Depression of the cat cortical visual evoked potential by soman

The effects of intravenous administration of the anticholinesterase agent soman (pinacolyl methylphosphonofluoridate, 3-15 micrograms/kg) on the visual evoked potential (VEP) were examined in cats using phase-reversed sine wave grating stimuli of different spatial frequencies and contrasts. Doses of 5-7 micrograms/kg caused a depression of the VEP across all spatial frequencies in an abrupt, non-graded fashion. Studies in which contrast was varied showed that VEP depression resulted primarily from a decrease in the system gain rather than a change in the contrast sensitivity, and that response depression increased with increasing contrast. The dominant changes in gain revealed by these studies are consistent with a modulation of potassium conductance in the cell membrane which previous studies have shown to be dependent on a cholinergic mechanism.     

Younger Age of Presentation and Extraosseous Tumour in IgD Myelomatosis

A study of 14 personal patients and 16 others in the literature shows that (1) IgD myelomatosis often presents at a significantly younger age than other forms of myelomatosis, and (2) during life extraosseous tumour can be detected in about two-thirds of these patients.The IgD form represents 1·5% of myelomatosis and shows an increased incidence of osteolytic lesions, hypercalcaemia, and renal failure, together with heavy Bence Jones proteinuria (90% type L).Like only Bence Jones myelomatosis, the IgD form seems to behave clinically in a more vicious manner.     

Evaluation of Potential Effectors of Agonal Glycolytic Rate in Developing Brain Measured In Vivo by 31P and 1H Nuclear Magnetic Resonance Spectroscopy

Abstract: Previously we have shown that hypercarbia produces a larger decrease in agonal glycolytic rate in 1-month-old swine than in newborns. In an effort to understand the mechanism responsible for this difference, we tested the hypothesis that hypercarbia produces age-related changes in the concentration of one or more effectors of phosphofructokinase activity. Specifically, in vivo ³¹P and ¹H NMR spectroscopy was used to compare changes in lactate levels, intracellular pH, free magnesium concentration, and content of phosphorylated metabolites for these two age groups at three intervals during the first 1.5 min of complete ischemia in the presence or absence of hypercarbia (P_aco ₂ = 102–106 mm Hg). Hypercarbia produced the same drop in intracellular brain pH for both age groups, but the decrease in phosphocreatine level and increase in inorganic phosphate content were greater in 1-month-olds compared with newborns. During ischemia there was no difference between the magnitude of change in intracellular pH and levels of phosphocreatine and inorganic phosphate in hypercarbic 1-month-olds versus newborns. Under control conditions, i.e., normocarbia and normoxia, the free Mg²⁺ concentration was lower and the fraction of magnesium-free ATP was higher for newborns than 1-month-olds. However, there was no change in these variables for either age group during hypercarbia and early during ischemia. Thus, age-related differences in the relative decrease in agonal glycolytic rate during hypercarbia could not be explained by differences in intracellular pH, inorganic phosphate content, or free magnesium concentration. The [ADP]_free at control was higher in newborns compared with 1-month-olds, and there was no age-related difference in [AMP]_free. These variables did not change for newborns when exposed to hypercarbia, but for 1-month-olds [ADP]_free and [AMP]_free increased during hypercarbia relative to control values. High-energy phosphate utilization during ischemia for hypercarbic 1-month-olds was reduced by 74% compared with normocarbic 1-month-olds during ischemia, whereas the reduction in energy utilization (14%) was not significant for hypercarbic versus normocarbic newborns during ischemia. Because hypercarbia reduces the rate of ATP depletion during ischemia in 1-month-olds to a greater extent than in newborns, the increase in [ADP]_free and [AMP]_free will be slower in the former age group. It follows therefore that for 1-month-olds, the agonal glycolytic rate would not be accelerated by ADP and AMP to the same degree during hypercarbia plus ischemia compared with normocarbic plus ischemia, whereas for newborns hypercarbia has relatively little impact on agonal glycolytic rate.     

Inhibition of cartilage breakdown by isothiazolones

Isothiazolones and isoselenazolones have been found to inhibit IL-1β induced breakdown of bovine nasal cartilage in an organ culture assay. The synthesis and preliminary SAR of these compounds are described. These compounds represent a novel, non-peptide lead series approach to the mediation of the chronic cartilage breakdown associated with arthritic disease.     

Nondestructive Measurement of Retinal Glucose Transport and Consumption In Vivo Using NMR Spectroscopy

Abstract: The cellular events underlying various retinopathies are poorly understood but likely involve perturbation of retinal glucose metabolism. Current methods for assessing this metabolism are destructive, thus limiting longitudinal studies. We hypothesize that following an intravitreous injection, the clearance rate of a glucose analogue will be a nondestructive index of retinal glucose transport and metabolism in vivo. First, radiolabeled glucose analogues were injected into the vitreous. After 40 min, the dominant clearance path was posterior via the retina and was consistent with a facilitated transport mechanism. Next, either [6,6-²H₂]glucose or 3-deoxy-3-fluoro- d -glucose was injected into the vitreous of rabbit eyes, and the clearance rate of each analogue was determined over 40 min using, respectively, ²H or ¹⁹F NMR. These rates were interpreted as a function of the retinal glucose transport and consumption. From the NMR data, the rate of retinal glucose consumption was ∼16 times slower than the transport of glucose. These data demonstrate that NMR measurements of glucose analogue clearance rate from the vitreous can provide a nondestructive index of retinal glucose transport and consumption in vivo.     

A prospective randomised controlled clinical trial comparing somatostatin and vasopressin in controlling acute variceal haemorrhage.

Twenty two patients were entered into a randomised controlled clinical trial comparing the efficacy of somatostatin and vasopressin in controlling acute variceal haemorrhage. Somatostatin was significantly more successful in controlling acute variceal haemorrhage than vasopressin (p = 0.003). Furthermore, no complications were observed during treatment with somatostatin.     

Changing semantic factors in case selection: Russian evidence from the last two centuries

We present a corpus-based study of variation in case assignment of the direct object of negated verbs in Russian over the past 200 years. Superficially the system of case forms available over this relatively short period has remained largely the same, but the way in which certain cases are used has been radically altered. This is particularly apparent in the treatment of the direct object of negated verbs. We argue that various semantic factors have been involved in bringing about this change, and that the role and significance of these factors has been changing over the period under investigation. This has implications for our understanding of the role of semantics in case assignment.