A Ferrofluid with Surface Modified Nanoparticles for Magnetic Hyperthermia and High ROS Production.

A ferrofluid with 1,2-Benzenediol-coated iron oxide nanoparticles was synthesized and physicochemically analyzed. This colloidal system was prepared following the typical co-precipitation method, and superparamagnetic nanoparticles of 13.5 nm average diameter, 34 emu/g of magnetic saturation, and 285 K of blocking temperature were obtained. Additionally, the zeta potential showed a suitable colloidal stability for cancer therapy assays and the magneto-calorimetric trails determined a high power absorption density. In addition, the oxidative capability of the ferrofluid was corroborated by performing the Fenton reaction with methylene blue (MB) dissolved in water, where the ferrofluid was suitable for producing reactive oxygen species (ROS), and surprisingly a strong degradation of MB was also observed when it was combined with H2O2. The intracellular ROS production was qualitatively corroborated using the HT-29 human cell line, by detecting the fluorescent rise induced in 2,7-dichlorofluorescein diacetate. In other experiments, cell metabolic activity was measured, and no toxicity was observed, even with concentrations of up to 4 mg/mL of magnetic nanoparticles (MNPs). When the cells were treated with magnetic hyperthermia, 80% of cells were dead at 43 °C using 3 mg/mL of MNPs and applying a magnetic field of 530 kHz with 20 kA/m amplitude.

Inconsistent condom use with known HIV-positive partners among newly diagnosed HIV-positive men who have sex with men interviewed for partner services in New York City, 2014.

OBJECTIVES: Condomless anal intercourse contributes significantly to the spread of HIV among men who have sex with men (MSM). Factors related to condomless anal intercourse with known HIV-positive partners among MSM are not well understood. The authors describe factors associated with inconsistent condom use with known HIV-positive partners prior to participants' diagnosis with HIV. METHODS: New York City health department disease intervention specialists interviewed newly HIV-diagnosed MSM ages ≥13 years reporting knowingly having anal sex with HIV-positive partners between June 2013 and October 2014. Univariate and bivariate statistics were calculated, in addition to logistic regression analysis. RESULTS: Among 95 MSM interviewed, 56% were >30 years and 74% had higher than a high school education. Respondents reported a median of 2 known HIV-positive sex partners. Drug or alcohol use during last sex with their last known HIV-positive partner was reported by 53% of participants. Sixty-five per cent of participants reported inconsistent condom use with last known HIV-positive partner. Inconsistent condom use with all HIV-positive partners was higher among individuals reporting two or more known HIV-positive partners since sexual debut than among those with one (90% vs 59%, p<0.01) and among those reporting feelings of love/emotional attachment as a reason for having sex (85% vs 63%, p=0.02). In the bivariate logistic regression models for inconsistent condom use, feelings of love or emotional attachment were the only significant predictor of inconsistent condom use (OR 3.43, 95% CI 1.23 to 9.58). After adjusting for confounding, the relationship feelings of love or emotional attachment continued to be the only significant predictor of inconsistent condom use (OR 3.69, 95% CI 1.06 to 12.82). CONCLUSIONS: Surveyed MSM engaged in high-risk behaviours, including condomless anal sex and drug or alcohol use during sex with persons known to be HIV-positive. These findings can inform interventions with MSM in serodiscordant partnerships.

Colostrum proinflammatory cytokines as biomarkers of bovine immune response to bovine tuberculosis (bTB).

Bovine colostrum contains compounds, which provide passive immune protection from mother to newborn calves. Little is known about cytokine levels and their role in bovine colostrum. Moreover, the capacity of bovine colostrum cells to mount specific immune responses after natural exposure to bovine tuberculosis (bTB) antigens in dairy herds has not been studied, thus far. The purpose of this study was to identify biomarkers for bTB infection measurable in bovine colostrum. The present study reveals that isolated-immune colostrum cells can mount a specific immune response against bTB antigens, by measuring the novo IFN-γ release in cell culture. We found that IFN-γ levels in the responders (Bov+) to bTB antigen were higher than in non-responders (Bov-). On the other hand, proinflammatory cytokines contained in colostrum's whey were tested in Tuberculin Skin Test (TST) reactor (TST+) and non-reactor (TST-) animals to assess their potential role as biomarker. We observed that IFN-γ levels were lower or undetectable, as opposed to IL4 levels were measurable, the TNF-α level was higher in TST- than TST+, while IL-6 levels showed the opposite reaction and with no statistical significance. Moreover, IL-1α mRNA expression levels were higher in colostrum mononuclear cells (CMC) in Bov+ cattle. Collectively, these data suggest that the differential expression of pro and anti-inflammatory cytokines could have relevant value to diagnose bTB in cattle.

Porcine circovirus type 2 protective epitope densely carried by chimeric papaya ringspot virus-like particles expressed in Escherichia coli as a cost-effective vaccine manufacture alternative.

Porcine circovirus type 2 (PCV2) still represents a major problem to the swine industry worldwide, causing high mortality rates in infected animals. Virus-like particles (VLPs) have gained attention for vaccine development, serving both as scaffolds for epitope expression and immune response enhancers. The commercial subunit vaccines against PCV2 consist of VLPs formed by the self-assembly of PCV2 capsid protein (CP) expressed in the baculovirus vector system. In this work, a PCV2 protective epitope was inserted into three different regions of papaya ringspot virus (PRSV) CP, namely, the N- and C-termini and a predicted antigenic region located near the N-terminus. Wild-type and chimeric CPs were modeled in silico, expressed in Escherichia coli, purified, and visualized by transmission electron microscopy. This is the first report that shows the formation of chimeric VLPs using PRSV as epitope-presentation scaffold. Moreover, it was found that PCV2 epitope localization strongly influences VLP length. Also, the estimated yields of the chimeric VLPs at a small-scale level ranged between 65 and 80 mg/L of culture medium. Finally, the three chimeric VLPs induced high levels of immunoglobulin G against the PCV2 epitope in immunized BALB/c mice, suggesting that these chimeric VLPs can be used for swine immunoprophylaxis against PCV2.

Self-assembly of hexahistidine-tagged tobacco etch virus capsid protein into microfilaments that induce IgG2-specific response against a soluble porcine reproductive and respiratory syndrome virus chimeric protein.

BACKGROUND: Assembly of recombinant capsid proteins into virus-like particles (VLPs) still represents an interesting challenge in virus-based nanotechnologies. The structure of VLPs has gained importance for the development and design of new adjuvants and antigen carriers. The potential of Tobacco etch virus capsid protein (TEV CP) as adjuvant has not been evaluated to date. FINDINGS: Two constructs for TEV CP expression in Escherichia coli were generated: a wild-type version (TEV-CP) and a C-terminal hexahistidine (His)-tagged version (His-TEV-CP). Although both versions were expressed in the soluble fraction of E. coli lysates, only His-TEV-CP self-assembled into micrometric flexuous filamentous VLPs. In addition, the His-tag enabled high yields and facilitated purification of TEV VLPs. These TEV VLPs elicited broader IgG2-specific antibody response against a novel porcine reproductive and respiratory syndrome virus (PRRSV) protein when compared to the potent IgG1 response induced by the protein alone. CONCLUSIONS: His-TEV CP was purified by immobilized metal affinity chromatography and assembled into VLPs, some of them reaching 2-µm length. TEV VLPs administered along with PRRSV chimeric protein changed the IgG2/IgG1 ratio against the chimeric protein, suggesting that TEV CP can modulate the immune response against a soluble antigen.

Identification of immunogenic proteins from ovarian tissue and recognized in larval extracts of Rhipicephalus (Boophilus) microplus, through an immunoproteomic approach.

Rhipicephalus (Boophilus) microplus ticks are obligatory hematophagous ectoparasites of cattle and act as vectors for disease-causing microorganisms. Conventional tick control is based on the use of chemical acaricides; however, their uncontrolled use has increased tSresistant tick populations, as well as food and environmental contamination. Alternative immunological tick control has shown to be partially effective. The only anti-tick vaccine commercially available at present in the world is based on intestinal Bm86 protein, and shows a variable effectiveness depending on tick strains or geographic isolates. Therefore, there is a need to characterize new antigens in order to improve immunological protection. The aim of this work was to identify immunogenic proteins from ovarian tissue extracts of R. microplus, after cattle immunization. Results showed that ovarian proteins complexed with the adjuvant Montanide ISA 50 V generated a strong humoral response on vaccinated cattle. IgG levels peaked at fourth post-immunization week and remained high until the end of the experiment. 1D and 2D SDS-PAGE-Western blot assays with sera from immunized cattle recognized several ovarian proteins. Reactive bands were cut and analyzed by LC-MS/MS. They were identified as Vitellogenin, Vitellogenin-2 precursor and Yolk Cathepsin. Our findings along with bioinformatic analysis indicate that R. microplus has several Vitellogenin members, which are proteolytically processed to generate multiple polypeptide fragments. This apparent complexity of vitellogenic tick molecular targets gives the opportunity to explore their potential usefulness as vaccine candidates but, at the same time, imposes a challenge on the selection of the appropriate set of antigens.

Bringing HIV partner services into the age of social media and mobile connectivity.

BACKGROUND: A substantial proportion of recent sex partners named by persons with sexually transmitted infections are not notified about their exposure despite attempts by public health officials. Although text messaging (texting) and Internet-based communications (dating Web sites, e-mail, etc) are used by a large segment of the public for regular communications, these tools have been underused for partner services (PS). METHODS: We augmented PS for HIV in New York City using texting and Internet-based means to contact persons for whom traditional information (landline telephone number, postal address) was unavailable. We compared traditional PS (traditionalPS), Internet-based PS (IPS) in January 2011 to October 2012, and texting PS (txtPS) from January 2012 (when txtPS was initiated) through October 2012 on outcomes of contact attempts, notification, and HIV testing. RESULTS: From January 2011 to October 2012, of 3319 partners elicited, 2604 and 275 partners had traditional and only Internet-based contact information and were selected for traditionalPS and IPS, respectively. From January to October 2012, 368 of 1569 partners had only texting-enabled cellphone numbers and were selected for txtPS. The contact rate for txtPS (285/368 [77%]) was significantly higher (P < 0.0001) than the contact rates for traditionalPS (1803/2604 [69%]) and IPS (112/275 [41%]). There was a higher likelihood of notifying contacted IPS (odds ratio, 2.1; 1.2-3.4) and txtPS (odds ratio, 2.4; 1.7-3.2) than traditionalPS partners (P ≤ 0.0001). However, among the notified partners, traditionalPS partners were significantly (P < 0.0001) more likely than txtPS or IPS partners to test for HIV after partner notification (69% vs 45% and 34%, respectively). CONCLUSIONS: Augmenting traditionalPS with txtPS and IPS enabled notification of hundreds of previously untraceable partners and several new HIV diagnoses.

[Generic diversity of Trichoptera (Insecta) of Paramo Rabanal (Cundinamarca-Boyacá, Colombia)]. / Diversidad genérica de Trichoptera (insecta) en dos microcuencas del Páramo Rabanal (Cundinamarca-Boyacá, Colombia).

Trichopterans are considered an important and diverse biotic element in continental aquatic ecosystems. The purpose of this study was to evaluate the assemblages of the order Trichoptera in two subwatersheds with a gradient of disturbance. Four sampling events were conducted in two subwatersheds in the Eastern Mountain Range of the Colombian Andes. For the analysis we used rarefaction curves, Bray-Curtis Index and Partitioning Diversity and total richness and Shannon's diversity as metrics. Although total richness was similar between both subwatersheds, abundance was always highest in streams within the conserved subwatershed. Each subwatershed was dominated by different genera, except Ochrotrichia, which was abundant at all sites. Alpha diversity was similar among streams in the conserved watershed, while a reduction in diversity potentially associated with the disturbance gradient was observed in streams of the disturbed subwatershed. Beta diversity (0Dbeta and 1Dbeta) between subwatersheds and among conserved streams was similar, while in disturbed streams a similar gradient to that of alpha diversity was found. The similitude analysis clustered streams according to their conservation status. Differences found in trichopteran assemblages do confirm that the use of their attributes is adequate to assess the conservation status of stream ecosystems. Rev. Biol. Trop. 62 (Suppl. 2): 97-110. Epub 2014 April 01.

[Leaf litter decomposition in six Cloud Forest streams of the upper La Antigua watershed, Veracruz, Mexico]. / Descomposición de hojarasca en seis arroyos de Bosque Mesófilo de Montaña en la cuenca alta del río La Antigua, Veracruz, México.

Leaf litter decomposition is an important stream ecosystem process. To understand factors controlling leaf decomposition in cloud forest in Mexico, we incubated leaf packs in different streams along a land use cover gradient for 35 days during the dry and wet seasons. We assessed relations between leaf decomposition rates (k), stream physicochemistry, and macroinvertebrates colonizing leaf packs. Physicochemical parameters showed a clear seasonal difference at all study streams. Leaves were colonized by collector-gatherer insects, followed by shredders. Assessment of factors related to k indicated that only forest cover was negatively related to leaf decomposition rates. Thus stream physicochemistry and seasonality had no impact on decomposition rates. We concluded that leaf litter decomposition at our study streams is a stable process over the year. However, it is possible that this stability is the result of factors regulating decomposition during the different seasons and streams.

Neutralizing antibody responses to the Delta variant of SARS-CoV-2 following vaccination with Ad5-nCoV (CanSino) in the Mexican population.

During the COVID-19 pandemic, the Ad5-nCoV vaccine was applied to the Mexican population before the WHO approved it. In a transversal study, we compare the CanSino vaccine efficacy and a natural SARS-CoV-2 infection in eliciting neutralizing antibodies against the SARS-CoV-2 Delta variant in Guadalajara, Mexico. Participants between 30-60 years were included in the study and classified into three groups: 1) Natural immunity (unvaccinated), 2) Vaccine-induced immunity (vaccinated individuals without a COVID-19 history), and 3) Natural immunity + vaccine-induced immunity. These groups were matched by age and gender. We assessed the ability of individuals' serum to neutralize the Delta variant and compared the results of the different groups using a neutralization test followed by plaque-forming units. Results showed that 39% of individuals' serum with a history of COVID-19 (natural immunity, Group 1) could not neutralize the Delta variant, compared to 33% in vaccinated individuals without COVID-19 (vaccine immunity, Group 2). In contrast, only 7% of vaccinated individuals with a history of COVID-19 (natural + vaccine immunities) could not neutralize the Delta variant. We concluded that the effectiveness of the Ad5-nCoV vaccine to induce neutralizing antibodies against the Delta variant is comparable to that of natural infection (61% vs. 67%). However, in individuals with both forms of immunity (Group 3), it increased to 93%. Based on these results, despite the Ad5-nCoV vaccine originally being designed as a single-dose regimen, it could be recommended that even those who have recovered from COVID-19 should consider vaccination to boost their immunity against this variant.

Molecular Phylogeny of the Family Cordulegastridae (Odonata) Worldwide.

In this study, we present the first attempt at a molecular phylogenetic analysis of the entire family of Cordulegastridae involving 60% of its known species. Our analysis is in favor of reclassification of the members of the family into four genera: (i) the monophyletic genus Anotogaster Selys, 1854, with the number of known species reduced by three synonymizations; (ii) the genus Cordulegaster Leach in Brewster, 1815 including all members of the boltonii group and, as a preliminary solution, the American species C. virginiae Novelo-Gutiérrez, 2018 and, very tentatively, C. diadema Selys, 1868. The bidentata group forms a genus of its own, for which we restored the name Thecagaster Selys 1854, stat. rev. Cordulegaster pekinensis McLachlan in Selys, 1886, currently considered as Neallogaster pekinensis, was placed by us in Thecagaster as well. The genus Neallogaster Cowley, 1934 needs further investigation involving all remaining species listed in it. The genus Zoraena Kirby, 1890, stat. rev., was recovered to accommodate the remaining American species of Cordulegaster. We synonymized three species of Anotogaster: Anotogaster gregoryi Fraser, 1923 = Anotogaster xanthoptera Lohmann, 1993, syn. nov.; Anotogasterkuchenbeiseri (Förster, 1899) = Anotogaster antehumeralis Lohmann, 1993, syn. nov.; Anotogaster kuchenbeiseri (Förster, 1899) = Anotogaster cornutifrons Lohmann, 1993, syn. nov., based on examination of the existing type specimens. The type of specimens of A. klossi Fraser, 1919 = A. flaveola Lohmann 1993 syn. confirm., were also examined, and their synonymy was confirmed. The isolated populations of A. sieboldii (Selys, 1854) from the archipelagos of Okinawa and Amami Oshima in Japan, respectively, should be regarded as separate species, which will be described elsewhere. Furthermore, we suggest the synonymization of Cordulegaster parvistigma Selys 1873 syn. nov. with Thecagaster brevistigma (Selys 1854) comb. restaur.

Patterned PVA Hydrogels with 3D Petri Dish® Micro-Molds of Varying Topography for Spheroid Formation of HeLa Cancer Cells: In Vitro Assessment.

Cell spheroids are an important three-dimensional (3D) model for in vitro testing and are gaining interest for their use in clinical applications. More natural 3D cell culture environments that support cell-cell interactions have been created for cancer drug discovery and therapy applications, such as the scaffold-free 3D Petri Dish® technology. This technology uses reusable and autoclavable silicone micro-molds with different topographies, and it conventionally uses gelled agarose for hydrogel formation to preserve the topography of the selected micro-mold. The present study investigated the feasibility of using a patterned Poly(vinyl alcohol) hydrogel using the circular topography 12-81 (9 × 9 wells) micro-mold to form HeLa cancer cell spheroids and compare them with the formed spheroids using agarose hydrogels. PVA hydrogels showed a slightly softer, springier, and stickier texture than agarose hydrogels. After preparation, Fourier transform infrared (FTIR) spectra showed chemical interactions through hydrogen bonding in the PVA and agarose hydrogels. Both types of hydrogels favor the formation of large HeLa spheroids with an average diameter of around 700-800 µm after 72 h. However, the PVA spheroids are more compact than those from agarose, suggesting a potential influence of micro-mold surface chemistry on cell behavior and spheroid formation. This was additionally confirmed by evaluating the spheroid size, morphology, integrity, as well as E-cadherin and Ki67 expression. The results suggest that PVA promotes stronger cell-to-cell interactions in the spheroids. Even the integrity of PVA spheroids was maintained after exposure to the drug cisplatin. In conclusion, the patterned PVA hydrogels were successfully prepared using the 3D Petri Dish® micro-molds, and they could be used as suitable platforms for studying cell-cell interactions in cancer drug therapy.

The Fluorescent Cell Line SW620-GFP Is a Valuable Model to Monitor Magnetic Hyperthermia.

In this work, the cell line SW620-GFP has been used in a complete magnetic hyperthermia assay, from the preparation of the ferrofluid with folate-coated iron oxide nanoparticles to in vivo experiments. The physical and chemical characterization of the nanoparticles evidenced their superparamagnetic behaviour, an average diameter of 12 ± 4 nm, a 2 nm coat thickness, and a high-power loss density. The main innovation of the work is the exclusive capability of viable SW620-GFP cells to emit fluorescence, enabling fast analysis of both, cell viability in vitro with an epifluorescence microscope and tumour size and shape in vivo in a non-invasive manner using the iBox technology. Moreover, with this imaging technique, it was possible to demonstrate the successful tumour size reduction in mice applying magnetic hyperthermia three times a week over 3 weeks.

Synergistic Strategies in Prostate Cancer Therapy: Electrochemotherapy and Electromagnetic Hyperthermia.

Prostate cancer is a significant global health problem, being the second most common cancer and the fifth leading cause of death in men worldwide. Standard chemotherapy, though effective, often lacks selectivity for tumor cells, resulting in dose-limiting side effects. To address this, innovative biomedical approaches such as electrochemotherapy and electromagnetic hyperthermia have emerged. Electrochemotherapy improves drug delivery by facilitating electroporation, thereby increasing intracellular concentrations of chemotherapeutic agents. This approach reduces dosages and associated adverse effects. Meanwhile, electromagnetic hyperthermia raises the temperature of tumor cells, enhancing their sensitivity to chemotherapy. While previous research has demonstrated the inhibitory effects of magnetic hyperthermia on prostate cancer cell growth both in vitro and in vivo, and its synergy with chemotherapy has shown enhanced tumor remission, limited studies have focused on electrochemotherapy alone or in combination with hyperthermia in prostate cancer models. This study aims to assess the synergistic effects of electromagnetic hyperthermia, with superparamagnetic iron oxide nanoparticles (SPIONs) and electrochemotherapy, with electroporation and the chemotherapeutic drugs bleomycin and cisplatin, on the prostate cancer-derived cell line DU-145/GFP and prostate-derived cell line RWPE-1. Results indicate enhanced cytotoxicity with both treatments (bleomycin and cisplatin) by adding electroporation, demonstrating a particularly pronounced effect with bleomycin. Combining electroporation with hyperthermia significantly augments cytotoxicity. Moreover, electroporation effectively reduced the time of exposure to electromagnetic hyperthermia while magnifying its cytotoxic effects. Future research in in vivo trials may reveal additional insights into the combined effects of these therapies.

Intergenerational photovoice projects: optimizing this mechanism for influencing health promotion policies and strengthening relationships.

Intergenerational photovoice groups are promising for promoting health through the topic that is explored and through group dynamics that can foster healthy relationships and communication. To investigate the potential benefits of intergenerational photovoice projects, photovoice groups were conducted in urban Minnesota, United States, and in rural Morelos, Mexico, between 2009 and 2012 with Mexican-origin adults and their adolescent relatives. Seven photovoice groups of adult-adolescent dyads met for eight sessions and developed exhibits highlighting their views on health and migration and made policy recommendations, using messages conveyed through their words and photographs. Informal process evaluation and focus groups were used to elicit feedback about photovoice project participation. Photovoice project themes were descriptively analyzed. Focus group evaluation data were thematically summarized, and facilitator reflections were descriptively summarized to identify factors associated with intergenerational photovoice groups. Seventy-five participants were recruited. Photovoice themes represented effects of migration on health, family, and well-being. The following two evaluative themes were identified: (a) participant sentiments about the benefits of photovoice participation and (b) facilitator observations of intergenerational photovoice group benefits and challenges. Participants described opportunities to learn new things and barriers to healthy relationships that the project was eliminating by providing them with time to work together. Used in health promotion, photovoice is a valuable tool that contributes to understanding the complex underlying factors influencing behaviors and health.

Description of the larva of Argia chelata Calvert, 1902 (Odonata: Coenagrionidae).

The larva of Argia chelata is described and figured. It falls into the group of Argia larvae with a moderately prominent ligula and two palpal seta, but it differs from its closest relatives by having labial palp with 2 setae plus one basal setella; the length of the ligula is 30% of its maximum width; basal tergites (1-5) lacking long, fine setae, mainly on midline; S8-10 mostly dark brown; paraprocts with spiniform setae on basal 0.25 and 0.55 of dorsal and ventral borders, respectively. Larvae were found in 2nd to 4th order shallow streams in cloud forest, crawling among debris, fine sand and mud where the water flow is slow or still, close to the shoreline. The larva is compared with A. lacrimans (Hagen), A. pima Garrison, and A. tonto Calvert, species apparently closely related. 

Two new species of Psephenops Grouvelle from Belize (Coleoptera: Byrrhoidea: Psephenidae), with a key to the known species from Mexico and Central America.

Two new species, Psephenops spiniparameri sp. nov. and P. shepardi sp. nov. are described, based on specimens collected from Cayo and Toledo Districts in Belize, bringing the total number of described species assigned to the genus to ten.

Revision of the Mesoamerican genus Cataractocoris Usinger (Hemiptera: Heteroptera: Nepomorpha: Naucoridae).

The genus Cataractocoris includes large waterfall-inhabiting insects that occur from Mexico to El Salvador and has received very little attention in the literature. Based on extensive field work during the past three years, we have collected saucer bugs (Heteroptera: Naucoridae) from many localities in central and southern Mexico. We here present detailed distributions and diagnostic information of the two described species of Cataractocoris and the description of a third species that occurs from Nayarit state in Mexico south to Guatemala. An illustrated taxonomic key to identify the species also is presented.

The larvae of Cora inca Selys, 1873 and Polythore gigantea (Selys, 1853) from Colombia (Odonata: Polythoridae), with a larval diagnoses of some genera in the family.

The larvae of Cora inca Selys, 1873 and Polythore gigantea (Selys, 1853) were found in first and second order forested streams at the Tatamá Natural National Park in the Colombian Western Andes. Their final larval stadia are here described and figured. Cora inca differs from the larvae of C. cyane Selys, 1853 and C. marina Selys, 1868 by a combination of features including presence of an irregular patch of minute, gray scales to each side of the ventral midline on the ventral pad of hypopharynx, paraprocts with five projections, and the position of epiproct and paraproct projections. On the other hand, the larva of P. gigantea differs from the larva of P. spaeteri Burmeister & Börzsöny, 2003 by antennal scape slightly shorter than 3rd antennomere, prementum 0.10x longer than its widest part, and the position of epiproct and paraproct projections. Although most of the larvae in the family Polythoridae are still unknown, here we discuss the main morphological characteristics that help to diagnose some of the genera in this family, presenting a regional taxonomic key that includes the genera Cora Selys, 1853, Euthore Selys, 1859, Miocora Calvert, 1917, and Polythore Calvert, 1917.

The rediscovery of Heteragrion azulum Dunkle, 1989 with additional notes on the female (Odonata: Heteragrionidae).

Some details of the morphology of the female of Heteragrion azulum Dunkle, 1989 are described for the first time such as the intersternite, and illustrated with high quality photographs, based upon two specimens collected in the tropical rain forest at the region of Los Tuxtlas, in the state of Veracruz, Mexico. A comparison with females of the other three species of Heteragrion Selys, 1862 occurring in Mexico is also provided. Additional data of males of H. azulum collected together with the females are also given, including some illustrations.