Showing papers by "University of Puerto Rico, Medical Sciences Campus published in 2015"

Colorectal Cancer Biomarkers: Where Are We Now?

Abstract: Colorectal cancer is one of the major causes of cancer-related death in the Western world. Patient survival is highly dependent on the tumor stage at the time of diagnosis. Reduced sensitivity to chemotherapy is still a major obstacle in effective treatment of advanced disease. Due to the fact that colorectal cancer is mostly asymptomatic until it progresses to advanced stages, the implementation of screening programs aimed at early detection is essential to reduce incidence and mortality rates. Current screening and diagnostic methods range from semi-invasive procedures such as colonoscopy to noninvasive stool-based tests. The combination of the absence of symptoms, the semi-invasive nature of currently used methods, and the suboptimal accuracy of fecal blood tests results in colorectal cancer diagnosis at advanced stages in a significant number of individuals. Alterations in gene expression leading to colorectal carcinogenesis are reflected in dysregulated levels of nucleic acids and proteins, which can be used for the development of novel, minimally invasive molecular biomarkers. The purpose of this review is to discuss the commercially available colorectal cancer molecular diagnostic methods as well as to highlight some of the new candidate predictive and prognostic molecular markers for tumor, stool, and blood samples.

The majority of transcripts in the squid nervous system are extensively recoded by A-to-I RNA editing.

Abstract: RNA editing by adenosine deamination alters genetic information from the genomic blueprint. When it recodes mRNAs, it gives organisms the option to express diverse, functionally distinct, protein isoforms. All eumetazoans, from cnidarians to humans, express RNA editing enzymes. However, transcriptome-wide screens have only uncovered about 25 transcripts harboring conserved recoding RNA editing sites in mammals and several hundred recoding sites in Drosophila. These studies on few established models have led to the general assumption that recoding by RNA editing is extremely rare. Here we employ a novel bioinformatic approach with extensive validation to show that the squid Doryteuthis pealeii recodes proteins by RNA editing to an unprecedented extent. We identify 57,108 recoding sites in the nervous system, affecting the majority of the proteins studied. Recoding is tissue-dependent, and enriched in genes with neuronal and cytoskeletal functions, suggesting it plays an important role in brain physiology.

The development and plasticity of alveolar type 1 cells.

Abstract: Alveolar type 1 (AT1) cells cover >95% of the gas exchange surface and are extremely thin to facilitate passive gas diffusion. The development of these highly specialized cells and its coordination with the formation of the honeycomb-like alveolar structure are poorly understood. Using new marker-based stereology and single-cell imaging methods, we show that AT1 cells in the mouse lung form expansive thin cellular extensions via a non-proliferative two-step process while retaining cellular plasticity. In the flattening step, AT1 cells undergo molecular specification and remodel cell junctions while remaining connected to their epithelial neighbors. In the folding step, AT1 cells increase in size by more than 10-fold and undergo cellular morphogenesis that matches capillary and secondary septa formation, resulting in a single AT1 cell spanning multiple alveoli. Furthermore, AT1 cells are an unexpected source of VEGFA and their normal development is required for alveolar angiogenesis. Notably, a majority of AT1 cells proliferate upon ectopic SOX2 expression and undergo stage-dependent cell fate reprogramming. These results provide evidence that AT1 cells have both structural and signaling roles in alveolar maturation and can exit their terminally differentiated non-proliferative state. Our findings suggest that AT1 cells might be a new target in the pathogenesis and treatment of lung diseases associated with premature birth.

Targeting c-MYC in platinum-resistant ovarian cancer

Abstract: The purpose of this study was to investigate the molecular and therapeutic effects of siRNA-mediated c-MYC silencing in cisplatin-resistant ovarian cancer. Statistical analysis of patient's data extracted from The Cancer Genome Atlas (TCGA) portal showed that the disease-free (DFS) and the overall (OS) survival were decreased in ovarian cancer patients with high c-MYC mRNA levels. Furthermore, analysis of a panel of ovarian cancer cell lines showed that c-MYC protein levels were higher in cisplatin-resistant cells when compared with their cisplatin-sensitive counterparts. In vitro cell viability, growth, cell-cycle progression, and apoptosis, as well as in vivo therapeutic effectiveness in murine xenograft models, were also assessed following siRNA-mediated c-MYC silencing in cisplatin-resistant ovarian cancer cells. Significant inhibition of cell growth and viability, cell-cycle arrest, and activation of apoptosis were observed upon siRNA-mediated c-MYC depletion. In addition, single weekly doses of c-MYC-siRNA incorporated into 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG-2000)-based nanoliposomes resulted in significant reduction in tumor growth. These findings identify c-MYC as a potential therapeutic target for ovarian cancers expressing high levels of this oncoprotein.

A New Quaternary Structure Epitope on Dengue Virus Serotype 2 Is the Target of Durable Type-Specific Neutralizing Antibodies

Abstract: Dengue virus serotype 2 (DENV2) is widespread and responsible for severe epidemics. While primary DENV2 infections stimulate serotype-specific protective responses, a leading vaccine failed to induce a similar protective response. Using human monoclonal antibodies (hMAbs) isolated from dengue cases and structure-guided design of a chimeric DENV, here we describe the major site on the DENV2 envelope (E) protein targeted by neutralizing antibodies. DENV2-specific neutralizing hMAb 2D22 binds to a quaternary structure epitope. We engineered and recovered a recombinant DENV4 that displayed the 2D22 epitope. DENV2 neutralizing antibodies in people exposed to infection or a live vaccine tracked with the 2D22 epitope on the DENV4/2 chimera. The chimera remained sensitive to DENV4 antibodies, indicating that the major neutralizing epitopes on DENV2 and -4 are at different sites. The ability to transplant a complex epitope between DENV serotypes demonstrates a hitherto underappreciated structural flexibility in flaviviruses, which could be harnessed to develop new vaccines and diagnostics. IMPORTANCE Dengue virus causes fever and dengue hemorrhagic fever. Dengue serotype 2 (DENV2) is widespread and frequently responsible for severe epidemics. Natural DENV2 infections stimulate serotype-specific neutralizing antibodies, but a leading DENV vaccine did not induce a similar protective response. While groups have identified epitopes of single monoclonal antibodies (MAbs), the molecular basis of DENV2 neutralization by polyclonal human immune sera is unknown. Using a recombinant DENV displaying serotype 2 epitopes, here we map the main target of DENV2 polyclonal neutralizing antibodies induced by natural infection and a live DENV2 vaccine candidate. Proper display of the epitope required the assembly of viral envelope proteins into higher-order structures present on intact virions. Despite the complexity of the epitope, it was possible to transplant the epitope between DENV serotypes. Our findings have immediate implications for evaluating dengue vaccines in the pipeline as well as designing next-generation vaccines.

Awareness of Post-Exposure Prophylaxis (PEP) and Pre-Exposure Prophylaxis (PrEP) Is Low but Interest Is High Among Men Engaging in Condomless Anal Sex With Men in Boston, Pittsburgh, and San Juan.

Abstract: This study examines awareness of and experiences with post-exposure prophylaxis (PEP) and pre-exposure prophylaxis (PrEP) among 228 men recruited in Boston, Pittsburgh, and San Juan between 12/2010 and 6/2012. All of them reported having condomless anal sex with a man in the prior year. Overall, 41% had heard of PEP, ranging from 16% in San Juan to 64% in Boston. Only 21% had heard of PrEP, ranging from 8% in San Juan to 36% in Boston. Three had used PEP, and none had used PrEP. After the methods were described to participants, interest in both was high, with intentions to use PEP and PrEP respectively at 9.1 and 7.7 (10-point scale). Increased public education is needed to raise awareness of these HIV prevention methods, especially among MSM who acknowledge potential risk behavior. It also seems likely that many such men would use these methods once they become aware of them.

The IRF5-TNPO3 association with systemic lupus erythematosus has two components that other autoimmune disorders variably share.

Abstract: Exploiting genotyping, DNA sequencing, imputation and trans-ancestral mapping, we used Bayesian and frequentist approaches to model the IRF5-TNPO3 locus association, now implicated in two immunothe ...

Clinical associations of anti-Smith antibodies in PROFILE: a multi-ethnic lupus cohort

Abstract: The aim of this study was to determine the association of anti-Sm antibodies with clinical manifestations, comorbidities, and disease damage in a large multi-ethnic SLE cohort. SLE patients (per American College of Rheumatology criteria), age ≥16 years, disease duration ≤10 years at enrollment, and defined ethnicity (African American, Hispanic or Caucasian), from a longitudinal US cohort were studied. Socioeconomic-demographic features, cumulative clinical manifestations, comorbidities, and disease damage (as per the Systemic Lupus International Collaborating Clinics Damage Index [SDI]) were determined. The association of anti-Sm antibodies with clinical features was examined using multivariable logistic regression analyses adjusting for age, gender, ethnicity, disease duration, level of education, health insurance, and smoking. A total of 2322 SLE patients were studied. The mean (standard deviation, SD) age at diagnosis was 34.4 (12.8) years and the mean (SD) disease duration was 9.0 (7.9) years; 2127 (91.6 %) were women. Anti-Sm antibodies were present in 579 (24.9 %) patients. In the multivariable analysis, anti-Sm antibodies were significantly associated with serositis, renal involvement, psychosis, vasculitis, Raynaud’s phenomenon, hemolytic anemia, leukopenia, lymphopenia, and arterial hypertension. No significant association was found for damage accrual. In this cohort of SLE patients, anti-Sm antibodies were associated with several clinical features including serious manifestations such as renal, neurologic, and hematologic disorders as well as vasculitis.

Rheumatic Manifestations in Patients with Chikungunya Infection.

Abstract: Chikungunya virus (CHIKV) infection is a common cause of febrile arthritis. The most common manifestations of acute infection are fever, symmetrical polyarthralgias or polyarthritis, myalgias, and maculopapular rash. Up to 80% of patients may develop musculoskeletal manifestations that persist longer than 3 months, causing impairment in their quality of life. The most common chronic manifestations are persistent or relapsing-remitting polyarthralgias, polyarthritis, and myalgias. Fingers, wrists, knees, ankles, and toes are the most frequently involved, but proximal joints and axial involvement can occur in the chronic stage. Chronic manifestations of CHIKV infection may resemble those of some autoimmune connective tissue diseases. Furthermore, CHIKV infection can cause cryoglobulinemia and may induce rheumatoid arthritis and seronegative spondyloarthropathies in genetically susceptible individuals. The Centers for Disease Control and Prevention recommend acetaminophen and non steroidal anti-inflammatory drugs for the acute rheumatic manifestations of CHIKV infection. However, some studies suggest that low-dose corticosteroids for about 1-2 months (depending on clinical course) are beneficial in relieving acute rheumatic symptoms. Conversely, hydroxychloroquine in combination with corticosteroids or other disease modifying anti-rheumatic drugs (DMARDs) has been successful in treating chronic rheumatic manifestations. Methotrexate and sulfasalazine (alone or in combination) have also been effective for chronic CHIKV arthritis. Patients with CHIKV infection should be closely monitored to identify those with chronic arthritis who would benefit from a rheumatologic evaluation and early treatment with DMARDs.

Chemical profile and in vivo hypoglycemic effects of Syzygium jambos, Costus speciosus and Tapeinochilos ananassae plant extracts used as diabetes adjuvants in Puerto Rico

Abstract: The increasing numbers of people who use plant-based remedies as alternative or complementary medicine call for the validation of less known herbal formulations used to treat their ailments. Since Puerto Rico has the highest rate of Type 2 diabetes within all the states and territories of the United States, and Puerto Ricans commonly use plants as diabetes adjuvants, it is important to study the plants’ physiological effects, and identify their bioactive compounds to understand their role in modulation of blood glucose levels. We present the phytochemical profiles and hypoglycemic effects of Tapeinochilus ananassae, Costus speciosus and Syzygium jambos. Phytochemicals in methanolic and aqueous extracts were analyzed by thin layer chromatography (TLC). Alkaloids (Bromocresol green, λ = 470 nm), flavonoids (AlCl3, λ = 415 nm), saponins (DNS, λ = 760 nm), tannins (FeCl3/K4Fe(CN)6, λ = 395 nm) and phenolics (Folin-Ciocalteau, λ = 765 nm) were quantified. Male C57BLKS/J (db/db) and C57BL/J (ob/ob) genetically obese mice were orally gavaged with aqueous extracts of lyophilized plant decoctions for 10wks. Our results show that T. ananassae had significantly greater amounts of flavonoids and tannins, while S. jambos showed the greatest concentration of phenolics and C. speciosus exhibited higher amounts of alkaloids. C57BLKS/J db/db treated with plant extracts show better glucose modulation when the extracts are administered in complement with an insulin injection. Finally, C57BL/J ob/ob mice on T. ananassae and S. jambos treatments show better blood glucose modulation over time. These results document for the first time the chemical profile of T. ananassae and provide evidence for a potential anti-diabetic efficacy of T. ananassae and S. jambos.

Dysregulation of Lysyl Oxidase Expression in Lesions and Endometrium of Women With Endometriosis

Abstract: Lysyl oxidases (LOXs) are enzymes involved in collagen deposition, extracellular membrane remodeling, and invasive/metastatic potential. Previous studies reveal an association of LOXs and endometriosis. We aimed to identify the mechanisms activated by upregulation of lysyl oxidases (LOX) in endometriotic cells and tissues. We hypothesized that LOX plays a role in endometriosis by promoting invasiveness and epithelial to mesenchymal transition (EMT).Methods:The LOX protein expression levels were measured by immunohistochemistry in lesions and endometrium on a tissue microarray (TMA) and in endometrial biopsies from patients and controls during the window of implantation (WOI). Estradiol regulation of LOX expression was determined by quantitative polymerase chain reaction (qPCR). Proliferation, invasion, and migration assays were performed in epithelial (endometrial epithelial cell), endometrial (human endometrial stromal cell), and endometriotic cell lines (ECL and 12Z). Pathway-focused multiplex qPCR was ...

Phase II studies to select the formulation of a multivalent HPV L1 virus-like particle (VLP) vaccine.

Abstract: Our objective was to develop a multivalent prophylactic HPV vaccine that protects against infection and disease caused by HPV16/18 (oncogenic types in existing prophylactic vaccines) plus additional oncogenic types by conducting 3 Phase II studies comparing the immunogenicity (i.e., anti-HPV6/11/16/18 geometric mean titers [GMT]) and safety of 7 vaccine candidates with the licensed quadrivalent HPV6/11/16/18 vaccine (qHPV vaccine) in young women ages 16-26. In the first study (Study 1), subjects received one of 3 dose formulations of an 8-valent HPV6/11/16/18/31/45/52/58 vaccine or qHPV vaccine (control). In Study 2, subjects received one of 3 dose formulations (termed low-, mid-, and high-dose formulations, respectively) of a 9-valent HPV6/11/16/18/31/33/45/52/58 vaccine (9vHPV vaccine) or qHPV vaccine (control). In Study 3, subjects concomitantly received qHPV vaccine plus 5-valent HPV31/33/45/52/58 or qHPV vaccine plus placebo (control). All vaccines were administered at day 1/month 2/month 6. In studies 1 and 3, anti-HPV6/11/16/18 GMTs at month 7 were non-inferior in the experimental arms compared with the control arm; however, there was a trend for lower antibody responses for all 4 HPV types. In Study 2, this immune interference was overcome with the mid- and high-dose formulations of the 9vHPV vaccine by increasing antigen and adjuvant doses. In all 3 studies, all vaccine candidates were strongly immunogenic with respect to HPV31/33/45/52/58 and were well tolerated. Based on the totality of the results, the middle dose formulation of the 9vHPV vaccine was selected for Phase III evaluation. Each 0.5mL dose contains 30μg/40μg/60μg/40μg/20μg/20μg/20μg/20μg/20μg of HPV6/11/16/18/31/33/45/52/58 virus-like particles, and 500μg of amorphous aluminum hydroxyphosphate sulfate adjuvant.ClinicalTrials.gov numbers NCT00260039, NCT00543543, and NCT00551187.

Disruptive environmental chemicals and cellular mechanisms that confer resistance to cell death

Abstract: Cell death is a process of dying within biological cells that are ceasing to function. This process is essential in regulating organism development, tissue homeostasis, and to eliminate cells in the body that are irreparably damaged. In general, dysfunction in normal cellular death is tightly linked to cancer progression. Specifically, the up-regulation of pro-survival factors, including oncogenic factors and antiapoptotic signaling pathways, and the down-regulation of pro-apoptotic factors, including tumor suppressive factors, confers resistance to cell death in tumor cells, which supports the emergence of a fully immortalized cellular phenotype. This review considers the potential relevance of ubiquitous environmental chemical exposures that have been shown to disrupt key pathways and mechanisms associated with this sort of dysfunction. Specifically, bisphenol A, chlorothalonil, dibutyl phthalate, dichlorvos, lindane, linuron, methoxychlor and oxyfluorfen are discussed as prototypical chemical disruptors; as their effects relate to resistance to cell death, as constituents within environmental mixtures and as potential contributors to environmental carcinogenesis.

Lupus risk variants in the PXK locus alter B-cell receptor internalization

Abstract: Genome wide association studies have identified variants in PXK that confer risk for humoral autoimmune diseases, including systemic lupus erythematosus (SLE) or lupus, rheumatoid arthritis and more recently systemic sclerosis. While PXK is involved in trafficking of epidermal growth factor Receptor (EGFR) in COS-7 cells, mechanisms linking PXK to lupus pathophysiology have remained undefined. In an effort to uncover the mechanism at this locus that increases lupus-risk, we undertook a fine-mapping analysis in a large multi-ancestral study of lupus patients and controls. We define a large (257kb) common haplotype that confers lupus risk detected only in European ancestral populations and spans the promoter through the 3’ UTR of PXK. The strongest association was found at rs6445972 with P < 4.62 x 10-10, OR 0.81 (0.75 – 0.86). Using stepwise logistic regression analysis, we demonstrate that one signal drives the genetic association in the region. Bayesian analysis confirms our results, identifying a 95% credible set consisting of 172 variants spanning 200kb. Functionally, we found that PXK operates on the B-cell antigen receptor (BCR); we confirmed that PXK influenced the rate of BCR internalization. Furthermore, we demonstrate that individuals carrying the risk haplotype exhibited a decreased rate of BCR internalization, a process known to impact B cell survival and cell fate. Taken together, these data define a new candidate mechanism for the genetic association of variants around PXK with lupus risk and highlight the regulation of intracellular trafficking as a genetically regulated pathway mediating human autoimmunity.

Linking Endotoxins, African Dust PM10 and Asthma in an Urban and Rural Environment of Puerto Rico

Abstract: African Dust Events (ADE) are a seasonal phenomenon that has been suggested to exacerbate respiratory and proinflammatory diseases in Puerto Rico (PR). Increases in PM10 concentration and the effects of biological endotoxins (ENX) are critical factors to consider during these storms. ENX promote proinflammatory responses in lungs of susceptible individuals through activation of the Toll-like receptors (TLR2/4) signaling pathways. The objective of the study was to evaluate the toxicological and proinflammatory responses stimulated by ADE PM10 ENX reaching PR using human bronchial epithelial cells. PM10 organic extracts from a rural and urban site in PR (March 2004) were obtained from ADE and non-ADE and compared. A retrospective data analysis (PM10 concentration, aerosol images, and pediatric asthma claims) was performed from 2000 to 2012 with particular emphasis in 2004 to classify PM samples. Urban extracts were highly toxic, proinflammatory (IL-6/IL-8 secretion), and induced higher TLR4 expression and NF-κB activation compared to rural extracts. ENX were found to contribute to cytotoxicity and inflammatory responses provoked by urban ADE PM10 exposure suggesting a synergistic potency of local and natural ENX incoming from ADE. The contribution of ADE PM10 ENX is valuable in order to understand interactions and action mechanisms of airborne pollutants as asthma triggers in PR.

Association of the Intestinal Microbiota and Obesity

Abstract: Obesity is a condition mainly caused by an alteration in energy intake, shifting towards positive energy balance, which can be influenced by genetic and environmental factors. The human gut is heavily populated with microbial organisms. Recent evidence suggests that obesity is influenced by specific bacterial phyla present in the human gut that have increased energy harvesting capabilities. The main objective of this review is to identify the microbial taxa that are related to obesity and weight loss. In this review, we also discuss the differences between the phylum ratio of the gut microbiota population of obese individuals and that of individuals who have healthy weight. It has been shown that obese individuals have a higher ratio of Firmicutes to Bacteroidetes than healthy weight individuals. The few studies to date have shown that weight-loss treatment may change microbial population of the gut, as there is a decrease in the ratio of Firmicutes to Bacteroidetes. Treating imbalances of the gut microbiota may offer new possibilities for treating obesity.

Childhood ADHD Symptoms Are Associated With Lifetime and Current Illicit Substance-Use Disorders and In-Site Health Risk Behaviors in a Representative Sample of Latino Prison Inmates

Abstract: OBJECTIVE: This study aimed to explore retrospective childhood ADHD symptomatology, psychiatric comorbidity, rates of substance-use disorders (SUD), as well as their association with high-risk health behaviors in prison and adverse health outcomes. METHOD: A randomly selected representative sample of inmates in the Puerto Rico correctional system (N = 1,179) was assessed with the Spanish-language Wender Utah Rating Scale (WURS); the Composite International Diagnostic Interview (CIDI) modules for lifetime/current major depression disorder (MDD), generalized anxiety disorder (GAD), and SUD; the Davidson Trauma Scale (DTS; posttraumatic stress disorder [PTSD]); and self-reports of in-site high-risk behaviors. RESULTS: Wald χ2 tests revealed significant associations of ADHD with MDD and PTSD, as well as increased risk for overdosing and intravenous drug use in prison. A logistic regression model adjusted for mood and anxiety comorbidity predicted lifetime SUD diagnosis (odds ratio = 2.38; 95% confidence interval = [1.15, 4.94]). CONCLUSION: Our results provide further evidence on the association of drug dependence and ADHD symptoms, and their overrepresentation among prison inmates. Language: en

HIV-infected microglia mediate cathepsin B-induced neurotoxicity.

Abstract: HIV-1-infected mononuclear phagocytes release soluble factors that affect the homeostasis in tissue. HIV-1 can prompt metabolic encephalopathy with the addition of neuronal dysfunction and apoptosis. Recently, we reported that HIV-1 enhances the expression and secretion of bioactive cathepsin B in monocyte-derived macrophages, ultimately contributing to neuronal apoptosis. In this research, we asked if microglia respond to HIV infection similarly by modifying the expression, secretion, and neurotoxic potential of cathepsin B and determined the in vivo relevance of these findings. HIV-1ADA-infected human primary microglia and CHME-5 microglia cell line were assessed for expression and activity of cathepsin B, its inhibitors, cystatins B and C, and the neurotoxicity associated with these changes. Human primary neurons were exposed to supernatants from HIV-infected and uninfected microglia in the presence of cathepsin B inhibitors and apoptosis was assessed by TUNEL. Microglial expression of cathepsin B was validated in brain tissue from HIV encephalitis (HIVE) patients. HIV-infected microglia secreted significantly greater levels of cathepsin B, cystatin B, and cystatin C compared to uninfected cells. Increased apoptosis was observed in neurons exposed to supernatants from HIV-1 infected microglia at day 12 post-infection. The cathepsin B inhibitor CA-074 and cathepsin B antibody prevented neuronal apoptosis. Increased microglia-derived cathepsin B, cystatin B, and cystatin C and caspase-3+ neurons were detected in HIVE brains compared to controls. Our results suggest that HIV-1-induced cathepsin B production in microglia contributes to neuronal apoptosis and may be an important factor in neuronal death associated with HIVE.

Citrus aurantium increases seizure latency to PTZ induced seizures in zebrafish thru NMDA and mGluR's I and II

Abstract: Citrus aurantium (CA), commonly known as bitter orange, is used in folk medicine to treat anxiety and insomnia. Studies performed with Essential oils from the peel of the fruit have shown to increase seizure latency to pentylenetetrazole (PTZ) and maximal electroshock seizure in animal models. With these experiments, we assessed a possible role of an aqueous extract from the leaf of the Citrus aurantium tree. Anticonvulsant properties of C. aurantium extracts were tested using adult zebrafish (Danio rerio). Zebrafish exposed to C. aurantium 28 mg/ml showed a 119 % increase on seizure latency compared to controls. We evaluated GABAA and glutamate receptors as mediators of this increase in seizure latency. We used the selective antagonist gabazine to rule out GABAA receptors as targets for the C. aurantium extract. With glutamate receptors, we used two approaches, an In vitro ligand binding assay and the In vitro model of PTZ induced seizures in zebrafish combined with selective receptor antagonists. The ligand binding assay revealed C. aurantium extracts at concentrations of 0.42mg/ml to 5.6mg/ml significantly reduced [3H]Glu binding and this interaction showed to be selective for iGluR and mGluR group II and III. This pattern of interactions was evaluated In vivo pretreating zebrafish with glutamate receptor antagonists and we confirmed NMDA and mGluR’s I and II are involved with the mechanism of C. aurantium extract. These study results support the relevance of natural products as feasible alternatives for drug development providing evidence of effectiveness and possible mechanism of action for the extract.

Urease and Dental Plaque Microbial Profiles in Children

Abstract: Objective Urease enzymes produced by oral bacteria generate ammonia, which can have a significant impact on the oral ecology and, consequently, on oral health. To evaluate the relationship of urease with dental plaque microbial profiles in children as it relates to dental caries, and to identify the main contributors to this activity. Methods 82 supragingival plaque samples were collected from 44 children at baseline and one year later, as part of a longitudinal study on urease and caries in children. DNA was extracted; the V3–V5 region of the 16S rRNA gene was amplified and sequenced using 454 pyrosequencing. Urease activity was measured using a spectrophotometric assay. Data were analyzed with Qiime. Results Plaque urease activity was significantly associated with the composition of the microbial communities of the dental plaque (Baseline P = 0.027, One Year P = 0.012). The bacterial taxa whose proportion in dental plaque exhibited significant variation by plaque urease levels in both visits were the family Pasteurellaceae (Baseline P<0.001; One Year P = 0.0148), especially Haemophilus parainfluenzae. No association was observed between these bacteria and dental caries. Bacteria in the genus Leptotrichia were negatively associated with urease and positively associated with dental caries (Bonferroni P<0.001). Conclusions Alkali production by urease enzymes primarily from species in the family Pasteurellaceae can be an important ecological determinant in children’s dental plaque. Further studies are needed to establish the role of urease-associated bacteria in the acid/base homeostasis of the dental plaque, and in the development and prediction of dental caries in children.

Long-term effects of tetanus toxoid inoculation on the demography and life expectancy of the Cayo Santiago rhesus macaques

Abstract: Tetanus was a major cause of mortality in the free-ranging population of rhesus monkeys on Cayo Santiago prior to 1985 when the entire colony was given its first dose of tetanus toxoid. The immediate reduction in mortality that followed tetanus toxoid inoculation (TTI) has been documented, but the long-term demographic effects of eliminating tetanus infections have not. This study uses the Cayo Santiago demographic database to construct comparative life tables 12 years before, and 12 years after, TTI. Life tables and matrix projection models are used to test for differences in: (i) survival among all individuals as well as among social groups, (ii) long-term fitness of the population, (iii) age distribution, (iv) reproductive value, and (v) life expectancy. A retrospective life table response experiment (LTRE) was performed to determine which life cycle transition contributed most to observed changes in long-term fitness of the population post-TTI. Elimination of clinical tetanus infections through mass inoculation improved the health and well-being of the monkeys. It also profoundly affected the population by increasing survivorship and long-term fitness, decreasing the differences in survival rates among social groups, shifting the population's age distribution towards older individuals, and increasing reproductive value and life expectancy. These findings are significant because they demonstrate the long-term effects of eradicating a major cause of mortality at a single point in time on survival, reproduction, and overall demography of a naturalistic population of primates.

Histamine Immunoreactive Elements in the Central and Peripheral Nervous Systems of the Snail, Biomphalaria spp., Intermediate Host for Schistosoma mansoni.

Abstract: Histamine appears to be an important transmitter throughout the Animal Kingdom. Gastropods, in particular, have been used in numerous studies establishing potential roles for this biogenic amine in the nervous system and showing its involvement in the generation of diverse behaviours. And yet, the distribution of histamine has only previously been described in a small number of molluscan species. The present study examined the localization of histamine-like immunoreactivity in the central and peripheral nervous systems of pulmonate snails of the genus Biomphalaria. This investigation demonstrates immunoreactive cells throughout the buccal, cerebral, pedal, left parietal and visceral ganglia, indicative of diverse regulatory functions in Biomphalaria. Immunoreactivity was also present in statocyst hair cells, supporting a role for histamine in graviception. In the periphery, dense innervation by immunoreactive fibers was observed in the anterior foot, perioral zone, and other regions of the body wall. This study thus shows that histamine is an abundant transmitter in these snails and its distribution suggest involvement in numerous neural circuits. In addition to providing novel subjects for comparative studies of histaminegic neurons in gastropods, Biomphalaria is also the major intermediate host for the digenetic trematode parasite, which causes human schistosomiasis. The study therefore provides a foundation for understanding potential roles for histamine in interactions between the snail hosts and their trematode parasites.

Sexual Health and Socioeconomic-Related Factors Among HIV-Positive Men Who Have Sex with Men in Puerto Rico

Abstract: Most of the research among HIV-positive populations has been approached from behavioral risk models. This is particularly true for those otherwise socially vulnerable groups like men who have sex with men (MSM). As a response to this pattern, we examined data from an ongoing health promotion research being conducted in Puerto Rico (PR). The study is limited to HIV-positive MSM and consists of the participation in a survey interview that includes domains used to assess indicators of socio-economic-related factors (age, educational level, employment, religion, and partnership status) and sexual health (sexual satisfaction, condom use, and sexual health knowledge(SHK)). Participants reported a relatively high level (75 %) of sexual satisfaction and inconsistent condom use (50.9 % reported always using a condom). A deficient (61 %) SHK was also reported. In multivariate analyses, a higher educational level was associated with higher sexual satisfaction (aβ = 3.223; 95 % CI 0.291–6.156) and higher levels of SHK (aβ = 1.328; 95 % CI 0.358–2.297), while unemployment was associated with less condom use (aOR 0.314; 95 % CI 0.122–0.810). Not having a primary sexual partner was associated with less sexual satisfaction (aβ = −3.871; 95 % CI −7.534–0.208) and more condom use (aOR 4.292; 95 % CI 1.310–14.068). Findings support the notion that men of a disadvantaged socioeconomic position may have a poorer sexual health status; with a lower level of education and unemployment leading this disparity. Findings also evidence that partnership status may have a role in the sexual health of HIV-positive MSM. To our knowledge, this is the first comprehensive analysis of sexual health and socioeconomic indicators among Hispanic/Latino HIV-positive MSM in PR and in the Caribbean. Findings provide valuable information to address the sexual health needs of an underserved population.

Early-Onset Neutropenia Induced by Rituximab in a Patient with Lupus Nephritis and Hemolytic Anemia

Abstract: Rituximab is an anti-CD20 monoclonal antibody that has been used to treat several complications of systemic lupus erythematosus (SLE) including nephritis, cerebritis, and hematological disorders. Neutropenia is among the adverse events associated with rituximab; this usually occurs several weeks after therapy. However, early-onset neutropenia has been reported only in a few cases. Herein, we describe a 36-year-old Hispanic SLE woman who developed severe early-onset neutropenia (0.3 × 109/L) after the second weekly rituximab infusion (375 mg/m2 weekly × 4) given for nephritis and hemolytic anemia. She also had early-onset thrombocytopenia after rituximab therapy. Both hematological disorders resolved 12 days after the fourth and final dose. This case, together with few others, suggests that early-onset neutropenia may occur during rituximab therapy. Even though rituximab-induced neutropenia seems to be transient, it may predispose SLE patients to severe complications such as infections.

Impact of Culturally Relevant Contextualized Activities on Elementary and Middle School Students’ Perceptions of Science: An Exploratory Study

Abstract: Although researchers have argued that textbooks should be customized to local cultures and experiences, they rarely are. Ciencia Puerto Rico, a non-profit group interested in promoting science literacy and education among Latino(a)s/Hispanics, identified a need to provide schools with culturally relevant materials. The result was the publication of the book iCiencia Boricua! Ensayos y anecdotas del cientifico puertorro, an anthology of short, multidisciplinary science essays written by Puerto Rican scientists to develop awareness of Puerto Rican science and scientists. The purposes of this manuscript are (a) to provide evidence of instances of contextualization and cultural relevance in iCiencia Boricua!, and (b) to determine the extent to which the use of iCiencia Boricua! and related activities changed the perception toward science of 57 elementary and middle school students enrolled in a public school in Puerto Rico, and which contextualized science activities students preferred. The results showed tha...

Longitudinal Analysis of Cerebrospinal Fluid and Plasma HIV-1 Envelope Sequences Isolated From a Single Donor with HIV Asymptomatic Neurocognitive Impairment.

Abstract: Objective: Combined antiretroviral treatment (cART) has changed the clinical presentation of HIV-associated neurocognitive disorders (HAND) to that of the milder forms of the disease. Asymptomatic neurocognitive impairment (ANI) is now more prevalent and is associated with increased morbidity and mortality risk in HIV-1–infected people. HIV-1 envelope (env) genetic heterogeneity has been detected within the central nervous system (CNS) of individuals with ANI. Changes within env determine co-receptor use, cellular tropism, and neuropathogenesis. We hypothesize that compartmental changes are associated with HIV-1 env C2V4 during ANI and sought to analyze paired HIV-1 env sequences from plasma and cerebrospinal fluid (CSF) of a female subject undergoing long-term cART. Methods: Paired plasma and CSF samples were collected at 12-month intervals and HIV-1 env C2V4 was cloned and sequenced. Results: Phylogenetic analysis of paired samples consistently showed genetic variants unique to the CSF. Phenotypic prediction showed CCR5 (R5) variants for all CSF-derived sequences and showed minor X4 variants (or dual-tropic) in the plasma at later time points. Viral compartmentalization was evident throughout the study, suggesting that the occurrence of distinctive env strains may contribute to the neuropathogenesis of HAND. Conclusions: Our study provides new insights about the genetic characteristics within the C2V4 of HIV-1 env that persist after longterm cART and during the course of persistent ANI.