Vibration attraction response is a plastic trait in blind Mexican tetra (Astyanax mexicanus), variable within subpopulations inhabiting the same cave.

Animals evolve their sensory systems and foraging behaviours to adapt and colonize new and challenging habitats such as the dark cave environment. Vibration attraction behaviour (VAB) gives fish the ability to locate the source of a water disturbance in the darkness. VAB evolved in the blind Mexican cave tetra, Astyanax mexicanus. VAB is triggered in cavefish by vibration stimuli peaking at 35 Hz, which is within the main spectrum of water fluctuations produced by many prey crustaceans and insects. VAB has a genetic component and is correlated to an increased number of head mechanosensory neuromasts in the eye orbital region when compared to surface fish. Previous competitive prey capture assays have supported the advantage of VAB for foraging in the dark. Despite its putative adaptive function, VAB has been described as absent in some Astyanax cave populations (Tinaja and Molino) but present in others (Pachón, Piedras, Toro and Sabinos). Here we have tested the occurrence of VAB in the field and in multiple cave populations using a vibrating device in natural pools. Our results confirmed the presence of VAB in caves such as Pachón, Toro and Sabinos but showed that VAB is also present in the Tinaja and Molino cave populations, previously reported as VAB-negative in laboratory experiments. Thus, VAB is available throughout the range of hypogean A. mexicanus. However, and most notably, within a given cave the levels of VAB were highly variable among different pools. Fish at one pool may express no VAB, while fish at another nearby pool of the same cave may actively show VAB. While a variety of environmental conditions may foster this diversity, we found that individuals inhabiting pools with a high abundance of organic matter have reduced expression of VAB. In contrast, in pools with little organic debris where fish probably depend more on hunting than on scavenging, VAB is enhanced. Our results suggest that expression of VAB is a plastic trait whose variability can depend on local conditions. Such plasticity may be required within and among caves where high environmental variability between pools results in a diverse availability of food.

Diagnostic criteria for depression in Parkinson's disease: a study of symptom patterns using latent class analysis.

Although major depression is one of the most frequent psychiatric disorders among patients with Parkinson's disease, diagnostic criteria have yet to be validated. The main aim of our study was to validate depressive symptoms using latent class analysis for use as diagnostic criteria for major depression in Parkinson's disease. We examined a consecutive series of 259 patients with Parkinson's disease admitted to 2 movement disorders clinics for regular follow-ups. All patients were assessed with a comprehensive psychiatric interview that included structured assessments for depression, anxiety, and apathy. The main finding was that all 9 Diagnostic and Statistical Manual (4th edition) diagnostic criteria for major depression (ie, depressed mood, diminished interest or pleasure, weight or appetite changes, sleep changes, psychomotor changes, loss of energy, feelings of worthlessness or inappropriate guilt, poor concentration, and suicidal ideation) identified a patient class (severe depression group) with high statistical significance. Latent class analysis also demonstrated a patient class with minimal depressive symptoms (no-depression group), and a third patient class with intermediate depressive symptoms (moderate depression). Anxiety and apathy were both significant comorbid conditions of moderate and severe depression. Taken together, our findings support the use of the full Diagnostic and Statistical Manual (4th edition) criteria for major depression for use in clinical practice and research in Parkinson's disease and suggest that anxiety may be included as an additional diagnostic criterion.

The construct of generalized anxiety disorder in Alzheimer disease.

OBJECTIVES: The objectives of this study were to examine the criterion validity in Alzheimer disease (AD) of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and the International Classification of Diseases, 10th Revision (ICD-10) criteria for generalized anxiety disorder (GAD), to clarify the symptoms associated with excessive anxiety and worry in AD, to examine the co-occurrence of GAD and depression in these patients, and to determine the neuropsychologic and functional impact of GAD in AD. RESULTS: One hundred forty-four of a consecutive series of 552 patients with probable AD (26%) reported excessive anxiety and worry difficult to control for most of the 6 months before the psychiatric evaluation. Excessive anxiety and worry were significantly associated with restlessness, irritability, muscle tension, fears, and respiratory symptoms of anxiety. Using these symptoms as diagnostic criteria, 56 of the 552 patients (10%) met revised diagnostic criteria for GAD as compared with 15% when using DSM-IV criteria and 9% when using the ICD-10 criteria. GAD was present in 38 of the 144 patients (26%) with major depression and in 12 of the 261 patients (5%) without depression. Patients with both GAD and depression showed more severe cognitive deficits than patients with either GAD or depression only. CONCLUSION: The authors validated a set of diagnostic criteria for anxiety in dementia. These criteria include restlessness, irritability, muscle tension, fears, and respiratory symptoms in the context of excessive anxiety and worry. Anxiety in AD is a frequent comorbid condition of major depression.

Traffic-related occupational exposures to PM2.5, CO, and VOCs in Trujillo, Peru.

A traffic-related exposure study was conducted among 58 workers (drivers, vendors, traffic police, and gas station attendants) and 10 office workers as controls in Trujillo, Peru, in July 2002. PM2.5 was collected, carbon monoxide (CO) was measured, volatile organic compounds (VOCs) were sampled and analyzed. Newspaper vendors had the highest full-shift CO exposures (mean +/- SD: 11.4 +/- 8.9 ppm), while office workers had the lowest (2.0 +/- 1.7 ppm). Bus drivers had the highest full-shift PM2.5 exposures (161 +/- 8.9 microg/m3), while gas station attendants (64 +/- 26.5 microg/m3) and office workers (65 +/- 8.5 microg/m3) were the lowest. Full-shift benzene/toluene/ethylbenzene/xylene exposures (BTEX) among gas station attendants (111/254/43/214 microg/m3) were much higher than those among van and taxi drivers. Several of the traffic-related occupational exposures studied were elevated and are of occupational health concern.

Squamous-cell carcinoma arising from an odontogenic cyst--the importance of computed tomography in the diagnosis of malignancy.

Primary intraosseous carcinoma of the mandible is rare, and when it occurs often arises within or closely associated with an odontogenic cyst. The purpose of this article is to show the role of computed tomography (CT) in the early detection of carcinomatous changes, because of its specificity in establishing the nature of the lesion. An unusual case of a squamous cell carcinoma that arose in an odontogenic cyst is described. The appearance on the panoramic radiograph was suggestive of a benign cystic lesion in the left side of the mandible, but when a CT scan was performed, the appearance of the lesion was compatible with malignancy. Histopathological analysis confirmed the suspicion of a squamous cell carcinoma, but without CT investigation it would be impossible to demonstrate that carcinomatous change had developed from a cystic lesion.

Problemas neuropsiquiátricos pós-AVC: diagnóstico, fisiopatologia e tratamento / Post-stroke neuropsychiatric problems: diagnosis, pathophysiology and treatment

Resumo: Depressäo é o transtorno psiquiátrico mais comum ocorrendo como conseqüência de acidente vascular cerebral (AVC). Aproximadamente entre 40 e 50 por cento destes pacientes iräo apresentar depressäo no primeiro mês após um AVC agudo. Depressäo pós-AVC pode ter um efeito significativo na reabilitaçäo para atividades de vida diária e funcionamento cognitivo nestes pacientes. Antidepressivos têm se mostrado eficazes no tratamento de depresäo pós-AVC. Estimulantes centrais e eletroconvulsoterapia (ECT) também parecem eficazes em estudo näo-controles. Mania é uma complicaçäo rara de AVC. Seus mecanismos ainda säo desconhecidos, e o tratamento é baseado em drogas que säo eficazes no tratamento da mania primária. O tratamento do transtorno bipolar pós-AVC também segue os critérios para tratamento do transtorno bipolar primário. Lítio é o tratamento principal, que também pode ser associado a antipsicóticos ou outros estabilizadores do humor, como o valproato de sódio ou carbamazepina. Outros problemas psiquiátrico associados com AVC incluem a ansiedade pós-AVC, a psicose pós-AVC e o riso e choro patológico. Ansiedade responde às drogas ansiolíticas, como os bensodiazepínicos. Existem duas formas básicas de abordar os pacientes com psicose pós-AVC. Uma destas formas utiliza terapia anticonvulsivante, e a outra utiliza antipsicóticos. Nortriptilina e citalopram têm se mostrado drogas eficazes em estudos duplo-cego, controlados, para o tratamento de riso e choro patológicos pós-AVC

Problemas neuropsiquiatricos pos-AVC-diagnostico, fisiopatologia e tratamento

Depressao e o transtorno psiquiatrico mais comum ocorrendo como consequencia de acidente vascular cerebral (AVC). Aproximadamente entre 40 e 50 por cento destes pacientes irao apresentar depressao no primeiro mes apos um AVC agudo. Depressao pos-AVC pode ter um efeito significativo na reabilitacao para atividades de vida diaria e funcionamento cognitivo nestes pacientes. Antidepressivos tem se mostrado eficazes na tratamento de depressao pos-AVC. Estimulantes centrais e eletroconvulsoterapia (ECT) tambem parecem ser eficazes em estudos nao-terapia (ECT) tambem parecem ser eficazes em estudos nao-controlados. Mania e uma complicacao rara de AVC. Seus mecanismos ainda sao desconhecidos, e o tratamento e baseado em drogas que sao eficazes no tratamento da mania primaria. O tratamento do transtorno bipolar pos-AVC tambem segue os criterios para tratamento do transtorno bipolar primario. Litio e o tratamento principal, que tambem pode ser associado a antipsicoticos ou outros estabilizadores do humor, como o valproato de sodio ou a carbomazepina. Outros problemas psiquiatricos associados com AVC incluem a ansiedade pos-AVC, a psicose pos-AVC e o riso e choro patologicos. Ansiedade responde as drogas ansioliticos, como os benzodiazepinicos. Existem duas formas basicas de abordar os pacientes com psicose pos-AVC. Uma destas formas utiliza terapia anticonvulsivante, e a outra utiliza antipsicoticos. Nortriptilina e citalopram tem se mostrado drogas eficazes em estudos duplo-cego, controlados, para o tratamento de riso e choro patologico pos-AVC.

Neuroimaging studies in depression

Técnicas de neuroimagem têm sido utilizadas extensivamente nos últimos anos para investigar anormalidades focais em estrutura e funçao cerebral associadas com depressao. Ressonancia nuclear magnética e tomografia computadorizada têm identficado anormalidades específicas em pacientes com depressao primária ou secundária. Alguns desses achados incluem lobos temporais ou amígdalas comparativamente menores, lesoes clinicamente silenciosas do lobo frontal esquerdo, substância brancasubjacente ou núcleos da base esquerdos, e atrofia subcortical. Alteraçoes em fluxo sanguíneo cerebral ou atividade metabólica no córtex prefrontal esquerda têm sido achados consistentes em pacientes com depressao primária. Estudos semelhantes em pacientes com depressao secundária têm encontrado anormalidades nos receptores de serotonina no córtex temporal esquerdo. Estes estudos sugeram que uma disfunçao do circuito límbico ventrolateral pode estar envolvido na etiologia da depressao primária ou secundária

Neuroimaging studies in depression / Neuroimaging studies in depression

Tecnicas de neuroimagem tem sido utilizadas extensivamente nos ultimos anos para investigar anormalidades focais em estrutura e funcao cerebral associadas com depressao. Ressonancia nuclear magnetica e tomografia computadorizada tem identificado anormalidade especificas em pacientes com depressao primaria ou secundaria. Alguns desses achados incluem lobos temporais ou amigdalas comparativamente menores, lesoes clinicamente silenciosas do lobo frontal esquerdo, substancia branca subjacente ou nucleos da base esquerdos, e atrofia subcortical. Alteracoes em fluxo sanguineo cerebral ou atividade metabolica no cortex prefrontal esquerdo tem sido achados consistentes em pacientes com depressao primaria. Estudos semelhantes em pacientes com depressao secundaria tem encontrado anormalidades nos receptores de serotonina no cortex temporal esquerdo. Estes estudos sugerem que uma disfuncao do circuito limbico ventrolateral pode estar envolvido na etiologia da depressao primaria ou secundaria.