DNA transfer when using gloves in burglary simulations

Several studies have demonstrated that DNA can be indirectly transferred from an individual onto a surface. Therefore, the presence of DNA that is compatible with a given person does not necessarily mean that this person has touched the surface on which the DNA was recovered. The present work simulates cases, where DNA is recovered on a door handle and compared to several reference DNA profiles. The DNA profile of the trace shares DNA components with a person of interest (POI). When asked about the DNA results, the POI says he has nothing to do with the incident and has never been at the scene. However, a possibility would be that the DNA came from his recently stolen gloves. Someone else, the alternative offender (AO), could have opened the door wearing his gloves (POI's gloves), and transferred his DNA (POI's DNA). Based on the above-mentioned scenario, 60 burglary simulations experiments were carried out to generate data to assess DNA results given these allegations. The quantity and quality of DNA profiles (NGM SElect) recovered when the POI opened/closed the door bare-handed or when someone else performed the same activity but using POI's gloves, were compared. The gloves were regularly worn during at least three months by their owner during the winter. On the contrary, the AO wore them only for two minutes. Among the traces collected on the door handles, less than 50% of the traces led to interpretable DNA profiles. In 30% of the cases (3/10), when the door was opened/closed with bare hands, the DNA found on the door handle led to a mixed DNA profile with the POI's DNA aligning with the major contributor. For the experiments where the AO opened/closed the door with the POI's gloves, the POI's DNA was compatible with 22% (11/50) of the mixed DNA profile, aligning with the major in 8% of the cases (4/50). The DNA profiles of the offices' occupants were observed on the door handles, but not the AO's. In addition to the results of the experiments, we show two examples of how one can assess results observed in casework. Given the possibility of indirect transfer of minute DNA quantities, this research emphasizes the need to evaluate DNA results given the activities when the POI has a legitimate reason that can explain the presence of their DNA.

Insecticide resistance and genetic structure of Aedes aegypti populations from Rio de Janeiro State, Brazil

Vector control largely relies on neurotoxic chemicals, and insecticide resistance (IR) directly threatens their effectiveness. In some cases, specific alleles cause IR, and knowledge of the genetic diversity and gene flow among mosquito populations is crucial to track their arrival, rise, and spread. Here we evaluated Aedes aegypti populations’ susceptibility status, collected in 2016 from six different municipalities of Rio de Janeiro state (RJ), to temephos, pyriproxyfen, malathion, and deltamethrin. We collected eggs of Ae. aegypti in Campos dos Goytacazes (Cgy), Itaperuna (Ipn), Iguaba Grande (Igg), Itaboraí (Ibr), Mangaratiba (Mgr), and Vassouras (Vsr). We followed the World Health Organization (WHO) guidelines and investigated the degree of susceptibility/resistance of mosquitoes to these insecticides. We used the Rockefeller strain as a susceptible positive control. We genotyped the V1016I and F1534C knockdown resistance (kdr) alleles using qPCR TaqMan SNP genotyping assay. Besides, with the use of Ae. aegypti SNP-chip, we performed genomic population analyses by genotyping more than 15,000 biallelic SNPs in mosquitoes from each population. We added previous data from populations from other countries to evaluate the ancestry of RJ populations.

All RJ Ae. aegypti populations were susceptible to pyriproxyfen and malathion and highly resistant to deltamethrin. The resistance ratios for temephos was below 3,0 in Cgy, Ibr, and Igg populations, representing the lowest rates since IR monitoring started in this Brazilian region. We found the kdr alleles in high frequencies in all populations, partially justifying the observed resistance to pyrethroid. Population genetics analysis showed that Ae. aegypti revealed potential higher migration among some RJ localities and low genetic structure for most of them. Future population genetic studies, together with IR data in Ae aegypti on a broader scale, can help us predict the gene flow within and among the Brazilian States, allowing us to track the dynamics of arrival and changes in the frequency of IR alleles, and providing critical information to improving vector control program.

Monitoring of insecticide resistance (IR) is mandatory for the effectiveness of vector control programs. We investigate six populations of Aedes aegypti regarding their IR status towards insecticides previously or currently in use, their frequency of IR alleles and resistance ratio, their genetic ancestry and structure, and the gene flow. We observed that Ae. aegypti populations from RJ are becoming susceptible to the larvicide organophosphate temephos. The resistance ratios of temephos are lower among populations where gene flow might be occurring. All RJ populations are highly resistant to deltamethrin, partially explained by the high frequency of kdr alleles. Besides, all populations are susceptible to pyriproxyfen’s insect growth regulator and the organophosphate malathion. Population genomic analyses using more than 15,000 SNPs identified three potential genetic clusters within RJ populations, with higher gene flow to and out of the touristic region called Região dos Lagos. IR data, together with knowledge of the genetic structure and gene flow among different mosquito populations, can help with vector control program decisions.

Evaluation of resistance to pyrethroid and organophosphate adulticides and kdr genotyping in Aedes aegypti populations from Roraima, the northernmost Brazilian State

Background

Roraima, the northernmost State in Brazil, borders Venezuela and Guyana. Although mostly covered by the tropical forests, the urban centers of this state are highly infested with Ae. aegypti and are endemic for dengue, Zika and chikungunya. We accessed the insecticide resistance status of Ae. aegypti populations from the capital Boa Vista, two cities on international borders (Pacaraima and Bonfim) and Rorainópolis bordering Amazonas State, in order to evaluate the chemical control efficacy in these localities.

Methods

Tests with World Health Organization (WHO)-like tubes impregnated with the pyrethroid deltamethrin (0.05% and 0.12%) and the organophosphate malathion (0.7%) were conducted with Ae. aegypti from Boa Vista, Pacaraima, Bonfim and Rorainópolis, collected in 2016 and 2018. Genotyping of kdr mutations, related to resistance to pyrethroids, was performed for the SNP variations at sites 1016 and 1534 of the voltage gated sodium channel gene (Na_V) with a TaqMan qPCR approach.

Results

Aedes albopictus was absent in our collections, and therefore only Ae. aegypti was tested. All Ae. aegypti populations were susceptible to 0.7% malathion in 2016; however, mortality dropped to under 90% in Bonfim and Pacaraima populations in 2018. All populations were resistant to 0.05% deltamethrin in both years. The time that 50% of females suffered knockdown (KdT₅₀) under exposure to 0.05% deltamethrin was 3.3–5.9-fold longer in mosquitoes from the natural populations compared to the susceptible Rockefeller strain. Only the Pacaraima population (2018) remained resistant to 0.12% deltamethrin. Kdr genotyping revealed the absence of the wild-type Na_VS haplotype (1016Val + 1534Phe) in the populations from Roraima, indicating that all tested insects had a genetic background for pyrethroid resistance. The double kdr Na_VR2 haplotype (1016Ile + 15434Cys) was present in higher frequencies in all populations except for Rorainópolis, where this haplotype seems to have arrived recently.

Conclusions

These results are important for the knowledge about insecticide resistance status of Ae. aegypti populations from Roraima and will help improve vector control strategies that may be applied to diverse localities under similar geographical and urban conditions.

The redox-sensing gene Nrf2 affects intestinal homeostasis, insecticide resistance, and Zika virus susceptibility in the mosquito Aedes aegypti

Production and degradation of reactive oxygen species (ROS) are extensively regulated to ensure proper cellular responses to various environmental stimuli and stresses. Moreover, physiologically generated ROS function as secondary messengers that can influence tissue homeostasis. The cap'n'collar transcription factor known as nuclear factor erythroid-derived factor 2 (Nrf2) coordinates an evolutionarily conserved transcriptional activation pathway that mediates antioxidant and detoxification responses in many animal species, including insects and mammals. Here, we show that Nrf2-mediated signaling affects embryo survival, midgut homeostasis, and redox biology in Aedes aegypti, a mosquito species vector of dengue, Zika, and other disease-causing viruses. We observed that AeNrf2 silencing increases ROS levels and stimulates intestinal stem cell proliferation. Because ROS production is a major aspect of innate immunity in mosquito gut, we found that a decrease in Nrf2 signaling results in reduced microbiota growth and Zika virus infection. Moreover, we provide evidence that AeNrf2 signaling also controls transcriptional adaptation of A. aegypti to insecticide challenge. Therefore, we conclude that Nrf2-mediated response regulates assorted gene clusters in A. aegypti that determine cellular and midgut redox balance, affecting overall xenobiotic resistance and vectorial adaptation of the mosquito.

Cancer in pregnancy: maternal and fetal implications on decision-making

BACKGROUND

Cancer complicates one out of 1,000 pregnancies. No standardized therapeutic interventions have been reported for these patients.

METHODS

Fifteen patients with cancer during pregnancy were diagnosed between 6.5 and 36 weeks of gestational age between January 1991 and December 2007.

RESULTS

Among the 15 cases one patient with early diagnosis (11 weeks) asked for interruption of pregnancy, two patients rejected chemotherapy in order to avoid fetal effects, seven patients underwent surgery during the first or second trimester, and two patients agreed to start the treatment only after delivery. Standard platinum-based chemotherapy (cisDDP) was postponed in six patients to the second trimester (administered after surgery in 2 cases). Chemotherapy was started between 18.3 and 29.6 weeks (median 22.3 weeks). One patient had pPROM (22.3 weeks) after chemotherapy with cisDDP. Ten patients were delivered by elective cesarean section and three by vaginal delivery. Mean gestational age at delivery was 33.5 weeks (range 32.1-40.0); mean weight at birth was 2,550 g (range 1,250-3,450). None of the newborns showed congenital malformations, and all had normal Apgar scores. Anemia occurred in two newborns. At a median follow-up of 56 months (range 2-198 months) all children were well and healthy. Eleven out of 15 mothers are alive and well, and one is alive with disease. An advanced neoplasm was diagnosed in three patients who died.

CONCLUSION

When platinum-based chemotherapy is administered during the 2nd-3rd trimester, adverse effects in newborns are comparable to those in the general population. Deliberate treatment delay to achieve fetal viability or to improve fetal outcome may be reasonable for patients with early-stage cancer.

Pattern of failure and value of follow-up procedures in endometrial and cervical cancer patients

OBJECTIVE

The aim of this study was to evaluate the outcome benefit of follow-up protocols for patients with recurrent endometrial and cervical cancer.

METHODS

A retrospective review on patients primarily treated at the Division of Gynecologic Oncology, University of Brescia, was performed. We focused our attention on recurrent patients and we evaluated the pattern of relapse and the presence of symptoms or signs of disease at recurrence and evidence of disease on routine follow-up test or visits.

RESULTS

The vast majority of recurrences occurred within the first 3 years after primary treatment (78% and 87% in endometrial and cervical cancers, respectively). A better overall survival from relapse was observed when vaginal relapse was compared to other sites in endometrial cancer patients and when pelvic recurrence was compared to distant sites in cervical cancer cases. Recurrent endometrial and cervical cancer patients were symptomatic in 52% and 65% of cases, respectively. Among asymptomatic recurrent endometrial cancer cases, pelvic examination, abdominal or pelvic ultrasound and CT could detect 92% of relapses, while the vast majority of cervical cancer relapses could be diagnosed by pelvic examination and/or CT (85%).

CONCLUSION

Endometrial cancer patients showed a significantly better prognosis when the recurrence was detected during follow-up visits, thus supporting the real advantage of our surveillance programs, while no statistically significant differences were found in survival of cervical cancer patients between the symptomatic and the asymptomatic group.