Corticosterone controls the developmental emergence of fear and amygdala function to predator odors in infant rat pups

In many altricial species, fear responses such as freezing do not emerge until sometime later in development. In infant rats, fear to natural predator odors emerges around postnatal day (PN) 10 when infant rats begin walking. The behavioral emergence of fear is correlated with two physiological events: functional emergence of the amygdala and increasing corticosterone (CORT) levels. Here, we hypothesize that increasing corticosterone levels influence amygdala activity to permit the emergence of fear expression. We assessed the relationship between fear expression (immobility similar to freezing), amygdala function (c-fos) and the level of corticosterone in pups in response to presentation of novel male odor (predator), littermate odor and no odor. CORT levels were increased in PN8 pups (no fear, normally low CORT) by exogenous CORT (3 mg/kg) and decreased in PN12 pups (express fear, CORT levels higher) through adrenalectomy and CORT replacement. Results showed that PN8 expression of fear to a predator odor and basolateral/lateral amygdala activity could be prematurely evoked with exogenous CORT, while adrenalectomy in PN12 pups prevented both fear expression and amygdala activation. These results suggest that low neonatal CORT level serves to protect pups from responding to fear inducing stimuli and attenuate amygdala activation. This suggests that alteration of the neonatal CORT system by environmental insults such as alcohol, stress and illegal drugs, may also alter the neonatal fear system and its underlying neural control.     

The occurrence of obstructive vs absorptive hydrocephalus in newborns and infants: relevance to treatment choices

Background and objective The classification of hydrocephalus in newborns and in infants is different from the classification in adulthood. This difference exists due to disparity in the source pathologies that produce the hydrocephalus, and the practical distinctions in prognosis and treatment choices. The objective of this paper is to present the spectrum of obstructive-communicating hydrocephalus, which is more complex in the pediatric group, and to propose the relevance of this particular classification to treatment options. Materials and methods The authors categorized infants with active hydrocephalus at time of presentation into the following four groups along the spectrum of communicating vs obstructive HCP. Group 1: patients with a purely absorptive (communicating) HCP. In these patients, tetraventricular dilatation is usually observed with occasional extraaxial fluid accumulation. An extracranial CSF diversion (shunt) is the treatment of choice. Group 2: patients with an obstructive component together with a persistent absorptive component. In these patients, a technically successful endoscopic procedure will not prevent progression of clinical symptoms of HCP. An extracranial CSF diversion (shunt) should be the treatment of choice even though some of these patients are currently treated by endoscopy. Group 3: patients with an obstructive component together with a temporary absorptive component. In these patients, a technically successful ETV should be followed by temporary CSF drainage [via LP, continuous spinal drainage (CLD), or ventriculostomy] with or without supplemental medical treatment (i.e., Diamox) for several days. Such temporary drainage may decrease failure rate in this subgroup. Group 4: patients with a purely obstructive HCP. In these patients, an endoscopic procedure (ETV) is the treatment of choice. According to this spectrum classification, the authors classify different entities with representative cases and discuss relevancy to treatment options and prognosis. Results The data suggest that obstructive hydrocephalus in the very young population may be rather a combination of obstructive and absorptive problem. The outcome of the patient depends mainly not only on the basic pathology causing the hydrocephalus but also on the treatment that is chosen and its complications. While bleeding and infection represent the major causes for communicating hydrocephalus, patients with complex pathologies of congenital type and intra- or interventricular obstructions may reflect obstructive hydrocephalus. Treatment of these patients may be successful by shuntless procedures if the absorptive problem is not the major component. In transient absorptive hydrocephalus, temporary measures were effective in many cases leading to successful procedures of ETV and/or posterior-fossa decompression in selected cases. Conclusions Shuntless procedures are the dream of a pediatric neurosurgeon provided it solves the problem and does not imply unacceptable risk. However, the benefit has to be evaluated years after the procedure is performed, as only prospective multicenter studies will truly show which procedure may have the best overall results in the developing child. Until such studies are available, understanding the basic pathology or the combination of pathologies leading to hydrocephalus in a given child may open the window of opportunities for other than shunt surgery in many hydrocephalic children with major obstructive component.     

侧脑室注射东莨菪碱和酚妥拉明对幼兔分辨学习的影响

目的 探讨东莨菪碱和酚妥拉明对幼兔分辨学习的影响。方法 将30只比利时纯种幼兔从生后13日龄随机分为三组：东莨菪碱组、酚妥拉明组和生理盐水对照组，观察不同日龄各组幼兔的分辨学习能力。结果 幼兔分辨学习的正确反应一般始于生后15日龄。侧脑室注射东莨菪碱对16日龄以前幼兔分辨学习无明显影响，对17日龄以后幼兔分辨学习产生明显抑制作用。侧脑室注射酚妥拉明对13—23日龄幼兔分辨学习均有明显抑制作用。结论 幼兔生后发育过程中学习能力的发展具明显的阶段性，其原因可能与神经递质系统的发育成熟有关。     

Does exposure to infectious diseases in infancy affect old-age mortality? Evidence from a pre-industrial population

Many studies have shown that health conditions experienced in childhood play an important role on an individual's adult mortality. Recent research suggests that past reductions in early life exposure to infectious diseases have been a major contributor to the historical decline in old-age mortality. Drawing on French-Canadian data from cohorts born in the 17th and 18th centuries, we test whether a progressive deterioration in early life conditions (as revealed by an increasing infant mortality rate) translates into a decrease in survival prospects in late life. We use traditional demographic measures such as the age-specific probability of death, and a series of proportional hazard models to control for familial and environmental conditions. Results point toward little evidence of any early life effects. The trend of increasing infant mortality does not correlate with a general increase of mortality in older ages within the same cohorts. Period changes affecting survival at older ages (war, epidemics) as well as demographic and biological characteristics shared within families have a much larger role in old-age mortality than early life characteristics shared within the same cohorts.     

阿奇霉素替代激素治疗婴幼儿喘息性支气管炎临床研究

目的评价阿奇霉素治疗婴幼儿喘息性支气管炎的疗效并探讨其作用机制。方法婴幼儿喘息性支气管炎60例,随机分为2组,各30例,A组用阿奇霉素治疗,B组用地塞米松治疗,分别观察3d后的临床疗效;2组均测定其外周血清IL-4,IFN-γ浓度变化,并与15例健康婴幼儿（对照组）血清IL-4,IFN-γ浓度对比。结果A组与B组临床总有效率差异无统计学意义;整个喘息性支气管炎组与正常对照组相比IFN-γ和IL-4值差异均有统计学意义,IFN-γ下降,IL-4升高;各组治疗前与治疗后相比差异均有统计学意义,A组治疗后血清IFN-γ浓度增高、IL-4浓度下降;B组治疗后血清IFN-γ浓度下降、IL-4浓度也下降,且2组IFN-γ/IL-4值均显著升高。结论阿奇霉素治疗婴幼儿喘息性支气管炎有较好的疗效,能与地塞米松有同样的调节TH1及TH2细胞因子使之趋于平衡,并且有更好的促进细胞免疫作用。     

小儿腹股沟嵌顿疝术式探讨

目的 探讨经腹横纹切口腹腔内行小儿腹股沟嵌顿疝还纳修补术的疗效。方法 自2000年以来我们共收治小儿腹股沟嵌顿疝36例，全部采用经腹横纹切口腹腔内还纳修补的方法，对本方法与传统治疗方法优缺点进行对比分析。结果 本方法无副损伤，无血肿与复发。结论 经腹横纹切口腹腔内行小儿腹股沟嵌顿疝还纳修补术是一种有效的方法，可推广应用。     

Clinicopathological Feature and Surgical Outcome of Choledochal Cyst in Different Age Groups: The Implication of Surgical Timing

Background/aims  Surgical resection of choledochal cysts (CC) has become standard treatment. However, surgery is not universally recommended in early infancy and/or asymptomatic patients. In order to investigate the optimal timing of CC excision, we analyzed clinicopathological data and surgical results from different age groups. Material and methods  This retrospective review included 107 patients (77 females, 30 males) who underwent CC resection at the National Taiwan University Hospital between January 1988 and December 2005. Patient demographic, clinical, and surgical data were collected and analyzed. Results  The patients were divided into three groups according to age at the time of surgery: <1 year old (group I, n = 26), 1−16 years old (group II, n = 48), and >16 years old (group III, n = 33). About two thirds of the patients in group I had jaundice, while abdominal pain related to inflammation was the commonest symptom in groups II and III. Group I suffered significantly fewer surgical complications and less severe liver fibrosis than groups II or III. Conclusion  CC surgery in infancy and in asymptomatic patients is safe and may prevent the complications of this condition. The results support a recommendation for early excision.     

小儿腹腔镜下疝囊高位结扎术的麻醉处理

目的探讨小儿腹腔镜下疝囊高位结扎术的麻醉处理方法和安全性。方法本组80例腹腔镜下疝囊高位结扎术患儿,ASAⅠ~Ⅱ级,以气管全麻下行术式,入室后连续监测HR、MAP、SpO2、气道峰压(PIP)、PETCO2及体温,并分别记录术前、气腹后5min、气腹后10min、放气后10min的各项监测指标。结果所有患儿麻醉均满意,无一例出现麻醉意外、并发症,CO2气腹后10、20min HR、MAP、PETCO2、PIP显著升高(p<0.05,p<0.01),SpO2无显著变化,放气后10min各项指标与术前相比差异无显著意义。结论面对小儿特殊的解剖、生理和CO2气腹对生理产生的影响,做好术前准备,选择正确的麻醉方法和合适的麻醉药物,维持稳定的循环,小儿可安全实施腹腔镜疝囊高位结扎手术。     

腹腔镜辅助胆道造影在幼婴延迟性黄疸诊断中的价值

目的探讨腹腔镜辅助胆道造影在幼婴延迟性黄疸诊断中的价值。方法首先脐部置镜观察胆囊及肝脏情况,如果胆囊大小正常或基本正常,通过右肋缘下trocar孔拖出胆囊底部,部分患儿需游离胆囊系膜。切开胆囊,插管行胆道造影。如果胆囊呈纤维闭锁状态,不能拖出腹腔外,中转开腹。切开胆囊插管失败,放弃造影。结果12例患儿直接从拖出胆囊行胆道造影显示婴儿肝炎综合征或胆汁淤积8例;2例显示为胆管发育不良;2例为肝内胆管闭锁。5例从肝脏游离胆囊系膜后拖出造影,2例显示为胆管发育不良,3例提示胆道闭锁。其余21例患儿胆囊呈条索状,不同程度肝硬化,放弃胆道造影,诊断为胆道闭锁。所有胆道闭锁患儿均行Kasai手术。结论腹腔镜探查、胆道造影是诊断胆道闭锁、鉴别幼婴延迟性黄疸简便、准确、安全的方法,能够显示整个胆树的解剖结构,避免过大或不必要的创伤。     

Renal acid excretion in early infancy

In early infancy, complex disorders of acid base metabolism are more frequent than in any other age group, with a predisposition to metabolic acidosis due to an age-related low renal capacity for acid excretion and an unphysiologically high actual renal acid load in nutrition with common formulas. Recently in preterm and small-for-gestational-age infants, persistent maximum renal net acid excretion (NAE) with subnormal or normal blood acid base status, impaired weight gain, and adaptive hormonal reactions have been observed. Incipient late metabolic acidosis is one example of a mixed disorder of acid base metabolism with maximum renal NAE in early infancy. Alkali therapy is highly effective and can be realized both on an individual basis, using urine pH screening as a diagnostic criterium for maximum renal acid stimulation, or on a general preventive level using modified standard formula with a reduced actual renal NAE similar to that seen on alimentation with human milk. From an integrated point of view, the low glomerular filtration rate and renal capacity for acid excretion beyond the developmental age of more than 44 weeks, may well be interpreted as the result of a specific adaptation to breast feeding sparing energy, and thus an evolutionary advantage for the survival of mother and child. Received July 10, 1996; received in revised form and accepted October 7, 1996