Purpose: Attaining lung isolation in the infant undergoing thoracic anesthesia can be challenging for the anesthesiologist. We describe a novel approach to performing lung isolation in an infant undergoing thoracotomy for lobectomy using an Arndt pediatric endobronchial blocker via an extraluminal technique.Clinical features: Lung isolation in an infant was achieved through the use of an Arndt pediatric endobronchial blocker placed externally to an endotracheal tube. The blocker's placement was facilitated through the use of a pediatric fibreoptic brochoscope placed through the guidewire of the extraluminally placed bronchial blocker. Conclusion:This novel technique may provide an easier and more reliable method of attaining single lung ventilation in infants and small children.

This research identifies the root pathogen Phytophthora cinnamomi as the primary cause of mortality in a 300-ha disease center of mixed oak trees in a native forest in southern Mexico. In increasing order of apparent field resistance to the disease, the major oak species are Quercus glaucoides, Q. peduncularis, and Q. salicifolia. P. cinnamomi was isolated from soil in the affected area from symptomatic trees and was successfully used to perform Koch's postulates on these three oak species. Artificial and natural infections produced vertically elongated discolorations in the outer xylem and distinctive phloem canker lesions with a sharp demarcation line between healthy and affected tissues. In Q. glaucoides there is little evidence that this oak species is able to resist the girdling effects of the phloem lesions, but in Q. peduncularis, and especially in Q. salicifolia, increased production of callus tissue around the phloem canker lesions suggests an active resistance mechanism that may allow these infected trees to survive somewhat longer. This particular incident is unlike other recent reports in other parts of the world of oak mortality caused by P. cinnamomi because the initial appearance of disease in this area is known (just prior to 1987), and it has subsequently expanded to the present area of 300 ha (in 1999) as a distinctive infection locus with periodically advancing infection fronts. This incident is also another dramatic illustration of the potential environmental damage that can result when P. cinnamomi is introduced into a simple forest ecosystem where the major overstory trees are susceptible to infection and are killed.

No abstract

Changes in climate are predicted to significantly affect the productivity of trees in the Great Lakes region over the next century. Forest management decisions, such as initial stand density, can promote climatic resiliency and moderate decreased productivity through the reduction of tree competition. The influences of climate (temperature and precipitation) and forest management (initial stand density) on the productivity of red pine (Pinus resinosa) across multiple sites within Huron National Forest, Michigan, were examined using dendrochronological methods. Two common planting regimes were compared in this analysis; low initial density (<988 trees per hectare) and high initial density (>1977 trees per hectare). Low initial density stands were found to have a higher climatic resilience by combining equal or greater measures of productivity, while having a reduced sensitivity to monthly and seasonal climate, particularly to summer drought.

Beech bark disease of American beech (Fagus grandifolia) is caused by the interaction of an introduced scale insect (Cryptococcus fagisuga) and the native fungus Nectria galligena, or N. coccinea var. faginata, which is thought to be introduced. Infestations of the insect precede development of the disease, and N. galligena is often found before N. coccinea var. faginata. Previously published records indicate that the beech scale extends as far west as eastern Ohio (2) and southern Ontario (Sajan, personal communication). The scale is now well established in several locations in both the Upper Peninsula (UP) and Lower Peninsula (LP) of Michigan. The scale insect has been found in beech stands throughout three counties (Oceana, Mason, and Muskegon) along the Lake Michigan shore in the LP, extending for at least 100 km from north to south, and occurring up to about 80 km inland. In the eastern UP, beech scale has been found in four counties (Alger, Chippewa, Luce, and Schoolcraft). The heaviest beech scale infestations are distributed around Ludington State Park in the west central LP and the Bass Lake Forest Campground in the eastern UP. The extent of the insect infestation suggests that it has been present in Michigan for many years, with anecdotal accounts placing the first observations of beech scale at Ludington State Park around 1990. These infection centers are distant from previously known beech scale infestations and are located in heavily used recreation areas, suggesting that the insect may have been transported by human activity. Perithecia of N. coccinea var. faginata were found in Ludington State Park in the LP at N 44° 1.951', W 86° 29.956' and perithecia of N. galligena were found at the Bass Lake site in the UP, at N 46° 27.748', W 85° 42.478'. The identity of the fungi collected from each location was confirmed by measurements of perithecium and ascospore morphology (1). Perithecia at both sites were scarce and difficult to find. Surveys planned for the summer and fall of 2001 will further delimit the occurrence and distribution of the pathogens involved in the disease in Michigan. To our knowledge, this is the first report of the beech scale and beech bark disease in Michigan, with N. galligena and N. coccinea var. faginata identified as the pathogens. References: (1) H. V. T. Cotter and R. O. Blanchard. Plant Dis. 65:332–334, 1981. (2) M. E. Mielke et al. Plant Dis. 69:905, 1985.