With the increasing difficulty of traditional chemical drug research and development,peptide drugs have gradually become a hot spot in drug research and development due to their advantages of high specificity,significant efficacy,easy metabolism and low toxicity.This review systematically expounds the physicochemical properties,main advantages and limitations of peptide drugs,and summarizes the currently common strategies for structural modification and delivery.It focuses on the application and target of approved peptide drugs in various diseases such as diabetes,cancer,bacterial and viral infections,multiple sclerosis,and osteoporosis.Furthermore,the research analyzes the challenges in the research and development of peptide drugs,including poor in vivo stability,low bioavailability,and limited routes of administration.It also discusses the prospects of new technologies based on molecular modification,nanodelivery systems,and computer-aided design.In summary,peptide drugs have shown unique advantages in multi-field therapy,but they still need to break through bottlenecks in preparation,delivery and drug resistance to provide new ideas and directions for future precision therapy.

Objective To compare SPECT/CT fusion imaging and MRI in the diagnosis of benign hip lesions. Methods Twenty-two patients suspected avascular necrosis of femoral head with hip discomfort, pain or action limited were analyzed retrospectively. All patients underwent radionuclide bone scan and MR examination within 5 days, and the diagnosis was proved with clinical follow-up. Results Eighteen necrosis of the femoral head and 4 hip arthritis including 1 patient with ankylosing spondylitis were found in 44 hip joints of 22 patients. MRI detected 17 femoral head necrosis and 4 hip arthritis, while SPECT/CT fusion image found out 18 femoral head necrosis and 4 hip arthritis. There was corresponding relationship in signs of hip lesions between MRI and SPECT/CT fusion imaging. Conclusion SPECT/CT fusion imaging and MRI has no markedly difference in the diagnosis of hip benign lesions, and is complementary to each other. SPECT/CT fusion image can distinguish the hip lesions from the femoral head lesions, and has a higher accuracy of diagnosing hip lesions than whole body bone scanning.

Objective To investigate the effect of hypert riglyceridemia on vascular endothelial function. Methods With high-resolution ultrasound, flow and nitroglycerin-induced dilatation of the brachial artery were determined in thirty hypertriglyceridemic patients and thirty healthy subjects as controls. Serum lipid and plasma endothelin (ET) were determined. Results In patients with hypertriglyceridemia,flow-induced vasodilatation was much reduced compared with that in the control subjects[(2.7±2.0)% vs (15.0±8.0)%, P<0.001］.However, vasodilatation in response to nitroglycerin were similar in both groups［(15.0±5.0)% vs (16.8±9.0)%, P>0.05].Plasma ET level in the hypertriglyceridemic group was significantly higher than that in the control group［(106.22±19.16) μg/L vs (72.37±14.06) μg/L, P<0.001].ConclusionEndothelium-dependent vasodilatation was impaired in patients with hypertriglyceridemia.

OBJECTIVETo investigate the effect of micronized fenofibrate on vascular endothelial function in patients with hypertriglyceridemia.

METHODSUsing high-resolution ultrasound, we measured flow- and nitroglycerin-induced dilatation of the brachial artery in 30 patients with hypertriglyceridemia before and after treatment with micronized fenofibrate at a dose of 200 mg once daily for 4 weeks. Simultaneously, both serum lipid and plasma endothelin (ET) levels were determined.

RESULTSAfter micronized fenofibrate therapy, serum triglyceride (TG) levels decreased significantly (P < 0.05). Plasma ET levels also decreased markedly [(82.66 +/- 15.46) microg/L vs. (106.22 +/- 19.16) microg/L, P < 0.001]. Flow-induced vasodilatation was much improved (11.0% +/- 9.0% vs 2.7% +/- 2.0%, P < 0.01). However, no significant changes in vasodilatation occurred in response to nitroglycerin (16.2% +/- 6.0% vs 15.0% +/- 5.0%, P > 0.05) in patients with hypertriglyceridemia.

CONCLUSIONSMicronized fenofibrate can improve impaired endothelium-dependent vasodilatation in patients with hypertriglyceridemia. Improving endothelial function may also be the mechanism responsible for the beneficial effects of micronized fenofibrate.

Adult ; Endothelium, Vascular ; drug effects ; physiology ; Female ; Fenofibrate ; pharmacology ; therapeutic use ; Humans ; Hypertriglyceridemia ; drug therapy ; Male ; Middle Aged ; Vasodilation ; drug effects

To explore the influence of angiotensinⅡ(AngⅡ) and aldosterone (Ald) on synthesis of collagen and activity of precollagenase secreted by cardiac fibroblasts.Sirus Red method was employed to evaluate collagen synthesis of cultured cardiac fibroblasts; typeⅠ collagen was measured by competitive ELISA; collagenase activity was tested by fluorescence spectrophotometry.At the doses of 10-9～10-7mol/L, AngⅡ could enhance gross and typeⅠ collagen production in a dose-dependent manner. Collagenase activity decreased with increasing concentration of AngⅡ. These effects of AngⅡcould be completely abolished by its receptor antagonist, saralasin. Ald might enhance gross and typeⅠ collagen production only at a higher concentration (10-7～10-8mol/L), whereas lower concentration (10-9mol/L) had no effect on it. These effects of Ald could be abolished by spironolactone,a specific Ald receptor antagonist. In addition, Ald could significantly decrease the activity of collagenase secreted from cultured cardiac fiboblasts at concentrations of 10-9～10-7mol/L within 24h，which could not be antagonized by 10-6mol/L spironolactone. The results suggested that AngⅡand Ald enhance cardiac fibroblasts collagen synthesis and inhibit collagenase activity ,resulting in net collagen accumulation resulted and acceleration of cardiac fibrosis.