Abstract Anticancer therapy often leads to premature ovarian insufficiency (POI) and infertility due to the extreme sensitivity of the ovarian follicle reserve to the effects of chemotherapy. Withanolides are known for their cytotoxic effect on cancer cells and low cytotoxicity on non-malignant or healthy cells. Therefore, this study aimed to investigate the in vivo effects of three withanolides derivatives: 27-dehydroxy-24,25-epoxywithaferin A (WT1), 27-dehydroxywithaferin A (WT2), and withaferin A (WTA) on fertility, and the ovarian preantral follicles of young female mice. To achieve this, mice received 7 intraperitoneal doses of WT1, WT2, or WTA at a concentration of 2 mg/kg (Experiment I) and 5 or 10 mg/kg (Experiment II) over 15 alternate days. In experiment I, two days after administration of the last dose, half of the mice were mated to evaluate the effects of withanolides on fertility. The other half of the mice, as well as all mice from experiment II, were sacrificed for histological, inflammation, senescence, and immunohistochemical analyses of the follicles present in the ovary. Regardless of the administered withanolide, the concentration of 2 mg/kg did not show toxicity on the follicular morphology, ovarian function, or fertility of the mice. However, at concentrations of 5 and 10 mg/kg, the three derivatives (WT1, WT2, and WTA) increased follicular activation, cell proliferation, and ovarian senescence without affecting inflammatory cells. Furthermore, at a concentration of 10 mg/kg, the three withanolides showed intensified toxic effects, leading to DNA damage as evidenced by the labeling of γH2AX, activated Caspase 3, and TUNEL. We conclude that the cytotoxic effect of the tested withanolide derivatives (WT1, WT2, and WTA) in the concentration of 2 mg/kg did not show toxicity on the ovary. However, in higher concentrations, such as 10 mg/kg, toxic effects are potentiated, causing DNA damage. POI (POI chemotherapy nonmalignant non malignant Therefore 27dehydroxy24,25epoxywithaferin 27dehydroxy2425epoxywithaferin dehydroxyepoxywithaferin 27 dehydroxy 24,25 epoxywithaferin 24 25 WT1 WT , (WT1) 27dehydroxywithaferin dehydroxywithaferin WT2 (WT2) (WTA mgkg mg kg Experiment I 1 II dose histological inflammation ovary morphology function However (WT1 activation proliferation Furthermore γH2AX γHAX γH AX 3 TUNEL potentiated 27dehydroxy24 25epoxywithaferin 2425 24,2 (WT2 (WT 27dehydroxy2 242 24, 27dehydroxy

Abstract Oviduct fluid extracellular vesicles (oEV) are essential for periconceptional events. The presence of EV has already been identified in the oviduct fluid (OF) from mammalian species, except in caprine. Therefore, this study aimed to isolate and characterize the caprine oEV (coEV). Initially, in Experiment 1, coEV were isolated from the OF of either each animal individually or from a pool of three animals. In experiment 2, coEV were isolated during the follicular or luteal phases of the estrous cycle. The coEV were characterized by size distribution, polydispersity index (PDI), and zeta potential using dynamic light scattering (DLS) analysis, as well as, by transmission electron microscopy (TEM) and dot blotting (DB). Our results indicated that the physicochemical characteristics of the coEV were similar (P > 0.05), regardless of the isolation method (individual or pool). However, coEV collected during the luteal phase were larger (P < 0.05) than those during the follicular phase. The TEM showed spherical and cup-shaped particles, characteristic of exosomes. The DB revealed the presence of exosomal proteins involved in the biogenesis of coEV. In conclusion, it is possible to isolate and characterize coEV from a single caprine female and the estrous cycle phase influences the vesicles average size and PDI. (oEV events (OF species Therefore . (coEV) Initially 1 animals 2 distribution PDI, PDI , (PDI) DLS (DLS analysis (TEM DB. (DB) P 0.05, 005 0.05 0 05 individual pool. pool) However cupshaped cup shaped particles exosomes conclusion (coEV (PDI (DB 00 0.0 0.

Abstract This study aimed to verify the impact of high-fat diet consumption for a prolonged period on oxidative stress, fetal growth, umbilical vascular system, and placental structures in pregnant goats. Twenty-two pregnant goats were grouped into the control diet (n= 11) and fat diet (n = 11). Flaxseed meal was added to the fat diet, replacing the corn grain of concentrate, from gestational day 100 to delivery date. Diets were isonitrogenous and isoenergetic, differing in fat content (2.8% vs. 6.3% dry matter). The fat group showed higher feed intake and total plasma lipid levels than the control group (P < 0.001). No difference was found in placentome, and umbilical vascular development. Fat diet-fed goats exhibited a lower systolic peak in the umbilical artery. At delivery, placental traits were similar with the exception of the cotyledon width (P = 0.0075), which was smaller in the fat group and cotyledon surface (P = 0.0047) for multiple pregnancy of fat diet. Cotyledonary epithelium showed more intense staining of lipid droplets and a greater area for lipofuscin staining in the fat group compared to control group (P < 0.001). The mean live weight of the kids was lower in the fat group in the first week after delivery than in control group. Thus, in goats, the continuous administration of a high-fat diet during pregnancy does not appear to modify the fetal-maternal vascular structures but has an impact on a part of the placental structure; therefore, its use must be carefully evaluated. highfat high stress growth system Twentytwo Twenty two n= n 11 11. . concentrate 10 date isoenergetic 2.8% 28 2 8 (2.8 vs 63 6 3 6.3 matter. matter matter) P 0.001. 0001 0.001 0 001 0.001) placentome development dietfed fed artery 0.0075, 00075 0.0075 , 0075 0.0075) 0.0047 00047 0047 Thus fetalmaternal maternal structure therefore evaluated 1 2.8 (2. 6. 000 0.00 00 0007 0.007 007 0.004 0004 004 2. (2 0.0 ( 0.

Abstract Due to the great interest in ovarian cryopreservation and, consequently conservation and restoration of female fertility in the last decades, different vitrification procedures (vitrification devices or solutions) have been developed, patented, and used both for academic research purposes and for clinical use. Therefore, the present study aimed to provide a systematic review and meta-analysis of data obtained from the application of different patented and non-patented vitrification devices and solutions in different countries. For this purpose, relevant observational studies published between the years 2000 to 2021 were selected to verify the efficiency of ovarian vitrification processes on parameters such as morphology, viability, and apoptosis in preantral ovarian follicles after transplantation or in vitro culture. Our research revealed that, although several countries were considered in the study, the United States and Japan were the countries that registered the most processes, and 22 and 16 vitrification devices and solutions out of a total of 51, respectively were patented. Sixty-two non-patented processes were also considered in the study in all countries. We also observed that transplantation and in vitro ovarian culture were the techniques predominantly used to evaluate the efficiency of the devices and vitrification solutions, respectively. In conclusion, this review showed that patented or non-patented protocols available in the literature are able to successfully preserve preantral follicles present in ovarian tissue. Despite the satisfactory results reported so far, adjustments in ovarian vitrification protocols in order to minimize cryoinjuries to the follicles remain one of the goals of cryopreservation and preservation of the female reproductive function. We found that vitrification alters the morphology and viability, and offers risks leading in some cases to follicular apoptosis. However, adjustments to current protocols to develop an optimal procedure can minimize damage by not compromising follicular development after vitrification/warming.

Abstract This study aimed to investigate the effect of growth and differentiation factor 9 (GDF-9) during the in vitro culture of isolated caprine early antral follicles. The isolated and selected early antral follicles were individually cultured for 18 days, and the following treatments were tested: α-MEM+ (control treatment) or α-MEM+ supplemented with 200 ng/mL GDF-9. The following endpoints were evaluated: follicular growth and morphology, estradiol production, oocyte nuclear maturation, and relative expression of key genes related to steroidogenesis (CYP19A1, CYP17, and insulin receptor) and basement membrane remodeling (MMP-9 and TIMP-2). In both treatments, a decrease was observed in the percentage of morphologically intact follicles with a concomitant increase in the rates of extruded and degenerated follicles (P < 0.05). The GDF-9 treatment showed higher rates of extruded follicles only on day 6 of culture (P < 0.05). Follicle diameter increased progressively throughout the culture period (P < 0.05) with similar diameters between treatments at all culture times (P > 0.05). Growth and differentiation factor 9 increased the daily growth rate from the first to the second third of culture, with higher values (P < 0.05) than control in the second third. Oocyte maturation rate as well as estradiol levels and relative mRNA expression for CYP19A1, CYP17, MMP-9, TIMP-2, and insulin receptor genes were similar between treatments (P > 0.05). This study shows for the first time that GDF-9 added to a culture medium increased the follicle growth rate of goat early antral follicles cultured in vitro.

Resumo Este estudo teve como objetivo investigar o efeito do GDF-9 durante o cultivo in vitro de folículos antrais iniciais caprinos isolados. Os folículos antrais iniciais isolados e selecionados foram cultivados individualmente por 18 dias, e os seguintes tratamentos foram testados: α MEM+ (tratamento controle) ou α-MEM+ suplementado com 200 ng/mL de GDF-9 (tratamento GDF-9). Os seguintes parâmetros foram avaliados: crescimento e morfologia folicular, produção de estradiol, maturação nuclear do oócito e expressão relativa de genes-chave relacionados a esteroidogênese (CYP19A1, CYP17 e receptor de insulina) e remodelamento da membrana basal (MMP-9 e TIMP-2). Em ambos os tratamentos, observou-se diminuição na porcentagem de folículos morfologicamente intactos com aumento concomitante nas taxas de folículos extrusos e degenerados (P < 0,05). O tratamento GDF-9 apresentou maiores taxas de folículos extrusos apenas no 6º dia de cultivo (P < 0,05). O diâmetro do folículo aumentou progressivamente ao longo do período de cultivo (P < 0,05) com diâmetros semelhantes entre os tratamentos em todos os tempos de cultivo (P > 0,05). O GDF-9 aumentou a taxa de crescimento diário do primeiro para o segundo terço de cultivo, sendo maior (P < 0,05) que o controle no segundo terço. A taxa de maturação oocitária assim como os níveis de estradiol e a expressão relativa de RNAm para os genes CYP19A1, CYP17, MMP-9, TIMP-2 e receptor de insulina foram similares entre os tratamentos (P > 0,05). Em conclusão, este estudo mostra pela primeira vez que GDF-9 adicionado a um meio de cultivo aumentou a taxa de crescimento de folículos antrais iniciais caprinos cultivados in vitro.

O presente estudo investigou os efeitos da proteína morfogenética óssea-6 (BMP-6) no desenvolvimento in vitro de folículos primordiais caprinos. Amostras de córtex ovariano de cabras foram cultivados por 1 ou 7 dias em Meio Essencial Mínimo (meio controle) suplementado com diferentes concentrações de BMP-6. As taxas de sobrevivência, ativação e crescimento foram avaliadas por histologia clássica e microscopia eletrônica de transmissão (MET). Após 7 dias de cultivo, a análise histológica demonstrou que a BMP-6 aumentou o percentual de folículos primordiais degenerados no dia 7 quando comparados ao controle fresco (D0). Além disso, houve um aumento significativo do diâmetro folicular e oocitário em ambos os períodos de cultivo em todos os tratamentos na presença de BMP-6. Com a progressão do cultivo do dia 1 para o dia 7, nos tratamentos com 1 ou 50ng/ml de BMP-6, foi observado um aumento significativo no diâmetro folicular. Entretanto, contrário ao observado no meio controle, a MET revelou que os folículos cultivados nesses tratamentos apresentavam sinais evidentes de atresia. Em conclusão, esse estudo demonstrou que a BMP-6 afeta negativamente a sobrevivência e a ultra-estrutura de folículos primordiais caprinos.

This study investigated the effects of bone morphogenetic protein 6 (BMP-6) on in vitro primordial follicle development in goats. Samples of goat ovarian cortex were cultured in vitro for 1 or 7 days in Minimum Essential Medium (control medium) supplemented with different concentrations of BMP-6. Follicle survival, activation and growth were evaluated through histology and transmission electron microscopy (TEM). After 7 days of culture, histological analysis demonstrated that BMP-6 enhanced the percentages of atretic primordial follicles when compared to fresh control (day 0). Nevertheless, BMP-6 increased follicular and oocyte diameter during both culture periods. As the culture period progressed from day 1 to day 7, a significant increase in follicle diameter was observed with 1 or 50ng/ml BMP-6. However, on the contrary to that observed with the control medium TEM revealed that follicles cultured for up to 7 days with 1 or 50ng/ml BMP-6 had evident signs of atresia. In conclusion, this study demonstrated that BMP-6 negatively affects the survival and ultrastructure of goat primordial follicles.

O presente trabalho investigou a taxa de degeneração de folículos primordiais caprinos in situ após conservação em PBS ou TCM 199, em diferentes temperaturas e tempos de incubação. Para cada animal, o par ovariano foi dividido em 19 fragmentos. Um fragmento foi escolhido aleatoriamente e imediatamente fixado (controle). Os 18 fragmentos ovarianos restantes foram aleatoriamente distribuídos em tubos contendo PBS ou TCM 199 e conservados a 4, 20 or 39ºC por 4, 12 or 24h. A conservação de fragmentos ovarianos em PBS ou TCM 199 a 20ºC por 12 e 24h ou a 39ºC, em todos os tempos de incubação testados, aumentou significativamente a percentagem de folículos primordiais degenerados (P<0,05). Ao contrário, em ambos os meios testados, a taxa de degeneração de folículos primordiais conservados a 4ºC em todos os tempos testados e a 20ºC por 4h foi similar ao controle (P>0,05). Em conclusão, este estudo mostrou que o PBS foi tão eficiente quanto o TCM 199 na conservação de folículos primordiais caprinos in situ, sendo os melhores resultados observados na temperatura de 4ºC.

The present work has investigated the degeneration rate of goat primordial follicles in situ after preservation in PBS or TCM 199 at different temperatures and incubation times. For each animal the ovarian pair was divided into 19 fragments. One ovarian fragment was taken randomly and immediately fixed (control). The other 18 ovarian fragments were randomly distributed in tubes containing PBS or TCM 199 and stored at 4º, 20º or 39ºC for 4, 12 or 24h. The storage of ovarian fragments in PBS or TCM 199 at 20ºC for 12h and 24h or at 39ºC, in all incubation times tested, increased significantly the percentage of degenerated primordial follicles (P<0.05). In contrast, for both media tested the degeneration rate of primordial follicles preserved at 4ºC for up to 24h and at 20ºC for 4h was similar to control values (P>0.05). In conclusion, this study shows that PBS was as efficient as TCM 199 in the preservation of goat primordial follicles in situ, being the best results observed at 4ºC.

O presente trabalho investigou a eficiência da solução salina 0,9% e tampão fosfato salina (PBS) na conservação de folículos pré-antrais caprinos in situ a diferentes temperaturas e tempos de incubação. O par ovariano de cada animal foi dividido em 19 fragmentos. Um fragmento foi escolhido aleatoriamente e fixado (controle). Os outros 18 fragmentos foram distribuídos aleatoriamente em tubos contendo solução salina 0,9% ou PBS a 4, 20 ou 39 °C por 4, 12 ou 24 h. Um total de 5.921 folículos pré-antrais foram analisados. A qualidade dos folículos pré-antrais foi avaliada através de histologia clássica. A incubação de fragmentos ovarianos em solução salina 0,9% ou PBS a 4 ºC não reduziu significativamente a percentagem de folículos morfologicamente normais quando comparados com o controle, exceto após a conservação em solução salina 0,9% por 24 h. A incubação de fragmentos ovarianos a 20 ou 39°C reduziu a percentagem de folículos pré-antrais normais quando comparados com o controle, exceto após conservação em PBS a 20°C por 4 h. Em conclusão, este estudo mostrou pela primeira vez que folículos pré-antrais caprinos podem ser conservados in situ com sucesso a 4 ºC em solução salina 0,9% por 12 h e em PBS por 24 h, e a 20 ºC em PBS por 4 h.

The present work investigated the efficiency of 0.9% saline solution and Phosphate Buffered Saline (PBS) in the preservation of goat preantral follicles in situ at different temperatures and incubation times. The ovarian pair of each animal was divided into 19 fragments. One ovarian fragment was taken randomly and fixed (control). The other 18 fragments were randomly distributed in tubes containing 0.9% saline solution or PBS at 4, 20 or 39 ºC for 4, 12 or 24 h. A total of 5,921 preantral follicles were examined. The quality of preantral follicles was evaluated by classical histology. The storage of ovarian fragments in 0.9% saline solution or PBS at 4 ºC did not reduce significantly the percentage of morphologically normal follicles when compared with the control, except after preservation in 0.9% saline solution for 24 h. The storage of ovarian fragments at 20 or 39°C reduced the percentage of normal preantral follicles when compared to the control, except after preservation in PBS at 20°C for 4 h. In conclusion, this study showed for the first time that goat preantral follicles can be stored in situ successfully at 4 ºC in 0.9% saline solution for 12 h and in PBS for 24 h, and at 20 ºC in PBS for 4 h.

O presente estudo investigou a eficiência da solução salina e solução à base de água de coco na preservação de folículos pré-antrais inclusos em tecido ovariano, em diferentes temperaturas e diferentes tempos de incubação. No abatedouro, o par ovariano foi dividido em 19 fragmentos; um fragmento ovariano foi imediatamente fixado para histologia clássica (controle-tempo zero). Os outros 18 fragmentos ovarianos foram conservados em ambas as soluções a 4ºC, 20ºC ou 39ºC por 4 h, 12 h ou 24 h. A análise histológica mostrou que a conservação de fragmentos ovarianos em ambas as soluções a 4ºC por até 24 h mantém a percentagem de folículos pré-antrais normais similar aos valores do controle. Ao contrário, a conservação a 20°C ou 39ºC, em ambas as soluções, reduziu significativamente a percentagem de folículos pré-antrais normais comparado aos valores do controle, exceto em solução salina a 20ºC por 4 h ou em solução à base de água de coco a 20ºC por 4 h e 12 h. Em conclusão, esse estudo mostrou que ambas as soluções podem ser usadas com igual eficiência para conservar folículos pré-antrais caprinos a 4°C, independente do tempo de incubação. No entanto, para conservar folículos pré-antrais caprinos a altas temperaturas, a solução à base de água de coco é recomendada.

The present study investigated the efficiency of saline solution and coconut water solution in the preservation of goat preantral follicles enclosed in ovarian tissue, at different temperatures and for different incubation periods. At the slaughterhouse, the ovarian pair was divided into 19 fragments; one ovarian fragment was immediately fixed for histology (control-time zero). The other 18 ovarian fragments were preserved in both solutions at 4ºC, 20ºC or 39ºC for 4 h, 12 h or 24 h. The histological analysis showed that the storage of ovarian fragments in both solutions at 4ºC for up to 24 h kept the percentage of normal preantral follicles similar to the control values. In contrast, preservation at 20°C or 39ºC, in either solution, reduced significantly the percentage of normal preantral follicles compared to the control values, except in saline solution at 20ºC for 4 h or in coconut water solution at 20ºC for 4 h and 12 h. In conclusion, this study shows that both solutions can be used with the same efficiency to preserve goat preantral follicles at 4°C, irrespective of the incubation time. However, to preserve goat preantral follicles at higher temperatures, coconut water solution is recommended.

O presente trabalho descreve os efeitos do estágio reprodutivo (animais impúberes, adultos não-gestantes e gestantes), posição anatômica do ovário (direito e esquerdo) presença de corpo lúteo funcional, peso do ovário e número de folículos antrais superficiais (FAS) sobre o número de folículos pré-antrais (FPA) isolados mecanicamente. Os FPA isolados foram divididos em 3 classes a saber: primordiais, primários e secundários. O número médio (± EP) de FPA isolados por ovário foi de 1.324 ± 193; 866 + 170 e 779 ± 139, respectivamente para ovários oriundos de animais impúberes, não-gestantes e gestantes, sendo observada diferença significativa somente entre animais impúberes e gestantes. A posição anatômica do ovário (exceto para os animais não-gestantes) e a presença ou ausência de corpo lúteo não exerceram nenhum efeito sobre o número e distribuição dos FPA isolados. De um modo geral, o número de folículos primários e secundários foi negativamente correlacionado com o peso ovariano. Já o número de folículos primordiais e secundários foi, respectivamente, positiva e negativamente correlacionado com o número de FAS. Analisando as categorias de animais isoladamente, observou-se que, nos animais impúberes, o número de folículos primordiais foi positivamente correlacionado com o número de FAZ, enquanto que o número de folículos primários e secundários foi negativamente correlacionado com o número de FAS. No tocante à categoria de animais gestantes, o número de folículos primários foi negativamente correlacionado com o peso ovariano. Dependendo da categoria de ovários estudada, foram observadas associações significativas entre o número de folículos primordiais, primários e secundários.

The aïm of this study was to describe the effects of reproductive stages (pre-pubertal, non-pregnant and pregnant adult animals), ovarian anatomic position (left or right), presence of functional corpus luteum, ovarian weight and number of superficial antral follicles on the number of preantral follicles mechanically isolated. The mean number (mean ± SEM) of isolated preantral follicles per ovary was 1,324 ± 193, 866 ±170 and 779 ± 139, respectively for prepubertal, non-pregnant and pregnant adult animals. Anatomic position (except for nonpregnant animals) and the presence or absence of corpus luteum dia nof affect the number and distribution of isolated preantral follicles. In general, the number of primary and secondary follicles was negatively correlated with the ovarian weight. The numbers of primordial and secondary follicles were, respectively, positively and negatively correlated with the number of superficial antral follicles. Analyzing animal categories separately, it was observed that in prepurbetal animals, the number of primordial follicles was positively correlated with the number of superficial antral follicles. However the numbers of primary and secondary follicles were negatively correlated with the number of superficial antral follicles. In the category of pregnant animals, the number of primary follicles was negatively correlated with the ovarian weight. According to ovary category analyzed, were observed significant correlation between the number of primordial, primary and secondary isolated follicles.

Com o objetivo de isolar mecanicamente folículos pré-antrais caprinos, 52 ovários de cabras sem raça definida (SRD) foram coletados em matadouros ou extraídos por ovariectomia. O protocolo utilizado para o isolamento dos folículos, denominado procedimento mecânico direto (PMD), consistiu no corte do tecido ovariano em pequenos fragmentos, utilizando-se um cortador de tecidos. Em seguida, os fragmentos obtidos foram dissociados mecanicamente com pipetas de pasteur (1600mim e 600mim de diâmetro) e a suspensão resultante, contendo os fragmentos ovarianos, foi sucessivamente filtrada em malhas de náilon (500mim e 100mim). A realização deste procedimento permitiu isolar um número médio (± EP) de 1.067 ± 160 folículos por ovário. Com a finalidade de aumentar o número de folículos pré-antrais isolados por ovário, foi utilizado um procedimento mecânico complementar (PMC), que consistiu em submeter os fragmentos retidos nas malhas de 500mim e 100mim às etapas descritas no PMD. A utilização desses fragmentos resultou em um incremento médio de 5,2% no total de folículos isolados por ovário. O número médio (± EP) de folículos isolados por ovário, utilizando-se o procedimento mecânico (PMD + PMC), foi 1.126 + 163. Independentemente do procedimento utilizado, observou-se uma grande variação individual no número de folículos isolados por ovário. Os limites mínimo e máximo desta variação foram 53 e 7.482 folículos, respectivamente. O tamanho dos folículos isolados variou de 15,0mim a 92,7mim. É viável a utilização do procedimento mecânico, descrito pela primeira vez, para o isolamento de folículos ovarianos pré-antrais caprinos.

For mechanical isolation of caprine preantral follicles, ovaries from 52 undefinined breed type goats were collected at a local slaughterhouse or cirurgically extracted. The method used for preantral follicle isolation was a direct mechanical procedure (DMP). Briefly, ovaries were cut into small fragments using a tissue chopper adjusted to 500mum. The ovarian fragments were suspended 80 times with a pasteur pipette and then, the suspension was filtered successively through 500 and 100mum nylon mesh filters. The DMP resulted in a large number of isolated preantral follicles. On average, 1,067 ± 160 (mean number ± SEM) preantral follicles were isolated per ovary. To increase the number of preantral follicles recovered per ovary, the ovarian fragments remaining in the 500 and 100mum nylon mesh filters were transferred to the tissue chopper, and the procedure was repeated (complementary mechanical procedure - CMP). The use of CM P resulted in a mean increment of 5.2% of the total preantral follicles isolated per ovary. The mean number (mean ± SEM) of follicles isolated per ovary using the mechanical procedure (DPM + CPM) was 1,126 + 163. Irrespective of the procedure used, the number of preantral follicles isolated was characterized by extreme individual variation. The limits minimum and maximum of this variation were 53 and 7,482, respectively. The diameter of follicles isolated showed a range from l5.0mum to 92.7 mum. In conclusion, these results showed, for the first time, that preantral follicles can be successfully isolated from caprine ovary by applying a mechanical procedure.