Cigarette smoke (CS) causes pulmonary emphysema in humans and elastin degradation plays a key role in its pathogenesis. Previous studies on CS-exposed animals have been equivocal and have not clearly demonstrated the progression of the disease. In this study, morphometry was used to assess lung modifications to alveolar septa, airspaces, elastic and collagen fibers, and alveolar macrophages. Male (n = 40) C57/BL6 mice were exposed 3 times/day, whole body, to CS from three cigarettes for 10, 20, 30, or 60 days. Control groups (n = 10) were sham-smoked or received no exposure (day 0, n = 10). Morphometry included measurements of volume fraction of alveolar septa and airspaces, elastic and collagen fibers, and surface fraction of elastic fibers and alveolar septa. Morphometrical differences in mice after 60 days of exposure were greater than those after 10, 20, or 30 days, suggesting a progression of the disease. Inflammatory lesions in the lungs of mice contained significantly more metalloelastase (MMP-12) in macrophages at 10, 20, and 30 days than in controls of mice exposed for 60 days. These results suggest that elastin degradation took place during development of pulmonary changes in mice exposed to CS, and activation of MMPs specific for elastin may be a determining factor for susceptibility to emphysema.
Since the World Health Organization (WHO) declared coronavirus infection (COVID-19) a Public Health Emergency of International Concern in January 2020, there have been many concerns about pregnant women and the possible effects of this emergency with catastrophic outcomes in many countries. Information on COVID-19 and pregnancy are scarce and spread throughout a few case series, with no more than 50 cases in total. The present review provides a brief analysis of COVID-19, pregnancy in the COVID-19 era, and the effects of COVID-19 on pregnancy.
Low maternal vitamin D levels have been associated with adverse pregnancy outcome. A recent study has suggested that low maternal vitamin D levels at the time of delivery are also associated with an almost fourfold increase in caesarean section risk. The aim of the present study was to investigate whether there is a difference in maternal serum 25-hydroxyvitamin D (25(OH)D) levels at 11-13 weeks' gestation according to the mode of delivery. Maternal serum 25(OH)D levels were measured at 11-13 weeks' gestation in 995 singleton pregnancies resulting in the birth of phenotypically normal neonates at term. The measured 25(OH)D levels were adjusted for maternal age, BMI, racial origin, smoking, method of conception and season of blood testing, and the adjusted levels (multiple of the median; MoM) were compared between those who subsequently delivered vaginally and those that delivered by caesarean section. Delivery was vaginal in 79·6 % of cases, by emergency caesarean section in 11·6 % and by elective caesarean section in 8·8 %. The median 25(OH)D level in our population was 46·82 (interquartile range (IQR) 27·75-70·13) nmol/l. The adjusted maternal median 25(OH)D levels in the emergency and elective caesarean section groups (0·99, IQR 0·71-1·46 MoM and 0·96, IQR 0·73-1·27 MoM, respectively) were not significantly different from the vaginal delivery group (0·99, IQR 0·71-1·33 MoM; P¼ 0·53 and P¼0·81, respectively). First-trimester maternal serum 25(OH)D levels are similar between women who subsequently have a vaginal delivery and those who deliver by elective or emergency caesarean section.
Key words: Vitamin D: Pregnancy: Caesarean section: Vaginal deliveryVitamin D has been implicated in the pathogenesis of CVD and diabetes mellitus (1,2) . Recent studies have also reported a link between maternal vitamin D deficiency and adverse pregnancy outcomes such as pre-eclampsia, gestational diabetes and small-for-gestational-age neonates (3 -5) .Vitamin D plays an important role in Ca homeostasis, bone mineralisation and muscle performance. The active metabolite of vitamin D, 1,25-dihydroxyvitamin D, binds to a vitamin Dspecific nuclear receptor in muscle tissue (6) , which leads to de novo protein synthesis, muscle cell growth (7) and improved muscle function (8) . A recent case-control study has reported that low maternal serum 25-hydroxyvitamin D (25(OH)D) concentration at the time of delivery was associated with an increased risk of caesarean section (emergency or elective) (9) , and this was attributed to the negative effect of vitamin D deficiency on muscle performance and uterine contractions.The aim of the present study was to assess further possible differences in maternal serum levels of 25(OH)D in the first trimester of pregnancy between women who subsequently have vaginal delivery compared with those who deliver by caesarean section. If vitamin D deficiency is associated with an increased risk of caesarean section due to suboptimal muscle function, this association would have been more marked in women...
Light cigarette (LC) exposure is supposed to be less hazardous with a decreased incidence of cancer and tobacco-associated diseases. C57BL/6 mouse groups were subjected to smoke from 3, 6 or 12 LC for 60 days and compared with mice exposed to ambient air (EAA) in order to study lung injury by morphometrical and biochemical methods. Bronchoalveolar lavage (BAL) analysis and histology and stereology were performed. Tissue from the right lung was used for measuring thiobarbituric acid reactive substances (TBARS) and Western blot analysis. One way anova was performed followed by the Student-Newman Keuls post-test (P < 0.05). The cellular content of BAL was 95% alveolar macrophages in all groups except in mice exposed to 3 LC, where 23% neutrophils were observed. Emphysema was not observed in three and 6 LC, but it was found in 12 LC parallel to increased volume density (Vv) of airspaces from 61.0 +/- 0.6 (EAA) to 80.9 +/- 1.0 (12 LC) and decreased Vv of elastic fibres from 17.8 +/- 0.9 (EAA) to 11.8 +/- 0.6 (12 LC). All exposed groups to LC showed low TBARS levels compared with mice EAA. Lung tissue from animals exposed to 12 LC showed decreased tissue inhibitor of metalloprotease-2 and increased matrix metalloprotease-12 detection, which suggests an imbalance in extracellular matrix (ECM). Increased tumour necrosis factor-alpha and nuclear factor-kappaB detection were observed in exposed groups to LC when compared with mice EAA. The data suggest that LC is so dangerous to lungs as full-flavour cigarettes inducing ECM imbalance and emphysema.
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