Approach to creating early diabetic peripheral neuropathy rat model / 北京大学学报(医学版)

OBJECTIVE@#To create the early diabetic peripheral neuropathy (DPN) rat model.@*METHODS@#After one-week adaption, 26 male Sprague-Dawley (SD) rats were divided into two groups, the control group (n=6) and the model group (n=20). High-sucrose/high-fat diet (D12451, 35% of energy from carbohydrate, 45% of energy from fat) was given to the model group for six weeks to induce insulin resistance, meanwhile normal diet was given to the control group. Afterwards, streptozocin (STZ) buffer solution (35 mg/kg bodyweight) was injected into abdomen of the model group to induce specific pancreatic injury, meanwhile an equal amount of buffer solution was given to the control group. Then 48 h later, type 2 diabetes mellitus (T2DM) was supposed to be successfully induced according to the random blood glucose more than 16.7 mmol/L in the model group. Then the basic features of the T2DM rats were evaluated, including body weight, fasting blood glucose (FBG), glucose tolerance (oral glucose tolerance test, OGTT), and insulin tolerance (intraperitoneal insulin tolerance test, IPITT). Subsequently, withdrawal thermal latency (WTL) was measured regularly to determine when the early DPN occurred. Once confirmed, sciatic nerve conduction velocity (NCV) of all the rats was conducted.@*RESULTS@#The T2DM rats were successfully induced in the model group through high-sucrose/high-fat diet for six weeks along with STZ intraperitoneal injection (35 mg/kg bodyweight). When compared to the control group, the T2DM rats had higher FBG (P<0.001), and the glucose tolerance and insulin tolerance were both damaged (P<0.001 in OGTT, P=0.002 in IPITT). It was on the 17th day when the T2DM rats became much more sensitive to heat stimulus compared to the control group (P=0.004). Meanwhile, the sciatic NCV was conducted. There was no significant difference between the early DPN group and the control group (P=0.196).@*CONCLUSION@#High-sucrose/high-fat diet for six weeks along with STZ intraperitoneal injection (35 mg/kg bodyweight) could successfully induce T2DM rat model, manifested by a certain extent of insulin resistance and deficiency of insulin secretion. It was about 17 days later when the early DPN emerged. In the early DPN, small fiber neuropathy came out earlier than large fiber neuropathy.

Evaluation of Diagnostic Efficiency of Ultrasound Features on Malignant Thyroid Nodules in Chinese Patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The aim of this study was to evaluate the efficacy of ultrasonic features in predicting the malignancy of thyroid nodules in a group of Chinese patients.</p><p><b>METHODS</b>In all, 762 patients with thyroid nodules (424 malignant and 338 benign) underwent ultrasound (US) check and surgery between March 2011 and July 2014 at Peking University First Hospital were identified. Univariate and receiver operating characteristic (ROC) analyses were performed to calculate the sensitivity, specificity, negative and positive predictive values of each US feature, and the accuracy of their combinations for prediction of malignancy.</p><p><b>RESULTS</b>Patients with malignant nodules were younger and without obvious risk history than those in the benign group (P < 0.001, P = 0.93). No individual US sign was fully predictive of a malignant lesion. The Youden indexes of irregular margins and hypoechogenicity were the first and second highest in all US features, which were 51.9% and 45.2%, respectively. The sensitivity of solid components (89.7%) and hypoechogenicity (89.2%) and the specificity of taller-than-wide shape (98.5%) and microcalcifications (90.6%) were the first and second highest in all US features. Intranodular flow on a color Doppler examination was a weak predictor of malignancy. Under ROC analysis excepting intranodular flow, the 95% confidence interval (CI) of areas under the curves of hypoechogenicity and irregular margins with any one of the US features were overlapped that of five-feature combinations (95% CI: 0.850-0.901).</p><p><b>CONCLUSIONS</b>We should be alert with taller-than-wide shape and microcalcifications. Intranodular flow was a weak predictor of malignancy. According to Youden indexes and ROC analysis, irregular margins and hypoechogenicity combined with solid component or taller-than-wide shapes or microcalcifications have a high predicative value for malignant thyroid nodules in Chinese patients.</p>

Efficacy and tolerability of exenatide monotherapy in obese patients with newly diagnosed type 2 diabetes: a randomized, 26 weeks metformin-controlled, parallel-group study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Incretin-based therapies provide additional options for treating type 2 diabetes. We aimed to evaluate the efficacy and tolerability of exenatide monotherapy in obese patients with type 2 diabetes.</p><p><b>METHODS</b>A 26-week, metformin controlled, parallel-group study was conducted among antidiabetic drug-naive obese patients aged > 18 years, and with type 2 diabetes. Participating patients were randomly assigned to receive exenatide or metformin treatments.</p><p><b>RESULTS</b>Fifty-nine patients (age (50.5 ± 8.6) years, body mass index (BMI) (30.2 ± 1.6) kg/m(2), and hemoglobin A1C (HbA(1C) (8.2 ± 1.2)%) were enrolled in the study. Glucose control and weight reduction improved in both groups receiving treatment. HbA(1C) and oral glucose tolerance test (OGTT) 2 hour glycemia reduction with exenatide was superior to that obtained with metformin ((-2.10 ± 1.79)% vs. (-1.66 ± 1.38)%, (-5.11 ± 2.68) mmol/L vs. (-2.80 ± 2.70) mmol/L, P < 0.05). Fast plasma glucose (FPG) reduction was not significantly different between the two groups ((-1.8 ± 2.0) mmol/L vs. (-1.6 ± 1.7) mmol/L, P > 0.05). Patients treated with exenatide achieved HbA(1C) of < 7% (97% of patients) and < 6.5% (79%) at end-point, vs. 93% and 73% with metformin (P > 0.05). Greater weight reduction was also achieved with exenatide ((-5.80 ± 3.66) kg) than with metformin ((-3.81 ± 1.38) kg, P < 0.01). Homeostasis model assessment of beta-cell function (HOMA-B) was not significantly increased, but the insulinogenic index and HOMA for insulin sensitivity (HOMA-S) were greatly improved in the exenatide group (P < 0.05). Nausea was the most common adverse effect in exenatide treatment (30% vs. 8%; P < 0.05), but most cases were of mild to moderate intensity. One case in the exenatide group was withdrawn early because of severe nausea. Hypoglycemia events were often observed during the first 4 weeks, with 12% of patients in the exenatide and 3.2% in metformin groups, respectively (P < 0.05). No incidents of severe hypoglycemia were reported.</p><p><b>CONCLUSIONS</b>Exenatide demonstrated more beneficial effects on HbA(1C), weight reduction and insulin resistance during 26 weeks of treatment, but there were more hypoglycemic events and mild-to-moderate nausea compared with metformin. These results suggested that exenatide monotherapy may provide a viable treatment option in newly developed type 2 diabetes.</p>