Prevalence and risk factors to Demodex folliculorum infection in eyelash follicles from a university population of Mexico.

Demodex folliculorum shows a high occurrence in the general population, however, its pathologic relevance is still controversial. In this prospective study, we evaluated the prevalence of D. folliculorum on eyelashes from 8,033 subjects of a university population (including 7,782 students, and 251 academics). Additional information on some risk factors to infection by the mites was evaluated, as well. A prevalence of 1.47% was found, where 118 individuals were positive for D. folliculorum; and, among them, 63 (53.4%) were women and 55 (46.6%) were men. Results showed a negative correlation with the age (r = -0.45), the highest prevalence was found in individuals between 19 and 22 years of age (2.1%, 84 patients). The number of D. folliculorum mites did not differ between the right and left eye; however, the use of cosmetics or facial cream, contact lens, hair removers, were factors present in patients infected with D. folliculorum. Although Demodex prevalence did not increase in line with weight, we found significantly higher prevalence in the 51-60 kg and 71-80 kg weight groups, and a particularly high prevalence in the over 81 kg weight group (2.6%). In conclusion, it was observed that the main population positive to infection consisted of young adults; this is in contrast with the international evidence reporting a high rate of infection in older adults. Besides, our results suggest that items of daily use such as cosmetics, facial cream, eyeliner, glasses, or contact lenses may be some of the main culprits of the infection by D. folliculorum.

Pesticide Exposure in the Cultivation of Carica papaya L. and Capsicum annuum L. in Rural Areas of Oaxaca, Mexico.

This study focuses on describing the diversity of pesticides, the knowledge and behaviors of their use, and the acute poisoning symptoms (APS) derived from their exposure from two agricultural production systems (papaya-Carica papaya L.- and chili-Capsicum annuum L.-) in Oaxaca, Mexico. Through surveys, sociodemographic information, characteristics of the production system, knowledge and behaviors in the handling of pesticides, and APS perceived by users were captured. Papaya producers are younger, have fewer years of activity, and have larger agricultural areas than chili producers. Insect attacks and diseases are an essential factor for the application of pesticides. Thirty-one active ingredients (Ais) were identified in papaya and thirty-seven in chili, predominantly insecticides and fungicides of toxicological category IV. Approximately 50% of users apply mixtures of different Ais, have little knowledge and inappropriate behavior in their handling, and report up to five acute pesticide poisoning symptoms, mainly burning and irritation of the skin, burning eyes, itchy skin, runny nose, headache, and watery eyes. The production of papaya and chili are relevant activities for generating economic income, but they risk the producer's and their family's health. Both systems are a potential scenario for the manifestation of diseases due to exposure to pesticides in the medium and long term.

IFN-γ-Preconditioned Human Gingival-Derived Mesenchymal Stromal Cells Inhibit Plasmacytoid Dendritic Cells via Adenosine.

Plasmacytoid dendritic cells (pDCs) are vital players in antiviral immune responses because of their high levels of IFN-α secretion. However, this attribute has also implicated them as critical factors behind the immunopathogenesis of inflammatory diseases, and no currently available therapy can efficiently inhibit pDCs' aberrant activation. Mesenchymal stromal cells (MSCs) possess stromal immunomodulatory functionality, regulating immune cell activation through several mechanisms, including the adenosinergic (CD39/CD73/adenosine) pathway. The IFN-γ preconditioning of bone marrow MSCs improves their inhibitory properties for therapy applications; however, isolating human gingival tissue-derived MSCs (hGMSCs) is more accessible. These cells have shown better immunomodulatory effects, yet the outcome of IFN-γ preconditioning and its impact on the adenosinergic pathway has not been evaluated. This study first validated the immunoregulatory properties of primary-cultured hGMSCs, and the results showed that IFN-γ preconditioning strengthens CD39/CD73 coexpression, adenosine production, and the regulatory properties of hGMSC, which were confirmed by describing for the first time their ability to reduce pDC activation and their IFN-α secretion and to increase the frequency of CD73+ pDC. In addition, when CD73's enzymatic activity was neutralized in hGMSCs, adenosine production and the IFN-γ preconditioning effect were restrained. This evidence might be applied to design hGMSCs- and adenosine-based immunotherapeutic strategies for treating inflammatory disorders that are associated with pDC overactivation.

Detection of Asymptomatic Sickle Cell Hemoglobin Carriers and Fetal Hemoglobin Regulating Genetic Variants in African Descendants from Oaxaca, Mexico.

Sickle cell anemia has been classified as a noninfectious neglected tropical disease and, although not exclusively, affects African descendants more frequently. This study aimed to detect asymptomatic sickle cell hemoglobin carriers (HbAS) in marginalized and vulnerable populations during a public health screening in African descendants from Oaxaca, Mexico, and to validate an amplification refractory mutation system (ARMS)-PCR methodology to detect fetal-hemoglobin (HbF)-regulating genetic variants in BCL11A toward affordable routine association of single nucleotide variants (SNVs) with HbF concentrations. To this aim, hemoglobin variants were detected by acidic citrate agar and alkaline cellulose acetate electrophoreses. SNVs in the hemoglobin subunit beta gene (HBB) were identified by the ß-globin mutation detection assay (ß-GMDA) and ARMS-PCR, respectively, and validated by Sanger sequencing. The association between genotypes and HbF concentrations was evaluated using Spearman's correlation coefficient. The results obtained during a directed screening in 140 self-identified African descendants revealed 42 HbS-carriers (30%), of which 39 showed normal total hemoglobin concentrations (92.8%), only 3 presented anemia (7.2%), and 9 showed quantifiable HbF concentration (21.4%). As validated by Sanger sequencing, the designed ARMS-PCR efficiently detected homozygous and heterozygous variants in BCL11A. In a cohort of 42 heterozygous (HbAS) and 27 healthy (HbAA) individuals from the same population, only one SNV (rs766432) showed statistically significant association with increasing HbF concentration, and two new unrelated homozygous silent variants were identified. This study reveals the need to raise coverage of HbS screening in vulnerable populations and shows a feasible low-cost ARMS-PCR methodology to determine the presence of SNVs in quantitative trait loci affecting HbF.

First case of chromoblastomycosis due to Phoma insulana.

Chromoblastomycosis is a chronic infection, caused by pigmented fungi affecting skin and subcutaneous tissues characterized by verrucous nodules or plaques. Fonsecaea pedrosoi and Cladophialophora carrionii are the prevalent agents in the endemic areas. Phoma is an uncommon agent of human infection and involved mainly with phaeohyphomycosis cases. The case of a patient with a history of laceration in foot followed by verrucous aspect and scaly lesions, which had evolved for 27 years is presented. On physical examination disease was clinically compatible with chromoblastomycosis and the microscopic examination of scales showed fumagoid cells. On culture a dematiaceous fungus was grown. The agent was confirmed to be Phoma insulana based on its morphology and PCR-sequencing. This fungal agent has not been previously reported in association with this pathology.

Irregular antibodies in no hemolytic autoimmune diseases are able to induce erythrophagocytosis.

Irregular antibodies are produced by alloimmunization because of pregnancies or blood transfusions. They are called "irregular" due to target erythrocyte antigens from "rare blood systems," those different from the ABO system. Irregular antibodies have been widely investigated in immunohematology since their presence in blood donors may lead to difficulties in blood typing and in blood cross-matching, or to induce hemolytic transfusion reactions. Nevertheless, their incidence and participation in the physiopathology of autoimmune diseases have not been thoroughly studied. In this work, we analyzed the presence and pro-hemolytic capabilities of irregular antibodies in patients with different autoimmune diseases lacking signs of hemolytic anemia, in comparison with healthy multiparous women. Five of 141 autoimmune patients (3.5 %) and two of 77 multiparous women (2.6 %) were positive. Although frequency was relatively low and similar in both populations, the targeted antigens were Kell (k, Kpb, Jsb) and Luth (Lub) in multiparous women, and the same plus Duffy (Fya), Kidd (Jka) and MNS (M, s) in autoimmune patients. Irregular antibodies from autoimmune patients did not induce complement-mediated hemolysis (intravascular), but they were able to induce macrophages-mediated phagocytosis (extravascular hemolysis) in vitro. It is the first approach exploring the presence of irregular antibodies associated with the loss of immune tolerance and demonstrating their hemolytic potential in autoimmune patients without hemolytic manifestations. The presence of irregular antibodies targeted to Duffy (Fya), Kidd (Jka) and MNS (M, s) antigens only in autoimmune patients suggests a loss of immune tolerance to these erythrocyte antigens.

Detection of Paragonimus mexicanus (Trematoda) metacercariae in crabs from Oaxaca, Mexico.

Metacercariae of Paragonimus mexicanus were collected in crabs Tehuana guerreroensis (Rathbun, 1933) in the municipality of Putla, Oaxaca, Mexico. Metacercariae were found in 20.8% of the crabs collected, with an average of 1.9 metacercarie per crab. Stained metacercariae showed the specific characteristics of P. mexicanus by morphology and sequencing a fragment of the 28S ribosomal gene obtained by PCR. These findings reveal that T. guerreroensis is an intermediate host for P. mexicanus; this new report is relevant considering the potential risk of transmission in the states of Oaxaca and Guerrero, Mexico.

Prevalence of Demodex mites in eyelashes among people of Oaxaca, Mexico.

This study was carried out to determine the prevalence of Demodex mites in eyelashes of people from different places from Oaxaca. One thousand and ten patients underwent epilation of eight eyelashes from each eye and they were processed to search Demodex which was found in 208 (20%) of the patients and among them male was more affected than female, 119 (57%) and 89 (43%), respectively. There was not found a relationship between clinical manifestations among these patients since 101 (49%) and 107 (51%) of them were symptomatic and asymptomatic, respectively. The range of age that was more affected was 96-105 (100%), followed by 86-95 (75%) and 76-85 (64%) years old. The less affected were individuals of 15-25 years old (11%). Demodex folliculorum was relatively high in the eyelashes of individuals in young and old people in the rural region studied. These people are generally the most vulnerable patients because they live in overcrowded conditions and poor hygiene which facilitates the direct infection. Demodex brevis was found in only one sample.