RESUMO
Molecular diagnostic tests have evolved very rapidly in the field of human health, especially with the arrival of the recent pandemic caused by the SARS-CoV-2 virus. However, the animal sector is constantly neglected, even though accurate detection by molecular tools could represent economic advantages by preventing the spread of viruses. In this regard, the swine industry is of great interest. The main viruses that affect the swine industry are described in this review, including African swine fever virus (ASFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine epidemic diarrhea virus (PEDV), and porcine circovirus (PCV), which have been effectively detected by different molecular tools in recent times. Here, we describe the rationale of molecular techniques such as multiplex PCR, isothermal methods (LAMP, NASBA, RPA, and PSR) and novel methods such as CRISPR-Cas and microfluidics platforms. Successful molecular diagnostic developments are presented by highlighting their most important findings. Finally, we describe the barriers that hinder the large-scale development of affordable, accessible, rapid, and easy-to-use molecular diagnostic tests. The evolution of diagnostic techniques is critical to prevent the spread of viruses and the development of viral reservoirs in the swine industry that impact the possible development of future pandemics and the world economy.
RESUMO
The feasibility of obtaining resistant starch type III (RS3) from malanga flour (Xanthosoma sagittifolium), as an unconventional source of starch, was evaluated using the hydrothermal treatment of autoclaving. The physicochemical characterization of RS3 made from malanga flour was carried out through the evaluation of the chemical composition, color attributes, and thermal properties. In addition, the contents of the total starch, available starch, resistant starch, and retrograded resistant starch were determined by in vitro enzymatic tests. A commercial corn starch sample was used to produce RS3 and utilized to compare all of the analyses. The results showed that native malanga flour behaved differently in most of the evaluations performed, compared to the commercial corn starch. These results could be explained by the presence of minor components that could interfere with the physicochemical and functional properties of the flour; however, the RS3 samples obtained from malanga flour and corn starch were similar in their thermal and morphological features, which may be related to their similarities in the content and molecular weight of amylose, in both of the samples. Furthermore, the yields for obtaining the autoclaved powders from corn starch and malanga flour were similar (≈89%), which showed that the malanga flour is an attractive raw material for obtaining RS3 with adequate yields, to be considered in the subsequent research.
Assuntos
Farinha , Amido Resistente , Xanthosoma/química , Zea mays/químicaRESUMO
High molecular weight chitosan (≈322 kDa) was obtained from chitin isolated from Brachystola magna (Girard) to produced biodegradable films. Their physicochemical, mechanical and water vapor permeability (WVP) properties were compared against commercial chitosan films with different molecular weights. Brachystola magna chitosan films (CFBM) exhibited similar physicochemical and mechanical characteristics to those of commercial chitosans. The CFBM films presented lower WVP values (10.01 × 10-11 g/m s Pa) than commercial chitosans films (from 16.06 × 10-11 to 64.30 × 10-11 g/m s Pa). Frankfurt-type sausages were covered with chitosan films and stored in refrigerated conditions (4 °C). Their quality attributes (color, weight loss, pH, moisture, texture and lipid oxidation) were evaluated at 0, 5, 10, 15 and 20 days. Sausages covered with CFMB films presented the lowest weight loss (from 1.24% to 2.38%). A higher increase in hardness (from 22.32 N to 30.63 N) was observed in sausages covered with CFMB films. Compared with other films and the control (uncovered sausages), CFMB films delay pH reduction. Moreover, this film presents the lower lipid oxidation level (0.10 malonaldehyde mg/sample kg). Thus, chitosan of B. magna could be a good alternative as packaging material for meat products with high-fat content.
Assuntos
Quitosana/química , Embalagem de Alimentos , Conservação de Alimentos , Gafanhotos/química , Produtos da Carne , Membranas Artificiais , AnimaisRESUMO
Bilateral ovariectomy is the best characterized and the most reported animal model of human menopause. Ovariectomized rodents develop insulin resistance (IR) and visceral obesity, the main risk factors in the pathophysiology of metabolic syndrome (MS). These alterations are a consequence of hypoestrogenic status, which produces an augment of visceral fat, high testosterone levels (hyperandrogenism), as well as inflammation, oxidative stress, and metabolic complications, such as dyslipidemia, hepatic steatosis, and endothelial dysfunction, among others. Clinical trials have reported that menopause per se increases the severity and incidence of MS, and causes the highest mortality due to cardiovascular disease in women. Despite all the evidence, there are no reports that clarify the influence of estrogenic deficiency as a cause of MS. In this review, we provide evidence that ovariectomized rodents can be used as a menopausal metabolic syndrome model for evaluating and discovering new, safe, and effective therapeutic approaches in the treatment of cardiometabolic complications associated to MS during menopause.
Assuntos
Doenças Cardiovasculares/metabolismo , Gordura Intra-Abdominal/patologia , Síndrome Metabólica/metabolismo , Animais , Doenças Cardiovasculares/patologia , Modelos Animais de Doenças , Feminino , Humanos , Resistência à Insulina , Gordura Intra-Abdominal/metabolismo , Menopausa , Síndrome Metabólica/patologia , Ovariectomia/métodos , Ovário/fisiologia , RoedoresRESUMO
The venereal diseases bovine trichomoniasis (BT) and bovine genital campylobacteriosis (BGC) cause economic losses in endemic areas like La Pampa province in Argentina, where beef cattle are usually managed extensively. The eradication of both diseases is a priority in Argentine. The aim of this case-control study was to identify shared and specific risk factors of both diseases from the data obtained from the Provincial Program for the Control and Eradication of BT and BGC in La Pampa (PCE). The study population included 5777 breeding beef herds tested for BT and BGC in 2013. The study comprised 3481 herds that were surveyed in situ by official PCE veterinarians, distributed as follows: 3159 negative herds (with no BT or BGC positive bulls), 121 BT case herds (with at least a BT positive bull), 170 BGC case herds (with at least a BGC positive bull) and 31 BT and BGC co-infected case herds (with at least a positive bull for each disease). Three multivariable analyses were performed in order to identify the risk factors using a logistic regression model. Results showed that the risk factors shared by both diseases were the number of bulls (OR for BT = 1.03, 95% CI: 1.02-1.04, p < 0.001; OR for BGC = 1.02, 95% CI: 1.01-1.03, p < 0.001; OR for BT and BGC co-infection = 1.02, 95% CI: 1.01-1.04, p = 0.003) and the presence in the previous year of each disease (OR for BT = 18.69, 95% CI: 11.82-29.57, p < 0.001; OR for BGC = 4.65, 95% CI: 3.18-6.81, p < 0.001; OR for BT and BGC co-infection = 39.18, 95% CI: 16.72-91.80, p < 0.001). Disease-specific risk factors were continuous breeding season for BT (OR = 1.59, 95% CI: 1.04-2.47, p = 0.034), and inadequate condition of the fences for BGC (OR = 1.51, 95% CI: 1.06-2.15, p = 0.022). An integrated approach to venereal disease management needs to consider the risk characteristics identified in this study. This could lead to reduce both diseases and improve the efficiency of BT and BGC control activities in La Pampa.
Assuntos
Infecções por Campylobacter/veterinária , Doenças dos Bovinos , Infecções Protozoárias em Animais/epidemiologia , Infecções Sexualmente Transmissíveis/veterinária , Animais , Argentina/epidemiologia , Infecções por Campylobacter/epidemiologia , Campylobacter fetus , Estudos de Casos e Controles , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Feminino , Modelos Logísticos , Masculino , Estudos Retrospectivos , Fatores de Risco , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/microbiologia , Infecções Sexualmente Transmissíveis/parasitologia , Inquéritos e Questionários , Tritrichomonas foetusRESUMO
We explore in detail the nontrivial and chaotic behavior of the traffic model proposed by Toledo et al. [Phys. Rev. E 70, 016107 (2004)] due to the richness of behavior present in the model, in spite of the fact that it is a minimalistic representation of basic city traffic dynamics. The chaotic behavior, previously shown for a given lower bound in acceleration/brake ratio, is examined more carefully and the region in parameter space for which we observe this nontrivial behavior is found. This parameter region may be related to the high sensitivity of traffic flow that eventually leads to traffic jams. Approximate scaling laws are proposed.
Assuntos
Dinâmica não Linear , Meios de Transporte , Algoritmos , Comportamento , Cidades , Simulação por Computador , Humanos , Modelos Estatísticos , Veículos Automotores , Tempo de ReaçãoRESUMO
Nos propusimos conocer si la hepatitis viral crónica afecta la concentración sérica de la eritropoyetina endógena en los pacientes con insuficiencia renal crónica terminal sometidos a tratamiento hemodialítico. Estudiamos a 40 pacientes pertenecientes a la Unidad de Hemodiálisis Fresenius Medical Care de Venezuela, con edades entre los 22 a 77 años, sin haber presentado sangramiento activo, ni haber recibido eritropoyetina humana recombinante ni transfusiones de sangre en los últimos tres meses. El análisis de eritropoyetina se efectuó por quimioluminiscencia. Los valores se expresaron en media aritmética ± DE, como sigue: Core: 8,8 ± 2,03 mU/mL; hepatitis B antígeno de superficie positivo y core positivo: 12,45 ± 1,85 mU/mL; hepatitis C: 15,33 ± 2,91 mU/mL; hepatitis B más hepatitis C: 12,55 ± 3,06m U/mL. El grupo control: 12 ± 2,47 mU/mL (no estadísticamente significativo). Concluimos que en los pacientes con insuficiencia renal crónica terminal en tratamiento hemodialítico crónico, la hepatitis crónica por VHB o VHC, no produce modificaciones de los niveles séricos de eritropoyetina endógena
Assuntos
Adulto , Masculino , Humanos , Feminino , Eritropoese , Hepatite B , Hepatite C , Hepatite Viral Humana , Nefrologia , Sorologia , VenezuelaRESUMO
Investigamos los valores de la eritropoyetina (EPO) endógena en pacientes con insuficiencia renal crónica terminal en tratamiento hemodialítico. Este estudio se llevó a cabo en 33 pacientes pertenecientes a la Unidad de Hemodiálisis Fresenius Medical Care de Venezuela, con edades compredidas entre los 22 a 77 años, 40 por ciento de raza caucásica, 22 por ciento de raza negra y 38 por ciento mestizos. Los criterios de inclusión fueron: no haber presentado en los últimos tres meses sangramiento activo, ni haber recibido EPO humana recombinante ni transfusiones de sangre en el mismo período de tiempo. Todos los pacientes recibieron tres sesiones de hemodiálisis por semana. Las muestras de sangre se obtuvieron antes de la primera y antes de la última sesión de hemodiálisis de la semana. El análisis de EPO se efectuó por quimioluminiscencia (Nichols Diagnostics Institute, USA). Los valores se expresaron en media aritmética ñ ES. Los valores de EPO endógena fueron de 10,43 ñ 1,35 mU/mL antes de la primera diálisis de la semana, y de 11,36 ñ 0,31 mU/mL antes de la última diálisis de la semana; los valores fueron menores a los descritos en la literatura para otros países. Los valores de EPO relacionados con la raza fueron 12,59 ñ 1,56 mU/mL para las caucásicos, 7,61 ñ 1,07 mU/mL para los negros y 11,09 ñ 1,62 mU/mL para los mestizos. No hubo diferencia en los valores de EPO en relación al día de la diálisis en que se tomó la muestra, ni en relación con la edad, el sexo y la patología de base, pero el tiempo en diálisis juega con 1 a 30 meses en diálisis con los pacientes que tienen de 1 a 60 meses en tratamiento
Assuntos
Humanos , Masculino , Feminino , Eritropoetina , Insuficiência Renal Crônica/terapia , Epidemiologia , Medicina , Urologia , VenezuelaRESUMO
The distribution of acetylcholinesterase histochemistry and choline-O-acetyltransferase immunohistochemistry in the basal forebrain was studied in newborn mice (P0) and until 60 days of postnatal life (P60). A weak acetylcholinesterase activity was found at P0 and P2 in the anterior and intermediate parts of the basal forebrain, and higher in the posterior region. The intensity of labeling, neuronal size and dendritic growth seems to increase progressively in all regions of basal forebrain from P4 to P10. The AChE+ cell count shows that in the anterior portion of the magnocellular basal nucleus the number of cells does not vary significantly from birth to the second month of postnatal life. However, in the intermediate and posterior portions of the nucleus the mean number of labeled cells increases significantly from birth to the end of the second week of postnatal life (P13). The choline-acetyltransferase immunoreactivity appears only detectable at the end of the first week (P6) as a slight immunoreaction, which increases progressively in intensity at P8, and at P10 seems to attain the same intensity of labeling found at P60. These results seem to indicate that the acetylcholinesterase could have a non-classic cholinergic role in the first stages of postnatal development, acting as a growth and cellular differentiation factor.
Assuntos
Acetilcolinesterase/análise , Colina O-Acetiltransferase/análise , Fibras Colinérgicas/enzimologia , Prosencéfalo/citologia , Prosencéfalo/crescimento & desenvolvimento , Animais , Anticorpos , Contagem de Células , Colina O-Acetiltransferase/imunologia , Histocitoquímica , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Vias Neurais , Prosencéfalo/enzimologiaRESUMO
BACKGROUND: The hydrolysis enzymes of the acetylcholine, acetylcholinesterase, and butyrylcholinesterase are involved in non-cholinergic functions such as proliferation processes and cellular adhesion. These enzymes have been found in several tumors other from brain tumors. METHODS: Thirty fresh brain tumor specimens were obtained from biopsies taken during neurosurgical procedures. The specimens were cut in two parts, one designated for routine histopathological control and the other for histochemical and growth studies. The formalin fixed specimens were serially cut at 10 microm in a freezing cryostat, mounted in gelatin-coated slides, and processed for sensitive histochemical detection of acetylcholinesterase and butyrylcholinesterase. The other specimens were processed for a HMEM cell growth culture. RESULTS: The results show the coexistence of acetylcholinesterase and butyrylcholinesterase in all tumors studied. Type II and III gliomas and oligodendrogliomas show moderate activity of both cholinesterases, whereas in type IV glioma and meningiomas the labeling of both cholinesterases was high. In the craniopharyngiomas a high acetylcholinesterase activity was observed and low level of butyrylcholinesterase labeling. The cell growth was high only in the cases in which butyrylcholinesterase activity was high, such as type IV glioma. In type II and III gliomas, oligodendroglioma, and craniopharyngioma the growth rate was slow. CONCLUSIONS: These results could indicate a possible relationship between the presence of butyrylcholinesterase and acetylcholinesterase in brain tumor tissue and cellular proliferation in tumorigenesis.
Assuntos
Acetilcolinesterase/metabolismo , Neoplasias Encefálicas/patologia , Butirilcolinesterase/metabolismo , Adesão Celular/fisiologia , Divisão Celular/fisiologia , Adolescente , Adulto , Craniofaringioma/patologia , Feminino , Glioma/patologia , Humanos , Masculino , Neoplasias Meníngeas/patologia , Meningioma/patologia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Oligodendroglioma/patologia , Neoplasias Hipofisárias/patologia , PrognósticoRESUMO
The malarial parasite Plasmodium vivax causes disease in humans, including chronic infections and recurrent relapses, but the course of infection is rarely fatal, unlike that caused by Plasmodium falciparum. To investigate differences in pathogenicity between P. vivax and P. falciparum, we have compared the subtelomeric domains in the DNA of these parasites. In P. falciparum, subtelomeric domains are conserved and contain ordered arrays of members of multigene families, such as var, rif and stevor, encoding virulence determinants of cytoadhesion and antigenic variation. Here we identify, through the analysis of a continuous 155,711-base-pair sequence of a P. vivax chromosome end, a multigene family called vir, which is specific to P. vivax. The vir genes are present at about 600-1,000 copies per haploid genome and encode proteins that are immunovariant in natural infections, indicating that they may have a functional role in establishing chronic infection through antigenic variation.
Assuntos
Genes de Protozoários , Plasmodium vivax/genética , Adulto , Animais , Anticorpos Antiprotozoários/imunologia , Cromossomos Artificiais de Levedura , DNA de Protozoário , Biblioteca Gênica , Variação Genética , Humanos , Malária Vivax/parasitologia , Família Multigênica , Plasmodium falciparum/genética , Plasmodium falciparum/patogenicidade , Plasmodium vivax/imunologia , Plasmodium vivax/patogenicidade , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Pseudogenes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , TelômeroRESUMO
The postnatal development of basal forebrain cholinergic projections to the medial prefrontal cortex in mice was analyzed by means of the double labeling track-tracing study. The tracer was injected into the medial prefrontal cortex of mice, on the day of birth (P0) to 60 days after birth. The total number of basal forebrain neurons increased from P4 to P8, and began to decrease until P13 (52.9% vs. the maximal average (P8)). After P13, the mean average remains stable up to P60. On the other hand, differential pattern of frontocortical projections of the anterior, intermediate, and posterior regions can be observed.
Assuntos
Fibras Colinérgicas/enzimologia , Córtex Pré-Frontal/citologia , Córtex Pré-Frontal/crescimento & desenvolvimento , Prosencéfalo/citologia , Prosencéfalo/crescimento & desenvolvimento , Acetilcolinesterase/análise , Animais , Animais Recém-Nascidos , Colina O-Acetiltransferase/análise , Camundongos , Camundongos Endogâmicos BALB C , Vias Neurais , Neurônios/enzimologia , Neurônios/ultraestrutura , Conjugado Aglutinina do Germe de Trigo-Peroxidase do Rábano SilvestreRESUMO
This article describes a case of massive mortality among horses which was probably due to intoxication by pyrrolizidine alkaloids from Heliotropium indicum. Over 4 years more than 75% of a population of about 110 horses on a farm in Costa Rica died after showing nervous neurological symptoms. Two clinical manifestations were encountered, an acute and a chronic one, both with a fatal outcome. Pathological findings in 2 horses coincided with those reported in the literature for intoxication by pyrrolizidine alkaloids and were not specific for VEE. However Venezuelan equine encephalitis (VEE) was the main differential diagnosis and could not completely be excluded because this disease was endemic in the region and VEE titres were found to be high. Taxonomic and toxicological investigations implicated Heliotropium indicum as the most probable principal cause of the intoxication.
Assuntos
Ração Animal/intoxicação , Doenças dos Cavalos/mortalidade , Alcaloides de Pirrolizidina/intoxicação , Animais , Costa Rica/epidemiologia , Diagnóstico Diferencial , Surtos de Doenças/veterinária , Doenças dos Cavalos/induzido quimicamente , Doenças dos Cavalos/virologia , CavalosRESUMO
OBJECTIVE: To determine the extension of the lesion implicated on the mechanism of the anal sphincter with endoanal ultrasound in patients with simple fistulae, managed with fistulotomy versus fistulectomy. SITE: Central Military Hospital. Colon and Rectum Service. DESIGN OF STUDY: A prospective, comparative, descriptive and longitudinal study was performed. METHODS: A total of 40 patients with anal simple fistula were studied from march 1997 to march 1998. They were divided in two randomized groups: group A (n = 20) patients treated with fistulectomy, and group B (n = 20) patients managed with fistulotomy. Endoanal ultrasound was practice at the time of the diagnosis and six weeks later to identify integrity of both internal and external anal sphincter, and to register them in separate form. RESULTS: There were no significant differences in sex and age distribution, nor in type of fistula. The average of internal anal sphincter lesion in inter-sphincteric fistulae treated with fistulotomy was 8.5 mm versus 9.08 with fistulectomy (p > 0.05). The average of internal and external anal sphincter lesion in trans-sphincteric fistulae managed with fistulotomy was 9.25 mm versus 11.38 with fistulectomy (p < 0.05). The global analysis showed that the average of the lesion in the sphincter, mechanism was larger in the fistulectomy versus fistulotomy (p < 0.05). CONCLUSION: The major muscular injury made to the sphincter mechanism is caused mainly by the fistulectomy in comparison with the conventional fistulotomy.
Assuntos
Canal Anal/fisiologia , Endossonografia , Fístula Retal/cirurgia , Adolescente , Adulto , Canal Anal/diagnóstico por imagem , Canal Anal/lesões , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fístula Retal/diagnóstico por imagem , Fatores de TempoRESUMO
The purpose of this case-control study was to determine the association between very-mild-to-moderate enamel fluorosis and exposure during early childhood to fluoridated water, mainly through ingestion of powdered milk. Analysis was performed on 136 residents of the optimally fluoridated community of San Felipe in the Chilean Fifth Region, who were categorised into one of three groups according to their age when water fluoridation was introduced in 1986: Group I was born after 1986; Group II was 16-24 months old in 1986; and Group III was >24 months of age. The case and control subjects were selected on the basis of a clinical examination given in July 1996. Dean's scoring system was used to determine fluorosis status. Risk factor exposure was ascertained by a questionnaire used in interviews with mothers of participating children. Logistic regression analysis, after adjustment for confounding variables, revealed that very-mild-to-moderate enamel fluorosis of permanent central maxillary incisors (CMI) was strongly associated both with the age of the subjects when water fluoridation began and with breast-feeding duration for children belonging to Group I. Subjects in Group I were 20.44 times more likely (95% CI: 5.00-93.48) to develop CMI fluorosis than children who were older than 24 months (Group III) when fluoridation began. Subjects who were between 16 and 24 months old when water fluoridation began were 4.15 times more likely (95% CI: 1.05-16.43) to have CMI fluorosis than children older than 24 months. An inverse association was found with breastfeeding duration (OR=0.86, 95% CI: 0.75-0.98) among Group I subjects but not in Groups II and III. Results obtained suggest that the current fluoride concentration in drinking water may be contributing to fluorosis. Further studies will be necessary to determine the relative competing risks of dental fluorosis and dental caries in Chilean children in order to establish the most appropriate water fluoridation level in Chile.
Assuntos
Fluoretação/efeitos adversos , Fluorose Dentária/epidemiologia , Fluorose Dentária/etiologia , Análise de Variância , Aleitamento Materno , Criança , Pré-Escolar , Chile/epidemiologia , Humanos , Lactente , Modelos Logísticos , Prevalência , Fatores de Risco , Inquéritos e Questionários , Chá/efeitos adversos , Cremes Dentais/efeitos adversosRESUMO
The purpose of this comparative study of caries and dental fluorosis experience in Chilean children was to estimate the optimal range of fluoride concentration in tap water under conditions currently prevailing in Chile. The sample included 2431 schoolchildren 7, 12 and 15 years old, life-long residents of five communities with fluoride concentrations in their tap water in the range 0.07-1.1 mg/L. The study population received an oral clinical examination including caries experience and an enamel fluorosis evaluation of the permanent dentition (Dean's scoring system). For 15-year-old children, the DMFT index changed from 5.06 to 2.60, and for 12-year-olds it changed from 3.10 to 1.36 when fluoride water concentration changed from 0.07 to 1.10 mg/L. For 7-year-old children the dmft index correspondingly changed from 3.67 to 1.59. The relationship between DMFT for 12-year-olds and water fluoride concentration was best fitted by a logarithmic function (r2=0.98). The Community Fluorosis Index (CFI) was used to assess enamel fluorosis in the study population, and it showed a linear relationship (r2=0.983) with increasing fluoride concentration of water for the 12-year-old group. Results obtained suggest that under current Chilean conditions, the optimal range of fluoride concentration in potable water should lie in the 0.5-0.6 mg/L range.
Assuntos
Cariostáticos/administração & dosagem , Cárie Dentária/epidemiologia , Fluoretação/normas , Fluoretos/administração & dosagem , Fluorose Dentária/epidemiologia , Adolescente , Análise de Variância , Cariostáticos/efeitos adversos , Criança , Chile/epidemiologia , Índice CPO , Cárie Dentária/prevenção & controle , Relação Dose-Resposta a Droga , Feminino , Fluoretação/efeitos adversos , Fluoretação/estatística & dados numéricos , Fluoretos/efeitos adversos , Fluorose Dentária/etiologia , Humanos , Masculino , Prevalência , Saúde da População UrbanaRESUMO
A critical role has been proposed for the switch from non-cytophilic IgG2 to cytophilic antibodies of IgG1 and IgG3 subclasses observed in the humoral immune responses to Plasmodium falciparum of some Africans. These Africans have acquired clinically immunity naturally, after several years of exposure to holo-endemic malaria. In the present study, the possibility that life-long exposure to low levels of malarial endemicity may be associated with changes in the IgG-subclass composition of antibodies to P. falciparum was investigated in a native Amazonian community. The subjects were 138 malaria-exposed but non-infected Karitiana Indians. In a separate investigation, the concentrations of IgG-subclass antibodies in acutely ill patients with severe malaria (N = 22) were compared with those in age- and sex-matched controls who had uncomplicated malaria (N = 44). Plasma concentrations of IgG against a detergent-soluble extract of P. falciparum schizonts were measured by quantitative ELISA, using indirect standardization. Among the Karitiana, the concentrations of anti-parasite antibodies of all subclasses increased with age, and there was no correlation between age and the proportion of such antibodies which was cytophilic. The predominance of cytophilic IgG1 and non-cytophilic IgG2 antibodies in all age-groups of the Karitiana provides an example of an intermediate pattern of immune responses to P. falciparum which contrasts with those previously described in both clinically immune and non-immune populations. Although mean concentrations of cytophilic IgG1 against P. falciparum were significantly higher in the controls than in the patients with severe malaria, there were no significant differences in other IgG subclasses. Lack of exposure to malaria in the past was associated with disease severity (odds ratio = 4.75; 95% confidence interval = 1.31-17.42), and may explain, at least partially, the occurrence of defective, low-IgG1 antibody responses to P. falciparum in those subjects who had severe malaria.
Assuntos
Anticorpos Antiprotozoários/sangue , Imunoglobulina G/sangue , Malária Falciparum/imunologia , Plasmodium falciparum/imunologia , Doença Aguda , Adolescente , Adulto , Idoso , Envelhecimento/imunologia , Animais , Brasil , Criança , Pré-Escolar , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Indígenas Sul-Americanos , Lactente , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de DoençaRESUMO
A critical role has been proposed for the switch from non-cytophilic IgG2 to cytophilic antibodies of IgG1 and IgG3 subclasses observed in the humoral immune responses to Plasmodium falciparum of some Africans. These Africans have acquired clinically immunity naturally, after several years of exposure to holo-endemic malaria. In the present study, the possibility that life-long exposure to low levels of malarial endemicity may be associated with changes in the IgG-subclass composition of antibodies to P. falciparum was investigated in a native Amazonian community. The subjects were 138 malaria-exposed but non-infected Karitiana Indians. In a separate investigation, the concentrations of IgG-subclass antibodies in acutely ill patients with severe malaria (N = 22) were compared with those in age- and sex-matched controls who had uncomplicated malaria (N = 44). Plasma concentrations of IgG against a detergent-soluble extract of P. falciparum schizonts were measured by quantitative ELISA, using indirect standardization. Among the Karitiana, the concentrations of anti-parasite antibodies of all subclasses increased with age, and there was no correlation between age and the proportion of such antibodies which was cytophilic. The predominance of cytophilic IgG1 and non-cytophilic IgG2 antibodies in all age-groups of the Karitiana provides an example of an intermediate pattern of immune responses to P. falciparum which contrasts with those previously described in both clinically immune and non-immune populations. Although mean concentrations of cytophilic IgG1 against P. falciparum were significantly higher in the controls than in the patients with severe malaria, there were no significant differences in other IgG subclasses. Lack of exposure to malaria in the past was associated with disease severity (odds ratio = 4.75; 95% confidence interval = 1.31-17.42), and may explain, at least partially, the occurrence of defective, low-IgG1 antibody responses to P. falciparum in those subjects who had severe malaria.