Very high blood oxygen affinity and large Bohr shift differentiates the air-breathing siamese fighting fish (Betta splendens) from the closely related anabantoid the blue gourami (Trichopodus trichopterus).

The Siamese fighting fish, Betta splendens, and the blue gourami, Trichopodus trichopterus, are two closely related air-breathing anabantoid fishes. B. splendens is a sedentary facultative air breather frequenting often hypoxic waters, while T. trichopterus is a more active obligatory air-breather inhabiting better oxygenated waters. Despite their close taxonomic relationship, previous studies have shown inter-specific differences in both physiological and morphological plasticity. Consequently, we hypothesized that B. splendens would have the higher blood oxygen affinity characteristics typical of more hypoxia-tolerant fishes. Whole blood oxygen equilibrium curves were determined at 27 °C and pHs of 7.62, 7.44 and 7.25. At a pH of 7.62, the blood O2 affinity (P50) of B. splendens was just 2.9 mmHg, while that of T. trichopterus was ~5 times higher at 14.7 mmHg. There were no significant differences in P50 between males and females in either species. The Bohr coefficient in B. splendens and T. trichopterus was -1.79 and - 0.83, respectively. B. splendens, unlike T. trichopterus, showed a large Root effect. Hills cooperatively coefficient, n, was ~2 in both species, indicating a significant binding cooperative between oxygen and hemoglobin. Collectively, these differences in blood O2 transport characteristics in these two closely related species are likely correlated with the differing habitats in which they breed and inhabit as adults, as well as different activity levels. Finally, the very high blood O2 affinity of B. splendens is not extraordinary among air-breathing fish, as revealed by a review of the literature of blood oxygen affinity in air-breathing fishes.

Environmental modulation of the onset of air breathing and survival of Betta splendens and Trichopodus trichopterus.

The effect of hypoxia on air-breathing onset and survival was determined in larvae of the air-breathing fishes, the three spot gourami Trichopodus trichopterus and the Siamese fighting fish Betta splendens. Larvae were exposed continuously or intermittently (12 h nightly) to an oxygen partial pressure (PO2 ) of 20, 17 and 14 kPa from 1 to 40 days post-fertilization (dpf). Survival and onset of air breathing were measured daily. Continuous normoxic conditions produced a larval survival rate of 65-75% for B. splendens and 15-30% for T. trichopterus, but all larvae of both species died at 9 dpf in continuous hypoxia conditions. Larvae under intermittent (nocturnal) hypoxia showed a 15% elevated survival rate in both species. The same conditions altered the onset of air breathing, advancing onset by 4 days in B. splendens and delaying onset by 9 days in T. trichopterus. These interspecific differences were attributed to air-breathing characteristics: B. splendens was a non-obligatory air breather after 36 dpf, whereas T. trichopterus was an obligatory air breather after 32 dpf.

Helicobacter pylori in the oral cavity is associated with gastroesophageal disease.

BACKGROUND: In Mexico, more than 80% of the population is infected with Helicobacter pylori. The frequency of H. pylori detection in the oral cavity is unknown, as its relationship with gastroesophageal pathology. AIM: To detect the presence of H. pylori in the oral cavity in Mexican population by PCR and to determine its association with gastroesophageal disease. METHODS: Patients were divided into two groups with different clinic conditions from whom gastric biopsy, dental plaque, and saliva samples were taken and analyzed. The first group comprised of hospitalized patients, the majority of whom were diagnosed with gastroesophageal disease, while the second group was selected from a dental clinic (ambulatory population) the majority of whom appeared to be healthy subjects. RESULTS: H. pylori was detected in gastric biopsy, dental plaque and saliva samples by PCR using a set of specific primers for the signal sequence of the vacuolating cytotoxin gene; detection of H. pylori in general was higher in gastric biopsy and dental plaque samples than in saliva samples. Detection of H. pylori in the oral cavity is significantly (P = 0.0001) associated with patients presenting gastroesophageal disease, while healthy subjects and those with other non-gastric disease do not present with H. pylori in their oral cavity. CONCLUSIONS: H. pylori detection in the oral cavity is associated to gastroesophageal disease. In addition, it is suggested that all patients presenting gastric symptoms and H. pylori detection in the oral cavity would begin bacterial treatment immediately.

Variación morfológica de la lagartija partenogenética Aspidoscelis rodecki (Squamata: Teiidae): implicaciones evolutivas y de conservación

Morphologic variation of the parthenogenetic lizard Aspidoscelis rodecki (Squamata: Teiidae): evolutionary and conservation implications. Post-formational divergence has been used for the recognition of new parthenogenetic species. Currently, the parthenogenetic lizard Aspidoscelis rodecki McCoy and Maslin 1962 is recognized as a single taxon that was derived from a single, parthenogenetically capable, hybrid. This lizard had been derived via hybridization between individuals of two gonochoristic species, Aspidoscelis angusticeps Cope 1878 and Aspidoscelis deppii Wiegmann 1834. The distribution of A. rodecki includes Isla Contoy and Isla Mujeres and the adjacent mainland of Quintana Roo, México. Previous studies have found post-formational divergence in genetic, chromatic and life-history characteristics among a continental population (Puerto Juárez) and an insular population (Isla Contoy). A meristic analysis was carried out to evaluate the morphological divergence among both populations of A. rodecki. We used 38 individuals from Puerto Juárez and 23 individuals from Isla Contoy. Nine meristic characters with discrimination value among species of the genus Aspidoscelis were used in both univariate (t-Student) and multivariate analyses (principal components and canonical variate analysis). According to both analyses, Puerto Juárez is meristically distinguishable from Isla Contoy. Both populations differ in five meristic characters and were a high correct classification in the canonical variate analysis: 97% of Puerto Juárez and 100% of Isla Contoy. A small sample from Isla Mujeres and a single specimen from Punta Sam (mainland) may represent different morphological groups. Due to the patterns of phenotypic variation, A. rodecki is considered as a single variable parthenogenetic species with high priority to conservation. The populations of A. rodecki have been extremely affected by the tourism developers. If the habitat of the parthenogenetic lizard (beach grasses) is allowed to stay, the expansion by the developers will not affect the survivorship of these populations. Nevertheless, the first sign of development is the total destruction of natural grasses that occurs on the beach, leaving only sand. There is a last chance to save the parthenogenetic lizard A. rodecki, but any effort will be useless without the support from the environmental authority of Mexico and cooperation from the developers. We suggest that Puerto Juárez and Isla Contoy receive separate management because they have unique portions of phenotypic variation of A. rodecki. The two lizard populations can be considered separate "Evolutionary Significant Units" (ESU). Rev. Biol. Trop. 56 (4): 1871-1881. Epub 2008 December 12.

La divergencia post-formación se ha utilizado para el reconocimiento de nuevas especies partenogenéticas. Actualmente, la lagartija partenogenética Aspidoscelis rodecki McCoy y Maslin 1962 es reconocida como una sola especie, que se originó de un híbrido partenogenético. Estudios previos han encontrado divergencia genética, en coloración y en características de historia de vida entre una población continental (Puerto Juárez) y una insular (Isla Contoy) en Quintana Roo, México. Se llevó a cabo un análisis merístico para evaluar la divergencia entre ambas poblaciones de A. rodecki. Se utilizaron 38 individuos de Puerto Juárez y 23 individuos de Isla Contoy. Se usaron nueve características merísticas y se realizaron análisis univariados (t de Student) y multivariados (análisis de componentes principales y análisis de variación canónica). De acuerdo a ambos análisis, Puerto Juárez es merísticamente distinguible de Isla Contoy. Ambas poblaciones difieren en cinco características merísticas y presentaron un alto porcentaje de clasificación en el análisis de variación canónica: 97% para Puerto Juárez y 100% para Isla Contoy. Una pequeña muestra de Isla Mujeres y un solo individuo de Punta Sam (continente) pueden representar otros grupos morfológicos. Con base en los patrones de variación fenotípica, A. rodecki es considerada como una sola especie partenogenética variable y prioritaria para la conservación. Debido a que cada población contiene una porción única de la variación de A. rodecki, Puerto Juárez e Isla Contoy merecen un manejo separado y se sugiere que cada una constituya una "Unidad Evolutiva Significativa" (ESU).

[Concurrent lymphoproliferative and myeloproliferative disorders in three patients]. / Coexistencia de Síndrome Lifoproliferativo Crónico y Síndrome Mieloproliferativo Crónico en tres pacientes.

We present two patients with a diagnosis of chronic lymphoproliferative syndrome, chronic lymphocytic leukemia B (CLL B) and lymphoplasmacytic non-Hodgkin's lymphoma (NHL), who developed chronic myeloproliferative syndrome: polycythemia vera (PV) and Philadelphia-positive chronic myeloid leukemia (CML) respectively, and a third patient with chronic myeloproliferative syndrome, polycythemia vera (PV), who developed an undefined immunophenotype cyclin D1-positive chronic lymphoproliferative syndrome. The cases included in literature are scarce, and it is not known whether some common mechanism can explain both processes' pathogeneses and the control mechanisms of one process over the other.

[Morphologic variation of the parthenogenetic lizard Aspidoscelis rodecki (Squamata: Teiidae): evolutionary and conservation implications]. / Variación morfológica de la lagartija partenogenética Aspidoscelis rodecki (Squamata: Teiidae): implicaciones evolutivas y de conservación.

Post-formational divergence has been used for the recognition of new parthenogenetic species. Currently, the parthenogenetic lizard Aspidoscelis rodecki McCoy and Maslin 1962 is recognized as a single taxon that was derived from a single, parthenogenetically capable, hybrid. This lizard had been derived via hybridization between individuals of two gonochoristic species, Aspidoscelis ungusticeps Cope 1878 and Aspidoscelis deppii Wiegmann 1834. The distribution of A. rodecki includes Isla Contoy and Isla Mujeres and the adjacent mainland of Quintana Roo, México. Previous studies have found post-formational divergence in genetic, chromatic and life-history characteristics among a continental population (Puerto Juárez) and an insular population (Isla Contoy). A meristic analysis was carried out to evaluate the morphological divergence among both populations of A. rodecki. We used 38 individuals from Puerto Juárez and 23 individuals from Isla Contoy. Nine meristic characters with discrimination value among species of the genus Aspidoscelis were used in both univariate (t-Student) and multivariate analyses (principal components and canonical variate analysis). According to both analyses, Puerto Juárez is meristically distinguishable from Isla Contoy. Both populations differ in five meristic characters and were a high correct classification in the canonical variate analysis: 97% of Puerto Juárez and 100% of Isla Contoy. A small sample from Isla Mujeres and a single specimen from Punta Sam (mainland) may represent different morphological groups. Due to the patterns of phenotypic variation, A. rodecki is considered as a single variable parthenogenetic species with high priority to conservation. The populations of A. rodecki have been extremely affected by the tourism developers. If the habitat of the parthenogenetic lizard (beach grasses) is allowed to stay, the expansion by the developers will not affect the survivorship of these populations. Nevertheless, the first sign of development is the total destruction of natural grasses that occurs on the beach, leaving only sand. There is a last chance to save the parthenogenetic lizard A. rodecki, but any effort will be useless without the support from the environmental authority of Mexico and cooperation from the developers. We suggest that Puerto Juárez and Isla Contoy receive separate management because they have unique portions of phenotypic variation of A. rodecki. The two lizard populations can be considered separate "Evolutionary Significant Units" (ESU).

Diferencias en los motivos de consulta entre pacientes que acuden derivados y por iniciativa propia a un Servicio de Cuidados Críticos y Urgencias de un hospital general / Differences in the consultation motives between referral and non-referral patients attending a Critical Care and Emergency Service at a general hospital

Objetivos: Analizar las diferencias existentes en los motivos de consulta entre pacientes pediátricos derivados y los que acuden por iniciativa propia (IP) a la sección de urgencias de un Servicio de Cuidados Críticos y Urgencias (SU). Métodos: Estudio observacional descriptivo. Se incluyeron pacientes de ambos sexos, con edades comprendidas entre 0 y 12 años, que no acudían por patología traumática. Se realizaron grupos dependiendo de si el paciente venía o no derivado, y según el nivel de gravedad. Resultados: Se incluyeron 411 pacientes, con una edad media de 3,10 años (IC 95%: 2,81-3,39), de los cuales el 52,6% fueron varones. Los motivos de consulta más frecuentes fueron dificultad respiratoria (30,7%), fiebre (25,3%) y patología gastrointestinal (22,6%). El 75,4% acudieron por IP y el 24,6% fueron derivados. Los motivos más frecuentes de acudir al SU de los pacientes que acudieron por IP, fueron: el 31,3% por no accesibilidad a un pediatra extrahospitalario, el 23,8% porque consideraban que no cabía más demora en la atención y el 14% porque deseaban una segunda opinión. De los pacientes que venían derivados, el 45,5% necesitó pruebas complementarias (PC), el 22,8% observación de urgencias o ingreso hospitalario (OU/IH), y el 31,7% fue alta directa (AD), mientras que si acudieron por IP, el 29,2% necesitó PC, el 3,9% OU/IH y el 66,9% AD (p = 0,0001). El 93,5% de los pacientes IP fueron clasificados como nivel 4 de gravedad frente al 80,2% de los derivados (p= 0,0001). Conclusiones: 1. El principal motivo de acudir al área de pediatría de un SU por IP es la no accesibilidad a un especialista en pediatría extrahospitalario. 2. Los motivos de consulta más frecuentes fueron dificultad respiratoria y fiebre. 3. Los pacientes derivados presentan significativamente una mayor necesidad de realización de PC, OU e IH y un mayor nivel de gravedad (AU)

Objectives: To analyse the differences between the consultation motives among patients attending a Critical Care and Emergency Service at a general hospital by comparing paediatric referral patients and those who were brought directly to the hospital. Methods: Observational descriptive study. Patients of both genders with an age range between 0 and 12 years were included who did not come to the hospital because of traumatisms. Referral and non-referral patients were further stratified according to the severity of their condition. Results: The total study population comprised 411 patients (52.6% males) with an average age of 3.10 years (95% CI 2.82-3.39). Only 24.6% were referral cases, the remaining 75.4% having come or been brought directly to the Service. The most frequent motives for consultation were respiratory problems (30.7%), fever (25.3%) and gastrointestinal conditions (22.6%). Among non-referral patients, the most frequent reasons for coming to the Emergency Service were lack of access to an extrahospitalary paediatrician (31.3%), considering that urgent attention was required (23.8%) and wish for a second opinion (14%). Among the referral patients, 45.5% required further complementary tests, 22.8% were admitted for observation or treatment, and 31.7% were discharged directly; the corresponding data for the non-referral patients were 92%, 3.9% and 66.9%, respectively (p = 0.0001). Among the non-referral patients, 93.5% were classed as “severity level 4”, versus only 80.2% of the referral ones (p = 0.0001). Conclusions: 1. The most frequent reason for seeking consultation at the paediatrics area of a hospitalary Emergency Service was the nonavailability of an extrahospitalary paediatrician. 2. The most frequent motives of consultation were respiratory problems and fever. 3. Referral patients significantly more often require complementary testing and admission, and significantly more often evidence more severe conditions (AU)

Serologic survey of domestic animals for zoonotic arbovirus infections in the Lacandón Forest region of Chiapas, Mexico.

A serologic survey in domestic animals (birds and mammals) was conducted in four communities located in the Lacandón Forest region of northeastern Chiapas, Mexico, during June 29 to July 1, 2001, with the objective to identify zoonotic arboviruses circulating in this area. We collected 202 serum samples from healthy domestic chickens, geese, ducks, turkeys, horses and cattle. The samples were tested by plaque-reduction neutralization test for antibodies to selected mosquito-borne flaviviruses (family Flaviviridae), including St. Louis encephalitis (SLE), Rocio (ROC), Ilheus (ILH), Bussuquara (BSQ), and West Nile (WN) viruses, and selected alphaviruses (family Togaviridae), including Western equine encephalitis (WEE), Eastern equine encephalomyelitis (EEE), and Venezuelan equine encephalitis (VEE) viruses. Neutralizing antibodies to SLE virus were detected in two (8%) of 26 turkeys, 15 (23%) of 66 cattle, and three (60%) of five horses. Antibodies to VEE virus were detected in 29 (45%) of 65 cattle. Because some of these animals were as young as 2 months old, we demonstrated recent activity of these two viruses. Sub-typing of the VEE antibody responses indicated that the etiologic agents of these infections belonged to the IE variety of VEE, which has been reported from other regions of Chiapas. WN virus-neutralizing antibodies were detected in a single cattle specimen (PRNT(90) = 1:80) that also circulated SLE virus-neutralizing antibodies (PRNT(90) = 1:20), suggesting that WN virus may have been introduced into the region. We also detected weak neutralizing activity to BSQ virus in four cattle and a chicken specimen, suggesting the presence of this or a closely related virus in Mexico. There was no evidence for transmission of the other viruses (ROC, ILH, EEE, WEE) in the study area.

[Bacteriological quality of human drinking water in high-margination zones in Chiapas]. / Calidad bacteriológica del agua para consumo humano en zonas de alta marginación de Chiapas.

OBJECTIVE: To analyze the bacteriological quality of drinking water (BQDW) and its association with diarrhoea and intestinal parasites in children 1 to 14 years old, in areas of high levels of poverty in Chiapas, Mexico. MATERIAL AND METHODS: From March to September 1998, drinking water was collected from a random sample of 99 households in the Border Region of Chiapas, Mexico; data on diarrhoeal disease (in the past 15 days) were collected and stool testing for intestinal parasites was performed in children 1 to 14 years old (n = 322). The BQDW was determined by the filtration membrane technique. Intestinal parasitic infections were determined by the Faust Method. The chi 2 statistic was used to analyse factors associated with BQDW. RESULTS: Only 31% of the water samples were adequate for human consumption. The BQDW and the presence of diarrhoea (informed by the mothers of the children) showed no association. Children living in households with inadequate BQDW had a higher prevalence of Entamoeba histolytica and a greater tendency to have intestinal parasites. CONCLUSIONS: It is necessary to develop programs that improve BQDW and to develop education efforts aimed at increasing the use of boiled water and the adequate management and care of community water storage sites.