RESUMO
The expanding urbanization of coastal areas has led to increased ocean sprawl, which has had both physical and chemical adverse effects on marine and coastal ecosystems. To maintain the health and functionality of these ecosystems, it is imperative to develop effective solutions. One such solution involves the use of biodegradable polymers as bioactive coatings to enhance the bioreceptivity of marine and coastal infrastructures. Our study aimed to explore two main objectives: (1) investigate PHA-degrading bacteria on polymer-coated surfaces and in surrounding seawater, and (2) comparing biofilm colonization between surfaces with and without the polymer coating. We applied poly(3-hydroxybutyrate) [P(3HB)) coatings on concrete surfaces at concentrations of 1% and 6% w/v, with varying numbers of coating cycles (1, 3, and 6). Our findings revealed that the addition of P(3HB) indeed promoted accelerated biofilm growth on the coated surfaces, resulting in an occupied area approximately 50% to 100% larger than that observed in the negative control. This indicates a remarkable enhancement, with the biofilm expanding at a rate roughly 1.5 to 2 times faster than the untreated surfaces. We observed noteworthy distinctions in biofilm growth patterns based on varying concentration and number of coating cycles. Interestingly, treatments with low concentration and high coating cycles exhibited comparable biofilm enhancements to those with high concentrations and low coating cycles. Further investigation into the bacterial communities responsible for the degradation of P(3HB) coatings identified mostly common and widespread strains but found no relation between the concentration and coating cycles. Nevertheless, this microbial degradation process was found to be highly efficient, manifesting noticeable effects within a single month. While these initial findings are promising, it's essential to conduct tests under natural conditions to validate the applicability of this approach. Nonetheless, our study represents a novel and bio-based ecological engineering strategy for enhancing the bioreceptivity of marine and coastal structures.
Assuntos
Ecossistema , Poli-Hidroxibutiratos , Polímeros , Ácido 3-Hidroxibutírico/metabolismo , Polímeros/química , Bactérias/metabolismoRESUMO
Cities all over the world are edging further into the ocean. Coastal reclamation is a global conservation issue with implications for ocean life, ecosystems, and human well-being. Using Malaysia as a case study, the coastal reclamation trends over three decades (1991-2021) were mapped using Landsat images and Normalized Difference Water Index (NDWI) via the Google Earth Engine platform. The changes in drivers and impacts of these coastal expansions throughout the decades were also reviewed. Twelve out of the 14 states in Malaysia had planned, active, or completed reclamations on their shorelines. Between 1991 and 2021, an absolute area of 82.64 km2 has been or will be reclaimed should all the projects be completed. The most reported driver for coastal expansion in Malaysia is for development and modernization (41 %), followed by rise in human population (20 %), monetary gains from the development of prime land (15 %), and agriculture and aquaculture activities (9 %). Drivers such as reduction of construction costs, financial advantage of prime land, oil and gas, advancement of technology, and tourism (Malaysia My Second Home (MM2H)) had only started occurring within the last decade, while others have been documented since the 1990's. Pollution is the most reported impact (24 %) followed by disruption of livelihoods, sources of income and human well-being (21 %), destruction of natural habitats (17 %), decrease in biodiversity (11 %), changes in landscapes (10 %), erosion / accretion (8 %), threat to tourism industry (6 %), and exposure to wave surges (3 %). Of these, changes in landscape, shoreline alignment, seabed contour, and coastal groundwater, as well as wave surges had only started to surface as impacts in the last two decades. Efforts to protect existing natural coastal and marine ecosystems, restore degraded ones, and fund endeavours that emphasize nature is needed to support sustainable development goals for the benefit of future generations.
Assuntos
Conservação dos Recursos Naturais , Ecossistema , Humanos , Conservação dos Recursos Naturais/métodos , Malásia , Biodiversidade , Poluição AmbientalRESUMO
BACKGROUND: Sudden cardiac arrest has been linked independently both to stressful neighborhood conditions and to polymorphisms in the ADRB2 gene. The ADRB2 gene mediates sympathetic activation in response to stress. Therefore, if neighborhood conditions cause cardiac arrest through the stress pathway, the ADRB2 variant may modify the association between neighborhood conditions, such as socioeconomic deprivation and incidence of cardiac arrest. METHODS: The Cardiac Arrest Blood Study Repository is a population-based repository of specimens and other data from adult cardiac arrest patients residing in King County, Washington. Cases (n = 1,539) were 25- to 100-year-old individuals of European descent who experienced out-of-hospital cardiac arrest from 1988 to 2004. Interactions between neighborhood conditions and the ADRB2 genotype on cardiac arrest risk were assessed in a case-only study design. Gene-environment independence was assessed in blood samples obtained from King County residents initially contacted by random-digit dialing. RESULTS: Fewer than 4% of study subjects resided in socioeconomically deprived neighborhoods. Nonetheless, the case-only analysis indicated the presence of supramultiplicative interaction of socioeconomic deprivation and the homozygous Gln27Glu variant (case-only odds ratio: 1.8 [95% confidence interval: 1.0, 2.9]). Interactions between population density and the homozygous Gln27Glu variant were weaker (case-only odds ratio: 1.2 [95% confidence interval: 0.97, 1.5]). CONCLUSIONS: Findings support a supramultiplicative interaction between the Gln27Glu ADRB2 variant and socioeconomic deprivation among individuals of European descent. This result is consistent with the hypothesis that the elevation in cardiac arrest risk associated with socioeconomic deprivation operates through the stress pathway.
Assuntos
Interação Gene-Ambiente , Parada Cardíaca Extra-Hospitalar/epidemiologia , Receptores Adrenérgicos beta 2/genética , Características de Residência/estatística & dados numéricos , Fatores Socioeconômicos , População Branca/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Parada Cardíaca Extra-Hospitalar/genética , Polimorfismo de Nucleotídeo Único , Washington/epidemiologiaRESUMO
OBJECTIVE: Ethnic differences in sudden cardiac arrest resuscitation have not been fully explored and studies have yielded inconsistent results. We examined the association of ethnicity with factors affecting sudden cardiac arrest outcomes. METHODS: Retrospective cohort study of 3551 white, 440 black and 297 Asian sudden cardiac arrest cases in Seattle and King County, Washington, USA. RESULTS: Compared with whites, blacks and Asians were younger, had lower socioeconomic status and were more likely to have diabetes, hypertension and end-stage renal disease (all p<0.001). Blacks and Asians were less likely to have a witnessed arrest (whites 57.6%, blacks 52.1%, Asians 46.1%, p<0.001) or receive bystander cardiopulmonary resuscitation (whites 50.9%, blacks 41.4%, Asians 47.1%, p=0.001), but had shorter average emergency medical services response time (mean in minutes: whites 5.18, blacks 4.75, Asians 4.85, p<0.001). Compared with whites, blacks were more likely to be found in pulseless electrical activity (blacks 20.9% vs whites 16.6%, p<0.001), and Asians were more likely to be found in asystole (Asians 41.1% vs whites 30.0%, p<0.001). One of the strongest predictors of resuscitation outcomes was initial cardiac rhythm with 25% of ventricular fibrillation, 4% of patients with pulseless electrical activity and 1% of patients with asystole surviving to hospital discharge (adjusted OR of resuscitation in pulseless electrical activity compared with ventricular fibrillation: 0.30, 95% CI 0.24 to 0.34, p<0.001, adjusted OR of resuscitation in asystole relative to ventricular fibrillation 0.21, 95% CI 0.17 to 0.26, p<0.001). Survival to hospital discharge was similar across all three ethnicities. CONCLUSIONS: While there were differences in some prognostic characteristics between blacks, whites and Asians, we did not detect a significant difference in survival following sudden cardiac arrest between the three ethnic groups. There was, however, an ethnic difference in presenting rhythm, with pulseless electrical activity more prevalent in blacks and asystole more prevalent in Asians.
Assuntos
Asiático , Negro ou Afro-Americano , Morte Súbita Cardíaca/etnologia , Morte Súbita Cardíaca/prevenção & controle , Disparidades nos Níveis de Saúde , Disparidades em Assistência à Saúde/etnologia , Parada Cardíaca Extra-Hospitalar/etnologia , Parada Cardíaca Extra-Hospitalar/terapia , Ressuscitação , População Branca , Fatores Etários , Comorbidade , Mortalidade Hospitalar/etnologia , Humanos , Parada Cardíaca Extra-Hospitalar/mortalidade , Alta do Paciente , Prevalência , Ressuscitação/efeitos adversos , Ressuscitação/mortalidade , Estudos Retrospectivos , Fatores de Risco , Fatores Socioeconômicos , Fatores de Tempo , Tempo para o Tratamento , Resultado do TratamentoRESUMO
Cerebral vasospasm is the leading cause of mortality and morbidity in patients after aneurysmal subarachnoid hemorrhage (SAH). However, the mechanism and adequate treatment of vasospasm are still elusive. In the present study, we evaluate the effect and possible mechanism of progesterone on SAH-induced vasospasm in a two-hemorrhage rodent model of SAH. Progesterone (8 mg/kg) was subcutaneously injected in ovariectomized female Sprague-Dawley rats one hour after SAH induction. The degree of vasospasm was determined by averaging the cross-sectional areas of basilar artery 7 days after first SAH. Expressions of endothelial nitric oxide synthase (eNOS) and phosphorylated Akt (phospho-Akt) in basilar arteries were evaluated. Prior to perfusion fixation, there were no significant differences among the control and treated groups in physiological parameters recorded. Progesterone treatment significantly (P < 0.01) attenuated SAH-induced vasospasm. The SAH-induced suppression of eNOS protein and phospho-Akt were relieved by progesterone treatment. This result further confirmed that progesterone is effective in preventing SAH-induced vasospasm. The beneficial effect of progesterone might be in part related to upregulation of expression of eNOS via Akt signaling pathway after SAH. Progesterone holds therapeutic promise in the treatment of cerebral vasospasm following SAH.
Assuntos
Óxido Nítrico Sintase/biossíntese , Progesterona/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/biossíntese , Hemorragia Subaracnóidea/tratamento farmacológico , Vasoespasmo Intracraniano/patologia , Animais , Feminino , Regulação da Expressão Gênica , Ratos , Transdução de Sinais/genética , Hemorragia Subaracnóidea/metabolismo , Hemorragia Subaracnóidea/patologia , Ativação Transcricional/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos , Vasoespasmo Intracraniano/tratamento farmacológico , Vasoespasmo Intracraniano/etiologiaRESUMO
Toona sinensis (TS) leaves are used as a vegetable and in traditional Chinese medicine. However, in vivo experiments regarding the anti-inflammatory function of TS leaves have not previously been conducted. The aim of this study was to investigate the potential role of TS leaf extract (TSL) in the prevention of sepsis-induced lung injury in vivo and on macrophage activation in vitro. The results showed that oral gavage pretreatment with TSL in rats for 30 days improved the survival of cecal ligation and puncture-induced sepsis, potentially by attenuating sepsis-induced histological lung damage rather than inflammatory cell infiltration. Furthermore, we demonstrated that pretreatment with TSL attenuated the lipopolysaccharide (LPS)-induced expression of inducible nitric oxide synthase, thereby inhibiting nitric oxide production and release in murine macrophage-like RAW 264.7 cells. Interestingly, TSL did not affect the LPS-induced release of other cytokines (e.g., tumor necrosis factor α and interleukin 1ß) but increased LPS-induced heme-oxygenase-1 expression. In conclusion, the study provides preliminary data for TSL on cecal ligation and puncture-induced sepsis. The beneficial impact of TSL needs extensive study to get solid evidence.
Assuntos
Meliaceae/química , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Sepse/tratamento farmacológico , Animais , Linhagem Celular , Modelos Animais de Doenças , Inflamação/patologia , Lipopolissacarídeos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/patologia , Masculino , Camundongos , Fitoterapia , Extratos Vegetais/farmacologia , Ratos Sprague-Dawley , Sepse/patologiaRESUMO
The leaves of Toona sinensis, a well-known traditional oriental medicine, have been prescribed for the treatment of enteritis and infection. Recently, aqueous extracts of Toona sinensis leaves (TSL-1) have demonstrated many biological effects both in vitro and in vivo. In the central nervous system, microglial activation and their proinflammatory responses are considered an important therapeutic strategy for neuroinflammatory disorders such as cerebral ischemia, Alzheimer's disease, and Parkinson's disease. The present study attempted to validate the effect of TSL-1 on microglia-mediated neuroinflammation stimulated by lipopolysaccharide (LPS). As inflammatory parameters, the production of nitric oxide (NO), inducible NO synthase, and tumor necrosis factor-α were evaluated. Our results demonstrate that TSL-1 suppresses LPS-induced NO production, tumor necrosis factor-α secretion, and inducible NO synthase protein expression in a concentration-dependent manner, without causing cytotoxicity. In addition, the inhibitory effects of TSL-1 in LPS-stimulated BV-2 microglia were extended to post-treatment suggesting the therapeutic potential of TSL-1. Therefore, this work provides the future evaluation of the role of TSL-1 in the treatment of neurodegenerative diseases by inhibition of inflammatory mediator production in activated microglia.
Assuntos
Meliaceae/química , Microglia/citologia , Microglia/efeitos dos fármacos , Extratos Vegetais/farmacologia , Folhas de Planta/química , Animais , Western Blotting , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Lipopolissacarídeos/farmacologia , Camundongos , Microglia/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
BACKGROUND: Apoptosis is implicated in vasospasm and the long-term sequelae of subarachnoid hemorrhage (SAH). This study tested the hypothesis that attenuation of SAH-induced apoptosis after 17ß-estradiol (E2) treatment is associated with an increase in phosphorylation of Akt via estrogen receptor-α (ER-α) in rats. MATERIALS AND METHODS: We examined the expression of phospho-Akt, ERα and ERß, and apoptosis in cerebral cortex, hippocampus, and dentate gyrus in a two-hemorrhage SAH model in rats. We subcutaneously implanted other rats with a silicone rubber tube containing E2; they received daily injections of nonselective estrogen receptor antagonist (ICI 182,780), selective ERα-selective antagonist (methyl-piperidino-pyrazole), or ERß-selective antagonist (R,R-tetrahydrochrysene) after the first hemorrhage. RESULTS: At 7 d after the first SAH, protein levels of phospho-Akt and ERα were significantly decreased and caspase-3 was significantly increased in the dentate gyrus. The cell death assay revealed that DNA fragmentation was significantly increased in the dentate gyrus. Those actions were reversed by E2 and blocked by ICI 182,780 and methyl-piperidino-pyrazole, but not R,R-tetrahydrochrysene. However, there were no significant changes in the expression of the protein levels of phospho-Akt, ERα, ERß, and caspase-3, and DNA fragmentation after SAH. CONCLUSIONS: The present study shows that a beneficial effect of E2 in attenuating SAH-induced apoptosis is associated with activation of the expression of phospho-Akt and ERα, and alteration in caspase-3 protein expression via an ERα-dependent mechanism in the dentate gyrus. These data support further the investigation of E2 in the treatment of SAH in humans.
Assuntos
Estradiol/uso terapêutico , Receptor alfa de Estrogênio/metabolismo , Estrogênios/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Hemorragia Subaracnóidea/metabolismo , Animais , Apoptose , Lesões Encefálicas/etiologia , Lesões Encefálicas/prevenção & controle , Caspase 3/metabolismo , Giro Denteado/metabolismo , Modelos Animais de Doenças , Regulação para Baixo , Masculino , Ratos , Ratos Sprague-Dawley , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/tratamento farmacológicoRESUMO
OBJECT: Apoptosis is implicated in vasospasm and long-term sequelae of subarachnoid hemorrhage (SAH). The authors observed that 17beta-estradiol (E2) can attenuate cerebral vasospasm, lower endothelin-1 production, and preserve normal endothelial nitric oxide synthase expression by reduction of inducible NO synthase expression in experimental SAH. The authors investigated the potential antiapoptotic effects of E2 in an experimental rat model of SAH. METHODS: The authors examined the antiapoptotic effects of E2 in a double-hemorrhage SAH model in male Sprague-Dawley rats. The rats underwent subcutaneous implantation of a Silastic tube containing corn oil either with or without E2, and some E2-treated animals also received ICI 182,780 (a nonselective estrogen receptor [ER] antagonist) for 7 days after SAH. The degree of vasospasm was determined by averaging the cross-sectional areas of the basilar artery 7 days after SAH. The expression of apoptotic indicators, including TNF-alpha, caspase 3, Bcl-2, Bax, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL), and cell death assays were used for detection of apoptosis. RESULTS: Treatment with E2 significantly attenuated SAH-induced vasospasm. Seven days after the induction of SAH, positive TUNEL-staining was seen, and DNA fragmentation was increased in the dentate gyrus. Increased TNF-alpha and cleaved caspase-3 protein expression and decreased Bcl-2 protein expression in the dentate gyrus were also observed. These changes were reversed with E2-treatment but not in the presence of ICI 182,780. However, the expression of Bax did not change after SAH either with or without E2 treatment. CONCLUSIONS: The authors found that E2 appears to confer an antiapoptotic effect that reduces secondary brain injury after SAH via estrogen receptor-dependent mechanisms. This finding provides support for possible future applications of E2 treatment for the reduction of secondary injury after SAH in patients.
Assuntos
Apoptose/efeitos dos fármacos , Estradiol/farmacologia , Hemorragia Subaracnóidea/patologia , Animais , Proteínas Reguladoras de Apoptose/fisiologia , Western Blotting , Encéfalo/patologia , Fragmentação do DNA , Giro Denteado/efeitos dos fármacos , Marcação In Situ das Extremidades Cortadas , Masculino , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/fisiologia , Transdução de Sinais/efeitos dos fármacos , Fixação de Tecidos , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima/efeitos dos fármacos , Proteína X Associada a bcl-2/fisiologiaRESUMO
BACKGROUND: Our previous study showed that 17beta-estradiol (E2) and an adenosine A(2A) receptor (AR-A(2A)) agonist could attenuate subarachnoid hemorrhage (SAH)-induced cerebral vasospasm via preventing the augmentation of iNOS expression and preserving the normal eNOS expression. This study tests the hypothesis that E2 attenuates SAH-induced vasospasm and apoptosis by activating adenosine AR-A(2A) and extracellular signal-regulated kinase 1 and 2 (ERK1/2), and by altering antiapoptotic and proapoptotic protein expression (Bcl-2 and Bax, respectively). MATERIALS AND METHODS: The two-hemorrhage SAH model in rat was used. Animals were treated with E2 with or without a nonselective estrogen receptor (ER) antagonist (ICI182,780). The cross sectional areas of the basilar artery and terminal dUTP nick-end labeling (TUNEL) were used to determine the degree of vasospasm and apoptosis, respectively. The expressions of Bcl-2, Bax, AR-A(2A), and ERK1/2 in the cerebral cortex, hippocampus, and dentate gyrus were investigated. RESULTS: E2 significantly attenuated vasospasm. Seven days after the first SAH, TUNEL scores were significantly increased, and protein levels of AR-A(2A), ERK1/2, and Bcl-2 were significantly decreased in the dentate gyrus only but not in the cortex and hippocampus. These changes were reversed by E2 while ICI182,780 abrogated the antiapoptotic and anti-spastic effects of E2. The expression of Bax did not change in the dentate gyrus after SAH with or without treatment. CONCLUSIONS: The down-regulated AR-A(2A) and ERK may play a role in vasospasm and apoptosis after SAH. The beneficial effect of E2 in the attenuating SAH-induced vasospasm and apoptosis may be due to an increased expression of AR-A(2A) and ERK via ER-dependent mechanisms. These data may support further investigation of E2 in the treatment of SAH in humans.
Assuntos
Giro Denteado/efeitos dos fármacos , Giro Denteado/metabolismo , Estradiol/farmacologia , Estrogênios/farmacologia , Receptor A2A de Adenosina/metabolismo , Hemorragia Subaracnóidea/metabolismo , Animais , Apoptose/efeitos dos fármacos , Giro Denteado/patologia , Estradiol/análogos & derivados , Estradiol/uso terapêutico , Fulvestranto , Masculino , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Modelos Animais , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Estrogênio/antagonistas & inibidores , Hemorragia Subaracnóidea/complicações , Vasoespasmo Intracraniano/tratamento farmacológico , Vasoespasmo Intracraniano/etiologia , Proteína X Associada a bcl-2/metabolismoRESUMO
We conducted a genome-wide association study testing single nucleotide polymorphisms (SNPs) and copy number variants (CNVs) for association with early-onset myocardial infarction in 2,967 cases and 3,075 controls. We carried out replication in an independent sample with an effective sample size of up to 19,492. SNPs at nine loci reached genome-wide significance: three are newly identified (21q22 near MRPS6-SLC5A3-KCNE2, 6p24 in PHACTR1 and 2q33 in WDR12) and six replicated prior observations (9p21, 1p13 near CELSR2-PSRC1-SORT1, 10q11 near CXCL12, 1q41 in MIA3, 19p13 near LDLR and 1p32 near PCSK9). We tested 554 common copy number polymorphisms (>1% allele frequency) and none met the pre-specified threshold for replication (P < 10(-3)). We identified 8,065 rare CNVs but did not detect a greater CNV burden in cases compared to controls, in genes compared to the genome as a whole, or at any individual locus. SNPs at nine loci were reproducibly associated with myocardial infarction, but tests of common and rare CNVs failed to identify additional associations with myocardial infarction risk.
Assuntos
Dosagem de Genes , Infarto do Miocárdio/genética , Polimorfismo de Nucleotídeo Único , Adulto , Idade de Início , Algoritmos , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Mutação/fisiologia , Infarto do Miocárdio/epidemiologia , Fatores de RiscoRESUMO
OBJECT: Cerebral vasospasm remains a major complication in patients who have suffered a subarachnoid hemorrhage (SAH). Previous studies have shown that 17beta-estradiol (E2) attenuates experimental SAH-induced cerebral vasospasm. Moreover, E2 has been shown to reduce neuronal apoptosis and secondary injury following cerebral ischemia. Adenosine A1 receptor (AR-A1) expression is increased following ischemia and may represent an endogenous neuroprotective effect. This study was designed to evaluate the efficacy of E2 in preventing cerebral vasospasm and reducing secondary injury, as evidenced by DNA fragmentation and AR-A1 expression, following SAH. METHODS: A double-hemorrhage model of SAH in rats was used, and the degree of vasospasm was determined by averaging the cross-sectional areas of the basilar artery 7 days after the first SAH. A cell death assay was used to detect apoptosis. Changes in the protein expression of AR-A1 in the cerebral cortex, hippocampus, and dentate gyrus were compared with levels in normal controls and E2-treated groups (subcutaneous E2, 0.3 mg/ml). RESULTS: The administration of E2 prevented vasospasm (p < 0.05). Seven days after the first SAH, DNA fragmentation and protein levels of AR-A1 were significantly increased in the dentate gyrus. The E2 treatment decreased DNA fragmentation and prevented the increase in AR-A1 expression in the dentate gyrus. There were no significant changes in DNA fragmentation and the expression of AR-A1 after SAH in the cerebral cortex and hippocampus in the animals in the control and E2-treated groups. CONCLUSIONS: The E2 was effective in attenuating SAH-induced cerebral vasospasm, decreasing apoptosis in the dentate gyrus, and reducing the expression of AR-A1 in the dentate gyrus after SAH. Interestingly, E2 appears to effectively prevent cerebral vasospasm subsequent to SAH as well as attenuate secondary injury by reducing both apoptosis and a compensatory increase in AR-A1 expression in the dentate gyrus.