Large adipocytes function as antigen-presenting cells to activate CD4(+) T cells via upregulating MHCII in obesity

BACKGROUND/OBJECTIVES

Although obesity is associated with low-grade inflammation and metabolic disorders, clinical studies suggested some obese people were metabolically healthy with smaller adipocyte size compared with metabolically abnormal obese (MAO). This indicated adipocyte size may be an important predictor underlay the distinction between MAO and metabolically healthy obese. As recent study has shown that adipocytes expressed class II major histocompatibility complex (MHCII), which functioned as APCs during obesity. However, the relationship between adipocyte hypertrophy and MHCII expression was not involved. Here we hypothesize that hypertrophic adipocytes could be associated with upregulating MHCII to influence adipose tissue metabolism.

METHODS

Adipocytes were sorted by fluorescence-activated cell sorting (FACS) according to the cell size from MAO mice. The activation of MHCII, T cells and related signaling molecules were examined by FACS, ELISA and western blotting. 3T3-L1 cell line and primary adipocytes were used to examine the effect of free fatty acids (FFA) on adipocytes enlargement and MHCII expression.

RESULTS

MAO mice had a significant increase in adipocytes size and FFA concentration. The large adipocytes from both obese and non-obese mice expressed higher levels of MHCII than small adipocytes. Importantly, large adipocytes from obese mice stimulated CD4(+) T cells to secrete more interferon (IFN)-γ. Furthermore, the activation of the JNK-STAT1 pathway was involved in upregulation of MHCII in large adipocytes. In vitro FFA treatment promoted adipocyte hypertrophy and expression of MHCII-associated genes.

CONCLUSIONS

This study demonstrates that large adipocytes highly express MHCII and function as APC to stimulate IFN-γ-expressing CD4(+) T cells, in which FFA may have important roles before IFN-γ elevated. These findings suggest that adipocyte hypertrophy, rather than overall obesity, is the major contributor to adipose tissue inflammation and insulin resistance.

Multilayered mucoadhesive hydrogel films based on thiolated hyaluronic acid and polyvinylalcohol for insulin delivery

A multilayered hydrogel film system based on hyaluronic acid-cysteamine (HA-Cym) and polyvinylalcohol (PVA) was fabricated. It contained a drug-impermeable backing layer, a supporting layer preventing direct contact between the loaded drug and the backing layer, a drug-loading layer and a mucoadhesive layer. Scanning electron microscopy demonstrated the presence of the distinct layers. The composition and preparation procedure of the films influenced their mucoadhesion, swelling, in vitro release of insulin and loaded insulin stability. Vacuum drying and crosslinked PVA with glutaraldehyde might reduce mucoadhesion, and they partially decreased the bioactivity of loaded insulin. Lyophilized hydrogel film with uncrosslinked PVA as a mucoadhesive layer possessed high mucoadhesion and showed no influence on the bioactivity of loaded insulin. The application of vacuum-dried PVA-crosslinked HA-Cym/PVA hydrogel film as a drug-impermeable backing layer would provide a controllable unidirectional insulin release. Therefore, such a multilayered hydrogel film system could be a promising mucoadhesive delivery system for controlled macromolecular drug release.

The radiation dose-regulated AND gate genetic circuit, a novel targeted and real-time monitoring strategy for cancer gene therapy

The AND gate functions such that when all inputs are activated the downstream gene will be transcribed and it is off otherwise. To accomplish optimal and targeted gene therapy in solid tumor patients, we have constructed an AND gate genetic circuit and investigated whether it could be activated by low-dose radiation in vitro and in vivo. The enhancement green fluorescent protein (EGFP) expression in different tumor cells transfected with control vector plxsn-EGFP confirmed that 2 Gy of radiation and 1% O(2) for 3 h could activate our AND gate. Besides, the obvious different levels of EGFP expression between 2 and 6 Gy of radiation demonstrated that the AND gate could be regulated by radiation doses. Additionally, through EGFP expression and the codistribution of p53 and HIF-1α in xenografts, we illustrated the targeted activation property of the AND gate and real-time monitoring to hypoxic districts in vivo. Moreover, significant growth inhibition and cell cycle arrest in vitro and apoptosis-inducing effects in vitro and in vivo proved that the AND gate induced ideal antitumor effects. In conclusion, the radiation dose-regulated AND gate genetic circuit could not only effectively monitor the therapeutic process in real-time but also induce ideal antitumor efficacy, and can be further exploited for personal therapy in clinical tumor patients.

Array of tapered semiconductor waveguides in a fiber for infrared image transfer and magnification

The proof-of-concept of an infrared imaging tip by an array of infrared waveguides tapered as small as 2 μm is demonstrated. The fabrication is based on a high-pressure chemical fluid deposition technique to deposit precisely defined periodic arrays of Ge and Si waveguides within a microstructured optical fiber template made of silica to demonstrate the proposed concept at wavelengths of 10.64 µm and 1.55 µm, respectively. The essential features of the imaging system such as isolation between adjacent pixels, magnification, optical throughput, and image transfer characteristics are investigated. Near-field scanning at 3.39 μm wavelength using a single tapered Ge core is also demonstrated.

Pyrosequencing the midgut transcriptome of the brown planthopper, Nilaparvata lugens

The brown planthopper, Nilaparvata lugens, is a serious pest threatening rice production across the world. To identify the main features of the gene expression and the key components of the midgut of N. lugens responsible for nutrition, xenobiotic metabolism and the immune response, we used pyrosequencing to sample the transcriptome. More than 190,000 clean sequences were generated, which led to about 30,000 unique sequences. Sequence analysis indicated that genes with abundant transcripts in the midgut of N. lugens were mainly sugar hydrolyases and transporters, proteases and detoxification-related proteins. Based on the sequence information, we cloned the candidate sucrase gene; this enzyme is likely to interact with the perimicrovillar membrane through its highly hydrophobic C-terminal region. Many proteases were identified, which supported the hypothesis that N. lugens uses the proteolysis system for digestion. Scores of detoxification genes were newly identified, including cytochrome P450s, glutathione S-transferases, caroxylesterases. A wealth of new transcripts possibly participating in the immune response were described as well. The gene encoding a peptidoglycan recognition protein was cloned. Unlike in Acyrthosiphon pisum, the immunodeficiency pathway may be present in N. lugens. This is the first global analysis of midgut transcriptome from N. lugens.

Suppression of the 2010 Alexandrium fundyense bloom by changes in physical, biological, and chemical properties of the Gulf of Maine

For the period 2005-2009, the abundance of resting cysts in bottom sediments from the preceding fall was a first-order predictor of the overall severity of spring-summer blooms of Alexandrium fundyense in the western Gulf of Maine and southern New England. Cyst abundance off mid-coast Maine was significantly higher in fall 2009 than it was preceding a major regional bloom in 2005. A seasonal ensemble forecast was computed using a range of forcing conditions for the period 2004-2009, suggesting that a large bloom was likely in the western Gulf of Maine in 2010. This did not materialize, perhaps because environmental conditions in spring-summer 2010 were not favorable for growth of A.fundyense. Water mass anomalies indicate a regional-scale change in circulation with direct influence on A. fundyense's niche. Specifically, near-surface waters were warmer, fresher, more stratified, and had lower nutrients than during the period of observations used to construct the ensemble forecast. Moreover, a weaker-than-normal coastal current lessened A. fundyense transport into the western Gulf of Maine and Massachusetts Bay. Satellite ocean color observations indicate the 2010 spring phytoplankton bloom was more intense than usual. Early-season nutrient depletion may have caused a temporal mismatch with A. fundyense's endogenous clock that regulates the timing of cyst germination. These findings highlight the difficulties of ecological forecasting in a changing oceanographic environment, and underscore the need for a sustained observational network to drive such forecasts.

Efficient Planning under Uncertainty with Macro-actions

Deciding how to act in partially observable environments remains an active area of research. Identifying good sequences of decisions is particularly challenging when good control performance requires planning multiple steps into the future in domains with many states. Towards addressing this challenge, we present an online, forward-search algorithm called the Posterior Belief Distribution (PBD). PBD leverages a novel method for calculating the posterior distribution over beliefs that result after a sequence of actions is taken, given the set of observation sequences that could be received during this process. This method allows us to efficiently evaluate the expected reward of a sequence of primitive actions, which we refer to as macro-actions. We present a formal analysis of our approach, and examine its performance on two very large simulation experiments: scientific exploration and a target monitoring domain. We also demonstrate our algorithm being used to control a real robotic helicopter in a target monitoring experiment, which suggests that our approach has practical potential for planning in real-world, large partially observable domains where a multi-step lookahead is required to achieve good performance.

Heterogeneity of gene expression in stromal fibroblasts of human breast carcinomas and normal breast

Breast carcinoma invasion is associated with prominent alterations in stromal fibroblasts. Carcinoma-associated fibroblasts (CAF) support and promote tumorigenesis, whereas normal mammary fibroblasts (NF) are thought to suppress tumor progression. Little is known about the difference in gene expression between CAF and NF or the patient-to-patient variability in gene expression. Paired CAF and NF were isolated from six primary human breast carcinoma specimens. RNA was extracted from low-passage cultures of CAF and NF and analyzed with Affymetrix Human Genome U133 Plus 2.0 arrays. The array data were examined with an empirical Bayes model and filtered according to the posterior probability of equivalent expression and fold difference in expression. Twenty-one genes (27 probe sets) were up-regulated in CAF, as compared to NF. Known functions of these genes relate to paracrine or intracellular signaling, transcriptional regulation, extracellular matrix and cell adhesion/migration. Ten genes (14 probe sets) were down-regulated in CAF, including the pluripotency transcription factor KLF4. Quantitative RT-PCR analysis of 10 genes validated the array results. Immunohistochemical staining for three gene products confirmed stromal expression in terms of location and relative quantity. Surprisingly, the variability of gene expression was slightly higher in NF than in CAF, suggesting inter-individual heterogeneity of normal stroma.

Progesterone Receptor (PR) Promoter Methylation – Role as a Predictive and Prognostic Marker in Breast Cancer

Estrogen receptor α expression is a well known and clinically utilized predictor of endocrine treatment response. In addition, loss of expression of the progesterone receptor (PR), an estrogen induced gene, has been shown to be associated with resistance to endocrine therapy. PR is known to be epigenetically regulated by DNA methylation, but only a few studies have correlated PR DNA methylation with its expression in breast cancer. Previous studies are contradictory and have been limited by small sample size. There is also evidence that differential expression of the two PR isoforms, PRA and PRB, might contribute to breast tumorigenesis, and altered hormone response. Whether PRA and/or PRB DNA methylation could predict response to endocrine therapy remains an open question. Further, there are no published studies so far testing whether PRA and/or PRB methylation have prognostic significance.Our objective was 1) to determine whether there was an association between PRA and/or PRB methylation levels with total PR expression in breast tumors, and 2) to determine if PRA and/or PRB methylation would have predictive and/or prognostic value. For this study, we utilized tumor DNA from patients with ER-positive breast tumors which were treated with adjuvant tamoxifen after surgery (n=500), and from patients treated with surgery only (n=500). PR expression was determined by ligand binding assay, and PRA and PRB promoter methylation was measured by bisulfite pyrosequencing.Both PRA and PRB methylation were significantly (p<0.0001) associated with PR expression, in an inverse relationship. Low PR expression was significantly (p=0.02) associated with worse overall survival (OS), and there was a trend towards shorter disease free survival (DFS) in the tamoxifen treated group. There was no association between PR expression and survival in the untreated group. PRA methylation was significantly (p<0.0001) associated with PRB methylation. Intriguingly, increased PRA methylation was significantly associated with shorter DFS (p=0.047) and OS (p=0.0067) in tamoxifen treated patients, and with shorter OS (p=0.008) in the untreated patients. In contrast, there was no significant association between PRB methylation and survival in either tamoxifen treated or untreated patients.Our results show that PR expression is significantly associated with PR methylation. The data suggest that PRA methylation is a predictive marker for tamoxifen response and also a prognostic marker for breast cancer progression. This is the largest study so far to elucidate the association of PRA and PRB methylation with PR status, response to tamoxifen, and tumor prognosis, and we believe that it provides useful insights into the role of PR methylation in breast tumorigenesis.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2002.

Participation of women in clinical trials for new drugs approved by the food and drug administration in 2000-2002

OBJECTIVE

This study aimed to track the inclusion of women in clinical trials for new drugs approved by the Food and Drug Administration (FDA) between 2000 and 2002 and to evaluate the extent of analyses by sex.

METHODS

Data were extracted from FDA reviewers' reports, summaries of clinical trials in New Drug Applications (NDAs), and product labeling and organized into a Microsoft Access database. The information collected includes subject enrollment by sex per clinical phase and sex differences in pharmacokinetics, safety, and efficacy as determined by either sponsors or reviewers.

RESULTS

There were 67 New Molecular Entities (NMEs) approved by the FDA between 2000 and 2002. A total of 397,825 subjects were enrolled in 2,323 clinical trials. If 9 sex-specific NMEs are excluded, 297,697 subjects were enrolled in 1,974 clinical trials. Forty-seven percent of participants were male, 49% were female, and 4% of subjects were not specified. Of the 58 sex-nonspecific products in the study, 71% (41 of 58) of sex analyses were performed either by the sponsor or FDA reviewers. Twenty-five NMEs were found to have sex differences in pharmacokinetics, efficacy or adverse events. However, no recommendation was made to adjust dosage based on sex differences.

CONCLUSIONS

The percentages of women and men participating in clinical trials varied by year, phase, and product type. However, the overall participation by women and men was comparable, suggesting an improvement in including more women in clinical trials when compared with the previous FDA study evaluating women's participation from 1995 through 1999. As with the previous study, however, a significant underrepresentation of women in early phase trials and in certain areas, such as cardiovascular products, was observed and continues to be an issue of concern. Lack of appropriate analyses by sex should also be noted as an issue of concern.

Heterogeneity of gene expression in stromal fibroblasts of breast carcinomas and normal breast

Abstract #105

Background: The cancer microenvironment plays a critical role in tumor development and progression. Cancer associated fibroblasts (CAF) constitute a significant component of the tumor stroma and participate in reciprocal communication with the tumor cells. Information on differential gene expression specifically in stromal fibroblasts is sparse and data describing the variability of gene expression in CAF and normal fibroblasts (NF) is currently lacking. The purpose of this study was to identify genes differentially expressed in CAF and matched NF and to analyze the heterogeneity of gene expression profiles in the two cell types.
 Materials and methods: Fibroblast cell cultures were established from 6 patients with primary invasive breast cancer. Gene expression profiles were generated using oligonucleotide microarrays (Affymetrix HG-U133 Plus 2.0). Differentially expressed genes were ranked using Empirical Bayes modeling. A cut-off value of 0.005 was chosen for the posterior probability of equivalent expression. Lists of overexpressed genes were generated after eliminating genes with less than two-fold overexpression.
 Results: 17 genes were overexpressed in CAF compared to NF with known functions in paracrine and intracellular signaling, transcription regulation and extracellular matrix production. Using the same posterior probability cut-off, we identified 7 genes which were expressed at least two-fold higher in NF than in CAF. These genes have purported roles in steroid hormone metabolism, transcription, migration and cell signaling. Using semiquantitative RT-PCR and immunohistochemistry, we confirmed the over- and underexpression of a subset of 10 differentially expressed genes. The heterogeneity of gene expression in CAF vs. NF was compared with F-tests to determine variances. The estimated probability of NF gene expression variance being higher than CAF gene expression variance was 0.547 with a 95% confidence interval of 0.543 to 0.551 (p<0.0001), indicating that gene expression is more variable in NF than in CAF. By ranking the q-values of individual genes we identified 3 known genes, which show a significant difference in variance between CAF and NF (p<0.05).
 Conclusion: Altered gene expression in fibroblasts likely contributes to tumor growth and progression by enhancing ECM production, promoting stromal-epithelial paracrine signaling and altering steroid hormone metabolism. The inter-individual heterogeneity of gene expression in NF may indicate that the mammary stroma varies between individuals, supporting the hypothesis that the ability of the stroma to act as a barrier to cancer development and tumor progression may also be variable. Conversely, the heterogeneous gene expression in NF may be a reflection of a relative synchronization and uniformity of gene expression in CAF.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 105.

Effect of Ultrasonic Degradation on In Vitro Antioxidant Activity of Polysaccharides from Porphyra yezoensis (Rhodophyta)

This article aims to study the effect of ultrasonic degradation on antioxidant activity of polysaccharides from Porphyra yezoensis (Rhodophyta) (PSPY), and to look for the relationship between molecular structure of fractions (F1, F2, and F3) from ultrasonic-degraded PSPY (UDPSPY) and their activities of scavenging hydroxyl and superoxide anion radicals, chelating ability of iron ion and reducing power. Results of antioxidant assays indicated that the UDPSPY had higher antioxidant activity of scavenging superoxide anion radical and hydroxyl radical than that of the PSPY. As antioxidant activities of the fractions are concerned, this result might suggest that decreasing molecular weight and increasing sulfate group content in the molecule were vital and necessary factors for improving antioxidant activity of PSPY. Decrease of molecular weight was the dominant reason for increasing activities of scavenging non-site and site specific hydroxyl radical and reducing power of F1, F2, and F3, and increase of sulfate group content in the molecule was the dominant reason for increasing activities of scavenging superoxide anion radical and chelating ferrous ions of F1, F2, and F3. It was possible that ultrasonic treatment could be a new and effective method for enhancing PSPY's antioxidant activity.

Significant alterations of biodistribution and immune responses in Balb/c mice administered with adenovirus targeted to CD40(+) cells

CD40 ligation has been shown to promote antigen-presenting functions of dendritic cells, which express CD40 receptor. Here we reported significantly altered biodistribution and immune responses with the use of CD40-targeted adenovirus. Compared with unmodified adenovirus 5, the CD40-targeted adenovirus following intravenous administration (i.v.) resulted in increased transgene expressions in the lung and thymus, which normally do not take up significant amounts of adenovirus. Intradermal injection saw modified adenovirus being mainly processed in local draining lymph nodes and skin. Following intranasal administration (i.n.), neither unmodified nor targeted viruses were found to be in the liver or spleen, which predominantly took up the virus following i.v. administration. However, inadvertent infection of the brain was found with unmodified adenoviruses, with the second highest gene expression among 14 tissues examined. Importantly, such undesirable effects were largely ablated with the use of targeted vector. Moreover, the targeted adenovirus elicited more sustained antigen-specific cellular immune responses (up to 17-fold) at later time points (30 days post boosting), but also significantly hampered humoral responses irrespective of administration routes. Additional data suggest the skewed immune responses induced by the targeted adenoviruses were not due to the identity of the transgene but more likely a combination of overall transgene load and CD40 stimulation.

A unified approach for lesion segmentation on MRI of multiple sclerosis

Accurate determination of lesion volumes on brain MR images is hampered by the presence of a large number of false positive and negative classifications. A strategy that combines parametric and nonparametric techniques is developed and implemented for minimizing the false classifications. Initially, CSF and lesions are segmented using Parzen window classifier. Image processing, morphological operations, and ratio map of proton density (PD) and T2 weighted images are used for minimizing false positives. Lesions are delineated using fuzzy connectedness principle. Contextual information was used for minimizing false negative lesion classifications. Gray and white matter classification is realized using HMRF-EM algorithm.

The relationship between polymorphisms of HCMV UL144 ORF and clinical manifestations in 73 strains with congenital and/or perinatal HCMV infection

Human cytomegalovirus (HCMV) displays genetic variability and can cause a wide range of diseases in neonates. To explore the relationship between polymorphisms and clinical manifestations, the UL144 genes from 73 clinical strains were sequenced. All of the strains, which came from 70 infants with suspected congenital and/or perinatal HCMV infection, were non-passage strains. Among them, 23 strains were from surgery specimens, and the others were from urine samples. Clinically, 12 infants displayed asymptomatic infection and 58 patients displayed symptomatic infection. The results showed that 36 patients (49.3%) were infected with strains belonging to UL144 group G1 (G1a 33/36, G1b 3/36), 19 patients (28.8%) were infected with strains belonging to group G2, and 15 patients (21.9%) were infected with strains belonging to group G3. This result indicated that UL144 group G1 was the predominant genotype in congenital and/or perinatal HCMV infection in northern China. Compared with the distribution pattern of strains in UL144 genotypes of data from Chicago, Iowa and Texas, and Japan by chi-square test, the difference was statistically significant. This suggested that the distribution pattern of strains in UL144 genotype was related to geographic location. However, no linkage was observed between the UL144 genotypes and the severity and/or outcome of HCMV disease.

Sequence variability of the human cytomegalovirus UL141 Open Reading Frame in clinical strains

Human cytomegalovirus (HCMV) displays genetic polymorphisms. HCMV disease and tissue tropism may be related to specific genomic variability among strains. This work analyzed the genetic polymorphism of UL141 open reading frame (ORF), one of the genes in HCMV UL/b' region, from 21 clinical strains. 8 previously published UL141 sequences in the GenBank were used for sequence comparison. Detailed sequence analysis showed that the UL141 gene was highly conserved at both the nucleotide and amino acid level. The coding regions were identical in size. The nucleotide and amino acid sequence identities among all strains were 96.9-100% and 97.6-100%, respectively.

Single-Crystalline Diluted Magnetic Semiconductor GaN:Mn Nanowires

Single-crystalline diluted magnetic semiconductor GaN:Mn nanowires with controlled Mn concentrations have been successfully synthesized and incorporated into devices. These nanowires exhibit Curie temperatures above room temperature, magnetoresistances near room temperature, and spin-dependent transport. The nanowires are used as building blocks for the fabrication of GaN:Mn/n-SiC based light-emitting diodes.

Characterisation of water behaviour in cellulose ether polymers using low frequency dielectric spectroscopy

The behaviour of water in hydroxypropylmethylcellulose (HPMC) K100LV, K4M, K15M, K100M, E4M, F4M and HPC polymers was characterised using low frequency dielectric spectroscopy (LFDS). Dielectric responses of 25% (w/w) HPMC K15M gels and deionised water were found to be similar at +22 and 0 degrees C. However, at -30 degrees C, a dielectric response typical of a solid was apparent. The melting of frozen water within gels was detected as increases in the magnitude of the dielectric response with increase in temperature. More than one phase transition was visible in the majority of gels studied which may be related to the presence of different states of water melting at different temperatures. In addition to polymer concentration, both polymer molecular weight and substitution level influenced the nature of the transitions. The magnitude of the dielectric response was increased in all HPMC gel systems in comparison to the response seen in deionised water. Drug addition affected the transitions occurring during the melting of ice in the gels. This may be related to the presence of ionic species in the systems. LFDS studies on cellulose ether gels have provided some interesting evidence for the existence of more than one state of water within such gel systems. The results are in good agreement with thermal analysis findings in similar gel systems.

[Bioreactor-landfill site for leaching solution treatment]

The study utilizes the system combined bioreactor with landfill site to treat leachate. The results show that the system helped the degradation of the organic pollutants in the leachate to be divided into two-phases, the hydrolytic fermentation and acid-production phases mainly occurred in the landfill site, the acidification rate was 40%-50%, the methane-production chiefly occurred in the bioreactor(UASB). It treated the leachate significantly and benefits the collection and utilization of methane gas. Also, the system accelerates the process of degrading municipal solid waste and stabilizing landfill site.

[A study on tongue cancer cell labeling using bromodeoxyuridine (BrdU) incorporation in vitro]

OBJECTIVE

The aim of this study is to evaluate of Bromodeoxyuridine (BrdU) label in the proliferation of the tongue cancer.

METHODS

The authors used 80 micrograms/ml BrdU or iododeoxyuridine (IdU) to label three cases of fresh tissue of tongue cancer and four bottles of Tca8113 cells in logarithmic growth period in vitro. They were fixed and embedded in the routine procedure, and then in serial sections. These specimens were labeled with BrdU polyclonal antibody (1:200), and PCNA monoclonal antibody (1:100), stained using immunohistochemical ABC method. The authors observed the shapes and sizes of those positive cells, counted their label indexes (LI) of BrdU- or IdU-positive cells and PCNA- positive cells respectively. Four bottles of Tca8113 cells were cultured for 1-4 days. One bottle of the cells was every day used in the experimental study about comparing the cells labeled BrdU with those of the S phase of FCM in same cultural time.

RESULTS

The positive cells generally owned a larger round nucleus, sometimes in company with sister cells. There was no difference of positive cells in these two kinds of labeling methods between the incorporation of BrdU or IdU and the expression of proliferating cell nuclear antigen (P > 0.05). The cells of S phase with FCM method were much more than that method with BrdU incorporation (P < 0.001).

CONCLUSION

The method of BrdU labeling could be used in tumor cellular proliferation studies.

Effect of leachate recycle and inoculation on microbial characteristics of municipal refuse in landfill bioreactors

Population development of key groups of anaerobic and aerobic bacteria involved in municipal refuse decomposition under laboratory landfill bioreactors with and without leachate recycle and inoculation was measured since modeling municipal refuse was landfilled in bioreactors for about 210 days. Hydrolytic fermentative bacteria (HFB), hydrogen-producing acetogenic bacteria (HPAB), methane-producing bacteria (MPB), sulfate-reducing bacteria (SRB), anaerobic and aerobic cellulolytic bacteria and denitrabacteria were enumerated by the most probable number technique. The results showed that the dominant microorganism groups were the methanogenic bacteria including hydrolytic fermentative, hydrogen-producing acetogenic and methane-producing bacteria. They were present in fresh refuse but at low values and positively affected by leachate recycle and refuse inoculation. The amounts of HFB or HPAB in digesters D4 and D5 operated with inoculation and leachate recycle reached their maximum values of 10(10)-10(12) cells/g dry refuse for HFB or 10(5)-10(6) cells/g dry refuse for HPAB on day 60, in digester D3 operated with leachate recycle on day 120 for HFB (10(9) cells/g dry refuse) or on day 90 for HPAB (10(5) cells/g dry refuse), and in digesters D1 and D2 on day 210 for HFB (10(9) cells/g dry refuse) or on day 90 for HPAB (10(4)-10(6) cells/g dry refuse). The population of methane-producing bacteria in digesters D4 and D5 sharply increased on days 60 and 90 respectively, however in digesters D1, D2 and D3 on day 120. Leachate recycle and inoculation changed the cellulolytic microorganisms composition of refuse ecosystem, the higher amounts of anaerobic cellulolytic bacteria were measured in digesters D4 and D5 (10(7) cells/g dry refuse), followed by digesters D3 (10(6) cells/g dry refuse), D2 or D1(10(4) cells/g dry refuse). However, the amounts of aerobic cellulolytic bacteria were much lower than that of anaerobic cellulolytic bacteria. And it was higher in digester D3 than those in digesters D1, D2, D4 and D5. The amounts of SRB and denitrabacteria were also higher in digester D5 than those in digesters D1, D2, D3 and D4. Refuse decomposition could be accelerated by leachate recycle and inoculation in the view of microorganism development.

Some features of intestinal absorption of intact fibrinolytic enzyme III-1 from Lumbricus rubellus

In order to investigate whether earthworm fibrinolytic enzyme III-1 (EFE-III-1) isolated from Lumbricus rubellus is capable of transporting into blood through intestinal epithelium and keeping its biological function in circulation, we have raised an antibody against EFE-III-1. The immunological results showed that 10-15% of intact EFE-III-1 was absorbed by the intestinal epithelium with the incubation chamber method [Vilhardt and Lundin, Acta Physiol. Scand. 126 (1986) 601-607]. The enzyme could be detected in the intestinal epithelial cells by immunohistochemistry. Furthermore, immunoreactive intact EFE-III-1 was found in serum or plasma after intraperitoneal injection of rats. Approx. 10% of the full-size enzyme could transport through the intestinal epithelium. The maximum remaining activity in blood could be assayed around 60 min after the intraperitoneal injection.

The role of factor XI in a dilute thromboplastin assay of extrinsic coagulation pathway

Blood coagulation has been thought to be composed of both intrinsic and extrinsic pathways. Recent evidence strongly supports the critical role of the extrinsic pathway in the initiation of blood coagulation. This investigation established an assay that examines the role of FXI in the thromboplastin-initiated (extrinsic) coagulation based on this new concept. Plasma clotting times were measured at different concentrations of thromboplastin with activated FXII inhibited (FXIIa-inhibited Diluted Thromboplastin Time, FXIIaiDTT). Only at low concentrations of thromboplastin was FXIIaiDTT of FXI-deficient plasma significantly prolonged than that of normal plasma. Depletion of FXI from normal plasma prolonged its FXIIaiDTT and replenishment of FXI shortened it. FXIIaiDTTs of both FVIII-deficient and FIX-deficient plasma were remarkably prolonged, and addition of normal plasma dose-dependently shortened it. Furthermore, earlier alpha-thrombin inhibition was directly correlated with decreasing FXa generation. The amount of FXa production was: platelet-rich plasma > platelet-poor plasma > FXI-deficient plasma. Therefore, our findings from the FXIIaiDTT assays not only support the critical role of extrinsic pathway in blood coagulation initiation, but also demonstrate the importance of FXI as an amplifier of thrombin generation in thromboplastin-initiated coagulation.