Marco A. Alvarenga

Marco A. Alvarenga
São Paulo State University | Unesp · Department of Animal Reproduction and Veterinary Radiology

PhD

About

235
Publications
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Publications

Publications (235)
Article
This study aimed to assess the safety of uterine lavage using ozonated saline in mares. Each liter of saline (NaCl 0.9%) was ozonated at 50 µg of ozone per mL for 7 min using a medical ozone generator. Then, uterine lavage was performed during estrus or 4h post-breeding and each liter of saline remained inside the uterus for 10 min before being rec...
Article
This study aimed to evaluate the effects of mesenchymal stem cell-conditioned medium (MSC-CM) on sperm parameters, intrauterine polymorphonuclear neutrophils (PMN), intrauterine fluid accumulation (IUF), and fertility in mares. In experiment 1, two ejaculates from ten stallions were extended to 50 million sperm/mL using a milk-based extender. There...
Article
This study aimed to assess the effects of sodium caseinate and cholesterol to extenders used for stallion semen cooling. Two ejaculates from nineteen stallions were extended to 50 million/mL in four different extenders and cooled-stored for 24h at 5°C. Extender 1 (E1), consisted of a commercially available skim-milk based extender. Extender 2 (E2),...
Article
Although stem cell therapy is a promising alternative for treatment of degenerative diseases, there are just few reports on the use of stem cells therapyin horse's reproductive system. This study aims to evaluate the effect of intratesticular injection of bone marrow mesenchymal stromal/stem cells (MSCs) in healthy stallions, and its outcome on sem...
Article
Full-text available
RESUMO Avaliou-se o efeito de curvas de congelação nos parâmetros espermáticos e na fertilidade, usando sêmen de alta e baixa congelabilidade. Experimento 1 - utilizou-se sêmen de quatro garanhões resistentes à congelação: grupo 1, palhetas refrigeradas até 5°C e congeladas com curva de -8°C/min; grupos 2 e 3, palhetas refrigeradas até 5°C (0,5°C/m...
Article
The aim of this study was to evaluate the effect of coconut water as a component of extender in different formulations for cooling equine sperm. One ejaculate of fourteen stallions was collected. Sperm was diluted to 50 × 10 ⁶ sperm/mL using five different extenders: ACP-105: powdered coconut water extender (ACP-105, ACP Biotecnologia, Brazil); ACP...
Article
Boar semen cannot be immediately cryopreserved, it need be hold at 17 °C prior to cryopreservation, holding time has been used to improve cryopreserved boar semen, since holding time allows a prolonged interaction between spermatozoa and seminal plasma components. However, until now only few periods of holding time have been studied, and boar semen...
Article
Anti-Müllerian hormone (AMH) is used as a marker of follicle population numbers and potential fertility in several species including horses but limited data exist across the lifespan. No one has decreased ovarian reserve experimentally to investigate whether a corresponding, quantitative decrease in AMH results. Concentrations of AMH across the lif...
Article
To date, no studies have been performed evaluating the effect of boar spermatozoa concentration in 0.5mL freezing straws, leading us to examine this question. Each sperm-rich fraction of the ejaculate (n=25) was diluted at five different sperm concentrations (100, 200, 300, 600 and 800 x 106 spermatozoa/mL), packaged in 0.5mL straws, and subsequent...
Article
The aim of this study was to investigate the influence of sperm concentration, sperm quality, and semen deposition site on uterine inflammatory response in mares. Twenty-five mares with healthy reproductive tracts were used for artificial inseminations (AIs) using frozen-thawed semen and divided into 5 experimental groups: Control—insemination with...
Article
Embryo mobility occurs as a result of prostaglandin production by the embryo and endometrium, promoting uterine smooth muscle contractions, which propels the embryonic vesicle through the lumen. Non-steroidal anti-inflammatory drugs (NSAIDs), as flunixin meglumine, are routinely used in equine medicine and can alter the conceptus mobility if applie...
Article
The aim of this study was to verify the effect of deslorelin and sulpiride association on double ovulation induction in mares. Ten mares were used for this study. Eight days after ovulation, luteolysis was induced and mares were submitted a daily ultrasonographic evaluation until observation of at least two follicles measuring between 20 and 25 mm....
Article
Radical hysterectomy is indicated as a last resource in pyometra that does not respond to pharmacological therapy, uterine torsion with vascular involvement and onset of necrosis, neoplasia, ruptures of impossible synthesis and rarely, segmental aplasia with accumulation of secretion. The incidence of pyometra is multifactorial, being an unusual co...
Article
Full-text available
The aim of this report is to describe a new methodology to successfully treat stallions diagnosed with urethral rent. Four stallions of ages ranging from 7 to 12 years (median 9) with hemospermia were admitted for clinical evaluation, breeding soundness examination and urethroscopy for inspection of the urethra and vesicular glands. Once the presen...
Article
This study aimed to evaluate the antioxidant properties of coenzyme Q10 (CoQ10) during cryopreservation of semen obtained from stallions having good and bad semen freezing ability (GFA vs. BFA, respectively). Forty ejaculates (n = 20 stallions) were split into five centrifugation and five freezing extenders containing different concentrations of Co...
Article
The donkey jack sex glands are larger compared to stallions, responsible for producing most part of seminal plasma and the second fraction of ejaculate, along with epididymis tail. Plugged ampullae occur by sperm accumulation obstructing the lumen, inducing decrease in sperm quality and may cause azoospermia. In this study, a Pêga breed donkey jack...
Article
Full-text available
Background: Semen cryopreservation causes DNA damage, thus requiring continuous monitoring. Objective: To compare two assays for sperm DNA fragmentation (SDF) from stallions with contrasting semen freezability. Materials and methods: Thirteen stallions were classified as good semen freezers (GSF) or bad semen freezers (BSF). Ejaculates were cr...
Article
Studies in mares have examined serum inhibin concentrations using immuno-assays unable to distinguish dimeric inhibin-A from inhibin-B isoforms. Inhibin-A and inhibin-B immuno-assays were used to investigate concentrations in cyclic mares, young and old (6 vs 19 years old, respectively) mares following hemi-ovariectomy, mares during pregnancy and i...
Article
This study compared hormone treatments given to mares during anestrus, spring transition, and different stages of the estrous cycle, by assessing uterine features and pregnancy rates after embryo transfer (ET). Embryo recipient mares (n = 160) were equally arranged as follows: G1-spontaneous ovulation (control), G2-anestrus, G3-spring transition, G...
Article
Full-text available
RESUMO A endometrose é uma alteração degenerativa das glândulas uterinas e do estroma circundante, caracterizada pelo arranjo periglandular de miofibroblastos e pela deposição de matriz extracelular (ECM). O presente trabalho objetivou avaliar a expressão de colágenos tipos I, III e IV e α-actina de músculo liso (α-SMA) nas endometroses equinas, pr...
Article
Persistent mating-induced endometritis (PMIE) results in decreased fertility in horses, thereby causing a significant impact in the horse market. Platelet-rich plasma (PRP), a modulator of the inflammatory response, has been largely used in veterinary medicine. Here, we investigated the effects of PRP on uterine inflammation, conception rate, endom...
Article
This study investigated the binding capacity of equine spermatozoa (both ejaculated and from different epididymal regions) to the oviductal epithelial cells (OECs) culture, before and after cryopreservation, using an oviduct explant assay. Ejaculated and epididymal sperm from caput, corpus, and cauda of 10 stallions were diluted and submitted to fr...
Conference Paper
Full-text available
A membrana dos espermatozoides suínos é a mais rica em ácidos graxos poliinsaturados dentre as espécies domésticas, o que deixa esses espermatozoides mais sensíveis aos danos causados pela criopreservação. Para minimizar os efeitos deletérios da criopreservação, é utilizado o Holding Time (HT), que é o período em que os espermatozoides ficam em con...
Conference Paper
Full-text available
Durante as etapas de criopreservação do sêmen suíno, é comum que ocorram diversos danos aos espermatozoides. As injúrias durante a criopreservação são muitas vezes causadas por choques térmicos, resultando em queda de motilidade, e a fim de minimizar a ocorrência desses efeitos deletérios, é utilizado o Holding Time (HT). Essa técnica consiste em r...
Conference Paper
Full-text available
Durante a criopreservação do sêmen, há geração de espécies reativas de oxigênio (EROs) que causam um estado de estresse oxidativo, culminando em crioinjúrias. O holding time (HT) é o período em que os espermatozoides ficam em contato com plasma seminal, à 17 °C, antes de serem submetidos à criopreservação. Essa interação com o plasma diminui as cri...
Conference Paper
Full-text available
Durante a criopreservação do sêmen ocorrem diversos eventos semelhantes a capacitação espermática. Durante essa criocapacitação, uma das alterações observadas na célula espermática é o aumento da fluidez da membrana plasmática. O espermatozoide suíno apresenta-se mais susceptível a esses eventos, devido as particularidades de sua membrana. Submeter...
Article
Morphological analysis of the sperm cells were accomplished from 19 stallions comparing six different techniques (DIC, Karras, Eosin-Nigrosin, Dip Quick 5′, Dip Quick modified, Dip Quick) in order to verify the possibility of using a modification of Dip Quick stain technique to evaluate the morphology of equine semen. Data of sperm morphology were...
Article
The aim of this study was to evaluate the effect of treatment using low doses of EPE on rates of ovulation and embryo recovery. Eight mares were used in this way: first cycle (n = 8)-control group (untreated); second cycle (n = 8)-treated group using 8.0 mg of EPE, bid, until at least two follicles reached =35 mm diameter. At this moment, was admin...
Article
The use of stallion frozen semen minimizes the spread of disease, eliminates geographic barriers, and preserves the genetic material of the animal for an unlimited time. Significant progress on the frozen thawed stallion semen process and consequently fertility has been achieved over the last decade. These improvements not only increased fertility...
Article
Full-text available
Boar semen cryopreservation remains a challenge due to the extension of cold shock damage. Thus, many alternatives have emerged to improve the quality of frozen-thawed boar sperm. Although the use of seminal plasma arising from boar sperm-rich fraction (SP-SRF) has shown good efficacy; however, the majority of actual sperm evaluation techniques inc...
Data
Minimal dataset underlying the findings. CT—control; CS—centrifuged and suspended in autologous seminal plasma (SP); CW—centrifuged and withdrawn SP; CWSP—CW containing autologous seminal plasma. (ZIP)
Data
Fluorochrome controls for manual flow cytometry compensation. (A) Sample subjected to three cycles of flash freezing (FF) in liquid nitrogen and then slowly thawed to induce damage to the plasma membranes followed by propidium iodide staining (PI positive). (I) Histogram showing the absence of PSA-FITC fluorescence; (II) histogram showing the absen...
Article
Full-text available
Boar spermatozoa arising from the sperm-rich ejaculate fraction are reported to have a more stable plasma membrane and are more resistant to cold shock and premature acrosome reaction than spermatozoa from the whole ejaculate. Furthermore, seminal plasma (SP) can increase the cryotolerance of boar spermatozoa, and in other domestic species, it has...
Article
Boar spermatozoa arising from the sperm-rich ejaculate fraction are reported to have a more stable plasma membrane and are more resistant to cold shock and premature acrosome reaction than spermatozoa from the whole ejaculate. Furthermore, seminal plasma (SP) can increase the cryotolerance of boar spermatozoa, and in other domestic species, it has...
Article
Chronic degenerative endometritis (CDE) is an important cause of fertility problems in older mares. It is estimated that 30% of mares breeding are over 18 years old and the high value of their progeny encourages the use of these animals in assisted reproduction procedures. Currently, cell-based therapies are broadly used in human and veterinary reg...
Article
Full-text available
This study compares two methods for seminal plasma removal by evaluating sperm recovery rates, and motility and morphology of cooled-stored semen. Ejaculates were divided into three groups: control, filtration and cushioned centrifugation. Semen was extended to 25 million sperm/ml using a skim-milk-based extender and stored at 5°C for all groups. S...
Article
Degenerative changes of the endometrium are directly related to age and fertility in mares. Chronic degenerative endometritis (CDE) is correlated with uterine fluid retention and reduced ability to clear uterine inflammation. Recent research in the areas of equine surgery and sports medicine has shown that platelet-rich plasma (PRP) treatment acts...
Article
Full-text available
The use of cryopreserved semen for insemination of mares facilitates breeding management but often results in reduced conception rates. This has been mainly attributed to changes in sperm membrane function caused by the freezing-thawing procedure. However, semen processing may also contribute to epigenetic changes in spermatozoa. In the present stu...
Article
Full-text available
Fertility rates of donkey semen in jennies are lower compared to mares. The aims of this study were to evaluate different sperm cryopreservation methods and insemination strategies to improve the fertility of donkey semen in jennies. Three experiments were performed: (1) the comparison of two freezing methods of donkey semen (conventional method an...
Article
The presence of anovulatory haemorrhagic follicles during the oestrous cycle of mares causes financial impacts, slowing conception and increasing the number of services per pregnancy. Non-steroidal anti-inflammatory drugs (NSAIDs) such as meloxicam and phenylbutazone are used in the treatment of several disorders in mares, and these drugs can impai...
Article
The present study aimed to evaluate pregnancy and pregnancy loss rates of recipients treated with alternative long-acting progesterone protocols, designed to synchronize acyclic and cyclic mares, regardless of their cycle phase. A total of 150 Campolina breed mares were used as recipients. Recipient mares were assigned to six different groups with...
Article
Full-text available
The penis and prepuce of the stallion have a high bacterial load on its surface, forming a natural microbial flora that contaminates the semen during ejaculation. Bacterial growth in semen may cause a decline on sperm quality, viability, and fertility and predisposes the occurrence of endometritis in inseminated mares. Thus, the aim of this study w...
Article
Full-text available
This study was aimed to test low doses of a GnRH agonist, deslorelin acetate (DA), for induction of multiple ovulations in mares and to determine its impact upon their reproductive efficiency. Seven mares aging from 8-20 years were used in three consecutive reproductive cycles. Mares were initially monitored by ultrasound irrespectively of cycle st...
Conference Paper
Full-text available
Post-thawed addition of seminal plasma (SP) in equine cryopreserved semen increased the integrity of plasma and acrosomal membranes (Andrade et al. 2011 Reprod. Dom. Anim. 46, 682-686) and these possibly affect sperm lifespan, improving fertility (Garcia et al. 2010 Anim. Reprod. Sci. 119, 160-165). This study was conducted to verify the pregnancy...
Article
The Mini-horse is a new equine breed that is on the rise in Brazil. These are animals with a maximum adult height of 98cm for females and 93cm for males, with a well-proportioned body. Those animals are easily handled by children and require small spaces with low maintenance costs. The Mini-horse is under constant genetic selection that is aimed ma...
Article
Several factors can interfere with sperm cryopreservation resistance, especially the genetic factors and those related to the plasma membrane composition of the sperm and seminal plasma. However, it is still unclear if the same factors that confer freezing resistance will perform the same role during the cooling process. Thus, the aim of this study...
Article
The aim of the present study was to evaluate the effect of cholesterol-loaded cyclodextrin on the quality and fertility of stallion frozen semen. Three ejaculates from each of 4 stallions were used. The semen was diluted (1:1) with a skim milk-based extender (Botu-Semen(TM), Botupharma, Brazil). The samples were divided into 2 groups: control group...
Article
Commercial freeze extenders have different composition and ratio of cryoprotectors; freezing and thawing protocols are different for each extender. The aim of this experiment was to observe the effect of thawing curve in stallion frozen semen with 2 commercial extenders. Two ejaculates from each of 9 stallions of different breeds (Quarter Horses an...
Article
In fixed time artificial insemination (FTAI) is frozen semen is commonly used, however the use of cooled semen is a practice alternative to reduce costs. The aim of this study was compare the difference in DNA fragmentation and plasma membrane integrity between chilled and frozen semen of bulls. Two ejaculates from 20 bulls were collected. Semen wa...
Article
Two studies were conducted to understand sperm cryosensitivity in an endangered equid, the Przewalski’s horse (Equus ferus przewalski), while testing the cryoprotectant ability of formamides. The first assessed the toxicity of permeating cryoprotectants (glycerol, methylformamide [MF] and dimethylformamide [DMF]) to Przewalski’s horse spermatozoa d...