[Influential factors of non-motor symptoms prognosis in Parkinson's disease patients undergoing deep brain stimulation]

Objective: To investigate the effects of electrode activated contact location, volume of tissue activated (VTA) and age on non-motor symptoms, such as emotional symptoms and cognitive function, in Parkinson's disease (PD) patients with deep brain stimulation (DBS). Methods: PD patients who underwent DBS of subthalamic nucleus (STN) at the Department of Functional Neurosurgery of Beijing Tiantan Hospital from September 1, 2020 to August 31, 2022 were retrospectively enrolled. The International Parkinson and Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), Montreal Cognitive Assessment (MoCA), and Mini-Mental State Examination Scales (MMSE) were used at the preoperative, 1-month and 12-month postoperative time points. In this study, patients were divided into middle-aged (age<60 years,n=39) and elderly (age≥60 years,n=62) groups to investigate the effect of age factor on the clinical outcome of surgery. Lead-DBS software was used to convert the patients' electrode reconstruction results into Montreal standard space, and the patients were divided into sensorimotor(n=43) and combined groups(n=53) according to the distribution of activation contact locations in the subzones of the STN. In addition, the patients were divided into a cognitive improvement group(n=57)and a cognitive deterioration group(n=44) based on the results of MoCA at 12 months. The positional information of the electrode activation contacts was collected and the VTA was calculated to analyze the effects on electrode activation electroshock location and activated tissue volume on patients' non-motor symptoms. Results: A total of 101 patients with PD were enrolled, including 46 males and 55 females, aged (62.6±8.4) years. Middle-aged patients had significantly higher MoCA scores, delayed recall scores, attention scores, and naming scores than older patients at 12 months postoperatively (all P<0.05). At 12-month follow-up, the improvement rate of MoCA score, HAMA score and HAMD score were -1.77%±20.36%, 39.65%±42.91% and 36.23%±45.45% respectively in sensorimotor group. At 12-month follow-up, the improvement rate of MoCA score, HAMA score and HAMD score was 11.69%±22.24%, 16.62%±68.10% and 2.30%±95.04% respectively in the combined group, and the difference between the two groups was statistically significant (MoCA: P=0.002; HAMA: P=0.040; HAMD: P=0.033) The distribution of VTA in the sensory motor area and marginal area of the left hemisphere STN in patients with improved cognitive function was significantly smaller than that in the deterioration group [(60.53±52.04)mm³vs (84.55±61.00)mm³, P=0.035; (41.81±33.36)mm³vs (59.05±45.46)mm³, P=0.030]. Conclusion: The effect of STN-DBS on emotional symptoms and cognitive function in PD patients is influenced by various factors and is closely related to the patient's age, electrode activation contact location and VTA.

[Statistical parametric mapping analysis of 18F-FDG PET in Parkinson's disease with mild cognitive impairment]

Objective: To investigate the characteristics of cerebral metabolism associated with mild cognitive impairment (MCI) Parkinson's disease (PD), cognitive normal PD and normal control to find a PET biomarker for the diagnose and estimate of PD-MCI. Methods: Forty-seven patients diagnosed with PD (included 15 with mild cognitive impairment) and 20 control subjects were enrolled. All the subjects were evaluated with FDG-PET and clinical scale. The statistical parametric mapping (SPM) were analyzed to determine metabolic patterns that may be useful in differentiating between the three groups. Results: SPM analysis showed that significant hypometabolism were observed in both side of front lobe, parietal lobe, left temporal lobe and left occipital lobe; in the contrast, the relative hypermetabolism had been observed in the cerebellum, vermis, hippocampus and supplement motor area (SMA) in patients with PD-MCI. PD without MCI showed hypometabolism in both side of front lob, caudate and putamen. PD-MCI showed that the significant hypermetabolism were in the insular and cerebellum while hypometabolism were in the both side of occipital compared to PD without MCI. Conclusion: A voxel-by-voxel based SPM method i. e. SPM8 analysis by PET scan is an effective way to analysis the FDG uptake pattern of PD patients. The hypermetabolism in the insula and cerebellum and hypometabolism in the both side of occipital may be a biomarker for make a diagnosis of PD-MCI.

Chondrogenesis of mesenchymal stem cells in a novel hyaluronate-collagen-tricalcium phosphate scaffolds for knee repair

Scaffolds are expected to play a key role in the induction of chondrogenesis of mesenchymal stem cells (MSCs) for cartilage tissue regeneration. Here, we report the development of a novel tricalcium phosphate-collagen-hyaluronate (TCP-COL-HA) scaffold that can function as a stem cell carrier to induce chondrogenesis and promote cartilage repair, and the investigation of chondroinductive properties of scaffolds containing varying amounts of TCP, COL and HA. TCP-COL-HA scaffolds, as well as TCP-COL scaffolds at two different TCP/COL ratios (50:50 and 25:75), were evaluated for their ability to induce cartilage regeneration from rabbit mesenchymal stem cells (rMSCs) in vitro and in vivo. Chondrogenic differentiation was evaluated by sulphated glycosaminoglycan quantification, collagen type II immunohistochemistry, and qRT-PCR. Mechanical strength was evaluated by the compression test. The results showed that the TCP-COL-HA scaffolds enhanced rMSC chondrogenesis to a greater degree than did the TCP-COL scaffolds; for the latter, the scaffold with the lower TCP/COL ratio (25:75) was superior in terms of promoting rMSC chondrogenesis. Similar results were obtained in an ectopic implantation model in nude mice. In a critical-size rabbit osteochondral defect-repair model, rMSCs seeded on TCP-COL-HA scaffolds showed greater cartilage regeneration and integration into surrounding tissue than the TCP-COL groups, in which cartilage repair was more efficient at the 25:75 than at the 50:50 ratio. These results indicate that the addition of HA and different TCP/COL ratios can affect the chondroinductive capacity of scaffolds, and suggest that the TCP-COL-HA scaffold can serve as an effective cell carrier for cartilage regeneration.

Effects of the consumption of rice from non-KBD areas and selenium supplementation on the prevention and treatment of paediatric Kaschin-Beck disease: an epidemiological intervention trial in the Qinghai Province

OBJECTIVE

Based on the aetiological hypothesis of Kaschin-Beck disease (KBD), different interventions were adopted, and the preventive and therapeutic effects of interventions was observed and evaluated in this trial.

DESIGN

A total of 358 children from seven villages of Qinghai Province in China were examined, and 280 children aged 6-11 years old were eligible for the trial. The children were divided into three groups that received either no intervention (n = 64), 150 kg/person of rice from non-KBD areas (n = 103) or 7 kg/family of selenium-iodine salt (n = 113) for 12 months. Data were collected and used to calculate the proportion of patients with X-ray lesions, the proportion of new patients and the metaphyseal repair rate. All indicators were analysed with Pearson chi-square or Fisher's exact tests. The registration number of this trial is ChiCTR-PNRC-12002309 (http://www.chictr.org).

RESULTS

After interventions, the proportion of patients with X-ray lesions increased dramatically in the control group and decreased significantly in two intervention groups; significant differences were seen between the control group and two intervention groups (P < 0.05). Moreover, significant differences were observed in the proportions of new patients and the metaphyseal repair rates between the control group and two intervention groups (P < 0.05). Additionally, the proportion of new patients was lowest and the metaphyseal repair rate was highest in group B.

CONCLUSIONS

The effects of eating rice from non-KBD areas and selenium supplementation on the prevention and treatment of paediatric KBD were notable, the consumption of rice might be the most effective and safest intervention and should be encouraged.

Effects of acrylamide on creatine kinase from rabbit muscle

The mechanism of inhibition of creatine kinase (CK) by acrylamide (Acr) has been examined (in vitro). Within the concentration range of 0 to 1 M, Acr markedly inhibited CK and depleted the protein thiols. Both inactivation and thiol depletion were time- and Acr concentration-dependent. Addition of dithiothreitol (DTT) did not reactivate CK inactivated by Acr. However, CK with 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) pre-blocked thiols can be reactivated by DTT after incubation with Acr. The transition-state analogue also had a significant protective effect on CK against Acr inhibition. We conclude that thiol alkylation is a critical event in inactivation of CK by Acr. Furthermore, Acr binding to CK changed its surface charge, which may be the same effect for the toxicity of Acr towards other proteins.

Dissociation and unfolding of GCN4 leucine zipper in the presence of sodium dodecyl sulfate

The dissociation and unfolding behavior of the GCN4 leucine zipper has been studied using SDS titration. Circular dichroism (CD) spectra showed that the alpha-helix content of the leucine zipper (20 microM) decreased during the sodium dodecyl sulfate (SDS) titration. However, the alpha-helix content of the leucine zipper still remained significant in the presence of 1 mM SDS, with little change detected when the SDS concentration further increased to 2 mM. The dimer dissociation of the leucine zipper is also a co-operative process during SDS titration; with no dimer remaining when SDS concentration reached 1 mM, as shown by electrophoresis and the the theta(222)/theta(208) ratio. Our results indicate that SDS efficiently induces leucine zipper dimer dissociation with the monomers still partially folded. The experimental results provide important evidence for the previous model that partial helix formation precedes dimerization in coiled coil folding.