Xylene Poisoning: A Report on One Fatal Case and Two Cases of Recovery after Prolonged Unconsciousness

Three cases of xylene poisoning occurred after prolonged inhalation of paint fumes. Analysis showed that xylene comprised more than 90% of the solvent in the paint, the total solvent comprising 34% of the paint by weight. One patient was dead on admission, while the other two recovered after at least 15 hours'' loss of consciousness. Both patients had transient liver cell damage, and one temporary impairment of renal function.     

Computer-assisted Follow-up Register for the North-East of Scotland

An automated follow-up register for the detection of iatrogenic thyroid disease has been established as a joint venture between the general practitioners in the north-east of Scotland and the thyroid clinic of Aberdeen General Hospitals.The data-processing operations in the system are handled by an International Computers Limited 4/50 computer. Patients are followed up at predetermined intervals and the system has been designed to process, screen, and store clinical and biochemical follow-up data and report results to the patients, general practitioners, and the hospital records department.     

Characterization and metabolism of ovine foetal lipids

1. Total phospholipid concentrations in liver, kidney and brain of the 140-day ovine foetus were only half of those in comparable maternal tissues. 2. Phosphatidylcholine was the predominant phospholipid in all foetal tissues examined. The most striking difference between foetal and maternal tissues in individual phospholipids was in the heart; foetal heart contained more ethanolamine plasmalogen than choline plasmalogen, whereas in adult tissue the concentration of these was reversed. Sphingomyelin content of foetal brain was only one-sixth of that of maternal brain tissue. 3. Oleic acid (18:1) was the predominant acid in the phospholipid extracted from foetal tissues, except in brain where palmitic acid (16:0) was slightly higher. In phospholipids from adult tissues there was a higher proportion of unsaturated fatty acids (linoleic acid, 18:2, and linolenic acid, 18:3) and a correspondingly lower proportion of oleic acid (18:1). The distribution of fatty acids in the neutral lipid fraction of foetal and maternal tissues was very similar; oleic acid (18:1) was generally the principal component. 4. (14)C derived from [U-(14)C]-glucose and [U-(14)C]fructose infused into the foetal circulation in utero was incorporated into the neutral lipids and phospholipids of heart, liver, kidney, brain and adipose tissue. 5. Phospholipid analysis revealed that the specific activity of phosphatidic acid was higher in liver than in other tissues. The specific activity of phosphatidylethanolamine was less than that of phosphatidylcholine in heart, but in other tissues they were about the same. The specific activities of phosphatidylinositol and phosphatidic acid in brain were very similar and were higher than the other components. The specific activity of phosphatidylserine was highest in liver and brown fat. 6. The pattern of incorporation of (14)C derived from [(14)C]glucose and [(14)C]fructose into foetal neutral lipids was similar. Diglyceride accounted for most of the radioactivity in brain, whereas triglyceride had more label in heart, liver, kidney and fat.     

Standing biomass and production in water drainages of the foothills of the Philip Smith Mountains, Alaska

In the foothills of the Philip Smith Mountains, Brooks Range, Alaska, tussock tundra is the most widely distributed vegetation, and it occurs on rolling hills and in valleys that were shaped by a sequence of Pleistocene glaciations. In this study, aboveground standing biomass and production were compared in "intertrack tundra" areas that were relatively homogenous with respect to downslope drainage and adjacent "water tracks" that acted to channel water flow to the valley bottom stream. Comparisons of biomass, leaf area index, and specific leaf weight were also made between upper and lower slope positions. Similarities and differences of vegetation structure are examined with respect to graminoid, deciduous shrub, evergreen shrub, herbaceous, and bryophyte components.
Water tracks were found to have 1.5–1.7 times the biomass of intertrack tundra, and production (excluding secondary growth) in water tracks was 40% greater than in intertrack tundra. The aboveground biomass for all areas studied and the annual production values were similar to those found in other studies of tussock tundra. While only slight differences in depth of thaw occurred in water tracks and intertrack tundra during June and early July, water tracks thawed more deeply with the onset of summer rains. Warmer temperatures at 40 cm depth in July and August may have increased nutrient availability, whereas greater rooting depth and movement of water may have increased nutrient capture in water tracks as compared with the intertrack areas. Greater biomass and a deeper thaw depth occurred at upper slope locations.     

A cross-species comparison of the apolipoprotein B domain that binds to the LDL receptor

Apolipoprotein (apo)-B-100 is the ligand that mediates the clearance of low density lipoprotein (LDL) from the circulation by the apoB,E (LDL) receptor pathway. Clearance is mediated by the interaction of a domain enriched in basic amino acid residues on apoB-100 with clusters of acidic residues on the apoB,E (LDL) receptor. A model has been proposed for the LDL receptor binding domain of apoB-100 based on the primary amino acid sequence (Knott, T. J., et al. 1986. Nature. 323: 734-738). Two clusters of basic residues (A: 3147-3157 and B: 3359-3367) are apposed on the surface of the LDL particle by a disulfide bridge between Cys 3167 and 3297. Support for this single domain model has been obtained from the mapping of epitopes for anti-apoB monoclonal antibodies that block the binding of apoB to the LDL receptor. Here we test this model by comparing the nucleotide (from 9623 to 10,442) and amino acid sequence (from 3139 to 3411) of apoB-100 in seven species (human, pig, rabbit, rat, Syrian hamster, mouse, and chicken). Overall, this region is highly conserved. Cluster B maintains a strong net positive charge and is homologous across species in both primary and secondary structure. However, the net positive charge of region A is not conserved across these species, but the region remains strongly hydrophilic. The secondary structure of the region between clusters A and B is preserved, but the disulfide bond is unique to the human sequence. This study suggests that the basic region B is primarily involved in the binding of apoB-100 to the apoB,E (LDL) receptor.