[Clinical efficacy of antibiotic bone cement combined with vacuum sealing drainage in treating diabetes mellitus complicated with necrotizing fasciitis]

Objective: To explore the clinical efficacy of antibiotic bone cement combined with vacuum sealing drainage (VSD) in treating diabetes mellitus complicated with necrotizing fasciitis. Methods: The retrospective observational study approach was used. From January 2020 to March 2022, 12 patients with type 2 diabetes complicated with necrotizing fasciitis who met the inclusion criteria were admitted to Wuxi Ninth People's Hospital, including 7 males and 5 females, aged 27 to 76 years. The initial diagnosis of lesions was in the lower limbs. After admission, bedside incision and drainage were performed timely, and a sample of wound exudate was collected for microbial cultivation. At the same time, the comprehensive supportive treatment was performed. At stage Ⅰ, debridement was performed, and the skin and soft tissue defect area was 40 cm×15 cm to 80 cm×25 cm after debridement. The dead space was filled with bone cement containing gentamicin and vancomycin and VSD was performed. After there was no obvious infection on the wound, the antibiotic bone cement was removed and wound repair surgery was performed at stage Ⅱ. The times of debridement, amputation, infection control, wound treatment method and wound healing at stage Ⅱ, total hospitalization day, and recurrence of necrotizing fasciitis during follow-up after the stage Ⅱ surgery. At the last follow-up, the walking function of patients was evaluated according to the scoring standards of American Orthopedic Foot and Ankle Association (AOFAS). Results: Eleven patients had wound infection control with one debridement surgery and did not undergo amputation surgery; one patient had significant foot gangrene, and the infection was controlled after one debridement and amputation of the gangrenous limb. Blood routine and infection indicators gradually returned to normal within 7 days after surgery. At stage Ⅱ, the wounds in 4 patients were sutured directly, the wounds in 6 patients were repaired with full-thickness inguinal skin graft, while the wounds in 2 patients were repaired with pedicled or tongue-shaped flaps at the wound edge. The wounds healed well after surgery, with no ulceration. The total hospitalization day of patients was 20 to 45 days. Follow-up for 3 to 24 months after stage Ⅱ surgery showed no recurrence of necrotizing fasciitis in any patient. At the last follow-up, the walking function was evaluated as excellent in 10 cases and good in 2 cases according to the AOFAS scoring standard. Conclusions: Antibiotic bone cement combined with VSD used in treating type 2 diabetes complicated with necrotizing fasciitis can effectively control infection and reduce the times of debridement, with good wound healing and walking function after surgery.

m6A Reader YTHDC1 Inhibits Ferroptosis and Radiosensitivity by Promoting SREBF1 mRNA Nuclear Export in Nasopharyngeal Carcinoma

PURPOSE/OBJECTIVE(S)

Radioresistance is the main reason for nasopharyngeal carcinoma (NPC) recurrence leading to treatment failure, and inducing ferroptosis has gradually been a new way to enhance radiosensitivity. N6-methyladenosine (m6A) is involved in regulation of numerous biological processes. However, whether m6A affects ferroptosis in NPC is still unclear. In this study, we conducted a siRNA library screening to identify m6A reader YTHDC1 as an essential oncogene that suppressed ferroptosis and radiosensitivity by promoting SREBF1 mRNA nuclear export in nasopharyngeal carcinoma.

MATERIALS/METHODS

The expression and function of YTHDC1 were assessed via CCK8 cell viability assay, immunostaining, real-time PCR, western blot, radiation clonogenic assay and fluorescence in situ hybridization assay. Ferroptosis was determined by detecting cell viability, lipid peroxidation, abnormal mitochondrial and cell death rate. The in vivo effects of YTHDC1 were examined with RSL3 treatment or lentivirus modification of YTHDC1 expression in radiated mouse models.

RESULTS

Based on RSL3-induced ferroptotic cell death model and a siRNA library about m6A modification associated gene screening, we identified m6A reader YTHDC1 could inhibit ferroptosis as well as radiosensitivity of NPC, both in vivo and in vitro. Mechanistically, YTHDC1 protein could recognize m6A sites in the CDS region and 3' untranslated region (3'UTR) of SREBF1 mRNA and promote SREBF1 mRNA nuclear export, which finally resulted in transcriptional upregulation of genes key to ferroptosis such as SCD and FASN. Furthermore, the high expression of YTHDC1 was negatively regulated by ZNF598 via ubiquitination and associated with unfavorable survival in NPC patients due to radioresistance.

CONCLUSION

Our findings reveal the critical role of YTHDC1 specifically in inhibiting ferroptosis and radiosensitivity via m6A-dependent mechanism and provide an exploitable target and therapeutic strategy for overcoming radioresistance in NPC.

[Risk factors of occult lymph node metastasis of levels Ⅲ and Ⅳ in papillary thyroid carcinoma]

Objective: To investigate the potential risk factors for occult lateral cervical lymph node metastasis (LNM) to levels Ⅲ and Ⅳ in patients with papillary thyroid carcinoma (PTC) and the necessity of super-selective lateral lymph node dissection for patients harboring these metastases. Methods: This prospective study included PTC patients who were operated by the same surgeon in the Department of Head and Neck Surgery of Cancer Hospital, Chinese Academy of Medical Sciences from October 2015 through October 2019. Preoperative ultrasound and enhanced Computer Tomography (CT) did not denote suspected enlarged lymph nodes in the lateral neck. All patients underwent lymph node dissection in levels Ⅲ and Ⅳ on the basis of original thyroid collar incision after LNM to level Ⅵ was confirmed by preoperative fine needlebiopsy or intraoperative frozen pathology. Results: Of all 143 patients, 74 (51.7%) had occult LNM in levels Ⅲ and Ⅳ confirmed by postoperative pathology. The average number of metastasized lymph nodes in levels Ⅲ and Ⅳ was 2.64±1.80, and that in level Ⅵ was 3.77±3.27. There was a significant linear positive correlation between the number of metastasized lymph nodes in level Ⅵ and that in levels Ⅲ and Ⅳ (r=0.341, P<0.001). That the metastasized lymph nodes in level Ⅵ equals three was the best predictor of occult lateral LNM to levels Ⅲ and Ⅳ. Univariate analysis showed that age <55 years, tumor size ≥2.0 cm, number of metastasized lymph nodes in level Ⅵ ≥3, and percentage of metastasized lymph nodes in the total number of dissected lymph nodes in level Ⅵ >50% were associated with occult LNM in levels Ⅲ and Ⅳ (P<0.05). Multivariate analysis showed that number of metastasized lymph nodes in level Ⅵ≥3 was an independent risk factor for occult LNM in levels Ⅲ and Ⅳ (P=0.006). Conclusions: Age, tumor size and LNM in level Ⅵ were associated with occult lateral LNM in PTC patients. Lymph node dissection in levels Ⅲ and Ⅳ could be considered for selective patients, since it will help to avoid secondary operation for residual tumor or recurrence resulted from insufficient treatment without increasing the incidence of complications or affecting patients' appearances.

[Effects of pedicled flap combined with membrane induction technique in repairing foot and ankle wounds in diabetic patients]

Objective: To explore the effects of pedicled flap combined with membrane induction technique in repairing foot and ankle wounds in diabetic patients. Methods: A retrospective observational study was conducted. From March 2019 to July 2021, 12 patients with diabetic foot and ankle wounds who met the inclusion criteria were admitted to Wuxi Ninth People's Hospital, including 7 males and 5 females, aged 20 to 92 years. The wound area before debridement was 4.0 cm×2.5 cm to 16.0 cm×12.5 cm. The patients underwent debridement+antibiotic cement tamponade in stage Ⅰ; according to the wound site, peroneal artery perforator flap or posterior tibial artery perforator flap was chosen to repair the wound in stage Ⅱ, with the area of the resected flap ranging from 4.5 cm×3.0 cm to 18.5 cm×14.0 cm. The donor site was directly closed in 4 patients or covered by full-thickness inguinal skin graft in 8 patients. After the operation of stage Ⅱ, the survival of flap and skin graft, the scar in donor and recipient sites of flap, the appearance of flap, and the function of ankle joint of affected extremity were followed up. The recovery of foot and ankle function was evaluated and rated by the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scoring System at the last follow-up. Results: During the follow-up of 4 to 15 months after the operation of stage Ⅱ, both the flap and skin graft survived, without obvious infection recurrence. Linear scars were left in donor and recipient sites of flap, with good appearance in flap. The function of ankle joint in the affected extremity was nearly normal. At the last follow-up, the AOFAS scores of patients were 79 to 93, with excellent in 8 cases and good in 4 cases. Conclusions: The pedicled flap combined with membrane induction technique for repairing foot and ankle wounds in diabetic patients has the advantage of simple operation, preserved ankle joint function, and less postoperative infection recurrence, which is worth popularizing in clinical practice.

[Analysis of success rate of organoid construction of nasopharyngeal carcinoma by first-day suspension method]

Objective: To investigate the efficacy of the first-day suspension method for improving the success rate of construction of nasopharyngeal carcinoma-patient derived organoids (NPC-PDO). Methods: The tumor samples of 14 nasopharyngeal carcinoma(NPC) patients, i.e.,13 males and 1 female, with a mean age of 43.0±12.0 years old, were collected from the Affiliated Tumor Hospital of Guangxi Medical University and the First Affiliated Hospital of Guangxi Medical University from January 2022 to July 2022. The tumor samples of 3 patients were digested into single cell suspension and divided into 2 groups, for comparing the efficacy of NPC-PDO construction by the direct inoculation method and the first-day suspension method. The remaining 11 patients were randomized to receive either the direct inoculation method or the first-day suspension method for NPC-PDO construction. The diameter and the number of spheres of NPC-PDO constructed by the two methods were compared by optical microscope; the 3D cell viability detection kit was used to compare the cell viability; the survival rates were compared by trypan blue staining; the success rates of the two construction methods were compared; the number of cases which could be successfully passaged for more than 5 generations and were consistent with the original tissue by pathological examination was counted; and the dynamic changes of cells in suspension overnight were observed by live cell workstation. The independent sample t-test was applied to compare the measurement data of the two groups, and the chi-square test was used to compare the classification data. Results: Compared with the direct inoculation, the diameter and the number of spheres of NPC-PDO constructed by the first-day suspension method were increased, with a higher cell activity, and the success rate of construction was obviously improved (80.0% vs 16.7%, χ²=4.41, P<0.05). In the suspension state, some of the cells aggregated and increased their ability to proliferate. Conclusion: The first-day suspension method can improve the success rate of NPC-PDO construction, especially for those whose original tumor sample size is small.

[Active surveillance for thyroid micro-malignant nodules]

Objective: To evaluate the effect of ultrasound diagnosis of thyroid micro-malignant nodules and accumulate practical experience for the management of active surveillance for them, so as to avoid overtreatment. Methods: A total of 949 patients who were diagnosed with thyroid malignant nodules using ultrasonography, with the nodules being less than 1 cm in size and without regional lymph node metastasis or distant metastasis, were included. They were treated by the same surgeon of the Department of Head and Neck Surgery, Cancer Hospital, Chinese Academy of Medical Sciences from February 2014 to December 2020. 112 patients chose immediate surgery. The rest patients were asked to accept ultrasound examination every 6 months to 1 year. Follow-up endpoints: tumor size growth of 3 mm, tumor volume increase greater than 50%, lymph node metastasis or distant metastasis. Results: The median follow-up time was 19 months. 713 patients underwent surveillance for more than 6 months. Of the 713 patients, 570 (79.9%) were women, with mean age at 43.5 years old. Tumor progression was observed in 47 (6.6%) patients with a cumulative incidence of 2.7% (1 year), 7.2% (2 years) and 9.5% (3 years). In multivariate analysis, patient age [HR=0.508, 95%CI: 0.275-0.939, P=0.031], lesion number [HR=2.945, 95%CI: 1.593-5.444, P=0.001] and tumor size [HR=2.245, 95%CI: 1.202-4.192, P=0.011] at the beginning of observation were independent risk factors for tumor progression in patients with minimal thyroid malignant nodules during follow-up. During a median (range) active surveillance of 19 (6-80) months, 74 patients chose surgery during the surveillance. Among the 186 patients who underwent surgery, only 3 patients were diagnosed with fibrotic nodules in pathology, while the rest were papillary thyroid carcinoma. The ultrasound accuracy reached 98.4%(183/186). Conclusions: Ultrasonography is an effective method of diagnosing malignant thyroid nodules. Thyroid micro-malignant nodules progress slowly. As a result, it is safe to observe them instead of taking immediate surgery. Patient age, lesion number and tumor size at the beginning of observation are independent risk factors for the tumor progression of malignant nodules.

Visible imaging system with changeable field of view on the HL-2A tokamak

A new visible imaging system characterizing a flexible optical design and delivering high resolution frames is established on the HL-2A tokamak. It features a modular configuration, consisting of a front-end imaging lens, a set of bilateral telecentric relay lenses, and a camera. To avoid the effects of plasma radiation (x and gamma-rays) and magnetic field variation on the camera, it should be away from the coils. Therefore, the length of the relay lenses determines the total size of the imaging system. The main feature of this imaging system is to realize the variation of field of view (FOV) by interchanging the front-end prime lenses or by using a zoom lens directly rather than designing the optical system afresh, which lowers the cost drastically. The primary purpose of varying FOV is to enrich the versatility of this system, i.e., focusing on a narrow FOV such as gas puff imaging or a wide FOV such as the plasma cross sections. During the HL-2A experiments, this visible imaging system is used to provide high quality pictures of the plasma-wall interaction, divertor detachment, pellet injections, and so on. The frames confirmed that a strong radiation close to the X point is correlated with the completely detached inner target.

[Death-related risk factors analysis of surgical treatment of myocardial infarction combined with ventricular septal rupture]

Objective: To in vestigate the death-related risk factors of surgical treatment of myocardial infarction (MI) combined with ventricular septal rupture (VSR). Methods: The clinical data of patients (68 cases) with ventricular septal rupture after myocardial infarction (PI-VSR) from January 2008 to December 2020 in Beijing Anzhen Hospital were retrospectively selected and analyzed. We followed up the surviving patients and divided them into the survival group and the death group according to the perioperative and follow-up results. The univariate analysis was performed on various indicators, and the Cox regression analysis was used to analyze the risk factors related to postoperative death. Results: A total of 68 patients (42 were male and 26 were female, with age 44-82 (64.3±8.2) years after surgical treatment of myocardial infarction combined with ventricular septal rupture were enrolled, 9 patients died during the perioperative period, 59 surviving patients were followed up for 0.1-10.5 years(mean, 4 years), and 7 deaths during follow-up. Based on this, 52 patients were selected as the survival group while 16 patients as the death group. The results of univariate analysis showed that age, VSR to operation time less than 7 days, killip grade ≥ grade 3, cardiogenic shock, preoperative use of IABP, emergent surgery were related to postoperative death. The factors with P<0.2 factors in univariate analysis were selected into the multivariate Cox regression analysis. Age ([OR=1.110(1.012-1.217), P=0.026], platelet count [OR=0.990(0.981-0.999), P=0.031], D dimer (OR=1.002[1.001-1.003], P=0.003), cardiogenic shock (OR=6.084[1.729-21.405], P=0.005) were independent risk factors for postoperative death. All patients were followed up, the survival rate of 2-year, 4-year, 6-year, 8-year, and 10-year was 77.5%, 77.5%, 71.0%, 71.0%, and 71.0%, respectively. Conclusions: Age, platelet count, D-dimer, and cardiogenic shock are risk factors for death after surgical treatment of myocardial infarction combined with ventricular septal rupture. Surgery is an effective method for the treatment of myocardial infarction combined with ventricular septal rupture. Long-term prognosis of the surviving patients during perioperative are relatively better.

[Analysis of clinical phenotype and genotype of Chinese children with disorders of sex development]

Objective: To explore the heterogeneity and correlation of clinical phenotypes and genotypes in children with disorders of sex development (DSD). Methods: A retrospective study of 1 235 patients with clinically proposed DSD in 36 pediatric medical institutions across the country from January 2017 to May 2021. After capturing 277 DSD-related candidate genes, second-generation sequencing was performed to analyzed the heterogeneity and correlation combined with clinical phenotypes. Results: Among 1 235 children with clinically proposed DSD, 980 were males and 255 were females of social gender at the time of initial diagnosis with the age ranged from 1 day of age to 17.92 years. A total of 443 children with pathogenic variants were detected through molecular genetic studies, with a positive detection rate of 35.9%. The most common clinical phenotypes were micropenis (455 cases), hypospadias (321 cases), and cryptorchidism (172 cases) and common mutations detected were in SRD5A2 gene (80 cases), AR gene (53 cases) and CYP21A2 gene (44 cases). Among them, the SRD5A2 mutation is the most common in children with simple micropenis and simple hypospadias, while the AMH mutation is the most common in children with simple cryptorchidism. Conclusions: The SRD5A2 mutation is the most common genetic variant in Chinese children with DSD, and micropenis, cryptorchidism, and hypospadias are the most common clinical phenotypes. Molecular diagnosis can provide clues about the biological basis of DSD, and can also guide clinicians to perform specific clinical examinations. Target sequence capture probes and next-generation sequencing technology can provide effective and economical genetic diagnosis for children with DSD.

[Prospects and reflections on the research and development of next-generation malaria vaccines]

Vaccination is one of the most effective intervention for the containment and elimination of infectious diseases. Recently, the world's first malaria vaccine RTS, S/AS01 was approved by WHO for use among children living in moderately and highly malaria endemic areas of Africa, which brings a hope for the research and development of malaria vaccines. Here, we review the current status of malaria vaccines development and provide a perspective on the development of next-generation malaria vaccines, so as to provide insights into the successful development of malaria vaccines.

Effects of maternal and progeny dietary selenium supplementation on growth performance and antioxidant capacity in ducklings

This study evaluated the effects of selenium (Se) supplementation in maternal and offspring diets on performance and antioxidant capacity of ducklings aged from 0 to 2 wk. A total of 144 female Longyan duck breeders aged 22-wk were allotted into 2 treatments and fed a control diet or a 0.16 mg Se/kg supplemented diet. At 40-wk, 120 offspring from each treatment were divided into 2 groups, with 6 replicates of 10 birds. Using a 2 × 2 factorial design, ducklings from each maternal dietary treatment were assigned to a control diet or a 0.16 mg Se/kg supplemented diet from hatch to 2-wk. Compared with Se-deficient diet, maternal diet supplemented with 0.16 mg Se/kg increased the BW of hatchlings (P < 0.01). There were interactions between maternal and progeny diet with 0.16 mg Se/kg in BW of ducklings aged 2 wk and BW gain (BWG) as ducklings from maternal Se/progeny none treatment had the lightest BW and BWG (P < 0.01). Maternal diet with 0.16 mg Se/kg decreased plasma concentration of uric acid and insulin-like growth factor 1 (P < 0.01), and progeny diet supplemented with 0.16 mg Se/kg increased the activities of glutathione peroxidase 3 (GPx3) in plasma and glutathione peroxidase 1 in erythrocyte (P < 0.01). Maternal diet with 0.16 mg Se/kg increased (P < 0.05) the hepatic activity of total superoxide dismutase (T-SOD). Progeny diet supplemented with 0.16 mg Se/kg increased (P < 0.01) hepatic activity of GPx3 and decreased (P < 0.01) the hepatic concentration of malondialdehyde. Interactions were detected between maternal and progeny diet with 0.16 mg Se/kg in hepatic activity of T-SOD and maternal and progeny diet supplemented with Se displayed the highest hepatic activity of T-SOD (P < 0.05). Overall, Se supplementation in the diet of duck breeders and offspring increased the antioxidant capacity of ducklings. Maternal Se supplementation increased the BW of hatchlings, whereas maternal and progeny dietary Se supplementation did not affect the BWG of ducklings aged from 0 to 2 wk. Se supplementation with additional 0.16 mg/kg in the diet of duck breeders and offspring displayed beneficial effects particularly on the antioxidant capacity in ducklings.

[Effect analysis on endoscopic transnasal resection of epidural cholesteatoma at paracentral skull base]

Objective: To indicate the clinical features of endoscopic transnasal resection of epidural cholesteatoma at paracentral skull base and to analyze its efficacy. Methods: The total excision rate, postoperative complications and postoperative curative effect of 7 patients (4 males and 3 females, aging from 32 to 63 years old) who underwent middle skull base surgery for epidural cholesteatoma resection under transnasal endoscope at Tianjin Huanhu Hospital between August 2017 and August 2020 were retrospectively reviewed. All patients were followed up for 6 to 36 months. The postoperative MRI, clinical symptoms and recurrence were reviewed. Descriptive statistical methods were used for analysis. Results: Among the 7 patients, there were total resection (complete resection of cyst contents and capsule) in 4 patients, near-total resection (complete resection of cyst contents, incomplete resection of cyst capsule) in 1 patient, and subtotal resection (incomplete resection of cyst contents and capsule) in 2 patients. The clinical symptoms of all patients were improved postoperatively with 1 patient who had no clinical symptoms. One case had postoperative cerebrospinal fluid rhinorrhea, which was cured after lumbar drainage and nasal iodoform gauge packing. Up to now, 7 patients (including patients with partial resection) had no recurrence. Conclusion: Endoscopic transnasal approaches may be effectively used for resection of epidural cholesteatoma in the paracentral skull base in carefully selected cases.

[Evaluation of the fresh air purification system in the classroom under heavy pollution weather]

Evaluate the effect of the fresh air purification system on the improvement of indoor PM_2.5 levels in a primary school classroom in Jinan City, Shandong Province. Our purpose is to explore the optimal operating time of the fresh air system and the main factors that affect the fresh air purification system to improve indoor air quality. From December 9, 2019 to December 10, 2019, two classrooms of the same area on the third floor of a primary school building in Jinan City, Shandong Province were selected as monitoring points. During the operation of the fresh air purification system, the PM_2.5 concentration in the classroom is reduced by an average of 48.1%-61.5% compared to the outdoor PM_2.5 concentration. After running for about 2 hours, the indoor PM_2.5 concentration decreased to a relatively stable concentration level. The operating time of the fresh air purification system, student activities between classes, indoor temperature, indoor relative humidity, and outdoor PM_2.5 concentration are important factors that affect the indoor particulate removal rate. In the case of a certain amount of fresh air and indoor area, closing doors and windows and appropriately extending the operation time of the fresh air purification system can improve the air quality in the classroom to a certain extent and protect the health of students.

[Preliminary study of superselective lymph node dissection in regional lateral cervical lymph node metastasis of papillary thyroid carcinoma]

Objective: To explore the applied value of super-selective cervical lymph node dissection in papillary thyroid carcinoma (PTC) patients with clinically suspicious lateral lymph node metastasis (LNM). Methods: We retrospectively analyzed the clinical data of 232 cN1b PTC patients who underwent surgery from September 2013 to May 2018 in the Department of Head and Neck Surgical Oncology, National Cancer Center. Among them, 90 cases received super-selective neck dissection (level Ⅲ and IV) and 142 cases underwent selective neck dissection (level Ⅱ-Ⅳ). The LNM of two groups were analyzed. Results: Postoperative pathological results showed that 173 cases had LNM in the central compartment. The LNM cases of level Ⅱ-Ⅳ were 47, 147 and 130, respectively. Eight patients of super-selective neck dissection and 6 of selective neck dissection had postoperative lymphatic fistulas (P=0.146). No patients in super-selective neck dissection group while 9 patients in the selective lymph node dissection group had postoperatively permanent impairment of shoulder mobility, the difference was statistically significant (P=0.015). In the super-selective neck dissection group, 2 patients had long-term postoperative incision discomfort, and 5 cases had obvious cicatrix after surgery. In the patients with selective neck dissection, 27 cases experienced long-term incision discomfort after surgery, and 26 patients had apparent scar tissue, the differences were statistically significant (P<0.005). There was no recurrence during the follow-up. Conclusions: Super-selective neck dissection is a feasible, safe and effective treatment for cN1b PTC patients. It can improve the quality of postoperative life and avoid the over treatment for patients.

[Comparison of quality of life of hypopharyngeal squamous cell carcinoma patients after laryngeal preservation surgery and total laryngectomy]

Objective: To evaluate and compare the quality of life (QOL) in patients with hypopharyngeal squamous cell carcinoma after laryngeal preservation surgery and total laryngectomy. Methods: We selected parts of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 and the Head and Neck Module (EORTC QLQ-C30 and EORTC QLQ-H&N35) and designed the QOL questionnaire. We investigated 42 patients with hypopharyngeal squamous cell carcinoma underwent laryngeal preservation surgery and 38 patients underwent total laryngectomy by QOL questionnaire and followed up their survival. Results: The somatic function dimension, psychological function dimension, and social function dimension of patients underwent laryngeal preservation surgery were (92.46±15.71), (80.56±22.67) and (90.08±19.50), respectively, which were higher than (79.39±32.75), (68.42±25.05) and (61.84±29.55) of the total laryngectomy group (P<0.05), while the economic dimension was not significantly different between the two groups (P>0.05). The social function dimension (including social support and socialization, family relationship) of laryngeal preservation surgery group were (89.04±25.47) for postoperative time < 70 months and (90.94±13.28) for postoperative time ≥70 months, which were higher than (65.48±29.14) and (57.35±30.32) of the total laryngectomy group (P<0.01). Conclusions: The somatic function dimension, psychological function and social function of patients with hypopharyngeal squamous cell carcinoma underwent laryngeal preservation surgery obtain a better QOL than patients underwent total laryngectomy. Therefore, we should improve the laryngeal function and QOL of patients under the premise of ensuring the survival rate.

[Endoscopic reconstruction of the posterior nares for the treatment of 46 children with congenital posterior atresia]

Objective:The aim of this study is to explore the influencing factors of the posterior nostril re-atresia by analyzing the clinical data of endoscopic posterior nostril reconstruction in the children with posterior nostril atresia. Method:Retrospectively reviewed 46 pediatric patients with congenital choanal atresia who underwent endoscopic posterior nostril reconstruction. Randomly divided the cases into the atresia group（19 cases） and the non-atresia group（27 cases） according to whether the new posterior nostril re-atresia again. Compared the difference of the clinical data between the two groups and observed the influencing factors of the posterior nostril re-atresia. Result:The gender, age, unilateral/bilateral atresia or U-shaped stent had no significant differences between the two groups. However, the nature of the atresia and granulation hyperplasia were significant differences between the two groups. Further analysis of the nature of the atresia revealed osseous atresia had higher rate of re-atresia than membranous atresia. Conclusion:Endoscopic posterior nostril reconstruction was a good method for the treatment of the children with congenital posterior nostril atresia. However, the children with osseous atresia had higher re-atresia rate.

[The efficacy of sublingual specific immunotherapy in children with allergic rhinitis]

Objective:To investigate the efficacy of single-allergen sublingual immunotherapy (SLIT) in children with allergic rhinitis and the potential relationship between sensitization status and efficacy and analyze the possible relationships between sensitized state and clinical efficacy. Method:One hundred and thirty children, aged 4-15 years old, with mites-induced respiratory allergic diseases had been arranged into the treatment group (n=70) or control group (n=50) and received SLIT with standardized dermatophagoides farinae extracts and pharmacotherapy for 1 year. Rhinitis and asthma symptoms and medications, visual analogue scale (VAS), skin prick test (SPT) and peak expiratory flows (PEF) were evaluated. After treatment, patients in the poly-sensitized group who completed the study had been analyzed as subgroup 1 (n=33) and subgroup 2 (n=37) according to the number of coexist allergens. Result:The global clinical parameters had been significantly improved after treatment. The treatment and control group rhinitis symptom score, symptomatic medication score and VAS scores were significantly reduced after 52 weeks treatment (all P<0.05). SLIT group dust mite grade skin reactions decreased after 52 weeks treatment (P<0.05). Dust mite skin reactions grade was greater than before treatment in the control group (P>0.05). Between the two groups, SLIT group rhinitis symptom score at 24 weeks, 36 weeks, 52 weeks were lower than the control group, the difference was statistically significant (P<0.05). SLIT group symptomatic medication score and VAS scores at 36 weeks and 52 weeks compared with the control group, the difference was statistically significant (P<0.05). Dust mite SLIT group grade skin reactions grade was lower than the control group at 52 weeks, the difference was statistically significant (P<0.05). In addition to the 36 weeks poly-sensitized group symptoms of allergic rhinitis score was lower than mono-sensitized group (P＜0.05) and at 24 weeks poly-sensitized group VAS score was lower than single allergy group (P<0.05), the comparison between subgroup 1 and subgroup 2 indicated that, there was no significant difference in symptoms scores, SPT, PEF and VAS at each scheduled follow-up visit. Conclusion:This study shows that SLIT can significantly reduce rhinitis symptoms and drug use, and improve the children with allergies. An equivalent efficacy of single-allergen SLIT is found in poly-sensitized and mono-sensitized children. The number of coexist positive allergens has a limited impact on the efficacy from a long-term perspective.

Development of a data-processing method based on Bayesian k-means clustering to discriminate aneugens and clastogens in a high-content micronucleus assay

Genotoxicants can be identified as aneugens and clastogens through a micronucleus (MN) assay. The current high-content screening-based MN assays usually discriminate an aneugen from a clastogen based on only one parameter, such as the MN size, intensity, or morphology, which yields low accuracies (70-84%) because each of these parameters may contribute to the results. Therefore, the development of an algorithm that can synthesize high-dimensionality data to attain comparative results is important. To improve the automation and accuracy of detection using the current parameter-based mode of action (MoA), the MN MoA signatures of 20 chemicals were systematically recruited in this study to develop an algorithm. The results of the algorithm showed very good agreement (93.58%) between the prediction and reality, indicating that the proposed algorithm is a validated analytical platform for the rapid and objective acquisition of genotoxic MoA messages.

Synchronization of Geodesic Acoustic Modes and Magnetic Fluctuations in Toroidal Plasmas

The synchronization of geodesic acoustic modes (GAMs) and magnetic fluctuations is identified in the edge plasmas of the HL-2A tokamak. Mesoscale electric fluctuations (MSEFs) having components of a dominant GAM, and m/n=6/2 potential fluctuations are found at the same frequency as that of the magnetic fluctuations of m/n=6/2 (m and n are poloidal and toroidal mode numbers, respectively). The temporal evolutions of the MSEFs and the magnetic fluctuations clearly show the frequency entrainment and the phase lock between the GAM and the m/n=6/2 magnetic fluctuations. The results indicate that GAMs and magnetic fluctuations can transfer energy through nonlinear synchronization. Such nonlinear synchronization may also contribute to low-frequency zonal flow formation, reduction of turbulence level, and thus confinement regime transitions.

Characterization and evolution of the mitochondrial DNA control region in Ranidae and their phylogenetic relationship

The control region is considered to be one of the most variable parts of animal mitochondrial DNA (mtDNA). We compared the mtDNA control region from 37 species representing 14 genera and 4 subfamilies of Ranidae, to analyze the evolution of the control region and to determine their phylogenetic relationship. All the Ranidae species had a single control region, except four species that had two repeat regions. The control region spanned the region between the Cyt b and tRNAleu genes in most of the Ranidae species. The length of the control region sequences ranged from 1186 bp (Limnonectes bannaensis) to 6746 bp (Rana kunyuensis). The average genetic distances among the species varied from 1.94% (between R. chosenica and R. plancyi) to 113.25% (between Amolops ricketti and Euphlyctis hexadactylus). The alignment of three conserved sequence blocks was identified. However, conserved sequence boxes F to A were not found in Ranidae. A maximum likelihood method was used to reconstruct the phylogenetic relationship based on a general time reversible + gamma distribution model. The amount of A+T was higher than G+C across the whole control region. The phylogenetic tree grouped members of the respective subfamilies into separate clades, with the exception of Raninae. Our analysis supported that some genera, including Rana and Amolops, may be polyphyletic. Control region sequence is an effective molecular mark for Ranidae phylogenetic inference.

DNA barcoding and phylogenetic relationships of Ardeidae (Aves: Ciconiiformes)

The avian family Ardeidae comprises long-legged freshwater and coastal birds. There has been considerable disagreement concerning the intrafamilial relationships of Ardeidae. Mitochondrial cytochrome c oxidase subunit I (COI) was used as a marker for the identification and phylogenetic analysis of avian species. In the present study, we analyzed the COI barcodes of 32 species from 17 genera belonging to the family Ardeidae. Each bird species possessed a barcode distinct from that of other bird species except for Egretta thula and E. garzetta, which shared one barcoding sequence. Kimura two-parameter distances were calculated between barcodes. The average genetic distance between species was 34-fold higher than the average genetic distance within species. Neighbor-joining and maximum likelihood methods were used to construct phylogenetic trees. Most species could be discriminated by their distinct clades in the phylogenetic tree. Both methods of phylogenetic reconstruction suggested that Zebrilus, Tigrisoma, and Cochlearius were an offshoot of the primitive herons. COI gene analysis suggested that the other herons could be divided into two clades: Botaurinae and Ardeinae. Our results support the Great Egret and Intermediate Egret being in separate genera, Casmerodius and Mesophoyx, respectively.

[Soft tissue sarcoma of larynx: a case report]

The clinical manifestation was gradually hoarseness for half a year, with aggravation of dyspnea in three days. Physical examination and laryngoscopy showed laryngeal neoplasm, the glottis was not exposed, pedicle, no adhesion with the surrounding. CT scan showed glottic soft-tissue, density, unclear boundary. Enhanced CT showed anterior commissure thickening and tumor invasion of supraglottic region. Preoperative biopsy results: fibroblasts and fibrocyte were arranged in a crisscross pattern. Postoperative pathology showed laryngeal soft tissue sarcoma.

DNA barcoding and phylogenetic relationships of genera Picoides and Dendrocopos (Aves: Picidae)

Picoides and Dendrocopos are two closely related genera of woodpeckers (family Picidae), and members of these genera have long been the subjects of phylogenetic debate. Mitochondrial cytochrome c oxidase subunit I (COI) is a powerful marker for the identification and phylogenetic study of animal species. In the present study, we analyzed the COI barcodes of 21 species from the two genera, and 222 variable sites were identified. Kimura two-parameter distances were calculated between barcodes. The average interspecific genetic distance was more than 20 times higher than the average intraspecific genetic distance. The neighbor-joining method was used to construct a phylogenetic tree, and all of the species could be discriminated by their distinct clades. Picoides arcticus was the first to split from the lineage, and the other species were grouped into two divergent clades. The results of this study indicated that the COI genetic data did not support the monophyly of Picoides and Dendrocopos.

DNA barcoding and phylogenetic relationships in Timaliidae

The Timaliidae, a diverse family of oscine passerine birds, has long been a subject of debate regarding its phylogeny. The mitochondrial cytochrome c oxidase subunit I (COI) gene has been used as a powerful marker for identification and phylogenetic studies of animal species. In the present study, we analyzed the COI barcodes of 71 species from 21 genera belonging to the family Timaliidae. Every bird species possessed a barcode distinct from that of other bird species. Kimura two-parameter (K2P) distances were calculated between barcodes. The average genetic distance between species was 18 times higher than the average genetic distance within species. The neighbor-joining method was used to construct a phylogenetic tree and all the species could be discriminated by their distinct clades within the phylogenetic tree. The results indicate that some currently recognized babbler genera might not be monophyletic, with the COI gene data supporting the hypothesis of polyphyly for Garrulax, Alcippe, and Minla. Thus, DNA barcoding is an effective molecular tool for Timaliidae species identification and phylogenetic inference.

Roles of p38 MAPK in the regulation of the inflammatory response to swine influenza virus-induced acute lung injury in mice

Swine influenza virus (SIV), one of the most important zoonotic agents, is associated with major public health concerns. The current study was conducted to investigate the role of p38 mitogen-activated protein kinase (p38 MAPK) in the regulation of the inflammatory response to acute lung injury (ALI) induced by SIV of H9N2 subtype (H9N2-SIV) in mice. For this purpose, BALB/c mice were intranasally infected with 20 LD(50) of H9N2-SIV (infected group), while non-infected mice served as control (control group). To assess the effect of p38 MAPK, its specific inhibitor SB203580 was employed followed by SIV infection (SB group). At various times after infection, mouse lungs were subjected to pathological and histological observations and detection of inflammatory cytokines tumor necrosis factor α (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 and phosphorylated p38 MAPK. The obtained results showed obvious inflammatory responses, injury and raised levels of inflammatory cytokines and phosphorylated p38 MAPK in the lungs of virus-infected mice. In the mice inoculated with the virus alone, the level of phosphorylated p38 MAPK increased from day 2 and peaked at day 6 post infection (p.i.). However, SB203580 caused lower increases in inflammatory cytokines and phosphorylated p38 MAPK and a milder lung injury. These findings indicate that the activation of p38 MAPK upregulated the inflammatory responses to H9N2-SIV-induced ALI, increased its severity and promoted the production of inflammatory cytokines.

DNA barcoding and evolutionary relationships of the Phasianidae family in China

A DNA barcode is a short sequence of standardized genomic region that is specific to a species. According to studies of bird species, the 694-bp sequence of the mitochondrial gene encoding cytochrome c oxidase 1 (COI) is extremely useful for species identification and phylogeny. In the present study, we analyzed the COI barcodes of 31 species from 18 genera belonging to the Phasianidae family in China. Kimura two-parameter (K2P) distances were calculated between barcodes. We found that the average genetic distance between congeneric species was 24 times higher compared to the average genetic distance within species. Each bird species had a barcode that was distinct to all other bird species. The neighbor-joining method was used to construct a phylogenetic tree, which grouped all of the genera into 2 divergent clades. In conclusion, DNA barcoding is an effective molecular tool for Phasianidae species identification and phylogenetic inference.

Dynamics of low-intermediate-high-confinement transitions in toroidal plasmas

The dynamic features of the low-intermediate-high-(L-I-H) confinement transitions on HL-2A tokamak are presented. Here we report the discovery of two types of limit cycles (dubbed type-Y and type-J), which show opposite temporal ordering between the radial electric field and turbulence intensity. In type-Y, which appears first after an L-I transition, the turbulence grows first, followed by the localized electric field. In contrast, the electric field leads type-J. The turbulence-induced zonal flow and pressure-gradient-induced drift play essential roles in the two types of limit cycles, respectively. The condition of transition between types-Y and -J is studied in terms of the normalized radial electric field. An I-H transition is demonstrated to occur only from type-J.

Impact of depression mood disorder on the adverse drug reaction incidence rate of anticancer drugs in cancer patients

The aim of this study was to explore the impact of depression mood disorder on the incidence of adverse drug reactions of anticancer drugs in cancer patients. The Hamilton Depression Scale 17 was used to evaluate the depression mood disorder level in 73 cancer patients before chemotherapy. Pharmacists monitored adverse drug reactions during the chemotherapy period. The relationship between depression mood disorder level and the incidence of adverse drug reactions was analysed. The frequency and extent of total adverse drug reactions were not related to depression mood disorder level. The frequency and extent of subjectively experienced adverse drug reactions such as anorexia, nausea and fatigue were related to depression mood disorder level. In conclusion, psychological support and intervention should be provided to cancer patients in order to improve patient adherence and cancer chemotherapy effectiveness, and to decrease the incidence of adverse drug reactions.

UV-induced grafting processes with in situ formed photomask for micropatterning of two-component biomolecules

We report a photolithographic process for micropatterning of two-component biomolecules on a transparent organic film via lateral functional polymer brushes of poly(sodium acrylate) (P(AA)) and poly(glycidyl methacrylate) (P(GMA)). The pattern of binary polymer brushes were prepared via consecutive UV-initiated grafting processes, under the assistance of the in situ formed poly (4,4'-bi[N-(4-vinylbenzyl) pyridinium]) (P(BVV)) photomask. The epoxy groups of the P(GMA) microdomains can be aminated for covalently coupling biotin, while the P(AA) microdomains were used for immobilizing immunoglobulin (IgG). The resulting biotin- and IgG-coupled microdomains interact specifically with their corresponding target proteins, avidin and anti-IgG, respectively.

Approximation of flammability region for natural gas-air-diluent mixture

The growing implementation of exhaust gas recirculation (EGR) in reducing NO(x) emissions of engine is of paramount motivation to perform a fundamental research on the flammability characteristics of fuel-air-diluent mixtures. In this work, the influences of EGR on the flammability region of natural gas-air-diluent flames were experimentally studied in a constant volume bomb. An assumption of critical burning velocity at flammability limit is proposed to approximately determine the flammability region of these mixtures. Based on this assumption, an estimation of the flammability map for natural gas-air-diluent mixtures was obtained by using the empirical formula of burning velocity data. The flammability regions of natural gas-air mixtures with EGR are plotted versus the EGR rate. From the comparison of estimated results and experimental measurements, it is suggested that the accuracy of prediction is largely dependent upon the formula of burning velocity used. Meanwhile, the influence of pressure on the critical burning velocity at flammability limit is also investigated. On the basis of the pressure dependence criterion, the estimation was performed for the circumstance of high temperature and pressure, and the prediction results still agree well with those of experiments.

[Cloning and sequencing of cytochrome c oxidase II(COII) gene of three species of mosquitoes]

OBJECTIVE

To determine and compare the complete sequence of COII gene from Anopheles sinensis, Aedes albopictus and Culex quinquefasciatus and to identify the molecular homology among these mosquitoes.

METHODS

The recombinant plasmids including COII gene from the three species of mosquitoes were obtained by the T-A cloning technique, and the COII genes were sequenced and analyzed.

RESULTS

The homology of the COII gene nucleotide sequence and the deduced amino acid sequence of COII among the three species of mosquitoes varied from 84.1% to 87.9% and from 85.1% to 89.5%, respectively. The C + G content of COII gene was 23.2%-24.9%, the frequency of transversion higher than that of transition.

CONCLUSION

Aedes albopictus and Culex quinquefasciatus are closely related species at their COII molecular level according to COII gene.

Determinants of Transcription of the Chorionic Gonadotropin /Luteinizing Hormone Receptor Gene in Human Breast Cells

Epidemiological evidence suggests that the earlier in life a woman becomes pregnant, the lower her chances for developing breast cancer later in life. This protective effect appears to be due to pregnancy hormone hCG inducing the nonreversible differentiation of proliferative terminal end buds into secretory type lobules. Perhaps this and other actions of hCG are mediated by newly discovered hCG/LH receptors in human breast cells. Thus the hCG actions in breast are potentially important for breast cancer prevention. Because of this importance, we investigated the cis-acting elements and trans-acting proteins that determine the transcription of human chorionic gonadotropin (hCG)/luteinizing hormone (LH) receptor gene in MCF-7, MDA-MB-231, and normal human breast epithelial HMEC cells. These cells contained major-4.8 and 1.8 kb-and minor-9.0, 6.0, and 1.2 kb-hCG/LH receptor transcripts with significantly higher levels in MCF-7 cells. Nuclear run-on transcription, as well as transfection with a fusion construct of luciferase gene and the -2056 to -1 bp of the 5'-flanking region of hCG/LH receptor gene, revealed that MCF-7 cells were transcriptionally more active than the other breast cells. Sequential deletion of the 5'-flanking region revealed that breast cells contained a promoter at -184 to -1 bp. Electrophoretic gel mobility shift assays demonstrated that breast cell nuclear extracts contained Ap2 and Egr promoter binding proteins. Sp1 was also present, but it could not bind because of competition with Egr for binding to a partially overlapping Egr/Sp1 site. The higher levels of Ap2 and Egr binding proteins may explain higher transcription of hCG/LH receptor gene in MCF-7 cells than in the other breast cells.

Sterol efflux mediated by endogenous macrophage ApoE expression is independent of ABCA1

Sterol efflux importantly contributes to preservation of cellular cholesterol homeostasis, and multiple pathways may be involved for mediating such efflux. Recently, an important role has been ascribed to ABCA1 in facilitating lipid efflux from cells, including macrophages, to extracellular lipid-free apolipoproteins. Macrophages are relatively unique among cells because they express apoprotein E (apoE) as a major protein product, and this endogenous expression of apoE increases sterol and phospholipid efflux from macrophages. The studies in this article were designed to test whether the sterol efflux mediated by the endogenous expression of apoE in macrophages was dependent on ABCA1 expression. These studies were facilitated by comparing apoE-expressing J774 cells (J774E(+)) with nonexpressing parental cells (J774E(-)). Sterol efflux was higher from J774E(+) cells compared with J774E(-) cells, but the increment in efflux between these cell types was not increased by induction of ABCA1 expression with cAMP. Induction of ABCA1 with cAMP, however, did increase sterol efflux to exogenously added apoA1 from both cell types. Inhibitors of ABCA1 activity significantly reduced (by 40% to 50%) sterol efflux from both J774E(+) and J774E(-) cells treated with cAMP and apoA1. This inhibitor did not, however, reduce the increment in sterol efflux due to the expression of endogenous apoE. The results of these studies indicate that the increment in sterol efflux mediated by the endogenous expression of apoE in macrophages does not depend on ABCA1 expression or activity.

Interaction with proteoglycans enhances the sterol efflux produced by endogenous expression of macrophage apoE

Endogenous expression of apolipoprotein (apo)E in macrophages facilitates cholesterol efflux in the presence and absence of extracellular sterol acceptors. A proteoglycan-associated pool of apoE has also been described. The relationship between a proteoglycan-associated pool of apoE and enhanced cholesterol efflux was investigated in these studies. Inhibition of proteoglycan expression reduced cholesterol efflux from apoE-expressing cells ( J774E(+)) in the presence and absence of HDL, but did not do so from nonexpressing cells ( J774E(-)). The effect of proteoglycan depletion on sterol efflux from J774E(+) cells was confirmed by measuring differences in cell sterol mass, secreted sterol mass, and sterol efflux rates. Furthermore, apoE-containing particles secreted from proteoglycan-depleted J774E(+) cells were denser than those secreted from J774E(+) cells with intact proteoglycan expression. Also, in J774E(+) cells with intact proteoglycans, apoE particles isolated from the cell surface proteoglycan layer were denser than secreted particles. The apoE-lipid particles isolated from the cell surface proteoglycan layer had a lower lipid-to-apoE and cholesterol-to-apoE ratio compared with secreted particles. In distinction, proteoglycan depletion of J774E(-) cells did not reduce sterol efflux produced by the exogenous addition of apoE. These observations indicate that one mechanism by which endogenous expression of apoE facilitates effective cholesterol efflux from macrophages is related to its retention at the cell surface in a proteoglycan-associated pool. Further, our data suggest that apoE arrives at the cell surface in a relatively lipid-poor state, and that a proximate source of lipid available to the proteoglycan-bound apoE at the cell surface resides in the plasma membrane.

Expression and function of P-glycoprotein in rats with carbon tetrachloride-induced acute hepatic failure

Acute hepatic failure was induced experimentally in rats by intraperitoneal injection of 2.5 mL kg(-1) carbon tetrachloride (CCl4), and the effects on the expression and function of P-glycoprotein in the liver, kidney and brain were evaluated. The CCl4 injection significantly increased the indicators of hepatic function (glutamate oxaloacetate transaminase, glutamate pyruvate transaminase), but not of renal function (blood urea nitrogen, glomerular filtration rate). In rats with acute hepatic failure, the hepatic P-glycoprotein concentration increased 1.5-fold and the ATP concentration decreased to approximately 40% that in control rats. In contrast, P-glycoprotein concentrations in the kidney and brain and ATP concentrations in the kidney remained unchanged. The in-vivo P-glycoprotein function in these tissues was suppressed as evaluated by biliary and renal secretory clearances and brain distribution of rhodamine 123, a P-glycoprotein substrate. These findings suggest that factors other than P-glycoprotein concentration are involved in the systemic suppression of P-glycoprotein function in diseased rats. In Caco-2 cells, plasma collected from CCl4-treated rats exhibited a greater inhibitory effect on P-glycoprotein-mediated transport of rhodamine 123 than that from control rats, suggesting the accumulation of an endogenous P-glycoprotein substrate/inhibitor in the plasma of diseased rats. In fact, the plasma concentration of corticosterone, an endogenous P-glycoprotein substrate, increased 2-fold in CCl4-treated rats compared with control rats. It was demonstrated that P-glycoprotein function is systemically suppressed in rats with CCl4-induced acute hepatic failure, not only in the target organ (liver), but also in other organs (kidney and brain), although the P-glycoprotein concentration remained unchanged in the kidney and brain, and increased in the liver. In the systemic suppression of the P-glycoprotein function in the diseased state, the alteration of plasma concentrations or components of endogenous P-glycoprotein-related compounds, such as corticosterone, would likely be involved.

Expression and function of P-glycoprotein in rats with glycerol-induced acute renal failure

The effect of glycerol-induced acute renal failure on P-glycoprotein expression and function was evaluated in rats. The in vivo function of P-glycoprotein was evaluated by measuring renal secretory and biliary clearance and brain distribution of rhodamine 123 (Rho-123), a P-glycoprotein substrate, under a steady-state plasma concentration. In acute renal failure rats, the P-glycoprotein level increased 2.5-fold in the kidney, but not in the liver and brain. In contrast, P-glycoprotein function in these tissues was suppressed. Interestingly, not only the renal but also the biliary clearance of Rho-123 was correlated with the glomerular filtration rate. In Caco-2 cells, plasma from renal failure rats exhibited a greater inhibitory effect on P-glycoprotein-mediated transport of Rho-123 than did plasma from control rats. In conclusion, P-glycoprotein function was systemically suppressed in acute renal failure, even though the level of P-glycoprotein remained unchanged or rather increased. This may be due to the accumulation of some endogenous P-glycoprotein substrates/modulators in the plasma in disease states.

Ecdysteroid hormones and metabolites of the stone crab, Menippe mercenaria

The Y-organs of the xanthid crab Menippe mercenaria secrete the ecdysteroids, 3-dehydroecdysone (3DE) and lesser amounts of 3-dehydro (or 2-dehydro)-25-deoxyecdysone (3D25dE) in vitro. These ecdysteroids were identified by elution-time comparisons with authentic standards, mass spectrography, and, for 3D25dE, infrared spectrometry. Tissues were incubated 18 hr with [(3)H]3DE. Activities representing 3beta-reductase and 20-hydroxylase generally were present, evidenced by finding in the tissue/medium extract labeled ecdysone (E) and 20-hydroxyecdysone (20E). Labeled 3-dehydro-20-hydroxyecdysone (3D20E) also appeared to be present. Tissue blanks and hemolymph were devoid of activity. Muscle was low, hypodermis was intermediate, and hindgut and gonads were high in activity of the enzymes. Consistent with the presence of these enzymes in peripheral tissues, ecdysteroid products identified in the hemolymph were 20E, 3D20E, and 25-deoxy-20-hydroxyecdysone (25d20E; ponasterone A). Structures of 20E and 3D20E were confirmed by co-elution with authentic standards in high-performance liquid chromatography (HPLC), co-elution of derivatives in gas chromatography, and mass spectroscopy. Ponasterone A (identified by HPLC co-elution with the standard), like 20E is present in the hemolymph in prominent amounts. These data indicate that Menippe, among crustaceans thus far studied, secretes a unique combination of ecdysteroid hormones, namely, a 3- (or 2-) oxo compound and a 25-deoxy compound. This represents a different kind of branch point from 5beta-diketol in ecdysteroid biosynthesis, in which the intermediate, 5beta-ketodiol is bypassed. A result is the joint appearance in the circulation of the hormones, 20E and ponasterone A, which in other species are singly prominent.

Characterization of Staphylococcus aureus cell wall glycan strands, evidence for a new beta-N-acetylglucosaminidase activity

Using sequential digestion with the glycyl-glycine endopeptidase lysostaphin followed by the pneumococcal N-acetylmuramyl-L-alanine amidase (amidase), the glycan strands of the peptidoglycan of Staphylococcus aureus were purified and analyzed by a combination of reverse-phase-high pressure liquid chromatography (HPLC) and mass spectrometry. Reverse-phase-HPLC resolved the glycan strands to a family of major peaks, which represented oligosaccharides composed of repeating disaccharide units (N-acetylglucosamine-[beta-1, 4]-N-acetylmuramic acid) with different degrees of polymerization and terminating with N-acetylmuramic acid residues at the reducing ends. The method allowed separation of strands up to 23-26 disaccharide units with a predominant length between 3 and 10 and an average degree of polymerization of approximately 6. Glycan strands with a higher degree of polymerization (>26 disaccharide units) represented 10-15% of the total UV absorbing glycan material. A unique feature of the staphylococcal glycan strands was the presence of minor satellite peaks that were present throughout the HPLC elution profile eluting either just prior or shortly after the major oligosaccharide peaks. A number of observations including mass spectrometric analysis suggest that the satellites are the products of an N-acetylglucosaminidase activity that differs from the atl gene product and that appears to be involved with modification of the glycan strand structure.

Evaluation of charge derivatization of a proteolytic protein digest for improved mass spectrometric analysis: de novo sequencing by matrix-assisted laser desorption/ionization post-source decay mass spectrometry

A simple mass spectrometric method to sequence a recombinant phosphoenolpyruvate carboxykinase of known structure and a novel variant of unknown structure isolated from Anaerobiospirillum succiniciproducens and Actinobacillus succinogenes 130Z, respectively, was evaluated. The proteolytic digests of the proteins were each chemically derivatized at the N-terminus by addition of a tris(trimethoxyphenyl)phosphoniumacetyl (TMPP(+)-Ac) group to produce peptides with a fixed positive charge. The derivatized digests were then partially separated by reversed-phase high-performance liquid chromatography. The fractions collected were subjected to matrix-assisted laser desorption/ionization post-source decay (MALDI/PSD) mass spectrometric analysis. The resulting spectra are sufficiently simple to allow the sequence to be read directly without extensive interpretation. This is in contrast to spectra of underivatized peptides obtained by MALDI/PSD or conventional tandem mass spectrometry, where full sequence interpretation can be challenging. Aided with a set of very simple established rules, it was shown that the sequence of TMPP(+)-Ac derivatives can be derived strictly from predictable fragment ion series. In most cases, this is sufficient to determine extensive, unambiguous, peptide sequences de novo. The partial sequence (35%) of the unknown phosphoenolpyruvate carboxykinase from Actinobacillus succinogenes 130Z was obtained entirely by the mass spectrometric method evaluated here, which provided the basis for evaluating homology and for the design of oligonucleotide probes for cloning the corresponding gene.

Serum antibodies to Balamuthia mandrillaris, a free-living amoeba recently demonstrated to cause granulomatous amoebic encephalitis

Free-living amoebae cause three well-defined disease entities: a rapidly fatal primary meningoencephalitis, a chronic granulomatous amoebic encephalitis (GAE), and a chronic amoebic keratitis. GAE occurs in immunocompromised persons. Recently, another type of free-living amoeba, Balamuthia mandrillaris, has been shown to cause GAE. The finding that this amoeba has caused infection in some healthy children has raised the possibility that humans may lack immunity to B. mandrillaris. Human serum was examined for the presence of surface antibodies specific for this amoeba by immunofluorescence. Sera from adults contained titers of 1/64-1/256 of anti-B. mandrillaris antibodies (IgM and IgG classes), which did not cross-react with other amoebae. Cord blood contained very low antibody levels, but levels similar to those in adults were seen in serum of 1- to 5-year-old children.