Some types of bacteria swim through rotating their flagella. The swimming mechanism of bacteria during flagella bundling and tumble process is analyzed. The effects of body rotation and flagellum′s polymorphic transitions on bundling processes and the wall effect phenomenon are also discussed. Finally, based on dynamics similarity, a new microrobot module is put forward to further studying the flagella swimming phenomena. The research would be very helpful for constructing the bionic swimming robots under the low Reynolds number.

Objective To investigate clinical features,treatments and prognostic factors of the patients with necrotizing fasciitis caused by vibrio infections and thus provide reference for the early treatment and prognostic assessment.Methods A retrospective analysis was conducted on clinical data of 56 patients with vibrio necrotizing fasciitis admitted to the emergency center of our hospital from May 1995 to June 2011.The clinical characteristics and treatments of the patients were summarized,and differences of clinical factors between the survival group and death group were compared.The possible influencing factors for prognosis were also analyzed.Results The main clinical manifestations included fever (61％),shock (84％) and organ dysfunction,of which renal insufficiency (88％) was the most common,with case fatality of 43％.Early pathological changes of limbs were only local swelling and pain,while skin ecchymosis,tension blood blisters,necrosis and subcutaneous crepitation were the signs of advanced stage.Comprehensive treatment regime including early administration of sensitive antibiotics plus surgical incision and drainage and medicine support was given.A series of factors were significantly different between the survival and death groups including the duration from the presentation of symptoms to hospital admission (P ＜ 0.05 ),limb lesions involving the trunk (P ＜ 0.01 ),creatine kinase level (P ＜ 0.05 ),and emergency incision and drainage ( P ＜ 0.01 ).Conclusions The most prominent clinical manifestations of vibrio necrotizing fasciitis are rapidly progressive local symptoms and signs,and sharp deterioration of systemic conditions.Delayed visiting,severe local lesions,and failure to emergency surgery may be the factors for poor prognosis.

Objective To modify the methods of operation and establishment of cerebral ischemia rat models made by thread occlusion. Method We randomly divided 120 male SD rats into a common group (n = 50), an improvement group (n = 60) and a sham-operated group (n - 10). Rats in the common and improvement groups were made into models using the common and improvement methods separately. All models were evaluated on the basis of physical sign indices and 2,3,5-triphenyltetrazolium chloride (TTC) staining. The TTC staining results were taken as gold standards. Then, we compared the achievement ratios of the two groups, and computed the sensitivity and specificity of every physical sign index based on these standards. The χ~2 or correction χ~2 test was used to compare the ratios. Results (1) The achievement ratio in the improvement group was significantly higher than that in the common group (71.67% vs. 52.00%, P = 0.034). (2) The sensitivity of evaluation for both common and improvement methods was 98.55%. However, the specificity of evaluation for the improvement method was significantly higher than that for the common method (100.00% vs. 40.00%, P =0.000). Conclusions The establishment achievement ratio and evaluation correctness of models are obviously elevated by modification of the operation and establishment methods.

This review presents the state of the art of pH-responsive polymeric micelles for cancer drug delivery. Solid tumors have a weakly acidic extracellular pH (pH < 7), and cancer cells have even more acidic pH in endosomes and lysosomes (pH 4-6). The pH-gradients in tumor can be explored for tumor targeting and drug release in cancer drug delivery by applying pH-responsive polymeric micelles. The pH-responsive polymeric micelles consist of a corona and a core, and are made of amphiphilic copolymers, in which there are pH-responsive polymeric blocks. Two types of pH-responsive polymers-protonizable polymers and acid-labile polymers have been mainly used to make pH-responsive micelles for drug delivery. The protonizable polymers are polybases or polyacids, and their water-soluble/insoluble or charge states undergo changes with the protonation or deprotonation stimulated by external acidity, while the acid-labile polymers change their physical properties by chemical reaction stimulated by the acidity. Polymeric micelles whose core or coronas respond to the tumor extracellular acidity can be explored for triggering the fast release of the carried drug, activating the targeting group and accelerating the endocytosis of drug-loaded polymeric micelles, and those whose core or coronas respond to the tumor lysosomal acidity can be used for facilitating their escape from the lysosomes and targeting the nucleus. Various in vivo and in vitro experiments demonstrated that pH-responsive polymeric micelles are effective for cellular targeting, internalization, fast drug release and nuclear localization, and hence enhancing the therapeutic efficacy and reducing the side effect of cancer chemical therapy.
Antineoplastic Agents ; administration & dosage ; therapeutic use ; Drug Delivery Systems ; Humans ; Hydrogen-Ion Concentration ; Micelles ; Nanoparticles ; Neoplasms ; drug therapy ; Polymers ; chemistry

OBJECTIVETo explore relations between ALT level and hepatitis B virus (HBV) specific CTL and non-specific CTL in patients with chronic hepatitis B (CHB).

METHODS148 cases of CHB were divided into three groups according to ALT level. 35 cases in group A, ALT > or =2 x upper limit of normal value (ULN)--5 x ULN (100-250 IU/L); 53 cases in group B, ALT > 5 x ULN-- < or =10 x ULN (251-500 IU/L); 60 cases in group C, ALT > 10 x ULN ( > 500 IU/L). Flow cytometry is used to determine non-specific CTV. HBV specific CTL was tested on 74 cases of CHB (17 in group A, 27 in group B and 30 in group C) with positive (HLA)-A2. Compare HBV specific CTL, non-specific CTL, HBV DNA levels and positive rate of HBeAg.

RESULTSHBV specific CTL: Group A (0.42 +/- 0.10)% is higher than group B (0.25 +/- 0.08)%, t = 6.37, P < 0.01, group B is higher than group C (0.17 +/- 0.004)%, t = 5.14, P < 0.01; Non-specific CTL: Group A (15.01 +/- 3.01)% is lower than group B (18.1 +/- 5.02)%, t = 2.81, P < 0.01, group B is lower than group C (21.5 +/- 6.11)%, t = 3.07, P < 0.01; HBV DNA level: Group A [(4.97 +/- 0.86) log10 copies/ml] is lower than group B [(5.92 +/- 0.92) log10 copies/ml], t = 4.87, P < 0.01. Group B is lower than group C [(6.37 +/- 0.71) log10 copies/ml], t = 2.92, P < 0.01; Positive HBeAg: Group A (15 cases, 42.86%) is lower than group B (32 cases, 60.38%), chi2 = 2.59, P > 0.05. Group B is lower than group C (41 cases, 68.33%), chi2 = 0.78, P > 0.05. Group A is lower than group C, chi2 = 5.929, P < 0.05.

CONCLUSIONThe higher the non-specific CTL of patients with CHB is, the higher the ALT level would be, whereas the lower the HBV specific CTL is, the stronger the HBV replication would be.

Adult ; Alanine Transaminase ; metabolism ; Female ; Hepatitis B virus ; genetics ; immunology ; physiology ; Hepatitis B, Chronic ; enzymology ; immunology ; virology ; Humans ; Lymphocyte Count ; Male ; T-Lymphocytes, Cytotoxic ; immunology ; Virus Replication ; Young Adult

OBJECTIVETo study the role of O(6)-methylguanine-DNA methyltransferase (hMGMT) in the development of human lung cancer.

METHODSReverse transcription-polymerase chain reaction (RT-PCR) method was applied to measure hMGMT mRNA expression in 150 lung cancer specimens, 40 normal lung tissues, and in the peripheral mononuclear blood cells from 50 lung cancer cases and 50 normal controls. The protein expressions of p53, C-MYC and K-RAS were assessed by immuno-histochemistry. The effects of some exposure factors on the expression of hMGMT gene were analyzed. The relationships between hMGMT gene and cancer related genes p53, C-MYC and K-RAS were investigated.

RESULTSThe mRNA of hMGMT was low or absent in 49 of 150 (32.7%) lung cancer specimens, whereas 2 of 40 (5%) normal lung tissues had reduced the levels of hMGMT mRNA. The low expression of hMGMT seemed to be a risk factor of lung cancer, with a OR of 9.22 (2.05-57.65). Reduced expression levels of hMGMT mRNA were observed in 10 of 50 (20%) lung cancer patients' peripheral mononuclear blood cells, and 2 of 50 (4%) blood cells among normal controls. When investigating the exposure factors which affecting the expression of hMGMT gene, we noticed that smoking was suppressing the expression of hMGMT gene. Interestingly, over-expression of K-RAS oncogene was significantly correlated with low expression of hMGMT (P < 0.05). However, the expressions of p53 and C-myc were not correlated with the status of hMGMT gene.

CONCLUSIONhMGMT might play an important role in the development of human lung cancer. Low expression of hMGMT gene seemed to be a risk factor for lung cancer which could be used as a valuable biomarker on susceptibility of human lung cancers.

Adult ; Aged ; Biomarkers, Tumor ; Carcinoma, Squamous Cell ; enzymology ; genetics ; China ; epidemiology ; DNA Repair ; genetics ; Female ; Genes, ras ; genetics ; Humans ; Lung Neoplasms ; enzymology ; genetics ; Male ; Middle Aged ; O(6)-Methylguanine-DNA Methyltransferase ; biosynthesis ; genetics ; metabolism ; Point Mutation ; RNA, Messenger ; biosynthesis ; genetics ; Smoking ; adverse effects ; ras Proteins ; biosynthesis ; genetics

Acquired Immunodeficiency Syndrome ; drug therapy ; epidemiology ; Anti-HIV Agents ; therapeutic use ; Antiretroviral Therapy, Highly Active ; China ; epidemiology ; Drug Resistance, Viral ; Humans

OBJECTIVETo study the clinicopathologic features and biologic behavior of renal cell carcinoma (RCC) with rhabdoid features.

METHODSTen cases of RCC with rhabdoid features collected during the period from 1995 to 2005 were enrolled into the study. The clinical findings were analyzed and the hematoxylin and eosin-stained sections were reviewed. Immunohistochemistry and electron microscopy were also performed.

RESULTSThe age of patients ranged from 33 to 69 years (mean age = 52 years). Nine of the patients were males and 1 female. Five patients showed evidence of perinephric invasion. Two patients presented with regional lymph node metastases and 1 patient showed distant metastasis to the lung. Histologically, the rhabdoid foci were characterized by loosely cohesive trabeculae, acini, lobules and clusters of rhabdoid cells in otherwise clear cell RCC (9 cases) or papillary RCC (1 case). The rhabdoid cells were round to polygonal in shape and contained globular eosinophilic inclusion bodies in the cytoplasm, eccentric nuclei, vesicular chromatin pattern and prominent nucleoli. Coagulative tumor necrosis was commonly seen. Immunohistochemical study showed that the rhabdoid cells were diffusely positive for CD10 (10/10), cytokeratin AE1/AE3 (10/10), epithelial membrane antigen (10/10) and vimentin (10/10). Focal staining for neuron-specific enolase and S-100 protein was also noted. They were negative for CK7, CK20 and myogenic markers (including myogenin, smooth muscle actin and muscle-specific actin). The mean Ki-67 labeling index of the rhabdoid component was higher than that of the non-rhabdoid component (P < 0.05). Follow-up information was available in 8 patients. While 6 patients are still alive without recurrence, 2 patients died of the disease 6 and 29 months respectively after the operation.

CONCLUSIONSRCC with rhabdoid elements are mainly observed in clear cell RCC and need to be distinguished from oncocytic renal tumors and malignant rhabdoid tumor of kidney. The higher proliferative activity in the rhabdoid areas may indicate more aggressive biologic behavior.

Adult ; Aged ; Carcinoma, Renal Cell ; metabolism ; pathology ; surgery ; Carcinoma, Transitional Cell ; metabolism ; pathology ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Humans ; Immunohistochemistry ; Keratins ; metabolism ; Kidney Neoplasms ; metabolism ; pathology ; surgery ; Lymphatic Metastasis ; Male ; Middle Aged ; Mucin-1 ; metabolism ; Nephrectomy ; Neprilysin ; metabolism ; Rhabdoid Tumor ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

OBJECTIVEThe expanded programme on immunization (EPI) is an important part of the social commonwealth projects providing health care service by the government, which benefits communities. Government has the responsibility for EPI's financing which should be covered by the national budget. It is essential that the cost of EPI service be scientifically estimated to provide propriety information for policy makers.

METHODSThis study, using the cost accounting theory of health economics, to calculate EPI service cost at different levels. 3 provinces, 3 prefectures, 9 counties, 18 towns and 12 villages were selected from three provinces Guizhou, Heilongjiang and Zhejiang from the western, central and eastern regions of the country.

RESULTSThe average costs for one EPI-targeted child in Guizhou, Heilongjiang and Zhejiang, were 15.68 Yuan, 29.00 Yuan and 31.09 Yuan, and the costs for one dose were 10.99 Yuan, 18.64 Yuan and 16.51 Yuan, respectively. The costs for complete immunization program for one child were 131.88 Yuan, 242.32 Yuan and 280.67 Yuan, respectively. The main factors affecting the cost would include the average personnel cost (salary and benefit cost) by different economic levels of areas, the number of EPI items developed, and the number of total doses for one child.

CONCLUSION(1) Obvious differences were found between different areas. (2) The proportion of the cost was not reasonably set because of the shortage of input. (3) Guideline for different areas to compensate the working item cost according to the number of the items should be formulated.

China ; epidemiology ; Cost-Benefit Analysis ; Health Expenditures ; statistics & numerical data ; Humans ; Immunization Programs ; economics ; organization & administration ; Population Surveillance ; methods ; Program Evaluation ; Socioeconomic Factors ; Vaccination ; statistics & numerical data

OBJECTIVETo observe the suppression of the expression of androgen receptor (AR) gene in PC3 cells after AR-specific siRNAs transfection, and to search for the siRNA (s) with the greatest suppressing efficiency.

METHODSFive AR-specific siRNAs were selected, RNAi expression vectors were constructed and transfected into PC3 cells, and the AR expression was detected by real time FQ-PCR and Western blot. A nonsense small RNA was set as negative control.

RESULTSCompared with the control group, the AR expression decreased in various degrees in the 5 experimental groups (P < 0.05), and siRNA1, siRNA4 and siRNA5 showed the greatest suppressing efficiency as compared with the other experimental groups, with statistically significant difference (P < 0.05).

CONCLUSIONThe AR-specific siRNAs could suppress the endogenous expression of target gene. Three siRNAs with great suppressing efficiency were identified and the expression vectors were constructed successfully. It can be applied in the future researches in vivo.

Blotting, Western ; Cell Line, Tumor ; Genetic Vectors ; genetics ; Humans ; Male ; Prostatic Neoplasms ; genetics ; metabolism ; pathology ; RNA Interference ; RNA, Small Interfering ; genetics ; Receptors, Androgen ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Transfection