Search

Abstract Background Longitudinal records of automatically-recorded vaginal temperature (TV) could be a key source of data for deriving novel indicators of climatic resilience (CR) for breeding more resilient pigs, especially during lactation when sows are at an increased risk of suffering from heat stress (HS). Therefore, we derived 15 CR indicators based on the variability in TV in lactating sows and estimated their genetic parameters. We also investigated their genetic relationship with sows’ key reproductive traits. Results The heritability estimates of the CR traits ranged from 0.000 ± 0.000 for slope for decreased rate of TV (SlopeDe) to 0.291 ± 0.047 for sum of TV values below the HS threshold (HSUB). Moderate to high genetic correlations (from 0.508 ± 0.056 to 0.998 ± 0.137) and Spearman rank correlations (from 0.431 to 1.000) between genomic estimated breeding values (GEBV) were observed for five CR indicators, i.e. HS duration (HSD), the normalized median multiplied by normalized variance (Nor_medvar), the highest TV value of each measurement day for each individual (MaxTv), and the sum of the TV values above (HSUA) and below (HSUB) the HS threshold. These five CR indicators were lowly to moderately genetically correlated with shoulder skin surface temperature (from 0.139 ± 0.008 to 0.478 ± 0.048) and respiration rate (from 0.079 ± 0.011 to 0.502 ± 0.098). The genetic correlations between these five selected CR indicators and sow reproductive performance traits ranged from − 0.733 to − 0.175 for total number of piglets born alive, from − 0.733 to − 0.175 for total number of piglets born, and from − 0.434 to − 0.169 for number of pigs weaned. The individuals with the highest GEBV (most climate-sensitive) had higher mean skin surface temperature, respiration rate (RR), panting score (PS), and hair density, but had lower mean body condition scores compared to those with the lowest GEBV (most climate-resilient). Conclusions Most of the CR indicators evaluated are heritable with substantial additive genetic variance. Five of them, i.e. HSD, MaxTv, HSUA, HSUB, and Nor_medvar share similar underlying genetic mechanisms. In addition, individuals with higher CR indicators are more likely to exhibit better HS-related physiological responses, higher body condition scores, and improved reproductive performance under hot conditions. These findings highlight the potential benefits of genetically selecting more heat-tolerant individuals based on CR indicators.

Climate change poses a growing threat to the livestock industry, impacting animal productivity, animal welfare, and farm management practices. Thus, enhancing livestock climatic resilience (CR) is becoming a key priority in various breeding programs. CR can be defined as the ability of an animal to be minimally affected or rapidly return to euthermia under thermally stressful conditions. The primary study objectives were to perform genome-wide association studies for 12 CR indicators derived from variability in longitudinal vaginal temperature in lactating sows under heat stress conditions. A total of 31 single nucleotide polymorphisms (SNPs) located on nine chromosomes were considered as significantly associated with nine CR indicators based on different thresholds. Among them, only two SNPs were simultaneously identified for different CR indicators, SSC6:16,449,770 bp and SSC7:39,254,889 bp. These results highlighted the polygenic nature of CR indicators with small effects distributed across different chromosomes. Furthermore, we identified 434 positional genes associated with CR. Key candidate genes include SLC3A2, STX5, POLR2G, and GANAB, which were previously related to heat stress responses, protein folding, and cholesterol metabolism. Furthermore, the enriched KEGG pathways and Gene Ontology (GO) terms associated with these candidate genes are linked to stress responses, immune and inflammatory responses, neural system, and DNA damage and repair. The most enriched quantitative trait loci are related to “Meat and Carcass”, followed by “Production”, “Reproduction”, “Health”, and “Exterior (conformation and appearance)” traits. Multiple genomic regions were identified associated with different CR indicators, which reveals that CR is a highly polygenic trait with small effect sizes distributed across the genome. Many heat tolerance or HS related genes in our study, such as HSP90AB1, DMGDH, and HOMER1, have been identified. The complexity of CR encompasses a range of adaptive responses, from behavioral to cellular. These results highlight the possibility of selecting more heat-tolerant individuals based on the identified SNP for CR indicators.

Abstract Background Junipers (Juniperus spp.) are woody native, invasive plants that have caused encroachment problems in the U.S. western rangelands, decreasing forage productivity and biodiversity. A potential solution to this issue is using goats in targeted grazing programs. However, junipers, which grow in dry and harsh environmental conditions, use chemical defense mechanisms to deter herbivores. Therefore, genetically selecting goats for increased juniper consumption is of great interest for regenerative rangeland management. In this context, the primary objectives of this study were to: 1) estimate variance components and genetic parameters for predicted juniper consumption in divergently selected Angora (ANG) and composite Boer x Spanish (BS) goat populations grazing on Western U.S. rangelands; and 2) to identify genomic regions, candidate genes, and biological pathways associated with juniper consumption in these goat populations. Results The average juniper consumption was 22.4% (± 18.7%) and 7.01% (± 12.1%) in the BS and ANG populations, respectively. The heritability estimates (realized heritability within parenthesis) for juniper consumption were 0.43 ± 0.02 (0.34 ± 0.06) and 0.19 ± 0.03 (0.13 ± 0.03) in BS and ANG, respectively, indicating that juniper consumption can be increased through genetic selection. The repeatability values of predicted juniper consumption were 0.45 for BS and 0.28 for ANG. A total of 571 significant SNP located within or close to 231 genes in BS, and 116 SNP related to 183 genes in ANG were identified based on the genome-wide association analyses. These genes are primarily associated with biological pathways and gene ontology terms related to olfactory receptors, intestinal absorption, and immunity response. Conclusions These findings suggest that juniper consumption is a heritable trait of polygenic inheritance influenced by multiple genes of small effects. The genetic parameters calculated indicate that juniper consumption can be genetically improved in both goat populations.

Phytochemical study of Psychotria schlechtendaliana (Rubiaceae) aerial parts resulted in the isolation of alkaloids 4 N oxide harmane (1) and strictosidinic acid (2), and the terpenoids sitosterol, estigmasterol, α-amyrin, β-amyrin and betulinic acid. The crude extract (CE), its fractions (hexane FH, chloroform FC, ethyl acetate FEA, hydromethanolic FHM, alkaloidal chloroform FCOH, alkaloidal aqueous FAq) and majority alkaloid (1) were investigated for their antiproliferative potential against nine human tumor cells lines and one non-tumoral human cell line (HaCat). CE, FH and FEA fractions exhibited strong growth inhibition for ovary cells (OVCAR-3, GI50 = 5.89; 1.36 and 6.59 μg mL-1, respectively) and FC, FH and FAq fractions showed potent activity on the growth of leukemia cell lines (K562, GI50 = 1.92; 7.23 and 8.81 μg mL-1, respectively). Compound 1 exhibited selective antiproliferative activity to breast cancer (MCF-7, GI50 = 32.7 μg mL-1) and was non-toxic to HaCat cells. To evaluate the anti-inflammatory effect, models of ear edema induced by croton oil and the enzyme myeloperoxidase (MPO) were used. FH and FC fractions exhibited anti-inflammatory effect and reduce ear edema compared to the control group. These fractions showed results superior to those exhibited by indomethacin (75.1%), FH (97.5%) and FC (95.5%) fractions.

This work presents the development of a low-cost spin coater for thin film deposition as an alternative to commercial equipment that have high acquisition cost. The proposed spin coater uses a brushless motor taken from an unused hard disk, which is activated through the association of an electronic speed controller (ESC) and an Arduino microcontroller. During deposition, the rotating substrate is attached with a vacuum clamping system. For the control, the system uses a Hall effect sensor to read the engine speed. The rotation readings performed by the equipment sensor were validated with a tachometer. Finally, TiO2 films were deposited on glass substrates with ITO (Indium Tin Oxide) and characterized by UV-Vis spectroscopy to obtain the transmittance of the films at different rotation speeds.

Abstract Background Spinal manipulation has been shown to affect muscle activity, posture, and pain. To date, no studies have examined the effect of manipulation on biomechanical factors during sitting. Therefore, the purpose of this study was to investigate the immediate effect of lumbar spinal manipulation on trunk muscle activation, spine posture and movements, and perceived ratings of transient pain in asymptomatic adults during prolonged office sitting. Methods Twenty healthy adults were recruited for a single laboratory session that included a standardized office sitting/data entry protocol (120 min total, 3 blocks of 40 min). Data were collected between July and August 2012. The first block (baseline) was immediately followed by two experimental blocks. Prior to the start of each experimental block, participants were transferred to a therapy plinth and placed side lying (right side down), and a random presentation of either a control or high velocity low amplitude thrust directed at L4/L5 was delivered. Continuous measures of muscle activity, spine posture, and spine movements were recorded throughout the sitting trials. Perceived transient pain was measured by visual analogue scale at 10-min intervals (including immediately before and after the randomized maneuvers). Results There were no significant differences in spine or pelvic posture or perceived back pain following either the manipulation or control maneuvers. Significantly reduced muscle activity and increased shifts of the lumbar spine angle were identified in the block following manipulation compared to both baseline and post control blocks. Conclusions Spinal manipulation does not appear to have an immediate impact on spine or pelvic posture in healthy adults but does appear to reduce muscle activity and increase spine movement during sitting. Future work should replicate this study with a larger population in a field setting. It may be worthwhile to explore the implication of reduced muscle activation and increased spine movements during prolonged sitting for office workers that receive manipulations or mobilizations during their workday.

Laptop use appears to contribute to poor working postures and neck pain among university students. Postural braces have the potential to improve upper back/neck posture and therefore might have a role as an ergonomic aid for this population. Therefore, the purpose of this study was to assess the short-term effects of scapular bracing on pain, fatigue, cervicothoracic posture, and the activity of the neck and upper-back muscles in healthy college students. A randomized controlled crossover trial was conducted to evaluate the self-reported pain and fatigue, the amplitude and median frequency of surface electromyography in neck extensors, upper trapezius, and lower trapezius, as well as the neck and shoulder sagittal alignment (measured by inertial sensors and digital photographs) during a 30-min typing task in a sample of young, healthy university students with or without a scapular brace. The brace condition resulted in significantly smaller levels of bilateral trapezius muscle activity (p < 0.01). Rounded shoulder posture was slightly better in the brace condition, but these differences were not significant (p > 0.05). There were no significant immediate differences in pain or fatigue scores, neck alignment, or the electromyographic activity of the other muscles tested between brace and non-brace conditions (all p > 0.05). However, bracing appears to immediately reduce the electromyographic activity of the lower trapezius muscles (p < 0.05). These findings shed some light on the possible advantages of scapular bracing for enhancing laptop ergonomics in this group of individuals. Future studies are warranted to evaluate the effects of different types of braces, the importance of matching the brace to the user, and the short- and long-term effects of brace use on computer posture and muscle activity.

Abstract The pool of β-Amyloid (Aβ) length variants detected in preclinical and clinical Alzheimer disease (AD) samples suggests a diversity of roles for Aβ peptides. We examined how a naturally occurring variant, e.g. Aβ(1–38), interacts with the AD-related variant, Aβ(1–42), and the predominant physiological variant, Aβ(1–40). Atomic force microscopy, Thioflavin T fluorescence, circular dichroism, dynamic light scattering, and surface plasmon resonance reveal that Aβ(1–38) interacts differently with Aβ(1–40) and Aβ(1–42) and, in general, Aβ(1–38) interferes with the conversion of Aβ(1–42) to a β-sheet-rich aggregate. Functionally, Aβ(1–38) reverses the negative impact of Aβ(1–42) on long-term potentiation in acute hippocampal slices and on membrane conductance in primary neurons, and mitigates an Aβ(1–42) phenotype in Caenorhabditis elegans. Aβ(1–38) also reverses any loss of MTT conversion induced by Aβ(1–40) and Aβ(1–42) in HT-22 hippocampal neurons and APOE ε4-positive human fibroblasts, although the combination of Aβ(1–38) and Aβ(1–42) inhibits MTT conversion in APOE ε4-negative fibroblasts. A greater ratio of soluble Aβ(1–42)/Aβ(1–38) [and Aβ(1–42)/Aβ(1–40)] in autopsied brain extracts correlates with an earlier age-at-death in males (but not females) with a diagnosis of AD. These results suggest that Aβ(1–38) is capable of physically counteracting, potentially in a sex-dependent manner, the neuropathological effects of the AD-relevant Aβ(1–42).

Fourteen phthalazine-triones bearing different substituents at C-4 position were synthesized through multicomponent reactions (MCR) by using phthalhydrazide, dimedone and diferent aldehydes as starting materials, p-sulfonic acid calix[4]arene as catalyst and ethyl lactate as solvent under microwave irradiation. Compounds 7–16 were obtained in excellent to moderate yields (94–51%) in only 10 min of reaction using this methodology. The antiproliferative activity against cancer cells was disclosed, for the first time, for synthesized compounds. The capacity of all compounds to inhibit cancer cells growth was dependent on the histological origin of cells. Compound 20 was active against more than one strain. Keywords: Catalysis, Green chemistry, Microwave assisted synthesis, Antiproliferative activity, p-Sulfonic acid calix[4]arene

The upregulation of endogenous antioxidants (i.e., preparation for oxidative stress, POS) is part of the biochemical responses underlying the adaptation of animals to adverse environments. Despite the phylogenetic diversity of animals in which POS has been described, most studies focus on animals under controlled laboratory conditions. To address this limitation, we have recently assessed the redox metabolism in the skeletal muscle of Proceratophrys cristiceps estivating under natural settings in the Caatinga. Here, we analyzed biochemical biomarkers in the muscle of another Caatinga species, Pleurodema diplolister, during the rainy (active) and dry (estivating frogs) seasons. We aimed to determine whether P. diplolister enhances its antioxidants during estivation under field conditions and to identify any effect of species on the biochemical responses of P. diplolister and P. cristiceps associated with estivation. To do so, we measured the activities of representative enzymes of intermediary metabolism and antioxidant systems, as well as glutathione and protein carbonyl levels, in the skeletal muscle of P. diplolister. Our findings revealed the suppression of oxidative metabolism and activation of antioxidant enzymes in estivating P. diplolister compared with active specimens. No changes in oxidative damage to proteins were observed and estivating P. diplolister had lower levels of disulfide glutathione (GSSG) and disulfide-to-total glutathione ratio (GSSG/tGSH) than those observed in active individuals. When data for P. diplolister and P. cristiceps were assembled and analyzed, significant effects of species were detected on the activities of metabolic enzymes (citrate synthase, isocitric dehydrogenase, malic enzyme, and creatine kinase) and antioxidant enzymes (catalase, glutathione peroxidase and glutathione transferase), as well as on GSSG/tGSH ratio. Such effects might underlie the physiological and behavioral differences between these two species that share the same microhabitat and survival strategy (i.e., to estivate) during the dry season. Despite some peculiarities, which reflect the physiological diversity of the mechanisms associated with estivation in the Brazilian Caatinga, both P. diplolister and P. cristiceps seem to balance the suppression of oxidative pathways, the maintenance of the capacity of oxygen-independent pathways, and the activation of endogenous antioxidants to preserve muscle function and be ready to resume activity whenever the unpredictable rainy period arrives.

ABSTRACT A total 120 piglets with an average live weight of 7.00 kg, weaned at 21 days, were used to evaluate the effect of neutral detergent fibre levels on the digestibility of nutrients and energy from the diets, productive performance, and the composition and rate of deposition of nutrients and energy in the bodies of piglets in the nursery phase. The animals were distributed according to a randomized-block design into five treatments, which consisted of neutral detergent fibre levels, with six replicates and four animals per plot. A quadratic effect was detected for the digestibility coefficients of nutrients and energy, feed intake and weight gain. The increase in fibre level promoted a linear increase in fat content in the carcass, blood, and body, whereas the energy in the carcass, organs, and body showed an inverse response. The results showed a quadratic effect on the nutrient deposition rate in the carcass, organs and body. In conclusion, the best digestibility of nutrients and energy from the diet is obtained with 10-11.5% neutral detergent fibre, as higher weight gain and greater protein deposition in the body are achieved at neutral detergent fibre levels of 10.6% and 10.3%, respectively.

A perovskita CaCu3Ti4O12 foi consolidada pela técnica se sinterização assistida por campo elétrico. Foi investigada a influência do tempo e da temperatura de sinterização na estrutura cristalina, na microestrutura e nas propriedades dielétricas da cerâmica policristalina. As amostras foram sinterizadas entre 750 e 930 °C, por tempos de 1 a 8 min. Os pós foram calcinados a 900 °C durante 18 h. As pastilhas foram caracterizadas por difração de raios X, microscopia eletrônica de varredura e por espectroscopia de impedância. O padrão da difração de raios X apresenta a estrutura do tipo perovskita e o parâmetro de rede calculado é de 7,40 Å. A densidade hidrostática aumenta com o aumento do tempo e da temperatura de sinterização. A observação das imagens do microscópio eletrônico de varredura revelam uma microestrutura heterogênea para todas as amostras. As perdas dielétricas são inferiores aos valores apresentados por outras técnicas de consolidação. A permissividade dielétrica é aproximadamente 10³ a 1 kHz. O aumento do tempo e da temperatura de sinterização torna as amostras friáveis.

An efficient and concise synthesis of nine populene D analogues was performed using an iodine-catalyzed Prins cyclization as the key transformation. The antiproliferative activity of these new pyrans against several cancer cell lines was then investigated. Among them, an isochromene with moderate activity (mean logGI50 = 0.91) was found. Additionally, compounds with selectivity toward the tumor cell lines NCI-ADR/RES, OVCAR-3, and HT29 were discovered.

The conductivity behaviour of the (Ce xY0.2-x)Sc0.6 Zr3.2O8-δ (0 < x < 0.2) system and composition Ce0.04Y0.02Sc0.67Zr3.27O 7.66 have been investigated as function of time using impedance spectroscopy. All samples were prepared by sol-gel and combustion process, sintered at 1500 °C for 12 h and the densities obtained were between 92 and 97%. The electrical measurements were performed at 600 °C. The conductivity values were fairly stable during the first 1800 h of the experiment but after this time the conductivity decreases. For some compositions of the system a semi-circle is detected through time, with capacitance values of an order of magnitude lower, 10-8 F/cm. This semi-circle becomes well defined with time. After the experiment, SEM pictures show that grain boundary is well defined and an increase of pore inside grains, in some cases the surface is damaged showing cracks and fissures indicating microstructure deterioration.O comportamento da condutividade do sistema (Ce xY0,2-x)Sc0,6Zr3,2O 8-δ (0 < x < 0,2) e da composição Ce0,04Y0,02Sc0,67Zr3,27O 7,66, foi investigado em função do tempo usando espectroscopia de impedância. Todas as amostras foram preparadas pelo processo de sol gel e combustão combinados, sinterizadas a 1500 ºC durante 12 h e as densidades obtidas estão entre 92 e 97%. Esta experiência foi executada a 600 °C. Os valores da condutividade apresentaram-se relativamente estáveis durante as primeiras 1800 h da experiência mas depois deste tempo de funcionamento a condutividade decresceu. Para algumas composições do sistema um semi-circulo apareceu ao longo do tempo, com valores de capacidade com ordem de grandeza 10-8 F/cm. Estes semi-círculos tornam-se melhor definidos com o tempo. Depois desta experiência as micrografias de microscopia eletrônica de varredura destas amostras mostram que a fronteira de grão é bem definida e que ocorreu um aumento de porosidade, e em algumas amostras a superfície ficou danificada mostrando fissuras e trincas na superfície indicando deterioração na microestrutura.

The in vitro schistosomicidal effects of the essential oil of Ageratum conyzoides L. (Ac-EO) against adult worms of Schistosoma mansoni is reported in this paper. Concerning this activity, Ac-EO was considered to be active, but less effective than the positive control (praziquantel, PZQ) in terms of separation of coupled pairs, mortality, decrease in motor activity, and tegumental alterations. However, Ac-EO caused an interesting dose-dependent reduction in the number of eggs of S. mansoni. Precocene I (74.30%) and (E)-caryophyllene (14.23%) were identified as the two major constituents of Ac-EO. These compounds were tested individually and were found to be much less effective than Ac-EO and PZQ. A mixture of the two major compounds in a ratio similar to that found in the Ac-EO was also less effective than Ac-EO, thus revealing that there are no synergistic effects between these components. These results suggest that the essential oil of A. conyzoides is very promising for the development of new schistosomicidal agents.

The goal of the study was to evaluate the ability of filamentous fungi to biotransform the pentacyclic triterpene lupeol. The microbial transformations were carried out in shake flasks in different media. Experiments were also run with control flasks. Samples of each culture were taken every 24 hours, extracted with ethyl acetate, and analyzed by GC-MS. The biotransformation of lupeol by Aspergillus ochraceus and Mucor rouxii afforded two compounds in each culture, which were detected in the cultures developed for more than seven days only in the Koch’s K1 medium. The obtained data demonstrated that A. ochraceus is a good biocatalyst to introduce double bonds in the lupeol structure, whereas M. rouxii exhibits ability to biocatalyze oxygen insertions in that pentacyclic triterpene. Mass spectrometry was demonstrated to be an efficient analytical method to select promising biocatalysts for the compound investigated in this study. The biotransformation processes were influenced by the culture medium and incubation period. The obtained results open the perspective of using A. ochraceus and M. rouxii in pentacyclic triterpene biotransformations.

Myrcia bella Cambess., Myrcia fallax (Rich.) DC. and Myrcia guianensis (Aubl.) DC. (Myrtaceae) are trees found in Brazilian Cerrado. They have been widely used in folk medicine for the treatment of gastrointestinal disorders, hemorrhagic and infectious diseases. Few reports have been found in the literature connecting their phenolic composition and biological activities. In this regard, we have profiled the main phenolic constituents of Myrcia spp. leaves extracts by ESI(−)Q-TOF-MS. The main constituents found were ellagic acid (M. bella), galloyl glucose isomers (M. guianensis) and hexahydroxydiphenic (HHDP) acid derivatives (M. fallax). In addition, quercetin and myricetin derivatives were also found in all Myrcia spp. extracts. The most promising antioxidant activity, measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, was found for M. fallax extracts (EC50 8.61 ± 0.22 µg·mL−1), being slightly less active than quercetin and gallic acid (EC50 2.96 ± 0.17 and 2.03 ± 0.02 µg·mL−1, respectively). For in vitro antiproliferative activity, M. guianensis showed good activity against leukemia (K562 TGI = 7.45 µg·mL−1). The best antimicrobial activity was observed for M. bella and M. fallax to Escherichia coli (300 and 250 µg·mL−1, respectively). In conclusion, the activities found are closely related to the phenolic composition of these plants.

Objetivou-se com este trabalho realizar o primeiro ciclo de seleção massal na população PM3 de melão. Foi usada a população PM3 de melão, obtida pelo Setor de Melhoramento Genético de Plantas do Centro de Ciências Agrárias da Universidade Federal de Alagoas (SMGP/CECA/UFAL). A colheita foi realizada aos 75 dias após a semeadura. Os frutos foram colhidos totalizaram 1188 frutos, os quais foram analisados a morfologia externa, objetivando a formação de classes fenotípicas em função dos caracteres qualitativos, culminando na obtenção de 40 classes fenotípicas. A classe fenotípica CF 17 foi selecionada por apresentar cor do fruto amarelo, ausência de costelas, ausência de rendilhamento, cor da polpa salmão e formato do fruto arredondado a ovalado. Em seguida foi feita uma seleção dos frutos de melão para os seguintes caracteres quantitativos dentro da classe fenotípica selecionada: peso do fruto acima de 740,0 gramas; diâmetro longitudinal acima de 11,0 cm; diâmetro transversal acima de 10,0 cm, espessura da polpa acima de 1,9 cm; espessura da casca acima de 0,2 cm; diâmetro da cavidade menor que 8,0 cm. A classe fenotípica CF 17 foi à única selecionada. First mass selection cycle in melon PM3 population (Cucumis melo L) Abstract: The objective of this work make the first mass selection cycle in melon PM3 population. It was used to melon PM3 population, obtained by the sector of improvement genetic of plants of center science land the Federal University of Alagoas (SMGP/CECA/UFAL). Plants were harvested at 75 days after sowing. The fruits were harvested totaled 1188 fruits, which were analyzed the external morphology, aiming at the formation of phenotypic classes on the basis of qualitative character, culminating in getting 40 phenotypic classes. Phenotypic class CF 17 has been selected for display color of yellow fruit, no ribs, no rendilhamento, color of salmon flesh and rounded to oval fruit shape. Then a selection of melon fruit was made to the following quantitative phenotypic characters within the selected class weight of the fruit above 740.0 grams; longitudinal diameter greater than 11.0 cm; transverse diameter greater than 10.0 cm, flesh thickness above 1.9 cm; shell thickness above 0.2 cm; cavity diameter smaller than 8.0 cm. Phenotypic class CF 17 was the selected one.

Immunoblot analysis was used to investigate antigenic differences among clinical isolates of Leishmania amazonensis and their role in the etiology of the diseases. Western blots of promastigote homogenates were analyzed with either monoclonal antibodies (MAbs) specific for the L. mexicana complex (M-4, M-6, M-9 and M-11) or polyclonal sera from L. amazonensis infected patients with the various forms of clinical disease. In the case of the MAbs, no significant variation was observed among the strains of L. amazonensis, isolated from cases of cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL), diffuse cutaneous leishmaniasis (DCL), visceral leishmaniasis (VL) or post kala-azar dermal leishmaniasis (PKDL), in either the relative morbility (Mr) or the quantitative amount (intensity) of the antigenic determinats. In the case of the sera of the infected patients, the patterns of antigenic reactivity of these strains revealed that, despite showing the presence of shared antigens, differences were observed between some of the antigenic components of the various isolates of L. amazonensis that were recognized by a single serum. Differences were also demonstrated between the antigenic determinants of a single isolate of L. amazonensis that were recognized by the different patient's sera. No apparent association was consistently found, however, between the Mr components identified in these isolates and clinical form of the disease or the geographical area of isolation. In addition, the spectrum of antigens recognized by the sera from patients with the same clinical form were not identical; although in some instances, similar Mr antigens were shared. These results indicate that isolates of L. amazonensis are not antigenically identical (homogeneous) and that the immune responses (antibodies) observed among infected patients are heterogeneous.