Phase I of the International Study of Asthma and Allergies in Childhood has provided valuable information regarding international prevalence patterns and potential risk factors in the development of asthma, allergic rhinoconjunctivitis and eczema. However, in Phase I, only six African countries were involved (Algeria, Tunisia, Morocco, Kenya, South Africa and Ethiopia). Phase III, conducted 5–6 years later, enrolled 22 centres in 16 countries including the majority of the centres involved in Phase I and new centres in Morocco, Tunisia, Democratic Republic of Congo, Togo, Sudan, Cameroon, Gabon, Reunion Island and South Africa. There were considerable variations between the various centres of Africa in the prevalence of the main symptoms of the three conditions: wheeze (4.0–21.5%), allergic rhinoconjunctivitis (7.2–27.3%) and eczema (4.7–23.0%). There was a large variation both between countries and between centres in the same country. Several centres, including Cape Town (20.3%), Polokwane (18.0%), Reunion Island (21.5%), Brazzaville (19.9%), Nairobi (18.0%), Urban Ivory Coast (19.3%) and Conakry (18.6%) showed relatively high asthma symptom prevalences, similar to those in western Europe. There were also a number of centres showing high symptom prevalences for allergic rhinoconjunctivitis (Cape Town, Reunion Island, Brazzaville, Eldoret, Urban Ivory Coast, Conakry, Casablanca, Wilays of Algiers, Sousse and Eldoret) and eczema (Brazzaville, Eldoret, Addis Ababa, Urban Ivory Coast, Conakry, Marrakech and Casablanca).

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Background Lectures are one of the most common teaching methods in medical education. Didactic lectures were perceived by the students as the least effective method. Teaching methods that encourage self-directed learning can be effective in delivering core knowledge leading to increased learning. Problem based learning has been introduced as an active way of learning but it has some obstacles in developing countries where the intake is huge with minimum resources. This study introduces a new teaching approach: lectures based on problems (LBP) and evaluates their effectiveness compared to traditional lectures (TL) in physiology teaching. Methods LBP and TL were applied in physiology teaching of medical students at University of Science and Technology during their study of introduction to physiology and respiratory physiology courses. Equal number of lectures was given as LBP and as TL in each course. Students were given quizzes at the end of each course which were used to compare the effectiveness of the two types of lectures. A questionnaire was used to assess students’ satisfaction about LBP and the perceived effects of the two methods on the students’ attitude and practice towards learning physiology. Results In LBP the students have better attention (P = 0.002) and more active role (P = 0.003) than in TL. Higher percentage of students think that LBP stimulated them to use references more (P = 0.00006) and to use the lecture time more effectively (P = 0.0001) compared to TL. However, there was no significant difference between LBP and TL in the awareness of the learning objectives. About 64% of students think that LBP is more enjoyable and it improved their understanding of physiology concepts. Comparison of the students’ quiz marks showed that the means of the students’ marks in the introduction to physiology and respiratory courses were higher in the quizzes of LBP than in TL with a significant difference between them ((P = .000), (P = .006) respectively. Conclusions LBP improved students’ understanding of physiology concepts and increased students’ satisfaction about physiology learning. LBP achieved some of the objectives of PBL with the minimum resources and it can be used to improve the effectiveness of the lectures.

The initial pathophysiological events that characterize CCK-hyperstimulation pancreatitis include the breakdown of the actin filament system and disruption of cadherin-catenin protein complexes. Cadherins and catenins are part of adherens junctions, which may act as anchor for the cellular actin filament system. We examined the composition and regulation of adherens junctions during CCK-induced acinar cell damage. Freshly isolated CCK-stimulated rat pancreatic acini were examined for actin filaments and functional adherens junctions by immunocytology and laser confocal scanning microscopy or by coprecipitation and immunoblotting for E-cadherin, beta- and alpha-catenin, p120(ctn), and phosphotyrosine. In addition to E-cadherin and beta-catenin, acinar cells express the cadherin-regulatory protein p120(ctn) and the attachment protein alpha-catenin. Both colocalize and coimmunoprecipitate with E-cadherin in one complex, and all colocalize with the terminal actin web. Supramaximal secretory CCK concentrations (10 nM) initiated tyrosine phosphorylation of p120(ctn) but not of beta-catenin within 2 min, preceding the breakdown of the terminal actin web by several minutes. Under these conditions, the cadherin-catenin association within the adherens junction complex remained intact. We describe for the first time supramaximal CCK-dependent tyrosine phosphorylation of the adherens junction protein p120(ctn) and demonstrate the presence of an intact adherens junction protein complex in acinar cells. p120(ctn) may participate in the actin filament breakdown during experimental conditions mimicking pancreatitis.

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