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Biomedical subjects

A Hussain

Publications and source records attributed to A Hussain.

At least 235 records · Page 13Linked to original sources
PubMedDate not supplied

Design, synthesis and characterisation of affinity ligands for glycoproteins.

The concepts of rational design and solid phase combinatorial chemistry were used to develop affinity adsorbents for glycoproteins. A detailed assessment of protein-carbohydrate interactions was used to identify key residues that determine monosaccharide specificity, which were subsequently exploited as the basis for the synthesis of a library of glycoprotein binding ligands. The ligands were synthesised using solid phase combinatorial chemistry and were assessed for their sugar-binding ability with the glycoenzymes, glucose oxidase and RNase B. Partial and completely deglycosylated enzymes were used as controls. The triazine-based ligand, histamine/tryptamine (8/10) was identified as a putative glycoprotein binding ligand, since it displayed particular affinity for glucose oxidase and other mannosylated glycoproteins. Experiments with deglycosylated control proteins, specific eluants and retardation in the presence of competing sugars strongly suggest that the ligand binds the carbohydrate moiety of glucose oxidase rather than the protein itself.

Adsorption↗
PubMedDate not supplied

A strategy for the generation of biomimetic ligands for affinity chromatography. Combinatorial synthesis and biological evaluation of an IgG binding ligand.

An IgG-binding ligand library comprising 88 adsorbents based on a known lead compound (Li et al., 1998) was generated on an agarose solid phase. Individual members of the library were synthesized in two chemical steps using cyanuric chloride as the scaffold immobilized on the beaded support. The library was screened for binding of pure human IgG, whence selected ligands from the library were further assessed for specificity by the purification of IgG from human plasma. The potential of this strategy for the rapid identification and evaluation of chemical leads was demonstrated by the discovery of ligands with IgG binding capabilities. It was found that ligands comprising 3-aminophenol and an aminonaphthol moiety substituted on a triazine nucleus generally performed better than other ligands in the library. An immobilized ligand 22/8 adsorbent was able to purify IgG with high yield and a purity >99% from diluted human plasma.

Adsorption↗
PubMedDate not supplied

Pectoralis major myocutaneous flap: analysis of complications in a VA population.

Forty-five cases of head and neck reconstruction with pectoralis major myocutaneous flaps (PMMF) between 1985 and 1990 were analyzed retrospectively for complications. Thirty-two cases were done at the VA Medical Center and 13 at Albany Medical Center, a private university hospital. Total complication rate was 58%. In the VA population, complication rate was 59% as compared to 54% at the Albany Medical Center, which appears statistically not significant. It has been suggested that VA populations tend to have poorer health and socioeconomic status and are more likely to have higher complication rates. This conjecture is not borne out by this study. Complications are described and compared.

Fistula↗
PubMedDate not supplied

Glucose-sensitive holographic sensors.

Holographic sensors for monitoring glucose were fabricated from hydrogel films containing chemical ligands based on phenylboronic acid. The films were transformed into reflection holograms using a diffusion method coupled with exposure to laser light. The diffraction wavelength of the holograms was used to monitor the swelling of the hydrogel film in the presence of glucose. Fully reversible changes in diffraction wavelength were demonstrated, highlighting the potential for using these holograms as glucose sensors.

Biosensing Techniques↗
PubMedDate not supplied

Vanadate induces normolipidemia and a reduction in the levels of hepatic lipogenic enzymes in obese Zucker rat.

The effects of vanadate administration on the plasma lipids and hepatic lipogenic enzymes were investigated in Zucker (fa/fa) rat, a model for obesity and non insulin-dependent diabetes. These animals were administered sodium orthovanadate through drinking water for a period of four months. The plasma levels of insulin, triacylglycerols and total cholesterol were significantly (p < 0.001) elevated in untreated obese control rats as compared to the lean animals. In the livers of obese rats, the number of insulin receptors decreased by 60% and the activities of lipogenic enzymes acetyl-CoA carboxylase and ATP-citrate lyase increased by 4.7- and 5.6-folds, respectively. The messenger RNA for ATP-citrate lyase as measured by Northern blot analysis showed a parallel increase in obese control rats. Treatment of these rats with vanadate caused 56-77% decreases in the plasma levels of insulin, triacylglycerols and total cholesterol. The insulin receptor numbers in vanadate-treated obese rats increased (119%) compared to levels in untreated obese animals. The elevated activities of acetyl-CoA carboxylase and ATP-citrate lyase observed in livers of obese rats were significantly reduced by vanadate. The messenger RNA for ATP-citrate lyase also decreased in vanadate-treated obese rats back to the lean control levels. This study demonstrates that vanadate exerts potent actions on lipid metabolism in diabetic animals in addition to the recognized effects on glucose homeostasis.

ATP Citrate (pro-S)-Lyase↗
PubMedDate not supplied

Roxatidine versus ranitidine in the treatment of patients with duodenal ulcer: a randomized, double-masked, multicenter study.

The comparative efficacy of roxatidine and ranitidine in the treatment of patients with acute duodenal ulcer was assessed at 4 and 6 weeks in this multicenter study. Ninety-four of 192 patients were given roxatidine in a single nightly dose of 150 mg, and 98 patients were given ranitidine in a single nightly dose of 300 mg. All the patients had endoscopically proven duodenal ulcer. Of the 171 assessable patients, ulcers were healed in 88% of the roxatidine group (73 of 83) and in 84% of the ranitidine group (74 of 88). No serious adverse events were reported in either group. We conclude that roxatidine 150 mg once daily is as effective and safe for the treatment of acute duodenal ulcer as ranitidine 300 mg once daily.

Administration, Oral↗