Effect of feeding protein deficient diet on phospholipid turnover and protein kinase C mediated protein phosphorylation in rat brain.

Feeding of protein deficient diet is known to alter the transmembrane signalling in brain of rat by reducing total protein kinase C (PKC) activity. Phospholipid metabolism regulates the activation of PKC through generation of second messengers and the extent of PKC activation accordingly influences the magnitude of phosphorylation of its endogenous substrate proteins. Thus it was speculated that ingestion of protein deficient diet may modify the turnover rate of membrane phospholipids and magnitude of phosphorylation of endogenous substrate proteins of PKC. The experiments were conducted on rats fed on three different types of laboratory prepared diets viz. casein (20% casein), deficient (4% protein, rice flour as source of protein) and supplemented (deficient diet supplemented with L-lysine and DL-threonine) for 28 days. The metabolism of phosphoinositides (PIs) and phosphatidyl choline (PC) was studied by equilibrium labeling with [3H] myo inositol and [14C methyl] choline chloride respectively. The phosphorylation of endogenous substrate proteins of PKC was studied by using 32P-gamma-ATP followed by SDS-PAGE and autoradiography. The results suggest that in deficient group, there is an increased incorporation of [3H] myo inositol in PIs and inositol phosphate pool in comparison to the casein group. The phosphatidyl inositol (PI) turnover reduced, although there was a marginal increase in the phosphatidyl inositol monophosphate (PIP) and phosphatidyl inositol bis phosphate (PIP2). Supplementation of diet showed a reversal of the pattern towards control to a considerable extent. In the deficient group, PC metabolism showed an increased incorporation of [14C methyl] choline in choline phospholipids but decreased incorporation in phosphoryl choline in comparison with the casein group. The increase in total PC contents was significant but marginal in residue contents. The turnover rate of PC increased only marginally and that of residue declined. Supplementation of diet reduced the total contents of PC and residue, but the turnover rate of PC and residue remained still higher. Phosphorylation of endogenous proteins showed four different proteins of 78, 46, 33 and 16 kDa to be the substrates of PKC in casein group. In deficient group, phosphorylation of these proteins increased markedly while supplementation of diet had a reversing effect rendering the values to be intermediate between casein and the supplemented group. The changes in phospholipid metabolism and in phosphorylation of endogenous substrate proteins of PKC suggest that dietary protein deficiency causes alterations in transmembrane signalling mechanism in rat brain. These effects are partially reversed by improving the quality of proteins in the diet.

Aortoaortic bypass: indications, techniques and results.

The standard surgical treatment of complex cases of aortic obstructions is difficult and sometimes even hazardous, thus necessitating the use of alternative surgical methods to manage these cases. Between 1986 and 1995, nine such patients underwent ascending aorta to descending/abdominal aorta bypass graft as an alternative procedure at a premier medical institution. There was no hospital death nor any significant morbidity. Preoperative systolic blood pressure in right upper limb ranged from 150 mm Hg to 230 mm Hg (mean 180.5 mm Hg) while postoperative systolic blood pressure in right upper limb ranged from 126 mm Hg to 150 mm Hg (mean 134 mm Hg), thereby showing marked improvement. Preoperative pressure gradient across the aortic obstruction ranged from 50 mm Hg to 120 mm Hg (mean 87.2 mm Hg). It was relieved in all except two patients who had resting gradients of 10 mm Hg and 12 mm Hg respectively. All the patients were relieved of their symptoms. After a mean follow-up of 33.3 months (range 6 to 108 months), all the patients are in New York Heart Association (NYHA) class I with evidence of good distal perfusion. This technique of bypassing the aortic obstruction has the added advantage of avoiding the complications associated with standard technique.

Hepatic ultrasonography in patients with lepromatous leprosy.

Hepatic Sonography was done in 36 patients with lepromatous Leprosy and 3 patients with borderline lepromatous leprosy with the view to assess abnormalities of size, changes in the echotexture and to observe the presence of any nodules and calcification in the liver. Routine liver function tests were also done in these patients. No definite abnormal sonographic findings were seen in the liver in a large majority of these patients. One patient, however, showed nodular changes in the liver.