The Treatment of Complex Urethral Strictures Using Ventral Onlay Buccal Mucosa Graft or Ventral Onlay Penile Skin Island Flap Urethroplasty: A Prospective Case Series

Objectives: To compare the outcome of free onlay Buccal Mucosa Graft (BMG) with onlay penile Skin Island Flap (SIF) urethroplasty in the treatment of complex urethral strictures. Patients and Methods: A prospective comparative study was conducted at the Universitas Academic Hospital in Bloemfontein, South Africa. Patients presenting with complex urethral strictures were allocated to receive either ventral onlay penile SIF urethroplasty or ventral onlay BMG urethroplasty. A complex urethral stricture was defined as a stricture length of more than 2.5 cm or previous failed procedures, including urethral dilatation, internal Optical Urethrotomy (OU) and urethroplasty. Successful treatment outcome or cure was defined as no further treatment of the urethral stricture required after urethroplasty. Statistical analysis was performed with the t-test or chi-square test as appropriate. Results: BMG and SIF urethroplasty were performed on 18 and 17 patients, respectively. The mean age of the patients was 49.1 years (range 21–77) for the SIF group and 44.3 years (range 27–73) for the BMG group (p= 0.28). The mean urethral stricture length in the BMG group was 2.9 cm (range 2.4–4.0) and 4.5 cm (range 2.4–7.0) in the SIF group (p= 0.002). The urethral stricture site was bulbar in 67% in the BMG group and 59% in the SIF group. The cure rate was 11/17 (64.7%) for the SIF group and 13/18 (72.2%) for the BMG group (p= 0.63). Conclusions: No statistically significant difference in outcome between BMG and SIF urethroplasty was observed. However, given the longer operation time and more extensive surgical dissection of SIF reported in other studies, we recommend onlay BMG urethroplasty for the treatment of complex strictures.Key Words: Urethral stricture, Urethroplasty, Buccal mucosa graft, Skin island fla

The Cytotoxic, Antimicrobial and Anticancer Properties of the Antimicrobial Peptide Nisin Z Alone and in Combination with Conventional Treatments

Nisin is an antimicrobial peptide commonly used as a food preservative since 1969. This peptide has potent antimicrobial activity against several Gram-positive bacterial strains, including clinically important and resistant pathogens. The combination of nisin with conventional antibiotics has been shown to improve the antimicrobial activity of these antibiotic agents. Apart from the antimicrobial properties of nisin, this AMP also displays promising anticancer potential towards several types of malignancies. The nisin Z variant is able to induce selective cytotoxicity in melanoma cells compared to non-malignant cells. It was shown that nisin Z disrupts the cell membrane integrity of melanoma cells and that cytotoxicity is likely due to the activation of an apoptotic pathway. In addition, when used in combination with the conventional chemotherapeutic agents, nisin Z has the potential to enhance the cytotoxicity of these chemotherapeutic agents against cultured melanoma cells. Nisin Z has great potential for clinical application considering its low cytotoxicity to non-malignant cells and its effectiveness against Gram-positive bacterial strains and certain cancers

Heritability and expression of selected mixograph parameters in progeny of parents varying for mixing time

The mixograph performs certain rheological measurements during dough mixing and is a good predictor of wheat end-use quality. The aim of this study was to determine the expression and the heritability of mixing characteristics measured with Mixsmart® software and some quality characteristics in hard red spring wheat parents and their F1 progeny. Six parents varying in midline peak time and envelope peak time were crossed in a half diallel design. Parents and progeny were planted in three different environments. General combining ability (GCA) was a significant source of variation for the measured characteristics, and parents differed widely in terms of GCA effects. Midline-development time, -peak integral and -peak time showed high narrow sense heritability. Envelope peak-integral and -tail width displayed high narrow sense heritability for some, but not all locations. High GCA:SCA (specific combining ability) ratios indicated the prevalence of additive gene effects for midline-development time, -peak integral and -peak time, indicating that these characteristics are largely genetically determined, and that selection for them should lead to genetic gain

A Modified Synchrotron Model for Knots in the M87 Jet

For explaining the broadband spectral shape of knots in the M87 jet from radio through optical to X-ray, we propose a modified synchrotron model that considers the integrated effect of particle injection from different acceleration sources in the thin acceleration region. This results in two break frequencies at two sides of which the spectral index of knots in the M87 jet changes. We discuss the possible implications of these results for the physical properties in the M87 jet. The observed flux of the knots in the M87 jet from radio to X-ray can be satisfactorily explained by the model, and the predicted spectra from ultraviolet to X-ray could be further tested by future observations. The model implies that the knots D, E, F, A, B, and C1 are unlikely to be the candidate for the TeV emission recently detected in M87.Comment: 12 pages, 1 figure, 2 tables, Accepted for publication in ApJ Letter

The WKB Approximation without Divergences

In this paper, the WKB approximation to the scattering problem is developed without the divergences which usually appear at the classical turning points. A detailed procedure of complexification is shown to generate results identical to the usual WKB prescription but without the cumbersome connection formulas.Comment: 13 pages, TeX file, to appear in Int. J. Theor. Phy

Solar Physics - Plasma Physics Workshop

A summary of the proceedings of a conference whose purpose was to explore plasma physics problems which arise in the study of solar physics is provided. Sessions were concerned with specific questions including the following: (1) whether the solar plasma is thermal or non-themal; (2) what spectroscopic data is required; (3) what types of magnetic field structures exist; (4) whether magnetohydrodynamic instabilities occur; (5) whether resistive or non-magnetohydrodynamic instabilities occur; (6) what mechanisms of particle acceleration have been proposed; and (7) what information is available concerning shock waves. Very few questions were answered categorically but, for each question, there was discussion concerning the observational evidence, theoretical analyses, and existing or potential laboratory and numerical experiments

Encouraging girls in math and science

The objective of this guide is to provide teachers with specific recommendations that can be carried out in the classroom without requiring systemic change. Other school personnel having direct contact with students, such as coaches, counselors, and principals, will also find the guide useful

Noise storm continua: power estimates for electron acceleration

We use a generic stochastic acceleration formalism to examine the power $L_{\rm in}$ (${\rm erg s^{-1}}$) input to nonthermal electrons that cause noise storm continuum emission. The analytical approach includes the derivation of the Green's function for a general second-order Fermi process, and its application to obtain the particular solution for the nonthermal electron distribution resulting from the acceleration of a Maxwellian source in the corona. We compare $L_{\rm in}$ with the power $L_{\rm out}$ observed in noise storm radiation. Using typical values for the various parameters, we find that $L_{\rm in} \sim 10^{23-26}$ ${\rm erg s^{-1}}$, yielding an efficiency estimate $\eta \equiv L_{\rm out}/L_{\rm in}$ in the range 10^{-10} \lsim \eta \lsim 10^{-6} for this nonthermal acceleration/radiation process. These results reflect the efficiency of the overall process, starting from electron acceleration and culminating in the observed noise storm emission.Comment: Accepted for publication in Solar Physic