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Sperm cell biology： current perspectives and future prospects

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Asian Journal of Andrology 2011年第1期13卷 3-5页

作者： r John Aitken ralf r henkel Discipline of Biological Sciences University of Newcastle Newcastle NSW 2308 Australia Department of Medical Biosdences University of the Western Cape Bellville 7535 South Africa

Major advances in biomolecular techniques as well as in the sensitivity and accuracy of mass spectrometers are transforming the scientific landscape by fueling unprecedented advances in analytical biochemistry--the ＇... 详细信息

关键词： Sperm cell biology perspectives

Estimate of oxygen consumption and intracellular zinc concentration of human spermatozoa in relation to motility

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Asian Journal of Andrology 2003年第1期5卷 3-8页

作者： ralf r.henkel Kerstin Defosse Hans-Wilhelm Koyro Norbert Weissmann Wolf-Bernhard Schill Center for Dermatology and Andrology University D-35385 Giessen GermanyCenter for Dermatology and Andrology University D-35385 Giessen GermanyInstitute for Plant Ecology University D-35385 Giessen GermanyCenter for Internal Medicine Justus Liebig University D-35385 Giessen GermanyCenter for Dermatology and Andrology University D-35385 Giessen Germany

Aim: To investigate the human sperm oxygen/energy consumption and zinc content in relation to motility. Methods: In washed spermatozoa from 67 ejaculates, the oxygen consumption was determined. Following calculation o... 详细信息

ract>Aim: To investigate the human sperm oxygen/energy consumption and zinc content in relation to motility. Methods: In washed spermatozoa from 67 ejaculates, the oxygen consumption was determined. Following calculation of the total oxygen consumed by the Ideal Gas Law, the energy consumption of spermatozoa was calculated. In addition, the zinc content of the sperm was determined using an atomic absorption spectrometer. The resulting data were correlated to the vitality and motility. results: The oxygen consumption averaged 0.24μmol/106 sperm×24 h, 0.28μmol/106 live sperm×24 h and 0.85μmol/106 live & motile sperm×24 h. Further calculations revealed that sperm motility was the most energy consuming process (164.31 mJ/106 motile spermatozoa×24 h), while the oxygen consumption of the total spermatozoa was 46.06 mJ/106 spermatozoa×24 h. The correlation of the oxygen/ energy consumption and zinc content with motility showed significant negative correlations (r= -0.759; Pr=-0.441; Prespectively). However, when correlating sperm energy consumption with the zinc content, a significant positive relation (r=0.323; P=0.01) was observed. Conclusion: Poorly motile sperm are actually wasting the available energy. Moreover, our data clearly support the 'Geometric Clutch Model' of the axoneme function and demonstrate the importance of the outer dense fibers for the generation of sperm motility, especially progressive motility.

关键词： oxygen energy consumption human spermatozoa sperm motility zinc

Sperm preparation： state-of-the-art--physiological aspects and application of advanced sperm preparation methods

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Asian Journal of Andrology 2012年第2期14卷 260-269页

作者： ralf henkel Department of Medical Biosciences University of the Western Cape Bellville 7535 South Africa

For assisted reproduction technologies （ArT）, numerous techniques were developed to isolate spermatozoa capable of fertilizing oocytes. While early methodologies only focused on isolating viable, motile spermatozoa, with progress of ArT, particularly intracytoplasmic sperm injection （ICSI）, it became clear that these parameters are insufficient for the identification of the most suitable spermatozoon for fertilization. Conventional sperm preparation techniques, namely, swim-up, density gradient centrifugation and glass wool filtration, are not efficient enough to produce sperm populations free of DNA damage, because these techniques are not physiological and not modeled on the stringent sperm selection processes taking place in the female genital tract. These processes only allow one male germ cell out of tens of millions to fuse with the oocyte. Sites of sperm selection in the female genital tract are the cervix, uterus, uterotubal junction, oviduct, cumulus oophorus and the zona pellucida. Newer strategies of sperm preparation are founded oni （i） morphological assessment by means of＇motile sperm organelle morphological examination （MSOM E）＇; （ii） electrical charge; and （ili） molecular binding characteristics of the sperm cell. Whereas separation methods based on electrical charge take advantage of the sperm＇s adherence to a test tube surface or separate in an electrophoresis, molecular binding techniques use Annexin V or hyaluronic acid （HA） as substrates. Techniques in this category are magnet-activated cell sorting, Annexin V-activated glass wool filtration, flow cytometry and picked spermatozoa for ICSI （PICSI） from HA-coated dishes and HA-containing media. Future developments may include raman microspectrometry, confocal light absorption and scattering spectroscopic microscopy and polarization microscopy.

关键词： advanced sperm selection biomimetics conventional sperm selection female genital tract physiological sperm selection

Critical evaluation of two models of flow cytometers for the assessment of sperm DNA fragmentation:an appeal for performance verification

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Asian Journal of Andrology 2019年第5期21卷 438-444页

作者： rakesh Sharma Sajal Gupta ralf henkel Ashok Agarwal American Center for reproductive Medicine Cleveland ClinicClevelandOH 44195USA Department of Medical Bioscience University of the Western CapeBellville 7535South Africa

Lack of standardized,reproducible protocols and referencO values is among the challenges faced when using new or upgraded versions of instruments in reproductive laboratories and flow *** deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)assay combined with flow cytometry routinely used for diagnostic measurement of sperm DNA fragmentation(SDF)is a unique *** change in the setting of the standard instrument,including upgrades of hardware or software,can lead to different results and may affect clinicians'decision for ***,we compared TUNEL results of SDF obtained from a standard(C6)flow cytometer with a newer version of the same instrument(C6 Plus)and examined the cutoff,sensitivity,and specificity without calibration(adjustment)and after *** sperm preparation and matched acquisition settings were used to examine the performance of two flow *** strength of agreement of the results between the two observers was also *** adjustment of the settings,overall concordance became high and the two cytometers showed 100%positive and negative predictive value with 100%area under the *** overall correlation coefficient observed between C6 and C6 Plus was highly significant(Pr=0.992;95%confidence interval[Cl]:0.982-0.997).After adjustment,the two cytometers showed very high precisi on of 98%and accuracy of>99%.The in terobserver agreeme nt on C6 flow cytometer for the two observers was 0.801±0.062 and 0.746±0.044 for C6 *** demonstrated a strong agreement between the samples tested on the two flow cytometers after calibration and established the robustness of both instruments.

关键词： DNA fragmentation flow cytometer oxidative stress sperm TUNEL assay

Laser-induced plasma formation in water with up to 400 mJ double-pulse LIBS

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Plasma Science and Technology 2024年第1期26卷 93-100页

作者： Marion henkel Michelle SIEMENS ralf METHLING Benjamin EMDE Jörg HErMSDOrF Steffen FrANKE Diego GONZALEZ Leibniz Institute for Plasma Science and Technology(INP) Felix-Hausdorff-Straße 2Greifswald 17489Germany Laser Zentrum Hannover e.V.(LZH) Hollerithallee 8Hannover 30419Germany

Double-pulse LIBS is a promising technique for deep-sea *** measurements in shallow water with up to 400 mJ each pulse were done to select laser parameters which promote optimized spectral line emission from plasma even at elevated pressures,where line broadening until loss of most of the spectral information can *** emission spectroscopy,using a Czerny-Turner spectrometer,has been applied to investigate the dependence of the emitted radiation on laser parameters and hydrostatic *** has been found,that higher laser pulse energies,especially with short pulse delay as required in high water pressure,can also have an adverse effect on the measured spectrum.

关键词： double-pulse LIBS underwater plasma formation emission spectrosocpy

The new 6^(th) edition of the WHO Laboratory Manualfor the Examination and Processing of HumanSemen: is it a step toward better standard operatingprocedure?

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Asian Journal of Andrology 2022年第2期24卷 123-124页

作者： Eric Chung Mohamed Arafa Florence Boitrelle Hussein Kandil ralf henkel ramadan Saleh rupin Shah Paraskevi Vogiatzi Armand Zini Ashok Agarwal AndroUrology Centre BrisbaneQLD 4000Australia University of Queensland Princess Alexandra HospitalBrisbaneQLD 4000Australia American Center for reproductive Medicine Cleveland ClinicClevelandOH 44195USA Department of Andrology Cairo UniversityCairo 12613Egypt Department of Urology Hamad Medical CorporationDoha 122104Qatar reproductive Biology Fertility PreservationAndrologyCECOSPoissy HospitalPoissyParis 78300France Saclay University UVSQINRAEBREEDJouy-en-Josas 78350France Fakih IVF Fertility Center Abu Dhabi 51133UAE Department of Metabolism Digestion and ReproductionImperial College LondonLondon SW72AZUK Department of Medical Biosciences University of the Western CapeBellville 7530South Africa LogixX Pharma ThealeBerkshire GU154DUUK Department of Dermatology Venereology and AndrologyFaculty of MedicineSohag UniversitySohag 82518Egypt Department of Urology Lilavati Hospital and Research CentreMumbaiMaharashtra 400001India Andromed Health and reproduction Fertility Diagnostics LaboratoryMaroussiAthens 10431Greece Department of Surgery McGill UniversityMontrealQC H3A 0G4Canada

Semen analysis(SA)remains the cornerstone of male infertility evaluation and should ideally be performed by an accredited andrology laboratory or in vitro fertilization(IVF)clinics based on the standards defined by the World Health Organization(WHO)for the Examination and Processing of Human Semen and in accordance with the International Organization for Standardization’s Basic Semen Examination on Specification and Test Methods.

关键词： Basic Human corners

The impact of male overweight on semen quality and outcome of assisted reproduction

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Asian Journal of Andrology 2014年第5期16卷 787-787页

作者： Kristian Leisegang ralf henkel School of Natural Medicine Faculty of Community and Health Sciences University of the Western Cape Bellville South Africa Department of Medical Bioscience Faculty of Science University of the Western Cape Bellville South Africa

The impact of obesity on male reproductive health remains a contested topic as evidence is inconclusive and inconsistent.1,2 Even more debatable is the effect of male obesity in assisted reproduction. In the manuscript, ＂the impact of male overweight on semen quality and outcome of assisted reproduction＂ published in Asian Journal ofAndrology, Thomsen et al.3 investigated the effect of male obesity on fertilization outcomes in intrauterine insemination, in vitro fertilization （IVF） and intracytoplasmic sperm injection （ICSI） programs further contributes to the increasing body of evidence in this field.

关键词： The impact male overweight

Importance of hydrogenotrophic, aceticlastic and methylotrophic methanogenesis for methane production in terrestrial, aquatic and other anoxic environments: A mini review

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Pedosphere 2020年第1期30卷 25-39页

作者： ralf CONrAD Max Planck Institute for Terrestrial Microbiology Karl-von-Frisch-Str.10Marburg 35043(Germany)

Microbial methanogenesis is a major source of the greenhouse gas methane(CH4).It is the final step in the anaerobic degradation of organic matter when inorganic electron acceptors such as nitrate,ferric iron,or sulfate have been *** of this degradation pathway is important for the creation of mechanistic models,prediction of future CH4 emission scenarios,and development of mitigation *** most anoxic environments,CH4 is produced from either acetate(aceticlastic methanogenesis)or hydrogen(H2)plus carbon dioxide(CO2)(hydrogenotrophic methanogenesis).Hydrogen can be replaced by other CO2-type methanogenesis,using formate,carbon monoxide(CO),or alcohols as *** ratio of these two pathways is tightly constrained by the stoichiometry of conversion *** the degradation of organic matter is complete(e.g.,degradation of straw in rice paddies),then fermentation eventually results in production of acetate and H2 at a ratio of>67%aceticlastic androgenotrophic ***,acetate production can be favored when heterotrophic or chemolithotrophic acetogenesis is enhanced,and H2 production can be favored when syntrophic acetate oxidation is *** typically occurs at low and elevated temperatures,***,temperature can strongly influence the methanogenic pathway,which may range from 100%aceticlastic methanogenesis at low temperatures to 100%hydrogenotrophic methanogenesis at high ***,if the degradation of organic matter is not complete(e.g.,degradation of soil organic matter),the stoichiometry of fermentation is not tightly constrained,resulting,for example,in the preferential production of H2,followed by hydrogenotrophic *** production of CH4 by either aceticlastic or hydrogenotrophic methanogenesis can also happen if one of the methanogenic substrates is not consumed by methanogens but is,instead,accumulated,volatilized,or utilized *** methano

关键词： electron acceptor fermentation methanogenic pathway organic matter degradation pH soil microbial community temperature Wood-Ljungdahl pathway

Bottomonium suppression in heavy-ion collisions and the in-medium strong force

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Nuclear Science and Techniques 2023年第4期34卷 185-187页

作者： ralf rapp Cyclotron Institute and Department of Physics and Astronomy Texas A&M UniversityCollege StationTX 77843-3366USA

A large suppression of various bottomonium states in ultra-relativistic heavy-ion collisions has been reported by the STAr collaboration at the relativistic Heavy-Ion *** observation is consistent with the formation of a quark-gluon plasma,but similar findings in more energetic collisions at the Large Hadron Collider suggest that a consistent picture requires additional *** states of a heavy quark (charm or bottom) and its antiquark,commonly referred to as quarkonia,have long been recognized as excellent probes of quark-gluon plasma(QGP) formation in high-energy collisions of atomic *** the vacuum,most quarkonium states are dominantly bound by a linearly rising potential (the so-called Cornell potential,see Fig.1),as a direct manifestation of the confinement property of Quantum Chromodynamics (QCD).

关键词： quark linearly vacuum