A survey of knowledge and awareness of Jordanian female university students of human papillomavirus infection and its vaccine.

OBJECTIVE: To assess the knowledge and awareness of Jordanian female university students regarding human papillomavirus (HPV) infection and its vaccine. MATERIALS AND METHODS: A self-administered, anonymous questionnaire was distributed to 450 participants at Jordan University of Science and Technology (JUST) in Jordan. The survey focused on three areas: knowledge and awareness of HPV infection, knowledge of HPV vaccine, and source of information about HPV infection and its vaccine. RESULTS: The survey response rate was 79.8%. Most of the respondents (about 68%) have heard about HPV and knew that the HPV is a virus in the genital area that is sexually transmitted, and 59% of them knew that persistent infection with PV virus can cause precancerous/cancerous diseases in the genital tract. Only 45% of the respondents have ever heard about HPV vaccine and 37.8% of them knew that HPV vaccine is very effective in preventing HPV infection and its related precancerous/cancerous diseases. Majority of the respondents, 78.7 % and 73.5%, who knew about HPV and HPV vaccine, respectively, had heard about it from healthcare providers. CONCLUSION: The study suggests that more health education and information about the HPV characteristics and HPV vaccine is needed for female university students.

A method to distinguish between pore and carrier kinetics applied to urea transport across the erythrocyte membrane.

Permeability coefficients (P) measured at various penetrant concentrations (C) by the perturbation method can be plotted to distinguish simple diffusion, simple pore kinetics and simple carrier kinetics as follows: for simple diffusion, 1/P = constant; for a simple pore, 1/P = 1/Po + 1/Po[1/Kin + 1/Ko]C; for a simple carrier, 1/P = 1/Po + 1/Po[1/Kin + 1/Ko]C + 1/Po[1/(K3K4)] C2 where Po is the maximal permeability at zero penetrant concentration and the K's are combinations of kinetic constants defining each of the transport steps. (Kin and Ko are the half-saturation constant for zero-trans efflux and influx, respectively; K3 is the half-saturation constant for equilibrium exchange, and K4 is related to the mobility of the free carrier). In human erythrocytes, permeability coefficients for diethylene glycol were constant suggesting simple diffusion. For glucose, a plot of 1/P versus concentration was nonlinear indicating carrier kinetics. Plots of 1/P versus penetrant concentrations gave straight lines with positive slopes for urea in human and bovine erythrocytes and for methylurea in human red cells, indicating these penetrants follow simple pore kinetics or simple carrier kinetics in which K4 is very large.

Osmotic stability of red cells in renal circulation requires rapid urea transport.

Urea transport by the human erythrocyte occurs via an asymmetric-facilitated diffusion system with high Michaelis constants and high maximal velocities; the equivalent permeability in the limit of zero urea concentration is approximately 10(-3) cm/s (J. Gen. Physiol. 81: 221-237, 239-253, 1983). A physiological role for this system is revealed by numerical integration of the appropriate equations that show that rapid urea transport is essential for red cell stability in passing through the renal medulla. The calculation compares two cells. Cell A transports urea with permeability characteristics of normal red cells; cell B has urea permeability similar to lipid bilayers. On entering the hypertonic medulla, both cells shrink, but only B swells on leaving the medulla. The osmotic stress for cell B is greater than for A. Cell B is close to hypertonic hemolysis in the medulla and to hypotonic hemolysis in the cortex. Cell B remains swollen for some time after its exit; the resulting decreased deformability presents a hazard if B reenters the microcirculation. Furthermore, cell B removes a significant fraction of the filtered load of urea and compromises the osmotic gradients in the medulla.