Biomedical subjects

Farah Khan

Publications and source records attributed to Farah Khan.

4 recordsLinked to original sources

PubMed2006

Vascularized fat transfer.

The use of free tissue transfers has dramatically improved the outcomes of soft tissue reconstructions of the face. This is particularly true when large volumes of soft tissue are needed or when the recipient bed has a compromised local blood supply. Although traditional fat grafting procedures often allow for satisfactory results in some patients, the use of scapular and parascapular free tissue transfers has markedly improved the predictability of these reconstructions, often in a single stage. As perforator flap reconstructions evolve over time, these types of flaps may eventually supplant the available fasciocutaneous free flaps as the flap of choice in these reconstructions primarily because of improved donor site scarring and morbidity.

Adipose Tissue↗

PubMed2006

Influence of Ramadan-type fasting on enzymes of carbohydrate metabolism and brush border membrane in small intestine and liver of rat used as a model.

During Ramadan, Muslims the world over abstain from food and water from dawn to sunset for a month. We hypothesised that this unique model of prolonged intermittent fasting would result in specific intestinal and liver metabolic adaptations and hence alter metabolic activities. The effect of Ramadan-type fasting was studied on enzymes of carbohydrate metabolism and the brush border membrane of intestine and liver from rat used as a model. Rats were fasted (12 h) and then refed (12 h) daily for 30 d, as practised by Muslims during Ramadan. Ramadan-type fasting caused a significant decline in serum glucose, cholesterol and lactate dehydrogenase activity, whereas inorganic phosphate increased but blood urea N was not changed. Fasting resulted in increased activities of intestinal lactate (+34%), isocitrate (+63%), succinate (+83%) and malate (+106%) dehydrogenases, fructose 1,6-bisphosphatase (+17%) and glucose-6-phosphatase (+22%). Liver lactate dehydrogenase, malate dehydrogenase, glucose-6-phosphatase and fructose 1,6-bisphosphatase activities were also enhanced. However, the activities of glucose-6-phosphate dehydrogenase and malic enzyme fell significantly in the intestine but increased in liver. Although the activities of alkaline phosphatase, gamma-glutamyl transpeptidase and sucrase decreased in mucosal homogenates and brush border membrane, those of liver alkaline phosphatase, gamma-glutamyl transpeptidase and leucine aminopeptidase significantly increased. These changes were due to a respective decrease and increase of the maximal velocities of the enzyme reactions. Ramadan-type fasting caused similar effects whether the rats fasted with a daytime or night-time feeding schedule. The present results show a tremendous adaptation capacity of both liver and intestinal metabolic activities with Ramadan-type fasting in rats used as a model for Ramadan fasting in people.

Adaptation, Physiological↗

PubMed2005

Effect of ischemia reperfusion on sodium-dependent phosphate transport in renal brush border membranes.

The effect of ischemia induced acute renal failure (ARF) on the transport of phosphate (Pi) after early (15-30 min) and prolonged (60 min) ischemia in the brush border membrane vesicles (BBMV) from rat renal cortex was studied. Sodium-dependent transport of Pi declined significantly and progressively due to ischemia. Western blot analysis of BBM from ischemic rats showed decreased expression of NaPi-2. A compensatory increase was observed in Pi uptake in BBMV from contralateral kidneys. There was no significant difference in NaPi-2 expression between BBMV from sham and contralateral kidneys. Early blood reperfusion for 15 min after 30 min ischemia caused further decline in Pi uptake. Prolonged reperfusion for 120 min caused partial reversal of transport activities in 30-min ischemic rats. However, no improvement in the transport of Pi was observed in 60-min ischemic rats after 120 min of blood reperfusion. Kinetic studies showed that the effect of ischemia and blood reperfusion was dependent on the Vmax of the Na-Pi transporter. Western blot analysis showed increased expression of NaPi-2 in the BBMs from ischemia-reperfusion animals. Further, a shift in the association of Na ions to transport one molecule of Pi was observed under different extracellular Na concentrations [Na]o. Feeding rats with low Pi diet and/or treatment with thyroid hormone (T3) prior to ischemia resulted in increased basal Pi transport. Ischemia caused similar decline in Pi transport in BBM from LPD and/or T3 animals. However, recovery in these animals was faster than the normal Pi diet fed (NPD) animals. The study suggests a change in the intrinsic properties of the Na-Pi transporter in rat kidneys due to ischemia. The study also indicates that treatment with T3 and feeding LPD prior to ischemia caused faster recovery of phosphate uptake due to ischemia-reperfusion injury.

Animals↗

PubMedDate not supplied

Effect of ischemia and reperfusion on enzymes of carbohydrate metabolism in rat kidney.

BACKGROUND: Ischemia results in rapid decline in mitochondrial electron transfer, resulting in decreased ATP levels, and fall in intracellular pH. The purpose of the study was to examine the effects of ischemia and reperfusion on the activities of enzymes of carbohydrate metabolism in rat kidney. METHODS: Ischemia was induced by occlusion of the left renal artery for specified times. The activities of Na-K ATPase, lactate dehydrogenase (LDH), Malate dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme (ME), glucose-6-phosphatase (G6Pase), and fructose-1, 6-bisphosphatase (FBPase) were studied in the homogenates of whole (WC), superficial (SCH), and juxtamedullary (JMCH) cortices and medulla (MH). RESULTS: The activities of LDH, G6Pase, FBPase, and ME rapidly increased whereas those of MDH and G6PDH decreased by brief ischemia of 5 min both in the cortex and medulla. Prolonged ischemia (15-60 min) caused progressive decrease in the enzyme activities. Reperfusion for 60 min caused complete recovery of the enzyme activities studied. CONCLUSIONS: The results demonstrate that activities of carbohydrate metabolism enzymes are restored by short-term reperfusion following 30 min ischemia.

Animals↗