Antioxidant and cytoprotective effects of avocado oil and extract (Persea americana Mill) against rotenone using monkey kidney epithelial cells (Vero).

Oxidative stress is known to be involved in development of numerous diseases including cardiovascular, respiratory, renal, kidney and cancer. Thus, investigations that mimic oxidative stress in vitro may play an important role to find new strategies to control oxidative stress and subsequent consequences are important. Rotenone, widely used as a pesticide has been used as a model to simulate oxidative stress. However, this chemical was found to produce several diseases. Therefore, the aim of this study was to investigate the antioxidant and cytoprotective effect of avocado (Persea americana Mill) extract and oil in monkey kidney epithelial cells (VERO) exposed to rotenone. VERO cells were exposed to IC50 of rotenone in conjunction with different concentrations of avocado extract and oil (ranging from 1 to 1000 µg/ml), for 24 hr. Subsequently, cell viability and oxidative metabolism were assessed. Data demonstrated that avocado extract and oil in the presence of rotenone increased cellular viability at all tested concentrations compared to cells exposed only to rotenone. In addition, extract and avocado oil exhibited antioxidant action as evidenced by decreased levels of reactive oxygen species (ROS), superoxide ion, and lipid peroxidation, generated by rotenone. Further, avocado extract and oil appeared to be safe, since these compounds did not affect cell viability and or generate oxidative stress. Therefore, avocado appears to display a promising antioxidant potential by decreasing oxidative stress.

A chemical compound based on methylxanthine-polyphenols lowers nitric oxide levels and increases post-thaw human sperm viability.

We produced a new chemical compound based on methylxanthines and polyphenols (CCMP) present in the chemical matrix of guaraná (Paullinia cupana), a seed extract with antioxidant properties. After supplementation with the standard extract of resveratrol, a well documented antioxidant found in other plant sources, we investigated whether this resveratrol-enriched compound could improve sperm viability and modulate differentially reactive oxygen species (ROS) and nitric oxide (NO) levels in thawed sperm. Sperm samples obtained from healthy young donors were treated with different concentrations of guaraná extract (0.1, 1, 5 or 10 mg/ml) and cells were frozen at -80°C for 24 h. In addition, the potential protective effects of guaraná treatment on sperm treated with pro-oxidant compound (200 µM hydrogen peroxide, H2O2) were assessed. Samples were also exposed to three concentrations of CCMP before being frozen in liquid nitrogen (-196°C) or in an ultrafreezer (-80°C) for 24 h, and both pre-freezing and post-thaw measurements of viability and oxidative stress were performed. Guaraná supplementation at 10 mg/ml significantly increased post-thaw viability and decreased oxidative metabolism of the sperm. Moreover, selected concentrations of CCMP improved viability and oxidative metabolism in sperm samples pre-freezing. Furthermore, CCMP showed cryoprotective activity by increasing viability and decreasing oxidative stress in post-thaw samples. In summary, these findings suggested that CCMP supplementation acts as a cryoprotectant to modulate ROS and NO levels in thawed sperm. CCMP could be used to enhance sperm quality and reproductive success.

LncRNA SOX9-AS1 triggers a transcriptional program involved in lipid metabolic reprogramming, cell migration and invasion in triple-negative breast cancer.

At the molecular level, triple-negative breast cancer (TNBC) is frequently categorized as PAM50 basal-like subtype, but despite the advances in molecular analyses, the clinical outcome for these subtypes is uncertain. Long non-coding RNAs (lncRNAs) are master regulators of genes involved in hallmarks of cancer, which makes them suitable biomarkers for breast cancer (BRCA) diagnosis and prognosis. Here, we evaluated the regulatory role of lncRNA SOX9-AS1 in these subtypes. Using the BRCA-TCGA cohort, we observed that SOX9-AS1 was significantly overexpressed in basal-like and TNBC in comparison with other BRCA subtypes. Survival analyzes showed that SOX9-AS1 overexpression was associated with a favorable prognosis in TNBC and basal-like patients. To study the functions of SOX9-AS1, we determined the expression levels in a panel of nine BRCA cell lines finding increased levels in MDA-MB-468 and HCC1187 TNBC. Using subcellular fractionation in these cell lines, we ascertained that SOX9-AS1 was located in the cytoplasmic compartment. In addition, we performed SOX9-AS1 gene silencing using two short-harping constructs, which were transfected in both cell models and performed a genome-wide RNA-seq analysis. Data showed that 351 lncRNAs and 740 mRNAs were differentially expressed in MDA-MB-468 while 56 lncRNAs and 100 mRNAs were modulated in HCC1187 cells (Log2FC < - 1.5 and > 1.5, p.adj value < 0.05). Pathway analysis revealed that the protein-encoding genes potentially regulate lipid metabolic reprogramming, and epithelial-mesenchymal transition (EMT). Expression of lipid metabolic-related genes LIPE, REEP6, GABRE, FBP1, SCD1, UGT2B11, APOC1 was confirmed by RT-qPCR. Functional analysis demonstrated that the knockdown of SOX9-AS1 increases the triglyceride synthesis, cell migration and invasion in both two TNBC cell lines. In conclusion, high SOX9-AS1 expression predicts an improved clinical course in patients, while the loss of SOX9-AS1 expression enhances the aggressiveness of TNBC cells.

The current advances of lncRNAs in breast cancer immunobiology research.

Breast cancer is the most frequently diagnosed malignancy and the leading cause of cancer-related death in women worldwide. Breast cancer development and progression are mainly associated with tumor-intrinsic alterations in diverse genes and signaling pathways and with tumor-extrinsic dysregulations linked to the tumor immune microenvironment. Significantly, abnormal expression of lncRNAs affects the tumor immune microenvironment characteristics and modulates the behavior of different cancer types, including breast cancer. In this review, we provide the current advances about the role of lncRNAs as tumor-intrinsic and tumor-extrinsic modulators of the antitumoral immune response and the immune microenvironment in breast cancer, as well as lncRNAs which are potential biomarkers of tumor immune microenvironment and clinicopathological characteristics in patients, suggesting that lncRNAs are potential targets for immunotherapy in breast cancer.

LINC00426 is a potential immune phenotype-related biomarker and an overall survival predictor in PAM50 luminal B breast cancer.

Background: Breast cancer (BRCA) represents the most frequent diagnosed malignancy in women worldwide. Despite treatment advances, BRCAs eventually develop resistance to targeted therapies, resulting in poor prognosis. The identification of new biomarkers, like immune-related long non-coding RNAs (lncRNAs), could contribute to the clinical management of BRCA patients. In this report, we evaluated the LINC00426 expression in PAM50 BRCA subtypes from two clinical independent cohorts (BRCA-TCGA and GEO-GSE96058 datasets). Methods and results: Using Cox regression models and Kaplan-Meier survival analyses, we identified that LINC00426 expression was a consistent overall survival (OS) predictor in luminal B (LB) BRCA patients. Subsequently, differential gene expression and gene set enrichment analyses identified that LINC00426 expression was associated with different immune-related and cancer-related pathways and processes in LB BRCA. Additionally, the LINC00426 expression was correlated with the infiltration level of diverse immune cell populations, alongside immune checkpoint and cytolytic activity-related gene expression. Conclusion: This evidence suggests that LINC00426 is a potential biomarker of immune phenotype and an OS predictor in PAM50 LB BRCA.

Nevirapine use, prolonged antiretroviral therapy and high CD4 nadir values are strongly correlated with undetectable HIV-DNA and -RNA levels and CD4 cell gain.

OBJECTIVES: To evaluate the correlations of the combination of undetectable HIV-DNA (<10 copies/10(6) peripheral blood mononuclear cells) and HIV-RNA (<1 copy/mL of plasma) levels and a CD4 cell count of >500 cells/mm(3) (defined as the treatment goal) in a group of 420 antiretroviral treatment (ART) responder patients. METHODS: A cross-sectional, open-label, multicentre trial was conducted in a cohort of 420 HIV-infected ART-treated subjects with viral loads persistently <50 copies/mL for a median observation time of 28.8 months. HIV-DNA and residual viraemia values and demographic, virological and immunological data were collected for each subject. RESULTS: Undetectable HIV-DNA was found in 16.6% (70/420) of patients and was significantly correlated with undetectable (<1 copy/mL) plasma viraemia (P = 0.0001). Higher CD4 cell count nadir (P < 0.001), a lower HIV-RNA viraemia at the start of treatment (P = 0.0016) and nevirapine use (P < 0.001) were correlated with an undetectable value of HIV-RNA. Twenty-six out of 420 patients (6.2%) reached the treatment goal. In multivariate analysis, higher nadir CD4 cell count (OR 3.86, 95% CI 1.47-10.16, P = 0.006), the duration of therapy (OR 1.07, 95% CI 1.02-1.12, P = 0.004) and the use of nevirapine (OR 2.59, 95% CI 1.07-6.28, P = 0.034) were independently related to this condition. CONCLUSIONS: Only 6.2% of ART-responder patients presented the combination of three laboratory markers that identified them as full responders. These results indicate the high variability of the ART-responding population and lead us to suggest caution in the selection of patients for possible simplification regimens.

Inflammatory cytokines in vitro production are associated with Ala16Val superoxide dismutase gene polymorphism of peripheral blood mononuclear cells.

Obesity is considered a chronic low-grade inflammatory state associated with a chronic oxidative stress caused by superoxide production (O(2)(-)). The superoxide dismutase manganese dependent (SOD2) catalyzes O(2)(-) in H(2)O(2) into mitochondria and is encoded by a single gene that presents a common polymorphism that results in the replacement of alanine (A) with a valine (V) in the 16 codon. This polymorphism has been implicated in a decreased efficiency of SOD2 transport into targeted mitochondria in V allele carriers. Previous studies described an association between VV genotype and metabolic diseases, including obesity and diabetes. However, the causal mechanisms to explain this association need to be more elucidated. We postulated that the polymorphism could influence the inflammatory response. To test our hypothesis, we evaluated the in vitro cytokines production by human peripheral blood mononuclear cells (PBMCs) carrier's different Ala16Val-SOD2 genotypes (IL-1, IL-6, IL-10, TNF-α, IFN-γ). Additionally, we evaluated if the culture medium glucose, enriched insulin, could influence the cytokine production. Higher levels of proinflammatory cytokines were observed in VV-PBMCs when compared to AA-PBMCs. However, the culture medium glucose and enriched insulin did not affect cytokine production. The results suggest that Ala16Val-SOD2 gene polymorphism could trigger the PBMCs proinflammatory cytokines level. However, discerning if a similar mechanism occurs in fat cells is an open question.

Performance of genotypic tropism testing on proviral DNA in clinical practice: results from the DIVA study group.

OBJECTIVE: The DIVA study is aimed at setting up a standardized genotypic tropism-testing on proviral-DNA for the routine clinical diagnostic-laboratory. METHODS: Twelve local centres and 5 reference centres (previously cross-validated) were identified. For inter-center validation-procedure, 60 peripheral-blood mononuclear cells (PBMCs) aliquots from 45 HAART-treated patients were randomly chosen for population V3 sequencing on proviral-DNA at local HIV centre and at reference-laboratory. Viral tropism was predicted by Geno2Pheno algorithm (False Positive Rate [FPR] = 20%) as proposed by the European-Guidelines. Quantification of total HIV-1 DNA was based on a method described by Viard (2004). RESULTS: Quantification of HIV-1 DNA was available for 35/45 (77.8%) samples, and gave a median value of 598 (IQR:252- 1,203) copies/10 PBMCs. A total of 56/60 (93.3%) samples were successfully amplified by both the reference and the local virological centers. The overall concordance of tropism prediction between local and reference centers was 54/56 (96.4%). Results of tropism prediction by local centers were: 33/54 (61.1%) R5 and 21/54 (38.9%) X4/DM. CONCLUSION: There was high concordance in the genotypic tropism prediction based on proviral DNA among different virological centers throughout Italy. Our results are in line with other European studies, and support the use of genotypic tropism testing on proviral DNA in patients with suppressed plasma HIV-1 RNA candidate to CCR5-antagonist treatment.

Cancer Genomics.

In the past decade, genomics has fundamentally changed our view of cancer biology, allowing comprehensive analyses of mutations, copy number alterations, structural variants, gene expression and DNA methylation profiles in large-scale studies across different cancer types. Efforts like The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) have fostered international collaborations for cancer genomic analyses and have generated public databases that give scientists around the world access to thoroughly curated data, which have been extensively used as a tool for further hypothesis driven research on several aspects of cancer biology. In parallel, some of these findings are being translated into specific clinical benefits for cancer patients. In this review, we provide a brief historical description of the evolution of international public cancer genome projects and related databases, as well as we discuss about their impact on general cancer research.

Amazonian fruits with potential effects on COVID-19 by inflammaging modulation: A narrative review.

The COVID-19 pandemic had a great impact on the mortality of older adults and, chronic non- transmissible diseases (CNTDs) patients, likely previous inflammaging condition that is common in these subjects. It is possible that functional foods could attenuate viral infection conditions such as SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), the causal agent of COVID-19 pandemic. Previous evidence suggested that some fruits consumed by Amazonian Diet from Pre-Colombian times could present relevant proprieties to decrease of COVID-19 complications such as oxidative-cytokine storm. In this narrative review we identified five potential Amazonian fruits: açai berry (Euterpe oleracea), camu-camu (Myrciaria dubia), cocoa (Theobroma cacao), Brazil nuts (Bertholletia excelsa), and guaraná (Paullinia cupana). Data showed that these Amazonian fruits present antioxidant, anti-inflammatory and other immunomodulatory activities that could attenuate the impact of inflammaging states that potentially decrease the evolution of COVID-19 complications. The evidence compiled here supports the complementary experimental and clinical studies exploring these fruits as nutritional supplement during COVID-19 infection. PRACTICAL APPLICATIONS: These fruits, in their natural form, are often limited to their region, or exported to other places in the form of frozen pulp or powder. But there are already some companies producing food supplements in the form of capsules, in the form of oils and even functional foods enriched with these fruits. This practice is common in Brazil and tends to expand to the international market.

The Proliferating Cell Nuclear Antigen (PCNA) Transcript Variants as Potential Relapse Markers in B-Cell Acute Lymphoblastic Leukemia.

Leukemia is the most common childhood malignancy in Mexico, representing more than 50% of all childhood cancers. Although treatment leads to a survival of up to 90% in developing countries, in our country, it is less than 65%. Additionally, ~30% of patients relapse with poor prognosis. Alternative splicing plays an important role in transcriptome diversity and cellular biology. This mechanism promotes an increase in the assortment of proteins with potentially distinct functions from a single gene. The proliferating cell nuclear antigen (PCNA) gene encodes two transcripts for the same protein of 261 amino acids, which is associated with several important cellular processes and with several types of cancer. However, the diversity of the transcript variants expressed in this condition is not clear. Then, we used microarray gene expression to identify changes in the exon expression level of PCNA. The data were validated using RT-PCR and Sanger sequencing, and three additional transcripts (PCNA_V3, PCNA_V4, and PCNA_V5) were identified. Computational analyses were used to determine the potential proteins resulting, their structure, and interactions with PCNA native protein and themselves. Additionally, the PCNA transcript variants were inhibited using specific siRNA, determining that their inhibition contributes to the malignant characteristics in vitro. Finally, we quantified the PCNA transcript variants in acute lymphoblastic leukemia samples and identified their expression in this disease. Based on the clinical characteristics, we determined that PCNA_V2 and PCNA_V4 are expressed at significantly low levels in relapsed B-ALL patients. We conclude that the low expression of PCNA_V2 and PCNA_V4 could be a potential molecular marker of relapse in acute lymphoblastic leukemia patients.

Lemongrass (Cymbopogon citratus (D.C.) Stapf) Presents Antitumoral Effect and Improves Chemotherapy Activity in Prostate Cancer Cells.

BACKGROUND: Prostate cancer is the most common visceral neoplasia in men and frequently presents chemotherapy resistance. In this context, lemongrass (Cymbopogon citratus (D.C.) Stapf) has been studied since it presents many important biological activities, such as anticancer. OBJECTIVE: We investigated the antitumor effect of lemongrass and in chemotherapy activity using prostate cancer cells line (DU-145). METHODS: DU-145 cells were exposed to different concentrations of aqueous extract of lemongrass (30; 100; 300; 500 and 1000 µg/mL), isolated and in combination with docetaxel, during 24 and 72 hours. After, cell viability and proliferation, oxidative metabolism, colony formation and cell cycle analyses were performed. Also, we exposed the African green monkey kidney cell line (VERO) to the same lemongrass concentrations to investigate a possible toxicity of this extract. RESULTS: Our findings suggested that lemongrass presented an antitumor effect and improved docetaxel chemotherapy activity by decreasing cell viability and proliferation as well as colony formation. Moreover, we found an oxidative stress increased and cell cycle arresting in G0 /G1 phase. In addition, this extract presented selectivity action for cancer cells, since it did not cause cytotoxicity in normal cells, ensuring non-toxic therapeutic concentrations. CONCLUSION: Lemongrass is a promising medicinal plant that could be used during chemotherapeutic treatment, in order to potentiate the antitumor response and decrease the resistance of prostate cancer.

Performance of rice straw as mono- and co-feedstock of Ulva spp. for thalassic biogas production.

The seasonal availability of Ulva spp. (U) poses a problem for the continuous operation of thalassic (TH) biogas digesters. Hence, rice straw (RS) was tested as an alternative substrate because of its abundance in Asian countries. The anaerobic monodigestion (AMD) of RS was performed under freshwater (FW) and TH conditions to investigate the TH biogas production performance using terrestrial biomass. Biological hydrolysis (BH-P) and 3% NaOH (NaOH-P) pretreatments were employed to minimize the limitation of biomass hydrolysis in the methane fermentation process. The BH-P [FW = 62.2 ± 30.9 mLCH4 g-1VS (volatile solids); TH = 75.8 ± 5.7 mLCH4 g-1VS] of RS led to higher actual methane yield (AMY) than NaOH-P (FW = 15.8 ± 22.8 mLCH4 g-1VS; TH = 21.4 ± 4.2 mLCH4 g-1VS) under both conditions (P = 0.008), while AMY of FW BH-P was comparable (P = 0.182) to TH BH-P. Thus, TH and BH-P was applied to the anaerobic co-digestion (ACD) of U and RS of varying mixture ratios. All ACD set-ups resulted in higher AMY (25U:75RS = 107.6 ± 7.9 mLCH4 g-1VS, 50U:50RS = 130.3 ± 10.3 mLCH4 g-1VS, 75U:25RS = 121.7 ± 2.7 mLCH4 g-1VS) compared with 100% RS (75.8 ± 5.7 mLCH4 g-1VS) or 100% U (94.8 ± 6.8 mLCH4 g-1VS) alone. While the AMY of 50U:50RS was comparable to 75U:25RS (P = 0.181), it is significantly higher (P = 0.003) than its estimated methane yield (EMY; 85.3 mLCH4 g-1VS), suggesting a synergistic effect on ACD of U and RS under 50:50 ratio. The results show that RS can be used as an alternative mono-feedstock for TH biogas production, and a high AMY can be obtained when RS is used as co-feedstock with U.

Association between manganese superoxide dismutase (MnSOD) gene polymorphism and elderly obesity.

Evidence suggests an association between obesity and oxidative stress caused by superoxide production. Since the dismutation of superoxide is catalyzed by superoxide dismutase enzymes, we tested the association between obesity and Ala16Val manganese-dependent superoxide dismutase gene (MnSOD) polymorphism. We analyzed 815 free-living community subjects (> or =60 years old) grouped into subjects who were either obese (BMI > or = 30 kg/m(2)) or non-obese (BMI < 25 kg/m(2)). Additionally, we investigated the possible interaction between the Ala16Val MnSOD gene polymorphism and obesity in the modulation of biochemical and nutritional variables. We found a positive association between MnSOD polymorphism and obesity, since higher VV frequency (28.2%) was observed in the obese group (P = 0.002, odds ratio 1.949, 95% CI: 1.223-3.008). This result was independent of sex, age, diabetes, dyslipidemia, hypertension, and metabolic syndrome. A possible biological explanation of the association described here could be a chronic state of superoxide enzyme imbalance present in VV carriers, which could affect differential metabolic pathways contributing to the obese state.

Stability of agar in the seaweed Gracilaria eucheumatoides (Gracilariales, Rhodophyta) during postharvest storage.

The status of the cell-wall polysaccharide of the red seaweed, Gracilaria eucheumatoides upon postharvest storage was assessed in this study. The yield, chemical composition, physical and textural properties of alkali-treated agar extract was determined at different time intervals within 31 months of storage at dried state after harvest. Minimal fluctuation in agar yield was observed, ranging from 22.9% to 29.0%. The gel strength of agar extracts averaged 318gcm(-2) until the third month of storage but decreased considerably thereafter. The relative viscosity and molecular weight of the extracts varied inversely with storage time. Results indicated that both physical and textural parameters of agar generally decreased with storage time, likely due to depolymerization as indicated by decrease in molecular weight. Agar extracted from seaweeds up to 3 months of storage could be considered to exhibit gel quality suitable for food applications. Prolonged storage of the seaweed harvest is not recommended.

Cytotoxic effects of moderate static magnetic field exposure on human periphery blood mononuclear cells are influenced by Val16Ala-MnSOD gene polymorphism.

Technological advancement has increasingly exposed humans to magnetic fields (MFs). However, more insights are necessary into the potential toxicity of MF exposure as a result of genetic variations related to oxidative metabolism. Therefore, the following study has assessed an in vitro cytotoxic effect of static magnetic field (SMF) (5 mT) on cells with Val16Ala polymorphism (AA, VA, and VV) in the manganese superoxide dismutase gene. Homozygous Val16Ala-superoxide dismutase 2 (SOD2) genotypes present oxidative imbalance that is associated with risk to several chronic degenerative diseases (VV produces less efficient and AA more efficient SOD2 enzyme). Blood samples from healthy adult subject carriers with different Val16Ala-SOD2 genotypes were obtained and exposed to MF at different times (0, 1, 3, 6 h). The cytotoxic effect as well as oxidative stress was evaluated after incubation of 24 h at 37 °C. In addition, apoptosis induction has been analyzed by flow cytometry as well as Bcl-2-associated X protein (BAX), B-cell lymphoma 2 (BCL-2), and caspases 8 and 3 gene expression. SMF cytotoxic effect has been observed in AA cells at all times of exposure, whereas AV cells presented higher mortality only after 6 h of exposure at SMF. Higher apoptosis induction has been observed in AA cells when compared to VV and AV cells. These results suggest a toxicogenetic SMF effect related to an imbalance in SOD2 activity.

[Sex and age associated to femur and rotula fractures]. / Fracturas del fémur y rodilla. Asociación con edad y sexo.

OBJECTIVE: To identify specific fractures risks of the following bones: distal femur, patella and tibia plateau, according to sex and age, with special interest in women >or= 50 y.o. MATERIAL AND METHODS: An epidemiologic case-control study was done between January 2002 and December 2005. The incidence rate for fractures were got by year, sex and age. The group exposed to the risk factors, was represented by female patients >or=50 y.o. The cases with fracture's worst prognosis were: distal femur (supracondylar, supraintercondylar or condylar), tibial plateau (Schatzker IV-VI); the control group was made with patients which fractures were in: proximal femur (Subtrocantheric, diaphysis), tibial plateau (Schatzker I-III). Descriptive and inferential analysis were done separately and together. RESULTS: 1578 Patients were studied. Incidence of fractures in the studied regions was of 5.9 per 10 000 persons/year (py), being of 5.7 and 4.9 per 10,000 py for men and women, respectively (p < 0.001). In subjects with age >or=50 y.o. the incidence rate was of 10.5 and 6.6 per 10 000 py for men and women, respectively. In the study patients less than 50 y.o. the incidence rate was of 1.6 per 10 000 py for both sexes (p < 0.001). The women >or=50 y.o. presented an OR of 5.1 (95% CI: 2.7-9.8, p < 0.001). CONCLUSIONS: In this study sample, the risk of fracture of the femur and the knee was greater in men than in women. In the >or= 50 y.o. age group, the ratio was inverted, with special interest in distal femur fractures. According to sex and age, no differences were identified in tibia plateau fractures.

Survivorship of coral juveniles in a fish farm environment.

Intensive fish farming is an emerging coastal activity that can potentially enhance sedimentation and promote eutrophication in fringing coral reefs. Here, we investigate the effect of fish farm effluent on the juvenile survivorship of the reef-building coral Seriatopora caliendrum. One-month old juvenile corals (on terracotta tiles) were deployed in fish farm and reference (reef) sites in Bolinao, the Philippines at a depth of 2m. After forty days, no survivor was recovered in the fish farm, while survivorship was low (11%) in the reference site, with the survivors' growth rate at 3.3polypsmo(-1) or 1.3mm(2)mo(-1). The fish farm deployed tiles were covered with muddy sediment and were colonized by barnacles, whereas those in the reference site were overgrown by a short stand of filamentous macroalgae. Environmental monitoring revealed higher nutrient levels (ammonia and phosphate), sedimentation rate, and organic matter flux, as well as diminished water transparency and dissolved oxygen levels in the fish farm compared to the reference site. Hence, intensive fish farming offers a suite of physical, chemical and biological modifications of the coastal marine environment which have a detrimental effect on the survivorship of coral juveniles.

Viral growth assay to evaluate the replicative capacity of HIV-1 isolates.

The replicative capacity of HIV is studied by carrying out replication-competition experiments with the insertion of the gene of interest. These assays cannot capture the complicated patterns of mutations of different genes.A cross sectional study was carried out on 10 HIV-infected nai;ve patients and on 15 patients failing HAART. The CD8-depleted PBMCs, with known proviral DNA and cellular HIV-RNA copy numbers, were cultured. A reference curve was determined using the data obtained from 10 nai;ve patients. The replicative capacity was calculated as the ratio multiplied by 100 of the p24 antigen level of isolates over the p24 antigen level determined on the reference curve.A linear correlation between p24 antigen level and the infectious doses of HIV-DNA alone or plus cellular RNA copy number of PBMCs was found in naive patients (r=0.63, P<0.001 and r=0.67, P<0.001, respectively). Although all patients failing therapy had strains with impaired replicative capacity, a wide range of values (0.1-74.5%) was detected. All strains with a replicative capacity above 10% had non-nucleoside reverse transcriptase inhibitors related mutations.A viral assay to evaluate the HIV replicative capacity is described. The high variability of replicative capacity confirms the need to undertake replicative capacity assay using the whole virus.

kappa-Carrageenan gel as agent to sequester paralytic shellfish poison.

The action of k-carrageenan gel to sequester paralytic shellfish poison (PSP) was tested and characterized. When an extract from a Philippine strain of Pyrodinium bahamense var. compressum was used as PSP solution, the PSP-sequestering property of kappa-carrageenan gel was found to be dependent on gel surface area, interaction time, and polysaccharide concentration. The interaction was also found to be affected by high concentrations of monovalent cations. The characteristics of kappa-carrageenan as a PSP-sequestering agent all point to cation exchange as its mechanism of action. It is also proposed that the polysaccharide gel can be utilized as an agent to alleviate PSP intoxication.