Provenance Establishment of Stingless Bee Honey Using Multi-element Analysis in Combination with Chemometrics Techniques

As consumption of stingless bee honey has been gaining popularity in many countries including Malaysia, ability to identify accurately its geographical origin proves pertinent for investigating fraudulent activities for consumer protection. Because a chemical signature can be location-specific, multi-element distribution patterns may prove useful for provenancing such product. Using the inductively coupled-plasma optical emission spectrometer as well as principal component analysis (PCA) and linear discriminant analysis (LDA), the distributions of multi-elements in stingless bee honey collected at four different geographical locations (North, West, East, and South) in Johor, Malaysia, were investigated. While cross-validation using PCA demonstrated 87.0% correct classification rate, the same was improved (96.2%) with the use of LDA, indicating that discrimination was possible for the different geographical regions. Therefore, utilization of multi-element analysis coupled with chemometrics techniques for assigning the provenance of stingless bee honeys for forensic applications is supported

MIXED GERM CELL TERATOMATOUS TUMOUR OF TESTIS IN ADULTS: DIAGNOSTIC CHALLENGES FOR A HISTOPATHOLOGIST (case report)

Background. Testicular tumours account for approximately 1-2 % of the total cancer cases in the male population globally and show higher incidence in the younger male age group of up to 15 years. The majority (~98 %) of testicular tumours are observed to be of the germ-cell origin which can either be of seminomatous type or non-seminomatous type. The non-seminomatous germ cell neoplasm may be pure or of mixed subtype. Objective was to emphasize the rare case of mixed germ cell teratomatous tumour of testis in adult man.Methods.  A mixed germ cell teratomatous tumour of testis comprising of yolk sac tumour and embryonal carcinoma in an adult Indian male is reported in the research.Results. A 45 year-old Indian male presented with enlargement of right testis which was found to be an encapsulated right testicular tumour on exploratory surgery which was followed by radical orchiectomy. Serum AFP and β-hCG levels were elevated to 380 ng/ml and 590 mg/ml respectively. Histopathology revealed a mixed germ cell teratomatous tumour of testis comprising of yolk sac tumour and embryonal carcinoma.Conclusions. In adults teratomas occur usually as a component of mixed germ cell tumours. However in the present case teratomatous embryoid yolk sac germ cell tumour of testis was observed in an Indian adult male. The prognosis of embryoid germ cell tumours of testis is generally poor. The possibility of this condition should always be considered in all cases that present with a testicular lump

Cryogenic Optical Position Encoders for Mechanisms in the JWST Optical Telescope Element Simulator (OSIM)

The JWST Optical Telescope Element Simulator (OSIM) is a configurable, cryogenic, optical stimulus for high fidelity ground characterization and calibration of JWST's flight instruments. OSIM and its associated Beam Image Analyzer (BIA) contain several ultra-precise, cryogenic mechanisms that enable OSIM to project point sources into the instruments according to the same optical prescription as the flight telescope images stars - correct in focal surface position and chief ray angle. OSIM's and BIA's fifteen axes of mechanisms navigate according to redundant, cryogenic, absolute, optical encoders - 32 in all operating at or below 100 K. OSIM's encoder subsystem, the engineering challenges met in its development, and the encoders' sub-micron and sub-arcsecond performance are discussed

Involvement of Complexin 2 in Docking, Locking and Unlocking of Different SNARE Complexes during Sperm Capacitation and Induced Acrosomal Exocytosis

Acrosomal exocytosis (AE) is an intracellular multipoint fusion reaction of the sperm plasma membrane (PM) with the outer acrosomal membrane (OAM). This unique exocytotic event enables the penetration of the sperm through the zona pellucida of the oocyte. We previously observed a stable docking of OAM to the PM brought about by the formation of the trans-SNARE complex (syntaxin 1B, SNAP 23 and VAMP 3). By using electron microscopy, immunochemistry and immunofluorescence techniques in combination with functional studies and proteomic approaches, we here demonstrate that calcium ionophore-induced AE results in the formation of unilamellar hybrid membrane vesicles containing a mixture of components originating from the two fused membranes. These mixed vesicles (MV) do not contain the earlier reported trimeric SNARE complex but instead possess a novel trimeric SNARE complex that contained syntaxin 3, SNAP 23 and VAMP 2, with an additional SNARE interacting protein, complexin 2. Our data indicate that the earlier reported raft and capacitation-dependent docking phenomenon between the PM and OAM allows a specific rearrangement of molecules between the two docked membranes and is involved in (1) recruiting SNAREs and complexin 2 in the newly formed lipid-ordered microdomains, (2) the assembly of a fusion-driving SNARE complex which executes Ca2+-dependent AE, (3) the disassembly of the earlier reported docking SNARE complex, (4) the recruitment of secondary zona binding proteins at the zona interacting sperm surface. The possibility to study separate and dynamic interactions between SNARE proteins, complexin and Ca2+ which are all involved in AE make sperm an ideal model for studying exocytosis

Type-1 Cannabinoid Receptors Reduce Membrane Fluidity of Capacitated Boar Sperm by Impairing Their Activation by Bicarbonate

Background Mammalian spermatozoa acquire their full fertilizing ability (so called capacitation) within the female genital tract, where they are progressively exposed to inverse gradients of inhibiting and stimulating molecules. Methodology/Principal Findings In the present research, the effect on this process of anandamide, an endocannabinoid that can either activate or inhibit cannabinoid receptors depending on its concentration, and bicarbonate, an oviductal activatory molecule, was assessed, in order to study the role exerted by the type 1 cannabinoid receptor (CB1R) in the process of lipid membrane remodeling crucial to complete capacitation. To this aim, boar sperm were incubated in vitro under capacitating conditions (stimulated by bicarbonate) in the presence or in the absence of methanandamide (Met-AEA), a non-hydrolysable analogue of anandamide. The CB1R involvement was studied by using the specific inhibitor (SR141716) or mimicking its activation by adding a permeable cAMP analogue (8Br-cAMP). By an immunocytochemistry approach it was shown that the Met-AEA inhibits the bicarbonate-dependent translocation of CB1R from the post-equatorial to equatorial region of sperm head. In addition it was found that Met-AEA is able to prevent the bicarbonate-induced increase in membrane disorder and the cholesterol extraction, both preliminary to capacitation, acting through a CB1R-cAMP mediated pathway, as indicated by MC540 and filipin staining, EPR spectroscopy and biochemical analysis on whole membranes (CB1R activity) and on membrane enriched fraction (C/P content and anisotropy). Conclusions/Significance Altogether, these data demonstrate that the endocannabinoid system strongly inhibits the process of sperm capacitation, acting as membrane stabilizing agent, thus increasing the basic knowledge on capacitation-related signaling and potentially opening new perspectives in diagnostics and therapeutics of male infertility

Membrane Cholesterol Regulates Lysosome-Plasma Membrane Fusion Events and Modulates Trypanosoma cruzi Invasion of Host Cells

Trypanosoma cruzi, is the etiological agent of a neglected tropical malady known as Chagas' disease, which affects about 8 million people in Latin America. 30–40% of affected individuals develop a symptomatic chronic infection, with cardiomyopathy being the most prevalent condition. T. cruzi utilizes an interesting strategy for entering cells: T. cruzi enhances intracellular calcium levels, which in turn trigger the exocytosis of lysosomal contents. Lysosomes then donate their membrane for the formation of the parasitophorous vacuole. Membrane rafts, cholesterol-enriched microdomains in the host cell plasma membrane, have also been implicated in T. cruzi invasion process. Since both plasma membrane and lysosomes collaborate in parasite invasion, we decided to study the importance of these membrane domains for lysosomal recruitment and fusion during T. cruzi invasion into host cells. Our results show that drug dependent depletion of plasma membrane cholesterol changes raft organization and induces excessive lysosome exocytosis in the earlier stages of treatment, leading to a depletion of lysosomes near the cell cortex, which in turn compromises T. cruzi invasion. Based on these results, we propose that cholesterol depletion leads to unregulated exocytic events of pre-docked lysosomes, reducing lysosome availability at the cell cortex and consequently compromising T. cruzi infection

Influence of taste disorders on dietary behaviors in cancer patients under chemotherapy

<p>Abstract</p> <p>Objectives</p> <p>To determine the relationship between energy and nutrient consumption with chemosensory changes in cancer patients under chemotherapy.</p> <p>Methods</p> <p>We carried out a cross-sectional study, enrolling 60 subjects. Cases were defined as patients with cancer diagnosis after their second chemotherapy cycle (n = 30), and controls were subjects without cancer (n = 30). Subjective changes of taste during treatment were assessed. Food consumption habits were obtained with a food frequency questionnaire validated for Mexican population. Five different concentrations of three basic flavors --sweet (sucrose), bitter (urea), and a novel basic taste, umami (sodium glutamate)-- were used to measure detection thresholds and recognition thresholds (RT). We determine differences between energy and nutrient consumption in cases and controls and their association with taste DT and RT.</p> <p>Results</p> <p>No demographic differences were found between groups. Cases showed higher sweet DT (6.4 vs. 4.4 μmol/ml; p = 0.03) and a higher bitter RT (100 vs. 95 μmol/ml; <it>p </it>= 0.04) than controls. Cases with sweet DT above the median showed significant lower daily energy (2,043 vs.1,586 kcal; p = 0.02), proteins (81.4 vs. 54 g/day; <it>p </it>= 0.01), carbohydrates (246 vs.192 g/day; <it>p </it>= 0.05), and zinc consumption (19 vs.11 mg/day; <it>p </it>= 0.01) compared to cases without sweet DT alteration. Cases with sweet DT and RT above median were associated with lower completion of energy requirements and consequent weight loss. There was no association between flavors DT or RT and nutrient ingestion in the control group.</p> <p>Conclusion</p> <p>Changes of sweet DT and bitter RT in cancer patients under chemotherapy treatment were associated with lower energy and nutrient ingestion. Taste detection and recognition thresholds disorders could be important factors in malnutrition development on patients with cancer under chemotherapy treatment.</p

Modeling the Effects of Cell Cycle M-phase Transcriptional Inhibition on Circadian Oscillation

Circadian clocks are endogenous time-keeping systems that temporally organize biological processes. Gating of cell cycle events by a circadian clock is a universal observation that is currently considered a mechanism serving to protect DNA from diurnal exposure to ultraviolet radiation or other mutagens. In this study, we put forward another possibility: that such gating helps to insulate the circadian clock from perturbations induced by transcriptional inhibition during the M phase of the cell cycle. We introduced a periodic pulse of transcriptional inhibition into a previously published mammalian circadian model and simulated the behavior of the modified model under both constant darkness and light–dark cycle conditions. The simulation results under constant darkness indicated that periodic transcriptional inhibition could entrain/lock the circadian clock just as a light–dark cycle does. At equilibrium states, a transcriptional inhibition pulse of certain periods was always locked close to certain circadian phases where inhibition on Per and Bmal1 mRNA synthesis was most balanced. In a light–dark cycle condition, inhibitions imposed at different parts of a circadian period induced different degrees of perturbation to the circadian clock. When imposed at the middle- or late-night phase, the transcriptional inhibition cycle induced the least perturbations to the circadian clock. The late-night time window of least perturbation overlapped with the experimentally observed time window, where mitosis is most frequent. This supports our hypothesis that the circadian clock gates the cell cycle M phase to certain circadian phases to minimize perturbations induced by the latter. This study reveals the hidden effects of the cell division cycle on the circadian clock and, together with the current picture of genome stability maintenance by circadian gating of cell cycle, provides a more comprehensive understanding of the phenomenon of circading gating of cell cycle