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1.
Ann Behav Med ; 58(7): 488-497, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38810223

RESUMO

BACKGROUND: Despite the high burden of anxiety and hypertension in Hispanic/Latino adults, little is known about their association in this population. PURPOSE: To examine the associations of anxiety symptoms with 6-year changes in blood pressure (BP) and incident hypertension in Hispanic/Latino adults. METHODS: We examined data from a probability sample of 10,881 Hispanic/Latino persons aged 18-74 who attended visits 1 (V1; 2008-2011) and 2 (V2; 2014-2017) of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a prospective cohort study. Anxiety symptoms were assessed at V1 using the 10-item Spielberger Trait Anxiety Scale (M = 17.1; Range = 10-40) and dichotomized using a cut-point of 20, the highest quartile in this cohort. BP was measured at both visits using a standardized protocol. RESULTS: Adults with elevated anxiety symptoms had a 1.02 mm Hg greater increase in systolic (p = .02) and a 0.75 mm Hg greater increase in diastolic BP (p = .02) over 6.1 years than those with lower symptoms, after adjusting for sociodemographic and clinical covariates. These associations differed by sex. Elevated anxiety was associated with a greater increase in systolic and diastolic BP in men only. Among persons without hypertension at V1 (N = 7,412), those with elevated anxiety symptoms at V1 had a 22% higher incidence of hypertension (p = .02) 6.1 years later. CONCLUSIONS: Our findings underscore the importance of screening for and treating elevated anxiety symptoms to help prevent hypertension. Further research on the role of sex and underlying mechanisms is warranted.


This study investigated the relationship between anxiety symptoms and changes in blood pressure, as well as the incidence of hypertension among Hispanic/Latino adults over time. Using data from 10,881 Hispanic/Latino adults who participated in the Hispanic Community Health Study/Study of Latinos, we found that men, but not women, with elevated anxiety symptoms experienced a greater increase in both systolic and diastolic blood pressure over a 6-year period compared to those with lower symptoms. Additionally, among 7,412 participants who were free of hypertension at baseline, individuals with elevated anxiety symptoms developed hypertension at a higher rate after 6 years of follow-up compared to those with lower symptoms. These findings suggest that anxiety symptoms play a role in the development of hypertension among Hispanic/Latino adults, underscoring the importance of screening for and addressing elevated anxiety to potentially prevent hypertension.


Assuntos
Ansiedade , Pressão Sanguínea , Hispânico ou Latino , Hipertensão , Humanos , Masculino , Feminino , Hispânico ou Latino/estatística & dados numéricos , Adulto , Pessoa de Meia-Idade , Hipertensão/epidemiologia , Hipertensão/etnologia , Ansiedade/epidemiologia , Ansiedade/etnologia , Adulto Jovem , Adolescente , Idoso , Pressão Sanguínea/fisiologia , Estudos Prospectivos , Incidência , Estados Unidos/epidemiologia
2.
J Therm Biol ; 123: 103893, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38924931

RESUMO

Species are expected to migrate to higher latitudes as warming intensifies due to anthropogenic climate change since physiological mechanisms have been adapted to maximize fitness under specific temperatures. However, literature suggests that upwellings could act as thermal refugia under climate warming protecting marine ecosystem diversity. This research aimed to predict the effects of climate warming on commercial and non-commercial fish species reported in official Mexican documents (>200 species) based on their thermal niche to observe if upwellings can act as potential thermal refugia. Present (2000-2014) and Representative Concentration Pathway (6.0 and 8.5) scenarios (2040-2050 and 2090-2100) have been considered for this work. Current and future suitability patterns, species distribution, richness, and turnover were calculated using the minimum volume ellipsoids as algorithm. The results in this study highlight that beyond migration to higher latitudes, upwelling regions could protect marine fishes, although the mechanism differed between the innate characteristics of upwellings. Most modeled species (primarily tropical fishes) found refuge in the tropical upwelling in Northern Yucatan. However, the highest warming scenario overwhelmed this region. In contrast, the Baja California region lies within the Eastern Boundary Upwelling Systems. While the area experiences an increase in suitability, the northern regions have a higher upwelling intensity acting as environmental barriers for many tropical species. Conversely, in the southern regions where upwelling is weaker, species tend to congregate and persist even during elevated warming, according to the turnover analysis. These findings suggest that tropicalization in higher latitudes may not be as straightforward as previously assumed. Nevertheless, climate change affects numerous ecosystem features, such as trophic relationships, phenology, and other environmental variables not considered here. In addition, uncertainty still exists about the assumption of increasing intensity of upwelling systems.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38699908

RESUMO

The effects of two prepared feeds were tested on growth, survival, enzymatic activity, nutritive reserves in the digestive gland and oxygen consumption of Octopus maya juveniles. For the first time, a semihumid paste (HD, control) and a dry diet, in pelleted form (PD, experimental) with the same formulation were used for this species. The experiment lasted for 42 days. Results indicate that growth rates were similar for both diets (p > 0.05); however, survival (70%) was higher with the PD compared to the HD (48%) (p < 0.05). The performance index was higher for octopuses fed the PD (p < 0.05). No differences in acid proteases activity were observed. However, a higher activity of alkaline proteases in the octopuses fed the PD was observed (p < 0.05). Ingestion rate was higher for octopuses fed the PD. Routine energy inversion was similar in both treatments (p > 0.05). A greater energy inversion was observed in octopuses fed the PD, whose active metabolism was double compared to the octopuses fed the HD. Results showed that the PD promoted similar growth compared to the HD diet but favored survival, and a greater investment in the active metabolism, reflected in the apparent heat increase.

4.
Anim Cogn ; 26(3): 1065-1072, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36809584

RESUMO

The Novel Object Recognition task (NOR) is widely used to study vertebrates' memory. It has been proposed as an adequate model for studying memory in different taxonomic groups, allowing similar and comparable results. Although in cephalopods, several research reports could indicate that they recognize objects in their environment, it has not been tested as an experimental paradigm that allows studying different memory phases. This study shows that two-month-old and older Octopus maya subjects can differentiate between a new object and a known one, but one-month-old subjects cannot. Furthermore, we observed that octopuses use vision and tactile exploration of new objects to achieve object recognition, while familiar objects only need to be explored visually. To our knowledge, this is the first time showing an invertebrate performing the NOR task similarly to how it is performed in vertebrates. These results establish a guide to studying object recognition memory in octopuses and the ontological development of that memory.


Assuntos
Octopodiformes , Reconhecimento Psicológico , Animais , Comportamento Exploratório , Percepção Visual , Reconhecimento Visual de Modelos
5.
J Therm Biol ; 114: 103495, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37276747

RESUMO

Ocean warming is expected to occur due to anthropogenic climate change bringing a spatial shift of marine communities. Experimental data that characterize the aerobic power budget via an aerobic scope, thermal metabolic scope, or thermal preferences have been proposed as tools that can describe species distribution since they characterize species fitness or performance under different temperatures. This study tested the potential relationship between observed occurrences and different physiological studies in the Americas for 11 commercially important species in Mexico. Projections were also developed for Mexico's exclusive economic zone under different climate warming scenarios. The physiological data were fitted from optimum up to pejus temperatures and projected to sea surface temperatures for present (2003-2014) and Representative Concentration Pathway (RCP) scenarios (RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5) for the period 2040-2050 and 2090-2100. For species with wide distributions in the Americas, the number of occurrences reported decreases at higher latitudes related to the decrease in species performance calculated from laboratory experiments. In addition, higher species occurrences are usually reported around optimum temperatures. Overall, the results suggest that pejus temperatures likely restrict latitudinal distribution, at least for widely distributed taxons. Regarding Mexican projections, the results varied widely by species. For example, in the Atlantic Ocean, Octopus maya and Panulirus argus are vulnerable to warming scenarios, while Centropomus undecimalis is not. Interestingly, northern Campeche Bank, the Gulf of California, and Western Baja California may act as thermal refugia for marine species indicating they could be assigned as protected areas to support fisheries throughout the Mexican exclusive economic zone. This research adds to the increasing evidence of the relationship between thermal niche and wild population distribution.


Assuntos
Mudança Climática , Meio Ambiente , México , Temperatura , Refúgio de Vida Selvagem , Ecossistema
6.
Bull Environ Contam Toxicol ; 111(5): 60, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37903889

RESUMO

Benzophenone-3 (BP-3) is an active ingredient in sunscreen lotions and personal-care products that protects against the damaging effects of ultraviolet rays. Given its worldwide dissemination, it has been linked with harmful effects on aquatic biota; however, its impact is not fully understood calling for further studies. To understand the impacts on an important economically and ecologically species, we evaluated the toxicity of BP-3 during the embryonic development of Octopus maya. Embryos were exposed to increasing concentrations of up to 500 µg BP-3/L until hatching. Antioxidant enzyme activities, oxidative-stress indicators, and B-esterases activities were measured at different developmental phases (organogenesis, activation, and growth). There were no significant differences between treatments, suggesting the lack of production of toxic metabolites that may be related to a protective chorion, an underdeveloped detoxification system, and the experimental conditions that limited phototoxicity.


Assuntos
Octopodiformes , Animais , Carboxilesterase/farmacologia , Estresse Oxidativo , Antioxidantes/farmacologia , Desenvolvimento Embrionário
7.
Bull Environ Contam Toxicol ; 110(3): 63, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36917264

RESUMO

No ecotoxicological information exists on phenanthrene (Phe) exposure in cephalopods, animals of commercial and ecological importance. This study investigated the effect of Phe on two B-esterases, Acetylcholinesterase (AChE) and Carboxylesterases (CbE), in Octopus maya embryos. Octopus embryos were exposed to different treatments: control (seawater), solvent control (seawater and DMSO 0.01%), 10 and 100 µg/L of Phe. AChE and CbE activities were measured at different developmental stages (blastula, organogenesis, and growth). B-esterase activities increased in control and solvent control as the embryos developed, showing no statistically significant differences between them. On the other hand, the embryos exposed to Phe had significant differences from controls, and between the high and low concentrations. Our results indicate that B-esterases are sensitive biomarkers of exposure to Phe in O. maya. Still, complementary studies are needed to unravel the toxicodynamics of Phe and the implications of the found inhibitory effect in hatched organisms.


Assuntos
Octopodiformes , Fenantrenos , Animais , Acetilcolinesterase , Esterases , Fenantrenos/toxicidade , Solventes
8.
Gen Comp Endocrinol ; 320: 114000, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35217062

RESUMO

The optic glands (OG) of cephalopods are a source of molecules associated with the control of reproductive traits and lifecycle events such as sexual maturation, reproductive behavior, feeding, parental care, and senescence. However, little is known about the role of the optic gland in Octopus maya adults during mating and egg laying. RNA sequencing, de novo transcriptome assembly, ubiquity and differential expression analysis were performed. First, we analyzed the expression patterns of transcripts commonly associated with OG regulatory functions to describe their possible role once the maturation of the gonad is complete. The transcriptomic profiles of the optic gland of both sexes were compared with emphasis on the signaling pathways involved in the dimorphism of reproductive traits. Results suggest that in the OG of males, the reproductive condition (mated or non-mated) did not affect the general expression profile. In contrast, more differentially expressed genes were observed in females. In mated females, the mRNA metabolic process and the response to norepinephrine were enriched, suggesting a high cellular activity in preparation for the laying of the embryos. Whereas in egg-laying females, energetic and metabolic processes were the most represented, including the oxidation-reduction process. Finally, the gene expression patterns in senescence females suggest a physiological response to starvation as well as upregulation of genes involved retrotransposon activity. In conclusion, more substantial fluctuations in gene expression were observed in the optic glands of the fertilized females compared to the males. Such differences might be associated with the regulation of the egg-laying and the onset of senescence.


Assuntos
Octopodiformes , Transcriptoma , Animais , Feminino , Perfilação da Expressão Gênica , Masculino , Octopodiformes/genética , Reprodução/genética , Análise de Sequência de RNA
9.
AIDS Behav ; 25(8): 2542-2550, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33742307

RESUMO

Under-detection of HIV/AIDS still burdens many low- and middle-income countries (LMICs). Our randomized trial investigated the effects of financial incentives and a behavioral nudge to induce HIV testing and learning HIV status in Ecuador. In the control group, 12.2% of participants agreed to testing, and 5.3% learned results. A financial incentive paid at testing increased the fraction of participants tested by 50.1 percentage points (95% CI 38.8 to 61.4) and the fraction who learned their status by 8.9 percentage points (95% CI 5.3 to 12.5); the nudge had no effect. The HIV-positive rate was 1.2% in the control group, and incentives prompted a 4.7 percentage point (95% CI 0.5 to 8.9) higher proportion of HIV-positive detection. Incentives also induced earlier testing, suggesting reduced procrastination. This suggests that information with appropriately timed small financial incentives can improve HIV testing and detection of new cases in the general population in LMIC settings.


Assuntos
Infecções por HIV , Motivação , Equador , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Teste de HIV , Humanos
10.
J Therm Biol ; 102: 103078, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34863472

RESUMO

The blue crab Callinectes sapidus is a widespread ectothermic species that supports large fisheries. Physiology of temperate and subtropical populations of blue crabs are well studied; however, a lack of information exists on tropical populations. Given the low locomotion capabilities of C. sapidus adult blue crabs, natural selection should favor traits that shape a particular thermal niche reflected through tolerance modulation to dissolved oxygen (DO). This study was designed to evaluate the thermal window and hypoxia sensitivity of the blue crab population in the southern Gulf of Mexico. The effect of acclimation temperatures from 20 °C to 34 °C on thermal preference (TP), critical thermal limits (CT), and thermal metabolic scope (TMS) was assessed in normoxia. Metabolic rate regulation over oxygen partial pressure (pO2) gradient was evaluated through oxygen consumption measurements at different degrees of acute hypoxia. Callinectes sapidus was observed tending to specialize towards higher temperatures, showing a mean TP from 26 °C to 33 °C. The lowest performance of aerobic pathways was observed at the coldest regimes and the highest at the warmest ones with mean TMS value being 35 % greater at 34 °C than 20 °C. Patterns for metabolic regulation were dependent on the interaction between environmental temperature and DO, in which the interval from 29 °C to 34 °C provoked a 50 % reduction in oxygen consumption when exposed to ∼20% air saturation levels. The results obtained showed that blue crabs distributed in the southern Gulf of Mexico could be close to their oxygen-temperature tolerance limits, which has important implications when climate change effects on species re-distribution is considered.


Assuntos
Braquiúros/fisiologia , Hipóxia/metabolismo , Termotolerância , Aerobiose , Animais , Feminino , Masculino
11.
J Therm Biol ; 99: 103023, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34420646

RESUMO

This study determined the physiological and metabolic responses of cultivated Yellowtail Kingfish (Seriola lalandi) juveniles in accordance with their recent thermal history. The fish were acclimated at 20, 23, 26, 29 and 32 °C for 21 days to determine the final preferred temperature, thermal tolerance and the effect of acclimation temperatures on their oxygen uptake and aerobic scope. The final preferred temperature of juveniles was established at 26 °C. The critical thermal maximum (CTmax) ranged from 34.2 to 36.9 °C, while the critical thermal minimum (CTmin) ranged from 10.9 to 17.3 °C, depending on acclimation temperature. With the CTmax and CTmin values, the thermal window was determined to have an area of 258°C2, which is characteristic of subtropical organisms. Although, the metabolic rate was relatively constant (ranging 390.6-449.8 mg O2 kg-0.8 h-1) between 20 and 26 °C (Q10 = 1.6, 1.0), an increase to 544.8 mg O2 kg-0.8 h-1 at 29 °C (Q10 = 1.9) and decrease of 478.4 mg O2 kg-0.8 h-1 at 32 °C (Q10 = 0.6) were observed. The maximum value obtained for aerobic scope was 310.9 mg O2 kg-0.8 h-1 at 26 °C. These results suggest that the acclimation temperature of 26 °C is an optimum thermal condition for a physiological and metabolic performance of yellowtail kingfish juveniles. On the contrary, the response observed during the evaluation of critical temperatures, oxygen uptake and aerobic scope indicated that yellowtail kingfish in the juvenile state could be vulnerable when it experiences for long periods (e.g., >21 days) temperatures above 29 °C. According to our results, the thermoregulatory behaviour of yellowtail kingfish in the juvenile stages could be one of the most important mechanisms to maintain its optimal physiological performance by actively selecting a stable thermal environment close to 26 °C. In addition, it was determined the limits of the pejus state of juvenile yellowtail kingfish at 29 °C, where an increase of oxygen uptake to maintain the aerobic energy metabolism was observed, this could certainly affect the growth of juveniles in culture systems if they do not return in a thermal range of 23-26 °C. These results can contribute to infer the different effects of acclimation temperature on the growth, thermal tolerance and respiratory capacity of S. lalandi juveniles on aquaculture systems.


Assuntos
Aclimatação , Peixes/metabolismo , Consumo de Oxigênio , Oxigênio/metabolismo , Termotolerância , Criação de Animais Domésticos , Animais , Temperatura
12.
Biochem Genet ; 58(1): 189-209, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31552565

RESUMO

The circadian clock is regulated at the molecular level by feedback circuits of a group of genes known as "clock genes", which establish a mechanism that controls circadian cellular physiology to maintain the balance between cell proliferation, response to DNA damage and apoptosis. Alterations in the expression of clock genes due to genetic or epigenetic mechanisms have been associated with multiple diseases including cancer. Even some clock genes such as the Per1, Per2, Bmal1 genes have been proposed as tumor suppressor genes, with a relevant role during carcinogenesis. At the molecular level, multiple mechanisms of molecular control have been described to link circadian transcription, cell cycle control, and tumorigenesis. In addition, recent findings describe an epigenetic control of circadian transcription, at the level of DNA methylation as well as in the modifications of histones. However, the link between the circadian epigenome and cancer remains unclear. In this article, we review the evidence that suggests a relationship between alterations in the expression of clock genes, with the development of cancer, from the epigenetic landscape.


Assuntos
Relógios Circadianos/genética , Epigênese Genética/genética , Histonas/metabolismo , Neoplasias/genética , Animais , Ciclo Celular/genética , Montagem e Desmontagem da Cromatina , Metilação de DNA , Humanos , Camundongos , Células Tumorais Cultivadas
13.
J Therm Biol ; 94: 102753, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33292994

RESUMO

Using data related to thermal optimal and pejus of the embryos of Octopus americanus from Brazil and O. insularis and O. maya from Mexico, this study aimed to project the potential distribution areas in the Gulf of Mexico and predict distribution shifts under different Representative Concentration Pathway scenarios (RCP 6 and 8.5) for the years 2050 and 2100. The different thermal tolerances elicited different responses to current and future scenarios. In this sense, O. insularis and O. maya thermal niches stretch from the Caribbean to Florida. Nevertheless, O. insularis may inhabit warmer areas than O. maya. Surprisingly, no area was considered thermally habitable for O. americanus, which could have been associated with the use of data of populations thermally adapted to temperate conditions south of Brazil. According to models, a warming scenario would cause a restriction of the available thermal niche of O. maya, while O. insularis could expand under RCP 6 scenarios. This restriction was more substantial in the RCP 8.5 scenario. Nevertheless, under the RCP 8.5 scenario, the temperature in 2100 may negatively affect even O. insularis, the species most thermal tolerant. If our results are accurate, the fishing yield of O. insularis will increase in the future, replacing the heavily exploited O. maya in the coasts of the southern Gulf of Mexico. Regarding O. americanus, no inference might be made until thermal tolerances of locally adapted populations can be studied.


Assuntos
Mudança Climática , Octopodiformes/fisiologia , Termotolerância , Animais , Brasil , Feminino , Golfo do México , México , Temperatura
14.
J Neurooncol ; 145(2): 233-239, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31624989

RESUMO

INTRODUCTION: Gliomas are tumors of the central nervous system. Despite new classifications, they are still divided in low and high-grade gliomas, being the latter of greater malignancy. The degree of malignancy is directly related with the angiogenic activity in tumoral tissues. We measured VEGF concentrations and angiogenic capacity in cerebrospinal fluid (CSF) from patients with high and low-grade gliomas. The purpose of this study was to find a biomarker that contributes in the differential diagnosis and prognosis of gliomas. METHODS: CSF was obtained from 19 individuals: 8 with low-grade gliomas, 6 with high-grade gliomas and 5 controls. VEGF concentration in CSF was measured by ELISA and the angiogenic capacity was measured by chick chorioallantoic membrane (CAM) test. RESULTS: The VEGF concentration was higher in patients with high-grade gliomas, compared to patients with low-grade gliomas and controls (2860 pg/mL ± 975 vs. 182.6 ± 37.1 and 47.4 ± 0.4, respectively). On the other hand, CSF from patients with high-grade gliomas generated a higher microvascular density (MVD) than patients with low-grade gliomas and controls (13.23 ± 0.6 vessels/9000µm2 vs. 9.3 ± 0.3 and 7.92 ± 0.2, respectively). Interestingly, there was not statistical differences in both VEGF levels and angiogenic capacity in patients with low-grade gliomas and controls. CONCLUSION: Together VEGF levels and angiogenic capacity in CSF can be used as a biological marker of gliomas malignancy.


Assuntos
Neoplasias Encefálicas/diagnóstico , Glioma/diagnóstico , Neovascularização Patológica , Fator A de Crescimento do Endotélio Vascular/líquido cefalorraquidiano , Neoplasias Encefálicas/líquido cefalorraquidiano , Neoplasias Encefálicas/fisiopatologia , Glioma/líquido cefalorraquidiano , Glioma/fisiopatologia , Humanos , Projetos Piloto , Prognóstico
15.
Cephalalgia ; 38(4): 794-797, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28490189

RESUMO

Background Nummular headache is a rare, recently described topographic headache defined by the circumscribed coin-shaped area of pain. It is classified as a primary headache. There is debate about whether it is due to a peripheral or central disturbance, and its relationship to migraine. Case reports We report two patients with presumed nummular headache secondary to Langerhans cell histiocytosis, both with resolution of their headaches after surgical resection. Conclusion Imaging in patients with clinical features of nummular headache is recommended, as this and other cases highlight that it may be symptomatic. There are no distinguishing clinical features to separate nummular headache from secondary mimics, and treatment of the underlying cause may be curative.


Assuntos
Granuloma Eosinófilo/complicações , Cefaleia/etiologia , Crânio/patologia , Adulto , Criança , Craniotomia , Granuloma Eosinófilo/cirurgia , Humanos , Masculino , Crânio/cirurgia
16.
BMC Cancer ; 16(1): 731, 2016 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-27619675

RESUMO

BACKGROUND: For several decades now an antagonism between Trypanosoma cruzi infection and tumor development has been detected. The molecular basis of this phenomenon remained basically unknown until our proposal that T. cruzi Calreticulin (TcCRT), an endoplasmic reticulum-resident chaperone, translocated-externalized by the parasite, may mediate at least an important part of this effect. Thus, recombinant TcCRT (rTcCRT) has important in vivo antiangiogenic and antitumor activities. However, the relevant question whether the in vivo antitumor effect of T. cruzi infection is indeed mediated by the native chaperone (nTcCRT), remains open. Herein, by using specific modified anti-rTcCRT antibodies (Abs), we have neutralized the antitumor activity of T. cruzi infection and extracts thereof, thus identifying nTcCRT as a valid mediator of this effect. METHODS: Polyclonal anti-rTcCRT F(ab')2 Ab fragments were used to reverse the capacity of rTcCRT to inhibit EAhy926 endothelial cell (EC) proliferation, as detected by BrdU uptake. Using these F(ab')2 fragments, we also challenged the capacity of nTcCRT, during T. cruzi infection, to inhibit the growth of an aggressive mammary adenocarcinoma cell line (TA3-MTXR) in mice. Moreover, we determined the capacity of anti-rTcCRT Abs to reverse the antitumor effect of an epimastigote extract (EE). Finally, the effects of these treatments on tumor histology were evaluated. RESULTS: The rTcCRT capacity to inhibit ECs proliferation was reversed by anti-rTcCRT F(ab')2 Ab fragments, thus defining them as valid probes to interfere in vivo with this important TcCRT function. Consequently, during infection, these Ab fragments also reversed the in vivo experimental mammary tumor growth. Moreover, anti-rTcCRT Abs also neutralized the antitumor effect of an EE, again identifying the chaperone protein as an important mediator of this anti mammary tumor effect. Finally, as determined by conventional histological parameters, in infected animals and in those treated with EE, less invasive tumors were observed while, as expected, treatment with F(ab')2 Ab fragments increased malignancy. CONCLUSION: We have identified translocated/externalized nTcCRT as responsible for at least an important part of the anti mammary tumor effect of the chaperone observed during experimental infections with T. cruzi.


Assuntos
Calreticulina/metabolismo , Neoplasias Mamárias Experimentais/prevenção & controle , Trypanosoma cruzi/metabolismo , Tripanossomíase/parasitologia , Animais , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/farmacologia , Calreticulina/antagonistas & inibidores , Calreticulina/farmacologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Feminino , Neoplasias Mamárias Experimentais/metabolismo , Camundongos , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/farmacologia
19.
J Therm Biol ; 54: 133-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26615735

RESUMO

The thermoregulatory behavior of the giant keyhole limpet Megathura crenulata was determined in a horizontal thermal gradient during the day at 18.9 °C and 18.3 °C for the night. The final preferendum determined for giant keyhole limpets was of 18.6±1.2 °C. Limpets' displacement velocity was 10.0±3.9 cm h(-1) during the light phase and 8.4±1.6 cm h(-1) during the dark phase. The thermotolerance (measured as CTMax at 50%) was determined in a keyhole limpet in three acclimation temperatures 17, 20, and 23 °C. Limpets were subjected to water increasing temperatures at a rate of 1 °C every 30 min, until they detached from the substrate. The critical thermal maximum at 50% was 27.2, 27.9 and 28.3 °C respectively.


Assuntos
Aclimatação/fisiologia , Gastrópodes/fisiologia , Animais , Comportamento Animal , Regulação da Temperatura Corporal/fisiologia , Temperatura
20.
J Therm Biol ; 53: 151-61, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26590468

RESUMO

On the Yucatan Peninsula there is an upwelling which allows access to a body of cold water that controls temperature in this area. This modulates the ecology and distribution of organisms that inhabit the continental shelf. The objective of this study was to determine the effect of different acclimation temperatures on the thermal biology of prey as mollusc, crustacean (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators as fish (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya. Octopus prey preferred temperatures between 23.5°C and 26.0°C, while predators preferred temperatures 26.4-28.5°C. The species with largest thermal windows were M. corona bispinosa (328.8°C(2)), C. similis (322.8°C(2)), L. dubia (319.2°C(2)), C. undecimalis (288.6°C(2)), O. chrysurus (237.5°C(2)), while the smallest thermal window was for S. pugilis (202.0°C(2)). The acclimation response ratios (ARR) estimated for prey ranged from 0.24-0.55 in animals exposed to CTMax and 0.21-0.65 in those exposed to CTMin. Amongst predators, ARR ranged from 0.30 to 0.60 and 0.41 to 0.53 for animals exposed to CTMax and CTMin, respectively. Correlating the optimal temperature limits of prey and predators with surface temperatures on the continental shelf and those 4m deep showed that the main prey, Callinectes similis and L. dubia, shared a thermal niche and that an increase in temperature could force these species to migrate to other sites to find optimal temperatures for their physiological functions. As a consequence the continental shelf community would undergo a structural change. Predators were found to be near their optimal temperatures in surface temperatures on the continental shelf. We conclude that they would remain in the area in a warming scenario. The size of the thermal window was related to the type of ecosystem inhabited by these species. These ARR intervals allowed us to categorize the species as temperate or tropical, according to the oceanographic conditions that prevail on the Yucatan Peninsula.


Assuntos
Aclimatação , Temperatura Baixa , Peixes/fisiologia , Moluscos/fisiologia , Comportamento Predatório , Animais
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