Molecular Phylogeny and Biogeography of the Amphidromous Fish Genus Dormitator Gill 1861 (Teleostei: Eleotridae).

Species of the genus Dormitator, also known as sleepers, are representatives of the amphidromous freshwater fish fauna that inhabit the tropical and subtropical coastal environments of the Americas and Western Africa. Because of the distribution of this genus, it could be hypothesized that the evolutionary patterns in this genus, including a pair of geminate species across the Central American Isthmus, could be explained by vicariance following the break-up of Gondwana. However, the evolutionary history of this group has not been evaluated. We constructed a time-scaled molecular phylogeny of Dormitator using mitochondrial (Cytochrome b) and nuclear (Rhodopsin and ß-actin) DNA sequence data to infer and date the cladogenetic events that drove the diversification of the genus and to relate them to the biogeographical history of Central America. Two divergent lineages of Dormitator were recovered: one that included all of the Pacific samples and another that included all of the eastern and western Atlantic samples. In contrast to the Pacific lineage, which showed no phylogeographic structure, the Atlantic lineage was geographically structured into four clades: Cameroon, Gulf of Mexico, West Cuba and Caribbean, showing evidence of potential cryptic species. The separation of the Pacific and Atlantic lineages was estimated to have occurred ~1 million years ago (Mya), whereas the four Atlantic clades showed mean times of divergence between 0.2 and 0.4 Mya. The splitting times of Dormitator between ocean basins are similar to those estimated for other geminate species pairs with shoreline estuarine preferences, which may indicate that the common evolutionary histories of the different clades are the result of isolation events associated with the closure of the Central American Isthmus and the subsequent climatic and oceanographic changes.

Desmopressin test in the diagnosis and follow-up of cyclical Cushing's disease.

OBJECTIVE: To assess the utility of the desmopressin (DDAVP) test in the diagnosis and follow-up of a cyclical Cushing's disease (CCS) case. MATERIAL AND METHODS: Laboratory tests included morning and midnight serum cortisol levels, 24h urine free cortisol excretion, midnight salivary cortisol levels, serum cortisol levels after low (1 mg) and high (8 mg) dexamethasone, plasma ACTH and serum cortisol levels after DDAVP. Magnetic resonance imaging (MRI) was used to assess the presence of a pituitary adenoma. The resected tumor specimen was studied by histological, immunohistochemical and cell biology techniques. RESULTS: A patient was referred to our unit with a diagnosis of Cushing's syndrome (CS) for further evaluation and treatment. However, no biochemical evidence of hypercortisolism was observed in the follow-up evaluations. Furthermore, the typical features of CS fluctuated throughout this period. A consistent positive response to the DDAVP stimulation test was observed during the diagnostic work-up, even when overt clinical features of CS were not apparent, raising suspicion for CCS. After two years of follow-up a definitive diagnosis of hypercortisolism was established. An MRI scan revealed a pituitary adenoma, as the source of ACTH production. After transphenoidal surgery, clinical signs of CS resolved and the response to DDAVP became negative. DDAVP induced a significant increase in ACTH levels in cultured pituitary adenoma cells, consistent with the in vivo DDAVP test results. CONCLUSIONS: Our case illustrates the utility of the DDAVP test in the evaluation of patients with suspected CCS. The DDAVP test could facilitate the management of CCS by shortening the time of diagnosis.

Molecular phylogeny and biogeography of the Cuban genus Girardinus Poey, 1854 and relationships within the tribe Girardinini (Actinopterygii, Poeciliidae).

Phylogenetic relationships among members of the freshwater fish tribe Girardinini were inferred to test existing colonization and diversification hypotheses for this group in the Caribbean. The genetic material examined was mitochondrial (cytochrome b, 1140 bp) and nuclear (RAG-1 and beta-actin, 2450 bp) DNA from 161 specimens representing 44 ingroup and three outgroup taxa. Our mtDNA and combined data matrix (mtDNA+nuclear DNA) results rendered a well-supported phylogeny for the tribe Girardinini and suggest the need to review the group's current taxonomy. From the data presented here, it may be inferred that the Girardinini diverged from other poeciliid fishes approximately 62 Mya ago in the Palaeocene period. This estimate, however, conflicts with the hypothesis that today's vertebrate fauna is the result of the more recent colonization of the Antillean islands during the Early Oligocene (35-33 Mya ago). The isolation of western, central and eastern Cuba during the Miocene and that of the Juventud Island and Guanahacabibes Peninsula during the Pliocene, are the main geologic events that could have promoted speciation in this group.

Long-term maintenance of low-dose antithyroid drugs versus drug withdrawal in patients with Graves' hyperthyroidism.

OBJECTIVE: The relapse rate of Graves' hyperthyroidism after finishing an antithyroid cicle is high. The objective of this work was to prospectively investigate the relapse rate of Graves' hyperthyroidism (GH) in patients with maintenance of a low dose of antithyroid drug (ATD) therapy. PATIENTS AND METHOD: From March 1997, all patients with GH consecutively attending the same center who remained euthyroid with low doses of synthetic ATD (carbimazole or methimazole: 2.5-5mg/day) on 2 consecutive follow-up visits (at 10-12 months) were included in this study. Instead of withdrawing ATD, the aim was to continue with this low dose for a 5-year period (group M: 53 patients). From March 1997, data were also collected from patients with GH who were consecutively followed-up and who, meeting the criteria for inclusion in group M, had stopped receiving ATD before the start of the study (March 1997) (group R: 31 patients). MAIN OUTCOME: GH relapse was observed in 12/53 patients in group M (22.64%) and in 24/31 patients in group R (77.42%) (p<0.000). CONCLUSIONS: The GH relapse rate was significantly lower with long-term maintenance of a low dose of ATD than with therapy withdrawal.

[Infectious pulmonary complications in HIV-infected patients in the high by active antiretroviral therapy era in Spain]. / Complicaciones infecciosas pulmonares en los pacientes con infección por el virus de la inmunodeficiencia humana en la era del tratamiento antirretroviral de gran actividad en España.

Pulmonary complications in HIV-infected patients are at present a first-rate problem. They are the main cause of hospital admission of these patients in our country. Most HIV-patients have a pulmonary complication during the evolution of the infection. The main etiologic diagnosis is bacterial pneumonia, especially pneumococcal pneumonia; the second most frequent cause is Pneumocystis jiroveci (previously named P. carinii) pneumonia and the third cause is mycobacteriosis, particularly Mycobacterium tuberculosis. From early studies, important changes in the epidemiology of HIV-related pulmonary complications have occurred. General prescription of P. jiroveci primary prophylaxis is probably one of the main causes, and, more recently, the use of highly active antiretroviral therapy may also be an underlying explanation. In this review, epidemiology, diagnosis and outcome of HIV-related pulmonary complications in our country are update.

Amplificación al azar del ADN de 5 poblaciones cubanas de peces larvívoros del género Rivulus

Se amplificó al azar el ADN de 10 individuos de 5 poblaciones de Rivulus colectados en la región occidental de Cuba. De la amplificación, empleando 5 cebadores, no resultó ningún marcador monomórfico, lo que evidenció una alta variabilidad genética entre los peces de las 5 poblaciones. Según la distancia genética entre los individuos, se forman 4 grupos, para cada uno de los cuales aparecen marcadores genéticos de RAPD (ADN polimórfico amplificado al azar) que son específicos, porque no se evidencian en el resto de los individuos. Estos resultados apoyan la utilización del RAPD como una herramienta eficiente para la caracterización genética de peces cubanos del género Rivulus.

DNA from 10 individuals from 5 populations of Rivulus collected in the western region of Cuba was amplified at random. No monomorphic marker resulted from the amplification by using 5 primers, which showed the high genetic variability existing among the fishes of the 5 populations. According to the genetic distance among the individuals, they were divided into 4 groups, for which there are specific genetic markers of RAPD, since they are not observed in the rest of the subjects. These results support the use of RAPD as an efficient tool for the genetic characterization of Cuban fishes of the Rivulus genus.

[Amplification at random of the DNA from 5 Cuban populations of larviphage fishes of the Rivulus genus]. / Amplificación al azar del ADN de 5 poblaciones cubanas de peces larvívoros del género Rivulus.

DNA from 10 individuals from 5 populations of Rivulus collected in the western region of Cuba was amplified at random. No monomorphic marker resulted from the amplification by using 5 primers, which showed the high genetic variability existing among the fishes of the 5 populations. According to the genetic distance among the individuals, they were divided into 4 groups, for which there are specific genetic markers of RAPD, since they are not observed in the rest of the subjects. These results support the use of RAPD as an efficient tool for the genetic characterization of Cuban fishes of the Rivulus genus.