Noradrenergic sympathetic innervation of the spleen: V. Acute drug-induced depletion of lymphocytes in the target fields of innervation results in redistribution of noradrenergic fibers but maintenance of compartmentation

Sympathetic noradrenergic fibers follow the vasculature into the white pulp of the spleen and branch from the periarteriolar plexuses into T lymphocyte zones. These lymphocytes, reported to express adrenergic receptors, are contacted directly by norepinephrine (NE) terminals and are putative targets of the locally released NE. Although this splenic innervation has been studied extensively, the functional interdependence of the lymphocytes and the sympathetic innervation is not well understood. To assess the effect of acute lymphocyte loss on the splenic innervation, T and B lymphocytes were depleted through treatment with cyclophosphamide (CY) or hydrocortisone acetate (HC). Despite reductions in spleen weight and cellularity, the total NE content (pmol) per spleen did not change. However, the NE concentration increased in the treated spleens. Although the general compartmental organization of the noradrenergic fibers in the treated spleens was similar to that of controls, the NE fibers redistributed and increased in density around the smaller central arteries in lymphocyte depleted spleens. The accommodation of these NE fibers to the changing environment of the white pulp suggests that the innervation to the spleen remains chemically stable despite a large disruption to the normal splenic milieu, but is capable of plasticity in the face of a shrinking white pulp.     

依据儿科高级生命支持指南行气管插管的错位发生率及对插管深度公式的探讨

目的　探讨多种儿童经口气管插管深度标准技术的准确性,包括儿科高级生命支持（PALS）指南公式预测法以及听诊双肺呼吸音、观察胸廓起伏的临床评估法,并设计更准确的预测公式指导临床。方法　回顾性分析2018年1月至2019年7月中国医科大学附属盛京医院小儿重症监护病房收治的经口气管插管的177例患儿。记录入院后初次插管时患儿的年龄、性别、体重、依据PALS指南公式计算的插管深度、临床评估后的实际插入深度以及胸片显示气管导管（endotracheal tube,ETT）尖端距离第二胸椎下缘和隆突的距离,并对上述数据进行统计分析。结果　依据PALS指南计算所得气管插管深度的错位率（过深或过浅）为74.01%,结合临床评估后,ETT错位率由74.0%下降至55.9%,临床评估对ETT的调整有实际意义。推测新公式：＜2岁患儿,采用1～5月龄：11 cm,6～11月龄：12 cm,12～23月龄：13 cm作为参考插管深度。 ≥2岁患儿：插管深度（cm）＝年龄（岁）×0.7+12。结论　依据PALS指南计算的气管插管深度错位率较高,通过听诊双肺呼吸音、观察胸廓起伏等临床评估后可提高ETT位置的合适率。PALS指南低估了2岁以上儿童ETT的最佳插入深度。新的公式有待验证。     

Temperature and Pressure Dependence of the Free Volume in Polyisobutylene from Positron Lifetime and Pressure‐Volume‐Temperature Experiments

Summary: The microstructure of the free volume and its temperature and pressure dependence in PIB were studied by PVT experiments and PALS. Employing the Simha–Somcynsky equation of state, the hole‐free volume fraction h and the specific free and occupied volumes, V_f = hV and V_occ = (1 ? h)V, respectively, and their expansivity and compressibility were calculated. From the PALS spectra analyzed using the LT9.0 software, the hole size distribution, the mean hole size 〈v_h〉 and mean dispersion σ_h were calculated. From a comparison of 〈v_h〉 with V_f, the hole density was obtained. It was found that PIB shows an unusual thermal expansion with glass‐like transitions at 210 K and 290 K (at 0 MPa). A similar behavior is observed for tan δ. It was found that at 296 K, 〈v_h〉 decreases exponentially from 80 ų at 0.1 MPa to the extremely low value of 10 ų at 1 300 MPa. Starting from a fluctuation approach, the free‐volume fluctuations and the characteristic length scale (ξ) of dynamic heterogeneity of structural relaxation were estimated from σ_h. It was found that ξ increases from ≈1.5 nm to ≈1.9 nm when the temperature decreases from 293 K to the glass transition temperature T_g = 207 K (at 0 MPa) or the pressure increases from 0.1 MPa to 200 MPa (at 296 K).

Fractional free volume and its mean fluctuation in PIB as determined from positron lifetime spectroscopy and PVT experiments analyzed with the Simha‐Somcynsky equation of state.     

Comparative analysis of the fate of donor dendritic cells and B cells and their influence on alloreactive T cell responses under tacrolimus immunosuppression

We have shown that tacrolimus (TAC)-induced liver allograft acceptance is associated with migration and persistence of donor B cells and dendritic cells (DC). To clarify whether these MHC class II+ leukocytes have favorable roles in inducing tolerance, we analyzed recipient T cell reactions after allogeneic B or DC infusion. LEW rat B cells localized exclusively in BN host B cell follicles without any direct contact with host T cells. While few donor DC migrated to T cell areas and marginal zones, they were captured by host APC, suggesting that allogeneic MHC class II+ cells may induce immune reactions via the indirect pathway. Although DC-infused non-immunosuppressed recipients showed enhanced ex vivo anti-donor responses, persistent in vitro donor-specific hyporeactivity was seen equally with donor DC or B cell infusion under TAC. The results indicate that donor MHC class II+ APC are capable of regulating recipient immune reactions under TAC. Possible involvement of the indirect pathway of allorecognition is discussed.     

Noradrenergic sympathetic innervation of the spleen: IV. Morphometric analysis in adult and aged F344 rats

Noradrenergic postganglionic sympathetic innervation of the spleen in 8-month-old (adult) and 27-month-old (aged) Fischer 344 (F344) rats was examined using fluorescence histochemistry for catecholamines coupled with stereologic point-counting analysis for quantitation of noradrenergic varicosities. Noradrenergic varicosities in the spleen were evaluated in four compartments: (1) vascular-, (2) trabecular-, (3) capsular-, and (4) parenchymal-associated fibers. The 27-month-old rats were subdivided further into two groups based upon behavioral testing for gustatory neophobia, a condition reported to be associated with acute locus coeruleus lesions in young rats and with diminished norepinephrine (NE) levels in central noradrenergic neurons in aged rats. In the 8-month-old rats, spleens displayed abundant innervation. Noradrenergic plexuses entered the spleen with the splenic artery and its branches, distributed into capsular and trabecular compartments, and followed the vasculature and trabeculae into splenic white pulp. Noradrenergic fibers entered the white pulp mainly in association with the central artery and its branches; liner and punctate varicosities branched mainly from vascular plexuses into the large, well-defined parenchyma of the white pulp, ending primarily among fields of T lymphocytes. Some fibers extended along the inner edge of the marginal zone and the parafollicular zone. Few noradrenergic varicosities were found in the red pulp. In both groups of aged rats, sympathetic noradrenergic innervation was diminished markedly.(ABSTRACT TRUNCATED AT 250 WORDS)     

病变血细胞膜对电磁波谱段特异反应的微观表现

机体在发生某些病变时,细胞膜结构在流变学、相态和电荷分布等方面的特性会有所改变。作为一种生物液晶材料,作者利用激光束和γ射线等特殊的电磁波谱段检测了癌症等病人的血细胞膜的特异微观表现,并与正常细胞比较,用正电子湮没谱分析技术验证。     

Muenster Parental Programme empowers parents in communicating with their infant with hearing loss

Objective

With the implementation of the Universal Newborn Hearing Screening (UNHS), the age of diagnosis of children with hearing loss (HL) has been steadily declining in the past years. Consequently, there is a need for early educational intervention methods that are suitable for infants at the preverbal level. To meet this need we have developed and evaluated the Muenster Parental Programme (MPP), a responsive parenting programme for parents of children with HL aged 3–18 months. It aims at enhancing the parents’ communicative skills towards their child.

Methods

The MPP is introduced following confirmation of a HL. Flanked by two individual counselling sessions, the programme comprises six group sessions and two single training sessions with video feedback. The focus of the programme lies in enhancing parents’ responsive behaviour and in reducing inappropriate initiative behaviour. The present study involved 29 parents of 24 children aged 6.6 (mean, range: 3–12) months at the outset of the MPP. The children's degree of HL ranged from moderate to profound. Parents of children with unilateral HL and/or risk for an additional developmental delay were included. The prospective study compared parent communication skills of a trained (N = 15) versus a control group (N = 14) before and after the MPP. For this purpose, instances of responsive behaviour to the signals of the child and total time of initiative behaviour within a 4-min video-sample were measured before and after completion of the study in both groups.

Results

Trained parents could enhance their responsiveness to vocal and preverbal signals of the child (Wilcoxon test, p = .002) and also their responsiveness to non-verbal signals (Wilcoxon test, p < .001). Moreover, parents reduced their inappropriate initiative behaviour (related t-test, p < .001). Pre-post comparisons in the control group were non-significant.

Conclusions

The increased parental responsiveness to infants with HL is of great importance as these early behaviours underlie later acquisition of speech, language, hearing and social communication skills. The MPP constitutes the first evaluated group concept for parents of infants with HL in the German-speaking countries and equally meets the needs of parents and professionals.     

GAP between knowledge and skills for the implementation of the ACCM/PALS septic shock guidelines in India: Is the bridge too far?

Objective:

To determine whether physicians were aware of and had the skills to implement the American College of Critical Care Medicine/Pediatric Advanced Life Support Course septic shock protocol.

Design:

A cross-sectional questionnaire survey.

Setting:

Four academic institutions in Chennai, Manipal, Mangalore, and Trivandrum - cities representing the three southern states of Tamil Nadu, Karnataka, and Kerala, respectively, between February and April 2006.

Interventions:

Pre and post lecture questions. They were evaluated using 11 questions testing knowledge and 10 questions testing their comfort level in performing interventions related to the initial resuscitation in septic shock.

Measurement and Main Result:

The ACCM/PALS sepsis guidelines were taught during the PALS course conducted in the four academic institutions. A total of 118 delegates participated, of whom 114 (97%) were pediatricians and four (3%) were anaesthetists. The overall mean number of correct responses for the 11 questions testing knowledge before and after the lecture was 2.1 and 4.07, respectively P=0.001(paired t test). Although, 42% of the respondents (n=50) were aware of the ACCM guidelines, 88% (n=104) did not adhere to it in their practice. A total of 86% (n=101) and 66% (n=78) did not feel comfortable titrating inotropes or intubating in the ED; 78% (n=92) and 67% (n=78), respectively felt that central venous access (CVA) and arterial pressure (AP) monitoring were unimportant in the management of fluid refractory shock. Of the physicians, 20% (n=24) had never intubated a patient, 78% (n=92) had not introduced a central venous catheter, and 76% (n=90) had never introduced an intra-arterial catheter.

Conclusions:

In view of the lack of skills and suboptimal knowledge, the ACCM/PALS sepsis guidelines may be inappropriate in its current format in the Indian setting. More emphasis needs to be placed on educating community pediatricians with a simpler clinical protocol, which has the potential to save many more children.