Resurgence of human respiratory syncytial virus during COVID-19 pandemic in Southern Brazil

Respiratory Syncytial Virus (RSV) is an important cause of respiratory infection in humans. Severe cases are common in children ≤2 years old, immunocompromised individuals, and the elderly. In 2020, RSV infection reduced in Rio Grande do Sul (RS), southern Brazil; however, in 2021 resurgence of RSV was observed. This study analyzed epidemiological and genetic features of RSV infection cases reported in 2021 in RS. Nasopharyngeal samples collected from individuals with respiratory infection negative for SARS-CoV-2, Influenza A and B viruses were assessed for the presence of RSV by real time RT-qPCR. RSV-A and RSV-B genomic sequencing and phylogenetic reconstructions were performed for genotyping and clade characterization. Among 21,035 respiratory samples analyzed, 2,947 were positive for RSV, 947 of which were hospitalized patients. Positive cases were detected year-round, with the highest number in June-July (winter). Children <1 year comprised 56.28% (n = 533) of the hospitalized patients infected with RSV, whereas 14.46% (n = 137) were individuals >60 years. Of a total of 361 deaths, 14.68% (n = 53) were RSV positive, mostly patients >60 years old (73.58%, n = 39). Chronic kidney disease, cardiopathy, Down syndrome and neurological diseases were associated with RSV infection. RSV-A was identified in 58.5% (n = 117/200) of the patients, and RSV-B in 41.5% (n = 83/200). Of 95 RSV genomes recovered from SARI cases, 66 were RSV-A GA.2.3.5 genotype, while 29 were RSV-B GB.5.0.5a genotype. This study provides epidemiological and molecular data on RSV cases in RS during the COVID-19 pandemic and highlights that investigation of different respiratory viruses is essential for decision-making and disease prevention and control measures.

Introduction, Dispersal, and Predominance of SARS-CoV-2 Delta Variant in Rio Grande do Sul, Brazil: A Retrospective Analysis

Mutations in the SARS-CoV-2 genome can alter the virus' fitness, leading to the emergence of variants of concern (VOC). In Brazil, the Gamma variant dominated the pandemic in the first half of 2021, and from June onwards, the first cases of Delta infection were documented. Here, we investigate the introduction and dispersal of the Delta variant in the RS state by sequencing 1077 SARS-CoV-2-positive samples from June to October 2021. Of these samples, 34.7% were identified as Gamma and 65.3% as Delta. Notably, 99.2% of Delta sequences were clustered within the 21J lineage, forming a significant Brazilian clade. The estimated clock rate was 5.97 × 10-4 substitutions per site per year. The Delta variant was first reported on 17 June in the Vinhedos Basalto microregion and rapidly spread, accounting for over 70% of cases within nine weeks. Despite this, the number of cases and deaths remained stable, possibly due to vaccination, prior infections, and the continued mandatory mask use. In conclusion, our study provides insights into the Delta variant circulating in the RS state, highlighting the importance of genomic surveillance for monitoring viral evolution, even when the impact of new variants may be less severe in a given region.

The applicability of fingernail lead and cadmium levels as subchronic exposure biomarkers for preschool children

Preschool children are exposed daily to metals in their homes and at daycare centers (DCC). Metal exposure and health effects are associated even at low levels, and children comprise a group of public health concern. Nail metals have been studied for exposure biomonitoring and compared to other biological media. The aim of this study was to explore the applicability of preschool fingernail lead and cadmium as subchronic exposure biomarkers. Nail lead and cadmium levels (NLL and NCL) of 602 preschool children (age: 1-4 years) who attended 21 DCC in São Paulo, Brazil, in 2013 were analyzed. Results were compared against blood lead and cadmium levels (BLL and BCL) found in a previous study. Inductively coupled plasma mass spectrometry (ICP-MS) analyses were performed for both samples. DCC and metal contaminated sites (MCS) were georeferencing. Logistic regression tests were applied to verify associations between nail metal levels and risk factors (sex, age, maternal education, secondary smoking, DCC geographic district, vehicle flow density, relative altitude and distance between DCC and nearest MCS) (p < 0.05). BLL was stratified by exposure level (low: <5 μg.dL^-1; high: >13.9 μg.dL^-1; medium: ≥5 μg.dL^-1 and ≤13.9 μg.dL^-1) and also tested the associations in order to verify if nail lead levels are affected by exposure intensity defined by blood metals concentrations. Radius distance and relative altitude of DCC to nearest MCS were associated with high NLL and NCL. Abnormal appearance of nails was associated with high NLL and low NCL. Lead and cadmium exposure magnitude had no significant impact on NLL. NLL should only be used for initial screening, and when financial resources are scarce, especially in areas located near contaminated sites. Preschool children were co-exposed to both lead and cadmium, reinforcing the need for broader studies evaluating exposure to environmental pollutants for more than one chemical element.

Homology Inference Based on a Reconciliation Approach for the Comparative Genomics of Protozoa

Protozoa parasites are responsible for several diseases in tropical countries, such as malaria, sleeping sickness, Chagas disease, leishmaniasis, amebiasis, and giardiasis, which together threaten millions of people around the world. In addition, most of the classic parasitic diseases due to protozoa are zoonotic. Understanding the biology of these organisms plays a relevant role in combating these diseases. Using homology inference and comparative genomics, this study targeted 3 protozoan species from different Phyla: Cryptosporidium muris (Apicomplexa), Entamoeba invadens (Amoebozoa), and Trypanosoma grayi (Euglenozoa). In this study, we propose a new approach for the identification of homologs, based on the reconciliation of the results of 2 different homology inference software programs. Our results showed that 46.1% (59/128) of the groups inferred by our reconciliation approach could be validated using this methodology. These validated groups are here called homologous Supergroups and were compared with SUPERFAMILY and Pfam Clans.

Airborne fungi in an intensive care unit

The presence of airborne fungi in Intensive Care Unit (ICUs) is associated with increased nosocomial infections. The aim of this study was the isolation and identification of airborne fungi presented in an ICU from the University Hospital of Pelotas - RS, with the attempt to know the place's environmental microbiota. 40 Petri plates with Sabouraud Dextrose Agar were exposed to an environment of an ICU, where samples were collected in strategic places during morning and afternoon periods for ten days. Seven fungi genera were identified: Penicillium spp. (15.18%), genus with the higher frequency, followed by Aspergillus spp., Cladosporium spp., Fusarium spp., Paecelomyces spp., Curvularia spp., Alternaria spp., Zygomycetes and sterile mycelium. The most predominant fungi genus were Aspergillus spp. (13.92%) in the morning and Cladosporium spp. (13.92%) in the afternoon. Due to their involvement in different diseases, the identified fungi genera can be classified as potential pathogens of inpatients. These results reinforce the need of monitoring the environmental microorganisms with high frequency and efficiently in health institutions.

Pneumonia due to Talaromyces marneffei in a Dog from Southern Brazil with Concomitant Canine Distemper Virus Infection

The pathological and molecular findings associated with Talaromyces marneffei-induced pneumonia with concomitant infection by canine distemper virus (CDV) are described in a dog. The principal pathological alteration occurred in the lungs. Histopathology confirmed multifocal granulomatous pneumonia associated with numerous intralesional and intracellular septate fission cells consistent with T. marneffei. A molecular assay designed to amplify a partial fragment of the 18S rRNA gene of T. marneffei provided positive results from two fungal cultures derived from the lung. Sequencing and phylogenetic analyses confirmed the results of polymerase chain reaction (PCR). Furthermore, antigens of the CDV N protein were identified within the bronchial epithelium by immunohistochemistry and a PCR assay amplified the CDV N gene from hepatic and pulmonary fragments. Collectively, the pathological and molecular techniques confirmed a diagnosis of T. marneffei-induced pneumonia with concomitant infection by CDV. These findings represent the first description of pulmonary penicilliosis in the dog and extend the geographical niche of this emerging infectious pathogen. In this case, infection by CDV may have induced immunosuppression, which facilitated the development of pulmonary penicilliosis.

Development and validation of HPLC method to determination of Methotrexate in children oncologic patients

OBJECTIVE

The acute lymphocytic leukemia is a hematopoietic cancer that occurs predominantly in children. Methotrexate is one of the most useful drugs in cancer chemotherapy. The aim of the study was to develop and validate the methodology of high performance liquid chromatography (HPLC) with ultraviolet detection for methotrexate dosage and to determine its concentration in plasma samples from children with leukemia.

PATIENTS AND METHODS

The study included patients from the outpatient care of pediatric oncology at the Faculty of Medicine of ABC carriers in treatment of leukemia. The study was conducted in chromatographic model Agilent 1100 with UV detector at 302 nm and by the method of ELISA microplate reader capable of reading absorbance at 450 nm.

RESULTS

We obtained satisfactory results of selectivity, accuracy, linearity, limit of quantification (LOQ), limit of detection (LOD), precision and robustness and apply the basic criteria for validation as RE No. 899, of May 29, 2003 Guide validation of analytical and bioanalytical National Agency Health Surveillance (ANVISA).

CONCLUSIONS

We conclude that results for linearity/concentration range, precision, robustness, limit of quantification and detection limits are within the acceptance criteria defined by ANVISA and that the developed analytical method is valid and feasible to be used as a tool in monitoring therapy of methotrexate.

Intracellular urease activity in the lichen Cladonia verticillaris, and its implication for toxicity

Urea is currently used as a nitrogen fertilizer in many plant cultures, such as sugar cane. Several lichen species grow in the edges of the fields fertilized with urea. This implies that the hydrolysis of an excess of urea by soil bacteria or by the lichens themselves would increase the concentration of ammonia in the lichen thallus to a level that may be toxic to the photobiont. However, Cladonia verticillaris produces urease through positive feedback by urea supplied from the medium. This urease is partially secreted to the media or retained on the external surface of algal cells, as demonstrated herein by an adequate cytochemical reaction. This implies that ammonia produced by urea hydrolysis will be immediately dissolved in the water filling the intercellular spaces on the thallus. A possible protection mechanism against eventual ammonia toxicity, derived from the results described here, is also discussed.

Allelopathic and bioherbicidal potential of Cladonia verticillaris on the germination and growth of Lactuca sativa

Responses to germination and initial growth of Lactuca sativa (lettuce) submitted to organic extracts and purified compounds of Cladonia verticillaris ("salambaia") were analyzed in this work. The experiments were conducted in laboratory conditions using extracts and pure compounds at different concentrations. None of the assays showed any influence on the germination of L. sativa seeds using C. verticillaris extracts; however, modifications in leaf area and seedling hypocotyl and root development occurred. In the growth experiments, seedlings exposed to ether or acetone extract showed diminished hypocotyl growth in detriment to the root stimulus, compared to controls. Increases in extract concentrations led to the formation of abnormal seedlings. To determine the allelochemicals of C. verticillaris, its principal components, fumarprotocetraric and protocetraric acids, were isolated and then analyzed by high performance liquid chromatography (HPLC). When the seedlings were exposed to the two acids separately, presented increased leaf area at all concentrations. In contrast, hypocotyl and root stimulus was observed only in the presence of protocetraric acid at different concentrations. Fumarprotocetraric as well as protocetraric acids, isolated and purified from C. verticillaris and Parmotrema dilatatum respectively, influenced the development of L. sativa seedlings at high concentrations, indicating a possible bioherbicide potential of these acids.

Safety and efficacy analysis of liposomal insulin-like growth factor-1 in a fluid gel formulation for hair-loss treatment in a hamster model

Insulin-like growth factor (IGF)-1 has shown some interesting results in studies examining its use as a hair-loss treatment. IGF-1 works by regulating cellular proliferation and migration during the development of hair follicles. Hepatotoxicity and myelotoxicity were evaluated in hamsters (Mesocricetus auratus) after topical application of the liquid gel vehicle (placebo), 1% IGF-1 or 3% IGF-1. No significant difference in the levels of aspartate aminotransferase or alanine aminotransferase was found between the control and treated groups. ELISA did not shown any increase in the plasma level of IGF-1. A haematopoietic niche was found, but it was not associated with myelotoxicity. Efficacy was determined by dermatoscopy analysis of hair density and microscopy analysis of hair diameter, with hair found to be thicker and with more rapid growth in the 3% group than in either the 1% group or the control group. These results strongly suggest that liposomal IGF-1 in a liquid gel formulation is a safe and efficient treatment for hair loss.

Electrochemical preparation of overlapped porous layers on anodic alumina

In this paper, we report the development of a new architecture on porous anodic alumina using the conventional two-step anodization method. The samples prepared in two identical steps using galvanostatic anodization exhibited two porous layers overlapped with distinct pore area distributions. The effects from the first anodization time and temperature on this different morphology were assessed using Factorial Design. The chemical removal time of the oxide formed during the first anodization was not relevant for the overlapped porous structure. The most important factor was the time of the first anodization required for formation of stable patterns on the substrate, which would be reproduced in the second anodization. A pore mismatch appeared because under galvanostatic control the changes in the actual area become important, which is not the case for sample preparation under potentiostatic control where the current density is adjusted according to the new boundary condition. The new architecture with mismatching layers may open the way for further applications of porous alumina as template for nanomaterial.

Cholesterol oxides as biomarkers of oxidative stress in type 1 and type 2 diabetes mellitus

BACKGROUND

Oxidative stress plays an important role in the pathophysiology of diabetes mellitus. The aim of this study was to evaluate the formation of cholesterol oxides (ChOx) as biomarkers of oxidative stress in subjects with impaired glucose tolerance (IGT) and diabetes.

METHODS

Blood plasma levels of cholesterol oxidation products were determined in the following groups: type 1 diabetes mellitus (DM1), type 2 diabetes (DM2), impaired glucose tolerance (IGT), children without diabetes (C1) and adults without diabetes (C2). The serum levels of cholest-5-ene-3alpha,7alpha-diol (7alpha-hydroxycholesterol, 7alpha-OH), cholest-5-ene-3beta,7beta-diol (7beta-hydroxycholesterol, 7beta-OH), 3beta-hydroxycholest-5-7-one (7-ketocholesterol, 7-K), 5alpha-cholestane-3beta,5,6beta-triol (cholestanetriol), 5,6alpha-epoxy-5alpha-cholestan-3alpha-ol (cholesterol-5alpha,6alpha-epoxide,), 5,6beta-epoxy-5beta-cholestan-3beta-ol (cholesterol-5beta,6beta-epoxide) and cholest-5-eno-3beta,25-diol (25-hydroxycholesterol, 25-OH) (trivial name and abbreviations indicated in parentheses) were quantified by gas chromatography using flame ionization detection.

RESULTS

The levels of total ChOx were elevated in the DM1 and DM2 groups compared to age-matched subjects without diabetes (p < 0.05). The concentrations of 7beta-hydroxycholesterol, cholesterol-alpha-epoxide and cholesterol-beta-epoxide were higher in the blood plasma of subjects in the DM2 group than in the blood plasma of subjects in the C2 and IGT groups (p < 0.05). Treatment of type 2 diabetic patients with oral hypoglycemic drugs associated with insulin resulted in lower concentrations of nitrotyrosine in the blood plasma without significant changes in the concentrations of glucose and glycated hemoglobin. Moreover, combination with statins in both treatments decreased the concentrations of ChOx.

CONCLUSIONS

ChOx are suitable biomarkers of oxidative stress and may be useful in clinical studies to follow drug effects on lipid oxidative modifications in diabetic patients.

Effect of usnic acid from the lichen Cladonia substellata on Trypanosoma cruzi in vitro: an ultrastructural study

Chemotherapy for Chagas' disease is still unsatisfactory due to toxicity and limited effectiveness of the available drugs. In this work we have investigated the effect of usnic acid, isolated from lichen Cladonia substellata, against Trypanosoma cruzi, in vitro. Incubation of culture epimastigotes with 5-30microg/ml of this compound resulted in growth inhibition in a dosis-dependent manner. Ultrastructural analysis of treated epimastigotes showed damage to mitochondria, with a marked increase in kinetoplast volume and vacuolation of the mitochondrial matrix. Intense lysis of bloodstream trypomastigotes was observed with all drug concentrations tested. Besides mitochondrial and kinetoplast damage, trypomastigotes also presented enlargement of the flagellar pocket, as well as intense cytoplasm vacuolation. Treatment of infected macrophages with 40 or 80microg/ml usnic acid induced marked cytoplasm vacuolation in intracellular amastigote forms, with disorganization of parasite kinetoplast and mitochondria, but with no significant ultrastructural damage to the host cells.

Injury and recovery of fast and slow skeletal muscle fibers affected by ACL myotoxin isolated from Agkistrodon contortrix laticinctus (Broad-Banded copperhead) venom

The response of different types of skeletal muscle fibers to a snake venom PLA2 myotoxin was tested in vivo by injecting ACL myotoxin (ACLMT) into mice. Both the soleus (slow-twitch) and gastrocnemius (fast-twitch) were examined at different time periods (3 h, 3 and 21 d) after the injection. All animals received 5 mg/kg myotoxin into the subcutaneous lateral region of the right hind limb, near the Achilles tendon; contralateral muscles were used as controls. Cross-sections (10 microm) of frozen muscle tissue were cut from the medial region of the muscle. Alternate serial sections were stained either with toluidine blue or for acid phosphatase, myofibrillar ATPase activity after alkali (pH 10.3) or acid preincubation (pH 4.3), succinate dehydrogenase or acetylcholinesterase. Several stages of necrosis were observed 3 h after ACLMT injection, in both superficial and deep regions of both muscles. In these same regions 3 d after injection, clusters of regenerated muscle fibers were present, and some of them presented AChE activity. Twenty-one days after ACLMT injection the muscle fibers of soleus and gastrocnemius presented only chronic signs of damage such as split fibers and centralized nuclei. Using m-ATPase reactions it was possible to determine that both muscle fiber types I and II were injured in both muscles. The number of type IIC fibers was significantly increased, and the number of type II fibers significantly decreased in the gastrocnemius 21 d after ACLMT injection, suggesting a change in muscle fiber type from type II to type I, through type IIC. The increased number of type IIC fibers and the presence of AChE activity in clusters of regenerating fibers and split fibers indicate that injury by ACLMT produces axonal remodeling and muscle fiber type change.

[Hepatic hemangioma. Analysis of 103 cases. Clinical considerations and imaging methods]

Hemangiomas are the most common benign vascular tumor found in the liver. In this study, 103 cases of hepatic hemangiomas were analysed in a retrospective manner. Image aspects such as those seen in ultrassonography, computed tomography, nuclear magnetic resonance and arteriography are discussed. The incidence was higher amongst the female sex, between individuals from 40 to 60 years old, which presented predominantly without symptoms (66%) and localized mainly in the right hepatic lobe (74%). The meaning of those aspects, when adopted, permits the clinicians to differentiate benign from malignant nodular lesions in the liver.

Angiography in primary myomas of the alimentary tract

Fifteen cases of smooth muscle tumor of the alimentary tract were collected for analysis from several institutions. The findings showed that angiography is the best method available for diagnosis and evaluation of such tumors but is unable to differentiate benign from malignant lesions unless arterial invasion is detected. Computer tomography, ultrasound, and angiography are compared in the diagnosis of one case. Additionally, the angiographic pattern of a leiomyoblastoma is presented, presumably for the first time.