Surgical treatment of nasopharyngeal cancer - a consensus recommendation from two Chinese associations

BACKGROUND

Surgical treatment is playing an increasingly important role in the management of nasopharyngeal carcinoma (NPC). This consensus focuses on the indications for optimal surgery, and surgical methods in the whole process of treatment for NPC to provide a useful reference to assist these difficult clinical decisions.

METHODOLOGY

A thorough review of available literature on NPC and surgery was conducted by the Association for the prevention and treatment of nasopharyngeal carcinoma in China, international exchange and promotion Association for medicine and healthcare, and the Committee on nasopharyngeal cancer of Guangdong provincial anticancer association. A set of questions and a preliminary draft guideline was circulated to a panel of 1096 experienced specialists on this disease for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the experts in two authoritative medical science and technology academic groups in the prevention and treatment of NPC in China for review and reconsideration.

RESULTS

The initial round of questions showed variations in clinical practice even among similar specialists, reflecting the lack of high-quality supporting data and resulting difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of surgery, including indications and surgical approaches.

CONCLUSION

By standardizing the surgical indications and practice, we hope not only to improve the surgical outcomes, but also to highlight the key directions of future clinical research in the surgical management of NPC.

Progress on lysosomal PPT1-mediated regulation of cellular homeostasis and pathogenesis

Palmitoyl protein thioesterase 1(PPT1) is a lysosomal enzyme that catalyzes the protein depalmitoylation. It is considered to play a crucial role in regulating lysosomes, mitochondria and lipid metabolism. PPT1 has been reported to play an important role in the occurrence and progression of diseases, such as neurological diseases and cancers. However, the regulatory mechanisms remain unknown. In this review, we summarize the progress of PPT1 function and mechanisms in neurological disorders and cancers, which will provide as reference and guidance for exploring the regulatory mechanisms of PPT1 and developing new drugs for treating related diseases in the future.

Chromosome-level Dinobdella ferox genome provided a molecular model for its specific parasitism

BACKGROUND

Dinobdella ferox is the most frequently reported leech species parasitizing the mammalian nasal cavity. However, the molecular mechanism of this special parasitic behavior has remained largely unknown.

METHODS

PacBio long-read sequencing, next-generation sequencing (NGS), and Hi-C sequencing were employed in this study to generate a novel genome of D. ferox, which was annotated with strong certainty using bioinformatics methods. The phylogenetic and genomic alterations of D. ferox were then studied extensively alongside the genomes of other closely related species. The obligatory parasitism mechanism of D. ferox was investigated using RNA-seq and proteomics data.

RESULTS

PacBio long-read sequencing and NGS yielded an assembly of 228 Mb and contig N50 of 2.16 Mb. Along Hi-C sequencing, 96% of the sequences were anchored to nine linkage groups and a high-quality chromosome-level genome was generated. The completed genome included 19,242 protein-coding genes. For elucidating the molecular mechanism of nasal parasitism, transcriptome data were acquired from the digestive tract and front/rear ends of D. ferox. Examining secretory proteins in D. ferox saliva helped to identify intimate connections between these proteins and membrane proteins in nasal epithelial cells. These interacting proteins played important roles in extracellular matrix (ECM)-receptor interaction, tight junction, focal adhesion, and adherens junction. The interaction between D. ferox and mammalian nasal epithelial cells included three major steps of pattern recognition, mucin connection and breakdown, and repair of ECM. The remodeling of ECM between epithelial cells of the nasal mucosa and epithelial cells of D. ferox may produce a stable adhesion environment for parasitism.

CONCLUSIONS

Our study represents the first-ever attempt to propose a molecular model for specific parasitism. This molecular model may serve as a practical reference for parasitism models of other species and a theoretical foundation for a molecular process of parasitism.

[Safety evaluation of simultaneous administration of quadrivalent influenza split virion vaccine and 23-valent pneumococcal polysaccharide vaccine in adults aged 60 years and older]

Objective: To evaluate the safety of simultaneous administration of quadrivalent influenza split virion vaccine and 23-valent pneumococcal polysaccharide vaccine in adults aged 60 years and older. Methods: From November 2021 to May 2022, eligible participants aged 60 years and older were recruited in Taizhou City, Jiangsu Province, China, and a total of 2 461 participants were ultimately enrolled in this study. Each participant simultaneously received one dose of quadrivalent influenza split virion vaccine and one dose of 23-valent pneumococcal polysaccharide vaccine. The safety was observed within 28 days after vaccination. Safety information was collected through voluntary reporting and regular follow-ups. Results: All 2 461 participants completed the simultaneous administration of both vaccines and the safety follow-ups for 28 days after vaccination. The mean age of the participants was (70.66±6.18) years, with 54.61% (1 344) being male, and all participants were Han Chinese residents. About 22.51% (554) of the participants had underlying medical conditions. The overall incidence of adverse reactions within 0-28 days after simultaneous vaccination was 2.07% (51/2 461), mainly consisting of Grade 1 adverse reactions [1.83% (45/2 461)], with no reports of Grade 4 or higher adverse reactions or vaccine-related serious adverse events. The incidence of local adverse reactions was 0.98% (24/2 461), primarily presenting as pain at the injection site [0.93% (23/2 461)]. The incidence of systemic adverse reactions was 1.42% (35/2 461), with fever [0.85% (21/2 461)] being the main symptom. In the group with underlying medical conditions and the healthy group, their overall incidence of adverse reactions was 2.53% (14/554) and 1.94% (37/1 907), respectively. The incidence of local adverse reactions in the two groups was 1.62% (9/554) and 0.79% (15/1 907), respectively, and the incidence of systemic adverse reactions was 1.44% (8/554) and 1.42% (27/1 907), respectively, with no statistically significant differences between them (all P>0.05). Conclusion: It is safe for adults aged 60 years and older to receive quadrivalent influenza split virion vaccine and 23-valent pneumococcal polysaccharide vaccine at the same time.

[Incidence and prognosis of olfactory and gustatory dysfunctions related to infection of SARS-CoV-2 Omicron strain: a national multi-center survey of 35 566 population]

Objective: This cross-sectional investigation aimed to determine the incidence, clinical characteristics, prognosis, and related risk factors of olfactory and gustatory dysfunctions related to infection with the SARS-CoV-2 Omicron strain in mainland China. Methods: Data of patients with SARS-CoV-2 from December 28, 2022, to February 21, 2023, were collected through online and offline questionnaires from 45 tertiary hospitals and one center for disease control and prevention in mainland China. The questionnaire included demographic information, previous health history, smoking and alcohol drinking, SARS-CoV-2 vaccination, olfactory and gustatory function before and after infection, other symptoms after infection, as well as the duration and improvement of olfactory and gustatory dysfunction. The self-reported olfactory and gustatory functions of patients were evaluated using the Olfactory VAS scale and Gustatory VAS scale. Results: A total of 35 566 valid questionnaires were obtained, revealing a high incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain (67.75%). Females(χ2=367.013, P<0.001) and young people(χ2=120.210, P<0.001) were more likely to develop these dysfunctions. Gender(OR=1.564, 95%CI: 1.487-1.645), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), oral health status (OR=0.881, 95%CI: 0.839-0.926), smoking history (OR=1.152, 95%CI=1.080-1.229), and drinking history (OR=0.854, 95%CI: 0.785-0.928) were correlated with the occurrence of olfactory and taste dysfunctions related to SARS-CoV-2(above P<0.001). 44.62% (4 391/9 840) of the patients who had not recovered their sense of smell and taste also suffered from nasal congestion, runny nose, and 32.62% (3 210/9 840) suffered from dry mouth and sore throat. The improvement of olfactory and taste functions was correlated with the persistence of accompanying symptoms(χ2=10.873, P=0.001). The average score of olfactory and taste VAS scale was 8.41 and 8.51 respectively before SARS-CoV-2 infection, but decreased to3.69 and 4.29 respectively after SARS-CoV-2 infection, and recovered to 5.83and 6.55 respectively at the time of the survey. The median duration of olfactory and gustatory dysfunctions was 15 days and 12 days, respectively, with 0.5% (121/24 096) of patients experiencing these dysfunctions for more than 28 days. The overall self-reported improvement rate of smell and taste dysfunctions was 59.16% (14 256/24 096). Gender(OR=0.893, 95%CI: 0.839-0.951), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), history of head and facial trauma(OR=1.180, 95%CI: 1.036-1.344, P=0.013), nose (OR=1.104, 95%CI: 1.042-1.171, P=0.001) and oral (OR=1.162, 95%CI: 1.096-1.233) health status, smoking history(OR=0.765, 95%CI: 0.709-0.825), and the persistence of accompanying symptoms (OR=0.359, 95%CI: 0.332-0.388) were correlated with the recovery of olfactory and taste dysfunctions related to SARS-CoV-2 (above P<0.001 except for the indicated values). Conclusion: The incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain is high in mainland China, with females and young people more likely to develop these dysfunctions. Active and effective intervention measures may be required for cases that persist for a long time. The recovery of olfactory and taste functions is influenced by several factors, including gender, SARS-CoV-2 vaccination status, history of head and facial trauma, nasal and oral health status, smoking history, and persistence of accompanying symptoms.

The roles and mechanism of STIM1 in tumorigenesis and metastasis

STIM1 (stromal interaction molecule 1) is one of the key components of the store operated Ca²⁺ entry channel (SOCE), which is located on the endoplasmic reticulum membrane and highly expressed in most kinds of tumors. STIM1 promotes tumorigenesis and metastasis by modulating the formation of invadopodia, promoting angiogenesis, mediating inflammatory response, altering the cytoskeleton and cell dynamics. However, the roles and mechanism of STIM1 in different tumors have not been fully elucidated. In this review, we summarize the latest progress and mechanisms of STIM1 in tumorigenesis and metastasis, thereby providing insights and references for the study on STIM1 in the field of cancer biology in the future.

Neofusicoccum cryptomeriae sp. nov. and N. parvum Cause Stem Basal Canker of Cryptomeria japonica in China

Cryptomeria japonica D. Don is a coniferous tree species widely grown in southern China for its high ornamental value. Recently, during disease surveys in China, a symptom of dieback occurred on C. japonica in Nanjing, Jiangsu Province, China. A total of 130 trees were surveyed and more than 90% showed the same symptom. The crowns of affected trees were brown when viewing from a distance, and the bark showed no difference from the healthy ones. In this study, 157 isolates were isolated from the 3 affected plants of C. japonica, and based on the living culture on PDA, the fungal isolates were preliminarily divided into 6 groups. Thirteen representative isolates were selected for the pathogenicity test, and seven of them showed obvious pathogenicity on C. japonica, causing stem basal canker. These isolates were identified based on comparisons of the DNA sequences of the internal transcribed spacer regions (ITS), partial translation elongation factor 1-alpha (tef1), β-tubulin (tub2), and DNA-directed RNA polymerase II subunit (rpb2) and combined with their morphological characteristics. Results showed that these seven isolates belong to two taxa in Neofusicoccum, including a species new to science. The new species, Neofusicoccum cryptomeriae, was hereby described and illustrated. The other species was N. parvum. Both species were pathogens of stem basal canker of Cryptomeria japonica.

The role and regulatory mechanism of FSCN1 in breast tumorigenesis and progression

FSCN1, an actin-bundling protein, is highly expressed in almost all metastatic tumors and is associated with the poor prognosis. In breast cancer FSCN1 is highly expressed in basal-like and triple negative subgroups. There is significant progress in understanding the role of fascin in breast cancer. Studies on FSCN1 in recent years have revealed that FSCN1 not only promotes tumor migration, invasion, metastic colonization, cancer cell self-renewal and drug resistance, but also regulates glucose and lipid metabolism and mitochondrial remodeling in tumor cells. In this review, we focus on the structure and regulatory mechanism of FSCN1 in breast tumorigenesis and metastasis, and discuss the clinical value of FSCN1 with the aim to provide a direction for further research in this field.

Progress on the role and mechanism of MT1-MMP in tumor metastasis

The matrix metallopeptidase family (matrix metallopeptidase, MMPs) is a class of zinc-dependent endopeptidases that can degrade most extracellular matrices. MT1-MMP (membrane type 1 metalloprotease) is an important metallopeptidase, which is located on plasma membrane and highly expressed in most tumors. MT1-MMP promotes cancer metastasis through affecting the extracellular matrix remodeling, angiogenesis, lipid metabolism, and inflammation. However, the mechanisms of MT1-MMP in different tumors have not been fully elucidated. In this review, we summarize the latest progress and the metastasis-promoting regulatory mechanisms of MT1-MMP in different tumors, which will provide references for its in-depth research and application in the field of cancer biology.

First Report of Top Blight of Cunninghamia lanceolata Caused by Diaporthe unshiuensis and Diaporthe hongkongensis in China

Cunninghamia lanceolata (Lamb.) Hook. is an important conifer species widely planted in southern China. A top blight, with an incidence of 20% (40/200 seedlings), occurred on 1-year-old seedlings of C. lanceolata in a nursery, Luzhai, Guangxi, China in August 2021. The disease mainly occurred on shoot tips. The infected needles and shoots appeared brown to brownish red. White conidial tendrils oozed from pycnidia under wet-weather conditions. Lesion margins from fresh samples were cut into small pieces (n=100), which were sterilized according to Mao et al., and placed on potato dextrose agar (PDA) at 25°C. Three isolates (GXJ2, GXJ4, and GXJ6) were obtained and deposited in The China Forestry Culture Collection Center (CFCC 55717, CFCC 55716, and CFCC 55722). The colony of GXJ2 on PDA was white, with sparse aerial mycelia, and became grey with time. The α conidia were fusiform, hyaline, and aseptate, 6.7±0.6 μm × 2.6±0.2 μm (n=30). The β conidia were filiform, hyaline, and curved, 30.4±2.1 μm × 1.4±0.1 μm (n=30). Colonies of GXJ4 and GXJ6 were white, with moderate aerial mycelia, which collapsed at the center, and the collapsed parts were iron-gray. The α conidia were 7.8±0.8 μm × 2.5±0.2 μm (n=30). The β conidia were absent. Morphological characters of 3 isolates matched those of Diaporthe spp.. The partial sequences of ITS, EF1-α, CAL, β-tub, and HIS genes were amplified with primers ITS1/ITS4, EF1-728F/EF1-986R and CAL228F/CAL737R, βt2a/βt2b and CYLH3F/H3-1b according to Gomes et al. 2013, respectively. The sequences for the five genes of each of 3 isolates were deposited in GenBank (Accession Nos. see Supplementary Table 1). BLAST results showed that the ITS, EF1-α, β-tub, HIS, and CAL sequences of GXJ2 were highly similar (>99%) with sequences of Diaporthe unshiuensis, while sequences of GXJ4 and GXJ6 were highly similar (>99%) to those of D. hongkongensis (Supplementary Table 1). Phylogenetic analyses using concatenated sequences placed GXJ2 in the clade of D. unshiuensis, while GXJ4 and GXJ6 in the clade of D. hongkongensis. Based on the phylogeny and morphology, GXJ2 was identified as D. unshiuensis, GXJ4 and GXJ6 as D. hongkongensis. Pathogenicity tests were performed on nine 1-year-old seedlings of C. lanceolata, and 10 needles at shoot tip per seedling were slightly wounded and inoculated with 5-mm mycelial plugs from one of 3 isolates. Three control seedlings were treated with PDA plugs. Each plant was covered with a plastic bag after inoculation and kept in an air-conditioned nursery at 25°C/16°C (day/night). The symptoms appeared 5-8 days after inoculation and were similar to those observed in the nursery. D. unshiuensis and D. hongkongensis were re-isolated from the inoculated seedlings and were confirmed based on morphology and ITS sequences. The controls were symptomless, and no fungus was isolated from them. D. unshiuensis was first reported as an endophyte on the fruit of Citrus unshiu, and caused peach constriction canker, shoot blight of kiwifruit. D. hongkongensis was first described from fruit of Dichroa febrifuga and caused shoot canker of pear, shoot blight and leaf spot of kiwifruit, and fruit rot of peach. This is the first report of D. unshiuensis and D. hongkongensis causing the top blight of C. lanceolata. This study provides a basis for controlling this newly emerging disease in the nursery.

[Analysis of relationship between distribution of pathogenic microorganisms in olfactory cleft and olfactory disorders among patients with upper respiratory inflammation during the prevention and control of COVID-19]

Objective: To explore the relationship between pathogens in the olfactory cleft area and olfactory disorders in patients with upper respiratory inflammation (URI) during the prevention and control of 2019 novel coronavirus disease (COVID-19). Methods: A total of 234 URI patients including acute upper respiratory infection, chronic rhinosinusitis (CRS), allergic rhinitis (AR) were continuously selected from September 2020 to March 2021 in Beijing Anzhen Hospital and 98 healthy adults were enrolled as controls. The secretions from the olfactory cleft of all subjects were collected with nasal swabs under nasal endoscopy. Multiple real-time fluorescent quantitative polymerase chain reaction detection method was used to detect nucleic acids of 33 types of respiratory pathogenic microorganism. Sniffin' Sticks olfactory test was performed on all patients with URI. URI patients with olfactory dysfunction were followed up for 9 (8, 10) months (M (Q₁, Q₃)). SPSS 20.0 software was used for statistical analysis. Results: Among the 98 controls, 9 (9.18%) were positive for pathogenic microorganisms, including 1 (1.02%) rhinovirus, 1 (1.02%) parainfluenza virus type 3, 3 (3.06%) enterovirus, 1 (1.02%) staphylococcus aureus and 3 (3.06%) Moraxella catarrhalis. Among the 234 URI patients, 111 (47.44%) had olfactory disorders and 123 (52.56%) had normal sense of smell. In the olfactory disorder group (111 cases), 38 cases (34.23%) were positive for pathogenic microorganisms, and 4 cases (3.60%) were mixed infection, including 11 cases of rhinovirus (9.91%), 5 cases of coronavirus 229E (4.50%), 2 cases of coronavirus OC43/NL63 (1.80%), 3 cases of parainfluenza virus type 1 (2.70%), 2 cases of enterovirus (1.80%), 1 case of influenza B virus type BV (0.90%), 11 cases of Staphylococcus aureus (9.91%), 7 cases of Moraxella catarrhalis (6.31%), and 1 case of Klebsiella pneumoniae (0.90%). In the normal smell group (123 cases), 18 cases (14.63%) were positive for pathogenic microorganisms, and 1 case (0.81%) was mixed infection, including 3 cases of rhinovirus (2.44%), 4 cases of coronavirus 229E (3.25%), 1 case of Influenza virus type 3 (0.81%), 3 cases of enterovirus (2.44%), 3 cases of Staphylococcus aureus (2.44%), 4 cases of Moraxella catarrhalis (3.25%), and 1 case of Klebsiella pneumoniae (0.81%). Univariate analysis between the two groups found that there were significant differences in the detection rate of pathogenic microorganisms, rhinovirus and Staphylococcus aureus between the groups (all P<0.05). The detection rate of parainfluenza virus type 1, Staphylococcus aureus, and rhinovirus were different between the patients with olfactory disorder and normal olfactory function in the three subgroups of acute upper respiratory tract infection, CRS and AR, respectively (χ² value was 3.88, 4.53 and 4.73, respectively, all P<0.05). During the follow-up period, among the 111 patients with olfactory disorder, 71 (63.96%) patients' olfactory function returned to normal, 32 (28.83%) patients' olfactory function improved but not completely returned to normal, 8 (7.21%) patients' olfactory function did not improve. Conclusions: During the prevention and control of COVID-19, rhinovirus or Staphylococcus aureus infection or colonization of URI patients is closely related to olfactory disorders. Parainfluenza virus type 1 infection can cause relatively persistent olfactory disorders in patients with acute upper respiratory tract infection. Staphylococcus aureus and rhinovirus colonization are related to the occurrence of olfactory dysfunction in CRS and AR patients respectively.

[Epidemiological characteristics of novel coronavirus pneumonia in Shijiazhuang, China]

Objective: To analyze the epidemiological characteristics of an outbreak of novel coronavirus pneumonia (COVID-19) in Shijiazhuang, Hebei Province in 2021 and to provide scientific basis for developing improved strategies to prevent and control the outbreak of COVID-19. Methods: Descriptive analysis of the outbreak of COVID-19 in Shijiazhuang, Hebei Province was performed with SPSS 21.0 and Excel software. The statistical analysis of the incubation period was performed using the rstan package in R4.0.4. Results: As of February 14^th 2021, a total of 942 local confirmed cases were reported in Hebei Province, 869 cases in Shijiazhuang, of which 847 cases were available for case information. This outbreak was mainly in rural areas, with the largest number of confirmed cases in Xiaoguozhuang village, 249 (29.4%); followed by Nanqiaozhai village, 128 (15.1%); and Liujiazuo village, 85 (10.0%). The outbreak lasted from January 2^nd, 2021 to February 14^th, 2021, and was mainly transmitted among the farmers as well as the students through dining parties, public gatherings and family contacts, showing an obvious time and occupation concentration trend. An analysis of 116 local confirmed cases in this outbreak with specific exposure time and onset time indicated that the median incubation period was 6 [interquartile range(IQR): 3.3, 10.0] days; whereas another report including 264 local confirmed cases with specific exposure time window showed that a median incubation period was 8.5 [95% confidence interval (CI): 1.8-18.8] days. Conclusions: This outbreak was mainly related to rural areas, and was associated with parties, public gatherings and family gatherings. Self-protection and isolation of key areas and populations at risk should be effectively implemented to avoid close contact and other measures to reduce the occurrence of COVID-19 aggregation. Based on the results of the incubation period of this outbreak, the isolation period could be recommended to be extended to three weeks.

Early and late recurrences in lymph node-negative gastric cancer: a retrospective cohort study

BACKGROUND

Predictors of recurrence in patients with lymph node-negative gastric cancer (GC) who have undergone curative resection have been widely investigated, but not the effects of predictors on timing of recurrence.

OBJECTIVE

Determine the factors associated with early and late recurrence in patients with node-negative GC.

DESIGN

Retrospective cohort.

SETTING

Academic tertiary care center.

PATIENTS AND METHODS

The study included patients with node-negative GC after curative resection between 2008 and 2018 at two institutions. Early and late recurrences were determined using a minimum P value approach to evaluate the optimal cutoff for recurrence-free survival (RFS). A competing risk model and landmark analysis were used to analyze factors associated with early and late recurrences.

MAIN OUTCOME MEASURES

Recurrence-free survival and factors associated with survival.

SAMPLE SIZE

606.

RESULTS

After a median follow-up of 70 months, 50 (8.3%) patients experienced recurrent disease. The optimal length of RFS for distinguishing between early (n=26) and late recurrence (n=24) was 24 months (P=.0013). The median RFS in the early and late recurrence groups was 11 and 32 months, respectively. Diffuse tumors (hazard ratio 3.358, P=.014), advanced T stage (HR 8.804, P=.003), perineural invasion (HR 10.955, P<.001), and anemia (HR 2.351, P=.018) were independent predictors of early recurrence. Mixed tumor location (HR 5.586, P=.002), advanced T stage (HR 5.066, P<.001), lymphovascular invasion (HR 5.902, P<.001), and elevated CA19-9 levels (HR 5.227, P<.001) were independent predictors of late recurrence. Similar results were obtained in the landmark analysis.

CONCLUSIONS

Individualized therapeutic and follow-up strategies should be considered in future studies because of distinct patterns in predictors of early and late recurrence.

LIMITATIONS

Retrospective design, small sample size.

CONFLICT OF INTEREST

None.

Spin-valley locking and bulk quantum Hall effect in a noncentrosymmetric Dirac semimetal BaMnSb2

Spin-valley locking in monolayer transition metal dichalcogenides has attracted enormous interest, since it offers potential for valleytronic and optoelectronic applications. Such an exotic electronic state has sparsely been seen in bulk materials. Here, we report spin-valley locking in a Dirac semimetal BaMnSb2. This is revealed by comprehensive studies using first principles calculations, tight-binding and effective model analyses, angle-resolved photoemission spectroscopy measurements. Moreover, this material also exhibits a stacked quantum Hall effect (QHE). The spin-valley degeneracy extracted from the QHE is close to 2. This result, together with the Landau level spin splitting, further confirms the spin-valley locking picture. In the extreme quantum limit, we also observed a plateau in the z-axis resistance, suggestive of a two-dimensional chiral surface state present in the quantum Hall state. These findings establish BaMnSb2 as a rare platform for exploring coupled spin and valley physics in bulk single crystals and accessing 3D interacting topological states.

[Three-dimensional changes of oropharyngeal airway after orthodontic extraction treatment in skeletal class Ⅰ adolescents]

Objective: To explore the effect of extraction on upper airway in skeletal class Ⅰ adolescents. Methods: According to random number table method, 30 skeletal class Ⅰteenagers who underwent orthodontic straight wire treatment were selected randomly in Department of Orthodontics, School of Stomatology, The Fourth Military Medical University between January 2016 and December 2019. There were 13 males and 17 females, aged (13.7±1.5) years (12.2-15.7 years). In all patients, four first premolars were removed and the upper and lower anterior teeth were retracted under non-maximal anchorage (non-implant anchorage or face bow). The cone-beam CT (CBCT) data before and after orthodontic extraction treatments were studied. The three-dimensional model of the upper airway was reconstructed and segmented, and the relevant indexes of oropharyngeal volume and cross-sectional area were measured. Cephalograms was generated to measure tooth-jaw indexes and hyoid position. The changes of each index before and after orthodontic treatment were compared. The correlation between the changes in the volume or sectional area of the oropharyngeal airway and the changes in the dental and maxillary indexes and the hyoid position was tested. Results: Compared with those before treatment, palatopharyngeal volume, glossopharyngeal volume, oropharyngeal total volume, and minimum transection area increased by 632 (558) mm³, 758 (549) mm³, 1 454 (955) mm³ and 14 (29) mm² respectively, and statistically significant differences were found (P<0.05). The minimum oropharyngeal area was mostly located in the glossopharynx. The cross-sectional area and the maximum anterior-posterior diameter of uvula tip decreased by (4±10) mm² and (0.4±0.8) mm respectively, and the difference was statistically significant (P<0.05). There was no significant difference in the maximum lateral diameter before and after treatment (P>0.05). The ratio of the maximum antero-posterior diameter to the maximum lateral diameter at the uvula tip decreased from 0.589 (0.034) before treatment to 0.535 (0.047) after treatment (P<0.05), indicating that its shape tends to be more elliptic after treatment. In addition, the change of cross-sectional area at the apex of uvula was positively correlated with the changes of mandibular central incisor lip inclination and the distances from the upper and lower central incisor points to the Frankfort plane perpendicular to the sella point (UI-FHp and LI-FHp) (P<0.05). Conclusions: The impact of orthodontic extraction treatment on oropharyngeal airway was generally small in skeletal class Ⅰ adolescents. However, it could change the shape of the airway to some extent. The change of airway cross-sectional area at the uvula tip was positively correlated with the retraction of anterior teeth.

[Distribution Characteristics of Viruses Microorganisms in a Water Supply System with Combined Ultraviolet Chloramine Disinfection]

To study the effect of combined ultraviolet (UV) chloramine disinfection on viruses in a drinking water supply system, a full-scale experiment was conducted to analyze the distribution, variability, community structure, and hosts of viruses using metagenomics. The results showed that the combined UV chloramine process reduced the number of virus species (6.13%) and gene abundance (51.97%) but did not completely remove the viruses from the water. The United States Environmental Protection Agency (USEPA) report that virus removal efficiencies from water can reach 99%-99.99% based on culturing methods. However, in this study, metagenomic analysis indicated a total virus removal rate of only 93.46%. Therefore, the detection of viruses in water using culturing method cannot reliably detect viruses in drinking water. Caudovirales are the most abundant type of virus in water supply systems and are sensitive to chloramine disinfection. Lentivirus, as a virus that can infect humans and vertebrates, has strong resistance to UV and chloramine disinfection. The main virus hosts in the studied water supply system were bacteria (61.50%). The viruses in the raw water were mainly parasitic in Synechococcus. The dominant virus host was Pseudomonas in both the effluent water and pipe network water. The gene abundance of the Pseudomonas aeruginosa host in the pipe network increased by 342.62%, which requires further attention as a virus risk in pipe network systems. Overall, combined UV chloramine disinfection was more effective at the removal of virus hosts than single UV disinfection (51.97% compared to 0.79%).

Prognostic value of lymphocyte-to-C-reactive protein ratio in patients with gastric cancer after surgery: a multicentre study

OBJECTIVE

The immune inflammation-based score is recognized as a prognostic marker for cancer. However, the most accurate prognostic marker for patients with gastric cancer remains undetermined. We aimed to evaluate the predictive value of the lymphocyte-to-C-reactive protein ratio for outcomes in gastric cancer patients after radical gastrectomy.

METHODS

A total of 607 gastric cancer patients treated at three Chinese institutions were included. Receiver operating characteristic curves were generated, and the areas under the curve were calculated to compare the predictive value among the inflammation-based score, lymphocyte-to-C-reactive protein ratio, C-reactive protein/albumin and neutrophil-lymphocyte, platelet-lymphocyte and lymphocyte-monocyte ratios. Cox regression was performed to determine the prognostic factors for overall survival.

RESULTS

The median follow-up time was 63 months (range: 1-84 months). The optimal cut-off value for lymphocyte-to-C-reactive protein ratio was 0.63. The patients were divided into the LCR <0.63 (LLCR, n = 294) group and the LCR ≥0.63 (HLCR, n = 313) group. LLCR was significantly correlated with poor clinical characteristics. Compared with inflammation-based score, lymphocyte-to-C-reactive protein ratio had the highest areas under the curve (0.695). Patients with LLCR experienced more post-operative complications than the HLCR group (20.4 vs. 12.1%, P = 0.006). Multivariate analysis showed that a higher lymphocyte-to-C-reactive protein ratio (HR: 0.545, 95%CI: 0.372-0.799, P = 0.002) was associated with better overall survival. The HLCR group had higher 5-year overall survival rate than the LLCR group (80.5 vs. 54.9%, P < 0.001).

CONCLUSIONS

Preoperative lymphocyte-to-C-reactive protein ratio levels can effectively predict the short-term and oncological efficacy of gastric cancer patients after radical gastrectomy with a predictive value significantly better than other inflammation-based score.

[Analysis of factors affecting olfactory disfunctions in patients with chronic rhinosinusitis with nasal polyps]

Objective: To analyze the factors affecting olfactory disfunctions in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Methods: This was a retrospective analysis. Eighty-eight patients with CRSwNP who underwent endoscopic sinus surgery in Beijing Anzhen Hospital from 2014 to 2018 were enrolled, including 22 males and 66 females, with the age of (48.1±11.3) years old(Mean±SD). Sniffin' Sticks olfactory test, Lund-Mackay score and modified sinus CT olfactory cleft score, nasal resistance and acoustic reflex examination, blood routine and blood biochemistry test, serum specific IgE test were performed before surgery and nasal polyps of all patients were collected for eosinophil count during surgery. According to bilateral total TDI score, the patients were divided into normal olfactory function group and olfactory disfunction group. The clinical baseline data were compared between the two groups. According to the results of single factor analysis, factors which were significant different between the two groups and clinically useful indicators were further included in the multivariate Logistic regression model analysis, then a model predicting olfactory disfunction in patients with CRSwNP was initially established. P<0.05 was considered statistically significant. Results: Among 88 patients with CRSwNP, 32 (36.4%) patients were with normal olfaction and 56 (63.6%) patients were with olfactory disfunction, including 40 (45.5%) of hyposmia and 16 (18.2%) of anosmia. Tissue eosinophil count, blood eosinophil percentage and blood urea concentration had significant difference between the two groups (12.7[2.0, 52.3]/HP (M[P(25), P(75)]) vs 38.6[16.2, 87.0]/HP, 2.75[1.60, 4.80]% vs 4.35[2.50, 6.60]%, (5.56±1.15) mmol/L vs (4.98±1.33) mmol/L, all P<0.05). Modified sinus CT olfactory cleft score and Lund-Mackay score except for ostiomeatal complex score were statistically significant between the two groups (all P<0.05). Multivariate Logistic regression analysis showed that the bilateral and total olfactory cleft score and blood urea concentration were statistically significant, in addition, the bilateral and total olfactory cleft score was a risk factor (OR=2.108, 95%CI: 1.407-3.159, P<0.001) and blood urea within a certain concentration was a protective factor (OR=0.461, 95%CI: 0.240-0.884, P=0.020). Further studies found that the area under the ROC curve of the model with tissue eosinophil count, blood eosinophil percentage, bilateral and total olfactory cleft score, total inspiratory volume and blood urea concentration was 0.888 (P<0.01), which had good predictive value for olfactory disorders in CRSwNP. Conclusions: The modified sinus CT olfactory cleft score is closely related to the olfactory disorders in patients with CRSwNP. A certain degree of elevated blood urea concentration may have a protective effect on the olfactory function of patients with CRSwNP.

First Report of Leaf Blotch of Salix babylonica Caused by Botryosphaeria dothidea in China

Salix babylonica L. (weeping willow) is an important ornamental tree commonly planted in China. Since 2018, a new disease with a high incidence has been observed on S. babylonica at the campus of Nanjing Forestry University (NFU), Nanjing, Jiangsu, China. The symptoms began as small dark brown lesions formed along the leaf margins and tips; and later became gray to brown in the center with dark brown borders. Small samples (3 to 4 mm2) from the lesion margins were surface-sterilized with 75% ethanol for 30 s and 1% NaClO for 90 s. Subsequently samples were, rinsed with sterile H2O, plated on potato dextrose agar (PDA) and incubated at 25°C. The same fungus was isolated in 95% of the samples. Pure cultures were obtained by monosporic isolation. A representative isolate, NFS1 was used for morphological and molecular characterization and deposited in China's Forestry Culture Collection Center (cfcc 54212). On PDA, colonies were initially white and gradually became grayish-green to dark gray from the center to the edge. After 1 week, colonies turned dark, and after 3 weeks black pycnidia developed on the surface of media. Conidia were one-celled, hyaline, smooth, and fusoid to ellipsoid. Conidia measurements were 23.0 ± 1.9 × 5.8 ± 0.7 µm (n = 50). The morphology matched the description of Botryosphaeria dothidea (Slippers et al. 2004). For an accurate identification, genomic DNA of NSF1 was extracted to amplify the internal transcribed spacer (ITS) region, the transcription eongation factor (tefa-1), beta-tubulin (β-tub), the large subunit (LSU), and small subunit (SSU) genes with the specific primers ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn, 1999), βt2a/βt2b (Glass and Donaldson, 1995), LR0R/LR05 (Schoch et al. 2009), and NS1/NS4 (White et al. 1990), respectively. The sequences were deposited in GenBank (Accession Nos. MN826233 for ITS, MN855215 for tefa-1, MN855216 for β-tub, MN886965 for LSU, and MN886966 for SSU). A BLAST search of GenBank showed that the ITS, tefa-1, β-tub, LSU and SSU sequences of NSF1 were similar to those of B. dothidea KY788304 (Identity = 527/532; 99%), MG459974 (Identity = 247/247; 100%), MH724212 (Identity = 404/404; 100%), DQ377850 (Identity = 865/867; 99%), and KX091154 (Identity = 1,043/1,045; 99%), respectively. A maximum likelihood and Bayesian posterior probability-based phylogenetic analyses using IQ-tree v. 1.6.8 and Mr. Bayes v. 3.2.6 with the concatenated sequences (ITS, tefa-1, β-tub, LSU, and SSU) placed NFS1 in the clade of B. dothidea. Based on the multi-gene phylogeny and morphology, NFS1 isolate was identified as B. dothidea. To fulfill Koch's postulates, 20 detached and 20 attached healthy 10-week-old leaves from three 30-year-old S. babylonica plants at the campus of NFU were inoculated with 5-mm mycelial plugs of isolate NFS1 of 3-day-old cultures grown on PDA. Control leaves were treated with agar plugs. The detached inoculated leaves were placed in Petri dishes on a piece of wet filter paper and incubated at 25°C. The attached leaves were enclosed in a plastic bag along with the branches with a wet cotton ball inside. Sterile H2O was sprayed into the plastic bags twice daily to keep moisture conditions and incubated for 5 days. The experiment was repeated two times. Within 5 days, all the inoculated points showed lesions similar to those obsrved in the field, whereas controls were asymptomatic. The same fungus was re-isolated from these lesions with a frequency of 100%. B. dothidea has been reported to infect a broad range of hosts, including S. babylonica in the USA (Grand 1985). This is the first report of B. dothidea on S. babylonica in China. This finding provides crucial information on this high risk disease to willow and basis for identifying management strategies.

[Anatomy and function of the Eustachian tube influence the development of chronic suppurative otitis media]

Objective:To explore the influence of anatomy and function of the Eustachian tube（ET） on the development of chronic suppurative otitis media. Method:We retrospectively enrolled 92 cases（184 ears） of adult patients with chronic suppurative otitis media（CSOM）, in whom 118 CSOM ears, 25 atelectasis ears and 41 normal ears were included. All patients underwent endoscopy, tympanometry, pure tone average, temporal bone computerized tomography scans and ET function test. Patients with pars flaccida retraction, cholesteatoma, ET obstruction or maxillofacial deformity were excluded. The length, angle and function of ET were analyzed. Result:The ET angle was （23.1±2.4） ° in CSOM ears, was （22.9±2.9） ° in atelectasis ears and was （25.1±3.0） ° in normal ears. The ETs were more horizontal in ears with CSOM and atelectasis（P<0.01）. The ET length was （39.2±4.3） mm in CSOM ears, was （41.7±5.8） mm in atelectasis ears and was （43.0±5.9） mm in normal ears. The ETs in CSOM ears were shorter compared to the ETs normal ears（P<0.01）. No significant difference was detected between the length of ETs of atelectasis ears and normal ears（P>0.05）. The ET dysfunction rate was 62% in CSOM ears, was 68% in atelectasis ears, which were both significantly higher than the dysfunction rate in normal ears（22%）（P<0.05）. Conclusion:The anatomical and functional changes of ETs contribute to the development of CSOM. For patients with more horizontal and shorter ETs as well as ETs dysfunction, more progressive treatment should be considered.

[Correlation of tissue eosinophil count and modified CT olfactory cleft score and olfactory function in patients with nasal polyps]

Objective:To investigate the effect of tissue eosinophil count on olfactory function in patients with chronic sinusitis with nasal polyps（CRSwNP）. Method:We prospectively selected 59 patients with CRSwNP. All the patients were not treated with oral or topical glucocorticoids for at least 1 month at the time of enrollment. All the nasal polyps were taken under local anesthesia in the outpatient department for eosinophil count and percentage calculation. The patients were divided into eosinophilic CRSwNP（ECRS group） and non-eosinophilic CRSwNP（non-ECRS group）. Baseline data was compared between the two groups. Spearman correlation analysis was performed on tissue eosinophil count and Lund-Mackay score, modified olfactory cleft scores, Sniffin' Sticks olfactory test, olfactory evoked potential peak latency and amplitude respectively. Result:Thirty-five of 59 patients with CRSwNP completed olfactory evoked potential test, from whom we collected stable waveforms. The ECRS group had a higher olfactory cleft area CT score, ethmoid sinus CT score and blood eosinophil count and percentage; there was a significant difference between the ECRS group and the non-ECRS group in single and bilateral odor test threshold（T value）（P=0.017）. There was no significant correlation between tissue eosinophil count and subjective olfactory VAS score（P>0.05）. Tissue eosinophil count was related to the bilateral T value in Sniffin' Sticks olfactory test（r=-0.322, P=0.013）, anterior and posterior olfactory cleft area scores（r=0.431 and 0.415, respectively, P=0.001） and olfactory evoked potential N1 latency（r=0.504, P=0.001） and P2 latency（r=0.374, P=0.020）, but not related to Lund-Mackay scores. In addition, there was a significant correlation between the unilateral T score in Sniffin' Sticks test and the unilateral olfactory evoked potential N1 latency（r=-0.505, P=0.002）. Conclusion:The increase of tissue eosinophilia was closely related to olfactory disfunctions in CRSwNP. It could be reflected by modified CT olfactory cleft score, Sniffin' Sticks olfactory test T value and oERP peak latency. In addition, T value was negatively consistent with latency of oERP N1 peak.

[Targeted-knockdown of Yes-associated protein inhibits the Warburg effect and the invasion of laryngeal cancer cells]

Objective: To investigate the migration and invasion behaviors of Hep-2 after the targeted knockdown of yes-associated protein (YAP). Methods: Hep-2 cells were knock-downed for YAP by shRNA as YAP-shRNA group, Hep-2 treated with non-specific shRNA as YAP-NC group, and Hep-2 with no treatment as control. Glucose uptake and lactate production in the cells were examined to assess Warburg effect. The migration and invasion behaviors of cells in three groups were observed. The expressions of vimentin and E-cadherin were detected by RT-PCR and Western Blot. The statistical software GraphPad Prism 7.0 was used to analyze significance of data. Two tailed Student' s t-tests was used to determine significance when only two groups were compared. P values of less than 0.05 was considered statistically significant. Results: Downregulation of YAP led to a obvious decrease in glucose uptake [(18.51±1.72)%] and lactate production [103.40±8.32] in Hep-2 cells compared with control [(41.20±1.11)% and 743.69±19.49, t=19.20 and 52.33, respectively, both P<0.01] and YAP-NC group [(39.60±0.78)% and 705.22±17.20, t=19.34 and 54.56, respectively, both P<0.01]. Compared with the control group (78.32±4.04) and YAP-NC group (77.28±3.11), the scratch healing ability of Hep-2 cells was significantly decreased in YAP-shRNA group (44.71±4.68). The P value was less than 0.01 (t=9.42 and 10.04). The number of cells with YAP-shRNA (33.30±4.19) passing through compartments was remarkable fewer than the control group (133.71±6.72) and YAP-NC group (126.32±4.21). The P value was less than 0.01 (t=21.96 and 27.13). The expression of E-cadherin protein in cells of YAP-shRNA group (6.16±0.11) was up-regulated compared with control (0.97±0.10, t=35.70, P<0.01) and YAP-NC group (1.13±0.09, t=36.28, P<0.01), while the expression of vimentin protein in cells of YAP-shRNA group (1.08±0.09) was down-regulated compared with control (5.67±0.12, t=29.91, P<0.01) and YAP-NC group (5.51±0.12, t=29.04, P<0.01). Conclusions: The down-regulation of YAP in Hep-2 inhibits the migration and invasion of cells via suppressing Warburg and EMT program.

[Effect of endoscopic sinus surgery on olfactory function in patients with chronic rhinosinusitis with nasal polyps]

Objective:To evaluate the effect of surgery on olfactory function in patients with chronic rhinosinusitis with nasal polyps（CRSwNP） by subjective and objective olfactory tests. Method:This was a retrospective study. Forty patients with CRSwNP who underwent endoscopic sinus surgery（ESS） from 2015 to 2017 in Beijing Anzhen Hospital were enrolled. Postoperative time was 6-46 months. The patients were followed up in October 2018 and examined using Sniffin' sticks olfactory test and olfactory event-related potentials （oERP）. The polyps collected during surgery were performed to eosinophil count and percentage calculation. They were divided into eosinophilic CRSwNP（ECRS） and non-eosinophilic CRSwNP（NECRS）. The subjective and objective olfactory functions between the two groups were compared before and after surgery respectively and the paired T test was performed between the postoperative and the preoperative Sniffin' sticks olfactory test. Covariance analysis was used to adjust the effect of different postoperative time on postoperative olfactory recovery. Result:There were 21（52.5%） ECRS and 19（47.5%） NECRS patients of the 40 patients with nasal polyps. There was statistical difference in the posterior ethmoid score and the posterior olfactory cleft score of CT. According to the criterion of total TDI increased more than 5.5, olfactory function in 21（52.5%） patients had improved. In addition, there was a significant improvement in olfactory function in ECRS group either in unilateral T/TDI or bilateral T/D/TDI, but only unilateral T/TDI increased in NECRS group. There was no significant difference in Sniffin' sticks olfactory test between the two groups, but there was a statistically significant difference in the latency of oERP after surgery. Conclusion:ESS could improve olfactory function in patients with CRSwNP by more than 50%. Bilateral olfactory improvement in ECRS was better than that in NECRS, but olfactory function in postoperative ECRS was still lower than that in NECRS. oERP can more objectively and accurately reflect the severity of olfactory disorders associated with eosinophilic inflammation.

[Clinical features and treatment outcome of inflammatory myofibroblastic tumor of the paranasal sinus]

Objective: To investigate the clinicopathological features and the clinical characteristics of inflammatory myofibroblastic tumor(IMT) of paranasal sinus. Method: Five cases of IMT of paranasal sinus treated from 2011 to 2018 were analyzed retrospectively. Of the 5 patients, CT and MRI were performed before operation. All tumors originated from paranasal sinus, and orbital, pterygopalatine fossa and palate was involved with variable degrees. All patients had been given operation and recovered well. Two cases received additional glucocorticoid therapy(prednisone) postoperatively. Result: After a follow-up of 3-80 months, one case recurred 2 years postoperatively and received surgery again. No recurrence was found after operation in the other four patients. The finial diagnosis depended on pathological findings. Postoperative pathological examination showed that the tumor cells were mainly composed of spindle fibroblasts and chronic inflammatory cells. Immunohistochemical staining showed positive expression of SMA protein. Conclusion: IMT of paranasal sinus is a rare clinical entity without specific clinical manifestations and the extent of the lesion can be assessed by imaging examinations. Pathological examination is required for final diagnosis. Radical resection should be taken for limited lesions. Besides surgery, corticosteroid administration and irradiation therapy is recommended in some circumstances. The overall prognosis is good.

[Comparison and analysis of spontaneous cerebrospinal fluid rhinorrhea with and without empty sella patients]

Objective:To investigate the clinical characteristics and the diagnosis and treatment of spontaneous cerebrospinal fluid rhinorrhea with and without empty sella.Method: Retrospective analysis clinical data of 51 patients with spontaneous cerebrospinal fluid rhinorrhea，comparison of non-empty sella syndrome of spontaneous cerebrospinal fluid rhinorrhea with empty sella syndrome of spontaneous cerebrospinal fluid rhinorrhea patients with general characteristics，localization and treatment effect.Result:The incidence of spontaneous cerebrospinal fluid rhinorrhea patients was higher in females than in males，BMI index was higher than the normal value.Of these 51 patients，5 of them were discharged after conservative treatment.Endoscopic sinus surgery was performed in 46 cases，of which 4 cases recurred and all had empty sella syndrome，the success rate of surgical repair was 91.3%.The age of empty sella group，the proportion of high blood pressure and the number of patients with surgical recurrence were significantly higher than those in the non-empty sella group（P<0.05）.The defect locations of two groups were most common in the ethmoid roof，there were no statistically significant differences in each defect location （P＞0.05）. Conclusion:The spontaneous cerebrospinal fluid leak was common in obese middle-aged women，most common defect location in ethmoid roof，nasal endoscopic repair success rate was high，with empty sella surgery were more likely to recur.

Highly Variable Expression of ESR1 Splice Variants in Human Liver: Implication in the Liver Gene Expression Regulation and Inter-Person Variability in Drug Metabolism and Liver Related Diseases

Estrogen receptor alpha (ESR1) plays an important role in many tissues including the liver. Numerous alternative splice variants of ESR1 exist that encode ESR1 proteins with varying functions. We aim to study ESR1 genomic organization and its mRNA expression profile in human liver by incorporating information from literature and genomic databases (Ensembl, NCBI and GTEx), and employing a quantitative method to measure all known ESR1 mRNA splice variants in 36 human livers. We re-constructed ESR1 genomic organization map that contains 29 exons. ESR1 mRNA splice variants with varying 5' untranslated region (5'UTR) and/or missing each of eight coding exons are readily detectable in liver and other tissues. Moreover, we found extensive inter-individual variability in splice variant pattern of ESR1 transcripts. Specifically, ESR1 transcripts lacking first coding exon are the main transcripts in liver, which encode ESR1 proteins missing N-terminal 173 amino acids (for example, ERα46), reported previously to have either constitutive activity or dominant negative effects depending on cellular context. Moreover, some livers predominantly express ESR1 transcripts missing exon 10 or 16, encoding C-terminal truncated ESR1 proteins with varying ESR1 activities. Inter-person variability in ESR1 expression profile may contribute to inter-person variability in drug metabolism and susceptibility to liver related diseases.

[Clinical application of pedicel frontal flap in reconstruction of the nasal defects]

Objective:The aim of this study is to explorethe application of improving the design of the myocutaneous flap and the transfer mode in nasal facial defect. Method:Six cases with nasal defects were treated by using lateral or median vascular frontal flap which is nourished by supratrochlear and supraorbital arteries. Three patients with basal cell carcinoma of external nose and three patients with cranial base tumor were hospitalized and underwent surgeries. Result:There were 6 cases in this cohort, with the largest defect being 6.5 cm×3.0 cm and the smallest one being 3.0 cm×2.5 cm in size. Except one patient was missing, the rest of the patients flaps survived, and wounds were healed by first intention. Among 6 patients, 3 patients were treated with lateral forehead flap, 2 patients were treated with median forehead flap, and 1 patient was treated with oblique forehead flap. The follow-up being conducted for 6 months to 12 months, the flaps were normal color and sensation, satisfactory appearance and functional recovery of forehead region. Conclusion:Forearm myocutaneous vessels running more constant, superficial, rich blood supply, easy to dissect and can provide a larger area flap, suitable for different causes of nasal facial defect repair. Large area of flap can be provided. These may be favorable choice for repair of the nasal defects. The tunnel through which the flap was transferred to the defect should be wide enough to avoid flap necrosis because of pedicel flap constriction.

[Application of modified brain protection double-lumen drainage tube in external drainage of chronic subdural hematoma]

Objective: To compare the clinical effects of modified double-lumen drainage tube and traditional silicone tube in external drainage of chronic subdural hematoma. Methods: Selected 49 patients suffering from chronic subdural hematoma hospitalized in the Department of Neurosurgery, the First Affiliated Hospital of Bengbu Medical College between July 2016 and June 2018 who underwent external drainage, and divided them randomly into experimental groups (using modified brain protection double lumen drainage tube in 23 cases) and control group (using traditional silicone drainage tube in 26 cases). Comparison of postoperative hematoma residual volume, the tube indwelling time, the numbers of drainage tube contact with brain tissue and arachnoid membrane, the numbers of infections, the numbers of postoperative epilepsy cases, and changes in Modified Rankin Scale scores between the two groups. Results: At the time of extubation, the residual amount of hematoma in the experimental group was (13±7) ml, and that in the control group was (17±8) ml. There was no significantly statistical difference in the residual amount of hematoma between the experimental group and the control group (P>0.05). The tube indwelling time of the experimental group was (2.0±0.9) days, and that of the control group was (2.7±0.8) days. The difference between the experimental group and the control group in the drainage tube indwelling time was statistically significant (P<0.05). No cases of drainage tube contact with brain tissue and/or arachnoid membrane appeared in the experimental group, and 7 cases of drainage tube contact with brain tissue or arachnoid membrane appeared in the control group. No infection occurred in both groups. No cases of epilepsy occurred in preoperative, and there were 0 cases of epilepsy in the experimental group and 1 case in the control group in postoperative. There were significantly statistical differences in each of the two groups in the modified Rankin scale before and after surgery (P<0.001), there was no significant difference in postoperative Modified Rankin Scale scores between the two groups. Conclusion: The modified brain protection double-lumen drainage tube has good drainage effect in the external drainage of chronic subdural hematoma, and the short tube retention time, causing fewer complications. It is a safe and effective tool for treating chronic subdural hematoma, and it is worthy of clinical promotion.

[Risk factors analysis for recurrence of the idiopathic benign paroxysmal positional vertigo]

Objective:To study the risk factors of recurrence in patients with benign paroxysmal positional vertigo(BPPV) after successful repositioning treatment. Method: Two hundred and two cases of confirmed BPPV patients, were followed-up for 10 months after particle repositioning, and the incidence of recurrence was analyzed. The risk factors for recurrence were analyzed by logistic regression. Result: 51 out of 202 confirmed BPPV patients complained of recurrence. There was significant difference of the duration of vertigo before treatment, the times of repositioning and SDS between the two group(P<0.05). While the sex, the age, the incubation period of BPPV, the duration time of BPPV, underlying diseases and the type of canal were not associated with the residual dizziness(P>0.05). Logistic regression analysis showed that the times of repositioning and the SDS were the risk factor for residual dizziness. Conclusion:The effective repositioning and the psychological care are very important to reduce the recurrence of BPPV.

[Treatment of high-risk and complicate foreign bodies in respiratory tract]

Objective:To explore the treatment of the high-risk and complicate foreign bodies in respiratory tract. Method:Retrospective analysis of 3 330 cases of respiratory foreign bodies were performed, from 2003 January to 2016 November, including 205 cases of high-risk and complicate cases, foreign bodies including plastic caps, plastic or glass lamp beads, animal bones, metal objects, and foreign bodies such as peanuts. Result:In one hundred and seventy-five cases, foreign bodies were taken out directly by hard bronchoscope, in twenty-eight cases, foreign bodies were removed by fiberoptic bronchoscope, one case of foreign body was removed with thoracotomy and one case of foreign body died. Conclusion::To treat high-risk foreign bodies in respiratory tract, sufficient preoperative preparation or rapid response are both important, including selecting the appropriate equipment, surgery and anesthesia, in order to successfully remove the foreign body and minimize complications.

Effect of the absence of the CcpA gene on growth, metabolic production, and stress tolerance in Lactobacillus delbrueckii ssp. bulgaricus

The catabolite control protein A (CcpA) is a kind of multi-effect regulatory protein. In the study, the effect of the inactivation of CcpA and aerobic conditions on the growth, metabolic production, and stress tolerance to heat, oxidative, and cold stresses in Lactobacillus delbrueckii ssp. bulgaricus was investigated. Results showed that inactivation of CcpA distinctly hindered growth. Total lactic acid concentration was significantly lower in aerobiosis for both strains and was lower for the mutant strain than L. bulgaricus. Acetic acid production from the mutant strain was higher than L. bulgaricus in aerobiosis compared with anaerobiosis. Enzyme activities, lactate dehydrogenase (LDH), phosphate fructose kinase (PFK), pyruvate kinase (PK), and pyruvic dehydrogenase (PDH), were significantly lower in the mutant strain than L. bulgaricus. The diameters of inhibition zone were 13.59 ± 0.02 mm and 9.76 ± 0.02 mm for L. bulgaricus in anaerobiosis and aerobiosis, respectively; and 8.12 ± 0.02 mm and 7.38 ± 0.02 mm for the mutant in anaerobiosis and aerobiosis, respectively. For both strains, cells grown under aerobic environment possess more stress tolerance. This is the first study in which the CcpA-negative mutant of L. bulgaricus is constructed and the effect of aerobic growth on stress tolerance of L. bulgaricus is evaluated. Although aerobic cultivation does not significantly improve growth, it does improve stress tolerance.

Endoscopic endonasal surgery for pterygopalatine fossa schwannoma via prelacrimal recess-maxillary sinus

OBJECTIVE

To explore a new approach for treating pterygopalatine fossa (PPF) schwannomas via endoscopic transnasal prelacrimal recess-maxillary sinus (MS).

METHODOLOGY

Five patients with PPF schwannomas underwent surgical resection of the tumors using this approach.

RESULTS

All patients had adequate exposure and complete tumor resection. No major postoperative complications were observed. No evidence of tumor recurrence was noted after follow-up with magnetic resonance imaging and serial evaluations for 12 to 40 months postoperatively. No patients had epiphora, and the shape of the inferior turbinate (IT) was favorable.

CONCLUSIONS

Treatment of PPF schwannoma via endoscopic transnasal prelacrimal recess-MS is safe and effective. Additionally, this approach is minimally invasive not only for the PPF, from which the benign lesions can be completely removed, but also for the MS. This is especially true with lesions of the prelacrimal and alveolar recesses that can be resected. This approach is necessary to prevent structural and functional damage of the nasal cavity, especially the IT and nasolacrimal duct, allowing better healing with decreased morbidity and shorter recovery periods.

[Effect of Qingyi Chengqi Decoction on severe acute pancreatitis patients: a clinical study]

OBJECTIVE

To observe the change of intra-abdominal pressure (IAP) in severe acute pancreatitis (SAP) patients, and to study the effect of Qingyi Chengqi Decoction (QCD) on it.

METHODS

Eighty-six SAP patients from Department of General Surgery and Department of Digestive Diseases, Qingyang People's Hospital, Gansu Province, who were in line with diagnosis standard of SAP, were assigned to the treatment group (44 cases) and the control group (42 cases) from March 2012 to May 2013. All patients received routine Western medicine. Those in the treatment group took QCD additionally. Main clinical symptoms and APACHE II were observed. The serum levels of amylase (AMY), C-reactive protein (CRP), and IAP were examined. The incidence of secondary infection rate (SIR), drainage rate (percutaneous catheter drainage and operation), mortality, and mean days in ward were also recorded.

RESULTS

Main clinical symptoms were significantly improved in the treatment group. APACHE II score, serum levels of AMY, CRP, and IAP obviously decreased in the treatment group. The incidence of SIR, drainage rate, and the mortality were also significantly lower in the treatment group than in the control group. The mean days in ward were also markedly shortened (P < 0.01).

CONCLUSION

QCD could relieve inflammatory response, lower IAP, SIR, and mortality, increase the curative rate and improve the prognosis of SAP.

Effective process to achieve enhanced electrochromic performances based on poly(4,4',4″-tris[4-(2-bithienyl)pheny]amine)/ZnO nanorod composites

Poly(4,4',4″-tris[4-(2-bithienyl)pheny]amine) (PTBTPA) was electrochemically synthesized on a ZnO-coated ITO electrode to form a PTBTPA/ZnO nanocomposite electrode. The composite film exhibited a noticeable electrochromism, with reversible color changes from orange in the reduced state (0 V), olive green in the middle state (0.9 V) to dark gray in the oxidized state (1.2 V). Furthermore, the composite film showed a fast switching time of 0.92 s and a high optical contrast of 65% at 1100 nm, and retained 97% of its original electroactivity after 500 cycles, while PTBTPA film had switching time of 1.63 s and an optical contrast of 52% at 1100 nm, and retained 75% of its original electroactivity. The results demonstrated that the electrochromic performances were significantly enhanced through incorporating PTBTPA with ZnO nanorods. ZnO nanorods were introduced to modify the structure of the electrode: on one hand, to offer a directional attraction for the counterions, and on the other hand, to enhance the adhesion between the polymer and the ITO electrode. Accordingly, a conducting polymer/inorganic nanocomposite system could improve the polymer's electrochromic performance, especially in terms of the switching speed and long-term stability of the electrochromic materials.

RLS adaptive filtering for physiological interference reduction in NIRS brain activity measurement: a Monte Carlo study

The non-invasive measurement of cerebral functional haemodynamics using near-infrared spectroscopy (NIRS) instruments is often affected by physiological interference. The suppression of this interference is crucial for reliable recovery of brain activity measurements because it can significantly affect the signal quality. In this study, we present a recursive least-squares (RLS) algorithm for adaptive filtering to reduce the magnitude of the physiological interference component. To evaluate it, we implemented Monte Carlo simulations based on a five-layer slab model of a human adult head with a multidistance source-detector arrangement, of a short pair and a long pair, for NIRS measurement. We derived measurements by adopting different interoptode distances, which is relevant to the process of optimizing the NIRS probe configuration. Both RLS and least mean squares (LMS) algorithms were used to attempt the removal of physiological interference. The results suggest that the RLS algorithm is more capable of minimizing the effect of physiological interference due to its advantages of faster convergence and smaller mean squared error (MSE). The influence of superficial layer thickness on the performance of the RLS algorithm was also investigated. We found that the near-detector position is an important variable in minimizing the MSE and a short source-detector separation less than 9 mm is robust to superficial layer thickness variation.

[The spatial distribution and dynamics of human rabies cases at the county level in Henan province]

OBJECTIVE

To study the spatial distribution and dynamics of human rabies cases at the county level, in Henan province to provide scientific evidence for the development of control program on rabies.

METHODS

Data of human rabies cases at the county level from 2004 to 2010 in Henan province were analyzed by Poisson distribution and negative binomial distribution. Data calculation was conducted manually.

RESULTS

According to the level of α = 0.05 being set, there were three different results appeared:the first was fitted negative binomial distribution in 2004, 2005, 2007 and 2009; the second was prioritized negative binomial distribution, but the poisson distribution could not be excluded in 2008 and 2010;the last one was fitted neither negative binomial distribution nor poisson distribution in 2006. By the clustering parameter k, the clustering degree at county level decreased from 2004 to 2008, then ascending in 2009 but descending again in 2010. The degree of clustering showed a positive correlation with the county mean cases in the prevalent counties (r = 0.807, P = 0.028).

CONCLUSION

As a whole, the distribution of human rabies at county level in Henan from 2004 to 2010 showed negative binomial distribution and presented the spatial clustering. However, the degree of clustering decreased in recent years and showed that the infection resource was possibly scattered more evenly at the county level.

[A study on the bonding properties of four resin cements]

OBJECTIVE

To evaluate the dentin and enamel bonding strength and resin-dentin interfaces of four resin cements.

METHODS

Twenty-four sound freshly extracted molars were sectioned with low-speed saw under running water. Two mesial-distal enamel disc and two buccal-lingual dentin discs were sectioned from each molar. Four resin cements (A group: Panavia(TM) F; B group: RelyX(TM) ARC; C group: RelyX(TM) Unicem; D group: Clearfil(TM) SA Cement) were applied to the surface of these enamel and dentin discs according to manufacturers' guidance. The bonded specimen were prepared for shear bond strength test and sectioned occluso-gingivally into two slabs for scanning electron microscopy (SEM) observation.

RESULTS

The bonding strength between resin and enamel in B group [(29.38 ± 6.28) MPa] was higher than that in D group [(27.25 ± 7.03) MPa], and both of them were significantly higher than those in A [(22.92 ± 7.13) MPa] and C group [(10.92 ± 3.41) MPa] (P < 0.05). The highest dentin bonding strength was shown in B group [(27.28 ± 6.79) MPa], followed by A [(14.23 ± 6.39) MPa], D [(10.09 ± 3.26) MPa] and C group [(6.43 ± 1.60) MPa, P < 0.05].

CONCLUSIONS

The four resin cements have different enamel or dentin bonding properties.

First Record of the Cereal Cyst Nematode Heterodera filipjevi in China

Cereal cyst nematode (CCN) is now recognized as a widespread and often damaging parasite of wheat in China. Only Heterodera avenae has been reported in China (4). However, molecular analysis of four samples from Beijing and one from Shanxi Province indicated genetic differences from H. avenae and other named species (3). Here we report the detection of H. filipjevi at a site in Henan Province that was not included in any previous study or report. The infested crop was rainfed winter wheat (Triticum aestivum) cv. Wenmai 19 in a field near Banpopu Village in Xuchang County (34.0447°N, 113.7415°E) with a long-established maize-wheat semiannual crop rotation. During the winter growing season, the crop was patchy with uneven growth and cyst nematode females were observed on the roots. In June 2009, soil was collected and mature cysts were extracted for morphological and molecular identification. Cysts were also kept at 4°C for 2 months and then incubated in shallow water at 15°C for a month to obtain second-stage juveniles (J2). Measurements (range; mean ± sd) of 10 cysts were body length including neck (569 to 786 μm; 699 ± 56), body width (403 to 600 μm; 523 ± 55), length:width ratio (1.3 to 1.5; 1.3 ± 0.1), neck length (61 to 125 μm; 106 ± 19) and width (49 to 83 μm; 69 ± 13), fenestra length (52 to 59 μm; 57 ± 2.9) and width (24.5 to 34.4; 27.9 ± 3.5), underbridge (64 to 101 μm; 85 ± 10), and vulval slit (7.4 to 10.0 μm; 9.6 ± 1.0). Lemon-shaped cysts were brown with a surface zigzag pattern. The vulval cone was bifenestrate with horseshoe-shaped semifenestra, with heavy underbridge and many bullae. The J2 (n = 22) measurements were body length (496 to 590 μm; 552 ± 24), body width (20.0 to 23.8; 21.5 ± 0.9), stylet (22.8 to 25.3; 24.0 ± 1.0) with anchor-shaped basal knobs, tail (47 to 64; 61.6 ± 4.4), and hyaline tail terminus (32 to 43; 40.2 ± 3.0). The J2 had up to four lateral lines, but the inner two were often the only lines clearly visible, and the shape of the stylet knobs, tail, and tail terminus were consistent with H. filipjevi. All morphological data and characters were consistent with H. filipjevi (1). Specimens have been lodged with the Australian National Insect Collection. DNA from single cysts was extracted to amplify the internal transcribed spacer region of rDNA by PCR with forward primer TW81 (5'-GTTTCCGTAGGTGAACCTGC-3') and reverse primer AB28 (5'-ATATGCTTAAGTTCAGCGGGT-3') (2). The PCR product was sequenced (Genbank Accession No. HM027892) and digested by restriction enzymes (AluI, CfoI, HaeI, HinfI, PstI, RsaI, TaqI, and Tru9I) to obtain restriction fragment length polymorphism profiles (2). Profiles for the Xuchang population consistently matched those published for H. filipjevi and were distinct from those of H. avenae and other species (3). Phylogenic analysis of the sequence further indicated conspecificity with H. filipjevi. These morphological and molecular data confirmed that the specimens from Xuchang were H. filipjevi, which represents the first detection of H. filipjevi in China, and extends the known distribution of the species from Europe, North America, South Asia, and West Asia to East Asia. This finding adds complexity to the management of CCN in China, especially for control by host resistance, which now must consider both species and pathotype diversity. References: (1) Z. A. Handoo. J. Nematol. 34:250, 2002. (2) S. A. Subbotin et al. Nematology 2:153, 2000. (3) S. A. Subbotin et al. Nematology 5:515, 2003. (4) H. X. Yuan et al. Australas. Plant Pathol. 39:107, 2010.

Well-width dependence of exciton-longitudinal-optical-phonon coupling in MgZnO/ZnO single quantum wells

The well-width dependence of the exciton-phonon interaction in Mg(0.1)Zn(0.9)O /ZnO single quantum wells (QWs) with a wedged structure was investigated by photoluminescence (PL) measurements at 4 K. Within the Frank-Condon approximation, the Huang-Rhys factor S, as a measure of the coupling strength between the exciton and the longitudinal-optical (LO) phonon, was extracted from the relative intensities between the first-order phonon replica and the zero-phonon peak. It was found that the value of S increased monotonically with the increase of the well width (L(W)). By studying the excitation-density-dependent PL spectra, this result was successfully explained by taking into account the internal electric field originating from the spontaneous and piezoelectric polarizations. The electric field is expected to push electrons and holes to the opposite sides in the well, and consequently results in the increase of S with increasing L(W).

Allelic imbalance on chromosomes 3p, 9p and 17p in malignant progression of laryngeal mucosa

Objectives/hypothesis:

To evaluate the character and significance of microsatellite deoxyribonucleic acid allelic imbalance in laryngeal squamous cell carcinogenesis.

Methods:

We investigated the frequency of expression and clinical relationships of loss of heterozygosity and microsatellite instability in 49 laryngeal premalignant and malignant lesions. Allelic imbalance was analysed using six polymorphic markers (D3S1234, D9S171, D9S1748, D9S162, D9SINFA and D17S796), via polymerase chain reaction – single sequence length polymorphism – silver staining.

Results:

Allelic loss was seen in 3.7 per cent of the six markers in hyperplastic lesions, 10.81 per cent in mild dysplasia, 26.03 per cent in moderate to severe dysplasia, and 38.67 per cent in laryngeal squamous cell carcinoma. Significant associations were found between allelic loss and clinical pathological grades (χ2 = 17.686, p = 0.000). No statistically significant difference was found in the frequency of microsatellite instability (χ2 = 0.314, p > 0.05). In the early stages of neoplastic change, the incidence of microsatellite instability was higher than that of loss of heterozygosity.

Conclusions:

Allelic imbalance was associated with the carcinogenesis and progression of laryngeal squamous cell carcinoma. Microsatellite analysis might provide new approaches to early genetic detection for patients with premalignant laryngeal lesions.

Randomized, prospective study of low-dose versus high-dose inhaled nitric oxide in the neonate with hypoxic respiratory failure

OBJECTIVE

There is little information on the response to very low doses of inhaled nitric oxide (iNO) in hypoxic near-term infants. The potential toxicities of iNO are dose related; thus, the ability to use lower doses safely and effectively may be advantageous. We hypothesized that there is no difference in the acute improvement in oxygenation between treatment with inhaled nitric oxide at 1 to 2 parts per million (ppm) or 10 to 20 ppm.

METHODS

We randomized near-term and term infants with hypoxic respiratory failure with oxygenation indices (OIs) of >/=10 and PaO(2) <100 on 2 separate blood gases taken at least 30 minutes apart. Infants with congenital diaphragmatic hernia were excluded. After parental consent was obtained, patients were randomized to receive a starting nitric oxide (iNO) dose of either 1 to 2 ppm (low-dose group, n = 15) or 10 to 20 ppm (high-dose group, n = 21). The response to iNO was assessed according to the increase in arterial PaO(2) and decrease in OI 30 to 60 minutes after exposure to the initial starting concentration. A response of <10% increase on PaO(2) and a <10% decrease in OI resulted in a doubling of iNO within the dose range protocol (1, 2, 4, and 8 ppm for the low-dose group; 10, 20, 40, and 80 ppm for the high-dose group).

RESULTS

Thirty minutes after the study gas was initiated, PaO(2) increased significantly overall in the low-dose (90.7 +/- 41 torr to 166.8 +/- 95.6 torr) and high-dose (76.2 +/- 32.7 torr to 198.7 +/- 142.8 torr) groups; the maximal increase was seen in the infants who initially were treated with 10 ppm. The OI also decreased significantly overall and also was significant in the high-dose group (21.0 +/- 13.7 to 11.4 +/- 10.4; low-dose: 18.3 +/- 7.1 to 13.2 +/- 12.3). There was a nonsignificant fall of PaCO(2) with iNO treatment (low dose 35 +/- 7.3 to 30 +/- 8.5 torr vs high dose 35.2 +/- 9.9 to 32.4 +/- 10.7 torr). A sustained response (ie, maintaining a PaO(2) and OI gain greater than 20% for the duration of the study gas administration) was greater in the high-dose group (53.3% vs 30.0%). In addition, dose increases were required more often in the low-dose group than in the high-dose group (80.0% vs 57.1%). Among patients who did not respond to the initial iNO dose, 100.0% and 83.3% responded at higher doses of iNO for the low- and high-dose groups, respectively. There were no differences for death, need for extracorporeal membrane oxygenation, or other outcomes between the groups.

CONCLUSIONS

We did not find any significant difference in response to low- versus high-dose iNO. An initial exposure to low-dose iNO does not compromise the response to higher doses if required and may result in less toxicity.

Effects of clonidine on myocardial beta-adrenergic receptor-adenyl cyclase-cAMP system after scalds in rats

AIM

To study the role of clonidine (Clo) on the myocardial beta-adrenergic receptor (beta-AR)-adenyl cyclase (AC)-cAMP system after the scalds in rats.

METHODS

A 30% skin-full-thickness scald was produced by immersing rats in 95 degrees C water for 9 s. Clo 0.1-3.0 mg.kg-1 was injected i.p. to rats at 30 min before scalds, yohimbine (Yoh) 0.05 mg.kg-1 or prazosin (Pra) 0.03 mg.kg-1 to rats at 30 min before i.p. Clo. beta-AR density and affinity, AC activity, phosphoric diester hydrolases (PDH) activity, and cAMP content were determined with radioreceptor assay, indirect method, enzymeradiochemical assay, and radioimmunoassay, respectively.

RESULTS

Clo inhibited the decrease of the myocardial beta-AR density, the attenuation of AC activity, and the reduction of cAMP content at 12 h after the scalds. Yoh partially reversed the effects of Clo on the three parameters. But Pra did not.

CONCLUSION

Clo reversed the changes of the myocardial beta-AR-AC-cAMP system resulted from the scalds in rats.

Purification, characterization, and specificity of dextranase inhibitor (Dei) expressed from Streptococcus sobrinus UAB108 gene cloned in Escherichia coli

The dextranase inhibitor gene (dei) from Streptococcus sobrinus UAB108 was previously cloned, expressed, and sequenced. Its gene product (Dei) has now been purified as a single band with apparent molecular mass of 43 kDa, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The specific activity of Dei increased 121-fold upon purification. Most Dei activity (91.2%) was located in the periplasmic fraction from recombinant Escherichia coli cells. Dei competitively inhibits dextranase (Dex). This competitive inhibition mechanism has been further shown by detection and recovery of the intermediate enzyme-inhibitor (Dex-Dei) complex by gel filtration technology using fast protein liquid chromatography. Calibration of their molecular masses indicated that native Dei exists as a tetramer, Dex exists as dimer, and the Dex-Dei complex consists of two Dex molecules with two Dei molecules. Deletion analysis indicates that the intact Dei molecule is essential for Dei activity but not for glucan binding and immune cross-reaction. Dei is a special kind of glucan-binding protein with ability to inhibit Dex with high specificity. It can inhibit endogenous Dex, which can make more branches in glucan with the cooperation of the glucosyltransferase GTF-I. This inhibition cause the accumulation of water-soluble glucan. The latter reaction product can inhibit plaque formation and adherence of the mutans group of streptococcal cells. Dei derived from S. sobrinus UAB108 can inhibit only Dex from S. sobrinus (serotypes d and g), S. downei (previously S. sobrinus, serotype h), and S. macacae (serotype h). This finding suggests that Dei is another important protein existing in some serotypes of the mutans group of streptococci which participates in sucrose metabolism through its interaction with Dex.

Cloning and DNA sequencing of the dextranase inhibitor gene (dei) from Streptococcus sobrinus

Some dextranase-deficient (Dex-) mutants of Streptococcus sobrinus UAB66 (serotype g) synthesize a substance which inhibits dextranase activity (S.-Y. Wanda, A. Camilli, H. M. Murchison, and R. Curtiss III, J. Bacteriol. 176:7206-7212, 1994). This substance produced by the Dex- mutant UAB108 was designated dextranase inhibitor (Dei) and identified as a protein. The Dei gene (dei) from UAB108 has been cloned into pACYC184 to yield pYA2651, which was then used to generate several subclones (pYA2653 to pYA2657). The DNA sequence of dei was determined by using Tn5seq1 transposon mutagenesis of pYA2653. The open reading frame of dei is 990 bp long. It encodes a signal peptide of 38 amino acids and a mature Dei protein of 292 amino acids with a molecular weight of 31,372. The deduced amino acid sequence of Dei shows various degrees of similarity with glucosyltransferases and glucan-binding protein and contains A and C repeating units probably involved in glucan binding. Southern hybridization results showed that the dei probe from UAB108 hybridized to the same-size fragment in S. sobrinus (serotype d and g) DNA, to a different-size fragment in S. downei (serotype h) and S. cricetus (serotype a), and not at all to DNAs from other mutans group of streptococci.

Adenosine's role in the genesis of bradyarrhythmias induced by acute myocardial hypoxia

A close or even causal relation between myocardial adenosine and bradyarrhythmias during acute myocardial hypoxia was testified in guinea pig, rabbit and dog mainly by using specific competitive antagonist and synchronous quantitative analysis of 3 variables: intensity of myocardial hypoxia, degree of endogenous adenosine increment and severity of bradyarrhythmias. Results disclosed: A) striking resemblance of the bradyarrhythmias with hypoxic origin to those caused by exogenous adenosine, B) same locality of A-V conduction block induced by both myocardial hypoxia and exogenous adenosine, C) precise parallelism among the above-listed 3 variables with very high correlativity (r = 0.99, P < 0.01), D) frequent accompaniment of reversal of hypoxic bradyarrhythmias through resupply of 21% O2 with normalization of preexisted increase in myocardial adenosine, E) satisfactory blockade of hypoxic bradyarrhythmias by adenosine's specific antagonist--aminophylline and their augmentation by adenosine's uptake inhibitor--dipyridamole, F) close similarity of the characteristic curve representing relation among the above 3 variables to that among intensity of myocardial hypoxia, degree of endogenous adenosine increment and amount of coronary blood flow in which adenosine's role as a mediator has been well documented and G) reproducible persistence of bradyarrhythmias during myocardial hypoxia irrespective of preliminary vagotomy and atropinization, denoting independence of the occurrence of such dysarrhythmias upon vagal drive, suggestive of a mechanism other than vagotonia. We advocated that hypoxia-induced bradyarrhythmias was caused by increment in endogenous adenosine.

[Screening of beta-N-acetylhexosaminidase forming strains and conditions for enzyme production]

About 1200 strains of microorganisms were screened including fungi, actinomyces, and bacteria, in which 237 strains producing the enzyme desired. The results showed that the beta-GlcNAcase and beta-GalNAcase always co-existed in one strain, though may be in different ratio. From strains mentioned above the authors screened out a potent beta-N-acetylhexosaminidase producing strain, Aspergillus tamarii S215, from the soil sample. The optimal conditions for enzyme production were as follows: the microorganisms was inoculated in a 5% wheat bran suspension, cultured at 28-30 degrees C on shaker for 5-6 days. The productivity can be moderately enhanced by the addition of cellobiose or glucosamine or galactosamine or by the extra supplement of (NH4)2SO4 and NH4NO3 as N sources. In the culture filtrate of Asp. tamarii, the alpha, (beta)-galactosidase, beta-glucosidase, alpha-mannosidase and beta-fucosidase were also found.