Vortex formation with a snapping shrimp claw

Snapping shrimp use one oversized claw to generate a cavitating high speed water jet for hunting, defence and communication. This work is an experimental investigation about the jet generation. Snapping shrimp (Alpheus-bellulus) were investigated by using an enlarged transparent model reproducing the closure of the snapper claw. Flow inside the model was studied using both High-Speed Particle Image Velocimetry (HS-PIV) and flow visualization. During claw closure a channel-like cavity was formed between the plunger and the socket featuring a nozzle-type contour at the orifice. Closing the mechanism led to the formation of a leading vortex ring with a dimensionless formation number of approximate ΔT*≈4. This indicates that the claw might work at maximum efficiency, i.e. maximum vortex strength was achieved by a minimum of fluid volume ejected. The subsequent vortex cavitation with the formation of an axial reentrant jet is a reasonable explanation for the large penetration depth of the water jet. That snapping shrimp can reach with their claw-induced flow. Within such a cavitation process, an axial reentrant jet is generated in the hollow cylindrical core of the cavitated vortex that pushes the front further downstream and whose length can exceed the initial jet penetration depth by several times.

Characteristics of males infected with common Neisseria gonorrhoeae sequence types in the Gonococcal Isolate Surveillance Project, San Francisco, California, 2009

We analyzed 265 urethral Neisseria gonorrhoeae specimens collected from symptomatic males at San Francisco's municipal sexually transmitted disease clinic, a participant in the Gonococcal Isolate Surveillance Project, during 2009. We used N. gonorrhoeae multiantigen sequence typing to describe characteristics of patients infected with common sequence type families. Specimens were classified into 6 homology-based families and 1 additional family of all other identified strains. Strain family results were combined with results of culture-based antibiotic sensitivity minimum inhibitory concentration, sociodemographic and behavioral risk data collected at the clinic, and presence or absence of the mosaic penicillin-binding protein 2 (penA) allele. Characteristics of patients were compared across strain families through the use of χ(2) statistics. Among men who have sex with men, strain distribution differed by those reporting receptive oral sex as their only urethral exposure (P = 0.04), by number of sex partners (P = 0.03), and by race/ethnicity (P < 0.001); there were no differences by age or human immunodeficiency virus status. Also, among men who have sex with men, strain family distributions differed for culture specimens with reduced susceptibility to a range of antibiotics, as well as with presence of the mosaic penA allele (all P < 0.001). The combination of molecular, phenotypic, and epidemiologic data on N. gonorrhoeae infection could help develop a more complete epidemiology of gonorrhea in the United States.

Heterozygosity for an inactivating mutation in low-density lipoprotein-related receptor 6 (Lrp6) increases osteoarthritis severity in mice after ligament and meniscus injury

OBJECTIVE

Wnt/β-catenin signaling plays an integral and complex role in cartilage development and maintenance. β-catenin signaling has been linked to osteoarthritis (OA), but the role of Lrp6-mediated Wnt/β-catenin signaling during OA remains unexplored. Mutations in the Wnt/β-catenin co-receptors LRP5 and LRP6 (low-density lipoprotein-related receptors 5 and 6) result in skeletal abnormalities, which tend to be more severe in Lrp6 mutant mice. We examined OA development, chondrocyte and osteoblast behavior, and β-catenin signaling after ligament and meniscus damage in mice with global heterozygous deletion of Lrp6.

DESIGN

Ligament and meniscus damage was surgically induced in Lrp6(+/-) and wild-type (WT) mice, and evidence of joint disease was assessed by Microcomputed tomography (micro-CT) and histology. Wnt/β-catenin signaling, proliferation, apoptosis, chondrogenesis, osteogenesis, and catabolic enzyme activity were measured.

RESULTS

Relative to WT mice, Lrp6(+/-) mice had lower nuclear β-catenin signaling within articular cartilage. After surgery, osteophytes and reduced articular cartilage were apparent in WT mice, but more severe in Lrp6(+/-) animals. Impairments to trabecular bone geometry occurred for WT and Lrp6(+/-) mice after surgery. Relative to WT mice, Lrp6(+/-) mice had reduced trabecular BMD and thickness, and Cyclin D1 and Lrp6 gene expression after surgery. There was an increase in apoptotic cells and serum matrix metalloproteinase-9 (MMP9) for Lrp6(+/-) mice after surgery, but no differences in cell proliferation occurred.

CONCLUSIONS

Heterozygous loss-of-function mutation in Lrp6 leads to less β-catenin signaling within articular cartilage and to increased degenerative joint disease after ligament and meniscus injury. Modulation of Lrp6 function could attenuate joint disease after damage to ligaments and the meniscus.

Abstract 3324: Cyclooxygenase-2 mediated breast cancer progression by induction of stem like cells and micro RNA

We established that elevated COX-2 expression by human and murine breast cancer cells promotes tumor progression and metastasis via multiple mechanisms primarily due to activation of the PGE-2 receptor EP4. COX-2 and HER-2, often co-expressed in human breast cancer, are both major determinants of cancer progression. Many of the HER-2 actions were shown to be COX-2 dependent, but the roles of COX-2 in the absence or presence of HER-2 in breast cancer initiation and sustenance remain unclear. To define these roles, we examined the consequences of introducing COX-2 gene into COX-2-ve, HER-2-ve, ER+ve, non-metastatic MCF-7 and COX-2-ve, ER-ve, HER-2-over-expressing SK-BR-3 human breast cancer cell lines. After stable integration of COX-2 cDNA, these two cell lines were named MCF-7-COX-2 and SKBR3-COX-2. When compared with their empty vector-transfected counterparts, they showed (1) epithelial-mesenchymal transition (down regulation of E Cadherin and up regulation Vimentin by qRT-PCR), (2) higher proliferative activity (BrdU uptake), (3) higher migratory and invasive abilities across microporous membranes (8μM pore size) in Boyden chambers, (4) upregulation of EP4 and angiogenic and lymphangiogenic factors VEGF-A, C and D (qRT PCR and western blot), (5) markedly increased stem like cell populations in vitro (spheroid forming ability of single cells in ultra-low attachment plates for successive generations) and an increase in ALDH activity (flow cytometry). (6) Above changes could be abrogated with specific COX-2 inhibitor NS-398 (Pfizer) or an EP4 antagonist ONO-AE3-208 (ONO Pharmaceuticals, Japan) at non toxic concentrations, indicating that all these functions are dependent on COX-2 and EP4 activity. (7) Intravenous injection of MCF-7-COX2 cells into immuno-deficient mice revealed a dramatic increase in their lung colony forming capacity at 4-6 weeks, as compared to empty vector-transfected cells. (8) Using differential gene and micro-RNA (miRNA) arrays we identified two miRNAs upregulated and their target fourteen tumor-suppressor like genes down-regulated by introducing COX-2 into MCF-7 cells. (9) We observed a positive co-relation between the miRNA and COX-2 expression in multiple COX-2 disparate cell lines, in which expression of miRNAs was inhibited by treatment with COX-2 inhibitors or EP4 antagonists. Current studies are testing the functions of the miRNAs by knockdown and knock-in studies, and utilizing human breast cancer tissues to explore the clinical relevance of these findings. Our model system allowing identification and characterization of COX-2 induced stem like cells in breast cancer should help defining COX-2 and EP4 mediated pathways controlling their biology and utilization of the novel miRNA markers for prognostic and therapeutic applications in the clinic. (Supported by the CBCF, Ontario Chapter and the OICR funds from the Government of Ontario to PKL).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3324. doi:1538-7445.AM2012-3324

2-De-oxy-α-d-arabino-hexopyran-ose

The title compound, C₆H₁₂O₅, is the α-pyran­ose form of the reducing aldose 2-de­oxy-d-arabino-hexose. The six-membered pyran­ose ring adopts a ⁴C₁ conformation, with the anomeric hy­droxy group in axial and the other substituents in equatorial positions. In the crystal, each of the four hy­droxy groups acts as an inter­molecular hydrogen-bond donor function, resulting in a three-dimensional hydrogen-bonded network.

Phenylboronic acid esters of the common 2-deoxy-aldoses

Phenylboronic acid esters are formed by the three common 2-deoxy aldoses: 2-deoxy-d-erythro-pentose ('2-deoxy-d-ribose'), 2-deoxy-d-lyxo-hexose ('2-deoxy-d-galactose'), and 2-deoxy-d-arabino-hexose ('2-deoxy-d-glucose'). The major species that was formed from equimolar quantities of boronic acid and the aldose, was the 3,4-monoester of the pentopyranose in a skew-boat conformation, and the 4,6-monoester in the case of the two hexopyranoses. A double molar quantity of boronic acid led, for both 2-deoxy-hexoses, to the diester of the open-chain aldehydo isomer as the major product: the 3,5:4,6-diester for the lyxo-configured deoxy-hexose, and the 3,4:5,6-diester of the arabino-configured isomer. Minor products of all reactions were identified by a combined NMR/DFT methodology.

Multiscale Simulations of Brittle Fracture and the Quantum-Mechanical Nature of Bonding in Silicon

We simulate the microscopic details of brittle fracture in silicon by dynamically coupling empirical-potential molecular dynamics of a strained sample to a quantum-mechanical description of interatomic bonding at the crack tip. Our simulations show brittle fracture at loads comparable to experiment, in contrast with empirical potential simulations that show only ductile crack propagation at much higher loading. While the ductility of the empirical potentials can be attributed to their short range, it is unclear whether the increased range of the tight-binding description is sufficient to explain its brittle behavior. Using the multiscale method we show that at a temperature of 1100 K, but not at 900 K, a dislocation is sometimes nucleated when the crack tip impinges on a vacancy. While this result is too limited in length and time scales to directly correspond to experimental observations, it is suggestive of the experimentally observed brittle to ductile transition.

Quantitative analysis of fitness and genetic interactions in yeast on a genome scale

Global quantitative analysis of genetic interactions is a powerful approach for deciphering the roles of genes and mapping functional relationships among pathways. Using colony size as a proxy for fitness, we developed a method for measuring fitness-based genetic interactions from high-density arrays of yeast double mutants generated by synthetic genetic array (SGA) analysis. We identified several experimental sources of systematic variation and developed normalization strategies to obtain accurate single- and double-mutant fitness measurements, which rival the accuracy of other high-resolution studies. We applied the SGA score to examine the relationship between physical and genetic interaction networks, and we found that positive genetic interactions connect across functionally distinct protein complexes revealing a network of genetic suppression among loss-of-function alleles.

Estradiol suppresses tissue androgens and prostate cancer growth in castration resistant prostate cancer

Background

Estrogens suppress tumor growth in prostate cancer which progresses despite anorchid serum androgen levels, termed castration resistant prostate cancers (CRPC), although the mechanisms are unclear. We hypothesize that estrogen inhibits CRPC in anorchid animals by suppressing tumoral androgens, an effect independent of the estrogen receptor.

Methods

The human CRPC xenograft LuCaP 35V was implanted into orchiectomized male SCID mice and established tumors were treated with placebo, 17β-estradiol or 17β-estradiol and estrogen receptor antagonist ICI 182,780. Effects of 17β-estradiol on tumor growth were evaluated and tissue testosterone (T) and dihydrotestosterone (DHT) evaluated by mass spectrometry.

Results

Treatment of LuCaP 35V with 17β-estradiol slowed tumor growth compared to controls (tumor volume at day 21: 785 ± 81 mm³ vs. 1195 ± 84 mm³, p = 0.002). Survival was also significantly improved in animals treated with 17β-estradiol (p = 0.03). The addition of the estrogen receptor antagonist ICI 182,780 did not significantly change survival or growth. 17β-estradiol in the presence and absence of ICI 182,780 suppressed tumor testosterone (T) and dihydrotestosterone (DHT) as assayed by mass spectrometry. Tissue androgens in placebo treated LuCaP 35V xenografts were; T = 0.71 ± 0.28 pg/mg and DHT = 1.73 ± 0.36 pg/mg. In 17β-estradiol treated LuCaP35V xenografts the tissue androgens were, T = 0.20 ± 0.10 pg/mg and DHT = 0.15 ± 0.15 pg/mg, (p < 0.001 vs. controls). Levels of T and DHT in control liver tissue were < 0.2 pg/mg.

Conclusions

CRPC in anorchid animals maintains tumoral androgen levels despite castration. 17β-estradiol significantly suppressed tumor T and DHT and inhibits growth of CRPC in an estrogen receptor independent manner. The ability to manipulate tumoral androgens will be critical in the development and testing of agents targeting CRPC through tissue steroidogenesis.

Low-Dose Fulvestrant Maintained Long-Term Complete Remission after Poor Response to Previous Endocrine Therapies in a Patient with Advanced Breast Cancer

We report a case of long-term (9 years) response to 4th-line endocrine treatment with fulvestrant given for advanced breast cancer after no or poor response to prior endocrine therapies. Complete remission was achieved with full dose and maintained even after dose reduction due to unanticipated intensity of mucosal toxicity. Complete remission was temporarily lost after fulvestrant was tentatively withdrawn (63 months after treatment start), but was re-achieved after renewal of half-dose treatment and last reconfirmed 90 months after treatment start. The pharmacokinetic profile provides evidence to hypothesize a unique sensitivity to fulvestrant in this patient which might explain both: toxicity and extraordinary efficacy.

PKB/AKT phosphorylation of the transcription factor Twist-1 at Ser42 inhibits p53 activity in response to DNA damage

Protein kinase B (PKB/Akt) is ubiquitously expressed in cells. Phosphorylation of its multiple targets in response to various stimuli, including growth factors or cytokines, promotes cell survival and inhibits apoptosis. PKB is upregulated in many different cancers and a significant amount of the enzyme is present in its activated form. Here we show that PKB phosphorylates one of the anti-apoptotic proteins--transcription factor Twist-1 at Ser42. Cells expressing Twist-1 displayed inefficient p53 upregulation in response to DNA damage induced by gamma-irradiation or the genotoxic drug adriamycin. This influenced the activation of p53 target genes such as p21(Waf1) and Bax and led to aberrant cell-cycle regulation and the inhibition of apoptosis. The impaired induction of these p53 effector molecules is likely to be mediated by PKB-dependent phosphorylation of Twist-1 because, unlike the wild-type mutant, the Twist-1 S42A mutant did not confer cell resistance to DNA damage. Moreover, phosphorylation of Twist-1 at Ser42 was shown in vivo in various human cancer tissues, suggesting that this post-translational modification ensures functional activation of Twist-1 after promotion of survival during carcinogenesis.

Antiangiogenic drugs in oncology: a focus on drug safety and the elderly - a mini-review

Angiogenesis is essential for normal tissue and even more so for solid malignancies. At present, inhibition of tumor angiogenesis is a major focus of anticancer drug development. Bevacizumab, a humanized antibody against VEGF, was the first antiangiogenic agent to be approved for advanced non-small cell lung cancer, breast cancer and colorectal cancer. The most commonly observed adverse events are hypertension, proteinuria, bleeding and thrombosis. Sunitinib, a small molecule blocking intracellular VEGF, KIT, Flt3 and PDGF receptors, which regulate angiogenesis and cell growth, is approved for the treatment of advanced renal cell cancer (RCC) and malignant gastrointestinal stromal tumor. The most frequent adverse events include hand-foot syndrome, stomatitis, diarrhea, fatigue, hypothyroidism and hypertension. Sorafenib, an oral multikinase inhibitor, is approved for the second-line treatment of advanced RCC and upfront treatment of advanced hepatocellular carcinoma. Most common adverse events with sorafenib are dermatologic (hand-foot skin reaction, rash, desquamation), fatigue, diarrhea, nausea, hypothyroidism and hypertension. More recently, cardiovascular toxicity has increasingly been recognized as a potential adverse event associated with sunitinib and sorafenib treatment. Elderly patients are at increased risk of thromboembolic events when receiving bevacizumab, and potentially for cardiac dysfunction when receiving sunitinib or sorafenib. The safety of antiangiogenic drugs is of special concern when taking these agents for longer-term adjuvant or maintenance treatment. Furthermore, newer investigational antiangiogenic drugs are briefly reviewed.

Phase Ib study of weekly mammalian target of rapamycin inhibitor ridaforolimus (AP23573; MK-8669) with weekly paclitaxel

BACKGROUND

The additive cytotoxicity in vitro prompted a clinical study evaluating the non-prodrug rapamycin analogue ridaforolimus (AP23573; MK-8669; formerly deforolimus) administered i.v. combined with paclitaxel (PTX; Taxol).

MATERIALS AND METHODS

Patients with taxane-sensitive solid tumors were eligible. The main dose escalation foresaw 50% ridaforolimus increments from 25 mg with a fixed PTX dose of 80 mg/m(2), both given weekly 3 weeks in a 4-week cycle. Collateral levels with a lower dose of either drug were planned upon achievement of the maximum tolerated dose in the main escalation. Pharmacodynamic studies in plasma, peripheral blood mononuclear cells (PBMCs) and skin biopsies and pharmacokinetic (PK) interaction studies at cycles 1 and 2 were carried out.

RESULTS

Two recommended doses were determined: 37.5 mg ridaforolimus/60 mg/m(2) PTX and 12.5 mg/80 mg/m(2). Most frequent toxic effects were mouth sores (79%), anemia (79%), fatigue (59%), neutropenia (55%) and dermatitis (48%). Two partial responses were observed in pharyngeal squamous cell and pancreatic carcinoma. Eight patients achieved stable disease > or =4 months. No drug interaction emerged from PK studies. Decrease of eukaryotic initiation factor 4E-binding protein1 (4E-BP1) phosphorylation was shown in PBMCs. Similar inhibition of phosphorylation of 4E-BP1 and mitogen-activated protein kinase was present in reparative epidermis and vascular tissues, respectively.

CONCLUSION

Potential antiangiogenic effects and encouraging antitumor activity justify further development of the combination.

Clinical development of namitecan (ST1968), a novel camptothecin derivative with high antitumor activity: Phase I clinical data

2570

Background: Namitecan is a new water-soluble camptothecin analogue which showed high antitumor activity in preclinical models. Aim of this trial was to determine safety, PK profile and activity in adult patients with advanced solid tumors. Methods: The dose escalation started at 2.5 mg i.v. on days 1 and 8 of a 21 day cycle (D1, D8 Q21D) and increased according to 3+3 cohort design depending on the observed toxicity. Dose limiting toxicity (DLT) definitions were: ANC <0.5x109/L for >5 days; PLT ≥ Grade 3 (CTC V3); grade ≥2 liver/renal toxicity not recovered by D22; any non-hematologic toxicity ≥ Grade 3; D8 dose skipping due to toxicity. Maximum tolerated dose (MTD) and recommended dose (RD) were the primary end-points. Blood and urine samples were collected at cycle 1 for PK evaluation. Results: 31 pts (11 endometrial ca., 5 CRC, 5 ovarian ca., 2 NSCLC, 8 other) have been included, with 6 dose levels evaluated (2.5; 5; 10; 15; 17.5 and 20 mg). 17.5 mg was introduced later when 2/7 DLTs at 20 mg were observed (ANC G4>5days, one with D8 skipping). At 17.5mg 2/4 pts experienced DLTs (ANC G4; D8 skipped). Uncomplicated neutropenia and thrombocytopenia were the most relevant G3/4 hematological toxicities. Other toxicities were mild or moderate asthenia, fatigue and alopecia. The MTD was defined at 17.5 mg and the RD was 15 mg. Stable disease ≥ 6 cycles was recorded in 6 pts (2 stable diseases ≥ 10 cycles). PK was linear and data suggest an entero-hepatic recirculation. No metabolites were found in plasma and the product resulted poorly excreted into urine. Conclusions: The MTD and RD of D1, D8 Q21D schedule have been identified. The study will continue with the evaluation of MTD and RD of a single administration per cycle (D1 Q21D), to optimize the schedule of treatment.

[Table: see text]

PML tumor suppressor is regulated by HIPK2-mediated phosphorylation in response to DNA damage

The promyelocytic leukemia (PML) tumor suppressor protein, a central regulator of cell proliferation and apoptosis, is frequently fused to the retinoic acid receptor-alpha (RARalpha) in acute PML. Here we show the interaction of PML with another tumor suppressor protein, the serine/threonine kinase homeodomain-interacting protein kinase (HIPK2). In response to DNA damage, HIPK2 phosphorylates PML at serines 8 and 38. Although HIPK2-mediated phosphorylation of PML occurs early during the DNA damage response, the oncogenic PML-RARalpha fusion protein is phosphorylated with significantly delayed kinetics. DNA damage or HIPK2 expression leads to the stabilization of PML and PML-RARalpha proteins. The N-terminal phosphorylation sites contribute to the DNA damage-induced PML SUMOylation and are required for the ability of PML to cooperate with HIPK2 for the induction of cell death.

Pin1 interacts with c-Myb in a phosphorylation-dependent manner and regulates its transactivation activity

Activity and stability of the proto-oncogene c-Myb are regulated by post-translational modifications, though the molecular mechanisms underlying such control are only partially understood. Here we describe the functional interaction of c-Myb with Pin1, an isomerase that binds to phosphorylated Ser/Thr-Pro motifs. We found that co-expression of c-Myb and Pin1 led to a net increase of c-Myb transactivation activity, both on reporter constructs as well as on an endogenous target gene. DNA-binding studies revealed that Pin1 did not increase the association of c-Myb with its response element in DNA. The increase of c-Myb transactivation activity was strictly dependent on the presence of an active catalytic center in Pin1. We provide evidence that c-Myb and Pin1 physically interacted, both upon ectopic expression of the proteins in HEK-293 cells as well as in the more physiological setting of HL60 cells, where c-Myb and Pin1 are resident proteins. By point mutating each individual Ser/Thr-Pro motif in c-Myb as well as by using deletion mutants we show that S528 in the EVES-motif was the docking site for Pin1. Mass spectrometry confirmed that S528 is phosphorylated in vivo. Finally, functional studies showed that mutation of S528 to alanine almost abolished the increase of transactivation activity by Pin1. This study reveals a new paradigm by which phosphorylation controls c-Myb function.

Phase 1b study defining the optimal dosing combinations of the mTOR inhibitor AP23573 and Paclitaxel (PTX)

3509

Background: AP23573 is a novel mTOR inhibitor with demonstrated anti-tumor activity in clinical trials. In vitro, AP23573 exhibits at least additive anti-proliferative activity in combination with a variety of agents including taxanes. This trial studied the combination of AP23573 and paclitaxel (PTX) in patients with advanced solid tumors. Methods: This was a modified, sequential (3+3) dose finding study with starting doses of 25 mg AP23573 i.v. and 80 mg/m2 PTX i.v. as Dose Level 1 (DL1) on days 1, 8 and 15 of a 28 day cycle. Doses of either drug were adjusted in successive cohorts. Blood samples and skin biopsies were collected for pharmacokinetic (PK) and pharmacodynamic (PD) studies. Dose limiting toxicity definitions included neutrophils <500/μL; thrombocytopenia = Grade 3 (CTC), any non- hematologic toxicities = Grade 2; missing 2 consecutive doses due to any toxicity. For PK and PD analysis, AP23573 and PTX were administered one day apart at the start of Cycle 1, reversing the sequence at Day 8. Results: Enrollment is complete and 29 patients with a variety of tumors (sarcoma, pancreatic, H&N, melanoma, thymoma) have been treated. Grade 3 thrombocytopenia and Grade 2 mouth sores were seen at DL1 as well as missed doses due to moderate (Grade 2) neutropenia. Adverse events include mouth sores and fatigue which were mild and reversible. Available PK data for AP23573 and PTX suggest no interaction. PD analysis in peripheral blood mononuclear cells demonstrates no interference by PTX on mTOR inhibition by AP23573. PD data in skin biopsies are forthcoming. Both 12.5 mg AP23573/80mg/m2 PTX and 37.5mg AP23573/60mg/m2 PTX are maximal dose combinations that appear to be well tolerated. Activity has been observed at multiple AP23573 mg/PTX mg/m2 dose levels (25/60, 12.5/80, 25/80). Five patients have been on study for >4 cycles, including 2 patients with partial responses (H&N and pancreatic). Conclusions: Combined therapy with AP23573 and PTX is safe. It is notable that evidence of anti-tumor activity was observed at modest doses of each drug when in combination. Combinations of these agents at both doses cited would be recommended for evaluation in trials examining efficacy in specific tumors.

No significant financial relationships to disclose.

Understanding help seeking behaviour among male offenders: qualitative interview study

OBJECTIVE

To explore the factors that influence help seeking for mental distress by offenders.

DESIGN

Qualitative study based on in-depth interviews with prisoners before and after release.

SETTING

One category B local prison in southern England.

PARTICIPANTS

35 male offenders aged 18-52, a quarter of whom had been flagged as being at risk of self harm.

RESULTS

Most respondents reported that they would not seek help from a general practitioner or other healthcare professional if experiencing mental distress. When followed up after release, none had sought medical help despite the fact that many had considerable emotional problems. Many participants were hesitant to seek help because they feared being given a formal diagnosis of mental illness. Some of these men feared the stigma that such a diagnosis would bring, whereas others feared that a diagnosis would mean having to confront the problem. Lack of trust emerged as the most prominent theme in prisoners' discourse about not seeking help from health professionals. Distrust towards the "system" and authority figures in general was linked to adverse childhood experiences. Distrust directed specifically at healthcare professionals was often expressed as specific negative beliefs: many perceived that health professionals (most often doctors) "just don't care," "just want to medicate," and treat patients "superficially." Those men who would consider going to a general practitioner reported positive previous experiences of being respected and listened to.

CONCLUSIONS

Distrust is a major barrier to accessing health care among offenders. Like most people, the respondents in this study wanted to feel listened to, acknowledged, and treated as individuals by health professionals. By ensuring that a positive precedent is set, particularly for sceptical groups such as ex-prisoners, general practitioners and prison doctors may be able to encourage future help seeking. Information specifically designed for prisoners is needed to help to de-stigmatise mental illness, and preparation for release should include provision of information about access to health and social services. Awareness training for health professionals is recommended: trust might be fostered in this population by seemingly trivial gestures that indicate respect.

Concerted escalation of dose and dosing duration in a phase I study of the oral camptothecin gimatecan (ST1481) in patients with advanced solid tumors

BACKGROUND

Gimatecan is an orally bioavailable camptothecin analogue with preclinical findings of promising antitumor activity. A phase I design of concerted dose escalation and dosing duration was implemented to assess the potential schedule dependency of tolerability that emerged from animal studies.

PATIENTS AND METHODS

Gimatecan was given daily for five consecutive days per week for 1, 2 or 3 weeks every 28 days. Plasma levels of total gimatecan were measured on the first and the last day of treatment in each schedule.

RESULTS

Overall, 108 patients were treated with 0.8-7.2 mg/m(2) of gimatecan per cycle. The main toxicity was myelosuppression with dose-limiting thrombocytopenia. In the 1-, 2- and 3-week schedule, the maximum tolerated doses were 4.5, 5.6 and 6.4 mg/m(2). Diarrhea and asthenia were of low grade and of minor clinical relevance, while the higher incidence of nausea and vomiting in the 1-week schedule required the use of antiemetic prophylaxis. Due to the prolonged half-life (approximately 77 h), the plasma concentration of gimatecan increased from the first to the last day of dosing. Six partial responses were observed.

CONCLUSIONS

Tolerability of gimatecan was schedule dependent. Further testing with schedules taking into account its long persistence in human plasma is worthwhile.

Optimizing the efficiency of high-field multivoxel spectroscopic imaging by multiplexing in space and time

A new strategy to yield information from the maximum number of voxels, each at the optimum signal-to-noise ratio (SNR) per unit time, in MR spectroscopic imaging (MRSI) is introduced. In the past, maximum acquisition duty-cycle was obtained by multiplexing in time several single slices each repetition time (TR), while optimal SNR was achieved by encoding the entire volume of interest (VOI) each TR. We show that optimal SNR and acquisition efficiency can both be achieved simultaneously by multiplexing in space and time several slabs of several slices, each. Since coverage of common VOIs in 3D proton MRSI in the human brain typically requires eight or more slices, at 3 T or higher magnetic fields, two or more slabs can fit into the optimum TR (approximately 1.6 s). Since typically four or less slices would then fit into each slab, Hadamard encoding is favored in that direction for slice profile reasons. It is demonstrated that per fixed examination length, the new method gives, at 3 T, twice as many voxels, each of the same SNR and size, compared with current 3D chemical shift imaging techniques. It is shown that this gain will increase for more extensive spatial coverage or higher fields.

A phase II trial of the novel oral camptothecin gimatecan (G) in women with anthracycline (A) and taxane (T) pre-treated advanced breast cancer

662

Background: Gimatecan (G) is a new oral camptothecin with a favourable therapeutic index in several tumor xenograft models and with documented antitumor activity in breast, endometrial and NSCLC cancer in Phase I. A Phase II trial was implemented to determine the antitumor activity of G in women with pre-treated metastatic breast cancer (MBC). Methods: A Simon 2-step design was used: patients with MBC who failed A & T were eligible. Treatment failure was defined as disease progressing after receiving both A and T (adjuvant or metastatic setting). All patients had ECOG 0–1. Baseline neuropathy > gr 1 or CNS metastases were criteria of exclusion. G was administered for 5 days every week on weeks 1 & 2 q4weeks at 4–5 mg/m2 total dose per cycle. Results: To date, 21 patients have received 67 cycles of G (median 3); 18 are evaluable for the 1st step analysis. Median age was 53 years (range, 32–70), all had received A & T prior treatment. The initial dose of 5 mg/m2 was reduced to 4 mg/m2 after treating the first 7 cases due to hematological toxicity (thrombocytopenia G3 30% and neutropenia G3–4 40%) that prevented the planned monthly retreatment. The toxicity at 4 mg/m2 included thrombocytopenia (% of cycles with any grade: 36%, G3 9%); neutropenia (G3 18%), diarrhea (1 case), nausea (81%, G3 18%), vomiting (G1 18%), and asthenia (G1 36%). To date, three confirmed partial responses (PR) lasting respectively 5.5, 5.7+, and 9.4+ months and two unconfirmed PR were observed in visceral and nodal sites. Accrual into step 2 is proceeding. Conclusions: Gimatecan at a dose of 4 mg/m2 is well tolerated and active. The antitumor activity of 27% observed in the first step of the study is unusual for camptothecins and prompted to continue to the second step and complete the ongoing enrolment of 43 patients overall.

[Table: see text]

Caveolin-1 interacts with the chaperone complex TCP-1 and modulates its protein folding activity

We report that caveolin-1, one of the major structural protein of caveolae, interacts with TCP-1, a hetero-oligomeric chaperone complex present in all eukaryotic cells that contributes mainly to the folding of actin and tubulin. The caveolin-TCP-1 interaction entails the first 32 amino acids of the N-terminal segment of caveolin. Our data show that caveolin-1 expression is needed for the induction of TCP-1 actin folding function in response to insulin stimulation. Caveolin-1 phosphorylation at tyrosine residue 14 induces the dissociation of caveolin-1 from TCP-1 and activates actin folding. We show that the mechanism by which caveolin-1 modulates TCP-1 activity is indirect and involves the cytoskeleton linker filamin. Filamin is known to bind caveolin-1 and to function as a negative regulator of insulin-mediated signaling. Our data support the notion that the caveolin-filamin interaction contributes to restore insulin-mediated phosphorylation of caveolin, thus allowing the release of active TCP-1.

Dose-finding study of weekly docetaxel, anthracyclines plus fluoropyrimidines as first-line treatment in advanced breast cancer

BACKGROUND

The efficacy and safety of prolonged fluoropyrimidines, either intravenously or orally, prompted their integration with taxanes and anthracyclines in the treatment of advanced breast cancer (ABC). We conducted three subsequent dose-finding studies on first-line chemotherapy in ABC with anthracyclines, either epirubicin (E) or doxorubicin (A), and docetaxel (T), both given on days 1 and 8 every 3 weeks, plus continuous infusion (CI) 5-fluorouracil (F) or capecitabine (X).

PATIENTS AND METHODS

Sixty-two patients (37% dominant visceral disease, 48% locally advanced disease, 45% two or more sites involved), received different doses of T (60--80 mg/m(2)), A (40--50 mg/m(2)) or E (60--90 mg/m(2)) and X (1,650 and 2,000 mg/m(2)), or CI F at a fixed daily dose of 200 mg/m(2). Cardiac function was monitored at baseline and then every four cycles by echocardiography.

RESULTS

The median number of cycles per patient with all regimens was four (range one to eight). Haematological and gastrointestinal toxicity defined the maximum tolerated doses, at T-80/E-90 mg/m(2) with TEF, T-70/A50/X-2,000 mg/m(2) with TAX and T-70/E-80/X-1,650 mg/m(2) with TEX. Two patients treated with TEF developed transient cardiac toxicity (dilatative cardiomyopathy and coronary subtotal stenosis requiring stenting) after cumulative E doses of 400 mg and 1,100 mg/m(2), respectively. Fifty-nine patients were evaluable for response; the overall response rates (ORR) were comparable between regimens (54% with TEF, 71% with TAX and 86% with TEX), with an 81% ORR in 31 patients with locally advanced disease.

CONCLUSIONS

The addition of fluoropyrimidines to weekly, intermittent ET is well tolerated and active in ABC.

Carotid endarterectomy--An evidence-based review: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology

OBJECTIVE

To assess the efficacy of carotid endarterectomy for stroke prevention in asymptomatic and symptomatic patients with internal carotid artery stenosis. Additional clinical scenarios, such as use of endarterectomy combined with cardiac surgery, are also reviewed.

METHODS

The authors selected nine important clinical questions. A systematic search was performed for articles from 1990 (the year of the last statement) until 2001. Additional articles from 2002 through 2004 were included using prespecified criteria. Two reviewers also screened for other relevant articles from 2002 to 2004. Case reports, review articles, technical studies, and single surgeon case series were excluded.

RESULTS

For several questions, high quality randomized clinical trials had been completed. Carotid endarterectomy reduces the stroke risk compared to medical therapy alone for patients with 70 to 99% symptomatic stenosis (16% absolute risk reduction at 5 years). There is a smaller benefit for patients with 50 to 69% symptomatic stenosis (absolute risk reduction 4.6% at 5 years). There is a small benefit for asymptomatic patients with 60 to 99% stenosis if the perioperative complication rate is low. Aspirin in a dose of 81 to 325 mg per day is preferred vs higher doses (650 to 1,300 mg per day) in patients undergoing endarterectomy.

CONCLUSIONS

Evidence supports carotid endarterectomy for severe (70 to 99%) symptomatic stenosis (Level A). Endarterectomy is moderately useful for symptomatic patients with 50 to 69% stenosis (Level B) and not indicated for symptomatic patients with <50% stenosis (Level A). For asymptomatic patients with 60 to 99% stenosis, the benefit/risk ratio is smaller compared to symptomatic patients and individual decisions must be made. Endarterectomy can reduce the future stroke rate if the perioperative stroke/death rate is kept low (<3%) (Level A). Low dose aspirin (81 to 325 mg) is preferred for patients before and after carotid endarterectomy to reduce the rate of stroke, myocardial infarction, and death (Level A).