Biomedical subjects

U Gaur

Publications and source records attributed to U Gaur.

5 recordsLinked to original sources

PubMed2001

Tumour targeted delivery of encapsulated dextran-doxorubicin conjugate using chitosan nanoparticles as carrier.

Doxorubicin (DXR) commonly used in cancer therapy produces undesirable side effects such as cardiotoxicity. To minimize these, attempts have been made to couple the drug with dextran (DEX) and then to encapsulate this drug conjugate in hydrogel nanoparticles. By encapsulation of the drug conjugate in biodegradable, biocompatible long circulating hydrogel nanoparticles, we further improved the therapeutic efficacy of the conjugate. The size of these nanoparticles as determined by quasi-elastic light scattering, was found to be 100+/-10 nm diameter, which favors the enhanced permeability and retention effect (EPR) as observed in most solid tumors. The antitumor effect of these DEX-DXR nanoparticles, was evaluated in J774A.1 macrophage tumor cells implanted in Balb/c mice. The in vivo efficacy of these nanoparticles as antitumor drug carriers, was determined by tumor regression and increased survival time as compared to drug conjugate and free drug. These results suggest that encapsulation of the conjugate in nanoparticles not only reduces the side effects, but also improves its therapeutic efficacy in the treatment of solid tumors.

Animals↗

PubMed2000

Biodistribution of fluoresceinated dextran using novel nanoparticles evading reticuloendothelial system.

The rapid clearance of circulating nanoparticles from the blood stream coupled with their high uptake by liver and spleen has thus far been overcome by reducing the particle size, and by making the particle surface hydrophilic with poloxamers and poloxamines. We have prepared hydrogel nanoparticles of polyvinylpyrrolidone of a size less than 100 nm diameter with precise size distribution. Since the inner cores of these particles are also hydrophilic, these particles are capable of encapsulating water-soluble compounds. Biodistribution of these particles shows practically negligible (<1%) uptake by the macrophages in liver and spleen, and approximately 5-10% of these particles remain in circulation even 8 h after i.v. injection. Increasing the surface hydrophobicity as well as particle size can increase the RES uptake of these particles. Because of longer residence in blood, the hydrogel nanoparticles have potential therapeutic applications particularly in cancer: the water-soluble cytotoxic agents encapsulated in these particles can be targeted to tumors while minimizing the likelihood of toxicity to reticuloendothelial system (RES).

Animals↗

PubMed1997

Academic performance of various categories of students admitted to Lady Hardinge Medical College, New Delhi.

A retrospective study of 4 consecutive academic batches of students was conducted to analyse the performance level of students in 3 university examinations of MBBS. The students were divided into 3 categories based on the criteria of entrance into the medical college. The category I included students who entered through a tough pre-medical test, category II comprised those nominated by government and defence personnel and category III included the Schedule Caste and Schedule Tribe students. The results of the category I was remarkably better than that of II while that of category III was dismal. The last two categories had a large number of students leaving the college without completing their course resulting in 5.4% wastage of precious medical seats and psychological distress. Necessary remedial measures must be planned at the earliest.

Adult↗

PubMed1996

Mastoid canals in adult human skulls.

Mastoid canals (tunnels) were observed in 41 (7.7%) of 265 dry human skulls. The canals were 2-27 mm long. This feature has not been reported before. dissection of 30 mastoid regions in cadavers showed that the canals contained a branch of the occipital artery and a vein. It is possible that during development of the mastoid process the squamous temporal bone ossifies over the vessels, giving rise to the canals.

Adult↗

PubMed1994

Submandibular gland with multiple ducts.

A morphological peculiarity was observed in the form of a submandibular gland having three ducts. These ducts opened separately into the oral cavity. Only the upper and the largest of these three ducts was in the usual position and had the expected relation to the lingual nerve. Such a condition is to be kept in mind by a surgeon or a radiologist performing sialography. Unless each of the duct in instilled he may miss pathological findings.

Adult↗