[Role and related mechanisms of LiaSR two-component system in acid tolerance and biofilm formation of Streptococcus mutans]

Objective: To investigate the role and related mechanisms of the LiaSR two-component system in acid tolerance and biofilm formation abilities of Streptococcus mutans (Sm) 593. Methods: The growth curves of various Sm strains in pH=5.5 brian heart infusion (BHI) medium were analyzed. And colony forming unit (CFU) was also performed to evaluate the acid tolerance of Sm. Laurdan probe, H+-K+adenosine triphosphate (ATP)ase activity analysis kit, proton permeability assay and real-time fluorescence quantitative PCR (RT-qPCR) were conducted to detect the acid tolerant mechanisms of LiaSR two-component system in Sm. Crystal violet staining, CFU, SYTOX probe and anthrone-sulfuric method were used to analyze the properties and structures of the Sm biofilms. RT-qPCR was conducted to detect the expression levels of underlying regulated genes. Results: The growth of mutants in acidic BHI were inhibited (P<0.05). The acid tolerance of mutants significantly decreased compared to the wild-type strain (P<0.05). In mutants, the activity of H+-ATPase (917.06±59.53 and 469.53±47.65) were elevated by 7.22-folds and 3.70-folds compared to the wild-type strain (127.00±50.71) (P<0.001, P<0.001) and the encoded gene atpD (3.39±0.21 and 1.94±0.17) were also elevated by 3.39-folds and 1.94-folds compared to the wild-type strain (1.00±0.15) (P<0.001, P=0.001). The Laurdan generalized polarization of mutants (0.18±0.04 and 0.18±0.05) increased significantly compared to the wild-type strain (0.08±0.05) (P=0.006, P=0.003) and the expression levels of fabM gene were decreased in mutants (0.52±0.11 and 0.57±0.05) by 1/2 (P=0.014, P=0.022). In liaR deletion mutant, the reduced terminal pH (4.76±0.01) can also be observed (P<0.001). The total amount of the biofilms of three Sm didn't show significant differences (P>0.05). But the number of viable bacteria of mutants' biofilms were decreased [Sm 593: (12.00±2.80)×107 CFU/ml; Sm ΔliaS: (2.95±1.13)×107 CFU/ml; Sm ΔliaR: (7.25±1.60)×107 CFU/ml] (P=0.001, P=0.024). The extracellular DNA were increased by 18.00-folds and 6.50-folds in mutants' biofilms (128.73±15.65 and 46.38±5.52) compared to the wild-type strain (7.16±3.62) (P<0.001, P=0.003). Water-soluble exopolysaccharides could be found up-regulated in liaS deletion mutant [(138.73±10.12) μg/ml] (P=0.003) along with the expression level of gtfC gene (1.65±0.39) (P=0.014). The expression level of gtfD were elevated by 47.43-folds and 16.90-folds in mutants (P<0.001, P=0.010). Conclusions: The LiaSR two-component system can promote the expression of fabM gene and increase the fluidity of Sm which contributes to acid tolerance. The LiaR can also decrease the proton permeability and restrict the entrance of H+. The LiaSR two-component system can negatively regulate the production of the extracellular matrix in Sm biofilm.

[Clinicopathological features of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma]

Objective: To investigate the clinicopathological features, immunophenotype and gene alterations of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA). Methods: Fifteen case of TL-LGNPPA diagnosed at Zhejiang Cancer Hospital (5 cases) and the First Affiliated Hospital, Zhejiang University School of Medicine (10 cases) from November 2011 to August 2020 were collected. Clinical and pathological examinations, immunohistochemical staining and next-generation sequencing were performed. The clinicopathological and molecular characteristics were summarized, and relevant literature was reviewed. Results: Fifteen patients were identified and included. Their median age was 36 years (range, 20-60 years). The male-female ratio was 1.0∶1.1. The most common symptoms were epistaxis and nasal obstruction. The neoplasms were located on the roof of the nasopharynx or the posterior margin of the nasal septum. The pathological features included complex papillary and glandular structures mainly composed of single or pseudostratified cubic and columnar cells, with mild to moderate cytological atypia. In some cases, spindle cell features, nuclear grooves, ground glass nuclei, squamous metaplasia, or scattered psammoma bodies were identified. In addition, nuclear polar reversal cells, hobnail cells and micropapillary structures were found, but have not been reported in previous literature. Immunohistochemistry showed that the tumor cells were diffusely positive for TTF1, CK7, vimentin and CKpan; focally positive for p40, CK5/6 and p16; and negative for Tg, NapsinA, CK20, CDX2, S-100 and PAX8. The Ki-67 positive rates ranged from 1% to 20% and were≤10% in thirteen cases (13/15). EBER in situ hybridization was negative in all cases. DNA sequencing of 6 specimens was performed and all specimens were found harboring gene mutations (EWSR1, SMAD2, ROS1, JAK3, GRIN2A, ERRCC5, STAT3, and TET2), but no hot spot gene alterations were found. No MSI-H and MMR related gene changes were detected. All tumors showed low tumor mutation burden. All 15 patients underwent endoscopic surgery, and only 1 of them underwent radiotherapy postoperatively. All patients were recurrence free and alive at the end of follow-up periods (range: 23 to 129 months). Conclusions: TL-LGNPPA is a rare indolent tumor of the nasopharynx and exhibits a unique morphology and immunophenotype. Endoscopic resection is an effective treatment for TL-LGNPPA with excellent overall prognosis.

[Relationship between onco-immunological and morphologic characteristics of lymphoepithelioma-like carcinoma and lymphocyte subtypes of peripheral blood]

Objective: To study the relationship between the onco-immunological and morphologic characteristics of lymphoepithelioma-like carcinoma (LELC) and peripheral blood lymphocyte subtypes and its clinical significance. Methods: The pathologic and clinical data of 117 LELC patients who were admitted to the Tumor Hospital of the University of Chinese Academy of Sciences from 2006 to 2018 were collected. The histological classification was based on previously reported morphological classification method. The onco-immunological and morphologic characteristics of the tumors such as lymphoid follicle formation and interstitial fibrous hyperplasia, patient's peripheral blood lymphocyte subtypes and prognosis data were collected. The relationship between various factors and their impact on prognosis were analyzed. Results: There were 117 patients, including 61 females and 56 males. The male to female ratio was 0.9∶1.0. The age of onset was 24-89 years (median 52 years). Primary sites included head and neck (68 cases), lungs (26 cases), stomach (15 cases), and others (eight cases). Morphologically, 54 cases were type Ⅰ, 62 cases were type Ⅱ, and one case could not be classified. The onco-immunological and morphologic features of the LELC tumors showed a continuous spectrum. Interstitial TILs were noted from focally to diffuse, and the interstitial fibrous tissues were from hardly visible to obvious sclerotic. Formation of lymphoid follicles was seen in 42 patients; obvious fibrosis was seen in 31 cases. Data of peripheral blood lymphocyte subtyping by flow cytometry were available in 73 cases. These data included CD3⁺total T cells, CD3⁺CD4⁺helper T cells, CD3⁺CD8⁺cytotoxic T cells, CD3^-CD56⁺natural killer (NK) cells, CD3^-CD19⁺B cells, CD4⁺CD45RA^-T helper induction subgroup, CD4⁺CD45RA⁺ T suppression induction subgroup, CD4⁺CD45RO⁺memory T cell subgroup, CD45RA⁺CD45RO⁺activated T cell subgroup, CD8⁺CD38⁺activated cytotoxic T cell, and CD25⁺lymphocytes and CD44⁺lymphocyte. The proportion of lymphocytes of each subtype was normal in most patients, but the proportion of CD44⁺lymphocytes in 61 cases (83.6%) was increased; the proportion of T cell suppression induced subgroups was decreased in 53 cases (72.6%). Correlation analysis found a significant correlation between clinical stage and NK cells (P=0.023); tumor histologic type and cytotoxic T cells were significantly positively correlated (P=0.012); while tumor cell morphologic differentiation was significantly related to total T cells (P=0.003) and NK cells (P=0.026); Formation of interstitial lymphoid follicles was positively correlated with memory T cell subsets (P=0.025); Tumor interstitial fibrosis was significantly positively correlated with T suppression-induced subpopulations (P=0.004), and was significantly negatively correlated with total T cells (P=0.023) and with the expression of CD44 adhesion molecules (P=0.003). Survival analysis found that lymphoid follicle formation was a favorable prognostic factor for LELC (P=0.001). Conclusions: The onco-immunological and morphologic features in LELC show a continuous spectrum; the tumor clinicopathological characteristics and onco-immunological morphology are closely related to peripheral blood T lymphocyte subtypes, and the formation of interstitial lymphoid follicles is a favorable prognostic factor for LELC.

[Effect of sctence information regulator 3 on temporomandibular joint osteoarthritis]

Temporomandibular joint osteoarthritis (TMJOA) is a common subclass of temporomandibular disorders, with complicated causes and limited treatment. In addition to inflammatory reaction, structural changes of temporomandibular joint (TMJ) as condylar osteophyte formation, sclerosis, erosion, and subchondral bone cysts will happen at the same time. At present, it is found that epigenetic regulation can affect the growth and development of TMJ and regulate the immune inflammatory reaction, so we can speculate that epigenetic modification is involved in the occurrence and development of TMJOA. This paper reviews the researches of silence information regulator 3 (SIRT3), which is a key factor in epigenetics, in the field of osteoarthritis and rheumatoid arthritis.In order to discuss the effect of SIRT3 on the growth and development of TMJ by mediating acetylation modification, such as bone, cartilage, synovium and blood vessels, as well as alleviating osteoarthritis and synovitis. By doing this, the understanding of TMJOA can be enriched, with the goal of finding a new possibility for the clinical treatment of TMJOA.

[Pathological features related to onco-immunity and their clinical significance of pancreatic ductal adenocarcinoma]

Objective: To investigate the tumor immunity-related pathologic features and clinical significance in pancreatic ductal adenocarcinoma (PDAC). Methods: All pathologic materials and clinical information of 192 PDAC patients from the Cancer Hospital of the University of Chinese Academy of Sciences from January 2010 to December 2020 were collected. The onco-immune microenvironment associated morphologic features were evaluated, and MHC-Ⅰ, PD-L1, CD3, and CD8 expression were detected by immunohistochemistry (IHC). Then the correlation between the factors and their influence on prognosis was analyzed. Results: There were 163 cases of non-specific adenocarcinoma (163/192, 84.90%), 18 cases of adeno-squamous carcinoma (18/192, 9.37%), and 11 cases of other rare subtypes (11/192, 5.73%). Perineural invasion was observed in 110 cases (110/192, 57.29%) and vascular invasion in 86 cases (86/192, 44.79%). There were 84 cases (84/182, 46.15%) with severe chronic inflammation. Tumor infiltrating immune cell numbers (TII-N) were increased in 52 cases (52/192, 27.08%). Lymphocytes and plasma cells were the main infiltrating immune cells in 60 cases (60/192, 31.25%), whereas in 34 cases (34/192, 17.71%) the tumors were mainly infiltrated by granulocytes, and 98 cases (98/192, 51.04%) showed mixed infiltration. CD3+T cells were deficient in 124 cases (124/192, 66.31%). CD8+T cells were deficient in 152 cases (152/192, 79.58%). MHC-Ⅰ expression was down-regulated in 156 cases (156/192, 81.25%), and PD-L1 was positive (CPS≥1) in 46 cases (46/192, 23.96%). Statistical analysis showed that TII-N was negatively correlated with vascular invasion (P=0.035), perineural invasion (P=0.002), stage (P=0.004) and long-term alcohol consumption (P=0.039). The type of immune cells correlated positively with chronic pancreatic inflammation (P=0.002), and negatively with tumor differentiation (P=0.024). CD8+T cells were positively correlated with CD3+T cells (P=0.032), MHC-Ⅰ expression (P<0.001) and PD-L1 expression (P=0.001), and negatively correlated with long-term smoking (P=0.016). Univariate analysis showed that histological nonspecific type (P=0.013) and TII-N (P<0.001) were the factors for good prognosis. Vascular invasion (P=0.032), perineural invasion (P=0.001), high stage (P=0.003) and long-term alcohol consumption (P=0.004) were adverse prognostic factors. COX multivariate risk analysis found that TII-N was an independent favorable factor for PDAC, while perineural invasion was an independent adverse risk factor. Conclusions: TII-N is an independent superior prognostic factor for PDAC, and significantly correlated with many factors; chronic alcohol consumption and smoking may inhibit onco-immunity in PDAC patients.

[Early infantile epileptic encephalopathy caused by PACS2 gene variation: three cases report and literature review]

Objective: To explore the clinical features of three early-onset infantile epileptic encephalopathy (EIEE) patients with variations in phosphofurin acidic cluster sorting protein 2 (PACS2) gene and to review related literature. Methods: The clinical data and genetic features of three early infantile epileptic encephalopathy 66 (EIEE66) patients with a PACS2 gene variant diagnosed by the Department of Neurology, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, from January 2019 to January 2020 were retrospectively analyzed. A literature search with "PACS2 gene" "PACS2" "epileptic encephalopathy, early infantile, 66" and"early infantile epileptic encephalopathy 66" as key words was conducted at PubMed, China National Knowledge Infrastructure (CNKI), and Wanfang Data Knowledge Service Platform (up to July 2020). Case reports of patients with PACS2 gene variants and related clinical data were chosen and reviewed. Results: Case 1, a girl aged 2 years and 2 months was hospitalized because of repetitive seizures within more than two years and 6 convulsions within 2 days due to fever. The seizures occurred at the age of 7 days, characterized by focal seizures and generalized tonic-clonic seizures. Sometimes, the frequency of seizures increased with high fever. Regular treatment had not been implemented in the early stage, later seizures were controlled by valproic acid treatment. Case 2, a female 5 months of age, was admitted due to recurrent convulsions in nearly five months. Focal seizures occured at the age of 5 days. And the brain magnetic resonance imaging (MRI) confirmed abnormal cerebellar hemispheres and cerebellar vermis, as well as cerebellar dysplasia. Several antiepileptic drugs and ketogenic diet were ineffective in the early months, and later seizures were controlled with the treatment with levetiracetam and valproic acid. Case 3, a five-month-old girl, was admitted because of recurrent convulsions for nearly five months. At the age of 3 days, she had tonic seizures, and showed good response to levetiracetam and valproic acid. All the three cases were accompanied by development delay and dysmorphic facial appearance, and got seizure-free with the treatment with valproic acid. All copy-number variant analysis and trio whole exome sequencing revealed a recurrent heterozygous missense variant (c.625G>A) in PACS2 gene. No related reports were found in Chinese journals, while 4 reports were found in English literature, describing 17 patients in total. With these 3 patients included, 20 cases had only two missense PACS2 gene variants, in whom 19 cases carried the variant c. 625G>A (p.Glu209Lys) and 1 case carried the variant c. 631G>A (p.Glu211Lys). Epilepsy was the first reported symptom in all patients, and 17 cases had seizures during the first week of life. Out of the various seizure types observed, focal seizures were the predominant types (13 cases), whereas tonic, clonic, tonic-clonic seizures and non-motor seizures (such as facial flushing) were also reported. Almost all patients showed facial dysmorphism and developmental delay to different degrees. Total of 16 patients had abnormal brain MRI recordings, and 13 cases had cerebellar hypoplasia. More specifically, 7 cases showed inferior vermian hypoplasia, and 3 cases showed hypothalamic fusion anomaly. The treatment was mainly aimed to control the symptoms. And the recommended effective treatment for epilepsy has not been reported yet. Conclusions: PACS2-related early infantile epileptic encephalopathy is an autosomal dominant disease, characterized by seizure onset within the first week of life in most cases, dysmorphic facial appearance, and various degrees of developmental retardation. Treatment with valproic acid showed good effect.

A dual apolipoprotein C-II mimetic-apolipoprotein C-III antagonist peptide lowers plasma triglycerides

Recent genetic studies have established that hypertriglyceridemia (HTG) is causally related to cardiovascular disease, making it an active area for drug development. We describe a strategy for lowering triglycerides (TGs) with an apolipoprotein C-II (apoC-II) mimetic peptide called D6PV that activates lipoprotein lipase (LPL), the main plasma TG-hydrolyzing enzyme, and antagonizes the TG-raising effect of apoC-III. The design of D6PV was motivated by a combination of all-atom molecular dynamics simulation of apoC-II on the Anton 2 supercomputer, structural prediction programs, and biophysical techniques. Efficacy of D6PV was assessed ex vivo in human HTG plasma and was found to be more potent than full-length apoC-II in activating LPL. D6PV markedly lowered TG by more than 80% within a few hours in both apoC-II-deficient mice and hAPOC3-transgenic (Tg) mice. In hAPOC3-Tg mice, D6PV treatment reduced plasma apoC-III by 80% and apoB by 65%. Furthermore, low-density lipoprotein (LDL) cholesterol did not accumulate but rather was decreased by 10% when hAPOC3-Tg mice lacking the LDL-receptor (hAPOC3-Tg × Ldlr^-/- ) were treated with the peptide. D6PV lowered TG by 50% in whole-body inducible Lpl knockout (iLpl^-/- ) mice, confirming that it can also act independently of LPL. D6PV displayed good subcutaneous bioavailability of about 80% in nonhuman primates. Because it binds to high-density lipoproteins, which serve as a long-term reservoir, it also has an extended terminal half-life (42 to 50 hours) in nonhuman primates. In summary, D6PV decreases plasma TG by acting as a dual apoC-II mimetic and apoC-III antagonist, thereby demonstrating its potential as a treatment for HTG.

[Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China]

The correct thoughts and principles of diagnosis and treatment of chronic refractory wounds need to be formulated. Through the relevant domestic and international consensus and based on clinical experience, the Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China is proposed. It is considered that in the diagnosis and treatment of chronic refractory wounds, in the case of fully understanding the patient's medical history, the following thoughts and principles should be complied in order. (1) Pay attention to the cleanliness of the wound after being cleaned. (2) Reasonably perform debridement to avoid being " excessive" or " not thorough". (3) Reasonably perform examination, diagnosis, and differential diagnosis of pathogenic factors. (4) Treat according to etiology. (5) Find comorbidities and prevent adverse outcomes. (6) Select the correct wound treatment method reasonably and timely. When the conservative wound care treatment is considered, pay attention to embodying the concept of etiological treatment, treat the wound according to the principles of safety, phase, selectivity, and effectiveness, and make a reasonable choice of continuing conservative treatment or surgical treatment in time after completing the preparation of the wound bed. When surgical treatment is considered, pay attention to the selection of reasonable surgical method and donor site, pay attention to the healing rate of surgical wound site and the outcome of donor site, and give reasonable protection to the wound site after surgery. (7) Carry out rehabilitation treatment after wound healing and related health education.

TRPV5 and TRPV6 are expressed in placenta and bone tissues during pregnancy in mice

We investigated the dynamic expression of calcium transporters, TRPV5 and TRPV6, in placenta and bone to determine their role in maternal and fetal calcium balance during gestation. In placenta, TRPV5 was expressed predominantly in syncytiotrophoblasts of the labyrinthine zone, whereas TRPV6 was expressed in spongiotrophoblasts of the junction zone. In bone, the two transporters were found in osteoblasts, osteoclasts, cartilage and bone matrices. During the first half of gestation, TRPV5 and TRPV6 levels in bone were increased on pregnancy day (P) 0.5, then decreased on P3.5 followed by a slight increase on P6.5. During the second half of pregnancy, both the proteins and their mRNAs gradually increased from P9.5 to P15.5-P17.5 in both bone and placenta, followed at parturition by relatively high amounts in placenta, but markedly decreased amounts in bone. The expression pattern is likely related to the fetal and maternal calcium requirement during gestation, which may be regulated by estrogen and other hormones, because the fetal demand for calcium is greatest during the last few days of gestation for rats; maternal calcium metabolism is designed to meet the calcium needs of the fetus during this period. We found that TRPV5 and TRPV6 are involved in calcium transport in the placenta and bone, and therefore play a role in calcium homeostasis during embryonic and fetal development.

Detection and analysis of laser driven proton beams by calibrated Gafchromic HD-V2 and MD-V3 radiochromic films

The radiochromic film (RCF) is a high-dose, high-dynamic range dosimetry detection medium. A stack of RCFs can be used to detect both spatial and energetic distribution of laser driven ion beams with a large divergence angle and continuous energy spectrum. Two types of RCFs (HD-V2 and MD-V3, from Radiation Products Design, Inc.) have been calibrated using MeV energy protons and carbon ions produced by using a 2 × 6 MV tandem electrostatic accelerator. The proportional relationship is obtained between the optical density and the irradiation dose. For protons, the responses are consistent at all energies with a variation of about 15%. For carbon ions, the responses are energy related, which should be noted for heavy ion detection. Based on the calibration, the broad energy spectrum and charge distribution of laser accelerated proton beam with energy from 3 to 8 MeV and pC charge were detected and reconstructed at the Compact LAser Plasma Accelerator at Peking University.

[Application value of endoscope in probing chronic wound with sinus tract in clinic]

Objective: To explore the application value of endoscope in probing the chronic wound with sinus tract in clinic. Methods: Twenty-eight chronic wounds with sinus tracts from 27 patients conforming to the inclusion criteria admitted to Outpatient Department of Wound Healing Center of Ruijin Hospital from December 2017 to March 2018 were investigated in a prospective and self-controlled trial. After being cleaned, the diameter of the opening of sinus tract was measured with a rule. A probe was used to measure the depth of a sinus tract according to the touch from the probe extremity in operation, and to measure the depth of a sinus tract that could be observed with naked eyes with the help of a pair of hemostatic forceps. Five minutes later, a probe was inserted deeply into the sinus tract to measure the depth under the endoscopic view combined with touch from the probe extremity in operation. Afterwards, the sinus tract was observed with endoscope, and the depth of the tract which could be observed under the endoscopic view was measured using a probe inserted deeply into the sinus tract. After completion of the above exploration, the sinus tract was infused with contrast agent Omnipaque 350 and scanned by computed tomography (CT) later to obtain its depth. The following indicators were calculated: the ratio of the depth of the sinus tract measured by CT to the diameter of the opening of the sinus tract (hereinafter referred to as the depth/diameter ratio of the sinus tract), the deviation rate comparing the depth of the sinus tract measured by conventional method (measured by probe only) and by endoscope (measured by probe under the endoscope view) with the depth of the sinus tract measured by CT (hereinafter referred to as the deviation rate of the measured depth of the sinus tract), the deviation rate comparing the depth of the sinus tract that could be observed measured by conventional method and by endoscope with the depth of the sinus tract measured by CT (hereinafter referred to as the deviation rate of the depth of the sinus tract that could be observed). Data were processed with paired t test. Pearson correlation analysis was applied to analyze the correlation between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method and by endoscope. Results: The depth/diameter ratio of the sinus tract of this group of wounds was 1-32 (8±7). The deviation rate of the measured depth of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method were (19±14)% and (79±18)%, respectively, both obviously larger than (9±9)% and (25±25)% by endoscope (t=3.837, 13.626, P<0.01). Positive correlation existed between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract by conventional method, and between the depth/diameter ratio of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method and by endoscope (r=0.514, 0.585, 0.651, P<0.01). However, there was no obvious correlation between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract by endoscope (r=0.113, P>0.05). Conclusions: Compared with the conventional method, application of endoscope is able to get more accurate data of chronic wounds with sinus tracts and observe the wounds with wider range.

Coexpression of novel furin-resistant LPL variants with lipase maturation factor 1 enhances LPL secretion and activity

LPL is a secreted enzyme that hydrolyzes triglycerides from circulating lipoproteins. Individuals lacking LPL suffer from severe hypertriglyceridemia, a risk factor for acute pancreatitis. One potential treatment is to administer recombinant LPL as a protein therapeutic. However, use of LPL as a protein therapeutic is limited because it is an unstable enzyme that is difficult to produce in large quantities. Furthermore, these considerations also limit structural and biochemical studies that are needed for large-scale drug discovery efforts. We demonstrate that the yield of purified LPL can be dramatically enhanced by coexpressing its maturation factor, LMF1, and by introducing novel mutations into the LPL sequence to render it resistant to proteolytic cleavage by furin. One of these mutations introduces a motif for addition of an N-linked glycan to the furin-recognition site. Furin-resistant LPL has previously been reported, but is not commonly used. We show that our modifications do not adversely alter LPL's enzymatic activity, stability, or in vivo function. Together, these data show that furin-resistant LPL is a useful reagent for both biochemical and biomedical studies.

[Clinical observation on soft and hard tissue changes of immediate implantation and immediate reconstruction in anterior region after loading 3 years]

OBJECTIVE

To observe the change of soft and hard tissue in dental immediate implantation and immediate reconstruction in anterior region after loading 3 years.

METHODS

Patients with single anterior tooth loss in the Department of Second Dental Center, Peking University School and Hospital of Stomatology from October 2008 to October 2012 were enrolled. The gingival papilla height, labial gingival margin level and peri-implant bone level were measured immediately after the permanent restoration and 3 years later.

RESULTS

In the study, 20 patients were treated by immediate implantation and immediate reconstruction for 22 implants; 24 patients were treated by delayed implant for 29 implants. Implant stability quotient (ISQ) value of the two groups showed no significant difference before permanent restoration (P>0.05). In all the cases after loading 3 years, the average mesial gingival papilla height in implant area of the immediate group and delayed group changed by (0.34±0.54) mm and (0.05±0.39) mm respectively (P=0.07), the distal gingival papilla height changed by (0.43±0.42) mm and (0.36±0.48) mm respectively (P=0.13), while the labial gingival margin level shrinkages were (0.70±0.40) mm and (0.62±0.34) mm respectively (P=0.23). Peri-implant bone losses in the mesial side were (1.02±0.50) mm and (0.88±0.46) mm respectively (P=0.53), while those in the distal side were (1.05±0.34) mm and (0.95±0.47) mm respectively (P=0.21). All these indicators showed no significant difference between the two groups (P>0.05); When the permanent prostheses delivered, the distributions of the gingival papilla index were different between the two groups whether in the mesial side or in the distal side (P<0.05).

CONCLUSION

The changes of the soft and hard tissue of the immediate implantation and immediate reconstruction in anterior region after loading 3 years were basically equivalent to the conventional implant restoration. But, the former was obviously better than the latter in reducing the duration of treatment and in getting the ideal dental papilla aesthetic effect.

Lipase maturation factor 1 affects redox homeostasis in the endoplasmic reticulum

Lipoprotein lipase (LPL) is a secreted lipase that clears triglycerides from the blood. Proper LPL folding and exit from the endoplasmic reticulum (ER) require lipase maturation factor 1 (LMF1), an ER-resident transmembrane protein, but the mechanism involved is unknown. We used proteomics to identify LMF1-binding partners necessary for LPL secretion in HEK293 cells and found these to include oxidoreductases and lectin chaperones, suggesting that LMF1 facilitates the formation of LPL's five disulfide bonds. In accordance with this role, we found that LPL aggregates in LMF1-deficient cells due to the formation of incorrect intermolecular disulfide bonds. Cells lacking LMF1 were hypersensitive to depletion of glutathione, but not DTT treatment, suggesting that LMF1 helps reduce the ER Accordingly, we found that loss of LMF1 results in a more oxidized ER Our data show that LMF1 has a broader role than simply folding lipases, and we identified fibronectin and the low-density lipoprotein receptor (LDLR) as novel LMF1 clients that contain multiple, non-sequential disulfide bonds. We conclude that LMF1 is needed for secretion of some ER client proteins that require reduction of non-native disulfides during their folding.

[Survival of patients with primary central nervous system diffuse large B-cell lymphoma: impact of gene aberrations and protein overexpression of bcl-2 and C-MYC, and selection of chemotherapy regimens]

Objective: To investigate the impact of clinicopathological features, gene rearrangements and protein expression of bcl-6, bcl-2, C-MYC and chemotherapy regime on the prognosis of patients with primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL). Methods: Thirty-three cases of PCNS-DLBCL diagnosed from January 2006 to December 2016 at Zhejiang Cancer Hospital were collected. The expression of CD10, bcl-6, bcl-2, MUM1 and MYC were detected by immunohistochemical staining (IHC). The presence of EB virus was detected by in situ hybridization(EBER). Copy number variation (ICN) and translocation status of bcl-6, bcl-2 and C-MYC genes were detected by fluorescence in situ hybridization (FISH). The relationship between the above indexes and the prognosis was analyzed by univariate, bivariate survival analysis and multiple Cox hazard regression analysis. Results: The study included 33 patients of PCNS-DLBCL, without evidence of primary or secondary immunodeficient disease. Male to female ratio was 1.36∶1.00, and the average age was 56 years. Twenty cases had single lesion while 13 had multiple lesions. Deep brain involvement was seen in 12 cases. All patients underwent partial or total tumor resection. Five patients received whole brain post-surgery radiotherapy, nine patients received high-dose methotrexate (HD-MTX) based chemotherapy, and 12 patients received whole-brain radiotherapy combined with HD-MTX based chemotherapy. Severn patients received no further treatment and rituximab was used in 8 patients. According to the Hans model, 27 cases were classified as non-GCB subtypes (81.8%). Bcl-2 was positive in 25 cases (75.8%, 25/33) and highly expressed in 8 (24.2%). MYC was positive in 12 cases (36.4%) and double expression of bcl-2 and MYC was seen in 6 cases. EBER positive rate was 10.0%(3/30), all of which had multiple lesions. Two bcl-6 gene translocations and 3 amplifications were found in 28 patients. Two translocations, 3 ICN or with both bcl-2 gene translocation and ICN were found in 30 patients. Four ICNs of C-MYC gene were found in 28 patients. Elevated protein in cerebrospinal fluid (CSF) was found in 13 patients. LDH increased in 10 cases. Follow-up period was 2-90 months with the average survival time of (23.0±3.7) months and two-year survival rate of 39.0%. Univariate survival analysis showed that overexpression of bcl-2 protein (≥70%) and MYC protein (≥40%), bcl-2 gene abnormality (including copy number increase and translocation), C-MYC gene copy number increased were adverse factors for survival. C-MYC/ bcl-2 gene double hit was seen in 2 cases. Bivariate survival analysis found that of bcl-2/MYC protein double expression and bcl-2 and C-MYC genes double aberration were significantly associated with adverse outcomes. Cox multivariate risk regression analysis found that gender, cerebrospinal fluid protein increasing, and ICN of C-MYC gene were independent poor prognostic factors. DH-MTX based comprehensive chemotherapy was associated with better prognosis. Conclusions: Double hit at genomic level (copy number variations and gene rearrangements) and double protein expression of bcl-2 and C-MYC in PCNS-DLBCL are significantly associated with an adverse outcome. DH-MTX based comprehensive treatment may prolong the patient survival.

[The understanding of Epstein-Barr virus associated lymphoproliferative disorder]

In recent years, there are increasing articles concerning Epstein-Barr virus associated lymphoproliferative disorder (EBV+ LPD), and the name of EBV+ LPD is used widely. However, the meaning of EBV+ LPD used is not the same, which triggered confusion of the understanding and obstacles of the communication. In order to solve this problem. Literature was reviewed with combination of our cases to clarify the concept of EBV+ LPD and to expound our understanding about it. In general, it is currently accepted that EBV+ LPD refers to a spectrum of lymphoid tissue diseases with EBV infection, including hyperplasia, borderline lesions, and neoplastic diseases. According to this concept, EBV+ LPD should not include infectious mononucleosis (IM) and severe acute EBV infection (EBV+ hemophagocytic lymphohistiocytosis, fatal IM, fulminant IM, fulminant T-cell LPD), and should not include the explicitly named EBV+ lymphomas (such as extranodal NK/T cell lymphoma, aggressive NK cell leukemia, Burkitt lymphoma, and Hodgkin lymphoma, etc.) either. EBV+ LPD should currently include: (1) EBV+ B cell-LPD: lymphomatoid granulomatosis, EBV + immunodeficiency related LPD, chronic active EBV infection-B cell type, senile EBV+ LPD, etc. (2) EBV+ T/NK cell-LPD: CAEBV-T/NK cell type, hydroa vacciniforme, hypersensitivity of mosquito bite, etc. In addition, EBV+ LPD is classified, based on the disease process, pathological and molecular data, as 3 grades: grade1, hyperplasia (polymorphic lesions with polyclonal cells); grade 2, borderline (polymorphic lesions with clonality); grade 3, neoplasm (monomorphic lesions with clonality). There are overlaps between EBV+ LPD and typical hyperplasia, as well as EBV+ LPD and typical lymphomas. However, the most important tasks are clinical vigilance, early identification of potential severe complications, and treating the patients in a timely manner to avoid serious complications, as well as the active treatment to save lives when the complications happened.

Involvement of the MAPK pathway in the pressure-induced synovial metaplasia procedure for the temporomandibular joint

Abnormal pressure is an important factor that contributes to bone adaptation in the temporomandibular joint (TMJ). We determined the effect of the mitogen-activated protein kinases (MAPK) pathway on the pressure-induced synovial metaplasia procedure for the TMJ, both in vitro and in vivo. Synovial fibroblasts (SFs) were exacted from rat TMJs and exposed to different hydrostatic pressures. The protein extracts were analyzed to determine the activation of ERK1/2, JNK, and p38. Surgical anterior disc displacement (ADD) was also performed on Japanese rabbits, and the proteins of TMJ were isolated to analyze pressure-induced MAPK activation after 1, 2, 4, and 8 weeks. The results showed that the activation of ERK1/2 and JNK in SFs significantly changed with increasing hydrostatic pressure, whereas p38 activation did not change. Moreover, p38 was activated in animals 1 week after surgical ADD. The levels of p38 gradually increased after 2 and 4 weeks, and then slightly decreased but remained higher than in the control 8 weeks after surgical ADD. Nevertheless, JNK was rarely activated after the ADD treatment. Our findings suggest the involvement of MAPK activation in the pressure-induced synovial metaplasia procedure with pressure loading in TMJ.

Sphere formation permits Oct4 reprogramming of ciliary body epithelial cells into induced pluripotent stem cells

Somatic cells can be reprogrammed to induced pluripotent stem (iPS) cells by defined sets of transcription factors. We previously described reprogramming of monolayer-cultured adult mouse ciliary body epithelial (CE) cells by Oct4 and Klf4, but not with Oct4 alone. In this study, we report that Oct4 alone is sufficient to reprogram CE cells to iPS cells through sphere formation. Furthermore, we demonstrate that sphere formation induces a partial reprogramming state characterized by expression of retinal progenitor markers, upregulation of reprogramming transcription factors, such as Sall4 and Nanog, demethylation in the promoter regions of pluripotency associated genes, and mesenchymal to epithelial transition. The Oct4-iPS cells maintained normal karyotypes, expressed markers for pluripotent stem cells, and were capable of differentiating into derivatives of all three embryonic germ layers in vivo and in vitro. These findings suggest that sphere formation may render somatic cells more susceptible to reprogramming.

Bioinformatic analysis of the effect of type II diabetes on skin wound healing

We examined the relationship between type 2 diabetes and skin wound healing. GSE38396 was downloaded from the Gene Expression Omnibus database and preprocessed using the RMA function of the Affy package. Differentially expressed genes (DEGs) were identified using the limma package, then DAVID was applied to per-form Gene Ontology functional annotation and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. MicroRNAs and their target genes were screened from the miRecords database and subjected to functional analysis. Finally, the STRING online database was applied to identify the protein-protein interaction relationships, and a combined score > 0.5 was considered to indicate an interaction. A total of 421 DEGs (208 upregulated and 213 downregulated genes) were identified in the skin lymphatic endothelial cells of patients with type II diabetes. Twenty-four microRNAs and 34 target genes were screened, including those involved in cell migration, regulation of cell proliferation, cell death, and cell adhesion regulation, among others. Protein-protein interaction network clustering analysis identified a module composed of 25 genes, and INTERPRO protein domain enrichment analysis showed that the protein domain of the clustering module main-ly contained the insulin-like growth factor binding proteins IGFBP3 and CYR61. IGFBP3 and CYR61 may play important roles in skin wound healing in diabetes patients. This information may be useful for developing methods to treat skin refractory wounds in type II diabetes.

Effects and toxicity of neoadjuvant chemotherapy preoperative followed by adjuvant chemoradiation in small cell neurdendocrine cervical carcinoma

OBJECTIVE

To determine the efficacy and toxicity of a combined-modality regimen of neoadjuvant chemotherapy (NACT) before primary radical surgery followed by adjuvant chemoradiation in small cell neuroendocrine cervical cancer (SCNEC) patients.

MATERIALS AND METHODS

The study was approved by the ethics committee of the present hospital. The records of 23 SCNEC patients who received NACT before primary radical surgery were reviewed at the Zhejiang Cancer Hospital between January 1998 and May 2010. All patients received one to four cycles of NACT and two to eight cycles of chemotherapy (NACT and adjuvant chemotherapy) on the basis of platinum, 17 (73.9%) patients received NACT using a regimen consisting of etoposide and cisplatin (EP). Eighteen (85.7%) patients received adjuvant chemotherapy using a regimen consisting of PE and EP. Kaplan-Meier and Cox regression methods were used for analyses.

RESULTS

Of the 23 eligible patients, 18 had Stages I-IIA, five had Stages IIB-IIIB disease. Twelve patients (52.2%) developed grade 3 and 4 neutropenia. Fourteen patients (60.9%) developed grade 3 and 4 anemia. The majority of grade 3 and 4 neutropenia and non-hematologic toxicities were usually self-limited. Three patients (13.0%) who postoperative pathology showed pathologic complete response (CR) had better prognosis than those did not show pathologic CR; the median survival was 69.5 months (range, 51.1-177.1), 54.5 months (range: 7.3-81.5), respectively. In univariate analysis, lymphovascular space invasion (LSI) (p = 0.013), and deep stromal invasion (DSI) (p = 0.001) were considered poor prognostic factors. With a median follow-up for surviving patients was 40.8 months (range, 7-177), 12 patients recurred, 11 of which had died. The estimated three- and five-year overall survival (OS) rates for all patients were 55.8% and 39.9%, respectively.

CONCLUSION

NACT before primary radical surgery followed by adjuvant chemoradiation or chemotherapy was well tolerated and seems to be effective for early stage SCNEC patients. Prospective clinical study is necessary and we hope that this research's results help to design a prospective clinical study.

[Clinical observation of the reliability of gingival contour by using temporary crown after loading 1 year]

OBJECTIVE

To observe the gingival contour and its variation following application of implant-supported temporary crowns on gingival contour in maxillary single tooth implant procedure after loading 1 year and to explore the reliability of soft tissue intervention using temporary crowns.

METHODS

In 78 (37 males and 41 females) patients with anterior maxillary single tooth loss from the Department of Second Dental Center, Peking University School and Hospital of Stomatology, the gingival contour was induced by using implant-supported temporary crowns prior to maxillary tooth implant till permanent restoration from March 2010 to November 2011. The gingival papilla height and labial gingival margin level were measured immediately after the permanent restoration and 1 year later.

RESULTS

In all the cases after loading 1 year, the average mesial and distal gingival papilla heights in the implant area increased by (0.16±0.58) mm and (0.10±0.53) mm, respectively. The labial gingival margin level was changed by (0.10±0.41) mm averagely. The difference in gingival contour shaped by temporary crown was not statistically significant after 1 year (P>0.05).

CONCLUSION

The soft tissue shaping technique on aesthetic rehabilitation in maxillary single tooth implant is clinically feasible with a good recent aesthetic effect under the condition that the complications are controlled stringently.

Transcriptomic and biochemical evidence for the role of lysine biosynthesis against linoleic acid hydroperoxide-induced stress in Saccharomyces cerevisiae

Amino acid biosynthesis forms part of an integrated stress response against oxidants in Saccharomyces cerevisiae and higher eukaryotes. Here we show an essential protective role of the l-lysine biosynthesis pathway in response to the oxidative stress condition induced by the lipid oxidant-linoleic acid hydroperoxide (LoaOOH), by means of transcriptomic profiling and phenotypic analysis, and using the deletion mutant dal80∆ and lysine auxotroph lys1∆. A comprehensive up-regulation of lysine biosynthetic genes (LYS1, LYS2, LYS4, LYS9, LYS12, LYS20 and LYS21) was revealed in dal80Δ following the oxidant challenge. The lysine auxotroph (lys1∆) exhibited a significant decrease in growth compared with that of BY4743 upon exposure to LoaOOH, albeit with the sufficient provision of lysine in the medium. Furthermore, the growth of wild type BY4743 exposed to LoaOOH was also greatly reduced in lysine-deficient conditions, despite a full complement of lysine biosynthetic genes. Amino acid analysis of LoaOOH-treated yeast showed that the level of cellular lysine remained unchanged throughout oxidant challenge, suggesting that the induced lysine biosynthesis leads to a steady-state metabolism as compared to the untreated yeast cells. Together, these findings demonstrate that lysine availability and its biosynthesis pathway play an important role in protecting the cell from lipid peroxide-induced oxidative stress, which is directly related to understanding environmental stress and industrial yeast management in brewing, wine making and baking.

InPBi single crystals grown by molecular beam epitaxy

InPBi was predicted to be the most robust infrared optoelectronic material but also the most difficult to synthesize within In-VBi (V = P, As and Sb) 25 years ago. We report the first successful growth of InPBi single crystals with Bi concentration far beyond the doping level by gas source molecular beam epitaxy. The InPBi thin films reveal excellent surface, structural and optical qualities making it a promising new III-V compound family member for heterostructures. The Bi concentration is found to be 2.4 ± 0.4% with 94 ± 5% Bi atoms at substitutional sites. Optical absorption indicates a band gap of 1.23 eV at room temperature while photoluminescence shows unexpectedly strong and broad light emission at 1.4-2.7 μm which can't be explained by the existing theory.

Prognostic factors and treatment comparison in small cell neuroendocrine cervical carcinoma

OBJECTIVE

To determine the clinicopathologic factors associated with survival in small cell neuroendocrine cervical cancer (SCNEC) patients.

MATERIALS AND METHODS

The study was approved by the ethics committee of the hospital. The records of 64 SCNEC patients from 9,474 Chinese patients with cervical cancer at the Zhejiang Cancer Hospital were reviewed. Kaplan-Meier and Cox regression methods were used for analyses.

RESULTS

Of 64 patients, 47 had Stages I-IIA, 12 had Stages IIB-IVA, and five had Stage IV-B disease. A total of 81.25% underwent surgery, 89.1% received chemotherapy, 62.5% received radiation, 34.4% received neoadjuvant chemotherapy (NACT), and 34.4% received concurrent chemoradiation (CCRT). The median follow-up for surviving patients was 35.7 months (range: 0.5-160), and 29 (50%) of the 58 patients with Stages I-III had either disease recurrence or progression. The median time to first relapse was 10.5 months (range: 0-88.2). The five-year overall survival of patients in Stages I-IIA and IIB-IVB disease was 54.4% and 9.8%, respectively (p = 0.001). Women with early-stage (Stages IIBIIA) disease had median survival rates of 94 months compared with 21.4 months in the advanced-stage (Stages IIB-IVB) group. In univariate analysis, advanced-stage (p = 0.001), without radical surgery (p = 0.002) and deep stromal invasion (DSI) (p = 0.000) were considered poor prognostic factors. In a multivariable analysis, tumor size > four cm (p = 0.048), postoperative radiation (p = 0.038) for early-stage patients and the FIGO stage (p = 0.040) of disease in the overall population remained as independent prognostic factor of survival.

CONCLUSION

The FIGO stage was found to be an independent prognostic factor of SCNEC. In addition, tumor size > four cm and DSI was associated with poor survival. Postoperative radiation for early-stage patients may not improve survival. The role of primary and postoperative NACT or CCRT is unclear. Clinical trials are needed.

Transcriptomic insights into the molecular response of Saccharomyces cerevisiae to linoleic acid hydroperoxide

Eukaryotic microorganisms are constantly challenged by reactive oxygen species derived endogenously or encountered in their environment. Such adversity is particularly applied to Saccharomyces cerevisiae under harsh industrial conditions. One of the major oxidants to challenge S. cerevisiae is linoleic acid hydroperoxide (LoaOOH). This study, which used genome-wide microarray analysis in conjunction with deletion mutant screening, uncovered the molecular pathways of S. cerevisiae that were altered by an arresting concentration of LoaOOH (75 μM). The oxidative stress response, iron homeostasis, detoxification through PDR transport and direct lipid β-oxidation were evident through the induction of the genes encoding for peroxiredoxins (GPX2, TSA2), the NADPH:oxidoreductase (OYE3), iron uptake (FIT2, ARN2, FET3), PDR transporters (PDR5, PDR15, SNQ2) and β-oxidation machinery (FAA2, POX1). Further, we discovered that Gpx3p, the dual redox sensor and peroxidase, is required for protection against LoaOOH, indicated by the sensitivity of gpx3Δ to a mild dose of LoaOOH (37.5 μM). Deletion of GPX3 conferred a greater sensitivity to LoaOOH than the loss of its signalling partner YAP1. Deletion of either of the iron homeostasis regulators AFT1 or AFT2 also resulted in sensitivity to LoaOOH. These novel findings for Gpx3p, Aft1p and Aft2p point to their distinct roles in response to the lipid peroxide. Finally, the expression of 89 previously uncharacterised genes was significantly altered against LoaOOH, which will contribute to their eventual annotation.

Facile and efficient reprogramming of ciliary body epithelial cells into induced pluripotent stem cells

Induced pluripotent stem (iPS) cells are attractive for cell replacement therapy, because they overcome ethical and immune rejection issues that are associated with embryonic stem cells. iPS cells have been derived from autonomous fibroblasts at low efficiency using multiple ectopic transcription factors. Recent evidence suggests that the epigenome of donor cell sources plays an important role in the reprogramming and differentiation characteristics of iPS cells. Thus, identification of somatic cell types that are easily accessible and are more amenable for cellular reprogramming is critical for regenerative medicine applications. Here, we identify ciliary body epithelial cells (CECs) as a new cell type for iPS cell generation that has higher reprogramming efficiency compared with fibroblasts. The ciliary body is composed of epithelial cells that are located in the anterior portion of the eye at the level of the lens and is readily surgically accessible. CECs also have a reduced reprogramming requirement, as we demonstrate that ectopic Sox2 and c-Myc are dispensable. Enhanced reprogramming efficiency may be due to increased basal levels of Sox2 in CECs. In addition, we are the first to report a cellular reprogramming haploinsufficiency observed when reprogramming with fewer factors (Oct4 and Klf4) in Sox2 hemizygous cells. Taken together, endogenous Sox2 levels are critical for the enhanced efficiency and reduced exogenous requirement that permit facile cellular reprogramming of CECs.

An improved infectivity assay combining cell culture with real-time PCR for rapid quantification of human adenoviruses 41 and semi-quantification of human adenovirus in sewage

A protocol for the rapid detection and semi-quantification of human enteric adenovirus based on the quantification of viral mRNA during cell culture infectivity assay was developed. Infectivity assays for adenovirus incorporated cell culture and reverse transcription real-time PCR, where viral mRNA detection was used to monitor the progress of adenovirus infection (CC/mRNA qPCR). The cell line used was G293. This specific infectivity assay was calibrated against different initial concentrations of human adenovirus 41. In addition, the expression of the host's housekeeping (HK) gene, GAPDH, served as internal control for the mRNA assays for quality assurance of the mRNA extraction and reverse transcription steps. The concentrations of infectious human adenoviruses in different sewage samples were estimated semi-quantitatively using the CC/mRNA qPCR assay and calibration obtained for adenovirus 41. A linear relationship between concentrations of viral mRNA (hexon gene) and infectious units was observed between 10(7) to 10(1) infectious units per assay (R(2) = 0.97) in samples analyzed 3-5 days post infection. The expressions of host cell GAPDH gene were not significantly affected by infections with different concentrations of human adenovirus 41, and between virus positive and negative cell cultures (p > 0.1). The estimated concentrations of human adenoviruses in sewage samples ranged between 10(2) to 10(3) mRNA-IU/L. Most of the viruses detected in sewage samples were from human adenovirus species F. The CC/mRNA qPCR assay can be used for quantifying infectious human adenovirus 41, estimating the levels of human adenoviruses in sewage samples, and applied to other sample settings. The CC/mRNA qPCR protocol described here represents an improvement in the detection of human enteric adenoviruses by reducing incubation time (5 days); whereas the conventional cell culture method requires longer incubation periods (10-20 days). More importantly, this protocol can be used to more rapidly and semi-quantitatively estimate the levels of infectious human adenoviruses in environmental samples.

Vimentin DNA methylation predicts survival in breast cancer

The Vimentin gene plays a pivotal role in epithelial-to-mesenchymal transition and is known to be overexpressed in the prognostically poor basal-like breast cancer subtype. Recent studies have reported Vimentin DNA methylation in association with poor clinical outcomes in other solid tumors, but not in breast cancer. We therefore quantified Vimentin DNA methylation using MALDI-TOF mass spectrometry in breast tumors and matched normal pairs in association with gene expression and survival in a hospital-based study of breast cancer patients. Gene expression data via qRT-PCR in cell lines and oligomicroarray data from breast tissues were correlated with percent methylation in the Vimentin promoter. A threshold of 20 percent average methylation compared with matched normal pairs was set for bivariate and multivariate tests of association between methylation and tumor subtype, tumor histopathology, and survival. Vimentin was differentially methylated in luminal breast cancer cell lines, and in luminal A, luminal B, and HER2-enriched breast tumor subtypes, but was rare in basal-like cell lines and tumors. Increased methylation was strongly correlated with decreased mRNA expression in cell lines, and had a moderate inverse correlation in breast tumors. Vimentin methylation predicted poor overall survival independent of race, subtype, stage, nodal status, or metastatic disease and holds promise as a new prognostic biomarker for breast cancer patients.

Implants placed simultaneously with maxillary sinus floor augmentations in the presence of antral pseudocysts: a case report

An antral pseudocyst on the maxillary sinus has previously been a contraindication for sinus augmentation. The authors report the case of a patient with an antral pseudocyst (16.7 mm × 27.6 mm) in his left sinus, who was referred for dental implant treatment. The surgical plan was to perform the sinus augmentation after removing the cyst whilest simultaneously placing implants. During the operation the cyst could not be found in the left sinus. The sinus augmentation was carried out successfully without sinus membrane perforation and the implants were placed according to plan. Three mouths later, the cyst was still present and good osseointegration of the implants was achieved. After the implants had been in place for a year, a CT scan showed that the cyst had decreased in size. The authors conclude that it is may not be necessary to remove a sinus cyst before sinus augmentation or during the sinus augmentation operation if the patient does not have any symptoms and the cyst is not large. In cases with large lesions or an unclear diagnosis, further evaluation is needed before surgical intervention.

Erythropoietin can promote survival of cerebral cells by downregulating Bax gene after traumatic brain injury in rats

BACKGROUND

Traumatic brain injury (TBI) is an important cause of adult mortality and morbidity. Erythropoietin (Epo) has been shown to promote the viability of cerebral cells by upregulating Bcl-2 gene; however, Epo may exert its antiapoptotic effect via the differential regulation of the expression of genes involved in the apoptotic process.

AIM

The present study examined the neuroprotective effect of Epo as a survival factor through the regulation of the Bax.

MATERIALS AND METHODS

Wistar rats were randomly divided into three groups: Recombinant human EPO treated (rhEPO) TBI, vehicle-treated TBI, and sham-operated. Traumatic brain injury was induced by the Feeney free-falling model. Rats were killed 5, 12, 24, 72, 120, or 168 h after TBI. Regulation of Bcl-2 was detected by reverse transcription-polymerase chain reaction (RT-PCR), western blotting and immunofluorescence.

RESULTS

Bax mRNA and protein levels were lower in the rhEPO)-treated rat brains than in the vehicle-treated rat brains. Induction of Bax expression peaked at 24 h and remained stable for 72-120 h in vehicle-treated rat brains, whereas induction of Bax expression was only slightly elevated in rhEPO-treated rat brains. The number of TdT-mediated dUTP Nick-End Labeling(TUNEL)-positive cells in the rhEPO-treated rat brains was far fewer than in the vehicle-treated rat brains.

CONCLUSIONS

Epo exerts neuroprotective effect against traumatic brain injury via reducing Bax gene expression involved in inhibiting TBI-induced neuronal cell death.

Renal outcome and evolution of disease activity in Chinese lupus patients after renal transplantation

Lupus nephritis constitutes the major cause of morbidity and mortality in SLE. The long-term outcome of renal transplantation in lupus patients remains controversial, and the recurrence of lupus activity is a major concern. This study aims to determine the long-term outcome of renal transplantation in Chinese lupus patients and the evolution of lupus activity. A total of 23 lupus patients undergoing renal transplantation were enrolled and compared with 94 matched controls. The overall patient and graft survival rates at 10 years post-transplant in lupus group were not different from the control group (95.2% and 57.7% vs. 90.7% and 66.3%). Recurrence of lupus nephritis in renal allograft and flare-ups of lupus activity were not observed in this study. The SLE group had less acute rejection than the control group (20.4% vs. 29.8%, P<0.05). The infection rate between the two groups was similar (39.1% vs. 51.1%, P=0.427), although SLE group had a significantly higher rate of developing avascular necrosis (17.4% vs. 2.1%, P=0.04). In conclusion, patient and graft survival rates and other major complications in Chinese lupus patients are comparable to non-lupus transplant recipients caused by other diseases. Chinese patients with SLE are suitable candidates for renal transplantation.

Severe emphysematous pyelonephritis in a renal allograft: successful treatment with percutaneous drainage and antibiotics

Emphysematous pyelonephritis is a rare, severe gas-forming infection of the kidney. Herein we report a case of a 51-year-old man who had received a cadaveric renal transplant 12 years ago. Post-transplant diabetes mellitus occurred 8 years later. He experienced urinary tract infection with graft pain one week before admission and presented with septic shock at the emergency room. Plain X-ray of the abdomen showed retroperitoneal air. A computed tomography scan of the abdomen showed retroperitoneal and extraperitoneal air being released from the graft kidney. These findings were compatible with extensive emphysematous pyelonephritis. The patient underwent percutaneous drainage. Blood culture and urine culture yielded Escherichia coli. After repeated percutaneous drainage and strong antibiotics for a prolonged period, the patient finally recovered.

Effect of pentoxifylline on graft function of renal transplant recipients complicated with chronic allograft nephropathy

BACKGROUND

Chronic allograft nephropathy (CAN) is characterized by a progressive deterioration of renal function with various degrees ofproteinuria. Currently, there is no effective treatment despite the introduction of new generations of immunosuppressants. Pentoxifylline (PTX) is a phosphodiesterase inhibitor that possesses antiproteinuric effect and has been proved to be effective in treating several glomerular diseases. The purpose of the current study was to examine the effect of PTX on renal transplant patients with established CAN.

MATERIALS AND METHODS

Renal transplant recipients with biopsyproven CAN were recruited for the study. All the patients had been on angiotensin-converting enzyme inhibitor or angiotensin receptor blocker for more than 1 year and were on a triple immunosuppressive regimen including corticosteroid, calcineurine inhibitor and mycophenolate mofetil. PTX in a dose of 1,200 mg/day was administered for at least 6 months. The following parameters were assessed at baseline, the 3rd and the 6th month post treatment: systolic and diastolic blood pressure, number of anti-hypertension drugs, serum creatinine (sCr),estimated glomerular filtration rate (eGFR), 24-hour urinary protein excretion (U/P), urinary N-acetylglucosaminidase (NAG) and intracytoplasmic Thl/Th2 cytokines production of peripheral blood CD4+ cells.

RESULTS

A total of 17 (11 male and 6 female) patients were enrolled in the study. The mean duration of follow-up post transplant was 10.6+/- 4.4 years. The baseline data of sCr, eGFR and U/P were 1.83+/-0.46 mg/dl, 38+/-8 ml/min and 2.65+/-2.15 g/day, respectively. Corresponding values at the 3rd and 6th month post treatment were 1.90+/-0.43 mg/dl (p = NS), 33+/-7 ml/min (p=NS), 2.13 +/-1.13 g/day (p < 0.05) and 2.03+/-0.64 mg/dl (p < 0.05), 32+/-10 ml/min (p < 0.05), 2.74 +/-0.93 g/day (p = NS), respectively. When individual data were analyzed, five cases (29.4%) showed a U/P significant reduction of more than 50% of baseline value, while in 10 cases (58.8%) the graft function remained either stable (9 cases) or improved (1 case) at the end of treatment. Urinary NAG was elevated at the 3rd month, but stabilized thereafter. The Thl/Th2 intracytoplasmic cytokine pattern of peripheral blood CD4+ cells showed a significant decrease of cells bearing TNF-alpha (15.0+/-14.4% vs 14.2+/-17.0%, p < 0.05) and cells bearing IL-10 (1.60 +/-1.23% vs 0.90+/-0.66%, p < 0.05) at the 3rd month.

CONCLUSION

In this pilot study, PTX seemed to be temporarily effective in reducing proteinuria. The graft function was stabilized in more than half of patients at the end of follow-up.

Acute pancreatitis following antilymphocyte globulin therapy in a renal transplant recipient

Acute pancreatitis is a rare complication following OKT3 therapy, which to our knowledge has never been reported in patients treated with antilymphocyte globulin (ALG). We herein report a case of a kidney transplantation patient who developed acute pancreatitis 2 days after treatment with ALG for grade IIb acute rejection. The symptoms subsided after discontinuing this drug. Resumption of ALG therapy triggered another episode of acute pancreatitis. Therefore, the clinical course strongly suggests that ALG was the etiological factor of acute pancreatitis in this particular patient.

Sirolimus in chronic allograft nephropathy

Chronic allograft nephropathy (CAN) is the most common cause of late renal transplant loss. Calcineurin inhibitor (CNI) nephrotoxicity is known to contribute to CAN. A sirolimus-based regimen way allow for early CNI reduction or elimination. The aim of the present study was to determine the efficacy and safety of a sirolimus-based regimen for CAN. From December 2001 to August 2003, kidney transplant (KTx) recipients with CAN were enrolled for treatment with sirolimus. Among 32 studied patients, 24 (75%) underwent graft biopsy before the initiation of sirolimus. Baseline maintenance immunosuppression consisted of cyclosporine/tacrolimus and prednisone with or without mycophenolate mofetil. The follow-up duration on sirolimus therapy was 8.5 +/- 5.9 months (range: 1 to 22 months). The average dosage of sirolimus was 1.8 +/- 0.5 mg/d at the end of follow-up. The mean trough level of sirolimus was 5.1 +/- 2.1 ng/mL. Sirolimus was effective in 16 (50%) patients while 3 (9.4%) patients improved (serum creatinine [Cr] decrease > 10%) and 13 (40.6%) maintained stable (change of serum Cr within 10%). Sirolimus was effective in 5 (35.7%) patients whose serum Cr was over 3.0 mg/dL but failed to rescue all four patients whose serum Cr was over 4.0 mg/dL. Eleven (68.8%) of 16 responders showed a reduction (29.8% +/- 13.8%) in CNI dosage. The most common adverse events were hyperlipidemia (37.5%), anemia (25%), and diarrhea (21.8%). Twelve patients discontinued sirolimus due to graft failure (4), severe infection (3), stroke related mortality (1), anemia (2), diarrhea (1), and edema (1). In conclusion, sirolimus is effective in 50% of KTx recipients with CAN, especially when the serum Cr is less than 3.0 mg/dL. However, the increased incidence of infection, diarrhea, and hyperlipidemia are of major concern.

Tuberculosis in patients with end-stage renal disease

OBJECTIVE

To elucidate the clinical manifestations and risk factors of the mortality rate in uraemic patients with tuberculosis (TB) infection.

DESIGN

We retrospectively analysed 62 patients with uraemia and active tuberculosis who were admitted to our hospital from 1990 through 2000. The patients were followed up for 2 years after discharge or until death.

RESULTS

There were 43 men and 19 women, with a mean age of 63 +/- 13 years. Extra-pulmonary TB was noted in 51.6%. The peritoneum and pleura were the two most common organs involved. Fever of unknown origin was the most common manifestation (77.4%). The corrected serum Ca2+ level of the patients was >10.5 mg/dl in 46.8%. C-reactive protein >6 mg/dl and leukocytosis (white blood cell count >10,000/mm3) at presentation were noted in more than half of the patients. A reversed serum albumin/globulin ratio and leukocytosis were found to be associated with mortality rate.

CONCLUSION

More than half of the TB infections in patients with end-stage renal disease presented with extra-pulmonary involvement. Fever of unknown origin, reversed serum albumin/globulin ratio, and unexplained hypercalcaemia in maintenance dialysis patients suggested the possibility of tuberculosis.

Cell migration: a novel aspect of pancreatic stellate cell biology

BACKGROUND

Pancreatic stellate cells (PSCs), implicated as key mediators of pancreatic fibrogenesis, are found in increased numbers in areas of pancreatic injury. This increase in PSC number may be due to increased local proliferation and/or migration of these cells from adjacent areas. The ability of PSCs to proliferate has been well established but their potential for migration has not been examined.

AIMS

Therefore, the aims of this study were to determine whether cultured rat PSCs have the capacity to migrate and, if so, to characterise this migratory capacity with respect to the influence of basement membrane components and the effect of platelet derived growth factor (PDGF, a known stimulant for migration of other cell types).

METHODS

Migration of freshly isolated (quiescent) and culture activated (passaged) rat PSCs was assessed across uncoated or Matrigel (a basement membrane-like substance) coated porous membranes (pore size 8 micro m) in the presence or absence of PDGF (10 and 20 ng/ml) in the culture medium. A checkerboard assay was performed to assess whether the effect of PDGF on PSC migration was chemotactic or chemokinetic.

RESULTS

Cell migration was observed with both freshly isolated and passaged PSCs. However, compared with passaged (culture activated) cells, migration of freshly isolated cells was delayed, occurring only at or after 48 hours of incubation when the cells displayed an activated phenotype. PSC migration through Matrigel coated membranes was delayed but not prevented by basement membrane components. PSC migration was increased by PDGF and this effect was predominantly chemotactic (that is, in the direction of a positive concentration gradient).

CONCLUSIONS

(i) PSCs have the capacity to migrate. (ii) Activation of PSCs appears to be a prerequisite for migration. (iii) PDGF stimulates PSC migration and this effect is predominantly chemotactic.

IMPLICATION

Chemotactic factors released during pancreatic injury may stimulate the migration of PSCs through surrounding basement membrane towards affected areas of the gland.

Non-point source pesticide removal by a mountainous wetland

Non-point source (NPS) pollution is believed to be one of the major causes of impairment of water bodies. Among NPS pollution, agricultural NPS pollution is considered to be the largest single category resulting in water quality deterioration. Pesticides are some the most ubiquitous of these agricultural NPS pollutants. In this study, a mountainous wetland was selected to investigate the effects of the natural wetland system on the NPS pesticide (atrazine) removal to maintain the surface water quality. The selected wetland receives water from two unnamed creeks, which drain primarily upgradient agricultural lands. Wetland investigation and monitoring were conducted from November 1999 to March 2001. Major storm events and baseline water quality samples were analyzed. Field results indicate that the wetland was able to remove NPS atrazine flushed from the upgradient agricultural lands after the occurrence of storm events. Laboratory aerobic and anaerobic bioreactor experiments were conducted to evaluate the biodegradation of atrazine under the intrinsic conditions of the wetland system. Microbial enumeration was conducted for a quick screen of bacterial activity in the studied wetland. Results from the study suggest that the methanogenesis process was possibly the dominant biodegradation pattern, and atrazine can be degraded under reductive dechlorinating conditions when sufficient intrinsic organic matter was provided. Results from this study can provide us with further knowledge on pesticide removal mechanisms in natural wetlands and evaluate the role of wetlands in controlling pesticide pollutants from stormwater runoff.

Synthesis and antitumor activity of novel C-7 paclitaxel ethers: discovery of BMS-184476

The preparation of C-7 paclitaxel ethers is described. Various substituted ethers were prepared via activation of the corresponding methylthiomethyl ether followed by alcohol addition. Variation of the C-7 ether group as well the 3' side chain position led to the discovery of a novel taxane, BMS-184476 (4), with preclinical antitumor activity superior to paclitaxel.

Lamivudine is effective for the treatment of reactivation of hepatitis B virus and fulminant hepatic failure in renal transplant recipients

Lamivudine is a potent inhibitor of hepatitis B virus (HBV) replication. The aim of this study is to elucidate the effectiveness of lamivudine for the treatment of HBV reactivation with or without fulminant hepatic failure in renal transplant recipients. Forty-two renal transplant recipients (30 men, 12 women) were enrolled onto this study. Eight patients presented with HBV reactivation without fulminant hepatic failure and were administered lamivudine (group I), 5 patients presented with HBV and hepatic failure and were administered lamivudine (group II), 5 patients presented with HBV and hepatic failure but were not administered lamivudine (group III), and 24 patients were asymptomatic HBV carriers who were not administered lamivudine (group IV). Lamivudine was administered at a dose of 100 or 150 mg once daily. A greater prevalence of recent use of a combination of antilymphocyte immunoglobulin (ALG) and methylprednisolone (MP) occurred in patients with hepatic failure (groups II and III) than those without hepatic failure (30% versus 6.3%; P = 0.043). However, there was no significant difference in the incidence of MP use alone (20% versus 25%; P = 0.746). Mortality rates for groups I, II, and III were significantly different (12.5%, 40%, 100%; P = 0.008). One patient in group I died of sepsis without evidence of HBV DNA, even in the terminal event. In group II, 3 of 5 patients (60%) were rescued by lamivudine therapy. In group III, without lamivudine treatment, there was a 100% mortality rate despite intensive plasmapheresis. HBV DNA was not detectable after lamivudine treatment in 7 of 8 patients in group I and 3 of 5 patients in group II. Creatinine levels did not change significantly during lamivudine treatment. Hepatitis B surface antigen and hepatitis B e antigen seroconversion rates after lamivudine treatment were 7.7% and 37.5%, respectively. We conclude that ALG is a potent trigger of HBV-related fulminant hepatic failure in renal transplant recipients, whereas lamivudine is an effective and lifesaving treatment. Prompt use of lamivudine is recommended in renal transplant recipients with evidence of HBV reactivation to prevent catastrophic fulminant hepatic failure.

Evaluation of TCDD biodegradability under different redox conditions

Polychlorinated dibenzo-p-dioxins have been generated as unwanted by-products in many industrial processes. Although their widespread distribution in different environmental compartments has been recognized, little is known about their fate in the ultimate environment sinks. The highly stable dioxin isomer 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been called the most toxic compound known to man. In this laboratory microcosm study, TCDD bioavailability was evaluated under five reduction/oxidation (redox) conditions including aerobic biodegradation, aerobic cometabolism, methanogenesis, iron reduction, and reductive dechlorination. Activated sludge and aquifer sediments from a TCDD and a pentachlorophenol (PCP) contaminated site were used as the inocula. Acetate, sludge cake, and cane molasses were used as the primary substrates (carbon sources) in cometabolism and reductive dechlorination microcosms. After a 90-day incubation period, microcosms constructed under reductive dechlorination conditions were the only treatment showing promising remediation results. The highest TCDD degradation rate [up to 86% of TCDD removal (with an initial concentration of 96 microg/kg of soil)] was observed in the microcosms with anaerobic activated sludge as the microbial inocula and sludge cakes as the primary substrates. Except for reductive dechlorination microcosms, no significant TCDD removal was observed in the microcosms prepared under other conditions. Thus, application of an effective primary substrate to enhance the reductive dechlorination process is a feasible method for TCDD bioremediation. Bioremediation expense can be significantly reduced by the supplement of some less expensive alternative substrates (e.g., sludge cakes, cane molasses). Results would be useful in designing a scale-up in situ or on-site bioremediation system such as bioslurry reactor for field application.

Long-term impact of hepatitis B, C virus infection on renal transplantation

Chronic liver disease and its complications are major problems in renal transplant recipients. Our aim was to elucidate the influence of hepatitis B, C virus infection on the long-term outcome of renal transplantation. Four hundred and seventy-seven patients who received renal transplantation between January 1984 and December 1999, and who were followed up at our hospital were enrolled. HBsAg was detected by the RIA method and anti-HCV Ab was assayed by the second-generation RIA kit. SGOT/ SGPT were checked every 3 months. Hepatoma was diagnosed by dynamic CT scan, elevated alpha-fetoprotein, hypervascularity by angiography and confirmed by pathological examination. The prevalence of HBV, HCV, coinfected HBV/HCV was 9.9% (n = 47), 28.5% ( n = 136), 3.1% (n = 15), respectively. The incidences of hepatoma in the HBV-/HCV-, HBV-/HCV+, HBV+/HCV-, HBV+/HCV+ groups were 1.4% (n = 4), 4.4% (n = 6), 6.4% (n = 3), 6.7% (n = 1), respectively (p = 0.114). The incidences of liver cirrhosis/hepatic failure were 3.2% (n = 9), 6.6% (n = 9), 21.3% (n = 10), 20% (n = 3), respectively (p < 0.001). The frequencies of chronic liver disease were 10.4% (n = 29), 45.6% (n = 62), 66% (n = 31), 80% (n = 12), respectively (p < 0.001). Patient and graft survival rates were lower in the HBV-infected group than in the other groups. Cox regression analysis revealed that HBV infection is likely an independent risk factor for patient mortality although the statistical significance was only borderline. Patients with HBV as well as HCV infection were not at risk of graft loss according to this model of analysis. Patients with HBV infection showed higher incidences of hepatoma, hepatic failure, graft failure and death. Therefore, HBV-infected patients who are candidates for renal transplantation should be carefully evaluated. It seems that HCV infection has little influence on the outcome of renal transplant recipients. A longer period of follow-up is needed to clarify the impact of HCV on renal transplant recipients.

A series of enediynes as novel inhibitors of topoisomerase I

A series of acyclic enediynes, 2-((6-substituted)-3-hexen-1,5-diynyl)benzonitriles (8--11), display potent inhibition against topoisomerase I without the formation of active biradical intermediates and show inhibitory activity against topoisomerase I at 10 microM, which is five times that of camptothecin from the results of agarose gel electrophoresis.

A regulatory region rearranged BK virus is associated with tubulointerstitial nephritis in a rejected renal allograft

A renal allograft transplant patient with high serum creatinine presented clinical symptoms of rejection. Sections of renal biopsy tissue showed mononuclear leukocyte infiltration in the tubulointerstitium and nuclear enlargement with inclusions in the tubular epithelium. The morphological characteristics resembled polyomavirus-induced interstitial nephritis. Electron microscopy of the nuclear inclusions showed paracrystalline arrays of naked viral particles with a diameter of 45 nm. Molecular studies revealed that a new variant of BK virus (BKV) with rearrangement at the regulatory region was involved in the nephritis. The BKV regulatory region contained a tandem repeat from the P-block to the Q-block causing duplication of several important transcriptional elements or transcriptional factor binding motifs. This is the first report to show a naturally occurring BKV variant with regulatory region rearrangement associated with tubulointerstitial nephritis.

Evaluation of the severity of traumatic rhabdomyolysis using technetium-99m pyrophosphate scintigraphy

A quantitative scoring method was designed to assess the extent of muscle damage. Technetium-99m pyrophosphate (99mTc-PYP) scintigraphy was performed for 9 patients experiencing crush injury in the Chichi (Taiwan) earthquake. The magnitude of muscle uptake of 99mTc-PYP was graded as follows: grade 0, less than bone radioactivity (BRA); grade 1, equal to BRA; grade 2, higher than BRA; or grade 3, greatly higher than BRA. The area of muscle injury was estimated according to the rule of nines. The sum of the muscle injury size multiplied by its corresponding grading was defined as the anterior or posterior score according to the anterior or posterior images. Each image was interpreted by two physicians and average anterior and posterior scores were calculated. The muscle score was defined as the geometric mean of the average anterior and posterior scores. Significant correlations were obtained between the muscle score and duration of time trapped (r = 0.868, p < 0.01), peak serum creatine kinase level (r = 0.866, p < 0.01), peak serum phosphorus level (r = 0.877, p < 0.01) and number of hospital days (r = 0.875, p < 0.01). A negative correlation between the muscle score and blood pH (r = -0.706, p < 0.01) was also observed. We concluded that this scoring method may be used as an adjunct for evaluating the locations of trauma and the severity of crush syndrome, and for predicting the duration of hospital stay.

Synthesis of metabolically blocked paclitaxel analogues

The stereospecific syntheses of the metabolically blocked 6-alpha-F, Cl, Br paclitaxel, and 6-alpha-F-10-acetyldocetaxel are described and in vitro and in vivo activity is presented.

Evaluation of atrazine removal processes in a wetland

Agricultural non-point source (NPS) pollution is considered to be the largest single category resulting in water quality deterioration. Pesticide is one of the main detrimental agricultural NPS constituents causing the impairment of water bodies. In this study, a mountainous wetland located in McDowell County, North Carolina, was selected to demonstrate the effects of the natural wetland system on the removal of NPS pesticide (atrazine) pollution to maintain the surface water quality. The selected wetland receives water from two unnamed creeks, which drain primarily agricultural lands. The hydraulic retention time (HRT) for the wetland was approximately 10.5 days based on the results from a dye release study. Water quality monitoring of the wetland was conducted from March to October 1998. One major storm and baseline water quality samples were analyzed. Analytical results indicate that the wetland completely removed NPS atrazine flushed from the upgradient agricultural lands. Laboratory microcosm experiments were conducted to evaluate the feasibility of using the wetland sediments as the microbial sources to enhance the atrazine biodegradation. Microcosm results suggest that atrazine can be degraded under anaerobic or reductive dechlorinating conditions when sucrose was provided as the primary substrate. Atrazine can also serve as the nitrogen source for the growth of microorganisms under anaerobic conditions. Results from this study can provide us with further knowledge on evaluating the role of wetlands in controlling pesticide pollutants from stormwater runoff.

Control of non-point source pollution by a natural wetland

Wetland creation and restoration is a reliable and efficient technology for the remediation of contaminated water. Knowledge from the natural wetland systems would be necessary to enhance the operational efficiency of constructed wetlands. In this study, a mountainous wetland located in McDowell County, North Carolina, USA was selected to demonstrate the effects of the natural filtration and restoration system on the maintenance of surface water quality. The hydraulic retention time (HRT) for the wetland was 10.5 days based on the results from a dye release study. Water quality monitoring of the wetland was conducted from May to August 1997. One major storm event and baseline water quality samples were collected and analyzed. Analytical results indicate that this wetland removed a significant amount of non-point source (NPS) pollutants [more than 80% N removal, 91% of total suspended solid removal, 59% of total phosphorus removal, and 66% of chemical oxygen demand (COD) removal] caused by the studied storm event. Sediment accretion monitoring results indicate that the accretion rate in the wetland was only 4 mm/year. Therefore, the wetland would require 100 years to fill at the measured sediment accretion rate. The high organic content of sediments (16%) indicates that the wetland is building the characteristic organic layer on the bottom of the wetland. Results from this study would be very useful in the maintenance of natural wetlands and design of constructed wetlands for water treatment.