Imunidade celular em caninos neonatos - do nascimento ao 45° dia de idade / Cellular immunity in canine newborns - from birth to the 45th day of life

O objetivo do presente trabalho foi acompanhar o desenvolvimento imunológico dos neonatos caninos, a fim de avaliar a imunidade celular pela análise dos leucócitos e linfócitos totais e das subpopulações de linfócitos T (CD4+ e CD8+) pela técnica de citometria de fluxo. Foram utilizados 30 cães neonatos de ambos os sexos, sem raça definida, aos três, 10, 17, 24, 31, 38 e 45 dias de idade. A contagem de leucócitos totais aos 45 dias (11.639±3.574) foi significativamente maior que no terceiro dia de idade (8.740±1.812) (P<0,05); não houve diferença entre a contagem total de linfócitos aos 45 dias em relação ao terceiro dia de idade. Quanto às subpopulações de LT CD4+ e LT CD8+, os percentuais de LT CD4+, aos três dias de idade (24,9±16,8 por cento), foram inferiores quando comparados à média entre o 10°, o 24° e o 31°dia (35,5 por cento), e os de CD8+, ao terceiro dia, menores em relação às médias do 10° e do 31° dia de idade. Pode-se concluir que as subpopulações de LT CD4+ e CD8+ sofrem oscilações durante o desenvolvimento pós-natal, sendo estas crescentes em relação aos níveis obtidos aos três dias de idade. A relação CD4+:CD8+ mostrou superioridade para o primeiro tipo celular, sendo que a maior relação entre CD4+ e CD8+ ocorreu no terceiro dia de idade. Com base nos resultados obtidos neste estudo, notaram-se as diferenças semanais nas populações linfocitárias, o que demonstra a dinâmica dessas células durante o período neonatal...

The aim of this study was to evaluate the immune development of newborn canines, evaluating the cellular immunity by analysis of leukocyte and lymphocyte totals and sub-population of T lymphocytes (CD4+ and CD8+) by the flow cytometry technique. Thirty neonatal mongrel dogs of both sexes were used, at 3, 10, 17, 24, 31, 38 and 45 days of age. The total leukocyte count to 45 days (11639±3574/µL) was significantly greater than on the third day of age (8740±1812) (p<0.05); There were no differences between the total count of lymphocytes at 45 days in relation to the third day of age. As for the subpopulations of CD4+ and CD8+, CD4+ cell percentages, at three days of age (24.9±16.8) they were inferior when compared to the average between the 10th, 24th and 31st day (35.5), and CD8+ cells, on the third day, were lower compared with averages from the 10th and 31st day of age. It can be concluded that the subpopulations of CD4+ and CD8+ cells undergo oscillations during development, with growing postnatal levels obtained at three days old. The CD4:CD8 ratio showed superiority to the first cell type, and the largest relationship between CD4+ and CD8+ occurred on the third day of age. Based on the results obtained in this study, the differences noted in lymphocyte populations weekly showed the dynamics of these cells during the neonatal period...

Morphometric and quantitative characterization of atrial ganglion neurons from the intercaval region in dogs with dilated cardiomyopathy / Caracterização morfométrica e quantitativa dos neurônios ganglionares atriais da faixa intercaval de cães com cardiomiopatia dilatada

The quantity, morphometry, and quality of atrial neurons from the intercaval region in dogs with dilated cardiomyopathy (DCM) were evaluated. Dogs with DCM had greater ganglion neurons than control dogs. The histologic evaluation of the ventricular myocardium and ganglion neurons confirmed DCM and showed the degeneration of ganglion neurons. Dogs with chronic DCM had a secondary cardioneuropathy owing to impaired parasympathetic neural control

Avaliaram-se quantitativa, morfométrica e qualitativamente os neurônios atriais da faixa intercaval de cães com cardiomiopatia dilatada (CMD). Os neurônios dos gânglios nervosos de cães com CMD eram maiores que os dos cães controle. A histopatologia do miocárdio ventricular e dos neurônios ganglionares confirmou a CMD e demonstrou evidente processo degenerativo neuronal ganglionar. Cães com CMD em fase crônica apresentavam cardioneuropatia secundária, provavelmente pela privação da inervação parassimpática cardíaca

CD4(+) T cells participate in the nephropathy of canine visceral leishmaniasis.

Renal involvement in visceral leishmaniasis (VL) is very frequent. The renal lesions of humans and dogs are similar but their pathogenesis has not been clearly elucidated. There is growing evidence that the cellular immune response is involved in the pathogenesis of immunologically mediated glomerulonephritis. Since T cells could participate in the pathogenesis of nephropathy, in the present study we investigated the possible involvement of CD4(+) and CD8(+) T cells in the nephropathy of canine VL. Six dogs naturally infected with Leishmania (Leishmania) chagasi from the endemic area in the Northeast of Brazil, the town of Teresina in the State of Piauí, were studied. An expressive inflammatory infiltrate of CD4(+) T cells both in glomeruli and in interstitium was present in 4 animals and absent in 2. CD8(+) T cells were detected only in one animal. CD4(+) T cells alone were observed in 3 animals; when CD8+ T cells were present CD4(+) T cells were also present. CD4(+) T cells were observed in cases of focal segmental glomerulosclerosis, diffuse membranoproliferative glomerulonephritis, diffuse mesangial proliferative glomerulonephritis and crescentic glomerulonephritis. CD8(+) T cells were present only in a case of crescentic glomerulonephritis. Leishmania antigen was detected in glomeruli and in interstitial inflammatory infiltrate in 4 animals and immunoglobulins were observed in 4 dogs. In this study we observed that T cells, in addition to immunoglobulins, are present in the renal lesion of canine VL. Further studies are in progress addressing the immunopathogenic mechanisms involving the participation of immunoglobulins and T cells in canine VL nephropathy.

CD4+ T cells participate in the nephropathy of canine visceral leishmaniasis

Renal involvement in visceral leishmaniasis (VL) is very frequent. The renal lesions of humans and dogs are similar but their pathogenesis has not been clearly elucidated. There is growing evidence that the cellular immune response is involved in the pathogenesis of immunologically mediated glomerulonephritis. Since T cells could participate in the pathogenesis of nephropathy, in the present study we investigated the possible involvement of CD4+ and CD8+ T cells in the nephropathy of canine VL. Six dogs naturally infected with Leishmania (Leishmania) chagasi from the endemic area in the Northeast of Brazil, the town of Teresina in the State of Piauí, were studied. An expressive inflammatory infiltrate of CD4+ T cells both in glomeruli and in interstitium was present in 4 animals and absent in 2. CD8+ T cells were detected only in one animal. CD4+ T cells alone were observed in 3 animals; when CD8+ T cells were present CD4+ T cells were also present. CD4+ T cells were observed in cases of focal segmental glomerulosclerosis, diffuse membranoproliferative glomerulonephritis, diffuse mesangial proliferative glomerulonephritis and crescentic glomerulonephritis. CD8+ T cells were present only in a case of crescentic glomerulonephritis. Leishmania antigen was detected in glomeruli and in interstitial inflammatory infiltrate in 4 animals and immunoglobulins were observed in 4 dogs. In this study we observed that T cells, in addition to immunoglobulins, are present in the renal lesion of canine VL. Further studies are in progress addressing the immunopathogenic mechanisms involving the participation of immunoglobulins and T cells in canine VL nephropathy

Avaliaçöes eletrocardiográficas nas fases aguda e crônica indeterminada em cäes experimentalmente infectados com Trypanosoma cruzi / Electrocardiographic evaluation of dogs experimentally infected with Trypanosoma cruzi during the acute and indeterminate chronic phases of infection

Grupos de cäes experimentalmente infectados com Trypanosoma cruzi (1,000 tripomastigotas/kg de peso, cepa Colombiana) e infectados e tratados com beta bloqueador (metoprolol) foram avaliados pela eletrocardiografia na fase aguda (semanalmente por 5 semanas) e na fase crônica indeterminada (mensalmente até 6 meses), com o objetivo de estudar a extensäo das lesöes cardíacas. As alteraçöes na fase aguda foram mais frequentes no grupo infectado, destacando-se o aumento da frequência cardíaca, a supressäo da mv e o aumento do intervalo PR, e na fase crônica indeterminada houve persistência do aumento da frequência cardíaca. No grupo infectado e tratado com metoprolol observou-se, durante a fase aguda, a supressäo da mv, e na crônica indeterminada, a manutençäo da frequência cardíaca dentro dos limites normais. As outras alteraçöes registradas, como aumento de onda Q, bloqueios átrio-ventriculares d e1§ e 2§ graus, distúrbios de conduçäo átrio-ventricular, taquicardia ventricular, extrassístole ventricular, assistolia, supressäo ou aumento de onda T, ocorreram principalmente no grupo infectado na fase aguda

Behavior problems and social competence in girls with true precocious puberty.

We report a controlled standardized behavioral assessment of 33 girls with true precocious puberty using the Child Behavior Checklist. Although a majority of the girls were reported not to have behavior problems, many were reported to have a dysphoric adjustment to their condition. Twenty-seven percent of the girls with true precocious puberty scored greater than 2 SD above the mean on the Total Behavior Problem scale 10 times the expected prevalence rate. They also scored significantly higher (P less than 0.01) than matched controls on both the internalizing or "overcontrolled symptom" and externalizing or "undercontrolled symptom" scales. Forty-eight percent scored greater than 2 SD above the mean on the Social Withdrawal scale. The high prevalence of reported problem behaviors in this sample may be related directly or indirectly to the precocious maturation mediated by biologic, psychologic, social, and environmental variables. Although elevated levels of sex steroids may directly contribute to increased aggressive and hyperactive behaviors, they may also be modified by social and environmental factors.

Responses to social and inanimate stimuli in early infancy.

The reactions of 38 infants to two social stimuli (mother and experimenter (E) smiling and talking) as well as a nonsocial stimulus (a rotating musical mobile) were observed longitudinally when they were 4-, 12-, and 20-weeks old. The durations of four responses were assessed: visual focus, smile, vocalization, and movement. By 12 weeks of age all four responses differentiated among the stimuli but not in the same way. Infants looked at the nonsocial stimulus more than they did at the social stimuli. Each of the other three responses was manifested more to the social stimuli. Infants were more active in the presence of their mothers than they were in the presence of the E, but at 20 weeks they looked at the E more and tended to smile at the E more. These results are discussed in terms of the discrepancy hypothesis.

Prediction of preschool social behavior from social-emotional development at one year.

In an attempt to directly investigate later consequences of the early mother-infant relationship, several measures of social-emotional and cognitive-motivational development at 12 months of age were correlated with two measures of preschool adjustment for 26 children. Results indicated that both of our measures of early social functioning were related to more optimal adjustment in a peer-setting at three-and-a-half years of age. Taken together, the results of the study provide empirical support for the widely held, but seldom tested, hypothesis that the quality of the early mother-infant tie has important consequences for the child's subsequent development in most areas.

Multidimensional sources of infant temperament.

Previous research on infant temperament has implicated a variety of prenatal and perinatal conditions, but most studies have investigated a single source of infant variability. This study examined the impact of several prenatal and perinatal factors on infant outcome according to a conceptual system of hypothetical models of influence. Seventy-five couples expecting their first child were recruited and interveiwed in the last trimester of pregnancy, providing demographic data and measures of the pregnancy experience and expectations of parenting. Childbirth information was obtained from hospital records, and infant behaviors were measured at three days of age by the Neonatal Behavioral Assessment Scale. Results indicate that the antecedent variables are themselves intercorrelated in that older, more highly educated, and financially secure couples are more likely to have a satisfying pregnancy and to be confident about childbirth and parenting than their young, more anxious counterparts. Two statistical methods--partial correlation and path analysis--were used to analyze relative relationships with infant behaviors. Results from both methods indicate that most of the antecedent variables (parental characteristics of age and socioeconomics, parental pregnancy orientation, and use of obstetric anesthesia) must be considered sources of infant behaviors. These findings thus demonstrate the imprecision of inferring a single causal pathway of parental or perinatal influence on infant temperament.