bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel ultrasensitive assay for plasma p‐tau217: Performance in individuals with subjective cognitive decline and early Alzheimer's disease
Authors: Gonzalez‐Ortiz Fernando , Ferreira Pamela C. L. , González‐Escalante Armand , Montoliu‐Gaya Laia , Ortiz‐Romero Paula , Kac Przemyslaw R. , Turton Michael , Kvartsberg Hlin , Ashton Nicholas J. , Zetterberg Henrik , Harrison Peter , Bellaver Bruna , Povala Guilherme , Villemagne Victor L. , Pascoal Tharick A. , Ganguli Mary , Cohen Anne D. , Minguillon Carolina , Contador Jose , Suárez‐Calvet Marc , Karikari Thomas K. , Blennow Kaj
Published: November 2023

INTRODUCTION

Detection of Alzheimer's disease (AD) pathophysiology among individuals with mild cognitive changes and those experiencing subjective cognitive decline (SCD) remains challenging. Plasma phosphorylated tau 217 (p‐tau217) is one of the most promising of the emerging biomarkers for AD. However, accessible methods are limited.

METHODS

We employed a novel p‐tau217 immunoassay (University of Gothenburg [UGOT] p‐tau217) in four independent cohorts (n = 308) including a cerebrospinal fluid (CSF) biomarker‐classified cohort (Discovery), two cohorts consisting mostly of cognitively unimpaired (CU) and mild cognitively impaired (MCI) participants (MYHAT and Pittsburgh), and a population‐based cohort of individuals with SCD (Barcelonaβeta Brain Research Center's Alzheimer's At‐Risk Cohort [β‐AARC]).

RESULTS

UGOT p‐tau217 showed high accuracy (area under the curve [AUC] = 0.80–0.91) identifying amyloid beta (Aβ) pathology, determined either by Aβ positron emission tomography or CSF Aβ42/40 ratio. In individuals experiencing SCD, UGOT p‐tau217 showed high accuracy identifying those with a positive CSF Aβ42/40 ratio (AUC = 0.91).

DISCUSSION

UGOT p‐tau217 can be an easily accessible and efficient way to screen and monitor patients with suspected AD pathophysiology, even in the early stages of the continuum.
A target enrichment probe set for resolving phylogenetic relationships in the coffee family, Rubiaceae
Authors: Ball Laymon D. , Bedoya Ana M. , Taylor Charlotte M. , Lagomarsino Laura P.
Published: November 2023

Premise

Rubiaceae is among the most species‐rich plant families, as well as one of the most morphologically and geographically diverse. Currently available phylogenies have mostly relied on few genomic and plastid loci, as opposed to large‐scale genomic data. Target enrichment provides the ability to generate sequence data for hundreds to thousands of phylogenetically informative, single‐copy loci, which often leads to improved phylogenetic resolution at both shallow and deep taxonomic scales; however, a publicly accessible Rubiaceae‐specific probe set that allows for comparable phylogenetic inference across clades is lacking.

Methods

Here, we use publicly accessible genomic resources to identify putatively single‐copy nuclear loci for target enrichment in two Rubiaceae groups: tribe Hillieae (Cinchonoideae) and tribal complex Palicoureeae+Psychotrieae (Rubioideae). We sequenced 2270 exonic regions corresponding to 1059 loci in our target clades and generated in silico target enrichment sequences for other Rubiaceae taxa using our designed probe set. To test the utility of our probe set for phylogenetic inference across Rubiaceae, we performed a coalescent‐aware phylogenetic analysis using a subset of 27 Rubiaceae taxa from 10 different tribes and three subfamilies, and one outgroup in Apocynaceae.

Results

We recovered an average of 75% and 84% of targeted exons and loci, respectively, per Rubiaceae sample. Probes designed using genomic resources from a particular subfamily were most efficient at targeting sequences from taxa in that subfamily. The number of paralogs recovered during assembly varied for each clade. Phylogenetic inference of Rubiaceae with our target regions resolves relationships at various scales. Relationships are largely consistent with previous studies of relationships in the family with high support (≥0.98 local posterior probability) at nearly all nodes and evidence of gene tree discordance.

Discussion

Our probe set, which we call Rubiaceae2270x, was effective for targeting loci in species across and even outside of Rubiaceae. This probe set will facilitate phylogenomic studies in Rubiaceae and advance systematics and macroevolutionary studies in the family.
The future of cosmeceuticals
Authors: Firsowicz Maya , Bur Delfina , Lain Ted
Published: November 2023

The present state of skincare addresses the consequences of photodamage, hormonal influences, and the cumulative impact of exposome exposure throughout a person's life. Treatments within the aesthetic domain either harness biological pathways to achieve rejuvenation, such as retinoids and antioxidants, or suppress them, like lightening ingredients. Emerging advancements encompass techniques that stimulate the differentiation of stem cells to generate younger keratinocytes and fibroblasts, activate macrophages to diminish proinflammatory cellular waste, and restore glycosaminoglycans within the dermal matrix. While these innovations have significantly enhanced the potential of skincare to revitalize the skin in recent years, obstacles to their adoption remain substantial, including complex multistep regimens, the elevated cost of novel technologies, and limited accessibility for a majority of consumers. The next phase of skincare innovation targets the root cause of aging, at the genetic and epigenetic level. By reversing the effect of the exposome at this level, it is conceivable that biological age and chronological age might no longer correlate. Additionally, the integration of artificial intelligence, the identification of biomarkers, and improved accessibility to genetic predisposition lab testing will combine to allow for greater personalization of skincare recommendations.
Finite element analysis for complex permittivity measurement of a dielectric plate and its application to inverse problem
Authors: Hirayama Koichi , Hayashi Yoshio
Published: November 2023

The resonant frequency and unloaded quality factor of a cylindrical cavity resonator are computed accurately by using the axisymmetric finite element method. Here the loss of both a dielectric sample and a shielding conductor is taken into account. A term with 1/r among the components of the finite element matrix is analytically integrated over a triangular ring quadratic element. Also, the inverse problem, that is, the estimation of the complex permittivity of a dielectric from a resonant frequency and an unloaded quality factor, is formulated and its usefulness is confirmed through some computed results for dielectric plates and deformed lossy sheets. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(5): 10–19, 2001
Device parameter dependence of temperature characteristics of lateral power MOSFET formed by solid‐phase epitaxy
Authors: Kodama Masahito , Sugiyama Takahide , Uesugi Tutomu
Published: November 2023

The device parameter dependence of temperature characteristics is evaluated for lateral power MOSFET having buried gates in the lower channel area and having trench gate/drains, produced by the solid‐phase epitaxy method. The device parameters considered were the gate length and the n‐drift length. The temperature coefficient (change rate) of the threshold value depends on the gate length and this tendency tends to increase as the gate length increases. However, there was no dependence on the n‐drift length. In addition, the temperature coefficient of the specific on‐resistance depends on the n‐drift length, to a degree that increases as the n‐drift length increases. However, there was no dependence on the gate length. The above facts indicate that the temperature dependence of the device characteristics tends to decrease as the device size decreases. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(5): 55–61, 2001
HBCU graduate works to bolster Black colleges
Authors: Elfman Lois
Published: November 2023

Dr. Dietra Y. Trent, like many students at historically Black colleges and universities, was a Pell Grant recipient from a rural area when she entered Hampton University in Virginia.
Joint engineering‐medical school programs prepare physicians for clinical challenges: An observational study
Authors: Gathman Tyler J. , Vasdev Ranveer M. S. , Smetak Miriam R. , Williams Anthony , Budde Anna , Iaizzo Paul A.
Published: November 2023

Background and Aims

Modern health care faces a plethora of challenges including the delivery of quality and cost‐efficient care. Physicians are first‐hand observers of clinical problems but may lack the requisite training and education to develop innovations that improve patient care. Few medical education programs address innovation, leadership, and transdisciplinary collaboration despite being highlighted by national medical and education organizations including the American Medical Association. The University of Minnesota has implemented the Augustine program over the last 10‐years to produce physicians that are leaders in medical innovation.

Methods

As a novel joint engineering‐medical school curriculum to educate medical students, residents, and fellows, the Augustine program incorporates engineering coursework, biomedical research, and a multidisciplinary design and business development experience to produce physicians capable of designing and marketing “disruptive technologies.” The Augustine program takes 1‐year to complete in addition to the 4‐year medical education and provides a Master of Biomedical Engineering upon completion.

Results

Augustine program graduates (n = 6) have reported significant contributions related to the joint engineering‐medical education including peer‐reviewed publications (Median: 13), deployable assets (Median: 2), and intellectual property (Median: 1). Most surveyed graduates (n = 5, 83%) continue to be active contributors to medical innovation and all (n = 6, 100%) utilize their transdisciplinary education to improve patient care.

Conclusion

Augustine program graduates impact the entire spectrum of innovation and continue to improve patient care. The program will seek to emphasize the inclusion of physician residents and fellows with position expansion. The addition of a multi‐week medical innovation clerkship will provide a more focused experience for students unable to dedicate an entire year to a transdisciplinary experience.
Clinical characteristics and prognostic analysis of idiopathic inflammatory myopathy with positive anti‐aminoacyl‐tRNA synthetase antibodies: A single center experience
Authors: Zhang Di , Wang Huijing , Zhou Xinpeng , Yang Jianguo , Liu Yuan , Wang Wenjing , Jiang Ping , Fan Bing
Published: November 2023

Objectives

To identify the differences of clinical characteristics, laboratory findings, and the long‐term outcomes in patients with anti‐synthetase syndrome (ASS) of different anti‐aminoacyl‐transfer RNA synthetase antibodies.

Methods

We retrospectively enrolled 119 patients with ASS, and the clinical characteristics and laboratory findings were collected. Additionally, multivariate COX regression analysis was performed to estimate the risk factors of prognosis in patients with ASS.

Results

The frequency of interstitial lung disease (ILD) reached 93.3% in our cohort, of 28 (23.5%) was classified as rapidly progressive (RP)‐ILD. The highest incidence of RP‐ILD was 36.4% in the PL12 group of ASS patients. The ILD group was characterized by an older age, a lower prevalence of V sign, and a higher prevalence of pulmonary symptoms when contrasted with the non‐ILD group. There were statistical differences of clinical significance in arthritis, myositis, mechanic's hands, triad, shawl sign, V sign, and Raynaud's phenomenon among the four subgroups (all p < .05). Additionally, the prevalence rates of arthritis, myositis, mechanic's hands, triad, and V sign in the anti‐Jo1 antibody‐positive group were significantly higher than anti‐Jo1 antibody‐negative patients with ASS (all p < .05). Multivariate Cox regression analysis showed mechanic's hands (odds ratio [OR] = 6.47, p < .001), anti‐nuclear antibodies (ANA) (OR = 2.13, p = .026), ILD (OR = 10.50, p < .001), and V sign (OR = 0.30, p = .007) were independent factors affecting the prognosis of patients with ASS. The incidences of RP‐ILD, arthritis, myositis, triad, mechanic's hands, and shawl sign were more frequent in the anti‐Ro52 antibody‐positive group than the anti‐Ro52 antibody‐negative patients with ASS (all p < .05).

Conclusions

Patients with ASS accompanied with ILD are highly prevalent. Mechanic's hands, ANA, and ILD may be a potential biomarker for predicting a poor prognosis in patients with ASS. Additionally, the detection of the anti‐Ro52 antibody provides valuable insights for managing and predicting disease progression and long‐term outcomes.
TACT: Text attention based CNN‐Transformer network for polyp segmentation
Authors: Zhao Yiyang , Li Jinjiang , Hua Zhen
Published: November 2023

Colorectal cancer (CRC) has been one of the top three disease in the world in terms of incidence for many years. Therefore, how to prevent and treat CRC has become a topic of concern for an increasing number of people, and colonoscopy is the most effective detection method in polyp examination. According to studies, 90% of CRC is caused by adenomatous polyps of the large intestine. In clinical practice, the diversity of polyps' size, number, and shape and the unclear boundary between polyps and colon folds can reduce the operator's accuracy of polyps segmentation and lead to a higher rate of missed diagnosis. To better address the inaccurate segmentation or high miss rate due to the above factors, we propose a text attention‐based CNN‐Transformer network for polyp segmentation (TACT) network to process the images in a way that minimizes operator subjectivity and miss rate. The network is based on the CNN‐Transformer structure, and on this basis, a fully attention progressive sampling module is added to more accurately divide the polyp boundary. Moreover, an auxiliary text classification task was added to focus on polyp size and number features in the form of text attention, which more effectively copes with the segmentation tasks of different sizes and different numbers of polyps. After comparing with multiple state‐of‐the‐art segmentation methods in four challenging datasets, our proposed TACT improves segmentation accuracy for polyps of different sizes in different datasets.
A Fragment of Prosaposin (SGP‐1) from Rooster Sperm Promotes Sperm‐Egg Binding and Improves Fertility in Chickens
Authors: HAMMERSTEDT ROY H. , CRAMER PALMER G. , BARBATO GUY F. , AMANN RUPERT P. , O'BRIEN JOHN S. , GRISWOLD MICHAEL D.
Published: November 2023

ABSTRACT: A protein isolated from the supernatant of cryopreserved rooster sperm was found to increase the capability of cryopreserved rooster sperm to bind in vitro to the perivitelline membrane of a chicken egg and substantially raise fertility after artificial insemination (AI). That activity was partially purified and termed universal primary sperm‐egg binding protein (UPSEBP). Insufficient protein remained from 6 × 1011 sperm, despite retention of bioactivity, to allow sequencing. We deduced that the protein may be related to prosaposin (also termed SGP‐1, for sulfated glycoprotein‐1), and we used published amino acid sequences of prosaposin as a guide for synthesis of peptides. Certain peptides were found to increase in vitro sperm‐egg binding and increase fertility of frozen‐thawed or fresh rooster sperm, in a manner similar to semipurified UPSEBP. Active epitopes were in a 60 amino acid sequence, reflecting the intervening sequence between saposins A and B, plus short extensions into saposins A and B. Highest activity was found when this synthetic peptide was oxidized to form a disulfide bond between terminal cysteines. Antibody against a synthetic peptide consisting of 58 of these 60 amino acids bound to a 7–9 kilodalton protein in UPSEBP. Collectively, the data support the conclusion that UPSEBP is a fragment of prosaposin. Because prosaposin is in semen in humans and animals, these observations have broad implications for possible cause and therapy of one type of subfertility.
Neonatally Administered Diethylstilbestrol Retards the Development of the Blood‐Testis Barrier in the Rat
Authors: TOYAMA YOSHIRO , OHKAWA MASAKI , OKU REIKO , MAEKAWA MAMIKO , YUASA SHIGEKI
Published: November 2023

ABSTRACT: Newborn rats were treated with 10 μg of diethylstilbestrol (DES) on alternate days from the 2nd to the 12th postnatal day, and the testes were sequentially examined up to 105 days of age by light, electron, and confocal laser microscopy. In control rats, spermatozoa and step 19 spermatids were observed in stage VIII seminiferous tubules at 56 days of age. Spermatogenic cells in DES‐treated rats differentiated normally from birth until 21 days of age, after which differentiation continued only to the pachytene‐spermatocyte stage. From this age onward, spermatogenic cells older than pachytene spermatocytes were not found until 56 days of age. After this point, the cells resumed differentiation and finally became spermatozoa by 91 days of age; that is, 35 days later than control rats. Electron and confocal laser microscopy showed that in the normal rat, the formation of the ectoplasmic specialization between adjoining Sertoli cells was observed as early as 20 days of age. In contrast, the specialization was not formed until 56 days of age in DES‐treated rats. Furthermore, the delay in functional maturation of this structure as the blood‐testis barrier was confirmed by intercellular tracer experiments. It is clear that neonatal administration of DES delayed the establishment of the blood‐testis barrier for 4 weeks. Consequently, during this period, pachytene spermatocytes were exfoliated from the seminiferous epithelium without completion of meiosis.
Chromatin Structure in Globozoospermia: A Case Report
Authors: LARSON K. L. , BRANNIAN J. D. , SINGH N. P. , BURBACH J. A. , JOST L. K. , HANSEN K. P. , KREGER D. O. , EVENSON D. P.
Published: November 2023

ABSTRACT: Sperm nuclear abnormalities in patients with globozoospermia have not been well characterized and may lead to the high rates of fertilization failure and embryo loss reported in patients with this form of teratozoospermia. This study used transmission electron microscopy (TEM), the sperm chromatin structure assay (SCSA), and single cell gel eletrophoresis assay (COMET) to assess if globozoospermia is associated with sperm chromatin structure abnormalities, DNA fragmentation, or both. The flow cytometric SCSA measures abnormal chromatin structure based on the susceptibility of sperm nuclear DNA to acid‐induced denaturation in situ. COMET measures DNA fragmentation in individual sperm nuclei based upon gel electrophoretic patterns. Although sperm concentration (113 million/mL) and motility (66%) were normal in the patient, there was complete acrosome deficiency. TEM and SCSA data confirmed light microscopic examination that showed that sperm populations included a mixture of round and elongated sperm heads. Even though 100% of sperm had abnormal head morphology, only 13% demonstrated DNA denaturation (COMPαt), which is below our threshold of 15% COMPαt, and consistent with high‐fertility patients. Of interest, 13% of the sperm were also positive in the COMET assay, supporting our previous observations that SCSA‐positive cells are also positive for DNA fragmentation. It was unexpected but of great interest that a human sperm population with 100% sperm morphology abnormalities had a chromatin integrity at the molecular level that is equivalent to sperm populations shown in previous studies to be highly fertile. These data are the first reported using SCSA and COMET assays to evaluate a patient with globozoospermia and support previous reports that intracytoplasmic sperm injection of globozoospermia may result in fertility/pregnancy. Lower success rates seen in some patients may be due to unrelated factors.
Larger Trinucleotide Repeat Size in the Androgen Receptor Gene of Infertile Men With Extremely Severe Oligozoospermia
Authors: PATRIZIO PASQUALE , LEONARD DEBRA G. B. , CHEN KE‐LIAN , HERNANDEZ‐AYUP SAMUEL , TROUNSON ALAN O.
Published: November 2023

ABSTRACT: Androgens are significant regulators of human spermatogenesis. Their action is mediated through the androgen receptor (AR), which binds to the androgen responsive element on DNA and regulates gene transcription. Men become infertile with spinobulbar muscular atrophy (Kennedy disease) caused by a trinucleotide repeat expansion, ≥40 CAG repeats, in the AR gene located on the X chromosome. In this prospective study, we investigated whether the variable size, larger repeats, of this trinucleotide could alter AR function and result in impaired spermatogenesis. A total of 69 infertile men were studied. Clinical and laboratory analysis showed idiopathic, nonobstructive azoospermia in 16 men, extremely severe oligozoospermia in 27 men (<1 million sperm/mL), and severe oligozoospermia in 26 men (1 to 5 million sperm/mL). Fertile control men (n = 45) were selected by documented paternity proven by linkage analysis. Leukocyte DNA was analyzed by polymerase chain reaction (PCR) amplification across the AR repeat region. Accurate size determination of the PCR product using an ABI 373 DNA sequencer allowed precise calculation of CAG repeat sizes. The AR gene was not analyzed for other types of mutations. The difference in CAG repeat size between infertile men and proven fertile controls was statistically significant, P = .03. Patients with extremely severe oligozoospermia had significantly longer CAG repeat tracts (mean, 25.4 ± 4.0; P = .0005; range 20–39) than controls (mean, 22 ± 2.8; range 12–30) or patients with severe oligozoospermia (mean, 22.2 ± 2.3; range 18–26). None of the 26 infertile men with sperm counts <1 million/mL had ≤19 CAG repeats compared with 6 out of 45 controls (13%; P = .06). This study suggests that some men with severe impairment of spermatogenesis have longer trinucleotide repeats in the AR gene. Although direct evidence is missing, lower affinity between androgen and the AR protein or decreased AR protein availability with longer repeats could be responsible for a diminished androgen effect on spermatogenesis. Two of the patients in the extremely severe oligozoospermia group had 35 and 39 CAG repeats, respectively (normal range is 11 to 33). Although not yet considered a mutation, longer trinucleotide repeats are unstable and might either expand or contract between generations. If they expand, conception through the use of intracytoplasmic sperm injection (ICSI), could result in the son of an ICSI daughter being affected not only by infertility but also by Kennedy disease.
Accessory Sperm as an Indication of Fertilizing Ability of Rabbit Spermatozoa Frozen in Egg Yolk—Acetamide With Detergent
Authors: ARRIOLA JAVIER , FOOTE ROBERT H.
Published: November 2023

ABSTRACT: Many factors besides initial semen quality affect fertilization rates as sperm interact with the environment of the female reproductive tract. One of these factors is sperm transport, which can be evaluated by accessory sperm counts. Dutch rabbits were used to test the effects on sperm transport, fertilization, and production of young when sodium and triethanolamine lauryl sulfate (STLS) detergent was added to a medium for sperm cryopreservation. When STLS was added in 10 concentrations ranging from 0% to 2.0% (vol/ vol) to an egg yolk—acetamide semen extender, optimal post‐thaw motility of rabbit sperm occurred when 0.2% to 0.7% STLS was included. However, when 0%, 0.2%, and 0.7% STLS was included to cryopreserve sperm used for insemination, the fertilization rates were 95%, 68%, and 75%, and the corresponding mean numbers of accessory sperm per embryo were 13.1, 1.7, and 0.4 (P < .05). In another experiment, increasing the acetamide concentration from 0.75 M to 1.25 M decreased fertilization rates from 66% to 35%, and was associated with 4.5 and 0.6 accessory sperm per embryo (P < .05). In the final experiment, 48 does inseminated with sperm cryopreserved with 0%, 0.35%, and 0.70% STLS were allowed to produce young. Corresponding pregnancy rates were 56%, 56%, and 31% (P < .05), and litter sizes were 5.6, 4.1, and 4.2 (P > .05). In these studies, low concentrations of STLS improved motility of frozen‐thawed sperm, but fertilization and pregnancy rates were reduced. Sperm transport was correspondingly reduced, and the accessory sperm count provided a reliable measure of the effect of STLS on fertility in contrast to the assessment of the percentage of motile sperm.
Testosterone Effects on Luteinizing Hormone and Follicle‐Stimulating Hormone Responses to Gonadotropin‐Releasing Hormone in the Mouse
Authors: HUANG BU‐MIIN , LEU SEW‐FEN , YANG HSI‐YUAN , NORMAN REID L.
Published: November 2023

ABSTRACT: Studies in the mouse have demonstrated for the first time in vivo regulation of gonadotropin‐releasing hormone (GnRH) on the minute‐to‐minute dynamics of luteinizing hormone (LH) and follicle‐stimulating hormone (FSH) release and the effects of testosterone on this regulation. Intact and castrated mice with different testosterone levels (3–9 ng/mL) were challenged with exogenous GnRH while under general anesthesia to block endogenous GnRH release. Plasma concentrations of LH and FSH were determined by radioimmunoassay from sequential blood samples collected from anesthetized mice with in‐dwelling catheters. The release of LH was correlated with the infusion of different doses of GnRH (0.35, 3.5, and 35 ng) in both intact and castrated mice (r = 0.942, ∼0.999). GnRH‐stimulated LH release was significantly lower in intact mice and in castrated mice with high testosterone levels than in castrated mice with low testosterone levels (P < .05). However, GnRH did not induce FSH release except in castrated males with low testosterone levels and at the highest dose of GnRH. The profiles of FSH release in intact mice and castrated mice with the highest testosterone levels were significant lower than the other groups (P < .05). In conclusion, release of LH, but not FSH, was correlated with increasing dosages of GnRH (r = 0.970), and testosterone significantly suppressed GnRH‐stimulated LH release in the mouse (P < .05).
Quality Control of Reactive Oxygen Species Measurement by Luminol‐Dependent Chemiluminescence Assay
Authors: KOBAYASHI HIROSHI , GIL‐GUZMAN ENRIQUE , MAHRAN AYMAN M. , SHARMA RAKESH K. , NELSON DAVID R. , JR ANTHONY J. THOMAS , AGARWAL ASHOK
Published: November 2023

ABSTRACT: A total of 28 donor semen samples were used to evaluate the characteristics of laboratory variability in measuring reactive oxygen species (ROS). The objectives of this study were to assess the interassay (same sample observed on different days by the same observers) variability; interdonor, intraobserver (replications of the same sample on the same day) variability; and interobserver (multiple observers on the same day with the same sample) variability of the luminal‐dependent chemiluminescence assay and to establish an optimal semen age and sperm concentration. Semen samples were collected from 6 healthy donors for 108 measures of ROS. ROS levels were measured by the assay using luminol as the probe. An additional assessment measured the effect of time (age of the sample) on ROS production in 12 donor samples at 60, 120, 180, and 240 minutes after the specimen was produced. Last, to evaluate the effect of sperm concentration on ROS production, ROS levels were measured in 10 donor sample aliquots with sperm concentrations ranging from 1 to 120 × 106/mL. In the controls, the mean ROS level was 0.218 × 106 counted photons per minute; the interassay variability standard deviation (SD) was 0.077. The interobserver SD was 0.002 for an interobserver reliability of 97.5% (coefficient of variation [CV] = 0.9%). The intraobserver (between replication) SD was 0.001 for an intraobserver reliability of 98.7% (CV = 0.5%). The interassay SD was 0.005 for an interassay reliability of 93.8% (CV = 2.0%). There was no statistically significant interobserver, intraobserver, or interassay variation (P > .80). ROS levels decreased significantly with time; a dramatic decline in ROS production was seen in the specimens that were more than 60 minutes old (P < .001). ROS values decreased by 31% at 120 minutes and 62% at 180 minutes compared with the 60‐minute‐old specimens. A linear relationship was seen between the ROS levels and sperm concentration in 8 of the 10 samples analyzed (R2 = .99). Our results demonstrate that the luminol‐dependent chemiluminescence assay for ROS measurement is both accurate and reliable when the sperm concentration is greater than 1 × 106/mL and the samples are analyzed within the first hour after specimen collection.
Relationship Between Seminal White Blood Cell Counts and Oxidative Stress in Men Treated at an Infertility Clinic
Authors: SHARMA RAKESH K. , PASQUALOTTO FABIO F. , NELSON DAVID R. , JR ANTHONY J. THOMAS , AGARWAL ASHOK
Published: November 2023

ABSTRACT: In semen, granulocytes are major producers of reactive oxygen species (ROS), which can damage sperm. The diagnosis of leukocytospermia is usually based on the World Health Organization (WHO) definition of 1 × 106 white blood cells per milliliter, but controversy remains over the minimum leukocyte level that impairs fertility. The goals of this study were to clarify the relationship between leukocyte count and oxidative stress and to establish the minimum leukocyte count associated with oxidative stress. To do so, we compared oxidative stress in semen samples with different leukocyte counts (by the Endtz test) after a simple wash‐and‐resuspend procedure and determined the correlation between leukocyte counts and oxidative stress (expressed as ROS‐TAC score, a composite score calculated from ROS levels and total antioxidant capacity (TAC), both measured with chemiluminescence assays). ROS‐TAC decreases as oxidative stress rises. We compared specimens from 271 men attending an infertility clinic and 28 healthy controls. About 9% of patients had WHO‐defined leukocytospermia and an additional 16% had some leukocytes. Samples with no seminal leukocytes had significantly lower ROS levels and significantly higher ROS‐TAC scores than samples with any seminal leukocytes, even very low levels. Oxidative stress was correlated with rising white blood cell (WBC) count (r = .39; P < .001). Receiver operating characteristics curves showed that ROS‐TAC score would be fairly accurate at distinguishing between patients with any leukocytes and those with no leukocytes (area under the curve, 75%). In conclusion, oxidative stress occurs even in patients with very low seminal WBC counts (between 0 and 1 × 106/mL) and rises with an increase in WBC count. Therefore, we are unable to determine a safe minimum WBC count; the presence of any WBCs is associated with oxidative stress and may therefore impair fertility. Complete removal of WBCs from semen samples used for assisted reproduction may help reduce oxidative stress.
Relationship of Bull Fertility to Sperm Nuclear Shape
Authors: OSTERMEIER G. CHARLES , SARGEANT GLEN A. , YANDELL BRIAN S. , EVENSON DONALD P. , PARRISH JOHN J.
Published: November 2023

ABSTRACT: The relationship between sperm nuclear shape and bull fertility was determined. Two groups of bulls, 3 per group, were selected. Bulls differed in fertility based on lifetime nonreturn rates. Digital images of propidium iodide‐stained sperm from each bull were collected and shape‐evaluated by Fourier harmonic amplitudes 0 to 5. A discriminant function (P < .05) was constructed based on harmonic amplitudes and the 2 fertility groups. When individual sperm were classified as being of high or lower fertility, the percentage of each bull's sperm placed in the high‐fertility group had a linear relationship (r = .89, P < .05) with fertility. To construct a plot of mean sperm shapes, a novel technique to automatically orient and identify the anterior tip of the sperm head was developed. The mean nuclear shape of high‐fertility sperm was more elongated and tapered than those of lower fertility. A discriminant function (P < .05) was also constructed that separated the 6 bulls into 2 groups based only on the harmonic amplitudes or sperm nuclear shape. The bulls were correctly classified into the 2 fertility groups. A comparison of sperm chromatin structure analysis (SCSA) and harmonic amplitudes found that overall size variance, anterior roundness, and posterior taperedness of sperm nuclei were related to chromatin stability (P < .05). Some of the differences observed in sperm nuclear shape between the high‐ and lower‐fertility bulls may be explained by varying levels of chromatin stability. However, sperm nuclear shape appears to contain additional information from chromatin stability alone. In this particular study, with 6 bulls, all with good chromatin quality, sperm nuclear shape was a better predictor of bull fertility.
A Redox‐Regulated Tyrosine Phosphorylation Cascade in Rat Spermatozoa
Authors: LEWIS BEVERLEY , AITKEN R. JOHN
Published: November 2023

ABSTRACT: Rat spermatozoa from both the caput and cauda epididymidis were shown to generate superoxide anion (O2) both spontaneously and following stimulation with NAD(P)H. Caput spermatozoa gave a significantly greater O2 response to NADPH stimulation than caudal cells, whereas in both cell types the responses to exogenous NADPH and NADH were approximately equivalent. Analysis of H2O2 production revealed that this oxidant was generated only by caudal epididymal cells and only in these cells did the stimulation of reactive oxygen species (ROS) production with NADPH lead to an increase in tyrosine phosphorylation. Stimulation of ROS production with NADPH increased intracellular cyclic adenosine monophosphate (cAMP) levels in both caput and caudal epididymal cells, but only in caudal cells did cAMP stimulate tyrosine phosphorylation, in keeping with the NADPH results. On the basis of these findings we propose that tyrosine phosphorylation in rat spermatozoa is driven by ROS acting via 2 different but complementary mechanisms; O2 stimulates tyrosine kinase activity indirectly through the elevation of intracellular cAMP while H2O2 acts directly on the kinase/phosphatase system, stimulating the former and inhibiting the latter. Zinc was examined as a potential regulator of this signal transduction cascade and was shown to suppress tyrosine phosphorylation in caput cells but to promote this activity in caudal spermatozoa, possibly through an inhibitory effect on tyrosine phosphatase activity. These results reveal the maturation of a redox‐regulated, cAMP‐mediated, signal transduction cascade during epididymal transit in the rat that is sensitive to zinc and plays a key role in the control of tyrosine phosphorylation events associated with capacitation.
Assessment of the Androgen Environment Within the Human Testis: Minimally Invasive Method to Obtain Intratesticular Fluid
Authors: JAROW JONATHAN P. , CHEN HAOLIN , ROSNER WILLIAM , TRENTACOSTE STEPHANIE , ZIRKIN BARRY R.
Published: November 2023

ABSTRACT: Previous studies of the rat have shown that testosterone concentrations within the interstitial and seminiferous tubular fluids of the testes are significantly higher than normal serum levels, and further, that although intratesticular testosterone concentration can be substantially reduced without an effect on spermatogenesis, the concentration that is minimally required to maintain spermatogenesis is also substantially higher than serum levels. The purpose of the present study was to adapt a minimally invasive technique to sample human intratesticular fluid to enable parallel observations in man. To this end, aspiration methods were first developed for the rat testis and then adapted to the human. The testosterone concentration in fluid obtained by unilateral aspiration of rat testes was approximately 50 ng/mL, similar to the known concentration in seminiferous tubular fluid. These aspiration methods were then adapted to obtain intratesticular fluid from human testes. Studies of 12 fertile human subjects demonstrated that percutaneous testicular aspiration could be performed safely and successfully using a 19‐gauge needle. Nine additional human subjects had bilateral testicular aspiration and simultaneous measurement of peripheral blood testosterone levels. Testicular aspirations yielded 8 to 117 μL of fluid from each testicle. The mean concentration of testosterone in aspirates obtained from the 21 patients was 609 ± 50 ng/mL. Dihydrotestosterone and 3α‐androstanediol concentrations were quite low, below the limits of detection of our assay. The SHBG/ABP concentration in the aspirates was 8.5 ± 1.1 nM. These results define testosterone as the major androgenic steroid in the human testis, as in the rat testis, and indicate that the testosterone concentration within the human testis is approximately 200‐fold greater than that of SHBG/ABP, and more than 100‐fold greater than the concentration of testosterone found in normal human serum.
Cryopreservation‐Thawing of Fractionated Human Spermatozoa Is Associated With Membrane Phosphatidylserine Externalization and Not DNA Fragmentation
Authors: DURU NAMIK K. , MORSHEDI MAHMOOD S. , SCHUFFNER ALESSANDRO , OEHNINGER SERGIO
Published: November 2023

ABSTRACT: The objective of these studies was to evaluate the effect of cryopreservation‐thawing of human spermatozoa on DNA fragmentation and membrane integrity. This was a prospective, controlled cohort study, performed at a university‐based infertility center. Ejaculates were examined from 5 donors and 16 men undergoing infertility evaluation. Purified sperm populations were prepared by gradient centrifugation, cryopreserved using a manual method and TEST‐yolk buffer and glycerol (TYB‐G), followed by quick‐thaw. Annexin V binding was used for assessing membrane translocation of phosphatidylserine, and terminal deoxynucleotidyl transferase‐me‐diated dUTP nick end labeling (TUNEL) was utilized for the evaluation of DNA fragmentation. The results were as follows: the percentage of live cells with intact membranes (annexin V−, live) was significantly reduced after cryopreservation‐thawing. On the other hand, the percentages of live cells with phosphatidylserine translocation (annexin V+, live) and of necrotic (dead) cells increased significantly after thawing. TUNEL revealed percentages of cells with DNA fragmentation in the prefreeze and postthaw samples that were not significantly different. In a further attempt to examine differences in response to various cryoprotection protocols, experiments were carried out using no cryoprotection, glycerol alone, or TYB‐G. Samples frozen with TYB‐G demonstrated significantly higher percentages of live cells without phosphatidylserine translocation than the other conditions. We concluded that cryopreservation‐thawing of human sperm from patients and donors was associated with membrane change, as revealed by membrane translocation of phosphatidylserine, while having no major impact on DNA fragmentation.
Semenogelin, the Main Protein of Semen Coagulum, Inhibits Human Sperm Capacitation by Interfering With the Superoxide Anion Generated During This Process
Authors: de LAMIRANDE EVE , YOSHIDA KAORU , YOSHIIKE MIKI , IWAMOTO TERUAKI , GAGNON CLAUDE
Published: November 2023

ABSTRACT: Semenogelin (Sg), the major protein of the human semen coagulum, is present at high concentrations in seminal vesicle secretions. It is degraded by the prostate‐specific antigen (PSA) to generate peptides of various biological activities that were found on and inside spermatozoa. Our aim was to determine the effect of Sg on capacitation, which is the series of transformations that spermatozoa must undergo to become fertile. At concentrations of 0.1 to 1.0 mg/mL (600‐ to 20‐fold lower than those of semen), Sg did not affect sperm motility (%) but completely prevented capacitation induced by fetal cord serum ultrafiltrate; a partial inhibition of capacitation was noted with 0.03 mg Sg/mL. There was also a dose‐dependent decrease in the tyrosine phosphorylation of fibrous sheath proteins and in the O2‐related chemiluminescence. Ribonuclease (RNase), which has as high an isoelectric point (pl = 9.7) as Sg (pl = 9.5), also prevented sperm capacitation and O2‐related chemiluminescence but to a lower extent, suggesting that one mechanism of Sg action on spermatozoa could be related to its positive charge at physiological pH. Sg at 1, but not 0.3 or 0.1 mg/mL, scavenged the O2 generated by the mix of xanthine + xanthine oxidase and modified the kinetics of the reaction; RNase did not have such effects. Therefore, Sg is a potential scavenger for O2 but probably also affects the sperm oxidase. Spermatozoa rapidly processed Sg; a high proportion of Sg was degraded after 15 minutes of incubation. The resulting polypeptide patterns were reminiscent of those obtained with PSA as a proteolytic enzyme. These data suggest that Sg, its degradation products, or both may be natural regulators of sperm capacitation and could prevent this process from occurring prematurely. One mechanism by which Sg acts could involve an interference with the O2 that is normally generated during this process.
The Role of Glucose in Supporting Motility and Capacitation in Human Spermatozoa
Authors: WILLIAMS ANDREW C. , FORD W. CHRISTOPHER L.
Published: November 2023

ABSTRACT: Glucose has been reported to be beneficial to human sperm for optimal capacitation and fertilization, although it is unclear whether glucose is required for providing extra metabolic energy through glycolysis, or for generating some other metabolic product. In this study, the effects of sugars on human sperm capacitation, motility, and energy production were investigated. The glucose concentration that supported the greatest number of acrosome reactions was 5.56 mmol L−1. Compared with incubations with no added sugar, this concentration of glucose, fructose, mannose, or galactose appeared to slightly increase the number of acrosome reactions occurring after 18 hours of capacitation, or following induction by 2 μmol A23187 + 3.6 mmol pentoxifylline L−1, but only glucose had a statistically significant effect. Glucose supported increased penetration of zona‐free hamster oocytes, but its advantage was not statistically significant. The addition of 5.56 mmol glucose or fructose L−1 to sugar‐free medium immediately increased the adenosine triphosphate (ATP) concentration and motility of sperm. These parameters were then stable for 3 hours, but declined markedly after 18 hours. In the absence of a glycolysable sugar, motility began to decline in the first hour and only 2% or 3% of sperm remained motile after 18 hours. Glucose or fructose was required to support hyperactivated motility. 2‐Deoxyglucose was detrimental to the ATP concentration and motility of sperm, and supported fewer spontaneous or progesterone‐stimulated acrosome reactions than were observed in the absence of a sugar. We conclude that glycolytic ATP production is required for vigorous motility and hyperactivation in human sperm. Other products of glucose metabolism are not essential to support capacitation, but they may have a small, enhancing effect.
Müllerian Inhibiting Substance Inhibits Testosterone Synthesis in Adult Rats
Authors: SRIRAMAN V. , NIU E. , MATIAS J. R. , DONAHOE P. K. , MACLAUGHLIN D. T. , HARDY M. P. , LEE M. M.
Published: November 2023

ABSTRACT: Müllerian inhibiting substance (MIS) is a gonadal hormone that causes regression of the Müllerian ducts during male sexual differentiation. Postnatally, MIS inhibits the proliferation and differentiation of immature Leydig cells, and transgenic mice that over‐express MIS have decreased serum testosterone concentrations. To elucidate the effects of MIS on androgen regulation in the postnatal testis, we examined testosterone synthesis in adult Sprague‐Dawley rats following intratesticular and intraperitoneal injections of MIS. Intratesticular MIS injection achieved high local concentrations of MIS (574.0 ± 60.0 ng/mL) at 4 hours, with a corresponding decline in serum testosterone concentrations to 0.7 ± 0.1 ng/mL, compared to 1.1 ± 0.2 ng/mL with intraperitoneal MIS and 1.6 ± 0.1 ng/mL with intratesticular vehicle (IT‐Veh) (P < .001). Intratesticular administration of MIS (IT‐MIS) resulted in much higher serum and testicular interstitial fluid MIS concentrations than the intraperitoneal route. To directly examine the testosterone production rate in MIS‐treated animals, we isolated Leydig cells from MIS and vehicle‐injected testes. Primary Leydig cells exposed to MIS had a lower testosterone production rate and decreased expression of p450c17 (hydroxylase/lyase) and luteinizing hormone (LH) receptor mRNAs than that of vehicle‐injected controls or the noninjected contralateral testis. In conclusion, intratesticular administration of MIS caused a decline in serum testosterone concentrations by decreasing the rate of testosterone biosynthesis, confirming that MIS can regulate adult Leydig cell androgen production. The ability of MIS to down‐regulate mRNA expression of the p450c17 and LH receptor genes suggests that this effect is mediated transcriptionally. These data indicate that, in addition to its role in embryonic differentiation of the male reproductive tract, MIS has a regulatory function in the postnatal testis. We conclude that one such function is for MIS to directly inhibit adult Leydig cell steroidogenesis.
Effects of Dietary Selenium on Sperm Motility in Healthy Men
Authors: HAWKES WAYNE CHRIS , TUREK PAUL J.
Published: November 2023

ABSTRACT: A deficiency of dietary selenium leads to immotile, deformed sperm and infertility in rats, whereas supplementation of the diet with selenium compounds has been associated with both beneficial and deleterious effects on sperm function, depending on the chemical form of selenium. We conducted a randomized, controlled, and blinded intervention study on the effects of selenium in food on semen quality. Eleven healthy men were fed a controlled diet of foods naturally high or low in selenium for 120 days while confined in a metabolic research unit. Dietary selenium was 47 μg/d for the first 21 days, then either 13 μg/d or 297 μg/d for 99 days, resulting in significant changes in selenium concentrations in blood and semen. Seminal plasma selenium concentration increased 50% with high selenium and decreased 40% with low selenium. The fraction of motile sperm in the high‐selenium group decreased by 32% by week 13 and ended 18% lower than baseline. Selenium concentrations changed in seminal plasma but not in sperm, and serum androgen concentrations were unchanged in both groups, indicating this effect was neither androgen dependent nor caused by a change in the selenium supply to the testes. Serum triiodothyronine decreased and thyroid‐stimulating hormone increased in the high‐selenium group, suggesting that altered thyroid hormone metabolism may have affected sperm motility. Although this decrease in sperm motility does not necessarily predict decreased fertility, the increasing frequency of selenium supplementation in the healthy population suggests the need for larger studies to more fully assess this potential side effect.