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1.
Rev Clin Esp ; 222(5): 293-298, 2022 May.
Artigo em Espanhol | MEDLINE | ID: mdl-33191944

RESUMO

This observational retrospective study aimed to investigate the usefulness of Sequential Organ Failure Assessment (SOFA), Quick SOFA (qSOFA), National Early Warning Score (NEWS), and quick NEWS in predicting respiratory failure and death among patients with COVID-19 hospitalized outside of intensive care units (ICU). We included 237 adults hospitalized with COVID-19 who were followed-up on for one month or until death. Respiratory failure was defined as a PaO2/FiO2 ratio ≤ 200 mmHg or the need for mechanical ventilation. Respiratory failure occurred in 77 patients (32.5%), 29 patients (12%) were admitted to the ICU, and 49 patients (20.7%) died. Discrimination of respiratory failure was slightly higher in NEWS, followed by SOFA. Regarding mortality, SOFA was more accurate than the other scores. In conclusion, sepsis scores are useful for predicting respiratory failure and mortality in COVID-19 patients. A NEWS score ≥ 4 was found to be the best cutoff point for predicting respiratory failure.

2.
Insect Mol Biol ; 29(4): 373-380, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32249467

RESUMO

The implementation of Integrated Pest Management in current agricultural practice is a convenient and very effective strategy to keep pest populations under control. The use of biological control agents, such as Phytoseiulus persimilis, is key for the success of such an approach. This predatory mite is widely used as it is very effective for controlling Tetranychus urticae, one of the most devastating crop pests. Here, we identify several mutations located in the voltage-gated sodium channel (VGSC) of commercially sourced P. persimilis that correlate with a reduced susceptibility to the pyrethroid deltamethrin. We found that the mites sourced from two different biocontrol product companies have intrinsic genotypic differences that correlate with their phenotype when tested with different concentrations of deltamethrin. Mites from Syngenta Bioline, carrying the mutations M918L and A1536T, were able to survive deltamethrin concentrations of up to 10 ppm, while the mites from Koppert Biological Systems, with the combination M918L, L925V and S1539T, survived treatment with 40 ppm. All of the point mutations identified in the predatory mite samples are located in a particular region of the VGSC, previously proposed as the binding site for this family of pesticides and identified as a 'hot spot' for resistance.


Assuntos
Proteínas de Artrópodes/genética , Resistência a Medicamentos/genética , Mutação , Nitrilas/farmacologia , Piretrinas/farmacologia , Tetranychidae/genética , Canais de Sódio Disparados por Voltagem/genética , Acaricidas/farmacologia , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/metabolismo , Sequência de Bases , Mutação Puntual , Alinhamento de Sequência , Tetranychidae/metabolismo , Canais de Sódio Disparados por Voltagem/metabolismo
3.
Allergol Immunopathol (Madr) ; 46(6): 552-556, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30017214

RESUMO

INTRODUCTION: Specific immunotherapy (SIT) is used to treat asthma and allergic rhinitis, and a dose-response relationship has been found for SIT efficacy, creating a need to accurately select the allergen used in therapy. This need is especially pronounced in poly-sensitized children living in areas where different pollen allergen sources coexist in the same season, as this circumstance complicates diagnostic efforts. In such cases, component-resolved diagnosis (CRD) can increase diagnostic accuracy and aid in SIT prescription. MATERIALS AND METHODS: We hypothesized that CRD results would lead to modifications in classical immunotherapy prescription based on sources such as medical history, season of symptom presentation, and skin testing. We studied a sample of children indicated for immunotherapy in whom classical methods had not pointed out the most relevant allergen due to sensitization to more than two pollens. We used a small panel of recombinant allergens, analyzing the percentage of changes to prescription considering the findings of molecular studies. RESULTS: Of the 70 children included, CRD led to modified immunotherapy prescription in 54.3%. Indications of single-allergen therapy increased from 18% to 51% when CRD was included. The decision to prescribe immunotherapy was reversed following CRD in 9.3% of cases. DISCUSSION: CRD use alters the choice of specific immunotherapy in poly-sensitized children. A wide panel of recombinant allergens may not be necessary to improve immunotherapy indication using molecular techniques; rather, a smaller panel adapted to include those allergens prevalent in the geographical area in question appears to be sufficient for more effective immunotherapy, also leading to an improved cost-benefit ratio.


Assuntos
Alérgenos/uso terapêutico , Antígenos de Plantas/uso terapêutico , Asma/diagnóstico , Dessensibilização Imunológica/métodos , Rinite Alérgica Sazonal/diagnóstico , Rinite Alérgica/diagnóstico , Alérgenos/imunologia , Antígenos de Plantas/imunologia , Asma/imunologia , Asma/terapia , Criança , Reações Cruzadas , Feminino , Humanos , Masculino , Pólen/imunologia , Prescrições , Rinite Alérgica/imunologia , Rinite Alérgica/terapia , Rinite Alérgica Sazonal/imunologia , Rinite Alérgica Sazonal/terapia , Testes Cutâneos
4.
Heredity (Edinb) ; 114(1): 56-64, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25074574

RESUMO

The recombination suppression models of chromosomal speciation posit that chromosomal rearrangements act as partial barriers to gene flow allowing these regions to accumulate genetic incompatibilities, thus contributing to the divergence of populations. Empirical and theoretical studies exploring the requirements of these models have mostly focused on the role of inversions. Here, the recombination landscape of heterozygosity for Robertsonian (Rb) fusions is investigated in the house mouse. Laboratory-bred F1 males and females between highly differentiated races from Tunisia (Rb: 2n=22, Standard, St: 2n=40) were produced in which all Rb fusions are present as trivalents in meiosis. Recombination patterns were determined by the analysis of chiasmata and compared with previous data on the Tunisian parental mice. A comparative analysis was performed on wild-caught male mice spanning the hybrid zone between two Italian races (2n=40, 2n=22). The results showed that the chiasma characteristics of both male and female Tunisian F1 and Italian hybrids clearly differed from those of Rb and St mice. Not only was the mean chiasma number (CN) intermediate between those of the parental mice in both geographic samples, but the distribution of chiasmata along the chromosomal arms of the F1 showed a distinct mosaic pattern. In short, the proximal region in the F1 exhibited a reduced CN similar to that observed in homozygous Rb, whereas distal regions more closely matched those in St mice. These results suggest that Rb rearrangements (homozygous or heterozygous) reduce recombination in the proximal regions of the chromosomes supporting their potential role in recombination-mediated speciation models.


Assuntos
Evolução Molecular , Genética Populacional , Camundongos/genética , Recombinação Genética , Translocação Genética , Animais , Cromossomos/genética , Cruzamentos Genéticos , Feminino , Fluxo Gênico , Heterozigoto , Itália , Cariótipo , Masculino , Modelos Genéticos , Mosaicismo , Tunísia
5.
Chromosoma ; 122(3): 209-20, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23515652

RESUMO

The composition and orientation of the house mouse satellite DNA sequences (minor, major, TLC) were investigated by a FISH and CO-FISH approach in 11 taxa belonging to three clades of the subgenus Mus. Using a phylogenetic framework, our results highlighted two distribution patterns. The TLC satellite, the most recently discovered satellite, was present in all clades but varied quantitatively among species. This distribution supported its appearance in the ancestor of the subgenus followed by independent evolution in species of each clade. In contrast, the minor and major satellites occurred in only two clades of the subgenus indicating the simultaneous and recent amplification of these sequences. In addition, although qualitative differences in the composition and orientation of the satellite sequences were observed among the taxa, none of the features studied were unique to the house mouse and could account for the extensive chromosomal plasticity evidenced in Mus musculus domesticus.


Assuntos
Cromossomos de Mamíferos/genética , DNA Satélite/genética , Evolução Molecular , Camundongos/genética , Animais , Sequência de Bases , Hibridização in Situ Fluorescente , Camundongos/classificação , Dados de Sequência Molecular , Filogenia , Especificidade da Espécie
6.
AIDS Care ; 26(8): 1036-41, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24625218

RESUMO

Despite ever improving advances in antiretroviral therapy, neurocognitive impairments such as asymptomatic and mild neurocognitive impairment remain a significant problem for the HIV-positive population. We distributed a post-neurocognitive impairment screening service evaluation questionnaire to assess satisfaction and anxiety. Subjects were HIV positive and aged 18-50. They were screened using the Brief Neurocognitive Score and International HIV Dementia Score as well as undergoing screening for anxiety (Generalised Anxiety Disorder Assessment [GAD-7]), depression (Participant Health Questionnaire Mood Scale [PHQ-9]) and memory (Everyday Memory Questionnaire [EMQ-R]). On completion, they were either reassured that the tests were normal or were referred for further investigation. Following assessment, subjects were asked to complete an anonymous satisfaction survey; 101 surveys were analysed. Forty-nine per cent of participants stated that they "felt better" following screening, 43% said it "made no difference", 6% stated it "worried me" and 1% "did not understand". On a scale of 0-10 of helpfulness, the mean score was 7.53. Forty-seven subjects indicated that they were referred for further investigation and 46 subjects that nothing else was needed; 8 reported they did not know. Those referred on rated satisfaction at a mean of 7.54/10 and those with normal screen as 7.09/10 (p = 0.46). Of the groups that were referred for further investigation, 6% said the test "worried them" compared to 4% in the non-referred group. Forty-nine per cent said they "felt better" despite an abnormal result compared to 50% in a normal screening result (p = 0.76). The results of this survey show that screening for neurocognitive impairment by this method is acceptable and helpful to participants. It did not lead to an increase in anxiety and there was no correlation between referred for further investigations and anxiety suggesting concerns about creating undue anxiety by screening and referral are unfounded.


Assuntos
Complexo AIDS Demência/diagnóstico , Infecções por HIV/complicações , Programas de Rastreamento/métodos , Testes Neuropsicológicos , Complexo AIDS Demência/etiologia , Adolescente , Adulto , Transtornos de Ansiedade/psicologia , Estudos de Avaliação como Assunto , Feminino , Infecções por HIV/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem
7.
AIDS Care ; 26(2): 160-8, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23869661

RESUMO

With increasingly successful management of HIV, focus has shifted away from AIDS-related complications to other chronic co-morbidities. For HIV-related cognitive problems, the true aetiopathogenesis and epidemiology remains unclear. Rather than a systematic review, this paper presents the challenges and the opportunities we faced in establishing our own clinical service. Papers were identified using Pubmed and the terms "screening", "HIV" and "neurocognitive". This article covers the background of HIV-associated neurocognitive disorders (HAND) with a focus on HIV-related neurocognitive impairment (NCI), detailing classification, prevalence, diagnostic categories and diagnostic uncertainties. Screening is discussed, including a comparison of the available screening tools for cognitive deficits in HIV-infected patients and the importance of practice effects. Discussed also are the normal ranges and the lack thereof and potential investigations for those found to have impairments. We conclude by discussing the role of NCI screening in routine clinical care at the current time.


Assuntos
Complexo AIDS Demência/diagnóstico , Soropositividade para HIV/complicações , Programas de Rastreamento , Complexo AIDS Demência/tratamento farmacológico , Complexo AIDS Demência/epidemiologia , Atividades Cotidianas , Comorbidade , Avaliação da Deficiência , Feminino , Soropositividade para HIV/epidemiologia , Soropositividade para HIV/psicologia , Humanos , Masculino , Programas de Rastreamento/métodos , Testes Neuropsicológicos , Prevalência , Avaliação de Programas e Projetos de Saúde , Qualidade de Vida , Fatores Socioeconômicos
8.
Rev Esp Quimioter ; 36(3): 259-266, 2023 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-36966384

RESUMO

Mycoplasma pneumoniae is a bacterium that lacks a cell wall. It produces infections all It produces infections world-wide, in epidemic outbreaks every 4-7 years, or endemically. Its clinical manifestations occur mostly in the respiratory tract and it is a common cause of atypical pneumonia. The treatment is with macrolides, tetracyclines or fluoroquinolones. Since 2000, an increase in resistance to macrolides has been detected worldwide, being more frequent in Asia. In Europe the frequency of resistance ranges between 1% and 25%, depending on the country. Molecular techniques and serology techniques provides very high sensitivity in diagnostic confirmation, being very useful for detecting and controlling M. pneumoniae outbreaks. The detection of resistance to macrolides requires a sequencing technique.


Assuntos
Mycoplasma pneumoniae , Pneumonia por Mycoplasma , Humanos , Mycoplasma pneumoniae/genética , Macrolídeos/farmacologia , Macrolídeos/uso terapêutico , Farmacorresistência Bacteriana , Pneumonia por Mycoplasma/tratamento farmacológico , Pneumonia por Mycoplasma/epidemiologia , Pneumonia por Mycoplasma/diagnóstico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Europa (Continente)/epidemiologia
9.
Heredity (Edinb) ; 108(1): 68-74, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22086078

RESUMO

Variation in the number and chromosomal location of nucleolar organizer regions (NORs) was studied in the house mouse, Mus musculus (2n=40). From an origin in Western Asia, this species colonized the Middle East, Europe and Asia. This expansion was accompanied by diversification into five subspecies. NOR diversity was revealed by fluorescence in situ hybridization using 18S and 28S probes on specimens spanning Asia to Western Europe. The results showed that the house mouse genome possessed a large number of NOR-bearing autosomes and a surprisingly high rate of polymorphism for the presence/absence of rRNA genes on all these chromosomes. All NOR sites were adjacent to the centromere except for two that were telomeric. Subspecific differentiation established from the NOR frequency data was concordant with the overall pattern of radiation proposed from molecular studies, but highlighted several discrepancies that need to be further addressed. NOR diversity in M. musculus consisted of a large number of polymorphic NORs that were common to at least two subspecies, and a smaller number of NORs that were unique to one subspecies. The most parsimonious scenario argues in favor of a subspecific differentiation by lineage sorting of ancestral NOR polymorphisms; only the unique NORs would have appeared by inter-chromosomal transposition, except for the two telomeric ones that may have originated by hybridization with another species. Such a scenario provides an alternative view from the one prevailing in most systematic and phylogenetic analyses that NORs have a high transposition rate due to concerted evolution of rRNA genes.


Assuntos
Cromossomos de Mamíferos/metabolismo , Evolução Molecular , Camundongos/genética , Região Organizadora do Nucléolo , Animais , Cromossomos de Mamíferos/genética , Genes de RNAr , Variação Genética , Hibridização in Situ Fluorescente , Filogenia , Polimorfismo Genético
10.
Phys Chem Chem Phys ; 14(25): 8903-9, 2012 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-22294200

RESUMO

The two forms of methyl salicylate bearing an intramolecular hydrogen bond (IMHB) are responsible for the three fluorescence emissions produced by this compound on electronic excitation in inert media. Whereas the form possessing an IMHB between its hydroxyl group and ether oxygen undergoes no excited state intramolecular proton transfer (ESIPT) in its first excited electronic state, that with an IMHB involving the carbonyl oxygen exhibits ESIPT with near-unity efficiency. Whereas the former species exhibits standard photophysical behaviour, the latter species exhibits two fluorescence emissions from the same electronic excited state; a photophysical scheme is proposed, which brings together all the available photophysical evidence for methyl salicylate in inert media.

11.
Rev Clin Esp (Barc) ; 222(5): 293-298, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35512908

RESUMO

This observational retrospective study aimed to investigate the usefulness of Sequential Organ Failure Assessment (SOFA), Quick SOFA (qSOFA), National Early Warning Score (NEWS), and quick NEWS in predicting respiratory failure and death among patients with COVID-19 hospitalized outside of intensive care units (ICU). We included 237 adults hospitalized with COVID-19 who were followed-up on for one month or until death. Respiratory failure was defined as a PaO2/FiO2 ratio ≤200mmHg or the need for mechanical ventilation. Respiratory failure occurred in 77 patients (32.5%), 29 patients (12%) were admitted to the ICU, and 49 patients (20.7%) died. Discrimination of respiratory failure was slightly higher in NEWS, followed by SOFA. Regarding mortality, SOFA was more accurate than the other scores. In conclusion, sepsis scores are useful for predicting respiratory failure and mortality in COVID-19 patients. A NEWS score ≥4 was found to be the best cutoff point for predicting respiratory failure.


Assuntos
COVID-19 , Insuficiência Respiratória , Sepse , Adulto , COVID-19/complicações , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva , Escores de Disfunção Orgânica , Prognóstico , Curva ROC , Estudos Retrospectivos
12.
Heredity (Edinb) ; 106(2): 348-56, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20531448

RESUMO

The speciation model of divergence by monobrachially homologous fusions (that is, with one arm in common) benefits from a wide conceptual acceptance, because heterozygotes between populations carrying such fusions suffer from high levels of meiotic dysfunction. The same meiotic configurations can also be generated by WART (whole-arm reciprocal translocation), rearrangements that are known to occur in mammals. Estimating the disadvantage of heterozygotes carrying monobrachially homologous fusions is required to evaluate the relevance of this mode of chromosomal evolution in diversification and speciation. House mice are an excellent study models because chromosomal races exist carrying monobrachially homologous fusions, and WARTs have been documented in this species. The fertility of heterozygote mice carrying the smallest number of monobrachially homologous fusions (that is, a chain of four chromosomes, C4) was investigated in laboratory-bred hybrids between two parapatric chromosomal races from the island of Madeira. Meiotic nondisjunction analyses and histological sections of testes showed that aneuploidy (16.7%) and germ cell death (50.9%) rates reached significantly higher mean values in hybrids than in homozygotes. In females, however, the histological analysis of ovarian follicle parameters revealed no significant differences between hybrid and homozygous individuals. Overall, the reproductive assays indicated that these C4-carrying hybrids were not sterile but showed an approximately 50% decrease in fertility compared to homozygous parental mice. Implications for modes of chromosomal evolution involving monobrachially homologous fusions are discussed.


Assuntos
Cromossomos/genética , Evolução Molecular , Fertilidade , Camundongos/genética , Aneuploidia , Animais , Feminino , Especiação Genética , Células Germinativas/citologia , Heterozigoto , Cariotipagem , Masculino , Não Disjunção Genética , Ovário/citologia , Portugal , Estatísticas não Paramétricas , Testículo/citologia , Translocação Genética
13.
Rev Neurol ; 73(10): 351-357, 2021 Nov 16.
Artigo em Espanhol | MEDLINE | ID: mdl-34755888

RESUMO

INTRODUCTION: Myotonic dystrophy type 1 is the most common muscular dystrophy in adults. It is a genetic disorder of autosomal dominant inheritance and one of its most striking features is its multi-systemic involvement with a wide clinical phenotype. PATIENTS AND METHODS: Data from 107 patients with a genetically confirmed diagnosis of the disease were retrospectively analysed from the database of a national reference division for neuromuscular diseases. Demographic and clinical data were collected over a 7-year period. RESULTS: The most frequent age of symptom onset was adulthood (66.4%). 35% showed exclusive distal weakness and a majority (63.6%) had clinical myotonia. Only 10 patients lacked neuromuscular symptoms at diagnosis and up to 9.5% were restricted to a wheelchair. The implantation of a pacemaker or cardioverter-defibrillator was conducted in 16 patients but no sudden cardiac death was detected. A venous thromboembolic disease incidence rate of 5.6 cases per 1000 patient-year was identified. More than half of the patients (54%) in the series developed respiratory failure. 13 patients died during the follow-up period, with respiratory failure being the main cause of death. CONCLUSIONS: The follow-up and clinical management of patients with DM1 should be multidisciplinary. In our series, the main cause of morbidity and mortality was respiratory disorders, whereas the incidence of cardiac disorders was lower. In addition, there is a notable frequency of complications derived from falls, which can have serious consequences. Finally, a higher than expected incidence of thromboembolic events was identified, which deserves further study in other cohorts of patients.


TITLE: Distrofia miotónica de tipo 1: una serie de 107 pacientes.Introducción. La distrofia miotónica de tipo 1 (DM1) es la distrofia muscular más frecuente en adultos, aunque puede comenzar a cualquier edad. Genéticamente determinada y de transmisión dominante, se caracteriza por la afectación constante, aunque variable, de múltiples sistemas. Pacientes y métodos. Se analizaron retrospectivamente datos de 107 pacientes con diagnóstico genético de DM1 en seguimiento en una unidad de referencia nacional en enfermedades neuromusculares raras. Se recopilaron datos demográficos y clínicos de un período de seguimiento de siete años. Resultados. El 66,4% de los pacientes comenzó en la edad adulta. El 35,5% tenía debilidad distal exclusiva y la mayoría (63,6%) presentaba miotonía clínica. Sólo 10 pacientes no tenían síntomas neuromusculares en el diagnóstico. En un 8,6%, las caídas ocasionaron complicaciones graves y hasta un 9,5% perdió la deambulación autónoma. Se implantó un dispositivo cardíaco en 16 pacientes y no se registró ninguna muerte súbita de origen cardíaco. Se identificó una tasa de incidencia de enfermedad tromboembólica venosa de 5,6 casos/1.000 pacientes-año. Un 54% de los pacientes desarrolló insuficiencia respiratoria. Durante el seguimiento fallecieron 13 pacientes y la insuficiencia respiratoria fue la principal causa de muerte (38,5%). Conclusiones. El manejo clínico y el seguimiento de los pacientes con DM1 debe ser multidisciplinar. En nuestra serie, la principal causa de morbimortalidad fueron los trastornos respiratorios, mientras que la incidencia de complicaciones cardiológicas graves fue baja. Destacan, además, las complicaciones derivadas de las caídas, que pueden tener consecuencias graves. Finalmente, se identificó una incidencia mayor de la esperada de eventos tromboembólicos, que merece ser estudiada en mayor profundidad.


Assuntos
Distrofia Miotônica/diagnóstico , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Distrofia Miotônica/complicações , Estudos Retrospectivos
14.
Heredity (Edinb) ; 104(4): 378-86, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19812611

RESUMO

By suppressing recombination and reducing gene flow, chromosome inversions favor the capture and protection of advantageous allelic combinations, leading to adaptive polymorphisms. However, studies in non-model species remain scarce. Here we investigate the distribution of inversion polymorphisms in the multimammate rat Mastomys erythroleucus in West Africa. More than 270 individuals from 52 localities were karyotyped using G-bands and showed widespread polymorphisms involving four chromosome pairs. No significant deviations from Hardy-Weinberg equilibrium were observed either through space or time, nor were differences retrieved in viability or sex contribution between cytotypes. The distribution of chromosomal variation, however, showed perfect congruence with that of mtDNA-based phylogeographic clades. Thus, inversion diversity patterns in M. erythroleucus appeared more related to historical and/or demographic processes than to climate-based adaptive features. Using cross-species chromosome painting and G-banding analyses to identify homologous chromosomes in related out-group species, we proposed a phylogenetic scenario that involves ancestral-shared polymorphisms and subsequent lineage sorting during expansion/contraction of West African savannas. Our data suggest that long-standing inversion polymorphisms may act as regions in which adaptation genes may accumulate (nucleation model).


Assuntos
Inversão Cromossômica , Murinae/genética , Polimorfismo Genético , África Ocidental , Animais , Animais Selvagens/genética , Camarões , Chade , Inversão Cromossômica/genética , Coloração Cromossômica , Feminino , Frequência do Gene , Geografia , Masculino , Filogenia
15.
J Theor Biol ; 252(1): 43-55, 2008 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-18321530

RESUMO

Animal searches cover a full range of possibilities from highly deterministic to apparently completely random behaviors. However, even those stochastic components of animal movement can be adaptive, since not all random distributions lead to similar success in finding targets. Here we address the general problem of optimizing encounter rates in non-deterministic, non-oriented searches, both in homogeneous and patchy target landscapes. Specifically, we investigate how two different features related to turning angle distributions influence encounter success: (i) the shape (relative kurtosis) of the angular distribution and (ii) the correlations between successive relative orientations (directional memory). Such influence is analyzed in correlated random walk models using a proper choice of representative turning angle distributions of the recently proposed Jones and Pewsey class. We consider the cases of distributions with nearly the same shape but considerably distinct correlation lengths, and distributions with same correlation but with contrasting relative kurtosis. In homogeneous landscapes, we find that the correlation length has a large influence in the search efficiency. Moreover, similar search efficiencies can be reached by means of distinctly shaped turning angle distributions, provided that the resulting correlation length is the same. In contrast, in patchy landscapes the particular shape of the distribution also becomes relevant for the search efficiency, specially at high target densities. Excessively sharp distributions generate very inefficient searches in landscapes where local target density fluctuations are large. These results are of evolutionary interest. On the one hand, it is shown that equally successful directional memory can arise from contrasting turning behaviors, therefore increasing the likelihood of robust adaptive stochastic behavior. On the other hand, when target landscape is patchy, adequate tumbling may help to explore better local scale heterogeneities, being some details of the shape of the distribution also potentially adaptive.


Assuntos
Comportamento Apetitivo/fisiologia , Modelos Biológicos , Atividade Motora/fisiologia , Animais , Ecossistema , Orientação , Processos Estocásticos
16.
AIDS Care ; 20(4): 485-7, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18449827

RESUMO

Facial lipoatrophy can be obvious and stigmatising. Poly-L-lactic acid (PLLA) has been used widely for the correction of HIV-associated facial lipoatrophy. Analysis of the PLLA treatment protocols of 441 consecutive patients was undertaken. Product dilution, product volume per session, number of sessions, time between sessions, facial areas treated, plane of injection and incidence of injection-site nodules were recorded. Assessments included the Hospital Anxiety and Depression Scale and the Appearance Satisfaction Questionnaire. During the learning curve 30 patients were treated every 2 weeks for a minimum of three sessions. A 3-ml dilution was used and a total of 5 ml was injected in the deep dermis of the buccal areas. The incidence of nodule formation was 31% and 52% of patients did not achieve resolution of their facial disfigurement. A total of 411 patients were treated every 4 weeks for a minimum of four sessions. A minimum 5-ml dilution was used and a minimum total of 10-ml was injected subcutaneously in the temporal, infraorbital and buccal areas. The incidence of nodule formation was 2.9% and 10% of patients did not achieve resolution of their facial disfigurement. Patient anxiety and depression scores and appearance satisfaction scores improved significantly with treatment.


Assuntos
Materiais Biocompatíveis/uso terapêutico , Técnicas Cosméticas , Síndrome de Lipodistrofia Associada ao HIV/tratamento farmacológico , Ácido Láctico/uso terapêutico , Polímeros/uso terapêutico , Adulto , Técnicas Cosméticas/efeitos adversos , Feminino , Síndrome de Lipodistrofia Associada ao HIV/psicologia , Humanos , Injeções Subcutâneas , Ácido Láctico/efeitos adversos , Masculino , Satisfação do Paciente , Poliésteres , Polímeros/efeitos adversos , Qualidade de Vida , Estudos Retrospectivos
17.
J Phys Chem A ; 112(5): 904-14, 2008 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-18193844

RESUMO

For a molecule which contains an intramolecular hydrogen bond (IMHB) in its chemical structure to undergo an excited singlet intramolecular proton transfer (ESIPT) process, on photoexcitation, there must occur a simultaneous increase, in a substantial manner, in the acidity of the proton donor and the basicity of the proton acceptor forming the IMHB [J. Am. Chem. Soc. 2001, 123, 11940]. For the reason that those changes occur on photoexcitation of the 2-hydroxyacetophenone but not for 1-hydroxy-acetonaphthone, one draws the conclusion that, while ESIPT is operative in the 1(pi,pi*)(1) electronic state of the monocyclic compound 2-hydroxyacetophenone, it is not operative in its bicyclic homolog 1-hydroxy-2-acetonaphthone. We have shown the photophysics of 1-hydroxy-2-acetonaphthone in its first excited electronic state to be governed by two stable, easily reconverted enol structures, the presence of which causes the peaks in the free-jet fluorescence excitation spectrum for the compound to split into two of similar strength. In this paper, we rationalize photophysical evidence for 1-hydroxy-2-acetonaphthone obtained by femtosecond spectroscopy over the past 13 years in the light of existing photophysical patterns based on steady-state spectra for the compound [J. Am. Chem. Soc. 1993, 115, 4321].

18.
J Phys Chem A ; 112(25): 5555-65, 2008 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-18510296

RESUMO

Methylation at the 1N position of 2-phenylimidazole provides the shortest wavelength for a liquid-state laser dye reported to date; that is, the 1-methyl-2-phenylimidazole molecule in cyclohexane solution yields amplified spontaneous emission (ASE) with a peak wavelength at 314.5 nm and a constant laser gain value of 5 cm(-1) from 310 to 317 nm. Methyl substitution in this case favors the appearance of laser action (owing to a torsion-vibrational mechanism) in cyclohexane as compared with the nonmethylated species which does not exhibit ASE in this solvent. The 2-(2'-hydroxyphenyl)imidazole molecules give rise to ASE with high gain values (ca. 9 cm(-1)) at 450 and 466 nm. The mechanism of population inversion is understood in terms of a vibronic coupling between the hydroxyl stretching motion and the torsional vibration of the phenyl and imidazole rings. The proton-transfer spectroscopy of 2-(2'-hydroxyphenyl)imidazoles is studied in dioxane, cyclohexane, dimethyl sulfoxide, methanol, and water. The greater the acidity of the solvent the greater the disruption of the intramolecular hydrogen bond; solvent acidity is the main parameter which favors formation of the open-form species in the ground electronic state. Methyl substitution at the 1N position favors formation of the open species for 2-hydroxyphenylimidazoles in the ground electronic state, which decreases their own capacity to undergo ASE. Low-temperature absorption spectroscopy confirms aggregation processes for 2-(2'-hydroxyphenyl)imidazoles in solution. In accordance with X-ray analyses in the solid phase, these molecules form associations through intermolecular chains of the type N-H...O or O-H...N.

20.
Int J STD AIDS ; 28(7): 715-722, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27510645

RESUMO

This study aimed to determine the prevalence of HIV neurocognitive impairment in HIV-infected men who have sex with men aged 18-50 years, using a simple battery of screening tests in routine clinical appointments. Those with suspected abnormalities were referred on for further assessment. The cohort was also followed up over time to look at evolving changes. HIV-infected participants were recruited at three clinical sites in London during from routine clinical visits. They could be clinician or self-referred and did not need to be symptomatic. They completed questionnaires on anxiety, depression, and memory. They were then screened using the Brief Neurocognitive Screen (BNCS) and International HIV Dementia Scale (IHDS). Two hundred and five HIV-infected subjects were recruited. Of these, 59 patients were excluded as having a mood disorder and two patients were excluded due to insufficient data, leaving 144 patients for analysis. One hundred and twenty-four (86.1%) had a normal composite z score (within 1 SD of mean) calculated for their scores on the three component tests of the BNCS. Twenty (13.9%) had an abnormal z score, of which seven (35%) were symptomatic and 13 (65%) asymptomatic. Current employment and previous educational level were significantly associated with BNCS scores. Of those referred onwards for diagnostic testing, only one participant was found to have impairment likely related to HIV infection. We were able to easily screen for mood disorders and cognitive impairment in routine clinical practice. We identified a high level of depression and anxiety in our cohort. Using simple screening tests in clinic and an onward referral process for further testing, we were not able to identify neurocognitive impairment in this cohort at levels consistent with published data.


Assuntos
Complexo AIDS Demência/diagnóstico , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/epidemiologia , Infecções por HIV/complicações , Homossexualidade Masculina/psicologia , Homossexualidade Masculina/estatística & dados numéricos , Programas de Rastreamento/métodos , Complexo AIDS Demência/epidemiologia , Adolescente , Adulto , Ansiedade/complicações , Ansiedade/epidemiologia , Ansiedade/psicologia , Transtornos Cognitivos/psicologia , Depressão/complicações , Depressão/epidemiologia , Depressão/psicologia , Infecções por HIV/psicologia , Humanos , Londres , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Prevalência , Fatores de Risco , Inquéritos e Questionários
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