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Biomedical subjects

A N Ghanem

Publications and source records attributed to A N Ghanem.

At least 19 recordsLinked to original sources

Magnetic field-like fluid circulation of a porous orifice tube and its relevance to the capillary-interstitial fluid circulation: preliminary report.

In 1886, Starling proposed a hypothesis for the capillary-interstitial fluid transfer in which capillary filtration is attributed to arterial pressure, based on Poiseuille's work in long uniform tubes. In 1967-8, the precapillary sphincter, pores and negative interstitial pressure were reported. In 1984, clinical observations inconsistent with Starling's hypothesis prompted a physical study to verify pressure dynamics in a porous orifice (G) tubes. Results demonstrate that, unlike in Poiseuille's tube, a fluid passing inside the lumen of the G tube exerts a negative energy pressure gradient on its wall; most negative over its proximal part causing inflow of fluid by suction and positive over its distal part causing fluid outflow. A net negative pressure gradient also occurs in a surrounding chamber C, causing fluid to flow in an opposite direction to lumen flow. An autonomous dynamic magnetic field-like G-C circulation occurred between lumen and surrounding fluid compartments. Reviewed literature support the contention that this sole phenomenon adequately explains the capillary-interstitial fluid transfer under both physiological and pathological haemodynamic conditions.

Animals↗

Osmotic and metabolic sequelae of volumetric overload in relation to the TUR syndrome.

In an attempt to understand the pathophysiology of the transurethral resection syndrome this prospective metabolic study was conducted on 100 consecutive patients undergoing transurethral resection of the prostate (TURP). The volume of glycine absorbed, intravenous fluid given and blood loss were calculated, and serum osmolality, sodium and glycine were measured before, during and after operation. The mean volume of glycine absorbed, fluid gain and blood loss were 0.6, 1.57 and 0.356 litres respectively. The mean weight of prostate resected was 30.8 g and resection time was 56.5 min. The mean serum osmolality dropped from 291 to 286 mOsm/l, sodium dropped from 138 to 132 mmol/l and glycine concentration increased from 293 to 3599 mumol/l post-operatively. Ten patients developed signs suggestive of the TURP syndrome. Multiple regression analysis showed that the most consistent statistically significant factors in relation to the syndrome were volumetric gain and hypo-osmolality. The latter proved to be the only significant factor later post-operatively. The increase in serum glycine and drop in serum sodium concentrations were the best serological markers, reaching significance only after excluding volumetric gain and osmolality from the analysis.

Aged↗