Application of microbial agents in organic solid waste composting: a review

The rapid growth of organic solid waste has recently exacerbated environmental pollution problems, and its improper treatment has led to the loss of a large number of biomass resources. Here, we expound the advantages of microbial agents composting compared with conventional organic solid waste treatment technology, and review the important role of microbial agents composting in organic solid waste composting from the aspects of screening and identification, optimization of conditions, mechanism of action, combination with other technologies and ultra-high-temperature and ultra-low-temperature microbial composting. We discuss the value of microorganisms with different growth conditions in organic solid waste composting, and put forward a seasonal multi-temperature composite microbial composting technology. Provide new ideas for the all-round treatment of microbial agents in organic solid waste in the future. © 2024 Society of Chemical Industry.

Effects of polyethylene microplastics on properties, enzyme activities, and the succession of microbial community in Mollisol: At the aggregate level

Soil, as a heterogeneous body, is composed of different-sized aggregates. There is limited data available on the potential role of microplastics (MPs) in microbial properties at the soil aggregate level. In this study, changes in microbial construction and diversity in farmland bulk soil and aggregates induced by polyethylene MPs (PE-MPs) were investigated at a dose of 0.5% (w/w) through 16s rDNA sequencing and enzyme activity measurements of different particle size aggregates in incubated soil. The presence of low-dose PE-MPs increased the proportion of >1 mm soil aggregates fraction, and decreased soil available nitrogen and available phosphorus in bulk soils. Furthermore, low-dose PE-MPs increased bacterial richness and diversity in 1-0.5 and < 0.25 mm fractions and decreased operational taxonomic unit, abundance-based coverage estimator, and Chao1 indices in bulk soil and >1 mm fractions. The levels of predicted functional genes taking part in the biodegradation and metabolism of exogenous substances also increased. At the phylum level, PE-MPs changed the proportion of Proteobacteria and Actinobacteria. The variations in soil aggregate properties were significantly correlated with the bacterial communities' composition and diversity. This study deepens our perception of the soil microenvironment, microbial community composition, and diversity in response to PE-MPs.

Radiotherapy for Patients with Locally Advanced Esophageal Squamous Cell Carcinoma Receiving Neoadjuvant Immunotherapy Combined with Chemotherapy

PURPOSE/OBJECTIVE(S)

With the success of immunotherapy in advanced esophageal cancer, neoadjuvant chemo-immunotherapy (CIT) is being increasingly used for local staged esophageal cancer, especially in the context of clinical trials, which brings similar pCR with neoadjuvant chemoradiotherapy and shows promising results. However, there is still a part of potentially operable patients can't undergo surgery after neoadjuvant chemo-immunotherapy. The follow-up treatment and prognosis of this population remain unclear.

MATERIALS/METHODS

Patients pathologically diagnosed with ESCC, clinical stage T1-3N+M0 or T3-4aNanyM0(AJCC 8th), PS 0-1 were retrospectively enrolled from 1/2020 to 6/2021 in Zhejiang Cancer Hospital. All patients firstly received PD-1 inhibitors (Camrelizumab, Sintilimab or Tislelizumab) plus chemotherapy (albumin paclitaxel,260 mg/m²on day 1 plus carboplatin AUC = 5 on day 1) every 3 weeks for 2-4 cycles. For those patients who did not receive surgery, definitive radiotherapy with 50.4Gy/28F or 50Gy/25F was adopted using VMAT, concurrent with chemotherapy or alone. The concurrent chemotherapy regimens included weekly TC (paclitaxel 50 mg/m 2, d1, carboplatin AUC = 2, d1) or S1 (60mg bid d1-14,29-42). The survival outcomes and treatment toxicity were recorded and analyzed.

RESULTS

A total of 56 eligible patients were finally identified from 558 patients who were treated in department of thoracic surgery, 31 patients showed no response to neoadjuvant CIT (6 with PD and 25 with SD), 25 patients achieved PR but did not receive surgery due to poor performance status or refuse to operation. Median age was 66(IQR 56-72) and 55(98.2%) were males. 12(19.6%) were stage II and 44(80.4%) were stage III. Among all the patients,25 (44.6%) received radiotherapy alone, and 31 (55.4%) received chemoradiotherapy after neoadjuvant CIT. The median follow-up was 11.8 months (IQR 8.6-20.1). The median PFS and OS were 16.5 months (95CI 12.9-21.4) and 18.6 months (95CI 11.2-NA), respectively. In the subgroup analysis, the median PFS for patients with PR to CIT was 20.2 moths (95CI:17.23-NA), and 12.9 moths (95CI: 0.68-20.4) for patients with SD or PD, HR was 0.45 (95CI:0.22- 0.93, P = 0.027). No significant difference was observed for patients received radiotherapy alone or chemoradiotherapy with HR = 1.36(95CI:0.69-2.71, P = 0.37). The most common AEs observed during this study were anemia (98.2%), Leukopenia (83.9%), Thrombocytopenia (53.6%). Adverse events of grade≥3 radiation-induced pneumonitis and esophagitis were 12.5% and 32.1%, especially, 6 patients (10.7%) died from esophageal fistula and 2 patients (3.6%) died from grade 5 pneumonitis.

CONCLUSION

For local advanced ESCC patients after neoadjuvant CIT who did not receive surgery, definitive radiotherapy was an optional treatment strategy. However, those patients with no response to CIT also showed poor response to radiotherapy, and particular attention should be paid to treatment related toxicity, especially esophageal fistula.

Different Radiation Dose of Neoadjuvant Chemoradiation for Resectable Thoracic Esophageal Squamous Carcinoma: A Randomized Phase II Clinical Trial

PURPOSE/OBJECTIVE(S)

Radiation dose used in the neoadjuvant chemoradiotherapy (nCRT) for patients with locally advanced esophageal squamous cell carcinoma (ESCC) varies in clinical practice, no prospective studies have been conducted on this issue. The hypothesis of this study is that higher radiation dose in nCRT was associated with improved progression free survival in resectable ESCC.

MATERIALS/METHODS

A phase II prospective randomized controlled trial was conducted from February 22, 2018 to February 22, 2021 in Zhejiang Cancer Hospital (NCT03381651). Patient with locally resectable advanced thoracic ESCC (cT2-T4aNxM0, T1-3N+M0) were randomized 1:1 to receive nCRT with different radiation doses of 50.4 Gy/28F and 41.4 Gy/23F, weekly TC regimen (paclitaxel 50 mg/m2, d1, carboplatin AUC = 2, d1) was administered as concurrent chemotherapy. The primary endpoint was 2-year progression free survival (PFS), and the secondary endpoints included complete pathological response (pCR) rate, overall survival (OS), local recurrence free survival (LRFS), and distant metastasis free survival (DMFS). The last follow-up date was February 22, 2022 and data analysis was performed from May 1, 2022, to October 31, 2022.

RESULTS

A total of 147 patients were enrolled in the prospective study, including 72 patients in 50.4 Gy/28F group and 75 patients in 41.4 Gy/23F group. Among all the patients, 101 patients finally underwent surgical resection, 23/46(50%) achieved pCR in the high-dose group, while 18/55(32.7%) achieved pCR in the low-dose group (P = 0.10). In intention-to-treat population analysis, 2-year PFS in the high-dose and low-dose groups were 53.5% (95% CI: 42.9-66.7%) and 45.5% (95% CI: 35.4%-58.5%), respectively, and hazard ratio (HR) was 0.72 (95% CI: 0.46-1.12, P = 0.14). Median PFS were 44.4 months (95% CI: 16-NA) versus 20.8 months (95% CI: 15-NA) in high and low dose groups. 2-year OS in the high and low-dose groups were 61.8% (95% CI: 51.2 -74.5%) and 60.5% (95% CI: 50.3 -72.8%), respectively, with a HR = 0.78(95% CI: 0.48-1.27, P = 0.32). Median OS were not arrived in both groups up to the last follow-up. In addition, 2-year LRFS were 87.9% (95% CI: 78.4-98.5%) and 74.8% (95% CI: 63.3-88.3%) in high and low-dose groups, while 2-year DMFS were 70.6% (95% CI: 58.3-85.5%) and 73.6% (95% CI: 61.7-87.8%), respectively. No significant statistical difference was observed between the two groups in terms of side effects during nCRT and postoperative complications.

CONCLUSION

Our results showed that neoadjuvant high-dose radiotherapy failed to improve overall survival in ESCC. However, it was found that pCR and local tumor control rates tended to be increased at 50.4 Gy/28F, compared to 41.4 Gy/23F, although the trend was not statistically significant. There was no significant difference in treatment side effects between the two groups. Longer-term follow-up is required to verify our findings.

Ubiquitin-Conjugating Enzyme OsUBC11 Affects the Development of Roots via Auxin Pathway

Rice has 48 ubiquitin-conjugating enzymes, and the functions of most of these enzymes have not been elucidated. In the present study, a T-DNA insertional mutant named R164, which exhibited a significant decrease in the length of primary and lateral roots, was used as the experimental material to explore the potential function of OsUBC11. Analysis using the SEFA-PCR method showed that the T-DNA insertion was present in the promoter region of OsUBC11 gene, which encodes ubiquitin-conjugating enzyme (E2), and activates its expression. Biochemical experiments showed that OsUBC11 is a lysine-48-linked ubiquitin chain-forming conjugase. OsUBC11 overexpression lines showed the same root phenotypes. These results demonstrated that OsUBC11 was involved in root development. Further analyses showed that the IAA content of R164 mutant and OE3 line were significantly lower compared with wild-type Zhonghua11. Application of exogenous NAA restored the length of lateral and primary roots in R164 and OsUBC11 overexpression lines. Expression of the auxin synthesis regulating gene OsYUCCA4/6/7/9, the auxin transport gene OsAUX1, auxin/indole-3-acetic acid (Aux/IAA) family gene OsIAA31, auxin response factor OsARF16 and root regulator key genes, including OsWOX11, OsCRL1, OsCRL5 was significantly down-regulated in OsUBC11 overexpressing plants. Collectively, these results indicate that OsUBC11 modulates auxin signaling, ultimately affecting root development at the rice seedling stage.

Toxicity effects of nanoplastics on soybean (Glycine max L.): Mechanisms and transcriptomic analysis

Microplastic (MP) pollution has become a major concern in recent years. In agricultural production, MPs can not only affect the growth of crops but also affect yield. Compared with micron-sized MPs, nanoplastics (NPs) may be more harmful to plants. However, the effects of NPs on plant growth and development have attracted relatively little attention. As such, research has currently plateaued at the level of morphology and physiology, and the molecular mechanisms are still unclear. In this study, soybeans (Glycine max L.) were treated with polystyrene nanoplastics (PS-NPs) to observe phenotypic changes and measure the effects of PS-NPs on diverse aspects of soybeans. Compared to the control group, the soybean stem and root lengths were inhibited by 11.78% and 12.58%, respectively. The reactive oxygen species content and the antioxidant enzyme activities changed significantly (p < 0.05). The accumulation of manganese (Mn) and magnesium (Mg) in the roots revealed that root transmembrane transport was affected by PS-NPs stress. The content of salicylic acid 2-O-β-glucoside was inhibited whereas the accumulation of l-tryptophan, the precursor of auxin synthesis, was significantly increased (p < 0.05) in leaves. Transcriptomic analysis showed that PS-NPs could affect soybean DNA repair, membrane protein transport, and hormone synthesis and response. This study revealed the toxicity of NPs to soybeans and that NPs affected a variety of biological processes through transcriptome and hormone metabolome analysis, which provides a theoretical basis to further study the molecular mechanism of the effects on plants.

[An optimized protocol of meniscus cell extraction for single-cell RNA sequencing]

OBJECTIVE

To optimize the protocol of meniscus cell extraction to enhance the efficiency of cell suspension preparation and maintain a high cell viability for single-cell RNA sequencing.

METHODS

We compared the efficiency of the routine cell extraction methods (short-time digestion and long-time digestion) and the optimized protocol for obtaining meniscus cell suspensions by evaluating the cell number obtained and the cell viability. Single-cell RNA sequencing datasets were analyzed to evaluate the stability of the cell suspension prepared using the optimized protocol. The reliability of the optimized protocol was assessed by comparing the single-cell RNA sequencing dataset obtained by the optimized protocol with published single-cell RNA sequencing datasets of the meniscus.

RESULTS

The optimized protocol harvested a greater number of cells (over 1×10⁵) than the routine protocols. The cell suspension prepared with the optimized protocol showed a cell viability higher than 80%, the highest among the 3 methods. Analysis of single-cell RNA sequencing datasets showed that the ratio of the mitochondrial genes was below 20% in over 80% of the cells. CD34⁺ cells, MCAM⁺ cells and COL1A1⁺ cells were identified in the datasets. Comparison with the publish datasets showed that the optimized protocol was capable of harvesting COL3A1⁺, COL1A1⁺, MYLK⁺, BMP2⁺, CD93⁺ and CDK1⁺ cells.

CONCLUSION

Single-cell suspension prepared from the meniscus can be stably obtained using the optimized protocol for single-cell RNA sequencing using the 10× Genomics platform.

Label-free sensing of exosomal MCT1 and CD147 for tracking metabolic reprogramming and malignant progression in glioma

Malignant glioma is a fatal brain tumor whose pathological progression is closely associated with glycolytic reprogramming, leading to the high expression of monocarboxylate transporter 1 (MCT1) and its ancillary protein, cluster of differentiation 147 (CD147) for enhancing lactate efflux. In particular, malignant glioma cells (GMs) release tremendous number of exosomes, nanovesicles of 30 to 200 nm in size, promoting tumor progression by the transport of pro-oncogenic molecules to neighboring cells. In the present study, we found that hypoxia-induced malignant GMs strongly enhanced MCT1 and CD147 expression, playing a crucial role in promoting calcium-dependent exosome release. Furthermore, it was first identified that hypoxic GMs-derived exosomes contained significantly high levels of MCT1 and CD147, which could be quantitatively detected by noninvasive localized surface plasmon resonance and atomic force microscopy biosensors, demonstrating that they could be precise surrogate biomarkers for tracking parent GMs' metabolic reprogramming and malignant progression as liquid biopsies.

Neddylation controls basal MKK7 kinase activity in breast cancer cells

The c-Jun NH2-terminal protein kinase (JNK) pathway has been implicated in mammary tumor development. However, the molecular mechanisms regulating JNK activity in breast cancer cells remain unclear. Here, we report that the inhibition of ubiquitination-like post-translational modification neddylation through different strategies results in enhanced basal JNK phosphorylation in human breast cancer cells. The upregulation of basal JNK phosphorylation upon neddylation inhibition is independent of the deneddylation of Cullins, the well-characterized neddylation substrates. Since augmented basal JNK phosphorylation via ectopic MKK7 expression impedes proliferation and the epithelial-to-mesenchymal transition (EMT) phenotype, the neddylation system might contribute to mammary tumor development partially through limiting basal JNK phosphorylation. Further exploration reveals that MKK7, a JNK-specific MAP2K, undergoes neddylation in human breast cancer cells. MKK7 co-precipitates with a fragment of Ran-binding protein 2 (RanBP2), a large multimodular and pleiotropic protein that has been recognized as a SUMO E3 ligase. Knockdown of RanBP2 attenuates MKK7 neddylation and augments basal JNK phosphorylation without affecting the neddylation of Cullins, whereas ectopic expression of a RanBP2 fragment possessing SUMO E3 activity (RanBP2ΔFG) manifests the opposite effects. In vitro neddylation assays confirm that RanBP2ΔFG works as the neddylation E3 ligase for MKK7. The basal kinase activity of endogenous MKK7 increases upon RanBP2 knockdown but decreases upon the ectopic expression of RanBP2ΔFG. Furthermore, purified MKK7 shows reduced basal kinase activity after in vitro neddylation by RanBP2ΔFG. Consistently, RanBP2 knockdown leads to reduced proliferation and impaired EMT phenotype in human breast cancer cells and the effects of RanBP2 knockdown are reversed by simultaneous MKK7 knockdown. Taken together, our data suggest that MKK7 undergoes neddylation in human breast cancer cells, which limits its basal kinase activity.

TBX6 null variants and a common hypomorphic allele in congenital scoliosis

BACKGROUND

Congenital scoliosis is a common type of vertebral malformation. Genetic susceptibility has been implicated in congenital scoliosis.

METHODS

We evaluated 161 Han Chinese persons with sporadic congenital scoliosis, 166 Han Chinese controls, and 2 pedigrees, family members of which had a 16p11.2 deletion, using comparative genomic hybridization, quantitative polymerase-chain-reaction analysis, and DNA sequencing. We carried out tests of replication using an additional series of 76 Han Chinese persons with congenital scoliosis and a multicenter series of 42 persons with 16p11.2 deletions.

RESULTS

We identified a total of 17 heterozygous TBX6 null mutations in the 161 persons with sporadic congenital scoliosis (11%); we did not observe any null mutations in TBX6 in 166 controls (P<3.8×10(-6)). These null alleles include copy-number variants (12 instances of a 16p11.2 deletion affecting TBX6) and single-nucleotide variants (1 nonsense and 4 frame-shift mutations). However, the discordant intrafamilial phenotypes of 16p11.2 deletion carriers suggest that heterozygous TBX6 null mutation is insufficient to cause congenital scoliosis. We went on to identify a common TBX6 haplotype as the second risk allele in all 17 carriers of TBX6 null mutations (P<1.1×10(-6)). Replication studies involving additional persons with congenital scoliosis who carried a deletion affecting TBX6 confirmed this compound inheritance model. In vitro functional assays suggested that the risk haplotype is a hypomorphic allele. Hemivertebrae are characteristic of TBX6-associated congenital scoliosis.

CONCLUSIONS

Compound inheritance of a rare null mutation and a hypomorphic allele of TBX6 accounted for up to 11% of congenital scoliosis cases in the series that we analyzed. (Funded by the National Basic Research Program of China and others.).

Association of the polymorphism of MMP2 with the risk and severity of lumbar disc degeneration in the Chinese Han population

OBJECTIVE

The present study aimed to determine whether the -735 C/T polymorphism of the Matrix Metalloproteinase 2 (MMP2) gene is associated with the risk and severity of lumbar disc degeneration (LDD) in the Chinese Han population.

PATIENTS AND METHODS

A total of 1008 patients with LDD and 906 healthy controls were enrolled in this study. The grade of disc degeneration was determined according to Schneiderman's classification for Magnetic Resonance Imaging (MRI). The -735 C/T polymorphism of MMP2 was genotyped using polymerase chain reaction and the restriction fragment length polymorphism method.

RESULTS

The genotype frequency of the -735 C/T polymorphism was in agreement with the Hardy-Weinberg equilibrium (p = 0.087). The frequencies of the -735CT and TT genotypes were significantly lower among LDD patients compared with normal controls (p < 0.001); CT and TT genotype were significantly associated with a decreased risk of LDD compared with the CC genotype (for TT genotype, p = 0.031; OR 0.413; 95% CI 0.184-0.924; for CT genotype, p < 0.001, OR 0.645, 95% CI 0.506-0.822). Patients with LDD showed significantly higher frequencies of the C allele than normal controls (p < 0.001), T allele was significantly associated with a decreased risk of LDD compared with the C allele (p < 0.001; OR 0.631; 95% CI 0.508-0.783). In addition, the -735TT and CT genotypes, as well as the T allele were associated with lower degenerative grades of LDD compared with CC genotype and the C allele, respectively (both p < 0.001).

CONCLUSIONS

The -735 C/T polymorphism of MMP2 may be associated with the risk and severity of LDD in the Chinese Han population.

Magnetic Properties and Crystal Structure of High Moment FeTaN Thin Films

High Moment single layer FeTaN films with excellent soft magnetic properties have been grown by high rate reactive dc magnetron sputtering. The best combination of properties (easy and hard axis coercivities < 1 Oe, saturation Magnetization > 1650 emu/cc, anisotropy field of 5 Oe, and initial permeability of 4800) are found in films containing ∼3.2 a/O Ta and ∼7.5 a/o N after 400°C annealing in a 200 Oe dc field for two hours. These properties are associated with a single phase, random, nanocrystalline structure consisting of a-Fe crystallites (grain size of ∼ 100Å) whose lattice is expanded by both Ta and N.

The impact of prior radiotherapy on fatal complications after self-expandable metallic stents (SEMS) for malignant dysphagia due to esophageal carcinoma

The esophageal stent has been demonstrated to serve as a safe and effective palliative treatment for advanced inoperable esophageal carcinoma. However, the safety of esophageal stents in patients with prior radiotherapy (RT) remains debated. This article aims to investigate the impact of prior RT on the incidence of fatal complications after self-expandable metallic stents for palliation of malignant dysphagia because of esophageal carcinoma. Between January 2007 and July 2010, 93 patients with malignant dysphagia because of esophageal carcinoma underwent placement of self-expandable metallic stents in our hospital. Patients were retrospectively separated into two groups: patients with RT before stent placement (RT group, n=57) and patients with no treatment before stent placement (no RT group, n=35).The median survival after stent placement was 77 days (7-842 days) in the RT group and 246 days (15-878 days) in the no RT group. Improvement in dysphagia score was similar in both groups. The fatal complications included fatal gastrointestinal hemorrhage and uncontrolled pneumonia. The incidence of fatal gastrointestinal hemorrhage and uncontrolled pneumonia were 28.1% and 5.7% (P=0.009), 28.1% and 5.7% (P=0.009), respectively. Logistic regression analysis showed a significant interaction between prior RT and fatal gastrointestinal hemorrhage (relative risk 7.82, 95% confidence interval 1.54-39.61; P=0.013). Mortality of massive hemorrhage was 5.7% (2/35), 0% (0/4), 12.5% (3/24), and 44.8% (13/29), respectively, in patients who received 0, 1Gy∼49Gy, 50Gy∼60Gy, and >60Gy (χ(2) =17.761; P=0.000). Logistic regression analysis disclosed prior RT did not significantly increase the risk of uncontrolled pneumonia (relative risk 1.47, 95% confidence interval 0.21-10.12; P=0.697).

Comparative study on the intracavity frequency-doubling 532 nm laser based on gray-tracking-resistant KTP and conventional KTP

A comparative study of a frequency-doubling 532 nm laser based on gray-tracking-resistant KTP (GTR-KTP) and conventional KTP is presented. The intracavity GTR-KTP was proved to have better temperature characteristics than that of conventional KTP. Within the normalized output power variation range of 0.8-1.0, GTR-KTP has a temperature tolerance of 35 degrees C, broader than the 21 degrees C obtained with conventional KTP. Under the laser diode (LD) pump power of 180 W, the maximum average output power at 532 nm was 40.6 W for GTR-KTP at a repetition frequency of 10 kHz. In the case of conventional KTP, the maximum available LD pump power was limited to 150 W, with the corresponding maximum green average output power of 27.2 W.

Over-expression of c-maf by chondrocytes in osteoarthritis

The c-maf gene expression profile was investigated in normal and osteoarthritic articular cartilage using in situ hybridization, qualitative reverse transcription-polymerase chain reaction (RT-PCR) and quantitative real-time RT-PCR. Osteoarthritic samples were obtained from 10 patients undergoing total knee replacement for severe osteoarthritis of the knee joints, and control samples from 10 trauma patients undergoing amputation. Expression of c-maf was significantly up-regulated in osteoarthritic cartilage compared with normal cartilage. Using in situ hybridization, distribution of a specific c-maf mRNA signal was found in the top zone and a decreased signal was found in the lower middle zone and the deep zone in osteoarthritic cartilage. A prominent c-maf mRNA signal was seen particularly in proliferating 'chondrocyte clusters'. In contrast, in normal cartilage almost no c-maf-positive cells were found. These findings suggest that c-maf may be important in chondrocyte hypertrophy and terminal differentiation, and may be involved in the pathogenesis of osteoarthritis.

Microbial populations in acid mineral bioleaching systems of Tong Shankou Copper Mine, China

AIMS

To understand the composition and structure of microbial communities in different acid mineral bioleaching systems, and to present a more complete picture of microbially mediated acid mine drainage production.

METHODS AND RESULTS

In Tong Shankou Copper Mine, China, two samples (named K1 and K2) from two different sites with bioleaching were studied. A bacterial 16S rDNA library and an archaeal 16S rDNA library of the sample from each site were constructed by 16S rDNA polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP) and sequencing. A total of 18 bacterial representative sequences and 12 archaeal representative sequences were obtained. Phylogenetic analysis indicated that 77.09% of the total bacterial clones were affiliated with Proteobacteria, and 21.22% of the total bacterial clones were closely related to Nitrospira. The rest of the bacterial clones were related to Firmicutes (1.68%). Sequences affiliated with the archaea of the Thermoplasma and Ferroplasma lineages were detected abundantly in the two samples. Unexpectedly, sequences affiliated with Sulfolobales and Methanothermus genera were also detected.

CONCLUSIONS

The molecular studies appear to be consistent with the environmental conditions existing at the sites, which coincides with previous studies. High concentrations of some elements (such as copper, iron and sulfur) seemed to be the key factors resulting in the diverse distribution of typical iron-oxidizing bacteria such as Leptospirillum species and Acidithiobacillus ferrooxidans.

SIGNIFICANCE AND IMPACT OF THE STUDY

Research on micro-organisms present in bioleaching systems especially archaea is not abundant. The acidophiles in the two bioleaching sites obtained from Tong Shankou Copper Mine, China, have not been reported until now. These results may expand our knowledge of the microbial diversity in the acid mineral bioleaching systems.

Understanding the complex dynamics of stock markets through cellular automata

We present a cellular automaton (CA) model for simulating the complex dynamics of stock markets. Within this model, a stock market is represented by a two-dimensional lattice, of which each vertex stands for a trader. According to typical trading behavior in real stock markets, agents of only two types are adopted: fundamentalists and imitators. Our CA model is based on local interactions, adopting simple rules for representing the behavior of traders and a simple rule for price updating. This model can reproduce, in a simple and robust manner, the main characteristics observed in empirical financial time series. Heavy-tailed return distributions due to large price variations can be generated through the imitating behavior of agents. In contrast to other microscopic simulation (MS) models, our results suggest that it is not necessary to assume a certain network topology in which agents group together, e.g., a random graph or a percolation network. That is, long-range interactions can emerge from local interactions. Volatility clustering, which also leads to heavy tails, seems to be related to the combined effect of a fast and a slow process: the evolution of the influence of news and the evolution of agents' activity, respectively. In a general sense, these causes of heavy tails and volatility clustering appear to be common among some notable MS models that can confirm the main characteristics of financial markets.

Identification of one intron loss and phylogenetic evolution of Dfak gene in the Drosophila melanogaster species group

Intron loss and its evolutionary significance have been noted in Drosophila. The current study provides another example of intron loss within a single-copy Dfak gene in Drosophila. By using polymerase chain reaction (PCR), we amplified about 1.3 kb fragment spanning intron 5-10, located in the position of Tyr kinase (TyK) domain of Dfak gene from Drosophila melanogaster species group, and observed size difference among the amplified DNA fragments from different species. Further sequencing analysis revealed that D. melanogaster and D. simulans deleted an about 60 bp of DNA fragment relative to other 7 Drosophila species, such as D. elegans, D. ficusphila, D. biarmipes, D. takahashii, D. jambulina, D. prostipennis and D. pseudoobscura, and the deleted fragment located precisely in the position of one intron. The data suggested that intron loss might have occurred in the Dfak gene evolutionary process of D. melanogaster and D. simulans of Drosophila melanogaster species group. In addition, the constructed phylogenetic tree based on the Dfak TyK domains clearly revealed the evolutionary relationships between subgroups of Drosophila melanogaster species group, and the intron loss identified from D. melanogaster and D. simulans provides a unique diagnostic tool for taxonomic classification of the melanogaster subgroup from other group of genus Drosophila.

Restoration of visual responses following transplantation of intact retinal sheets in rd mice

PURPOSE

To correlate the functional outcomes with histologic findings following transplantation of fetal retinal sheets in rd mice, and to investigate the mechanisms of visual function restoration.

METHODS

Twenty-one postnatal day 31-38 rd/rd (C3H/HeJ) mice were transplanted in one eye with retinal sheets (1.0 x 0.4 mm) obtained from embryonic day (E) 17 enhanced-green-fluorescent protein (eGFP) mice. Five mice underwent sham surgery without insertion of tissue. Four to five weeks after transplantation, visual responses to a light flash were recorded across the superior colliculus (SC) in seven eyes of seven transplanted mice that had clear corneas and lenses, and in all five sham surgery mice. Following the SC recording, the eyes were enucleated and processed for immunohistochemistry and examined using confocal microscopy.

RESULTS

In three out of the seven eyes (43%), positive responses were recorded in the SC in an area topographically corresponding to the placement of the transplant in the host retina. No responses were recorded in the untreated eyes of 5-week-old and 9-week-old rd/rd mice, and in the 9-week-old sham surgery mice. In contrast, visual responses were recorded over the entire SC in normal eyes. The response onset latencies of the 3 transplanted mice with responses were similar to those of normal control mice. The organization of the graft did not appear to correlate as expected with the electrophysiology results, as eyes with well-organized, laminated grafts showed no response whereas the three light-responsive eyes had rosetted or disorganized grafts. All three light-responsive eyes demonstrated much higher levels of recoverin immunoreactivity in the host retina overlying the graft compared with untreated age-matched rd/rd mice.

CONCLUSION

Restoration of the SC visual response does not appear to depend on a well-organized transplant in the rd mouse. Increased recoverin-staining in the host retina in light-responsive animals suggested that host cone rescue was the likely mechanism of vision restoration in this transplant model.

Alternative culture conditions for isolation and expansion of retinal progenitor cells

PURPOSE

To investigate different in vitro model systems for retinal progenitor cell (RPC) isolation and expansion.

METHODS

RPCs were isolated from embryonic day (E) 17 Long Evans rat retinas. Three different culture media: (1) modified serum free defined media (2) serum-containing media and (3) embryonic stem cell (ES)-conditioned media were used for RPC isolation and long term expansion. Expression of various cellular markers and cell morphologies were compared among the three culture systems at different passages by immunostaining and confocal microscopy.

RESULTS

All three culture systems could maintain RPCs as nestin-positive cells (78-87%) after long-term in vitro expansion. However, RPCs appeared to proliferate faster in the serum-free culture system. The ES-conditioned media provided the best RPC survival. Cells appeared smaller at early passages compared with later passages. This morphology change occurred at P9-P10 in the serum-free medium, and at P5-P6 in the other two culture systems.

CONCLUSIONS

The serum-free medium may be superior for preventing RPC differentiation during expansion.

Heterogenous and compartment-specific activation of nonlymphocytic, mononuclear cells in intraabdominal sepsis

Although sepsis is associated with increased production of cellular pro- and anti-inflammatory mediators by monocyte/macrophages, the compartmentalization and nature of such activation has not been clearly defined. The authors examined the activation of nonlymphocytic mononuclear cells in different compartments in the cecal ligation and puncture (CLP) model of septic peritonitis. Control and CLP rat mononuclear cells from the peritoneal cavity, bronchoalveolar, as well as the lung vascular compartment were isolated 24 and 48 hours post surgery and release of nitric oxide (NO), interleukin (IL)-12, and monocyte chemoattractant protein-1 (MCP-1) was measured from culture media. Peritoneal macrophages (PMs) from CLP rats increased release of all three mediators compared to controls. Cells from the lung vascular compartment after CLP increased release of NO, but MCP-1 release was unchanged. Levels of IL-12 were not detectable. Similarly, bronchoalveolar macrophages (BMs) of CLP rats had increased release of NO, whereas IL-12 was not detectable. Release of MCP-1 increased 48 hours after CLP. Almost all PMs and BMs possessed innate phagocytic ability that was not altered during sepsis. The percentage of cells in the lung vascular compartment that had phagocytic ability, increased 48 hours post CLP, versus controls. The authors also evaluated lung injury at 24 hours after surgery by measurement of bronchoalveolar lavage protein and LDH activity. There was an increase in both these parameters 24 hours after CLP as compared to controls. Thus, there was heterogenous and compartment-specific activation of mononuclear cells in sepsis. There was nonspecific inflammatory activation in the primary site of injury. In a remote organ (lung), the authors show for the first time that there was selective activation of NO without increased release of the proinflammatory cytokine, IL-12. Phagocytic activity was maintained in the bronchoalveolar compartment whereas in the lung vascular compartment, the percentage of phagocytic cells increased.

[Cloning and analyzing of the conserved protein gene in Streptococcus sanguinis ATCC10556]

OBJECTIVE

To clone and analyze the conserved protein gene in Streptococcus sanguinis(S.s) ATCC10556.

METHODS

Southern blotting hybridization, molecular cloning techniques and dot blotting hybridization were employed to obtain the target clone which harbored the specific DNA fragment. The nucleotide sequence of the target clone was determined. The gene and its product were analyzed by Genework software and bioinformatics techniques.

RESULTS

The conserved protein gene in Streptococcus sanguinis ATCC10556 was cloned for the first time and named as Streptococcus sanguinis conserved protein gene (Sscp gene). The Genbank accession number for Sscp gene is AY032739. The conserved protein gene in S.s ATCC10556 (named sscp163) was a transmembrane protein and contained two AAA domains.

CONCLUSION

sscp163 protein might take part in the cell division in Streptococcus sanguinis; its function is similar to that of FtsK in E.coli.

Role of IFN-gamma in bacterial containment in a model of intra-abdominal sepsis

Interferon-gamma (IFN-gamma) is a specific activator of macrophage function and plays a critical role in the host immune defense to bacterial infection. In this study we examined the role of IFN-gamma in the regulation of bacterial load in the cecal ligation and puncture (CLP) model of intra-abdominal sepsis in the rat. In initial studies, levels of IL-12, MCP-1, and IFN-gamma were measured in the peritoneal lavage fluid 24 and 48 h after CLP. IL-12 and MCP-1 levels were both significantly increased at 24 h after CLP compared to sham controls and this difference was maintained at 48 h after CLP. Interestingly, IFN-gamma levels were not significantly increased 24 h after CLP, but were increased at 48 h after CLP. These results clearly suggest that although an inflammatory response had occurred 24 h post-surgery, with increases in the proinflammatory cytokine IL-12 and the potent chemotactic agent MCP-1, levels of IFN-gamma in CLP rats were similar to sham controls. To further investigate the role of IFN-gamma on the development of sepsis we examined the effect(s) of administering anti-IFN-gamma antibody on bacterial load after CLP. We show that use of anti-IFN-gamma antibody can significantly decrease bacterial load in the peritoneum. The mechanism of the effect(s) of anti-IFN-gamma is probably by increasing intestinal adhesions to seal the cecum and reduce bacterial movement into the peritoneum.

[Clinical application of TRAFIX internal fixation system in correction of scoliosis]

OBJECTIVE

To evaluate the results of TRAFIX internal fixation system in correction of adolescent scoliosis.

METHODS

From October 1997 to June 1999, 27 patients with idiopathic scoliosis received spinal instrumentation with TRAFIX system. Their average age was 14.2 years (from 11 to 21). Four patients of the 27 underwent anterior release, while 1 patient accepted revision approach. The average follow up time was 26 months (13-37 months).

RESULTS

The measurements for primary coronal deformity before and after surgery were 65 degrees (42 degrees-110 degrees) and 29.2 degrees (3 degrees-64 degrees) respectively. The average curve correction was 55.4%. The average fused segments were 11.5 vertebrae. The distance between the center of apex and C7 plumb line was 52.1 mm before operation (25-94 mm) and 28.5 mm after surgery (4-62 mm).

CONCLUSION

The TRAFIX internal fixation system provides three-dimensional correction with refinement, convenient and reliable fixation.

[The postburn changes of the plasma levels of PGE2 and TNF alpha in burn patients]

OBJECTIVE

To explore the postburn changes of the plasma levels of PGE2 and TNF alpha and their relationship with burn severity and sepsis.

METHODS

Twenty-four burn patients were enrolled in the study and were randomly divided into four groups based on burn area and sepsis in reference to normal group (10 healthy adult volunteers). The plasma levels of PGE2 and TNF alpha at different postburn time points in all burn patients and in healthy volunteers were determined by radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA), respectively.

RESULTS

The postburn plasma PGE2 level increased in most patients but decreased in the patients with major burn or sepsis, even to the level lower than that in normal control. On the other hand, the postburn plasma TNF alpha level increased in all patients, especially obvious in those with sepsis. And the changes were not correlated to burn area and postburn time. Moreover, the postburn plasma TNF alpha level was negatively correlated to that of PGE2.

CONCLUSION

Decreased postburn plasma PGE2 level was correlated to high incidence of burn sepsis. And PGE2 might down-regulate TNF alpha production.

Sensitive and specific enzyme-linked immunosorbent assay for the diagnosis of Wuchereria bancrofti infection in urine samples

We developed an enzyme-linked immunosorbent assay (ELISA) that detects filaria-specific immunoglobulin G4 antibodies in unconcentrated urine. The ELISA was positive in 87 of 91 (95.6%) urine samples collected from people with Wuchereria bancrofti microfilariae, antigen, or both. Of 298 urine samples collected in Thailand, Lao People's Democratic Republic, and Japan, where no human filariasis is known, 295 (99.0%) were negative by ELISA. Various intestinal nematode and fluke infections did not interfere with the ELISA. Urine samples with sodium azide could be kept at 37 degrees C for 4 weeks, and the time of urine collection did not influence ELISA results. This ELISA can be used to identify endemic foci of filariasis.

The distraction reduction fixation system and its application in spondylolisthesis

OBJECTIVE

An internal fixation apparatus--distraction reduction fixation system (DRFS) was designed to satisfy the clinical needs for spondylolisthesis.

METHODS

Since 1996, 53 patients were treated with DRFS. Among them, 35 had spondylolisthesis, 12 had lumbar canal stenosis accompanied with instability, 2 had vertebral tumors and 4 suffered from spinal fracture. The average age was 53.6 years old (ranged 24 approximately 72 yrs). The mean time for follow-up was 30.6 months (16 approximately 44 months).

RESULTS

The slip rate was 0.15 +/- 0.10 before operation, and decreased to 0.09 +/- 0.07 after operation. Entire slip reposition was achieved in 19 cases (54.3%). The change in height of the intervertebral space within the fixation segments was 0.7 +/- 0.17.

CONCLUSION

DRFS achieved better results for spondylolisthesis less II degree and no other adverse effects were found. Compared with other foreign and domestic techniques, it had advantages in less implants, less operation gears required and ease to utilize in operation. It was proved to be an ideal internal fixation apparatus.

Three-dimensional correction of scoliosis using TSRH instrumentation

OBJECTIVE

To evaluate the results of TSRH instrumentation in the correction of coronal, sagittal and rotational deformity of scoliosis.

METHODS

From January 1998 to December 1999, thirty-two consecutive patients (6 males, 26 females)with scoliosis underwent anterior or posterior spinal instrumentation and fusion using TSRH instrumentation. Of these cases, 21 were idiopathic scoliosis and 11 were congenital scoliosis. The average age at surgery was 16.4 years (range, 11 approximately 45 years). The mean Cobb angle at surgery was 71.2 degrees range, 44 degrees approximately 125 degrees) in the coronal plane, and 49. degrees range, 16 degrees aprroximately 67degrees in the sagittal plane. Rotational deformity (Nash-Moe) ranged from I to III degree. Preoperative apical translation averaged 4.8 cm (range, 3 approximately 9 cm).

RESULTS

The average follow-up duration was 13.3 months (range, 10 approximately 24 months). At the final follow-up, the mean Cobb angle in the coronal plane was 26.6 (range, 10 degrees approximately 73 degrees), with a 63.8% of improvement. Sagittal alignment was well maintained with a mean Cobb angle of 28 degrees (range, 10 degrees approximatelky 45 degrees). The average correction of rotation of the apical vertebra was I degree. The average apical translation was 1.6 cm (range, 0.5 approximately 5.0 cm) representing a correction rate of 66, 7%. Complication was noted in two cases with an incidence of 3.1%, one case had superficial infection and the other one had lower hook dislocation. There was no neurologic deficit and pseudoarthrodesis in this series.

CONCLUSION

TSRH instrumentation is an effective and convenient three-dimensional correction system with a lower rate of complication, which can not only correct the coronal and rotational deformity, but maintain the sagittal alignment as well.

Management of post-traumatic aniridia with retinal detachment

PURPOSE

To reconstruct the anatomic and functional impairment in patients with post-traumatic aniridia, aphakia, and retinal detachment.

METHODS

Four patients with unilateral aniridia and aphakia as well as retinal detachment as results of severe eye injuries underwent scleral buckling, vitrectomy, membrane peeling, endolaser photocoagulation, silicone oil or gas temponade, combined with iris diaphragm-IOL implantation.

RESULTS

All four patients achieved successfully anatomic and functional reconstruction after surgery. During five to 22 months postoperative follow-up, all retinas remained attached. The final visual acuity increased from finger counting to 0.1-0.3.

CONCLUSIONS

The combination of vitreoretinal surgery and iris diaphrgm-IOL implantation is an effective method for post-traumatic aniridia, aphakia and traumatic retinal detachment. It could ameliorate photophobia and improve the biocular vision. Furthermore, artificial iris diaphragm implantation could prevent silicone oil-endothelia contact and salvage silicone keratopathy.

Efficient syntheses of imidazolo[1,2-a]pyridines and -[2, 1-a]isoquinolines

2-Aminopyridines 1a-c and 1-aminoisoquinoline with 1-chloromethylbenzotriazole give 2-amino-1-[alpha-benzotriazol-1-ylmethyl]pyridinium chlorides 2a-c and 1-amino-2-(alpha-benzotriazol-1-ylmethyl)isoquinolinium++ + chloride 12, respectively. Compounds 2a-c and 12 react with aryl aldehydes 3a-h to afford imidazolo[1,2-a]pyridines 7a-k and imidazolo[2, 1-a]isoquinolines 13a,b in good yields.

[Effects of 1 alpha(OH)D3 on trabecular and cortical bone in ovariectomized rats]

OBJECTIVE

To study the pharmaceutical effects of 1 alpha(OH)D3 on trabecular and cortical bone in ovariectomized (OVX) rats.

METHODS

41 female Wistar rats of six months old were randomly divided into 5 groups: (1) Baseline control; (2) Sham control; (3) 6 weeks after OVX (OVXb); (4) 14 weeks after OVX (OVXe); (5) OVX + 0.1 microgram/(kg.d) 1 alpha(OH)D3 (O + VD), treatment started 6 weeks after OVX and lasted 8 weeks. Histomorphometry analysis of tibia, peripheral quantitative computed tomography (pQCT) scanning of femur, bone biomechanical test and serum and urinary biochemical parameters were determined.

RESULTS

The levels of bone turnover indexes increased in OVX rats, OVX also resulted in reducing of trabecular, bone mass and biomechanical properties. The ratio of urinary deoxypyridinoline crosslink/creatinine was decreased by 67.0% in O + VD group compared with OVXe group 67.0% [(43.50 +/- 11.20) nmol.L-1/mmol.L-1 vs(131.80 +/- 14.90) nmol.L-1/mmol.L-1, P < 0.01]. Percent trabecular area (Cn-BV/TV) was increased by 89.8% in O + VD group compared with OVXe group (11.03 +/- 0.73 vs 5.81 +/- 1.29, P < 0.05). Trabecular bone mineral content and density were increased by 77.3% and 91.3% compared with OVXe respectively (P < 0.05). Although cancellous maximal load and stiffness increased in O + VD group, but no statistical significance. 1 alpha(OH)D3 also enhanced polar moment of inertia (PMI) and maximal load of cortical bone in femur compared with OVXe (23.70 +/- 1.63 vs 18.23 +/- 1.41, P < 0.01 and 171.69 +/- 9.92 vs 147.58 +/- 11.29, P < 0.05 respectively).

CONCLUSION

1 alpha(OH)D3 inhibited the higher bone turnover induced by OVX, increased trabecular bone in proximal tibia and bone mass in distal femur. 1 alpha(OH)D3 also improved the mechanical properties of cortical bone in femur.

[Differentiation of embryonic stem cells into neuronal cells in vitro]

OBJECTIVE

To investigate the probabilities of embryonic stem (ES) cells differentiating into neuronal cells in vitro.

METHODS

Mouse ES-D3 cells were cultured on the ES conditioned media without mLIF (mouse leukemic inhibitory factor, mLIF) for 4 days until ES cell aggregations was formed (embryonic bodies, EBs). The EBs were dissociated with trypsin and exposed to retinoic acid (RA) for another 4 days, and then replated onto adhesive substrate. Immunohistochemistry and RT-PCR assay were performed to identify the properties of the differentiated cells.

RESULTS

The treated cells expressed neuronal proteins such as MAP-2 and GFAP. RT-PCR assay further identified that the induced cells expressed transcripts for neural associated genes including GABA-gamma subunit receptor, brain factor-1 and tyrosine hydroxylase (TH).

CONCLUSION

ES cells can be successfully induced into neuronal cells expressing multiple properties of neurons in vitro, which could provide resourceful materials for neural transplantation.