A comparative study on the functional outcomes of patients who underwent internal versus external fixation for Tibial Plateau fractures two years post-surgery

Introduction@#Tibial plateau fractures are due to high energy trauma brought about by axial compression forces and associated varus or valgus component. @*Objective@#Patients diagnosed with tibial plateau fractures from January to December 2018 treated with internal vs. external fixation will be described according to their Schatzker classification. The study further aims to compare the functional outcomes between the two groups in terms of surgery done. @*Methods@#A chart review determined the distribution of demographics. The Modified Rasmussen Score (MRS) was used to determine the clinical and radiographic parameters after taking a new knee radiograph and assessment from the rehabilitation department. The MRS determined the functional outcomes of the said patients. Ethical considerations and proper informed consent were upheld after being reviewed by the hospital’s research committee. @*Results@#Out of 48 patients, 35 underwent internal fixation via open reduction using plates and/or screws, while 13 underwent external fixation using hybrid external fixator. The demographic profile showed mostly males between ages 20 to 49 years old. Most cases were due to vehicular accidents affecting the left lower extremity. In terms of Schatzker classification, the most common was type VI. The computed mean MRS of the internal fixation group was 30.43 while the external fixation group was 30.00, generally showing no significant difference. @*Conclusion@#Surgical intervention of tibial plateau fractures aims for anatomic reduction using internal or external fixation. There was no significant difference on the functional outcome of the two groups despite classifying the respondents according to Schatzker type, hence we can conclude that external fixation be chosen as the treatment of choice for tibial plateau fractures when properly indicated.

Hp infection rate, antibody typing and logistics regression analysis of 1111 physical examination people in plateau area / 公共卫生与预防医学

Objective To explore the Helicobacter pylori (Hp) infection rate and antibody typing of 1111 physical examination people in plateau area, and to analyze the risk factors of Hp infection by logistics regression analysis. Methods 1111 healthy people with physical examination in plateau area from January 2022 to December 2022 were selected as the research subjects. The Hp infection rate and antibody typing were calculated, and the risk factors of Hp infection were analyzed by logistics regression analysis. Results The Hp infection rate of physical examination people in plateau area was 62.47% (694/1 111). The infection rate of type I HP in infected patients was higher than that of type Ⅱ HP(75.50% vs 24.50%) (χ2=361.141, P2=4.418, 8.708, 16.565, 32.583, P=0.036, 0.003, 2=5.153, P=0.023). Often eating pickled or barbecued foods [OR (95%CI)=2.038 (1.049-3.961)], history of chronic gastric disease [OR(95%CI)=1.706 (1.132-2.569)] and family members living together≥4 [OR (95%CI)=1.857 (1.135-3.037)] were risk factors of Hp infection, and regular garlic consumption [OR (95%CI)=0.559 (0.346-0.903)] was a protective factor (P=0.036, 0.011, 0.014, 0.018). Conclusion The Hp infection rate and antibody Ure positive rate are higher in physical examination people in plateau area, and chronic gastric disease history and often eating pickled or barbecued foods are risk factors of Hp infection.

Effects of plateau environment on tear indexes and related anatomical structures of rabbits / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effects of hypobaric hypoxia in plateau on tear indexes and related anatomical structures in rabbits.METHODS: A total of 18 healthy New Zealand rabbits were selected and randomly divided into plateau group and control group, with 9 rabbits(18 eyes)in each group. The plateau group was housed in the Simulated Climate Cabin for Special Environment of Northwest of China, simulating hypobaric hypoxia at an altitude of 6 000 m. The control group was housed in a clean animal room with atmospheric pressure and oxygen. Changes in the tear meniscus height and non-invasive tear break-up time were detected by using RHCT-1 corneal topographer dry eye comprehensive analysis system, changes in tear secretion was measured by Schirmer Ⅰ test, before intervention and on the 3, 7 d, 2 and 4 wk. Meanwhile, the changes in tear composition before and after intervention in the plateau environment were analyzed using Raman Spectroscopy. The histopathological changes of the lower lid conjunctiva, cornea, lacrimal gland, and Hardarian gland were observed by hematoxylin-eosin(HE)staining after 4 wk of intervention, and the expression of mucin 5AC(MUC5AC)in conjunctiva was detected by immunohistochemistry.RESULTS: Compared with the control group, Schirmer Ⅰ test, tear meniscus height, first and average non-invasive tear break-up time in the plateau group decreased significantly since 3 d, and the difference was significant with the extension of observation time(P<0.05). The above indexes increased from 2 wk. After 4 wk of intervention, the protein and lipid content of the tear composition of rabbits in the plateau group increased, and the nucleic acid content decreased compared with the pre-intervention period. Compared with the control group, rabbits in the plateau group showed thickening of corneal stromal edema, an increase in the number of conjunctival cup cells, increase in the level of expression of MUC5AC, an increase in the level of expression of MUC5AC, an atrophy and flattening of cytoplasm in lacrimal epithelial cells, an enlargement of glandular lumen, and no obvious destructive changes in the Hardarian glands.CONCLUSION: Acute plateau environment can destroy the homeostasis of rabbit ocular surface, so that the tear secretion and the tear film stability decreases, but within a certain period of time, rabbits undergo compensation with the habituation to the hypobaric hypoxia environment, which can increase the tear secretion to a certain extent and restore the tear film stability.

Research progress on biomechanics for internal fixation in tibial plateau fracture / 中国修复重建外科杂志

OBJECTIVE@#To review the biomechanical research progress of internal fixation of tibial plateau fracture in recent years and provide a reference for the selection of internal fixation in clinic.@*METHODS@#The literature related to the biomechanical research of internal fixation of tibial plateau fracture at home and abroad was extensively reviewed, and the biomechanical characteristics of the internal fixation mode and position as well as the biomechanical characteristics of different internal fixators, such as screws, plates, and intramedullary nails were summarized and analyzed.@*RESULTS@#Tibial plateau fracture is one of the common types of knee fractures. The conventional surgical treatment for tibial plateau fracture is open or closed reduction and internal fixation, which requires anatomical reduction and strong fixation. Anatomical reduction can restore the normal shape of the knee joint; strong fixation provides good biomechanical stability, so that the patient can have early functional exercise, restore knee mobility as early as possible, and avoid knee stiffness. Different internal fixators have their own biomechanical strengths and characteristics. The screw fixation has the advantage of being minimally invasive, but the fixation strength is limited, and it is mostly applied to Schatzker typeⅠfracture. For Schatzker Ⅰ-Ⅳ fracture, unilateral plate fixation can be used; for Schatzker Ⅴand Ⅵ fracture, bilateral plates fixation can be used to provide stronger fixation strength and avoid the stress concentration. The intramedullary nails fixation has the advantages of less trauma and less influence on the blood flow of the fracture end, but the fixation strength of the medial and lateral plateau is limited; so it is more suitable for tibial plateau fracture that involves only the metaphysis. Choosing the most appropriate internal fixation according to the patient's condition is still a major difficulty in the surgical treatment of tibial plateau fractures.@*CONCLUSION@#Each internal fixator has good fixation effect on tibial plateau fracture within the applicable range, and it is an important research direction to improve and innovate the existing internal fixator from various aspects, such as manufacturing process, material, and morphology.

Abordaje posterior en fracturas de meseta tibial complejas en pacientes tratados quirúrgicamente en el IAHULA / Posterior approach in complex tibial plateau fractures IAHUL A Surgically treated patients

Las fracturas de meseta tibial compleja se asocian a traumatismo de alta energía, principalmente en accidentes de motocicleta, siendo un desafío para el cirujano ortopedista. En la década de 1970, Schatzker propuso una clasificación radiológica para las fracturas de la meseta tibial, que destacaba la morfología de los seis tipos principales. Las imágenes de tomografía computarizada y tridimensional, han cambiado la comprensión y el tratamiento de las fracturas de la meseta tibial. Recientemente, esa clasificación original se complementó con una más amplia; puesto que, se introdujo el fragmento en cuña dividida y la continuidad de la columna posterior como determinantes de la estabilidad articular y el papel fundamental que desempeña en el tratamiento de las fracturas de la meseta tibial, con ellos también la importancia de abordajes quirúrgicos que permitan la visualización posterior para una adecuada reducción. El estudio documenta las técnicas de fijación interna y abordajes posteriores realizadas en el IAHULA, valorando los resultados clínicos en cuanto a dolor y satisfacción del paciente, como consolidación, pseudoartrosis o falla en la técnica de osteosíntesis realizada. El resultado a partir de las escalas de evaluación de la AO y KOOS, arrojaron que, con un efecto excelentes se agrupa un 28,6% y bueno a un 42,9%, indicando la importancia de la fijación de la columna posterior, para prevenir artrosis postraumática temprana e inestabilidad articular(AU)

A complex fracture of the posterior tibial plateau are related to high energy traumatisms, mainly during motorcycle accidents, becoming a challenge to the ortopedic surgen. During the seventies, Stchatzker proposed a radiologic classification for the tibial plateau fractures that pointed the morphology of six main types. The computarized and tridimensional tomographic images have changed the comprehension and treatment of these fractures. Recently, the original classification was complemented with a more broaded approach due to the introduction of the fragment in divided crib and the continuity of the posterior column as factors determining the articular stability and the fundamental roll played in the treatment of fractures of the tibial plateau, as well as the important roll of surgical approaches that allow the posterior visualization for a correct reduction. This research documents the technics of internal fixation and posterior approach developed in the IAHULA, evaluating the clinic results about patients' pain level and comfort, as well as the radiologic findings of consolidation, pseudoarthrosis, or fail in the technic of osteosynthesis developed. The results from a point of view of the evaluation scales of the AO and KOOS, show 28.6% with excellent outcomes, and 42.9% with good outcomes, indicating the importance of the fixation of the posterior column to prevent early start of posttraumatic arthrosis and articular instability(AU)

Rendimiento Biomecánico de las Placas de Tibia Proximal Utilizadas en Fracturas de Platillos Tibiales evaluado a través de Modelos de Elementos Finitos: Protocolo de Revisión Sistemática / A systematic Review Protocol Examining the Biomechanical Performance of Proximal Tibial Plates used in Tibial Plate Fractures assessed by Finite Element Analysis

Objetivo. Analizar el rendimiento biomecánico de las placas de tibia proximal utilizadas en fracturas de platillos tibiales evaluado a través de modelos de elementos finitos. Métodos. Se realizará una búsqueda exhaustiva en PubMed/Medline, Embase, Lilacs, Web of Science y Google Scholar. No se utilizará ninguna restricción de idioma o estado de publicación. Dos revisores examinarán de forma independiente los posibles artículos elegibles, de acuerdo con los criterios de selección predefinidos. Se incluirán los estudios que evalúen el rendimiento de los platillos tibiales proximales utilizados en las fracturas del platillo tibial evaluadas mediante el análisis de elementos finitos. La extracción de datos sobre las características del estudio, los métodos, los resultados y la evaluación del riesgo de sesgo se realizará mediante un formulario estandarizado. Considerando el diseño de estudio no se requiere evaluación por comité de ética. Los resultados de esta revisión se difundirán a través de la publicación en revistas revisadas por pares, redes sociales y congresos de la especialidad. Se espera que los resultados de esta revisión permitan optimizar los resultados del manejo quirúrgico de las fracturas de platillos tibiales. Número de registro PROSPERO: CRD42023396015.

Objetive. To analyze the biomechanical performance of proximal tibial plates used in tibial plate fractures evaluated through finite element modeling. Methods. A comprehensive search will be conducted in PubMed/Medline, Embase, Lilacs, Web of Science, and Google Scholar. No language or publication status restrictions will be used. Two reviewers will independently review potential eligible articles according to predefined selection criteria. Studies evaluating the performance of proximal tibial splints used in tibial splint fractures assessed by finite element analysis will be included. Data extraction on study characteristics, methods, results, and risk of bias assessment will be performed using a standardized form. Considering the study design, evaluation by an ethics committee is not required. The results of this review will be disseminated through publication in peer-reviewed journals, social networks and specialty congresses. It is expected that the results of this review will allow optimizing the results of the surgical management of tibial plate fractures. PROSPERO registration number: CRD42023396015.

Prevalence of Echinococcus infection in small mammals captured from Shiqu County, Sichuan Province from 2015 to 2020 / 中国血吸虫病防治杂志

Objective To investigate the prevalence of Echinococcus infection in small mammals in Shiqu County, Sichuan Province from 2015 to 2020, so as to provide insights into echinococcosis control in Shiqu County. Methods One setting with frequent activity of small mammals was sampled as the survey site from each of 9 townships where human alveolar echinococcosis was hyperendemic, in Shiqu County, Sichuan Province from 2015 to 2020. Two quadrats measuring 50 m × 50 m were assigned in each survey site during the period between July and August from 2015 to 2020 to capture all small mammals in quadrats, and the species of small mammals were identified by morphological characteristics. All captured small mammals were dissected in the field and Echinococcus infection was identified by visual examinations. The affected organs of Echinococcus-infected small mammals were collected, and Echinococcus infection was detected using PCR assay, with Echinococcus species characterized. The prevalence of Echinococcus infection was calculated in small mammals, and the trends in the prevalence of Echinococcus infection were analyzed during the period from 2015 to 2020. In addition, the prevalence of Echinococcus infection was compared in small mammals using visual examinations and PCR assay. Results A total of 2 692 small mammals were captured in the survey sites of Shiqu County from 2015 to 2020, and morphology characterized 1 360 Microtus fuscus (50.52%) and 1 332 Plateau pika (49.48%). The prevalence rates of Echinococcus infection were 35.63%, 19.16%, 21.41%, 8.40%, 7.68% and 4.44% by visual examinations and 18.96%, 5.36%, 5.61%, 4.58%, 3.30% and 0.37% by PCR assay in small mammals in Shiqu County from 2015 to 2020, both showing a tendency towards a decline year by year (χ2 = 215.024 and 117.045, both P values < 0.001). The prevalence of Echinococcus infection was significantly higher in small mammals by visual examinations than by PCR assay during the period from 2015 to 2020 except in 2018 (χ2= 33.597, 21.815, 51.373, 17.268 and 9.537, all P values < 0.01). PCR assay detected a reduction in the prevalence of E. multilocularis infection from 10.21% to 0.37% and a reduction in the prevalence of E. shiquicus infection from 8.75% to 0 in small mammals in Shiqu County from 2015 to 2020, both appearing a tendency towards a decline year by year (χ2 = 117.045 and 43.436, both P values < 0.001). In addition, the prevalence of E. multilocularis and E. shiquicus infections reduced from 15.19% to 0.45% and from 8.23% to 0 in M. fuscus, and the prevalence of E. multilocularis and E. shiquicus infections reduced from 7.76% to 0 and from 9.01% to 0 in P. pika in Shiqu County from 2015 to 2020. Conclusions M. fuscus and P. pika were dominant species of small mammals in Shiqu County, Sichuan Province from 2015 to 2020, and E. multilocularis infection was mainly found in M. fuscus and E. shiquicus infection mainly found in P. pika. The prevalence of Echinococcus infection appeared a tendency towards a decline in both M. fuscus and P. pika year by year during the period from 2015 to 2020.

Analysis of plague monitoring results in natural focus of Marmota sibirica plague in Hulunbuir Plateau from 2009 to 2020 / 中华地方病学杂志

Objective:To analyze the plague monitoring results of Marmota sibirica plague natural focus in Hulunbuir Plateau, and to study the characteristics of development and variation of the plague focus. Methods:From 2009 to 2020, monitoring was conducted in Manzhouli City, Prairie Chenbarhu Banner, Xin Barag Left Banner, and Xin Barag Right Banner from May to September each year. The one-day bow-clip method was used to investigate the density of the Spermophilus dauricus, and the 5-meter clamp method was used to investigate other small rodents. The classification and identification of ectoparasite fleas were done by using low power microscope. According to "Diagnostic Criteria for Plague" (WS 279-2008), the detectable materials of rats and fleas were tested, and Yersinia pestis was isolated and cultured. The serums of collected rats were detected by indirect hemagglutination test. Results:From 2009 to 2020, the average density of dauricus in Marmota sibirica plague natural focus of Hulunbuir Plateau was 0.45/hm 2, and the capture rate of other small rodents was 1.25% (787/63 091). A total of 9 species, 8 genera and 4 families of rodents were captured. The total flea infection rate of Spermophilus dauricus was 28.37% (1 945/6 856) and the fleas index was 1.04. A total of 3 species, 3 genera and 2 families of fleas were collected. A total of 6 674 Spermophilus dauricus were dissected and 6 787 fleas were cultured in 2 537 groups. The Yersinia pestis test was negative. A total of 6 795 serum samples from Spermophilus dauricus were detected, of which 11 were positive with a positive detection rate of 0.16%. The highest titer of positive serum was 1∶1 280. Indirect hemagglutination test positive materials were found for 5 consecutive years from 2010 to 2014; the positive serums were found in Manzhouli City and Xin Barag Right Banner. Conclusions:The Yersinia pestis antibady positive serum of Spermophilus dauricus has been detected in Marmota sibirica plague focus of Hulunbuir Plateau for many years, which is worthy of high vigilance. In the future, continuous surveillance should be carried out, bacterial detection should be strengthened, possible plague outbreaks should be detected in time, and various plague prevention and control should be done well.

Genotyping and traceability analysis of Brucella isolated from Himalayan marmot in Qinghai-Tibet Plateau by MLVA / 中华地方病学杂志

Objective:To observe multiple locus variable-number tandem repeat analysis (MLVA) typing of Brucella isolated from Himalayan marmot in Qinghai-Tibet Plateau of Qinghai Province, and to explore the relationship between the strains and strains previous isolated from Qinghai Province. Methods:Blood samples of Himalayan marmot were collected in Qinghai-Tibet Plateau of Qinghai Province from March 2019 to October 2020. Pathogens were isolated and cultured from Brucella antibody positive samples identified by using the rose bengal test (RBT). Conventional biological methods and molecular biological methods (BCSP31-PCR and AMOS-PCR) were used for strain identification. At the same time, MLVA method was used to genotype the isolated strains, and cluster analysis was used to analyze the genetic relationships between the strains based on the genotype of 70 Brucella isolated from different hosts in Qinghai Province. Results:A total of 1 466 blood samples of Himalayan marmot were collected from Qinghai-Tibet Plateau. Two strains of Brucella were isolated and cultured from 64 RBT-positive samples, named QH2013054 and QH2013062, respectively. They were identified as Brucella ovis biotype Ⅲ by conventional and molecular biological methods. The MLVA genotyping results showed that QH2013054 and QH2013062 were different at the Bru16 locus, indicating different MLVA genotypes. Cluster analysis showed that strain QH2013054 had the same MLVA genotype as 7 strains, among which 6 strains were from 3 farmers and 3 sheep from the same family in Gonghe County, and 1 strain was from a farmer in Menyuan Hui Autonomous County. The strain QH2013062 had the same MLVA genotype as 4 strains, including 3 strains from 3 farmers in Menyuan Hui Autonomous County and 1 strain from a farmer in Tu Autonomous County of Huzhu. Conclusions:The strains of Brucella isolated from Himalayan marmot in Qinghai-Tibet Plateau of Qinghai Province have the same MLVA genotype as some strains of Brucella isolated from humans and sheep in Qinghai Province. It is speculated that the host humans, sheep and Himalayan marmot in Qinghai-Tibet Plateau may have a common source of infection.

Risk assessment and prevention management of venous thromboembolism in hospitalized patients in plateau area / 中华健康管理学杂志

Objective:To explore the risk assessment and prevention management of hospital-associated venous thromboembolism (HA-VTE) in plateau area.Methods:This was a prospective observational study. A total of 200 patients hospitalized for acute medical diseases or surgery in the People′s Hospital of Tibet Autonomous Region from May to June 2022 were consecutively enrolled. Padua score or Caprini risk assessment model was used for dynamic risk assessment and stratification of VTE in all patients. At the same time, bleeding risk was assessed according to age, complications, trauma history, drug therapy, invasive procedures and other factors. The implementation of mechanical and/or drug prophylaxis was dynamically recorded during hospitalization. The change of VTE risk and prevention during hospitalization were the primary outcome, and the occurrence of HA-VTE events and bleeding events during hospitalization or within 90 days after enrollment were the secondary outcome.Results:A total of 196 patients were enrolled in the study, including 130 (66.3%) in internal medicine and 66 (33.7%) in surgery. There were 64 (49.2 %) and 27 (40.9%) patients with high risk of VTE within 1 day after admission among medical and surgical patients, respectively. During hospitalization, 58 (44.6%) and 49 (74.2%) patients with high risk of VTE were re-evaluated among medical and surgical patients, respectively. There were 39 (30.0%) medical patients and 54 (81.8%) surgical patients who had an increased risk of VTE due to changes in their conditions. In terms of VTE prevention, 32 patients (16.3%) received VTE prophylaxis, only 17 medical patients (8.7%) with high risk of VTE received drug prophylaxis, and 2 patients (1.0%) with high risk of VTE developed HA-VTE events after drug prophylaxis. A total of 8 (4.1%) surgical patients received drug prophylaxis, of which 1 (0.5%) received mechanical prophylaxis at the same time, and no surgical patients experienced HA-VTE events after prophylaxis. HA-VTE events occurred in 11 patients (5.6%) during hospitalization or within 90 days after enrollment.Conclusion:Considering the complex and changeable risk factors of VTE, insufficient VTE prevention and high incidence of HA-VTE in hospitalized patients in plateau areas, Padua score and Caprini risk assessment model are recommended for early, dynamic and full VTE risk assessment of patients, so as to standardize the VTE prevention and improve the quality of health management of hospitalized patients in plateau areas.

Effect of Pin Holes Location of Unicompartmental Knee Arthroplasty on Postoperative Tibial Plateau Mechanical Properties / 中国医疗器械杂志

OBJECTIVE@#The purpose of this study is to explore the biomechanical characteristics of the tibia after unicompartmental knee arthroplasty with different distributions of two-pin holes, and to optimize the two-pin holes scheme to reduce the risk of tibial fractures after unicompartmental knee arthroplasty.@*METHODS@#Lower limbs model is segmented and reconstructed from computed tomography images. Four combinations of two pin holes created for tibial cutting guide placement are simulated with finite element analysis.@*RESULTS@#In the third mode, the positioning hole at the proximal medial edge of the tibial plateau has the highest stress value, and the position of the positioning hole near the medial edge of the proximal tibial plateau appears stress concentration.@*CONCLUSIONS@#The present study revealed that placing tibial cutting guide holding pins centrally would lower the risks of periprosthetic fracture of the medial tibial plateau.

Osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation in treatment of tibial plateau fractures involving posterolateral column collapse / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effectiveness of osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation in the treatment of tibial plateau fractures involving posterolateral column collapse.@*METHODS@#A clinical data of 23 patients with tibial plateau fractures involving posterolateral column collapse, who had undergone osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation between January 2015 and June 2021, was retrospectively analyzed. There were 14 males and 9 females with an average age of 42.6 years ranging from 26 to 62 years. The causes of injury included traffic accident in 16 cases, falling from height in 5 cases, and other injuries in 2 cases. According to Schatzker classification, there were 15 cases of type Ⅴ and 8 cases of type Ⅵ. The time from injury to operation was 4-8 days with an average of 5.9 days. The operation time, intraoperative blood loss, fracture healing time, and complications were recorded. The depth of articular surface collapse of posterolateral column and posterior inclination angle (PSA) of the tibial plateau were compared before operation and at 2 days and 6 months after operation; fracture reduction of tibial plateau fracture was evaluated by Rasmussen anatomic score. The recovery of knee function was evaluated by Hospital for Special Surgery (HSS) score at 2 days and 6 months after operation.@*RESULTS@#All 23 patients were completed the operation successfully. The operation time was 120-195 minutes, with an average of 152.8 minutes; the intraoperative blood loss was 50-175 mL, with an average of 109.5 mL. All patients were followed up 12-24 months, with an average of 16.7 months. One patient had superficial wound infection after operation, and the incision healed after dressing change; primary healing of incision of other patients was obtained. The fracture healing time was 12-18 weeks, with an average of 13.7 weeks. No failure of internal fixation, varus and valgus deformity of the knee joint, and instability of the knee joint was found at last follow-up. One patient developed joint stiffness and the range of motion of the knee joint was 10°-100°; the range of motion of the knee joint of other patients was 0°-125°. At 2 days and 6 months after operation, the depth of articular surface collapse of posterolateral column, PSA, and Rasmussen anatomic scores significantly improved when compared with those before operation ( P<0.05). There was no significant difference between the two postoperative time points ( P>0.05). The HSS score at 6 months after operation was significantly higher than that at 2 days after operation ( P<0.05).@*CONCLUSION@#For tibial plateau fractures involving posterolateral column collapse, reduction and internal fixation through osteotomy of non-core weight-bearing area of the lateral tibial plateau has the advantages of fully expose the posterolateral column fragment, good articular surface reduction, sufficient bone grafting, and fewer postoperative complications. It is beneficial to restore knee joint function and can be widely used in clinic.

Preliminary analysis of qualitative changes in suspended red blood cells under different low-pressure and hypoxic conditions / 中国输血杂志

【Objective】 To evaluate the quality of suspended red blood cells (SRBC) under low-pressure and hypoxic conditions, in order to lay a theoretical foundation for airline delivery, air drop and storage of SRBC on plateau. 【Methods】 The low-pressure and hypoxic conditions (0.026 MPa and 0.047 MPa) were simulated by a pressure control device. SRBC were divided into 3 groups (5 bags/group, 1.5 U/bag). Each group was stored in 0.026 MPa environment at 2℃-6℃ for 24 hours (named 0.026 MPa), in 0.047MPa environment at 2℃-6℃ for 7 days (named 0.047 MPa), and in a blood storage refrigerator at 4℃ (named the control), respectively. The storage cell characteristics were examined on day 2, 9, 14, 28 and 35. 【Results】 We found that HCT, MCV, K+, Na+, FHb, hemolytic ratio, 2, 3-DPG and rheological properties in group 0.026 MPa and 0.047 MPa were not significant different compared with that in control (P>0.05). The consumptions of Glu in group 0.026 MPa and 0.047 MPa were significantly higher (P<0.05), and a transient increase in LAC concentration of group 0.026 MPa and 0.047MPa were observed, compared to the control. 【Conclusion】 The conditions of low-pressure and hypoxia have no significant effect on the quality of suspended red blood cells.

Risk factors for unplanned readmission in patients with acute myocardial infarction in Plateau Area / 公共卫生与预防医学

Objective To explore the risk factors of unplanned readmission in patients with acute myocardial infarction in plateau area. Methods The convenience sampling method was used to select 220 patients with acute myocardial infarction in the hospital's internal medicine department from January 2020 to May 2021. The patients were divided into two groups according to whether they had unplanned readmission within one year, 79 patients were included in readmission group, and 141 patients without unplanned readmission were included in non-readmission group. Clinical data of the 220 patients with acute myocardial infarction in plateau area were collected by reviewing electronic medical records, and laboratory examination and angiography examination were performed 1 day before discharge. Univariate and multivariate logistic regression analysis were carried out, and ROC curve risk prediction model was established. Results There were statistically significant differences in age, history of myocardial infarction, history of PCI, history of stroke, blood calcium, and Kilip cardiac function between the two groups (P < 0.05). Logistic regression analysis showed that age ≥60 years old, history of myocardial infarction, history of PCI, history of stroke, blood calcium and Kilip cardiac function grading were positively correlated with unscheduled readmission (P < 0.05). The ROC curve was drawn with the occurrence of unplanned readmission as the state variable. The AUC area was 0.801, the predictive sensitivity was 88.94%, and the specificity was 57.92%. Conclusion Unplanned readmission of AMI patients in plateau areas is related to multiple factors. It is necessary to identify high-risk groups as early as possible in combination with risk factors and develop individualized intervention measures.

Effect of altitude hypoxia on blood-brain barrier after subarachnoid hemorrhage based on phosphatidylinositol 3-kinase/protein kinase B/nuclear factor κB pathway in rats / 解剖学报

Objective To investigate the effect of plateau hypoxia on the blood-brain barrier after subarachnoid hemorrhage (SAH) in rats. Methods Adult male SD rats (n = 78) were randomly divided into 4 groups: sham group (sham), SAH model group (SAH), plateau hypoxia sham group (Hp sham) and plateau hypoxia SAH model group (Hp SAH). The rat model of plateau hypoxia was established through low-pressure simulation chamber (altitude 5000 m), and the SAH model was established by endovascular perforation method. At 24 hours after SAH, neurobehavior score and SAH grade were assessed. The morphological changes of neurons and apoptosis of nerve cells in the CA1 region of hippocampal were observed by the staining of Nissl and TUNEL. The expression of phosphorylated PI3K (p-PI3K), PI3K, phosphorylated Akt (p-Akt), Akt, phosphorylated nuclear factor κB (p-NF-κB), NF-κB, matrix metalloproteinase-9 (MMP-9), occludin and claudin-5 in hippocampal were detected by the method of Western blotting. The expression of occludin and claudin-5 proteins in the CA1 region of hippocampal were observed by immunofluorescent staining. Results At 24 hours after SAH, the neurobehavior score decreased significantly and SAH grade increased significantly in the SAH and Hp SAH group (P< 0.05). Neurobehavior score decreased significantly in the Hp SAH group compared with the SAH group (P < 0.05). In the SAH group, neurons in the CA1 region of hippocampus were atrophied and deformed, the arrangement were disordered, the number of neurons decreased significantly, and the apoptosis of nerve cells increased significantly(P< 0.05). Plateau hypoxia could aggravate the morphological damage of neurons and apoptosis of nerve cells. The expression of p-PI3K/PI3K, p-Akt/Akt, occludin and claudin-5 proteins decreased significantly, while the expression of p-NF-κB/NF-κB and MMP-9 proteins increased significantly in the SAH and Hp SAH group (P< 0.05). The expression of p-PI3K/PI3K and MMP-9 proteins increased significantly in Hp SAH group compared with the SAH group. The expression of claudin-5 protein increased significantly in Hp sham group compared with the sham group (P < 0.05). Immunofluorescent staining showed that the expression of occludin and claudin-5 proteins in the CA1 region of hippocampus decreased in the SAH group. Plateau hypoxia could further decreased the expression of occludin and claudin-5 proteins. Conclusion Plateau hypoxia aggravates blood-brain barrier disruption after subarachnoid hemorrhage in rats through inhibiting PI3K/Akt/NF-κB pathway.

The protective effect of betelnut polyphenols on exercise-induced fatigue at high altitude and its network pharmacology in rats / 中国药理学通报

Aim: To explore the protective effect of betelnut polyphenols on high altitude exercise-induced fatigue in rats, and to select the main targets to carry out network pharmacology research to preliminarily explore its protective mechanism. Methods: We compared the protective effects of areca catechu polyphenols on high altitude exercise fatigue in rats in low, medium and high dose groups (400, 800, and 1600 mg·kg

The protective effect of catechin on acute high-altitude hypoxic injury / 中国药理学通报

Aim To study the protective effect of catechin on acute altitude injury in rats. Methods Rats were randomly divided into six groups: control group, altitude hypoxia model group, rhodiola capsule group, low -, middle-and high dose of catechin groups. After three days of preventive administration, animals were rushed to 4 010 m altitude. After five days of continuous administration, abdominal aortic blood of rats was collected for blood gas detection. Cardiac, brain and lung tissues were collected for HE staining to observe the pathological changes. MDA content, GSH content, NO content, SOD activity of myocardial, brain and lung tissues were detected, so were IL-6 and TNF-α content in serum. Results Compared with the control group, blood oxygen saturation of rats of altitud hypoxia model group was significantly reduced, while myocardial, brain and lung tissues were damaged to different degrees. MDA and NO content increased, while GSH content and SOD activity decreased. The serum inflammatory factors TNF-α and IL-6 levels were elevated significantly. After catechin treatment, blood oxygen saturation of hypoxia rats significantly increased (P < 0. 05). HE staining results showed that myocardial, brain and lung tissue injury was alleviated to some extent. MDA, NO, IL-6 and TNF-α content were down-regulated, while GSH content and SOD activity were up-regulated respectively. Conclusions Catechin can resist high altitude hypoxia and protect the main organs from hypoxia injury in rats acute exposed to altitude, which is related to alleviating oxidative stress and inflammation caused by acute hypoxia exposure.

Exploring the links between gut microbiome changes and irritable bowel syndrome in Han populations in the Tibetan Plateau / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The gut microbiome shows changes under a plateau environment, while the disbalance of intestinal microbiota plays an important role in the pathogenesis of irritable bowel syndrome (IBS); however, the relationship between the two remains unexplored. In this work, we followed up a healthy cohort for up to a year before and after living in a plateau environment and performed 16S ribosomal RNA (rRNA) sequencing analysis of their fecal samples. Through evaluating the participants' clinical symptoms, combined with an IBS questionnaire, we screened the IBS sub-population in our cohort. The sequencing results showed that a high-altitude environment could lead to changes in the diversity and composition of gut flora. In addition, we found that the longer the time volunteers spent in the plateau environment, the more similar their gut microbiota composition and abundance became compared to those before entering the plateau, and IBS symptoms were significantly alleviated. Therefore, we speculated that the plateau may be a special environment that induces IBS. The taxonomic units g_Alistipes, g_Oscillospira, and s_Ruminococcus_torques, which had been proved to play important roles in IBS pathogenesis, were also abundant in the IBS cohort at high altitudes. Overall, the disbalance of gut microbiota induced by the plateau environment contributed to the high frequency of IBS and the psychosocial abnormalities associated with IBS. Our results prompt further research to elucidate the relevant mechanism.

Effects of plateau hypoxia on population pharmacokinetics and pharmacodynamics of metformin in patients with Type 2 diabetes / 中南大学学报(医学版)

OBJECTIVES@#Metformin is the basic drug for treating diabetes, and the plateau hypoxic environment is an important factor affecting the pharmacokinetics of metformin, but there have been no reports of metformin pharmacokinetic parameters in patients with diabetes mellitus type 2 (T2DM) in the high-altitude hypoxic environment. This study aims to investigate the effect of the hypoxic environment on the pharmacokinetics and assess the efficacy and safety of metformin administration in patients with Type 2 diabetes mellitus (T2DM).@*METHODS@#A total of 85 patients with T2DM taking metformin tablets in the plateau group (n=32, altitude: 1 500 m) and control group (n=53, altitude: 3 800 m) were enrolled according to the inclusion and exclusion criteria, and 172 blood samples were collected in the plateau group and the control Group. A ultra-performance liquid chromatography/tandem mass spectrometry (UFLC-MS/MS) method was established to determine the blood concentration of metformin, and Phoenix NLME software was used to establish a model of pharmacokinetics of metformin in the Chinese T2DM population. The efficacy and serious adverse effects of metformin were compared between the 2 groups.@*RESULTS@#The population pharmacokinetic modeling results showed that plateau hypoxia and age were the main covariates for model building, and the pharmacokinetic parameters were significantly different between the plateau and control groups (all P<0.05), including distribution volume (V), clearance (CL), elimination rate constant (Ke), half-life(T1/2), area under the curve (AUC), time to reach maximum concentration (Tmax). Compared with the control group, AUC was increased by 23.5%, Tmax and T1/2 were prolonged by 35.8% and 11.7%, respectively, and CL was decreased by 31.9% in the plateau group. The pharmacodynamic results showed that the hypoglycaemic effect of T2DM patients in the plateau group was similar to that in the control group, the concentration of lactic acid was higher in the plateau group than that in the control group, and the risk of lactic acidosis was increased after taking metformin in the plateau population.@*CONCLUSIONS@#Metformin metabolism is slowed down in T2DM patients in the hypoxic environment of the plateau; the glucose-lowering effect of the plateau is similar, and the attainment rate is low, the possibility of having serious adverse effects of lactic acidosis is higher in T2DM patients on the plateau than on the control one. It is probably suggested that patients with T2DM on the plateau can achieve glucose lowering effect by extending the interval between medication doses and enhancing medication education to improve patient compliance.

Effects of orientation and distance of goats on blast lung injury characteristics on a plateau above 4500-meter / 中华创伤杂志(英文版)

PURPOSE@#High explosives are used to produce blast waves to study their biological effects. The lungs are considered as the critical target organ in blast-effect studies. The degree of lung hemorrhaging is related to both the explosive power and the increased lung weight. We studied the characteristics of the biological effects from an air explosion of a thermobaric bomb in a high-altitude environment and the lethality and lung injury severity of goats in different orientations and distances.@*METHODS@#Goats were placed at 2.5, 3, 4, and 5 m from the explosion center and exposed them to an air blast at an altitude of 4700-meter. A group of them standing oriented to the right side and the other group seated facing the explosion center vertically. The lung injuries were quantified according to the percentage of surface area contused, and using the pathologic severity scale of lung blast injury (PSSLBI) to score the 4 injury categories (slight, moderate, serious and severe) as 1, 2, 3, and 4, respectively. The lung coefficient (lung weight [g]/body weight [kg]) was the indicator of pulmonary edema and was related to lung injury severity. Blast overpressure data were collected using blast test devices placed at matching locations to represent loadings to goats. All statistical analyses were performed using SPSS, version 26.0, statistical software (SPSS, Inc., Chicago, IL, USA).@*RESULTS@#In total, 127 goats were involved in this study. Right-side-standing goats had a significantly higher mortality rate than those seated vertical-facing (p < 0.05). At the 2.5 m distance, the goat mortality was nearly 100%, whereas at 5 m, all the goats survived. Lung injuries of the right-side-standing goats were 1 - 2 grades more serious than those of seated goats at the same distances, the scores of PSSLBI were significantly higher than the seated vertical-facing goats (p < 0.05). The lung coefficient of the right-side-standing goats were significantly higher than those of seated vertical-facing (p < 0.05). Mortality, PSSLBI, and the lung coefficient results indicated that the right-side-standing goats experienced severer injuries than the seated vertical-facing goats, and the injuries were lessened as the distance increased. The blast overpressure was consistent with these results.@*CONCLUSION@#The main killing factors of the thermobaric bomb in the high-altitude environment were blast overpressure, blast wind propulsions and burn. The orientation and distances of the goats significantly affected the blast injury severity. These results may provide a research basis for diagnosing, treating and protecting against injuries from thermobaric explosions.