COVID-19 could cause long term peripheral nerve demyelination and axonal loss: A One Year Prospective Cohort Study

BackgroundThere is a lack of studies on large-sample, medium-, or long-term follow-up data of peripheral neuropathy (PNP) in the COVID-19 survivors. This study evaluated the characteristics and related risk factors of PNP in the medium- and long-term rehabilitation, which provided real-world study data for the complete recovery of COVID-19 patients. MethodsThis study was a prospective cohort study of the COVID-19 survivors. We collected data on baseline characteristics, symptoms at onset and after discharge during the 6-month and 12-month follow-up. Peripheral nerves were measured by electromyography and inducible potentiometer. We used multivariable logistic regression to analyze the influencing factors of PNP. Additionally, we compared the difference between the two measurements among the population who completed both measurements. Results313 patients were included in the study and all of them underwent nerve conduction study. 67 patients completed two measurements at 6-month and 12-month follow-up. Commonly reported symptoms contained memory loss (86%), hair loss (28%), anxiety (24%), and sleep difficulties (24%). 232 patients (74%) were found with PNP, including 51 (16%) with mononeuropathy and 181 (58%) with generalized PNP. Patients with measurement at 12-month follow-up had a higher prevalence of generalized PNP (p=0.006). For pathological types, 64 (20%) patients had only axonal loss, 67 (21%) had only demyelination, and 101 (32%) had a mixed type. There was no significant difference in the prevalence of accompanying symptoms after discharge between the two groups with or without PNP. After adjustment, age was positively associated with PNP (OR=1.22 per 10-year increase of age, 95% CI, 1.05-1.41). Compared with less than the median amount of IgG at discharge, higher amount of IgG was associated with decreased risk of F-wave abnormality (OR=0.32, 95%CI, 0.11-0.82), but no significant difference in other types of PNP. Conclusions and RelevanceSARS-CoV-2 could cause PNP in hospital survivors with COVID-19, which persisted and was associated with age, education, and IgG antibody at discharge, but had no significant correlation with symptoms after discharge.

Biomechanics relationships of lumbar disc herniation and spondylolisthesis with transplanted implants / 中国组织工程研究

BACKGROUND:The purpose of lumbar disc protrusion and spondylolysis operation is not only to anterior decompression and fusion,but also to maintain the mechanical stability of vertebrae by holding the normal stress spot range of instantaneous center of rotation (ICR).OBJECTIVE:Using mechanical tenet to explain the pathological relationship between lumbar disc protrusion and spondylolysis,and to summarize the treatments for 68 cases with lumbar disc herniation and spondylolisthesis.METHODS:Totally 68 cases of lumbar disc protrusion and spondylolisthesis suffered lumbago or sciatica simultaneously.All patients were treated by the surgical method containing posterior whole or half laminectomy exploration decompression,discectomy,intervertebral fusion and the short segment posterior pedicle screw reduction and internal fixation.RESULTS AND CONCLUSION:All patients received 1.5 years follow-up.According to Stamffer criterion of therapeutic effectiveness,63 patients were good,and 5 patients were average,with 92.6% good rate.Due to abnormal ICR,the pathological disc and spondylolysis were reciprocal causation.Following implantation,the stress of ICR was kept in a normal range,and the anterior sliding power of vertebrae was reduced,which can maintain the mechanical stability of vertebrae.

Experimental study of the effects of time-phased cryopreservation and resuscitation on biological characters of osteoblasts / 生物医学工程学杂志

This is an in vitro study to explore the effects of cryopreservation and resuscitation on the biological characteristics of osteoblasts at different times. Osteoblasts taken from the crania of newly born SD rats were cultured. Comparative studies were made on the cells' proliferation, the activity of alkaline phosphatase (ALP), and the number of live cells among fresh cultured osteoblasts and cells after the inception of cryopreservation and resuscitation at time-periods of one, three, six months respectively. The results showed that there were no significant differences among four groups in cell proliferation and in activity of ALP (P > 0.05). Yet, after cryopreservation and resuscitation, there were significant differences between the six-month group and the other three groups (P < 0.05). The results also showed, after cryopreservation and resuscitation, there were no significant differences between the control group and the one-month and three-month groups, respectively (P > 0.05). These findings indicated that the live cells might decrease in number after the osteoblasts were cryopreserved for too long a period, but after cryopreservation and resuscitation, the cells still retained the original biological characteristics of osteoblasts.

An experimental research on different temperature sintered bone as carrier of bone morphogenetic protein / 生物医学工程学杂志

This study was conducted to find perfect temperature sintered bone as carrier of bone morphogenetic protein (BMP). The different temperature active sintered bones, which were made up of calcine bone and bone morphogenetic protein, were implanted into the defects of rabbit radius. Compared with the sintered bone of 600 degrees C, the sintered bone of 900 degrees C and 1200 degrees C could induce more pieces of bone formation and be replaced by new bone. There were more pieces of new bone formation in sintered bone of 900 degrees C and 1200 degrees C than those in sintered bone of 600 degrees C (P<0.05). There was no difference between the sintered bone of 900 degrees C and 1 200 degrees C (P>0.05). In comparison with the sintered bone of 600 degrees C and 1200 degrees C, the sintered bone of 900 degrees C may be the choicest carrier of bone morphogenetic protein.

Effects of kangfengshi granules on expressions of osteoprotegerin, RANKL and M-CSF in bone tissues of rats with collagen-induced arthritis / 中西医结合学报

OBJECTIVE: To observe the effects of Kangfengshi Granules (KFSG) on expressions of the mRNAs of osteoprotegerin (OPG), receptor activator of nuclear factor-kappaB ligand (RANKL) and macrophage colony stimulating factor (M-CSF) in bone tissues of rats with collagen-induced arthritis. METHODS: Forty SD rats were randomly divided into four groups: normal control group, untreated group, cyclosporine A (CsA)-treated group and KFSG-treated group. Except the rats in the normal control group, all the other rats received subcutaneous injection of collagen II to establish collagen-induced arthritis (CIA) models. Then the rats in each group were fed normal saline or corresponding drugs for four weeks. Total RNA was extracted from carpal and digital bones. The expressions of OPG, RANKL and M-CSF mRNAs were examined by real-time PCR. RESULTS: The total incidence of arthritis induced by collagen II in the rats was approximately 90%. The expression levels of RANKL and M-CSF mRNAs and the RANKL mRNA/OPG mRNA ratio in the untreated group, KFSG-treated group and CsA-treated group were all significantly higher than those in the normal control group, while the expression levels of OPG mRNA in those three groups were significantly lower than that in the normal control group. The expression level of OPG mRNA in the KFSG-treated group was obviously higher while the expression level of M-CSF mRNA and the RANKL mRNA/OPG mRNA ratio in the same group were both lower as compared with those in the untreated group. CONCLUSION: The molecular mechanism of effects of KFSG on bone erosion and destruction induced by rheumatoid arthritis is closely correlated with up-regulating the expression of OPG mRNA, down-regulating the expression of M-CSF mRNA and RANKL mRNA/OPG mRNA ratio.