Publications by authors named "Basma A Ahmed"

Context: Compared with the relatively benign effects of increased subcutaneous adipose tissue (SAT), increased visceral adipose tissue (VAT) volume is a causal risk factor for hypertension, hyperlipidemia, type 2 diabetes, and cardiovascular disease. In rodents, increased VAT volume and triglyceride density and ectopic lipid accumulation in kidneys and liver have been induced by alterations in the gut microbiome. However, few studies have characterized these relationships in humans.

View Article and Find Full Text PDF

Childhood obesity is a growing worldwide problem. In adults, lower cold-induced brown adipose tissue (BAT) activity is linked to obesity and metabolic dysfunction; this relationship remains uncertain in children. In this cross-sectional study, we compared cold-induced supraclavicular (SCV) BAT activity (percent change in proton density fat fraction [PDFF]) within the SCV region after 1 h of whole-body cold exposure (18°C), using MRI in 26 boys aged 8-10 years: 13 with normal BMI and 13 with overweight/obesity.

View Article and Find Full Text PDF

In rodents, lower brown adipose tissue (BAT) activity is associated with greater liver steatosis and changes in the gut microbiome. However, little is known about these relationships in humans. In adults (n = 60), we assessed hepatic fat and cold-stimulated BAT activity using magnetic resonance imaging and the gut microbiota with 16S sequencing.

View Article and Find Full Text PDF

Context: In rodents, cold exposure induces the activation of brown adipose tissue (BAT) and the induction of intracellular triacylglycerol (TAG) lipolysis. However, in humans, the kinetics of supraclavicular (SCV) BAT activation and the potential importance of TAG stores remain poorly defined.

Objective: To determine the time course of BAT activation and changes in intracellular TAG using MRI assessment of the SCV ( BAT depot) and fat in the posterior neck region ( non-BAT).

View Article and Find Full Text PDF

The activation of brown adipose tissue (BAT) is associated with reductions in circulating lipids and glucose in rodents and contributes to energy expenditure in humans indicating the potential therapeutic importance of targetting this tissue for the treatment of a variety of metabolic disorders. In order to evaluate the therapeutic potential of human BAT, a variety of methodologies for assessing the volume and metabolic activity of BAT are utilized. Cold exposure is often utilized to increase BAT activity but inconsistencies in the characteristics of the exposure protocols make it challenging to compare findings.

View Article and Find Full Text PDF

Over the last few years, the implication of the (pro)renin receptor [(P)RR] in the pathogenesis of end-organ damage has been shown through many different studies. The (P)RR plays a dual role when stimulated by renin or prorenin as it enhances both cell surface production of angiotensin and stimulates angiotensin-independent intracellular signaling cascades. Since Ichihara's group demonstrated activation of prorenin when it was bound to antibodies targeted against a specific region in the renin prosegment, they designed a complementary decapeptide to this region called the handle region to use as a potential (P)RR blocker (PRRB).

View Article and Find Full Text PDF