A rat model of cerebral small vascular disease induced by ultrasound and protoporphyrin.

Cerebral small vascular disease (CSVD) has a high incidence worldwide, but its pathological mechanisms remain poorly understood due to the lack of proper animal models. The current animal models of CSVD have several limitations such as high mortality rates and large-sized lesions, and thus it is urgent to develop new animal models of CSVD. Ultrasound can activate protoporphyrin to produce reactive oxygen species in a liquid environment. Here we delivered protoporphyrin into cerebral small vessels of rat brain through polystyrene microspheres with a diameter of 15 µm, and then performed transcranial ultrasound stimulation (TUS) on the model rats. We found that TUS did not affect the large vessels or cause large infarctions in the brain of model rats. The mortality rates were also comparable between the sham and model rats. Strikingly, TUS induced several CSVD-like phenotypes such as cerebral microinfarction, white matter injuries and impaired integrity of endothelial cells in the model rats. Additionally, these effects could be alleviated by antioxidant treatment with N-acetylcysteine (NAC). As control experiments, TUS did not lead to cerebral microinfarction in the rat brain when injected with the polystyrene microspheres not conjugated with protoporphyrin. In sum, we generated a rat model of CSVD that may be useful for the mechanistic study and drug development for CSVD.

(-)-Carvone Inhibits Oxytocin-induced Writhing Via Uterine Relaxation in Rodents.

(-)-Carvone, a ketone monoterpene, is the main component of essential oils from several medicinal plants and has been reported to have anti-arthriric, anticonvulsive, antidiabetic, anti-inflammatory, anticancer, and immunomodulatory effects. Therefore, this study aimed to investigate the spasmolytic activity of (-)-carvone in rodent models. The isolated virgin rat uterus was mounted in an organ bath apparatus, and the relaxing effect of ( -)-carvone and its mechanism of action were evaluated in tonic contractions induced by carbachol, KCl, PGF2α, or oxytocin. The animal model of primary dysmenorrhea was replicated with the injection of estradiol benzoate in female mice for three consecutive days, followed by intraperitoneal administration of oxytocin. Non-clinical acute toxicity evaluation was also performed. (-)-Carvone potency and effectiveness were larger in carbachol (pEC50 = 5.41 ± 0.14 and Emax = 92.63 ± 1.90% at 10-3 M) or oxytocin (pEC50 = 4.29 ± 0.17 and Emax = 86.69 ± 1.56% at 10-3 M) contractions. The effect of ( -)-carvone was altered in the presence of 4-aminopyridine, glibenclamide, L-NAME, or methylene blue. Mice pre-treated with (-)-carvone at a dose of 100 mg/kg showed a significant reduction in the number of writhing after oxytocin administration. No toxicity was observed after oral administration of 1 g/kg ( -)-carvone. Taken together, we showed that (-)-carvone reduced writhing by a spasmolytic effect, probably through the participation of KV and KATP channels and the nitric oxide pathway.

Asprosin-induced alterations in female rat puberty and reproductive hormonal profiles.

OBJECTIVE: To investigate the comprehensive effects of daily chronic asprosin administration on various pubertal and reproductive parameters in female rats. This study aims to elucidate the role of asprosin in regulating the onset of puberty and its influence on hormonal profiles and ovarian histology. METHODS: Asprosin was administered intraperitoneally (i.p.) at a dose of 500 ng/kg daily for eight weeks. Hormonal assays and histological analyses were performed to evaluate the effects of asprosin on the onset of puberty and reproductive function. RESULTS: Daily chronic administration of asprosin accelerated the onset of the first oestrus. Hormonal assays revealed significant elevations in serum levels of Follicle-Stimulating Hormone (FSH) and Oestradiol (E2), while Inhibin B levels decreased. Histological evaluations demonstrated an increased number of primary and secondary follicles in ovarian tissue, without affecting primordial follicle counts or reproductive organ weights. CONCLUSIONS: Role of adipokines in regulating puberty and reproductive function has increasingly gained recognition. This study aimed to provide the first comprehensive examination of the effects of daily chronic asprosin administration on pubertal and reproductive parameters in female rats. Utilising hormonal assays and histological analyses, asprosin was administered intraperitoneally (i.p.) at a dose of 500 ng/kg, daily, for eight weeks. Our findings revealed that daily chronic administration of asprosin accelerated the onset of the first oestrus. Hormonal assays showed significant elevations in serum levels of Follicle-Stimulating Hormone (FSH) and Oestradiol (E2), while Inhibin B levels decreased. Histological evaluations demonstrated an increased number of primary and secondary follicles in ovarian tissue, without affecting primordial follicle counts or reproductive organ weights. These results provide new insights into asprosin's role in advancing the age of first oestrus and modulating hormonal profiles, thereby offering potential benefits to the female reproductive system.

Impact of low-to moderate-intensity exercise training on the mRNA expression of purine receptors across various vessels in SHR.

OBJECTIVE: In this study, we developed an exercise training protocol for assessing both blood pressure dynamics and mRNA expression levels of purine receptors in various vascular tissues during physical activity. The objective is to assess the impact of exercise training on blood pressure regulation in spontaneously hypertensive rats (SHR) and purine receptors in vascular tissues. METHODS: Wistar Kyoto (WKY) and SHR rats were randomly allocated into sedentary (Sed) and exercise training (ExT) groups. Rats in the Sed groups were allowed unrestricted movement, whereas those in the ExT groups underwent a 16-week regimen of low- to moderate-intensity treadmill exercise. Throughout the intervention period, blood pressure measurements and body weight recordings were conducted. Additionally, mRNA expressions of purine receptors P2X1, P2Y1, and P2Y2 in renal artery (RA), internal carotid artery (Int), thoracic aorta (Aor), and caudal artery (Cau) tissues were assessed. RESULTS: In the Sed group, body weight of SHR rats was observed to be lower compared to the three other groups. Over the course of the exercise regimen, blood pressure in the ExT group of SHR rats reduced gradually, converging towards levels similar to those observed in WKY rats by the conclusion of the exercise period. Regarding mRNA expression patterns of P2X1 receptors across the four blood vessels, WKY and SHR rats demonstrated similar sequences, consistently displaying the highest expression levels in the Cau. Conversely, mRNA expressions of P2Y1 and P2Y2 receptors exhibited distinct sequences across the four blood vessels in both WKY and SHR rats. Notably, compared to the Sed group of WKY rats, mRNA expression of P2X1 receptor in the Int of SHR rats revealed an increase, while expressions in the Aor of WKY rats and the Cau of SHR rats decreased following exercise. Expression of P2Y1 receptor mRNA decreased across all four types of blood vessels in SHR rats. Post-exercise, P2Y1 receptor mRNA expression increased in the Aor, decreased in the Cau of WKY rats, and increased in the Int and renal artery (RA) of SHR rats. Conversely, expressions of P2Y2 receptor mRNA decreased in the Int and Aor of SHR rats. Except for the Aor of WKY rats, expressions of P2Y2 receptor mRNA increased in the other arteries of both rat types following exercise. CONCLUSION: Differences in the distribution of purine receptor subtypes among distinct arterial segments in both WKY and SHR rats were observed. Exercise training was found to enhance mRNA expression levels of P2Y receptors in these rat models. This finding implies that exercise training might reduce hypertension in SHR rats by bolstering the purinergic relaxation response.

Pharmacodynamic, pharmacokinetic and rat brain receptor occupancy profile of NLX-112, a highly selective 5-HT1A receptor biased agonist.

NLX-112 (i.e., F13640, befiradol) exhibits nanomolar affinity, exceptional selectivity and full agonist efficacy at serotonin 5-HT1A receptors. NLX-112 shows efficacy in rat, marmoset and macaque models of L-DOPA induced dyskinesia (LID) in Parkinson's disease and has shown clinical efficacy in a Phase 2a proof-of-concept study for this indication. Here we investigated, in rats, its pharmacodynamic, pharmacokinetic (PK) and brain 5-HT1A receptor occupancy profiles, and its PK properties in the absence and presence of L-DOPA. Total and free NLX-112 exposure in plasma, CSF and striatal ECF was dose-proportional over the range tested (0.04, 0.16 and 0.63 mg/kg i.p.). NLX-112 exposure increased rapidly (Tmax 0.25-0.5h) and exhibited approximately threefold longer half-life in brain than in plasma (1.1 and 3.6h, respectively). At a pharmacologically relevant dose of 0.16 mg/kg i.p., previously shown to elicit anti-LID activity in parkinsonian rats, brain concentration of NLX-112 was 51-63 ng/g from 0.15 to 1h. In microPET imaging experiments, NLX-112 showed dose-dependent reduction of 18F-F13640 (i.e., 18F-NLX-112) brain 5-HT1A receptor labeling in cingulate cortex and striatum, regions associated with motor control and mood, with almost complete inhibition of labeling at the dose of 0.63 mg/kg i.p.. Co-administration of L-DOPA (6 mg/kg s.c., a dose used to elicit LID in parkinsonian rats) together with NLX-112 (0.16 mg/kg i.p.) did not modify PK parameters in rat plasma and brain of either NLX-112 or L-DOPA. Here, we demonstrate that NLX-112's profile is compatible with 'druggable' parameters for CNS indications, and the results provide measures of brain concentrations and 5-HT1A receptor binding parameters relevant to the anti-dyskinetic activity of the compound.

A rare case of Streptobacillus moniliformis epidural abscess requiring neurosurgical decompression.

Background: Streptobacillus moniliformis is the primary causative agent of rat bite fever, an infectious disease transmitted through contact with rats through bites, scratches, or exposure to excrement. Before this report, only two instances of spinal epidural abscess (SEA) due to S. moniliformis infection have been documented. We present the case of a 76-year-old male who developed a cervical SEA secondary to S. moniliformis infection, requiring neurosurgical decompression of the spinal cord. Case Description: A 76-year-old male presented to the emergency department with bilateral shoulder and back pain, upper extremity weakness, left hip pain, and left thumb pain. He denied any recent exposure to pets or animals, and the initial workup did not yield the source of the infection. Enhanced magnetic resonance imaging of the cervical spine demonstrated C6-7 discitis/osteomyelitis and an associated ventral SEA, as well as discitis/osteomyelitis of the C2 vertebral body and C5-6 endplates. Subsequently, the patient underwent a C3-7 laminectomy and received a 6-week postoperative course of intravenous ceftriaxone, resulting in complete resolution of the abscess. Blood tests revealed the presence of S. moniliformis, which the patient attributed to potential rat exposure at his workplace. Conclusion: Identification and diagnosis of S. moniliformis infection requires a high index of suspicion. Neurosurgeons should consider this rare pathogen in the differential diagnosis of SEA to facilitate early detection, diagnosis, and surgical intervention, ultimately improving patient outcomes.

A reinforcement schedule with two types of temporal information.

Decades of research on reinforcement schedules have demonstrated that temporal information regarding the arrival or nonarrival of biologically significant events controls animal behavior. The fixed interval (FI) schedule, which is a time-based reinforcement schedule, suggests that responses are regulated by the time elapsed since the last reinforcement. This raises the question of how behavior is controlled when two distinct temporal cues regarding the availability of reinforcers are simultaneously presented. We modified the random interval (RI) schedule to create a reinforcement schedule incorporating two types of temporal information: the time elapsed since the last reinforcement, and the inter-reinforcement interval (IRI). Through long-term operant conditioning in rats, we examined how temporal information controls responses. When two temporal cues were available, we found that behavior was influenced by each cue. Moreover, we discovered that the effects of these cues could be analytically separated within the dynamics of response rates. The findings revealed that in controlling behavior, living organisms can utilize two temporal cues rather than relying on a single, clear cue.•We modified the random interval (RI) schedule to create a reinforcement schedule incorporating two types of temporal information.•When two temporal cues were available, we found that behavior was influenced by each cue.•Rats can utilize two temporal cues rather than relying on a single, clear cue.

Hematological and biochemical characterization of aging farm male rat strains in the National Center for Geriatrics and Gerontology.

Laboratory rats, like mice, are a type of animal commonly used in scientific investigations as well as in basic aging and geriatric research. The selection of a rat strain is an important first step in the planning and design of an experiment due to physiological, anatomical, and ethological variations in each strain, which may significantly modify the expected results. In the present study, we characterized age-related changes, from 3 months old (mo) to 24 mo, in three male rat strains commonly used in medical research: RccHan®ï¸:WIST (RccHan:WIST), F344/NSlc (F344), and Slc:SD Rat (SD). The body weight, water/food consumption, and survival rate of each strain were physiologically evaluated. Hematological and biochemical values were analyzed every three months. Hematological results showed a decrease in lymphocytes and increases in other leukocytes from 12 mo in F344 and SD rats. The incidence of hematological disorder was 10-15% in F344 and SD rats from 18 mo. Increases in hepatic biochemical parameters (alanine transaminase (GPT/ALT) and aspartate transaminase (GOT/AST)) and cytopathological parameters (creatine phosphokinase (CPK)) were observed in male F344 rats at 12 mo. Triglycerides (TG) serum levels were significantly elevated in the 12 mo RccHan:WIST rats, while Lipase (LIP) levels were significantly reduced in 24 mo. The present results revealed significant variations in hematological and biochemical values in the different laboratory male rat strains due to genetic and nutritional-metabolic factors specific to each strain.

Decellularization of Rat Submandibular Gland for Salivary Gland Tissue-Engineering Applications.

OBJECTIVES: This study describes a robust and versatile method for decellularization of rat submandibular glands (SMGs). METHODS: Briefly, rat SMGs were harvested and subjected to perfusion cycles using an anionic detergent. Native and decellularized SMG tissues were subjected to histological analysis using hematoxylin and eosin (H&E) stain and immunohistochemical staining using Hoescht reagent. Further, complementary DNA was synthesized using the native and decellularized SMG tissues and subjected to quantitative reverse transcription polymerase chain reaction (RT-PCR) using rat-specific genes (i.e., α-amylase [Amyl], aquaporin 5 [Aqp5], mucin 19 [Muc19] and glyceraldehyde-3-phosphate dehydrogenase [GAPDH]). The total DNA within native and decellularized SMG tissues were also quantified. RESULTS: H&E staining of SMG tissues revealed preserved ECM content. Decellularized SMG scaffolds lacked cellular material but retained collagen bundles similar to native SMGs. Hoechst reagent immunostaining showed cell nuclei and DNA present in native SMG but not in decellularized SMG scaffolds. Quantitative RT-PCR analysis showed specific amplification products of salivary gland-specific genes (Amyl, Muc19 and Aqp5) and GAPDH in the native SMG tissues. However, no amplification product was observed in the cDNAs from the decellularized SMG scaffolds, confirming the absence of DNA. Quantification of the DNA content showed that the decellularized SMG scaffolds had significantly lower DNA content than native SMG tissue. CONCLUSIONS: Results from this study demonstrated that the decellularization protocol was effective in removing cellular material while preserving the extracellular matrix components and structural integrity of the native SMG tissue.

The effects of different lung parts, age, and batches on the lung microbiota of healthy rats.

BACKGROUND: Rat models are valuable tools to study the lung microbiota in diseases. Yet the impacts of different lung parts, young and mature adult stages, and the different batches of the same conditions on the healthy rat lung microbiome have not been investigated. METHODS: The rat lung microbiome was analyzed to clarify the lung part-dependent and age-dependent differences and to evaluate the effects of several 'batch environmental factors' on normal rats, after eliminating potential contamination. RESULTS: The results showed that the contamination could be identified and excluded. The lung microbiome from left and right lung parts was very similar so one representative part could be used in the microbiome study. There were significantly different lung microbial communities between the young and mature adult groups, and also between the different feeding batches groups of the same repetitive feeding conditions, but a common lung microbiota characterized by Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria as the most dominant phyla were present in all adult rats. It indicated that the experiment under the same condition of the same rats batch was needed to compare the difference in the lung microbiota and repeated experiments were necessary to confirm the results. CONCLUSION: These data represented that the lung bacterial communities were dynamic and rapidly susceptible to environmental influence, clustered strongly by age or different feeding batches but similar in the different lung tissue parts. This study improved the basic understanding of the potential effects on the lung microbiome of healthy rats.

Disparity in temporal and spatial relationships between resting-state electrophysiological and fMRI signals.

Resting-state brain networks (RSNs) have been widely applied in health and disease, but the interpretation of RSNs in terms of the underlying neural activity is unclear. To address this fundamental question, we conducted simultaneous recordings of whole-brain resting-state functional magnetic resonance imaging (rsfMRI) and electrophysiology signals in two separate brain regions of rats. Our data reveal that for both recording sites, spatial maps derived from band-specific local field potential (LFP) power can account for up to 90% of the spatial variability in RSNs derived from rsfMRI signals. Surprisingly, the time series of LFP band power can only explain to a maximum of 35% of the temporal variance of the local rsfMRI time course from the same site. In addition, regressing out time series of LFP power from rsfMRI signals has minimal impact on the spatial patterns of rsfMRI-based RSNs. This disparity in the spatial and temporal relationships between resting-state electrophysiology and rsfMRI signals suggests that electrophysiological activity alone does not fully explain the effects observed in the rsfMRI signal, implying the existence of an rsfMRI component contributed by 'electrophysiology-invisible' signals. These findings offer a novel perspective on our understanding of RSN interpretation.

The brain contains many cells known as neurons that send and receive messages in the form of electrical signals. The neurons in different regions of the brain must coordinate their activities to enable the brain to operate properly. Researchers often use a method called resting-state functional magnetic resonance imaging (rsfMRI) to study how different areas of the brain work together. This method indirectly measures brain activity by detecting the changes in blood flow to different areas of the brain. Regions that are working together will become active (that is, have higher blood flow and corresponding rsfMRI signal) and inactive (have lower blood flow and a lower rsfMRI signal) at the same time. These coordinated patterns of brain activity are known as "resting-state brain networks" (RSNs). Previous studies have identified RSNs in many different situations, but we still do not fully understand how these changes in blood flow are related to what is happening in the neurons themselves. To address this question, Tu et al. performed rsfMRI while also measuring the electrical activity (referred to as electrophysiology signals) in two distinct regions of the brains of rats. The team then used the data to generate maps of RSNs in those brain regions. This revealed that rsfMRI signals and electrophysiology signals produced almost identical maps in terms of the locations of the RSNs. However, the electrophysiology signals only contributed a small amount to the changes in the local rsfMRI signals over time at the same recording site. This suggests that RSNs may arise from cell activities that are not detectable by electrophysiology but do regulate blood flow to neurons. The findings of Tu et al. offer a new perspective for interpreting how rsfMRI signals relate to the activities of neurons. Further work is needed to explore all the features of the electrophysiology signals and test other methods to compare these features with rsfMRI signals in the same locations.

Efficacy of colchicine and melatonin in the treatment of rat endometriosis model: An animal study.

OBJECTIVE: This study investigates the therapeutic effects of colchicine and melatonin on endometriotic implants in an experimentally created endometriosis model in rats. STUDY DESIGN: Forty-four adult female Wistar albino rats weighing between 260 and 300 g, 8 weeks old, were selected for the study. The unilateral uterine horn of rats with a bicornuate uterus was excised for 1 cm, washed with sterile saline, incised longitudinally, and the endometrium was exposed. A 0.5*0.5 cm endometrial tissue sample taken with a scalpel was implanted with suturing (4/0 Vicryl) to the abdominal wall. Forty-four rats were divided into four groups. Group 1 was randomized as the endometriosis group (control), Group 2 as endometriosis + colchicine treatment, Group 3 as endometriosis + melatonin treatment, and Group 4 as the endometriosis + melatonin + colchicine treatment group. The colchicine (Sigma Chemical Co., St Louis, Missouri) group was administered orally at a dose of 0.1 mg/kg, and the Melatonin group orally at a dose of melatonin (20 mg/kg per day). Treatment continued daily for 30 days. RESULTS: In the post-treatment focal diameter measurements, the endometrial focal diameter in the colchicine and colchicine + melatonin group was significantly lower than the control group (p=0.026). Bcl-2 levels of the colchicine group were lower than the control group and the melatonin group (p=0.021). CONCLUSION: Colchicine and melatonin reduce adhesion to the peritoneal surface in ectopic endometrial cells. It also acts by increasing apoptosis and decreasing cell survival.

Lung carcinogenicity by whole body inhalation exposure to Anatase-type Nano-titanium Dioxide in rats.

To investigate the carcinogenicity of anatase-type nano-titanium dioxide (aNTiO2), F344/DuCrlCrlj rats were exposed to aNTiO2 aerosol at concentrations of 0, 0.5, 2, and 8 mg/m3. The rats were divided into 2 groups: carcinogenicity study groups were exposed for two years, and satellite study groups were exposed for one year followed by recovery for 1 day, 26 weeks, and 52 weeks after the end of exposure. In the carcinogenicity groups, bronchiolo-alveolar carcinomas were observed in two 8 mg/m3-exposed males, showing an increasing trend by Peto's test. However, this incidence was at the upper limit of JBRC's historical control data. Bronchiolo-alveolar adenomas were observed in 1, 2, 3, and 4 rats of the 0, 0.5, 2, and 8 mg/m3-exposed females and were not statistically significant. However, the incidence in the 8 mg/m3-exposed females exceeded JBRC's historical control data. Therefore, we conclude there is equivocal evidence for the carcinogenicity of aNTiO2 in rats. No lung tumors were observed in the satellite groups. Particle-induced non-neoplastic lesions (alveolar epithelial hyperplasia and focal fibrosis) were observed in exposed males and females in both the carcinogenicity and satellite groups. Increased lung weight and neutrophils of bronchoalveolar lavage fluid were observed in the 8 mg/m3-exposed carcinogenicity groups. The aNTiO2 deposited in the lungs of the satellite group rats was decreased at 26 weeks after the end of exposure compared to 1 day after the end of exposure. At 52 weeks after the end of exposure, the decreased level was the same at 26 weeks after the end of exposure.

Modulation of sensory input to the spinal cord: Contribution of focal epidural polarization and of GABA released by interneurons and glial cells.

Modulation of input from primary afferent fibres has long been examined at the level of the first relays of these fibres. However, recent studies reveal that input to the spinal cord may also be modulated at the level of the very entry of afferent fibres to the spinal grey matter before action potentials in intraspinal collaterals of afferent fibres reach their target neurons. Such modulation greatly depends on the actions of GABA via extrasynaptic membrane receptors. In the reported study we hypothesized that the increase in excitability of afferent fibres following epidural polarization close to the site where collaterals of afferent fibres leave the dorsal columns is due to the release of GABA from two sources: not only GABAergic interneurons but also glial cells. We present evidence, primo, that GABA released from both these sources contributes to a long-lasting increase in the excitability and a shortening of the refractory period of epidurally stimulated afferent fibres and, secondo, that effects of epidural polarization on the release of GABA are more critical for these changes than direct effects of DC on the stimulated fibres. The experiments were carried out in deeply anaesthetized rats in which changes in compound action potentials evoked in hindlimb peripheral nerves by dorsal column stimulation were used as a measure of the excitability of afferent fibres. The study throws new light on the modulation of input to spinal networks but also on mechanisms underlying the restoration of spinal functions.

Hepatoprotective potential of taxifolin in type 2 diabetic rats: modulation of oxidative stress and Bcl2/Bax/Caspase-3 signaling pathway.

BACKGROUND: Diabetes mellitus (DM) is a global metabolic problem. Several factors including hyperglycemia, oxidative stress, and inflammation play significant roles in the development of DM complications. Apoptosis is also an essential event in DM pathophysiology, -with B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X (Bax) determining apoptotic susceptibility. The present study aimed to elucidate the protective effects of two doses of taxifolin (TXF) on liver damage in diabetic rats and explore the possible mechanisms of action. METHODS AND RESULTS: DM was induced in eighteen rats through intraperitoneal injections of 50 mg/kg streptozotocin and 110 mg/kg nicotinamide. Diabetic rats received daily oral intubation of 25 and 50 mg/kg TXF for 3 months. In the untreated diabetic group, there was a significant increase in fasting and postprandial glucose levels, glycosylated hemoglobin A1C (HbA1c), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6), while insulin and adiponectin levels decreased significantly. Both TXF doses mitigated hyperglycemia, regulated cytokine production, and increased insulin level. Gene expressions and protein levels of Bax, caspase 3, and cytochrome c were significantly increased, while Bcl-2 was significantly decreased in the livers of diabetic rats, effects that were significantly ameliorated after TXF treatment. The results of the TUNEL assay supported the apoptotic pathway. Additionally, TXF significantly decreased lipid peroxidation and enhanced antioxidant enzyme activity in diabetic rats. Liver enzymes and histopathological changes also showed improvement. CONCLUSIONS: TXF mitigated diabetes-associated hepatic damage by reducing hyperglycemia, oxidative stress, inflammation, and modulating anti-/pro-apoptotic genes and proteins. A dose of 50 mg/kg TXF was more effective than 25 mg/kg and is recommended for consumption.

Simultaneous estimation of paclitaxel and bortezomib via LC-MS/MS: pharmaceutical and pharmacokinetic applications.

Aim & Objective: This study evaluates the potential of combining paclitaxel (PTX) and bortezomib (BTZ) for breast cancer therapy. Materials & Methods: The nanoformulation was optimized via Box-Behnken Design (BBD), with method validation adhering to US-FDA guidelines. Results: Multiple reaction monitoring transitions for PTX, BTZ and internal standard were m/z 855.80→286.60, 366.80→226.00 and 179.80→110.00, respectively. Elution done on C18 Luna column with 0.1% FA in MeOH:10 mM ammonium acetate. The size of nanoformulation was 133.9 ± 1.97 nm, PDI 0.19 ± 0.01 and zeta potential -19.20 ± 1.36 mV. Pharmacokinetics showed higher Cmax for PTX-BTZ-NE (313.75 ± 10.71 ng/ml PTX, 11.92 ± 0.53 ng/ml BTZ) versus free PTX-BTZ (104 ± 13.06 ng/ml PTX, 1.9 ± 0.08 ng/ml BTZ). Conclusion: Future findings will contribute to the treatment of breast cancer using PTX and BTZ.

[Box: see text].

Efficacy of immune checkpoint inhibitors in advanced non-small cell lung cancer patients with rare KRAS mutations: a real-world retrospective study.

Background: Kirsten rat sarcoma homolog (KRAS) mutations are one of the key drivers in non-small cell lung cancer (NSCLC) and FDA-approved specific inhibitors of KRAS-G12C mutation are available clinically. However, inhibitors of certain KRAS mutation subtypes remain unavailable, especially rare KRAS mutations including G13C, G13D, and Q61H. In this study, we retrospectively investigated the outcomes of NSCLC patients with rare KRAS-mutation to determine if they may benefit from immune checkpoint inhibitors (ICIs). Methods: Our retrospective study involved 240 advanced NSCLC patients with KRAS mutations, who visited Shanghai Chest Hospital from July 2018 to July 2021. Complete clinical and pathological data were recorded and progression-free survival (PFS) and overall survival (OS) were adopted as primary endpoints. Results: The median follow-up time was 36.5 months (range, 30.8-42.1 months) and the median OS was 9.7 months (range, 7.6-11.8 months). Of the 240 patients evaluated, 130 (54.2%) received chemotherapy and 110 (45.8%) received ICI-based treatment. Among the patients who received chemotherapy, patients with rare KRAS-mutations presented worse survival outcomes (median PFS, 3.4 vs. 4.1 months, P=0.047; median OS, 5.2 vs. 7.1 months, P=0.02) than conventional KRAS-mutant patients. PFS and OS of rare KRAS-mutation patients were prolonged after immunotherapy (median PFS 7.3 vs. 3.4 months, P<0.001; median OS, 13.3 vs. 5.2 months, P<0.001) and had no significant difference compared with conventional KRAS-mutant patients, in part of them whose programmed death-ligand 1 (PD-L1) expression data before immunotherapy were available (n=72), patients with a higher rate of PD-L1 positive tumor cells (≥50%) presented elevated PFS and OS. Conclusions: Despite having potential survival disadvantage compared with other NSCLC patients, rare KRAS-mutant patients (other than G12A, C, D, V) could benefit specifically from ICI-based therapy and survival outcomes are correlated with PD-L1 expression.

Comparative study on corneal epithelium healing: effects of crosslinked hyaluronic acid and amniotic membrane extract eye drops in rats.

Introduction: Corneal ulcers are common lesions in both human and veterinary medicine. However, only a few studies have evaluated the efficacy of cross-linked hyaluronic acid (X-HA) eye drops on corneal wound healing. To our knowledge, this is the first study to demonstrate and compare the efficacy of amniotic membrane extract eye drops (AMEED) and X-HA for corneal wound healing in rats. Material and methods: A total of 15 male Wistar rats (30 eyes) were used in this study. Then, 10 eyes were treated with X-HA, AMEED, or 0.9% saline. After general and topical anesthesia, a superficial corneal ulcer was created using a corneal trephine. The defect was further polished with a diamond burr. Three groups of 10 eyes each were treated with either one drop of 0.75% X-HA or AMEED or 0.9% saline (control), administered every 12 h for a duration of 72 h. The median epithelial defect area (MEDA), expressed as a percentage of the total corneal surface, was measured at 0, 12, 24, 36, 48, and 72 h. Re-epithelization time scores were also evaluated. The Kruskal-Wallis test was used to compare median times for re-epithelization and histopathologic scores between groups, while the Friedman test (for paired data) was employed to compare results from the serial analysis of MEDA and vascularization scores between groups. Results: MEDA was not significantly different between X-HA and AMEED. However, MEDA was significantly smaller in the X-HA group compared to the control group at 36 h (2.73 interquartile range (IQR) 5.52% x 9.95 IQR 9.10%, P=0.024) and 48 h (0.00 IQR 0.26% x 6.30 IQR 8.54%, P=0.030). The overall time for re-epithelization was significantly lower in the X-HA group (3.00 IQR 3.00) compared to the AMEED (6.5 IQR 3.00) and control (7.00 IQR 1.00) groups (P=0.035). Vascularization, hydropic degeneration, and epithelial-stromal separation were significantly less observed in samples in the X-HA-treated compared to samples in the AMEED- and saline-treated groups. Significantly more corneal epithelium cells were labeled for caspase3 in samples from the AMEED- and saline-treated groups compared to those from the X-HA-treated group. Discussion: Topical X-HA has been shown to accelerate corneal epithelial healing. AMEED did not decrease corneal re-epithelialization time. X-HA may also potentially be used as an adjunct therapy for treating corneal ulcers in clinical situations.

Velocity of cerebrospinal fluid in the aqueduct measured by phase-contrast MRI in rat.

Cerebrospinal fluid (CSF) circulation plays a key role in cerebral waste clearance via the glymphatic system. Although CSF flow velocity is an essential component of CSF dynamics, it has not been sufficiently characterized, and particularly, in studies of the glymphatic system in rat. To investigate the relationship between the flow velocity of CSF in the brain aqueduct and the glymphatic waste clearance rate, using phase-contrast MRI we performed the first measurements of CSF velocity in rats. Phase-contrast MRI was performed using a 7 T system to map mean velocity of CSF flow in the aqueduct in rat brain. The effects of age (3 months old versus 18 months old), gender, strain (Wistar, RNU, Dark Agouti), anesthetic agents (isoflurane versus dexmedetomidine), and neurodegenerative disorder (Alzheimer' disease in Fischer TgF344-AD rats, males and females) on CSF velocity were investigated in eight independent groups of rats (12 rats per group). Our results demonstrated that quantitative velocities of CSF flow in the aqueduct averaged 5.16 ± 0.86 mm/s in healthy young adult male Wistar rats. CSF flow velocity in the aqueduct was not altered by rat gender, strain, and the employed anesthetic agents in all rats, also age in the female rats. However, aged (18 months) Wistar male rats exhibited significantly reduced the CSF flow velocity in the aqueduct (4.31 ± 1.08 mm/s). In addition, Alzheimer's disease further reduced the CSF flow velocity in the aqueduct of male and female rats.

Functional involvement of the sternohyoid muscle during breathing and swallowing in rats.

The sternohyoid muscle depresses the hyoid bone, but it is unclear whether the muscle contributes to respiratory and swallowing mechanisms. This study aimed to clarify whether the sternohyoid muscle participates in the respiration and swallowing reflex and how the activity is modulated in two conditions: with airway stenosis and with a fixed sternohyoid muscle length. Electromyographic activity in the sternohyoid, digastric, thyrohyoid, and diaphragm muscles was recorded in anesthetized rats. The sternohyoid muscle activity was observed in the inspiratory phase and during swallowing, and was well coordinated with digastric and thyrohyoid muscle activity. With airway stenosis, the respiratory activity per respiratory cycle was facilitated in all assessed muscles but the facilitation of activity per second occurred only in the digastric, thyrohyoid, and sternohyoid muscles. With airway stenosis, the swallowing activity was facilitated only in the digastric muscle but not in the thyrohyoid and sternohyoid muscles. Swallowing activity was not observed in the sternohyoid muscle in the condition with the sternohyoid muscle length fixed, although increased inspiratory activity remained. The current results suggest that (1) the sternohyoid muscle is slightly activated in the inspiratory phase, (2) the effect of airway stenosis on respiratory function may differ between the upper airway muscles and diaphragm, and (3) swallowing activity in the sternohyoid muscle is not dominantly controlled by the swallowing central pattern generator but instead occurs as a myotatic reflex.