Photochemical degradation of ciprofloxacin in UV and UV/H2O2 process: kinetics, parameters, and products.

Photochemical degradation of fluoroquinolone ciprofloxacin (CIP) in water by UV and UV/H2O2 were investigated. The degradation rate of CIP was affected by pH, H2O2 dosage, as well as the presence of other inorganic components. The optimized pH value and H2O2 concentration were 7.0 and 5 mM. Carbonate and nitrate both impeded CIP degradation. According to liquid chromatography-tandem mass spectrometry analysis, four and 16 products were identified in UV and UV/H2O2 system, respectively. Proposed degradation pathways suggest that reactions including the piperazinyl substituent, quinolone moiety, and cyclopropyl group lead to the photochemical degradation of CIP. Toxicity of products assessed by Vibrio qinghaiensis demonstrated that UV/H2O2 process was more capable on controlling the toxicity of intermediates in CIP degradation than UV process.

[Measurement of objective parameters associated with pharyngeal swallowing function in Chinese adults].

OBJECTIVE: To obtain a series of objective criteria associated with pharyngeal swallowing function using dynamic swallow study in Chinese adults. METHODS: Dynamic videofluoroscopic swallow studies were performed on 80 normal adult volunteers. There were 40 males and 40 females aged from 20 to 60 years old. Measurement software Avidemux 2.5 and Image J were used to measure the objective parameters which were closely related to the pharyngeal swallowing function in the swallowing process, such as maximum displacement of the hyoid bone (HmaxD), pharyngeal transit time (PTT), pharyngeal constriction ratio(PCR), and maximum opening of the esophageal entrance (EEmax). RESULTS: In the 80 adults, the HmaxD, PTT, PCR, and EEmax were (1.91 ± 0.48) cm (x(-) ± s), (0.82 ± 0.15) s, 94.9% ± 3.41%, and (0.91 ± 0.05) cm respectively. The HmaxD of the male (2.04 ± 0.46) cm was significantly larger than that of the female (1.78 ± 0.47) cm (t = 2.44, P = 0.017), but the PTT, PCR, and EEmax had no significant difference between different gender and age groups (P > 0.05). CONCLUSIONS: Objective parameters of the HmaxD, PTT, PCR, and EEmax during swallowing are obtained in Chinese adults. These data are important for assessment of the swallow function and these data provide a foundation for further research on assessment of swallowing function in Chinese.

[Morphology of cricopharyngeal muscle under suspension laryngeal endoscope].

OBJECTIVE: To observe the morphologic features of cricopharyngeal muscle (CPM) under suspension laryngeal endoscope. METHODS: This prospective study was conducted on a series of 100 consecutive patients who undergone endoscopic microlaryngeal surgery with intubation general anesthesia. The suspension laryngoscope was introduced down to postcricoid area approaching esophageal inlet. By lifting the larynx with the laryngoscope, the mucosa-covered cricopharyngeal muscle was easily identified as the mound of tissue just at the posterior pharyngeal wall. The image of cricopharyngeal muscle under the laryngoscope was saved. RESULTS: In 94 out of 100 patients, CPM could be visualized with laryngoscope. In the other 6 patients, both CPM and glottic could not be exposed because of cervical vertebra stiffness and obesity. According to the image of CPM under the laryngoscope, the shape of the CPM was divided into three types. It was named for flat type in which there was no mound of tissue visible at the posterior pharyngeal wall and esophageal cavity could be visible completely, semi-bar type in which there was a bar at the posterior pharyngeal wall and partial esophageal cavity could be visible and full-bar type in which the bar contact esophageal anterior wall and esophageal cavity could not be visible. There were 14(14.9%) patients as flat type, 59(62.8%) as semi-bar type and 21(22.3%) as full-bar type. No significant difference was found between adults group and the aged (≥ 65 years old) group (χ(2) = 1.224, P = 0.747) and reflux associated group and non-reflux associated group respectively (χ(2) = 5.252, P = 0.072). CONCLUSIONS: The CPM could be well exposed in most of the patients with suspension laryngeal endoscope. It provides anatomy basis for endoscopic cricopharyngeal myotomy.

[Electronic laryngoscope for transnasal esophageal examination].

OBJECTIVE: To evaluate the value of electronic laryngoscope for transnasal esophagoscopy. METHODS: The electronic laryngoscope was used for transnasal esophagoscopy in 50 patients from June 2009 to June 2011 in our department. There were 32 males and 18 females with their age ranged from 16-88 years (mean 53.8 years). Before esophagoscopy, 1% ephedrine-dicaine mixture was sprayed into the nasal and pharyngeal cavities for topical anesthesia. The esophagoscopy was used for screening examination in the patients with reflux, globus sensation, dysphagia, head and neck cancer, suspected foreign body, and vocal cord paralysis, etc. RESULTS: The transnasal esophagoscopy with electronic laryngoscope was performed successfully in all the patients. Mild nausea and vomiting occurred in 4 patients, but no patient required to stop the examination. Of the 50 patients, 38 patients (76%) had normal findings and 12 patients (24%) had positive findings of the esophagus. Esophageal cancer was diagnosed in one patient, esophageal foreign body in 2 patients, esophageal injury in one patient, candidal esophagitis in 3 patients, esophagitis in 3 patients, and achalasia of the cardia in 2 patients. CONCLUSIONS: The electronic laryngoscope for transnasal esophagoscopy is an alternative to conventional esophagoscopy, which is useful for screening the esophagus in the patients with reflux, globus, dysphagia, head and neck cancer, and suspected foreign body, etc.

[Intraoperative facial nerve monitoring in parotid gland surgery].

OBJECTIVE: To re-evaluate the value and the methods of intraoperative facial nerve monitoring in parotid gland surgery. METHODS: Sixty-five cases received intraoperative facial nerve monitoring in parotidectomy (test group) since 2000 - 2008. The facial nerve was identified through central trunk method (n = 18), branch method (n = 35) and mixed method (n = 12). Most patients accepted general anesthesia by incubation. The operating duration and minimum electronic stimulation threshold values of EMG in evoked facial muscle were recorded. Facial nerve was identified though branch method (n = 44) and no intraoperative facial nerve monitoring was performed in parotidectomy (control group). RESULTS: There were four cases (6.1%) of mild temporary paralysis and no permanent post-operative paralysis of facial nerve in the test group. The average operating duration was 1.8 hour. The minimum reactive electronic stimulation threshold of EMG in evoked facial muscle was 0.08 mA. The range of suitable electronic stimulation threshold of EMG was from 0.2 mA to 1.0 mA. While there were nine cases (20.5%) of mild temporary paralysis and two cases (4.5%) of permanent post-operative paralysis of facial nerve in the control group and the average operating duration was 3.0 hours. CONCLUSION: Intraoperative facial nerve monitoring (IFNM) in parotidectomy can assist a surgeon to confirm and identify the facial nerve and exercise precautions so as to shorten operating duration and prevent potential surgical complications.

Tumorigenesis by human herpesvirus 8 vGPCR is accelerated by human immunodeficiency virus type 1 Tat.

Human herpesvirus 8 (HHV-8), also called Kaposi's sarcoma (KS) herpesvirus, can cause KS but is inefficient. Untreated human immunodeficiency virus type 1 (HIV-1) coinfection is a powerful risk factor. The HHV-8 chemokine receptor, vGPCR (ORF74), activates NF-kappaB and NF-AT, and their levels of activation are synergistically increased by HIV-1 Tat. Transgenic vGPCR mice develop KS-like tumors. A cell line derived from one such tumor expresses vGPCR and forms tumors in nude mice. Here we show that transfection of DNA encoding HIV-1 tat (but not a transactivation-defective mutant) into these tumor cells increases NF-kappaB and NF-AT activation levels and accelerates tumor formation. Tumorigenesis was also accelerated when Tat DNA was transfected into normal cells and the transfected cells were mixed with the tumor cells and injected into a single site. Tumorigenesis was also increased when the two cell types were injected at separate sites, suggesting that tumorigenesis is accelerated by Tat through soluble factors.

Kaposi's sarcoma-like tumors in a human herpesvirus 8 ORF74 transgenic mouse.

The product of human herpesvirus 8 (HHV-8) open reading frame 74 (ORF74) is related structurally and functionally to cellular chemokine receptors. ORF74 activates several cellular signaling pathways in the absence of added ligands, and NIH 3T3 cells expressing ORF74 are tumorigenic in nude mice. We have generated a line of transgenic (Tg) mice with ORF74 driven by the simian virus 40 early promoter. A minority (approximately 30%) of the Tg mice, including the founder, developed tumors resembling Kaposi's sarcoma (KS) lesions, which occurred most typically on the tail or legs. The tumors were highly vascularized, had a spindle cell component, expressed VEGF-C mRNA, and contained a majority of CD31(+) cells. CD31 and VEGF-C are typically expressed in KS. Tumors generally (but not always) occurred at single sites and most were relatively indolent, although several mice developed large visceral tumors. ORF74 was expressed in a minority of cells in the Tg tumors and in a few other tissues of mice with tumors; mice without tumors did not express detectable ORF74 in any tissues tested. Cell lines established from tumors expressed ORF74 in a majority of cells, expressed VEGF-C mRNA, and were tumorigenic in nude mice. The resultant tumors grew rapidly, metastasized, and continued to express ORF74. Cell lines established from these secondary tumors also expressed ORF74 and were tumorigenic. These data strongly suggest that ORF74 plays a role in the pathology of KS and confirm and extend previous findings on the tumorigenic potential of ORF74.