Maternal sensitivity and infant autonomic and endocrine stress responses

Background

Early environmental exposures may help shape the development of the autonomic nervous system (ANS) and hypothalamic–pituitary–adrenal (HPA) axis, influencing vulnerability for health problems across the lifespan. Little is known about the role of maternal sensitivity in influencing the development of the ANS in early life.

Aims

To examine associations among maternal sensitivity and infant behavioral distress and ANS and HPA axis reactivity to the Repeated Still-Face Paradigm (SFP-R), a dyadic stress task.

Study design

Observational repeated measures study.

Subjects

Thirty-five urban, sociodemographically diverse mothers and their 6-month-old infants.

Outcome measures

Changes in infant affective distress, heart rate, respiratory sinus arrhythmia (RSA), and T-wave amplitude (TWA) across episodes of the SFP-R were assessed. A measure of cortisol output (area under the curve) in the hour following cessation of the SFP-R was also obtained.

Results

Greater maternal insensitivity was associated with greater infant sympathetic activation (TWA) during periods of stress and tended to be associated with greater cortisol output following the SFP-R. There was also evidence for greater affective distress and less parasympathetic activation (RSA) during the SFP-R among infants of predominantly insensitive mothers.

Conclusions

Caregiving quality in early life may influence the responsiveness of the sympathetic and parasympathetic branches of the ANS as well as the HPA axis. Consideration of the ANS and HPA axis systems together provides a fuller representation of adaptive versus maladaptive stress responses. The findings highlight the importance of supporting high quality caregiving in the early years of life, which is likely to promote later health.     

The relationship between elastase and lactoferrin in healthy, gingivitis and periodontitis sites

OBJECTIVES: To compare the relative amounts of elastase (primary polymorphonuclear leucocyte granule constituent) and lactoferrin (secondary PMN granule constituent) in the gingival crevicular fluid (GCF) of healthy, gingivitis and periodontitis sites.
DESIGN: This cross-sectional study looked at the two GCF constituents in three categories of disease status within the same subject.
MATERIALS AND METHODS: Patients with chronic adult periodontitis were screened and those exhibiting all three types of sites ie periodontally healthy, gingivitis and periodontitis sites were recruited (n = 10) and had GCF collected from the three sites. Lactoferrin and elastase were measured in eluates of GCF by enzyme-linked immunosorbent assay.
RESULTS: The absolute amount of lactoferrin measured in ng per 30 s samples was significantly lower in healthy and gingivitis sites as compared to periodontitis sites however this difference failed to reach significance when the concentration of lactoferrin in GCF was used as the analytical unit. No significant differences were found for elastase levels at any sites when expressed as either absolute amounts or concentrations. Secondary granule release, as evidenced by lactoferrin levels, occurs during cell migration and the process is independent of primary granule release, which is thought to correlate with PMN activation. The relationship between granule constituents in the samples showed significant differences, the highest lactoferrinlelastase ratio being at periodontitis sites (P < 0.001).
CONCLUSIONS These findings imply a change in the relative amounts of elastase and lactoferrin released at different disease level sites, with an almost 10-fold increase in the proportion of lactoferrin to elastase in periodontitis sites over healthy and gingivitis sites. This variation in the release by PMNs of primary and secondary granule constituents may indicate alterations in PMN function in different disease environments.     

Haemodynamic Studies During the Management of Severe Tetanus

Detailed invasive haemodynamic studies were performed in 27of 32 patients with severe tetanus. Nineteen had severe uncomplicatedtetanus and eight had associated major complications, chieflyinfection and pulmonary complications. The results were comparedwith those obtained from 15 healthy male volunteers who servedas controls. There were two deaths in 32 patients (mortality6.25 per cent). Severe tetanus without major complications wascharacterized by a high output hyperkinetic circulatory statewith tachycardia (heart rate 131 (19.2) beats/minute), increasedstroke volume index (43.1 (10.7) ml/m²), increased cardiac index(5.48 (0.94)1/min/m²) and a normal left ventricular stroke workindex (60.5 (15.9) g/m/m²). Volume loading demonstrated a significanthaemodynamic response and increased vascular capacitance. Evenso the maximum percent rise from baseline values of these indicesafter volume load was significantly higher in controls (p <0.001). Autonomic cardiovascular disturbances affected bothsympathetic and parasympathetic activity. Hypertension and tachycardiaalternating with hypotension and bradycardia were related tosudden fluctuations in systemic vascular resistance. Our studiessuggested some degree of myocardial dysfunction in patientswith severe uncomplicated tetanus. The haemodynamics of severetetanus were masked and altered by complicating infection, pneumonia,and atelectasis.     

Development of specific receptors for N-formylated chemotactic peptides in a human monocyte cell line stimulated with lymphokines

A human monocyte-like cell line, U937, when grown in continuous culture, does not secrete lysosomal enzymes or migrate towards chemotactic factors. When the cells are stimulated by lymphokines, however, they develop the ability both to migrate directionally and to secrete enzymes in response to several types of chemoattractants. The development, by stimulated cells, of chemotactic and secretory responses to one class of chemoattractants, the N- formylated peptides, is accompanied by the appearance on the cells of specific binding sites for these substances. Using tritiated N-formyl- methionyl-leueyl-phenylalanine (fMet-Leu-[(3)H]Phe) as a ligand, it was determined that unstimulated U937 cells possess no detectable binding sites. However, after stimulation with lymphocyte culture supernates for 24, 48, and 72 h, they developed 4,505 (+/-) 1,138, 22,150(+/-) 4,030, and 37,200 (+/-) 8,000 sites/cell, respectively. The dissociation constants for the interaction of fMet-Leu-[SH]Phe with the binding sites were approximately the same regardless of stimulation time and ranged between 15 and 30 nM. The binding of fMet-Leu-[(3)H]Phe by stimulated U937 cells was rapid and readily reversed by the addition of a large excess of unlabeled peptide. The affinity of a series of N-formylated peptides for binding to U937 cells exactly reflected the potency of the peptides in inducing lysosomal enzyme secretion and chemotaxis. The availability of a continuous human monocytic cell line that can be induced to express receptors for N-formylated peptides will provide a useful tool not only for the characterization of such receptors but also for the delineation of regulatory mechanisms involved in cellular differentiation and the chemotactic response.     

KT1000／KT2000关节测量仪对前交叉韧带损伤诊断及重建术后移植物稳定性的评估价值

目的:虽然前交叉韧带的重建手术已趋成熟,但重建术后韧带稳定性的量化评估仍缺乏一种有效的方法。探讨KT1000/KT2000关节测量仪在膝关节前交叉韧带损伤中的诊断价值以及在韧带重建术后移植物稳定性评估中的应用价值。方法:选择2006-01/2007-01于上海交通大学附属第六人民医院行关节镜下重建手术的膝关节前交叉韧带完全损伤患者80例,对治疗方案均知情同意。①术前利用KT1000/KT2000关节测量仪进行膝关节稳定性的测量,并与抽屉试验、Lachman试验、轴移试验及MRI影像学等检查方法进行对比,验证其敏感度。②分别在术后3个月、6个月、1年以及1年以上利用KT1000/KT2000关节测量仪进行随访测量,采用国际膝关节文献委员会评分对测量结果进行前交叉韧带的稳定性评估,评估标准:等级A为韧带紧张度良好;等级B为韧带紧张度接近正常;等级C为韧带紧张度异常;等级D为韧带紧张度严重异常。结果:80例前交叉韧带完全损伤患者全部进入结果分析。①KT1000测量仪在诊断前交叉韧带损伤时较前抽屉试验及轴移试验敏感率高(P=0.001,0.037),而与Lachman试验及MRI影像学检查敏感率差异无显著性意义(P=0.807,0.598)。②随访结果:术后3个月随访到80例患者,A级68例,B级12例;术后6个月随访到76例患者,A级55例,B级19例,C级1例;术后1年随访到70例患者,A级48例,B级20例;C级2例;术后1年以上随访到68例患者,A级42例,B级22例,C级4例。结论:KT1000/KT2000关节测量仪测量膝关节稳定性的敏感度较高,不仅可应用于膝关节前交叉韧带损伤的临床诊断,还可以评价手术效果,对前交叉韧带重建术后评估移植物稳定性提供了一个量化依据。