhibitor, regenerated non-hyperhydric bud clusters and hyperhydric shoots. These were separated mechanically, subcultured to growth and rooting medium and transplanted ex vitro resulting in phenotypically true-to-type plantlets. The potential of liquid cultures for aspen shoot biomass production from roots is discussed.

Neoadjuvant hormonal ablative therapy before radical prostatectomy: a review. Is it indicated?

PURPOSE

Neoadjuvant hormonal ablation therapy has been used to decrease the rate of positive surgical margins in patients treated with radical prostatectomy. We reviewed the available literature to determine whether this therapy is indicated and beneficial.

MATERIALS AND METHODS

We performed a MEDLINE key word search and assessed randomized prospective articles. Data were analyzed for the rate of positive surgical margins, seminal vesicle invasion and lymph node metastasis as well as surgical characteristics, including operative time, blood loss, hospital stay, rate of complications and difficulty of surgical dissection. In addition, these data were evaluated for prostate specific antigen-free survival.

RESULTS

Neoadjuvant hormonal therapy decreased the rate of positive margins in 6 of the 7 randomized prospective studies. In none of 4 randomized prospective series was there an improved rate of seminal vesicle invasion with neoadjuvant hormonal therapy. Of 4 studies 3 showed no improvement in the rate of lymph node metastasis after neoadjuvant hormonal therapy compared with that in controls. Similarly there was no improvement in prostate specific antigen-free survival and no significant difference in operative time, operative blood loss, transfusion or hospital stay in patients treated with neoadjuvant hormonal therapy and controls. In addition, in 2 of 3 studies there was no difference in the complication rate.

CONCLUSIONS

Analysis of the available literature revealed no significant improvement in outcome to support the routine administration of neoadjuvant hormonal therapy before prostatectomy.

Protein kinase Ctheta: a new essential superstar on the T-cell stage

Recent studies have identified protein kinase C&theta; (PKCtheta), a member of the Ca(2+)-independent PKC family, as an essential component of the T-cell synapse that cooperates with calcineurin to activate the interleukin-2 (IL-2) gene. Several selective functions of PKCtheta involved in the activation and survival of T cells are reviewed herein. Among these, the nuclear factor-kappaB (NF-kappaB) signaling cascade appears to be the most critical target of PKCtheta in the T-cell receptor/CD28 costimulatory pathway that leads to T-cell activation.