Childbirth and consequent atopic disease: emerging evidence on epigenetic effects based on the hygiene and EPIIC hypotheses.

BACKGROUND: In most high and middle income countries across the world, at least 1:4 women give birth by cesarean section. Rates of labour induction and augmentation are rising steeply; and in some countries up to 50% of laboring women and newborns are given antibiotics. Governments and international agencies are increasingly concerned about the clinical, economic and psychosocial effects of these interventions. DISCUSSION: There is emerging evidence that certain intrapartum and early neonatal interventions might affect the neonatal immune response in the longer term, and perhaps trans-generationally. Two theories lead the debate in this area. Those aligned with the hygiene (or 'Old Friends') hypothesis have examined the effect of gut microbiome colonization secondary to mode of birth and intrapartum/neonatal pharmacological interventions on immune response and epigenetic phenomena. Those working with the EPIIC (Epigenetic Impact of Childbirth) hypothesis are concerned with the effects of eustress and dys-stress on the epigenome, secondary to mode of birth and labour interventions. This paper examines the current and emerging findings relating to childbirth and atopic/autoimmune disease from the perspective of both theories, and proposes an alliance of research effort. This is likely to accelerate the discovery of important findings arising from both approaches, and to maximize the timely understanding of the longer-term consequences of childbirth practices.

The EPIIC hypothesis: intrapartum effects on the neonatal epigenome and consequent health outcomes.

There are many published studies about the epigenetic effects of the prenatal and infant periods on health outcomes. However, there is very little knowledge regarding the effects of the intrapartum period (labor and birth) on health and epigenetic remodeling. Although the intrapartum period is relatively short compared to the complete perinatal period, there is emerging evidence that this time frame may be a critical formative phase for the human genome. Given the debates from the National Institutes of Health and World Health Organization regarding routine childbirth procedures, it is essential to establish the state of the science concerning normal intrapartum epigenetic physiology. EPIIC (Epigenetic Impact of Childbirth) is an international, interdisciplinary research collaboration with expertise in the fields of genetics, physiology, developmental biology, epidemiology, medicine, midwifery, and nursing. We hypothesize that events during the intrapartum period - specifically the use of synthetic oxytocin, antibiotics, and cesarean section - affect the epigenetic remodeling processes and subsequent health of the mother and offspring. The rationale for this hypothesis is based on recent evidence and current best practice.

Race and ethnicity as variables in Nursing Research, 1952-2000.

BACKGROUND: Although the use of race and ethnicity as variables in research has increased over the past five decades, there is confusion regarding the meaning of the terms, as well as how the words are defined and determined in scientific inquiry. OBJECTIVE: To review the use of race and ethnicity as variables in nursing research literature. METHODS: Original research articles published in Nursing Research in the years, 1952, 1955, and every 5 years thereafter through 2000 were reviewed. Those articles describing human characteristics (N = 337) were analyzed for content concerning: (a) frequency of racial and ethnic terms, (b) words used for racial and ethnic categories, (c) detinitions of racial and ethnic terms, and (d) how a study participant's race or ethnicity was determined. RESULTS: Racial and ethnic variables were mentioned in 167 of the 337 reviewed articles. Eighty-one terms and word phrases were used for these variables. In only five articles were the variables defined. Race and ethnic labels were often intermixed and the majority of studies provided no information about how categorization of the participant's race or ethnicity was made. In addition, there was relatively little growth in the number of studies that had racial/ethnic groups, other than Whites, as the majority of the sample. CONCLUSION: Racial and ethnic variables provide nurse researchers with many challenges. Although race and ethnicity were widely used in Nursing Research articles, the categories were not defined in the majority of papers, and methods used to determine a participant's race or ethnicity were unclear. In order to construct a common and consistent understanding of racial and ethnic categories, nurse researchers should be explicit regarding the rationale related to their use of the categories and the assumptions underlying particular racial and ethnic categorizations.

Seasonal differences in finger skin temperature and microvascular blood flow in healthy men and women are exaggerated in women with primary Raynaud's phenomenon.

AIMS: Patients with primary Raynaud's phenomenon (PRP) have more severe symptoms in the winter. The aetiology of this is more complex than simply increased vasoconstriction in response to the immediate ambient temperature. The aim of this study was to investigate differences in skin temperature (Tsk), microvascular blood flow and responses to endothelium-dependent and independent vasodilators in healthy controls, and women with PRP under identical environmental temperatures but in different seasons. METHODS: Ten women with PRP were compared with age matched women (10) and men (10). Finger skin responses were recorded immediately on arrival, after stabilizing in a temperature regulated laboratory at 22-24 degrees C, and at matched warm (35 degrees C) and cold (15 degrees C) Tsk in the winter and summer. Baseline red blood cell flux (r.b.c. flux), and the change in flux in response to iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) were recorded by laser Doppler fluxmetry at the warm and cold Tsk. RESULTS: Arrival Tsk were significantly cooler for all subjects during the winter (mean seasonal difference -2.6 degrees C, P < 0.0001), and markedly colder in subjects with PRP (mean seasonal difference -3.5 degrees C, P < 0.0005). Statistically significant seasonal differences persisted in all subjects at stable Tsk despite an identical laboratory temperature (mean difference 1.3 degrees C, P < 0.0001). To achieve comparable controlled finger Tsk a significantly colder local environment was required for male controls (mean of -2.1 degrees C, P < 0.0001), and a significantly warmer environment for subjects with PRP (mean of + 2.4 degrees C, P < 0.0001) compared with female controls. This needed to be warmer in the winter, by a mean of 2.4 degrees C, than the summer for all subjects. Vasodilatation in response to ACh, but not SNP, was significantly smaller (P < 0.0001) in the PRP group compared with the female controls for all visits, with most of this difference arising in the winter visits (P < 0.01). CONCLUSIONS: There is a seasonal and persistent influence on finger Tsk, and microvascular blood flow in healthy men and women, which modifies the observed responses to immediate changes in finger Tsk. The seasonal differences are greater in women than men, and are further exaggerated in women with PRP, in whom this is associated with reduced endothelium-dependent vasodilatation.

Sisters of the Yam: African American women's healing and self-recovery from intimate male partner violence.

In this womanist ethnographic investigation African American women (N = 21) survivors of intimate male partner violence were interviewed about their resilience-recovering experiences. This article foregrounds the role of therapeutic support groups in African American women's healing experience and addresses how race and ethnicity shape the lives and the recovering process for many African American women. The findings are important to practitioners who strive to provide assistance and interventions for African American women as well as other women of color.

Colonizing images and diagnostic labels: oppressive mechanisms for African American women's health.

The purpose of this article is to present colonizing images of African American women and describe how colonizing images and diagnostic labels function together to serve as oppressive mechanisms for African American women's health. The mammy, the matriarch, the welfare mother, the Jezebel, and the Black lady overachiever are representational images of African American women that contribute to how they are viewed and treated within the health care arena.

Womanism: a methodologic framework for African American women.

Although nurse scholars have become increasingly engaged in feminist research and theory development, only a few have included important feminist thoughts expressed by African American womanist theorists. This article presents an abbreviated review and synthesis of Afrocentric ways of knowing, which includes Black feminist, womanist, and Afrocentric perspectives. A developing methodology for use with African American women is also described.

An investigation into variability in microvascular skin blood flow and the responses to transdermal delivery of acetylcholine at different sites in the forearm and hand.

AIMS: Transdermal iontophoresis in combination with laser Doppler fluxmetry (LDF) are useful techniques for examining dermal microcirculatory responses to different vasodilators. Differences in skin and microcirculation structure could influence the recorded baseline flux, and the observed vasodilatation. To examine this we compared baseline flux and the response of microvascular blood flow to a single vasodilator, acetylcholine, at sites in the forearm and hand. METHODS: Baseline microcirculation flow was recorded by LDF in a temperature controlled laboratory. The change in flux with iontophoresis of identical doses of acetylcholine, 150 microA for 40 s, was recorded at 12 different sites in the forearm and hand in 10 female and 3 male subjects. RESULTS: Baseline flux patterns and the vasodilatation to identical periods of iontophoresis of acetylcholine were site dependent. Palmar sites showed a higher baseline flux, but no vasodilatation to iontophoresis of acetylcholine. In contrast the volar forearm, dorsal hand and finger sites showed lower site-dependent baseline flux, but did vasodilate. CONCLUSIONS: Patterns of baseline flux are specific to sites on the hand and forearm reflecting differences in underlying microvascular structure. The vasodilatation to transdermal delivery of acetylcholine is also site dependent, but differences in skin structure may be more important than the underlying microvasculature in determining the response.

Removal of interproximal subgingival plaque by hand and automatic toothbrushes.

Subgingival plaque removal at interproximal sites by automatic and hand toothbrushes was compared with control sites at which cleansing was not performed. There were 58 patients, 35 to 63 years of age, each with one hopeless tooth requiring extraction. Each patient was randomly assigned to one of four test groups: hand brush; automatic toothbrush 1; automatic toothbrush 2; and no brushing. The brushing instructions as stated by the manufacturers were demonstrated and the patient brushed the sextant containing the test tooth for 20 seconds. The level of the gingival margin was marked at each interproximal test site. The teeth were extracted and processed for SEM, and subgingival plaque was viewed at X100 and X2000 magnifications. A montage of photomicrographs of the gingival groove to the occlusal margin of the bacterial plaque at X100 magnification was made and the distance from the groove to the margin was measured. An ANOVA was performed using P = 0.05 level for significance. Due to processing difficulties, only 33 specimens were available for analysis. The average distances from the groove to the subgingival plaque front for the four test groups were 0.514, 0.132, 0.163, and 0.111 mm respectively. The maximum distance (1.5 mm) of plaque removal was greatest for the hand toothbrush. Due to the large standard deviation (0.636 compared to 0.146, 0.250, and 0.124 respectively), the hand brushing group was excluded from ANOVA. There were no statistically significant differences among the automatic toothbrushes and the no brushing control (P = 0.8393). It was concluded that a single session of oral hygiene instruction with an automatic toothbrush did not result in subgingival interproximal plaque cleansing.