Oxidized Low-density Lipoproteins and Lipopolysaccharides Augment Carotid Artery Plaque Vulnerability in Hypercholesterolemic Microswine

Atherosclerosis is a chronic inflammatory disease and hypercholesterolemia is a risk factor. This study aims to compare the potency of lipopolysaccharide (LPS) and oxidized low-density lipoproteins (oxLDL) to induce plaque formation and increase plaque vulnerability in the carotid artery of hypercholesterolemic Yucatan microswine. Atherosclerotic lesions at the common carotid artery junction and ascending pharyngeal artery were induced in hypercholesterolemic Yucatan microswine at 5-6 months of age with balloon angioplasty. LPS or oxLDL were administered intraluminally at the site of injury after occluding the arterial flow temporarily. Pre-intervention ultrasound (US), angiography, and optical coherence tomography (OCT) were done at baseline and just before euthanasia to assess post-op parameters. The images from the US, OCT, and angiography in the LPS and the oxLDL-treated group showed increased plaque formation with features suggestive of unstable plaque, including necrotic core, thin fibrous caps, and a signal poor region more with oxLDL compared to LPS. Histomorphology of the carotid artery tissue near the injury corroborated the presence of severe lesions in both LPS and oxLDL-treated pigs but more in the oxLDL group. Vascular smooth muscle and endothelial cells treated with LPS and oxLDL showed increased folds changes in mRNA transcripts of the biomarkers of inflammation and plaque vulnerability compared to untreated cells. Collectively, the results suggest that angioplasty-mediated intimal injury of the carotid arteries in atherosclerotic swine with local administration of LPS or ox-LDL induces vulnerable plaques compared to angioplasty alone and oxLDL is relatively more potent than LPS in inducing vulnerable plaque.

Influence of nano-silica additions on hydration characteristics and cytotoxicity of calcium aluminate as biomaterial

Composites of nano-calcium aluminate 'CA' biocement, synthesized by a solid state reaction, were prepared with 5, 10 and 20 wt.% of nano-SiO₂ particles. The influence of nano-SiO₂ particle additions on the physico-mechanical properties and hydration characteristics of CA biocement was studied. Calcium ion concentrations and, pH values of the curing medium were measured. The hydration characteristics of pure and composite CA phase were studied by determining the X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). Evaluation of cytotoxicity against the skin normal human cell line BJ-1 was carried out. The results showed that the bulk density and micro-hardness of the composite CA containing 10 wt.% of nano-SiO₂ were better than those of pure CA and composite prepared with higher weight percentages of nano-SiO₂. Both pure and composite CA bio-cements showed no cytotoxicity, making these materials suitable for medical applications.

Design, synthesis, molecular modeling and anti-hyperglycemic evaluation of novel quinoxaline derivatives as potential PPARγ and SUR agonists

In our effort to develop potent anti-hyperglycemic agents with potential agonistic activities toward PPARγ and SUR, three novel series of quinoxaline derivatives bearing sulfonylurea or sulfonylthiourea moieties with different linkers were designed and synthesized. Some of the newly synthesized compounds were evaluated in vivo for their anti-hyperglycemic activities in STZ-induced hyperglycemic rats. Compounds 15_a, 15_e, 19_b and 24_a exhibited the highest anti-hyperglycemic activities with % reduction in blood glucose level of (50.58, 43.84, 45.10 and 49.62, respectively). Additionally, eight compounds revealed potent anti-hyperglycemic activities were further evaluated in vitro for their PPARγ binding affinity and insulin-secreting ability as potential mechanisms for anti-hyperglycemic activity. Four compounds (15_a, 15_b, 15_d and 15_e) significantly bound to PPARγ with IC₅₀ values of 0.482, 0.491, 0.350 and 0.369μM, respectively. Moreover, Compounds 15_a and 15_b have demonstrated induction of insulin-secretion with EC₅₀ values of 0.92 and 0.98μM, respectively. Furthermore, molecular docking and pharmacophore generation techniques were carried out to investigate binding patterns and fit values of the designed compounds with PPARγ and SUR, respectively.

The timing of breastfeeding initiation and its correlates in a cohort of rural Egyptian infants

Recent data on the patterns and correlates of the timing of breastfeeding initiation in newborns are scanty for many countries including Egypt. To obtain such data in four villages in rural Bilbeis, we recruited apparently healthy, single neonates and their apparently healthy mothers within 4 days of child birth, and followed them prospectively during 1987 through 1989. All 150 neonates included in the analyses were breastfed for some duration. At the time of the first breastfeed, 36, 37, and 27 per cent of the neonates were aged < 2, 2-5, and > or = 6 hours, respectively. All neonates had received the first breastfeed by age 72 hours. In a multivariate, polytomous logistic regression model, modern birth attendants and longer ( > 8 hours) duration of labour were significantly associated with deferment of breastfeeding initiation till the neonate was aged > or = 6 hours. Breastfeeding initiation appeared to be unduly delayed in our study mothers and infants given that they were apparently healthy during the early post-partum period. Later initiation of breastfeeding was associated with indiscriminate prelacteal feeding, earlier termination of breastfeeding, and unwelcome supplementation practices. Our findings emphasize the need to initiate and/or strengthen programmes to promote appropriate breastfeeding practices in Bilbeis and other comparable areas.

Breast-feeding in Egypt

Planning, implementation and evaluation of programmes to promote appropriate infant feeding practices require detailed, current information about these practices in the target populations. To estimate the prevalences and identify the correlates of overall breast-feeding and of exclusive breast-feeding in different age periods during infancy, a cohort of 152 apparently healthy neonates and their mothers were followed during October 1987 through April 1989 in rural Bilbeis, Sharqiya Governorate, Egypt. Feeding data were collected through twice weekly home visits thus reducing the potential for bias in our findings due to respondent recall errors. The prevalence of overall breastfeeding in the infants declined from 100% in age period 0-11 weeks to 89% in age period 36-47 weeks. Mothers with previous living children were associated with significantly higher (odds ratio [OR]: 6.53, 95% confidence interval [CI]: 1.33-32.09) and ownership of refrigerators was associated with significantly lower (OR: 0.18, 95% CI: 0.05-0.67) overall breast-feeding prevalences in age periods 24-35 and 36-47 weeks, respectively. The prevalence of exclusive breast-feeding in breast-fed infants dropped from 20% in age period 0-11 weeks to 0% in age period 36-47 weeks. After multivariate adjustment, prelacteal feeding was significantly negatively (OR: 0.12, 95% CI: 0.04-0.37) associated with exclusive breast-feeding in age period 0-11 weeks. Nearly 90% of Bilbeis infants were breast-fed at age 47 weeks, but the initiation of supplementation at 0-11 weeks in 80% of breast-fed infants is contrary to current recommendations.(ABSTRACT TRUNCATED AT 250 WORDS)

Prelacteal infant feeding practices in rural Egypt

Data collected during a prospective cohort study of infant feeding and health in rural Bilbeis, Egypt, were analysed to define prelacteal infant feeding practices, identify their determinants, and assess whether these practices were predictive of breastfeeding and supplementation patterns and diarrhoea incidence during infancy. Sixty per cent (89/149) of study infants were prelacteally fed sugar-water, teas, or both. Lack of milk in the mother's breast (74 per cent), and maternal exhaustion or illness following labour (29 per cent) were the two most commonly stated reasons for prelacteal feeding. After multivariate adjustment, significantly higher incidence of prelacteal feeding was associated with childbirth during the warmer months [odds ratio (OR): 2.4; 95 per cent confidence interval (CI): 1.1-5.1], birth attendants with modern training (OR: 5.5; 95 per cent CI: 1.7-17.5), and labour lasting > 8 hours (OR: 2.3; 95 per cent CI: 0.1-4.9). Prelacteally fed infants were significantly less likely to be exclusively breastfed in age periods 0-3, 4-7, and 8-11 weeks. Diarrhoea incidence was higher among prelacteally fed infants in age periods 0-11, 12-23, and 36-47 weeks. Indiscriminate practice of prelacteal feeding and early supplementation of breastfeeding need to be discouraged.