[Effects of climate changes on the distribution of Rhipicephalus microplus in China]

OBJECTIVE

To identify the environmental factors affecting the geographical distribution of Rhipicephalus microplus in China, and to examine the impact of climate changes on the distribution of R. microplus in China.

METHODS

The national and international publications pertaining to the geographical distribution of R. microplus in China were retrieved, and the geographical location was extracted. The suitable habitats of R. microplus and the dominant environmental factors affecting the distribution of suitable habitats of R. microplus were predicted in China based on the geographical data and environmental variables using the ArcGIS 10.7 software and the maximum entropy model.

RESULTS

Among the main climatic factors affecting the geographical distribution of R. microplus in China, the factors contributing more than 10% to the suitable habitats of R. microplus mainly include the annual mean precipitation (38.2%), the average temperature of the coldest quarter (28.4%) and the precipitation of the driest month (14.2%). The current suitable habitats of R. microplus were mainly found in southern China, and the high-, medium- and low-suitable areas accounted for 8.6%, 13.1% and 10.5% of the total land area of China, respectively. The suitable habitats of R. microplus were predicted to increase by 399 800 km² in China using the maximum entropy model under the RCP 4.5 emissions scenario in 2070, and the emerging suitable habitats were mainly distributed in Gansu Province, Ningxia Hui Autonomous Region, Qinghai Province, Hebei Province, Shaanxi Province, Liaoning Province, Inner Mongolia Autonomous Region, Shandong Province, Sichuan Province and Tibeten Autonomous Region. In addition, the suitable habitats of R. microplus were predicted to show an overall expansion towards northward from present to 2070.

CONCLUSIONS

Climate changes affect the distribution of suitable habitats of R. microplus in China, and annual mean precipitation may be a key factor affecting the distribution of suitable habitats of R. microplus.

[Effects of environmental factors on the distribution of suitable habitats of Ixodes ovatus in China]

OBJECTIVE

To identify the environmental factors affecting the distribution of suitable habitats of Ixodes ovatus, and to examine the effects of environmental changes on the distribution of suitable habitats of I. ovatus.

METHODS

Data pertaining to the distribution of I. ovatus in China were captured by literature review. The distribution of suitable habitats of I. ovatus in China was simulated using the maximum entropy model with the environmental variable data and the I. ovatus distribution data. In addition, the potential distribution of suitable habitats of I. ovatus was predicted based on the 2050 and 2070 environmental data.

RESULTS

The current suitable habitats of I. ovatus cover 3.11 million km², accounting for 32.28% of the total land area of China, and they are mainly concentrated in southwestern and northwestern China. Among the screened 16 environmental factors, the standard deviation of seasonal variation of temperature, average annual precipitation and altitude were predominant environmental factors affecting the distribution of suitable habitats of I. ovatus, and these three variables contributed 76.5% to the distribution of suitable habitats of I. ovatus in China. The suitable habitats of I. ovatus were predicted to showing a tendency towards expansion to northwestern and northeastern China in 2050 and 2070, and the proportion of highly suitable habitats of I. ovatus was predicted to increase.

CONCLUSIONS

Moderate climate, adequate precipitation and high altitude are favorable for the survival of I. ovatus. Future climate changes may cause expansion of suitable habitats of I. ovatus in China.

[Prediction of suitable habitats of Ixodes persulcatus in China]

OBJECTIVE

To evaluate the effects of environmental factors the distribution of Ixodes persulcatus, and to predict the future suitable habitats of I. persulcatus in China.

METHODS

The known distribution sites of I. persulcatus in China were captured from national and international published literatures. The effects of 14 environmental factors on the distribution of I. persulcatus were examined using the Jackknife test, including mean annual temperature, mean monthly temperature range, isothermality, temperature seasonality, maximum temperature of the warmest month, minimum temperature of the coldest month, temperature annual range, mean temperature of the wettest quarter, mean temperature of the driest quarter, mean temperature of the wet-test quarter, mean temperature of the coldest quarter, annual mean precipitation, precipitation of the wettest month, precipitation of the driest month, precipitation seasonality, precipitation of the wettest quarter, precipitation of the driest quarter, precipitation of the warmest quarter, precipitation of the coldest quarter, elevation, slope, aspect and vegetation. The suitable habitats of I. persulcatus were predicted in China using the maximum entropy model and ArcGIS 10.7 software with the environmental factors.

RESULTS

Currently, the highly suitable habitats of I. persulcatus covered an area of 886 600 km² in China, which were predominantly located in northeastern China. The environmental factors that contributed more than 10% to the distribution of the suitable habitats of I. persulcatus in China included annual temperature variation range (39.1%), the coldest quarterly precipitation (23.2%), and the annual mean precipitation (11.9%). Based on the maximum entropy model, the suitable habitats of I. persulcatus were predicted to show a shrinking tendency towards northeastern China in 2070.

CONCLUSIONS

The suitable habitat of I. persulcatus strongly correlates with temperature and precipitation, and climate and environmental changes may lead to shrinking of the future suitable habitat of I. persulcatus in China.

Propofol improves intestinal ischemia-reperfusion injury in rats through NF-κB pathway

OBJECTIVE

The aim of this study was to investigate the effects of propofol on intestinal ischemia-reperfusion injury in rats through the nuclear factor-kappa B (NF-κB) pathway.

MATERIALS AND METHODS

A total of 24 Sprague-Dawley rats were selected and randomly divided into three groups, including sham operation group, ischemia group and propofol group. Rats in sham operation group were only treated with isolation of superior mesenteric artery, which was clipped for 1 h and reperfused for 2 h in ischemia group. Meanwhile, propofol (60 mg/kg) was injected into the femoral vein 1 h before ischemia in propofol group. TUNEL assay was performed to detect cell apoptosis of intestinal tissues. Real-time quantitative polymerase chain reaction (RT-qPCR) was conducted to measure the expression levels of malondialdehyde (MDA), superoxide dismutase (SOD), myeloperoxidase (MPO), caspase-3 and B-cell lymphoma-2 (Bcl-2) in rats of each group. Western blotting was utilized to detect the protein expression levels of NF-κB pathway related molecules, such as myeloid differential protein-88 (MyD88), v-rel avian reticuloendotheliosis viral oncogene homolog A (RelA) and NF-κB. Furthermore, changes in plasma cytokine levels were determined via enzyme-linked immunosorbent assay (ELISA).

RESULTS

The number of apoptotic cells in ischemia group was remarkably higher than that in sham operation group (p<0.05). However, it decreased notably in propofol group compared with ischemia group (p<0.05). In comparison with sham operation group, significantly up-regulated expression of caspase-3 and down-regulated expression of Bcl-2 were observed in the intestinal tissues of rats in ischemia group (p<0.05). Caspase-3 was lowly expressed, while Bcl-2 was highly expressed in the intestinal tissues of rats in propofol group compared with ischemia group (p<0.05). In addition, no statistically significant differences were observed in the expression level of SOD among sham operation group, ischemia group and propofol group (p>0.05). The expression levels of MDA and MPO were overtly higher in the intestinal tissues of rats in ischemia group than those in sham operation group and propofol group (p<0.05). Besides, the protein expression levels of MyD88, RelA and NF-κB in the intestinal tissues of rats in ischemia group were remarkably higher than those in sham operation group and propofol group (p<0.05). The activity of the NF-κB pathway in the intestinal tissues of rats in propofol group significantly declined compared with ischemia group (p<0.05). Moreover, compared with sham operation group, plasma levels of TNF-α, interleukin (IL)-2, IL-6 and IL-4 increased significantly in rats of ischemia group (p<0.05). However, they were markedly lower in propofol group than those in ischemia group (p<0.05).

CONCLUSIONS

Propofol protects rats from intestinal ischemia-reperfusion injury through the NF-κB pathway.

An experimental study on stress-shielding effects of locked compression plates in fixing intact dog femur

Background

In orthopedic application, stress-shielding effects of implant materials cause bone loss, which often induces porosis, delayed bone healing, and other complications. We aimed to compare the stress-shielding effects of locked compression plate (LCP) and limited-contact dynamic compression plate (LC-DCP) in dogs with plate-fixed femurs.

Methods

Bilateral intact femurs of 24 adult dogs were fixed by adult forearm 9-hole titanium plates using minimally invasive plate osteosynthesis (MIPPO) technology, with LCP on the left and LC-DCP on the right femurs. Dogs were sacrificed at 6 weeks, 12 weeks, and 24 weeks after surgery, and bone specimens were used to evaluate the efficacies of different fixing methods on bones through X-ray, dual-energy X-ray absorptiometry (DEXA), histology, MicroCT, and biomechanics analyses.

Results

X-ray results showed significant callus formation and periosteal reaction in the LC-DCP group. Bone cell morphology, degree of osteoporosis, and bone mineral density (BMD) changes of the LCP group were significantly better than that of the LC-DCP group. MicroCT results showed that the LCP group had significantly reduced degree of cortical bone osteoporosis than the LC-DCP group. Tissue mineral density (TMD) in the LCP group was higher than that in the LC-DCP group at different time points (6 weeks, 12 weeks, and 24 weeks). Biomechanics analyses demonstrated that the compressive strength and flexural strength of bones fixed by LCP were better than that by LC-DCP.

Conclusions

Stress-shielding effects of LCP are significantly weaker than that of LC-DCP, which is beneficial to new bone formation and fracture healing, and LCP can be widely used in clinic for fracture fixation.

Long noncoding RNA FAM201A mediates the metastasis of lung squamous cell cancer via regulating ABCE1 expression

OBJECTIVE

Long noncoding RNA (lncRNA) family with sequence similarity 201-member A (FAM201A) is a novel lncRNA promoting the development of various cancers. However, the biological function of FAM201A on the metastasis of lung squamous cell carcinoma (LSCC) remains unknown. The aim of this study was to explore the molecular mechanism of FAM201A and its target protein in advanced LSCC.

PATIENTS AND METHODS

Quantitative Polymerase Chain Reaction (qPCR) was applied to evaluate FAM201A expression in lung cancer tissues. The impact of high FAM201A expression on the overall survival in patients with lung cancer was tested using the log-rank test. The relevance between aberrant FAM201A and clinicopathological characteristics in patients with lung cancer was analyzed using the Chi-square tests. Cell proliferation was assayed using the Cell Counting Kit-8 (CCK-8) and a transwell assay, and the mice xenograft models were applied to determine the promoting effects of FAM201A on LSCC in vitro and in vivo. The underlying regulatory mechanism was explored through RNA transfection, qPCR, and Western blotting. The correlation between ATP-binding cassette transporter E1 (ABCE1) and FAM201A expression was verified using Spearman's correlation coefficient.

RESULTS

FAM201A is aberrantly elevated in tissues from patients with non-small cell lung cancer. High levels of FAM201A expression were more likely to present in patients with squamous type, M1 stage, and inferior overall survival. Differential expression was found between non-metastatic and metastatic squamous carcinoma, but not in adenocarcinoma. FAM201A knockdown inhibits cell proliferation, migration, and invasion of LSCC cells in vitro, and represses tumor growth in vivo. Furthermore, ABCE1 in LSCC cells was downregulated by silencing FAM201A. The tissue level of ABCE1 was positively correlated with FAM201A expression in patients with LSCC.

CONCLUSIONS

FAM201A may markedly induce migration and invasion of LSCC, resulting in the M1 stage and poor survival. These findings suggest the FAM201A-ABCE1 axis as a novel therapeutic target in LSCC.

Epidemiological Investigation of OHCWs with COVID-19

During the coronavirus disease 2019 (COVID-19) pandemic, there is an important risk of infection in health care workers, including oral health care workers (OHCWs), due to the characteristics of dental practice. In this retrospective study, data pertaining to the 31 OHCWs diagnosed with COVID-19 in Wuhan, Hubei Province, were retrieved and analyzed. Questionnaires were administered to the subjects over the Internet and telephone. Clinical and epidemiological characteristics and information on the use of personal protective equipment (PPE) were collected. There were 22 females and 9 males, with a median age of 39 y. Although the severity of most cases of COVID-19 (93.5%) was mild or moderate, 1 case was severe, and another case was critical, resulting in death. Fever was the main first symptom of COVID-19, followed by fatigue and myalgia. Most of the OHCWs routinely used PPE such as medical masks, gloves, caps, and work clothes while performing clinical work. N95 or KN95 masks were rarely available because of the scarcity of PPE during the outbreak. Nineteen OHCWs reported a contact history, among whom 7 worked in a fever clinic, 5 reported contact with dental patients suspected of having COVID-19, and 7 reported contact with family members with COVID-19–related symptoms at least 1 d earlier. Our findings indicated that there were few clusters of COVID-19 in dental settings. Since the outbreak, the Hospital of Stomatology, Wuhan University, has provided emergency dental treatment, and none of their staff were infected while providing dental service, which indicates that comprehensive measures such as the use of advanced PPE and environmental disinfection can prevent cross-infection in dental practice. The analysis of the procedures followed during the emergency treatments indicated that OHCWs preferred to recommend conservative treatment to patients, suggesting that attention should be paid to the psychological impact of COVID-19 on dental practitioners.

[Effects of pedicled anterolateral thigh flaps in repairing skin and soft tissue defects in perineal region caused by necrotizing fasciitis]

Objective: To explore the effects of pedicled anterolateral thigh flaps in repairing skin and soft tissue defects in perineal region caused by necrotizing fasciitis. Methods: From March 2014 to December 2018, 6 patients with skin and soft tissue defects in perineal region caused by necrotizing fasciitis were admitted to Department of Burns of Hanzhong Central Hospital (hereinafter referred to as our hospital). Two female patients had labia major defects and 4 male patients had scrotum defects, with age of 43-68 years. The areas of skin and soft tissue defects after debridement were 4%-8% total body surface area. The wounds in non-joint and non-functional area were repaired with free split-thickness skin grafts from medial femoral region, and the residual wounds areas in perineal region after repair were 10 cm×4 cm-22 cm×10 cm, which were repaired with pedicled anterolateral thigh flaps, with area of 12 cm×5 cm-24 cm×12 cm. The secondary wounds in the donor sites were sutured directly or repaired with free split-thickness skin grafts from medial thigh on the same or opposite side of the wounds. The bacterial culture result of wound exudate, drug sensitivity test result, and blood bacterial culture result on admission were recorded. The postoperative flap survival was observed. The length of hospital stay, debridement times, and antibiotics use time were recorded. The flap swelling condition was observed to evaluate whether flap thinning operation was necessary, the sensory recovery of the flap and hip joint activity were evaluated, and the scrotum function of male patients was evaluated by urologist in our hospital during follow-up. Results: The bacterial culture results of wound exudate in 5 patients on admission showed Escherichia coli with 4 of them having the same bacteria and the other one having methicillin-resistant Staphylococcus aureus detected in their blood samples. All the flaps survived in 6 patients after the operation, with total length of hospital stay of (22±5) d, debridement of 3-5 times, and antibiotics use time of (13±3) d. During follow-up of 3 to 6 months after the operation, the flaps were slightly bloated in 2 patients, and the flap thinning operation was performed 6 months after wound repair. The sensory function recovered to normal in 2 flaps of patients with anterolateral femoral cutaneous nerve, and the superficial sensory function in the other flaps of patients recovered in different degrees.The hip joint activity was close to normal in all the patients, and the scrotum function was normal in 4 male patients. Conclusions: The pedicled anterolateral thigh flap showed good effects in repairing skin and soft tissue defects on perineal region caused by necrotizing fasciitis, with good appearance and function after operation, and the method is simple, safe, and easy to apply.

Molecular catalysis of CO2 reduction: recent advances and perspectives in electrochemical and light-driven processes with selected Fe, Ni and Co aza macrocyclic and polypyridine complexes

Earth-abundant Fe, Ni, and Co aza macrocyclic and polypyridine complexes have been thoroughly investigated for CO2 electrochemical and visible-light-driven reduction. Since the first reports in the 1970s, an enormous body of work has been accumulated regarding the two-electron two-proton reduction of the gas, along with mechanistic and spectroscopic efforts to rationalize the reactivity and establish guidelines for structure-reactivity relationships. The ability to fine tune the ligand structure and the almost unlimited possibilities of designing new complexes have led to highly selective and efficient catalysts. Recent efforts toward developing hybrid systems upon combining molecular catalysts with conductive or semi-conductive materials have converged to high catalytic performances in water solutions, to the inclusion of these catalysts into CO2 electrolyzers and photo-electrochemical devices, and to the discovery of catalytic pathways beyond two electrons. Combined with the continuous mechanistic efforts and new developments for in situ and in operando spectroscopic studies, molecular catalysis of CO2 reduction remains a highly creative approach.

[Clinical application effect of blood circulation enhancement technique in repairing large area of skin and soft tissue defects of extremities with super large free anterolateral thigh flap]

Objective: To observe the clinical application effect of blood circulation enhancement technique in repairing large area of skin and soft tissue defects of extremities with super large free anterolateral thigh flap. Methods: From March 2014 to March 2017, 6 patients with large area of skin and soft tissue defects of extremities were hospitalized in our unit, including 5 males and 1 female, aged 27-65 years, 1 case of electric injury, 2 cases of coal burn, 3 cases of traffic injury, 2 cases involving upper limb, and 4 cases involving lower limb. After debridement, the wound area ranged from 26 cm×8 cm to 36 cm×15 cm, and the bone exposure area ranged from 24 cm×7 cm to 35 cm×14 cm. The blood circulation enhancement technique was used when the wound with bone exposure was repaired with super large free anterolateral thigh flap. The area of flaps ranged from 28 cm×10 cm to 38 cm×16 cm. The donor site of flap and the primary wound without bone exposure were repaired with medial thigh split-thickness skin graft of the donor leg of flap. The blood circulation enhancement technique mode during operation and the survival of flaps after operation were recorded, and the recovery of donor and recipient areas and the occurrence of complications were followed up. Results: Three patients were treated with simple vascular supercharging technique during flap transplantation, and the other 3 patients were treated with vascular supercharging and turbocharging technique during flap transplantation. All the flaps survived well in 6 patients without vascular crisis. Follow-up for 3 to 12 months after surgery showed that the blood flow of the flaps was good and the depth and superficial sensation recovered to varying degrees. Except for 1 case of upper limb flap, the other flaps had no obvious swelling and needed no second thinning. There were only depressed scars in the donor sites, and no obvious scar hyperplasia in the area without bone exposure repaired by the skin grafts. No short-term or long-term complications were found. Conclusions: The application of blood circulation enhancement technique in repairing large area of skin and soft tissue defects of extremities with super large free anterolateral thigh flaps provides reliable blood supply for the flaps and results in good effect after operation, which is worth popularizing.

Generation of a neutralizing antibody against RD114-pseudotyped viral vectors

The feline endogenous RD114 glycoprotein has proved to be an attractive envelope to pseudotype both retroviral and lentiviral vectors. As a surface protein, its detection on packaging cells as well as viral particles would be useful in different fields of its use. To address this, we generated a monoclonal antibody against RD114 by immunization of rats, termed 22F10. Once seroconversion was confirmed, purified 22F10 was cloned into murine Fc and characterized with a binding affinity of 10nM. The antibody was used to detect RD114 and its variant envelopes on different stable viral packaging cell lines (FLYRD18 and WinPac-RD). 22F10 was also shown to prevent the infections of different strains of RD-pseudotyped vectors but not related envelope glycoproteins by blocking cell surface receptor binding. We are the first to report the neutralization of viral particles by a monoclonal αRD114 antibody.

microRNA-mediated GAS1 downregulation promotes the proliferation of synovial fibroblasts by PI3K-Akt signaling in osteoarthritis

Hyperplastic synovial fibroblasts (SFs) serve a critical role in the pathogenesis of knee osteoarthritis (OA); however, the molecular mechanism involved in OA during synovial tissue hyperproliferation remains unclear. Growth arrest-specific gene 1 (GAS1), a cell growth repressor gene, was found to be downregulated in OASFs according to previous preliminary experiments. It was therefore hypothesized that reduced GAS1 expression may participate in the hyperproliferation of SFs in OA development, downstream of possible microRNA (miR) regulation, in hyperplastic OASFs. In the present study, GAS1 expression was indeed decreased in OASFs and interleukin-1β-induced SFs by reverse transcription-quantitative PCR and western blot analysis. Further cell viability assays, cell cycle and apoptosis analyses revealed that the overexpression of GAS1 can inhibited proliferation, induced cell cycle arrest and promoted apoptosis in SFs. In contrast, GAS1 knockdown in SFs accelerated cell proliferation, enhanced cell cycle progression and suppressed apoptosis. Notably, the suppressive effects of GAS1 were mediated through the inactivation of the PI3K-Akt pathway. Finally, miR-34a-5p and miR-181a-5p were predicted and subsequently verified to directly target the 3′-untranslated region of the GAS1 gene, downregulating GAS1 levels in OASFs and IL-1β-induced SFs. In conclusion, the present study demonstrated that downregulation of GAS1 can lead to the hyperproliferation of SFs in OA pathogenesis through the PI3K-Akt pathway, and miR-34a-5p and miR-181a-5p are potential regulators of GAS1 expression in OA. Therefore, it may be promising to investigate the potential of GAS1 as a novel therapeutic target for preventing SF hyperplasia in OA.

Microwave Ablation of Primary Malignant Pelvic Bone Tumors

Background: En bloc tumor resection followed by reconstruction is a widely used surgical treatment for malignant pelvic bone tumors. High rates of complications and mechanical instability often contribute to poor postoperative results. We attempted en bloc microwave ablation (MWA) in situ to improve the outcome.

Methods: From May 1995 to December 2015, 104 patients with primary pelvic malignancy received radical MWA in our department. After careful dissection of the tumor-bearing bone from surrounding normal tissues with safe margins, a microwave antenna array was inserted into the tumor mass to emit electromagnetic energy, inducing tumor cellular death via thermocoagulation. The loose, devitalized tumor tissues were removed by cutting or curettage, leaving a defective bone scaffold. Re-strengthening by autograft or allograft was needed in most patients.

Results: The over 3 years survival rate was 51.5% for high-grade malignancies (among them, 26.9% were osteosarcoma) and 94.8% for low-grade malignancies (chondrosarcoma). In most of the living patients, cosmetic and useful limbs were preserved. The mean functional score (Musculoskeletal Tumor Society) was 27 or 90% (range: 25–30, 75–100%). Among the 56 patients who belonged to the excellent function group, 11 were followed up for more than 10 years. The local recurrence rate was 8.6%. Among the 9 patients with recurrence, 5 died from disease, 2 were treated by hemipelvic amputation, and 2 underwent revision surgery with MWA and gained local control. The deep infection rate was 5.6%. All six patients with infection were healed by irrigation, debridement, and systemic antibiotic administration.

Conclusion: Local, microwave-induced hyperthermia for treating malignant pelvic bone tumors is an effective alternative method. The oncological and functional results are encouraging. The use of MWA should be continued to evaluate and improve this new therapeutic system.

[Clinical effects of perforating branch flaps of medial vastus muscle in repairing secondary wounds in donor sites of free anterolateral femoral perforator flaps]

Objective: To investigate the clinical effects of perforating branch flaps of medial vastus muscle in repairing secondary wounds in donor sites of free anterolateral femoral perforator flaps. Methods: From August 2014 to December 2016, 12 patients (8 males and 4 females, aged 35-72 years) with skin and soft tissue defects of extremities associated with tendon and bone exposure were treated in Hanzhong Central Hospital. The sizes of the primary wounds after debridement were 10 cm×8 cm-22 cm×14 cm, and the wounds were repaired with 12 cm×10 cm-24 cm×16 cm free anterolateral femoral perforator flaps. The anterolateral femoral donor sites, which were 8.0 cm×4.0 cm-14.0 cm×7.5 cm in the secondary wounds after skin extensional suture, were repaired with perforating branch flaps of medial vastus muscle in the size of 9.0 cm×5.0 cm-15.0 cm×8.5 cm. The medial femoral donor sites were sutured directly. Results: All the perforating branch flaps of medial vastus muscle and free anterolateral femoral perforator flaps survived in 12 patients. Following up for 6 to 12 months, the medial femoral perforator flaps had good local shape and texture. The flaps of 8 patients without cutaneous nerve transection were sensitive. The sensation of the flaps of the other 4 patients gradually recovered, and the functions of the ipsilateral knee joints were normal. Conclusions: The medial femoral perforator flap has a stable anatomy and abundant blood supply, which can be used to repair the secondary wound in the donor site of the free anterolateral femoral perforator flap conveniently. It is safe and easy to be popularized. Moreover, it has a good shape and function after operation.

Prevalence and Risk Factors for Frailty among Community-Dwelling Older People in China: A Systematic Review and Meta-Analysis

OBJECTIVE

To systematically assess the prevalence of frailty, including prefrailty, stratified prevalence according to frailty criteria, gender, age, and region, and the risk factors for frailty in China.

DESIGN

We conducted a systematic literature review and meta-analysis using articles available in 8 databases including PubMed, Cochrane Library, Web of Science, CINAHL Plus, China Knowledge Resource Integrated Database (CNKI), Wanfang Database, Chinese Biomedical Database (CBM), and Weipu Database (VIP).

SETTING

Cross-sectional and cohort data from Chinese community.

PARTICIPANTS

Community-dwelling adults aged 65 and older.

MEASUREMENTS

Two authors independently extracted data based upon predefined criteria. Where data were available we conducted a meta-analysis of frailty parameters using a random-effects model.

RESULTS

We screened 915 different articles, and 14 studies (81258 participants) were ultimately included in this analysis. The prevalence of frailty and prefrailty in individual studies varied from 5.9% to 17.4% and from 26.8% to 62.8%, respectively. The pooled prevalence of frailty and prefrailty were 10% (95% CI: 8% to 12%, I2 = 97.4%, P = 0.000) and 43% (95% CI: 37% to 50%, I2 = 98.0%, P = 0.000), respectively. The pooled frailty prevalence was 8% for the Fried frailty phenotype, 12% for the frail index, and 15% for the FRAIL scale. Age-stratified meta-analyses showed the pooled prevalence of frailty to be 6%, 15%, and 25% for those aged 65-74, 75-84, and ≥85 years old, respectively. The pooled prevalence of frailty was 8% for males and 11% for females. The pooled prevalence of frailty in Mainland China, Taiwan, and Hong Kong was 12%, 8%, and 14%, respectively. The pooled frailty prevalence was 10% in urban areas and 7% in rural areas. After controlling for confounding variables, increasing age (OR = 1.28, 95% CI: 1.2 to 1.36, I2 = 98.0%, P = 0.000), being female (OR = 1.29, 95% CI: 1.16 to 1.43, I2 =92.7%, P=0.000), activities of daily living (ADL) disability (OR = 1.72, 95% CI: 1.57 to 1.90, I2 = 99.7%, P = 0.000), and having three or more chronic diseases (OR = 1.97, 95% CI: 1.78 to 2.18, I2 = 97.5%, P = 0.000) were associated with frailty.

CONCLUSIONS

These findings of this review indicate an overall pooled prevalence of frailty among Chinese community-dwelling older people of 10%. Increasing age, being female, ADL disability, and having three or more chronic diseases were all risk factors for frailty. Further research will be needed to identify additional frailty risk factors in order to better treat and prevent frailty in the community.

The effect of temperature-control microwave on HELA and MG-63 cells

Context

Hyperthermia has now been used to treat many kinds of solid malignancies. However, the applied thermal parameters about heat temperature and time varied all over the world, and no consensus about the optimal formula had been reached. Microwave ablation, as one of thermal ablation methods, is usually applied based on the fixed parameters of power and duration. As a result, too high temperature or overheating might not be avoided and excessive heating might cause some additional side effects to normal tissues.

Aims

To explore the optimal parameters of power and duration for the HELA and MG-63 cells in vitro.

Settings and Design

With a temperature-controlled microwave workstation, a microwave thermal ablation experiment was performed in vitro.

Subjects and Methods

The HELA and MG-63 cells were heated with 40°C, 45°C, 50°C, 55°C, and 60°C lasting for 5-30 min, respectively. Then, the cell viability was detected using four methods: Flow cytometer assay, nicotinamide adenine dinucleotide-diaphorase staining, Calcein-acetoxymethyl ester staining immediately after treatment, and CCK-8 assay 24 h later.

Results

The temperature-controlled microwave has an excellent ablation effect on both cell lines. Furthermore, when the thermal stimulation reached 55°C 25 min and 55°C 20 min for the HELA and MG-63 cells, respectively, or 60°C 5 min for both, all the viability indexes indicated immediately devitalization.

Conclusion

It presented a preliminary minimum lethal dose of heat was validated on the cellular level in vitro, which should be verified and corrected further in vivo.

[Antiseptic effect of compound lysostaphin disinfectant and its preventive effect on infection of artificial dermis after graft on full-thickness skin defect wound in rats]

Objective: To study the antiseptic effect of compound lysostaphin disinfectant and its preventive effect on infection of artificial dermis after graft on full-thickness skin defect wound in rats. Methods: (1) Each one standard strain of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were selected. Each 20 clinical strains of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were collected from those isolated from wound exudates of burn patients hospitalized in our wards from January 2014 to December 2016 according to the random number table. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of compound lysostaphin disinfectant to above-mentioned strains were detected. The experiment was repeated 3 times. Compared with the corresponding standard strain, the clinical strain with higher MIC and/or MBC was considered as having decreased sensitivity to the disinfectant. The percentage of strains of each of the three kinds of bacteria with decreased sensitivity was calculated. (2) Artificial dermis pieces were soaked in compound lysostaphin disinfectant for 5 min, 1 h, 2 h, and 4 h, respectively, with 21 pieces at each time point. After standing for 0 (immediately), 12, 24, 36, 48, 60, 72 h (with 3 pieces at each time point), respectively, the diameters of their inhibition zones to standard strains of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were measured. The experiment was repeated 3 times. The shortest soaking time corresponding to the longest standing time, after which the disinfectant-soaked artificial dermis could form an effective inhibition zone (with diameter more than 7 mm), was the sufficient soaking time of the disinfectant to the artificial dermis. (3) Forty Sprague-Dawley rats were divided into post injury day (PID) 3, 7, 14, and 21 sampling groups according to the random number table, with 10 rats in each group. A full-thickness skin defect wound with a diameter of 20 mm was made on both sides of the spine on the back of each rat. Immediately after injury, the artificial dermis without any treatment was grafted on the wound on left side of the spine (hereinafter referred to as control wound), while the sufficiently soaked artificial dermis with compound lysostaphin disinfectant was grafted on the wound on right side of the spine (hereinafter referred to as disinfectant wound). On PID 3, 7, 14, and 21, the gross condition of wounds of all the surviving rats was observed, and the new infection rates of control wounds and disinfectant wounds were calculated. Then, the rats in the sampling group with corresponding time were killed, and the full-thickness wound tissue containing artificial dermis was collected for quantitative analysis of bacteria. Bacteria content of the uninfected control wounds and that of the uninfected disinfectant wounds were compared. Data were processed with chi-square test and Wilcoxon rank sum test. Results: (1) The MIC of compound lysostaphin disinfectant to standard strains of Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter baumannii were 1/32, 1/32, and 1/512 of the original concentration of the disinfectant, respectively, and the MBC were 1/32, 1/16, and 1/512 of the original concentration of the disinfectant, respectively. The percentages of clinical strains of Klebsiella pneumoniae, Acinetobacter baumannii and Staphylococcus aureus with decreased sensitivity to compound lysostaphin disinfectant were 15% (3/20), 20% (4/20), and 10% (2/20), respectively. (2) After being soaked in compound lysostaphin disinfectant for 2 and 4 h, the longest standing time, after which the artificial dermis could form an effective inhibition zone against Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus, were 24, 36, and 48 h respectively, longer than 12, 24, and 24 h of soaking for 5 min and 24, 24, and 36 h of soaking for 1 h. The sufficient soaking time of compound lysostaphin disinfectant to artificial dermis was 2 h. (3) On PID 3, no infection symptom was observed in all the wounds, and so both the new infection rate of control wounds and that of disinfectant wounds were 0. The artificial dermis was transparent but not well connected with the wound. On PID 7, the new infection rate of control wounds was 20.00% (6/30), which was obviously higher than 3.33% (1/30) of disinfectant wounds, χ(2)=4.043, P<0.05. On the infected wound, a large amount of purulent exudates were observed, and the artificial dermis was not connected with the wound and degraded partially. On the uninfected wound, artificial dermis was transparent and had a partial connection with the wound. On PID 14 and 21, no new infected wound was observed, and so both the new infection rate of control wounds and that of disinfectant wounds were 0. There was no obvious improvement on the infected wounds. The collagen layers of artificial dermis in the uninfected wound established a good connection with the wound and were separating from the silica gel layer gradually. Infection occurred in 2, 3, 1 control wound (s) in PID 7, 14, and 21 sampling groups, respectively, and in 1 disinfectant wound in PID 14 sampling group. The bacteria content of the infected wounds tissue was 0.79×10(6) to 7.22×10(9) colony-forming unit (CFU)/g. The bacteria content of uninfected control wounds tissue in PID 3, 7, and 14 sampling groups were (3.43±1.88)×10(2,) (2.37±0.43)×10(3,) and (8.40±1.03)×10(3) CFU/g, respectively, which were significantly higher than (0.33±0.12)×10(2,) (0.43±0.17)×10(3,) (2.16±0.52)×10(3) CFU/g of uninfected disinfectant wounds tissue (Z=-3.780, -3.554, -3.334, P<0.05). The bacteria content of uninfected control wounds tissue and that of uninfected disinfectant wounds tissue in PID 21 sampling group were similar (Z=-0.490, P>0.05). Conclusions: Compound lysostaphin disinfectant has quite strong antibacterial ability against Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus. Clinical strains of the three kinds of bacteria were highly sensitive to compound lysostaphin disinfectant. Saturation of absorption of compound lysostaphin disinfectant achieves in artificial dermis after 2 hours' soaking. After 24, 36, and 48 hours' standing, the soaked artificial dermis still has the antibacterial effect on Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus, respectively. The infection rate and the bacteria content of full-thickness skin defect wound in rats are all decreased when grafted with soaked artificial dermis.