BACKGROUND:Kidney deficiency and blood stasis syndrome are common traditional Chinese medicine syndromes observed in knee osteoarthritis,which serve as fundamental pathogenesis factors.There exists a significant connection between the two.Previous studies have demonstrated that kidney deficiency and blood stasis syndrome effectively contribute to knee joint cartilage degeneration and the progression of knee osteoarthritis.However,the mechanisms underlying the promotion of knee joint cartilage damage remain unclear and require further investigation. OBJECTIVE:To investigate the influence of kidney deficiency and blood stasis syndrome on the progression of knee osteoarthritis in Sprague-Dawley rats. METHODS:Sixteen Sprague-Dawley rats were randomly divided into two groups:a model observation group and a control group,with eight rats in each group.Animal models of kidney deficiency were induced by ovary removal in the model observation group,while the control group was given a sham procedure for ovarian removal.Two months after modeling,both groups underwent modified HULTH surgery to induce knee osteoarthritis.One week after modified HULTH surgery,the model observation group was subcutaneously given adrenaline hydrochloride to make blood stasis models,while the control group was subcutaneously given normal saline.At the 5th week after modified HULTH surgery,blood rheology,coagulation parameters,triiodothyronine,tetraiodothyronine,and estradiol levels were measured.Knee joint X-ray images were taken,and knee joint sections were stained with safranin O-fast green,hematoxylin-eosin,and immunohistochemistry. RESULTS AND CONCLUSION:Compared with the control group,the model observation group exhibited significant increases in whole blood viscosity at low,medium,and high shear rates,as well as increased plasma viscosity.Fibronectin levels in the coagulation parameters were significantly increased,while prothrombin time and activated partial thromboplastin time were significantly decreased.Triiodothyronine,tetraiodothyronine,and estradiol levels were all significantly decreased.Radiographic results showed that the model observation group exhibited more severe degree of knee joint space narrowing and surface roughness,with the appearance of high-density shadows.Hematoxylin-eosin and safranin O-fast green staining demonstrated more severe cartilage damage in the model observation group,with significantly higher OARSI and Mankin scores compared with the control group.Compared with the control group,immunohistochemistry results showed a significant reduction in the expression of extracellular matrix type II collagen and aggrecan protein in the cartilage of the model observation group rats.Moreover,there was a significant increase in the expression of matrix metalloproteinase 13 and aggrecanase 5,which are inflammatory factors.These results indicate that the Sprague-Dawley rat model of knee osteoarthritis with kidney deficiency and blood stasis was successfully established.Kidney deficiency and blood stasis syndrome further aggravate cartilage extracellular matrix degradation and cartilage degeneration by promoting the expression of inflammatory factors,thereby promoting the progression of knee osteoarthritis in rats.

BACKGROUND: Insufficient cerebral perfusion is suggested to play a role in the development of Alzheimer disease (AD). However, there is a lack of direct evidence indicating whether hypoperfusion causes or aggravates AD pathology. We investigated the effect of chronic cerebral hypoperfusion on AD-related pathology in humans. METHODS: We enrolled a group of cognitively normal patients (median age: 64 years) with unilateral chronic cerebral hypoperfusion. Regions of interest with the most pronounced hypoperfusion changes were chosen in the hypoperfused region and were then mirrored in the contralateral hemisphere to create a control region with normal perfusion. 11C-Pittsburgh compound-positron emission tomography standard uptake ratios and brain atrophy indices were calculated from the computed tomography images of each patient. RESULTS: The median age of the 10 participants, consisting of 4 males and 6 females, was 64 years (47-76 years). We found that there were no differences in standard uptake ratios of the cortex (volume of interest [VOI]: P = 0.721, region of interest [ROI]: P = 0.241) and grey/white ratio (VOI: P = 0.333, ROI: P = 0.445) and brain atrophy indices (Bicaudate, Bifrontal, Evans, Cella, Cella media, and Ventricular index, P > 0.05) between the hypoperfused regions and contralateral normally perfused regions in patients with unilateral chronic cerebral hypoperfusion. CONCLUSION Our findings suggest that chronic hypoperfusion due to large vessel stenosis may not directly induce cerebral β-amyloid deposition and neurodegeneration in humans.
Aged ; Alzheimer Disease/pathology* ; Amyloid beta-Peptides/metabolism* ; Arteries ; Atrophy ; Brain/metabolism* ; Cerebral Cortex/metabolism* ; Cerebrovascular Circulation ; Constriction, Pathologic/pathology* ; Female ; Humans ; Magnetic Resonance Imaging/methods* ; Male ; Middle Aged ; Positron-Emission Tomography/methods*