[A case report of bronchial granular cell tumor]

Granular cell tumor (GCT) is a relatively rare tumor that develops in soft tissues at various sites in the body, and GCT originating in the bronchus is rather rare. Here, we reported a case of primary GCT of the bronchial to improve the understanding of this disease.

DL-3-n-butylphthalide improves the endothelium-dependent vasodilation in high-fat diet-fed ApoE-/- mice via suppressing inflammation, endothelial necroptosis and apoptosis

Impaired endothelium-dependent vasodilation in atherosclerosis is a high-risk factor for myocardial infarction and ischemic stroke, and inflammation, necroptosis and apoptosis contribute to endothelial dysfunction in atherosclerosis. Although DL-3-n-butylphthalide (NBP) has been widely used in treating ischemic stroke, its effect on endothelium-dependent vasodilation remains unknown. This study aims to explore whether NBP is able to improve endothelium-dependent vasodilation in atherosclerosis and the underlying mechanisms. Male ApoE-/- mice were fed with a high-fat diet (HFD) for 9-16 weeks to establish a model of atherosclerosis. NBP were given to the mice after eating HFD for 6 weeks and atorvastatin served as a positive control. The endothelium-dependent vasodilation, the blood flow velocity, the atherosclerotic lesion area, the serum levels of lipids, inflammatory cytokines and necroptosis-relevant proteins (RIPK1, RIPK3 and MLKL), and the endothelial necroptosis and apoptosis within the aorta were measured. Human umbilical vein endothelial cells (HUVECs) were incubated with oxidized low-density lipoprotein (ox-LDL) for 48 h to mimic endothelial injury in atherosclerosis, lactate dehydrogenase release, the ratio of necroptosis and apoptosis and the expression of necroptosis-relevant proteins were examined. Similar to atorvastatin, NBP improves endothelium-dependent vasodilation, decreases aortic flow velocity and reduces atherosclerotic lesion area in HFD-fed ApoE-/- mice, concomitant with a reduction in serum lipids, inflammatory cytokines and necroptosis-relevant proteins, and endothelial necroptosis and apoptosis. Consistently, NBP inhibited necroptosis and apoptosis in ox-LDL-treated HUVECs. Based on these observations, we conclude that NBP exerts beneficial effects on improving the endothelium-dependent vasodilation in atherosclerosis via suppressing inflammation, endothelial necroptosis and apoptosis.

[Effects of advanced platelet-rich fibrin on deep partial-thickness burn wounds in nude mice]

Objective: To explore the effects of advanced platelet-rich fibrin (A-PRF) on deep partial-thickness burn wounds in nude mice and its mechanism. Methods: The experimental study method was adopted. Forty healthy volunteers in Subei People's Hospital were recruited, including 32 females and 8 males, aged 60 to 72 years. Leukocyte platelet-rich fibrin (L-PRF) and A-PRF membranes were prepared after venous blood was extracted from them. The microstructure of two kinds of platelet-rich fibrin (PRF) membranes was observed by field emission scanning electron microscope. The number of samples was 3 in the following experiments. The L-PRF and A-PRF membranes were divided into L-PRF group and A-PRF group and cultured, and then the release concentrations of platelet-derived growth factor-AB (PDGF-AB) and vascular endothelial growth factor (VEGF) in culture supernatant were determined by enzyme-linked immunosorbent assay on culture day 1, 3, 7, and 14. Mice L929 fibroblasts (Fbs) were divided into L-PRF group and A-PRF group, and cultured with L-PRF or A-PRF conditioned medium, respectively. On culture day 1, 3, and 7, the cell proliferation activity was detected by thiazole blue method. The cell migration rate was detected and calculated at 24 h after scratching by scratch test. Thirty-six male BALB/c nude mice aged 6-8 weeks were selected to make a deep partial-thickness burn wound on one hind leg, and then divided into normal saline group, L-PRF group, and A-PRF group, according to the random number table, with 12 mice in each group. The wounds of nude mice in normal saline group were only washed by normal saline, while the wounds of nude mice in L-PRF group and A-PRF group were covered with the corresponding membranes in addition. The wounds of nude mice in the 3 groups were all bandaged and fixed with dressings. On treatment day 4, 7, and 14, the wound healing was observed and the wound healing rate was calculated. Masson staining was used to observe the new collagen in wound tissue, and immunohistochemical staining was used to detect the percentage of CD31 positive cells in the wound. Data were statistically analyzed with independent sample t test, analysis of variance for repeated measurement, analysis of variance for factorial design, one-way analysis of variance, and least significant difference test. Results: L-PRF membrane's dense network structure was composed of coarse fibrin bundles, with scattered white blood cells and platelets with complete morphology. A-PRF membrane's loose network structure was composed of fine fibrin bundles, with scattered small amount of deformed white blood cells and platelets. On culture day 1, the release concentration of PDGF-AB in PRF culture supernatant in A-PRF group was significantly higher than that in L-PRF group (t=5.73, P<0.05), while the release concentrations of VEGF in PRF culture supernatant in the two groups were similar (P>0.05). On culture day 3, 7, and 14, the release concentrations of PDGF-AB and VEGF in PRF culture supernatant in A-PRF group were significantly higher than those in L-PRF group (with t values of 6.93, 7.45, 5.49, 6.97, 8.97, and 13.64, respectively, P<0.05). On culture day 3, 7, and 14, the release concentrations of PDGF-AB and VEGF in PRF culture supernatant in the two groups were all significantly higher than those in the previous time points within the group (P<0.05). On culture day 1, 3, and 7, the proliferation activity of mice Fbs in A-PRF group was 0.293±0.034, 0.582±0.054, and 0.775±0.040, respectively, which were significantly stronger than 0.117±0.013, 0.390±0.036, and 0.581±0.037 in L-PRF group (with t values of 8.38, 5.14, and 6.16, respectively, P<0.05). At 24 h after scratching, the migration rate of mice Fbs in A-PRF group was (60.9±2.2)%, which was significantly higher than (39.1±2.3)% in L-PRF group (t=11.74, P<0.05). On treatment day 4, the wound exudates of nude mice in L-PRF group and A-PRF group were less with no obvious signs of infection, while the wounds of nude mice in normal saline group showed more exudation. On treatment day 7, the wounds of nude mice in L-PRF group and A-PRF group were dry and crusted, while there was still a small amount of exudate in the wounds of nude mice in normal saline group. On treatment day 14, the wounds of nude mice in A-PRF group tended to heal; a small portion of wounds remained in nude mice in L-PRF group; the wound of nude mice was still covered with eschar in normal saline group. On treatment day 4, 7, and 14, the wound healing rate and percentage of CD31 positive cells of nude mice in L-PRF group were all significantly higher than those in normal saline group (P<0.05); compared with those in normal saline group and L-PRF group, the wound healing rate of nude mice in A-PRF group was significantly increased (P<0.05), the newborn collagen was orderly and evenly distributed, with no excessive deposition, and the percentage of CD31 positive cells was significantly increased (P<0.05). Conclusions: The stable fibrin network structure of A-PRF can maintain the sustained release of growth factors, accelerate cell proliferation, and promote cell migration, so as to shorten the healing time and improve the healing quality of deep partial-thickness burn wounds in nude mice.

Inhibition of MALT1 reduces ferroptosis in rat hearts following ischemia/reperfusion via enhancing the Nrf2/SLC7A11 pathway

The dysregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and/or solute carrier family 7 member 11 (SLC7A11) is believed to contribute to ferroptosis in the hearts suffered ischemia/reperfusion (I/R), but the mechanisms behind the dysregulation of them are not fully elucidated. Mucosa associated lymphoid tissue lymphoma translocation gene 1 (MALT1) can function as a paracaspase to cleave specified substrates and it is predicted to interact with Nrf2. This study aims to explore whether targeting MALT1 can reduce I/R-induced ferroptosis via enhancing the Nrf2/SLC7A11 pathway. The SD rat hearts were subjected to 1h-ischemia plus 3h-reperfusion to establish the I/R injury model, which showed myocardial injuries (increase in infarct size and creatine kinase release) and up-regulation of MALT1 while downregulation of Nrf2 and SLC7A11 concomitant with the increased ferroptosis, reflecting by an increase in glutathione peroxidase 4 (GPX4) level while decreases in the levels of acyl-CoA synthetase long chain family member 4 (ACSL4), total iron, Fe2+ and lipid peroxidation (LPO); these phenomena were reversed in the presence of MI-2, a specific inhibitor of MALT1. Consistently, similar results were achieved in the cultured cardiomyocytes subjected to 8h-hypoxia plus 12h-reoxygenation. Furthermore, micafungin, an antifungal drug, could also exert beneficial effect on mitigating myocardial I/R injury via inhibition of MALT1. Based on these observations, we concluded that inhibition of MALT1 can reduce I/R-induced myocardial ferroptosis through enhancing the Nrf2/SLC7A11 pathway; and MALT1 might be used as a potential target to seek novel or existing drugs (such as micafungin) for treating myocardial infarction.

The SPATA2/CYLD pathway contributes to doxorubicin-induced cardiomyocyte ferroptosis via enhancing ferritinophagy

Ferroptosis is an iron-dependent cell death and contributes to doxorubicin-induced cardiotoxicity, but the mechanisms behind intracellular iron overload in cardiomyocyte after administration of doxorubicin remain largely unknown. Ferritinophagy is a selective type of autophagy and could be a novel source for intracellular free iron. Spermatogenesis-associated protein 2 (SPATA2), a member of the TNF signaling pathway, can recruit cylindromatosis (CYLD, a deubiquitinating enzyme) to regulate cell death. This study aims to explore whether ferritinophagy is the source for intracellular iron overload in cardiomyocyte upon doxorubicin treatment and whether the SPATA2/CYLD pathway is involved in regulation of nuclear receptor coactivator 4 (NCOA4) level, the selective cargo receptor for ferritinophagy. The C57BL/6J mice were subjected to a single injection of doxorubicin, which showed the compromised cardiac functions, accompanied by the upregulation of SPATA2 and CYLD and the enhanced interaction between them, the increases in ferritinophagy (reflecting by increases in NCOA4 and ratio of LC3Ⅱ/LC3Ⅰ while decreases in NCOA4 ubiquitination and ferritin) and ferroptosis (reflecting by intracellular iron overload and increase of acyl-CoA synthetase long chain family member 4). Consistently, similar results were achieved in the cultured cardiomyocytes after incubation with doxorubicin. Knocked down of SPATA2 notably reduced doxorubicin-induced cardiomyocyte injury concomitant with the attenuated ferritinophagy and the decreased ferroptosis. Based on these observations, we conclude that a novel pathway of SPATA2/CYLD has been identified, which contributes to doxorubicin-induced cardiomyocyte ferroptosis via enhancing ferritinophagy through a mechanism involving the deubiquitination of NCOA4.

Combination of ponatinib with deferoxamine synergistically mitigates ischemic heart injury via simultaneous prevention of necroptosis and ferroptosis

Necroptosis, ferroptosis and cyclophilin D (Cyp D)-dependent necrosis contribute to myocardial ischemia/reperfusion (I/R) injury, and ponatinib, deferoxamine and cyclosporine are reported to inhibit necroptosis, ferroptosis and Cyp D-dependent necrosis, respectively. This study aims to explore whether the any two combination between ponatinib, deferoxamine and cyclosporine exerts a better cardioprotective effect on I/R injury than single medicine does. The H9c2 cells were subjected to 10 h of hypoxia (H) plus 4 h of reoxygenation (R) to establish H/R injury model. The effects of any two combination between ponatinib, deferoxamine and cyclosporine on H/R injury were examined. On this basis, a I/R injury model in rat hearts was established to focus on the effect of ponatinib, deferoxamine and their combination on myocardial I/R injury and the underlying mechanisms. In H/R-treated H9c2 cells, all three medicines can attenuate H/R injury (decrease in LDH release and necrosis percent). However, only the combination of ponatinib with deferoxamine exerted synergistic effect on reducing H/R injury, showing simultaneous suppression of necroptosis and ferroptosis. Expectedly, administration of ponatinib or deferoxamine either before or after ischemia could suppress necroptosis or ferroptosis in the I/R-treated rat hearts as they did in vitro, concomitant with a decrease in myocardial infarct size and creatine kinase release, and the combination therapy is more efficient than single medication. Based on these observations, we conclude that the combination of ponatinib with deferoxamine reduces myocardial I/R injury via simultaneous inhibition of necroptosis and ferroptosis.

[Research advances on mechanism of exosomes derived from adipose derived stem cells in the treatment of chronic wounds]

Exosomes are a kind of membrane vesicle with a diameter of 30-150 nm. It is formed by the budding of multiple vesicles in cells, which can fuse with the cell membrane and be released into the extracellular matrix. Adipose derived stem cells (ADSCs) have the potential of self-renewal and multi-directional differentiation. They can transport the active substance, regulate the inflammatory response, cell migration, proliferation, differentiation and angiogenesis via the action of paracrine exosomes, so as to enhance the ability of wound repair, promote wound healing, and inhibit the formation of scars. Chronic wounds refer to the wounds that can not reach the anatomic and functional integrity through the normal, orderly, and timely repair process, and the course of the wound healing is more than 4 weeks. At present, there are various treatment methods for chronic wounds, among which ADSCs, although showing a good application prospect, have some limitations due to ethical issues, while exosomes can avoid this problem. This article reviews the treatment of chronic wounds with ADSC exosomes.

Ferroptosis occurs in phase of reperfusion but not ischemia in rat heart following ischemia or ischemia/reperfusion

Ferroptosis is an iron-dependent regulated necrosis. This study aims to evaluate the contribution of ferroptosis to ischemia or reperfusion injury, and lay a basis for precise therapy of myocardial infarction. The Sprague-Dawley (SD) rat hearts were subjected to ischemia for different duration or the hearts were treated with 1 h-ischemia plus different duration of reperfusion. The myocardial injury was assessed by biochemical assays and hematoxylin & eosin (HE) staining. The ferroptosis was evaluated with the levels of acyl-CoA synthetase long-chain family member 4 (ACSL4), glutathione peroxidase 4 (GPX4), iron, and malondialdehyde. Iron chelator (deferoxamine) was applied to verify the contribution of ferroptosis to ischemia and reperfusion injury. The results showed that ischemic injury (infarction and CK release) was getting worse with the extension of ischemia, but no significant changes in ferroptosis indexes (ACSL4, GPX4, iron, and malondialdehyde) in cardiac tissues were observed. Differently, the levels of ACSL4, iron, and malondialdehyde were gradually elevated with the extension of reperfusion concomitant with a decrease of GPX4 level. In the ischemia-treated rat hearts, no significant changes in myocardial injury were observed in the presence of deferoxamine, while in the ischemia/reperfusion-treated rat hearts, myocardial injury was markedly attenuated in the presence of deferoxamine concomitant with a reduction of ferroptosis. Based on these observations, we conclude that ferroptosis occurs mainly in the phase of myocardial reperfusion but not ischemia. Thus, intervention of ferroptosis exerts beneficial effects on reperfusion injury but not ischemic injury, laying a basis for precise therapy for patients with myocardial infarction.

Ubiquitin-specific protease 7 promotes ferroptosis via activation of the p53/TfR1 pathway in the rat hearts after ischemia/reperfusion

Iron overload triggers the ferroptosis in the heart following ischemia/reperfusion (I/R) and transferrin receptor 1 (TfR1) charges the cellular iron uptake. Bioinformatics analysis shows that the three molecules of ubiquitin-specific protease 7 (USP7), p53 and TfR1 form a unique pathway of USP7/p53/TfR1. This study aims to explore whether USP7/p53/TfR1 pathway promotes ferroptosis in rat hearts suffered I/R and the underlying mechanisms. The SD rat hearts were subjected to 1 h-ischemia plus 3 h-reperfusion, showing myocardial injury (increase in creatine kinase release, infarct size, myocardial fiber loss and disarray) and up-regulation of USP7, p53 and TfR1 concomitant with an increase of ferroptosis (reflecting by accumulation of iron and lipid peroxidation while decrease of glutathione peroxidase activity). Inhibition of USP7 activated p53 via suppressing deubiquitination, which led to down-regulation of TfR1, accompanied by the decreased ferroptosis and myocardial I/R injury. Next, H9c2 cells underwent hypoxia/reoxygenation (H/R) in vitro to mimic the myocardial I/R model in vivo. Consistent with the results in vivo, inhibition or knockdown of USP7 reduced the H/R injury (decrease of LDH release and necrosis) and enhanced the ubiquitination of p53 along with the decreased levels of p53 and TfR1 as well as the attenuated ferroptosis (manifesting as the decreased iron content and lipid peroxidation while the increased GPX activity). Knockdown of TfR1 inhibited H/R-induced ferroptosis without p53 deubiquitination. Based on these observations, we conclude that a novel pathway of USP7/p53/TfR1 has been identified in the I/R-treated rat hearts, where up-regulation of USP7promotes ferrptosis via activation of the p53/TfR1 pathway.

[Correlation analysis of newly diagnosed coal worker's pneumoconiosis and GDP in Hubei Province from 2006 to 2015]

Objective: To analysis the distribution characteristics of coal worker's pneumoconiosis in Hubei Province during 2006-2010 (the 11th Five-Year Plan period) and 2011-2015 (the 12th Five-Year Plan period) , and its correlation with the gross domestic product (GDP) of Hubei Province from 1986 to 2015. Methods: In September 2019, the data of newly diagnosed coal worker's pneumoconiosis reported in Occupational Disease and Occupational Health Information Monitoring System from 2006 to 2015 and the GDP data from 1986 to 2015 in Hubei Province were collected. The distribution characteristics of time, region, enterprise size, industry and economic type of coal-worker's pneumoconiosis and its correlation with GDP were analyzed. Results: In 2006-2015, 3807 new cases of coal worker's pneumoconiosis were reported in Hubei Province. The time distribution generally ascended as a wave trend. The number of new cases reached its peak in 2013 (722 cases) . GDP growth continued between 1986-1995, 1996-2005 and 2006-2015, especially in 2006-2015. New cases of coal worker's pneumoconiosis were mainly distributed in Huangshi city, Yichang city and Enshi prefecture, accounting for 82.40% (3137/3807) of the total cases. The proportion of new cases in Huangshi city was higher than that in Yichang city and Enshi prefecture (χ(2)=272.66, 243.19, P<0.05) . New cases were mainly distributed in coal mining industry (3103 cases, 81.51%) , small-sized and medium (1675 cases, 44.00%) , and private enterprises (1621 cases, 42.58%) . The rank correlation (r(s)) of coal worker's pneumoconiosis in 2006-2015 with GDP in1986-1995, 1996-2005 and 2006-2015 were 0.157, 0.144, 0.200, respectively, and there were no significant differences (P>0.05) . Conclusion: The coalworker's pneumoconiosis in Hubei Province are mostly distributed in small and medium-sized private enterprises, and the regional distribution is concentrated in Huangshi city, Yichang city and Enshi prefecture. The concentration of cases is closely related to the number and energy production of local coal mines. There is no correlation between the growth of GDP and the distribution of cases.

Analysis of Driver-Passenger Relationship and Restoration of Accident Process Based on 3D Laser Scanning Technology

Abstract

Objective To discuss the application of 3D laser scanner and computer technology in restoration of the accident scene and reconstruction of the accident process, as well as identification of the driver-passenger relationship. Methods The scene of a traffic accident, the accident vehicle and the vehicle of the same type as accident vehicle were scanned using 3D laser scanner. The accident scene, traces and accident vehicle were integrated using computer technology to restore the accident scene, and the accident process was reconstructed and analyzed by combining the characteristics of the body injuries. Results By restoring the accident scene and reconstructing the accident process with 3D laser scanner, it was determined that Wu was in the driving seat at the time of the accident. Conclusion It is more objective and scientific to use 3D laser scanning technology to restore the accident scene, reconstruct the accident process and analyze the moving track of the driver and passengers in the vehicle. It will help to improve the accuracy of forensic identification of road traffic accidents.

Arctiin protects rat heart against ischemia/reperfusion injury via a mechanism involving reduction of necroptosis

RIPK1/RIPK3/MLKL (Receptor-interacting protein kinase 1/Receptor-interacting protein kinase 3/Mixed lineage kinase domain-like protein) pathway-mediated necroptosis contributes to myocardial ischemia/reperfusion (I/R) injury, and Arctiin can prevent myocardial fibrosis and hypertrophy. This study aims to explore the effect of Arctiin on myocardial I/R injury and the underlying mechanisms. SD rat hearts or cardiomyocytes were subjected to I/R or hypoxia/reoxygenation (H/R) to establish the I/R or H/R injury model. The methods of biochemistry, PI/DAPI (propidium iodide/4',6-Diamidino-2-Phenylindole) and H&E (Hematoxylin & eosin) staining were used to evaluate the I/R or H/R injury. The effects of Arctiin on necroptosis in I/R-treated hearts or H/R-treated cardiomyocytes were assessed. The results showed that Arctiin reduced myocardial I/R injury (decreases in myocardial infarction and creatine kinase release), concomitant with a decrease in levels of necroptosis-associated proteins (RIPK1/p-RIPK1, RIPK3/p-RIPK3 and MLKL/p-MLKL) in I/R-treated rat hearts. Consistently, the necrosis and LDH release in H/R-treated cardiomyocytes were attenuated in the presence of Arctiin, accompanied by suppression of necroptosis-relevant proteins. Furthermore, H/R-induced reactive oxygen species (ROS) generation and mitochondrial dysfunctions (increase in mitochondrial membrane potential and decrease in ATP production) were impaired by Arctiin. Using the program of the Molecular Operating Environment (MOE), we predict that RIPK1 and MLKL (but not RIPK3) might be the potential targets of Arctiin. Based on these observations, we conclude that Arctiin can protect the rat heart from I/R injury, and its beneficial effect is related to reduction of necroptosis via scavenging reactive oxygen species and restoring mitochondrial functions or targeting RIPK1 and/or MLKL.

Upregulation of mitochondrial E3 ubiquitin ligase 1 in rat heart contributes to ischemia/reperfusion injury

Mitochondrial dysfunctions are responsible for myocardial injury upon ischemia/reperfusion (I/R), and mitochondrial E3 ubiquitin ligase 1 (Mul1) plays an important role in maintaining mitochondrial functions. This study aims to explore the function of Mul1 in myocardial I/R injury and the underlying mechanisms. The Sprague-Dawley rat hearts were subjected to 1 h of ischemia plus 3 h of reperfusion, which showed the I/R injury (increase in infarct size and creatine kinase release) and the elevated total and mitochondrial protein levels of Mul1 and p53 accompanied by the enhanced interactions between Mul1 and p53 as well as p53 and small a ubiquitin-like modifier (SUMO1). Consistently, hypoxia/reoxygenation (H/R) treated cardiac (H9c2) cells displayed cellular injury (apoptosis and necrosis), upregulation of total and mitochondrial protein levels of Mul1 and p53, and enhanced interactions between p53 and SUMO1 concomitant with mitochondrial dysfunctions (an increase in mitochondrial membrane potential and reactive oxygen species production with a decrease in ATP production); these phenomena were attenuated by knockdown of Mul1 expression. Based on these observations, we conclude that a novel role of Mul1 has been identified in the myocardial mitochondria, where Mul1 stabilizes and activates p53 through its function of SUMOylation following I/R, leading to p53-mediated mitochondrial dysfunction and cell death.

Inhibition of Phosphoglycerate Mutase 5 Reduces Necroptosis in Rat Hearts Following Ischemia/Reperfusion Through Suppression of Dynamin-Related Protein 1

PURPOSE

Necroptosis is an important form of cell death following myocardial ischemia/reperfusion (I/R) and phosphoglycerate mutase 5 (PGAM5) functions as the convergent point for multiple necrosis pathways. This study aims to investigate whether inhibition of PGAM5 could reduce I/R-induced myocardial necroptosis and the underlying mechanisms.

METHODS

The SD rat hearts (or H9c2 cells) were subjected to 1-h ischemia (or 10-h hypoxia) plus 3-h reperfusion (or 4-h reoxygenation) to establish the I/R (or H/R) injury model. The myocardial injury was assessed by the methods of biochemistry, H&E (hematoxylin and eosin), and PI/DAPI (propidium iodide/4',6-diamidino-2-phenylindole) staining, respectively. Drug interventions or gene knockdown was used to verify the role of PGAM5 in I/R (or H/R)-induced myocardial necroptosis and possible mechanisms.

RESULTS

The I/R-treated heart showed the injuries (increase in infarct size and creatine kinase release), upregulation of PGAM5, dynamin-related protein 1 (Drp1), p-Drp1-S616, and necroptosis-relevant proteins (RIPK1/RIPK3, receptor-interacting protein kinase 1/3; MLKL, mixed lineage kinase domain-like); these phenomena were attenuated by inhibition of PGAM5 or RIPK1. In H9c2 cells, H/R treatment elevated the levels of PGAM5, RIPK1, RIPK3, MLKL, Drp1, and p-Drp1-S616 and induced mitochondrial dysfunctions (elevation in mitochondrial membrane potential and ROS level) and cellular necrosis (increase in LDH release and the ratio of PI⁺/DAPI⁺ cells); these effects were blocked by inhibition or knockdown of PGAM5.

CONCLUSIONS

Inhibition of PGAM5 can reduce necroptosis in I/R-treated rat hearts through suppression of Drp1; there is a positive feedback between RIPK1 and PGAM5, and PGAM5 might serve as a novel therapeutic target for prevention of myocardial I/R injury.

[Endoscopic management of ingested foreign bodies in the upper gastrointestinal tract in childhood: a retrospective study of 1 334 cases]

Objective: To explore the clinical features and complications of foreign bodies in the upper gastrointestinal tract in children and to investigate the effectiveness of endoscopic management. Methods: Data of patients with foreign bodies in upper gastrointestinal tract were collected retrospectively at Endoscopy Center, the Children's Hospital, Zhejiang University School of Medicine, from January 2011 to December 2016. Clinical characteristics, the types of foreign bodies, the location and duration of foreign body impaction were summarized. The risk factors of complications and endoscopic removal failure were analyzed by using Logistic regression analysis. Results: A total of 1 334 patients (825 males and 509 females) were enrolled. The median age was 2.5 years, with a range from 0.25 to 15 years and peak age 1-3 years. Twenty patients had esophageal diseases. The most common foreign body ingested was coin (n=964, 72.3%). Foreign bodies were most commonly located in the esophagus (n=1 002, 75.1%), especially in the upper esophagus (n=857, 85.5%). The duration of foreign body impaction ranged from 3 hours to 5 years. Among 1 334 patients, 252 patients (18.9%) developed complications, including ulcers (n=101, 40.0%) and perforations(n=13, 5.2%). The success rate of endoscopic removal was 96.6% (n=1 288). By Logistic regression analysis, sharp foreign body ingestion (OR=6.893, 95%CI: 4.421-10.746) , esophageal impaction (OR=5.253, 95%CI:3.352-8.233) and foreign body impaction longer than 24 hours (OR=4.336, 95%CI:3.091-6.082) were risk factors of complications. Sharp foreign body ingestion was the risk factor of endoscopic failure (OR=5.372, 95%CI:2.773-10.406) . Conclusions: Coin is the most common foreign body in upper gastrointestinal tract. Sharp foreign bodies impacted in the esophagus over 24 hours increase the risk of complications. Endoscopic removal of foreign bodies from the upper gastrointestinal tract in children has a high success rate. Sharp foreign body ingestion increases the risk of failure in endoscopic removing.

[Effect of enteral nutrition on accidental upper gastrointestinal injury in children]

Objective: To evaluate the effectiveness of enteral nutrition in children with accidental upper gastrointestinal injury. Methods: The medical records of 128 patients with mechanical or chemical gastrointestinal mucosal injury, who were hospitalized in Department of Gastroenterology, Children's Hospital of Zhejiang University School of Medicine from January 1, 2011 to December 30, 2017, were collected. All cases were treated with enteral nutrition. The clinical features and etiologies were retrospectively analyzed. Weight-for-age Z score and lab findings including white blood cells, C-reactive protein, neutrophils, albumin, prealbumin, urea nitrogen and hemoglobin before and after treatment were extracted. The clinical characteristics, the duration of enteral nutrition and gastrointestinal mucosal healing between different etiologies were further analyzed. Normal distribution variables and categorized variables were compared with t test and χ(2) test respectively, and abnormal distribution data was compared with Wilcoxon test. Results: Among all the cases, 77 were males and 51 were females. The average age was (29±22) months. The mean duration of hospitalization and enteral nutrition were (11±7)d and (27±20)d respectively. Vomiting was the most common clinical presentation (72 cases, 56.3%). In 79 cases the problems were caused by mechanical injury, among which coins were most commonly seen. The rest 49 cases were caused by chemical injury. However, the duration of hospitalization ((13±8) d vs. (10±6)d, t=-3.089, P=0.002) and enteral nutrition ((39±22) vs. (19±14) d, t=-5.365, P=0.000) were longer in children with chemical injury than those with mechanical injury. A total of 112 cases got complete blood count and C-reactive protein both before and after enteral nutrition. Inflammatory markers, including leukocytes ((7.7±2.7) ×10(9)/L vs. (13.7±5.0) ×10(9)/L, t=12.244, P <0.05), neutrophils ((3.4±1.9)×10(9)/L vs. (9.4±4.6) ×10(9)/L, t=13.655, P<0.05), and C-reactive proteins (5.0(3.0,7.8) vs. 13.5(6.0,40.5) mg/L, Z=7.776, P <0.05) were significantly decreased. The nutritional markers, including the weight-for-age z score (-0.1 ± 1.0 vs. 0.0 ± 1.0, t=-2.622, P=0.010) and the prealbumin (0.1 ± 0.1 vs. 0.2 ± 0.0 g/L, t=-3.671, P=0.001) were significantly increased. Fifty-five (82.1%) children in mechanical injury group recovered in 4 weeks, while 27 (79.4%) children in chemical injury group recovered in 7 weeks. Conclusion: Enteral nutrition can provide adequate nutritional requirements for children with upper gastrointestinal injury, and may help to decrease imflammation and improve mucosal healing.

Oral immunization with a Lactobacillus casei-based anti-porcine epidemic diarrhoea virus (PEDV) vaccine expressing microfold cell-targeting peptide Co1 fused with the COE antigen of PEDV

AIMS

The aims of this study were to develop an effective M cell-targeting oral vaccine, involving Lactobacillus casei to deliver the porcine epidemic diarrhoea virus (PEDV) core neutralizing epitope (COE) antigen conjugated with M cell-targeting peptide Co1 as an adjuvant, against PEDV infection.

METHODS AND RESULTS

Genetically engineered L. casei 393 (L393) strains expressing PEDV COE antigen only (pPG-COE/L393) or fused-expressing COE and M cell-targeting peptide Co1 (pPG-COE-Co1/L393) were constructed, and the immunogenicity upon administration as an oral vaccine was evaluated. The results showed that higher anti-PEDV serum IgG and mucosal SIgA antibody responses were induced in mice orally immunized with strain pPG-COE-Co1/L393 as compared to the mice immunized with strain L393 expressing COE alone or carrying the empty plasmid. In addition, the use of the Co1 ligand elicited a splenocyte proliferative response more effectively in comparison with the COE antigen alone and supported a skewed T helper 2 type of immune response against PEDV.

CONCLUSIONS

pPG-COE-Co1/L393 can effectively induce mucosal, humoural and Th2-type cellular immune responses against PEDV infection via oral administration. Furthermore, M cell-targeting peptide ligand Co1 is a good mucosal adjuvant.

SIGNIFICANCE AND IMPACT OF THE STUDY

Lactobacillus casei delivering the COE antigen of PEDV conjugated with a M cell-targeting peptide Co1 as an immune adjuvant is a promising oral vaccine candidate for PEDV.

Fasudil ameliorates the ischemia/reperfusion oxidative injury in rat hearts through suppression of myosin regulatory light chain/NADPH oxidase 2 pathway

Fasudil is a potent Rho-kinase (ROCK) inhibitor and can relax smooth muscle or cardiac muscle contraction through decreasing the phosphorylation level of myosin regulatory light chain (p-MLC₂₀ or p-MLC2v), while p-MLC2v can function as a transcription factor to promote the NADPH oxidase 2 (NOX2) expression in rat hearts subjected to ischemia/reperfusion (I/R). This study aims to explore whether fasudil can protect the rat hearts against I/R oxidative injury through suppressing NOX2 expression via reduction of p-MLC2v level. The SD rat hearts were subjected to 1h-ischemia plus 3h-reperfusion, which showed myocardial injuries (myocardial fiber loss and disarray, increase of creatine kinase release and myocardial infarction/apoptosis), increase in ROCK activity and nuclear p-MLC_2v level concomitant with up-regulation of NOX2 and H₂O₂ production; these phenomena were attenuated by fasudil in a dose-dependent manner. Next, we verified the cardioprotective effect of fasudil and the underlying mechanisms in hypoxia-reoxygenation (H/R) -treated H9c2 cells. Consistent with the results in vivo, the H/R-treated H9c2 cells showed cellular injury (increase in apoptotic ratio), elevation in ROCK activity and nuclear p-MLC_2v level, accompanied by up-regulation of NOX2 and H₂O₂ production; these effects were blocked in the presence of fasudil in a dose-dependent way. Based on these observations, we conclude that beneficial effect of fasudil against myocardial I/R or H/R oxidative injury is related to the suppression of NOX2 expression through decrease of the p-MLC2v level. Our findings also highlight that intervention of MLC2v phosphorylation by drugs may provide a novel strategy to protect heart from I/R oxidative injury.

[Clinical analysis of enteral nutrition in 47 children]

OBJECTIVE

To explore the efficacy and safety of the application of enteral nutrition (EN) in gastrointestinal disease in children, and to explore the possibility of the implementation of family EN.

METHOD

Retrospective analysis of disease spectrum, EN approach, preparation, speed and time as well as adverse reactions and outcomes in 47 pediatric patients with gastrointestinal disease underwent EN therapy during July 2014 to March 2015. The nutrition indicators before and after EN therapy were compared by paired t-test.

RESULT

A total of 47 patients were selected, 27 male (57%) and 20 female (43%), aged 0.8 (0.3, 4.0) years, 9 with mechanical or chemical damage to the esophagus, 7 with inflammatory bowel disease (including ulcerative colitis and Crohn's disease), 6 with chronic diarrhea, 5 with acute pancreatitis, 3 with acute diarrhea and severe malnutrition, 3 with short bowel syndrome, 3 with improper feeding, 3 with feeding difficulties, 3 with protein losing enteropathy, 2 with post-enterostomy, 2 with enterocolitis, 1 with gastroesophageal reflux, were diagnosed. Of 47 cases, 22 were given oral nutrition, 28 were fed with nasogastric tube and 4 with nasojejunal tube feeding, 2 with percutaneous endoscopic gastrojejunostomy tube feeding for each. In these tube-feeding cases, 20 cases were treated with continuous infusion and 21 cases with intermittent infusion. Eleven cases were fed with amino acid formula; 21 cases took the choice of peptide formulations; 16 cases chose whole protein formula, including six cases who chose 3.3-4.2 kJ/ml higher energy density formula, 10 cases selected common energy density formula including breast milk. Twenty-one cases suffered from different degrees of adverse reactions, including vomiting in 7 cases, abdominal pain and bloating in 3, diarrhea in 12, secondary respiratory infections in 5. Five patients were discharged after giving up of treatment by parents due to poor efficacy on primary disease; 3 cases were transferred to other departments for further treatment; 15 cases were discharged with a feeding tube for family nutrition and specialist out-patient treatment. The rest 24 cases were all improved and discharged. There were significant differences in nutrition indicators before and after EN, weight-for-age Z score (WAZ)(-2.3±1.9 vs. -1.9±1.8, t=4.156, P=0.000), weight-for-height Z score (WHZ)(-1.9±1.7 vs. -1.2±1.5, t=3.714, P=0.001), albumin ((35±9)g/L vs.(39±6) g/L, t=3.017, P=0.005) and prealbumin ((0.11±0.05)g/L vs.(0.18±0.07)g/L, t=5.144, P=0.000).

CONCLUSION

EN is suitable for a variety of children's digestive diseases, which can improve the nutritional status of the patients and was safe for clinical application. As the implementation of EN is simple and has good compliance, family EN is proven to be feasible.

Analysis of the genome sequence of infectious hematopoietic necrosis virus HLJ-09 in China

Infectious hematopoietic necrosis virus (IHNV) is a highly contagious disease of juvenile salmonid fish. Six genome target fragments of the complete genome sequence of IHNV HLJ-09 were amplified by RT-PCR, and the 3'-terminal and 5'-terminal region of the genomic RNA were amplified using the RACE method. The complete genome sequence of HLJ-09 comprises 11,132 nucleotides (nt) (Accession number JX649101) and is different from that of other IHNV strains published in GenBank. Homology comparison and phylogenetic analysis of six ORF sequences were carried out using HLJ-09 and other IHNV strains published in GenBank. From phylogenetic tree analysis, the N gene, M gene, and P gene had the closest genetic relationship to IHNV-PRT from Korea. Phylogenetic analysis for the full length of the G gene showed that the HLJ-09 strain exhibited very close homology to the ChYa07, RtNag96, RtUi02, and RtGu01 strains from Korea and Japan, indicating that the HLJ-09 strain belonged to the genotype JRt. Ultimately, the Chinese IHNV HLJ-09 strain may have originated in Korea and Japan.

The diagnostic value of high-resolution ultrasonography for the detection of anterior disc displacement of the temporomandibular joint: a meta-analysis employing the HSROC statistical model

The study aimed to assess the diagnostic value of high-resolution ultrasonography (HR-US) in the detection of anterior disc displacement (ADD) of the temporomandibular joint. Relevant trials reported in MEDLINE, the Chinese National Knowledge Infrastructure Database, the Chinese Biomedical Literature Database, and Embase were identified. A manual search was also performed. The quality of retrieved data was evaluated using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria. Data were extracted and cross-checked, and a statistically rigorous meta-analysis was performed using a hierarchical summary receiver operating characteristic model (HSROC). The clinical utility of results was assessed using Fagan nomograms (Bayes theory). All data were evaluated using Stata software. A total 11 studies including 1096 subjects were included in the analysis; all reported the utility of HR-US for the diagnosis of ADD with reduction (ADDWR) and without reduction (ADDWoR). For ADDWR, the weighted sensitivity and specificity were 0.83 (95% confidence interval (CI) 0.78-0.88) and 0.85 (95% CI 0.76-0.92) respectively. The lambda value was 3.41 (95% CI 2.37-4.46) and the Fagan nomogram pre-test probability 58%, with a positive likelihood ratio (LR) of 6.01. The positive post-test probability was 89%, with a negative LR of 0.20. The negative post-test probability was 21%. The positive increase in diagnostic utility was 31% and the negative decrement in that value 37%. For ADDWoR, the weighted sensitivity and specificity values were 0.72 (95% CI 0.59-0.81) and 0.90 (95% CI 0.86-0.93), respectively. The lambda value was 3.69 (95% CI 2.39-4.99) and the Fagan nomogram pre-test probability 38%, with a positive LR of 7.00. The positive post-test probability was 82%, with a negative LR of 0.32. The negative post-test probability was 16%. The increase in diagnostic utility was 44% and the negative decrement in that value 22%. HR-US delivers acceptable performance when used to diagnose ADD, being superior for the detection of ADDWoR than ADDWR, and exhibiting a lower negative diagnostic value in the detection of ADDWoR than ADDWR. HR-US may serve as a new method for the rapid diagnosis of ADD. The method has the advantages of simplicity and low cost. Given the uncertainty in some of the estimated values, more high-quality studies are needed to assess that diagnostic efficacy.

Low adenosine triphosphate activity in CD4+ cells predicts infection in patients with lupus nephritis

OBJECTIVES

The ImmuKnow (Cylex) assay has been reported to predict the risk of infection in some diseases; however, it is uncertain whether ImmuKnow can predict the risk of infection in lupus nephritis (LN) patients receiving immunosuppressive therapy.

METHODS

The ImmuKnow Immune Cell Function Assay (Cylex, Inc., Columbia, MD, USA) was applied to measure the activity of CD4+ T cells, as a marker of global immune-competence. The correlation between changes in T cell activation and the relative risk of over-immunosuppression as well as infection was studied. The amount of adenosine triphosphate (ATP) produced by CD4+ T cells in response to phytohemagglutinin (PHA) was measured for 74 LN patients without infection, 22 LN patients with severe infection (i.e. required hospitalisation), and 28 healthy controls.

RESULTS

No correlation was found between the ATP level and systemic lupus erythematosus (SLE) activity. The mean ATP level was significantly lower in LN patients with infection than that in healthy controls (p<0.01) and non-infected LN patients (p<0.01). The mean ATP level in non-infected LN patients was not significantly different compared to healthy controls. A cut-off ATP value of 300 ng/mL predicted infection in LN patients with a specificity of 77% and a sensitivity of 77%. Multi-variable partial correlation coefficient between the ATP assay and severe infection was r =-0.040, p<0.001; CRP was r=0.962, p<0.001.

CONCLUSIONS

The ImmuKnow assay may be effective in identifying an increased risk of infection in LN patients but is not correlated with SLE activity. Combined CRP value will increase the diagnostic rate of severe infection in SLE. Larger studies are required to establish clinical advantages of this assay in SLE treatment.

Mesenchymal Stem Cells Genetically Modified with the Angiopoietin-1 Gene Enhanced Arteriogenesis in a Porcine Model of Chronic Myocardial Ischaemia

The direct injection by thoracoscope of mesenchymal stem cells (MSCs) that had been genetically modified to express angiopoietin-1 was investigated in a porcine model to determine their effect on arteriogenesis and the effectiveness of this technique. Chronic myocardial ischaemia was established using a thoracoscope to insert an ameroid constrictor around the left circumflex coronary artery. Six weeks after establishing the ischaemia, 20 pigs were randomly divided into three groups to receive injections by thoracoscope of either genetically-modified MSCs, unmodified MSCs or phosphate-buffered saline into the ischaemic border area. The injections were repeated 1 month later. The genetically modified MSCs were found to restore blood flow significantly more than the other observed treatments and immunohistochemical evaluation of arteriogenesis supported this finding. In conclusion, the injection of MSCs that had been genetically modified to express angiopoietin-1 improved arteriogenesis and increased collateral blood flow in the myocardial ischaemic area. Thoracoscope delivery of the injection was safe and minimally invasive.

14 bp deletion polymorphism in the HLA-G gene is a risk factor for idiopathic dilated cardiomyopathy in a Chinese Han population

Human leukocyte antigen (HLA) has been reported to be associated with the pathogenesis of autoimmune-associated idiopathic dilated cardiomyopathy (IDC). However, the HLA-G in this context is limited. In the current study, a total of 117 IDC patients and age and sex matched 401 unrelated healthy controls in a Chinese Han population were HLA-G genotyped for the 14 bp insertion and deletion polymorphism. IDC patients showed markedly increased frequencies of -14 bp/-14 bp genotype [Pc = 0.00049, odds ratio (OR) = 2.17] and -14 bp alleles (Pc = 4.1 x 10(-5), OR = 1.97) when compared with healthy controls. Whereas the frequencies of +14 bp/+14 bp genotype (Pc = 0.0036, OR = 0.35) and +14 bp alleles (Pc = 4.1 x 10(-5), OR = 0.51) were significantly lower in IDC. These data, for the first time, indicated that 14 bp insertion/deletion polymorphism in HLA-G gene could be a genetic risk factor for the susceptibility to IDC.

Treatment of lycorine on SCID mice model with human APL cells

In our previous study, lycorine, a natural alkaloid extracted from Amaryllidaceae, exhibited anti-leukemia effects in vitro. To determine whether lycorine has an anti-tumor effect in vivo, a series of experiments were carried out in this study. HL-60 cells (5 × 10⁶) were inoculated i.v. into severe combined immuno-deficiency (SCID) mice after these mice had been irradiated (total body receiving 200 cGy χ irradiation). Treatment was given once a day from day 2 to 6, and from day 14 to 18. Lycorine (5 or 10 mg/kg/day i.p.) was found to decrease the percentages of immature granular leukocytes and of monocytes among the peripheral blood cells, and the mean survival time of both lycorine-treated groups was longer than that of the control group. Compared with the asynchronous and cytosine arabinoside- (Ara-C) treated (20 mg/kg/day i.p.) group, treatment with lycorine was more effective. Lycorine was also found to alleviate the infiltration of tumor cells into the liver, bone, and marrow. When SCID mice inoculated with HL-60 cells were then treated with lycorine, no severe adverse effects were observed. This study revealed that lycorine, when tested in the human leukemia xenograft models, appears to exhibit anti-tumor activity in vivo and is a useful therapy against acute promyelocytic leukemia.

Investigation of serum protein systems in Chinese pigs

Polymorphisms of transferrin (Tf), pre-albumin (Pa), haemopexin (Hpx), ceruloplasmin (Cp) and amylase (Am) of Duroc pigs and Hunan indigenous pigs were investigated using horizontal starch gel electrophoresis. Allele frequencies of Durocs determined in 2004 were compared with frequencies presented in the paper by Baker L.N. (1968) Serum protein variation in Duroc and Hampshire pigs. Vox Sanguinis15, 154-8. The number of serum protein alleles decreased over time and allele frequencies aggregated across certain alleles, including TfB, PaA, Hpx3, CpB and AmB. Differences in allele frequencies, average heterozygosities and standard genetic distances between the Duroc pigs and Hunan indigenous pig populations were examined. The relationship between Durocs and Hunan indigenous pigs was found to be more distant than those among the three Hunan indigenous pig populations.

Increased p53 phosphorylation after microtubule disruption is mediated in a microtubule inhibitor- and cell-specific manner

p53 is present at low levels in unstressed cells. Numerous cellular insults, including DNA damage and microtubule disruption, elevate p53 protein levels. Phosphorylation of p53 is proposed to be important for p53 stabilization and activation after genotoxic stress; however, p53 phosphorylation after microtubule disruption has not been analysed. The goal of the current study was to determine if p53 phosphorylation increases after microtubule disruption, and if so, to identify specific p53 residues necessary for microtubule inhibitor-induced phosphorylation. Two dimensional gel analyses demonstrated that the number of p53 phospho-forms in cells increased after treatment with microtubule inhibitors (MTIs) and that the pattern of p53 phosphorylation was distinct from that observed after DNA damage. p53 phosphorylation also varied in a MTI-dependent manner, as Taxol and Vincristine induced more p53 phospho-forms than nocodazole. Further, MTI treatment increased phosphorylation of p53 on serine-15 in epithelial tumor cells. In contrast, serine-15 phosphorylation of p53 did not increase in MTI-treated primary cultures of human fibroblasts. Analysis of ectopically expressed p53 phospho-mutant proteins from Taxol- and nocodazole-treated cells indicated that multiple p53 amino terminal residues, including serine-15 and threonine-18, were required for Taxol-mediated phosphorylation of p53. Taken together, the results of this study demonstrate that distinct p53 phospho-forms are induced by MTI treatment as compared to DNA damage and that p53 phosphorylation is mediated in a MTI- and cell-specific manner. Oncogene (2001) 20, 113 - 124.

[Influence of IFN-alpha and IFN-alpha combined with GM-CSF on expression of the genes related to cell apoptosis of MNCs from bone marrow in CML patients]

OBJECTIVE

To investigate the effects of interferon-alpha(IFN-alpha) and IFN-alpha combined with granulocytic macrophage colony-stimulating factor(GM-CSF) on expression of bcr-abl, bcl-2 and c-myc genes in the mononuclear cells(MNCs) from bone marrow(BM) of the patients with chronic myelogenous leukemia at chronic phase(CML-CP).

METHODS

The MNCs were collected from bone marrow of 14 CML-CP patients by centrifugalization in lymphocyte-separation medium, and cultivated in the medium with IFN-alpha and IFN-alpha plus GM-CSF for 24 hours. The expression levels of bcr-abl, bcl-2, c-myc and beta-actin were detected by using relatively quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and optical density scanning technology for the amplified fragments. The statistical differences between each inducing experimental group and the control were analyzed by t-test in pairs.

RESULTS

Both IFN-alpha (200 U.ml-1) and IFN-alpha combined with GM-CSF (10 ng.ml-1) significantly inhibited bcr-abl gene expression, meanwhile IFN-alpha partially suppressed c-myc and bcl-2 gene expression, and GM-CSF significantly inhibited bcl-2 gene expression but partially upregulated bcr-abl and c-myc gene expression levels on the basis of IFN-alpha effects.

CONCLUSIONS

Both IFN-alpha and IFN-alpha plus GM-CSF can inhibit the expression of anti-apoptosis gene such as bcr-abl and bcl-2, and regulate the expression of c-myc. It is the possible mechanism of IFN-alpha therapy or combined therapy on CML at chronic phase that the malignant clone expansion is inhibited by promoting apoptotic cell death.

p53-dependent expression of PIG3 during proliferation, genotoxic stress, and reversible growth arrest

The p53-inducible gene 3 (PIG3) was recently identified in a screen for genes induced by p53 before the onset of apoptosis. PIG3 shares significant homology with oxidoreductases from several species. In this study, PIG3-specific antibodies were used to analyze cellular PIG3 protein levels under control and genotoxic stress conditions. PIG3 protein was localized to the cytoplasm and induced in primary, non-transformed, and transformed cell cultures after exposure to genotoxic agents. The induction of PIG3 was p53-dependent and occurred with delayed kinetics as compared with other p53 downstream targets, such as p21 and MDM2. Using a p53-inducible cell model system, in which p53-mediated growth arrest is reversible, we found that PIG3 levels were increased during p53-mediated growth arrest. Interestingly, elevated levels of PIG3 were maintained in cells that resumed cycling in the absence of ectopic p53 expression, suggesting that PIG3 is a long-lived reporter, which may be useful for detecting transient activation of p53.

p53 regulation of G(2) checkpoint is retinoblastoma protein dependent

In the present study, we investigated the role of p53 in G(2) checkpoint function by determining the mechanism by which p53 prevents premature exit from G(2) arrest after genotoxic stress. Using three cell model systems, each isogenic, we showed that either ectopic or endogenous p53 sustained a G(2) arrest activated by ionizing radiation or adriamycin. The mechanism was p21 and retinoblastoma protein (pRB) dependent and involved an initial inhibition of cyclin B1-Cdc2 activity and a secondary decrease in cyclin B1 and Cdc2 levels. Abrogation of p21 or pRB function in cells containing wild-type p53 blocked the down-regulation of cyclin B1 and Cdc2 expression and led to an accelerated exit from G(2) after genotoxic stress. Thus, similar to what occurs in p21 and p53 deficiency, pRB loss can uncouple S phase and mitosis after genotoxic stress in tumor cells. These results indicate that similar molecular mechanisms are required for p53 regulation of G(1) and G(2) checkpoints.

Mitotic phosphorylation of Bcl-2 during normal cell cycle progression and Taxol-induced growth arrest

There is increasing evidence that prolonged mitotic arrest initiates apoptosis; however, little is known about the signaling pathways involved. Several studies have associated deregulated Cdc2 activity with apoptosis. Herein, we report that the anti-apoptotic protein, Bcl-2, undergoes cell cycle-dependent phosphorylation during mitosis when there is elevated Cdc2 activity. We found that paclitaxel (Taxol(R)) treatment of epithelial tumor cells induced a prolonged mitotic arrest, elevated levels of mitotic kinase activity, hyperphosphorylation of Bcl-2, and subsequent cell death. The Taxol-induced Bcl-2 phosphorylation was dose-dependent. Furthermore, phosphorylated Bcl-2 remained complexed with Bax in Taxol-treated cells undergoing apoptosis. Immunoprecipitation experiments revealed a Bcl-2-associated kinase capable of phosphorylating histone H1 in vitro. However, the kinase was likely not cyclin B1/Cdc2, since cyclin B1/Cdc2 was not detectable in Bcl-2 immunoprecipitates, nor was recombinant Bcl-2 phosphorylated in vitro by cyclin B1/Cdc2. The results of this study further define a link between mitotic kinase activation and the apoptotic machinery in the cell. However, the role, if any, of prolonged Bcl-2 phosphorylation in Taxol-mediated apoptosis awaits further definition of Bcl-2 mechanism of action. Taxol may increase cellular susceptibility to apoptosis by amplifying the normal downstream events associated with mitotic kinase activation.

Introduction of dissolution error as a result of different openings in vessel covers

Vessel covers are required in dissolution studies to retard solvent evaporation. Sufficient openings on the cover are required by the current United States Pharmacopeia (USP) "to allow ready insertion of a thermometer and for withdrawal of specimens/samples." However, the area of the opening has not been regulated by the USP. The purpose of this work was to measure the loss of the dissolution solvent as a result of openings in vessel covers and to investigate errors caused by the solvent loss. The method used in the study involved measurements of the opening areas in three commercial vessel covers and determinations of solvent loss under a typical dissolution condition. The results showed that the openings in the three covers varied from 75 mm2 to 2285 mm2; this was 1-30% of the total vessel open area for a USP standard vessel. The volume of the dissolution solvent was reduced by 0.6-3.4% for an 8-hr dissolution study, and 1.7-9.7% for a 24-hr study when the three different vessel covers were used. The rate of solvent loss exhibited a linear relationship with the area of the opening in the covers. A slower rate of reduction was found for a smaller initial volume of the solvent. The conclusion was that higher dissolution results were produced if the solvent loss was not considered.

Effects of halothane on the sarcoplasmic reticulum Ca2+ stores and contractile proteins in rabbit pulmonary arteries

BACKGROUND

The authors' purpose of this study was to elucidate the mechanisms of direct effects of halothane on the contractile proteins and Ca2+ release from the sarcoplasmic reticulum Ca2+ stores using isolated skinned strips (sarcolemma permealized with saponin) from rabbit pulmonary arteries.

METHODS

The sarcoplasmic reticular Ca2+ stores were examined by immersing the skinned strips sequentially in solutions to load Ca2+ into and release Ca2+ from the sarcoplasmic reticulum using caffeine, inositol 1,4,5-trisphosphate, or halothane. The contractile proteins were assessed by activating the strips with Ca2+ followed by administration of halothane (with or without protein kinase C inhibitors). Tension, fura-2 fluorescence activated by Ca2+ release, and phosphorylation of myosin light chains were measured.

RESULTS

Halothane (0.07-3.00%) increased Ca2+, tension, and phosphorylation of myosin light chains in a dose-dependent manner. Halothane decreased accumulation of Ca2+ in the sarcoplasmic reticulum and enhanced the caffeine-induced tension transients. In strips pretreated with caffeine or inositol 1,4,5-trisphosphate, halothane-induced tension transients were reduced but Ca2+ was not. In strips activated by 1 microM Ca2+, halothane (0.5-3.0%) decreased 20-45% of the activated force at 15 min. Halothane (3%) transiently increased the force (20%) associated with increases in Ca2+ and phosphorylation of myosin light chains. The increased force was abolished and the subsequent relaxation was enhanced by the protein kinase C inhibitor bisindolylmaleimide but not by indolocarbazole Gö-6976.

CONCLUSIONS

In skinned pulmonary arterial strips, halothane, at clinical concentrations, inhibits uptake of Ca2+ by and induces release of Ca2+ from intracellular stores possibly shared by caffeine and inositol 1,4,5-trisphosphate, which are regulated by phosphorylation of myosin light chains. The time-dependent inhibition of the contractile proteins by halothane may be mediated by Ca2+-independent protein kinase C.

Mechanisms of action of enflurane on vascular smooth muscle. Comparison of rabbit aorta and femoral artery

BACKGROUND

This study was performed to elucidate the mechanisms of action of enflurane by comparing the vascular smooth muscle responses of conduit arteries of larger (aorta) and smaller (femoral artery) diameter to enflurane using isolated rings and skinned strips.

METHODS

Isolated intact rings (endothelium denuded) of aorta and femoral artery from rabbits were activated by various concentrations of norepinephrine (NE) and the effects of enflurane were examined at the steady-state force. In a separate study, the rings were pretreated with verapamil before the NE activation and tested with enflurane. In the saponin-treated arterial strips ("skinned"), the effects of enflurane on Ca2+ uptake or release from the sarcoplasmic reticulum were studied using caffeine-induced tension transients.

RESULTS

In isolated aortic rings, enflurane (0.9%-5%) enhanced tension development at low NE concentrations (5 and 30 nM) but depressed it at highest concentration (10 microM). In contrast, enflurane depressed tension development in the femoral artery at all NE concentrations. Enflurane caused significant increase in the NE-activated force in rings pretreated with verapamil. In skinned strips, enflurane (1%-3%) decreased Ca2+ uptake (concentration resulting in 50% depression: 1.8% for aorta and 2.5% for femoral artery) and increased Ca2+ release from the sarcoplasmic reticulum (59%-208% for aorta and 10%-55% for femoral artery). These effects were dose-dependent. Enflurane potentiated ryanodine depression of caffeine-induced tension transients.

CONCLUSIONS

Enflurane has similar mechanisms of action in aorta and femoral artery: blocking Ca2+ influx, and causing, at least in part, Ca2+ release from the sarcoplasmic reticulum through the ryanodine-receptor channel. These cellular actions of enflurane account for the depression in femoral artery and enhancement in aorta of NE-activated force in isolated rings.