N6022 attenuates cerebral ischemia/reperfusion injury-induced microglia ferroptosis by promoting Nrf2 nuclear translocation and inhibiting the GSNOR/GSTP1 axis

Stroke poses a significant risk of mortality, particularly among the elderly population. The pathophysiological process of ischemic stroke is complex, and it is crucial to elucidate its molecular mechanisms and explore potential protective drugs. Ferroptosis, a newly recognized form of programmed cell death distinct from necrosis, apoptosis, and autophagy, is closely associated with the pathophysiology of ischemic stroke. N6022, a selective inhibitor of S-nitrosoglutathione reductase (GSNOR), is a "first-in-class" drug for asthma with potential therapeutic applications. However, it remains unclear whether N6022 exerts protective effects in ischemic stroke, and the precise mechanisms of its action are unknown. This study aimed to investigate whether N6022 mitigates cerebral ischemia/reperfusion (I/R) injury by reducing ferroptosis and to elucidate the underlying mechanisms. Accordingly, we established an oxygen-glucose deprivation/reperfusion (OGD/R) cell model and a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model to mimic cerebral I/R injury. Our data, both in vitro and in vivo, demonstrated that N6022 effectively protected against I/R-induced brain damage and neurological deficits in mice, as well as OGD/R-induced BV2 cell damage. Mechanistically, N6022 promoted Nrf2 nuclear translocation, enhancing intracellular antioxidant capacity of SLC7A11-GPX4 system. Furthermore, N6022 interfered with the interaction of GSNOR with GSTP1, thereby boosting the antioxidant capacity of GSTP1 and attenuating ferroptosis. These findings provide novel insights, showing that N6022 attenuates microglial ferroptosis induced by cerebral I/R injury through the promotion of Nrf2 nuclear translocation and inhibition of the GSNOR/GSTP1 axis.

Therapeutic strategies targeting the NLRP3‑mediated inflammatory response and pyroptosis in cerebral ischemia/reperfusion injury (Review)

Ischemic stroke poses a major threat to human health. Therefore, the molecular mechanisms of cerebral ischemia/reperfusion injury (CIRI) need to be further clarified, and the associated treatment approaches require exploration. The NOD‑like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome serves an important role in causing CIRI, and its activation exacerbates the underlying injury. Activation of the NLRP3 inflammasome triggers the maturation and production of the inflammatory molecules IL‑1β and IL‑18, as well as gasdermin‑D‑mediated pyroptosis and CIRI damage. Thus, the NLRP3 inflammasome may be a viable target for the treatment of CIRI. In the present review, the mechanisms of the NLRP3 inflammasome in the intense inflammatory response and pyroptosis induced by CIRI are discussed, and the therapeutic strategies that target the NLRP3‑mediated inflammatory response and pyroptosis in CIRI are summarized. At present, certain drugs have already been studied, highlighting future therapeutic perspectives.

[First report of invasive Pomacea snails in Shandong Province]

OBJECTIVE

To characterize the species of invasive Pomacea snails that were discovered for the first time in Shandong Province.

METHODS

Pomacea snails samples were collected in the field of Jining City, Shandong Province on October 2021 for morphological identification. Pomacea snails were randomly sampled and genomic DNA was extracted from foot muscle tissues of Pomacea snails for multiplex PCR amplification. The PCR amplification product was sequenced. Then, the sequence was aligned and a phylogenetic tree was created using the software MegAlign 7.1.0. In addition, Angiostongylus cantonensis infection was detected in Pomacea snails with the lung microscopy.

RESULTS

A total of 104 living Pomacea snails were collected, and all were characterized as Pomacea spp. based on morphological features. Of 12 randomly selected adult Pomacea snails, multiplex PCR assay and sequencing identified eleven snails as P. canaliculata and one as P. maculata. No A. cantonensis infection was detected in 104 Pomacea snails.

CONCLUSIONS

This is the first report of invasive Pomacea snails in Shandong Province, where P. canaliculata and P. maculata are found.

[Effects of the removal of invasive Moso bamboo on soil microbial biomass and enzyme activities in subtropical forests]

Removal of invasive plant species is the first step to restoring the invaded ecosystems. The soil microbial biomass and extracellular enzyme activities were measured in Moso bamboo (Phyllostachys edulis) pure forest (completely invasion), invasive P. edulis removal forest (secondary succession 5 years after clear cutting), and the evergreen broadleaved forest (no invasion) in Tianmu Mountain. The results showed that compared with P. edulis pure forest, invasive P. edulis removal significantly increased the contents of soil organic carbon (SOC), nitrate nitrogen, available phosphorus and potassium, as well as microbial biomass carbon (MBC) and microbial biomass phosphorus (MBP), while significantly decreased microbial biomass nitrogen (MBN). The activities of α-glucosidase (AG), β-glucosidase (BG), leucine aminopeptidase (LAP) and phenol oxidase (POX) in the forest with removal of invasive P. edulis were significantly higher than those in P. edulis pure forest, while invasive P. edulis removal did not change the activities of cellodisaccharide hydrolase (CBH), β-N-acetyl-glucosaminopeptidase (NAG), acid phosphatase (ACP) and peroxidase (PER). Furthermore, the activities of AG, BG and LAP were positively correlated with SOC and MBC, while the increase in POX activity was positively correlated with soil nitrate content. In addition, MBC, MBN and MBP, and activities of AG, BG, NAG, LAP and ACP in P. edulis removal forest forest were significantly higher than those in evergreen broadleaved forests. Taken together, the removal of invasive P. edulis could increase soil nutrient contents, microbial biomass and extracellular enzyme activities, thus could be considered as an effective way to restore the invaded forests. Our results provide important theoretical basis for controlling P. edulis invasion in subtropical forests.

[Soil denitrifying enzyme activity and its influencing factors in a bamboo forest riparian zone in the upper reaches of the Taihu Lake Basin, China]

Soil denitrifying enzyme activity (DEA) was measured by acetylene inhibition technique, along with exploration of factors influencing DEA in a bamboo forest riparian zone in the upper reaches of the Taihu Lake Basin during summer. Our aim was to provide important insights into the assessment of ecological functions of bamboo forest riparian zone on reducing nitrogen pollution in rivers. The results showed that the riparian soil DEA ranged from 6.32 to 23.22 μg N·kg^-1·h^-1, with a mean value of 14.65 μg N·kg^-1·h^-1. The vertical distribution (0-40 cm soil profile) of DEA was affected by several factors, such as soil organic carbon (SOC), total nitrogen (TN), nitrate nitrogen (NO₃^--N), soil water content, and activity of carbon and nitrogen hydrolase, which resulted in decreased DEA with increasing soil depth. The horizontal changes in DEA (at the same soil depth but at different distances from river) was mainly governed by the variation in SOC concentration. In this area, the concentration of soil dissolved organic carbon was relatively low, which might inhibit the soil DEA during summer.

[Surveillance of Enterobius vermicularis infections among children in Shandong Province from 2016 to 2020]

OBJECTIVE

To investigate the prevalence and changing trend of Enterobius vermicularis infections among children in Shandong Province, so as to provide the scientific evidence for the adjustment and development of the enterobiasis control strategy.

METHODS

Soil-borne nematodiasis surveillance sites were assigned in 51 counties (districts, cities) in Shandong Province from 2016 to 2020, and the E. vermicularis infections were detected using a modified Kato-Katz technique and the cellophane tape method among children at ages of 3 to 9 years living in these surveillance sites. The epidemiological profiles of E. vermicularis-infected children were descriptively analyzed.

RESULTS

A total of 5 060 children at ages of 3 to 9 years were detected in 51 soil-borne nematodiasis surveillance sites in Shandong Province from 2016 to 2020, and the overall prevalence of E. vermicularis infections was 2.23%. The annual prevalence of E. vermicularis infections was 3.99% (26/651), 1.70% (14/824), 0.96% (8/837), 2.90% (45/1 552) and 1.67% (20/1 196) from 2016 to 2020, respectively, with a significant difference detected among years (χ² = 21.455, P < 0.01). The prevalence of E. vermicularis infections was 1.25% (15/1 198), 1.85% (14/755), 3.18% (84/2 640) and 0 (0/467) among children from central, eastern, southern and northern Shandong Province (χ² = 27.326, P < 0.01). In addition, there was no significant difference in the prevalence of E. vermicularis infections between male (1.98%, 56/2 831) and female children (2.56%, 57/2 229) (χ² = 1.916, P > 0.05); however, there was age-specific prevalence of E. vermicularis infections among children (χ² = 16.448, P < 0.05), with the greatest prevalence detected among children at ages of 6 years (3.18%, 25/786), and the lowest prevalence seen among children at ages of 3 years (0.75%, 6/800).

CONCLUSIONS

The prevalence of E. vermicularis infections remained at a medium level among children at ages of 3 to 9 years in Shandong Province from 2016 to 2020, with region-specific prevalence found across the province. An integrated strategy is required for enterobiasis control.

A critical review on the electrospun nanofibrous membranes for the adsorption of heavy metals in water treatment

Electrospun nanofibrous membranes (ENFMs) have many superior advantages, such as large specific surface area, high porosity, easy modification, good flexibility, and easy separation for recycling, which are consider as excellent adsorbents. In this paper, the research progress in the adsorption of heavy metals in water treatment by ENFMs is reviewed. Three types of ENFMs, including organic polymer ENFMs, organic polymer/inorganic material composite ENFMs and inorganic ENFMs are summarized, and their adsorption capacities for heavy metals in water are compared. The adsorption selectivity and capacity of ENFMs for heavy metals are depended largely on the type and number of functional groups on the surface of membranes, and usually the more the functional groups, the higher the adsorption capacity. The adsorption mechanisms of ENFMs are also mainly determined by the type of functional groups on the membrane. At present, the main challenge is to achieve the mass production of high-quality nanofibers and their actual application in the treatment of heavy metal-containing wastewater. Therefore, more consideration should be focused on the improvement of stability, mechanical strength and reusability of ENFMs. This review may provide an insight for the development of ENFMs-based adsorbents for heavy metals separation and water purification in the future.

[Epidemiological characteristics of imported malaria in Shandong province, 2017-2018]

Objective: To understand epidemiological characteristics of imported cases of malaria in Shandong province and provide scientific basis for timely adjustment of prevention and control measures. Methods: The incidence data of malaria, case investigation data and case review data by Shandong Provincial Reference Laboratory for Malaria Diagnosis from 2017 to 2018 were collected. Software SPSS 18.0 was used for statistical analysis and software QGIS 2.18 was used for mapping. Results: A total of 442 imported cases of malaria were reported in Shandong from 2017 to 2018, and the main infection source was in Africa (97.96%, 433/442). All the 17 prefectures in Shandong reported imported malaria cases, mainly in Jining (88 cases), Yantai (65 cases), Weihai (46 cases), Qingdao (44 cases) and Dezhou (42 cases), accounting for 64.48% (285/442). The cases were distributed in 77.37%(106/137) of counties of the province. The cases were reported in every month without seasonal characteristics. The median (M) of time interval between onset and the first medical care seeking was 2 days, and the interquartile range (IQR) was 3 days. The M of time interval between the first medical care seeking and final diagnosis was 0 day, and the IQR was 3 days. The proportion of medical care seeking on onset day was only 27.83% (123/442). Only 69.68% (308/442) of cases were diagnosed with malaria in the first medical care seeking, and the diagnostic accuracy of medical institutions below the county level was lower than other medical institutions (all P<0.01). Only 51.13% (226/442) of cases were diagnosed with malaria in the first medical care seeking, the differences in the rates among medical institutions at different levels were not significant (P>0.05). Conclusions: The imported malaria in Shandong was characterized by a large number of cases, multiple infection sources and wide area distribution during 2017-2018. The awareness of timely medical care seeking in the cases was low, meanwhile the awareness and ability of malaria diagnosis and treatment in primary medical institutions were still inadequate. It is necessary to adjust the prevention and control measures accordingly.

[Analysis of drug - resistant gene polymorphisms in Plasmodium falciparum imported from Equatorial Guinea to Shandong Province in 2015 and 2016]

OBJECTIVE

To investigate the drug-resistant gene polymorphisms in Plasmodium falciparum imported from Equatorial Guinea to Shandong Province.

METHODS

From 2015 to 2016, blood samples were collected from imported P. falciparum malaria patients returning from Equatorial Guinea to Shandong Province, and genome DNA of the malaria parasite was extracted. The drug-resistant Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, and K13 genes of P. falciparum were amplified using a PCR assay, followed by DNA sequencing, and the sequences were aligned.

RESULTS

The target fragments of all 5 drug-resistant genes of P. falciparum were successfully amplified and sequenced. There were 72.8%, 18.6%, and 8.6% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfcrt gene, respectively, and all mutant haplotypes were CVIET (the underline indicates the mutation site). There were 20.0%, 61.4% and 18.6% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfmdr1 gene, respectively, and the mutant haplotypes mainly included YF and NF (the underlines indicate the mutation sites). There were 1.4%, 98.6%, and 0 of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfdhfr gene, respectively, and AIRNI was the predominant mutant haplotype (the underline indicates the mutation site). There were 1.4%, 94.3%, and 4.3% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfdhps gene, respectively, and SGKAA was the predominant mutant haplotype (the underline indicates the mutation site). The complete drug-resistant IRNGE genotype consisted of 8.6% of the Pfdhfr and Pfdhps genes, and the K13 gene A578S mutation occurred in 1.4% of the parasite samples.

CONCLUSIONS

There are mutations in the Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, and K13 genes of P. falciparum imported from Equatorial Guinea to Shandong Province, with a low frequency in the Pfcrt gene mutation and a high frequency in the Pfmdr1, Pfdhfr, and Pfdhps gene mutations, and the K13 gene A578S mutation is detected in the parasite samples.

[Quality of malaria blood smears from fever patients in Zibo City, Shandong Province from 2011 to 2018]

OBJECTIVE

To analyze the quality of malaria blood smears from fever patients in Zibo City from 2011 to 2018, so as to provide the scientific evidence for the development of the malaria post-elimination surveillance strategy.

METHODS

All negative malaria blood smears from fever patients reexamined in the municipal microscopic examination station and all positive blood smears in Zibo City during the period from 2011 to 2018 were reexamined, and the blood smear preparation, dyeing, cleanliness and reexamination results were analyzed.

RESULTS

A total of 2 141 negative malaria blood smears and 39 positive blood smears were re-reviewed by the municipal microscopic examination station of Zibo City from 2011 to 2018, with a 99.44% qualification rate of negative blood smears preparation, a 97.62% qualification rate of dyeing, a 93.65% qualification rate of cleanliness, and a 100% consistence with the re-review, and no missing diagnosis was found. A total of 39 positive blood smears were re-reviewed, with a 46.15% qualification rate of blood smears preparation, a 61.54% qualification rate of dyeing, a 76.92% qualification rate of cleanliness, and a 97.44% consistence with the re-review, and a blood smear mistaking the Plasmodium species was found. There were significant differences in the qualification rate of blood smears preparation and dyeing among all districts (counties) in Zibo City (all P values < 0.05), and no significant difference was detected in the qualification rate of blood smear cleanliness (χ² = 13.72, P >0.05), while significant differences were seen in the qualification rate of blood smears preparation, dyeing and cleanliness each year from 2011 to 2018 (all P values < 0.05).

CONCLUSIONS

The quality of malaria blood smears is high in all districts of Zibo City; however, the quality of city-level blood smears remains to be improved. Further actions to improve the training of grassroots microscopic examinations and quality control of malaria blood smears are required to ensure the capability of microscopic examinations of Plasmodium during the malaria post-elimination stage.

c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 is a critical regulator for arthritis progression by meditating inflammation in mice model

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. However, the pathogenesis of RA is not fully understood. Here, we reported that c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 (JSAP1, also known as JNK-interacting protein 3 (JIP3)) was significantly important for collagen-induced arthritis (CIA) in mice. Mice with JIP3 knockout (JIP3^-/-) showed a significant decrease in arthritis index and swollen joint count in CIA mice. The histopathology of spleen and joint was markedly alleviated by JIP3 deficiency in CIA mice. Excessive macrophage activation in CIA mice was also inhibited by JIP3 deletion. CIA-induced RANKL/RANK/OPG system mRNA expression was blocked in JIP3-knockout mice. In addition, CIA-triggered cytokine secretion and TLRs/NF-κB activation was inactivated by JIP3-deficiency. In line with the inhibition of inflammation by JIP3-knockout, it also significantly suppressed JNK pathway activation induced by CIA, as evidenced by the down-regulation of p-JNK, p-c-Jun, AFT-2 and Elk-1 in joints. In vitro, RANKL-exposed RAW264.7 cells showed a significant reduction of osteoclast formation using TRAP staining. Moreover, JIP3 inhibition reduced the RANKL-caused expression of osteoclastic genes and inflammatory regulators, as well as activation of TLRs/NF-κB and JNK signaling pathways. Importantly, we found that promoting JNK activity could abrogate JIP3 knockdown-suppressed osteoclastic genes expression, inflammatory response and NF-κB activation. These findings suggested that JIP3 could significantly impede osteoclast formation and function by regulating JNK activation, illustrating a novel therapeutic strategy for managing arthritis and preventing bone destruction.

[The progress of narrow band imaging endoscopy in diagnosis of vocal cord leukoplakia]

SummaryThe appearances of vocal cord leukoplakia are largely identical in the macroscopic examination even though the pathological character may differ. This makes it difficult for physicians to evaluate the extent of dysplasia of vocal cord leukoplakia and detect the occurrence of canceration using the conventional laryngoscopy, which might result in overtreatment or undertreatment of vocal cord leukoplakia in different patients. Therefore, an accurate preoperative assessment of the pathological character of vocal cord leukoplakia shows clinical significance in the selection of an appropriate treatment plan and predicting the prognosis of a patient. Recent studies have found that narrow band imaging（NBI） endoscopy can facilitate the early and differential diagnosis of head and neck cancers by observing the intraepithelial papillary capillary loop（IPCL） patterns at the mucosal surfaces. In this paper, the recent progress of NBI endoscopy in the diagnosis of vocal cord leukoplakia is reviewed.

[Effects of low temperature on trehalose and trehalase contents in Culex pipiens pallens]

OBJECTIVE

To examine the effect of low temperature on trehalose and trehalase levels in Culex pipiens pallens.

METHODS

The fourth instar larvae and female adult mosquitoes of Cx. pipiens pallens were exposed at 4 ℃ for 0, 1, 3, 6, 12, 18, 24 h and 0, 1, 3, 6, 12, 18, 24, 36, 48, 72 h, respectively. Then, the trehalose and trehalase contents were detected by enzyme-linked immunosorbent assay (ELISA) in mosquitoes.

RESULTS

The contents of trehalose and trehalase significantly increased in the larval and female adult mosquitoes post-exposure to low temperature. The changing trend of trehalose levels was consistent in the larval and female adult mosquitoes, and the highest levels were (2.458 8 ± 0.379 2) mg/g and (2.825 7 ± 0.211 1) mg/g 3 h post-exposure to low temperature, respectively. The trehalose and trehalase levels fluctuated greatly within the first 6 h post-exposure to low temperature. Following adaptation for a period of time, the trehalose and trehalase levels remained at a relatively high level.

CONCLUSIONS

Low temperature may induce the production of trehalose and trehalase in Cx. pipiens pallens, and the trehalose and trehalase may play an important role in the improvement of the cold resistance.

Dual‑sensitive HRE/Egr1 promoter regulates Smac overexpression and enhances radiation‑induced A549 human lung adenocarcinoma cell death under hypoxia

The aim of this study was to construct an expression vector carrying the hypoxia/radiation dual‑sensitive chimeric hypoxia response element (HRE)/early growth response 1 (Egr‑1) promoter in order to overexpress the therapeutic second mitochondria‑derived activator of caspases (Smac). Using this expression vector, the present study aimed to explore the molecular mechanism underlying radiotherapy‑induced A549 human lung adenocarcinoma cell death and apoptosis under hypoxia. The plasmids, pcDNA3.1‑Egr1‑Smac (pE‑Smac) and pcDNA3.1‑HRE/Egr-1‑Smac (pH/E‑Smac), were constructed and transfected into A549 human lung adenocarcinoma cells using the liposome method. CoCl2 was used to chemically simulate hypoxia, followed by the administration of 2 Gy X‑ray irradiation. An MTT assay was performed to detect cell proliferation and an Annexin V‑fluorescein isothiocyanate apoptosis detection kit was used to detect apoptosis. Quantitative polymerase chain reaction and western blot analyses were used for the detection of mRNA and protein expression, respectively. Infection with the pE‑Smac and pH/E‑Smac plasmids in combination with radiation and/or hypoxia was observed to enhance the expression of Smac. Furthermore, Smac overexpression was found to enhance the radiation‑induced inhibition of cell proliferation and promotion of cycle arrest and apoptosis. The cytochrome c/caspase‑9/caspase‑3 pathway was identified to be involved in this regulation of apoptosis. Plasmid infection in combination with X‑ray irradiation was found to markedly induce cell death under hypoxia. In conclusion, the hypoxia/radiation dual‑sensitive chimeric HRE/Egr‑1 promoter was observed to enhance the expression of the therapeutic Smac, as well as enhance the radiation‑induced inhibition of cell proliferation and promotion of cycle arrest and apoptosis under hypoxia. This apoptosis was found to involve the mitochondrial pathway.

Lentiviral-mediated RNA interference targeting the PLK1 gene inhibits invasion and metastasis of esophageal squamous cell carcinoma cells

AIM: To investigate the inhibitory effect of lentiviral-mediated RNA interference targeting the PLK1 gene on invasion and metastasis of esophageal squamous cell carcinoma (ESCC) cells.

METHODS: RT-PCR and Western blot were used to detect the expression of PLK1 mRNA and protein in different ESCC cells. Based on the mRNA sequence of human PLK1 gene, interference fragments were designed, and interference efficiency was detected by Western blot. The in vitro effect of PLK1 siRNA on migration and invasion of ESCC cells was assessed by wound-healing assay and Matrigel chemoinvasion assay. The most efficient interference fragment was cloned into the lentiviral vector pGLV/H1/GFP+Puro and sequenced. The resulting recombinant lentiviral vector and packaging plasmids were transfected into 293T cells, and packaged virus particles were used to infect ESCC cells. Interference efficiency was assessed using fluorescence quantitative PCR and Western blot. The in vivo effect of recombinant lentiviral vector on invasion and metastasis of ESCC cells was studied using a nude mouse model of pulmonary metastasis.

RESULTS: The ESCC cell line TE-8 overexpressed PLK1, and the most efficient PLK1 siRNA could obviously inhibit migration and invasion of TE-8 cells in vitro. The lentiviral vector for RNA interference targeting the PLK1 gene was successfully constructed. The prepared recombinant virus particles could infect TE-8 cells and significantly inhibit the metastasis of ESCC cells in vivo.

CONCLUSION: Lentiviral-mediated RNA interference targeting PLK1 could obviously inhibit invasion and metastasis of ESCC cells. PLK1 may promote the malignant development of ESCC.

Well-oriented ZZ-PS-tag with high Fc-binding onto polystyrene surface for controlled immobilization of capture antibodies

The site specificity and bioactivity retention of antibodies immobilized on a solid substrate are crucial requirements for solid phase immunoassays. A fusion protein between an immunoglobulin G (IgG)-binding protein (ZZ protein) and a polystyrene-binding peptide (PS-tag) was constructed, and then used to develop a simple method for the oriented immobilization of the ZZ protein onto a PS support by the specific attachment of the PS-tag onto a hydrophilic PS. The orientation of intact IgG was achieved via the interaction of the ZZ protein and the constant fragment (Fc), thereby displayed the Fab fragment for binding antigen. The interaction between rabbit IgG anti-horseradish peroxidase (anti-HRP) and its binding partner HRP was analyzed. Results showed that the oriented ZZ-PS-tag yielded an IgG-binding activity that is fivefold higher than that produced by the passive immobilization of the ZZ protein. The advantage of the proposed immunoassay strategy was demonstrated through an enzyme-linked immunosorbent assay, in which monoclonal mouse anti-goat IgG and HRP-conjugated rabbit F(ab')2 anti-goat IgG were used to detect goat IgG. The ZZ-PS-tag presented a tenfold higher sensitivity and a wider linear range than did the passively immobilized ZZ protein. The proposed approach may be an attractive strategy for a broad range of applications involving the oriented immobilization of intact IgGs onto PS supports, in which only one type of phi-PS (ZZ-PS-tag) surface is used.

The tumor suppressor gene RhoBTB1 is a novel target of miR-31 in human colon cancer

miRNAs are a class of endogenous non-coding RNA, which can regulate downstream target genes through binding to the 3'UTR of those genes. Numerous studies have indicated that abnormal expression of miRNAs is implicated in tumor development. Aberrant expression of miR-31 has been found in various cancers, including colorectal cancer. Here, we show that miR-31 is upregulated in human colon cancer tissues and cell lines, and that repression of miR-31 inhibited colon cancer cell proliferation and colony formation in soft agarose. To further elucidate the mechanism underlying the role of miR-31 in promoting colon cancer, we used online miRNA target prediction databases and found that the tumor suppressor RhoTBT1 may be a target of miR-31. Imunohistochemistry assay revealed that RhoBTB1 was significantly decreased in HT29 cells. In addition, ectopic expression of miR-31 reduced RhoBTB1 in the colon cancer cell line HT29. The results suggested that suppression of RhoBTB1 may be responsible for colon tumorigenesis, which was inhibited directly by miR-31. The results of MTT and soft agarose colony-formation assays showed that knockdown of RhoBTB1 by RNAi induced cell proliferation, and colony formation in soft agarose, which mimicked the function of miR-31. This further suggested that suppression of RhoBTB1 was responsible for colon tumorigenesis. In conclusion, we found that miR-31 acts as an oncogene in colon cancer and identified RhoBTB1 as a new target of miR-31 further study demonstrated that miR-31 contributed to the development of colon cancer at least partly by targeting RhoBTB1.

[Evaluation of soil lead contamination by biomarkers in leaves of Vicia faba L. seedlings]

Stress proteins (HSP70 and HSP60) and other related biological parameters were investigated in leaves of Vicia faba L. seedlings subjected to soil lead stress. The seedlings were cultivated outdoors in pots for five weeks. Results showed that total lead content, superoxide radical (O2*-) and lipid peroxidation productions in the leaves increased with the increase of extraneous lead in soils. Significant correlation was found between the O2*- and lipid peroxidation productions (r = 0.973, p < 0.01). Activities of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were activated. Moreover, HSP70 and HSP60 increased more sensitively than the other parameters in response to lead stress. This indicates lead might cause lipid peroxidation in the leaves by mediation of O2*-. The activated antioxidative enzymes alleviated the stress and damage of reactive oxygen species. HSP70 and HSP60 are potential biomarkers for early warning of lead-contaminated soils. Additionally, concentrations of soil lead and related biological parameters should be combined.

Clinical measurement of antibodies against acetylcholine receptor (AchR), SOD and LPO in patients with myasthenia gravis (MG) before and after thymectomy

The antibodies against acetylcholine receptor AchR and levels of SOD and LPO were measured in 11 patients with myasthenia gravis (MG), and the results were compared with normal controls and patients with diseases other than MG. The results showed that the antibodies against AchR were higher as compared with other groups before and after operation. The post-operative level of antibodies was obviously lower than the pre-operative value. An slight increase in SOD and significant decrease in mean value of LPO after surgery were noted. The possible mechanism was discussed.

Rupture of thoracic aortic aneurysm into the lung with formation of pseudoaneurysm: diagnosis and treatment

Three patients with rupture of thoracic aortic aneurysm into the lung with formation of pseudoaneurysm were admitted to our hospital in 1991, of whom, 2 had ascending aortic aneurysms which ruptured into the right upper pulmonary lobe, and another one had descending aortic aneurysm rupturing into the left upper lobe. All 3 cases were misdiagnosed as having pulmonary carcinoma or mediastinal tumor by the other hospital as well as by us. Correct diagnosis was made by aortography or at exploratory thoracotomy. Our preliminary experiences in the diagnosis and treatment of the disease are presented in this paper.

Surgical treatment of double-chamber right ventricle and its associated anomalies

A report on the results of surgical treatment of 5 cases of DCRV and its associated anomaly was presented in this paper. No definite diagnosis of DCRV was made prior to operation. It was found that 2 cases had DCRV as an isolated anomaly, another 2 had the disease associated with VSD, and the remaining 1 had DCRV with right ventricle to left atrium cannulation. Muscular membrane septum type was found in 3 cases, and muscular bundle type in 2.4 cases diagnosed as having DCRV or DCRV with other heart anomalies during operation were treated properly and discharged fully recovered. 1 case died of acute heart insufficiency. Pathologic anatomy and physiology, associated anomalies of DCRV, and some experience with the operative approach were discussed in this article.

Octopamine selectively modifies the slow component of sensory adaptation in an insect mechanoreceptor

The effects of octopamine were studied on the dynamic behavior of the sensory neuron in the cockroach femoral tactile spine. The neuron is a rapidly adapting mechanoreceptor in which adaptation occurs by elevation of the threshold for action potential encoding. The threshold follows increases or decreases of membrane potential, with a delay that involves two separate exponential components. Previous evidence has associated the slow component with sodium pumping and the fast component with sodium channel inactivation. Octopamine reversibly raised the resting threshold and increased but slowed the slow component. These data indicate that octopamine has specific effects on membrane-ionic processes in insect sensory neurons.

[Therapeutic effects of epimeric glycyrrhizic acids on hepatic injury in rats]

The effects of the epimeric glycyrrhizic acids (GA), 18 alpha-form and 18 beta-form, on D-galactosamine (Gal)-induced acute liver injury and fulminating hepatic failure (FHF) in rats were studied. In rats of acute liver injury, extensive liver parenchymal cell damage was observed by the elevation of alanine aminotransferase (ALT) activity and confirmed by significant histopathological changes 24 and 48 h after ip Gal 450 mg.kg-1. Moreover, marked elevation in the liver putrescine levels occurred along with that of serum ALT. The spermidine and spermine levels did not alter significantly. GA 18 alpha-form 300 mg.kg-1 ip suppressed the elevation of serum ALT and liver putrescine levels, and improved all the histopathologic features. On the other hand, GA 18 beta-form 300 mg.kg-1, which exhibited inhibitory effects 24 h after ip Gal, showed no action 48 h after ip Gal. The ALT levels in the serum from GA 18 alpha-form, 18 beta-form, vs control groups after 24 h were 70 +/- 24 (P < 0.01) and 78 +/- 42 (P < 0.01) vs 155 +/- 57, and after 48 h were 74 +/- 25 (P < 0.01) and 258 +/- 99 (P > 0.05) vs 293 +/- 110. The putrescine contents (nmol.g-1) in the liver from GA 18 alpha-form, 18 beta-form, vs control after 24 h were 34 +/- 9 (P < 0.01) and 51 +/- 12 (P < 0.01) vs 139 +/- 29, and after 48 h were 16 +/- 3 (P < 0.01) and 150 +/- 11 (P > 0.05) vs 156 +/- 23.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective action of selenium and manganese on xanthine and xanthine oxidase induced oxidative damage to cultured heart cells

Ventricular myocytes from neonatal Wistar rats were cultured with 80% Dulbecoo's modified Eagle medium and 20% fetal bovine serum. An appropriate amount of xanthine and xanthine oxidase was added to the culture medium to increase the content of free radicals in cardiac cells. Variation in action potential and input impedance of cardiac myocytes indicated the oxidative damage to the membrane. The ultrastructure of heart cells, characteristically the myofilaments and mitochondria, was damaged. Electron spin resonance measurement demonstrated that xanthine and xanthine oxidase elevated the free radical content, while selenium (Se) and manganese (Mn) reduced the free radicals in cultured heart cells. Supplementation of 0.173 microgram/ml Se and 0.1 microgram/ml Mn into the culture medium separately or simultaneously antagonized the damage induced by xanthine and xanthine oxidase. The possible mechanism might be the production of superoxide anion free radical leading to free radical damage to cardiac cells. Se and Mn might play a role as scavengers through glutathione peroxidase and superoxide dismutase respectively and thus protect cardiac cells from free radical damage.

[Evolution of autologous graft interface in rats: experimental study]

With purpose to study the evolution of autologous venous graft interface, an experimental model utilizing an autologous venous patch to repair an infrarenal abdominal aortic defect in rats was developed. A small piece of both the jugular vein and the aorta were first excised. After implantation and reestablishment of blood flow, the animals were subsequently sacrificed in groups of 3 at the following intervals: 10 seconds, 1 minute, 10 minutes, 30 minutes, 1 hour, 6 hours, 12 hours, 24 hours, 7 days, 30 days and 90 days. All the patches and adjacent aortae were collected and studied using scanning electron microscopy, with the following results: 1) the endothelial lining of both the autologous vein patch and the adjacent aorta is destroyed before implantation due to operative manipulation; 2) after blood flow reestablishment, the patch and adjacent aortic interfaces are reactive to platelets and other blood cells; 3) New endothelial lining begins to appear from the 7th day after implantation, but the regeneration is not complete at 3 months. From the model, it is deducted that the endothelial repair of autologous venous patch and its adjacent aorta involves a very slow process.