With the wide application of contrast media in modem medicine,contrast-induced nephropathy (CIN) has attracted more clinical attention.Renal ischemia and renal tubular toxicity have been considered to be the pathogenesis of CIN.The most promising biomarkers,except for serum creatinine,include neutrophil gelatinase associated lipocalin (NGAL),cystatin C (Cys C),kidney injury molecule-1 (KIM-1),urine N-acetyl beta-D amino glucosidase (NAG) and micro molecular RNA (microRNA).Before use of contrast media for angiography,both the patient's own risk factors and the contrast-associated risk factors should be carefully evaluated.The patient's own risk factors include basic renal function,diabetes,anemia,homocysteine,etc.The contrast-associated risk factors include the osmotic pressure,viscosity,dosage,application frequency of the used contrast agent,etc.At present,hydration therapy is still the main method for CIN,and other therapeutic methods include medication,such as statins,vasodilators,antioxidants,traditional Chinese medicine,etc.,and blood purification therapy.This paper aims to make a brief summary about the research progress in CIN,focusing on its diagnosis,pathogenesis,risk factors and preventive measures.

Objective To observe the effect of remote post-ischemic conditioning(RPIOC)on the cerebral blood flow,neural function and prognosis of patients with acute cerebral infarction and the risk factors for short-term prognosis.Methods 133 patients with acute cerebral infarction in the Second Hospital of Beijing from January 2016 to December 2017 were selected,and randomly divided into the RIPOC group(66 cases,with RPIOC)and the control group(67 cases,without RIPOC).In the first day after hospital,patients in the RIPOC group were given RIPOC,which was tightening the left aim with a tonometer bandage for 5 minutes per time and 2 times a day at an interval of 5 minutes.All patients were provided routine treatment.All patients' cerebral blood flow,neural function and survival data were recorded.Recovery was assessed by modified Rankin Scale(mRS)180 d after stroke.Logistic regression was used to evaluate the risk factors for prognosis.Results Of the 133 patients enrolled,there were 67 males.The mean age was (73.1 ± 10.1)year.Basic clinical characteristics,neural function and cerebral blood flow were similar between groups(P＞0.05).After 10 d treatment,cerebral blood flow and neural function was significantly increased (P＜0.05)in the RIPOC group.After 180 d follow up,the RIPOC group had significantly higher rate of adverse cerebrovascular events(P＜0.05).Logistic regression analyses demonstrated that advanced age(P =0.003),hypertension(P =0.03)and high NIHSS score(P =0.005)were all risk factors for prognosis.Conclusions RIPOC can enhance the cerebral blood flow,activities of daily living,limb function and prognosis.However,it does not reduce the risk of mortality.Advanced age,hypertension and high NIHSS score are risk factors for short-term prognosis.

Objective: To evaluate the cognitive impairment in elderly patients with minor ischemic stroke and to analyze risk factors for stroke recurrence. Methods: This was a retrospective case-control study.Ninety-five elderly patients with acute ischemic stroke hospitalized in the neurology department of Second People's Hospital of Liaocheng were enrolled from January 2016 to January 2017.Based on the National Institutes of Health Stroke Scale(NIHSS), all cases were divided into the minor stroke group(NIHSS score≤3, n=62)and the medium-severe stroke group(NIHSS score>3, n=33). After 12-month follow-up, the NIHSS, modified Rankin scale(mRS)and Montreal cognitive assessment(MoCA)were used to evaluate the study subjects. Results: Of the 95 patients, there were 62 males(65.3%)and 33 females(34.7%), with age of(68.3±6.7)years.No significant differences were found in baseline characteristics of age, male ratio, subtypes and history between two groups(all P>0.05). But, the treatment rate of intravenous thrombolysis was lower in minor stroke group than in medium-severe stroke group[6.5%(4 cases)vs.42.4%(14 cases)(P<0.01)]. The scores of NIHSS[(1.0±0.5)vs.(3.2±1.1), P<0.01], mRS[(1.6±0.7)vs.(2.4±1.1), P<0.01]were lower in the minor stroke group than in the medium-severe group.After a mean follow-up of(12.6±1.9)months, the rate of cognitive impairment was comparable between the two groups(P>0.05), while the rate of post stroke depression had a significant difference between two groups(P<0.05). Furthermore, there was lower rate of mortality and stroke recurrence in the minor stroke group than in the medium-severe group(0.0% or 0/62 vs.30.3% or 10/33, and 21.0% or 13/62 vs.42.4% or 14/33, P<0.05). Cox proportional hazard model showed that baseline NIHSS score, diabetes and stroke history were the risk factors for stroke recurrence in patients with minor stroke(P<0.05). Conclusions The treatment rate of intravenous thrombolysis with rt-PA, mortality rate and stroke recurrence rate are lower in patients with minor stroke than in patients with medium-severe stroke, while the incidence of post stroke cognitive impairment is high.High score of baseline NIHSS, diabetes and stroke history are risk factors for stroke recurrence in elderly patients with minor stroke.