Recent trends in preparation and biomedical applications of iron oxide nanoparticles.

The iron oxide nanoparticles (IONPs), possessing both magnetic behavior and semiconductor property, have been extensively used in multifunctional biomedical fields due to their biocompatible, biodegradable and low toxicity, such as anticancer, antibacterial, cell labelling activities. Nevertheless, there are few IONPs in clinical use at present. Some IONPs approved for clinical use have been withdrawn due to insufficient understanding of its biomedical applications. Therefore, a systematic summary of IONPs' preparation and biomedical applications is crucial for the next step of entering clinical practice from experimental stage. This review summarized the existing research in the past decade on the biological interaction of IONPs with animal/cells models, and their clinical applications in human. This review aims to provide cutting-edge knowledge involved with IONPs' biological effects in vivo and in vitro, and improve their smarter design and application in biomedical research and clinic trials.

Identification of antimalarial targets of chloroquine by a combined deconvolution strategy of ABPP and MS-CETSA.

BACKGROUND: Malaria is a devastating infectious disease that disproportionally threatens hundreds of millions of people in developing countries. In the history of anti-malaria campaign, chloroquine (CQ) has played an indispensable role, however, its mechanism of action (MoA) is not fully understood. METHODS: We used the principle of photo-affinity labeling and click chemistry-based functionalization in the design of a CQ probe and developed a combined deconvolution strategy of activity-based protein profiling (ABPP) and mass spectrometry-coupled cellular thermal shift assay (MS-CETSA) that identified the protein targets of CQ in an unbiased manner in this study. The interactions between CQ and these identified potential protein hits were confirmed by biophysical and enzymatic assays. RESULTS: We developed a novel clickable, photo-affinity chloroquine analog probe (CQP) which retains the antimalarial activity in the nanomole range, and identified a total of 40 proteins that specifically interacted and photo-crosslinked with CQP which was inhibited in the presence of excess CQ. Using MS-CETSA, we identified 83 candidate interacting proteins out of a total of 3375 measured parasite proteins. At the same time, we identified 8 proteins as the most potential hits which were commonly identified by both methods. CONCLUSIONS: We found that CQ could disrupt glycolysis and energy metabolism of malarial parasites through direct binding with some of the key enzymes, a new mechanism that is different from its well-known inhibitory effect of hemozoin formation. This is the first report of identifying CQ antimalarial targets by a parallel usage of labeled (ABPP) and label-free (MS-CETSA) methods.

A Modified Approach with Caval Transection for Supracardiac Total Anomalous Pulmonary Venous Connection: Comparison Between Conventional and Sutureless Surgery in 173 Patients.

The efficacy of primary sutureless repair for supracardiac total anomalous pulmonary venous connection (TAPVC) needs to be confirmed. This study aimed to compare the long-term outcomes between the conventional surgery and the sutureless technique with a modified approach in superior TAPVC. Between January 2008 and December 2018, 173 patients with supracardiac TAPVC underwent surgery either with the conventional procedure (n = 130) or the sutureless repair (n = 43). Multivariate analysis and competing-risk analysis were used to identify risk factors for early death and postoperative pulmonary venous obstruction (PVO), respectively. Among 173 patients who underwent repair of supracardiac TAPVC, 46 (28%) had preoperative PVO, and 22 (12.7%) had postoperative PVO. The sutureless group had a lower postoperative PVO rate compared with the conventional group (p = 0.027). The risk factors for death were age ≤ 28 days [odds ratio (OR), 11.56; 95% confidence interval (CI) 1.33-100.47, p = 0.015], weight ≤ 3 kg (OR 9.57; 95% CI 1.58-58.09, p = 0.009), emergency operation (OR 19.24; 95% CI 3.18-116.35, p = 0.002), cardiopulmonary bypass time (OR 2.16; 95% CI 1.36-3.43, p = 0.003), cross-clamp time (OR 1.73; 95% CI 1.20-2.50, p = 0.022), and duration of ventilation (OR 1.11; 95% CI 1.02-1.21, p = 0.027). Age ≤ 28 days [Hazard Ratio (HR) 1.92; 95% CI 1.92-11.02, p < 0.001] and preoperative PVO (HR 41.70; 95% CI 8.15-213.5, p < 0.001) were associated with postoperative PVO. The sutureless repair is a reliable technique for supracardiac TAPVC. Age ≤ 28 days is associated with 30-day mortality and postoperative PVO.

Latent pseudorabies virus infection in medulla oblongata from quarantined pigs.

Pseudorabies virus (PRV) is a major pathogen in pig husbandry and is also a risk to human well-being. Pigs with latent PRV infection carry the virus lifelong, and it can be activated under conducive conditions. This poses a very important challenge to the control of the virus and may even prevent its elimination. To investigate latent infection with wild-type (wt) PRV, and also infection due to the use of live attenuated vaccines on farms, 80 pigs from two large-scale swine operations were traced. At 6 months old, the quarantined pigs were slaughtered and brain samples were collected. A PCR assay targeting the gB and gE genes was developed to detect PRV DNA fragments in medulla oblongata. Five of the samples (6.3%) were gB and gE gene fragment double-positive, 60 of the samples (75%) were gB single-positive, and 15 samples (18.7%) showed double-negative. A portion of latency-associated transcripts (LATs), EP0 mRNA, were found to be present in the gB gene fragment positive samples. Furthermore, the five double-positive samples were transmitted blindly, and apparent cytopathic effects were found in three of the five samples in the fourth generation. By means of Western blotting, PCR and sequencing, two of the isolated viruses were found to be related to vaccine strain Bartha-K61. Another was closely related to domestic epidemic strains HN1201 and LA and relatively unrelated to other Asian isolates. These results suggest that the live vaccines are latently present in brains, in a manner similar to wt PRV, and this poses potential safety issues in the pig husbandry industry. Wt PRV and live vaccine viruses were found to co-exist in pigs, demonstrating that the live vaccines were unable to confer complete sterilizing immunity, which may explain outbreaks of pseudorabies on vaccinated farms.

High serum lactate dehydrogenase and dyspnea: Positive predictors of adverse outcome in critical COVID-19 patients in Yichang.

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak in China, constitutes a Public Health Emergency of International Concern. It is well known that COVID-19 patients may have increased serum lactate dehydrogenase (LDH) levels in the early stage. The clinical changes in LDH may have predictive value in disease evolution and prognosis in critically ill COVID-19 patients. AIM: To examine serum LDH and clinical characteristics in patients with COVID-19 and their predictive value for prognosis. METHODS: This retrospective study analyzed the clinical data of forty-seven critical COVID-19 patients in the intensive care unit of the Third People's Hospital of Yichang City from January 27 to March 25, 2020 and divided them into survivors and non-survivors. The patients were diagnosed according to the World Health Organization interim guidance and critical cases met any one of the following criteria: Respiratory failure and required mechanical ventilation, the occurrence of shock, and the combined failure of other organs that required intensive care unit monitoring and treatments, according to the diagnostic criteria of critical COVID-19. Clinical data including symptoms, detection of SARS-CoV-2, chest computed tomography (CT) images, changes in serum LDH in different clinical phases, and prognosis were collected. Statistical analysis of the data was performed. Continuous variables were expressed as median (interquartile range) and compared with the Mann-Whitney U test. Categorical variables were compared with the Chi-square test. Survival data were analyzed using Kaplan-Meier survival curves and log-rank tests. RESULTS: According to chest CT images, we observed the alveolitis and fibrosis stages in all critical patients in this study. Most non-survivors died in the fibrosis stage. Non-survivors had fewer days of hospitalization, shorter disease duration, shorter duration of alveolitis and fibrosis, and had dyspnea symptoms at disease onset (P = 0.05). Both first and lowest LDH values in the alveolitis stage were more pronounced in non-survivors than in survivors (449.0 U/L vs 288.0 U/L, P = 0.0243; 445.0 U/L vs 288.0 U/L, P = 0.0199, respectively), while the first, lowest and highest values of serum LDH in non-survivors were all significantly increased compared to survivors in the fibrosis phase (449.0 U/L vs 225.5 U/L, P = 0.0028; 432.0 U/L vs 191.0 U/L, P = 0.0007; 1303.0 U/L vs 263.5 U/L, P = 0.0001, respectively). The cut-off points of first LDH values in the alveolitis and fibrosis phase for distinction of non-survivors from survivors were 397.0 U/L and 263.0 U/L, respectively. In the fibrosis stage, non-survivors had more days with high LDH than survivors (7.0 d vs 0.0 d, P = 0.0002). Importantly, patients with high LDH had a significantly shorter median survival time than patients with low LDH in the alveolitis phase (22.0 d vs 36.5 d, P = 0.0002), while patients with high LDH also had a significantly shorter median survival time than patients with low LDH in the fibrosis phase (27.5 d vs 40.0 d, P = 0.0008). The proportion of non-survivors with detectable SARS-CoV-2 until death in the alveolitis stage was significantly increased compared with that in the fibrosis stage (100% vs 35.7%, P = 0.0220). CONCLUSION: High LDH and dyspnea symptoms were positive predictors of an adverse outcome in critical COVID-19. The rapid progressive fibrosis stage was more perilous than the alveolitis stage, even if SARS-CoV-2 is undetectable.

Carnosine ameliorates morphine-induced conditioned place preference in rats.

The histidine-containing dipeptide, carnosine (beta-alanyl-L-histidine), is present in high concentrations in mammalian brain of mammals. There are many theories about its biological functions, such as anti-inflammatory agent, free radical scavenger, and protein glycosylation inhibitor, however, the role of carnosine in morphine addiction is less understood. Therefore, the objectives of this study were to determine the effects of carnosine on the development of morphine-induced conditioned place preference (CPP) and investigate its possible mechanism of action in Sprague-Dawley rats. Intraperitioneal (i.p.) injection of carnosine (200, 500, 1000 mg/kg) significantly inhibited the development of morphine-induced CPP in a dose-dependent manner. Although carnosine had no appreciable effect on the levels of histamine in the ventral tegmental area (VTA), nucleus accumbens (NAc) and prefrontal cortex (PFC), it significantly decreased glutamate level in the VTA, dopamine levels in the NAc and PFC, and DOPAC level in the NAc of morphine-treated rats. These results indicate that carnosine inhibits morphine-induced CPP in rats, and its action may be due to modulation of dopaminergic and glutaminergic activity. The study suggests that carnosine has potential as a new anti-addictive drug.

Proteomic analysis of rat prefrontal cortex in three phases of morphine-induced conditioned place preference.

Morphological alterations of synapse are found after morphine administration, suggesting that regulation of synaptic plasticity may be one of the mechanisms of neuroadaptation in addiction. However, the molecular basis underlying the abnormal synapse morphological and physiological changes in the morphine-induced dependence, withdraw, and relapse is not well understood. As prefrontal cortex (PFC) is one of the most important brain regions, which provides executive control over drug use and is severely impaired in many addicts, systematic analysis of the biochemical and molecular alteration of synaptic fraction of PFC in morphine-induced neuroadaptation is necessary. In this study, differential protein expression profiling of synaptic fraction of rat PFC based on morphine-induced conditioned place preference (CPP) model was performed with two-dimensional gel electrophoresis (2-DE). Our results showed that a total of 80 proteins were differentially expressed by 2-DE analysis during three phases of CPP assay. Of them, 58 were further identified by mass spectrometry. These proteins were classified into multiple categories, such as energy metabolism, signal transduction, synaptic transmission, cytoskeletal proteins, chaperones, and local synaptic protein synthetic machinery according to their biological functions. Our study provides a global view of synaptic-related molecular networking in PFC under morphine-induced dependence, withdraw, and relapse, indicative of a concerted biological process in neuroadaptation under chronic morphine exposure.

[Advances in study of structures and functions of conantokins].

Conantokin is a distinct family of conotoxin superfamily. Its members share considerable overall sequence homology. Their defining attributes include a high relative content of gamma-carboxyglutamic acid (Gla). They are generally devoid of disufide-loop contrasted with other conotoxins (except for conantokin-R). Upon binding to metal ions, the content of alpha-helix conformation increases in different degrees. They inhibit NMDA (N-methyl-D-aspartate) receptors; moreover, different conantokin species present different NMDA receptor subunit specificity. It can induce sleep-like symptoms in young mice when delivered intracranially. Analysis of sequences and structures indicates that the high conserved residues of these peptides are determinative in their structures and functions. In this article, the relationships of their structures and functions are reviewed in detail.

Endogenous histamine inhibits the development of morphine-induced conditioned place preference.

AIM: The conditioned place preference (CPP) paradigm was used to investigate the effects of endogenous histamine on the processes leading to morphine-induced reward-seeking behavior in Sprague-Dawley rats. METHODS: The model of CPP was used to assess the rewarding effect of morphine. The levels of histamine, glutamate, gamma-aminobutyric acid (GABA), dopamine (DA) and 3, 4-dihydroxyphenylacetic acid (DOPAC) in rat brains were measured with high-performance liquid chromatography. Immunohistochemistry technique was used to observe the morphological changes of neurons. RESULTS: Intraperitoneal injection of morphine (2, 5 or 10 mg/kg) induced the development of CPP in a dose-dependent manner. In addition, morphine administrations (10 mg/kg) decreased the histamine content and reduced the number and size of histaminergic neurons in the tubero-mammillary nucleus (TM), as well as markedly increasing the DOPAC/DA ratios in the ventral tegmental area (VTA) and nucleus accumbens (NAc). Intraperitoneal injection of histidine (50, 100 or 200 mg/kg) dose-dependently inhibited the development of morphine-induced CPP. Bilateral lesions of the TM, which decreased the histamine levels in the VTA and NAc, potentiated the development of CPP induced by morphine (1 mg/kg, a dose that produced no appreciable effect when given alone) and increased the DOPAC/DA ratios in the VTA and NAc, but did not change the glutamate or GABA levels in these nuclei. Histidine reversed the effects of the TM lesions. CONCLUSION: These results indicate that endogenous histamine plays a role in inhibiting the development of morphine-induced reward-seeking behavior, and the inhibition may involve the modulation of dopaminergic activity.

Effect of glycine site/NMDA receptor antagonist MRZ2/576 on the conditioned place preference and locomotor activity induced by morphine in mice.

OBJECTIVE: To study the effect of glycine site/NMDA (N-methyl-D-aspartate) receptor antagonist MRZ2/576 on the conditioned place preference (CPP) and locomotor activity induced by morphine in mice. METHODS: Different doses (1.25, 2.5 and 5 mg/kg, i.p.) of MRZ2/576 were used to evaluate the effect of MRZ2/576 on the acquisition and expression of CPP induced by morphine (5 mg/kg) in mice. In addition, we examined the locomotor activity of mice in conditioning and testing phase of CPP paradigm. RESULTS: MRZ2/576 alone could not establish place preference, but a 5 mg/kg dose of MRZ2/576 could block both acquisition and expression of morphine-induced CPP. In testing phase of CPP, there was no statistical difference for locomotor activity between the groups; injection of MRZ2/576 showed a dose-dependent decrease of locomotor activity on both control and morphine-treated mice, especially 5 mg/kg of MRZ2/576 significantly suppressed the locomotor activity of mice. CONCLUSION: Based on the present results, we assume that MRZ2/576 can antagonize the rewarding effect of morphine, suggesting that this glycine site/NMDA receptor antagonist could be used to treat addictions due to its light side effect profile.

Chronic morphine drinking establishes morphine tolerance, but not addiction in Wistar rats.

OBJECTIVE: Some animal models apply morphine in the drinking water to generate addiction, but related reports are not free of conflicting results. Accordingly, this study aimed to figure out if chronic consumption of morphine in the drinking water can induce morphine addiction in Wistar rats. METHODS: For 3 weeks, the animals received a daily morphine dose of 35 mg/kg by offering a calculated volume of sugar water (5% sucrose) with morphine (0.1 mg/ml) to each rat; animals receiving just sugar water served as controls. Immediately after the treatment phase, the tail immersion test was used to check for morphine tolerance, and all animals were then kept on tap water for one week (withdrawal phase). Afterwards, all rats were allowed to choose their drinking source by offering two bottles, containing sugar water without and with morphine, simultaneously for two days (preference phase). RESULTS: While the chronic consumption of morphine led to a reduction in body weight and to morphine tolerance, the morphine-treated Wistar rats did not show any preference for the opiate-containing sugar water. CONCLUSION: Body weight loss and tolerance do not reveal a condition of drug craving, and current animal models should be re-evaluated regarding their potential to establish morphine addicted animals.

Changes of CREB in rat hippocampus, prefrontal cortex and nucleus accumbens during three phases of morphine induced conditioned place preference in rats.

OBJECTIVE: To investigate the changes in CREB (cAMP response element binding protein) in hippocampus, PFC (prefrontal cortex) and NAc (nucleus accumbens) during three phases of morphine induced CPP (conditioned place preference) in rats, and to elucidate the role of CREB during the progress of conditioned place preference. METHODS: Morphine induced CPP acquisition, extinction and drug primed reinstatement model was established, and CREB expression in each brain area was measured by Western Blot methods. RESULTS: Eight alternating injections of morphine (10 mg/kg) induced CPP, and 8 d saline extinction training that extinguished CPP. CPP was reinstated following a priming injection of morphine (2.5 mg/kg). During the phases of CPP acquisition and reinstatement, the level of CREB expression was significantly changed in different brain areas. CONCLUSION: It was proved that CPP model can be used as an effective tool to investigate the mechanisms underlying drug-induced reinstatement of drug seeking after extinction, and that morphine induced CPP and drug primed reinstatement may involve activation of the transcription factor CREB in several brain areas, suggesting that the CREB and its target gene regulation pathway may mediate the basic mechanism underlying opioid dependence and its drug seeking behavior.

[Establishment of computer-based video-tracking conditioned place preference experiment system in mice].

OBJECTIVE: To establish the computer-based video-tracking conditioned place preference (CPP) system in mice. METHODS: The CPP system was composed of computer, camera, soundproof box, shuttle box and analytical software. The results of morphine-induced conditioned place preference were used to evaluate the experiment system. And the effect of morphine-induced locomotor activity in drug-paired compartment was studied in mice. RESULTS: Low (1 mg/kg, i.p.), moderate (3 mg/kg, 5 mg/kg, i.p.) and high (10 mg/kg, i.p.) dose of morphine significantly prolonged the time mice spent in drug-paired compartment compared with saline, but there was no dose-response relation. Moderate and high dose of morphine significantly enhanced locomotor activity, among which 5 mg/kg and 10 mg/kg morphine induced behavior sensitization in drug-paired compartment during the conditioning sessions. CONCLUSION: The computer-based video-tracking conditioned place preference experiment system in mice established successfully is reliable and stable.