University faculty on student motivation to use medical education apps and barriers to their usage.

OBJECTIVE: University teachers, who primarily provide guidance and advice to their students, can play a significant role in educational process transformation. As there is no particular e-learning framework, it is important to understand the factors and variables that may impact both its effective usage and further successful implementation. The current study aims to outline the influence of university faculty, and possible barriers preventing medical students from using apps for learning purposes. SUBJECTS AND METHODS: Α cross-sectional study was conducted with an online survey questionnaire. The population of the study included 1,458 students from all the seven Greek schools of medicine. RESULTS: University faculty (51.7%), followed by fellow students and friends (55.6%), constitute the second most common source of information on adopting apps for medical education. 45.8% of students rated their educational guidance as insufficient/inadequate, 33.0% as moderate, 18.6% as quite good, and only 2.7% as sufficient/complete. University professors have proposed certain apps to 25.5% of students. PubMed (41.7%), Medscape (20.9%), and Complete Anatomy (12.2%) were the leading suggestions. The main barriers to app usage were the lack of knowledge of apps' benefits (28.8%), insufficient updates of their content (21.9%), their cost-effectiveness (19.2%), and financial reasons (16.2%). Most students preferred using free apps (51.4%) and 76.7% preferred universities to cover apps' expenses. CONCLUSIONS: University faculty represent the main source of information regarding the adaptation of medical apps in the educational process. However, students need improved and enhanced guidance. The main barriers are ignorance about apps and financial reasons. The majority prefer free apps and universities to cover their cost.

Medical application usage traits by students in Greece.

OBJECTIVE: Medical applications ("apps") can offer innovative educational capabilities, facilitating the acquisition of learning objectives and enhancing decision making. The present study aims at demonstrating the usage characteristics and relevant perceptions among students in seven medical schools in Greece. MATERIALS AND METHODS: A descriptive cross-sectional study was conducted through an online survey. Popularity, usage patterns and medical student perceptions regarding medical apps were studied. RESULTS: A total of 1,458 undergraduate medical students participated, 99.2% owned a smartphone, 72.8% were aware of medical apps' existence, although only 53.9% used them. Apps awareness was higher in higher-ranked universities. Overall, 46% used 1-3 apps, 7.9% more than four apps. 40.3% stated apps' usage at least 1-3 times a month, followed by 16.0% using them 1-3 times per week. Only 2.5% reported daily usage. Students who used more apps tend to use them more frequently. 77.3% used at least half of the downloaded apps. Awareness of medical apps, number of apps in use and frequency of usage tend to increase in each succeeding year of study. The most popular apps and the main reasons of usage are presented in this study. Current and future perceptions have been investigated. No disparities have been observed between genders. CONCLUSIONS: Overall medical apps usage was relatively low, despite the high percentage of smartphone ownership. Quantitative traits are enhanced across the progression of medical studies. Utilization frequency is higher in those using more apps. Distinct utilization patterns were identified between preclinical and clinical students, possibly depicting particular needs, portraying apps as a special adjunctive educational tool.

Sertoli cell proliferation in the fetal and neonatal rat testis: a continuous phenomenon?

Sertoli cell population kinetics, as evidenced by semi-quantitative immunolabeling for proliferating cell nuclear antigen (PCNA) and Ki-67, in developing Wistar rat male gonads of embryos and neonates [14.5 days post conception (dpc)-7 days post partum (dpp)], was investigated. Throughout the examined period a gradual increase of immunolabeled Sertoli cell number, associated with intense mitotic activity, was observed. PCNA labeling index of Sertoli cells increased from 66.67 (at 14.5 dpc) to 89.74 (at 18.5 dpc) and then dropped to 75.24 (at 20.5 dpc). At birth, the percentage of PCNA immunoreactive Sertoli cells reached 98.70% and remained high thereafter, attaining a peak value of 99.90% at 7 dpp. The percentage of Ki-67 immunoreactive Sertoli cells in the fetal testis increased from E14.5 (43.95%) to E20.5 (77.40%). The proliferation rate did not alter considerably in the neonatal testis until 5 dpp. At this point, a significant increase of the Ki-67 labeling index was observed and a peak value of 95.76% was reached at 7 dpp. The pattern of Sertoli cell proliferation with age and the establishment of the final Sertoli cell number in vivo established in the present study was compared to the results from earlier investigations reported in the literature and the observed fluctuation of dividing cell numbers, associated with immunolabeling results throughout the examined period, complements and extends existing data. An appraisal of the timing of Sertoli cell proliferation in other species, namely mouse and man, is presented. The current investigation may be useful in evaluating the potential influence of factors interfering with normal mitotic activity of Sertoli cells, including cell selection mechanisms, such as apoptosis, senescence, DNA repair and hormonal/paracrine growth modulation.

Evaluation of immunohistochemical markers of germ cells' proliferation in the developing rat testis: a comparative study.

Germ cells' proliferation during testicular organogenesis in Wistar rat embryos and neonates [14.5, 18.5, 20.5 days post conception (dpc), birth (day 0), 1, 3, 5, 7 days post partum (dpp)] was evaluated via immunohistochemistry, using the PCNA and Ki-67 nuclear antibodies. Estimation of the reactive/total cell ratio, per visual field [labeIing index (LI)] was achieved using the Image Pro Plus Software. Immunostaining of the fetal testis, with both antibodies, revealed increasing germ cells' numbers between 14.5 dpc and birth. From birth onwards, a sharp decline of germ cells' population was observed in the first 3 days of postnatal life. Then, a transient increase of the LI, between 3 and 5 dpp, was noted. Afterwards, proliferation of germ cells ceased. These results indicate that, during fetal and neonatal life, two peaks of proliferative activity of germ cells are noticed. Following estimation of the LI for both PCNA and Ki-67, a prominent labeling for the first antibody was observed throughout the examined period. Ki-67 staining follows a similar pattern, showing, however, significant fluctuation in the obtained values, in comparison to PCNA. The significant differences observed don't seem to be simply a result of the different half lives of the two markers, but rather a consequence of additional underlying cellular activity associated with PCNA, such as DNA repair.

Helicobacter pylori in liquid culture: evaluation of growth rates and ultrastructure.

This study investigated the growth of Helicobacter (H.) pylori in Brucella broth supplemented with either IsoVitaleX (1% vol/vol), hemin (.01% wt.vol), agar (0.3% wt/vol), or blood agar blocks (1.5% wt/vol agar). IsoVitaleX was found to significantly shorten the lag phase, while hemin inhibited the growth within the first 24 hours but later acted as a growth stimulant. There was a tendency toward stronger growth when blood agar blocks were added to the medium. Subsequent electron microscopic evaluation revealed that cells of H. pylori were attached to blood agar block surfaces. In contrast, the supplementation of Brucella broth with agar did not significantly increase the cell density. When H. pylori was grown in the presence of IsoVitaleX, strongly stainable electron-dense bodies (140-200 nm) were seen in the cytoplasms. Incubation of cultures on rotary shakers at 10 rpm significantly enhanced growth. The addition of glycerol (15% vol/vol) or fetal bovine serum (15% vol/vol) showed good ultrastructural preservation of bacteria with undamaged cell walls and cytoplasmic membranes, and cytoplasms were ribosome-dense. Cell counts revealed that cultures stored in glycerol or fetal bovine serum had a significantly lower loss in viability when compared with cultures stored without cryopreservatives. Unprotected cells of H. pylori showed on electron micrographs, clumping, cell lysis, and flagellar damage. Finally, the survival rates of H. pylori after multiple thawing from storage at -80 degrees C were best in Brucella broth/glycerol, Brucella broth/fetal bovine serum, and Brucella broth without cryopreservative (in descending order).

Immunogenicity and safety of recombinant Helicobacter pylori urease in a nonhuman primate.

Groups of squirrel monkeys (Saimiri spp.), predetermined to be free of Helicobacter infections in the gastric mucosa, were immunized orally with 0.5-4.5 mg of Helicobacter pylori recombinant urease (rUrease) and 25-500 micrograms of Escherichia coli heat-labile enterotoxin (LT) adjuvant. Oral immunization with rUrease resulted in a markedly elevated serum immunoglobulin G (IgG) antibody response with peak levels at 45 days after immunization. No significant gastric inflammation or cytotoxicity was evident in rUrease immunized monkeys as determined by light and electron microscopy. Twenty-five micrograms of LT was a sufficient and safe adjuvant dosage, whereas higher dosages resulted in diarrhea and lethargy. Animals developed a serum IgG antibody response to LT that did not impede the production of anti-rUrease antibody levels. The results of this investigation indicate that rUrease is immunogenic in a nonhuman primate.

An optimal design problem in rhythmometry.

A trigonometric regression model is assumed for a problem involving circadian rhythm exhibited by peak expiratory flow. Experimental designs are sought with a view to estimating a particular nonlinear function of the parameters. Both optimal and nonoptimal, but more practicable, designs are derived and their relative efficiencies are established.