bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacokinetic Study of Injectable Testosterone Undecanoate in Hypogonadal Men
Authors: ZHANG GUI‐YUAN , GU YI‐QUN , WANG XING‐HAI , CUI YU‐GUI , BREMNER WILLIAM J.
Published: October 2023

ABSTRACT: Testosterone undecanoate (TU) provides testosterone (T) replacement for hypogonadal men when administered orally but requires multiple doses per day and produces widely variable serum T levels. We investigated the pharmacokinetics of a newly available TU preparation administered by intramuscular injection to hypogonadal men. Eight patients with Klinefelter1 s syndrome received either 500 mg or 1,000 mg of TU by intramuscular injection; 3 months later, the other dose was given to each man (except to one, who did not receive the 1,000‐mg dose). Serum levels of reproductive hormones were measured at regular intervals before and after the injections. Mean serum T levels increased significantly at the end of the first week, from less than 10 nmol/L to 47.8 ± 10.1 and 54.2 ± 4.8 nmol/ L for the lower and higher doses, respectively. Thereafter, serum T levels decreased progressively and reached the lower‐normal limit for adult men by day 50 to 60. Pharmacokinetic analysis showed a terminal elimination half‐life of 18.3 ± 2.3 and 23.7 ± 2.7 days and showed a mean residence time of 21.7 ± 1.1 and 23.0 ± 0.8 days for the lower and higher doses, respectively. The area under the serum T concentration‐time curve and the T‐distribution value related to serum T concentration were significantly higher following the 1,000‐mg dose than following the 500‐mg dose. The 500‐mg dose, when given as the second injection, yielded optimal pharmacokinetics (defined as mean peak T values not exceeding the normal range and persistence of normal levels for at least 7 weeks), suggesting that repeated injections of 500 mg at 6–8‐week intervals may provide optimal T replacement. The mean serum levels of estradiol were normalized following the injections, and prolactin levels were normal throughout the study. Significant decrease of serum luteinizing hormone (LH) and follicle‐stimulating hormone (FSH) levels was observed, with the decrease in LH levels being more pronounced. There were no significant differences in serum LH and FSH levels between the two doses. Sex hormone‐binding globulin (SHBG) levels before any T therapy were near the upper limit of normal for adult men and were reduced by approximately 50% just prior to the second dose of TU. The decreased SHBG levels produced by the first TU injection could have led to lower peak total T levels and to a more rapid clearance of T following the second TU injection. We conclude that single‐dose injections of TU to hypogonadal men can maintain serum T concentration within the normal range for at least 7 weeks without immediately apparent side effects. It is likely that this form of T would require injections only at 6–8‐week or longer intervals, not at the 2‐week intervals necessary with currently used T esters (enanthate and cypionate). This injectable TU preparation may provide improved substitution therapy for male hypogonadism and, in addition, may be developed as an androgen component of male contraceptives.
Cytoplasmic Extrusion and the Switch From Creatine Kinase B to M Isoform are Completed by the Commencement of Epididymal Transport in Human and Stallion Spermatozoa
Authors: HUSZAR GABOR , PATRIZIO PASQUALE , VIGUE LYNNE , WILLETS MELANIE , WDJKER CLYNN , ADHOOT DAVID , JOHNSON LARRY
Published: October 2023

ABSTRACT: Although in several species there is a relationship between epididymal sperm transport and fertility, in human in vitro fertilization (IVF), spermatozoa recovered from the caput epididymidis or even the rete testis are fertile. We studied two objective markers of sperm maturity in the sperm of men and stallions: creatine kinase (CK) concentrations, which are a measure of cytoplasmic retention in immature spermatozoa, and the ratio of CK‐M and CK‐B isoforms (% CK‐M/[CK‐M + CK‐B]), which is proportional to the incidence of mature sperm. The CK markers and the fertilizing function are closely related: Immature sperm with cytoplasmic retention do not bind to the zona, because during cytoplasmic extrusion, the sperm plasma membrane is also remodeled. We examined whether changes in sperm CK values are still ongoing during epididymal transport, or if cellular maturation is completed prior to the arrival of sperm in the caput epididymidis. The incidences of mature sperm in human caput and corpus epididymidis (studied in six men with obstructive azoospermia of various pathogeneses) were (mean ± SEM) 55.7 ± 2.2 and 49.3 ± 7.6%, respectively; and the sperm CK‐M ratios in the caput epididymidis of three men were 72, 75, and 70%, values that are similar to those of ejaculated sperm. In four segments of the proximal and distal epididymis of three stallions (the origin of sperm was also verified by the position of the cytoplasmic droplet) and in ejaculate of five stallions, the incidences of mature sperm were 88.2 ± 6.2, 89.0 ± 6.7, 90.3 ± 7.8, 87.6 ± 5.9, and 86.7 ± 0.8%, and the respective CK‐M ratios were 75.0 ± 8.7, 84.2 ± 2.9,87.9 ± 1.2, 92.5 ± 1.5, and 69.3 ± 3.5%. There were no differences in the incidences of mature and immature spermatozoa or in CK‐M ratios among sperm arising from the various epididymal regions or from the ejaculate in men or stallions. Thus, the cellular maturation events in sperm, as detected by the CK markers, are completed by the time the sperm commences epididymal transport. These findings are in agreement with the IVF fertility of sperm aspirated from the male reproductive tract. The data may also suggest that the primary role of sperm epididymal transport in men is to remodel the plasma membrane to enhance sperm functional integrity in the diverse environments of the male and female reproductive tracts prior to fertilization.
Catalase and Oviductal Fluid Reverse the Decreased Motility of Bovine Sperm in Culture Medium Containing Specific Amino Acids
Authors: LAPOINTE SERGE , SIRARD MARC‐ANDRE
Published: October 2023

ABSTRACT:The motility and velocity of bovine spermatozoa incubated in TCM‐199 are reduced in comparison with those incubated in a simpler media made for sperm, such as modified Tyrode (Sp‐Talp). Moreover, a previous study showed that oviductal cells conditioned media prevented this decreased motility in TCM‐199. Preliminary results lead us to suspect that amino acids in TCM‐199 were involved in the reduced survival. Therefore, the current experiment aimed at determining which amino acids were involved and what their mechanism of action involved. Amino acids were added separately in Sp‐Talp at the final concentration found in TCM‐199. Frozen‐thawed bovine spermatozoa were washed twice by centrifugation in Sp‐Talp and diluted to 25 × 106/ml in the amino acid media. After 6 hours of incubation at 37°C, sperm motility and velocity were recorded. The percentage of motile sperm was significantly lower in the presence of phenylalanine (6% ± 2,P< 0.05) compared with the control (46% ± 2). Sperm velocity (VAP, μm/second) was lower in the presence of phenylalanine (50 ± 4) and tyrosine (89 ± 3) compared with the control (119 ± 4,P< 0.05). Increased concentrations of the three aromatic amino acids (0,0.2, 1, five times TCM‐199 concentrations) decreased both sperm motility and velocity in a dose‐dependent manner. Cysteine and methionine, added at 250 μg/ml, showed a negative effect on sperm motility and/or velicity, as did the three aromatic amino acids. Presence of catalase (0.01 mg/ml) in the amino acid‐supplemented Sp‐Talp for 6 hours kept sperm motility and velocity at control levels, suggesting that the toxic effect of amino acids acts on sperm by excess hydrogen peroxide production. Because the oviduct contains amino acids, and its role as a reservoir for sperm survival is well known, oviductal fluid was collected and tested. Oviductal fluid reversed the negative effect of amino acids, similar to the action of the catalase. Oviductal fluid also kept the peroxide concentrations of media containing phenylalanine at basal levels (<10 μM) compared with phenylalanine alone (∼40 μM). These results suggest the presence of catalase activity in oviductal fluid.
Rat Testicular Germ Cells and Epididymal Sperm Contain Active P450 Aromatase
Authors: JANULIS LYNN , BAHR JANICE M. , HESS REX A. , JANSSEN SARAH , OSAWA YOSHIO , BUNICK DAVID
Published: October 2023

ABSTRACT: Although testosterone is the principal sex steroid produced by the testis, estrogen is known to be produced by both Leydig and Sertoli cells during different developmental periods. Additionally, evidence is unfolding to suggest that germ cells might also participate in the synthesis of estrogen within the male reproductive tract. We have recently reported that the messenger ribonucleic acid (mRNA) for P450 aromatase (P450arom), the enzyme that converts androgen to estrogen, is synthesized by rat germ cells. Therefore, the present study was conducted to determine which germ cell types synthesize active P450arom and to measure the activity of this enzyme in germ cells throughout spermatogenesis and in maturing sperm during epididymal transit. First, P450arom activity was measured in pachytene spermatocytes, round spermatids, and a mixture of round spermatids, elongating spermatids, and residual bodies using the tritiated water (3H2O) assay. Second, sperm isolated from different regions of the epididymis were assayed for P450arom activity. Sperm isolated from the caput epididymis with attached efferent ductules had the higher P450arom activity, whereas sperm isolated from the corpus and cauda epididymides had lower P450arom activity. The decrease in P450arom activity in cauda sperm was further confirmed by immunocytochemistry. On the basis of these observations, we conclude that rat testicular germ cells from pachytene spermatocytes through elongating spermatids and epididymal sperm contain active P450arom and that sperm lose aromatase activity as they mature during epididymal transit. Therefore, both post‐pachytene rat germ cells and epididymal sperm are capable of estrogen synthesis and are an additional, potentially significant, source of estrogen in the male reproductive tract.
Dogfish Shark (Squalus acanthias) Testes Contain a Relaxin
Authors: STEINETZ BERNARD G. , SCHWABE CHRISTIAN , CALLARD IAN P. , GOLDSMTTH LAURA T.
Published: October 2023

ABSTRACT: Relaxin is a 6‐kd polypeptide that exerts important hormonal effects in many female mammals. Relaxin is produced by the ovary, placenta, or uterus in many mammalian species. The functions of relaxin in the male mammal are not yet firmly established, but there is some evidence suggesting an exocrine effect on sperm motility and fertilizability. In the male mammals that have been studied, relaxin is produced by the prostate gland (human) or seminal vesicles (boar). However, in the bird, the testis is the likely source of relaxin. Among the elasmobranchs, ovaries obtained from dogfish sharks have been shown to contain a polypeptide hormone that is structurally, biologically, and immunologically similar to mammalian relaxins, but the male reproductive tract of this species has not previously been investigated as a potential source of relaxin. Extracts of testes obtained from mature dogfish sharks have now been tested by a specific relaxin bioassay and by a homologous porcine radioimmunoassay for the presence of relaxin. Both crude and partially purified testicular extracts contained unmistakable guinea pig pubic symphysis—“relaxing” activity and relaxin‐like immunoactivity. Following immunoaffinity purification, the shark testis polypeptide had an apparent specific activity of 88 μg porcine relaxin equivalents per milligram in the radioimmunoassay, which is similar to the immunoactivity of pure shark ovarian hormones. These data, therefore, strongly support the view that in dogfish sharks, the male as well as the female gonad produces relaxin. Furthermore, as the dogfish shark has existed as a species for about 200 million years, the data suggest that testicular relaxin appeared early in vertebrate evolution.
Spermatogenesis in Early and Chronic Phases of Experimental Spinal Cord Injury in the Rodent Model
Authors: HIRSCH IRVIN H. , HUANG BIN , CHANCELLOR MICHAEL B. , RIVAS DAVID A. , SALZMAN STEVEN K. , JOST LORNA K. , EVENSON DONALD P.
Published: October 2023

ABSTRACT: A rodent model was used to study the degree and dynamics of potential spermatogenic alterations during both acute and chronic phases after experimental spinal cord injury (SCI). Sexually mature Sprague‐Dawley rats underwent controlled impact SCI by exposure of the thoracic spine, T‐10 laminectomy, and intraoperative somatosensory‐evoked potential latency and amplitude. A 50 gm‐cm SCI was produced in 35 experimental subjects. Sham surgery was performed on 16 control subjects through exposure of the dura without weight drop. SCI was verified by obliteration of the somatosensory‐evoked potential following injury and subsequent neurologic assessment (modified hindlimb Tarlov scale) 4 weeks after injury. Flow cytometry with acridine orange as the DNA probe was used to measure potential spermatogenic alterations in testicular cell development and integrity of epididymal sperm chromatin structure between 2 and 20 weeks following SCI. Flow cytometric analysis revealed that nine of the 35 SCI animals demonstrated altered spermatogenesis; it is not clear whether these effects are specific or nonspecific stress related. These responder animals contributed to dramatic differences in relative percent testicular haploid cells (spermatids) and concurrent differences in percent diploid cells at 2, 4, 8, 12, and 16 weeks. Percentages within the three spermatid populations (round, elongating, and elongated) also differed at these time points. The sperm chromatin structure assay (SCSA) revealed significant epididymal sperm nuclear structure differences at 2, 4, and 12 weeks (P < 0.001). These findings are in concordance with our clinical observations of spermatogenesis in spinal cord injured men and suggest that significant spermatogenic deficit may occur, even in the early phase of injury.
Determination of the Steady‐State Intracellular Chloride Concentration in Capacitated Human Spermatozoa
Authors: GARCIA MANUEL A. , MEIZEL STANLEY
Published: October 2023

ABSTRACT: Chloride channels participate in the mammalian sperm acrosome reaction (AR). However, the mechanism by which sperm regulate intracellular Ch concentration ([Cl−]1) is not known. The steady‐state [Cl−]1, has also never been reported for mammalian spermatozoa. Therefore, using chloride‐sensitive fluorescent dyes, we sought to determine the steady‐state [Cl−]1, of capacitated human spermatozoa by a null‐point measurement technique. We found that the [Cl−]1 was sufficiently elevated (a conservative estimate of ≥41 mM) such that the opening of chloride channels should result in a Ch efflux and, hence, in depolarization. Moreover, the [Cl]1 does not remain constant under varying extracellular Ch concentrations ([Cl]0.
Evidence for the Role of Heterotrimeric Guanine Nucleotide‐Binding Regulatory Proteins in the Regulation of the Mouse Sperm Adenylyl Cyclase by the Egg's Zona Pellucida
Authors: LECLERC PIERRE , KOPF GREGORY S.
Published: October 2023

ABSTRACT: Sperm acrosomal exocytosis is the result of a complex set of signal transduction pathways activated physiologically by the egg's extracellular matrix, the zona pellucida. In the mouse, the zona pellucida has been demonstrated to induce an increase in sperm intracellular pH, Ca2+ and cyclic adenosine monophosphate (cAMP) concentrations as well as to activate proteins of the G, class (G; guanine nucleotide‐binding regulatory proteins). We recently reported that the mouse zona pellucida could activate the adenylyl cyclase of mouse sperm. It is not known, however, whether zona pellucida stimulation of adenylyl cyclase activity is mediated through G proteins. In the present study, we demonstrate that the sperm membrane‐bound adenylyl cyclase activity is stimulated by the G protein activators guanosine‐5′‐Othiotriphosphate (GTPγS) and mastoparan in a concentration‐dependent manner. The maximal adenylyl cyclase activity measured with these two G protein activators is similar to the stimulation observed with the zona pellucida, but the effect of GTP‐γS is not additive or synergistic with the effects of mastoparan or the zona pellucida. Pertussis toxin treatment of sperm membranes inhibits the zona pellucida stimulation of adenylyl cyclase activity, while the basal or forskolin‐induced activation of the enzyme is not affected. Partial inhibition of the stimulatory effect of the zona pellucida on the adenylyl cyclase activity is observed with guanosine‐5′‐Othiodiphosphate (GDPβS), another G protein antagonist. To a reconstitution system containing Lubrol‐PX, where zona pellucida or GTP‐βS stimulation of the sperm enzyme is not observed, addition of G protein βγ subunits restores the activation of the sperm adenylyl cyclase by the zona pellucida and GTPγS without affecting the enzyme activity under basal or forskolin‐stimulated conditions. These results support our hypothesis that mouse sperm adenylyl cyclase is stimulated by the zona pellucida through a pertussis toxin‐sensitive pathway involving G proteins of the G, class.
Rat Seminal‐Vesicle Secretory Protein SVS II Binds DNA With a Preference for the 5′ Regulatory Region of Secretory Protein SVS IV Gene: Co‐Isolation With Components of the Nuclear Matrix
Authors: HORTON MICHAEL J. , GETZENBERG ROBERT H.
Published: October 2023

ABSTRACT: In rats, the ventral prostate and seminal vesicles produce distinct sets of proteins whose functions and tissue‐specific regulation by androgens remain unclear. We have utilized the genes encoding the major secretory protein of seminal vesicles, SVS IV, and the C3 subunit of prostatein of the ventral prostate to study how the nuclear matrix might determine their tissue‐specific gene expression. Nuclear matrix proteins were prepared from purified nuclei with DNase and 2 M NaCl, separated in SDS gels, and transferred onto membranes for DNA‐binding (southwestern) and immunological (western) analyses. The 5′ region of the SVS IV gene (SVS IV‐7S) bound to a 45,000‐kDa molecular‐weight protein band in the nuclear matrix of seminal vesicles but not to that of ventral prostate, kidney, or liver. Sequencing revealed that this band was a seminal‐vesicle secretory protein, SVS II, whose identity was confirmed with an anti‐SVS II antiserum in western blots. Actin‐like protein, similar in mobility to SVS II, was detected in seminal‐vesicle and ventral prostate nuclear matrix, but not in seminal‐vesicle fluid. Reducing agent (10 mM dithiothreitol) and acidic (pH 6.5) buffer did not eliminate SVS II, but isolation of nuclear matrices with ammonium sulfate, nucleases, and urea decreased SVS II immunoreactivity and removed actin‐like protein. SVS II binding to SVS IV‐7S DNA was greater than its binding to either a comparable fragment of the C3 gene or linearized pUC‐19 plasmid, and it was not eliminated by a 100‐fold competition. When seminal‐vesicle fluid was mixed with rat liver, some SVS II co‐isolated with the nuclear‐matrix proteins, indicating that nonspecific interactions contribute to its association with the nucleo‐skeleton. However, these interactions may not represent the intracellular behavior of SVS II in seminal‐vesicle epithelium. Sequence comparisons indicate significant homologies between SVS II and some other seminal proteins, including bovine caltrin, which, under the name seminalplasmin, is known to possess antimicrobial activity. Collectively, these data suggest that in addition to its known functions, SVS II may also bind extraneous DNA in seminal fluid. Additionally, SVS II may participate as a structural component in the organization of a tissue‐specific seminal‐vesicle nuclear matrix.
Molecular Cloning and Developmental Expression of the Major Fibrous Sheath Protein (FS 75) of Rat Sperm
Authors: EL‐ALFY MOHAMED , MOSHONAS DEMETRA , MORALES CARLOS R. , OKO RICHARD
Published: October 2023

ABSTRACT: The fibrous sheath (FS) is a cytoskeletal structure that encases the axoneme in the principal piece of the spermatozoon tail. In the rat, it is composed of several proteins, of which a 75‐kDa polypeptide (FS 75), as estimated by PAGE, is the most prominent. The objectives of this study were to clone and sequence this protein and to characterize its transcriptional and translational origins during spermatogenesis. Initially, we isolated two overlapping cDNA segments that encoded a large part of the FS 75 protein but lacked the initiation codon for translation. Both clones were obtained by screening a rat testicular phagemid cDNA library with an anti‐FS 75 polyclonal antibody. An upstream portion of the FS 75 mRNA containing the initiation codon was obtained by polymerase chain reaction with a pair of specific primers. Accounting for the overlap in all segments, 2786 nt of an approximately 3‐kb FS 75 mRNA was obtained. The amino acid sequence of the longest possible open reading frame of the rat FS 75 was found to be similar to two previously cloned variants of the major FS polypeptide of mouse spermatozoa. Sequence analysis of the rat FS cDNA revealed anchoring kinase A protein domains and several kinase phosphorylation sites, supporting the idea that this protein plays a crucial role in the motility of spermatozoa. The presence of a potential N‐myristoylation site suggests that this protein may covalently bind to the inner leaflet of the plasma membrane (PM), which in turn may explain the close association of the FS and PM from early development. Developmental northern blot analysis and in situ hybridization revealed that the FS 75 mRNA is haploid expressed, with an abundant level of mRNA in late round spermatids. Maximum levels of the FS 75 polypeptide, as determined by immunocytochemistry, correlated with a rapid decline in corresponding mRNA levels in step 14–16 spermatids. Since transcription termination occurs several steps earlier, the bulk of FS 75 mRNA appears to be translationally regulated.
Comparison of Fresh and Cryopreserved Human Sperm Attachment to Bovine Oviduct (Uterine Tube) Epithelial Cellsin Vitro
Authors: ELLINGTON JOANNA E. , BROEMELING LYLE D. , BRODER STEVE J. , JONES ALLISON E. , CHOKER DRU ANNE , WRIGHT RAY W.
Published: October 2023

ABSTRACT:Formation of a prefertilization sperm reservoir in mammals is thought to occur via sperm cell attachment to fallopian tube or oviduct epithelial cells (OEC). Recent data suggests that such an interaction also occurs for human sperm in the fallopian tube. We have previously validated anin vitrosperm‐OEC coculture system utilizing bovine OEC monolayers to study postejaculatory human sperm physiology. This study was done to evaluate aspects of human sperm attachment to OEC in coculture and to determine if such attachment and subsequent sperm survival differ between fresh and cryopreserved human sperm. In experiment 1, aliquots of fresh (n= 4) or cryopreserved sperm (n= 3) from normospermic donors were placed into coculture with OEC monolayers at dilutions ranging from 2 ± 105to 15 ± 106sperm per well. Numbers of each type of sperm attaching to OEC at each concentration were determined. In experiment 2, fresh and cryopreserved sperm from the same donors (n= 4) were put into OEC coculture to observe numbers attaching and subsequent survival time for each sperm type. Sperm attachment to OEC occurred in a linear, dose‐dependent manner for fresh and cryopreserved sperm in experiment 1, both as a function of total sperm numbers and as a function of numbers of motile sperm applied (R2± 0.79). However, cryopreserved sperm attached to the OEC at a slower rate than fresh (as a function of the average increase in the number of sperm attaching per unit increase in the number of sperm applied; P < 0.05), with an overall lower percentage of the total and motile sperm applied attaching to OEC (P < 0.01) for cryopreserved versus fresh sperm. Fewer cryopreserved sperm also attached to the OEC, as compared with fresh sperm, in experiment 2 (P < 0.05), even after correcting for motility differences between the sperm types. Sperm survival time in coculture was also decreased for cryopreserved sperm as compared with fresh sperm (P = 0.005). Understanding the kinetics of sperm and OEC interactions may be useful for developing improved cryopreservation protocols or bioassays of sperm function.
An Improved Mouse Sperm–Oocyte Plasmalemma Binding Assay: Studies on Characteristics of Sperm Binding in Medium With or Without Glucose
Authors: REDKAR ANJALI A. , OLDS‐CLARKE PATRICIA J.
Published: October 2023

ABSTRACT: Sperm binding to the oocyte plasmalemma is crucial to subsequent steps in fertilization. However, the usual in vitro assay for sperm–oocyte binding does not distinguish between nonspecific attachment and specific binding leading to fusion and penetration. Since zona pellucida‐free pronuclear zygotes should not bind sperm (because of the block to polyspermy at the level of the oocyte membrane), a procedure has been developed to remove virtually all sperm from zona‐free pronuclear zygotes (2PNZ). After six washes with a 90‐μm‐bore pipette, there were 0.5 ± 0.2 sperm/2PNZ (n = 83). Therefore, these washing conditions were used to define sperm–oocyte binding. The relationship of binding to oocyte penetration was determined for outbred mouse oocytes coincubated in complete medium with (B6 ± 129)F1 hybrid sperm (107/ml). Binding was maximal (29 ± 5 sperm per oocyte) during the first 30 minutes but decreased significantly to 4.6 ± 1.4 by 60 minutes of coincubation (over 10 trials). Oocyte penetration was 99 ± 1% by 30 minutes, while the number of decondensed sperm nuclei per oocyte increased significantly to 7.5 ± 0.6 at 60 minutes. These data suggest that the block to polyspermy involves detachment of bound sperm. Similar coincubations were carried out in medium without glucose (NoG), as this medium has been reported to inhibit fusion without affecting binding. However, binding was only 11 ± 2 at 30 minutes but increased to 25 ± 4 at 60 minutes, suggesting that binding was retarded in NoG. When gametes were coincubated in NoG for 5 hours, about half of the oocytes were penetrated, suggesting that the lack of glucose did not inhibit fusion but instead delayed it. These data suggest that if sperm binding is to be determined in complete medium, the time of the block to polyspermy should be determined prior to selecting the appropriate time to assay binding. Furthermore, using the same coincubation period for the binding assay in control and treated sperm may not be appropriate if the treatment alters the time of maximal binding.
Potential Daily Sperm Production, Sertoli Cell Number, and Seminiferous Tubule Characteristics in Beef Bulls Fed Conventional or Gossypol‐Enriched Diets
Authors: CERELLI JUSTIN S. , JOHNSON LARRY
Published: October 2023

ABSTRACT: The objective of this study was to determine the amount of germ cell degeneration throughout spermatogenesis in the bull and to determine if gossypol‐enriched diets enhance that degeneration. Twenty‐six adult beef bulls in two different sets of treatment groups were chosen for the study. The first set of bulls were broken into three groups, receiving soybean meal (<0.03 g gossypol per bull, per day), cottonseed meal (1.8 g gossypol per bull, per day), or whole cottonseed (16 g gossypol per bull per day). The second set of bulls were fed 4 g of gossypol per day for 180 days and then were placed in their respective treatment groups of 0 g or 4 g of gossypol per day for 72 days to evaluate the effect of continued gossypol treatment versus stopping treatment. Hence, one group received gossypol for 180 days, followed by withdrawal for 72 days. The treated group received gossypol up to castration at 250 days. In both sets of bulls, significant germ cell degeneration occurred between B spermatogonia and primary spermatocytes (i.e., at the end of mitosis and into the beginning of meiosis), with no subsequent degeneration throughout the rest of spermatogenesis. For both sets of bulls, the gossypol‐enriched diet fed had no effect on the nuclear volume or number per gram parenchyma of any germ cell or Sertoli cell. Therefore, gossypol did not augment the amount of germ cell degeneration that occurred between B spermatogonia and homogenate‐resistant (mature) spermatids in either set of bulls. Gossypol‐enriched diets also had no effect on volume density, diameter, luminal diameter, or basement membrane thickness of seminiferous tubules for the first set of bulls. The second set of bulls, with continued diets enriched with gossypol, had a larger number of B spermatogonia per gram than did bulls removed from the gossypol‐enriched diet. In conclusion, the bull did experience significant degeneration of germ cells between B spermatogonia and pachytene primary spermatocytes, with no subsequent loss throughout the rest of spermatogenesis, and the gossypol‐enriched diet did not further enhance germ cell degeneration.
HLA‐DR Antigen and HLA‐DRB1 Genotyping with Nonobstructive Azoospermia in Japan
Authors: TSUJIMURA AKIRA , TAKAHARA SHIRO , KTTAMURA MASAYA , NQURA HIDENOBU , KOGA MINORU , SADA MASAHARU , TSUJI TAKAYUKI , MATSUMIYA KIYOMI , OKUYAMA AKIHIKO
Published: October 2023

ABSTRACT: We previously reported that the HLA‐A33, ‐B13, and ‐B44 antigens, which are major histocompatibility complex class I molecules, are involved in the susceptibility of nonobstructive azoospermia in Japanese men. In this report, HLA‐DR antigens, which are class II molecules, are investigated by advanced DNA typing in addition to classical serological typing to study a more complex genotype of HLA‐DRB2. Genotyping was performed by the polymerase chain reaction‐sequence‐specific primer (PCR‐SSP) method of analysis and/or by a commercial rapid assay based on the polymerase chain reaction (PCR), followed by reverse dotblot hybridization of PCR products (the Inno‐LiPA assay). The allele frequencies of the HLA‐DR13 antigen and the ‐DRB1*1302 allele were significantly higher in Japanese subjects with nonobstructive azoospermia compared with a control group of healthy Japanese men, and these alleles were associated with relative risks for nonobstructive azoospermia of 4.2 and 4.9, respectively. If we suppose this strong linkage to both HLA class I and II antigens is due to linkage disequilibrium, it may suggest the existence of a novel gene involved in spermatogenesis in the class III region, which is located between the class I and class II regions and contains several genes other than HLA.
Effects of Liver Disease and Transplantation on the Human Prostate
Authors: JIN BO , MCCAUGHAN GEOFFREY W. , HANDELSMAN DAVID J.
Published: October 2023

ABSTRACT: A major determinant of late‐life prostate diseases is hormonal exposure during earlier life, but the effects of androgens in midlife on the human prostate have been little studied. In order to identify hormonal effects on the prostate during the long latent period of midlife, we studied the effects of chronic androgen deficiency on the prostate during midlife by examining men with severe liver disease before and after liver transplantation. Patients (n = 15, median 57, range 38–65 years old) with severe liver disease but no known prostate disease being evaluated for liver transplantation underwent 21 prostate ultrasound studies, 12 prior to and 9 after liver transplantation, with six men undergoing both studies. Controls were 42 prostate ultrasound studies (2:1 matching) from age‐matched healthy men. Total‐ and central‐prostate volumes were measured with a 7.5‐MHz biplane transducer planimetrically at 2.5‐mm intervals with a stepper device from base to apex of the prostate. Overall, total‐ and central‐prostate volumes were not significantly different between patients with chronic liver disease before and after liver transplantation and age‐matched healthy controls. This appeared to be due to a bimodal distribution, with most men (12 men, 17 studies) having smaller prostate volumes and a minority (3 men, 4 studies) having previously undiagnosed, macroscopic, benign prostatic hyperplasia. The reduction in prostate volume prior to transplantation was significantly correlated with severity of liver disease (Child‐Pugh score). Before liver transplantation, prostate‐specific antigen (PSA) concentrations were significantly lower and prostatic acid phosphatase increased, and both were normalized after liver transplantation. Plasma testosterone concentrations were decreased before transplantation and remained low after transplantation. Sex hormone–binding globulin level was significantly elevated before and reduced to subnormal after liver transplantation. Estradiol concentrations were unchanged by liver disease or transplantation. We conclude that prostate volumes, particularly that of the central zone, are usually reduced by the functional androgen deficiency of chronic liver disease and tend to be restored toward normal by liver transplantation, depending on the degree of rectification of circulating plasma testosterone concentrations. Prostate glands with established benign prostatic hyperplasia may be less responsive to these hormonal changes.
Varicocele‐Associated Decrease in Antioxidant Defenses
Authors: BARBIERI ELLY R. , HIDALGO MARIA E. , VENÉGAS ANDRES , SMITH ROSITA , LISSI EDUARDO A.
Published: October 2023

ABSTRACT: Varicocele is associated with an oxidative stress condition. We have measured the antioxidant defenses of varicocele patients both at the local (seminal plasma) and systemic (blood plasma) levels. The antioxidant defenses, as evaluated by the total reactive antioxidant potential parameter, decrease both in the seminal (controls = 676 ± 128; patients = 386 ± 186) and blood (controls = 519 ± 63; patients = 268 ± 110) plasma of varicocele patients. Compared with controls, patients with both normal spermiograms and spermiograms altered in motility or morphology demonstrated lower values. The results obtained suggest that varicocele‐associated oxidative stress is evidenced both at the local and systemic levels. This conclusion is supported by results showing that urinary spontaneous chemiluminescence is also significantly increased in the patients.
Temporal Variations in Testicular Microcirculation
Authors: BERGH ANDERS , LISSBRANT ERIK , COLLIN OLA
Published: October 2023

ABSTRACT: Temporal variations in microcirculatory blood flow in the testis and blood pressure were examined in intact, pentobarbital‐anesthetized rats with a two‐channel laser Doppler flowmeter. The laser Doppler probes that measure local blood flow in a tissue volume of about 2 mm3 were placed either over the mid portion of the left and right testes or on the right testes 1 cm apart. Testicular microcirculation was characterized by a prominent vasomotion with a frequency of 5.3 ± 1.4 cycles per minute and with an amplitude of 73 ± 32% (mean ± SD) of the mean. In addition to this large and rapid variation in local blood flow, there were also major variations from minute to minute in the average blood flow, vasomotion frequency, and vasomotion amplitude at 40 and 53 minutes. Such variations in local blood flow, vasomotion frequency, and vasomotion amplitude were correlated with each other at two different sites on the same testis (rs = 0.39, rs, = 0.82, rs, = 0.64, respectively, P ± 0.001), and they were all correlated with systemic blood pressure (rs = 0.41, rs, = 0.61, rs = 0.32, respectively, P ± 0.001). Minute‐to‐minute variations in local blood flow, vasomotion frequency, and vasomotion amplitude were also correlated between the right and left testes (rs = 0.58, rs, = 0.75, rs, = 0.57, respectively, P ± 0.001). There are substantial temporal variations in testicular microcirculation. These variations are to some extent related to temporal changes in systemic blood pressure, but changes in the ultralocal environment are probably more important. The functional significance of, and the factors responsible for, local variations in testicular microcirculation remain to be elucidated.
FSH Immunoneutralization Acutely Impairs Spermatogonial Development in Normal Adult Rats
Authors: MEACHEM S. J. , MCLACHLAN R. I. , STANTON P. G. , ROBERTSON D. M. , WREFORD N. G.
Published: October 2023

ABSTRACT: Follicle‐stimulating hormone (FSH) plays an important part in testicular development. Its role in the regulation of spermatogenesis in the adult, however, remains controversial. This study aimed to explore the role of FSH in the maintenance of adult rat spermatogenesis by using immunoneutralization to selectively withdraw FSH action for periods of up to 8.5 days and then assessing the outcome by quantification of germ cell number. Adult rats received either an ovine polyclonal rat FSH antibody (FSHAb, 2 mg/ kg subcutaneous daily—a dosage known to neutralize >90% of FSH in serum) for 2, 4, 7, or 8.5 days or a control sheep immunoglobulin (ConAb, 2 mg/kg) for 8.5 days. Testes were perfusion fixed, and germ cell numbers per testis were quantified using the optical disector (sic) stereological method. The percentage of seminiferous tubules displaying apoptotic cells was determined by the in situ end labeling method (TUNEL). FSHAb treatment for 4, 7, or 8.5 days significantly reduced the number of type A/intermediate spermatogonia (∼74% of control values) associated with stages I‐IV. Similar reductions were seen in type B spermatogonial and preleptotene spermatocyte numbers after 8.5 days of FSHAb treatment (∼69% of control values; P < 0.05). Decreases (P 0.05) in the numbers of pachytene spermatocytes in stages I‐III and VIII, round spermatids in stages I‐III, VII, and VIII (∼70% of control values), and step 19 elongated spermatids in stage VII (51% of control values) were achieved after 8.5 days of FSHAb treatment. Compared with control, FSHAb treatment increased the percentage of stage XIV‐III tubules containing TUNEL‐positive cells by about twofold after 7 days of FSHAb treatment (P < 0.05). This study supports a role for FSH in the maintenance of quantitatively normal adult rat spermatogenesis, specifically by regulating A3 and A4 spermatogonial subtypes. FSH may act on these spermatogonia by enhancing the stage‐dependent survival of type A spermatogonia. Effects at other sites in spermatogenesis are suggested by the changes in spermatocyte and spermatid populations. However, to clarify these effects, selective FSH withdrawal would need to be prolonged until steady state had been achieved.
Implementing the Lexical Approach: Putting Theory Into Practice
Authors: Qing‐sheng Pan , Ha Van Sinh
Published: October 2023

Michael Lewis. Hove, England: Language Teaching Publications, 1997.
Varieties of English
Authors: Trites Latricia
Published: October 2023

Susan M. Gass and Natalie Lefkowitz. Ann Arbor: The University of Michigan Press, 1995.
Microvascular Disease Associates with Larger Osteocyte Lacunae in Cortical Bone in Type 2 Diabetes Mellitus
Authors: Zanner Sebastian , Goff Elliott , Ghatan Samuel , Wölfel Eva Maria , Ejersted Charlotte , Kuhn Gisela , Müller Ralph , Frost Morten
Published: October 2023

Clinical studies indicate that microvascular disease (MVD) affects bone microstructure and decreases bone strength in type 2 diabetes mellitus (T2D). Osteocytes are housed in small voids within the bone matrix and lacunae and act as sensors of mechanical forces in bone. These cells regulate osteoclastic bone resorption and osteoblastic bone formation as well as osteocytic perilacunar remodeling. We hypothesized that MVD changes morphometric osteocyte lacunar parameters in individuals with T2D. We collected iliac crest bone biopsies from 35 individuals (10 female, 25 male) with T2D with MVD (15%) or without MVD (21%) with a median age of 67 years (interquartile range [IQR] 62–72 years). The participants were included based on c‐peptide levels >700 pmol L−1, absence of anti‐GAD65 antibodies, and glycated hemoglobin (HbA1c) levels between 40 and 82 mmol mol−1 or 5.8% and 9.7%, respectively. We assessed osteocyte lacunar morphometric parameters in trabecular and cortical bone regions using micro‐computed tomography (micro‐CT) at a nominal resolution of 1.2 μm voxel size. The cortical osteocyte lacunar volume (Lc.V) was 7.7% larger (p = 0.05) and more spherical (Lc.Sr, p < 0.01) in the T2D + MVD group. Using linear regression, we found that lacunar density (Lc.N/BV) in trabecular but not cortical bone was associated with HbA1c (p < 0.05, R2 = 0.067) independently of MVD. Furthermore, Lc.V was larger and Lc.Sr higher in the center than in the periphery of the trabecular and cortical bone regions (p < 0.05). In conclusion, these data imply that MVD may impair skeletal integrity, possibly contributing to increased skeletal fragility in T2D complicated by MVD. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
Storm tracks and cyclogenesis over the Southern Ocean: An overview with the HadGEM3‐GC3.1 model
Authors: de Souza Marcelo Rodrigues , Piva Everson Dal
Published: October 2023

Extratropical cyclones play an important role in shaping the weather and climate over vast regions across the globe. To effectively understand and manage the impact of these meteorological events, it is crucial to explore deeper into their structure and behaviour. Here, we have evaluated the characteristics and spatial distribution of extratropical cyclones that had their genesis in the Southern Ocean (SO) in the present climate, based on data from the HadGEM3‐GC3.1‐MM (HG3) global model and the ERA5 reanalysis. Both in winter and summer, cyclone tracks are spatially structured, forming a belt around the entire Antarctic continent, with greater concentration in the SO sector adjacent to the southern Pacific Ocean. The regions of the Somov, Amundsen and Bellingshausen seas exhibited a higher track density of moderate and strong cyclones, indicating a correlation with the strongest baroclinicity in these areas. In both datasets, the maximum occurrence of cyclogenesis was located over the regions of the Somov Sea and the Antarctic Peninsula, making these regions very important in the general configuration of cyclones along the SO. Despite underestimating the total number of cyclones along the SO, the HG3 model showed a good ability to represent the main patterns of cyclonic activity around the Antarctic continent, as well as its average behaviour. Knowing the characteristics and the behaviour of extratropical cyclones in such an important area for global climate is essential for understanding their role in weather and future climate resulting from climate change.
Raman identification of pigments and opacifiers: Interest and limitation of multivariate analysis by comparison with solid state spectroscopical approach—II. Arsenic‐based opacifiers and relation with cobalt ores
Authors: Burlot Jacques , Vangu Divine , Bellot‐Gurlet Ludovic , Colomban Philippe
Published: October 2023

Raman analysis is a noninvasive technique that can be conducted on‐site via a mobile system. However, the presence in variable quantity of different crystalline or amorphous phases (glassy matrix, opacifiers and pigments) in the enamel leads to the partial observation of Raman signatures, signatures often not being characterized in the literature. We study here the phases observed in the white, blue and yellow/green enamels of French and Chinese objects from the 18th century and compare the effectiveness of a solid‐state spectroscopic approach (identification of the parameters determining the vibrational modes in relation to the structures) and the multivariate chemometric approach (PCA and Hierarchical Clustering), carried out on the global or partial spectra, or on the parameters extracted from the first approach. The incorporation of the spectra of neighbouring or similar phases from the literature into the corpus of processed data, in particular those obtained for phases that are not initially structurally characterized, is decisive for the quality of the results. At least four different lead arsenates are identified. The combination of visual observation of the peaks and multivariate analysis shows that the shape, position and area of the band associated with the main As‐O stretching vibration around 820 cm−1 vary according to several criteria related to production techniques specific to certain workshops. The contribution of multivariate analysis based on spectra alone appears to be very limited compared to the examination of spectroscopic parameters.
Matrix effects demystified: Strategies for resolving challenges in analytical separations of complex samples
Authors: Williams Madison L. , Olomukoro Aghogho Abigail , Emmons Ronald V. , Godage Nipunika H. , Gionfriddo Emanuela
Published: October 2023

Matrix effects can significantly impede the accuracy, sensitivity, and reliability of separation techniques presenting a formidable challenge to the analytical process. It is crucial to address matrix effects to achieve accurate and precise measurements in complex matrices. The multifaceted nature of matrix effects which can be influenced by factors such as target analyte, sample preparation protocol, composition, and choice of instrument necessitates a pragmatic approach when analyzing complex matrices. This review aims to highlight common challenges associated with matrix effects throughout the entire analytical process with emphasis on gas chromatography‐mass spectrometry, liquid chromatography‐mass spectrometry, and sample preparation techniques. These techniques are susceptible to matrix effects that could lead to ion suppression/enhancement or impact the analyte signal at various stages of the analytical workflow. The assessment, quantification, and mitigation of matrix effects are necessary in developing any analytical method. Strategies can be implemented to reduce or eliminate the matrix effect by changing the type of ionization, improving extraction and clean‐up methods, optimization of chromatography conditions, and corrective calibration methods. While development of an effective strategy to completely mitigate matrix effects remains elusive, an integrated approach that combines sample preparation, analytical extraction, and effective instrumental analysis remains the most promising avenue for identifying and resolving matrix effects.
Holocene climate change shifted Southern Ocean biogeochemical cycling and predator trophic dynamics
Authors: Michelson Chantel I. , Polito Michael J. , Wunder Michael B. , Emslie Steven D. , McCarthy Matthew D. , Patterson William P. , McMahon Kelton W.
Published: October 2023

Studies of Antarctic paleo‐archives have produced conflicting hypotheses on the relative impact of long‐term climate change and historic exploitation of marine mammals on Southern Ocean krill predator foraging ecology. We disentangle these hypotheses using amino acid stable isotope analysis on a 7000‐yr Holocene archive of Adélie penguin (Pygoscelis adeliae) eggshells to differentiate variation in diet and trophic dynamics from baseline biogeochemical cycling as drivers of the rapid decline in krill predator bulk tissue δ15N values in recent centuries. Contrary to previous hypotheses suggesting solely trophic dynamic mechanisms as drivers of this decline, we identified an abrupt decline in source amino acid δ15N values, indicative of major changes in biogeochemical cycling at the base of the Southern Ocean food web that mirrored the decline in penguin bulk tissue δ15N values. These abrupt shifts in penguin δ15N values and associated biogeochemical cycling aligned with climatic events during the Little Ice Age that decreased surface δ15NNO3−, likely connected to a proposed increase in Ekman upwelling via a southward migration of the Westerlies. This baseline shift was in addition to a long‐term, gradual decline in penguin trophic position over the Holocene that began prior to both recent anthropogenic climate change and a proposed “krill‐surplus” following historic marine mammal exploitation in the 19th and 20th centuries. In resolving these outstanding hypotheses about drivers of Southern Ocean food web dynamics, this study emphasizes the fundamental importance of climate‐induced variability in biogeochemical cycling on ecological processes and improves the ability of paleo‐archives to inform the ecological consequences of future environmental change in the Southern Ocean.