Advances of the regulatory mechanism of cyclin, cyclin- dependent kinases and related kinase inhibitors in cell cycle progression / 生物工程学报

Cell cycle plays a crucial role in cell development. Cell cycle progression is mainly regulated by cyclin dependent kinase (CDK), cyclin and endogenous CDK inhibitor (CKI). Among these, CDK is the main cell cycle regulator, binding to cyclin to form the cyclin-CDK complex, which phosphorylates hundreds of substrates and regulates interphase and mitotic progression. Abnormal activity of various cell cycle proteins can cause uncontrolled proliferation of cancer cells, which leads to cancer development. Therefore, understanding the changes in CDK activity, cyclin-CDK assembly and the role of CDK inhibitors will help to understand the underlying regulatory processes in cell cycle progression, as well as provide a basis for the treatment of cancer and disease and the development of CDK inhibitor-based therapeutic agents. This review focuses on the key events of CDK activation or inactivation, and summarizes the regulatory processes of cyclin-CDK at specific times and locations, as well as the progress of research on relevant CDK inhibitor therapeutics in cancer and disease. The review concludes with a brief description of the current challenges of the cell cycle process, with the aim to provide scientific references and new ideas for further research on cell cycle process.

The anti-oxidative effect of Ramulus mori polysaccharides on diabetic nephropathy mice / 中国药理学通报

Aim To investigate the influence of Ramu-lus mori polysaccharides ( RMP) on blood glucose and anti-oxidative effect in streptozotocin ( STZ )-induced diabetic mice .Methods Diabetic mice were induced by intraperitoneal injection with 120 mg? kg -1 STZ and were randomly divided into the following 5 groups with 20 animals per group: model group , valsartan group ( 20 mg? kg -1 ) , low-, medium-, high-dose (0.3,0.6,1.2 g? kg -1 ) of RMP groups.Other 20 normal mice were treated as normal control group .The mice were administered orally for 90 d.On 45 d of ad-ministration , the 24 h urine was collected through met-abolic cages for urine protein detection .Pathological changes of kidney tissues were observed through HE staining .The serum levels of urea nitrogen ( BUN) and creatinine ( Cr ) were detected by automatic biochemical analyzer; and the manganese superoxide dismutase (Mn-SOD), catalase(CAT), malonaldehyde(MDA) and mitochondrial respiratory chain complex Ⅰ,Ⅲac-tivity of kidney tissues were also determined .ELISA method was used to detect ROS content in renal cortex . The SIRT1 , FOXO1 and NF-κB protein expressions were analyzed by Western blot .Results Compared with model group, the FBG, microalbuminuria, BUN and Cr were decreased by RMP medication ( P <0.05).The activities of Mn-SOD, CAT and mitochon-drial respiratory chain complex Ⅰ,Ⅲ in RMP groups were enhanced , while MDA and ROS levels were re-duced. Moreover, the expressions of SIRT1 and FOXO1 were up-regulated by RMP , the expression of NF-κB was down-regulated ( P<0.05) .Conclusion RMP exerts renal protective effect through up-regula-ting the expressions of SIRT1 and FOXO1 in renal cor-tex , which may relate to the improvement of anti-oxida-tive capability .

Modified free vascularized fibular grafting for the osteonecrosis of the femoral head / 中华显微外科杂志

Objective To evaluate the short term results of repairing osteonecrosis of the femoral head by modified free vascularized fibular grafting through Smith-Peterson approach without cutting the rectus femoris.Methods Between January,2009 and September,2012,14 osteonecrotic hips of 14 patients who underwent free vascularized fibular grafting were retrospectively studied including 10 male and 4 female.The follow up period was 24 months.The preoperative and postoperative symptoms relief,recovery of hip function (Harris score),radiographic assessment (X-ray).Results All patients got postoperative ipsilateral hip pain relief.Average Harris hip score improved significantly (68.47 ± 5.33,86.80 ± 4.72 points in preoperation and postoperation,respectively; paired t test,t =18.724,P ＜ 0.01).Postoperative X-ray results showed there were no progresses of osteonecrosis and no collapse in the operative side within 2 years follow-up.Conclusion The short term treatment results of femoral head avascular necrosis were satisfactory by using free vascularized fibular graft through Smith-Peterson approach without cutting off the rectus femoris and it may be a relatively practical option of surgical approach.

Lower motor neuron lesion caused by single level lower thoracic disc protrusion / 中华骨科杂志

Objective To investigate clinical features of lower motor neuron lesion (LMNL) caused by the single level lower thoracic disc protrusion (LTDP),and to observe clinical outcomes of surgical treatment.Methods Between January 1997 and December 2009,17 patients with LMNL caused by single level LTDP underwent en bloc resection of the superior articular process,Cave-in 360° circumferential decompression and internal fixation in our hospital.MRI and CT scans were taken to confirm lesion levels:T10-11 in 4 patients of whom 3 had patellar clonus and ankle clonus,T11-12 in 5 patients of whom 4 had ankle clonus,and T12L1 in 8 patients who only had positive Babinski sign.The neurologic status was assessed using the Japanese Orthopaedic Association (JOA) scoring system.The muscle strength of the tibialis anterior was assessed using the Manual Muscle Test (MMT).Sagittal Cobb angle and cross-sectional area of the dural sac at the level of maximal compression in MRI were also observed.Results All patients were followed up for 22 to 76 months (average,48.6 months).The mean JOA score increased from preoperative 5.88±1.11 to 9.53±0.94 at final follow-up (t=16.143,P＜0.05).The muscle strength of the tibialis anterior recovered to more than grade 4 in all patients.Postoperative Cobb angle was unchanged compared with that before operation.MRI indicated that the cross-sectional area of the dural sac at the level of maximum compression increased from preoperative 35.8±7.3 mm2 to postoperative 132.9±6.5 mm2 (t=70.78,P＜0.05).Conclusion LMNL can be caused by LTDP.The eu bloc resection of the superior articular process,Cave-in 360° circumferential decompression and internal fixation can provide a satisfactory decompression effect and marked recovery of neurological function.