Hemorrhagic shock and encephalopathy: further description of a new syndrome.

Abrupt onset of coma, seizures, severe shock, and hyperpyrexia occurred in two previously healthy children. Their illnesses closely resembled a clinical syndrome of uncertain cause, the hemorrhagic shock and encephalopathy syndrome. Our patients had striking similarities to as well as certain differences from reported patients. Based on the similarities, we believe our two cases represent additional occurrences of the syndrome. Based on the differences, we conclude that the syndrome should be labeled "shock and encephalopathy syndrome" and that the prognosis may be improved by early aggressive treatment of shock.

Summer survival of the green spruce aphid, Elatobium abietinum, in North East Scotland.

In North East Scotland small numbers of all developmental stages of the green spruce aphid survived on Sitka spruce needles during the summer months despite the nutritional inadequacy of these needles for aphid survival following population collapse in early summer. The surviving adults lost weight and fat reserves in response to time and contained low numbers of embryos. No metabolic acclimatization of the respiration rate occurred in response to exposure to different temperatures. Aphid respiration rates during summer were significantly higher than those in winter. Therefore, it was concluded that no summer aestivation occurred. Summer survival was dependent on the ability of a few aphids of all instars to survive on the nutritionally inadequate host, these aphids possibly possessing higher than normal fat reserves or feeding on marginally nutritionally superior trees or shoots.

A comparison of Elatobium abietinum populations on Sitka spruce trees differing in needle retention during aphid outbreaks.

No difference in the rate of symptom development and needle loss was evident between resistant and susceptible trees. Population growth rates, which were higher on current year needles in the upper crown, adult weights, reproductive state and instar ratios were similar for aphids from both resistant and susceptible trees. Overwintering survival rates were higher on susceptible trees and were the main cause of the higher number of aphids found on susceptible trees and on the lower crown in comparison with the resistant trees and the upper crown. The supercooling points of needles from resistant trees were higher than those from susceptible trees during the three coldest months of the year-December, January and February. As the aphid freezes at the same temperature as the needle on which it feeds differences in needle freezing temperatures can result in greater aphid mortality on the resistant trees at the temperatures prevailing in NE Scotland during the period of the study. No correlation was found between provenance latitude and supercooling ability of the needles although a very great variability was evident between individual trees. Changes in the form of the super-cooling temperature frequency curves indicated a gradual increase in the quantity of nucleators present in the spruce needles during the winter, the change being more pronounced in the resistant needles.

The effects of nutrition and density on the production of alate Elatobium abietinum on Sitka spruce.

Observations over a period of 10 years showed that, in Northeastern Scotland, alatae of E. abietinum regularly appeared in mid-May, the timing being unrelated to aphid density. The peak number of alatae produced was, however, correlated with aphid density. Following an initially high level the proportion of alatae dropped to virtually nil by mid-June, whilst over the same period the aphid population density increased. Amino acid levels in spruce needles were considerably higher during the period of alate formation than they were at the termination of alate production. It is suggested that a high amino acid level was the main factor controlling the formation of alatae and that population density affected the proportions of these alatae only when nutritional levels were favourable for alate formation.

Management of life-threatening asthma with intravenous isoproterenol infusions.

Thirty-four patients with life-threatening childhood status asthmaticus were treated with intravenous isoproterenol infusions. Twenty-seven responded favorably; seven failed to respond and underwent mechanical ventilation. Intravenously administered isoporterenol was a useful therapeutic adjunct in the treatment of these severe attacks. Complications in these cases were rare, but cardiac arrhythmia, rebound bronchospasm, and acute mobilization of secretions need to be considered. Further evaluation of the efficacy of intravenous infusions of isoproterenol in status asthmaticus would be valuable.

The effect of needle age on the acceptability of Sitka spruce needles to the aphid, Elatobium abietinum (Walker).

A comparison of the feeding behaviour of E. abietinum on current year needles and previous year needles of P. sitchensis revealed that during the summer months the aphids preferentially settled on previous year needles, this response not being evident in winter. Aphids on current year needles in summer took a much longer period of time to commence sap uptake than in winter, intake ceasing following a very short feeding period. On previous year needles sap uptake in December commenced after a shorter feeding period than in June. Analysis of total and soluble nitrogen levels in Sitka spruce needles showed that current year needles had initially higher levels during shoot elongation in May and early June, but that previous year needles had higher levels for most of the remainder of the year. Quantitative analyses of amino acids revealed that in current year needles the levels were generally lower than in previous year needles. Less marked proportional differences were observed between previous year needles in May and in July/August when the needles were unsuitable. Addition of amino acids in solution into cut current year shoots resulted in increased longevity on shoots containing introduced iso-leucine, histidine and methionine and revealed a general imbalance of the amino acids.

The effects of nitrogen levels in sitka spruce needles on Elatobium abietinum (Walker) populations in North-Eastern Scotland.

In the past seven years five serious outbreaks of E. abietinum have occurred in north-eastern Scotland. These were usually characterised by a rapid build-up of numbers from April to June followed by a sudden drop in late June and early July. Rapidly increasing populations were characterised by low adult/first instar nymph ratios, slowly increasing populations exhibited higher ratios. More alatae were present when aphid numbers were high. This resulted in a decreased production of nymphs. The total soluble nitrogen level in Sitka spruce needles decreased from May to August. Most individual amino acid levels also decreased. Several essential amino acids, including methionine, histidine aud iso-leucine, were in short supply for much of this period. Amino acid levels in aphid extracts also decreased from May to July. The size of the adult aphids remained constant throughout April to late June but dry and fresh weight decreased from late April onwards. The lipid proportion of the dry weight decreased from May to August as did the number of adults bearing embryos. From July onwards a small, decreasing population of aphids existed which showed reduced rates of development and reproduction.