Trypanosoma cruziand myoid cells from seminiferous tubules: interaction and relation with fibrous components of extracellular matrix in experimental Chagas' disease

The main transmission route of Trypanosoma cruzi is by triatomine bugs. However, T. cruzi is also transmitted through blood transfusion, organ transplantation, ingestion of contaminated food or fluids, or is congenital. Sexual transmission, although suggested since the discovery of Chagas' disease, has remained unproven. Sexual transmission would require T. cruzi to be located at the testes and ovaries. Here we investigated whether T. cruzi is present in the gonads of mice infected with 10⁴ T. cruzi trypomastigotes from the CL strain. Fourteen days after experimental infection, histopathological examination showed alterations in the extracellular matrix of the lamina propria of the seminiferous tubules. Furthermore, amastigotes were present in seminiferous tubules, within myoid cells, and in the adjacencies of the basal compartment. These results indicate that T. cruzi is able to reach seminiferous tubule lumen, thus suggesting that Chagas' disease could potentially be transmitted through sexual intercourse. Complementary studies are required to demonstrate that Chagas' disease can be transmitted by coitus.     

Genetic polymorphisms in the dopamine-2 receptor (DRD2), dopamine-3 receptor (DRD3), and dopamine transporter (SLC6A3) genes in schizophrenia: Data from an association study

Objective

To investigate the association between dopaminergic polymorphisms [DRD2 −141C Ins/Del, DRD3 Ser9Gly, and SLC6A3 VNTR] and schizophrenia.

Methods

Two hundred and eighty-eight outpatients with schizophrenia (DSM-IV criteria) [mean age (SD) = 36.4 (12.4), 60.1% males] and 421 unrelated healthy controls [mean age (SD) = 40.6 (11.3), 51.3% males] from a homogeneous Spanish Caucasian population were genotyped using standard methods.

Results

There was a significant difference in genotype distribution for the DRD2 −141C Ins/Del polymorphism [(χ² (2) = 12.35, corrected p = 0.012]. The − 141C Del allele was more common in patients than in controls [0.19 vs. 0.13; χ² (1) = 9.14, corrected p = 0.018, OR (95% CI) = 1.57 (1.17–2.10)]. Genotype and allele distributions for DRD3 Ser9Gly and SLC6A3 VNTR polymorphisms were similar in both groups. However, there was tentative evidence of an interaction effect between DRD3 Ser9Gly and SLC6A3 VNTR [Wald = 9.56 (4), p = 0.049]. Compared to the SLC6A3 10/10 genotype category, the risk of schizophrenia was halved among those with 9/10 [OR = 0.51 (95% CI = 0.30–0.89), p = 0.017]. This protective effect was only present in combination with DRD3 Ser/Ser genotype because of the significant interaction between 9/10 and both Ser/Gly [OR = 2.45 (95% CI = 1.16–5.17), p = 0.019] and Gly/Gly [OR = 3.80 (95% CI = 1.24–11.63), p = 0.019].

Conclusions

This study provides evidence that a genetic variant in the DRD2 gene and possible interaction between DRD3 and SLC6A3 genes are associated with schizophrenia. These findings warrant examination in replication studies.     

Influence of resting energy expenditure on weight gain in adolescents taking second-generation antipsychotics

Background & aims

: Weight gain is an undesirable side effect of second-generation antipsychotics (SGAs). We performed this study to examine the influence of SGAs on resting energy expenditure (REE) and the relationship of REE to weight gain in adolescent patients.

Methods

Antipsychotic-naïve or quasi-naïve (<72 h of exposure to antipsychotics) adolescent patients taking olanzapine, quetiapine, or risperidone in monotherapy were followed up for one year. We performed a prospective study (baseline, 1, 3, 6, and 12 months after treatment) based on anthropometric measurements, bioelectrical impedance analysis, and indirect calorimetry (Deltatrac™ II MBM-200) to measure REE. We also analyzed metabolic and hormonal data and adiponectin concentrations.

Results

Forty-six out of the 54 patients that started treatment attended at least 2 visits, and 16 completed 1 year of follow-up. Patients gained 10.8 ± 6.2 kg (60% in the form of fat mass) and increased their waist circumference by 11.1 ± 5.0 cm after 1 year of treatment. The REE/kg body mass ratio decreased (p = 0.027), and the REE/percentage fat-free mass (FFM) ratio increased (p = 0.007) following the fall in the percentage of FFM during treatment. Weight increase was significantly correlated with the REE/percentage FFM ratio at all the visits (1–3–6–12 months) (r = 0.69, p = 0.004 at 12 months).

Conclusions

SGAs seem to induce a hypometabolic state (reflected as decreased REE/kg body mass and increased REE/percentage FFM). This could explain, at least in part, the changes in weight and body composition observed in these patients.     

ATZ (3-amino-1,2,4-triazole) injected into the fourth cerebral ventricle influences the Bezold-Jarisch reflex in conscious rats

OBJECTIVES:

Many studies have investigated the importance of oxidative stress on the cardiovascular system. In this study we evaluated the effects of central catalase inhibition on cardiopulmonary reflex in conscious Wistar rats.

METHODS:

Male Wistar rats were implanted with a stainless steel guide cannula in the fourth cerebral ventricle. The femoral artery and vein were cannulated for mean arterial pressure and heart rate measurement and for drug infusion, respectively. After basal mean arterial pressure and heart rate recordings, the cardiopulmonary reflex was tested with a dose of phenylbiguanide (PBG, 8 µg/kg, bolus). Cardiopulmonary reflex was evaluated before and µl15 minutes after 1.0 µL 3‐amino‐1,2,4‐triazole (ATZ, 0.01g/100µL)0.01 g/100 µL) injection into the fourth cerebral ventricle. Vehicle treatment did not change cardiopulmonary reflex responses.

RESULTS:

Central ATZ significantly increased hypotensive responses without influencing the bradycardic reflex.

CONCLUSION:

ATZ injected into the fourth cerebral ventricle increases sympathetic inhibition but does not change the parasympathetic component of the cardiopulmonary reflex in conscious Wistar rats.     

The influence of cyclosporin a on mechanical retention of dental implants previously integrated to the bone: a study in rabbits

BACKGROUND: Immunosuppressive agents may induce severe changes on bone metabolism and may impair the osseointegration process during the implant healing. No data are available concerning the influence of cyclosporin A on dental implants previously integrated to the bone. The aim of this study was to evaluate the influence of cyclosporin A administration on the mechanical retention of bone previously integrated to dental implants. METHODS: Eighteen female New Zealand rabbits were submitted to an implant surgery. Each animal received one commercial dental implant of 10 x 3.75 mm. After 12 weeks of an undisturbed healing period, six animals were randomly sacrificed and the removal torque test was performed (group A). In addition, six animals were submitted to a daily injection of cyclosporin A in a dosage of 10 mg/kg (group C), and six animals received saline solution as a control (group B). After 12 weeks of cyclosporin A administration, groups B and C were sacrificed and submitted to a removal torque test in which higher values can be interpreted as higher mechanical bone retention to the implant surface or higher osseointegration. RESULTS: The removal torque results were 30.5 (+/-9.8) Ncm for group A, 50.17 (+/-17.5) Ncm for group B, and 26 (+/-7.8) Ncm for group C. The statistical analysis showed significant differences between groups A and B (P <0.05) and groups B and C (P <0.01). CONCLUSION: Cyclosporin A administration may impair the mechanical retention of dental implants previously integrated to the bone.     

Smear layer removal and chelated calcium ion quantification of three irrigating solutions

The purpose of this study was to evaluate, by scanning electron microscopy (SEM), smear layer removal and quantify, by atomic absorption spectrophotometry, the amount of calcium ion present in the chelating solutions after their use. Sixteen extracted canines were instrumented using the step-back technique and were assigned to 3 groups according to the irrigating solution used: G1: 1 mL 17% EDTAC between each file; G2: 1 mL 17% CDTA; G3: 1 mL 17% EGTA. The solutions were collected after use. The teeth were cleaved longitudinally, evaluated under SEM and assessed for smear layer by blinded examiners and scored from 1 to 4. In order to quantify calcium ion release, the collected solutions were examined by atomic absorption spectrophotometry. Freidman's test was used for statistical analysis of SEM values and showed that canals irrigated with 17% EDTAC and 17% CDTA had significantly less smear layer throughout the canals than 17% EGTA (p<0.01). For analysis of the collected solutions, Tukey's test was used and showed that EDTAC and CDTA had a greater amount of calcium ions (22.8+/-7.54 and 60.6+/-20.67 microg/mL, respectively) compared to EGTA (70.5+/-14.2 microg/mL) (p<0.01). The association both methodologies may contribute to the understanding of how these solutions act in the root canal.