Effects of early environment on emotional development and motor coordination ability of rats / 中华实用儿科临床杂志

Objeaive To explore the effects of the function of hypothalamus-pituitary-adrenal (HPA) axis on emotional development and motor coordination ability by studying the influences of early environment on long-term behaviors of developing rats.Methods Forty-five neonatal rats were randomly divided into 3 groups:the enriched environment group (EE group),the isolated environment group (IE group) and the normal environment group (NE group),with 15 cases in each group.There were 15 rats nurtured separately in EE group,IE group or NE group.The rat motor coordination abilities were tested by straight walking test on postnatal day 28 (P28) and the emotional behaviors were evaluated by handling test at P29.The levels of serum corticosterone(CORT) of rats were detected by using emission immunology method.The morphology of neural cells in rat brain was examined by adopting HE staining.Results In the straight walking test,the motor coordination abilities of rats in EE group ＞ NE group ＞ IE group(F =49.30,P ＜ 0.000).In the handing test,the scores of reaction for stressful stimuli and painful stimuli in IE group were (1.14 ± 0.36,1.93 ±0.83) ＜ (1.47 ±0.64,2.60 ±0.91) in NE group ＜ (2.07 ±0.73,3.43 ±0.65) in IE group (all P ＜ 0.01).The base serum CORT levels were (32.56 ± 9.05) μg/L in EE group ＞ (24.96 ± 6.19) μg/L in NE group ＞ (15.53 ± 6.78) μg/L in IE group (F =19.71,P ＜ 0.001).After a lower-dose adrenocorticotropic hormone stimulation test,the concentration of CORT was (18.24 ± 5.53) μg/L in EE group ＜ (21.71 ± 6.05) μg/L in NE group ＜ (28.09 ±6.51) μg/L in IE group (F=10.25,P ＜0.000).The HE staining showed the number of neural cells in striaturn and amygdale of rats were[(72.80 ±6.81) cell/HP,(73.53 ±6.14) cell/HP] in EE group ＞ [(65.67 ± 8.98) cell/HP,(61.47 ±6.57) cell/HP] in NE group ＞ [(53.33 ± 6.84) cell/HP,(48.13 ± 6.53) cell/HP] in IE group (all P ＜ 0.001).Conclusions Early environment can affect emotional reaction,motor behavior and brain development of immature rats by regulating HPA axis function.Early isolation environment can lead to HPA axis dysfunction,which can make nerve cell damage and emotion and motor coordination ability dysfunction.On the contrary,early enriched environment can moderate the hyperactivity of HPA axis after stress and promote brain development and ameliorate long-term behavioral development.

Effects of early environment on the expression of brain-derived neurotrophic factor and its receptor and brain development / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effect of early environment on the learning-memory ability of rats and the expression of brain-derived neurotrophic factor (BDNF) and its receptor, tyrosine kinase receptor B (TrkB), and to explore the influence of early environment on development of rat brain in developing stage and possible regulation mechanisms.</p><p><b>METHODS</b>Forty-five newborn Sprague-Dawley rats were randomly divided into three groups (15 rats in each group): enriched environment group (EE group), isolated environment group (IE group) and normal control group (NC group). The pups were nurtured separately in their groups. The learning-memory abilities of the rats were measured by "Y"-arm maze test 28 to 29 days after birth. The number of neural cells and the expression of BDNF and TrkB in the hippocampal CA3 and frontal lobe were were detected by Nissl's staining and immunohistochemistry respectively.</p><p><b>RESULTS</b>The results of the "Y"-arm maze test showed that rats in the EE group needed less training times, and retained a higher percentage of memory than the other two groups(P<0.01). Rats in the IE group needed more training times, and retained a lower percentage of memory than the NC group (P<0.01). By Nissl's staining, the numbers of neural cells in the hippocampal CA3 and frontal lobe were highest in the EE group followed by the NC group. They were lowest in the IE group (P<0.01). By immunohistochemistry, the expression of BDNF in the hippocampal CA3 and frontal lobe were highest in the EE group followed by the NC group. It was lowest in the IE group (P<0.01). Results were similar for expression of TrkB.</p><p><b>CONCLUSIONS</b>Early environment can affect the long-term brain development and brain function of rats by influencing the expression of BDNF and its receptor TrkB in the hippocampus and frontal lobe.</p>

Multifactor analysis of postoperative mechanical ventilation supporting time in infants with congenital heart diseases / 中南大学学报(医学版)

OBJECTIVE@#To analyze the multiple factors affecting the postoperative mechanical ventilation supporting time in infants less than 10 kg with simple congenital heart diseases and to seize time by the forelock of extube and improve the outcome of surgical treatment.@*METHODS@#Data of 231 infants less than 10 kg with atrial septal defect(ASD),ventricular septal defect, and combining patent ductus arteriosus were retrospectively analyzed. The multivaricate stepwise logistic regression statistics were done for the predisposing factors affecting the ventilative supporting time.@*RESULTS@#The ventilative supporting time was 3~375 (average 23.5 h) h. The multivaricate stepwise logistic regression analysis indicated that severe pulmonary hyperpressure, cross-cramp aortic time, cardiopulmonary bypass time, preoperational pulmonary infection, membrane oxygenator, modified ultrafiltration, weight, and postoperative complications were significantly correlated to the ventilative supporting time.@*CONCLUSION@#Severe pulmonary hyperpressure, preoperational pulmonary infection, long cross-cramp aortic time, long cardiopulmonary bypass time, postoperative complications all prolong the ventilation supporting time; the use of membrane oxygenator and modified ultrafiltration during the operation and big weight can diminish the pulmonary complications and shorten the ventilation supporting time.

Observation of Testis Tissue in Experimental Cryptorchidism after Orchiopexy in Various-Day-Rats / 实用儿科临床杂志

ObjectiveTo observe testis tissue changes of experimental cryptorchidism after orchiopexy in various-day-rats.MethodsSeventy-two Sprague-Dawley(SD) male rats were divided into 3 groups randomly and made artificial cryptorchidism:unilateral cryptorchidism group(n=24),bilateral cryptorchidism group(n=24)and sham operation group(n=24)at age 21-day-old.Intra-abdominal testicle was resetting in 2 weeks,at age 40 days and 60 days,the rats were sacrificed for detection tubular fertility index(TFI) and mean tubular diametar(MTD) with hematoxylin-eosine staining and germ cell apoptosis by terminal deoxynucleotidyl transferase mediated d-UTP nick end labeling(TUNEL) assay.ResultsThere were significant differences of MTD,TFI and apoptosis index(AI) between cryptorchidism and scrotal testes(P0.05).The AI of cryptorchidism testes of unilateral cryptorchidism group were significantly lower than that of bilateral cryptorchidism group in 40 days(P0.05).ConclusionsAI of artificial resetting testis is increased and contralateral descended testes in unila-teral cryptorchidism have various damage.It is to lighten that pathological damage of testes of cryptorchidism with prolongation of reset time.