Background Recent advancements in ultra-low power electronics and wireless devices have facilitated the widespread adoption of wearable technology for fitness and health monitoring, paving the way for personalized medicine. Microneedle-based devices, comprising small epidermal patches that penetrate the skin\'s stratum corneum to potentially access biomarkers in the extracellular fluid of the viable epidermis, represent a promising innovation in this field. Objectives This project aimed to develop and validate a novel method to evaluate microneedle engagement in the skin in real-time. To our knowledge, there are no studies published to date that have characterized the electrical impedance of stratum corneum and epidermis using the tape stripping method to selectively remove cell layers. Additionally, no studies have been published comparing the electrical impedance of fresh to frozen-thawed porcine skin. The objective of this study was to develop and validate a novel method to evaluate microneedle engagement in skin, in real-time, that does not require processing of the tissue. Methods A tape stripping technique was employed to selectively remove the stratum corneum from fresh and frozen-thawed porcine skin samples which were then electrically characterized using an excitation frequency of 5 kHz with a peak Voltage of 1 V. Results This study demonstrated a mean impedance reduction of 97.08 ± 1.3 % for fresh porcine skin, and 98.04 ± 0.3 % for frozen-thawed porcine skin when transitioning from the surface stratum corneum to the viable epidermis. The correlation between the reduction of impedance and the number of tape strips across all 18 test sites was significant (r = 0.98, p < 0.00001). However, comparing the skin impedance of the fresh and frozen-thawed specimens showed poor equivalence, with the frozen-thawed sites approximately 5.5 times the impedance of the fresh sites before any tape stripping, and 4.19 times greater after 30 tape strips. Conclusions These findings suggest that monitoring for an interelectrode impedance decrease of greater than 95% between two projections of a microneedle device could provide a rapid and effective evaluation of skin engagement, crucial for advancing the development and clinical application of microneedle-based technologies in personalized medicine. The study also underscores the impact of the freeze-thaw process on the mechanical and electrical properties of skin, which is crucial for standardizing testing protocols.

Introduction: Animal models that closely mimic human burn wound healing processes are essential for developing effective burn wound treatments. Pigs are useful animal models for studying burn wound healing. From their extensive literature review, Andrews and Cuttle (2017) reported mean temperature and exposure time values. This study was done to provide initial burn depth for another experiment comparing two burn wound treatments. The secondary goal was to validate a systematic review on porcine burn model standardization. Material and Methods: Six four-week-old Large White x Landrace gilts were housed in a closed structure for 10 days to acclimatize. The procedures were performed under general anesthesia. A round 2.5 cm copper plate welded to an aluminum rod with a wooden handle caused the injuries. The burning device was used to reach a contact temperature of 110 C on the pig\'s skin. The objective was to create a superficial partial thickness (SPT) burn for 10 seconds (Group 10s) and a deep partial thickness (DPT) burn for 20 seconds (Group 20s) using a plate heated at 110ºC. No stabilizer or pressure controller was used. Wounds were conclusively dressed and harvested 24 hours later. The usual hematoxylin-eosin protocol was used to cut and stain 4-micron sections. Results: A significant difference (p 0.01) was observed in dermis involvement, with a mean of 85.61 % (95% CI= 80.62 to 90.61) for group 10s and 123.71% (95% CI= 114.91 to 132.50) for group 20s. An exposure time of 20 seconds increased dermis depth-related total collagen denaturation by almost 50% compared to 10 seconds. Conclusions: In conclusion, our experiment produced DPT burns in 10 seconds and FT burns in 20 seconds without a pressure application device.

Extracellular vesicles, also known as exosomes, influence numerous cellular functions by regulating different signaling pathways. However, their role in animal reproduction remains understudied. This study aimed to evaluate the effects of porcine follicular fluid-derived exosomes (pff-Exos) on porcine oocyte in vitro maturation and parthenogenetic embryo development. We obtained pff-Exos through mixed-method ultracentrifugation and size-exclusion chromatography. Transmission electron microscopy revealed an increase in the expression of exosome markers in the first four of thirteen fractions. The number of pff-Exo was 2.2 × 106 particles per microliter. The highest maturation rate of porcine oocytes treated with pff-Exo was observed with 1.1 × 107 particles of pff-Exo in the absence of porcine follicular fluid (pFF) culture conditions. Moreover, increased expression of Gdf9 and Bmp15 was observed. The developmental rate was the highest upon treatment with 1.1 × 107 particles of pff-Exo, which increased the total cell number in blastocysts. Embryonic development to the 2-cell stage was similar between the control and pff-Exo groups; however, development to the 4-cell stage and blastocyst was significantly increased in the pff-Exo group (61.6 ± 6.08 % and 29.72 ± 1.41 %, respectively; P < 0.05) compared with that in the control group (42.0 ± 5.19 % and 18.14 ± 1.78 %, respectively). The expression levels of Oct4, Sox2, Bcl2, Elf4, and Gcn5 significantly increased at the pff-Exo 2-cell stage, whereas those of Bax, Hdac1, Hdac6, and Sirt6 decreased. Specifically, the Oct4, Sox2, Elf4, Gcn5, and Hdac6 levels remained stable in pff-Exo 4-cell embryos, whereas those of p53 and Hat1 were reduced and increased, respectively. Treatment with pffExos significantly increased H3K9 and H3K14 acetylation levels. These results demonstrate that pff-Exo affects the in vitro maturation of porcine oocytes and early embryonic development by regulating gene expression.

Ballistic gelatin has been extensively used in ballistics research for decades, but calibration standards were established on limited datasets, and only few studies have attempted to recreate these experiments with biological tissues. Recent studies have demonstrated better biofidelity with 20% ordnance ballistic gelatin, but researchers have discredited the use of synthetic gelatin claiming different behavior than ordnance gelatin. To investigate the use of synthetic clear gelatin as an acceptable surrogate of biological tissue, depth of penetration was compared between low-velocity impacts of various projectiles into porcine tissue (n = 192), post-mortem human subjects (n = 29), and Clear Ballistics synthetic gelatin (n = 39). The predicted depth of penetration of the 0.177\" steel BB (38.1 mm) was consistent with the manufacturer\'s calibration standard (31.75-44.45 mm) and within calibration bounds of recently proposed empirical equations. Compared to impacts in biological tissue, synthetic gelatin demonstrated the least variability in depth of penetration (R2 = 0.96). Using ANCOVA, velocity was a significant covariate (p < 0.001), and there were no significant differences in normalized depth of penetration over density between porcine tissue, post-mortem human subjects, and 20% synthetic gelatin (p = 0.22). Ultimately, this study confirmed the use of 20% synthetic gelatin as an acceptable tissue simulant using standard calibration methods for use in future ballistic studies.

Introduction: Animal models that closely mimic human burn wound healing processes are essential for developing effective burn wound treatments. Pigs are useful animal models for studying burn wound healing. From their extensive literature review, Andrews and Cuttle (2017) reported mean temperature and exposure time values. This study was done to provide initial burn depth for another experiment comparing two burn wound treatments. The secondary goal was to validate a systematic review on porcine burn model standardization. Materials and Methods: Six four-week-old Large White x Landrace gilts were housed in a closed structure for 10 days to acclimatize. The procedures were performed under general anesthesia. A round 2.5 cm copper plate welded to an aluminum rod with a wooden handle caused the injuries. The burning device was used to reach a contact temperature of 110ºC on the pig\'s skin. The objective was to create a superficial partial thickness (SPT) burn for 10 seconds (Group 10s) and a deep partial thickness (DPT) burn for 20 seconds (Group 20s) using a plate heated at 110ºC. No stabilizer or pressure controller was used. Wounds were conclusively dressed and harvested 24 hours later. The usual hematoxylin-eosin protocol was used to cut and stain 4-micron sections. Results: A significant difference (p 0.01) was observed in dermis involvement, with a mean of 85.61 % (95% CI= 80.62 to 90.61) for group 10s and 123.71% (95% CI= 114.91 to 132.50) for group 20s. An exposure time of 20 seconds increased dermis depth-related total collagen denaturation by almost 50% compared to 10 seconds. Conclusions: In conclusion, our experiment produced DPT burns in 10 seconds and FT burns in 20 seconds without a pressure application device.

DNA methylation plays a critical role in regulating gene expression during testicular development. However, few studies report on candidate genes related to the DNA methylation regulation of porcine testicular development. This study examined the differentially expressed genes (DEGs) and their methylation levels in testicular tissues from pigs at 60 days of age (60 d) and 180 days of age (180 d) using RNA-Seq and whole genome bisulfite sequencing (WGBS). It was determined that DNA methylation primarily occurs in the cytosine-guanine (CG) context, and the analysis identified 106,282 differentially methylated regions (DMRs) corresponding to 12,385 differentially methylated genes (DMGs). Further integrated analysis of RNA-Seq and WGBS data revealed 1083 DMGs negatively correlated with the expression of DEGs. GO analysis showed that these genes were significantly enriched in spermatogenesis, germ cell development, and spermatid differentiation. The screening of enriched genes revealed that hyper-methylation repressed ADAM30, ADAM3A, DPY19L2, H2BC1, MAK, RPL10L, SPATA16, and YBX2, while hypo-methylation elevated CACNA1I, CADM1, CTNNB1, JAM2, and PAFAH1B3 expression. Additionally, the methylation status of the key genes ADAM3A, ADAM30, YBX2, JAM2, PAFAH1B3, and CTNNB1 was detected by bisulfite sequencing PCR (BSP). This study offers insights into the epigenetic regulation mechanisms underlying porcine testicular development.

Reproduction is classically controlled by gonadotropin-releasing hormone (GnRH-I) and its receptor (GnRHR-I) within the brain. In pigs, a second form (GnRH-II) and its specific receptor (GnRHR-II) are also produced, with greater abundance in peripheral vs. central reproductive tissues. The binding of GnRH-II to GnRHR-II has been implicated in the autocrine/paracrine regulation of gonadal steroidogenesis rather than gonadotropin secretion. Blood samples were collected from transgenic gilts, with the ubiquitous knockdown of GnRHR-II (GnRHR-II KD; n = 8) and littermate controls (n = 7) at the onset of estrus (follicular) and 10 days later (luteal); serum concentrations of 16 steroid hormones were quantified by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Upon euthanasia, ovarian weight (OWT), ovulation rate (OR), and the weight of each excised Corpus luteum (CLWT) were recorded; HPLC-MS/MS was performed on CL homogenates. During the luteal phase, serum progesterone concentration was reduced by 18% in GnRHR-II KD versus control gilts (p = 0.0329). Age and weight at puberty, estrous cycle length, and OWT were similar between lines (p > 0.05). Interestingly, OR was reduced (p = 0.0123), and total CLWT tended to be reduced (p = 0.0958) in GnRHR-II KD compared with control females. Luteal cells in CL sections from GnRHR-II KD gilts were hypotrophic (p < 0.0001). Therefore, GnRH-II and its receptor may help regulate OR, CL development, and progesterone production in gilts.

UNASSIGNED: Aneurysm pathophysiology remains poorly understood, in part from the disparity of murine models with human physiology and the requirement for invasive aortic exposure to apply agents used to create aneurysm models. A retrievable drug infusion stent graft (RDIS) was developed to isolate the aortic wall intraluminally for drug exposure. We hypothesized that an RDIS could deliver aneurysm-promoting enzymes to create a porcine model of thoracic aneurysms without major surgical exposure.
UNASSIGNED: Retrievable nitinol stent graft frames were designed with an isolated drug delivery chamber, covered with polytetrafluoroethylene, and connected to a delivery wire with a drug infusion catheter installed to the outer chamber. Institutional Animal Care and Use Committee-approved Yorkshire pigs (n = 5) underwent percutaneous access of the femoral artery, baseline aortogram and stent placement in the thoracic aorta followed by 30-minute exposure to a cocktail of elastase, collagenase, and trypsin. After aspiration of excess drug, stent retrieval, and femoral artery repair, animals were recovered, with angiograms at 1 and 4 weeks followed by explant. Histological analysis, in situ zymography, and multiplex cytokine assays were performed.
UNASSIGNED: The RDIS isolated a segment of anterior aorta angiographically, while the center lumen preserved distal perfusion during drug treatment (baseline femoral mean arterial pressure, 70 ± 14 mm Hg; after RDIS, 75 ± 12; P = .55). Endovascular induction of thoracic aneurysms did not require prior mechanical injury and animals revealed no evidence of toxicity. Within 1 week, significant aneurysmal growth was observed in all five animals (1.4 ± 0.1 cm baseline to 2.9 ± 0.7 cm; P = .002) and only within the treated region of the aorta. Aneurysms persisted out to 4 weeks. Aneurysm histology demonstrated loss of elastin and collagen that was otherwise preserved in untreated aorta. Proinflammatory cytokines and increased matrix metalloproteinase activity were increased significantly within the aneurysm.
UNASSIGNED: An RDIS achieves isolated drug delivery while preserving distal perfusion to achieve an endovascular porcine model of thoracic aneurysms without major surgery. This model may have value for surgical training, device testing, and to better understand aneurysm pathogenesis. Most important, although the RDIS was used to simulate aortic pathology, this tool offers intriguing horizons for focused therapeutic drug delivery directly to aneurysms and, more broadly, focused locoregional drug delivery to vessels and vascular beds.

It is known that asymmetrical maternal transcripts play an important role in the cell fate of the early embryo, but few studies are available in mammal oocytes especially in pig. To investigate the spatial factors in pig oocytes, the oriented bisection was established for collecting karyoplasts (NSOs) and cytoplasts (SSOs) with more than 95% efficiency. Subsequently, RNA-Seq and LC-MS/MS analysis were performed on NSOs and SSOs. Although no differentially expressed genes (DEGs) could be detected between NSOs and SSOs, 89 of the differentially expressed proteins (DEPs) were detected, that 58 proteins higher expressed but 31 proteins lower expressed in NSOs compared with SSOs. These DEPs mainly participated in the \'cell cycle\' and \'ribosome\' pathway, while the up-regulated DEPs were mainly GO in \'spindle\' and \'positive regulation of translation\', and the down-regulated DEPs were in \'cytosolic small ribosomal subunit\' and \'mRNA binding\'. The up-regulated DEP SIRT5 which are related to the regulation of gene expression, epigenetic were further detected and revealed. A spatial asymmetry of maternal factors at the protein level was firstly detected in pig mature oocytes.

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