Phase II study of the histone deacetylase inhibitor belinostat in thymic malignancies

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Background: Thymic malignancies are rare tumors. Chemotherapy is used for advanced disease. There is no established role of second-line therapy in patients with refractory or recurrent disease. Belinostat is an HDAC inhibitor with activity in cutaneous and peripheral T cell lymphoma and is being investigated in several solid tumors. One prolonged minor response (31 m) was seen in a phase I study of this agent in a patient with thymoma. Methods: Patients with recurrent thymoma or thymic carcinoma, progressing after platinum-based chemotherapy were eligible. They were also required to have measurable disease, PS 0–2 and normal organ functions. Belinostat was given iv at 1.0 g/m2 on days 1–5 of a 21-day cycle until disease progression or intolerable side effects. Correlative markers of activity in blood and tumor were performed. Results: From December 07 to December 08, 22 patients have been accrued from 2 institutions; 12 patients were males, median age 52 (23–72), 14 thymomas and 8 thymic carcinomas, mean number of prior regimens 3.5 (1–10), 16 prior tumor resection and 3 myasthenia gravis. A median of 4 cycles have been given (1–15+). Treatment was well tolerated, with nausea being the most common side effect and well controlled with prophylactic antiemetics. 21 patients are evaluable for response: 2 had a partial response (9+, 9+ m), 13 stable disease (3–11+ m) and 6 progression. No responses were seen in 8 evaluable patients with thymic carcinomas. Acetylated lysine and tubulin were analyzed in lymphocytes and monocytes by multiparameter flow cytometry. An increase of protein acetylation (2–10 fold) over baseline was observed at 1 hour post-infusion on day 3 of the first cycle in all patients analyzed. Other correlative markers are being investigated. Conclusions: The thymoma cohort has been expanded to the second stage of the study. Belinostat has activity in patients with recurrent or refractory thymoma.

No significant financial relationships to disclose.

A biological sub-micron thickness optical broadband reflector characterized using both light and microwaves

Broadband optical reflectors generally function through coherent scattering from systems comprising one of three designs: overlapped; chirped; or chaotic multilayer reflectors. For each, the requirement to scatter a broad band of wavelengths is met through the presence of a variation in nanostructural periodicity running perpendicular to the systems' outer surfaces. Consequently, the requisite total thickness of the multilayer can often be in excess of 50 mum. Here, we report the discovery and the microwave-assisted characterization of a natural system that achieves excellent optical broadband reflectivity but that is less than 1 mum thick. This system, found on the wing scales of the butterfly Argyrophorus argenteus, comprises a distinctive variation in periodicity that runs parallel to the reflecting surface, rather than perpendicular to it. In this way, the requirement for an extensively thick system is removed.

Dilatation in the femoral vascular bed does not cause retrograde relaxation of the iliac artery in the anaesthetized pig

AIM

We tested the hypothesis that dilatation of a feeding artery may be elicited by transmission of a signal through the tissue of the arterial wall from a vasodilated peripheral vascular bed.

METHODS

In eight pentobarbital anaesthetized pigs, acetylcholine (ACh, an endothelium-dependent vasodilator) was injected intra-arterially above (upstream) and below (downstream) a test segment of the left iliac artery, the diameter of which was measured continuously by sonomicrometry.

RESULTS

Under control conditions, ACh injections upstream and downstream of the test segment caused dilatation. Downstream injection dilated the peripheral arterioles, resulting in increased blood flow and proximal dilatation. This is a shear stress, nitric oxide (NO)-dependent response. The experiment was then repeated after applying a stenosis to prevent the increased flow caused by downstream injection of ACh; the stenosis was placed either above the site of diameter measurement to allow retrograde conduction, or below that site to prevent distally injected ACh reaching the measurement site. Under these conditions, downstream injection of ACh had a minimal effect on the shear stress of the test segment with no increase in test segment diameter. This was not due to endothelial damage or dysfunction as injection of ACh upstream still caused a large increase in test segment diameter.

CONCLUSIONS

Our results indicate that dilatation of the feeding artery of a vasodilated bed is caused by increased shear stress within the feeding artery and not via a signal transmitted through the arterial wall from below.

Geographic prevalence and multilevel determination of community-level factors associated with herpes simplex virus type 2 infection in Chennai, India

Herpes simplex virus type 2 (HSV-2) is one of the most prevalent sexually transmitted infections, and it increases the risk of transmission of human immunodeficiency virus type 1 at least twofold. Individual-level factors are insufficient to explain geographic and population variation in HSV-2, suggesting the need to identify ecologic factors. The authors sought to determine the geographic prevalence and community-level factors associated with HSV-2 after controlling for individual-level factors among slums in Chennai, India. From March to June 2001, participants aged 18-40 years voluntarily completed a survey and were tested for HSV-2. Community characteristics were assessed through interviews with key informants and other secondary data sources. Multilevel nonlinear analysis was conducted. Eighty-five percent of eligible persons completed the survey; of these, 98% underwent HSV-2 testing, producing a final sample of 1,275. Participants were of Tamil ethnicity, were predominantly female and married, and were on average 30 years old. Fifteen percent were infected with HSV-2, and there was significant variation in HSV-2 prevalence among communities. After controlling for individual-level factors, the authors identified community-level factors, including socioeconomic status and the presence of injection drug users, that were independently associated with HSV-2 and explained 11% of the variance in prevalence. Future studies are needed to test mechanisms through which these community-level factors may be operating.

Cosmetic effectiveness of topically applied hydrolysed keratin peptides and lipids derived from wool

BACKGROUND/PURPOSE

Skin moisturisation, elasticity, feel and appearance can all be improved through the topical application of protein hydrolysates. Recent studies suggest that supplementing intercellular lipids of the stratum corneum can enhance the functioning of the skin.

METHODS

In this study, a hydrolysed keratin peptide (molecular weight <1000 Da) was prepared from wool and tested on skin in two different formulations: an aqueous solution and an internal wool lipids (IWL) liposome suspension. In vivo long-term studies were performed to evaluate the water barrier function of the skin after topical application of different formulations. During the treatment period, hydration and elasticity were determined. A sorption-desorption test was also performed to assess the hygroscopic properties and water-holding capacity of the different treated skin sites.

RESULTS

Significant differences were found between the control and treated sites, with the treated areas showing an increase in hydration and elasticity as a result of keratin peptide application. Measurements also indicated that the keratin formulations reinforce the skin barrier integrity, improving its water-holding capacity.

CONCLUSION

A combination of the keratin peptide with the IWL showed beneficial effects, indicating that this combination is suitable for designing new cosmetics products.

Stable computed-torque control of robot manipulators via fuzzy self-tuning

Computed-torque control is a well-known motion control strategy for manipulators which ensures global asymptotic stability for fixed symmetric positive definite (proportional and derivative) gain matrices. In this paper, we show that global asymptotic stability also holds for a class of gain matrices depending on the manipulator state. This feature increases the potential of the computed-torque control scheme to handle practical constraint in actual robots such as presence of friction in the joints and actuators with limited torque capabilities. We illustrate this potential by means of a fuzzy self-tuning algorithm to select the proportional and derivative gains according to the actual tracking position error. Experiments on a two degrees of freedom robot arm show the usefulness of the proposed approach.

Patterns of participation of patients in cancer clinical trials in Ireland

BACKGROUND

In the United States the overall participation in cancer clinical trials (CCT) is less than 3% [Avis et al. in J Clin Oncol 24:1860-1867 (2006); Lara et al. in J Clin Oncol 19:1728-1733 (2001)]. In Europe there is little data on participation in such trials.

AIM

We aim to gather information on factors influencing CCT enrolment in Ireland.

METHODS

From November 2005 to 28 February 2006 all consecutive patients considered for systemic therapy were assessed for eligibility re participation in available CCTs.

RESULTS

A total of 290 patients were included. Overall 2.4% of patients were recruited to one of the available CCTs. The main reasons for failure of trial recruit were: no trial for cancer type (60%), no trial for stage (21%), ineligible by trial criteria (16.1%), patient declined (0.3%), and physician discretion (2.6%). Only one patient, who was otherwise eligible, declined entry into a clinical trial.

CONCLUSIONS

Irish patients with cancer are very willing to participate in CCTs. Current levels of recruitment compare favourably with international levels.

Wool peptide derivatives for hand care

Hands experience much greater wear and tear during normal daily routines compared with most other parts of the body, and thereby demand specific needs from cosmetics targeted at hand care. Keratin proteins are the major structural component of the outer layers of the skin. In this work a novel keratin fraction from wool, which has high cystine content present in the S-sulphonated form, has been developed to target hand care applications. In vivo long-term studies were performed to evaluate the water-holding capacity and elasticity of hand skin following topical application of keratins. Moreover, protection of healthy skin against detergent-induced dermatitis was evaluated after topical application of the keratin-active formulation. Significant results in the measured biophysical parameters were found, which indicated an improvement in the skin's water-holding capacity, hydration, and elasticity for volunteers with dry skin as a result of the keratin peptide treatment. Results also indicated that the keratin peptide treatment can prevent some of the damaging effects associated with surfactant exposure.

Is the effect of probiotics on atopic dermatitis confined to food sensitized children?

BACKGROUND

Probiotics have previously been shown to reduce the severity of atopic dermatitis (AD) in infants and children.

OBJECTIVE

To examine the effect of two probiotics (Lactobacillus rhamnosus and Bifidobacteria lactis) on established AD in children.

SUBJECTS AND METHODS

Atopic children with current dermatitis received 2 x 10(10) colony forming units/g of probiotic (n=29) or placebo (n=30). Both were given daily as a powder mixed with food or water. SCORing Atopic Dermatitis (SCORAD; developed by the European Task Force on Atopic Dermatitis) a measure of the extent and severity of AD, was assessed at baseline, 2 and 12 weeks after starting treatment and 4 weeks after treatment was discontinued.

RESULTS

SCORAD geometric mean score at baseline was 26.0 (21.9-30.8) in the probiotic group and 35.1 (28.9-42.8) in the placebo group (P=0.02). After adjustment for these between-group baseline differences there was no significant improvement in AD at 12 weeks, SCORAD geometric mean ratio: 0.80 (95% confidence level (CI) 0.62-1.04, P=0.10). Among the food sensitized children, there was an improvement in those treated with probiotics, SCORAD geometric mean ratio: 0.73 (95% CI 0.54-1.00, P=0.047).

CONCLUSION

In this study a combination of Lactobacillus rhamnosus and Bifidobacteria lactis improved AD only in food sensitized children.

Differential inhibition by hyperglycaemia of shear stress- but not acetylcholine-mediated dilatation in the iliac artery of the anaesthetized pig

Clinical hyperglycaemia affects vascular endothelial function, but the effect on shear stress-induced arterial dilatation has not yet been established. We hypothesized that hyperglycaemia would inhibit this response via impaired glycocalyx mechanotransduction. Experiments were carried out in the anaesthetized pig in which pressure, blood flow and diameter of the left iliac artery were measured at two sites: proximal (d1) and distal (d2). Infusion of glucose, sufficient to raise blood glucose to 16-30 mm along the whole length of the artery, attenuated the shear stress-dependent dilatation in both sections of the artery with preservation of the responses to acetylcholine. The distal site was then isolated using snares and the lumen exposed to blood containing 25-35 mm glucose for 20 min. In the control situation, after exposure of both sections to normoglycaemia (5.7 mm glucose), both sections of artery showed increases in diameter in response to shear stress and acetylcholine. Hyperglycaemia attenuated the shear stress-dependent dilatation in the distal section only (P < 0.25), but not the response to acetylcholine. It is concluded from these results that the hyperglycaemia-impaired dilatation is consistent with loss of mechanotransducing properties of the endothelial glycocalyx by hyperglycaemia. These findings offer a possible explanation for the increased incidence of vascular disease in diabetic patients.

Specific substitutions in the echinocandin target Fks1p account for reduced susceptibility of rare laboratory and clinical Candida sp. isolates

An association between reduced susceptibility to echinocandins and changes in the 1,3-beta-d-glucan synthase (GS) subunit Fks1p was investigated. Specific mutations in fks1 genes from Saccharomyces cerevisiae and Candida albicans mutants are described that are necessary and sufficient for reduced susceptibility to the echinocandin drug caspofungin. One group of amino acid changes in ScFks1p, ScFks2p, and CaFks1p defines a conserved region (Phe 641 to Asp 648 of CaFks1p) in the Fks1 family of proteins. The relationship between several of these fks1 mutations and the phenotype of reduced caspofungin susceptibility was confirmed using site-directed mutagenesis or integrative transformation. Glucan synthase activity from these mutants was less susceptible to caspofungin inhibition, and heterozygous and homozygous Cafks1 C. albicans mutants could be distinguished based on the shape of inhibition curves. The C. albicans mutants were less susceptible to caspofungin than wild-type strains in a murine model of disseminated candidiasis. Five Candida isolates with reduced susceptibility to caspofungin were recovered from three patients enrolled in a clinical trial. Four C. albicans strains showed amino acid changes at Ser 645 of CaFks1p, while a single Candida krusei isolate had a deduced R1361G substitution. The clinical C. albicans mutants were less susceptible to caspofungin in the disseminated candidiasis model, and GS inhibition profiles and DNA sequence analyses were consistent with a homozygous fks1 mutation. Our results indicate that substitutions in the Fks1p subunit of GS are sufficient to confer reduced susceptibility to echinocandins in S. cerevisiae and the pathogens C. albicans and C. krusei.

Bladder dysfunction in Duchenne muscular dystrophy

Although bladder function is thought to be unaffected in Duchenne muscular dystrophy, 46/88 boys interviewed had urinary problems. Nine underwent video urodynamics, showing in eight a small capacity, hyperreflexic bladder, and in the ninth (post spinal surgery) hyperreflexia and detrusor sphincter dyssynergia. Urinary dysfunction is a treatable feature of DMD.

Studies of the pathogenesis of bovine pestivirus-induced ovarian dysfunction in superovulated dairy cattle

Two experiments (Experiment I, n=12 Holstein-Friesian heifers; Experiment II, n=8 Jersey cows) were conducted to investigate the pathogenesis of bovine pestivirus-induced ovarian dysfunction in cattle. In both experiments the cattle were superovulated with twice daily injections of a porcine pituitary extract preparation of follicle stimulating hormone (FSH-P), for 4 days commencing on Day 10+/-2 after a presynchronised oestrus. The heifers received a total dose of 30 mg and the cows 32 mg of FSH-P. Prostaglandin F(2alpha) (PGF(2alpha)) was administered 48 h after commencement of superovulation and all cattle were artificially inseminated (AI) between 48 and 66h after PGF(2alpha) treatment. In both experiments bovine pestivirus seronegative cattle (Experiment I, n=6; Experiment II, n=4) were inoculated intranasally with an Australian strain of non-cytopathogenic bovine pestivirus (bovine viral diarrhoea virus Type 1) 9 days prior to AI. Bovine pestivirus infection was confirmed by seroconversion and/or virus isolation in all of the inoculated cattle, consistent with a viremia occurring approximately between Day 5 prior to AI and the day of AI. Ovarian function was monitored in both experiments by daily transrectal ultrasonography and strategic blood sampling to determine progesterone, oestradiol-17beta, luteinising hormone (LH) and cortisol profiles. Non-surgical ova/embryo recovery was performed on Day 7 after AI. In Experiment II half the cattle were slaughtered on Day 2 and the remainder on Day 8 after AI, and the ovaries submitted for gross and histopathological examination including immunohistochemistry to demonstrate the presence of bovine pestivirus antigen. In both studies, comparisons were made between infected and confirmed uninfected (control) animals. Overall the bovine pestivirus infected cattle had significantly lower (P<0.05) ova/embryo recovery rates compared to the control cattle. There was evidence of either an absence (partial or complete) of a preovulatory LH surge or delay in timing of the LH peak in the majority (90%) of infected heifers and cows, and histologically, there was evidence of non-suppurative oophoritis with necrosis of granulosa cells and the oocyte in follicles from the infected cows. By contrast only 20% of the control heifers and cows had evidence of absence of a pre-ovulatory LH surge. These experiments collectively demonstrate that bovine pestivirus infection during the period of final growth of preovulatory follicles may result in varying degrees of necrosis of the granulosa cells with subsequent negative effects on oestradiol-17beta secretion which in turn negatively affects the magnitude and/or timing of the preovulatory LH surge.