Microsatellite DNA analysis of genetic effects of harvesting in old-growth eastern white pine (Pinus strobus) in Ontario, Canada.

Microsatellite DNA markers from 13 simple sequence repeat (SSR) loci were used to compare genetic diversity between preharvest pristine and postharvest residual gene pools of two adjacent virgin, old-growth ( approximately 250 years) stands of eastern white pine (Pinus strobus L.) in Ontario. There was concurrence in genetic diversity changes in the postharvest gene pools of the two stands. The total and mean numbers of alleles detected in each stand were reduced by approximately 26% after tree density reductions of approximately 75%. Approximately 18 and 21% of the low-frequency (0. 25 > P > or = 0.01) alleles and 76 and 92% of the rare (P < 0.01) alleles were lost from residual stands A and B, respectively, after harvesting. Multilocus gametic diversity was reduced by 38 and 85% and genotype additivity by approximately 50% in the residual stands after harvesting. Latent genetic potential of each stand was reduced by approximately 40%. Although heterozygosity was reduced (1-5%) in the postharvest residual stands, the reductions were not substantial and not comparable to those using other genetic diversity measures. The reductions in genetic diversity measures were slightly higher than those theoretically expected in postbottleneck populations according to drift theory. In the absence of substantial gene migration that could ameliorate the genetic losses, the ability of the postharvest white pine gene pools to adapt to changing environmental and disease conditions may have been compromised. The microsatellite DNA results for genetic effects of harvesting in old-growth eastern white pine stands were similar to those that we reported earlier from allozyme analysis (Buchert et al. 1997). The results indicate that silvicultural practices should ensure that the gene pools of remaining pristine old-growth stands are reconstituted in the regenerating stands.

The influence of advanced glycation endproducts (AGE) on the expression of human endothelial adhesion molecules.

Advanced glycation endproducts (AGEs) possibly play a dominant role in the pathogenesis of macrovascular disease in diabetes. Recent studies could demonstrate that glycated albumin (AGE-BSA) was able to stimulate vascular cell adhesion molecule-1 (VCAM.1) on endothelial cells. The aim of this study was to find out if AGE-BSA was not only able to enhance the expression of vascular cell adhesion molecule-1, but also of intercellular adhesion molecule-1 (ICAM-1) and E-Selectin on human endothelial cells. Stimulation of endothelial cells with AGE-BSA for six hours predominantly increased the expression of VCAM-1, but ICAM-1 and E-Selectin were also upregulated as shown by immunoilluminometric assay (ILMA).

Abdominal pain in children: an emergency practitioner's guide.

Children suffer from dozens of etiologies of abdominal pain. Diseases manifest themselves differently in children than in adults, and vary even within childhood age groups. Physicians must tailor examination styles to maximize information obtained from the history and physical examination. Extra-abdominal causes of pain as well as recurrent causes must be considered. Patients with undiagnosed abdominal pain should be reexamined within 24 hours. Pain lasting more than several hours may represent a serious problem.