Biomedical subjects

M Sohail

Publications and source records attributed to M Sohail.

22 records · Page 2Linked to original sources

PubMed1995

Interaction of the chromosomal Tn 551 with two thermosensitive derivatives, pS1 and p delta D, of the plasmid pI9789 in Staphylococcus aureus.

The plasmid pI9789::Tn552 carries genes conferring resistance to penicillins and to cadmium, mercury and arsenate ions. The presence of Tn551 at one location in the chromosome of Staphylococcus aureus enhances the frequency of suppression of thermosensitivity of replication of the plasmids pS1 and p delta D which are derivatives of pI9789::Tn552. Bacteriophage propagated on the bacteria in which thermosensitivity of replication had been suppressed was used to transduce cadmium resistance to S. aureus PS80N. The cadmium-resistant transductants obtained carried plasmid pS1 or p delta D with a copy of Tn551 inserted into a specific site on pS1 but into several different sites on p delta D. The possible mechanisms of the suppression are discussed.

Base Sequence↗

PubMedDate not supplied

Linkage mapping of a new syndromic form of X-linked mental retardation, MRXS7, associated with obesity.

A new syndromic form of X-linked mental retardation associated to obesity, MRXS7, has been localised to Xp11.3-Xq23 in a large Pakistani family. The ten affected males show clinical manifestations of mental retardation, obesity and hypogonadism. The family was genotyped by a set of microsatellite markers spaced at approximately 10 cM intervals on the X chromosome. Linkage to five adjacent microsatellite markers, mapping in the pericentromeric area, was established and a maximum two-point lod score of 3.86 was reached at zero recombination with marker DXS1106. Reduced recombination events around the centromere prevented precise mapping of the gene.

Adolescent↗

PubMedDate not supplied

Nitric oxide induction in a rat model of selective pancreatic ischemia and reperfusion.

BACKGROUND/AIMS: Ischemia and reperfusion of the pancreas may be important in aggravating the course of acute pancreatitis. In a rat model of selective pancreatic ischemia and reperfusion, we studied plasma levels of nitric oxide and expression of nitric oxide synthase in the pancrease and lung. METHODOLOGY: Pancreatic ischemia was achieved by occlusion of the 4 main pancreatic arteries for 40 min; this was followed by a 7-hour reperfusion period (group A, 10 rats). Outcome measures were compared with those of animals undergoing a sham operation (group B, 10 rats). RESULTS: Pancreatic damage in group A animals was demonstrated by increased serum alpha-amylase and by macroscopic and microscopic evidence. Total nitric oxide synthase activity in pancrease and lung was higher than in shams [median: 0.73 vs. 0.54 pmol/mg protein/min in the pancreas (P = 0.0082); 1.38 vs. 0.68 pmol/mg protein/min in the lung (P = 0.023)]; this was mainly due to activation of the inducible isoform of the enzyme. There was an associated 58.2% increase in plasma levels of nitric oxide metabolites [from mean 55.0 to 131.6 mumol/L (P < 0.001)]. Immunohistochemistry confirmed expression of inducible nitric oxide synthase and nitric oxide-mediated oxidative damage (nitrotyrosine) in both pancreas and lung. CONCLUSIONS: Ischemia and reperfusion of the pancreas induces pancreatic damage, overexpression of inducible nitric oxide synthase and oxidative damage within the pancreas and lung.

Animals↗

PubMedDate not supplied

Echomorphologic and histopathologic characteristics of unstable carotid plaques.

BACKGROUND AND PURPOSE: Our hypothesis was that the carotid plaques associated with retinal and cerebrovascular symptomatology and asymptomatic presentation may be differ from each other. The aim of this study was to identify the sonographic and histopathologic characteristics of plaques that corresponded to these three clinical manifestations. METHODS: The echo process involved duplex preoperative imaging of 71 plaques (67 patients, 21 plaques were associated with retinal, 25 with cerebrovascular symptoms, and 25 were asymptomatic), which was performed in a longitudinal fashion. Appropriate frames were captured and digitized via S-video signal in a computer and digitized sonograms were normalized by two echo-anatomic reference points: the gray scale median (GSM) of the blood and that of the adventitia. The GSM of the plaques was evaluated to distinguish dark (low-GSM) from bright (high-GSM) plaques. Subsequent to endarterectomy, the plaques were sectioned transversely, and a slice at the level of the largest plaque area was examined for the relative size of necrotic core and presence of calcification and hemorrhage. RESULTS: Retinal symptomatology was associated with a hypoechoic plaque appearance (median GSM: 0), asymptomatic status with a hyperechoic plaque appearance (median GSM: 34), and cerebrovascular symptomatology with an intermediate plaque appearance (median GSM: 16) (P = .001). The histopathologic characteristics did not disclose differences between the three clinical groups. The hypoechoic plaque appearance was associated only with the presence of hemorrhage (median GSM for the hemorrhagic plaques, 6, and for the non-hemorrhagic ones, 20 [P = .04]). The relative necrotic core size and the presence of calcification did not show any echomorphologic predilection. CONCLUSION: Our results showed that distinct echomorphologic characteristics of plaques were associated with retinal and cerebrovascular symptomatology and asymptomatic status. Histopathologically, only the presence of hemorrhage proved to have an echomorphologic predilection.

Aged↗