Malignant tumors are major diseases that endanger human health. Due to their complex and variable microenvironment, most anti-tumor drugs cannot precisely reach the focal tissue and be released in a controlled manner. Intelligent responsive nano carriers have become a hot spot in the field of anti-tumor drug delivery systems. As an excellent nano material, mesoporous silica has the advantages of non-toxic, stable, adjustable pore volume and pore diameter, and easy functional modification on the surface. By virtue of its perceptive response to the tumor microenvironment or physiological changes, it can achieve the targeted drug release or controlled drug release of the drug delivery system in the tissue, making it an ideal carrier for intelligent response drug delivery system. In this paper, we review the design strategies and current research status of smart responsive anti-tumor drug delivery systems based on mesoporous silica, in order to provide a reference for the development of anti-tumor drug nanoformulations.

Objective：To investigate the correct expression of dengue 2 virus 43 strain NS1 gene in transfected BHK-21 cell. Methods：The D2-43 DNA fragment coding for signal peptide plus NS1 protein was cloned between KpnⅠ site and EcoR Ⅰ site of expression plamid pcDNA3.1. The obtained recombinant vector pcDNA-NS1 was transfected into BHK-21 cells with electroporation technique. After selection by G418, resistant clones were screened by RT-PCR and Western blotting test. Results：The RT-PCR results of four in five randomly selected cell clones were positive. Western blotting test showed that NS1 gene could be expressed in BHK-21 cells. Conclusions：NS1 protein was capable of being expressed and appropriately processed in pcDNA-NS1 transfected BHK-21 cells. The present results suggest the feasibility of NS1-based DNA immunization.

BACKGROUNDThe cause of the adjacent segment degeneration (ASD) after fusion remains unknown. It is reported that adjacent facet joint stresses increase after anterior cervical discectomy and fusion. This increase of stress rate may lead to tissue injury. Thus far, the load rate of the adjacent segment facet joint after fusion remains unclear.

METHODSSix C2-C7 cadaveric spine specimens were loaded under four motion modes: Flexion, extension, rotation, and lateral bending, with a pure moment using a 6° robot arm combined with an optical motion analysis system. The Tecscan pressure test system was used for testing facet joint pressure.

RESULTSThe contact mode of the facet joints and distributions of the force center during different motions were recorded. The adjacent segment facet joint forces increased faster after fusion, compared with intact conditions. While the magnitude of pressures increased, there was no difference in distribution modes before and after fusion. No pressures were detected during flexion. The average growth velocity during extension was the fastest and was significantly faster than lateral bending.

CONCLUSIONSOne of the reasons for cartilage injury was the increasing stress rate of loading. This implies that ASD after fusion may be related to habitual movement before and after fusion. More and faster extension is disadvantageous for the facet joints and should be reduced as much as possible.

Biomechanical Phenomena ; Humans ; In Vitro Techniques ; Lumbar Vertebrae ; physiopathology ; Range of Motion, Articular ; physiology ; Spinal Fusion ; adverse effects ; Spine ; physiopathology

BACKGROUNDEndovascular therapy is a treatment option for localized occlusion of the subclavian artery. In this report the long-term experience with 59 patients is presented.

METHODSBetween June 1998 and September 2008, we used endovascular therapy to treat 61 subclavian arterial obstructive lesions in 59 patients (46 males and 13 females, 34 - 82 years of age with a mean age (61.9 + or - 11.0) years). Twenty patients (34%) had clinical symptoms due to vertebrobasilar insufficiency, 26 (44%) had disabling arm ischemia, and 13 (22%) had both symptoms. We performed all procedures under local anesthesia. The approaches were from the femoral artery (n = 47), brachial artery (n = 1, involving bilateral subclavian disease) or both (n = 11). Sixty stents were implanted. All patients were followed-up at 1, 3, 6, and 12 months post-procedure, and annually thereafter.

RESULTSWe achieved technical success in 58 (95.1%) arteries, all of which were stented. There were three technical failures; two were due to the inability to cross over an occlusion, necessitating the switch to an axillo-axillary bypass, and the third was due to shock after digital subtraction angiography and prior to stenting. Arterial stenosis pre- and post-stenting was (83.6 + or - 10.8)% and (2.5 + or - 12.5)% (P < 0.01). Clinical success was achieved in 55 of the 59 patients (93.4%). Of the four clinical failures, three were technical and the remaining patient had a stent thrombosis. Systolic blood pressure difference between the two brachial arteries was (44.7 + or - 18.5) vs. (2.2 + or - 3.9) mmHg (P < 0.01). Primary patency was 98% at 12 months, 93% at 24 months, and 82% at 5 years. Five patients were lost to follow-up by 12 months post-stenting. Significant recurrent obstruction developed in five patients with resumption of clinical symptoms. The overall survival rate was 98.2% at 12 months, 89.5% at 24 months, and 84.5% at 5 years.

CONCLUSIONSEndovascular therapy for proximal subclavian arterial obstructive lesions is effective and successful. This minimally invasive treatment may be the first choice of treatment for proximal subclavical arterial obstructive lesions.

Adult ; Aged ; Aged, 80 and over ; Arterial Occlusive Diseases ; pathology ; therapy ; Female ; Humans ; Male ; Middle Aged ; Stents ; Subclavian Artery ; pathology ; Subclavian Steal Syndrome ; pathology ; therapy ; Vertebrobasilar Insufficiency ; pathology ; therapy

OBJECTIVETo analyze the surgical treatment and prognosis of non-traumatic acute lower limb ischemia, and compare the morbidity and prognosis of acute arterial embolism and acute arterial thrombosis.

METHODSThe clinical data of 154 acute lower limb ischemia patients surgically treated from July 1999 to December 2007 were retrospectively analyzed. Fogarty catheter embolectomy was used in all patients; in which, 128 cases underwent Fogarty catheter embolectomy only, 8 cases Fogarty catheter embolectomy combined with endarterectomy, 13 cases Fogarty catheter embolectomy combined with vascular reconstruction with prosthetic graft or great saphenous vein, 5 cases Fogarty catheter embolectomy combined with amputation. The patients were divided into two groups according to pathogenesis: acute arterial embolism group (99 cases) and acute arterial thrombosis group (55 cases). The morbidity, amputation, perioperative mortality rates and high risk factors of amputation in the two groups were compared.

RESULTSFemale experienced acute arterial embolism more often than man (60.6% vs 39.4%, P < 0.05), and more acute arterial thrombosis occurred in man (72.7% vs 27.3%, P < 0.05). The amputation rate of all cases was 9.7%, and perioperative mortality rate was 11.7%. The amputation rate in acute arterial embolism group was lower than acute arterial thrombosis group (5.1% vs 18.2%, P < 0.05). The perioperative mortality rates in the two groups were equal (11.1% vs 12.7%, P > 0.05). The statistically high risk factor of amputation for two groups was ischemic time, and smoking and diabetes were high risk factors for acute arterial thrombosis.

CONCLUSIONSMen experiences acute arterial thrombosis more often, and women experiences acute arterial embolism more often. The amputation rate of acute arterial embolism is lower than acute arterial thrombosis, and acute arterial thrombosis has more high risk factors of amputation.

Acute Disease ; Adult ; Aged ; Aged, 80 and over ; Embolism, Cholesterol ; complications ; Female ; Follow-Up Studies ; Humans ; Ischemia ; etiology ; surgery ; Lower Extremity ; blood supply ; Male ; Middle Aged ; Prognosis ; Retrospective Studies ; Thrombosis ; complications ; Treatment Outcome

OBJECTIVETo study the possible effect of tetracycline on protease-resistant activity in vitro and infectivity in vivo of a scrapie strain 263K.

METHODSScrapie pathogens were incubated with tetracycline at different concentrations for various periods of time and protease-resistant PrP signals were evaluated with proteinase K-treatment and Western blots. The preparations treated with tetracycline were intracerebrally inoculated into golden hamsters and typical TSE manifestations were noted. PrPSc in brain tissues of the infected animals was detected by PrP specific Western blot assays.

RESULTSProtease-resistant PrP was significantly reduced in or removed from the preparations treated with tetracycline in a dose-dependant manner. Compared with the control group after incubated for 53.75 +/- 0.50 days, the preparations treated with 5 mmol/L and 20 mmol/L tetracycline prolonged the incubation time of 61.5 +/- 1.73 and 59.5 +/- 0.58 days (P < 0.05).

CONCLUSIONTreatment of scrapie pathogen 263K with tetracycline reduces or removes its protease-resistant activity in vitro.

Animals ; Brain ; pathology ; Cricetinae ; Peptide Hydrolases ; metabolism ; PrPSc Proteins ; metabolism ; pathogenicity ; Scrapie ; pathology ; Tetracycline ; pharmacology ; Time Factors

Objective To analyze the viscoelastic properties of adjacent segments after anterior fusion under prolonged flexion, and further reveal the mechanism of accelerated adjacent segment degeneration after intervertebral fusion. Methods The same prolonged flexion lasted 30 minutes was applied on the two-level ovine lumbar specimen before and after anterior fusion respectively, and the moment relaxation and viscoelastic deformation of adjacent segments were measured. The moment relaxation curves from two groups were then fitted to obtain the quantitative viscoelastic results. Results After fusion，the initial and final moment in two groups significantly increased by 30.68% and 34.34%, and the viscoelastic deformation of the adjacent segments increased by 28.21%. The Prony model could perfectly fit the moment relaxation curves (R2=99.50%). The integral stiffness significantly increased by 47.82% and 31.14% for two groups, while the viscoelasticity significantly decreased by 27.19% and 28.16%, respectively(P<0.05). Conclusions After intervertebral fusion, to maintain the same posture with the same time, the joints should bear larger loads than before. The viscoelastic deformation of adjacent segments becomes larger, which increases the risk of instability or injury, and further leads to the accelerated degeneration of adjacent segments. The mechanism of quasi-static daily loading on adjacent segment degeneration should be focused in clinical research.

OBJECTIVETo study the preventive and therapeutic effects of recombinant IFN-alpha2b for nasal spray on SARS-CoV infection in Macaca mulata (rhesus monkey).

METHODSTen rhesus monkeys were divided into two groups, 5 in interferon group, and 5 in control group. Before and after SARS-CoV attack, the virus was detected in samples such as pharyngeal swab in all the two groups by Real-time PCR (RT-PCR) and virus isolation was performed.

RESULTSAfter virus attack, the level of SARS-CoV-specific IgG and neutralizing antibody were induced by SARS-CoV in the interferon group was weaker than in control group. Hematology items showed no apparent changes after virus attack in treated group. Through pathological examination, the morphology of the lung tissues of two Macaques in the treated group was normal, while the other three displayed the interstitial pneumonia with the thickened septum and infiltration with mononuclear cells. Among which, one monkey showed part of thickened septum fused with each other. These lesions in the interferon treated animals were similar to those seen in the animals in control group, but with smaller scope of pathological changes. No significant abnormity was detected in other organs.

CONCLUSIONRecombinant IFN-alpha2b could effectively interdict or weaken SARS-CoV injury in monkeys.

Animals ; Antiviral Agents ; therapeutic use ; Cercopithecus aethiops ; Disease Models, Animal ; Female ; Interferon-alpha ; therapeutic use ; Lung ; drug effects ; pathology ; virology ; Macaca mulatta ; Male ; Monkey Diseases ; drug therapy ; prevention & control ; virology ; Random Allocation ; Recombinant Proteins ; SARS Virus ; drug effects ; isolation & purification ; Severe Acute Respiratory Syndrome ; drug therapy ; prevention & control ; virology ; Vero Cells

Objective The aim of this study is to investigate the macrolide resistance rate and molecular type withmultiple-locus variable-number tandem-repeat analysis (MLVA) of Mycoplasma pneumoniae of Beijing in 2016 in pediatric patients. Methods Real-time quantitative polymerase chain reaction (PCR) was used to identify M. pneumoniae, and MLVA was performed. The domain V of the 23S rRNA was sequenced to detect macrolide-resistant point mutations. We also investigated the activities of antibiotics against M. pneumoniae isolates in vitro. Results The PCR detection rate of M. pneumoniae in children in Beijing was 40％, and the macrolide resistance rate was 66％. The A2063G mutation in the 23S rRNA V region is the dominant mutation (137/146, 93.84％), whereas the A2064G mutation is rare (9/146, 6.16％). Seventy-three samples were typed successfully by MLVA typing, including 86.3％ (63/73) were MLVA type 4-5-7-2, and 13.7％ (10/73) were MLVA type 3-5-6-2. No other types were found. No strains were resistant to levofloxacin or tetracycline. Conclusion In 2016, a specific decrease in the macrolide resistance rate occurred in Beijing. The detection rate and macrolide resistance rate of outpatients are lower than those of inpatients. The A2063G mutants M. pneumoniae have high levels of resistance to erythromycin and azithromycin. The primary MLVA type is 4-5-7-2, followed by 3-5-6-2. No other MLVA types were detected. No strains resistant to tetracycline or levofloxacin were found in vitro.

OBJECTIVETo evaluate the efficacy and safety of capecitabine as first-line therapy in patients with advanced and recurrent colorectal cancer.

METHODSFrom December 2000 to November 2001, sixty patients with advanced and recurrent colorectal cancer received first-line capecitabine treatment given at a dose of 1250 mg/m(2) twice daily, on days 1 - 14 every 21 days. At least 2 cycles were administered.

RESULTSThe overall response rate was 23.3% with 14 PR, 24 SD (40.0%) and 15 PD. The median survival time was 14.7 months. The survival rate was 63.9% at 12-months and 33.4% at 24-months. Grade III-IV adverse effects were diarrhea in 4 patients (6.6%), anemia in 2 (3.3%) and hand-foot syndrome (HFS) in 1 (1.7%); Grade I-II adverse effects were hyperpigmentation in 20 (33.3%), HFS in 18 (30.0%) and diarrhea in 10 (16.7%).

CONCLUSIONCapecitabine is an efficacious and better-tolerated alternative treatment for the patients with advanced and recurrent colorectal cancer.

Adult ; Aged ; Antimetabolites, Antineoplastic ; therapeutic use ; Capecitabine ; Colorectal Neoplasms ; drug therapy ; mortality ; Deoxycytidine ; adverse effects ; analogs & derivatives ; therapeutic use ; Female ; Fluorouracil ; analogs & derivatives ; Humans ; Male ; Middle Aged ; Survival Rate