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Biomedical subjects

M Laidlaw

Publications and source records attributed to M Laidlaw.

8 recordsLinked to original sources
PubMed1994

Cortical granule biogenesis is active throughout oogenesis in sea urchins.

Cortical granules are secretory vesicles formed in the eggs of most animals and are essential for the prevention of polyspermy in these organisms. We have studied the biogenesis of cortical granules in sea urchin oocytes by identifying cDNA clones that encode proteins targeted selectively to the cortical granules. These cDNA clones were identified by an immunoscreen of a cDNA library using antibodies to proteins of the fertilization envelope. Four different mRNAs were identified, ranging from 4 kb to 13 kb in length, that encoded proteins targeted specifically to cortical granules. Accumulation of these mRNAs began very early in oogenesis, in oocytes approximately 10-15 microns in diameter, and continued throughout oogenesis. The mRNAs reached peak abundance (on a per cell basis) in germinal vesicle stage oocytes, and the accumulation of each mRNA was linear with respect to oocyte growth. During breakdown of the germinal vesicle these mRNAs were degraded so that in eggs the mRNA signals were at background levels. Antibodies generated to recombinant proteins made from each of these cDNA clones showed that in the oocyte each cognate protein appeared early in oogenesis. These proteins accumulated only in cortical granules: no accumulation was seen in the cytoplasm, in Golgi, or in other vesicles, and no heterogeneity of the contents was seen within the population of cortical granules. Using these antibodies we show that cortical granules accumulated linearly throughout oogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Fatal disseminated BCG infection in an 18-year-old boy.

Death from disseminated infection with BCG (bacille Calmette-Guérin) after routine vaccination is rare, and various immune defects may be responsible. An 18-year-old boy died with widespread lymph-node, bone, lung, and liver involvement 6 years after BCG vaccination. Total numbers of B lymphocytes and T lymphocytes were normal, but T lymphocytes, while transforming normally in the presence of non-specific mitogens, did not transform in the presence of purified protein derivative. Delayed-type hypersensitivity skin tests were negative. Monocytes containing alpha-naphthylacetate esterase were absent.

Adolescent↗
PubMedDate not supplied

Public speaking: a tool for career advancement.

Health care managers and executives find themselves with increasingly limited career prospects in today's financially restricted environment. How can a knowledgeable professional advance in his or her career? The author suggests public speaking as an excellent means to promote career advancement. The article suggests how to develop ideas for a speech and offers tips on presentation techniques.

Canada↗