Enzymic studies of glycol and glycerol lipids containing O-alkyl bonds in liver and tumor tissues

The utilization of [1-¹⁴C]hexadecyl-[2-³H]ethyleneglycol and [1-¹⁴C]hexadecyl-[2-³H]glycerol as substrates for acyltransferase, phosphotransferase, phosphorylcholine, and phosphorylethanolamine transferase, and O-alkyl cleavage activities in cell-free preparations from normal rat liver and preputial gland tumors of mice was investigated. Our studies demonstrate that alkylethyleneglycols, like alkylglycerols, can serve as substrates for acyltransferases in both the liver and tumor microsomes; the product alkylacylethyleneglycerol can be readily deacylated by pancreatic lipase. A polar lipid was formed from the alkylethyleneglycol by the tumor homogenates in the presence of ATP and Mg²⁺; although the small quantities formed precluded absolute identification, its thin-layer Chromatographic behavior in acidic and basic solvent systems indicated that a free phosphate group was present. As expected, phosphorylbase transferases in these preparations did not utilize either the alkylethyleneglycol or alkylglycerol as substrates. The O-alkyl moiety of hexadecyl-ethyleneglycol was oxidized to hexadecanal by a tetrahydropteridine-dependent cleavage enzyme in rat liver microsomes, whereas in the tumor microsomes this activity was not present. We conclude that alkylethyleneglycols are metabolized in a manner similar to alkylglycerols and perhaps by identical enzymes.     

Tremacron hongheense,a New Species of Gesneriaceaefrom Southeastern Yunnan,China

A new species of Gesneriaceae from Honghe County, Southeastern Yunnan, China, Tremacron hongheense WH. Chen & YM. Shui, is described and illustrated. The new species is similar to Tremacron forrestii Craib, but differs by its leaf blade adaxially sparsely long setose (vs. densely white appressed pubescent and sparsely rusty brown villous), corolla tube outside short white glandular (vs. nearly glabrous), corolla lobes red and thickening at apex, especially adaxial lip (vs. yellow and not thickening), stamens 16-18cm long (vs. 04-12cm long), staminode 05-14cm long (vs. 02-04cm long).     

Effects of grazing on plant species diversity and carbon partitioning in semiarid rangelands of northeastern China

Grasslands are one of the most widespread landscapes worldwide, covering approximately one-fifth of the world’s land surface, where grazing is a common practice. How carbon storage responds to grazing in steppes remains poorly understood. We quantified the effects of grazing on community composition and species diversity, and carbon storage in two typical grasslands of northeastern China, one in Horqin and the other one in Hulunbeier. In both grasslands, grazing did not influence plant species diversity. However, it substantially decreased aboveground carbon by 31% and 54% in Horqin and Hulunbeier, respectively. Fenced and grazing treatments showed a similar belowground carbon at both locations. The predominant carbon pool in the study grassland ecosystem was found in the upper 100 cm soil depth, from 98.2 to 99.1% of the total carbon storage. There were no significant effects of grazing on soil carbon neither in the whole profile nor in the uppermost 20 cm soil depth in the two study grasslands. Studies on the effects of varying rangeland management, such as region disparity and grazing systems, may have important consequences on species diversity and carbon partitioning, and thus on rangeland stability and ecosystem functioning.     

Peak plasma interleukin-6 and other peripheral markers of inflammation in the first week of ischaemic stroke correlate with brain infarct volume, stroke severity and long-term outcome

Background

Cerebral ischaemia initiates an inflammatory response in the brain and periphery. We assessed the relationship between peak values of plasma interleukin-6 (IL-6) in the first week after ischaemic stroke, with measures of stroke severity and outcome.

Methods

Thirty-seven patients with ischaemic stroke were prospectively recruited. Plasma IL-6, and other markers of peripheral inflammation, were measured at pre-determined timepoints in the first week after stroke onset. Primary analyses were the association between peak plasma IL-6 concentration with both modified Rankin score (mRS) at 3 months and computed tomography (CT) brain infarct volume.

Results

Peak plasma IL-6 concentration correlated significantly (p < 0.001) with CT brain infarct volume (r = 0.75) and mRS at 3 months (r = 0.72). It correlated similarly with clinical outcome at 12 months or stroke severity. Strong associations were also noted between either peak plasma C-reactive protein (CRP) concentration or white blood cell (WBC) count, and all outcome measures.

Conclusions

These data provide evidence that the magnitude of the peripheral inflammatory response is related to the severity of acute ischaemic stroke, and clinical outcome.