Regulation of neurotrophin receptor expression by retinoic acid in mouse sympathetic neuroblasts

We have studied the effect of retinoic acid on the expression of the neurotrophin receptors trkA, trkC, and p75 by neuroblasts and neurons at different axial levels along the embryonic mouse paravertebral sympathetic chain. In dissociated cultures of sympathetic neuroblasts, retinoic acid inhibited the developmental increase in trkA mRNA expression and the developmental decrease in trkC mRNA expression that normally occurs in these cells but did not affect p75 mRNA expression. At higher concentrations, retinoic acid also increased the proliferation of sympathetic neuroblasts. After sympathetic neuroblasts became postmitotic, retinoic acid no longer affected receptor expression. Studies with retinoic acid receptor agonists and antagonists indicated that the effects of retinoic acid on neurotrophin receptor expression were mediated mainly by alpha retinoic acid receptors, not beta or gamma receptors. The observation that alpha-antagonists increased trkA mRNA expression in intact sympathetic ganglion explants suggests that endogenous retinoic acid is a physiological regulator of trkA receptor expression.     

Phonon Interactions in an Anisotropic Phonon System Leading to a Suprathermal Distribution in Liquid 4He

The relaxation rates of high energy phonons are calculated for a highly anisotropic phonon system which can be realised by phonon pulses in liquid ⁴He. We find that the creation rate for these phonons is very much greater than the decay rate over almost all of the momentum range. As a consequence, we have the unusual behaviour of the distribution function, for the high energy phonons, not being the Bose–Einstein distribution function. From our results we expect that the distribution function will be very much greater than the Bose–Einstein one and also to have a quite different momentum dependence. The analytic expressions which are derived, enable us to explain the physical reasons for a suprathermal distribution of high energy phonons which are predicted to occur in highly anisotropic phonon systems.     

Noninvasive Versus Invasive Doppler Renal Blood Velocity and Flow Measurements

We compared simultaneous noninvasive and invasive determinations of blood velocity and flow in the renal arteries of 5 mongrel dogs. Noninvasive measurements of blood velocity spectra (?FN) were made using an ultrasonic echo-Doppler duplex scanner. Vessel diameters (DN) and Doppler angles (?N) were measured from sector images of the renal artery. Invasive measurements of blood velocity spectra (?F1) were made using a catheter Doppler velocimeter. Vessel lumen diameter (D1) and Doppler angle (?1) were measured angiographically. Using the Doppler and continuity equations, temporal mean blood velocities (VN, V1) and flows (QN, Q1) of five cardiac cycles were calculated. The ranges of velocity (8-48 cm/s) and flow (40-380 ml/min) were varied by pharmacological intervention. Standard linear regressions (n = 33) were Results suggest that simultaneous noninvasive echo-Doppler and invasive catheter Doppler measurements of canine renal artery blood velocity and flow correlate significantly. Nevertheless, large standard errors of the estimates exist which suggest that important systematic and experimental errors are present in both methods.     

Atropine poisoning after drinking Indian tonic water

After 13.5 years in vivo a 2-0 Terylene frontalis loop was excised because of an insufficiency. Histology showed a persisting giant cell reaction while lymphocytes were almost totally absent. The fibrils of the suture seemed to be intact. However, they were separated by ingrowing connective tissue which, on theoretical grounds, should improve the function of the frontal muscle on the upper eyelid. Therefore, insufficiency of the loop was probably caused by the (subclinical) foreign body reaction or the long-lasting mechanical stress leading to tissue damage.     

Rubral tremor associated with cavernous angioma of the midbrain

The insecticidal activity of five alkylfurans against the generalist insect herbivore beet armyworm, Spodoptera exigua, was examined. Two naturally occurring compounds, the avocadofurans 2-(pentadecyl)furan (1) and 2-(heptadecyl)furan (2), previously isolated from specialized avocado idioblast oil cells, and three homologues, 2-(tetradecyl)furan (3), 2-(hexadecyl)furan (4), and 2-(octadecyl)furan (5), were synthesized. Bioassays of alkylfurans 1-5 using a 9-day diet-incorporation initiated with neonates showed that all alkylfurans tested significantly increased S. exigua larval mortality and reduced larval weights, with maximal biological activity detected among the naturally occurring alkylfurans 1 and 2.     

Simulated weather variables effects on millet fertilized with phosphate rock in the Sahel

The Sudano–Sahelian agroecological zone is characterized by low and variable rainfall regimes and P deficiency. The present study complements previous research efforts and the objective was (i) to use the Newhall Simulation Model (NSM) to characterize three ICRISAT research sites, and (ii) to use output of NSM to develop an empirical model to guide efficient use of rainfall and fertilizers. The results show that length of the periods that rainfall exceeded evapotranspiration was larger in Bengou than in Gobery and Sadoré. Total positive moisture balance during the three growing seasons was 85.7 mm at Bengou and 19.7 mm at Sadoré. The model explained 52% of the variability in millet yields based on curvilinear response to P fertilizer, standardized May–June (R_mj) rainfall, and the number of wet days in the year (BW₃). Yields appear more sensitive to BW₃ than to R_mj. Their respective elasticity coefficients (E _c ) were 0.62 and 0.09. Assessment of the model using R²=0.76 and the D-index = 0.85 showed reasonable agreement between model estimation and actual field yields. The study demonstrates the application of simulation models as a cost-effective means in terms of time and funds to agronomic research.     

Early ambulation after coronary angioplasty and stenting with six French guiding catheters and low-dose heparin

The safety and feasibility of early ambulation was evaluated prospectively in 907 patients undergoing elective coronary angioplasty and stenting with the use of 6Fr guiding catheters, low-dose heparin (5,000 IU), and immediate postprocedural sheath removal by comparing ambulation after 4 hours with immobilization for at least 12 hours. Because no excess in puncture site complications (2.3% vs 2.2%) could be demonstrated after 4-hour ambulation, it is concluded that early ambulation after 6Fr guiding catheter angioplasty by the femoral route with low-dose heparin is feasible, safe, and may facilitate a shorter hospital stay.     

Evaluation of the echinocandin antifungal MK-0991 (L-743,872): efficacies in mouse models of disseminated aspergillosis, candidiasis, and cryptococcosis

The in vivo activity of the Merck antifungal echinocandin drug candidate MK-0991 (L-743,872) was evaluated in mouse models of disseminated candidiasis, aspergillosis, and cryptococcosis. The echinocandins are potent inhibitors of 1,3-beta-D-glucan synthase. Two models of disseminated candidiasis were used. In a Candida albicans mouse survival model with both DBA/2N and CD-1 mice, estimates of the 50% effective doses (ED50s) of MK-0991 were 0.04 and 0.10 mg/kg of body weight/dose at 21 days after challenge, respectively. In a C. albicans target organ assay (TOA) with DBA/2N mice, MK-0991 at levels of > or =0.09 mg/kg/dose significantly reduced the numbers of C. albicans CFU/g of kidneys compared to the numbers in the kidneys of control mice from 1 to 28 days after challenge. Even when given as a single intraperitoneal dose either 30 min or 24 h after challenge, MK-0991 was effective and significantly reduced the numbers of C. albicans CFU/g of kidney compared to those in the controls. MK-0991 was >300-fold less active when it was administered orally than when it was administered parenterally. MK-0991 was efficacious in mouse TOAs against other C. albicans strains and Candida species including Candida tropicalis, Candida (Torulopsis) glabrata, Candida lusitaniae, Candida parapsilosis, and Candida krusei. MK-0991 was ineffective against disseminated Cryptococcus neoformans infections. In the model of disseminated aspergillosis in mice, MK-0991 at doses of > or =0.02 mg/kg/dose significantly prolonged the survival of DBA/2N mice, with estimates of the ED50 and ED90 of MK-0991 being 0.03 and 0.12 mg/kg/dose, respectively, at 28 days after challenge. MK-0991 is a potent, parenterally administered therapeutic agent against disseminated candidiasis and aspergillosis that warrants further investigation in human clinical trials.