Gingival changes during pregnancy: I. Influence of hormonal variations on clinical and immunological parameters

Estrogen signaling in microvascular arteries: parturition reduces vasodilation by reducing 17β-estradiol and nNOS

Few studies have examined the potential effects of childbirth on the responses of the female vasculature--especially the resistance microvasculature of non-reproductive tissues. In the present study we have investigated the response of mesenteric microvascular resistance vessels to estrogen (E2), an important vasoactive hormone. Vessels were obtained from either nulliparous or postpartum female Sprague-Dawley rats, and isometric tension studies were performed. We found that E2 induced a concentration-dependent, endothelium-independent relaxation of microvessels precontracted with 10(-5) M phenylephrine; however, E2-induced relaxation was reduced by nearly half in vessels from postpartum animals compared to nulliparous controls. Inhibiting nitric oxide synthase activity with 10(-4) M L-NMMA or L-NPA (which exhibits selectivity for type 1 or nNOS) attenuated the relaxation effect of E2 on arteries from nulliparous animals. In contrast, L-NPA had little effect on arteries from postpartum animals, suggesting a reduced influence of nNOS after parturition. Moreover, expression of nNOS protein in microvessels was decreased 39% in the postpartum state compared to arteries from nulliparous animals. We propose that the impaired E2-induced relaxation response of microvessels from postpartum animals reflects a downregulation of NO production due to lower nNOS expressed in vascular smooth muscle cells. We measured a 73% decrease in serum E2 levels in the postpartum state compared to nulliparous animals. Because E2 has been shown to increase nNOS protein expression, we propose that lower E2 levels after parturition decrease expression of nNOS, leading to a reduced vasodilatory capacity of resistance microvessels.

Impact of periodontitis definition in epidemiological research. Results from the EPIPAP study in postpartum women

The purpose of this investigation was to study the impact of using various definitions of periodontitis on the frequency of periodontitis and on the associations with some known risk factors for periodontitis in a population of postpartum women in France. A clinical examination was performed within 2-4 d postpartum in 932 at-term women at five maternity units. We studied six definitions of periodontitis; five were applicable if at least two teeth were found to have the following: (i) a proximal clinical attachment level (CAL) of ≥ 3 mm; (ii) a probing depth (PD) of ≥ 4 mm; (iii) a PD of ≥ 4 mm and a CAL of ≥ 3 mm at the same site; (iv) a proximal PD of ≥ 5 mm or a proximal CAL of ≥ 4 mm; or (v) a PD of ≥ 4 mm and a CAL ≥ 3 mm and bleeding on probing at the same site. The sixth definition required the involvement of four teeth with a PD of ≥ 4 mm and a CAL of ≥ 3 mm at the same site. Associations between case status according to each definition and maternal characteristics (age, educational level, smoking before pregnancy, and time since last dental visit) were analyzed using generalized estimating equation models. The definition of periodontitis had an impact on the frequency of periodontitis, which ranged from 12.1% to 37.7%, and produced different ORs for the associations with risk factors for periodontitis.

The neurobiology of lipid metabolism in autism spectrum disorders

Autism is a neurodevelopmental disorder characterized by impairments in communication and reciprocal social interaction, coupled with repetitive behavior, which typically manifests by 3 years of age. Multiple genes and early exposure to environmental factors are the etiological determinants of the disorder that contribute to variable expression of autism-related traits. Increasing evidence indicates that altered fatty acid metabolic pathways may affect proper function of the nervous system and contribute to autism spectrum disorders. This review provides an overview of the reported abnormalities associated with the synthesis of membrane fatty acids in individuals with autism as a result of insufficient dietary supplementation or genetic defects. Moreover, we discuss deficits associated with the release of arachidonic acid from the membrane phospholipids and its subsequent metabolism to bioactive prostaglandins via phospholipase A(2)-cyclooxygenase biosynthetic pathway in autism spectrum disorders. The existing evidence for the involvement of lipid neurobiology in the pathology of neurodevelopmental disorders such as autism is compelling and opens up an interesting possibility for further investigation of this metabolic pathway.