[Clinical effect of modified vertical rectus abdominis myocutaneous flap in repairing skin and soft tissue defects after abdominoperineal resection for rectal cancer]

Objective: To investigate the clinical effect of the modified vertical rectus abdominis myocutaneous flap in repairing the skin and soft tissue defect after abdominoperineal resection for rectal cancer. Methods: This study was a retrospective observational study. From June 2019 to July 2022, five male patients with low rectal cancer who were conformed to the inclusion criteria were admitted to the Department of Basic Surgery of Xiangya Hospital of Central South University, with ages ranging from 65 to 70 years and the sizes of the perianal skin ulcers ranging from 5 cm×4 cm to 11 cm×9 cm, and all of them underwent abdominoperineal resection. The secondary skin and soft tissue defects in the perineum with an area of 8 cm×6 cm-14 cm×12 cm (with the depth of pelvic floor dead space being 10-15 cm) were repaired intraoperatively with transplantation of modified vertical rectus abdominis myocutaneous flaps with the skin area being 9 cm×7 cm-16 cm×12 cm, the volume of the muscle being 18 cm×10 cm×5 cm-20 cm×12 cm×5 cm, and the vessel pedicle being 18-20 cm in length. During the operation, most of the anterior sheath of the rectus abdominis muscle was retained, the flap was transferred to the recipient area through the abdominal cavity, the remaining anterior sheaths of the rectus abdominis muscle on both sides of the donor area were repeatedly folded and sutured, the free edge of the transverse fascia of the abdomen was sutured with the anterior sheath of the rectus abdominis muscle, and the donor area skin was directly sutured. After the operation, the survival of the transplanted myocutaneous flap was observed. The occurrence of complications in the perineal recipient area was recorded within 2 weeks after the operation. The recovery of the perineal recipient area and the abdominal donor area was observed during follow-up, and the occurrence of complications in the donor area of the abdomen as well as the recurrence of tumors and metastasis were recorded. Results: All transplanted myocutaneous flaps in 5 patients survived after surgery. One patient had dehiscence of the incision in the perineal recipient area 2 days after surgery, which healed after 7 d with intermittent dressing changes and routine vacuum sealing drainage treatment. In the other 4 patients, no complications such as incisional rupture, incisional infection, or fat liquefaction occurred in the perineal recipient area within 2 weeks after surgery. Follow-up for 6-12 months after discharge showed that the skin of the perineal recipient area had good color, texture, and elasticity, and was not bloated in appearance; linear scars were left in the perineal recipient area and the abdominal donor area without obvious scar hyperplasia or hyperpigmentation; no complications such as incisional rupture, incisional infection, intestinal adhesion, intestinal obstruction, or weakening of the abdominal wall strength occurred in the abdominal donor area, and the abdominal appearance was good with no localized bulge or formation of abdominal hernia; there was no local recurrence of tumor or metastasis in any patient. Conclusions: The surgical approach of using the modified vertical rectus abdominis myocutaneous flap to repair the skin and soft tissue defects after abdominoperineal resection for rectal cancer is relatively simple in operation, can achieve good postoperative appearances of the donor and recipient areas with few complications, and is worthy of clinical promotion.

[A brief discussion on the harvest of thinned perforator flap, detection of perforator vessels, and evaluation of flap blood supply]

Repair and reconstruction surgery is not just a simple repair and reconstruction of tissue and organ defects in different parts, but also requires perfect repair that matches the defect and confuses the real. The thinning strategy of perforator flap is one of its main contents. In recent years, the concept of pure skin perforator flap and its clinical application have overturned the traditional concept that flaps must carry subdermal vascular plexus and improved our understanding of flap surgery, and it is expected to enhance the level of repair and reconstruction. This article explores the harvest of thinned perforator flaps, especially the harvest of innovative pure skin perforator flap with the thickness similar to full thickness skin, as well as the preoperative detection of perforator vessels, blood supply evaluation of perforator flaps, and their clinical applications. It proposes a "Jinshan" repair that perfectly matches the recipient area defect, and also prospects research on the perforasome and three-dimensional visualized digital anatomy of pure skin perforator flaps.

[Revealing Driving Factors of Urban O3 Based on Explainable Machine Learning]

Driven by precursor emissions, meteorological conditions, and other factors, atmospheric ozone (O₃) has become the main pollutant affecting urban air quality in summer. The current deductive models driven by physical and chemical mechanisms require a large number of parameters for the analysis of O₃ pollution, and the calculation timeliness is poor. The data-driven inductive models are efficient but have problems such as poor explanation. In this study, an explainable model of data-driven Correlation-ML-SHAP was established to reveal the strongly correlated influencing factors of O₃ concentration. Additionally, the machine learning ML module coupled with the explainable SHAP module was used to calculate the contributions of driving factors to O₃ concentration, so as to realize the quantitative analysis of driving factors. The O₃ pollution process in the summer of 2021 in Jincheng City was used as an example to carry out the application research. The results showed that the Correlation-ML-SHAP model could reveal and use strong driving factors to simulate O₃ concentration and quantify influence contribution, and the ML module used the XGBoost model to achieve the best simulation accuracy. Air temperature, solar radiation, relative humidity, and precursor emission level were the strong driving factors of O₃ pollution in Jincheng City in summer 2021, and the contribution weights were 32.1%, 21.3%, 16.5%, and 15.6%. The contribution weights of air temperature, solar radiation, and precursor emission level increased by 3.4%, 1.2%, and 1.2% on polluted days, respectively, and the contribution weights of precursor emission level rose to third place on polluted days. Each driving factor had a nonlinear interaction effect on O₃ concentration. When the air temperature exceeded 24℃, or the relative humidity was lower than 70%, there was a 94.9% and 94.1% probability of positive contribution to O₃ pollution, respectively. Under such meteorological conditions, ρ(NO₂) exceeded 9 μg·m^-3, or ρ(CO) exceeded 0.7 mg·m^-3, and there was a 94.9% and 99.3% probability of positive contribution to O₃ pollution, respectively. The southeast wind speed was lower than 5.8 m·s^-1, or the south wind speed was lower than 5.3 m·s^-1, both of which contributed positively to O₃ pollution. The model quantitatively analyzed the influence contribution of various driving factors on urban O₃ concentration, which could provide a basis for the prevention and control of urban atmospheric O₃ pollution in summer.

[Deepening the Action on Salt Reduction in China-suggestions on strategy and implementation plan]

Excessive sodium/salt intake is the leading dietary risk factor for the loss of healthy life in the Chinese population. The "Healthy China 2030" Action Plan set the goal of reducing salt intake by 20% by 2030. However, salt intake in China is still at a very high level in the world, with adults reaching 11 g/d, more than twice the recommended limit of 5 g/d. The current policies and action plans of China have targeted catering workers, children, adolescents, and home chefs in salt, oil, and sugar reduction actions. However, there are still obvious deficiencies in the coordinated promotion and implementation. This study, therefore, proposed a set of comprehensive strategies (named CHRPS that is composed of communication and education, salt reduction in home cooking, salt reduction in restaurants, reducing salt content in pre-packaged food, and surveillance and evaluation) and key implementation points for further deepening the salt reduction action in China. These strategies were developed based on the main sources of dietary sodium for Chinese residents, the status of"knowledge, attitude and practice"in salt reduction, evidence of effective intervention measures, existing policies and requirements, and the salt reduction strategies of the World Health Organization and experience from some other countries. As a scientific reference, the CHRPS strategies will help the government and relevant organizations quickly implement salt reduction work and facilitate the earlier realization of China's salt reduction goal.

[Repair methods of complex facial defect wounds involving paranasal sinuses and their clinical effectiveness]

Objective: To explore the repair methods of complex facial defect wounds involving paranasal sinuses and their clinical effectiveness. Methods: A retrospective observational study was conducted. From January 2020 to May 2022, 5 patients admitted to the Department of Burns and Plastic Surgery of Xiangya Hospital of Central South University and 4 patients admitted to the Department of Burns and Plastic Surgery of Chenzhou First People's Hospital with complex facial defect wounds involving paranasal sinuses met the inclusion criteria, including 6 males and 3 females, aged 35-69 years, including 4 patients with titanium mesh exposure combined with paranasal sinuses injury and 5 patients with tumor involving paranasal sinuses. After an adequate assessment of the damage by a multiple discipline team, titanium mesh removal, paranasal sinus debridement, and paranasal sinus mucosa removal were performed in patients with exposed titanium mesh, and radical tumor resection was performed in patients with tumors, with postoperative skin and soft tissue defects areas of 5.0 cm×2.5 cm to 18.0 cm×7.0 cm, anterior paranasal sinus wall defects/absence areas of 3 cm×2 cm to 6 cm×4 cm, and sinus cavity depths of 1 to 4 cm. Depending on the perforator course of the descending branch of the lateral circumflex femoral artery, the anterolateral femoral chimeric flap or anterolateral femoral myocutaneous flap (with flap area of 9 cm×4 cm to 19 cm×8 cm, muscle size of 5 cm×3 cm×3 cm to 11 cm×6 cm×3 cm) was transplanted to repair the defect, and the donor site wound was sutured directly. The type of tissue flap transplanted, the blood vessel of the recipient area, and the vascular anastomosis way during the operation, the recovery of the donor and recipient areas and the occurrence of complications after operation were observed. The appearance and blood supply of the recipient area and the recurrence of ulcers and tumors were followed up. Results: The anterolateral femoral myocutaneous flap transplantation was performed in 6 patients, and the anterolateral femoral chimeric flap transplantation was performed in 3 patients. The blood vessels in recipient areas were facial arteries and veins in 3 cases and superficial temporal arteries and veins in 6 cases. The superficial temporal arteries and veins were bridged with blood vessels in tissue flaps by flow-through way in 2 patients, and end-to-end anastomosis of blood vessels in donor and recipient areas was performed in 7 patients. After operation, all the tissue flaps survived, and the facial defect wounds were well repaired without cerebrospinal fluid leakage or paranasal sinus secretion leakage, no intracranial infection occurred, and the wounds in donor areas were healed well. Follow-up of 6-35 months after operation showed that all the patients had good blood supply in the recipient area, and the shape was acceptable; 4 patients with exposed titanium mesh had no recurrence of ulceration, and 5 patients with tumor had no local tumor recurrence or metastasis. Conclusions: Based on an adequate assessment of the extent of paranasal sinuses involved in the facial wound and the nature of the defect, good clinical effects can be achieved by using the anterolateral femoral muscle flap or the anterolateral femoral chimeric flap transplantation to repair complex facial defect wounds with open paranasal sinuses.

[Sternal bone marrow cell morphology evaluation utility for diagnostic categorization in patients with acquired hypocellular bone marrow failure syndromes]

Objective: Diagnostic value assessment of sternal bone marrow cell morphology in patients with acquired hypocellular bone marrow failure syndromes (BMFS) characterized by normal cytogenetics. Methods: A total of 194 eligible patients with an acquired hypocellular BMFS pre-sternum diagnosis in Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College from June 2014 to January 2019 were reviewed. Sternal bone marrow evaluation was performed, and a post-sternum diagnosis was made. Clinical characteristics and overall survival (OS) were then compared among patients with different post-sternum diagnosis. Binary logistic regression was used to develop a predictive scoring system. Results: In 152 patients with pre-sternum AA diagnosis, 29 patients with a pre-sternum idiopathic cytopenia of undetermined significance (ICUS) diagnosis, and 13 patients with a pre-sternum clonal cytopenia of undetermined significance (CCUS) diagnosis, sternal bone marrow evaluation resulted in a change of diagnosis to hypocellular myelodysplastic syndrome (hypo-MDS) in 42.8% (65/152) , 24.1% (7/29) , and 30.8% (4/13) , respectively. Patients with a post-sternum hypo-MDS diagnosis showed a significant difference in OS compared with patients with a post-sternum AA diagnosis (P=0.005) . Patients with ICUS/CCUS showed no difference in OS compared with AA and hypo-MDS (P=0.095 and P=0.480, respectively) . A 4-item predictive scoring system to identify hypocellular BMFS patients that need sternal bone marrow evaluation was developed, including age > 60 years old (OR=6.647, 95% CI 1.954-22.611, P=0.002, 2 points) , neutrophil alkaline phosphatase score ≤ 160 (OR=2.654, 95% CI 1.214-5.804, P=0.014, 1 point) , abnormal erythroid markers evaluated by flow cytometry on iliac bone marrow (OR=6.200, 95% CI 1.165-32.988, P=0.032, 2 points) , and DAT (DNMT3A, ASXL1, TET2) genes mutation (OR=4.809, 95% CI 1.587-14.572, P=0.005, 1 point) . The Akaike information criterin (AIC) was 186.1. Conclusion: Patients with a pre-sternum acquired hypocellular BMFS diagnosis characterized by normal cytogenetics may not reach accurate diagnostic categorization without sternal bone marrow cell morphology evaluation, which could be considered a diagnostic tool for this patient population. A predictive scoring system was developed, and when the total score is ≥ 2 points, sternal bone marrow evaluation should be performed for accurate diagnostic categorization that is critical to optimal patient care.

Osteochondral explants for diarthrodial joint diseases: bridging the gap between bench and bedside

Diarthrodial joint diseases, affecting hundreds of millions of people worldwide, mainly include osteoarthritis and cartilage injuries. No consensus on joint disease models has been achieved so far owing to the complex aetiologies, pathophysiological mechanisms and heterogeneity of disorders. The disease models established using isolated chondrocytes or small animals have the weaknesses of lacking native extracellular matrix and inter-species differences in anatomical and biomechanical cartilage properties. Osteochondral explants (OCEs) from large-animal or human joints present characteristics of native articular cartilage, showing promising potential for application in research on joint diseases. The present review focuses on OCEs and highlights the OCE sources, harvesting techniques, culture systems, applications and future developments. The OCE-centred ex vivo system has the potential to develop into preclinical models mimicking human joint diseases to help elucidate disease mechanisms, prompt therapeutic strategies and facilitate the clinical translation of findings in basic research.

A Simplified Method for RNA Isolation from Biofabricating Hydroxyapatite Scaffolds and Identification of Appropriate Reference Genes

Purpose

To validate a simplified RNA isolation method from biofabricating hydroxyapatite (HAp) scaffolds seeded with mesenchymal stem cells (MSCs) and to identify the appropriate reference gene.

Methods

Ten MSCs-HAp composites were used for RNA isolation by methods based on simplified homogenization steps and column-based purification procedures, while the remaining RNA (n = 13) was extracted by traditional single-step isolation methods. The differences between the two procedures regarding the operation time, RNA quantity and quality were evaluated. Quantitative real-time PCR (qRT-PCR) analysis was performed to identify the appropriate reference gene.

Results

The simplified method showed significant superiority in operation time (P < 0.001), RNA concentration (P < 0.001), A260/280 ratio (P = 0.005) and A260/230 ratio (P < 0.001). The average integrity number and 28 s/18 s ratio of RNA yielded by the simplified method were 9.1 ± 0.2 and 1.3 ± 0.1, respectively. The qRT-PCR analysis results indicated that the cycle threshold (Ct) values of GAPDH were significantly higher than those of the remaining 2 reference genes (ACTB and RPL13A) in the RNA samples obtained by the simplified and traditional methods (P < 0.05). The standard deviations of the ΔCt value (the difference between the Ct value and the minimum) of ACTB were higher than those of GAPDH or RPL13A, regardless of the RNA isolation method.

Conclusion

The simplified method could extract intact RNA from biofabricating MSCs-HAp scaffolds and was superior to the traditional single-step procedure in operation time, RNA quantity and quality. GAPDH was identified as the most appropriate reference gene in MSCs-HAp scaffold composites due to its high quantity and good stability.

[Analysis of pregnancy-related adverse outcomes in patients with severe hypothyroidism during pregnancy]

Objective: To analyze the pregnancy-related adverse outcomes in patients with severe hypothyroidism during pregnancy. Methods: Using cross-sectional study, a total of 47 pregnant women with severe hypothyroidism in the Peking University First Hospital from January 2007 to December 2020 were retrospectively collected by electronic case system. According to the occurrence of adverse pregnancy events (defined as any pregnancy complication or adverse maternal-fetal/neonatal outcomes), the patients were divided into pregnancy-related adverse outcomes group (n=33) and no pregnancy-related adverse outcomes group (n=15). The demographic data, thyroid function and thyroid autoantibody levels during pregnancy, pregnancy complications and maternal-fetal/neonatal outcomes of the two groups were recorded and analyzed. Results: The age of severe hypothyroidism women was (30.5±4.1) years. The median of gestational week at delivery was 38.6 (36.3, 39.9) weeks, the median of gestational week for diagnosis was 7.0 (6.0, 8.8) weeks, the median of the highest TSH level was 32.7(23.1,60.2)mU/L and the period of reaching the target TSH level for the first time was 6.0(4.0, 10.0)weeks. Most cases (82.5%, 33/40) had thyroid autoimmunity. All women were treated with levothyroxine (L-T₄) during pregnancy. A total of 37 cases (77.1%, 37/48) of them obtained the recommended target values. Fourty cases (83.3%, 40/48) gave birth. The birth weight of newborns was (3 041±452) g, the body length was (49.4±2.1) cm, and the head circumference was (33.6±0.7) cm. The period of reaching to target TSH level for the first time in patients without pregnancy-related adverse outcomes was shorter [5.0 (3.0, 9.0) vs 8.0 (4.5, 12.5) weeks) ] (P=0.033), and the times of thyroid function monitoring were more frequent [ (8.2±3.5) vs (6.0±3.6) times] (P=0.049) than the group with pregnancy-related adverse outcomes. Conclusions: The incidence of pregnancy complications and adverse maternal-fetal/neonatal outcomes is high in patients with severe hypothyroidism during pregnancy. Intense follow-up, treatment and restoration of euthyroidism as prompt as possible may improve pregnant outcomes.

[Clinical and laboratory features compared between JAK2 exon12 and JAK2 V617F mutated polycythemia vera]

Objective: To compare clinical and laboratory features between JAK2 exon12 and JAK2 V617F mutated polycythemia vera (PV) . Method: We collected data from 570 consecutive newly-diagnosed subjects with PV and JAK2 mutation, and compared clinical and laboratory features between patients with JAK2 exon12 and JAK2 V617F mutation. Results: 543 (95.3%) subjects harboured JAK2 V617F mutation (JAK2 V617F cohort) , 24 (4.2%) harboured JAK2 exon12 mutations (JAK2 exon12 cohort) , and 3 (0.5%) harboured JAK2 exon12 and JAK2 V617F mutations. The mutations in JAK2 exon12 including deletion (n=10, 37.0%) , deletion accompanied insertion (n=10, 37.0%) , and missense mutations (n=7, 25.9%) . Comparing with JAK2 V617F cohort, subjects in JAK2 exon12 cohort were younger [median age 50 (20-73) years versus 59 (25-91) years, P=0.040], had higher RBC counts [8.19 (5.88-10.94) ×10(12)/L versus 7.14 (4.11-10.64) ×10(12)/L, P<0.001] and hematocrit [64.1% (53.7-79.0%) versus 59.6% (47.2%-77.1%) , P=0.001], but lower WBC counts [8.29 (3.2-18.99) ×10(9)/L versus 12.91 (3.24-38.3) ×10(9)/L, P<0.001], platelet counts [313 (83-1433) ×10(9)/L versus 470 (61-2169) ×10(9)/L, P<0.001] and epoetin [0.70 (0.06-3.27) versus 1.14 (0.01-10.16) IU/L, P=0.002] levels. We reviewed bone marrow histology at diagnosis in 20 subjects with each type of mutation matched for age and sex. Subjects with JAK2 exon12 mutations had fewer loose megakaryocyte cluster (40% versus 80%, P=0.022) compared with subjects with JAK2 V617F. The median follow-ups were 30 months (range 4-83) and 37 months (range 1-84) for cohorts with JAK2 V617F and JAK2 exon12, respectively. There was no difference in overall survival (P=0.422) and thrombosis-free survival (P=0.900) . Conclusions: Compared with patients with JAK2 V617F mutation, patients with JAK2 exon12 mutation were younger, and had more obvious erythrocytosis and less loose cluster of megakaryocytes.

[Research advances on the role of competing endogenous RNAs in wound healing]

Wound healing, as one of the important public health issues, has been a worldwide problem. Due to the unique biological wound environment, wound healing is a very complex process with current treatments requiring long cycles, being poorly effective, and bringing high economic burden to patients. An increasing number of studies have shown that non-coding RNAs (ncRNAs) play important roles in wound healing process. The competing endogenous RNAs (ceRNAs) hypothesis in recent years is a new proposal on the inter-regulation of RNAs, which suggests a "mode of communication" between different RNAs. ceRNA regulatory network (ceRNET) combines the functions of protein-coding mRNA with ncRNA (e.g., microRNA, long non-coding RNA, pseudogenes, and circular RNA). Recent studies have shown that ceRNAs play important roles in wound healing, which may provide new effective therapeutic targets for wound healing. This paper starting with ceRNET systematically reviewed the research progress on the effects of various ceRNAs in wound healing and the future research challenges, with the aim to deeply explore the molecular mechanisms and clinical significance of ceRNAs in the process of wound healing.

[24 hours urinary sodium and potassium excretion and association with blood pressure among people aged 18-75 years old in six Chinese provinces]

Objective: To analyze the level of sodium and potassium intake and their association with blood pressure among people aged 18 to 75 years old in six provinces. Methods: From October to December 2018, participants aged 18 to 75 years were selected from Hebei, Hunan, Sichuan, Jiangxi, Qinghai and Heilongjiang provinces by using cluster random sampling method. Demographic characteristics and lifestyle information were collected by using questionnaire survey. Physical measurement and 24-hour urine collection were also conducted. Results: A total of 2 636 subjects were finally included in the analysis. The average urine sodium, potassium and sodium-to-potassium molar ratio were(4 438.4±1 822.8)mg/d, (1 566.2±646.3)mg/d, and 5.2±2.2, respectively. According to World Health Organization standards, 94.5% and 98.7% of the respondents had excessive sodium intake and insufficient potassium intake. After adjusting for related factors, each 1 000 mg increase in sodium excretion was associated with increased systolic blood pressure (1.65 mmHg, 95%CI: 1.07, 2.22) and diastolic blood pressure (0.53 mmHg, 95%CI: 0.21, 0.84), and each 1 000 mg increase in potassium excretion was associated with decreased systolic blood pressure (3.02 mmHg, 95%CI:-4.25, -1.80) and diastolic blood pressure (1.27 mmHg, 95%CI:-2.05, -0.48). Conclusion: The sodium intake in Chinese population remains excessive and potassium intake is insufficient. Sodium and potassium could be associated with blood pressure and the intervention of reducing sodium and supplementing potassium should be conducted in the corresponding population.

[Repair methods and clinical effects of full-thickness burn wounds deep to tendon or even bone in fingers]

Objective: To explore the repair methods and clinical effects of full-thickness burn wounds deep to tendon or even bone in fingers. Methods: A retrospective non-randomized controlled trial was conducted on the 98 patients with full-thickness finger burns deep to tendon or even bone who met the inclusion criteria and were hospitalized in Xiangya Hospital of Central South University from January 2010 to December 2019. Among the 98 patients, there were 81 males and 17 females, aged from 1 to 72 years, with 160 fingers involved. The wound area of each of affected fingers ranged from 2.0 cm×1.5 cm to 12.0 cm×3.5 cm, and the maximum wound area after merging the affected fingers was 12.0 cm×10.0 cm. For adult hands with multiple full-thickness burn wounds deep to tendon or even bone in multiple fingers or children with full-thickness finger burns deep to tendon or even bone, pedicled abdominal flaps were selected. For adults with single or two fingers with full-thickness burns deep to tendon or even bone, the pedicled internal hand flaps and free tissue flaps were selected. The free tissue flap repair requires good vascular conditions in the recipient area with arteries and veins available for anastomosis. For thumb nail burns deep to tendon or even bone or partial absence of the thumb after burns, the thumbs were reconstructed with the first toenail flap or dorsal foot flap with the second toe. In this study, 45 pedicled abdominal flaps were used to repair the wounds in 91 fingers, 37 pedicled internal hand flaps were used to repair the wounds in 37 fingers, 26 free tissue flaps were used to repair the wounds in 28 fingers, 3 first toenail flaps were used to reconstruct 3 patients' thumb nails and to repair hand wounds, and 1 dorsal foot flap with the second toe was used to reconstruct 1 patient's thumb and to repair hand and wrist wounds. The tissue flap area was from 2.0 cm×1.5 cm to 20.0 cm×10.0 cm. The wound in the donor site was repaired by direct suture or full-thickness skin grafting from the medial upper arm of the affected limb or split-thickness skin grafting from the outer thigh. The postoperative survival of the tissue flap, postoperative complications, and appearance and function of the flap donor site were observed. For the patients who were followed up, their finger functions were evaluated at the last follow-up using the trial criteria for replantation function evaluation of the amputated finger issued by the Hand Surgery Society of the Chinese Medical Association, and the satisfaction of the patients was investigated using the Efficacy Satisfaction Scale. Data were statistically analyzed with Kruskal-Wallis H test and Nemenyi test. Results: Of the 112 tissue flaps, 104 tissue flaps survived completely and had good blood circulation; 1 pedicled thumb dorsal ulnar reverse island flap, 1 pedicled finger artery cutaneous branch reverse island flap, and 1 free grafted anterolateral thigh perforator flap were slightly necrotic at the end, which were repaired with outer thigh split-thickness skin graft after dressing change and granulation tissue growth; 2 free grafted tarsal external artery flaps and 1 pedicled thumb dorsal ulnar reverse island flap suffered from postoperative venous return obstruction, which survived after partial suture removal and heparin saline cleansing of the wound; 1 pedicled modified dorsal metacarpal artery retrograde island flap and 1 free grafted peroneal artery perforator flap were necrotic, which were repaired by a pedicled abdominal flap and a lateral upper arm flap free transplantation respectively in stage Ⅱ. After transplantation, the tissue flaps had good shape, soft texture, and good elasticity, without bloating. There was no functional disorder in the flap donor site, and only slight scar remained. A total of 117 fingers of the 72 patients received 3-24 months of outpatient or telephone follow-up. At the last follow-up, the excellent and good rates of function evaluation of fingers repaired with pedicled abdominal flap, pedicled internal hand flap, and free tissue flap were respectively 77.3% (51/66), 96.3% (26/27), and 95.8% (23/24). The function of fingers repaired with free tissue flap and pedicled internal hand flap was significantly better than that with pedicled abdominal flap (P<0.01). The satisfaction of patients with fingers repaired by free tissue flaps was significantly higher than that by pedicled abdominal flap (P<0.05). Conclusions: According to the specific situation of full-thickness burn wounds deep to tendon or even bone in fingers, the pedicled abdominal flap is used to repair the multiple full-thickness burn wounds deep to tendon or even bone in multiple fingers of adult or the full-thickness burn wounds deep to tendon or even bone in fingers of children, the pedicled internal hand flap or free tissue flap is used to repair the full-thickness burn wounds deep to tendon or even bone in single or two fingers of adult patients, and the first toenail flap or the dorsal foot flap with the second toe is used to reconstruct the thumbs with full-thickness burn deep to tendon or even bone, with high postoperative tissue flap survival rate and few complications. The functional recovery of the affected finger is better after repair with free tissue flap and pedicled internal hand flap, and the patients' satisfaction is the highest after free tissue flap repair.

[Discussions on the causes and evaluation of mangled injury and the optimization of its repair strategy]

Many reasons can cause damage to a certain part of body, with the damaged tissue showing some corresponding characteristics. There are many uncertainties in the repair of damaged body parts, making it difficult to achieve the ideal function and appearance. In recent years, the repair of mangled injury has made significant progress, but it still faces many challenges. Based on the clinical practice and the current progress in the assessment and repair of mangled injury, this paper summarizes the causes, clinical features, injury assessment, treatment options, repair measures, and the risks of limb salvage, and then puts forward some personal opinions on the definition of mangled injury and treatment strategy optimization for reference.

[Urinary sodium, urine potassium and sodium-potassium ratio, and influencing factors of family cooks and family members in six regions of China]

Objective: To investigate the sodium intake, potassium intake, sodium- potassium ratio and influencing factors of family cooks and members in six regions of China. Methods: Using the multistage random sampling method, a total of 1 576 family cooks and their family members were recruited from 6 regions in China. Questionnaire survey and physical examination were conducted to collect basic information. 24 h urine was collected to test 24 h urinary sodium and potassium levels. Results: After excluding unqualified urine samples, a total of 1 530 people were included in the study. For all participants, 24 h urine sodium value was (4.39±1.93) g, 24 h urine potassium value was (1.59±0.62) g and sodium-potassium ratio was 5.02±2.18. 24 h urinary sodium was negatively correlated with age, female, junior high school education or above, and annual family income (P<0.05), and positively correlated with perceived salty taste, BMI and SBP (P<0.05). The 24 h urine potassium value was negatively correlated with eating out almost everyday (P<0.05), but positively correlated with BMI and unwillingness to reduct salt (P<0.05). The sodium-potassium ratio was negatively correlated with age, female and junior high school education or above annual family income (P<0.05), and positively correlated with perceived salty taste, SBP and eating out 3-5 d/week (P<0.05). Conclusions: The 24 h urinary sodium value and sodium potassium ratio of family cooks and family members in six regions of China are still at high level, while the 24 h urine potassium value is low, with multiple factors. Therefore, it is necessary to carry out long-term comprehensive salt reduction intervention for family cooks and their members.

[Fibrosis-driving cells in patients with primary myelofibrosis and myelodysplastic syndromes with myelofibrosis]

Objective: To compare fibrosis-driving cells in patients with primary myelofibrosis (PMF) and patients with myelodysplastic syndromes (MDS) with myelofibrosis (MF) (MDS-MF) . Methods: Bone marrow biopsy sections of patients with newly diagnosed PMF and MDS (10 each randomly selected for MF-0/1, MF-2, and MF-3) were stained with specific immunofluorescence antibodies to label Gli1, LeptinR, alpha smooth muscle actin (α-SMA) , CD45, and ProcollagenⅠ. Images captured by confocal microscopy were analyzed by Fiji-ImageJ to calculate the cell counts of Gli1(+), LeptinR(+) cells, and fibrosis-driving cells including α-SMA(+), α-SMA(+)/Gli1(+), α-SMA(+)/LeptinR(+), and ProcollagenⅠ(+)/CD45(+) cells. Results: Patients with PMF and MDS with MF-2/3 had higher LeptinR(+), α-SMA(+), α-SMA(+)/Gli1(+), and Procollagen Ⅰ(+)/CD45(+) cell counts compared with those with MF-0/1 (all P values<0.05) . However, patients with PMF with MF-2/3 presented with higher Gli1(+) and α-SMA(+)/LeptinR(+) cell counts than those with MF-0/1 (P=0.001 and 0.006) , whereas these cells were similar between patients with MDS with MF-0/1 and MF-2/3 (P=0.169 and 0.067) . In patients with MF-0/1, all fibrosis-driving cells did not differ between PMF and MDS (all P>0.05) . However, in patients with MF-2/3, Procollagen Ⅰ(+)/CD45(+) cell counts were higher in patients with PMF compared with those with MDS (P=0.007) , while other fibrosis-driving cell counts were similar between these two groups (all P>0.05) . MF grade and fibrosis-driving cell counts were not correlated with overall survival in patients with either PMF or MDS. Conclusion: α-SMA(+) cells in patients with PMF originated from both Gli1(+) and LeptinR(+) cells, whereas α-SMA(+) cells in patients with MDS-MF only originated from Gli1(+) cells; patients with PMF had higher ProcollagenⅠ(+)/CD45(+) cell counts than those with MDS-MF.

[Genetic characteristics and prognostic values of RAS mutations in patients with myelofibrosis]

目的

分析骨髓纤维化（MF）患者RAS基因突变的分子特征及其临床特点和预后意义。

方法

收集2011年12月至2019年12月在我中心有二代基因测序数据的226例MF患者临床资料，回顾性分析RAS基因突变特征、与临床和实验室参数之间的关系，及对总生存（OS）期的影响。

结果

226例原发性骨髓纤维化（PMF）及真性红细胞增多症（PV）或原发性血小板增多症（ET）后骨髓纤维化（post-PV/ET MF）患者中，共14例（6.2％）检出RAS基因突变：NRAS突变9例（4.0％），KRAS突变8例（3.5％），NRAS及KRAS突变并存3例（1.3％）。所有NRAS突变均发生在第12-13号密码子。RAS基因突变多为亚克隆突变，常与SETBP1、SRSF2、MPL共同发生。伴RAS基因异常患者平均突变基因个数（3.36个）与无RAS基因异常组（1.77个）相比，差异有统计学意义（P<0.001）。RAS基因突变患者与无突变患者相比，外周血单核细胞水平升高（P＝0.003），血小板水平减低（P＝0.026），骨髓原始细胞比例升高（P＝0.022），脾脏肋缘下≥10 cm患者比例更高（P＝0.005）。突变组患者非常高危（VHR）染色体核型比例（18.2％，2/11）显著高于无突变组患者（2.3％，3/133）（P＝0.031）。单因素分析中，NRAS基因突变的MF患者及PMF患者的OS时间较无突变患者显著缩短（P＝0.001，P＝0.008）。多因素分析显示，NRAS突变是影响OS的独立预后不良因素。

结论

RAS突变常与外周血单核细胞水平升高、血小板计数减低、骨髓原始细胞比例升高、VHR染色体核型等高危临床特征及实验室参数相关，多为发生在MF晚期的亚克隆突变。伴NRAS基因突变PMF及MF患者的OS时间显著缩短。

[Pathological characteristics of megakaryocytes in myeloproliferative neoplasms and their correlation with driver gene mutations]

Objective: To investigate the pathological characteristics of megakaryocytes in myeloproliferative neoplasms(MPN)and their correlations with driver gene mutations. Methods: Trephine specimens administered for 160 patients with MPN from February 2012 to October 2017 were reevaluated according to the World Health Organization(WHO)'s(2016)diagnostic criteria. Results: This cohort of patients included 72(45.0%)men, with the median age of 59(range, 13-87)years, comprising 39 with polycythemia vera(PV), 33 with essential thrombocythemia(ET), 37 with prefibrotic/early-primary myelofibrosis(pre-PMF), 37 with overt PMF, 1 with post-ET MF, 2 with post-PV MF, and 11 with MPN-unclassifiable(MPN-U)after the re-diagnosis. With PV, ET, pre-PMF, and overt PMF changes, proportions of dense clusters, hypolobulated nuclei, and naked nuclei of megakaryocytes gradually increased, whereas erythropoiesis gradually decreased. Proportions of reticulin, collagen, and osteosclerosis grades of ≥1 also increased. Dense clusters, hypolobulated nuclei, and naked nuclei of megakaryocytes were negatively correlated with erythropoiesis and positively correlated with granulopoiesis and fibrosis. In patients with pre- and overt PMF, dense clusters and naked nuclei of megakaryocytes were positively correlated with fibrosis. Patients with JAK2V617F MPN had significantly increased erythropoiesis(P=0.022). Patients with CALR-mutated MPN were characterized by increased loose and dense clusters; paratrabecular distribution and naked nuclei of megakaryocytes(P=0.055, P=0.002, P=0.018, P=0.008); and increased reticulin, collagen, and osteosclerosis(P=0.003, P<0.001, P=0.001). In patients with pre- and overt PMF, patients with JAK2V617F had increased cellularity(P=0.037). CALR-mutated patients had increased dense clusters and giant sizes of megakaryocytes, collagen, and osteosclerosis(P=0.055, P=0.059, P=0.011, P=0.046). Conclusion: Megakaryocytes showed abnormal MPN morphology and distribution, which were related to fibrosis. CALR mutation was probably associated with abnormal morphology and distribution of megakaryocytes and fibrosis.

[Establishment and test results of an artificial intelligence burn depth recognition model based on convolutional neural network]

Objective: To establish an artificial intelligence burn depth recognition model based on convolutional neural network, and to test its effectiveness. Methods: In this evaluation study on diagnostic test, 484 wound photos of 221 burn patients in Xiangya Hospital of Central South University (hereinafter referred to as the author's unit) from January 2010 to December 2019 taken within 48 hours after injury which met the inclusion criteria were collected and numbered randomly. The target wounds were delineated by image viewing software, and the burn depth was judged by 3 attending doctors with more than 5-year professional experience in Department of Burns and Plastic Surgery of the author's unit. After marking the superficial partial-thickness burn, deep partial-thickness burn, or full-thickness burn in different colors, the burn wounds were cut according to 224×224 pixels to obtain 5 637 complete wound images. The image data generator was used to expand images of each burn depth to 10 000 images, after which, images of each burn depth were divided into training set, verification set, and test set according to the ratio of 7.0∶1.5∶1.5. Under Keras 2.2.4 Python 2.8.0 version, the residual network ResNet-50 of convolutional neural network was used to establish the artificial intelligence burn depth recognition model. The training set was input for training, and the verification set was used to adjust and optimize the model. The judging accuracy rate of various burn depths by the established model was tested by the test set, and precision, recall, and F1_score were calculated. The test results were visualized to generate two-dimensional tSNE cloud chart through the dimensionality reduction tool tSNE, and the distribution of various burn depths was observed. According to the sensitivity and specificity of the model for the recognition of 3 kinds of burn depths, the corresponding receiver operator characteristics (ROC) curve was drawn, and the area under the ROC curve was calculated. Results: (1) After the testing of the test set, the precisions of the artificial intelligence burn depth recognition model for the recognition of superficial partial-thickness burn, deep partial-thickness burn, or full-thickness burn were 84% (1 095/1 301), 81% (1 215/1 499) and 82% (1 395/1 700) respectively, the recall were 73% (1 095/1 500), 81% (1 215/1 500) and 93% (1 395/1 500) respectively, and the F1_scores were 0.78, 0.81, and 0.87 respectively. (2) tSNE cloud chart showed that there was small overlapping among different burn depths in the test results for the test set of artificial intelligence burn depth recognition model, among which the overlapping between superficial partial-thickness burn and deep partial-thickness burn and that between deep partial-thickness burn and full-thickness burn were relatively more, while the overlapping between superficial partial-thickness burn and full-thickness burn was relatively less. (3) The area under the ROC curve for 3 kinds of burn depths recognized by the artificial intelligence burn depth recognition model was ≥0.94. Conclusions: The artificial intelligence burn depth recognition model established by ResNet-50 network can rather accurately identify the burn depth in the early wound photos of burn patients, especially superficial partial-thickness burn and full-thickness burn. It is expected to be used clinically to assist the diagnosis of burn depth and improve the diagnostic accuracy.

Modulation of rumen fermentation and microbial community through increasing dietary cation-anion difference in Chinese Holstein dairy cows under heat stress conditions

AIMS

The effect of increasing dietary cation-anion difference (DCAD) on rumen fermentation and ruminal microbial community in dairy cows under heat stress (HS) conditions were evaluated.

METHODS AND RESULTS

This study was performed as a two-period cross-over design during the summer season, with eight lactating dairy cows randomly distributed to either a control DCAD diet (CON: 33·5 mEq/100 g DM) or high DCAD diet (HDCAD: 50·8 mEq/100 g DM). Throughout the present study, the temperature and humidity index (THI; 80·2 ± 4·29) was generally elevated above the threshold (THI = 72) that is reported to cause HS in lactating dairy cows. Rumen liquid samples were collected on 15 and 21 d during each 21 d-period. The absolute concentration of ruminal total volatile fatty acid (TVFA) in HDCAD treatment was significantly (P < 0·05) higher than those in the control, whilst the ruminal pH, NH₃ -N, and VFA molar percentages were unaffected through increasing DCAD. Furthermore, the copy numbers of the cellulolytic bacteria Ruminococcus albus and Ruminococcus flavefaciens in rumen fluid significantly (P < 0·05) rose along with the increment of DCAD. Although the Alpha diversity indexes and the bacterial microbiota structure were unaffected, increasing DCAD significantly (P < 0·05) enriched the phylum Fibrobacteres and genus Fibrobacter in the microflora of rumen fluid, whilst the genera Flexilinea and Dubosiella were the most differentially abundant taxa in the control.

CONCLUSIONS

Increasing DCAD under HS conditions resulted in a greater concentration of total VFA without affecting rumen bacteria diversity or structure, although the enrichment of some cellulolytic/hemicellulolytic bacteria was observed.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present study provides information on the modulation of rumen fermentation and microbial community through the increment of DCAD in Holstein dairy cows under HS conditions.

[Clinical effectiveness of simultaneous reconstructions of multiple joint scar contracture deformity of limb]

Objective: To explore the clinical effects of simultaneous reconstruction of multiple joint scar contracture deformity of limb. Methods: From January 2010 to June 2018, 24 patients with multiple joint scar contracture deformity of the same limb were reconstructed in simultaneous operations in Xiangya Hospital of Central South University, including 16 males and 8 females, aged 3-42 years, with 15 patients having deformities in the upper limbs and 9 patients having deformities in the lower limbs. One operation was performed to repair contracture deformity of axillary fossa and elbow in 3 patients, cubital fossa and palmar of wrist in 4 patients, cubital fossa and hand in 5 patients, palmar of wrist, palm, and palmar of finger in 3 patients, groin and medial knee in 2 patients, popliteal fossa and posterior ankle in 1 patient, and anterior ankle and dorsum of foot in 6 patients. After the release of various joint scar contractures, the area of skin defect was 140 to 580 cm(2). Autologous full-thickness skin grafts were used in 7 patients, autologous medium-thickness skin grafts were used in 4 patients, autologous full-thickness skin grafts combined with local skin flaps were used in 9 patients, and allogeneic acellular dermal matrix and autologous thin skin grafts were used in 4 patients. Comprehensive measures for rehabilitation were taken and the survival of the skin graft was observed after operation. Six months to eight years after the operation, all the patients were followed up for the functions of the affected limbs, among which the functions of the upper limbs were evaluated according to the trial standard for the evaluation of the functions of the upper limbs of the Hand Surgery Society of the Chinese Medical Association. The joint mobility, walking, and squatting function of lower extremity were examined after operation. Recurrence of contractures in all the affected limbs and reoperation were recorded. Results: The grafts survived after operation in 22 patients. Two patients had necrosis in small full-thickness skin area, of which one was healed by skin grafting after debridement, and the other one was healed after dressing changes. The deformity of scar contracture at each repaired joint was completely or partially corrected. During a follow-up for 6 to 96 months, the upper limb functions of 15 patients were rated excellent in 12 patients and good in 3 patients. Among the 9 patients of lower limb scar contractures, except for one 3-year-old child who experienced recurrence of medial knee scar contracture and underwent surgical release and skin grafting 5 years later, the remaining 8 patients basically recovered normal joint functions with pretty good outcomes. Conclusions: For continuous scar contracture deformity of multiple joints of the same limb, simultaneous surgical release and skin grafting can reduce operation frequency and obtain better outcomes of surgical operation.

ARRB1-Promoted NOTCH1 Degradation Is Suppressed by OncomiR miR-223 in T-cell Acute Lymphoblastic Leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is a type of aggressive leukemia with inferior prognosis. Although activating mutations of NOTCH1 are observed in most T-ALL cases, these mutations alone are not sufficient to drive the full development of T-ALL. β-Arrestins (ARRB) are versatile and multifunctional adapter proteins that regulate diverse cellular functions, including promoting the development of cancer. However, the role of ARRBs in T-ALL has largely remained elusive. In this study, we showed that ARRB1 is expressed at low levels in assayed T-ALL clinical samples and cell lines. Exogenous ARRB1 expression inhibited T-ALL proliferation and improved the survival of T-ALL xenograft animals. ARRB1 facilitated NOTCH1 ubiquitination and degradation through interactions with NOTCH1 and DTX1. Mechanistically, the oncogenic miRNA (oncomiR) miR-223 targets the 3'-UTR of ARRB1 (BUTR) and inhibits its expression in T-ALL. Furthermore, overexpression of the ARRB1-derived miR-223 sponge suppressed T-ALL cell proliferation and induced apoptosis. Collectively, these results demonstrate that ARRB1 acts as a tumor suppressor in T-ALL by promoting NOTCH1 degradation, which is inhibited by elevated miR-223, suggesting that ARRB1 may serve as a valid drug target in the development of novel T-ALL therapeutics.Significance: These findings highlight a novel tumor suppressive function of the adaptor protein β-arrestin1 in T-ALL.

[Advances in the research of cold atmosphere plasma in the treatment of chronic wounds]

Chronic wounds are characterized by complex pathogenesis, long course of disease, and occur mostly in middle-aged and elderly people. As the population ages, chronic wounds have gradually become significant burden on the affected patients and the healthcare system. In the past decade, cold atmosphere plasma (CAP) was found to have the effects of resisting infection and promoting wound healing. By reviewing recent researches on the treatment of chronic wounds and biological effects of CAP at home and abroad, this article summarizes the research progress of CAP in the treatment of chronic wounds, aiming at providing a reference for the treatment of chronic wounds.

[Strengthen standardized diagnosis and treatment to improve the prognosis of electric burn]

Because of the complex injury mechanism, hidden tissue injury, and severe systemic injury, the clinical diagnosis and treatment of electric burn still face many challenges, and the mortality and disability rate are still high. In view of the particularity of electric burn and the prognosis of electric burn, especially the quality of wound repair, the author puts forward some personal views on fluid resuscitation, organ protection, and wound repair on the basis of summarizing the new methods of diagnosis and treatment of electric burn at home and abroad at present, and preliminarily explores the standardized diagnosis and treatment of electric burn.

[Clinical characteristics and repair effect of 136 patients with electric burns of upper limb]

Objective: To analyze clinical characteristics and wound repair methods and effects of patients with upper limb electric burns. Methods: Medical records of 136 patients with upper limb electric burn who met the inclusion criteria and hospitalized in our unit from January 2015 to March 2019 were retrospectively analyzed. Proportion in patients with electric burns in the same period, gender, age, admission time, categories, injury causes, injury voltage, burn area and depth of upper limb, simultaneous injury of both upper limbs, and early wound treatment measure of patients with upper limb electric burn were recorded. The main repair methods of each affected limb were classified and recorded. The overall efficacy of the patients was recorded, including postoperative wound complications and healing condition. The patients repaired with distal pedicled flaps and those with free flaps were followed up for 3 to 6 months. The survival rate of flaps were recorded, the function of affected limbs after operation was evaluated, and the satisfaction degree of patients was investigated by Curative Effect Score Table. The amputation rate, age, and burn area of upper limbs of patients caused by high-voltage and low-voltage electricity were compared. Data were processed with Wilcoxon rank sum test, chi-square test, or Fisher's exact probability test. Results: (1) The number of upper limb electric burn patients accounted for 88.3% of 154 patients with electric burns hospitalized in the same period, including 117 males and 19 females, aged 1 year and 2 months to 72 years [(34±18) years], admitted 1 h to 48 d after injury, including 51 electricians, 32 rural migrant workers, 31 students and preschool children, and 22 patients belonging to other categories. Patients of the first two categories were mainly injured by work accidents, and those of the latter two categories mainly suffered from touching power source or power leakage. Among all the patients, 75 cases were injured by high-voltage electric burn, and 61 cases were injured by low-voltage electric burn, with burn area of upper limb from 0.2% to 16.0% [2% (1%, 5%)] total body surface area (TBSA) and area of wounds deep to bone from 0.2% to 15.0% [2% (1%, 5%)] TBSA. Two upper limbs in 54 cases were simultaneously injured, accounting for 39.7%. Early fasciotomy was performed for 73 limbs. (2) Thirteen affected limbs were treated with dressing change, 2 affected limbs were sutured directly after debridement, 56 affected limbs were repaired by skin grafting, 12 affected limbs were repaired by local flap, 45 affected limbs were repaired by distal pedicled flap, 22 affected limbs were repaired by free flap, and 40 affected limbs were amputated (accounting for 21.1%). (3) One case died of pulmonary infection, sepsis, and multiple organ failure after operation, and the rest patients were all cured. One case with avulsion of abdominal flap was repaired by skin grafting after dressing change. The anterolateral thigh flap in one case necrotized after transplantation, which was replaced by pedicled abdominal flap. Seven cases had small erosion on the pedicle or margin after transplantation of abdominal flap and were healed by dressing change. Six cases had local bruising at the distal end after transplantation of abdominal flap and were healed after conservative treatment such as hyperbaric oxygen. The other flaps survived well. (4) The survival rate of distal pedicled flap grafting was 97.8% (44/45), which was close to that of free flap grafting (95.5%, 21/22, P>0.05). The function recovery of affected limb after free flap grafting was better than that of distal pedicled flap grafting (Z=-3.054, P<0.01), but their satisfaction degree of patients was similar (Z=-0.474, P>0.05). (5) Patients with high-voltage electric burn had higher amputation rate, older age, and larger upper limb burn area than those with low-voltage electric burn (χ(2)=4.743, Z=-2.801, -6.469, P<0.05 or P<0.01). Conclusions: Upper extremity electric burn often occurs in children, electricians, and rural migrant workers with high rate of amputation. Teachers and parents should strengthen safety education for children and manage power source of life well. Workers should improve safety awareness and operate standardly. Fasciotomy for relaxation should be performed for electric burn wound as soon as possible, and flap grafting can effectively repair wound after early debridement. The function recovery of affected upper limb repaired with free flap grafting is better.

[A study of clinical characteristics and prognosis of primary myelofibrosis patients with thrombocytopenia in varied degrees]

目的

探讨不同血小板水平原发性骨髓纤维化（PMF）患者的临床特征及其预后。

方法

对1990年5月1日至2017年4月30日在中国医学科学院血液病医院就诊的1 305例PMF患者进行回顾性分析。

结果

1 305例PMF患者中，重度血小板减少（PLT<50×10⁹/L）、轻度血小板减少［PLT（50～99）×10⁹/L］、无血小板减少患者（PLT≥100×10⁹/L）分别为320例（24.5％）、198例（15.2％）和787例（60.3％）。在血小板计数越低的组别中，HGB<100 g/L患者比例、WBC<4×10⁹/L患者比例和外周血原始细胞≥3％患者比例、异常染色体核型患者比例和预后不良染色体核型患者比例越高（P<0.001，P<0.001，P＝0.004，P<0.001，P<0.001），JAK2V617F突变阳性率越低（P<0.001）。血小板计数与脾肿大、HGB、WBC呈正相关（P值均<0.001，相关系数分别为0.131、0.445、0.156），与体质性症状和外周血原始细胞比例呈负相关（P值分别为0.009、0.045，相关系数为−0.096、−0.056）。重度血小板减少、轻度血小板减少、无血小板减少组患者中位生存时间分别为32、67、89个月（P<0.001）。血小板减少程度分组［HR＝1.693（95％CI 1.320～2.173），P<0.001］和动态国际预后积分系统（DIPSS）预后分级［HR＝2.051（95％CI 1.511～2.784），P<0.001］均为PMF患者独立不良预后因素。

结论

血小板计数越低的PMF患者出现贫血、白细胞减少和外周血原始细胞比例增高的比例越高、临床表现越重、预后越差，临床上应采取更加积极的治疗措施。

[Progress on salt reduction and prevention of chronic non-communicable disease]

Salt reduction is one of the effective strategy for chronic non-communicable disease control and prevention recommended by World Health Organization. Research evidences on salt reduction emerge recently and some issues remain controversial. With the aim of providing reference for the future salt reduction action, this article reviewed the current evidence and strategies on the source of salt intake, the relationship between salt and health, the cost-effectiveness of salt reduction, as well as the targets and strategies of salt reduction. It also elaborated the main controversial issues in salt reduction, including salt reduction in population, evaluation method of salt intake, substitute salt, iodine intake, and the effectiveness of salt reduction strategy. The international and internal salt reduction activities were introduced as well.

[Retrospect of development and progress over the past 60 years and going further while carrying out practice]

This article briefly describes the establishment and development of Department of Burns and Reconstructive Surgery of Xiangya Hospital of Central South University. Over the past 60 years, our department has achieved great achievements in the treatment of burns by the combination of traditional Chinese medicine with western medicine, treatment of severe burns, and burn wounds repaired by flaps, and established Hunan burn rescue medical collaboration network. With the development of society and the change of disease spectrum, the future development direction of our department mainly focuses on treatment of severe burns, scar prevention, and treatment of acute and chronic wounds.

[Clinical application of negative pressure dressing in the full-thickness skin grafting]

Objective: To investigate the effect of different negative pressure of wound negative pressure dressing (NPD) on the survival of full-thickness skin grafts of patients. Methods: One hundred and eleven patients who need skin grafting, conforming to the inclusion criteria were hospitalized in our unit from August 2012 to March 2017, and their clinical data were retrospectively analyzed. Forty-seven patients hospitalized from August 2012 to October 2015 were assigned into traditional treatment group. Sixty-four patients hospitalized from November 2015 to March 2017 were divided into -9.975 kPa negative pressure treatment group (n=34) and -13.300 kPa negative pressure treatment group (n=30). Patients in traditional treatment group received conventional dressing after full-thickness skin grafting. Patients in -9.975 kPa and -13.300 kPa negative pressure treatment groups received -9.975 kPa and -13.300 kPa NPD based on traditional treatment after vacuum sealing, respectively. Dot necrosis area of skin grafts and erosion and escharosis of graft edges of patients in the three groups on post operation day 10 were observed. The percentage of dot necrosis area of skin grafts and occurrence rate of erosion and escharosis of skin graft edges were calculated, respectively. Data were processed with chi-square test, Fisher's exact test, and Kruskal-Wallis H test. Results: Percentages of dot necrosis area of skin grafts of patients in traditional treatment group and -9.975 kPa and -13.300 kPa negative pressure treatment groups were 17.81%, 3.20%, and 3.00%, respectively. Percentage of dot necrosis area of skin grafts of patients in traditional treatment group was significantly higher than that in -9.975 kPa and -13.300 kPa negative pressure treatment groups (Z=-5.770, -4.690, P<0.001). Percentages of dot necrosis area of skin grafts of patients in -9.975 kPa and-13.300 kPa groups were close (Z=-0.619, P>0.05). The occurrence rates of erosion and escharosis of skin graft edges of patients in traditional treatment group and -9.975 kPa and -13.300 kPa negative pressure treatment groups were 78.7% (37/47), 32.4 (11/34), and 36.7% (11/30), respectively. Erosion and escharosis of skin graft edges of patients in -9.975 kPa and -13.300 kPa negative pressure treatment groups were better than those in traditional treatment group (P<0.001). Erosion and escharosis of skin graft edges of patients in -9.975 kPa and -13.300 kPa negative pressure treatment groups were close (P>0.05). Conclusions: The use of -9.975 kPa and -13.300 kPa NPD in skin grafts after full-thickness skin grafting significantly diminishes the occurrence rates of dot necrosis area of skin grafts and erosion and escharosis of graft edges.

[Prognostic value of JAK2, MPL and CALR mutations in Chinese patients with primary myelofibrosis]

目的

评价JAK2、MPL和CALR基因突变在中国原发性骨髓纤维化（PMF）患者中的预后意义。

方法

回顾性分析402例PMF患者的临床资料及JAK2、MPL和CALR基因突变，应用Kaplan-Meier、Log-rank和Cox回归模型进行相关预后因素分析。

结果

402例PMF患者中男209例，女193例，中位年龄55(15~89）岁。JAKV617F基因突变189例（47.0%），MPLW515基因突变13例（3.2%），CALR基因突变81例（20.1%）[1型突变30例（37.0%），2型突变48例（59.3%），少见型突变3例（3.7%）]，119例（29.6%）未检测到JAK2、MPL和CALR基因突变。单因素分析显示，2型CALR突变或未检测到JAK2、MPL和CALR基因突变的患者中位生存期（74个月）短于检测到JAK2、MPL或1型及少见型CALR基因突变的患者（168个月）[HR=2.990（95% CI 1.935~4.619），P <0.001]。因此，将基因突变类型分为预后不良组（2型CALR突变和未检测到JAK2、MPL和CALR基因突变）和预后良好组（JAKV617F、MPLW515、1型及少见型CALR基因突变）。经多因素分析提出了中国PMF患者的动态国际预后积分系统（DIPSS-Chinese）分子预后积分系统，各参数赋值如下：DIPSS-Chinese低危组0分，中危组1分，高危组2分，2型CALR突变或未检测到JAK2、MPL和CALR基因突变积1分。402例患者中，低危组（0分）132例（32.8%），中危-1组（1分）143例（35.6%），中危-2组（2分）106例（26.4%），高危组（3分）21例（5.2%）。低危组中位生存时间未达到，中危-1组为156(95% CI 117~194）个月，中危-2组为60(95% CI 28~91）个月，高危组为22（95% CI 10~33）个月，总生存差异具有统计学意义（P<0.001）。DIPSS-Chinese分子预后积分系统较DIPSS-Chinese有更准确的预测能力（−2 log似然比分别为855.6和869.7，P=0.005）。

结论

在中国PMF患者中，2型CALR突变和未检测到JAK2、MPL和CALR突变是独立的不良预后因素，DIPSS-Chinese分子预后积分系统有更好的预测价值。

A Targeted DNAzyme-Nanocomposite Probe Equipped with Built-in Zn(2+) Arsenal for Combined Treatment of Gene Regulation and Drug Delivery

As catalytic nucleic acids, DNAzymes have been extensively used in the design of sensing platforms. However, their potentials as intelligent drug carriers for responsive drug release in gene therapy and chemotherapy were rarely explored. Herein, we report a dual-functional probe composed of gold nanoparticles (GNPs), catalytic Zn(2+)-dependent DNAzyme, anticancer drug doxorubicin (Dox), targeted AS1411 aptamer and acid-decomposable ZnO quantum dots (ZnO QDs) to achieve intracellular gene regulation and drug delivery in a controlled manner. By means of aptamer-guided targeting and receptor-mediated endocytosis, the probes were specifically internalized into the HeLa cells and trapped in the acidic endo-/lysosomes, where the ZnO QDs as the built-in Zn(2+) arsenal were promptly dissolved to offer Zn(2+), leading to the activation of DNAzyme to cleave the substrate strands, and subsequent drug release. Meanwhile, as designed, one part of the cleaved substrate, hybridized with the overexpressed miR-21 in the target cells, thereby declining its intracellular level. Taken together, the down-regulation of miR-21 has a synergistic effect with Dox to efficiently eradicate the cancer cells. Thus, the favorable biocompatibility, cancer cell specificity and combined treatment make the probe promising for therapy of multidrug-resistant cancer and in vivo application.

Versatile Microfluidic Platform for the Assessment of Sialic Acid Expression on Cancer Cells Using Quantum Dots with Phenylboronic Acid Tags

This work describes a versatile microfluidic platform for evaluation of cell-surface glycan expression at the single-cell level using quantum dots (QDs) tagged with phenylboronic acid. The platform was integrated with dual microwell arrays, allowing the introduction of cells in two states using the same cell culture chamber. The simultaneous analysis of cells in the same environment minimized errors resulting from different culture conditions. As proof-of-concept, the expressions of sialic acid (SA) groups on K562 cells, with or without 3'-azido-3'-deoxythymidine (AZT) treatment, were evaluated in the same chamber. 3-Aminophenylboronic acid functionalized CdSeTe@ZnS-SiO2 QDs (APBA-QDs) were prepared as probes to recognize SA groups on K562 cells with only one-step labeling. The results showed that the expression of SA moieties on K562 cells was increased by 18% and 31% after treatment with 20 and 40 μM AZT, respectively. Performing the drug treatment and control experiments simultaneously in the same chamber significantly improved the robustness and effectiveness of the assay. The strategy presented here provides an alternative tool for glycan analysis in a sensitive, high-throughput, and effective manner.

Keloid microRNA expression analysis and the influence of miR-199a-5p on the proliferation of keloid fibroblasts

The purpose of this study was to identify microRNAs (miRNAs) involved in keloid formation and determine their influence on the proliferation of keloid fibroblasts (KFs). Eight specimens each of resected keloid tissue and normal skin tissue were collected. miRNAs that are differentially expressed in keloid tissue and normal skin were detected using an miRNA microarray and verified by quantitative real-time polymerase chain reaction (RT-PCR). Seventeen differentially expressed miRNAs, including miR-199a-5p, were identified by microarray hybridization. qRT-PCR analysis confirmed the decrease in miR-199a-5p expression in keloid vs normal tissue that was detected by the microarray analysis. Mimics of differentially expressed miRNAs were then transfected into a KF cell line, and the effect of miRNA overexpression on the proliferation of KFs was assayed using the EdU assay. Compared with mock-transfected cells, KFs transfected with a miR-199a-5p mimic showed significantly lower cell proliferation and an altered cell cycle, with cells having significantly longer S and G2/M phases. The significantly lower expression of miRNA-199a-5p in keloids likely influences the cell cycle of KFs and restrains their proliferation, suggesting that miR-199a-5p probably plays a role in the regulation of KF proliferation.

Multi-shell structured fluorescent-magnetic nanoprobe for target cell imaging and on-chip sorting

In this paper, we have developed a core-triple-shell structured multi-functional nanoprobe Fe3O4/SiO2/CdSeTe@ZnS-SiO2/polydopamine with strong fluorescence and a fast magnetic response for specifically recognizing, fluorescently labeling, and magnetically sorting target tumor cells on a microfluidic chip. The outer polydopamine layer not only effectively alleviated the quenching effect of the interlayer quantum dots but also provided a convenient and versatile functional interface to readily conjugate with the recognizing model molecules of aptamer KH1C12 with amine, thiol, or carboxyl groups. Moreover, the polydopamine isolation and PEG decoration equipped the as-fabricated nanoprobes with little cytotoxicity and nonspecific affinity, leading to the effective and specific profiling of the protein epitopes expressed on the target tumor cells. Taking advantage of the magnetic property and specific recognition, the modified nanoprobe was utilized to label and isolate HL-60 cells from a homogeneous cell mixture of HL-60 and K562 cells on a microfluidic chip. Combining with the high throughput of the microfluidic chip, 1.0 × 10(4) HL-60 cells were readily separated from 2.0 × 10(4) cells in only 10 min with 98% separation efficiency, markedly improved in comparison with conventional strategies. This study presents an innovative strategy for developing highly integrated nanoprobes of strong fluorescence and magnetic controllability, opening up a promising probe-based avenue for biological imaging and separation.

Chemical composition and antioxidant, antimicrobial activities of the essential oils of Thymus marschallianus Will. and Thymus proximus Serg

Chemical composition and antioxidant, antimicrobial activities of the essential oils from Thymus marschallianus Will. and Thymus proximus Serg. growing in the wild in Xinjiang were studied. Samples were collected from the aerial parts of the plants with simultaneous distillation-extraction apparatus. The yields ranged between 1.22%+/- 0.01 and 0.16%+/- 0.01 (weight/dry weight), respectively, 53 and 60 kinds of volatiles, representing 99.6% and 99.7% of the essential oils, respectively, were identified in extracts from T. marschallianus and T. proximus by GC/MS analysis. The main components were Thymol (28.0% to 32.9%), p-Cymene (7.7% to 25.4%), and gamma-Terpinene (18.0% to 22.4%). Antioxidant activities of the oils were evaluated using metal chelating, reductive potential, 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, and modified thiobarbituric acid reactive substances assay. Antimicrobial activities of the oils were investigated on Escherichia coli, Staphylococcus aureus, Bacillus subtilis, yeast, Rhizopus, and Penicillium. The inhibition zones (IZ) and minimum inhibitory concentration (MIC) values were 5.0 to 35.7 mm in diameter and 1.81 to 4.52 microL/mL, respectively.

PRACTICAL APPLICATION

Due to the economical impacts of spoiled foods and the consumer's concerns over the safety of foods, a lot of attention has been paid to naturally derived compounds. Fresh and dried Thymus species as well as their processed products have been widely used as flavorings since ancient times; however, during the last few decades, they also have become a subject for a search of natural antioxidants and antimicrobial agents. Biological activities of Thymus essential oils depend on their chemical composition, which is determined by the genotype and influenced by environmental conditions. Recent studies have showed that Thymus species have strong antimicrobial and antioxidant activities. To the best of our knowledge, the properties of Thymus species growing wild in the Xinjiang have not been reported before.

Sequence variations in the MBL gene and their relationship to pulmonary tuberculosis in the Chinese Han population

SETTING

The mannan binding lectin (MBL) gene is thought to play a role in human innate immune response to tuberculosis (TB) infection.

OBJECTIVE

To investigate the possible association between MBL sequence variants and TB infection in the Chinese Han population.

DESIGN

A total of 152 male pulmonary tuberculosis (PTB) patients and 293 healthy male subjects were recruited. Six MBL single nucleotide polymorphisms (SNPs) (A/B, A/C, A/D, H/L, Y/X and P/Q) were genotyped and haplotyped using the combined analysis of polymerase chain reaction using sequence-specific primers (PCR-SSP) and the PCR-sequence specific oligonucleotide probe (PCR-SSOP) assay. The genotype and haplotype frequencies were compared between TB cases and controls using an unconditional logistic regression model.

RESULTS

Neither the genotypes nor the haplotypes of the five loci were significantly associated with the disease when considered individually. After the haplotypes were regrouped, however, the XB haplotype group coding for diminished MBL levels was present at a significantly higher frequency in the patients compared with the YA group (OR 1.57, 95% CI 1.02-2.41, P < 0.05).

CONCLUSION

No convincing evidence of association between MBL sequence variants and PTB was observed individually, although the low-producing XB haplotype group may serve as a minor risk factor for PTB infection in the male Chinese Han population.

RNAi-hTERT Inhibition Hepatocellular Carcinoma Cell Proliferation via Decreasing Telomerase Activity

BACKGROUND

RNA interference (RNAi), which has been demonstrated as having great potentional in the fields of gene function and gene therapy, was applied to inhibit the expression of some endogenous genes. Human telomerase reverse transcriptase (hTERT) is highly expressed in hepatocellular carcinoma cells.

MATERIALS AND METHODS

In combination with DNA vector-based RNAi, quantitative real-time reverse transcription polymerase chain reaction, telomeric repeat amplification protocol-enzyme-linked immunosorbent assay, 3-(4,5 dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assay, and xenograft tumor animal techniques, we first constructed three pTZU6 + 1-shRNA-hTERT vectors and their corresponding site-mutated vectors, then transfected them into hepatocarcinoma HepG2, SMMC-7721 cells, and normal liver L02 cells, respectively, injected them into xenograft hepatocarcinoma tumor tissues to induce RNAi, and then detected the alteration of cell and tumor proliferation, telomerase activity, hTERT, and c-myc expression in each treatment.

RESULTS

The cell proliferation of hepatocellular carcinoma cells both in vitro and in vivo was significantly inhibited by ph1-shRNA, the most effective segment targeted hTERT gene. ph1-shRNA could inhibit telomerase activity, hTERT, and c-myc expression in hepatocarcinoma cells and xenograft tumor tissues compare with the cells treated with empty vector pTZU6 + 1. However, there were no obvious effects on normal liver L02 cells. Moreover, even a single base mutation in siRNAs transcription template would significantly reduce the ability of siRNAs to induce RNA silencing.

CONCLUSIONS

RNAi-hTERT could inhibit the proliferation of hepatocarcinoma cells specifically via the suppression of telomease activity, hTERT, and c-myc expression. Therefore, hTERT and c-myc play key roles in hepatocarcinoma tumorgenesis, and an RNAi-targeted hTERT strategy would be a potential approach for hepatocarcinoma therapy.

Transcript regulation of human telomerase reverse transcriptase by c-myc and mad1

Telomerase activity is highly positive correlated to most malignant neoplasms. Human telomerase reverse transcriptase (hTERT) is the rate-limiting factor of telomerase activity. Recent studies have shown that the expression of hTERT is mainly determined by its transcript regulation. Among the transcript regulation factors of hTERT, c-myc and mad1 are well known. Here, we constructed c-myc and mad1 eukaryotic expression vectors, then co-transfected them with the wild-type (Tw) or mutant hTERT promoter (Td) luciferase reporter plasmid, which were double-mutated in the E-box sequences from CACGTG to CACCTG of Tw. The change of luciferase activity in different cells was detected. The results showed that Tw was obviously activated in T24 and EJ bladder cancer cells, but not in normal fibrocytes. c-myc and mad1 had positive and negative effects respectively on the Tw transcript in a dose-dependent manner, while the roles of c-myc and mad1 in regulating the Td transcript were reversed. c-myc combined with mad1 can down-regulate Tw but not Td. These observations indicate that c-myc and mad1 can regulate the hTERT transcript in a different manner in hTERT positive cells, but not in normal cells. This may provide an insight into some telomerase-related carcinogenesis mechanisms.

[Experimental research of targeting hTERT gene inhibited in hepatocellular carcinoma therapy by RNA interference]

BACKGROUND & OBJECTIVE

RNA interference (RNAi) is a new gene blocking technology that silences target gene at post-transcription level induced by the small interference RNA (siRNA). RNAi has been demonstrated great prospect in gene functional research and gene therapy areas. Nowadays, RNAi has been reported to be used to inhibit the expression of endogenous genes including cyclophilin, GAPDH, p53, and c-myc; and there were some progresses in the therapy of the diseases caused by AIDS and hepatitis viruses with RNAi. However, hTERT gene, which was highly expressed in hepatocellular carcinoma and other malignant neoplasm, has not been researched by RNAi. In present research, we utilized RNAi to inhibit hTERT gene expression in vitro and in vivo, investigated the feasibility and specificity of gene therapy for hepatocellular carcinoma.

METHODS

Small interference RNAs homologous to hTERT gene were designed,pTZU6+1-shRNA-hTERT vector was constructed and transfected into hepatocellular carcinoma SMMC-7721 cells and transplanted SMMC-7721 tumor in nude mice to induce RNAi. The changes of hTERT gene expression and tumor cell proliferation in both siRNA treatment groups and control group were determined by flow cytometry, reverse transcription polymerase chain reaction (RT-PCR), immunochemistry in vitro and in vivo.

RESULTS

The expression of hTERT had been obviously inhibited by RNAi in vitro. The inhibition rate of cell growth was 37.5% after pTZU6+1-shRNA-hTERT vector was transfected to hepatocellular carcinoma SMMC-7721 cells; the phase of cell cycle indicated the reduction of S phase, while G(1)/G(0) phase increased. The mRNA level of hTERT decreased from 99.4% to 53.1%, its protein expression reduced from 86.3% to 46.6%. The tumor size reduced after treated with pTZU6+1-shRNA-hTERT vector in vivo; hTERT mRNA level decreased from 99.1% to 76.2%, and its protein expression decreased from 87.2% to 61.8% in siRNA treatment group. In contrast, there were no changes in control groups in vitro and in vivo.

CONCLUSION

RNAi inhibits the hTERT gene expression and proliferation of hepatocellular carcinoma SMMC-7721 cells with specificity, and is a possible new approach for neoplasm gene therapy.

VDR and NRAMP1 gene polymorphisms in susceptibility to pulmonary tuberculosis among the Chinese Han population: a case-control study

OBJECTIVE

To explore the potential role of vitamin D receptor (VDR) gene and natural-resistance-associated macrophage protein 1 (NRAMP1) gene polymorphisms in susceptibility to pulmonary tuberculosis (PTB) in the Chinese Han population.

DESIGN

In an unmatched case-control study, 120 well defined PTB patients and 240 unrelated normal controls were enrolled. Information on potential risk factors of PTB was collected using a standard questionnaire. Genetic polymorphisms of VDR gene (TaqI and FokI) and NRAMP1 gene (INT4, D543N and 3'UTR) were analysed using PCR and RFLP. Unconditional logistic regression was performed, and odds ratios (ORs), their 95% confidence intervals (CI) and P values were estimated using maximum likelihood methods.

RESULTS

Univariate analysis demonstrated that FokI-ff homozygotes, D543N G/A and 3'UTR TGTG+/del heterozygotes occurred more frequently in patients than in controls. The crude ORs were 2.345 (95%CI 1.222-4.499), 2.590 (95%CI 1.043-6.434) and 1.890 (95%CI 1.171-3.051), respectively, compared with their corresponding common genotypes. The P values were 0.033, 0.041 and 0.030, respectively. After adjusting for exposure history and BCG immunisation in the multivariate analysis, the adjusted ORs were 4.625 (95%CI 1.737-12.312), 2.415 (95%CI 1.079-8.759) and 2.187 (95%CI 1.146-4.175), with P values of 0.002, 0.036 and 0.018, respectively. Neither univariate nor multivariate analysis disclosed any significant association between the disease and TaqI or INT4.

CONCLUSIONS

Polymorphisms in the VDR and NRAMP1 gene are statistically associated with susceptibility to PTB in the Chinese Han population.

[Detection of anti-Spirometra erinaceieuropaei antibody using ELISA]

OBJECTIVE

To study specific diagnosis of Spirometra erinaceieuropaei.

METHODS

An enzyme-linked immunosorbent assay (ELISA) was studied using highly pure gene engineering antigen expressed by the recombination of the cloned cysteine proteinase gene of Spirametra erinaceieuropaei with expression vector pMAL-c2. Six sera from patient infected with Spirometra erinaceieuropaei were detected using this method.

RESULTS AND CONCLUSION

The results showed that the gene engineering antigen reacted strongly with the sera from Spirometra erinaceieuropaei-infected patients, but did not with the sera from Cysticercus cellulosae-infected patients.

Granulocytic Ehrlichiae in Ixodes persulcatus ticks from an area in China where Lyme disease is endemic

A total of 372 adult Ixodes persulcatus ticks were collected from vegetation in a forest area of Heilongjiang Province in northeastern China, where Lyme disease is known to be endemic. The ticks were examined for the presence of granulocytic ehrlichiae by heminested PCR with primers derived from the 16S rRNA gene. Of 310 ticks obtained from the Dahe forestry farm, two pools (each containing 5 ticks) were found positive, with a minimum infection rate of 0.6%. Ehrlichial DNA was also detected in one female (1.6%) of 62 ticks collected from the Yulin forestry farm. The overall minimum infection rate of the 372 I. persulcatus adults was 0.8%. The nucleotide sequences of 919-bp PCR products from the three positive tick specimens were identical to each other and very closely related to the members of the Ehrlichia phagocytophila genogroup. This is the first identification of granulocytic ehrlichiae in ticks in Asia and the first report of infection in I. persulcatus anywhere.

Identification of Ehrlichia chaffeensis by nested PCR in ticks from Southern China

A total of 717 ticks collected from southern China were examined by nested PCR for the presence of Ehrlichia chaffeensis. Sixteen (55. 2%) of 29 adult Amblyomma testudinarium ticks and 28 (11.7%) of 240 adult and at least 4.2% of 215 nymphal (pooled specimens) Haemaphysalis yeni ticks tested positive. Four other species of ticks were negative. Selected positive amplicons were confirmed by DNA sequencing.