Does spaced education improve clinical knowledge among Family Medicine residents? A cluster randomized controlled trial

Advances in Health Sciences Education - Spaced education is a learning strategy to improve knowledge acquisition and retention. To date, no robust evidence exists to support the utility of spaced...     

Optimization of propofol dose shortens procedural sedation time, prevents resedation and removes the requirement for post-procedure physiologic monitoring

Objective: To examine the effect of propofol dosing (total dose and number of doses) on patient sedation time and likelihood of resedation. Methods: This was a prospective, observational patient series in an urban district hospital ED with 42 000 attendances per annum. Patients undergoing an emergent procedure requiring procedural sedation were included. Titrated intravenous propofol was administered according to departmental procedure. Standardized consent and data collection forms were used. Time taken for the patient to become conversational after first administration was recorded and any resedation documented. Results: Four hundred patients, undergoing 404 procedures, were enrolled for the period commencing August 2004 until March 2006. The mean initial propofol bolus was 0.8 mg/kg (SD 0.6), and mean total propofol dose was 1.8 mg/kg (SD 1.0), comprising a mean of 2.3 (SD 2.1) doses of 15.8 mg (SD 11.4). Mean sedation time was 11.8 min (SD 6.9), and increased sedation times were associated with higher total propofol dose and number of boluses (P < 0.0001). Resedation occurred in two patients (0.5%, 95% CI 0–1.6%). Conclusion: Shorter sedation times are seen with lower doses of propofol. Patients do not need prolonged post‐procedure monitoring because the occurrence of spontaneous resedation associated with propofol use is a rare event. This has implications for patient flow and staff resource allocation in a busy ED.     

TGF-�� isoforms inhibit IGF-1-induced migration and regulate terminal differentiation in a cell-specific manner

Following muscle injury, the damaged tissue and influx of inflammatory cells stimulate the secretion of growth factors and cytokines to initiate repair processes. This release of chemotactic signaling factors activates resident precursor cells and stimulates their mobilization and migration to the site of injury where terminal differentiation can occur. The three transforming growth factor-β (TGF-β) isoforms, and insulin-like growth factor-1 (IGF-1) are among the known regulatory factors released following muscle damage. We investigated the effect of recombinant active TGF-β1, -β2, -β3 and IGF-1 on C2C12 skeletal muscle satellite cell and P19 embryonal carcinoma cell terminal differentiation and migration. C2C12 myoblast fusion as well as P19 embryoid body formation and myogenic differentiation was assessed following 72?h TGF-β treatment (5?ng/ml), whereas the effect of the TGF-β isoforms on migration was determined following 7?h incubation. Our results showed that TGF-β decreases C2C12 myoblast fusion in an isoform-independent manner, whereas in the P19 cell lineage, results demonstrate that TGF-β1 specifically and significantly increased P19 embryoid body formation, but not expression of Connexin-43 or Myosin Heavy Chain. IGF-1 significantly increased migration compared to TGF-β isoforms, which, on their own, had no significant effect on the mobilization of either C2C12 or P19 cells. TGF-β isoforms decreased IGF-1-induced migration of both cell lineages. By distinguishing the factors involved in, and the molecular signals required for, myoblast recruitment during repair processes, strategies can be developed towards improved cell-mediated therapies for muscle injury.     

Effect of lead and organophosphates on sperm morphology

Lead and organophosphates can exert a toxic action on the male reproductive function. A cross-sectional study involving 40 men was undertaken to investigate the effect of these toxins on sperm morphology. Based on the percentage of morphologically normal spermatozoa, subjects were divided into two groups. The control group (sperm morphology greater than or equal to 20% normal forms) consisted of 18 patients, and the study group (sperm morphology less than 5% normal forms) consisted of 22 patients. Lead, pseudocholinesterase, dibucaine, and fluoride levels were measured in blood samples of these men. The 22 men with low morphologically normal forms (less than 5%) did not display significantly different levels of the abovementioned substances compared to the control group.     

The pharmacokinetics of oral indoramin during pregnancy.

1. The pharmacokinetics of indoramin (Baratol; Wyeth) and its active metabolite 6-hydroxyindoramin administered to 13 women as a single 37.5 mg dose of indoramin were compared under pregnant and post-partum conditions. 2. No significant differences were observed between values determined under pregnant and post-partum conditions, for any pharmacokinetic parameter. Cmax and AUC values in individual subjects differed, in most cases, by no more than two-fold, i.e. the same order of magnitude as intra-subject variation seen in volunteers dosed repeatedly with indoramin. 3. Median values of Cmax, AUC(0.24) and t 1/2,z were of a similar order to values seen previously in normal volunteers after a single 37.5 mg dose. 4. It is concluded that in treating hypertension associated with pregnancy, this study does not provide evidence to depart from the usual clinical practice of titrating indoramin dosage with control of blood pressure as the end-point, keeping in mind the restriction of the dose-limiting side-effect of sedation.     

Influence of aflatoxin B 1 and aflatoxin B 2 on rat liver lysosomal acid deoxyribonuclease

The in vitro effects of aflatoxins B₁ and B₂ were studied on the permeability of isolated rat liver lysosomes. Only aflatoxin B₁ altered the lysosomal membrane with the consequent release of lysosomal enzymes. The results of the in vivo experiment with aflatoxin B₁ show that the specific activity of acid DNase in liver lysosomes was markedly decreased in the rats dosed aflatoxin B₁ while the specific activity of the cytoplasmic acid DNase, or nonsedimentable acid DNase, was dramatically increased. The results are discussed in relation to a hypothesis concerning the role of lysosomes in carcinogenesis.     

Easily identifiable bony landmarks as an aid in targeted regional ankle blockade

Regional anesthesia around the ankle joint is well suited to a large number of surgical procedures of the foot. Previous studies have alluded to the variable nerve distribution of the foot, which may result in incomplete blocks. The aim of the study was to determine the position of the nerves in relation to the ankle joint to easily identifiable bony and prominent soft tissue landmarks to aid more accurate targeting of these nerves. A number of 94 ankles (47 left; 47 right) were dissected to expose the tibial, sural, deep fibular (peroneal), superficial fibular (peroneal), and saphenous nerves. The distance of the nerves relative to easy to find bony landmarks was measured. A distance (alpha) was measured from the middle of the tibial nerve to the most medial aspect of the medial malleolus. Measurement beta was considered from the inferior tip of the lateral malleolus to the anterior border of the sural nerve on a horizontal plane. Measurement delta was taken from the medial border of the deep fibular (peroneal) nerve to the most anterior aspect of the medial malleolus. epsilon was measured from the middle of the superficial fibular (peroneal) nerve to the most anterior aspect of the medial malleolus on a horizontal plane. The saphenous nerve was measured (gamma) from its medial border to the most anterior aspect of the medial malleolus on a horizontal plane. Factors such as sex, length, and ankle side were also analyzed concerning their influence on the position of the nerves. This study suggests that a greater degree of certainty may possibly be attained when palpable and easy to find bony landmarks are used to determine the position of the nerves around the ankle and ensure a simple to perform, predictable, and selectively targeted block.     

Deviation from Michaelis - Menten kinetics for esterase E-II from the venom of Bitis gabonica, using synthetic arginine amides as substrates

Steady state kinetic studies on the reaction between esterase E-II from the venom of Bitis gabonica and the fluorogenic substrates, N-α-benzoyl-l-phenylalanyl-l-valyl-l-arginine-4-methylcoumaryl-7 and N-α-benzoyl-l-arginine-4-methylcoumaryl-7-amide were found to deviate from Michaelis-Menten kinetics. Analysis of algebraic graphs and application of non-linear regression allowed an empirical rate law to be selected. The results revealed a rate equation of at least third degree at pH values above 7.0 and of 2:2 degree in the pH range 6–7. The data were interpreted in terms of a molecular model involving an enzyme with one catalytic site and several auxiliary or regulatory sites which, through cooperative effects, may either activate or inhibit the enzyme. Substrate activation is observed at low substrate values and might follow from an obligatory order of binding involving two of the sites, the modifier substrate molecule binding before the substrate molecule undergoing transformation to products. Inhibitory sites apparently become available only at alkaline pH. The inhibition is only noted at high substrate concentrations and is of the partial type.     

Influence of disodium etidronate on Paget's disease of bone

The use of agents that decrease bone resorption, notably the calcitonins, diphosphonates and mithramycin, has been shown to result in symptomatic and/or biochemical improvement in patients with Paget's disease of bone (osteitis deformans). The effects of short-term (6 months), low-dose (5 mg/kg body mass/d) etidronate disodium, a diphosphonate compound at present subject to registration in this country, on the clinical and laboratory manifestations of this disorder were examined. Marked symptomatic improvement was noted in 70% of patients, while biochemical parameters of bone turnover, namely serum alkaline phosphatase level (44%) and urine hydroxyproline excretion (56%), decreased significantly (P less than 0.001). A technetium-99m bone scan revealed an impressive reduction in uptake of isotope in 50% of patients. The drug was well tolerated and no adverse reactions (clinical, biochemical or haematological) were evident. It is concluded that short-term low-dose etidronate disodium affords a convenient and effective therapeutic alternative in patients with symptomatic Paget's disease.