Microsurgical testicular sperm extraction for testicular failure: the South African experience and first successful pregnancy

CITATION: Zarrabi, A. D. & Kruger, T. F. 202). Microsurgical testicular sperm extraction for testicular failure : the South African experience and first successful pregnancy. South African Journal of Surgery, 59(2):52-56, doi:10.17159/2078-5151/2021/v59n2a3230.The original publication is available at: http://www.scielo.org.zaBACKGROUND: In men with non-obstructive azoospermia (NOA), biological fatherhood is only possibly by specialised microsurgical sperm retrieval techniques (micro-TESE), only recently introduced to South Africa. This study aimed to analyse the spectrum of causes of NOA and the outcomes of micro-TESE, including live births, following the use of this technique in South Africa METHODS: This was a retrospective review of all micro-TESE cases performed in South Africa by a single surgeon from 2014 to 2018. Data collected prospectively included: patient demographics, preoperative blood results, cause of azoospermia, intraoperative findings and postoperative complications. The primary outcome measured was surgical success of micro-TESE, which was defined as testicular sperm successfully retrieved and cryopreserved. Subsequent live births from assisted reproductive technology (ART) using the cryopreserved sperm were also documented RESULTS: Twenty-six men with NOA underwent micro-TESE between May 2014 and April 2018. Mean preoperative total testosterone level was 12.0 nmol/l (IQR 5.2) and follicle-stimulating hormone level 23.5 IU/l (IQR 15.6). Genetic testing was performed as part of the preoperative work-up in only 10 of the 26 patients. A specific cause of NOA was identified in 9 of the 26 patients and included Klinefelter syndrome (1 patient), Y-chromosome AZFc microdeletion (1 patient), undescended testicles (5 patients) and chemotherapy (2 patients). The average testicular volume was 9.05 ml (IQR 5.6), and the mean duration of surgery 95.8 minutes (IQR 28.0). The overall sperm retrieval rate was 34.6%. A single pregnancy and subsequent live birth were recorded from a total of eight cycles of intracytoplasmic sperm injection (ICSI): four female partners had one ICSI cycle each and two females underwent two cycles each. Frozen and thawed sperm was used in seven of the ICSI cycles and fresh sperm in one cycle CONCLUSION: In this South African series, sperm retrieval rates of micro-TESE for non-obstructive azoospermia were comparable to those reported internationally. Preoperative genetic testing should be increased to optimise the selection of surgical candidatesPublisher's versio

Fourth-generation SM imprints in B -> K^*l^+l^- decays with polarized K^*

The implication of the fourth-generation quarks in the B -> K^*l^+l^- (l=mu,tau) decays, when K^* meson is longitudinally or transversely polarized, is presented. In this context, the dependence of the branching ratio with polarized K^* and the helicity fractions (f_{L,T}) of K^* meson are studied. It is observed that the polarized branching ratios as well as helicity fractions are sensitive to the NP parameters, especially when the final state leptons are tauons. Hence the measurements of these observables at LHC can serve as a good tool to investigate the indirect searches of new physics beyond the Standard Model.Comment: 13 pages, 10 figures, V2: some of the graphs are modified according to the new data from recent experiments. arXiv admin note: substantial text overlap with arXiv:1107.569

The SASSCAL contribution to climate observation, climate data management and data rescue in Southern Africa

A major task of the newly established "Southern African Science Service Centre for Climate Change and Adaptive Land Management" (SASSCAL; www.sasscal.org) and its partners is to provide science-based environmental information and knowledge which includes the provision of consistent and reliable climate data for Southern Africa. Hence, SASSCAL, in close cooperation with the national weather authorities of Angola, Botswana, Germany and Zambia as well as partner institutions in Namibia and South Africa, supports the extension of the regional meteorological observation network and the improvement of the climate archives at national level. With the ongoing rehabilitation of existing weather stations and the new installation of fully automated weather stations (AWS), altogether 105 AWS currently provide a set of climate variables at 15, 30 and 60 min intervals respectively. These records are made available through the SASSCAL WeatherNet, an online platform providing near-real time data as well as various statistics and graphics, all in open access. This effort is complemented by the harmonization and improvement of climate data management concepts at the national weather authorities, capacity building activities and an extension of the data bases with historical climate data which are still available from different sources. These activities are performed through cooperation between regional and German institutions and will provide important information for climate service related activities

The Forward-Backward Asymmetry in the B→πℓ+ℓ−B \to \pi\ell^+\ell^- Decay

Using the most general effective Hamiltonian comprising scalar,vector and tensor type interactions, we have written the branching ratio, the forward-backward (FB) asymmetry and the normalized FB asymmetry as functions of the new Wilson coefficients. It is found that the branching ratio depends on all new coefficients,but the dependence of asymmetries on coefficients could be analyzed only for one Wilson coefficient.Comment: 14 pp, 7 figure

The Electric Dipole Moment and CP Violation in B→Xsl+l−B \to X_s l^+ l^- in SUGRA Models with Nonuniversal Gaugino Masses

The constraints of electric dipole moments (EDMs) of electron and neutron on the parameter space in supergravity (SUGRA) models with nonuniversal gaugino masses are analyzed. It is shown that with a light sparticle spectrum, the sufficient cancellations in the calculation of EDMs can happen for all phases being order of one in the small tan$\beta$ case and all phases but $\phi_{\mu}$ ($|\phi_{\mu}| <\sim \pi/6$) order of one in the large tan$\beta$ case. This is in contrast to the case of mSUGRA in which in the parameter space where cancellations among various SUSY contributions to EDMs happen $|\phi_{\mu}|$ must be less than $\pi/10$ for small $tan\beta$ and ${\cal{O}}(10^{-2})$ for large $tan\beta$. Direct CP asymmetries and the T-odd polarization of lepton in $B\to X_s l^+l^-$ are investigated in the models. In the large tan$\beta$ case, $A_{CP}^2$ and $P_N$ for l=$\mu$ ($\tau$) can be enhanced by about a factor of ten (ten) and ten (three) respectively compared to those of mSUGRA.Comment: 12 pages, latex, 4 figures, a few change

Population genetic structure and predominance of cyclical parthenogenesis in the bird cherry–oat aphid Rhopalosiphum padi in England

Genetic diversity is determinant for pest species' success and vector competence. Understanding the ecological and evolutionary processes that determine the genetic diversity is fundamental to help identify the spatial scale at which pest populations are best managed. In the present study, we present the first comprehensive analysis of the genetic diversity and evolution of Rhopalosiphum padi, a major pest of cereals and a main vector of the barley yellow dwarf virus (BYDV), in England. We have used a genotyping by sequencing approach to study whether i) there is any underlying population genetic structure at a national and regional scale in this pest that can disperse long distances; ii) the populations evolve as a response to environmental change and selective pressures, and; iii) the populations comprise anholocyclic lineages. Individual R. padi were collected using the Rothamsted Insect Survey's suction‐trap network at several sites across England between 2004 and 2016 as part of the RIS long‐term nationwide surveillance. Results identified two genetic clusters in England that mostly corresponded to a North – South division, although gene flow is ongoing between the two subpopulations. These genetic clusters do not correspond to different life cycles types, and cyclical parthenogenesis is predominant in England. Results also show that there is dispersal with gene flow across England, although there is a reduction between the northern and southern sites with the Southwestern population being the most genetically differentiated. There is no evidence for isolation‐by‐distance and other factors like primary host distribution, uncommon in the south and absent in the southwest, could influence the dispersal patterns. Finally, results also show no evidence for the evolution of the R. padi population, and it is demographically stable despite the ongoing environmental change. These results are discussed in view of their relevance to pest management and the transmission of BYDV

Modeling electrolytically top gated graphene

We investigate doping of a single-layer graphene in the presence of electrolytic top gating. The interfacial phenomena is modeled using a modified Poisson-Boltzmann equation for an aqueous solution of simple salt. We demonstrate both the sensitivity of graphene's doping levels to the salt concentration and the importance of quantum capacitance that arises due to the smallness of the Debye screening length in the electrolyte.Comment: 7 pages, including 4 figures, submitted to Nanoscale Research Letters for a special issue related to the NGC 2009 conference (http://asdn.net/ngc2009/index.shtml

On the injectivity of the circular Radon transform arising in thermoacoustic tomography

The circular Radon transform integrates a function over the set of all spheres with a given set of centers. The problem of injectivity of this transform (as well as inversion formulas, range descriptions, etc.) arises in many fields from approximation theory to integral geometry, to inverse problems for PDEs, and recently to newly developing types of tomography. The article discusses known and provides new results that one can obtain by methods that essentially involve only the finite speed of propagation and domain dependence for the wave equation.Comment: To appear in Inverse Problem

Severe ovarian hyperstimulation after follicular aspiration

The original publication is available at http://www.samj.org.zaCITATION: Van der Merwe, J. P., Michell, W. L. & Kruger, T. F. 1988. Severe ovarian hyperstimulation after follicular aspiration. South African Medical Journal, 73:426-427.In order to maximise the changes of pregnancy, most successful in vitro fertilisation programmes use a combination of ovulation induction agents. This treatment can lead to the hyperstimulation syndrome. Aspiration of the follicles is believed to avoid this syndrome. Despite this approach, hyperstimulation syndrome may still develop. The clinical picture and treatment of a patient with severe hyperstimulation is discussed.Publisher’s versio