Interactive audience response systems in oral and maxillofacial radiology undergraduate lectures

Objectives

To evaluate the impact of audience response systems (ARS) on student participation (SP) during Oral and Maxillofacial Radiology (OMR) undergraduate lectures and on final examination scores (FES). Furthermore, an analysis of unanimity assessed the influence of ARS on students’ responses. Students’ perceptions were also assessed.

Methods

A controlled crossover study was designed. Four lectures covering topics of OMR were each taught with ARS and without ARS (i.e. hand‐raising method). SP and FES were compared between ARS and HR groups. Unanimity of answers was analyzed for both groups. Questionnaires assessed students’ impressions about ARS.

Results

Mean SP of ARS and HR groups were 97.6% and 47.3%, respectively, and this difference was statistically significant (P<.05). Mean FES for the ARS group (77%) was slightly higher than HR group (75.1%), however, not statistically significant. There was positive correlation between SP and FES. With ARS, only 5.7% of the questions were unanimous, whilst 51.4% were unanimous with HR method. Most students reported that the use of ARS had positive influence on their attention (92%), participation (96%), classmates’ participation (82.7%), interest (74.7%), and learning (86.7%). For the five‐point scale ratings of the relevance of ARS features, anonymity had an average 3.6, whilst other items received an average 4.6 or higher.

Conclusions

ARS significantly increased participation in OMR lectures; however, an increase in FES could not be associated with ARS by itself. Not taking into consideration which method was used to answer questions posed during lectures, higher participation correlated with higher scores. ARS is well‐accepted and students believe that these devices positively influence their performance. Among the recognized advantages of ARS, anonymity was considered the least relevant.     

Gamma (immune) interferon production by leukocytes from a patient with a TG cell proliferative disease

We report a patient with a disease characterized by proliferation of T cells with Fc receptors for IgG (TG). However, unlike lymphoid cells from normal individuals or from patients with other lymphoid malignancies, the patient's lymphocytes spontaneously produced gamma interferon (IFN-gamma) in vitro. The peripheral lymphocytes consisted of 95% TG cells, which exhibited the morphological characteristics of T- cell chronic lymphocytic leukemia (CLL) and were normal on cytochemical and chromosome analysis. The majority of TG cells were OKT3+, OKT8+, and OKT4-, 3A1-. These cells failed to express suppressor cell activity and displayed depressed levels of natural killer activity, but mediated antibody-dependent cell-mediated cytotoxicity. The spontaneous production of IFN-gamma by human peripheral lymphoid cells as demonstrated in this study may serve as a probe for studying the relationship between IFN-gamma and the proliferation of human T-cell subsets.     

Acute monoblastic leukemia in infancy and early childhood: successful treatment with an epipodophyllotoxin

Four of five infants and young children with acute monoblastic leukemia, a disease that heretofore has been highly refractory to therapy, were successfully treated with sequential infusions of a podophyllin derivative employed as a single agent over a protracted period of time. In three of the five children, monocytic leukemia cutis was present at birth. Treatment was begun in two of them when the disease had progressed to systemic involvement at a few months of age, and in the third when disease was still localized. The other two children were 11 and 18 months of age at initial presentation with widespread disease. Four children are off therapy 11 months, 26 months, 5 years, and 6 years, respectively.     

High-level expression and purification of a recombinant human erythropoietin produced using a baculovirus vector

Conditions presently have been established for the high-level expression and simplified purification of recombinant human erythropoietin produced in Spodoptera frugiperda cells. Expression, as mediated by infection with a recombinant baculovirus, was accomplished in suspension culture using reduced levels of serum and media supplements experimentally determined to provide optimum levels of factor production (500,000 U/L). Purification of this recombinant human erythropoietin to virtual homogeneity (greater than or equal to 99%) was accomplished via a simple three-step procedure involving isocratic elution from DEAE-Sephacel, reverse-phase high performance liquid chromatography (HPLC) on a C4 medium, and the single-step elution of purified hormone from concanavalin A agarose. Overall, an 890-fold purification was accomplished with a recovery of 80% as assayed in vitro. Biologically, this purified erythropoietin is highly active, possessing a specific activity in vitro of 200,000 U/mg protein. Chemically, this erythropoietin (molecular weight [mol wt] 26,200) appears exceptionally uniform in its oligosaccharide constitution (30%) as contrasted with heterogeneously glycosylated erythropoietins derived from mammalian cells (mol wt 30,000 to 38,000; 40% to 50% complex-type oligosaccharide). Thus, human erythropoietin as presently produced in an insect cell line comprises not only an abundant source of highly active, readily purified hormone for studies of its mechanism of action and cell surface receptor, but also represents a uniquely homogeneous form that should prove advantageous for direct structural analyses.     

Antispasmodic and relaxant effects of the hidroalcoholic extract of Pimpinella anisum (Apiaceae) on rat anococcygeus smooth muscle

The present work describes the mechanisms involved in the muscle relaxant effect of ethanol:water (40:60, 60:40 and 80:20) aerial parts extracts of Pimpinella anisum. Three hidroalcoholic extracts in which the proportion of ethanol was 40% (HA(40%)), 60% (HA(60%)) or 80% (HA(80%)) were tested for activity in the rat anococcygeus smooth muscle. The three extracts (50 microg/mL) inhibited acetylcholine-induced contraction. The extract HA(60%) (5-50 microg/mL) concentration dependently relaxed acetylcholine-pre-contracted tissues (31.55+/-3.56%). Conversely, HA(40%) and HA(80%) did not exert relaxant action. Pre-incubation of the preparations with N(G)-nitro-L-arginine methyl ester (L-NAME, 100 microM), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 3 microM) and oxyhemoglobin (10 microM) reduced the relaxation induced by HA(60%) (percentage of relaxation: 6.81+/-1.86%, 13.13+/-5.87% and 2.12+/-1.46%, respectively). Neither indomethacin (10 microM) nor tetraethylammonium (1 mM) affected the relaxation induced by HA(60%). Incubation of the tissues with L-NAME significantly enhanced the maximal contraction induced by acetylcholine, indicating an inhibitory role for NO in the modulation of the contractile response of anococcygeus smooth muscle to acetylcholine. However, simultaneous addition of L-NAME and HA(60%) resulted in an effect similar to that observed with L-NAME alone, further confirming the observation that Pimpinella anisum acts by realizing NO. Additionally, HA(60%) did not alter CaCl(2)-induced contraction. Collectively, our results provide functional evidence that the effects elicited by the hidroalcoholic extract of Pimpinella anisum involve the participation of NO and subsequent activation of the NO-cGMP pathway. The relaxant action displayed by Pimpinella anisum justifies its use in the folk medicine as an antispasmodic agent.