[Reassessment of practice of Chinese surgeons since introduction of the watch and wait strategy after neoadjuvant therapy for rectal cancer]

Objective: To investigate perspectives and changes in treatment selection by Chinese surgeons since introduction of the watch-and-wait approach after neoadjuvant therapy for rectal cancer. Methods: A cross-sectional survey was conducted using a questionnaire distributed through the "Wenjuanxing" online survey platform. The survey focused on the recognition and practices of Chinese surgeons regarding the strategy of watch-and-wait after neoadjuvant therapy for rectal cancer and was disseminated within the China Watch-and-Wait Database (CWWD) WeChat group. This group targets surgeons of deputy chief physician level and above in surgical, radiotherapy, or internal medicine departments of nationally accredited tumor-specialist or comprehensive hospitals (at provincial or municipal levels) who are involved in colorectal cancer diagnosis and treatment. From 13 to 16 December 2023, 321 questionnaires were sent with questionnaire links in the CWWD WeChat group. The questionnaires comprised 32 questions encompassing: (1) basic physician characteristics (including surgical volume); (2) assessment methods and criteria for clinical complete response (cCR); (3) patients eligible for watch-and-wait; (4) neoadjuvant therapies and other measures for achieving cCR; (5) willingness to implement watch-and-wait and factors influencing that willingness; (6) risks and monitoring of watch-and-wait; (7) subsequent treatment and follow-up post watch-and-wait; (8) suggestions for development of the CWWD. Descriptive statistics were employed for data analysis, with intergroup comparisons conducted using the χ2 or Fisher's exact probability tests. Results: The response rate was 31.5%, comprising 101 responses from the 321 individuals in the WeChat group. Respondents comprised 101 physicians from 70 centers across 23 provinces, municipalities, and autonomous regions nationwide, 85.1% (86/101) of whom represented provincial tertiary hospitals. Among the respondents, 87.1% (88/101) had implemented the watch-and-wait strategy. The approval rate (65.6%, 21/32) and proportion of patients often informed (68.8%, 22/32) were both significantly higher for doctors in oncology hospitals than for those in general hospitals (27.7%, 18/65; 32.4%, 22/68) (χ2=12.83, P<0.001; χ2=11.70, P=0.001, respectively). The most used methods for diagnosing cCR were digital rectal examination (90.1%, 91/101), colonoscopy (91.1%, 92/101), and rectal T2-weighted magnetic resonance imaging (86.1%, 87/101). Criteria used to identify cCR comprised absence of a palpable mass on digital rectal examination (87.1%, 88/101), flat white scars or new capillaries on colonoscopy (77.2%, 78/101), absence of evident tumor signals on rectal T2-weighted sequences or T2WI low signals or signals equivalent to the intestinal wall (83.2%, 84/101), and absence of tumor hyperintensity on diffusion-weighted imaging with no corresponding hypointensity on apparent diffusion coefficient maps (66.3%, 67/101). As for selection of neoadjuvant regimen and assessment of cCR, 57.4% (58/101) of physicians preferred a long course of radiotherapy with or without induction and/or consolidation capecitabine + oxaliplatin, whereas 25.7% (26/101) preferred immunotherapy in combination with chemotherapy and concurrent radiotherapy. Most (96.0%, 97/101) physicians believed that the primary lesion should be assessed ≤12 weeks after completion of radiotherapy. Patients were frequently informed about the possibility of achieving cCR after neoadjuvant therapy and the strategy of watch-and-wait by 43.6% (44/101) of the responding physicians and 38.6% (39/101) preferred watch-and-wait for patients who achieved cCR or near cCR after neoadjuvant therapy for rectal cancer. Capability for multiple follow-up evaluations (70.3%, 71/101) was a crucial factor influencing physicians' choice of watch-and-wait after cCR. The proportion who patients who did not achieve cCR and underwent surgical treatment was lower in provincial tertiary hospitals (74.2%, 23/31) than in provincial general hospitals (94.5%, 52/55) and municipal hospitals (12/15); these differences are statistically significant (χ2=7.43, P=0.020). The difference between local recurrence and local regrowth was understood by 88.1% (89/101) of respondents and 87.2% (88/101) agreed with monitoring every 3 months for 5 years. An increase in local excision or puncture rates to reduce organ resections in patients with pCR was proposed by 64.4% (65/101) of respondents. Conclusion: Compared with the results of a previous survey, Chinese surgeons' awareness of the watch-and-wait concept has improved significantly. Oncologists in oncology hospitals are more aware of the concept of watch-and-wait.

Palladium-Catalyzed Cascade Heck Coupling and Allylboration of Iododiboron Compounds via Diboryl Radicals

Geminal bis(boronates) are versatile synthetic building blocks in organic chemistry. The fact that they predominantly serve as nucleophiles in the previous reports, however, has restrained their synthetic potential. Herein we disclose the ambiphilic reactivity of α-halogenated geminal bis(boronates), of which the first catalytic utilization was accomplished by merging a formal Heck cross-coupling with a highly diastereoselective allylboration of aldehydes or imines, providing a new avenue for rapid assembly of polyfunctionalized boron-containing compounds. We demonstrated that this cascade reaction is highly efficient and compatible with various functional groups, and a wide range of heterocycles. In contrast to a classical Pd(0/II) scenario, mechanistic experiments and DFT calculations have provided strong evidence for a catalytic cycle involving Pd(I)/diboryl carbon radical intermediates.

[Effects of gelatin methacrylate anhydride hydrogel loaded with small extracellular vesicles derived from human umbilical cord mesenchymal stem cells in the treatment of full-thickness skin defect wounds in mice]

Objective: To investigate the effects of gelatin methacrylate anhydride (GelMA) hydrogel loaded with small extracellular vesicles derived from human umbilical cord mesenchymal stem cells (hUCMSCs-sEVs) in the treatment of full-thickness skin defect wounds in mice. Methods: This study was an experimental study. hUCMSCs-sEVs were extracted by ultracentrifugation, their morphology was observed through transmission electron microscope, and the expression of CD9, CD63, tumor susceptibility gene 101 (TSG101), and calnexin was detected by Western blotting. The human umbilical vein endothelial cells (HUVECs), the 3rd and 4th passages of human epidermal keratinocytes (HEKs) and human dermal fibroblasts (HDFs) were all divided into blank control group (routinely cultured) and hUCMSC-sEV group (cultured with the cell supernatant containing hUCMSCs-sEVs). The cell scratch test was performed and the cell migration rates at 6, 12, and 24 h after scratching were calculated, the cell Transwell assay was performed and the number of migration cells at 12 h after culture was calculated, and the proportion of proliferating cells was detected by 5-acetylidene-2'-deoxyuridine and Hoechst staining at 24 h after culture, with sample numbers being all 3. The simple GelMA hydrogel and the GelMA hydrogel loaded with hUCMSCs-sEVs (hereinafter referred to as hUCMSC-sEV/GelMA hydrogel) were prepared. Then the micromorphology of 2 kinds of hydrogels was observed under scanning electron microscope, the distribution of hUCMSCs-sEVs was observed by laser scanning confocal microscope, and the cumulative release rates of hUCMSCs-sEVs at 0 (immediately), 2, 4, 6, 8, 10, and 12 d after soaking hUCMSC-sEV/GelMA hydrogel in phosphate buffer solution (PBS) were measured and calculated by protein colorimetric quantification (n=3). Twenty-four 6-week-old male C57BL/6J mice were divided into PBS group, hUCMSC-sEV alone group, GelMA hydrogel alone group, and hUCMSC-sEV/GelMA hydrogel group according to the random number table, with 6 mice in each group, and after the full-thickness skin defect wounds on the back of mice in each group were produced, the wounds were performed with PBS injection, hUCMSC-sEV suspenson injection, simple GelMA coverage, and hUCMSC-sEV/GelMA hydrogel coverage, respectively. Wound healing was observed on post injury day (PID) 0 (immediately), 4, 8, and 12, and the wound healing rates on PID 4, 8, and 12 were calculated, and the wound tissue was collected on PID 12 for hematoxylin-eosin staining to observe the structure of new tissue, with sample numbers being both 6. Results: The extracted hUCMSCs-sEVs showed a cup-shaped structure and expressed CD9, CD63, and TSG101, but barely expressed calnexin. At 6, 12, and 24 h after scratching, the migration rates of HEKs (with t values of 25.94, 20.98, and 20.04, respectively), HDFs (with t values of 3.18, 5.68, and 4.28, respectively), and HUVECs (with t values of 4.32, 19.33, and 4.00, respectively) in hUCMSC-sEV group were significantly higher than those in blank control group (P<0.05). At 12 h after culture, the numbers of migrated HEKs, HDFs, and HUVECs in hUCMSC-sEV group were 550±23, 235±9, and 856±35, respectively, which were significantly higher than 188±14, 97±6, and 370±32 in blank control group (with t values of 22.95, 23.13, and 17.84, respectively, P<0.05). At 24 h after culture, the proportions of proliferating cells of HEKs, HDFs, and HUVECs in hUCMSC-sEV group were significantly higher than those in blank control group (with t values of 22.00, 13.82, and 32.32, respectively, P<0.05). The inside of simple GelMA hydrogel showed a loose and porous sponge-like structure, and hUCMSCs-sEVs was not observed in it. The hUCMSC-sEV/GelMA hydrogel had the same sponge-like structure, and hUCMSCs-sEVs were uniformly distributed in clumps. The cumulative release rate curve of hUCMSCs-sEVs from hUCMSC-sEV/GelMA hydrogel tended to plateau at 2 d after soaking, and the cumulative release rate of hUCMSCs-sEVs was (59.2±1.8)% at 12 d after soaking. From PID 0 to 12, the wound areas of mice in the 4 groups gradually decreased. On PID 4, 8, and 12, the wound healing rates of mice in hUCMSC-sEV/GelMA hydrogel group were significantly higher than those in the other 3 groups (P<0.05); the wound healing rates of mice in GelMA hydrogel alone group and hUCMSC-sEV alone group were significantly higher than those in PBS group (P<0.05). On PID 8 and 12, the wound healing rates of mice in hUCMSC-sEV alone group were significantly higher than those in GelMA hydrogel alone group (P<0.05). On PID 12, the wounds of mice in hUCMSC-sEV/GelMA hydrogel group showed the best wound epithelization, loose and orderly arrangement of dermal collagen, and the least number of inflammatory cells, while the dense arrangement of dermal collagen and varying degrees of inflammatory cell infiltration were observed in the wounds of mice in the other 3 groups. Conclusions: hUCMSCs-sEVs can promote the migration and proliferation of HEKs, HDFs, and HUVECs which are related to skin wound healing, and slowly release in GelMA hydrogel. The hUCMSC-sEV/GelMA hydrogel as a wound dressing can significantly improve the healing speed of full-thickness skin defect wounds in mice.

Uridine diphosphate glucuronosyltransferase 1A1 prevents the progression of liver injury

BACKGROUND

Uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) plays a crucial role in metabolizing and detoxifying endogenous and exogenous substances. However, its contribution to the progression of liver damage remains unclear.

AIM

To determine the role and mechanism of UGT1A1 in liver damage progression.

METHODS

We investigated the relationship between UGT1A1 expression and liver injury through clinical research. Additionally, the impact and mechanism of UGT1A1 on the progression of liver injury was analyzed through a mouse model study.

RESULTS

Patients with UGT1A1 gene mutations showed varying degrees of liver damage, while patients with acute-on-chronic liver failure (ACLF) exhibited relatively reduced levels of UGT1A1 protein in the liver as compared to patients with chronic hepatitis. This suggests that low UGT1A1 levels may be associated with the progression of liver damage. In mouse models of liver injury induced by carbon tetrachloride (CCl4) and concanavalin A (ConA), the hepatic levels of UGT1A1 protein were found to be increased. In mice with lipopolysaccharide or liver steatosis-mediated liver-injury progression, the hepatic protein levels of UGT1A1 were decreased, which is consistent with the observations in patients with ACLF. UGT1A1 knockout exacerbated CCl4- and ConA-induced liver injury, hepatocyte apoptosis and necroptosis in mice, intensified hepatocyte endoplasmic reticulum (ER) stress and oxidative stress, and disrupted lipid metabolism.

CONCLUSION

UGT1A1 is upregulated as a compensatory response during liver injury, and interference with this upregulation process may worsen liver injury. UGT1A1 reduces ER stress, oxidative stress, and lipid metabolism disorder, thereby mitigating hepatocyte apoptosis and necroptosis.

Sulfonamides (SAs) exposure causes neurobehavioral toxicity at environmentally relevant concentrations (ERCs) in early development of zebrafish

Antibiotics, due to their stability and persistence in the environment, can have chronic impacts on various ecosystems and organisms. However, the molecular mechanisms underlying antibiotic toxicity at environmental concentrations, particularly the neurotoxic effects of sulfonamides (SAs), remain poorly understood. In this study, we assessed the neurotoxicity of six SAs including the sulfadiazine (SD), sulfathiazole (ST), sulfamethoxazole (SMX), sulfisoxazole (SIZ), sulfapyridine (SPD), and sulfadimethoxine (SDM) by exposing zebrafish to environmentally relevant concentrations (ERCs). The SAs exhibited concentration-dependent effects on zebrafish behavior, including spontaneous movement, heartbeat, survival rate, and body metrics, ultimately leading to depressive-like symptoms and sublethal toxicity during early life stages. Notably, even the lowest SA concentration (0.05 μg/L) induced neurotoxicity and behavioral impairment in zebrafish. We observed a dose-dependent increase in melancholy behavior as indicated by increased resting time and decreased motor activity in zebrafish larvae. Following exposure to SAs from 4 to 120 h post-fertilization (hpf), key genes involved in folate synthesis [sepiapterin reductase a (spra), phenylalanine hydroxylase (pah), tyrosine hydroxylase (th), and tryptophan hydroxylase 1 (tryptophan 5-monooxygenase) a tryptophan hydroxylase (tph1a)] and carbonic anhydrase (CA) metabolism [carbonic anhydrase II (ca2), carbonic anhydrase IV a (ca4a), carbonic anhydrase VII (ca7), and carbonic anhydrase XIV (ca14)] were significantly downregulated or inhibited at different concentrations. Our findings demonstrate that acute exposure to six SAs at environmentally relevant concentrations induces developmental and neurotoxic effects in zebrafish, impacting folate synthesis pathways and CA metabolism. These results provide valuable insights into the potential role of antibiotics in depressive disorders and neuroregulatory pathways.

Real-space observation of ultraconfined in-plane anisotropic acoustic terahertz plasmon polaritons

Thin layers of in-plane anisotropic materials can support ultraconfined polaritons, whose wavelengths depend on the propagation direction. Such polaritons hold potential for the exploration of fundamental material properties and the development of novel nanophotonic devices. However, the real-space observation of ultraconfined in-plane anisotropic plasmon polaritons (PPs)-which exist in much broader spectral ranges than phonon polaritons-has been elusive. Here we apply terahertz nanoscopy to image in-plane anisotropic low-energy PPs in monoclinic Ag₂Te platelets. The hybridization of the PPs with their mirror image-by placing the platelets above a Au layer-increases the direction-dependent relative polariton propagation length and the directional polariton confinement. This allows for verifying a linear dispersion and elliptical isofrequency contour in momentum space, revealing in-plane anisotropic acoustic terahertz PPs. Our work shows high-symmetry (elliptical) polaritons on low-symmetry (monoclinic) crystals and demonstrates the use of terahertz PPs for local measurements of anisotropic charge carrier masses and damping.

Fibulin2: a negative regulator of BMSC osteogenic differentiation in infected bone fracture healing

Bone fracture remains a common occurrence, with a population-weighted incidence of approximately 3.21 per 1000. In addition, approximately 2% to 50% of patients with skeletal fractures will develop an infection, one of the causes of disordered bone healing. Dysfunction of bone marrow mesenchymal stem cells (BMSCs) plays a key role in disordered bone repair. However, the specific mechanisms underlying BMSC dysfunction caused by bone infection are largely unknown. In this study, we discovered that Fibulin2 expression was upregulated in infected bone tissues and that BMSCs were the source of infection-induced Fibulin2. Importantly, Fibulin2 knockout accelerated mineralized bone formation during skeletal development and inhibited inflammatory bone resorption. We demonstrated that Fibulin2 suppressed BMSC osteogenic differentiation by binding to Notch2 and inactivating the Notch2 signaling pathway. Moreover, Fibulin2 knockdown restored Notch2 pathway activation and promoted BMSC osteogenesis; these outcomes were abolished by DAPT, a Notch inhibitor. Furthermore, transplanted Fibulin2 knockdown BMSCs displayed better bone repair potential in vivo. Altogether, Fibulin2 is a negative regulator of BMSC osteogenic differentiation that inhibits osteogenesis by inactivating the Notch2 signaling pathway in infected bone.

[Establishment and application of the ten-fold rehydration formula for emergency resuscitation of pediatric patients after extensive burns]

Objective: To investigate the scientificity and feasibility of the ten-fold rehydration formula for emergency resuscitation of pediatric patients after extensive burns. Methods: A retrospective observational study was conducted. The total burn area of 30%-100% total body surface area (TBSA) and body weight of 6-50 kg in 433 pediatric patients (250 males and 183 females, aged 3 months to 14 years) with extensive burns who met the inclusion criteria and admitted to the burn departments of 72 Class A tertiary hospitals were collected. The 6 319 pairs of simulated data were constructed after pairing each body weight of 6-50 kg (programmed in steps of 0.5 kg) and each total burn area of 30%-100% TBSA (programmed in steps of 1%TBSA). They were put into three accepted pediatric rehydration formulae, namely the commonly used domestic pediatric rehydration formula for burn patients (hereinafter referred to as the domestic rehydration formula), the Galveston formula, and the Cincinnati formula, and the two rehydration formulae for pediatric emergency, namely the simplified resuscitation formula for emergency care of patients with extensive burns proposed by the World Health Organization's Technical Working Group on Burns (TWGB, hereinafter referred to as the TWGB formula) and the pediatric ten-fold rehydration formula proposed by the author of this article--rehydration rate (mL/h)=body weight (kg) × 10 (mL·kg-1·h-1) to calculate the rehydration rate within 8 h post injury (hereinafter referred to as the rehydration rate). The range of the results of the 3 accepted pediatric rehydration formulae ±20% were regarded as the reasonable rehydration rate, and the accuracy rates of rehydration rate calculated using the two pediatric emergency rehydration formulae were compared. Using the maximum burn areas (55% and 85% TBSA) corresponding to the reasonable rehydration rate calculated by the pediatric ten-fold rehydration formula at the body weight of 6 and 50 kg respectively, the total burn area of 30% to 100% TBSA was divided into 3 segments and the accuracy rates of the rehydration rate calculated using the 2 pediatric emergency rehydration formulae in each segment were compared. When neither of the rehydration rates calculated by the 2 pediatric emergency rehydration formulae was reasonable, the differences between the two rehydration rates were compared. The distribution of 433 pediatric patients in the 3 previous total burn area segments was counted and the accuracy rates of the rehydration rate calculated using the 2 pediatric emergency rehydration formulae were calculated and compared. Data were statistically analyzed with McNemar test. Results: Substitution of 6 319 pairs of simulated data showed that the accuracy rates of the rehydration rates calculated by the pediatric ten-fold rehydration formula was 73.92% (4 671/6 319), which was significantly higher than 4.02% (254/6 319) of the TWGB formula (χ2=6 490.88,P<0.05). When the total burn area was 30%-55% and 56%-85% TBSA, the accuracy rates of the rehydration rates calculated by the pediatric ten-fold rehydration formula were 100% (2 314/2 314) and 88.28% (2 357/2 670), respectively, which were significantly higher than 10.98% (254/2 314) and 0 (0/2 670) of the TWGB formula (with χ2 values of 3 712.49 and 4 227.97, respectively, P<0.05); when the total burn area was 86%-100% TBSA, the accuracy rates of the rehydration rates calculated by the pediatric ten-fold rehydration formula and the TWGB formula were 0 (0/1 335). When the rehydration rates calculated by the 2 pediatric emergency rehydration formulae were unreasonable, the rehydration rates calculated by the pediatric ten-fold rehydration formula were all higher than those of the TWGB formula. There were 93.07% (403/433), 5.77% (25/433), and 1.15% (5/433) patients in the 433 pediatric patients had total burn area of 30%-55%, 56%-85%, and 86%-100% TBSA, respectively, and the accuracy rate of the rehydration rate calculated using the pediatric ten-fold rehydration formula was 97.69% (423/433), which was significantly higher than 0 (0/433) of the TWGB formula (χ2=826.90, P<0.05). Conclusions: The application of the pediatric ten-fold rehydration formula to estimate the rehydration rate of pediatric patients after extensive burns is more accurate and convenient, superior to the TWGB formula, suitable for application by front-line healthcare workers that are not specialized in burns in pre-admission rescue of pediatric patients with extensive burns, and is worthy of promotion.

[Summary of community smoking cessation intervention theory]

This paper analyzes the literatures about community-based smoking cessation interventions in recent decades and introduces the effectiveness of cessation interventions developed under different theoretical frameworks applied in the community. Because of the severe smoking prevalence in China and the shortage of existing smoking cessation services, the application of smoking cessation services in reducing the smoking rate in Chinese is discussed to provide a reference for the theoretical framework and practical application of community smoking cessation intervention research in China.

K63 Ubiquitination of P21 Can Facilitate Pellino-1 in the Context of Chronic Obstructive Pulmonary Disease and Lung Cellular Senescence

Chronic obstructive pulmonary diseases (COPD) is a kind of age-related, airflow-obstruction disease mostly caused by cigarette smoke. However, the relationship between COPD and lung cellular senescence is still not fully understood. Here, we found silencing Pellino-1 could inhibit the protein level of P21. Then, through constructing cell lines expressed ubiquitin-HA, we found that the E3 ubiquitin ligase Pellino-1 could bind to senescence marker p21 and modify p21 by K63-site ubiquitination by co-IP assays. Furthermore, we found that p21-mediated lung cellular senescence could be inhibited by silencing Pellino-1 in a D-galactose senescence mice model. Moreover, by constructing a COPD mouse model with shPellino-1 adenovirus, we found that silencing Pellino-1 could inhibit COPD and inflammation via reduction of SASPs regulated by p21. Taken together, our study findings elucidated that silencing E3 ligase Pellino-1 exhibits therapeutic potential for treatment to attenuate the progression of lung cellular senescence and COPD.

Two new dinor-eudesmane sesquiterpenoids from the roots of Chloranthus multistachys

Two new dinor-eudesmane sesquiterpenoids, named multistalin A (1), and multistalin B (2), together with three sesquiterpene glycosides (3-5), and a norlabdane-type diterpene (6) were isolated from the root extract of Chloranthus multistachys Pei. Their structures were elucidated on the basis of spectroscopic analysis including 1D, 2D NMR techniques and HR-ESI-MS. In addition, the cytotoxicity activities of the isolated compounds against selected cancer cells (Hela and A-549) were evaluated by MTT assay.

Radical modulated regioselective difunctionalization of vinyl enynes: tunable access to naphthalen-1(2H)-ones and allenic alcohols

A novel and efficient radical-modulated difunctionalization of vinyl enynes has been disclosed using TEMPO as a radical regulator. Facile access to structurally diverse 3-bromo-naphthalen-1(2H)-ones and 4-bromo-allenic alcohols was realized via 1,2-addition/1,2-migration or 1,4-addition, respectively. This protocol represents the first example of radical-modulated metal-free difunctionalization of 1,3-enynes with high regioselectivity.

Identifying novel therapeutic targets in gastric cancer using genome-wide CRISPR-Cas9 screening

Genome-scale CRISPR-Cas9 screening technology is a powerful tool to systematically identify genes essential for cancer cell survival. Herein, TKOv3, a genome-scale CRISPR-Cas9 knock-out library, was screened in the gastric cancer (GC) cells, and relevant validation experiments were performed. We obtained 854 essential genes for the AGS cell line, and 184 were novel essential genes. After knocking down essential genes: SPC25, DHX37, ABCE1, SNRPB, TOP3A, RUVBL1, CIT, TACC3 and MTBP, cell viability and proliferation were significantly decreased. Then, we analysed the detected essential genes at different time points and proved more characteristic genes might appear with the extension of selection. After progressive selection using a series of open datasets, 41 essential genes were identified as potential drug targets. Among them, methyltransferase 1 (METTL1) was over expressed in GC tissues. High METTL1 expression was associated with poor prognosis among 3 of 6 GC cohorts. Furthermore, GC cells growth was significantly inhibited after the down-regulation of METTL1 in vitro and in vivo. Function analysis revealed that METTL1 might play a role in the cell cycle through AKT/STAT3 pathways. In conclusion, compared with existing genome-scale screenings, we obtained 184 novel essential genes. Among them, METTL1 was validated as a potential therapeutic target of GC.

A bimodal burst energy distribution of a repeating fast radio burst source

The event rate, energy distribution and time-domain behaviour of repeating fast radio bursts (FRBs) contain essential information regarding their physical nature and central engine, which are as yet unknown^1,2. As the first precisely localized source, FRB 121102 (refs. ^3-5) has been extensively observed and shows non-Poisson clustering of bursts over time and a power-law energy distribution^6-8. However, the extent of the energy distribution towards the fainter end was not known. Here we report the detection of 1,652 independent bursts with a peak burst rate of 122 h^-1, in 59.5 hours spanning 47 days. A peak in the isotropic equivalent energy distribution is found to be approximately 4.8 × 10³⁷ erg at 1.25 GHz, below which the detection of bursts is suppressed. The burst energy distribution is bimodal, and well characterized by a combination of a log-normal function and a generalized Cauchy function. The large number of bursts in hour-long spans allows sensitive periodicity searches between 1 ms and 1,000 s. The non-detection of any periodicity or quasi-periodicity poses challenges for models involving a single rotating compact object. The high burst rate also implies that FRBs must be generated with a high radiative efficiency, disfavouring emission mechanisms with large energy requirements or contrived triggering conditions.

Comparison of outcomes between neoadjuvant imatinib and upfront surgery in patients with localized rectal GIST: An inverse probability of treatment weighting analysis

BACKGROUND AND OBJECTIVES

This study aimed to compare outcomes between neoadjuvant imatinib and upfront surgery in patients with localized rectal gastrointestinal stromal tumors (GIST) patients.

METHODS

Eighty-five patients with localized rectal GIST were divided into two groups: upfront surgery ± adjuvant imatinib (Group A, n = 33) and the neoadjuvant imatinib + surgery + adjuvant imatinib (Group B, n = 52). Baseline characteristics between groups were controlled for with inverse probability of treatment weighting (IPTW) adjusted analysis.

RESULTS

The response rate to neoadjuvant imatinib was 65.9%. After the IPTW-adjusted analysis, patients who underwent neoadjuvant therapy had better distant recurrence-free survival (DRFS) and disease-specific survival (DSS) compared with those who underwent upfront surgery (5-year DRFS 97.8 vs. 71.9%, hazard ratio [HR], 0.15; 95% CI, 0.03-0.87; p = 0.03; 5-year DSS 100 vs. 77.1%; HR, 0.11; 95% CI, 0.01-0.92; p = 0.04). While no significant association was found between overall survival (OS) and treatment groups (p = 0.07), 5-year OS was higher for the neoadjuvant group than upfront surgery group (97.8% vs. 71.9%; HR, 0.2; 95% CI, 0.03-1.15).

CONCLUSIONS

In patients with localized rectal GIST, neoadjuvant imatinib not only shrunk the tumor size but also decreased the risk of metastasis and tumor-related deaths when compared to upfront surgery and adjuvant imatinib alone.

Visible-Light-Induced 1,4-Hydroxysulfonylation of Vinyl Enynes with Sulfonyl Chlorides: The Bridge of Chloride Linking Water and Enynes

A novel visible-light-induced 1,4-hydroxysulfonylation of vinyl enynes with sulfonyl chlorides has been established, providing a highly efficient protocol to access multisubstituted sulfonyl allenic alcohols. Control experiments and mechanistic studies disclose that the target products result from sequential reactions of hydroxyl and tosyl radicals, among which chloride anion plays a key role to generate the requisite ^•OH, thus bridging water and enynes. Moreover, the vinyl pendant is believed to decisively affect the site-selectivity of hydroxyl radical.

Increased expression of microRNA-26a-5p predicted a poor survival outcome in osteosarcoma patients: An observational study

MicroRNA (miR)-26a-5p is an oncogene significantly associated with osteosarcoma. We try to evaluate expression of circulating miR-26a-5p in osteosarcoma patients and evaluate its significance.A total of 243 consecutive osteosarcoma patients and 96 healthy participates were enrolled. Circulating miR-26a-5p levels were evaluated by using real-time quantitative reverse transcription polymerase chain reactions (RT-PCR). The association between circulating miR-26a-5p level and survival outcomes was evaluated by univariate and multivariate analysis.Circulating miR-26a-5p levels in osteosarcoma patients was significantly higher than that of healthy volunteers (P < .05). Upregulated miR-26a-5p was significantly related to advanced cancer and metastasis (both P < .05). Moreover, patients with a high serum miR-26a-5p had a poorer overall survival than those with a low serum miR-26a-5p levels (P < .05). Circulating miR-26a-5p level also been showed as independent risk factor for osteosarcoma in multivariate analysis (hazard ratio [HR], 0.38; 95% confidence interval [CI]: 0.11-0.98; P < .01).Circulating miR-26a-5p was significantly upregulated in osteosarcoma patients and remarkably associated with poor prognosis, indicating that circulating miR-26a-5p might serve as a useful diagnostic and prognostic biomarker for osteosarcoma.

Computer-aided three-dimensional assessment of periodontal healing distal to the mandibular second molar after coronectomy of the mandibular third molar: a prospective study

Background

The periodontal healing distal to the mandibular second molar (M2M) after coronectomy of the M3M has shown controversial results. We aimed to combine a digital method with cone-beam computed tomography (CBCT) and estimate periodontal healing of M2M after M3M coronectomy. An accurate and stable indicator in three dimensions was also explored tentatively.

Methods

Patients with a M3M in contact with the inferior alveolar canal were included. CBCT was applied immediately after coronectomy (baseline) and 6-months later. Data were investigated with digital software for registration. Previously reported and coronectomy-related factors were included for univariate and multivariate analyses.

Results

A total of 181 patients (213 M3Ms) completed 6-month follow-up. Significant reduction in the distal intra-bony defect (DBD) depth of the M2M was shown (1.28 ± 1.24 mm, P < 0.001). DBD depth of the M2M at baseline was the most influential factor (r = 0.59), followed by preoperative M3M condition, age, rotation and migration of the root complex. Remaining enamel (OR = 6.93) and small retromolar space (0.67) contributed to re-contact of the root complex and M2M. Bone volume regenerated in the distal 2 mm was associated significantly with DBD-depth reduction (r = 0.74, P < 0.001).

Conclusions

Bone volume regenerated in the distal 2 mm of the M2M denoted stability of distal periodontal healing of the M2M. DBD depth at baseline was the most influential factor for healing of a DBD of the M2M after M3M coronectomy. The remaining enamel and a small retromolar space could contribute to re-contact of the root complex and the M2M.

Trial registration

China Clinical Trial Center, ChiCTR1800014862. Registered 10 February 2018,

Pulmonary pathology of early-phase COVID-19 pneumonia in a patient with a benign lung lesion

Aims

An ongoing outbreak of 2019 novel coronavirus (CoV) disease (COVID‐19), caused by severe acute respiratory syndrome (SARS) CoV‐2, has been spreading in multiple countries. One of the reasons for the rapid spread is that the virus can be transmitted from infected individuals without symptoms. Revealing the pathological features of early‐phase COVID‐19 pneumonia is important for understanding of its pathogenesis. The aim of this study was to explore the pulmonary pathology of early‐phase COVID‐19 pneumonia in a patient with a benign lung lesion.

Methods and results

We analysed the pathological changes in lung tissue from a 55‐year‐old female patient with early‐phase SARS‐CoV‐2 infection. In this case, right lower lobectomy was performed for a benign pulmonary nodule. Detailed clinical, laboratory and radiological data were also examined. This patient was confirmed to have preoperative SARS‐CoV‐2 infection by the use of real‐time reverse transcription polymerase chain reaction and RNA in‐situ hybridisation on surgically removed lung tissues. Histologically, COVID‐19 pneumonia was characterised by exudative inflammation. The closer to the visceral pleura, the more severe the exudation of monocytes and lymphocytes. Perivascular inflammatory infiltration, intra‐alveolar multinucleated giant cells, pneumocyte hyperplasia and intracytoplasmic viral‐like inclusion bodies were seen. However, fibrinous exudate and hyaline membrane formation, which were typical pulmonary features of SARS pneumonia, were not evident in this case. Immunohistochemical staining results showed an abnormal accumulation of CD4+ helper T lymphocytes and CD163+ M2 macrophages in the lung tissue.

Conclusion

The results highlighted the pulmonary pathological changes of early‐phase SARS‐CoV‐2 infection, and suggested a role of immune dysfunction in the pathogenesis of COVID‐19 pneumonia.

[Magnetic resonance imaging morphological study of the effects of juvenile febrile convulsions on the brain structure of medial temporal lobe epilepsy]

Objective: To investigate the effect of febrile convulsions on gray matter volume (GMV) in medial temporal lobe epilepsy (mTLE) and its correlation with disease duration. Methods: A retrospective study was conducted to collect 41 mTLE patients with a history of febrile convulsions (mTLE-FC), 42 mTLE patients with no initial precipitating injury (mTLE-noIPI), and 42 normal and age and sex matched normal controls. High-resolution T1-weighted (T(1)WI) whole brain MR scans were performed on all subjects. Voxel-based morphometry were used to obtain GMV brain maps, and the GMV differences between the three groups of subjects were compared (P<0.01, GRF corrected). Finally, Spearmen rank correlation analysis was used to explore the correlation between GMV changes and the course of disease. Results: Compared with the normal control subjects, each mTLE group showed extensive GMV reduction, mainly in the affected hippocampus, thalamus, temporal lobe, and bilateral cerebellum. Further analysis found that mTLE-FC group had more significant reductions in GMV than the mTLE-noIPI group in the affected hippocampus, amygdala, inferior temporal gyrus, contralateral hippocampus, para hippocampus, and inner cingulate gyrus. At the same time, the affected amygdala and hippocampal GMV in the mTLE-FC group was significantly negatively related to the course of disease (r=-0.381, P=0.014), while the mTLE-noIPI group had no downward trend (r=0.081, P=0.611). The atrophic trend of the affected amygdala and hippocampus in patients with mTLE-FC was significantly greater than that in patients with mTLE-noIPI (P=0.029, permutation test). Conclusions: There is extensive damage to the gray matter structure of bilateral cerebral hemispheres, mainly in the hippocampus, in mTLE patients. The brain damage of mTLE patients with a history of juvenile fever convulsions is more extensive and serious, and the trend of progressive exacerbation with the course of the disease is more obvious, suggesting mTLE associated with juvenile fever convulsions may have different pathophysiological mechanisms.

Role of Tenascin-X in regulating TGF-β/Smad signaling pathway in pathogenesis of slow transit constipation

BACKGROUND

Chronic constipation is a gastrointestinal functional disease that seriously harms physical and mental health and impacts the quality of life of patients. Its incidence rate is 2%-27%. Slow transit constipation (STC) is a common type of chronic functional constipation, accounting for 10.3%-45.5% of such cases. Scholars have performed many studies on the pathogenesis of STC. These studies have indicated that the occurrence of STC may be related to multiple factors, such as dysfunction of the enteric nervous system, interstitial cells of Cajal (ICC) damage, and changes in neurotransmitters regulating intestinal peristalsis.

AIM

To investigate the role of Tenascin-X (TNX) in regulating the TGF-β/Smad signaling pathway in the pathogenesis of STC.

METHODS

This study included an experimental group and a control group. The experimental group included 28 patients with severe colonic STC, and the control group included 18 patients with normal colon tissues. Immunohistochemistry (IHC) was used to detect c-Kit, a specific marker of the ICC. Western blot, immunofluorescence, and IHC were used to detect the localization and expression of TNX and TGF-β/Smad.

RESULTS

IHC showed that the number of ICC with positive c-Kit expression was significantly reduced in the colon of STC patients (22.17 ± 3.28 vs 28.69 ± 3.53, P < 0.05) and that the distribution was abnormal. Western blot results showed that c-Kit and Smad7 levels were significantly decreased in the colon of STC patients (c-kit: 0.462 ± 0.099 vs 0.783 ± 0.178, P < 0.01; Smad7: 0.626 ± 0.058 vs 0.799 ± 0.03, P < 0.01) and that TNX and Smad2/3 levels were higher in the STC group (TNX: 0.868 ± 0.028 vs 0.482 ± 0.032, P < 0.01). There was no significant difference in TGF-β between the two groups (0.476 ± 0.028 vs 0.511 ± 0.044, P = 0.272). Pearson correlation analysis showed that the TNX protein exhibited a strong correlation with Smad2/3 and Smad7 (P < 0.05, |R| > 0.8) and TGF-β (P < 0.05, |R| = 0.7).

CONCLUSION

The extracellular matrix protein TNX may activate the TGF-β/Smad signaling pathway by upregulating the Smad 2/3 signaling protein and thereby induce slight or complete epithelial stromal cell transformation, leading to an abnormal distribution and dysfunction of ICC in the diseased colon, which promotes the occurrence and development of STC.

Nomogram for predicting pathological complete response and tumor downstaging in patients with locally advanced rectal cancer on the basis of a randomized clinical trial

Background

Preoperative fluoropyrimidine with radiotherapy was regarded as the standard of care for locally advanced rectal cancer (LARC). The model for predicting pCR in LARC patients was based on standard treatment only. This study aimed to establish a nomogram with pretherapeutic parameters and different neoadjuvant regimens for predicting pathologic complete response (pCR) and tumor downstaging or good response (ypT0-2N0M0) after receiving neoadjuvant treatment in patients with LARC based on a randomized clinical trial.

Methods

Between January 2011 and February 2015, 309 patients with rectal cancer were enrolled from a prospective randomized study (NCT01211210). All pretreatment clinical parameters were collected to build a nomogram for predicting pCR and tumor downstaging. The model was subjected to bootstrap internal validation. The predictive performance of the model was assessed with concordance index (C-index) and calibration plots.

Results

Of the 309 patients, 53 (17.2%) achieved pCR and 132 (42.7%) patients were classified as tumor downstaging with ypT0-2N0M0. Based on the logistic-regression analysis and clinical consideration, tumor length (P = 0.005), tumor circumferential extent (P = 0.036), distance from the anal verge (P = 0.019), and neoadjuvant treatment regimen (P < 0.001) showed independent association with pCR following neoadjuvant treatment. The tumor length (P = 0.015), tumor circumferential extent (P = 0.001), distance from the anal verge (P = 0.032), clinical T category (P = 0.012), and neoadjuvant treatment regimen (P = 0.001) were significantly associated with good tumor downstaging (ypT0-2N0M0). Nomograms were developed to predict the probability of pCR and tumor downstaging with a C-index of 0.802 (95% confidential interval [CI], 0.736–0.867) and 0.730 (95% CI, 0.672–0.784). Internal validation revealed good performance of the calibration plots.

Conclusions

The nomogram provided individual prediction responses to different preoperative treatment for patients with rectal cancer. This model might help physicians in selecting an optimized treatment, but warrants further external validation.

Quercetin and Isoquercitrin Inhibiting Hepatic Gluconeogenesis Through LKB1-AMPKα Pathway

Objective

To observe the impact of quercetin and isoquercitrin on gluconeogenesis in hepatocytes.

Methods

Mouse primary hepatocytes were cultured with lactic acid and pyruvic acid. After treatment with quercetin and isoquercitrin for 24 hours, the glucose concentration in the culture supernatant was determined. RT-PCR was used to detect the mRNAs of PEPCK, G6Pase, LKB1, and AMPKα. Protein levels of LKB1, AMPKα, and Thr172 phosphorylation were evaluated by Western blot.

Results

The glucose concentration in the gluconeogenesis group (GN) was significantly higher than in the control group (C), but the glucose concentrations in the high level quercetin(group 80Q) and high level isoquercitrin (group 80I) were significantly lower than in the group GN, P<0.01. In the group 80Q, and group 80I, the mRNA levels of PEPCK and LKB1were significantly lower than in the group GN (P<0.01), and the G6Pase mRNA were significantly lower than in the group GN (P<0.05). The protein levels of LKB1 and the phosphorylation of AMPKα Thr172 in the group 80Q, group 40I, and group 80I were higher than in the group GN. The effects of quercetin and isoquercitrin on LKB1 and AMPKα were similar to those of metformin.

Conclusions

Quercetin and isoquercitrin inhibit gluconeogenesis in hepatocytes, which may be related to the LKB1 upregulation and phosphorylation of AMPKα.

Surgical outcomes of subtotal colectomy with antiperistaltic caecorectal anastomosis vs total colectomy with ileorectal anastomosis for intractable slow-transit constipation

Background

Few studies have compared the surgical outcomes of different surgical procedures currently used to treat refractory colonic slow-transit constipation (STC), despite the increase in the number of cases. This study aimed to analyse the long-term surgical outcomes of subtotal colectomy with antiperistaltic caecorectal anastomosis (SC-ACRA) vs total colectomy with ileorectal anastomosis (TC-IRA) for severe STC.

Methods

Between January 2005 and January 2015, we retrospectively collected clinical data of 55 patients who underwent TC-IRA (n = 35) or SC-ACRA (n = 20) for severe STC at our institution. The post-operative functional outcomes between the two groups were compared.

Results

There were no significant differences in age (P = 0.655), sex (P = 0.234), period of constipation (P = 0.105) and defecation frequency (P = 0.698) between the TC-IRA and SC-ACRA groups. During a median follow-up period of 72 months (range, 12–120 months), there were no significant differences between the TC-IRA and SC-ACRA groups regarding the median number of bowel movements per day [3 (1/6–7) vs 3 (1/6–5), P = 0.578], Cleveland Clinic Florida Constipation Score [2 (0–20) vs 2 (0–19), P = 0.454], Cleveland Clinic Incontinence Score [0 (0–5) vs 0 (0–2), P = 0.333] and Gastrointestinal Quality of Life Index [122 (81–132) vs 120 (80–132), P = 0.661]. Moreover, there was no significant difference in the incidence of post-operative complications between the two groups (37.1% vs 25.0%, P = 0.285).

Conclusions

Our findings indicate that both TC-IRA and SC-ACRA are effective treatments for severe STC, with similar long-term outcomes.

Regulating Fluorescent Aptamer-Sensing Behavior of Zeolitic Imidazolate Framework (ZIF-8) Platform via Lanthanide Ion Doping

Nanoscale metal-organic frameworks (NMOFs) have been proved to be effective quenching platforms for fluorescent detection of DNA via fluorophore-quencher pairs. Zeolitic imidazolate framework-8 (ZIF-8) is one type of the most promising NMOFs because of its excellent biocompatibility and easy preparation. However, ZIF-8 is rarely used as platforms for fluorescence sensing of DNA because of its bad fluorescence quenching property. In this study, lanthanide ions were doped into ZIF-8 to regulate its fluorescence quenching behavior. The La³⁺ doped ZIF-8 (ZIF-8-La) showed the best quenching efficiency on dye-labeled DNA. The signal-to-background ratio was around 3 times higher than ZIF-8. Furthermore, a core-shell La³⁺-doped ZIF-8 (CS-ZIF-8-La) was designed to modify more La³⁺ on the surface of ZIF-8. Compared with ZIF-8-La, the CS-ZIF-8-La exhibited the same fluorescence sensing behavior toward positive-dye-labeled DNA, but showed completely contrary quenching property on the negative-dye-labeled DNA. On the basis of this phenomenon, CS-ZIF-8-La was successfully used as quenching platform for designing a ratiometric sensor for DNA and microRNA.

[The role of poloxamer 188 for cord blood mononuclear cells into megakaryocytes cultivation and induction in three-dimensional WAVE Bioreactor]

目的

观察泊洛沙姆188（P188）对体外三维（3D）培养诱导脐血单个核细胞向巨核细胞分化的影响。

方法

将分离的脐血单个核细胞分别接种于细胞瓶和细胞培养袋中，后者采用WIGGENS摇床模拟生物反应器进行3D培养。在巨核细胞诱导培养基中加入P188体外培养14 d，观察细胞形态、计数细胞数并计算细胞存活率，采用流式细胞术观察巨核细胞表面标志表达情况。

结果

与采用传统的细胞培养瓶二维（2D）培养诱导巨核细胞相比，2D+P188培养组巨核系CD41⁺、CD41⁺/CD61⁺、CD61⁺细胞数明显增加（P值均<0.01）；在3D培养中加入P188，细胞体积变大，核形状不规则，胞质含紫红色颗粒，细胞分化更接近成熟。2D培养、3D培养及3D+P188培养组组间巨核细胞表面标志CD41、CD41/CD61、CD61表达水平差异有统计学意义（P值均<0.01）。LSD-t检验两两比较显示，与2D培养相比，3D培养诱导巨核细胞存活率及细胞数均降低（P值分别为0.018、0.027），3D+P188培养组细胞数、细胞存活率与2D和3D培养组比较差异均无统计学意义（P值均>0.05）。而3D培养组巨核细胞CD41/CD61表达水平为（36.30±1.27）%，高于2D培养组的（23.95±1.34）%（P=0.002），3D+P188培养组CD41/CD61表达水平更高[（59.45±1.20）%]。

结论

3D培养有利于巨核系祖细胞诱导分化，但细胞存活率低，加入P188，细胞生存状态好，且诱导效率更高。

[Diagnostic accuracy of cone beam computed tomography with different resolution settings for external root resorption]

OBJECTIVE

To evaluate the diagnostic accuracy of cone beam computed tomography (CBCT) with different resolution settings in detecting the simulated external root resorption defects.

METHODS

External root resorption defects were simulated in 51 human single rooted premolar teeth. Cavities simulating root resorption defects of 1 mm in diameter and 0.1 mm, 0.2 mm, and 0.3 mm in depth were drilled in the cervical, middle and apical thirds of lingual surfaces of the teeth. In addition to the 51 locations as controls, a total of 102 cavities were obtained in the present study. Specimens were placed in a human dry mandible and scanned by ProMax 3D and DCT PRO CBCT with different resolution settings, respectively. The three-dimensional CBCT images were evaluated by two experienced observers. The data were analyzed with receiver operating characteristics (ROC) analysis. ROC curves were generated and the area under ROC curve (Az) was employed to express the diagnostic accuracy.

RESULTS

The diagnostic accuracy (Az value) of ProMax 3D CBCT with high, normal and low resolution settings were 0.867, 0.703 and 0.665 (P < 0.05), respectively. Defects with depths of 0.2 mm and 0.3 mm were easier to be detected than those with depths of 0.1 mm (P < 0.05). The images obtained by high resolution mode scanning had obvious advantages in detecting smaller defects (depth 0.1 mm and 0.2 mm). The DCT PRO CBCT provided 4 resolution settings including normal quality + normal resolution, normal quality + high resolution, high quality + normal resolution and high quality + high resolution. The Az values for those 4 resolution settings were 0.527, 0.725, 0.743, and 0.794 (P < 0.05), respectively. Similar to ProMax 3D CBCT, the scanning mode with high resolution played a better role in detecting the defects with depth of 0.1 mm. Except for the scanning setting mode with normal quality + normal resolution, the other three modes could well be evaluated for the defects with depth of 0.2 mm and 0.3 mm.

CONCLUSION

It is concluded that the diagnostic ability for external root resorption of CBCT could be affected by resolution settings. Computer-aid imaging method can improve the CBCT diagnostic accuracy for external root resorption without increasing the radiation dose level during CBCT scanning.

[Clinicopathological characteristics and diagnosis of IgG4related sialadenitis]

Immunoglobulin G4-related sialadenitis (IgG4-RS) is a newly recognized immune-mediated disease and one of immunoglobulin G4-related diseases (IgG4-RD). Our multidisciplinary research group investigated the clinicopathological characteristics and diagnosis of IgG4-RS during the past 10 years. Clinically, it showed multiple bilateral enlargement of major salivary glands (including sublingual and accessory parotid glands) and lacrimal glands. The comorbid diseases of head and neck region including rhinosinusitis, allergic rhinitis, and lymphadenopathy were commonly seen, which could occur more early than enlargement of major salivary glands. Internal organ involvements, such as autoimmune pancreatitis, sclerosing cholangitis, and interstitial pneumonia could also be seen. Thirty-five (38.5%) patients had the symptom of xerostomia. Saliva flow at rest was lower than normal. Secretory function was reduced more severely in the submandibular glands than in the parotid glands. Serum levels of IgG4 were elevated in almost all the cases and the majority of the patients had increased IgE levels. CT, ultrasonography, and sialography showed their imaging characteristics. Histologically it showed marked lymphoplasmacytic inflammation, large irregular lymphoid follicles with expanded germinal centers, prominent cellular interlobular fibrosis, eosinophil infiltration, and obliterative phlebitis. Their immunohistological examination showed marked IgG-positive and IgG4-positive plasma cell infiltration and high IgG4/IgG ratio. The disease could be divided into three stages according to severity of glandular fibrosis. The serum IgG4 level was higher and the saliva secretion lower as glandular fibrosis increased. IgG4-RS should be differentiated from other diseases with enlargement of major salivary gland and lacrimal gland, such as primary Sjögren syndrome, chronic obstructive submandibular sialadenitis, and eosinophilic hyperplastic lymphogranuloma.

[Endoscopy-assisted transoral removal of deep hilar and intraparenchymal stones in the Wharton's duct]

Objective: To investigate the different surgical approaches and long-term outcomes of endoscopy-assisted transoral removal of deep hilar and intraparenchymal stones in the Wharton's duct. Methods: From January 2008 to March 2018, 481 consecutive patients with deep hilar and intraparenchymal calculi in the Wharton's duct underwent endoscopy-assisted transoral removal at Deparment of Oral and Maxillofacial Radiology, Peking University School and Hospital of Stomatology. There were 250 males and 231 females. Their ages ranged from 9-86 years. We operated 476 patients under local anesthesia on an outpatient basis, and the remaining 5 were operated under general anesthesia. On the basis of ultrasonography, spiral CT, sialography and endoscopy, the calculi were classified into 4 types: hilum stones (located at the hilum or proximally with a distance <5 mm from the hilum), infra-hilum stones (intra-glandular stones with a distance of 5-10 mm from the hilum), intraparenchymal stones (with a distance ≥10 mm from the hilum), and multiple stones (concomitant hilum and intra-glandular stones). The treatment approaches included: hilum duct slitting, intraparenchymal duct slitting, submandibulotomy and intraductal retrieval. The success rate, immediate safety and effectiveness of different types of stones were evaluated. After surgery, the patients were followed up, and gland function was analyzed on the basis of clinical symptoms and signs. Results: The calculi sizes varied from 3 to 25 mm, with a mean of 7.8 mm. The calculi were located in the right submandibular gland in 259 patients, in the left submandibular gland in 219 patients and in bilateral glands in 3 patients. The calculi were successfully removed in 446 glands, with a success rate of 92.1% (446/484). The success rate varied according to the stone sites: 97.8% (363/371) for hilum stones, 64.4% (29/45) for infra-hilum stones, 4/16 for intraparenchymal stones and 96.2% (50/52) for multiple stones. The main treatment methods applied included hilum duct slitting in 347 glands, intraparenchymal duct slitting in 13, submandibulotomy in 4, intraductal retrieval in 73, and hilum duct slitting accompanied by intraductal retrieval in 9. Ductal breakage occurred in 2 glands. All patients complained of mild to moderate pain with a duration of 3-7 days. Nine had temporal lingual nerve injury. During 3-120 months' follow-up (mean 36 months) of the total 484 glands, 1.6% (7/446) developed ranula, 1.3% (6/446) experienced obturation of the main duct and 2.0% (9/446) had recurrent stones. The remaining 95.1% (424/446) glands were symptom-free with good function. Conclusions: Endoscopy-assisted transoral removal of deep hilar and intraparenchymal submandibular calculi is a safe and effective gland-preserving procedure. According to the depth, size and number of the calculi, variant surgical approaches should be attempted to maximize the success rate and to minimize the side effects.

Secondary phosphine oxides stabilized Au/Pd nanoalloys: metal components-controlled regioselective hydrogenation toward phosphinyl (Z)-[3]dendralenes

A series of gold/palladium nanoalloys stabilized by secondary phosphine oxides have been prepared and applied in selective hydrogenation for the first time.

Design, Synthesis, and SAR Studies of Heteroarylpyrimidines and Heteroaryltriazines as CB2 R Ligands

Herein we describe the design and synthesis of a new series of heteroarylpyrimidine/heteroaryltriazine derivatives on the basis of quinazoline-2,4(1H,3H)-diones as CB₂ R-selective ligands using a bioisosterism strategy. An acetamide group was explored to displace the enamine linker of the lead compound for the purpose of stereoisomerism elimination and hydrophilicity increase. As a result, some of the synthesized compounds showed high bioactivity and selectivity for CB₂ R in calcium mobilization assays, and four displayed CB₂ R agonist activity, with EC₅₀ values below 30 nm. The compound exhibiting the highest agonist activity toward CB₂ R (EC₅₀ =7.53±3.15 nm) had a selectivity over CB₁ R of more than 1328-fold. Moreover, structure-activity relationship (SAR) studies indicated that the substituents on the nucleus play key roles in the functionality of a ligand, with one such example demonstrating CB₂ R antagonist activity. Additionally, molecular docking simulations were conducted with the aim of better understanding of these new derivatives in relation to the structural requirements for agonists/antagonists binding to CB₂ R.

[Dosimetry of cone-beam computed tomography and multi-slice computed tomography scanning for temporal bone]

Objective: To compare the effective radiation dose levels of cone-beam computed tomography (CBCT) with those of multi-slice computed tomography (MSCT) when scanning for the temporal bone. Methods: The absorbed doses of CBCT and MSCT scanners were detected using thermoluminescent dosimeters (TLDs) that were placed in a head and neck phantom and a RGD-3D dose reader.Then the effective doses were calculated and expressed according to the International Commission on Radiation Protection (ICRP) 2007 guidelines. Results: Three-dimensional images about temporal bone can obtained by both CBCT and MSCT scanners in this study.The effective dose value of CBCT scanning for bilateral and unilateral temporal bone was 164.1 μSv (bone marrow: 32.1 μSv; thyroid gland: 10.6 μSv; salivary glands: 31.0 μSv), and 98.1 μSv (bone marrow: 17.4 μSv; thyroid gland: 6.2 μSv; salivary glands: 16.1 μSv), respectively.The dose of MSCT scanning for bilateral temporal bone was 714.6 μSv (bone marrow: 95.1 μSv; thyroid gland: 127.8 μSv; salivary glands: 135.7 μSv). Conclusions: When scanning for the temporal regions, the dose levels for CBCT are lower than those for MSCT.Dose levels reduction for CBCT could be obtained when smaller regions were scanned.

[Expression and potential clinical significance of cytidine triphosphate: phosphocholine cytidylyltransferase-α in oral squamous cell carcinoma]

Objective: To examine the expression and potential clinical significance of CCT (cytidine triphosphate: phosphocholine cytidylyltransferase)-α in oral squamous cell carcinoma (OSCC). Methods: Fifty-eight OSCC and paired adjacent non-malignant epithelia samples (between May 2016 and July 2016) were obtained from dental center, Second Xiangya Hospital, Central South University. CCT-α expression was examined by immunohistochemistry. The relationship between CCT-α and clinicopathological features of OSCC patients was analyzed. Quantitative real-time PCR and Western blot were performed to measure the expression of CCT-α mRNA and protein level in several OSCC cell line and two normal oral epithelial cell line. Results: Immunohistochemistry showed that CCT-α positive staining was found in cell nuclear of OSCC cells and adjacent epithelial cells. CCT-α was positively expressed in OSCC, which was significantly higher than that adjacent to carcinoma tissues (P=0.000). The expression of CCT-α in oral squamous cell carcinoma was correlated with smoking, alcohol consumption, tumor size, differentiation degree and lymph node metastasis. The expression level of CCT-α protein was significantly increased in patients with a history of smoking and alcohol consumption (P=0.001, P=0.004). With the increase of tumor diameter, the expression of CCT-α protein was significantly increased (P=0.005). According to histopathological grade, the lower the degree of tumor differentiation, the higher the expression level of CCT-α protein (P=0.000). The expression of CCT-α protein was significantly higher in patients with lymph node metastasis compared with no lymph node metastasis (P=0.000). Quantitative real-time PCR results showed the CCT-α mRNA expression level was significantly higher in OSCC cells than that in normal oral epithelial cells (P=0.016). The protein expression level of CCT-α was significantly higher in OSCC cells than that in normal oral epithelial cells. Conclusions: CCT-α may play a critical role in the carcinogenesis and development of OSCC.

[Endoscopy-assisted sialodochoplasty for the treatment of severe sialoduct stenosis]

OBJECTIVE

To evaluate the effects of endoscopy-assisted sialodochoplasty for the treatment of severe sialoduct stenosis with concurrent megaducts.

METHODS

From Jul.2010 to Dec. 2016, 8 patients presenting with severe parotid duct stenosis and 3 patients with occlusion of the Wharton's duct underwent endoscopy-assisted sialodochoplasty.All these patients had concurrent severe ductal ectasiaand manifested a painful swelling of the involved salivary glands.The diameter of ectasia and length of stenosis of the sialoducts were measured preoperatively by sialography, computed tomography, or ultrasonography. The megaducts were opened transorally and sutured to the buccal or oral floor mucosa, therefore creating a neo-ostium. All the patients were followed up periodically after operation. The treatment effects were evaluated by clinical signs, sialogram and sialometry.

RESULTS

The length of the Stensen's duct stenosis was 5-12 mm, and the diameter of the concurrent ectasia was 8-16 mm. The length of the Wharton's duct stenosis was 10-20 mm, and the diameter of the concurrent ectasia was 6-8 mm.The neo-ostiums healed uneventfully 2 weeks after operation. The duration of the follow-up varied from 6 to 78 months (median: 24 months). Among the 8 patients with Stensen's duct stenosis, two experienced re-obliteration of the neo-ostium, but the buccal bulge and clinical symptoms disappeared; one reported recurrent clinical symptoms after initial alleviation, which could be controlled with self-massaging; the remaining 5 patients had satisfactory clinical results, i.e., disappearance of the obstruction symptoms and buccal bulge, patent ostium,clean saliva and improvement of the ductal ectasia on sialogram. Three patients with Wharton's duct occlusion were asymptomatic with clear saliva and patent ostium;two exhibited approximately normal appearance and one showed improvement of the sialogram.Sialometry was performed in 9 patients with patent neo-ostium of the involved glands,the resting saliva flow rate of the affected glands showed no differences compared with the normal side, and stimulated flow rate showed a significant increase, though less than the control side.The clinical results included good in 5 patients, fair in 4 patients, and poor in 2 patients, with a total effective rate of 82% (9/11).

CONCLUSION

Endoscopy-assisted sialodochoplasty appears to be effective and can be a viable option for patients presenting with severe sialoducts tenosis and concurrent ectasia.

The disseminated intravascular coagulation score is a novel predictor for portal vein thrombosis in cirrhotic patients with hepatitis B

BACKGROUND

The development of portal vein thrombosis (PVT) in cirrhotic patients has not been fully elucidated. The disseminated intravascular coagulation (DIC) score, which is based on readily available and relatively inexpensive coagulation parameters, including platelet count, fibrin-related markers, prothrombin time and fibrinogen, has not been reported regarding PVT development in cirrhotic patients to date. We aimed to evaluate the prognostic value of the DIC score in predicting PVT development in cirrhotic patients with hepatitis B.

MATERIAL AND METHODS

A total of 109 cirrhotic patients with hepatitis B were included. Clinical data, laboratory tests and imaging were collected from the patients at baseline and every three months after enrollment. All patients were followed until the study endpoint (either occurrence of PVT or 12months after baseline). We measured routine laboratory parameters and conducted imaging examinations in cirrhotic patients and evaluated the prognostic value of the DIC score as a novel predictor for PVT in patients with cirrhosis. We also compared the effectiveness of the DIC score with other common coagulation and hemodynamic parameters.

RESULTS

Among the 109 patients, 14 (12.8%) developed PVT. At the study endpoint, significant increases in D-dimer, Child-Pugh score and DIC score (all P<0.001) and significantly reduced portal flow velocity (P<0.001) were noted in the PVT group. Among the selected factors, the DIC score had the largest area under the curve (AUC) (0.845), followed by the Child-Pugh score (0.778), D-dimer (0.732), and portal vein velocity (0.709).

CONCLUSION

Among the selected factors, the DIC score showed non-significantly higher diagnostic performance in predicting the PVT development in cirrhotic patients compared with other factors. A validation cohort of the study is needed in the near future.

Amidoalkylindoles as Potent and Selective Cannabinoid Type 2 Receptor Agonists with in Vivo Efficacy in a Mouse Model of Multiple Sclerosis

Selective CB₂ agonists represent an attractive therapeutic strategy for the treatment of a variety of diseases without psychiatric side effects mediated by the CB₁ receptor. We carried out a rational optimization of a black market designer drug SDB-001 that led to the identification of potent and selective CB₂ agonists. A 7-methoxy or 7-methylthio substitution at the 3-amidoalkylindoles resulted in potent CB₂ antagonists (27 or 28, IC₅₀ = 16-28 nM). Replacement of the amidoalkyls from 3-position to the 2-position of the indole ring dramatically increased the agonist selectivity on the CB₂ over CB₁ receptor. Particularly, compound 57 displayed a potent agonist activity on the CB₂ receptor (EC₅₀ = 114-142 nM) without observable agonist or antagonist activity on the CB₁ receptor. Furthermore, 57 significantly alleviated the clinical symptoms and protected the murine central nervous system from immune damage in an experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis.

Endemic Variation of H9N2 Avian Influenza Virus in China

Forty-two H9N2 subtype AIV strains were isolated from vaccinated commercial chickens in China from 2012 to 2015. Their HA genes had nucleotide sequence homology from 86.7% to 99.7%, and similarity to the classic vaccine strain was 88.6%-92.6%. A comparison was carried out with published HA genes (410 H9 strains) and whole genomes (306 strains) isolated in China during 2012-2015. Interestingly, 99.1% (448/452) of Chinese H9N2 AIV belonged to lineage h9.4.2, and 98.5% (445/452) of the viruses belonged to h9.4.2.5. Meanwhile, 99.6% (443/445) of lineage 9.4.2.5 viruses had PSRSSR↓GLF instead of PARSSR↓GLF motifs in the HA cleavage sites; 98.2% (444/452) of HA genes showed human receptor binding associated mutation Q226L. A total of 96.8% (337/348) of the viruses had three amino-acid deletions at 63-65 in the NA stalk, associated with enhanced virulence in chickens and mice; 97.1% (338/348) of M2 proteins had the S31N mutation associated with adamantane resistance in humans. Two H9 viruses isolated in this study were highly homologous to the human-origin H9N2 virus reported in 2013. The isolates were divided into four different genotypes (U, S, V, and W). Genotype S was the major one, accounting for 94.8% (330/348). Genotypes V and W were new reassortment genotypes, with genotype W recombined with the PB2 gene originating from the new wild waterfowl-like lineage. According to the cross-HI antibody titer data, HA gene evolution, and isolation history, the isolates were divided into A, B, and C antigenic groups successively. All the antigenic group viruses were found to circulate throughout China. This study emphasizes the importance of updated vaccine and strengthened veterinary biosecurity on poultry farms and trade markets.

Factors associated with Staphylococcus aureus nasal carriage and molecular characteristics among the general population at a Medical College Campus in Guangzhou, South China

BACKGROUND

The nasal cavity is the main colonization site of Staphylococcus aureus (S. aureus) in human body. Nasal carriage may be a strong risk factor for some serious infection. There was still limited information about the nasal carriage for S. aureus in south China.

METHODS

Sought to determine the prevalence and molecular characteristics of S. aureus nasal carriage, 295 volunteers residing on a medicine campus were investigated and sampled the nasal cavity swab. Selected S. aureus isolates were carried through molecular analysis, including pulsed-field gel electrophoresis (PFGE), multilocus sequence analysis, staphylococcal cassette chromosome mec (SCCmec) and virulence gene detection.

RESULTS

A total of 73 S. aureus isolates were recovered from separate subjects (24.7%, 73/295), with one methicillin-resistant S. aureus (MRSA) isolate (0.3%, 1/295). Among the 73 isolates, 71 isolates were successfully grouped into 13 pulsotypes by PFGE analysis, with profiles A and L the most prevalent; 12 sequence types (STs) were found among the 23 isolates which had similar drug resistant spectrum. ST59, ST188 and ST1 were the most prevalent, accounting for 17.4, 13.0 and 13.0% of all isolates, respectively. The MRSA isolate presented ST8-SCCmec III. 56.5% of isolates carried both the staphylococcal enterotoxin A (sea) and enterotoxin B (seb) genes. 83.6% of the S. aureus isolates were resistant to penicillin, all isolates were susceptible to quinupristin/dalfopristin, levofloxacin, teicoplanin and vancomycin. The most common risk factors for S. aureus carriage were being male, age ≤30 years, and nasal cavity cleaning habits.

CONCLUSIONS

Colonization by S. aureus was greater among male and young age (20-30 years) students and those with irregularity nasal cleaning. The S. aureus isolates selected were revealed into various sequence types and pulsotypes, indicating molecular heterogeneity among S. aureus isolates from the populations in the medical college in Guangzhou.

Analysis of the drug-resistant characteristics of Klebsiella pneumoniae isolated from the respiratory tract and CTX-M ESBL genes

The main aim of this study was to understand the relationship between the drug-resistant characteristics of Klebsiella pneumoniae and CTX-M-type extended spectrum β-lactamases (ESBLs), and to detect the distributions of CTX-M-type ESBLs in clinically isolated strains. CTX-M ESBL genes isolated from the clinical samples were amplified by polymerase chain reaction and identified by sequence analysis; the antibiotic susceptibility of the samples was determined using the Kirby-Bauer disc-diffusion method. One hundred and five strains among the 246 isolated strains of K. pneumoniae tested positive for ESBL production (42.68%); 92 of these produced CTX-M ESBLs. Of the 92 CTX-M ESBL strains, 81 produced CTX-M-1 ESBLs and 11 produced CTX-M-25 ESBLs. Fifty-seven of the CTX-M-1 ESBL- and six of the CTX-M-25 ESBL-producing bacteria had CTX-M ESBL genes that coexisted in the plasmid and chromosome. The Kirby-Bauer antibiotic susceptibility method revealed that CTX-M ESBL-positive strains showed a higher rate of resistance to cefazolin, cefoxitin, cefuroxime, ceftazidime, cefotaxime, aztreonam, levofloxacin, and cotrimoxazole, compared to the CTX-M ESBL-negative strains (P < 0.05). The CTX-M ESBL genes were commonly observed in the K. pneumoniae isolated from respiratory tract samples; these were significantly associated with the drug-resistant characteristics of K. pneumoniae to β-lactam antibiotics.

Simultaneous determination of eight flavonoids in the flowers of Matricaria chamomilla by high performance liquid chromatography

An HPLC method was developed for simultaneous determination of five flavones (apigenin, three apigenin 7-O-glucoside acylated derivatives, and luteolin) and three methoxylated flavonols in Matricaria chamomilla. Full validation of the assay was carried out including linearity, LODs, LOQs, precision, repeatability, stability, and accuracy. The results demonstrated that the method developed was simple, accurate, and reliable. Five batches of M. chamomilla samples were determined using the developed method, and total contents of the eight flavonoids ranged from 1.843 to 2.134 mg/g. Among them, the content of apigenin was the highest with values of 0.538 to 0.618 mg/g. In addition, the extract solution from M. chamomilla exhibited a significant dose-dependent inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity, with a 50% inhibition (SC50) at a concentration of 3.06 +/- 0.09 mg/mL, and the flavonoids apigenin-7-O-(6"-acetyl)-glucoside, luteolin, apigenin, eupatolitin, and chrysosplenol D played an important role in the antioxidant activities of the extract solution from M. chamomilla.

[Chemical constituents from rizomes of Homalomena occulta]

Column chromatography on silica gel and Sephadex LH-20 was used to study the chemical constituents of Homalomena occulta. The chemical structures of the separated compounds were elucidated by spectroscopic data analyseS. Twelve compounds were obtained and identified as 5-pentylresorcinol-b-glucoside (1), protocatechuic acid (2), 4-hydroxybenzoic acid (3), vanillic acid (4), 5-hydroxymethyl-2-furancarboxylic acid (5), 2-furoic acid (6), 5-hydroxymethyl-2-furfural (7), (R) -malic acid (8), (R) -dimethyl malate (9), trimethyl 1,2,3-propanetricarboxylate (10), 4-hydroxytetrahydrofuran-2-one (11) and (1S, 2S, 4S)-p-menthane-1,2, 4-triol (12). Among them, compound 1 was a new natural product, and compounds 4-12 were isolated from the genus for the first time.

[Status and thinking of supervision and management of Chinese herbal medicine]

The article briefly introduces the status of the supervision and administration of Chinese herbal medicine, and summarizes the problems existing in the process of supervision and management. Meanwhile provides the countermeasures and suggestions of strengthening the supervision and administration of Chinese herbal medicine.

[Understanding of strengthen supervision and administration of herbal extracts]

The article briefly introduces the development history and status of the supervision and administration of herbal extracts, and summarizes the problems existing in the process of supervision and management. Meanwhile provides the countermeasures and suggestions of strengthening the supervision and administration of herbal extracts.

Preparation of magnetic molecularly imprinted polymer for selective recognition of resveratrol in wine

The magnetic molecularly imprinted polymers (MMIPs) for resveratrol were prepared by using surface molecular imprinting technique with a super paramagnetic core-shell nanoparticle as a supporter. Rhapontigenin, which is the analogues of resveratrol, was selected as dummy template molecules to avoid the leakage of trace amount of resveratrol. Acrylamide and ethylene glycol dimethacrylate were chosen as functional monomers and cross-linker, respectively. The obtained MMIPs were characterized by using scanning electron microscopy, Fourier transform infrared spectrum, X-ray diffraction and vibrating sample magnetometer. High performance liquid chromatography was used to analyze the target analytes. The resulting MMIPs exhibited high saturation magnetization of 53.14emug(-1) leading to the fast separation. The adsorption test showed that the MMIPs had high adsorption capacity for resveratrol and contained homogeneous binding sites. The MMIPs were employed as adsorbent of solid phase extraction for determination of resveratrol in real wine samples, and the recoveries of spiked samples ranged from 79.3% to 90.6% with the limit of detection of 4.42ngmL(-1). The prepared MMIPs could be employed to selectively pre-concentrate and determine resveratrol from wine samples.