Stimulating Anaerobic Degradation of Butyrate via Syntrophomonas wolfei and Geobacter sulfurreducens: Characteristics and Mechanism.

Anaerobic digestion (AD) has been widely applied for the degradation of organic wastewater due to its advantages of high-load operation and energy recovery. However, some challenges, such as low treatment capacity and instability caused by the accumulation of volatile fatty acids, limit its further application. Here, S. wolfei and G. sulfurreducens were initially co-cultured in the anaerobic anode of bio-electrochemical system for degrading butyric acid. Butyrate degradation characteristics in different conditions were quantitatively described. Moreover, G. sulfurreducens simultaneously strengthened the consumption of H2 and acetic acid via direct interspecies electron transfer, thereby strengthening the degradation of butyric acid via a co-metabolic process. During butyrate degradation, the co-culture of S. wolfei and G. sulfurreducens showed more advantages than that of S. wolfei and methanogens. This present study provides a new perspective of butyrate metabolism, which was independent of methanogens in an AD process.

Iron-modified biochar boosts anaerobic digestion of sulfamethoxazole pharmaceutical wastewater: Performance and microbial mechanism.

The accumulation of volatile fatty acids (VFAs) caused by antibiotic inhibition significantly reduces the treatment efficiency of sulfamethoxazole (SMX) wastewater. Few studies have been conducted to study the VFAs gradient metabolism of extracellular respiratory bacteria (ERB) and hydrogenotrophic methanogen (HM) under high-concentration sulfonamide antibiotics (SAs). And the effects of iron-modified biochar on antibiotics are unknown. Here, the iron-modified biochar was added to an anaerobic baffled reactor (ABR) to intensify the anaerobic digestion of SMX pharmaceutical wastewater. The results demonstrated that ERB and HM were developed after adding iron-modified biochar, promoting the degradation of butyric, propionic and acetic acids. The content of VFAs reduced from 1166.0 mg L-1 to 291.5 mg L-1. Therefore, chemical oxygen demand (COD) and SMX removal efficiency were improved by 22.76% and 36.51%, and methane production was enhanced by 6.19 times. Furthermore, the antibiotic resistance genes (ARGs) such as sul1, sul2, intl1 in effluent were decreased by 39.31%, 43.33%, 44.11%. AUTHM297 (18.07%), Methanobacterium (16.05%), Geobacter (6.05%) were enriched after enhancement. The net energy after enhancement was 0.7122 kWh m-3. These results confirmed that ERB and HM were enriched via iron-modified biochar to achieve high efficiency of SMX wastewater treatment.

Two-stage hybrid microalgal electroactive wetland-coupled anaerobic digestion for swine wastewater treatment in South China: Full-scale verification.

Constructed wetlands have been widely used for organic wastewater treatment owing to low operating costs and simple maintenance. However, there are some disadvantages such as unstable efficiency in winter. In this study, a microalgal electroactive biofilm-constructed wetland was coupled with anaerobic digestion for full-scale treatment of swine wastewater. In a 12-month outdoor trial, the overall removal efficiencies of chemical oxygen demand, ammonium, nitrate, total nitrogen, total phosphorus, and nitrite reached 98.26%/95.14%, 97.96%/92.07%, 85.45%/66.04%, 95.07%/91.48%, 91.44%/91.52%, and 85.45%/84.67% in summer/winter, respectively. Hydrolytic bacteria were dominant in the anaerobic digestion part, and Cyanobium, Shewanella, and Azoarcus were enriched in the microalgal electroactive biofilm. The operating cost of the entire system was approximately 0.118 $/m3 of wastewater. These results confirm that the microalgal electroactive biofilm significantly enhances the efficiency and stability of constructed wetlands. In conclusion, the anaerobic digestion-microalgal electroactive biofilm-constructed wetland is technically and economically feasible for the treatment of swine wastewater.

Endoscopic endonasal surgery for clival chordoma and chondrosarcoma.

BACKGROUND: Conventional microsurgical approaches are limited to exposing the lateral and bilateral regions because of surgical trauma. Total removal of clival chordoma and chondrosarcoma is very difficult. This study was undertaken to determine the potential role of an endoscopic endonasal approach in improved management of clival chordoma and chondrosarcoma. METHODS: Seven patients with chordoma and 2 patients with chondrosarcoma treated by endoscopic endonasal surgery between November 2002 and February 2006 were studied prospectively. The mean age was 35 years. The follow-up periods ranged from 3 to 39 months. RESULTS: Total removal was achieved in 6 cases of chordoma and 1 case of chondrosarcoma, with subtotal removal in 1 case of chordoma and of chondrosarcoma. At the last follow-up, 7 patients had no evidence of disease and 1 was alive with disease. The chordomas had recurred in 1 patient after 5 months with subtotal removal. CONCLUSION: The use of nasoendoscopy to perform clival chordoma and chondrosarcoma surgery is not limited to merely the minimally invasive aspects. It provides better visualization of the deeper anatomical structures in the skull base and affords a means to 'look around corners'. This approach promises a simple and rapid access to the clivus. It is both a safe and efficient procedure.

Oxymatrine induces nasopharyngeal cancer cell death through inhibition of PI3K/AKT and NF­κB pathways.

Oxymatrine may inhibit tumor cell proliferation, induce cell cycle arrest, promote apoptosis, induce tumor cell differentiation and fight against tumor angiogenesis, as well as inhibit tumor invasion and metastasis. The present study aimed to investigate the anticancer effects of oxymatrine on nasopharyngeal cancer (NPC) cell death, and the underlying molecular mechanisms of these effects. NPC HK­1 cells were incubated overnight and treated with oxymatrine (0, 2, 4, 6 and 8 mg/ml) for 1, 2 or 3 days. The results demonstrated that oxymatrine significantly inhibited NPC cell proliferation in a time­ and dose­dependent manner. Oxymatrine treatment also induced apoptosis, induced the activities of caspase­3 and caspase­9, promoted p53 and Bax protein expression, and suppressed cyclin D protein expression in these cells. The protein expression levels of phosphoinositide 3 kinase (PI3K), phosphorylated (p)­AKT, p­mammalian target of rapamycin, p­p70 ribosomal protein S6 kinase and nuclear factor (NF)­κB were significantly downregulated by oxymatrine treatment. In conclusion, results from the present study suggested that oxymatrine may induce NPC cell death through the inhibition of PI3K/AKT and NF­κB signaling pathways.

Olfactory route for cerebrospinal fluid drainage into the cervical lymphatic system in a rabbit experimental model.

The present study analyzed the anatomical association between intracranial subarachnoid space and the cervical lymphatic system. X-ray contrast medium and Microfil(®) (Microfil compounds fill and opacify microvascular and other spaces of non-surviving animals and post-mortem tissue under physiological injection pressure) were injected into the cisterna magna of the rabbit, and perineural routes of cerebrospinal fluid outflow into the lymphatic system were visualized. Under a surgical operating microscope, Microfil was found within the subarachnoid space and along the olfactory nerves. At the nasal mucosa, a lymphatic network was identified near the olfactory nerves, which crossed the nasopharyngeal region and finally emptied into the superficial and deep cervical lymph nodes. Under a light microscope, Microfil was visible around the olfactory nerves and within lymphatic vessels. These results suggested that cerebrospinal fluid drained from the subarachnoid space along the olfactory nerves to nasal lymphatic vessels, which in turn, emptied into the cervical lymph nodes. This anatomical route, therefore, allowed connection between the central nervous system and the lymphatic system.

[Construction, expression and refolding of recombinant luteinizing hormone releasing hormone-angiogenin toxin].

OBJECTIVE: To express, purify and refold recombinant luteinizing hormone releasing hormone-angiogenin (LHRH-Ang) toxin using E. coli. expression system. METHODS: Recombinant LHRH-Ang expression vector was constructed by replacing of EGF fragment in plasmid pET28a/EGF-Ang with LHRH-PII fragment amplified from plasmid pET28/MSH-PE40. DNA sequencing would be used to verify the correction of fused LHRH-PII-Ang gene. Then, E. coli strain BL21 (DE3) was transformed by pET28a/LHRH-Ang vector. Expression of recombinant LHRH-Ang toxin was induced by Isopropyl-ß-D-Thiogalactoside (IPTG). Refolding effects of gradient dialysis was evaluated by SDS-PAGE. RESULTS: Prokaryotic expression vector pET28a/LHRH-Ang, containing LHRH-PII-Ang fusion gene, was constructed by PCR amplification, restriction enzyme digestion and ligation method. Sequence correction of fusion gene was confirmed by DNA sequencing. After IPGT induction, recombinant LHRH-Ang protein was expressed in BL21 (DE3) as inclusion body, it took 18.43% of total protein. Inclusion body was resolved in 8 mol/L urea and purified by DEAE-Sepharose FF column, the purity was 85%. Recombinant LHRH-Ang toxin was refolded and concentrated by gradient dialysis and PEG 20000, respectively. CONCLUSIONS: Recombinant LHRH-Ang protein was expressed in E. coli and refolded successfully.

[Endoscopic endonasal surgery for clival tumor].

OBJECTIVE: To review our experience with endoscopic endonasal approach for surgical management of clival tumors. METHODS: Twenty-four patients with clival tumors treated by endoscopic endonasal surgery between August 2002 and November 2005 were studied prospectively. The operative technique was described in detail. There were 5 chordoma, 2 ossifying fibroma, 1 meningioma, 1 craniopharyngioma, 1 hemangioblastoma, 6 squamous cancer, 2 chondrosarcoma, 2 chondrosarcoma, 1 lymphoma, 1 malignant giant cell tumor and 2 metastatic carcinoma. RESULTS: Total tumor removal was obtained in 22 cases, subtotal removal in 2 case. Follow-up ranged 12 to 51 months. Three patients dead. Five patients with total removal recurred, one of them dead. Two patients with subtotal removal dead, one with chondrosarcoma and one with chordoma. The complications included subarachnoid hemorrhage in 1 patient, and transient cerebrospinal leakage in 2 cases. CONCLUSIONS: The use of nasoendoscopy to perform clival tumor surgery is not only limited to the minimally invasive aspect, it also provides better visualization of deeper structures in the skull base, provides the ability to 'look around corners' and wide exposed field. This approach permits us to manage clival lesions properly.

[The diagnosis and treatment of cerebrospinal rhinorrhea caused by transsphenoidal cephalocele through transnasal endoscopic surgery].

OBJECTIVE: To inquire into the feasibility of transnasal endoscopic surgery for the diagnosis and treatment of cerebrospinal rhinorrhea caused by transsphenoidal meningo encephalocele. METHOD: Three cases of cerebrospinal rhinorrhea caused by transsphenoidal meningo encephaloceles were managed by transnasal endoscopic surgery. Different repair materials such as muscle, fascia, artificial dural material were applied into the defect site. RESULT: All cases were successful treated, 1 of them complicated with meningitis, the others were cured without any complication. One reoccurred after 6 months and was successful repaired after second surgery during 1-3 year follow-up. CONCLUSION: The treatment of transnasal endoscopic surgery for cerebrospinal rhinorrhea caused by transsphenoidal cephalocele is a feasible, mini-wound and safe approach.

[Using of titanium mesh for the reconstruction of skull base defect].

OBJECTIVE: The purpose of this study is to evaluate the possibility and surgical principle of titanium mesh used for the reconstruction of skull base bone defect. METHODS: The clinical data of 11 patients with defect of skull base bone repaired with titanium mesh were retrospectively analysed. RESULTS: Among 11 patients, there were 6 patients with skull base tumor, 3 patients with fibrosis hyperplasia, 2 patients with encephalomeningocele. The surgical approach included craniofacial approach in 7 patients, transfrontal and extended transfrontal approach in 3 patients, trans-midface approach in 1 patient. The anterior and lateral skull base was repaired in 2 patients, anterior and middle skull base and sellar repaired in 6 patients, anterior skull base and orbital floor repaired in 3 patients. In early postoperative period, there were 3 patients with intracranial pneumatosis, but without symptom, and 1 patient with transient cerebrospinal leakage. Following-up for average 14.4 months, there was no titanium mesh displacement and intracranial infection in all patients. CONCLUSIONS: The titanium mesh used for the repair of skull base bone defect was both possible and safe.

[Endoscopic intrasellar tumor surgery].

OBJECTIVE: To report the experience with the perioperative management of endoscopic intrasellar tumor surgery in fifty-two patients with intrasellar tumor who underwent an endoscopic transsphenoidal approach to the sella. METHODS: The application of transnasal endoscopic technique to the management of pituitary adenomas in 49 patients, of craniopharyngioma in two patients and of meningeoma in one patient. RESULTS: Forty-eight of forty-nine cases with pituitary adenomas and two cases with craniopharyngioma were removed completely, the majority of one case with invasive pituitary adenoma and the meningeoma were removed on purpose to decompress. The symptoms of headache, visual desturbance, amenorrhea, galactorrhea ect. were cured or improved. The endocrinological evaluation: the high preoperative prolactin (PRL) and growth hormone (GH) level were decreased to normal values after the operation. Transient and permanent diabetes insipidus occurred in five patients and one patient with pituitary adenomas respectively after the operation, only one case required the treatment. One patient with craniopharyngioma had postoperative epilypsy. Two patients with pituitary adenomas and one patient with craniopharyngioma had recurrence within the one-year (recurrence rate 5.8%) during the follow-up 3-72 months after the surgery. No patient developed a delayed cerebrospinal fluid leak, meningitis, optic nerves injury, internal carotid injury, or other endocrine complications. CONCLUSION: This new technique offers simple and rapid access to the sella turcica and also, direct visualization, improves the surgeons ability to resect tumors, it is a safe, minimally invasive and efficient procedure for removing intrasellar tumor.