[Research progress on the impact of diet on the early-onset colorectal cancer]

The incidence of early-onset colorectal cancer has been gradually increasing in recent years. Studies have shown that early-onset CRC is closely related to modifiable risk factors such as diet, but there is still a lack of consistent conclusions and a systematic review of relevant research results. In this review, we comprehensively summarized the association between diet and the early-onset CRC, clarified the association and relative risk between different dietary patterns, common food types and nutrients and the occurrence of early-onset CRC, and elaborated the underlying physiological mechanisms. Enhancing the understanding of dietary risk factors, which are modifiable exogenous risk factors, is expected to serve as a reference for the formulation of primary prevention strategies for early-onset CRC.

[Epidemiological characteristics of early-onset colorectal cancer: a prospective cohort study from a single center]

Objective: To explore the differences in distribution of colorectal cancer-related risk factors between patients with early-onset colorectal cancer (EOCRC) and those with late-onset colorectal cancer (LOCRC) in a Chinese cohort, and to provide reference and guidance for the prevention, diagnosis, and treatment of EOCRC. Methods: Using data from the National Colorectal Cancer Cohort study cohort, 5377 patients with newly diagnosed colorectal cancer (CRC) attending the Department of Colorectal Surgery and Oncology of the Second Affiliated Hospital, Zhejiang University School of Medicine from June 2018 to February 2023 were included in the study cohort. Questionnaires capturing epidemiological features, including lifestyle and dietary habits, were administered. The patients were divided into two groups, the cut-off age being 50 years. Those aged ≥50 years were defined as having LOCRC and those aged <50 years as having EOCRC. Wilcoxon (continuous variates) or χ2 tests (categorical variates) were performed to compare differences in epidemiological features. Results: A total of 3799 people who had completed the questionnaire were included in this study, 491 of whom had EOCRC and 3308 LOCRC. The response rate to the questionnaire was 70.7%. The median ages of patients in the EOCRC and LOCRC groups were 43 and 66 years, respectively. There was a higher proportion of female patients (48.5% [253/491] vs. 35.8% [1184/3308], χ2=28.8, P<0.001) in the EOCRC than the LOCRC group. Patients with EOCRC and lower body mass index (medium 22.1 kg/m2 vs. 22.9 kg/m2, W=744 793, P=0.005) and lower proportion of abdominal obesity (87.2% [428/491] vs. 93.8% [3103/3308], χ2=38.3, P<0.001). Patients with EORC significantly less commonly reported a history of hypertension (5.9% [29/491] vs. 41.6% [1375/3308], χ2=231.8, P<0.001), diabetes (1.4% [7/491] vs. 14.4% [476/3308], χ2=63.6, P<0.001) and cardiovascular and cerebrovascular diseases (0.8% [4/491] vs. 7.3% [241/3308], χ2=28.6, P<0.001). However, the proportion of patients with a family history of CRC was significantly higher (P<0.05) in the EOCRC group (10.2% [50/491] vs. 6.9% [227/3 308], χ2=6.5, P=0.010]. In terms of lifestyle, patients with EOCRC had shorter sleep duration (median: 8.0 hours vs. 8.5 hours, W=578 989, P<0.001), and were less likely to participate in physical exercise (29.5% [145/491] vs. 38.7% [1281/3308] χ2=15.0, P<0.001) or engage in physical work (65.2% [320/491] vs. 74.1% [2450/3308], χ2=16.7, P<0.001). Meanwhile, in the EOCRC group a lower percentage of patients were smokers (29.3% [144/491] vs. 42.7% [1411/3308], χ2=46.9,P<0.001) and they smoked less (median 17.6 pack/year vs. 30.0 pack/year,W=55 850,P<0.001). Fewer patients in the EOCRC group habitually drank alcohol (21.0% [103/491] vs. 38.0% [1257/3308], χ2=57.5, P<0.001) or tea (17.5% [86/491] vs. 28.7% [948/3308], χ2=26.2, P<0.001) than in the LOCRC group. Compared with the LOCRC group, patients with EOCRC had a higher frequency of intake of fresh meat, fresh fruit, eggs, and dairy products and a lower frequency of intake of preserved meat and pickled vegetables; these differences are statistically significant (all P<0.05). There was no statistically significant difference in consumption of fresh vegetables or a high-sugar diet between the two groups (both P>0.05). Conclusions: This study highlights disparities in adverse lifestyle and dietary habits between patients in China with EOCRC versus LOCRC.

[Analysis of factors influencing the efficacy and prognosis of surgical treatment for primary malignant pelvic bone tumors]

Objective: To analyze the prognostic factors and the influence of surgical margin to prognosis. Methods: A retrospective analysis was performed for 208 pelvic tumors who received surgical treatment from January 2000 to December 2017 in our instituition. Survival analysis was performed using the Kaplan-Meier method and Log rank test, and impact factor analysis was performed using Cox regression models. Results: There were 183 initial patients and 25 recurrent cases. According to Enneking staging, 110 cases were stage ⅠB and 98 cases were stage ⅡB. 19 lesions were in zone Ⅰ, 1 in zone Ⅱ, 15 in zone Ⅲ, 29 in zone Ⅰ+Ⅱ, 71 in zone Ⅱ+Ⅲ, 29 in zone Ⅰ+Ⅳ, 35 in zone Ⅰ+Ⅱ+Ⅲ, 3 in zone Ⅰ+Ⅱ+Ⅳ, and 6 in zone Ⅰ+Ⅱ+Ⅲ+Ⅳ. Surgical margins including Intralesional excision in 7 cases, contaminated margin in 21 cases, marginal resection in 67 cases, and wide resection in 113 cases. Local recurrence occurred in 37 cases (17.8%), 25 cases were performed by reoperation and 12 cases received amputation finally. The 5-year recurrence rate of marginal resection was higher than wide resection (P＜0.05), and the recurrence-free survival rate of marginal resection was lower than wide resection (P＜0.05). There was significant differences in recurrence rate and recurrence-free survival rate between R0 and R1 resection (P＜0.05). 92 cases were not reconstructed and 116 cases were reconstructed after pelvic surgery. At the last follow-up, 63 patients (30.3%) died, and the 5-year, 10-year and 15-year survival rates were 70.4%, 66.8% and 61.3%, respectively. The 5-year survival rate of stage ⅠB and ⅡB tumor was 90.4% and 46.8%, respectively. There were 29 cases had postoperative wound complications (13.8%), 1 case with pelvic organ injury. The final function was evaluated in 132 patients, with an average MSTS score of 25.1±3.6. Cox multivariate analysis showed that surgical staging, R0/R1 margin and metastasis were independent prognostic factors for pelvic tumors. Conclusions: The safe surgical margin is the key factor for recurrence-free of pelvic tumor. The survival rate of stage ⅡB pelvic tumors was significantly lower than that of stage ⅠB tumors. Wound infection is the main postoperative complication. Surgical staging, R0/R1 margin and metastasis were independent prognostic factors of pelvic tumors.

Polycationic Open-Shell Cyclophanes: Synthesis of Electron-Rich Chiral Macrocycles, and Redox-Dependent Electronic States

π-Conjugated chiral nanorings with intriguing electronic structures and chiroptical properties have attracted considerable interests in synthetic chemistry and materials science. We present the design principles to access new chiral macrocycles (1 and 2) that are essentially built on the key components of main-group electron-donating carbazolyl moieties or the π-expanded aza[7]helicenes. Both macrocycles show the unique molecular conformations with a (quasi) figure-of-eight topology as a result of the conjugation patterns of 2,2',7,7'-spirobifluorenyl in 1 and triarylamine-coupled aza[7]helicene-based building blocks in 2. This electronic nature of redox-active, carbazole-rich backbones enabled these macrocycles to be readily oxidized chemically and electrochemically, leading to the sequential production of a series of positively charged polycationic open-shell cyclophanes. Their redox-dependent electronic states of the resulting multispin polyradicals have been characterized by VT-ESR, UV-vis-NIR absorption and spectroelectrochemical measurements. The singlet (ΔES-T = -1.29 kcal mol-1) and a nearly degenerate singlet-triplet ground state (ΔES-T(calcd) = -0.15 kcal mol-1 and ΔES-T(exp) = 0.01 kcal mol-1) were proved for diradical dications 12+2• and 22+2•, respectively. Our work provides an experimental proof for the construction of electron-donating new chiral nanorings, and more importantly for highly charged polyradicals with potential applications in chirospintronics and organic conductors.

Synthesis of π-Conjugated Chiral Aza/Boracyclophanes with a meta and para Substitution

We herein describe the synthesis of a new class of axially chiral aza/boracyclophanes (BDN1, BXN1, BDB1 and BXB1) using binaphthyls as chiral building blocks and the main-group (B/N) chemistry with tunable electronic effects. All macrocycles substituted with triarylamine donors or triarylborane acceptors are strongly luminescent. These macrocycles showed two distinct meta and para π-conjugation pathways, leading to the formation of quasi figure-of-eight and square-shaped conformations. Interestingly, comparison of such structural models revealed that the former type of macrocycles BXN1 and BXB1 gave higher racemization barriers relative to the other ones. The results reported here may provide a new approach to engineer the optical stability of π-conjugated chiral macrocycles by controlling π-substitution patterns. The ring constraints induced by macrocyclization were also demonstrated to contribute to the configurational persistence as compared with the open-chain analogues p-BTT and m-BTT.

The therapeutic effect of decitabine combined with HAG in acute myeloid leukemia: a retrospective case-control analysis

OBJECTIVE

Explore the efficacy of decitabine combined with homoharringtonine + cytarabine + granulocyte colony-stimulating factor (HAG) in the treatment of acute myeloid leukemia (AML).

PATIENTS AND METHODS

A retrospective analysis of clinical data of 125 patients with AML was done. Of them, 61 patients received a simple HAG treatment (HAG group), and 64 received decitabine combined with an HAG regimen (combined group). Treatment efficacy, immune function before and after the treatment, levels of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and incidence of adverse reactions in the two groups were compared.

RESULTS

The total response rate of the combined group (84.38%) was higher than that of the HAG group (65.63%) (p < 0.05). After the treatment, levels of CD4+ and CD4+/CD8+ in both groups increased and were significantly higher in the combined group compared to the HAG group. Levels of CD8+, bFGF and VEGF decreased compared to pre-treatment levels and were significantly lower in the combined group than in the HAG group (p < 0.05). There was no significant difference in the rate of adverse reactions between the two groups (p > 0.05).

CONCLUSIONS

Compared to HAG treatment alone, the combination of decitabine and HAG in the treatment of AML is safe, can significantly improve the immune function of the patients, regulate bFGF and VEGF levels, and improve overall treatment efficacy.

Priority list of potential endocrine-disrupting chemicals in food chemical contaminants: a docking study and in vitro/epidemiological evidence integration

Diet is an important exposure route of endocrine-disrupting chemicals (EDCs), but many unfiltered potential EDCs remain in food. The in silico prediction of EDCs is a popular method for preliminary screening. Potential EDCs in food were screened using Endocrine Disruptome, an open-source platform for inverse docking, to predict the binding probabilities of 587 food chemical contaminants with 18 human nuclear hormone receptor (NHR) conformations. In total, 25 contaminants were bound to multiple NHRs such as oestrogen receptor α/β and androgen receptor. These 25 compounds mainly include pesticides and per- and polyfluoroalkyl substances (PFASs). The prediction results were validated with the in vitro data. The structural features and the crucial amino acid residues of the four NHRs were also validated based on previous literature. The findings indicate that the screening has good prediction efficiency. In addition, the epidemic evidence about endocrine interference of PFASs in food on children was further validated through this screening. This study provides preliminary screening results for EDCs in food and a priority list for in vitro and in vivo research.

Sarcoeleganolides H-K, new anti-thrombotic cembranes from soft coral Sarcophyton elegans

Chemical investigation of soft coral the Sarcophyton elegans collected from the South China Sea led to the identification of four new cembranes, namely sarcoeleganolides H-K (1-4). Their structures and absolute configurations were established by 1D and 2D NMR spectroscopy, quantum chemical calculations of NMR chemical shifts and electronic circular dichroism (ECD) data analysis. Moreover, compound 2 exhibited moderate anti-thrombotic activity in zebrafish.

Two new spongian diterpene derivatives from the aquaculture sponge Spongia officinalis Linnaeus, 1759

2β,3α,19-Triacetoxy-17-hydroxyspongia-13(16),14-diene (1), a novel acetoxy diterpenoid, and 18-nor-2,17-hydroxyspongia-1,4,13(16),14-quaien-3-one (2), belonging to the rare 18-nor-spongian carbon skeleton, together with six related known metabolites (3‒8), were isolated from the aquaculture Spongia officinalis Linnaeus, 1759. Their structures were elucidated by comprehensive spectroscopic analysis, quantum chemical calculation of NMR parameters, and electronic circular dichroism (ECD). Compounds 3, 4, and 5 exhibited moderate inhibition against STAT3/NF-κB, HIF-1, Wnt signalling pathways. Compounds 1, 3, and 5 showed cytotoxicity activities against K562 cell line with IC₅₀ values of 7.3, 3.5, and 6.4 μM, respectively.

Ergonomic risk factors and work-related musculoskeletal disorders in clinical physiotherapy

Objectives

The purpose of this study was to objectively quantify and evaluate the ergonomic risk of clinical physiotherapy practices and evaluate physiotherapists for work-related musculoskeletal disorders and pain.

Methods

Twenty-nine physiotherapists in the rehabilitation department of a large-scale tertiary hospital were recruited in this study. The sampling period lasted for 2 weeks for each physiotherapist and interval sampling was adopted to avoid duplication of cases. Therapist posture during physiotherapy was captured, tracked and analyzed in real time using structured light sensors with an automated assessment program. The quantification of ergonomic risk was based on REBA (Rapid Entire Body Assessment) and the RPE (perceived physical exertion) scores of the therapists were recorded before and after treatment, respectively.

Results

Two hundred and twenty-four clinical physiotherapy cases were recorded, of which 49.6% were high risk and 33% were very high risk, with none of the cases presenting negligible risk. The positioning (p < 0.001) of physiotherapist had a considerable impact on ergonomic risk and pediatric physiotherapy presented a higher risk to physiotherapists than adults (p < 0.001). The RPE score of physiotherapist after performing physiotherapy was greater than before physiotherapy and was positively correlated with the REBA distribution.

Conclusion

Our study creates an automatic tool to assess the ergonomic risk of physiotherapy practices and demonstrates unacceptable ergonomic risk in common practices. The high prevalence of musculoskeletal disorders and pains recommends that rehabilitation assistance devices should be optimized and standard ergonomic courses should be included in physiotherapists' training plans.

[Identification of Chinese herbs in the Qing Royals--Fu Shen and Fu Shen Mu]

The use of Fu Shen and Fu Shen Mu as medicines has had a long history. Today Fu Shen is still taken as bulk medicinal materials, whereas Fu Shen Mu had disappeared in the medical market. Fu Shen, Yun Fu Shen, Bai Fu Shen, and Bao Mu Fu Shen were used in clinical application in the Qing Royals. Bai Fu Shen and Fu Shen Mu are still kept as speciment in the Palace Museum today. It was found that Bai Fu Shen in the Qing Royals was the same as Fu Shen after peeling and pine roots recorded in the herbal literatures of the Ming and Qing dynasties, with their character tests and historical analysis. It can be inferred that Fu Shen, Yun Fu Shen and Bai Fu Shen recorded in the Qing Royals were actually Fu Shen, with pine roots in sclerotia and after peeling and pine roots removed in processing. Bao Mu Fu Shen and Bao Fu Shen should refer to Fu Shen with pine roots. Fu Shen Mu should mean Fu Shen without white sclerotia and peel during processing. Fu Shen, currently used clinically, is Bao Mu Fu Shen in the Qing Dynasty. Fu Shen distinguishes greatly from Fu Shen Mu in their effects. Such identification and analysis of herbs provides a way of thinking for further hurb studies of the Qing Dynasty.

Jellynolide A, pokepola esters, and sponalisolides from the aquaculture sponge Spongia officinalis L

Jellynolide A, an unreported bicyclic diterpenoid with an unprecedented penta-substituted carbon skeleton which implied an irregular biogenic pathway, together with four pairs of rare phosphate triesters, (±)-pokepola ester B-E, one undescribed related racemic furanoterpenoid, (±)-sponalisolide C, one undescribed furanoterpenoid, (-)-sponalisolide D, and two known (±)-sponalisolide B and dendrolasin carboxylic acid were isolated from the aquaculture Spongia officinalis L. Their structures were elucidated by comprehensive spectroscopic analysis, quantum chemical calculation of NMR parameters, and electronic circular dichroism (ECD). The plausible biosynthetic pathway of jellynolide A was proposed. (±)-Pokepola ester C exhibited significant inhibition against Wnt, HIF1 signaling pathways. (+)-Pokepola ester B and (-)-pokepola ester D showed moderate cytotoxicity activities.

Spontaneous oxidation of I− in water microdroplets and its atmospheric implications

Water microdroplets can oxidize I− into I˙, presenting a previously unknown source of I˙ and I2 in atmospheric water.

[Current status and thoughts of non-surgical treatment of knee osteoarthritis]

Knee osteoarthritis (KOA) is a worldwide disease, and also the main cause of pain and disability in the motor system. Due to the aging population in China, extension of life expectancy and increased number of obese people, the number of people affected by KOA continues to surge. Neither surgical nor non-surgical treatment can change the disease process, but these interventions can reduce pain and disability. The treatment principle of KOA is to start with non-surgical treatment, which has been considered as the first choice for KOA patients due to its advantages of less complications, minimal invasiveness, and low medical cost. This article describes the non-surgical treatment of KOA, aiming to provide new insights into the clinical treatment of KOA.

[MiR- 4719 inhibits migration and invasion of human breast cancer cells via targeting ARHGAP36]

OBJECTIVE

To detect the expression of miR-4719 in breast cancer tissues and cells and explore its role in regulating invasion and migration of breast cancer cells.

OBJECTIVE

qRT-PCR was used to detect the expression of miR-4719 and ARHGAP36 in 30 pairs of human breast cancer tissues and adjacent tissues, two breast cancer cell lines (BT549 and MDA-MB- 231) and normal breast cells (MCF-10A). Bioinformatic methods were utilized to analyze the relationship between miR-4719 expression and overall survival of breast cancer patients and predict the potential target gene miR- 4719. miR-4719 mimics, ARHGAP36 shRNA and ARHGAP36 plasmids were transfected into breast cancer cells to test the effects of miR-4719 overexpression, ARHGAP36 knockdown and ARHGAP36 overexpression on cell migration and invasion using wound healing assay and Transwell assay. A dual-luciferase reporter assay was used to verify the direct binding between miR-4719 and 3'-UTR of ARHGAP36.

OBJECTIVE

Compared with those in adjacent tissues or normal breast cells, the expressions of miR-4719 were significantly decreased and the expression of ARHGAP36 was increased in breast cancer tissues (P < 0.001) and breast cancer cell lines (P < 0.01). A low expression of miR-4719 was correlated with a poorer overall survival of breast cancer patients (P < 0.05). Overexpression of miR-4719 and ARHGAP36 knockdown both significantly attenuated the invasion and migration abilities of breast cancer cells (P < 0.05). The expression of miR-4719 was inversely correlated to that of ARHGAP36 in breast cancer tissues (P < 0.01). Dual-luciferase reporter assay confirmed that ARHGAP36 was the target gene of miR-4719 (P < 0.01), and exogenous miR-4719 could significantly lower the expression of ARHGAP36 (P < 0.05). ARHGAP36 overexpression significantly reversed the inhibitory effects of miR-4719 mimics on migration and invasion of breast cancer cells (P < 0.05).

OBJECTIVE

The expression of miR-4719 is aberrantly decreased in breast cancer tissues to promote migration and invasion of breast cancer cells by up-regulating ARHGAP36 expression.

Osteopenia/osteoporosis develops in the early phase of disease in patients with idiopathic inflammatory myopathies

Objective: To study the relationship between different disease-related variables and bone mineral density (BMD) in patients with idiopathic inflammatory myopathies (IIMs).Method: Demographic and clinical data were retrospectively collected from the medical records of all patients diagnosed with IIMs during 2003-2018 in the Rheumatology Department, Sahlgrenska University Hospital, Gothenburg, Sweden. BMD measurements by dual-energy X-ray absorptiometry (DXA) were compared among three patient groups categorized according to the time when DXA was performed in relation to the diagnosis: during the first month, 2-6 months, and 7-24 months after diagnosis.Results: In total, 48 patients were included in the study. BMD correlated positively with body mass index and the presence of myositis-specific autoantibodies. As expected, age and diseases duration had negative associations with BMD. Importantly, osteopenia and osteoporosis were significantly more common in patients who underwent DXA at later time-points of the disease than in those who underwent DXA during the first month after diagnosis.Conclusions: Reduced BMD is common in patients with IIMs. The development of osteopenia/osteoporosis starts in the early phase of myositis (within 6 months), and immediate osteoporosis prophylaxis at diagnosis is necessary.

Utility of Contrast-Enhanced T2 FLAIR for Imaging Brain Metastases Using a Half-dose High-Relaxivity Contrast Agent

BACKGROUND AND PURPOSE

Efficient detection of metastases is important for patient' treatment. This prospective study was to explore the clinical value of contrast-enhanced T2 FLAIR in imaging brain metastases using half-dose gadobenate dimeglumine.

MATERIALS AND METHODS

In vitro signal intensity of various gadolinium concentrations was explored by spin-echo T1-weighted imaging and T2 FLAIR. Then, 46 patients with lung cancer underwent nonenhanced T2 FLAIR before administration of half-dose gadobenate dimeglumine and 3 consecutive contrast-enhanced T2 FLAIR sequences followed by 1 spin-echo T1WI after administration of half-dose gadobenate dimeglumine. After an additional dose of 0.05 mmol/kg, 3D brain volume imaging was performed. All brain metastases were classified as follows: solid-enhancing, ≥ 5 mm (group A); ring-enhancing, ≥ 5 mm (group B); and lesion diameter of <5 mm (group C). The contrast ratio of the lesions on 3 consecutive phases of contrast-enhanced T2 FLAIR was measured, and the percentage increase of contrast-enhanced T2 FLAIR among the 3 groups was compared.

RESULTS

In vitro, the maximal signal intensity was achieved in T2 FLAIR at one-eighth to one-half of the contrast concentration needed for maximal signal intensity in T1WI. In vivo, the mean contrast ratio values of metastases on contrast-enhanced T2 FLAIR for the 3 consecutive phases ranged from 63.64% to 83.05%. The percentage increase (PI) values of contrast-enhanced T2 FLAIR were as follows: PI_A < PI_B (P = .001) and PI_A < PI_C (P < .001). The degree of enhancement of brain metastases on contrast-enhanced T2 FLAIR was lower than on 3D brain volume imaging (P < .001) in group A, and higher than on 3D brain volume imaging (P < .001) in group C.

CONCLUSIONS

Small or ring-enhancing metastases can be better visualized on delayed contrast-enhanced T2 FLAIR using a half-dose high-relaxivity contrast agent.

Adoptive transfer of immunomodulatory M2 macrophages suppresses experimental autoimmune encephalomyelitis in C57BL/6 mice via blockading NF-κB pathway

Macrophages play important roles in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), and M2 macrophage may have anti-inflammatory effects. In this study, we elucidated the roles of M1 and M2 macrophages in the pathogenesis of EAE and the effects of treatment with M2 macrophages that target certain proinflammatory cytokines and with immunomodulatory preparations that beneficially influence the disease course. We found macrophages increased at the onset of clinical signs in the EAE group, consistent with an increased proportion of M1 macrophages and low numbers of M2 macrophages. As the disease progressed and the symptoms worsened, M1 macrophages decreased and M2 macrophages gradually increased until the peak. In the recovery stage, M2 macrophages gradually decreased. Treatment with M2 macrophages inhibited the nuclear factor kappa B (NF-κB) pathway, alleviated the symptoms of EAE, reduced inflammatory cell infiltration and demyelination in the central nervous system and decreased the numbers of macrophages in the spleens. BAY-11-7082, an NF-κB blocking agent, could reduce the total number of macrophages both in vivo and in vitro, effectively prevented EAE development and significantly inhibited EAE symptoms in mice. Our study demonstrates that macrophages may play a crucial role in the pathogenesis of EAE, while M2 macrophages have anti-inflammatory effects. Transfer of M2 macrophages to EAE mice can block the NF-κB pathway successfully and relieve EAE symptoms. Application of NF-κB blockers is useful in the prevention and treatment of EAE.

[Predictive value of sentinel lymph node biopsy in prognosis of acral melanoma]

Objective: To explore the application of sentinel lymph node biopsy (SLNB) and its prognostic value in the treatment of acral melanoma. Methods: We retrospective analyzed 118 patients who underwent sentinel lymph node biopsy from Mar 2012 to Jun 2019 with effective follow-up data available in our institute. We ruled out palpable regional lymph node metastasis with preoperative imaging of MRI and ultrasonography, used the (99)Tc(m)-Dextran (Dx) as a tracer, with intraoperative γ-ray probe positioning for SLN capture. Wide resection and reconstruction in primary lesion followed by complete lymph node dissection were underwent SLN positive patients. Cox regression model were used to analyze the prognostic factors. Results: The patients had an average disease history of 53.6 months (2-360 months), the primary lesion located at hands and feet in 84 cases, while 27 cases were subungual and 7 cases were cutaneous. The mean Breslow depth was 3.6 mm, and 72 cases (61.0%) combined with ulceration. The average number of SLN was 2.8, the SLN positive rate was 24.6% (29/118), and the false-negative rate was 2.5% (3/118). There were 24 cases (20.3%) developed clinically positive metastasis, including 7 cases displayed distant metastasis combined with lymph node metastasis (5.9%), 8 cases with clinically positive lymph node metastasis alone (6.8%), and 9 cases with distant metastasis (7.6%). There were 33 patients in stage Ⅰ, 56 patients in stage Ⅱ and 29 patients in stage Ⅲ, with a 5-years overall survival rate of 69.5%. The Breslow depth is an independent risk factor of SLN positive. While Breslow depth, SLN status, SLN positive number and clinically detectable metastasis are independent prognostic factors of the overall survival (P<0.05). Conclusions: Patients without clinically positive regional lymph node metastasis under imaging and physical examinations, SLNB can provide accurate pathologic staging and play an accurate prediction role in the prognostic evaluation. SLNB should be carried out routinely in clinical practice.

[Preliminary observation on the treatment of primary pterygium with modified conjunctival transplantation and amniotic membrane transplantation combined with use of interferon eye drops]

Objective: To observe the clinical effect of modified conjunctival transplantation and amniotic membrane transplantation combined with use of interferon (IFN) alpha-2b eye drops in the treatment of primary pterygium. Methods: This was a prospective case-control study. Patients with primary pterygium were treated from June 1, 2018 to December 31, 2018 in the Department of Ophthalmology, Beijing Tongren Hospital, and they were divided into two groups (the experimental group and the control group) by the method of randomized block design. Patients in the experimental group received modified conjunctival transplantation and amniotic membrane transplantation combined with use of IFN alpha-2b eye drops, while patients in the control group received pterygium resection combined with conjunctival autograft transplantation. The pterygium type and size were observed before operation, while visual acuity, intraocular pressure and anterior segment details were recorded either. The follow-up was done at 1 week, 2 weeks, 1 month, 3 months, 6 months and 12 months after operation. The visual acuity, corneal epithelial defect, and pterygium recurrence were observed. All data in this manuscript are enumeration data, the expected frequency of pterygium type distribution in the two groups was more than 5, and the chi square test was used, fisher's exact test was used to compare the other data between the two groups. Results: Seventy patients (77 eyes) with pterygium were in this study, including 30 males and 40 females, aged from 50-70 years old. There were 35 cases (38 eyes) in the experimental group and 35 cases (39 eyes) in the control group. 12 months after operation there were 54 cases (60 eyes) including 28 cases (30 eyes) in the experimental group and 26 cases (30 eyes) in the control group with complete data. The corneal epithelium defects of 1 eye in each group was repaired within 7-14 days after operation, and the rest eyes were completely repaired within 7 days after operation. There was no significant difference in the distribution of corneal epithelial healing between the two groups (P= 1.00). There was no significant difference between the two groups in the number of eyes distribute with decreased visual acuity (2 eyes in each group), stable visual acuity (15 eyes in the experimental group and 23 eyes in the control group), and improved visual acuity (13 eyes in the experimental group and 5 eyes in the control group) (P=0.053). There was no recurrence in the two groups at 12 months after surgery, and there was no significant difference between the two groups in the number of patients with conjunctival hyperplasia of grades 1, 2 and 3 (P=0.405). Conclusions: Modified conjunctival transplantation and amniotic membrane transplantation combined with use of IFN alpha-2b eye drops got low recurrence rate for primary pterygium and less damage to the healthy conjunctival tissue. This combined treatment strategy provides a new choice for the treatment of pterygium. (Chin J Ophthalmol, 2020, 56: 768-773).

Preoperative status and treatment of osteoradionecrosis of the jaw: a retrospective study of 252 cases

Osteoradionecrosis of the jaw (ORNJ) is one of the most devastating and progressive complications of head and neck radiotherapy. It can cause emaciation, deformity, and pathological fractures, resulting in decreased quality of life. The aim of this study was to evaluate the preoperative index and outcomes of treatment for ORNJ. A retrospective study of 252 ORNJ cases treated at one institution between January 2010 and January 2018 was made. The abnormal items from the preoperative examination and follow-up after different treatments were recorded, and the differences between the noteworthy items were compared using univariate and multivariate models. Most ORNJ patients in the middle and late stages had abnormal items, such as hypoproteinaemia, anaemia, and leucocytosis. Partial mandibulectomy with flap reconstruction was significantly more effective than without reconstruction. Advanced ORNJ patients tended to have more abnormal items, which might have a negative influence on treatment. For better outcomes, it is essential and effective to completely remove the necrotic lesion and reconstruct it with a flap. The surgeons should provide sufficient perioperative management and strive for suitable surgical treatment.

Suppression of p38/HBP1 pathway alleviates hyperosmotic stress-induced senescent progression of chondrocyte senescence

This study aims to explore the effect of p38 mitogen-activated protein kinase and its downstream target HMG-box transcription factor 1 (HBP1) in the chondrocyte (CH) senescence caused by hyperosmotic stress. Human cartilage tissue with or without osteoarthritis (OA) were collected to detect the differential expression of p38 and HBP1 by Western blot. CHs were isolated from cartilage without OA and used the hyperosmotic medium to accelerate CH senescence in vitro. A p38 inhibitor and siRNA were used to mediate the expression of p38 and HBP1. The viability of CHs was determined by cell counting kit 8 (CCK8) assay. CH-related mRNA expression was analyzed by quantitative real-time polymerase chain reaction (RT-PCR). Immunofluorescence was also used to detect collagen II and beta-galactosidase expression. Senescent cells were increased in both OA cartilage and hyperosmotic stress treatment with a marked upregulation of p38 and HBP1. Suppression of p38 activation reversed the hyperosmotic stress-induced CH senescence and led to an inhibition of HBP1, p16, Runx-2, MMP-13, collagen X expression, and an upregulation of collagen II and SOX-9 expression. Moreover, the silencing of HBP1 also played a protective effect on CH senescence. The suppression of the p38/HBP1 pathway alleviates the hyperosmotic stress-induced senescent progression of CHs.

High-quality high-order harmonic generation through preplasma truncation

By introducing preplasma truncation to cases with an initial preplasma scale length larger than 0.2λ, the efficiency of high-order harmonics generated from relativistic laser-solid interactions can be enhanced by more than one order of magnitude and the angular spread can be confined into near-diffraction-limited divergence. Numerical simulations show that density truncation results in more compact oscillation of the surface electron sheet and the curvature of the reflection surface for the driving laser is greatly reduced. This leads to an overall improvement in the harmonic beam quality. More importantly, density truncation makes the harmonic generation weakly dependent on the preplasma scale length, which provides a way to relax the extremely high requirement on the temporal contrast of the driving laser pulse. A feasible scheme to realize the required preplasma truncation is also proposed and demonstrated by numerical simulations.

[Synchronous multicentric osteosarcoma: treatment and prognostic factor analysis]

Objective: To identify the clinical outcome and prognostic factors of synchronous multicentric osteosarcoma (SMOS). Methods: The clinical data of 2 602 conventional osteosarcoma patients admitted to Beijing Jishuitan Hospital from January 1995 to June 2018 were retrospectively analyzed. Finally, 56 (2.1%) cases were confirmed as SMOS according to clinical and imaging database, medical record and pathological results.All epidemiological data of SMOS cases,initial diagnosis time, tumor site, number of lesions, chemotherapy, surgical treatment, alkline phosphatase (AKP),lactate dehydrogenase (LDH) and oncological results were collected in our institution. The Survival rate, comparison of various parameters, univariate analysis and multivariate Cox regression were performed with statistical software. Results: There were 41 males and 15 females enrolled in this research, the median and mean ages were 15 and 18 years (range, 8-50 years) respectively. All of them were multi-site involved, whereas the initial complaints of sites distribution were 32 cases of femur, 13 cases of tibia, 4 cases of humerus, 3 cases of fibula, 2 cases of spine, 1 case of sternum and 1 case of calcaneus. Forty-four of 56 cases performed adjuvant chemotherapy and 31 of them underwent surgical treatment. The mean follow-up time was 15.4 (range, 1-186) months. Thirty-five cases died of disease at the end of the follow-up. The 5-year survival rate was 10.4%. According to the number of lesions stratification, the 2-year survival rates in patients with low (<5 sites) and high (≥5 sites) tumor load was 33.6% and 0, respectively (χ(2)=6.697, P=0.010). The 2-year survival rate of chemotherapy and non-chemotherapy patients was 20.8% and 0, respectively (χ(2)=6.998, P=0.008), the value of AKP after chemotherapy(median: 272 IU/L) significantly decreased when compared with that at the initial diagnosis (median: 454 U/L) (Z=-3.274, P=0.001).The 2-year survival rate in patients with and without standard chemotherapy was 55.6% and 0, respectively (χ(2)=8.798, P=0.003). The 2-year survival rate was 25.0% in the surgical group and 0 in the non-surgical group, respectively (χ(2)=7.942, P=0.005). Multivariate cox regression analysis with the forward Wald method indicated that standard chemotherapy was the only variable contributor to survival and prognosis of multifocal osteosarcoma. Conclusions: SMOS has low survival rate and poor prognosis. Chemotherapy and surgery can improve the survival rate, standard chemotherapy is an independent prognostic factor.

Stable DHLA–PEG capped PbS quantum dots: from synthesis to near-infrared biomedical imaging

Stability, biocompatibility and near-infrared photoluminescence of PbS nanocrystals capped with PEG-based ligands open up realistic prospects for non-invasive bioimaging applications.

Low temperature difference thermoacoustic prime mover with asymmetric multi-stage loop configuration

Environmentally friendly and low-cost technologies to recover low-grade heat source into usable energy can contribute to ease the energy shortage. Thermoacoustic technology is expected as one promising approach in this ascendant field. In this work, the multi-stage looped thermoacoustic prime movers with asymmetric configuration, which can provide travelling-wave resonator and appropriate acoustic field for efficient regenerator, have been proposed and experimentally studied. The presented looped thermoacoustic prime movers can start to oscillate with quite low temperature difference along the regenerator. The lowest onset temperature difference obtained in the experiments is only 17 °C (the corresponding heating temperature is 29 °C), which can be achieved in both three-stage and four-stage looped thermoacoustic prime movers, with CO2 of 1 MPa or 1.5 MPa as the working fluid. An electric generator driven by a three-stage looped thermoacoustic prime mover with low heating temperature was tested to achieve the acoustic to electric conversion.

Correlation between methylation of the p16 promoter and cervical cancer incidence

OBJECTIVE

To study the methylation of the promoter of the p16 gene in cervical cancer patients and explore the correlation between methylation and the incidence of cervical cancer.

PATIENTS AND METHODS

We recruited 78 patients with cervical cancer and 48 healthy individuals. The methylation-specific PCR was used to detect the methylation status in the promoter of the p16 gene. The mRNA expression of p16 was studied by quantitative fluorescence PCR. The protein expression of p16 was monitored by Enzyme-linked immunosorbent assay (ELISA) and Western blot. Immunohistochemistry was applied to detect the expression and distribution of p16 in cervical tissues.

RESULTS

The methylation sequencing results showed that samples from cervical cancer patients had a methylation rate of 78.52% in the p16 gene promoter region compared with a much lower rate of 9.8% in the control group (9.8%). Quantitative fluorescence PCR indicated that the p16 mRNA expression was significantly reduced in cervical cancer patients compared with controls. ELISA and Western blot results showed that expression of the p16 protein in cancer tissue was 0.81 ± 0.12 µg/l, whereas in the healthy controls it was 3.21 ± 0.24 µg/l. Immunohistochemical results showed that the p16 protein was mainly present in the cytoplasm. The rate of p16 positive cells in the healthy cervical tissue 83.29% was higher than in cervical cancer 10.18%.

CONCLUSIONS

The methylation of the p16 gene promoter could significantly reduce p16 expression, losing its tumor suppressor activity and promoting the development of cervical cancer.

Association between single nucleotide polymorphisms in AKT1 and the risk of prostate cancer in the Chinese Han population

AKT1, also known as v-akt murine thymoma viral oncogene homolog 1, is involved in the regulation of cell-survival and anti-apoptotic activities, which may affect the pathogenesis of various cancers. However, the association between genetic variants of AKT1 and the risk of developing prostate cancer has not been investigated before. This study investigated the associations between three polymorphisms (rs1130214, rs3730358, and rs2494732) in AKT1 and the risk of development of prostate cancer in the Chinese Han population. Sequenom MassARRAY & iPLEX technology were used to genotype these polymorphisms in 493 Chinese Han patients with prostate cancer and 309 age-matched healthy individuals. Compared to the CC genotype of the rs3730358 polymorphism, the CT genotype of the same polymorphism was strongly associated with a decreased risk of prostate cancer (OR = 0.617, 95%CI = 0.390-0.976, P = 0.037). However, there was no significant difference between the allele frequency of the rs3730358 polymorphism and those of the other two polymorphisms (P > 0.05). Moreover, no significant difference was found in the haplotype analysis (P > 0.05). Our study found that the variant genotype CT of rs3730358 of AKT1 was associated with a decreased risk of prostate cancer, which suggested that this polymorphism could play an important role in the development of the disease.

Effect of Oleracein E, a Neuroprotective Tetrahydroisoquinoline, on Rotenone-Induced Parkinson's Disease Cell and Animal Models

Oleracein E (OE), a tetrahydroisoquinoline possessing potent antioxidant activity, was first isolated from a traditional Chinese medicine, Portulaca oleraea L., and is hypothesized to be a neuroprotectant. In the present study, we evaluated the effects of racemic OE on rotenone-induced toxicity in Parkinson's disease (PD) cell and animal models. Pretreatment with OE (10 μM, 2 h) decreased lactic acid dehydrogenase (LDH) release and the apoptosis rate in rotenone (5 μM, 24 h)-treated SH-SY5Y human neuroblastoma cells. Further mechanistic study indicated that OE reduced reactive oxygen species (ROS) levels, inhibited extracellular signal-regulated kinase (ERK) 1/2 phosphorylation, reduced rotenone-induced up-regulation of the proapoptotic protein Bax, and prevented cytochrome C release and caspase-3 activation. In a rotenone-treated (intragastric 30 mg/(kg·d), 56 d) C57BL-6J mouse model, OE (intragastric 15 mg/(kg·d), 56 d) improved motor function, as indicated by an increased moving distance in the spontaneous activity test and sustained time on the rota-rod test. OE also elevated superoxide dismutase (SOD) activity, decreased malonaldehyde content, and reduced ERK1/2 phosphorylation in the midbrain and striatum of mice treated with rotenone. Furthermore, OE preserved tyrosine hydroxylase-positive neurons and maintained the density of dopaminergic (DAergic) fibers in the substantia nigra pars compacta (SNpc). Some of the effects of OE on PD models were similar to those of the positive control selegiline hydrochloride. Our results demonstrated that OE protects DAergic neurons against rotenone toxicity through reducing oxidative stress and down-regulating stress-related molecules. OE is worth exploring further for its neuroprotectant properties in the prevention and treatment of PD.

Rapamycin protects against neuronal death and improves neurological function with modulation of microglia after experimental intracerebral hemorrhage in rats

Intracerebral hemorrhage (ICH) results in a devastating brain disorder with high mortality and poor prognosis and effective therapeutic intervention for the disease remains a challenge at present. The present study investigated the neuroprotective effects of rapamycin on ICH-induced brain damage and the possible involvement of activated microglia. ICH was induced in rats by injection of type IV collagenase into striatum. Different dose of rapamycin was systemically administrated by intraperitoneal injection beginning at 1 h after ICH induction. Western blot analysis showed that ICH led to a long-lasting increase of phosphorylated mTOR and this hyperactivation of mTOR was reduced by systemic administration of rapamycin. Rapamycin treatment significantly improved the sensorimotor deficits induced by ICH, and attenuated ICH-induced brain edema formation as well as lesion volume. Nissl and Fluoro-Jade C staining demonstrated that administration with rapamycin remarkably decreased neuronal death surrounding the hematoma at 7 d after ICH insult. ELISA and real-time quantitative PCR demonstrated that rapamycin inhibited ICH-induced excessive expression of TNF-α and IL-1β in ipsilateral hemisphere. Furthermore, activation of microglia induced by ICH was significantly suppressed by rapamycin administration. These data indicated that treatment of rapamycin following ICH decreased the brain injuries and neuronal death at the peri-hematoma striatum, and increased neurological function, which associated with reduced the levels of proinflammatory cytokines and activated microglia. The results provide novel insight into the neuroprotective therapeutic strategy of rapamycin for ICH insult, which possibly involving the regulation of microglial activation.

Change in serum TSH levels within the reference range was associated with variation of future blood pressure: a 5-year follow-up study

Controversy exists on the relationship between serum thyrotropin (TSH) and blood pressure, and only a few prospective studies are available up to now. The study aimed to investigate the association between serum TSH within the reference range and blood pressure through a 5-year follow-up study. A total of 623 subjects with normal TSH were followed up for 5 years, including the measurement of demographic data, blood pressure, height, weight and serum TSH. Finally, 531 subjects were included in this prospective study. Body mass index (BMI), prevalence of hypertension, and systolic and diastolic blood pressure were all higher at follow-up than at baseline. Adjusted for age, gender, smoking status, BMI and homoeostasis model assessment of insulin resistance (HOMA-IR) at baseline, multiple linear regression analyses found no relationship between serum TSH at baseline and levels of blood pressure at follow-up, but the changes in serum TSH levels during follow-up was positively associated with the changes in systolic blood pressure (B=2.134, P<0.05), which became more significant in women but not significant in men. The change of systolic blood pressure in group of TSH increase >0.5 mIU l^-1 was significantly higher than in group of TSH decrease >0.5 mIU l^-1 within reference, after adjusting for age, gender, smoking status, BMI and HOMA-IR at baseline. This result became more significant in women, but no statistical significance was observed in men. Co-variation with serum TSH levels and blood pressure was observed during 5-year follow-up among people with normal TSH.

Differentiation-inducing effects of betamethasone on human glioma cell line U251

We studied the differentiation-inducing effect of beta-methasone on human glioma cell line U251 cultured in vitro, and the underlying mechanism. U251 cells were divided into two groups: control group cells, cultured in Dulbecco's Modified Eagle's medium containing 10% fetal bovine serum; and medication group cells, treated with 15 μM betamethasone. Morphological cell changes were observed by inverted microscope, cell cycle changes were ascertained by flow cytometry, and vimentin expression was checked by immunocytochemistry. The expression levels of extracellular signal-regulated protein ki-nase (ERK), phosphorylated ERK (pERK), and glial fibrillary acidic protein (GFAP) were assessed by western blot. Compared with the control group, U251 cell processes increased significantly, but declined 96 h after betamethasone took effect. After 48 h, the percentage of S-phase cells decreased significantly (28.77 to 20.42%; P = 0.014); the percent-age of strongly positive vimentin cells decreased significantly (91 to 51%; P = 0.0092); and the ratio of expression of GFAP protein to the internal control β-actin increased significantly (0.24 to 0.53; P = 0.1). The level of ERK protein did not change significantly 48 and 96 h after the action of betamethasone, and the pERK/ERK ratios were 0.37 and 0.23, respectively, which were significantly reduced compared with the control group (P = 0.028 and 0.006). Betamethasone has a significant effect on the induction and differentiation of U251 cells, and its mechanism may be related to the inhibition of the abnormal activation of the ERK signal pathway.

A short-wavelength infrared emitting multimodal probe for non-invasive visualization of phagocyte cell migration in living mice

For the non-invasive visualization of cell migration in deep tissues, we synthesized a short-wavelength infrared (SWIR) emitting multimodal probe that contains PbS/CdS quantum dots, rhodamine 6G and iron oxide nanoparticles. This probe enables multimodal (SWIR fluorescence/magnetic resonance) imaging of phagocyte cell migration in living mice.

Blockade of the CXCR6 signaling inhibits growth and invasion of hepatocellular carcinoma cells through inhibition of the VEGF expression

Chemokines have been shown to play a critical role in tumor development and progression. However, little is known about the function and molecular mechanisms of CXCR6 in multiple malignancies. In the present study, we aimed to investigate the role of CXCR6 in human hepatocellular carcinoma (HCC). The expression of CXCR6 was examined by immunohistochemical assay using a tissue microarray procedure. A loss-of-function experiment was performed to explore the effects of lentivirus-mediated CXCR6 shRNA (shCXCR6) on cell proliferation and invasive potential by MTT and Transwell assays in HCC cell line (SMMC-7721). It was found that the expression of CXCR6 protein was significantly increased in HCC tissues compared with that in adjacent non-cancerous tissues (ANCT) (63.04&#x0025; vs 36.96&#x0025;, P=0.019), and correlated with the lymph-vascular space invasion in HCC patients (P=0.038). Knockdown of CXCR6 repressed cell proliferation and invasion of HCC cells followed by the down-regulation of vascular endothelial growth factor (VEGF). Taken together, our findings show that high expression of CXCR6 is positively associated with distant invasion of HCC patients, and blockade of CXCR6 signaling suppresses the growth and invasion of HCC cells through inhibition of the VEGF expression, suggesting that CXCR6 may represent a promising therapeutic target for the treatment of HCC.

A comprehensive genetic study reveals a crucial role of CYP90D2/D2 in regulating plant architecture in rice (Oryza sativa)

Brassinosteroids (BRs) are essential regulators of plant architecture. Understanding how BRs control plant height and leaf angle would facilitate development of new plant type varieties by biotechnology. A number of mutants involved in BR biosynthesis have been isolated but many of them lack detailed genetic analysis. Here, we report the isolation and characterization of a severe dwarf mutant, chromosome segment deleted dwarf 1 (csdd1), which was deficient in BR biosynthesis in rice. We isolated the mutant by screening a tissue culture-derived population, cloned the gene by mapping, and confirmed its function by complementary and RNAi experiments, combined with physiological and chemical analysis. We showed that the severe dwarf phenotype was caused by a complete deletion of a cytochrome P450 gene, CYP90D2/D2, which was further confirmed in two independent T-DNA insertion lines in different genetic backgrounds and by RNA interference. Our chemical analysis suggested that CYP90D2/D2 might catalyze C-3 dehydrogenation step in BR biosynthesis. We have demonstrated that the CYP90D2/D2 gene plays a more important role than previously reported. Allelic mutations of CYP90D2/D2 confer varying degrees of dwarfism and leaf angle, thus providing useful information for molecular breeding in grain crop plants.

High-speed impact test using an inertial mass and an optical interferometer

A high-speed impact testing method for evaluating mechanical properties of materials is proposed using an inertial mass and a dual beat-frequencies laser Doppler interferometer (DB-LDI). In this method, an inertial mass levitated using an aerostatic linear bearing is made to collide with the material being tested at a high initial velocity. During the collision, the velocity of the mass, which is even higher than the critical velocity (±0.56 m/s) defined by the frequency difference of the Zeeman laser, is accurately measured using the DB-LDI. The position, acceleration, and impact force of the mass are calculated from the measured velocity. Using the proposed method, the mechanical properties of a visco-elastic material under a high-speed impact loading condition can be accurately evaluated.

Inactivation of salmonella on tomato stem scars by edible chitosan and organic Acid coatings

This study was conducted to investigate the efficacy of antimicrobial coatings for inactivation of Salmonella on the surface of tomato stem scars. Scars were inoculated with a four-strain cocktail of Salmonella (serovars Montevideo, Newport, Saintpaul, and Typhimurium) and coated with acid-chitosan solutions. The chitosan coating with three acids (3A plus chitosan), the chitosan coating with one acid, and the three-acid solution without chitosan reduced the populations of Salmonella by 6.0, 3.6, and 5.3 log CFU per stem scar, respectively. Addition of allyl isothiocyanate (10 μl/ml) to the 3A plus chitosan coating did not significantly increase (P > 0.05) the antimicrobial efficacy. Although the populations of Salmonella in the controls (ca. 7.5 log CFU per stem scar) did not change significantly throughout the 14-day storage period at 10° C, Salmonella cells were reduced to undetectable levels (< 0.7 log CFU per stem scar) in the samples treated with 3A plus chitosan coating after two days of storage, and no growth was observed for the remaining storage period. Results from this study demonstrate that coatings of acid plus chitosan provide an alternative antimicrobial intervention for decontamination of tomatoes.

Local structure of NiAl compounds investigated by extended X-ray absorption fine-structure spectroscopy

The local structures of pure NiAl and Ti-, Co-doped NiAl compounds have been obtained utilizing extended X-ray absorption fine-structure (EXAFS) spectroscopy. The results provide experimental evidence that Ni antisite defects exist in the Ni-rich NiAl compounds. The site preference of Ti and Co has been confirmed. Ti occupies the Al sublattice, while Co occupies the Ni sublattice. The structure parameters obtained by EXAFS were consistent with the X-ray diffraction results. Owing to the precipitation of α-Cr, the local structure of NiAl-Cr has not been obtained, making the site preference of Cr unclear.

Ectopic expression of glucagon receptor in skeletal muscles improves glucose homeostasis in a mouse model of diabetes

AIMS/HYPOTHESIS

Excessive secretion of glucagon partially contributes to the development of diabetic hyperglycaemia. However, complete blocking of glucagon action will lead to adverse effects, since glucagon exerts certain beneficial effects via its receptor in many organs. We aimed to study the effects of a 'decoy receptor' for circulating glucagon on modulating beta cell function and glucose homeostasis in mice by over-producing the glucagon receptor (GCGR) in skeletal muscles.

METHODS

We generated transgenic mice in which the expression of Gcgr is driven by the muscle specific creatine kinase (Mck) promoter, and assessed the effects of glucagon on the modulation of glucose homeostasis under conditions of extremes of glucose influx or efflux.

RESULTS

Mck/Gcgr mice showed increased circulating levels of glucagon and insulin, resulting in an unchanged ratio of glucagon-to-insulin. The levels of hepatic glucose-6-phosphatase (G6PC) and fructose-1,6-bisphosphatase (F1,6P2ase) were significantly decreased, whereas the phosphorylation level of pancreatic cAMP-response-element-binding-protein (CREB) was significantly increased in these transgenic mice. Under basal conditions, the mice displayed normal blood glucose levels and unchanged glucose tolerance and insulin sensitivity when compared with their age-matched wild-type (WT) littermates. However, following multiple low-dose streptozotocin injections, Mck/Gcgr mice exhibited a delay in the onset of hyperglycaemia compared with the WT controls. This was associated with preserved beta cell mass and beta cell secretory capacity in response to glucose challenge.

CONCLUSIONS/INTERPRETATION

We suggest that mild and chronic hyperglucagonaemia, through a strategy involving neutralising peripheral glucagon action, provides beneficial effects on beta cell function and glucose homeostasis. Mck/Gcgr mice thus represent a novel mouse model for studying the physiological effects of glucagon.