Multidisciplinary approach detects speciation within the kissing bug Panstrongylus rufotuberculatus populations (Hemiptera, Heteroptera, Reduviidae)

BACKGROUND Panstrongylus rufotuberculatus (Hemiptera-Reduviidae) is a triatomine species with a wide geographic distribution and a broad phenotypic variability. In some countries, this species is found infesting and colonising domiciliary ecotopes representing an epidemiological risk factor as a vector of Trypanosoma cruzi, etiological agent of Chagas disease. In spite of this, little is known about P. rufotuberculatus genetic diversity. METHODS Cytogenetic studies and DNA sequence analyses of one nuclear (ITS-2) and two mitochondrial DNA sequences (cyt b and coI) were carried out in P. rufotuberculatus individuals collected in Bolivia, Colombia, Ecuador and Mexico. Moreover, a geometric morphometrics study was applied to Bolivian, Colombian, Ecuadorian and French Guiana samples. OBJECTIVES To explore the genetic and phenetic diversity of P. rufotuberculatus from different countries, combining chromosomal studies, DNA sequence analyses and geometric morphometric comparisons. FINDINGS We found two chromosomal groups differentiated by the number of X chromosomes and the chromosomal position of the ribosomal DNA clusters. In concordance, two main morphometric profiles were detected, clearly separating the Bolivian sample from the other ones. Phylogenetic DNA analyses showed that both chromosomal groups were closely related to each other and clearly separated from the remaining Panstrongylus species. High nucleotide divergence of cyt b and coI fragments were observed among P. rufotuberculatus samples from Bolivia, Colombia, Ecuador and Mexico (Kimura 2-parameter distances higher than 9%). MAIN CONCLUSIONS Chromosomal and molecular analyses supported that the two chromosomal groups could represent different closely related species. We propose that Bolivian individuals constitute a new Panstrongylus species, being necessary a detailed morphological study for its formal description. The clear morphometric discrimination based on the wing venation pattern suggests such morphological description might be conclusive.

Influence of symmetric and asymmetric alterations of maxillary canine gingival margin on the perception of smile esthetics among orthodontists, dentists, and laypersons.

Introduction: Esthetics is one of the major concerns among people seeking orthodontic treatment, and its perception varies from person to person. Our objective was to determine the differences in the perception of smile esthetics among orthodontists, general dentists, and laypersons with respect to alteration in the maxillary canine gingival margin in close‑up smile analyses. Materials and Methods: Close‑up photograph of an ideal Indian female smile was selected. The images were digitally altered to create symmetrical images with the gingival margin levels of maxillary canine matching the central incisors. Twelve alterations were created in the gingival margin of the canine with discrepancies of 1, 2, and 3 mm in relation to the most superior point on the labial gingival margin of patient’s central incisor and divided under four groups. Finally, close‑up images of the smile were assessed by orthodontist, general dentist, and layperson who indicated the level of attractiveness of each smile on a visual analogue score. The data collected were then statistically analyzed by one‑way analysis of variance followed by Newman–Keul’s range test. Results: Most evaluators considered all the three components, i.e., lips, teeth, and gingiva while assessing the smile’s attractiveness. Statistically significant differences were observed between different evaluator groups when considering bilateral increase in crown height by 2 and 3 mm. The perceptions of asymmetries in the gingival margin levels of the maxillary canines were 1.0 mm for orthodontists and 2.0 mm for laypersons. Conclusion: The result of this study suggested that the orthodontists were more critical than dentist and layperson in evaluating smile esthetics.

Evaluation of the Effect of EDTA, EGTA and Citric Acid on the Microhardness and Roughness of Human Radicular Dentin – An In Vitro Study.

Context: Smear layer is a negative factor which prevents adhesion of the filling material to the dentinal walls. Chelating agents are used during cleaning and shaping of the root canals so as to remove the smear layer. Aims: To evaluate the effect of 17%EDTA, 17%EGTA, and 19% CITRIC ACID solutions on microhardness of root canal dentin using Vicker’s Hardness Tester and surface roughness using Computerized Roughness Tester. Settings and Design: Methods and Material: Sixty non carious specimens were divided into four groups and subjected to varied treatments as follows: 1) Group I – 17%EDTA + 5% NaOCl for 150 sec 2) Group II – 17%EGTA + 5% NaOCl for 150 sec 3) Group III – 19% Citric Acid + 5% NaOCl for 150 sec 4)Group IV – Distilled water. Each group was divided into subgroup ‘a’ and ‘b’. ‘a’ group were subjected to microhardness testing and ‘b’ group were subjected to surface roughness. Statistical Analysis Used: Results were subjected to Anova and Tukeys test. Results: Difference in microhardness values was significant between Ia and IIa (p<0.05, 0.029) and groups IIa and IIIa (p-0.001). Citric acid decreased the overall microhardness of the root canal dentin more than other irrigants. EGTA caused minimum reduction in microhardness. Maximum increase in surface roughness was seen in citric acid group and minimum increase in EGTA group. Conclusions: EDTA, EGTA and citric acid drastically reduce the microhardness and increase the surface roughness of radicular dentin. EGTA caused minimum reduction in microhardness and citric acid caused maximum increase in surface roughness.

The effect of air abrasion on the retention of metallic brackets bonded to fluorosed enamel surface.

Background: Bonding brackets to fluorosed enamel remains a clinical challenge and bracket failure at the compromised enamel interface is common. Objective: To check the effect of air abrasion on the retention of metallic brackets bonded to fluorosed enamel surface. Materials and Methods: Sixty freshly extracted human premolar teeth having moderate to severe dental fluorosis as per Dean's criteria were collected and divided into three groups of 20 each. The groups were treated as follows: In group I, acid etching was followed by bonding with Transbond XT® ; in group II, sandblasting and acid etching was followed by bonding with Transbond XT® ; and in group III, sandblasting and acid etching was followed by bonding with Enlight LC® . An Instron™ universal testing machine was used for determining the debonding force, and from this the shear bond strength was computed. The sample with highest shear bond strength from each group was selected for the scanning electron microscopy (SEM) study. The prepared specimens were examined under a JSM-840A scanning electron microscope (JEOL Ltd, Tokyo, Japan) operated at 20 kV. Photographs were taken at progressively higher magnifications of ×50, ×100, ×500, and ×1000 to view the enamel surface and the adhesive remaining on the enamel surface after debonding. The shear bond strengths of the groups were compared using the one-way ANOVA (analysis of variance) and Tukey post hoc test. The distribution of adhesive remnant index (ARI) score was compared using the Chi-square test. Results: The mean shear bond strength in group I was 10.36 MPa, with a standard deviation of 0.225. The corresponding values in group II and group III were 11.41±0.237 MPa and 11.39±0.201 Mpa, respectively. There was a statistically significant difference between the three groups in the mean shear bond strength values. Conclusion: Sandblasting followed by acid etching provides significantly higher bond strength values compared to acid etching alone, irrespective of the bonding material employed.

Replaced Right Hepatic Artery Associated with Uncommon Triplet Right Renal Vein: Embryological Perspective and Clinical Importance 45

Vascular variations in the abdomen are common and mostly asymptomatic. Knowledge of these variations are of tremendous clinical importance in patients undergoing invasive endovascular interventions such as liver transplantation, renal transplantation, and vascular reconstruction for congenital and acquired lesions and trans-arterial chemoembolization for the hepatic tumors. During regular dissection classes for the medical undergraduates, we encountered concurrent vascular variations in an elderly male cadaver. In the present case, we report multiple vascular anomalies involving the right hepatic artery and the right renal vein. The right hepatic artery branched off from superior mesenteric artery, and it was identified as a replaced right hepatic artery. The right kidney was drained by three renal veins, the uppermost among the three twisted around the superior branch of the right renal artery before terminating into the inferior vena cava. In addition, the left kidney was supplied by two renal arteries, and drained by a single renal vein.

Absence of domestic triatomine colonies in an area of the coastal region of Ecuador where Chagas disease is endemic

Rhodnius ecuadoriensis is considered the second most important vector of Chagas disease in Ecuador. It is distributed across six of the 24 provinces and occupies intradomiciliary, peridomiciliary and sylvatic habitats. This study was conducted in six communities within the coastal province of Guayas. Triatomine searches were conducted in domestic and peridomestic habitats and bird nests using manual searches, live-bait traps and sensor boxes. Synantrhopic mammals were captured in the domestic and peridomestic habitats. Household searches (n = 429) and randomly placed sensor boxes (n = 360) produced no live triatomine adults or nymphs. In contrast, eight nymphs were found in two out of six searched Campylorhynchus fasciatus (Troglodytidae) nests. Finally, Trypanosoma cruzi DNA was amplified from the blood of 10 percent of the 115 examined mammals. Environmental changes in land use (intensive rice farming), mosquito control interventions and lack of intradomestic adaptation are suggested among the possible reasons for the lack of domestic triatomine colonies.

Life cycle, feeding and defecation patterns of Rhodnius ecuadoriensis (Lent & León 1958) (Hemiptera: Reduviidae: Triatominae) under laboratory conditions

Rhodnius ecuadoriensis is the second most important vector of Chagas Disease (CD) in Ecuador. The objective of this study was to describe (and compare) the life cycle, the feeding and defecation patterns under laboratory conditions of two populations of this specie [from the provinces of Manabí (Coastal region) and Loja (Andean region)]. Egg-to-adult (n = 57) development took an average of 189.9 ± 20 (Manabí) and 181.3 ± 6.4 days (Loja). Mortality rates were high among Lojan nymphs. Pre-feeding time (from contact with host to feeding initiation) ranged from 4 min 42 s [nymph I (NI)] to 8 min 30 s (male); feeding time ranged from 14 min 45 s (NI)-28 min 25 s (male) (Manabí) and from 15 min 25 s (NI)-28 min 57 s (nymph V) (Loja). The amount of blood ingested increased significantly with instar and was larger for Manabí specimens (p < 0.001). Defecation while feeding was observed in Manabí specimens from stage nymph III and in Lojan bugs from stage nymph IV. There was a gradual, age-related increase in the frequency of this behaviour in both populations. Our results suggest that R. ecuadoriensis has the bionomic traits of an efficient vector of Trypanosoma cruzi. Together with previous data on the capacity of this species to infest rural households, these results indicate that control of synanthropic R. ecuadoriensis populations in the coastal and Andean regions may have a significant impact for CD control in Ecuador and Northern Peru.