Prevalence of Risk Factors and Lifestyle Choices Associated with Increased Cancer in Participants in Trinidad and Tobago

In the Caribbean, cancer has been identified as the second leading cause of death and has created an immense challenge for healthcare services and expenses throughout the region. According to the World Health Organization (WHO), cancer incidence will increase by 58%, from 2015 to 2035, and cancer mortality throughout this period will increase by 67%. This research project outlined the socio-demographic risk factors and lifestyle choices known to increase the risk of developing various forms of cancer that are present in the population of Trinidad & Tobago. Knowledge of these risk factors will allow members of the public to evaluate their lifestyles. Subsequently, they can determine if they are putting themselves at risk for certain malignancies, since different types of cancers have specific socio- demographic factors and lifestyle choices associated with them.

Comparison of techniques of detecting immunoglobulin-binding protein reactivity to immunoglobulin produced by different avian and mammalian species.

The rationale of this study was to use several immunological assays to investigate the reactivity of immunoglobulin binding protein (IBP) to immunoglobulins from various avian and mammalian species. The IBP studied were Staphylococcal protein A (SpA), Streptococcal protein G (SpG), Peptostreptococcal protein L (SpL) and recombinant protein LA (SpLA). The various immunological techniques used were double immunodiffusion (Ouchterlony technique) that tested positive high protein reactivities, direct and competitive enzyme-linked immunosorbent assays (ELISAs) that tested moderate and low positive protein binding capacities, respectively. In addition to sandwich ELISAs, immunoblot analyses and Ig-purification by SpA-affinity chromatography, which were sensitive tests and helpful in the screening and confirmatory tests were also used. The Ouchterlony technique showed that compared to the other proteins, SpLA had the highest range of reactivity with animal sera and purified immunoglobulins while SpL was least reactive. With the direct ELISA, SpL reacted with the raccoon sera, rabbit IgG and with IgY from bantam hens and pigeons. While with the direct ELISA, SpA reacted with sera from skunk, coyote, raccoon, mule, donkey and human. The sandwich ELISA revealed high reactivity of both SpG and SpLA with mammalian sera titres ranging from 1:32 (raccoon serum) to 1:1024 (mule and donkey sera). These results suggest that IBP can be used for the detection of immunoglobulin using various immunological assays and this is important for the diagnosis of infectious diseases in animal and bird populations studied and in the purification of immunoglobulins.

Superhydrophobicity and liquid repellency of solutions on polypropylene.

The sliding of drops of aqueous solutions of organic liquids over a superhydrophobic polypropylene (SH-PP) surface has been studied experimentally. The multi-scale roughness of this surface is intrinsically inhomogeneous. Careful analysis of the wettability of each solution enables us to establish the statistics of the advancing and receding contact angles. We consider a threshold value of the receding static contact angle, above which drop sliding and rebound are facilitated as the criterion for superhydrophobicity. The percentage of receding contact angles greater than this threshold is then used as a practical index of superhydrophobicity (SHI). The variation of the SHI is compared with surface tension of the solution and various wetting parameters. A linear correlation is found between the SHI and the work of wetting defined by γ(LG)cosθ(0) where γ(LG) is the surface tension of the solution and θ(0) is the static contact angle of the solution over the corresponding smooth surface. Such a correlation can be used as a predictive tool of the superhydrophobicity of a given surface with various liquids.

Can we predict the spreading of a two-liquid system from the spreading of the corresponding liquid-air systems?

We present new data obtained from the spreading of a series of oil droplets, on top of a hydrophobic grafted silicon substrate, in air and immersed in water. We follow the contact angle and radius dynamics of hexane, dodecane, hexadecane, dibutyl phthalate, and squalane from the first milliseconds to approximately 1 s. Analysis of the images allows us to make several hundred contact angle and droplet radius measurements with great accuracy. The G-Dyna (Seveno et al. Langmuir 2010, 25, 13034) software is then used to fit the data with one of the wetting theories, the molecular-kinetic theory (MKT) (Blake et al. J. Colloid Interface Sci.1969, 30, 421), which takes into account the dissipation at the three-phase zone at the contact line. This theory allows us to extract the coefficient of friction of the contact line, which expresses the relationship between the driving force, that is, the unbalanced Young force, and the contact-line velocity V. It is first shown that the MKT is appropriate to describe the experimental data and then that the contact-line friction is a linear function of the viscosity as theoretically predicted. This is checked for oil-air and oil-water systems. A linear relation between the contact-line friction measured in oil-water systems and the contact-line frictions of the parent single liquid system seems plausible. To the best of our knowledge, this is the first trial to establish a link between the dynamics of wetting in liquid-liquid and in liquid-air systems.

Past climate changes explain the phylogeography of Vitellaria paradoxa over Africa.

The evolution of the savanna biome has been deeply marked by repeated contraction/expansion phases due to climate perturbations during the Quaternary period. In this study, we investigated the impact of the last glacial maximum (LGM) on the present genetic pattern of Vitellaria paradoxa (shea tree), a major African savanna tree. A range-wide sampling of the species enabled us to sample 374 individuals from 71 populations distributed throughout sub-Sahelian Africa. Trees were genotyped using 3 chloroplasts and 12 nuclear microsatellites, and were sequenced for 2 polymorphic chloroplast intergenic spacers. Analyses of genetic diversity and structure were based on frequency-based and Bayesian methods. Potential distributions of V. paradoxa at present, during the LGM and the last interglacial period, were examined using DIVA-GIS ecological niche modelling (ENM). Haplotypic and allelic richness varied significantly across the range according to chloroplast and nuclear microsatellites, which pointed to higher diversity in West Africa. A high but contrasted level of differentiation was revealed among populations with a clear phylogeographic signal, with both nuclear (F(ST) = 0.21; R(ST) = 0.28; R(ST) > R(ST) (permuted)) and chloroplast simple sequence repeats (SSRs) (G(ST) = 0.81; N(ST) = 0.90; N(ST) > N(ST) (permuted)). We identified a strong geographically related structure separating western and eastern populations, and a substructure in the eastern part of the area consistent with subspecies distinction. Using ENM, we deduced that perturbations during the LGM fragmented the potential eastern distribution of shea tree, but not its distribution in West Africa. Our main results suggest that climate variations are the major factor explaining the genetic pattern of V. paradoxa.

Dynamics of wetting revisited.

We present new spreading-drop data obtained over four orders of time and apply our new analysis tool G-Dyna to demonstrate the specific range over which the various models of dynamic wetting would seem to apply for our experimental system. We follow the contact angle and radius dynamics of four liquids on the smooth silica surface of silicon wafers or PET from the first milliseconds to several seconds. Analysis of the images allows us to make several hundred contact angle and droplet radius measurements with great accuracy. The G-Dyna software is then used to fit the data to the relevant theory (hydrodynamic, molecular-kinetic theory, Petrov and De Ruijter combined models, and Shikhmurzaev's formula). The distributions, correlations, and average values of the free parameters are analyzed and it is shown that for the systems studied even with very good data and a robust fitting procedure, it may be difficult to make reliable claims as to the model which best describes results for a given system. This conclusions also suggests that claims based on smaller data sets and less stringent fitting procedures should be treated with caution.

Isolation and characterization of 15 nuclear microsatellite markers for Baillonella toxisperma Pierre (Sapotaceae), a low-density tree species of Central Africa.

Baillonella toxisperma is a scattered endemic species of the Guineo-Congolian forest. We developed 15 nuclear microsatellite markers specifically for B. toxisperma to analyse the genetic diversity of 188 individuals distributed in two natural populations in Gabon. On average, 8.3 alleles per locus were identified; observed heterozygosity ranged from 0.056 to 0.872 and expected heterozygosity from 0.282 to 0.823 among populations. Only three loci showed a significant departure to Hardy-Weinberg equilibrium, but no linkage disequilibrium was observed for any pair of loci.

Isolation and characterization of microsatellite markers for Acacia senegal (L.) Willd., a multipurpose arid and semi-arid tree.

Acacia senegal is a multipurpose African tree that improves the soil fertility of degraded areas. The species is exploited mainly for gum arabic, but it also supplies fuel wood and fodder for animals. Despite its wide distribution in Africa, no microsatellite markers have yet been characterized for this species. In this study, we characterized 11 polymorphic microsatellite loci specifically designed for A. senegal and analysed 247 individuals from three populations from Niger. On average, 10.9 alleles per locus were detected and expected heterozygosity ranged from 0.160 to 0.794, showing the ability of the markers to detect genetic diversity in this species.

Superhydrophobic surfaces from various polypropylenes.

Superhydrophobic surfaces were prepared from solutions of isotactic polypropylenes of various molecular weights using soft chemistry. Varying the conditions of the experiments (polymer concentration and initial amount of the coated solution) allowed us to optimize the superhydrophobic behavior of the polymer film. Results show that decreasing the concentration and/or film thicknesses decreases the probability to get superhydrophobicity for all polypropylenes tested. Measurement and analysis of advancing and receding contact angles as well as estimation of surface homogeneity were performed. Similar results were obtained with syndio- as well as atactic polypropylenes.

Drop impact on porous superhydrophobic polymer surfaces.

Water drop impacts are performed on porous-like superhydrophobic surfaces. We investigate the influence of the drop size and of the impact velocity on the event. The Cassie-Baxter/Wenzel transition is observed to be a function of the drop size, as well as the outcomes of the impact or deposition process, which can be deposition, rebound, sticking, or fragmentation. A quantitative analysis on the experimental conditions required to observe rebound is provided. Our analysis shows that the wettability hysteresis controls the limit between deposition and rebound events. This limit corresponds to a constant Weber number. A survey of literature results on impact over patterned superhydrophobic surfaces is provided as a comparison.

Genetic diversity and population structure of an insular tree, Santalum austrocaledonicum in New Caledonian archipelago.

We present a study of the genetic diversity and structure of a tropical tree in an insular system. Santalum austrocaledonicum is endemic to the archipelago of New Caledonia and is exploited for oil extraction from heartwood. A total of 431 individuals over 17 populations were analysed for eight polymorphic microsatellite loci. The number of alleles per locus ranged from 3 to 33 and the observed heterozygosity per population ranged from 0.01 in Mare to 0.74 in Ile des Pins. The genetic diversity was lowest in the most recent islands, the Loyautes, and highest in the oldest island, Grande Terre, as well as the nearby small Ile des Pins. Significant departures from panmixia were observed for some loci-population combinations (per population FIS = 0-0.03 on Grande-Terre and Ile des Pins, and 0-0.67 on Loyautes). A strong genetic differentiation among all islands was observed (FST = 0.22), and the amount of differentiation increased with geographic distance in Iles Loyaute and in Grande Terre. At both population and island levels, island age and isolation seem to be the main factors influencing the amount of genetic diversity. In particular, populations from recent islands had large average FIS that could not be entirely explained by null alleles or a Wahlund effect. This result suggests that, at least in some populations, selfing occurred extensively. Conclusively, our results indicate a strong influence of insularity on the genetic diversity and structure of Santalum austrocaledonicum.

Detection of red blood cell antibodies using bacterial antiglobulins: a new assay [abstract]

OBJECTIVE: To develop an agglutination technique using Staphylococcal protein A (SpA) and Steptococcalprotein G (SpG) to detect human red blood cell antibodies. METHODS: Blood samples were obtained from the National Transfusion Service of Jamaica. SpA, SpG, and anti-IgG, -C3d were commercial preparations. SpA and ApG were incubated with sensitized human red blood cells (RBC) to assess their RBC agglutinating capacity. The Ouchterlony technique was used to determine binding between the bacterial antigens and the IgG in human serum. Polyethyleneglycol (PEG) was used as an agglutination enhancer. Agglutination techniques for a large number of samples were developed, using 96 percent well polystyrene microplates and a microscope for visualizing the agglutination techniques to detect human anti-RBC IgG was compared with the traditional Coombs' test. Sensitivity and specificity were determined. RESULTS: SpA and SpG did not appear to cause agglutination of the red cells sensitized in vivo and in vitro. However, no precipitation bands were formed between human serum and the supernatant obtained after reaction of the sensitized RBC with SpA and SpG (Ouchterlony technique). These results indicated that indeed there was binding of SpA and SpG with the sensitized cells since they were not available for binding with human serum. In additon, SpA and SpG agglutinated the sensitized red blood cells in the presence of the PEG. When compared to the Coombs' test, the following results were obtained with new techniques. For the direct method, sensitivity was 93.8 percent and 95.1 percent for SpA and SpG respectively (n= 81), and specificity was 91.4 percent and 93.5 percent for SpA and SpG, respectivley (n= 93). For the indirect method, sensitivity was 96.3 percent and 97.5 percent for SPA and SpG, respectively (n= 81) and its specificity was 100 percent for both proteins (n= 85). CONCLUSION: Agglutination techniques using SpA and SpG constitute alternative and feasible tests for the detection of human red blood cell antibodies. (AU)

Depolarization and neurotrophins converge on the phosphatidylinositol 3-kinase-Akt pathway to synergistically regulate neuronal survival.

In this report, we have examined the mechanisms whereby neurotrophins and neural activity coordinately regulate neuronal survival, focussing on sympathetic neurons, which require target-derived NGF and neural activity for survival during development. When sympathetic neurons were maintained in suboptimal concentrations of NGF, coincident depolarization with concentrations of KCl that on their own had no survival effect, synergistically enhanced survival. Biochemical analysis revealed that depolarization was sufficient to activate a Ras-phosphatidylinositol 3-kinase-Akt pathway (Ras-PI3-kinase-Akt), and function-blocking experiments using recombinant adenovirus indicated that this pathway was essential for approximately 50% of depolarization-mediated neuronal survival. At concentrations of NGF and KCl that promoted synergistic survival, these two stimuli converged to promote increased PI3-kinase-dependent Akt phosphorylation. This convergent PI3-kinase-Akt pathway was essential for synergistic survival. In contrast, inhibition of calcium/calmodulin-dependent protein kinase II revealed that, while this molecule was essential for depolarization-induced survival, it had no role in KCl- induced Akt phosphorylation, nor was it important for synergistic survival by NGF and KCl. Thus, NGF and depolarization together mediate survival of sympathetic neurons via intracellular convergence on a Ras-PI3-kinase-Akt pathway. This convergent regulation of Akt may provide a general mechanism for coordinating the effects of growth factors and neural activity on neuronal survival throughout the nervous system.

Characterization of the microtubule-binding domain of microtubule-associated protein 1A and its effects on microtubule dynamics.

To determine how MAP1a interacts with microtubules we expressed several 6myc-tagged MAP1a fragments in P19 EC and HeLa cells. Confocal immunofluorescence microscopy showed that the fragment consisting of amino acids (aa) 1-281 of MAP1a did not bind while the fragment consisting of aa 1-630 did, indicating that the region of MAP1a between aa 281 and 630 contains a microtubule-binding domain. Deletion of the basic repeats from aa 336-540 did not result in loss of microtubule binding, suggesting that the regions flanking the basic repeats can bind MAP1a to microtubules. These observations were confirmed using an in vitro microtubule binding assay. The levels of acetylation and detyrosination of polymerized microtubules were assessed by quantitative dot blotting in cells expressing MAP1a fragments or MAP2c. Compared with untransfected cells, the polymerized tubulin in cells expressing full-length MAP1a was more acetylated and detyrosinated, but these increases were smaller than those seen in cells expressing MAP2c. Consistent with this, the microtubules in MAP2c expressing cells were more resistant to colchicine than those in cells overexpressing MAP1a. These data implicate aa 281-336 and/or 540-630 of MAP1a in microtubule binding and suggest that MAP1a is less able to stabilize microtubules than MAP2c.

Embolic thrombus on mitral anulus calcification.

Embolic thrombus on mitral anulus calcification (MAC) was demonstrated in an 83-year-old woman with retinal embolism. Mitral anulus calcification has been associated with a significant increase of stroke in elderly people. Atrial fibrillation and calcific emboli have been reported, and embolic thrombus by MAC may be another potential cause.

[Heart valve prosthesis from autologous pericardium. Preliminary results apropos of 15 patients]. / La prothèse cardiaque en péricarde autologue. Résultats préliminaires à propos de 14 patients.

The concept of a heart valve prosthesis made from autologous pericardium is based on the idea of creating and developing a valve with a longer life than heterografts or homografts due to the absence of tissue degeneration causing the deterioration of both of these types of bioprostheses. The first attempts using the fascia lata or the pericardium, implanted in the seventies, were unsuccessful due to problems with pretreatment of the pericardium and other purely technical difficulties. J. Love et al then developed a technique based on Carpentier's earlier work, where a valve is made extemporaneously using the autologous pericardium. We applied this technique in 14 patients from June 1994 to 1995. The mean age of the patients was 68 years (7 males, 7 females). The aortic valve was replaced in all cases. Preoperative findings were: aortic stenosis (n = 7), aortic regurgitation (n = 1), aortic valve disease (n = 6). Two patients also had mitral valve disease and 3 had coronary artery disease. There were no operative deaths and no patients were lost to follow up. Clinical state was satisfactory with a follow-up of 1 to 10 months. Postoperative Doppler echocardiography was performed at 3 and 6 months and showed gradients were very low. This group of patients demonstrated the value and applicability of the concept. The validity of the technique will be evaluated as a function of the long-term results.

Accumulation of microtubule-associated protein 1A (MAP1A) in differentiating P19 embryonal carcinoma cells.

We have examined the accumulation of MAP1A in retinoic acid induced P19 embryonal carcinoma (EC) neurons. By immunofluorescent confocal microscopy, MAP1A was detected in the mitotic spindle of undifferentiated cells but was not evident in association with the interphase microtubules in most cells. By day 4 of differentiation, when neurite outgrowth was underway, MAP1A was co-localize with microtubules in all neurites but was absent from growth cones. By day 8, substantial neurite outgrowth had occurred and MAP1A was seen in all processes. At day 12, no further neurite outgrowth was evident and existing neurites were organized into fascicles. Western blotting and ELISA showed that MAP1A protein levels increased during differentiation. Peak accumulation occurred no later than day 8, coinciding with the period of neurite outgrowth, and then decreased after day 8. The results suggest that in differentiating P19 EC cells MAP1A modulates microtubule dynamics during neurite outgrowth.

[Myxoma of the mitral valve; apropos of 2 surgically treated cases. Review of the literature]. / Myxome de la valve mitrale; á propos de deux cas opérés. Revue de la littérature.

The authors report two cases of anterior mitral valve myxoma. This is an exceedingly rare localisation and these cases add to the other 8 previously reported cases. Intracardiac tumours and valvular endocarditis may be detected non-invasively by echocardiography but the precise diagnosis may be extremely difficult: mitral valve myxoma is an exceptionally rare condition. Treatment was surgical in both reported cases.

Thrombosis of the abdominal aorta. A rare complication of the intraaortic balloon pumping device.

We describe a patient who died due to thrombosis of the abdominal aorta and its branches after placement of an intraaortic balloon pumping device. This rare complication, which occurred despite careful insertion technique, underscores the need to select balloon size as a function of the individual patient's morphology.