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1.
Mil Med ; 188(Suppl 6): 215-224, 2023 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-37948205

RESUMO

INTRODUCTION: Overweight and obesity trends are on the rise among both civilian and military beneficiaries. The purpose of this narrative review was to evaluate nutrition, behavioral, lifestyle, pharmacotherapy, and alternative approaches to weight management (WM) among adults with a focus toward identifying gaps and evidence-based strategies that could support or enhance current and future WM programming among military adult beneficiaries. MATERIALS AND METHODS: A trained research team identified publications (January 2013-January 2020) for abstract review using key search terms and inclusion criteria. Two independent researchers conducted both the abstract review and full-paper bias scoring using selected Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. All eligible studies were assessed for bias and categorized based on key themes. The study was registered in PROSPERO, the international prospective register of systematic reviews. RESULTS: The research team identified 741 articles, with 278 meeting final inclusion criteria. The mean bias score was 7.5 ± 3.9 (score of 0-13; higher indicating fewer bias factors), with 64% scoring ≥9. Factors contributing to low bias included intervention compliance, dropout rate, and inability to blind participants. The most common published weight-loss interventions included a combination of therapies (59%), diet/supplement (17%), other approaches (12%), behavior change (7%), and exercise (6%). Themes identified to improve WM outcomes included leveraging technology, increasing intervention interactions, community support, emphasis on early weight loss, pharmacotherapy risk-benefit, enhanced behavioral component, resistance exercise, mindfulness, and benefits of quality-of-life measures. CONCLUSIONS: Reviewers identified several validated tools and techniques to augment and update existing WM programming to improve health and weight outcomes. The review affirmed use of individualized dietary patterns and not a "one-size-fits-all approach" as well as incorporating more comprehensive and team-approached treatments to make the best use of tools and strategies to enhance outcomes.


Assuntos
Militares , Programas de Redução de Peso , Adulto , Humanos , Obesidade/terapia , Sobrepeso/terapia , Exercício Físico , Redução de Peso
2.
Sci Data ; 6: 190022, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30778257

RESUMO

Elysia chlorotica, a sacoglossan sea slug found off the East Coast of the United States, is well-known for its ability to sequester chloroplasts from its algal prey and survive by photosynthesis for up to 12 months in the absence of food supply. Here we present a draft genome assembly of E. chlorotica that was generated using a hybrid assembly strategy with Illumina short reads and PacBio long reads. The genome assembly comprised 9,989 scaffolds, with a total length of 557 Mb and a scaffold N50 of 442 kb. BUSCO assessment indicated that 93.3% of the expected metazoan genes were completely present in the genome assembly. Annotation of the E. chlorotica genome assembly identified 176 Mb (32.6%) of repetitive sequences and a total of 24,980 protein-coding genes. We anticipate that the annotated draft genome assembly of the E. chlorotica sea slug will promote the investigation of sacoglossan genetics, evolution, and particularly, the genetic signatures accounting for the long-term functioning of algal chloroplasts in an animal.


Assuntos
Gastrópodes/genética , Genoma , Animais , Anotação de Sequência Molecular , Fotossíntese
3.
J Infect Dis ; 217(7): 1118-1127, 2018 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-28968675

RESUMO

Background: Aspergillus flavus is one of the most common agents of invasive aspergillosis and is associated with high mortality. The orotomides are a new class of antifungal agents with a novel mechanism of action. An understanding of the pharmacodynamics (PD) of the lead compound F901318 is required to plan safe and effective regimens for clinical use. Methods: The pharmacokinetics (PK) and PD of F901318 were evaluated by developing new in vitro and in vivo models of invasive fungal sinusitis. Galactomannan was used as a pharmacodynamic endpoint in all models. Mathematical PK-PD models were used to describe dose-exposure-response relationships. Results: F901318 minimum inhibitory concentrations (MICs) ranged from 0.015 to 0.06 mg/L. F901318 induced a concentration-dependent decline in galactomannan. In the in vitro model, a minimum concentration:MIC of 10 resulted in suppression of galactomannan; however, values of approximately 10 and 9-19 when assessed by survival of mice or the decline in galactomannan, respectively, were equivalent or exceeded the effect induced by posaconazole. There was histological clearance of lung tissue that was consistent with the effects of F901318 on galactomannan. Conclusions: F901318 is a potential new agent for the treatment of invasive infections caused by A flavus with PDs that are comparable with other first-line triazole agents.


Assuntos
Acetamidas/farmacocinética , Acetamidas/uso terapêutico , Antifúngicos/farmacocinética , Antifúngicos/uso terapêutico , Aspergillus flavus/efeitos dos fármacos , Aspergilose Pulmonar Invasiva/tratamento farmacológico , Piperazinas/farmacocinética , Piperazinas/uso terapêutico , Pirimidinas/farmacocinética , Pirimidinas/uso terapêutico , Pirróis/farmacocinética , Pirróis/uso terapêutico , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Aspergilose Pulmonar Invasiva/microbiologia , Aspergilose Pulmonar Invasiva/patologia , Camundongos , Triazóis/farmacocinética , Triazóis/uso terapêutico , Voriconazol/farmacocinética , Voriconazol/uso terapêutico
4.
FEMS Microbiol Lett ; 364(14)2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28854673

RESUMO

The genome sequence of the obligate chemolithoautotroph Hydrogenovibrio crunogenus paradoxically predicts a complete oxidative citric acid cycle (CAC). This prediction was tested by multiple approaches including whole cell carbon assimilation to verify obligate autotrophy, phylogenetic analysis of CAC enzyme sequences and enzyme assays. Hydrogenovibrio crunogenus did not assimilate any of the organic compounds provided (acetate, succinate, glucose, yeast extract, tryptone). Enzyme activities confirmed that its CAC is mostly uncoupled from the NADH pool. 2-Oxoglutarate:ferredoxin oxidoreductase activity is absent, though pyruvate:ferredoxin oxidoreductase is present, indicating that sequence-based predictions of substrate for this oxidoreductase were incorrect, and that H. crunogenus may have an incomplete CAC. Though the H. crunogenus CAC genes encode uncommon enzymes, the taxonomic distribution of their top matches suggests that they were not horizontally acquired. Comparison of H. crunogenus CAC genes to those present in other 'Proteobacteria' reveals that H. crunogenus and other obligate autotrophs lack the functional redundancy for the steps of the CAC typical for facultative autotrophs and heterotrophs, providing another possible mechanism for obligate autotrophy.


Assuntos
Carbono/metabolismo , Ciclo do Ácido Cítrico , Fontes Hidrotermais/microbiologia , Piscirickettsiaceae/metabolismo , Crescimento Quimioautotrófico , Glucose/metabolismo , Oxirredução , Filogenia , Piscirickettsiaceae/classificação , Piscirickettsiaceae/genética , Ácido Pirúvico/metabolismo
5.
mBio ; 5(1): e00725-13, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-24473125

RESUMO

UNLABELLED: Cryptococcal meningoencephalitis is an urgent global health problem. Induction regimens using 14 days of amphotericin B deoxycholate (dAmB) are considered the standard of care but may not be suitable for resource-poor settings. We investigated the efficacy of conventional and abbreviated regimens of dAmB for cryptococcal meningoencephalitis in both murine and rabbit models of cryptococcal meningoencephalitis. We examined the extent to which immunological effectors contribute to the antifungal effect. We bridged the results to humans as a first critical step to define regimens suitable for further study in clinical trials. There were significant differences in the murine plasma-versus-cerebrum dAmB concentration-time profiles. dAmB was detectable in the cerebrum throughout the experimental period, even following the administration of only three doses of 3 mg/kg. dAmB induced a fungistatic effect in the cerebrum with a 2- to 3-log10 CFU/g reduction compared with controls. The effect of 3 days of therapy was the same as that of daily therapy for 14 days. There was no evidence of increased numbers of CD3(+) CD4(+) or CD3(+) CD8(+) cells in treated mice to account for the persistent antifungal effect of an abbreviated regimen. The administration of dAmB at 1 mg/kg/day for 3 days was the same as daily therapy in rabbits. The bridging studies suggested that a human regimen of 0.7 mg/kg/day for 3 days resulted in nearly maximal antifungal activity in both the cerebrum and cerebrospinal fluid. An abbreviated regimen (3 days of therapy) of dAmB appears to be just as effective as conventional induction therapy for cryptococcal meningoencephalitis. IMPORTANCE: Cryptococcal meningitis is a significant and neglected infection that is associated with excessive morbidity and mortality. In well-resourced health care settings, induction therapy with at least 2 weeks of amphotericin B deoxycholate (dAmB) is advocated. Multiple clinical studies suggest that dAmB is the drug of choice for cryptococcal meningitis. In many parts of the world where the burden of cryptococcal meningitis is highest, it is infeasible to administer dAmB for prolonged periods. This paper provides the experimental basis for the efficacy of abbreviated regimens of dAmB for cryptococcal meningitis. The concept was explored in two well-validated laboratory animal models of cryptococcal meningitis, and the results were bridged to humans by using a range of mathematical modeling techniques. A 3-day regimen is as effective as the standard 14-day course. An abbreviated regimen is significantly more feasible and may enable better antifungal therapy to be administered to many patients with this frequently lethal disease.


Assuntos
Anfotericina B/administração & dosagem , Anfotericina B/farmacocinética , Antifúngicos/administração & dosagem , Antifúngicos/farmacocinética , Ácido Desoxicólico/administração & dosagem , Ácido Desoxicólico/farmacocinética , Meningite Criptocócica/tratamento farmacológico , Animais , Líquido Cefalorraquidiano/química , Cérebro/química , Modelos Animais de Doenças , Combinação de Medicamentos , Masculino , Camundongos , Plasma/química , Coelhos
6.
Biol Bull ; 227(3): 300-12, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25572217

RESUMO

The horizontal transfer of functional nuclear genes, coding for both chloroplast proteins and chlorophyll synthesis, from the food alga Vaucheria litorea to the sea slug Elysia chlorotica has been demonstrated by pharmacological, polymerase chain reaction (PCR), real time PCR (qRT-PCR), and transcriptome sequencing experiments. However, partial genomic sequencing of E. chlorotica larvae failed to find evidence for gene transfer. Here, we have used fluorescent in situ hybridization to localize an algal nuclear gene, prk, found in both larval and adult slug DNA by PCR and in adult RNA by transcriptome sequencing and RT-PCR. The prk probe hybridized with a metaphase chromosome in slug larvae, confirming gene transfer between alga and slug.


Assuntos
Proteínas de Algas/genética , Gastrópodes/genética , Transferência Genética Horizontal/genética , Estramenópilas/genética , Animais , Cromossomos/genética , Hibridização in Situ Fluorescente , Transcriptoma
7.
J Infect Dis ; 208(2): 351-61, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23599314

RESUMO

BACKGROUND: Cryptococcal meningoencephalitis is a lethal infection with relatively few therapeutic options. The optimal dosage of liposomal amphotericin B (LAmB) alone or in combination with flucytosine is not known. METHODS: A murine model of cryptococcal meningoencephalitis was used. The fungal density in the brain was determined using quantitative cultures. Pharmacokinetic-pharmacodynamic relationships were determined for LAmB and flucytosine administered alone. The effect of the combination was described using the Greco model and a mathematical model. The results were bridged to humans. RESULTS: Inoculation resulted in hematogenous dissemination and logarithmic growth within the central nervous system. There was histological evidence of multifocal infection throughout the brain. Both LAmB and flucytosine produced a dose-dependent reduction in fungal burden. The effect of the combination of agents in the brain was additive. Bridging studies suggested that a human dosage of LAmB 3 mg/kg/d resulted in a submaximal antifungal effect. Regimens of LAmB 6 mg/kg/d alone, LAmB 3 mg/kg/d plus flucytosine 50 mg/kg/d, and LAmB 3 mg/kg/d plus flucytosine 100 mg/kg/d all resulted in near-maximal antifungal activity. CONCLUSIONS: Potential regimens for further study in clinical trials include LAmB 6 mg/kg/d alone, LAmB 3 mg/kg/d plus flucytosine 50 mg/kg/d, and LAmB 3 mg/kg/d plus flucytosine 100 mg/kg/d.


Assuntos
Anfotericina B/farmacologia , Antifúngicos/farmacologia , Cryptococcus neoformans/efeitos dos fármacos , Flucitosina/farmacologia , Meningite Criptocócica/tratamento farmacológico , Meningoencefalite/tratamento farmacológico , Anfotericina B/farmacocinética , Animais , Antifúngicos/farmacocinética , Encéfalo/efeitos dos fármacos , Encéfalo/microbiologia , Cryptococcus neoformans/isolamento & purificação , Quimioterapia Combinada , Flucitosina/farmacocinética , Humanos , Hospedeiro Imunocomprometido , Masculino , Meningite Criptocócica/imunologia , Meningite Criptocócica/metabolismo , Meningite Criptocócica/microbiologia , Meningoencefalite/microbiologia , Camundongos , Testes de Sensibilidade Microbiana , Modelos Biológicos
8.
Antimicrob Agents Chemother ; 56(8): 4439-49, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22687510

RESUMO

We have shown previously that high-dose lipid amphotericin preparations are not more efficacious than lower doses in aspergillosis. We studied toxicity, drug concentrations and localization, and quantitative infection concurrently, using a 4-day model of central nervous system (CNS) aspergillosis to assess early events. Mice given Aspergillus fumigatus conidia intracerebrally, under a cyclophosphamide immunosuppressive regimen, were treated for 3 days (AmBisome at 3 or 10 mg/kg of body weight, Abelcet at 10 mg/kg, amphotericin B deoxycholate at 1 mg/kg, caspofungin at 5 mg/kg, or voriconazole at 40 mg/kg). Sampling 24 h after the last treatment showed that AmBisome at 3 but not at 10 mg/kg, as well as Abelcet, caspofungin, and voriconazole, reduced brain CFU. All regimens reduced renal infection. Minor renal tubular changes occurred with AmBisome or Abelcet therapy, whereas heart, lung, and brain showed no drug toxicity. Amphotericin B tissue and serum concentrations did not correlate with efficacy. Endothelial cell activation (ICAM-1 and P-selectin in cerebral capillaries) occurred during infection. Amphotericin B derived from AmBisome and Abelcet localized in activated endothelium and from Abelcet in intravascular monocytes. In 10-day studies dosing uninfected mice, minor renal tubular changes occurred after AmBisome or Abelcet at 1, 5, or 10 mg/kg with or without cyclophosphamide treatment; nephrosis occurred only with Abelcet in cyclophosphamide-treated mice. Hepatotoxicity occurred with AmBisome and Abelcet but was reduced in cyclophosphamide-treated mice. Marked CFU reduction by AmBisome at 3 mg/kg occurred in association with relatively more intense inflammation. Abelcet renal localization appears to be a precursor to late nephrotoxicity. Hepatotoxicity may contribute to high-dose Abelcet and AmBisome failures. Our novel observation of endothelial amphotericin localization during infection may contribute to amphotericin mechanism of efficacy.


Assuntos
Anfotericina B/uso terapêutico , Antifúngicos/uso terapêutico , Aspergillus fumigatus/efeitos dos fármacos , Ácido Desoxicólico/uso terapêutico , Neuroaspergilose/tratamento farmacológico , Anfotericina B/sangue , Anfotericina B/farmacologia , Animais , Antifúngicos/farmacologia , Aspergillus fumigatus/patogenicidade , Encéfalo/efeitos dos fármacos , Encéfalo/microbiologia , Caspofungina , Ciclofosfamida , Ácido Desoxicólico/sangue , Ácido Desoxicólico/farmacologia , Combinação de Medicamentos , Equinocandinas/farmacologia , Equinocandinas/uso terapêutico , Células Endoteliais/efeitos dos fármacos , Coração/efeitos dos fármacos , Coração/microbiologia , Terapia de Imunossupressão , Molécula 1 de Adesão Intercelular/biossíntese , Rim/efeitos dos fármacos , Rim/microbiologia , Lipopeptídeos , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Masculino , Camundongos , Nefrose , Neuroaspergilose/sangue , Neuroaspergilose/microbiologia , Selectina-P/biossíntese , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Triazóis/farmacologia , Triazóis/uso terapêutico , Voriconazol
9.
Mol Biol Evol ; 29(6): 1545-56, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22319135

RESUMO

Analysis of the transcriptome of the kleptoplastic sea slug, Elysia chlorotica, has revealed the presence of at least 101 chloroplast-encoded gene sequences and 111 transcripts matching 52 nuclear-encoded genes from the chloroplast donor, Vaucheria litorea. These data clearly show that the symbiotic chloroplasts are translationally active and, of even more interest, that a variety of functional algal genes have been transferred into the slug genome, as has been suggested by earlier indirect experiments. Both the chloroplast- and nuclear-encoded sequences were rare within the E. chlorotica transcriptome, suggesting that their copy numbers and synthesis rates are low, and required both a large amount of sequence data and native algal sequences to find. These results show that the symbiotic chloroplasts residing inside the host molluscan cell are maintained by an interaction of both organellar and host biochemistry directed by the presence of transferred genes.


Assuntos
Clorófitas/genética , Gastrópodes/genética , Expressão Gênica , Transferência Genética Horizontal , Genes de Cloroplastos , Fotossíntese/genética , Animais , Sequência de Bases , Perfilação da Expressão Gênica , Genoma , Anotação de Sequência Molecular , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sequência de DNA
10.
Med Mycol ; 49(8): 834-47, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21539507

RESUMO

Invasive pulmonary aspergillosis remains problematic in immunocompromised patient populations. We studied potential therapeutic options in a murine model of pulmonary aspergillosis in triamcinolone-suppressed DBA/2 mice infected intranasally with conidia from Aspergillus fumigatus. Mice were treated with liposomal-amphotericin B (AmBi; AmBisome), lipid-complexed amphotericin B (ABLC; Abelcet), voriconazole (VCZ), micafungin (MICA), caspofungin (CAS) or deoxycholate amphotericin B (AMBd) given alone or in combination. Monotherapy with AmBi, ABLC, AMBd, CAS or MICA had activity in prolonging survival; however, only AMBd or CAS reduced fungal burden in the lungs and kidneys. Combinations of AmBi plus CAS or MICA prolonged survival, but were not better than monotherapy. VCZ was ineffective and AMBd plus CAS showed a possible antagonism. AmBi or ABLC at higher dosages, or loading-doses of AmBi resulted in reduced survival. Histopathology showed increased incidence of serious renal and mild hepatic toxicity in triamcinolone-treated mice given an amphotericin B regimen compared to no or only triamcinolone (minimal renal changes occurred with CAS or VCZ with or without triamcinolone); suggestive of combined toxicity of triamcinolone and the amphotericin B in AmBi or ABLC. Infected treated mice showed progressive pulmonary disease including abscesses, angioinvasion and abundant intralesional fungi. High loading-doses of AmBi were associated with nephrosis and damage to other tissues. No monotherapy or combination regimen showed superiority for the treatment of pulmonary aspergillosis in corticosteroid suppressed mice and the potential for combined drug toxicity was enhanced in these mice. High dosages of lipid-formulated amphotericin B also proved unsatisfactory. Additional studies are needed to evaluate improved treatment.


Assuntos
Antifúngicos/uso terapêutico , Aspergillus fumigatus/efeitos dos fármacos , Aspergilose Pulmonar Invasiva/tratamento farmacológico , Anfotericina B/administração & dosagem , Anfotericina B/uso terapêutico , Anfotericina B/toxicidade , Animais , Antifúngicos/administração & dosagem , Antifúngicos/toxicidade , Caspofungina , Contagem de Colônia Microbiana , Ácido Desoxicólico/administração & dosagem , Ácido Desoxicólico/uso terapêutico , Ácido Desoxicólico/toxicidade , Modelos Animais de Doenças , Combinação de Medicamentos , Quimioterapia Combinada , Equinocandinas/administração & dosagem , Equinocandinas/uso terapêutico , Equinocandinas/toxicidade , Humanos , Aspergilose Pulmonar Invasiva/mortalidade , Lipopeptídeos/administração & dosagem , Lipopeptídeos/uso terapêutico , Lipopeptídeos/toxicidade , Masculino , Micafungina , Camundongos , Camundongos Endogâmicos DBA , Pirimidinas/administração & dosagem , Pirimidinas/uso terapêutico , Pirimidinas/toxicidade , Triazóis/administração & dosagem , Triazóis/uso terapêutico , Triazóis/toxicidade , Voriconazol
11.
Antimicrob Agents Chemother ; 53(2): 772-5, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18936190

RESUMO

We compared the efficacy of combination posaconazole-liposomal amphotericin B (LAmB) therapy to monotherapy with either drug in diabetic ketoacidotic or neutropenic mice with disseminated zygomycosis caused by Rhizopus oryzae. Combination therapy was no better than LAmB alone, and posaconazole monotherapy did not improve survival or reduce fungal burden versus placebo.


Assuntos
Anfotericina B/uso terapêutico , Antifúngicos/uso terapêutico , Triazóis/uso terapêutico , Zigomicose/tratamento farmacológico , Anfotericina B/administração & dosagem , Animais , Antifúngicos/administração & dosagem , Encéfalo/microbiologia , Encéfalo/patologia , Cetoacidose Diabética/complicações , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Rim/microbiologia , Rim/patologia , Lipossomos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neutropenia/complicações , Rhizopus , Triazóis/administração & dosagem , Zigomicose/microbiologia
12.
Am J Physiol Regul Integr Comp Physiol ; 295(1): R155-65, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18434439

RESUMO

The brain renin-angiotensin system plays an important role in the regulation of arterial pressure in response to stress, in part due to activation of AT1 receptors in the hypothalamic median preoptic nucleus (MnPO) by endogenous angiotensin II (ANG II). N-methyl-d-aspartate (NMDA) receptors are also involved in the angiotensinergic signaling pathway through the MnPO. We investigated whether AT1 and NMDA receptors in the MnPO are responsible for variable hemodynamic response patterns to stress. Cocaine or startle with cold water evoked a pressor response in Sprague-Dawley rats due, in some rats [vascular responders (VR)], to a large increase in systemic vascular resistance (SVR) and, in other rats [mixed responders (MR)], to small increases in SVR and cardiac output (CO). Microinjection of the GABAA agonist muscimol into the MnPO to block synaptic transmission attenuated the cocaine- or stress-induced increase in SVR and the decrease in CO seen in VR without altering either response in MR. Likewise, administration of either an AT1 receptor antagonist, losartan, or an NMDA receptor antagonist, MK-801, attenuated the increase in SVR and the decrease in CO in VR in response to either cocaine (losartan and MK-801) or startle with cold water (losartan) without altering either response in MR. We propose that the MnPO is responsible for greater SVR responses in VR and that AT1 and NMDA receptors play an important role in greater SVR responses in VR. These data provide additional support for the critical role of the MnPO in cardiovascular responses to stress.


Assuntos
Pressão Sanguínea/fisiologia , Área Pré-Óptica/fisiologia , Receptor Tipo 1 de Angiotensina/fisiologia , Receptores de N-Metil-D-Aspartato/fisiologia , Estresse Fisiológico/fisiopatologia , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Animais , Cateterismo/normas , Cocaína/farmacologia , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Agonistas GABAérgicos/farmacologia , Losartan/farmacologia , Microinjeções , Muscimol/farmacologia , Área Pré-Óptica/anatomia & histologia , Ratos , Ratos Sprague-Dawley , Reflexo de Sobressalto/fisiologia , Estresse Fisiológico/induzido quimicamente , Fatores de Tempo
13.
Am J Bot ; 95(4): 399-413, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21632364

RESUMO

Cabomba is a small water lily genus that is native to the New World. Studies of pollen development and associated changes in the anther yield valuable characters for considering the evolution of reproductive biology in seed plants. Here we characterized the complete ontogenetic sequence for pollen in Cabomba caroliniana. Anthers at the microspore mother cell, tetrad, free microspore, and mature pollen grain stages were studied using scanning electron, transmission electron, and light microscopy. Tetragonal and decussate tetrads both occur in C. caroliniana, indicating successive microsporogenesis. The exine is tectate-columellate, and the infratectal columellae are the first exine elements to form, followed by a continuous tectum and a thin foot layer. A lamellate endexine initiates in the early free microspore stage, but becomes compressed in mature grains. Tectal microchannels and sculptural rods also initiate during the early free microspore stage, and significant pollenkitt deposition follows, supporting the hypothesis that these elements function in entomophily. The tapetum is morphologically amoeboid, with migratory tapetal cells directly contacting developing free microspores within the anther locule. Results from this study illustrate the importance of including ontogenetic data in analyzing pollen characters and in developing evolutionary and ecological hypotheses. The new palynological data also emphasize the character plasticity that occurs in basal angiosperms.

14.
Am J Physiol Regul Integr Comp Physiol ; 291(3): R719-27, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16601259

RESUMO

We examined whether ANG II receptors in the central nervous system mediate hemodynamic responses to pharmacological (cocaine) and behavioral (cold water) stressors. After administration of cocaine (5 mg/kg iv), rats were classified as vascular responders (VR) if their pressor response was due entirely to an increase in systemic vascular resistance (SVR) despite a decrease in cardiac output (CO). Cocaine elicited a pressor response in mixed responders (MR) that was dependent on small increases in both SVR and CO. ANG II (30 ng/5 microl icv, 5 min before cocaine) augmented the decrease in CO in VR and prevented the increase in CO in MR. Administration of [Sar(1),Thr(8)]ANG II (20 microg/5 microl icv; sarthran) before cocaine attenuated the decrease in CO and the large increase in SVR in VR so that they were no longer different from MR. Losartan (20 microg icv) or captopril (50 microg icv) preceding cocaine administration also attenuated the decrease in CO and the large increase in SVR seen in VR only. The role of angiotensin was not specific for cocaine, because ANG II (icv) pretreatment before startle with cold water (1 cm deep) enhanced the decrease in CO and the increase in SVR in both MR and VR, whereas losartan (icv) pretreatment before startle attenuated the decrease in CO and the increase in SVR in VR so that they were no longer different from MR. These data suggest that central ANG II receptors mediate the greater vascular and cardiac responsiveness in vascular responders to acute pharmacological and behavioral stressors.


Assuntos
Receptores de Angiotensina/metabolismo , Estresse Fisiológico/induzido quimicamente , Estresse Fisiológico/metabolismo , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Débito Cardíaco/efeitos dos fármacos , Débito Cardíaco/fisiologia , Cocaína/farmacologia , Temperatura Baixa , Masculino , Ratos , Ratos Sprague-Dawley , Organismos Livres de Patógenos Específicos , Volume Sistólico/efeitos dos fármacos , Volume Sistólico/fisiologia , Resistência Vascular/efeitos dos fármacos , Resistência Vascular/fisiologia
15.
Regul Pept ; 127(1-3): 1-10, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15680464

RESUMO

Cocaine produces characteristic behavioral and autonomic responses due to its unique pharmacological properties. Many of the autonomic responses resemble those to acute behavioral stress. Both cocaine and behavioral stress have been shown to evoke an increase in sympathetic nerve activity that is primarily responsible for the peripheral cardiovascular responses. We noted varying hemodynamic and sympathetic response patterns to cocaine administration and to acute behavioral stress in rats that correlate with the predisposition to develop both a sustained increase in arterial pressure and cardiomyopathies. Several lines of evidence suggest that the autonomic response patterns are dependent on the actions of central peptides including angiotensin II (Ang II) and corticotropin-releasing hormone (CRH). This is based on observations demonstrating that intracerebroventricular (icv) administration of receptor antagonists for Ang II or CRH attenuated the decrease in cardiac output (CO) and increase in vascular resistance noted in some animals after cocaine administration or startle. In contrast, icv Ang II enhances the cardiodepression associated with cocaine administration or startle. Based on this and other evidence, we propose that the autonomic response patterns to startle and to cocaine are closely related and dependent on central Ang II and CRH. Furthermore, we suggest that these central peptides may be responsible for varying predisposition to cardiovascular disease.


Assuntos
Angiotensina II/metabolismo , Cocaína/farmacologia , Hormônio Liberador da Corticotropina/metabolismo , Hemodinâmica , Estresse Fisiológico , Simpatomiméticos/farmacologia , Vasoconstritores/farmacologia , Animais , Sistema Nervoso Autônomo/efeitos dos fármacos , Sistema Nervoso Autônomo/fisiologia , Comportamento/efeitos dos fármacos , Comportamento/fisiologia , Doenças Cardiovasculares/fisiopatologia , Suscetibilidade a Doenças , Hemodinâmica/efeitos dos fármacos , Hemodinâmica/fisiologia , Humanos
16.
Toxicol Appl Pharmacol ; 200(2): 146-58, 2004 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-15476867

RESUMO

Petroleum oil enters the coastal marine environment through various sources; marine mammals such as sea otters that inhabit this environment may be exposed to low concentrations of petroleum hydrocarbons through ingestion of contaminated prey. The inability to perform controlled studies in free-ranging animals hinders investigations of the effects of chronic petroleum oil exposure on sea otter morbidity and mortality, necessitating the development of a reliable laboratory model. We examined the effects of oral exposure to 500 ppm bunker C fuel oil over 113-118 days on American mink, a species phylogenetically related to the sea otter. Hematological parameters and organs were examined for fuel oil-associated changes. Hepatic cytochrome P4501A1 mRNA expression and fecal cortisol concentrations were also measured. Ingestion of fuel oil was associated with a decrease in erythrocyte count, hemoglobin concentration (Hgb), hematocrit (HCT), and an increase in mean corpuscular volume (MCV). Total leukocytes were elevated in the fuel oil group from increases in neutrophils, lymphocytes, and monocytes. Significant interactions between fuel oil and antigen challenge were found for erythrocyte parameters, monocyte and lymphocyte counts. Liver and adrenal weights were increased although mesenteric lymph node weights were decreased in the fuel oil group. Hepatic cytochrome P4501A1 mRNA was elevated in the fuel oil group. Fecal cortisol concentration did not vary between the two groups. Our findings show that fuel oil exposure alters circulating leukocyte numbers, erythrocyte homeostasis, hepatic metabolism and adrenal physiology and establish a framework to use mink as a model for sea otters in studying the systemic effects of marine contaminants.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Óleos Combustíveis/toxicidade , Vison/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Citocromo P-450 CYP1A1/biossíntese , Citocromo P-450 CYP1A1/genética , Dinitrobenzenos/metabolismo , Contagem de Eritrócitos , Fezes/química , Hemoglobinas/metabolismo , Histocitoquímica , Hidrocortisona/metabolismo , Contagem de Leucócitos , Hepatopatias/sangue , Hepatopatias/metabolismo , Masculino , Vison/sangue , Modelos Animais , Tamanho do Órgão/efeitos dos fármacos , Lontras/sangue , Lontras/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Distribuição Aleatória , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
Vet Immunol Immunopathol ; 101(3-4): 179-90, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15350748

RESUMO

The relationship between exposure to environmental contaminants and immunotoxicity in vulnerable marine species is unknown. In this study, we used American mink (Mustela vision) as a surrogate species for the sea otter to examine the immunotoxic effects of chronic exposure to a low concentration of bunker C fuel oil (500 ppm admixed in the feed for 113-118 days). The mink immune system was monitored over time by flow cytometric analysis for alterations in the immunophenotype of blood lymphocytes and monocytes and by mitogen-stimulated proliferation assays for changes in peripheral blood mononuclear cell function. Fuel oil exposure caused a mild, yet significant (P < 0.05) increase in the absolute numbers of specific peripheral blood lymphocyte subsets (CD3+T cells) and monocytes, an increase in the level of expression of functionally significant cell surface proteins (MHC II, CD18), and an increase in mitogen-induced mononuclear cell proliferative responses. This heightened state of cellular activation along with the increase in specific cell surface protein expression on both the innate and adaptive immune cells is similar to the pro-inflammatory or "adjuvant-like" effect described in laboratory models of polycyclic aromatic hydrocarbon exposure in other species. These results show the benefits of using a controlled laboratory model for detecting and characterizing subtle petroleum oil-induced perturbations in immune responses. In addition this study establishes a framework for studying the effects of environmental petroleum oil exposure on the immune system of free-ranging marine mammals. Expansion of these studies to address biolgical significance is warranted.


Assuntos
Óleos Combustíveis/toxicidade , Leucócitos Mononucleares/efeitos dos fármacos , Vison/imunologia , Poluentes Químicos da Água/toxicidade , Animais , Antígenos CD/imunologia , Contagem de Células Sanguíneas/veterinária , Concanavalina A/imunologia , Citometria de Fluxo/veterinária , Imunofenotipagem/veterinária , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/imunologia , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Masculino , Vison/sangue , Mitógenos de Phytolacca americana/imunologia , Distribuição Aleatória , Poluentes Químicos da Água/imunologia
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