Effects of Harvest Time and Hydrodistillation Time on Yield, Composition, and Antioxidant Activity of Mint Essential Oil.

In this study, we assessed the effects of different harvest times (9 a.m., 1 p.m., and 5 p.m.) and hydrodistillation times (60, 90, and 120 min) on the yield, chemical composition, and antioxidant activity of the spearmint (Mentha spicata L.) essential oil (EO) sourced from the Amazon region. EO yield was ≥1.55% and was not significantly influenced (p ≥ 0.05) by the different harvest times and hydrodistillation times. Thirty-one different organic compounds were identified, of which menthol (91.56-95.68%), menthone (0.6-2.72%), and isomenthone (0.55-1.46%) were the major constituents. The highest menthol content in the EO was obtained from samples collected at 9 a.m., with a hydrodistillation time of 60-90 min, compared to other harvest and hydrodistillation times. This suggests that exposure to sun and light, which is greater at harvest times of 1 p.m. and 5 p.m., decreased the menthol content and altered the chemical composition of Mentha EO. Furthermore, the sample harvested at 9 a.m. and hydrodistilled for 60 min showed the highest antioxidant activity (61.67 equivalent mg of Trolox per g of EO), indicating that antioxidant activity is strongly affected by light exposure and the contact duration of the sample with boiling water during hydrodistillation.

Stability and Antioxidant Activity of Pouteria macrophylla Fruit Extract, a Natural Source of Gallic Acid.

Pouteria macrophylla (cutite) fruits are rich in phenolic acids, resulting in antioxidant and skin depigmenting activity. The aim of this study, then, is to evaluate the cutite extract stability under three variations of light, time, and temperature using a Box-Behnken experimental design to analyze through the surface response the variations of the total phenolic content (TPC), antioxidant activity (AA), and gallic acid content (GA). A colorimetric assay was also performed, and a decrease in the darkening index was noticed due to the high phenolic coloration in the presence of light, indicating less degradation to extract stability. The experimental planning showed variations in all responses, and second-order polynomial models were calculated and considered predictable, as well as the effects were significant. The TPC exhibited a variation in less concentrated samples (0.5% p/v) at higher temperatures (90 °C). In contrast, the temperature was the only influential variable for AA, where only higher temperatures (60-90 °C) were able to destabilize the fruit extract. Differently, GA showed only the concentration as the influential variable, exhibiting that neither temperature nor time of exposure could affect the gallic acid content stability of P. macrophylla extract. For this, P. macrophylla extract was shown to be highly stable, providing a great perspective on cosmetic application.

Evaluation of targets for Strongyloides genus specific molecular diagnosis in experimental strongyloidiasis.

Strongyloides venezuelensis has been used in different experimental studies, such as those aimed at the evaluation of diagnostic techniques for human strongyloidiasis, mainly the molecular diagnosis. In this study, three regions (genus, 18S and 28S targets) of Strongyloides ribosomal DNA were evaluated for the molecular diagnosis of experimental strongyloidiasis. Rats were infected subcutaneously with 400 or 4000 S. venezuelensis infective larvae (400iL3 and 4000iL3), and kept for 35 days. Fecal samples were collected daily to count eggs per gram of feces (EPG) and to perform the polymerase chain reaction (PCR). Egg count started on the 5th day post-infection (pi) and ended on days 33 and 34 pi, in 400iL3 and 4000iL3 groups, respectively. Based in EPG, fecal samples were selected from days 2, 5, 8, 11, 15, 23 and 35 pi for DNA extraction; PCR (genus, 18S and 28S); and sequencing. The PCR-28S products showed higher values of identity (95-100%) in the database with the Strongyloides sequences. Therefore, it is possible to reinforce the application of PCR-28S in the diagnosis of experimental and human strongyloidiasis.

Xylella fastidiosa subsp. pauca Strains Fb7 and 9a5c from Citrus Display Differential Behavior, Secretome, and Plant Virulence.

Xylella fastidiosa colonizes the xylem of various cultivated and native plants worldwide. Citrus production in Brazil has been seriously affected, and major commercial varieties remain susceptible to Citrus Variegated Chlorosis (CVC). Collective cellular behaviors such as biofilm formation influence virulence and insect transmission of X. fastidiosa. The reference strain 9a5c produces a robust biofilm compared to Fb7 that remains mostly planktonic, and both were isolated from symptomatic citrus trees. This work deepens our understanding of these distinct behaviors at the molecular level, by comparing the cellular and secreted proteomes of these two CVC strains. Out of 1017 identified proteins, 128 showed differential abundance between the two strains. Different protein families were represented such as proteases, hemolysin-like proteins, and lipase/esterases, among others. Here we show that the lipase/esterase LesA is among the most abundant secreted proteins of CVC strains as well, and demonstrate its functionality by complementary activity assays. More severe symptoms were observed in Nicotiana tabacum inoculated with strain Fb7 compared to 9a5c. Our results support that systemic symptom development can be accelerated by strains that invest less in biofilm formation and more in plant colonization. This has potential application in modulating the bacterial-plant interaction and reducing disease severity.

Proteomic and Metabolomic Analyses of Xylella fastidiosa OMV-Enriched Fractions Reveal Association with Virulence Factors and Signaling Molecules of the DSF Family.

Xylella fastidiosa releases outer membrane vesicles (OMVs) known to play a role in the systemic dissemination of this pathogen. OMVs inhibit bacterial attachment to xylem wall and traffic lipases/esterases that act on the degradation of plant cell wall. Here, we extended the characterization of X. fastidiosa OMVs by identifying proteins and metabolites potentially associated with OMVs produced by Temecula1, a Pierce's disease strain, and by 9a5c and Fb7, two citrus variegated chlorosis strains. These results strengthen that one of the OMVs multiple functions is to carry determinants of virulence, such as lipases/esterases, adhesins, proteases, porins, and a pectin lyase-like protein. For the first time, we show that the two citrus variegated chlorosis strains produce X. fastidiosa diffusible signaling factor 2 (DSF2) and citrus variegated chlorosis-DSF (likewise, Temecula1) and most importantly, that these compounds of the DSF (X. fastidiosa DSF) family are associated with OMV-enriched fractions. Altogether, our findings widen the potential functions of X. fastidiosa OMVs in intercellular signaling and host-pathogen interactions.

Changes in cardiovascular responses to chemoreflex activation of rats recovered from protein restriction are not related to AT1 receptors.

NEW FINDINGS: What is the central question of this study? In this study, we sought to investigate whether cardiovascular responses to peripheral chemoreflex activation of rats recovered from protein restriction are related to activation of AT1 receptors. What is the main finding and its importance? This study highlights the fact that angiotensinergic mechanisms activated by AT1 receptors do not support increased responses to peripheral chemoreflex activation by KCN in rats recovered from protein restriction. Also, we found that protein restriction led to increased resting ventilation in adult rats, even after recovery. The effects of a low-protein diet followed by recovery on cardiorespiratory responses to peripheral chemoreflex activation were tested before and after systemic angiotensin II type 1 (AT1 ) receptor antagonism. Male Fischer rats were divided into control and recovered (R-PR) groups after weaning. The R-PR rats were fed a low-protein (8%) diet for 35 days and recovered with a normal protein (20%) diet for 70 days. Control rats received a normal protein diet for 105 days (CG105 ). After cannulation surgery, mean arterial pressure, heart rate, respiratory frequency, tidal volume and minute ventilation were acquired using a digital recording system in freely moving rats. The role of angintensin II was evaluated by systemic antagonism of AT1 receptors with losartan (20 mg kg-1 i.v.). The peripheral chemoreflex was elicited by increasing doses of KCN (20-160 µg kg min-1 , i.v.). At baseline, R-PR rats presented increased heart rate and minute ventilation (372 ± 34 beats min-1 and 1.274 ± 377 ml kg-1  min-1 ) compared with CG105 animals (332 ± 22 beats min-1 and 856 ± 112 ml kg-1  min-1 ). Mean arterial pressure was not different between the groups. Pressor and bradycardic responses evoked by KCN (60 µg kg-1 ) were increased in R-PR (+45 ± 13 mmHg and -77 ± 47 beats min-1 ) compared with CG105 rats (+25 ± 17 mmHg and -27 ± 28 beats min-1 ), but no difference was found in the tachypnoeic response. These differences were preserved after losartan. The data suggest that angiotensin II acting on AT1 receptors may not be associated with the increased heart rate, increased minute ventilation and acute cardiovascular responses to peripheral chemoreflex activation in rats that underwent postweaning protein restriction followed by recovery.

Inhibition of cyclin-dependent kinase CDK1 by oxindolimine ligands and corresponding copper and zinc complexes.

Oxindolimine-copper(II) and zinc(II) complexes that previously have shown to induce apoptosis, with DNA and mitochondria as main targets, exhibit here significant inhibition of kinase CDK1/cyclin B protein. Copper species are more active than the corresponding zinc, and the free ligand shows to be less active, indicating a major influence of coordination in the process, and a further modulation by the coordinated ligand. Molecular docking and classical molecular dynamics provide a better understanding of the effectiveness and kinase inhibition mechanism by these compounds, showing that the metal complex provides a stronger interaction than the free ligand with the ATP-binding site. The metal ion introduces charge in the oxindole species, giving it a more rigid conformation that then becomes more effective in its interactions with the protein active site. Analogous experiments resulted in no significant effect regarding phosphatase inhibition. These results can explain the cytotoxicity of these metal complexes towards different tumor cells, in addition to its capability of binding to DNA, and decreasing membrane potential of mitochondria.

An engineered innate immune defense protects grapevines from Pierce disease.

We postulated that a synergistic combination of two innate immune functions, pathogen surface recognition and lysis, in a protein chimera would lead to a robust class of engineered antimicrobial therapeutics for protection against pathogens. In support of our hypothesis, we have engineered such a chimera to protect against the gram-negative Xylella fastidiosa (Xf), which causes diseases in multiple plants of economic importance. Here we report the design and delivery of this chimera to target the Xf subspecies fastidiosa (Xff), which causes Pierce disease in grapevines and poses a great threat to the wine-growing regions of California. One domain of this chimera is an elastase that recognizes and cleaves MopB, a conserved outer membrane protein of Xff. The second domain is a lytic peptide, cecropin B, which targets conserved lipid moieties and creates pores in the Xff outer membrane. A flexible linker joins the recognition and lysis domains, thereby ensuring correct folding of the individual domains and synergistic combination of their functions. The chimera transgene is fused with an amino-terminal signal sequence to facilitate delivery of the chimera to the plant xylem, the site of Xff colonization. We demonstrate that the protein chimera expressed in the xylem is able to directly target Xff, suppress its growth, and significantly decrease the leaf scorching and xylem clogging commonly associated with Pierce disease in grapevines. We believe that similar strategies involving protein chimeras can be developed to protect against many diseases caused by human and plant pathogens.

Effectiveness of a course on family health in the knowledge of doctors of the Mais Médicos program.

OBJECTIVE: The aim of this study was to analyze the effectiveness of the distance education course in family health in the knowledge of physicians from the Mais Médicos program. METHOD: This is a quantitative, quasi-experimental study, without a pretest and posttest control group, carried out from August 2019 to September 2021. In all modules, physicians responded to a pretest and posttest to verify their knowledge of the subject. RESULTS: There was a statistically significant difference in all modules with higher average scores in the posttests; the modules with the greatest emphasis are child health care: growth and development; approach to cancer in primary health care; and family health strategy and territorialization. CONCLUSION: The effectiveness of the distance education course was verified, as evidenced by the significant improvement of knowledge in all the modules studied.

ASIA syndrome: Adverse reaction or autoimmunity?

Introduction: Adjuvant-Induced Autoimmune / Auto-inflammatory Syndrome (ASIA) is an immune-mediated condition by the exposure of material previously considered inert, such as silicone, aluminum salts, mineral oils, hyaluronic acid and metallic implants. In addition to a genetic component, there is a risk of development of an undifferentiated connective tissue disease, which varies clinically and laboratorially depending on the adjuvant material used. Patients and methods: This paper addresses two cases reported, in caucasian subjects, born and residents in Madeira Island, Portugal. In this article are described two different histological patterns occurring in ASIA patients, due to mammoplasty with silicone. Conclusion: Although ASIA does not meet the diagnostic requirements for connective tissue disease, there is a close relationship with the development of autoimmune conditions. These cases aim to alert the medical community to the existence of this entity, encourage the notification of situations arising from exposure to adjuvants and investigate the presence of a genetic predisposition and a suggestive histological pattern in excisional biopsies of satellite adenomegalies.

Poor Agreement between Responses to the International Physical Activity Questionnaire and Objective ActiGraph® Data among Persons with Major Depressive or Bipolar Disorders.

The purpose of this research was to investigate the degree of agreement between data from the International Physical Activity Questionnaire-Short Form (IPAQ) and accelerometer (ActiGraph®) readings for physical activity (PA), classified as moderate, vigorous, and moderate-vigorous PA, and sedentary behavior (SB) in participants with major depressive or bipolar disorder. Following a cross-sectional observational design (n = 30), participants used an accelerometer for 4 to 7 days (minimum of 10 h per day) and answered the IPAQ (for the same period as accelerometer use). Our results suggest significant differences (p < 0.05) when comparing the ActiGraph® and IPAQ data: for moderate PA, 155 min vs. 25 min per week; for moderate-vigorous PA, 157 min vs. 50 min per week; and for SB, 8 h vs. 3 h per day. Spearman's correlation coefficients (ActiGraph® and IPAQ) were low for moderate PA, vigorous PA, and moderate-vigorous PA (rho = 0.03 to 0.13). The Bland-Altman plot showed a bias of -75 min for moderate PA, 9 min for vigorous PA, -66 min for moderate-vigorous PA, and -5 h for SB. Considering the differences observed and the objectivity of the ActiGraph® measurements, whenever possible, we recommend ActiGraph® measurements of PA and SB for these clinical groups.

Seasonal dynamics of Amblyomma sculptum: a review.

BACKGROUND: Amblyomma sculptum is a hard tick that is associated with domestic animals and the transmission of Brazilian spotted fever. This association has motivated several field studies on this ixodid tick within its distribution area in South America. Thorough knowledge of the seasonal dynamics of A. sculptum in different ecological scenarios is required in order to better understand the biological characteristics of this tick and develop techniques for the control and prevention of diseases transmitted by this vector. In this article, we systematically review the seasonal dynamics of A. sculptum and tick collection methodology. METHODS: A systematic search of the Scopus, Web of Science, PubMed and Scielo databases was carried out for articles (including dissertations and theses) on the population dynamics of A. sculptum. The inclusion criterion was the report of seasonal dynamic studies on A. sculptum through surveys carried out for at least 1 year with, as methodology, tick collection in the environment and/or tick count/collection on A. sculptum primary hosts (horses or capybaras). Studies carried out before the reclassification of Amblyomma cajennense sensu lato in 2014, which referred to Amblyomma cajennense in areas where it is currently known that only A. sculptum occurs, were also included. Articles meeting the inclusion criterion, but not available in online databases, were also added based on the authors' experience on the subject. Sixteen articles and one thesis were selected for inclusion in this systematic review. RESULTS: Most of the studies were carried out in the southeastern region of Brazil, with a few also carried out in the northeast, center-west and south of Brazil and northwest of Argentina. Five techniques/methods were applied across these studies: CO2 traps, dragging, flagging, visual searches and tick counting on animals, used alone or in combination. CONCLUSION: Seasonal dynamics of A. sculptum was found to be similar in almost all of the areas studied, with larvae predominating during the autumn, nymphs in the winter and adults in the spring and summer.

The streptozotocin-induced rat model of diabetes mellitus evidences significant reduction of myosin-Va expression in the brain.

Diabetes mellitus is a disease characterized by increased glucose levels in the blood. Hyperglycemia causes damage to the brain tissue, and induces significant changes in synaptic transmission. In this investigation, we have found a significant alteration in the expression of the molecular motor involved in the synaptic vesicles transport, myosin-Va, and its distribution in rat brains of streptozotocin-induced diabetes model. Brains were removed after 20 days, homogenized and analysed by Western blotting, qRT-PCR and immunohistochemistry. Myosin-Va presented significantly lower levels of both mRNA and protein in diabetic than those observed in non-diabetic animals. Moreover, neuronal and glial cells of the occipital and frontal cortex exhibited decreased myosin-Va immunostaining in diabetic rat brains. In conclusion, diabetic rat brains displayed altered expression and distribution of myosin-Va, and these finding may contribute to the basic understanding about this myosin role in brain function related to diabetes.

Heart Dissemination: A Clinical Case of Melanoma.

Introduction. Primitive malignant heart tumours are rare, specific cases. The presence of cardiac metastases, often in the pericardium, besides indicating disseminated oncological disease, represents a diagnostic challenge since they tend to be asymptomatic. Malignant cutaneous melanoma (MCM) is the neoplasm that most often affects the heart. Patients and Methods. The authors describe a case report of a 59-year-old female patient with a history of non-insulin-treated diabetes mellitus, arterial hypertension, dyslipidemia, and remitting cutaneous malignant melanoma who underwent skin excision, lymphadenectomy, and adjuvant chemotherapy in 1996. In April 2014, she resorted to emergency service due to epigastric pain and progressive tiredness. Due to the persistence of the complaints, abdominal ultrasound was performed, which showed a large pericardial effusion, corroborated later by teleradiography and echocardiography. The patient underwent pericardiocentesis, which isolated neoplastic cells. A computed tomography study of the chest, abdomen, and pelvis revealed bilateral and pericardial pleural effusion, as well as alterations suggestive of pericardial and pulmonary metastasis. Later, fine-needle aspiration puncture of the left posterior cervical nodule confirmed histologically malignant melanoma metastasis. Discussion. Given the natural history of melanoma that when metastasized has an overall survival of 15-20% for 5 years, its metastatic spread may occur several years after its surgical excision. Thus, patients with a history of melanoma and heart failure who develop new cardiac symptoms of unknown aetiology should undergo imaging studies such as echocardiography, computed tomography, and magnetic resonance imaging.

Rhipicephalus microplus seasonal dynamic in a Cerrado biome, Brazil: An update data considering the global warming.

The present study evaluated over two years the seasonal dynamics of Rhipicephalus microplus in a Cerrado biome of midwestern Brazil (Goiânia, Goiás) and correlated the current climatic conditions (environmental temperature, insolation, rainfall, relative humitidy and saturation deficit of the atmosphere) of this site with 30 years ago. In addition, the data collected in the present research were compared with climatic conditions data and R. microplus population dynamics conducted by our group in other regions (Formiga, Minas Gerais and Jaboticabal, São Paulo) within the same biome. For the parasitic phase dynamics, R. microplus females (4.5-8.0 mm) counts were performed on tick natural infested cows kept in Panicum maximum paddocks. To verify the larvae dynamics on pasture the flannel dragg technique on natural infested pasture was performed, and the height of the grass was measured. Five peaks of engorged R. microplus females on animals and larvae infestations on pastures were observed. Being three and two peaks during the rainy and dry season of the year, respectively. Insolation (r = 0.8758; P = 0.00009; R²â€¯= 0.7670), rainfall (r = -0.8572; P = 0.0002; R²â€¯= 0.7348), maximum environmental temperature in summer (r = 0.9999; P < 0.0087; R²â€¯= 0.9988) and the saturation deficit of the atmosphere in autumn (r = -0.9789; P = 0.0211; R²â€¯= 0.9582) influenced the seasonal dynamics of R. microplus larvae on pastures. While the forage height did not influence the number of larvae found on pasture (r = 0.1545; P = 0.7682; R²â€¯= 0.0239). The comparison between the climatic data of the last 30 years with the current climatological data (2012 to 2019) in the state of Goiás, and the comparison with R. microplus population dynamics from other two locations in the same biome indicated that the increase of the environmental temperature due to the global warming possibly is a determining factor which increase the number of one or up two tick annual peaks. In addition, this climatic variable was responsible for increase the population density of ticks on pastures and animals observed in July/winter of the present study, in comparison to other regions with the same biome, as discussed in this work.

The Fossil Birds of Peter Lund.

The Danish naturalist Peter Wilhelm Lund (1801-1880), regarded as the father of Brazilian palaeontology and archaeology, is known mainly for his work with fossil mammals of Quaternary age from the limestone caves of the Lagoa Santa region in the state of Minas Gerais, southeastern Brazil. However, during one decade of fieldwork (1835-1844), he also collected a large number of remains of other animal groups from these caves. Birds were well represented and, following assessment by the Danish ornithologist Oluf Winge (1855-1889), most of the specimens collected by Lund belong to species still living in the area. Here we present an overview of the bird remains (fossil and recent), found by Lund and others in the region, we update their taxonomic attributions, and comment on the history of the material, making information previously published only in Danish available in English.

Acute Pyelonephritis Associated with Ruptured Abdominal Aortic Aneurysm: An Unusual Presentation.

We describe a rare presentation of acute pyelonephritis associated with a ruptured abdominal aortic aneurysm. A 68-year-old female presented to the emergency department with a 3 day history of cystitis. General examination revealed the acute onset of pain in the left flank accompanied by fever and chills. Blood tests revealed leucocytosis 25,400×109/L and C-reactive protein 495 mg/L (<6.1), while urinary sediment analysis revealed many leucocytes and gram-negative bacteria. The patient was admitted with acute pyelonephritis. On the third day of admission, the urine culture isolated Escherichia coli sensitive to the antibiotic prescribed; however, the patient clinically deteriorated. A computed tomography scan revealed a ruptured abdominal aortic aneurysm involving the left renal artery. The patient underwent an exploratory laparotomy but uncontrollable haemorrhage led to a fatal outcome. This case highlights a rare case of acute pyelonephritis associated with a ruptured abdominal aortic aneurysm. A computed tomography scan or abdominal ultrasound should be considered whenever a patient has acute pyelonephritis with a C-reactive protein >400 mg/L in order to exclude complications and other potentially fatal pathologies. LEARNING POINTS: Acute pyelonephritis can lead to a ruptured abdominal aortic aneurysm.There should be a high index of suspicion for other concomitant acute pathologies in patients with pyelonephritis and a C-reactive protein >400 mg/L.A low threshold for abdominal imaging, either a computed tomography scan or abdominal ultrasound, may allow for the diagnosis of pathologies with a high mortality rate, such as a ruptured abdominal aortic aneurysm, at an early stage and thus result in better prognosis.

Acute Iatrogenic Agranulocytosis: A Rare and Dire Case of an Adverse Drug Reaction to Be Aware.

BACKGROUND: Iatrogenic agranulocytosis (IA), by nonchemotherapeutic drugs, is a rare adverse event, resulting in a neutrophil count under 0.5 × 109 cells/L with fever or other suggestive signs of infection. METHODS: This paper discusses the possible mechanisms responsible for agranulocytosis induced by nonchemotherapeutic drugs. It also describes three cases as well as potential ways to handle such iatrogenic situations. CONCLUSION: Neutropenia under 0.1 × 109 cells/L predispose patients to potentially fatal infections. Empiric broad-spectrum antibiotic and hematopoietic growth factors may be helpful in shortening hospitalization and prevent further infectious complications. Not all drugs associated with IA require frequent hematological monitoring, except medications such as clozapine, ticlopidine, and antithyroids.

Ants (Hymenoptera: Formicidae) as Potential Mechanical Vectors of Pathogenic Bacteria in a Public Hospital in the Eastern Amazon, Brazil.

Studies related to ants found in hospital environments have aroused interest in their role as mechanical vectors of pathogenic microorganisms. The objective of the current research was to determine the species composition and bacterial contamination of ant species found in a public hospital in the eastern Amazonian region. Ants were captured using bait containing honey and sterilized sardines in 15 locations within the Macapá Emergency Hospital, Amapá. Ants were identified morphologically using specific keys. Bacteria were first inoculed in a Brain Heart Infusion broth and then plated on 5% Agar with blood or MacConkey media. Bacterial species were identified through biochemical procedures. In total, 9,687 ants were collected, with 69.8% from the dry season and 30.2% from the rainy season. Nine species of ants were identified belonging to three subfamilies: the Monomorium pharaonis (Linnaeus 1758) being the most common, comprising 39.2% of the total specimens. Only one ant species was found in each bait, facilitating microbiological analyses. In total, 92 bacteria isolates were identified comprising 12 species. Pseudomonas aeruginosa Schroeter 1872 (Pseudomonadales: Pseudomonadaceae) was pathogenic bacteria, most frequently isolated, comprising 10.9% of the positive samples. The most contaminated ant in the study was M. pharaonis with 38.3%. It was the dominant ant species in this hospital environment. Its wide prevalence, forage day and night of this vector in hospital facilitated bacterial contamination. The presence of bacteria on ants may be associated with the dissemination of pathogens which cause hospital infections, making pest control a necessity in these institutions.

Immunoreactivity of proteins within 30-40 kDa range during the acute and the recovery phases in rats experimentally infected with Strongyloides venezuelensis.

In experimental infection with Strongyloides venezuelensis, the acute and recovery phases can be distinguished, unlike human infections caused by Strongyloides stercoralis. The objective of this study was to evaluate the production of anti-Strongyloides IgG antibodies and the recognition of immunogenic protein bands during the acute and the recovery phases in rats experimentally infected with S. venezuelensis. Rats were infected subcutaneously with 400 or 4,000 S. venezuelensis infective larvae. The acute phase was characterized by elimination of a large number of eggs in the faeces on days 6-14 post infection; the recovery phase was characterized by the resolution of the infection between days 30 and 35 post infection. Differences in IgG levels were observed in the acute and the recovery phases. Different antigenic fractions were recognized in both phases of infection. It is concluded that proteins within the 30-40 kDa range are immunoreactive markers for both the acute and the recovery phases in rats experimentally infected with S. venezuelensis, particularly using membrane antigen.