Efficient degradation of polystyrene microplastic pollutants in soil by dielectric barrier discharge plasma

In this study, the atmospheric dielectric barrier discharge (DBD) plasma was proposed for the degradation of polystyrene microplastics (PS-MPs) for the first time, due to its ability to generate reactive oxygen species (ROS). The local temperature in plasma was found to play a crucial role, as it enhanced the degradation reaction induced by ROS when it exceeded the melting temperature of PS-MPs. Factors including applied voltage, air flow rate, and PS-MPs concentration were investigated, and the degradation products were analyzed. High plasma energy and adequate supply of ROS were pivotal in promoting degradation. At 20.1 kV, the degradation efficiency of PS-MPs reached 98.7% after 60 min treatment, with gases (mainly COx, accounting for 96.4%) as the main degradation products. At a concentration of 1 wt%, the PS-MPs exhibited a remarkable conversion rate of 90.6% to COx, showcasing the degradation performance and oxidation degree of this technology. Finally, the degradation mechanism of PS-MPs combined with the detection results of ROS was suggested. This work demonstrates that DBD plasma is a promising strategy for PS-MPs degradation, with high energy efficiency (8.80 mg/kJ) and degradation performance (98.7% within 1 h), providing direct evidence for the rapid and comprehensive treatment of MP pollutants.

Mass concentration and distribution characteristics of microplastics in landfill mineralized refuse using efficient quantitative detection based on Py-GC/MS

Landfilling is the most traditional disposal method of domestic waste. Plastic waste in landfill sites could degrade to microplastics (MPs) and diffuse to the surrounding environment with leachate. However, MPs pollution in landfill mineralized refuse has not been well recognized. In the present research, a detection method for mixed MPs of polyethylene (PE), polypropylene (PP), and polystyrene (PS) based on Py-GC/MS was established and verified. The method is suitable for the rapid quantitative detection of large-batch of complex solid matrix samples, with an average deviation of less than 10%. Based on the method, samples from a landfill site in South China were studied, where PE was found to be the main component. The total concentration of MPs in mineralized refuse was 7.62 kg/t in the old area and 5.49 kg/t in the young area. Further analysis showed that the content of MPs was correlated with that of plastic waste and the landfill age, indicating that a considerable proportion was secondary MPs. The reserves of MPs in landfill sites may have reached an alarming number. In the absence of adequate safeguards, quantities of MPs may spread from the landfill sites, resulting in serious pollution of the surrounding soil and groundwater.

Dielectric barrier discharge plasma for the remediation of microplastic-contaminated soil from landfill

The huge amount of plastic waste accumulated in landfills has caused serious microplastic (MP) pollution to the soil environment, which has become an urgent issue in recent years. It is challenging to deal with the non-biodegradable MP pollutants in actual soil from landfills. In this study, a coaxial dielectric barrier discharge (DBD) system was proposed to remediate actual MP-contaminated landfill soil due to its strong oxidation capacity. The influence of carrier gas type, applied voltage, and air flow rate was investigated, and the possible degradation pathways of MP pollutants were suggested. Results showed the landfill soil samples contained four common MP pollutants, including polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC) with sizes ranging from 50 to 1500 μm. The MP pollutants in the soil were rapidly removed under the action of reactive oxygen species (ROS) generated by DBD plasma. Under the air flow rate of 1500 mL min^-1, the maximum remediation efficiency represented by mass loss reached 96.5% after 30 min treatment. Compared with nitrogen, when air was used as the carrier gas, the remediation efficiency increased from 41.4% to 81.6%. The increased applied voltage from 17.5 to 24.1 kV could also promote the removal of MP contaminants. Sufficient air supply was conducive to thorough removal. However, when the air flow rate reached 1500 mL min^-1 and continued to rise, the final remediation efficiency would be reduced due to the shortened residence time of ROS. The DBD plasma treatment proposed in this study showed high energy efficiency (19.03 mg kJ^-1) and remediation performance (96.5%). The results are instructive for solving MP pollution in the soil environment.

Curcumin prevents obesity by targeting TRAF4-induced ubiquitylation in m6 A-dependent manner

Obesity has become a major health problem that has rapidly prevailed over the past several decades worldwide. Curcumin, a natural polyphenolic compound present in turmeric, has been shown to have a protective effect on against obesity and metabolic diseases. However, its underlying mechanism remains largely unknown. Here, we show that the administration of curcumin significantly prevents HFD-induced obesity and decreases the fat mass of the subcutaneous inguinal WAT (iWAT) and visceral epididymal WAT (eWAT) in mice. Mechanistically, curcumin inhibits adipogenesis by reducing the expression of AlkB homolog 5 (ALKHB5), an m6 A demethylase, which leads to higher m6 A-modified TNF receptor-associated factor 4 (TRAF4) mRNA. TRAF4 mRNA with higher m6 A level is recognized and bound by YTHDF1, leading to enhanced translation of TRAF4. TRAF4, acting as an E3 RING ubiquitin ligase, promotes degradation of adipocyte differentiation regulator PPARγ by a ubiquitin-proteasome pathway thereby inhibiting adipogenesis. Thus, m6 A-dependent TRAF4 expression upregulation by ALKBH5 and YTHDF1 contributes to curcumin-induced obesity prevention. Our findings provide mechanistic insights into how m6 A is involved in the anti-obesity effect of curcumin.

YBX1 Protects against Apoptosis Induced by Oxygen-Glucose Deprivation/Reoxygenation in PC12 Cells via Activation of the AKT/GSK3β Pathway

Reperfusion therapies for ischaemic stroke can induce secondary injury accompanied by neuronal death. The Y-box binding protein 1 (YBX1), an oncoprotein, is critical for regulating tumour cell proliferation and apoptosis. Thus, we wanted to know whether YBX1 could regulate neuronal cell apoptosis caused by cerebral ischaemia/reperfusion (I/R). We established a model of cerebral I/R-induced injury in vitro by oxygen-glucose deprivation/reoxygenation (OGD/R) treatment and determined YBX1 expression using Western blot. Next, the effect of YBX1 on the apoptosis and viability of OGD/R-treated PC12 cells was evaluated by flow cytometry, MTT assay, and Western blot. Besides, the release of lactate dehydrogenase (LDH) and the activity of catalase (CAT) and superoxide dismutase (SOD) were detected to evaluate oxidative stress of PC12 cells induced by OGD/R. The regulatory roles of YBX1 in the AKT/GSK3β pathway were examined by Western blot. As a result, OGD/R treatment down-regulated YBX1 expression in PC12 cells. YBX1 over-expression attenuated the growth inhibition and apoptosis of PC12 cells induced by OGD/R. Besides, the increase of LDH release and the decrease of SOD and CAT activities caused by OGD/R were reversed by YBX1 over-expression. Moreover, YBX1 over-expression could activate the AKT/GSK3β pathway in OGD/ R-treated PC12 cells. Therefore, YBX1 could protect against OGD/R-induced injury in PC12 cells through activating the AKT/GSK3β signalling pathway, and thus YBX1 has the potential to become a therapeutic target for cerebral I/R-induced injury.

Phosphorylation of 5-LOX: The Potential Set-point of Inflammation

Inflammation secondary to tissue injuries serves as a double-edged sword that determines the prognosis of tissue repair. As one of the most important enzymes controlling the inflammation process by producing leukotrienes, 5-lipoxygenase (5-LOX, also called 5-LO) has been one of the therapeutic targets in regulating inflammation for a long time. Although a large number of 5-LOX inhibitors have been explored, only a few of them can be applied clinically. Surprisingly, phosphorylation of 5-LOX reveals great significance in regulating the subcellular localization of 5-LOX, which has proven to be an important mechanism underlying the enzymatic activities of 5-LOX. There are at least three phosphorylation sites in 5-LOX jointly to determine the final inflammatory outcomes, and adjustment of phosphorylation of 5-LOX at different phosphorylation sites brings hope to provide an unrecognized means to regulate inflammation. The present review intends to shed more lights into the set-point-like mechanisms of phosphorylation of 5-LOX and its possible clinical application by summarizing the biological properties of 5-LOX, the relationship of 5-LOX with neurodegenerative diseases and brain injuries, the phosphorylation of 5-LOX at different sites, the regulatory effects and mechanisms of phosphorylated 5-LOX upon inflammation, as well as the potential anti-inflammatory application through balancing the phosphorylation-depended set-point.

The rates of second lung cancers and the survival of surgically-resected second primary lung cancers in patients undergoing resection of an initial primary lung cancer

BACKGROUND

The Lung Cancer Screening Trial demonstrated improved overall survival (OS) and lung cancer specific survival (LCSS), likely due to finding early-stage NSCLC. The purpose of our investigation is to evaluate whether long-term surveillance strategies (4+ years after surgical resection of the initial lung cancer(1LC)) would be beneficial in NSCLC patients by assessing the rates of second lung cancers(2LC) and the OS/LCSS in patients undergoing definitive surgery in 1LC as compared to 2LC (>48 months after 1LC) populations.

METHODS

SEER13/18 database was reviewed for patients during 1998-2013. Log-rank tests were used to determine the OS/LCSS differences between the 1LC and 2LC in the entire surgical group(EG) and in those having an early-stage resectable tumors (ESR, tumors <4 cm, node negative). Joinpoint analysis was used to determine rates of second cancers 4-10 year after 1LC using SEER-9 during years 1985-2014.

RESULTS

The rate of 2LCs was significantly less than all other second cancers until 2001 when the incidence of 2LCs increased sharply and became significantly greater than all other second cancers in females starting in year 2005 and in men starting in year 2010. OS/LCSS, adjusted for propensity score by using inverse probability weighting, demonstrated similar OS, but worse LCSS for 2LCs in the EG, but similar OS/LCSSs in the ESR group.

CONCLUSION

Because the rate of 2LCs are increasing and because the OS/LCSS of the 1LC and 2LC are similar in early-stage lesions, we feel that continued surveillance of patients in order to find early-stage disease may be beneficial.

Microbial Community and Short-Chain Fatty Acid Mapping in the Intestinal Tract of Quail

Simple Summary

Quail is an economically important type of poultry, valued for its high meat quality and abundant egg nutrition. It is also an important laboratory research animal, widely used in developmental biology and toxicology tests. Since the gut microbiota plays a vital role in the host’s growth and health, we investigated the microbiota inhabiting the duodenum, jejunum, ileum, cecum, and colorectum of quail in the present study, using 16S rRNA gene sequencing and qPCR. The concentrations of short-chain fatty acids (SCFAs) were evaluated using gas chromatography. We found that the microbiota in the cecum was different from other intestinal sections and the enriched inhabitants of SCFA-producing bacterial genera made cecum the core locations of SCFA production in quail. The results of this study will provide fundamental data for further quail microbiology and functional studies.

Abstract

Quail is raised throughout China for egg and meat production. To deeply understand the gastrointestinal microbial composition and metabolites of quail, the present study characterized the microbiota inhabiting five intestinal locations of eight-week-old quail using 16S rRNA gene sequencing and qPCR, and evaluated the concentrations of short-chain fatty acids (SCFAs) in each individual location using gas chromatography. The results showed that Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, and Deferribacteres were the five most abundant phyla in the intestinal tract of quail. Firmicutes was largely dominant (>95%) in the small intestine, whereas Bacteroidetes increased significantly in the cecum (19.19%) and colorectum (8.09%). At the genus level, Lactobacillus was predominant in almost all sections (>50%) except in the cecum (7.26%), where Megamonas, Faecalibacterium, and Bacteroides were dominant. qPCR data indicated that the population sizes of both the total bacteria and proportions of the Firmicutes, Bacteroidetes, and Bacteroides group increased going from the proximal toward the distal end of the intestine in quail. The SCFA-producing bacterial genera Bacteroides, Faecalibacterium, Alistipes, Blautia, Parabacteroides, and Clostridium were of higher richness in the cecum and colorectum, where, accordingly, more SCFAs were produced. These findings will be helpful for the future study of quail microbiology, as well as its relationship with productive performance and health.

[Treatment of parotid hemangioma in children]

Objective:To summarize the treatment and effect of children with parotid hemangioma. Method:Thirty-three children with parotid hemangioma were treated with drug in 22 cases, 9 of which received propranolol orally, accounting for 27%; 13 cases underwent B-ultrasound guided bleomycin injection, accounting for 40%; another 11 cases were used. The treatment of surgical removal of hemangioma, accounting for 33%. Result:In 22 children with drug therapy, the evaluation criteria were evaluated by Achauer et al. 12 cases of grade Ⅳ, accounting for 54.5%; 7 cases of grade Ⅲ, accounting for 31.8%; 2 cases of grade Ⅱ, accounting for 9%. For example, accounted for 4.5%; 2 of them（1 in gradeⅠand Ⅱ） were treated with drug therapy for 6 months after surgical resection of hemangioma. Eleven children underwent surgical resection of hemangioma, and 8 patients underwent complete resection of the tumor, accounting for 73%. Among them, 3 patients had residual hemangiomas during operation, and the residual tumor was treated with bleomycin. This group of medications showed that children aged<12 months, after oral propranolol, the tumors were reduced to varying degrees, the most significant change within 1 week after administration, and then the tumor was further reduced until the end of treatment. Conclusion:B-ultrasoun lower bleomycin injection in children with parotid hemangioma is effective, and the incidence of adverse reactions is low, but multiple courses of treatment are required. For patients with poor drug treatment, recurrence or limited range, surgical resection of blood vessels can be selected. Tumor surgery should pay attention to the choice of indications and surgical operation skills, reduce the risk of facial nerve injury and postoperative facial scars. There are many different treatments for infantile hemangioma, but there is still no treatment for all children. The drug treatment of this group showed that after oral propranolol, the tumors were all reduced to varying degrees, the color became lighter, the texture became softer, and the change was most significant within 1 week after administration, and then the tumor was further reduced until the end of treatment. B-ultrasound guided bleomycin injection in children with parotid hemangioma is effective. After 1-2 courses of treatment, the tumor shrinks significantly and the incidence of adverse reactions is low. Drug treatment of parotid hemangioma in children is simple. A safe and effective method. For children with poor drug treatment, recurrence or limited range, surgical treatment of hemangioma can be selected. Surgery should pay attention to the choice of indications and surgical operation skills, reduce the risk of facial nerve injury and postoperative facial scars.

[Determination of relative elements of hard metal in workplace air and urine by inductive coupled plama]

Objective: To establish a rapid detection method regarding the air conditions of workplace and the workers' urine included Tungsten, Cobalt, Nickel, Titanium, Cadmium, Manganese, Lead and its compounds based on inductively coupled plasma mass spectrometry (ICP-MS) . Methods: The experiment adopts ICP-MS to deter-mine those metals in workshop air and workers urine, evaluate the detection's limitation, the precision and accuracy of the method. Using the membrane filter and urine freeze - dried metal standard material to verify this method. Results: Each element of correlation coefficient was greater than 0.999. The recovery rate of air samples was 91.6%~104.6%, within-batch RSD precision was 1.41%~3.50%, between-run precision was 1.28%~4.31%, urine samples recovery rate was 93.0%~102.6%, within - batch RSD precision was 1.25%~3.56%, between - run precision was 1.58%~4.67%, According to the method every element was within the scope of the standard reference, it was also showed that the established method is accurate and reliable. Conclusion: ICP-MS is an effective and feasible method to detect the workshop air and the workers' urine which included Tungsten, Cobalt, Nickel, Titanium, Cadmium, Manganese, Lead and its compounds.

[Sclerotherapy for faciocervical lymphatic malformations under digital subtraction angiography in children]

Objective:To investigate the efficacy and advantages of fluoroscopy sclerotherapy treatment for the faciocervical lymphatic malformations (LMs) under digital subtraction angiography (DSA) in children. Method:Retrospective analysis of 48 cases of lymphatic malfromations who were treated with intratumoral injection of Pingyangmycin and iohexol under DSA and fluoroscopy, and followed up in Kunming children's hospital. Result:Forty-eight cases of children were treated 1 to 5 intratumoral injection of Pingyangmycin and iohexol that carried out under DSA and fluoroscopy. Follow up ranged from 6 to 18 months, 22 cases (45.83%) were cured, 19 cases (39.85%) were markedly effective, 5 cases (10.42%) were effective and 2 cases (4.17%) were ineffective. The total effective rate was 95.83% with no scarring, pigmentation and significant postoperative complications. Conclusion:Intratumoral injection of Pingyangmycin under DSA is an effective and safe method for treatment of lymphatic malformations in children and has the advantages of positioning accuracy, less damage, fewer complication and no influence on apperarence and function.

Low molecular weight polyethylenimine as a transgenic vector for tumor gene therapy

We constructed a polymer composed of a series of small molecule polyethylenimine (PEI) using 4-arm polyethylenimine (PEG) as a core for tumor gene therapy. N,N'-carbonyldiimidazole and N-succinimidyl-3-(2-pyridyldithio) propionate were used as chemical connecting reagents to synthesize 4-arm PEG-PEI2000 and 4-arm PEG-PEI2000-MC11. Chemical characterization was performed using (1)H-NMR. The retardation effect of polymers on plasmid DNA was observed using electrophoretic mobility shift and MTT assays to test the toxicity of the polymers. The gene delivery capability of 4-arm PEG-PEI2000 and 4-arm PEG-PEI2000-MC11, and the effect of MC11 were determined by an in vitro gene delivery experiment with human hepatoma HepG2 cells. At a N:P ratio of 3, the 4-arm PEG-PEI2000 could retard successfully plasmid DNA with low toxicity. In experiments in vitro, when the N:P ratio was 30, the gene delivery efficiency of 4-arm PEG-PEI2000 in HepG2 cells was five times that of PEI2000; After connecting ligand MC11, however, the gene delivery efficiency was twice as great. Free MC11 effectively inhibited the gene delivery efficiency of the 4-arm PEG-PEI2000-MC11. Four-arm PEG-PEI2000 has low toxicity and high gene delivery efficiency, and is an effective gene delivery vector after linking ligand MC11.

Two polymorphisms of CD44 3'UTR weaken the binding of miRNAs and associate with naso-pharyngeal carcinoma in a Chinese population

OBJECTIVE

CD44 is a member of adhesion molecule families whose function is closely associated with cancer cell metastatic spread and drug resistance. CD44 is expressed as a wide variety of isoforms but 3' untranslated region (3'UTR) is conserved relatively and it is confirmed that more than ten miRNAs regulate the expression of CD44. The aim of this paper is to investigate the association between polymorphisms existed in CD44 3'UTR and nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS

We scanned 1.5kb of CD44 3'UTR in a 287 patients and 507 controls Chinese Han population. After statistical analysis we found that the minor alleles of rs13347 C/T and rs115214213 T/C are associated with NPC (OR = 1.94 95% CI = 1.44-2.62; OR = 2.07 95% CI = 1.65-2.60). By using bioinformatics tools, we found that rs115214213 may exist in the target region of miR-590-3p. Subsequently, we confirmed that miR-590-3p can repress CD44 expression and promote the apoptosis of CNE2 cells induced by cisplatin in vitro. After that, our transient transfection focusing on reporter gene expression modulated by CD44 3'UTR demonstrated that the presence of an rs13347T allele and rs115214213C allele led to greater transcriptional activity than the rs13347C allele and rs115214213T allele. Similarly, more CD44 expression was shown in minor allele carriers in our western blotting results.

CONCLUSIONS

All these findings suggest that CD44 rs13347C>T and rs115214213T>C polymorphisms may affect NPC development by improving CD44 expression.

Autophagy and chemotherapy resistance: a promising therapeutic target for cancer treatment

Induction of cell death and inhibition of cell survival are the main principles of cancer therapy. Resistance to chemotherapeutic agents is a major problem in oncology, which limits the effectiveness of anticancer drugs. A variety of factors contribute to drug resistance, including host factors, specific genetic or epigenetic alterations in the cancer cells and so on. Although various mechanisms by which cancer cells become resistant to anticancer drugs in the microenvironment have been well elucidated, how to circumvent this resistance to improve anticancer efficacy remains to be defined. Autophagy, an important homeostatic cellular recycling mechanism, is now emerging as a crucial player in response to metabolic and therapeutic stresses, which attempts to maintain/restore metabolic homeostasis through the catabolic lysis of excessive or unnecessary proteins and injured or aged organelles. Recently, several studies have shown that autophagy constitutes a potential target for cancer therapy and the induction of autophagy in response to therapeutics can be viewed as having a prodeath or a prosurvival role, which contributes to the anticancer efficacy of these drugs as well as drug resistance. Thus, understanding the novel function of autophagy may allow us to develop a promising therapeutic strategy to enhance the effects of chemotherapy and improve clinical outcomes in the treatment of cancer patients.

Sustained performance by red and white muscle fibres from the dogfish Scyliorhinus canicula

The mechanical performance of red and white muscle fibres from dogfish was compared during a long series of contractions with sinusoidal movement or under isometric conditions at 12°C (normal in vivo temperature). Power output was measured during sinusoidal movement at 0.75 Hz and peak-to-peak amplitude about 12% L0. Tetanus duty cycle was 33% (0.44 s) at phase −8% (first stimulus at 0.107 s before shortening started). Initially, the red fibres produced only about one third as much power as the white fibres, 6.57±0.63 W kg−1 wet mass (mean ± s.e.m.) and 18.3±2.3, respectively. Red fibres were better at sustaining power output; it declined rapidly to about 60% of its initial value and then remained relatively steady for up to 450 cycles of movement. Force during shortening declined, but force during stretch did not increase: force always relaxed to a low value before stretch started. By contrast, net power output by white fibres declined rapidly to zero within about 50 cycles. Two changes contributed: decline in force during shortening and an increase in force during stretch because relaxation became progressively less complete during the series of contractions. In isometric series (0.44 s stimulation every 1.33 s, cycle frequency 0.75 Hz), red and white fibres sustained peak isometric force similarly; in the 50th cycle force was 59±3% and 56±4% of initial values. The time required for force to relax to 10% of its maximum value decreased during the series for red fibres and increased for white fibres.

Professionalism: the major factor influencing job satisfaction among Korean and Chinese nurses

BACKGROUND

The nursing shortage has become an internationally important issue. Nurses' professionalism and job satisfaction have been recognized as strong factors influencing their turnover. As international interchanges in nursing education are growing between Korea and China, understanding the commonalities and differences in factors associated with job satisfaction is critical to improving nurses' job retention.

AIM

To compare the factors influencing job satisfaction among Korean and Chinese nurses.

METHOD

A cross-sectional survey was conducted. The participants were comprised of 693 nurses at three general hospitals in Jinan, People's Republic of China and 593 nurses at two general hospitals in Seoul, Korea. A questionnaire was designed to measure the nurses' professionalism and job satisfaction. Stepwise multiple regression analysis was performed to identify factors related to job satisfaction.

RESULTS

Professionalism was the common factor influencing job satisfaction in Korean and Chinese nurses. Professionalism was positively related to job satisfaction in both groups. Additional factors associated with job satisfaction were demographics and job characteristics such as age, job position and department of work, which were significant only in Korean nurses.

CONCLUSIONS

Professionalism was the most important factor influencing job satisfaction in both Korean and Chinese nurses. Enhancing nursing professionalism is recommended as a common strategy to improve nurses' job retention across different healthcare systems.

Nucleostemin mRNA is expressed in both normal and malignant renal tissues

Nucleostemin (NS), a p53-binding protein, has been shown essential for stem and cancer cell proliferation and implicated in oncogenesis. To explore potential contributions of NS to the development of clear cell renal cell carcinomas (ccRCCs), we determined NS expression in ccRCC cell lines, and in paired normal and malignant renal tissues from 31 patients with ccRCC. Nucleostemin mRNA and/or protein expression was observed in all four cell lines and 27 of 31 (87%) tumour specimens. Surprisingly, 16 of 31 (52%) adjacent normal renal samples also expressed NS mRNA and its levels in four of them were comparable with those in paired tumour tissues. Three of the patients had detectable NS mRNA in their normal renal tissues whereas lacked its expression in the matched tumours. Compared to the oncogene c-MYC expression in these same samples, NS expression showed a much less specificity for ccRCC. We further demonstrated that NS mRNA expression was closely associated with cellular proliferation in normal fibroblasts or T lymphocytes and renal cell carcinoma cell lines. Collectively, NS expression widely occurs in normal and malignant renal tissues, and is likely a proliferation marker rather than a unique regulator of cell proliferation and survival in stem and cancer cells.

Isometric and isovelocity contractile performance of red muscle fibres from the dogfish Scyliorhinus canicula

Maximum isometric tetanic force produced by bundles of red muscle fibres from dogfish, Scyliorhinus canicula (L.), was 142.4+/-10.3 kN m(-2) (N=35 fibre bundles); this was significantly less than that produced by white fibres 289.2+/-8.4 kN m(-2) (N=25 fibre bundles) (means +/- S.E.M.). Part, but not all, of the difference is due to mitochondrial content. The maximum unloaded shortening velocity, 1.693+/-0.108 L(0) s(-1) (N=6 fibre bundles), was measured by the slack-test method. L(0) is the length giving maximum isometric force. The force/velocity relationship was investigated using a step-and-ramp protocol in seven red fibre bundles. The following equation was fitted to the data: [(P/P(0))+(a/P(0))](V+b)=[(P(0)(*)/P(0))+(a/P(0))]b, where P is force during shortening at velocity V, P(0) is the isometric force before shortening, and a, b and P(0)(*) are fitted constants. The fitted values were P(0)(*)/P(0)=1.228+/-0.053, V(max)=1.814+/-0.071 L(0) s(-1), a/P(0)=0.269+/-0.024 and b=0.404+/-0.041 L(0) s(-1) (N=7 for all values). The maximum power was 0.107+/-0.005P(0)V(max) and was produced during shortening at 0.297+/-0.012V(max). Compared with white fibres from dogfish, the red fibres have a lower P(0) (49%) and V(max) (48%), but the shapes of the force/velocity curves are similar. Thus, the white and red fibres have equal capacities to produce power within the limits set by the isometric force and maximum velocity of shortening of each fibre type. A step shortening of 0.050+/-0.003L(0) (N=7) reduced the maximum isometric force in the red fibres' series elasticity to zero. The series elasticity includes all elastic structures acting in series with the attached cross-bridges. Three red fibre bundles were stretched at a constant velocity, and force (measured when length reached L(0)) was 1.519+/-0.032P(0). In the range of velocities used here, -0.28 to -0.63V(max), force varied little with the velocity.

Coumaroyl flavonol glycosides from the leaves of Ginkgo biloba

Two coumaroyl flavonol glycosides, isorhamnetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside], and kaempferol 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside]-7-O-beta-D-glucopyranoside, were isolated from the n-BuOH extract of Ginkgo biloba leaves. These two, together with six other flavonol glycosides, kaempferol 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside], quercetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside], quercetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside]-7-O-beta-D-glucopyranoside, quercetin 3-O-beta-D-glucopyranosyl-(1-2)-alpha-L-rhamnopyranoside, quercetin 3-O-beta-rutinoside, and quercetin 3-O-beta-D-glucopyranoside, showed profound antioxidant activities in DPPH and cytochrome-c reduction assays using the HL-60 cell culture system.

[Genetic polymorphism of polyacrylamide gel electrophoresis loci in patients after non-myeloablative allogeneic peripheral blood stem cell transplantation]

OBJECTIVE

To understand the information of donor and recipient in the mixed hematopoietic chimerism after non-myeloablative allogeneic peripheral blood stem cell transplantation(NM-APBSCT).

METHODS

DNA samples were extracted with phenol/chloroform method and were amplified by PCR technique in heparin-blood or heparin-bone-marrow. The PCR products were analyzed using polyacrylamide gel electrophoresis and silver staining means.

RESULTS

The amplified fragment length polymorphism was found in the short tandem repeat loci of 10 healthy persons and 8 leukemia patients who were not treated with hematopoietic stem cells transplantation; the bands of silver staining originated from donors and recipients were found in 3 patients after NM-APBSCT, but the brightness in the bands of donor and recipient was different.

CONCLUSION

Polymorphism for mixed hematopoietic chimerism can be estimated timely, sensitively and exactly; and the results may be used to guide adoptive immunotherapy for patients after NM-APBSCT. The silver means were simple without contamination of isotopes and without using special equipment. The methods may benefit common hospitals to develop work in this respect.

Four new isoflavone triglycosides from Sophora japonica

Four new isoflavone triglycosides, genistein 7-O-beta-D-glucopyranoside-4'-O-[(alpha-L-rhamnopyranosyl)-(1-->2)-beta-D-glucopyranoside] (1), genistein 7-O-beta-D-glucopyranoside-4'-O-[(beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside] (2), genistein 7-O-alpha-L-rhamnopyranoside-4'-O-[(alpha-L-rhamnopyranosyl)-(1-->2)-beta-D-glucopyranoside] (3), and genistein 7-O-alpha-L-rhamnopyranoside-4'-O-[(beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside] (4), together with nine known compounds, namely, genistein 7-O-beta-D-glucopyranoside-4'-O-beta-D-glucopyranoside, sophorabioside, prunetin 4'-O-beta-D-glucopyranoside, sophororicoside, genistin, rutin, kaempferol 3-O-beta-rutinoside, quercetin 3-O-beta-D-glucopyranoside, and kaempferol 3-O-beta-D-glucopyranoside, were isolated from the pericarps of Sophora japonica. The structures of 1-4 were determined by spectroscopic methods.

2,3-Butanedione monoxime increases speed of relaxation in single muscle fibres of frog

The effects of 2,3-butanedione monoxime (BDM) on intracellular Ca2+ transient and cross-bridge function were studied in frog single fibres from the anterior tibialis muscle of Rana temporaria (sarcomere length, 2.2 microm; temperature, 2-4 degrees C). The fluorescent dye fluo-3 was used to monitor the intracellular free calcium concentration ([Ca2+]i) during isometric contractions. BDM (1-5 mM) reduced the amplitude of the Ca2+ transient during twitches, but this effect was too small to explain the marked inhibition of BDM on twitch force. [Ca2+]i reached at the end of 1-s tetanic stimulation was not significantly affected by BDM (1.0 and 1.8 mM) while the maximum tetanic tension was substantially reduced. The rate of relaxation during isometric tetanus was increased by BDM whereas the rate of decay of the Ca2+ transient was reduced in the presence of BDM. The results strongly suggest that BDM, under the experimental conditions used, mainly affects the contractile machinery resulting in altered performance of the cross-bridges. These effects of BDM were evaluated in terms of the cross-bridge model of Huxley (1957) which was fitted to the experimental force-velocity data in the presence and absence of BDM.

[History of development in the transplantation of hematopoietic stem cell]

Some malignant and nonmalignant hematological diseases can be cured by the transplantation of allogeneic stem cell. It is thought to be one of the landmarks in the development of modern medicine. Hematopoietic stem cell transplantation has been performed for about one hundred years in the phases of germination, early investigation and development. The great challenge now is how to perfect the technique and to extend the applied areas.

[p15 gene expression in acute lymphoblastic leukemia cell line Molt4 induced by arsenic trioxide]

OBJECTIVE

To explore the correlation between arsenic trioxide and gene methylation in an acute lymphoblastic cell line.

METHODS

Methylation of p15 gene in Molt4 cell line was detected by polymerase chain reaction (PCR) using methylation specific primer (MSP) and the expression of this gene after arsenic trioxide treatment was detected by reverse transcriptase PCR (RT-PCR). The cell cycle and cell growth curve were also observed by flow cytometry.

RESULTS

p15 gene failed to express in molt4 after methylation. The expression was recovered, cell growth was inhibited, and G(1) cell cycle arrest was observed, when the cells exposed to arsenic.

CONCLUSION

Arsenic trioxide could activate the expression of p15 gene and reverse cell cycle negative regulation.

[Event-related potentials and suicide behavior in patients with affective disorder]

OBJECTIVE

To investigate P300 and contingent negative variations (CNV) of patients with affective disorder and its clinical significance.

METHODS

39 depressives, 22 maniacs and 33 normal controls were included in this study. Both P300 and CNV were recorded in every subject, using a nicolet spirit instrument.

RESULTS

Both depression and mania groups presented prolonged P300-P3b latency and decreased P300-P3 and CNV amplitudes compared with normal controls. Decreased P300 & CNV amplitudes were further related to the history of suicide behavior in the two patient groups.

CONCLUSION

The clinical significance of event-related potentials was confirmed in this study, while the biological correlates of suicide behavior need further and intensive study.

Heat production and oxygen consumption during metabolic recovery of white muscle fibres from the dogfish Scyliorhinus canicula

Oxygen consumption and heat production were measured during contraction and recovery of isolated, white muscle fibres from dogfish (Scyliorhinus canicula) at 19 degrees C. The contraction period consisted of 20 isometric twitches at 3 Hz; this was followed by a recovery period of 2 h without stimulation. We tested the hypothesis that recovery is wholly oxidative (not glycolytic) in these fibres. The following features support this hypothesis. (i) The ratio of total heat produced to oxygen consumed, 451+/−34 kJ mol(−)(1) (mean +/− s.e.m., N=29), was close to that expected for either the oxidation of carbohydrate, 473 kJ mol(−)(1), or the oxidation of fat, 439 kJ mol(−)(1). Even assuming the maximum value (95 % confidence limit) of the observed heat production, glycolysis could account for resynthesis of at most 18 % of the ATP used during the contractions. (ii) When the difference in rates of diffusion of oxygen and heat within the muscle are taken into account, the time courses of oxygen consumption and heat production match each other well during the entire recovery period. The efficiency of recovery (=energy used for ATP synthesis/energy available for ATP synthesis) was estimated from the results. This value, 84.0+/−20.1 % (mean +/− s.e.m., N=29), is relatively high and represents the first such measurement in functioning muscle.

[Study on the methylation of p15 gene CpG islands in acute leukemia: using methylation-specific PCR method]

OBJECTIVE

To explore the feasibility of the methylation of p15 gene CpG islands as a common gene marker for all types of acute leukemias(AL).

METHODS

The methylation of p15 gene CpG islands in bone marrow from 40 cases of newly diagnosed or relapsed AL, 5 cases of AL in CR and 8 of normal subjects was analyzed by using methylation-specific PCR methods(MSP), and the product of MSP was sequenced.

RESULTS

p15 gene CpG islands were methylated in 80% (32/40) of the newly diagnosed or relapsed AL, no difference between AML and ALL was observed. One positive result was found in the 5 AL patients in CR and this patient soon relapsed. The bone marrow cells from 8 normal subjects did not have p15 gene CpG islands methylation, which suggested that such methylation was peculiar to AL cells. DNA sequencing confirmed the right expected sequence. The sensitivity of MSP was 10(-3).

CONCLUSION

The methylation of p15 gene CpG islands occurs very commonly in every types of AL. It can be used as a gene marker for ALs and for minimal residual disease in CR. MSP needs neither special methylation-sensitive restricted sites, nor high volume of DNA. There is no radioactive pollution, and the sample need not be fresh. MSP is a very sensitive, simple and specific method for the detection of DNA methylation.

[The clinical significance of lung resistance-related protein gene (lrp), multidrug resistance-associated protein gene (mrp) and mdr-1/p170 expression in acute leukemia]

OBJECTIVE

To evaluate the relationship between lrp, mrp, mdr-1/p170 and multidrug resistance in acute leukemia (AL).

METHODS

85 AL patients were divided into three groups: untreated (A), complete remission (B) and relapsed/refractory (C). The expression of lrp, mrp and mdr-1 mRNA was detected with RT-PCR assay and that of p170 measured with immunocytochemistry.

RESULTS

The frequency of lrp gene expression in ANLL A, B and C group was 11.11%, 9.09% and 36.36%, in ALL A, B, C group it was 0%, 20.00% and 46.67%; the frequency of mrp gene expression in ANLL A, B, C group was 44.44%, 9.09% and 59.09%, in ALL A, B, C group it was 28.57%, 20.00% and 53. 33%; the frequency of mdr-1 gene expression in ANLL A, B, C group was 0%, 4.54% and 59.09%, in ALL A, B, C group it was 0%, 0% and 33.33%; p170 expression in ANLL C group was (9.45 +/- 14.66) %, it was the highest value in the three groups; statistics showed that there was no correlationship among the expressions of lrp, mrp and mdr-1 gene, P > 0.05; patients with lrp and mdr-1 expression had a lower complete remission (CR) percentage than those who had not in the untreated group; the combination of lrp, mrp and mdr-1 gene detection turned out to be a more sensitive, specific and accurate way in evaluation of multidrug resistance (MDR).

CONCLUSION

Overexpression of one or more genes of lrp, mrp and mdr-1/p170 is associated with MDR in AL. Expression of lrp, mrp and mdr-1/p170 is good indicators in clinical MDR. Two or three factors of lrp, mrp and mdr-1 are more valuable in the evaluation of MDR than any one of these three factors. The mechanisms of mrp, lrp and mdr-1 causing MDR are different, it means that the mechanisms of MDR are complicated the combination of lrp, mrp and mdr-1/p170 detection may be the best way to evaluate MDR.

[Low fever of unknown reason in patients undergoing autologous stem cell transplantation after hematopoietic reconstitution: a clinical analysis of 13 cases]

OBJECTIVE

To investigate the reason of low fever in patients undergoing autologous stem cell transplantation after hematopoietic reconstitution.

METHODS

The reasons for low fever in 13 patients undergoing autologous stem cell transplantation after hematopoietic reconstitution were comprehensively analyzed.

RESULTS

After analysis of clinical features, laboratory tests, imaging and microbiological data, no reason was found for the low fever. There was no effect on the fever with anti-microbial therapy. However the low fever was controlled by low dose prednisone 5-10 mg/d or dexamethasone 2-4 mg.

CONCLUSION

The reason for the low fever is not clear; it is probably nonspecific low fever induced by high-dose radiotherapy or high-dose chemotherapy.

[Cognitive evoked potentials in patients with schizophrenia]

OBJECTIVE

To investigate the features of cognitive evoked potentials (CEPs) in schizophrenics and the changes of CEPs between the duration of episode and remission.

METHODS

The present study was made with stimuli of auditory, visual, and somatosensory modalities. CEPs were recorded from 31 episodical schizophrenics and 25 of them were retested when their clinical symtoms rempitted.

RESULTS

The episodical patients showed significantly longer A latency (P < 0.05) and PINV latency (P < 0.01), and smaller A-S2' area (P < 0.01). Shorter latency was associated with P2 of auditory evoked potential, visual evoked potential and somatosensory evoked potential (P < 0.05), P1 of AEP, N2 of VEP, and N1 of SEP (P < 0.05). Longer latency was associated with P3 of AEP (P < 0.05). Diminished amplitude was associated with N1-P2 of AEP and N1-P2 of VEP, P2 of VEP, and P2-N2 of SEP (P < 0.05). The follow-up study revealed that when the psychiatric symptoms remitted, the waveform of CEPs became more steady; amplitude B of CNV, N1-P2 of VEP and P2-N2 of SEP were increased (P < 0.05); the amplitude P2 of AEP and VEP, and P1 of AEP were increased into the normal range.

CONCLUSION

The variations of CEPs are the state marker of schizophrenia.