Assessing the importance of four sandfly species (Diptera: Psychodidae) as vectors of Leishmania mexicana in Campeche, Mexico.

Localized cutaneous leishmaniasis represents a public health problem in many areas of Mexico, especially in the Yucatan Peninsula. An understanding of vector ecology and bionomics is of great importance in evaluations of the transmission dynamics of Leishmania parasites. A field study was conducted in the county of Calakmul, state of Campeche, during the period from November 2006 to March 2007. Phlebotomine sandfly vectors were sampled using Centers for Disease Control light traps, baited Disney traps and Shannon traps. A total of 3374 specimens were captured in the two villages of Once de Mayo (93.8%) and Arroyo Negro (6.1%). In Once de Mayo, the most abundant species were Psathyromyia shannoni, Lutzomyia cruciata, Bichromomyia olmeca olmeca and Psychodopygus panamensis (all: Diptera: Psychodidae). The Shannon trap was by far the most efficient method of collection. The infection rate, as determined by Leishmania mexicana-specific polymerase chain reaction, was 0.3% in Once de Mayo and infected sandflies included Psy. panamensis, B. o. olmeca and Psa. shannoni. There were significant differences in human biting rates across sandfly species and month of sampling. Ecological niche modelling analyses showed an overall overlap of 39.1% for the four species in the whole state of Campeche. In addition, the finding of nine vector-reservoir pairs indicates a potential interaction. The roles of the various sandfly vectors in Calakmul are discussed.

Triatoma dimidiata (Latreille) abundance and infection with Trypanosoma cruzi in a rural community of Yucatan, Mexico.

The present is a longitudinal study that describes the abundance of Triatoma dimidiata (Latreille) (Hemiptera: Reduviidae) and its infection with Trypanosoma cruzi in a rural community of Yucatan, Mexico. From a total of 370 individuals collected, 81.3% were adults, most from intradomicile ecotope (282/301), but nymphs were more abundant in peridomicile (58/69). The overall proportion of infected bugs was 21.9% (23.9% of adults and 13% of nymphs). The infection proportion was similar between intradomicile and peridomicile ecotopes (22.8% and 18.1%, respectively). Overall, 76.5% (36/47) of the houses and their backyards were infested. Of those, 27.7% were colonized and 75% had infected triatomines. Our data showed different proportions on infestation, colonization and bug density. Ninety-seven percent of overall peridomicile abundance was distributed in chicken coops, doghouses, opossum nests and dove cages. Triatomine entomological indices showed higher infestation and density inside domiciles, but higher colonization in the peridomicile. The abundance, the amount of infected intradomicile adult T. dimidiata and the incidence of infestation showed a seasonal pattern, with 63.7% of all individuals collected during the late dry season (April to June). We showed the peridomicile colonization of animal shelters and suggest it as a relevant source of T. dimidiata individuals. As infected bugs were found in both ecotopes, the studied area is under a high risk of T. cruzi transmission to humans.

Seroprevalence of antibodies against the excreted antigen superoxide dismutase by Trypanosoma cruzi in dogs from the Yucatan Peninsula (Mexico).

Numerous studies have shown the role of dogs as a reservoir for the American trypanosomiasis, as the bridge connecting sylvatic and peridomestic cycles. The objective of this study was to determine the prevalence of American trypanosomiasis in the dog population (630 sera) from seven localities in the Yucatan Peninsula (city of Mérida and the towns of Molas, Playa del Carmen, Akumal, Xcalacoop, Xcalac and Xahuachol). These data are key for developing control measures for the disease. The sera were analysed to detect antibodies against Trypanosoma cruzi, using Fe-SOD excreted as the antigenic fraction by ELISA and Western blot as confirmation. The total prevalence found in the Yucatan Peninsula was some 14.76%, with 10.74% in the state of Yucatan (city of Mérida, towns of Molas and Xcalacoop) and 21.34% in the state of Quintana Roo (towns of Playa del Carmen, Akumal, Xcalac and Xahuachol). However, a more thorough epidemiological study of the dog population, both wild and urban, in the Yucatan Peninsula will be required to design a control strategy for these diseases, paying particular attention to the population affected and even broadening the study to other Mexican states as well as neighbouring countries. These results again confirm that iron-superoxide dismutase excreted by T. cruzi constitutes a good source of antigen for serodiagnosis in epidemiological studies.

Incrimination of the mosquito, Aedes taeniorhynchus, as the primary vector of heartworm, Dirofilaria immitis, in coastal Yucatan, Mexico.

Mosquito collections were carried out on microfilaraemic dogs, positive for Dirofilaria sp., for 18 consecutive nights in the coastal town of Celestún, Yucatan, southeast Mexico, during the rainy season (August) of 2007. A total of 292 female mosquitoes representing 12 species of dipteran Culicidae were collected: Anopheles albimanus (Wiedemann); Anopheles crucians (Wiedemann); Anopheles pseudopunctipennis (Theobald); Culex coronator (Dyar & Knab); Culex interrogator (Dyar & Knab); Culex nigripalpus (Theobald); Culex quinquefasciatus (Say); Culex salinarius (Coquillett); Aedes aegypti (Linnaeus); Aedes scapularis (Rondani); Aedes sollicitans (Walker), and Aedes taeniorhynchus (Wiedemann). Aedes taeniorhynchus and Cx. quinquefasciatus were the species found most commonly feeding on the dogs. Filarial nematodes were observed by microscopy in nine of the mosquito species collected; however, third-instar larvae were only observed in Ae. taeniorhynchus and An. crucians. Of 76 Ae. taeniorhynchus specimens found positive for Dirofilaria sp. by dissection, 14 were confirmed to be positive for Dirofilaria immitis (Leidy) by polymerase chain reaction (PCR). The resulting infection rate for D. immitis confirmed by PCR (6.2%) is higher than any infection rate for Ae. taeniorhynchus previously reported from the Americas.

[Congenital mitral stenosis. Experience in 1991-2001]. / Estenosis mitral congénita. Experiencia 1991-2001.

OBJECTIVE: To describe ten years of experience with congenital mitral stenosis. METHOD: All cases with congenital mitral stenosis from January 1991 to 2001 were analized. RESULTS: 16 patients with congenital mitral stenosis were found, mean age 3 +/- 3.08 years. TYPES OF OBSTRUCTIONS: Mitral commisures combined with tendinous cords fusion (45%), parachute mitral valve 37%, supravalvar mitral ring in one, fusion between papillary muscle and leaflets in one, and double mitral orifice in one. Hemodynamic (in mmHg) findings: wedge pressure 18.4 +/- 4, pulmonary artery systolic 61 +/- 21, diastolic 34 +/- 15, mean 47 +/- 18 mmHg, mean transvalvar gradient (MTG) 12.9 +/- 7.3, PRU 5.5 +/- 3.8. Four patients received medical treatment. Surgical results: Six patients underwent mitral repair, and four were subjected to mitral valve replacement (two with previous mitral repair). Global mortality was 2 (12.5%). Follow-up was 3.5 +/- 3 years. There was a significant difference when the initial MTG 22.6 +/- 11.5 mmHg before surgical repair was compared with the final MTG 4.75 +/- 1.5 (P < 0.05), also when initial MTG 12 +/- 2.3 before mitral valve replacement was compared with the final MTG 6 +/- 1.15 mmHg (P < 0.05). CONCLUSION: Most patients are candidates for mitral surgical repair, however at mid term one third will require mitral valve replacement.

Judgments of social appropriateness by children and adolescents with autism.

Children and adolescents with autism (autism group, n = 19) and those without autism (Nonautism group, n = 19) of similar age and IQ were asked to make judgments of the social appropriateness of 24 videotaped, staged scenes with adult actors. Each scene depicted an appropriate or an inappropriate interaction. Half contained verbalizations, and half did not. After each scene, the participant was asked: (1) Was that o.k. or was something wrong with it? If the participant judged the scene was wrong, she or he was asked: (2) What was wrong with it?; and (3) Why was that wrong? Both groups correctly identified inappropriate behaviors most of the time, and correct behaviors almost all of the time. However, the Nonautism group detected inappropriate behaviors significantly more often than the Autism group, for verbal but not nonverbal scenes. It was also significantly easier for both groups to identify inappropriate behaviors in the nonverbal than in the verbal scenes. Ratings of the explanations given for Question 3 differed significantly between the groups for verbal but not for nonverbal scenes, with Nonautism participants more likely to give explanations involving social norms and principles, and the Autism group more likely to give explanations that were irrelevant or idiosyncratic.

Direct communication between right pulmonary artery and left atrium.

A case of direct communication between right pulmonary artery and left atrium is reported. The diagnosis was made before surgical correction. A surgical ligation of the fistula resolved the cyanosis of the patient. Selective angiocardiogram of the right pulmonary artery 4 months after surgery revealed no residual shunt. This very rare malformation should be considered in the clinical setting of unexplained cyanosis. This is the number 50 case reported in the literature.

[Atrioventricular discordance. Clinico-surgical experience 1990-2000]. / Discordancia atrioventricular. Experiencia clínico-quirúrgica 1990-2000.

OBJECTIVE: To know the incidence of ventriculoarterial connections combined with atrioventricular discordance, associated lesions and surgical results, including the first case with anatomical correction. METHOD: All patients with atrioventricular discordance by echocardiography from 1990 to March 2000 were analyzed. RESULTS: Thirty six patients with atrioventricular discordance were found. Ages ranged from 0.1 to 46 years, with a mean 9.2 years (SD 5.9 years). Atrial chambers were situs solitus in 88.9%, inversus in 11.2%. The ventriculoarterial connections were discordant in 28 (77.7%), double outlet right ventricle in 4 (11.1%) (one of them was a "criss cross" heart), single outlet (pulmonary atresia) in 4 (11.1%), and double outlet left ventricle in 1 (2.7%). Associated lesions: Ventricular septal defect with pulmonary stenosis or atresia was present in 21 (58%), ventricular septal defect with no pulmonary obstruction was observed in 10 (28%). Five had tricuspid regurgitation with right ventricular disfunction, (two adults). Surgical results: 22 (61%) required 28 surgical procedures: 8 (36%) were palliative and 19 (86%) were corrective, one of them was our first anatomical correction. Operative mortality in all was 40.1%, postoperative atrioventricular block was observed in 9 (40.1%). CONCLUSION: Right ventricular dysfunction is not uncommon. Surgical results revealed high mortality and high pacemaker requirement for atrioventricular block.

Comparative study of DNA vaccines encoding various antigens against Leishmania mexicana.

Leishmaniases represent an important public health problem in large parts of the world. In the south-east of Mexico, the major species isolated from patients is Leishmania mexicana mexicana, causing localised cutaneous leishmaniasis, and the development of a vaccine is a key objective for the control of this parasite. We thus performed a comparative study of DNA vaccines encoding L. m. mexicana gp63 and CPb, L. m. amazonensis gp46, and L. major LACK to define the best antigen(s) candidate(s). cDNAs encoding these antigens were subcloned into the VR1012 plasmid, and susceptible BALB/c mice were immunised with two i.m. injections of 100 microg of plasmid DNA. All mice immunised with VR1012-GP46, VR1012-CPb and VR1012-GP63 showed increased IgG levels against L. m. mexicana, but not those immunised with VR1012-LACK. Two to three weeks after the last immunisation, mice were challenged by the injection of 4 x 10(6) L. m. mexicana parasites in the foot pad to evaluate protection. Measurement of lesion size indicated that mice immunised with VR012-GP46, VR012-GP63 and VR1012-CPb were partially protected against infection, whereas the other plasmids had no effect. Thus, these plasmids represent good candidates for further development of DNA immunisation against L. m. mexicana.

Emotion recognition in autism: verbal and nonverbal information.

This study examined the roles of verbal and nonverbal sources of information in the ability of persons with and without autism to recognize emotion. Child, adolescent, and young adult participants in four groups [Lower Functioning Autism (LFA) (n = 17), High Functioning Autism (HFA) (n = 18), Lower Functioning Comparison (LFC) (n = 18), and High Functioning Comparison (HFC) (n = 23)] identified emotions shown (happy, angry, sad, surprised, or neutral) in video clips of individuals expressing emotion verbally, nonverbally, or both. Verbal expressions of emotion were either Explicit, Implicit, or Neutral, whereas nonverbal expressions were Animate or Flat (3 x 2). Pairwise ANCOVAs indicated no group differences between HFA and HFC groups or between the LFA and LFC groups, and indicated instead group differences between higher and lower functioning persons. With groups collapsed into High Functioning (HF) and Lower Functioning (LF), significant group differences were found. Performance of LF individuals suggested they had difficulty inferring how a person felt based on what the person said, if the emotion was not explicitly named. Performance of HF individuals suggested they relied more on nonverbal than on verbal information to determine a speaker's emotion, except where the emotion was explicitly named. Results suggested that persons with autistic spectrum disorders can use affective information from multiple sources in much the same ways as persons of comparable developmental level without autism.