[Correlation analysis between imaging classification of varus knee osteoarthritis and axis angle of tibiofemoral and patellofemoral joints].

OBJECTIVE: To explore correlation between imaging classification of knee osteoarthritis (KOA) and axis angle of tibiofemoral and patellofemoral joints. METHODS: A retrospective analysis of 739 middle-aged and elderly patients with KOA (1 026 knee joints) who underwent vertical X-ray examination of both lower limbs and lateral knee joints from September 2018 to December 2020. Among them, 63 patients with K-L 0 grade (95 knee joints), 100 patients with K-L 1 grade (130 knee joints), 161 patients with K-L 2 grade (226 knee joints), 187 patients with K-L 3 grade (256 knee joints), and 228 patients of K-L 4 grade (319 knee joints). According to relative position of knee joint center and line between hip joint center and ankle joint center, the affected knee was divided into varus group(844 knees joints) and valgus group (182 knees joints). According to Install-Salvati method, the affected knee was divided into three groups, such as high patella (patella height>1.2 mm, 347 knees joints), median patella (patella height ranged from 0.8 to 1.2 mm, 561 knees joints), and low patella (patella height<0.8 mm, 118 knees joints). Lower femur angle, upper tibia angle, femoral neck shaft angle, femoral tibial angle, joint gap angle, hip-knee-ankle angle, patella-femoral angle and patella height among different groups were observed and compared. RESULTS: (1) In varus KOA group, there were statistical differnces in hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, joint space angle, and femoral neck shaft angle of patients with different K-L grades (P<0.05). Hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, joint space angle and K-L grade were significantly positively correlated at 0.01(P<0.05);femoral neck shaft angle and K-L grade showed negative correlation at 0.01(P<0.05). (2) In valgus KOA group, hip-knee-ankle angle, there were statistical differences in tibiofemoral angle, inferior femoral angle, superior tibial angle, joint space angle, and femoral neck shaft angle of patients with different K-L grades(P<0.05). Hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, and femoral neck shaft angle showed negative correlation with K-L grades at level of 0.01 (P<0.05);joint gap angle and K-L grades showed significantly positive correlation at level of 0.01(P<0.05). (3) In high patella group, there were statistically differences in patellar height and patellar femoral angle of different K-L grades(P<0.05);there were no statistical difference in patella height and patellar femoral angle of different K-L grades in median patella group. There was no significant difference in patella heightin low patella group with different K-L grades(P>0.05), and there was statistical difference in patellofemoral angle(P<0.05). Patellar height and patella-femoral angle of high patella group were significantly positively correlated with K-L grades at the level of 0.01 (P<0.05);patella height and patella-femoral angle were not correlated with K-L grades in median patella group(P>0.05). There was no correlation between height of patella and K-L grade in low patella group (P>0.05). There was significant negative correlation between patella-femoral angle and K-L grade at level of 0.05 (P<0.05). CONCLUSION: Inferior femoral angle, tibiofemoral angle, joint gap angle, hip-knee-ankle angle, femoral neck shaft angle and high patella are related to K-L classification of varus KOA, which could be used for early diagnosis and provide objective data for efficacy analysis of conservative treatment.

Autophagy in fate determination of mesenchymal stem cells and bone remodeling.

Mesenchymal stem cells (MSCs) have been widely exploited as promising candidates in clinical settings for bone repair and regeneration in view of their self-renewal capacity and multipotentiality. However, little is known about the mechanisms underlying their fate determination, which would illustrate their effectiveness in regenerative medicine. Recent evidence has shed light on a fundamental biological role of autophagy in the maintenance of the regenerative capability of MSCs and bone homeostasis. Autophagy has been implicated in provoking an immediately available cytoprotective mechanism in MSCs against stress, while dysfunction of autophagy impairs the function of MSCs, leading to imbalances of bone remodeling and a wide range of aging and degenerative bone diseases. This review aims to summarize the up-to-date knowledge about the effects of autophagy on MSC fate determination and its role as a stress adaptation response. Meanwhile, we highlight autophagy as a dynamic process and a double-edged sword to account for some discrepancies in the current research. We also discuss the contribution of autophagy to the regulation of bone cells and bone remodeling and emphasize its potential involvement in bone disease.

[Detection of deletional determinants of alpha-thalassemia in Li people in Hainan province by a single tube multiplex polymerase chain reaction method].

OBJECTIVE: To develop a single tube multiplex polymerase chain reaction technique (mPCR) and use it to screen 3 deletional alpha-globin genes, namely -alpha(3.7), -alpha(4.2) (single gene deletion), and --SEA (South East Asia double gene deletion) in the Li people in Hainan province. METHODS: Based on previously developed 3 separate PCR methods used to detect the -alpha(3.7), -alpha(4.2), --SEA respectively, a single tube mPCR was investigated, optimized, and used to detect the genotypes of 40 samples from well-known alpha-thalassemia patients and 116 non-relative individuals of Li nationality in Hainan province. RESULTS: The results of the 40 samples detected by mPCR were the same as those by the 3 separate PCR Methods. Among the 116 sample, the combined incidence of -alpha(3.7) and -alpha(4.2) was found to be as high as 38.0%, and the -alpha(4.2) genotype was more frequent than the -alpha(3.7) genotype in the Li people. No --(SEA) deletion was found in the Li people. CONCLUSION: The mPCR technique shows a good sensitivity and specificity. The Hainan Li people has the highest incidence of -alpha(3.7) and -alpha(4.2) among Chinese.

[Application of fetal DNA in maternal plasma for non-invasive prenatal diagnosis of fetal sex].

To investigate the feasibility and possibility of application of fetal DNA from maternal plasma for noninvasive prenatal diagnosis of fetal sex, plasma DNAs in blood samples of 73 pregnant women at the gestational period of 26 to 41 weeks were extracted by column separation and nested polymerase chain reaction were employed to amplify the SRY gene. A comparison was made between the amplification results and the real sex of the fetus after their delivery. The concordance rate of SRY gene amplification results of plasma free DNA with real fetal sex was 91.78% (67/73), the sensitivity rate was 97.37% (37/38), and the specific rate was 85.71% (30/35). The cell-free fetal DNA in maternal blood can be one of the valuable material sources for noninvasive prenatal diagnosis and the method of nested PCR could be useful for fetal sex determination. The specific rate of the test was 91.78%. It is of significance to prevent sex-linked inheritant diseases.

[Study on genetic diagnosis and prenatal diagnosis of alpha-thalassemia].

OBJECTIVE: To develop a single-tube multiplex polymerase chain reaction (mPCR) technique to detect three common deletional alpha-thalassemias (alpha-Thal) in Chinese, and to perform genetic diagnosis and prenatal diagnosis for an alpha-Thal family from Hebei province, China. METHODS: Fourty-two blood samples including samples from one alpha-Thal family from Hebei province were assayed. The mPCR containing 7 primers, gel electrophoresis and DNA sequencing were used for the genetic diagnosis and prenatal diagnosis. RESULTS: The gene types of the fourty-two DNA samples analyzed by the mPCR-gel electrophoresis technique were in accordance with the results by Southern blot and three separate PCR techniques. A HbH child and a fetus of the alpha-Thal family were diagnosed as--(SEA)/alpha(cs)alpha and alpha alpha/alpha alpha respectively by using the mPCR and DNA sequencing. The result of postnatal analysis of the cord blood was consistent with the prenatal result (alpha alpha/alpha alpha). CONCLUSION: The developed mPCR technique can be used for genetic diagnosis and prenatal diagnosis of the 3 deletional alpha-Thal in Chinese.

Detection of three common, deletional alpha-thalassemia determinants in Southern China by a single-tube multiplex polymerase chain reaction method.

alpha-Thalassemia (thal) is one of the most common inherited disorders in the world and in Southern China. Three large deletions of the alpha-globin gene, namely the -alpha3.7 and -alpha4.2 (single gene deletions), and --SEA (Southeast Asian double gene deletion), are the main alpha-thal abnormalities in Southern China. We have developed a reliable, single-tube multiplex polymerase chain reaction (m-PCR) assay for these three most frequently observed determinants in Southern China. By using this assay, we detected 40 alpha-thal patients from Guangdong, Guangxi Province, and analyzed 116 blood samples from the Li ethnic group of Hainan Province. To our surprise, the combined incidence of -alpha3.7 and -alpha4.2 was found to be as high as 38.0% among the Li people, and the -alpha4.2 genotype is more frequent than -alpha3.7 in the Li people. No SEA deletions were found in the Li samples.