Agomelatine ameliorates doxorubicin-induced cortical and hippocampal brain injury via inhibition of TNF-alpha/NF-kB pathway

Side effects of doxorubicin (DOX) are mainly due to oxidative stress, with the involvement of inflammatory and apoptotic mechanisms. Agomelatine (AGO) is a melatonin receptor agonist with antioxidant, anti-inflammatory, and anti-apoptotic features. This study aimed to evaluate the effects of AGO with different doses on DOX-induced neurotoxicity. Rats were divided into four groups as control, DOX (40 mg/kg, intraperitoneal single dose), DOX + AGO20 (20 mg/kg AGO oral gavage for 14 days), and DOX + AGO40 (40 mg/kg AGO oral gavage for 14 days). On day 14, brain tissues were collected for biochemical, histopathological, and genetic examinations. DOX significantly increased malondialdehyde and decreased superoxide dismutase and catalase (CAT) levels. CAT levels were significantly increased only in the DOX + AGO40 group compared to the DOX group (p = 0.040) while other changes in oxidant and antioxidant indicators were insignificant. DOX-induced significant increases in TNF-alpha and NF-κB were reversed following both low and high-dose AGO administration in a dose-dependent manner (p < 0.001 for both doses). Cellular shrinkage, pycnotic change, and vacuolization in apoptotic bodies were apparent in the cortical and hippocampal areas of DOX-treated samples. Both doses of AGO alleviated these histopathological changes (p = 0.01 for AGO20 and p = 0.05 for AGO40). Significantly increased apoptosis shown with caspase-3 immunostaining in the DOX group was alleviated following AGO administration, with additional improvement after high-dose treatment (p < 0.01 for DOX compared to both AGO groups and p < 0.05 for AGO40 compared to AGO20). AGO can be protective against DOX-induced neurotoxicity by antioxidant, anti-inflammatory, and anti-apoptotic mechanisms in a dose-dependent manner.

Biphasic Regulation of Apoptosis Following Gastric Irreversible Electroporation Using Tissue Immunohistochemistry of Activated Caspase-3 with TUNEL Method

The regulation of apoptosis is the primary goal of ablation therapy. Irreversible electroporation (IRE) is a promising non-thermal tissue ablation-based therapy that induces apoptosis by manipulating electrical conditions. This study aimed to investigate IRE-induced gastric tissue apoptosis in response to changes in the electric field intensity, followed by the repair process. Among the 52 rats used in this study, 24 were used to explore apoptosis, and 28 were used to study regeneration. The apoptosis-to-necrosis ratio of the electrical field strength was evaluated using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and caspase-3 immunohistochemistry. The size of IRE-induced ulcers in the gastric tissue continuously increased with increasing electrical intensity (r2 = 0.830, p < 0.001). The level of apoptosis gradually decreased after peaking at 200 V (1000 V/cm). The size of the 400 V-ablated ulcers continued to decrease, and they were not visible by day 14. The proliferation and migration of epithelial cells with fibroblasts were observed on day 3 and augmented on day 7 post-ablation. This investigation demonstrated the biphasic activation of apoptosis with respect to the electrical field strength. Visually and histologically, IRE-induced gastric ulcers demonstrated complete tissue regeneration after two weeks.

Efficient ultrasound-mediated drug delivery to orthotopic liver tumors - Direct comparison of doxorubicin-loaded nanobubbles and microbubbles

Liver metastasis is a major obstacle in treating aggressive cancers, and current therapeutic options often prove insufficient. To overcome these challenges, there has been growing interest in ultrasound-mediated drug delivery using lipid-shelled microbubbles (MBs) and nanobubbles (NBs) as promising strategies for enhancing drug delivery to tumors. Our previous work demonstrated the potential of Doxorubicin-loaded C3F8 NBs (hDox-NB, 280 ± 123 nm) in improving cancer treatment in vitro using low-frequency unfocused therapeutic ultrasound (TUS). In this study, we investigated the pharmacokinetics and biodistribution of sonicated hDox-NBs in orthotopic rat liver tumors. We compared their delivery and therapeutic efficiency with size-isolated MBs (hDox-MB, 1104 ± 373 nm) made from identical shell material and core gas. Results showed a similar accumulation of hDox in tumors treated with hDox-MBs and unfocused therapeutic ultrasound (hDox-MB + TUS) and hDox-NB + TUS. However, significantly increased apoptotic cell death in the tumor and fewer off-target apoptotic cells in the normal liver were found upon the treatment with hDox-NB + TUS. The tumor-to-liver apoptotic ratio was elevated 9.4-fold following treatment with hDox-NB + TUS compared to hDox-MB + TUS, suggesting that the therapeutic efficacy and specificity are significantly increased when using hDox-NB + TUS. These findings highlight the potential of this approach as a viable treatment modality for liver tumors. By elucidating the behavior of drug-loaded bubbles in vivo, we aim to contribute to developing more effective liver cancer treatments that could ultimately improve patient outcomes and decrease off-target side effects.

Immune Effects of Cryoablation in Woodchuck Hepatocellular Carcinoma

Objectives

Local and systemic immune responses evoked by locoregional therapies such as cryoablation are incompletely understood. The aim of this study was to characterize cryoablation-related immune response and the capacity of immune drugs to augment immunity upon cryoablation for the treatment of hepatocellular carcinoma (HCC) using a woodchuck hepatocellular carcinoma model.

Materials and Methods

Twelve woodchucks chronically infected with woodchuck hepatitis virus and with hepatocellular carcinoma underwent imaging with contrast-enhanced CT. Partial cryoablation of tumors in three woodchucks was performed. Fourteen days after cryoablation, liver tissues were harvested and stained with H&E and TUNEL, and immune infiltrates were quantified. Peripheral blood mononuclear cells (PBMC) were collected from ablated and nonablated woodchucks, labeled with carboxyfluorescein succinimidyl ester (CFSE) and cultured with immune-modulating drugs, including a small PD-L1 antagonist molecule (BMS-202) and three TLR7/8 agonists (DSR 6434, GS-9620, gardiquimod). After incubation, cell replication and immune cell populations were analyzed by flow cytometry.

Results

Local immune response in tumors was characterized by an increased number of CD3+ T lymphocytes and natural killer cells in the cryolesion margin compared to other tumor regions. T regulatory cells were found in higher numbers in distant tumors within the liver compared to untreated or control tumors. Cryoablation also augmented the systemic immune response as demonstrated by higher numbers of PBMC responses upon immune drug stimulation in the cryoablation group.

Conclusions

Partial cryoablation augmented immune effects in both treated and remote untreated tumor microenvironments, as well as systemically, in woodchucks with HCC. Characterization of these mechanisms may enhance development of novel drug-device combinations for treatment of HCC.

Efficient ultrasound-mediated drug delivery to orthotopic liver tumors - Direct comparison of doxorubicin-loaded nanobubbles and microbubbles

Liver metastasis is a major obstacle in treating aggressive cancers, and current therapeutic options often prove insufficient. To overcome these challenges, there has been growing interest in ultrasound-mediated drug delivery using lipid-shelled microbubbles (MBs) and nanobubbles (NBs) as promising strategies for enhancing drug delivery to tumors. Our previous work demonstrated the potential of Doxorubicin-loaded C3F8 NBs (hDox-NB, 280 ± 123 nm) in improving cancer treatment in vitro using low-frequency ultrasound. In this study, we investigated the pharmacokinetics and biodistribution of sonicated hDox-NBs in orthotopic rat liver tumors. We compared their delivery and therapeutic efficiency with size-isolated MBs (hDox-MB, 1104 ± 373 nm). Results showed a similar accumulation of hDox in tumors treated with hDox-MBs and unfocused therapeutic ultrasound (hDox-MB+TUS) and hDox-NB+TUS. However, significantly increased apoptotic cell death in the tumor and fewer off-target apoptotic cells in the normal liver were found upon the treatment with hDox-NB+TUS. The tumor-to-liver apoptotic ratio was elevated 9.4-fold following treatment with hDox-NB+TUS compared to hDox-MB+TUS, suggesting that the therapeutic efficacy and specificity are significantly increased when using hDox-NB+TUS. These findings highlight the potential of this approach as a viable treatment modality for liver tumors. By elucidating the behavior of drug-loaded bubbles in vivo, we aim to contribute to developing more effective liver cancer treatments that could ultimately improve patient outcomes and decrease off-target side effects.

Dataset of acute oral toxicity and subacute neurotoxicity risk assessments of flavonoid-enriched fraction extracted from Oroxylum Indicum on Sprague Dawley rats

Oroxylum indicum is a medicinal herb that garnered enormous attention in drug discovery for human diseases such as neurodegenerative, cardiovascular, arthritis and hepatitis diseases. Pharmacokinetic study confirmed that the pharmacological actions of this herb are associated with its prominent flavonoid bioactive components. Here, the data set of liquid chromatography-mass spectroscopy (LC-MS), neurological functions, relative organ weight (ROW), hematological, biochemical and histopathological parameters of flavonoid-enriched fraction (FEF)-treated Sprague Dawley (SD) rats were presented. The data set was generated from three study groups namely: Sighting Study, Acute Toxicity Study and Subacute Neurotoxicity Study with study duration of 14 days (for Sighting Study and Acute Toxicity Study) and 28 days (for Subacute Neurotoxicity Study) by strictly following the procedures set in Organisation for Economic Co-operation and Development (OECD) Guidelines 420 and 424 in vivo. Rats in sighting study were treated with dosage of 5, 50, 300 and 2000 mg/kg FEF (n = 1/dosage/gender), respectively, and were observed for mortality, toxicity signs and behavioural changes. The highest dosage at which none of the animal showed sign of mortality in the sighting study was selected as the test dosage for subsequent acute toxicity study (n = 5/dosage/gender). Meanwhile, for subacute neurotoxicity study, SD rats (n = 5/dosage/gender) were treated with repeated dosage of 50 mg/kg for 28 days. Neurological behaviours of treated rats were observed daily, while their body weight were measured weekly. Whole blood was collected at the end of the study via cardiac puncture into ethylenediaminetetraacetic acid (EDTA) tubes for hematological evaluation that included the measurements of red blood cells (RBC), hemoglobin (Hb), packed cell volumes (PCV), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), platelet, white blood cells (WBC) count and WBC differentials. Meanwhile, blood serum were collected into slow sand filter (SST) tubes for biochemical evaluation that included measurements of total protein (TP), albumin, bilirubin, alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Vital organs such as brain, liver, kidneys, heart, lungs and reproductive organs also were collected, sliced and stained with hematoxylin and eosin (H&E) at the end of the study for histopathological assessments.

Effects of Acute and Chronic Trypanosoma cruzi Infection on Pregnancy Outcomes in Mice: Parasite Transmission, Mortality, Delayed Growth, and Organ Damage in Pups

Chagas disease is caused by Trypanosoma cruzi. This study aimed to determine the effects of T. cruzi infection on fertility rate and health of the newborn pups in pregnant mice. Female mice were challenged with T. cruzi and mated at 21 days (acute parasitemic phase) or 90 days (chronic parasite persistence phase) after infection. Pups were examined for growth up to 20 days after birth; and parasite burden in brain, heart, skeletal muscle, and intestine was measured by real-time quantitative PCR. The inflammatory infiltrate, necrosis, and fibrosis in pups' heart and brain tissues were evaluated by histology. T. cruzi infection in dams delayed the onset of pregnancy, decreased the fertility rate, and led to vertical transmission of parasite to the pups. Furthermore, infected dams delivered pups that exhibited decreased survival rate, decreased birth weight, and decreased growth rate. Significantly increased inflammation, necrosis, and fibrosis of cardiac and brain tissues were noted in pups born to infected dams. Initial challenge with higher parasite dose had more detrimental effects on fertility rate and pups' health in both acutely and chronically infected dams. In conclusion, mice offer a promising model to evaluate the efficacy of new vaccines and therapeutic drugs in controlling the acute and chronic maternal T. cruzi infection and congenital transmission to newborns, and in improving the fertility rate and pups' health outcomes.

Establishment of an Animal Model of Disk Degeneration by Intradiskal Injection of Monosodium Iodoacetate

BACKGROUND

Disk degeneration (DD) stands for the most common cause of low back pain. The establishment of an animal model plays an intrinsic role in the clarification of the physiopathology of DD. The purpose of this study is to select an optimal dose of monosodium iodoacetate (MIA) that may generate a reliable model of DD.

METHODS

Thirty-four rats were used in this study. The disks (Co7/8, Co8/9, and Co 9/10) received 1 shot of intradiskal injection of 0.02 mg, 0.1 mg, and 0.5 mg of MIA solution, respectively. Half of the rats were euthanized 3 weeks after MIA injection, and the other half 6 weeks after injection.

RESULTS

Magnetic resonance imaging evaluation showed that the mean T2-weighted signal intensity at 6 weeks decreased significantly in the 0.1 and 0.5 mg groups. The disk height of the control group was significantly higher than those of the 0.1 mg and 0.5 mg groups. Histologic and macroscopic results revealed time-and-dose-depending degeneration in the disks that received MIA. Additionally, MIA produced cell death in the nucleus pulposus cells with an elevated percentage. The injected disk with 0.1 mg MIA demonstrated a progressive degeneration, the disk injected with 0.5 mg MIA induced DD acutely 3 weeks post MIA injection, while the dose of 0.02 mg of MIA did not show much degeneration.

CONCLUSIONS

We concluded that 0.1 mg MIA is the most suitable dose to establish a model of DD, which enabled us to replicate the onset, progression, and outcome of diverse histopathologies of DD in the clinic.

Comparative analysis of the immune response to RFA and cryoablation in a colon cancer mouse model

The immune response to radiofrequency ablation (RFA) and cryoablation (CRA) was characterized and compared in a colon cancer mouse model. All studies were conducted under a research protocol approved by the National Institutes of Health, Clinical Center, Animal Care and Use Committee. BALB/cJ mice were inoculated with CT26 cells, and randomized to RFA, CRA, or sham treatment. Mice were sacrificed 3 days post-treatment, and tumor, spleen, and serum were harvested. Cell death was determined by Caspase-3 immunohistochemical and TUNEL stains. Immune response was analyzed using flow cytometry, serum cytokine assay and immunohistochemistry. Cell death, necrosis, and apoptosis induced by ablation were comparable in RFA and CRA. Decreased frequency of systemic T-regulatory cells was found in the CRA group. Both RFA and CRA reduced frequencies of several myeloid-derived suppressor cell (MDSC) subpopulations. RFA induced pro-inflammatory cytokine secretion including TNF-α and IL-12 as well as anti-inflammatory cytokines IL-5, and IL-10. CRA augmented secretion of a wider array of cytokines compared to RFA with both pro- and anti-inflammatory properties including IL-1β, IL-5, IL-6, IL-10, and KC GRO. In the tumor microenvironment, RFA reduced the number of T-regulatory cells, a finding not observed with CRA. Reduction of immune suppression via decreases in T-regulatory cells and MDSC was found to be induced by RFA or CRA. CRA augmented a wider range of cytokines than RFA, which were mainly pro-inflammatory, but also anti-inflammatory. In the tumor microenvironment, RFA demonstrated more pronounced anti-tumoral immunity. Further delineation of specific immunomodulation induced by ablation could inform drug-device development and may play a role in future hypothesis-driven immunomodulatory paradigms that combine immunotherapy drugs with tumor destruction for the treatment of metastatic colon cancer.

Comparison of sampling methods for next generation sequencing for patients with lung cancer

Introduction

Success of next generation sequencing (NGS) analysis is becoming indispensable in the treatment of advanced lung cancer. However, the advantages and disadvantages of each sampling method in the NGS analysis have not yet been clarified.

Methods

We compared the success rates of NGS analysis, and DNA and RNA yields for transbronchial biopsy (TBB), endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA), computed tomography (CT)‐guided biopsy, fluid sample, and surgical biopsy for NGS analysis in patients through the lung cancer genomic screening project for individualized medicine (LC‐SCRUM)‐Asia, a nationwide NGS screening project. In case, sufficient samples could not be collected by TBB and EBUS‐TBNA, re‐biopsy (genome re‐biopsy) was performed.

Results

A total of 223 patients were enrolled and success rates of NGS analysis were not different between samples obtained through TBB, EBUS‐TBNA, and CT‐guided biopsy; however, success rates for fluid samples and surgical biopsy samples were significantly higher than those of other methods. The risk of genome re‐biopsy was higher with TBB for centrally located lesions. CT‐guided biopsy yielded more samples but had a lower success rate for analysis of RNA‐based NGS than TBB.

Conclusions

TBB is the mainstay of sampling methods, but for centrally located lesions, EBUS‐TBNA may be a better strategy. For CT‐guided biopsy, the success rate of RNA‐based NGS analysis is low. Fluid samples are expected to yield successful results as surgical biopsy samples, but the latter are better for sample preservation. Determining the optimal method for genome biopsy for each case is important.

Tissue-reactive drugs enable materials-free local depots

Local, sustained drug delivery of potent therapeutics holds promise for the treatment of a myriad of localized diseases while eliminating systemic side effects. However, introduction of drug delivery depots such as viscous hydrogels or polymer-based implants is highly limited in stiff tissues such as desmoplastic tumors. Here, we present a method to create materials-free intratumoral drug depots through Tissue-Reactive Anchoring Pharmaceuticals (TRAPs). TRAPs diffuse into tissue and attach locally for sustained drug release. In TRAPs, potent drugs are modified with ECM-reactive groups and then locally injected to quickly react with accessible amines within the ECM, creating local drug depots. We demonstrate that locally injected TRAPs create dispersed, stable intratumoral depots deep within mouse and human pancreatic tumor tissues. TRAPs depots based on ECM-reactive paclitaxel (TRAP paclitaxel) had better solubility than free paclitaxel and enabled sustained in vitro and in vivo drug release. TRAP paclitaxel induced higher tumoral apoptosis and sustained better antitumor efficacy than the free drug. By providing continuous drug access to tumor cells, this material-free approach to sustained drug delivery of potent therapeutics has the potential in a wide variety of diseases where current injectable depots fall short.

DEAD-Box RNA Helicase DDX47 Maintains Midgut Homeostasis in Locusta migratoria

Tissue homeostasis is critical for maintaining organ shape, size, and function. The condition is regulated by the balance between the generation of new cells and the loss of senescent cells, and it involves many factors and mechanisms. The midgut, an important part of the intestinal tract, is responsible for digestion and nutrient absorption in insects. LmDDX47, the ortholog of DEAD-box helicase 47 from Locusta migratoria, is indispensable for sustaining a normal midgut in the nymphs. However, the underlying cellular and molecular mechanisms remain to be elucidated. In this study, LmDDX47 knockdown resulted in atrophy of the midgut and gastric cecum in both nymph and adult locusts. After LmDDX47 knockdown, the number of regenerative and columnar cells in the midgut was significantly reduced, and cell death was induced in columnar tissue. LmDDX47 was localized to the nucleolus; this was consistent with the reduction in 18S rRNA synthesis in the LmDDX47 knockdown group. In addition, the acetylation and crotonylation levels of midgut proteins were significantly increased. Therefore, LmDDX47 could be a key regulator of midgut homeostasis, regulating 18S rRNA synthesis as well as protein acetylation and crotonylation in the migratory locust.

Intradiscal injection of monosodium iodoacetate induces intervertebral disc degeneration in an experimental rabbit model

Background

Establishing an optimal animal model for intervertebral disc (IVD) degeneration is essential for developing new IVD therapies. The intra-articular injection of monosodium iodoacetate (MIA), which is commonly used in animal models of osteoarthritis, induces cartilage degeneration and progressive arthritis in a dose- and time-dependent manner. The purpose of this study was to determine the effect of MIA injections into rabbit IVDs on the progression of IVD degeneration evaluated by radiographic, micro-computerized tomography (micro-CT), magnetic resonance imaging (MRI), and histological analyses.

Methods

In total, 24 New Zealand White (NZW) rabbits were used in this study. Under general anesthesia, lumbar discs from L1–L2 to L4–L5 had a posterolateral percutaneous injection of MIA in contrast agent (CA) (L1–L2: CA only; L2–L3: MIA 0.01 mg; L3–L4: 0.1 mg; L4–L5: 1.0 mg; L5–L6: non-injection (NI) control). Disc height was radiographically monitored biweekly until 12 weeks after injection. Six rabbits were sacrificed at 2, 4, 8, and 12 weeks post-injection and processed for micro-CT, MRI (T2-mapping), and histological analyses. Three-dimensional (3D) disc height in five anatomical zones was evaluated by 3D reconstruction of micro-CT data.

Results

Disc height of MIA-injected discs (L2–L3 to L4–L5) gradually decreased time-dependently (P < 0.0001). The disc height of MIA 0.01 mg-injected discs was significantly higher than those of MIA 0.1 and 1.0 mg-injected discs (P < 0.01, respectively). 3D micro-CT analysis showed the dose- and time-dependent decrease of 3D disc height of MIA-injected discs predominantly in the posterior annulus fibrosus (AF) zone. MRI T2 values of MIA 0.1 and 1.0 mg-injected discs were significantly decreased compared to those of CA and/or NI controls (P < 0.05). Histological analyses showed progressive time- and dose-degenerative changes in the discs injected with MIA (P < 0.01). MIA induced cell death in the rabbit nucleus pulposus with a high percentage, while the percentage of cell clones was low.

Conclusions

The results of this study showed, for the first time, that the intradiscal injection of MIA induced degenerative changes of rabbit IVDs in a time- and dose-dependent manner. This study suggests that MIA injection into rabbit IVDs could be used as an animal model of IVD degeneration for developing future treatments.

Environmentally relevant mixtures of phthalates and phthalate metabolites differentially alter the cell cycle and apoptosis in mouse neonatal ovaries†

Phthalates are a group of chemicals used as additives in various consumer products, medical equipment, and personal care products. Phthalates and their metabolites are consistently detected in humans, indicating widespread and continuous exposure to multiple phthalates. Thus, environmentally relevant mixtures of phthalates and phthalate metabolites were investigated to determine the effects of phthalates on the function of the ovary during the neonatal period of development. Neonatal ovaries from CD-1 mice were cultured with dimethyl sulphoxide (DMSO; vehicle control), phthalate mixture (0.1-100 μg/mL), or phthalate metabolite mixture (0.1-100 μg/mL). The phthalate mixture was composed of 35% diethyl phthalate, 21% di(2-ethylhexyl) phthalate, 15% dibutyl phthalate, 15% diisononyl phthalate, 8% diisobutyl phthalate, and 5% benzylbutyl phthalate. The phthalate metabolite mixture was composed of 37% monoethyl phthalate, 19% mono(2-ethylhexyl) phthalate, 15% monobutyl phthalate, 10% monoisononyl phthalate, 10% monoisobutyl phthalate, and 8% monobenzyl phthalate. After 96 h of culture, ovaries were harvested for histological analysis of folliculogenesis, gene expression analysis of cell cycle and apoptosis regulators, and immune staining for cell proliferation and apoptosis. The metabolite mixture significantly decreased the number and percentage of abnormal follicles (100 μg/mL) compared to controls. The metabolite mixture also significantly increased the expression of cell cycle inhibitors (100 μg/mL) and the antiapoptotic factor Bcl2l10 (10 μg/mL) compared to controls. The phthalate mixture did not significantly alter gene expression or follicle counts, but ovaries exposed to the phthalate mixture (0.1 μg/mL) exhibited marginally significantly increased apoptosis as revealed by DNA fragmentation staining. Overall, these data show that parent phthalates and phthalate metabolites differentially impact ovarian function.

Morphologic assessment of hypertonic citrate adenine, histidine-tryptophan-ketoglutarate, and university of Wisconsin solutions for hypothermic uterus preservation in rats

AIM

Optimizing perfusate for static cold storage is one of the key ways of reducing organ dysfunction and rejection in organ transplantation. Here, we tested the effectiveness of the three different solutions for hypothermic uterus preservation.

METHODS

Twenty rats were divided into four groups, five in each group. Uterine grafts were retrieved and perfused in situ. The uteri were preserved at 4°C in normal saline as control group (group NS), hypertonic citrate adenine (group HCA), histidine-tryptophan-ketoglutarate (group HTK), or university of Wisconsin solutions (group UW) for 0, 12, 24, and 48 h, respectively. HE, electron microscopy, TUNEL staining, and Cleaved Caspase3 immunohistochemical staining were assessed at each time point.

RESULTS

There was no significant difference in the uterine retrieval time, perfusion time, and the amount of perfusion solution in NS, HCA, HTK, and UW groups (p > 0.05). HCA and HTK can well preserve the pathological morphology of rat uterine tissues for up to 24 h, and the apoptosis rates of the two groups are 7.2% and 7.1%, respectively, with no statistical difference (p > 0.05). Still, the protective effect of HTK on the ultrastructure of cells was much better than HCA. There was a significant difference in the apoptosis rate of UW (6.5%), HTK (8.8%), and HCA (9.4%) at 48 h, with mitochondrial and endoplasmic reticulum structure well preserved only in UW.

CONCLUSION

At 4°C, normal saline is not suitable to preserve rat uterus for more than 12 h. The morphologic results would favor the use of HTK rather than HCA for short-term hypothermic uterus preservation (≤24 h). UW is better than HTK and HCA for 48 h hypothermic uterus preservation.

Role of Claudins in Renal Branching Morphogenesis

Claudins are a family of tight junction proteins that are expressed during mouse kidney development. They regulate paracellular transport of solutes along the nephron and contribute to the final composition of the urinary filtrate. To understand their roles during development, we used a protein reagent, a truncated version of the Clostridium perfringens enterotoxin (C-CPE), to specifically remove a subset of claudin family members from mouse embryonic kidney explants at embryonic day 12. We observed that treatment with C-CPE decreased the number and the complexity of ureteric bud tips that formed: there were more single and less bifid ureteric bud tips when compared to control-treated explants. In addition, C-CPE-treated explants exhibited ureteric bud tips with larger lumens when compared to control explants (p < .05). Immunofluorescent analysis revealed decreased expression and localization of Claudin-3, -4, -6, and -8 to tight junctions of ureteric bud tips following treatment with C-CPE. Interestingly, Claudin-7 showed higher expression in the basolateral membrane of the ureteric bud lineage and poor localization to the tight junctions of the ureteric bud lineage both in controls and in C-CPE-treated explants. Taken together, it appears that claudin proteins may play a role in ureteric bud branching morphogenesis through changes in lumen formation that may affect the efficiency by which ureteric buds emerge and branch.

Observational Study Design in Veterinary Pathology, Part 2: Methodology

Observational studies are a basis for much of our knowledge of veterinary pathology, yet considerations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offered advice on planning and carrying out an observational study. Part 2 of the series focuses on methodology. Our general recommendations are to consider using already-validated methods, published guidelines, data from primary sources, and quantitative analyses. We discuss 3 common methods in pathology research—histopathologic scoring, immunohistochemistry, and polymerase chain reaction—to illustrate principles of method validation. Some aspects of quality control include use of clear objective grading criteria, validation of key reagents, assessing sample quality, determining specificity and sensitivity, use of technical and biologic negative and positive controls, blinding of investigators, approaches to minimizing operator-dependent variation, measuring technical variation, and consistency in analysis of the different study groups. We close by discussing approaches to increasing the rigor of observational studies by corroborating results with complementary methods, using sufficiently large numbers of study subjects, consideration of the data in light of similar published studies, replicating the results in a second study population, and critical analysis of the study findings.