AIM:To investigate the perfusion parameters using dynamic contrast-enhanced magnetic resonance imaging ( DCE-MRI) in rectal cancer patients so as to explore its potential value in estimating the microvascular condition including perfusion and permeability .METHODS:The data of 38 rectal cancer patients examined with DCE-MRI was ret-rospectively analyzed .The perfusion parameters of carcinoma and normal rectal wall in each case were calculated , inclu-ding volume transfer constant (Ktrans), rate constant of back flux (Kep), extravascular extracellular space fractional volume (Ve) and initial area under curve (iAUC).The mean values of tumor and normal rectal wall , mucinous and nonmucinous carcinoma, poorly and moderately-to-well differentiated carcinoma , case with or without lymph node metastasis were com-pared.RESULTS:All the parameters of rectal cancer were higher than normal rectal wall (P<0.01).No significant difference was found between poorly and moderately-to-well differentiated carcinoma in terms of K trans, Kep and Ve, neither was the case with or without lymph node metastasis .The cases with lymph node metastasis had lower iAUC than those with-out (P<0.05).CONCLUSION:Quantitative perfusion DCE-MRI answered the microvascular perfusion and permeability change of rectal cancer compared with normal rectal wall , besides it could be used to distinguish between mucinous and nonmucinous carcinoma , which demonstrated its value in the evaluation of rectal cancer .However , it should not be recom-mended to predict the degrees of tumor cell differentiation and lymph node metastasis just according to the perfusion param -eters.

Objective To explore that whether the normoxic low altitude measurement of arterial blood pressure would predict subsequent susceptibility to acute mountain sickness ( AMS) during rapid ascent to high altitude .Methods Arterial blood pressure ( using a wrist sphygmomanometer ) was determined in two hundred and four healthy lowlanders first exposed to 3700 m-altitude (Lhasa) from plain (500 m) by air, and the Lake Louise self-report questionnaire(LLS) was used to assess AMS.We compared the low altitude blood pressure related indicators of two groups ( AMS and non-AMS ) and analyzed the relationship of diagnostic score and blood pressure related indicators .Results ①The incidence of AMS in the selected subjects was 53.92% by LLS.AMS scores increased markedly at high-altitude (P<0.05 versus low altitude).②Diastolic blood pressure (DBP) and mean arterial BP (MABP) in the AMS group were higher than those in the non-AMS group(P<0.05).The low altitude DBP levels for diagnosis of AMS at high-altitude (3700 m) had an area under curve(AUC) =0.598, P<0.05, with sensitivity of 56.3%, specificity of 63.2%, and cut-off point of 72.5 mmHg. Conclusion ①After acute exposure to high altitude , the incidence of AMS increases significantly .②A higher baseline DBP may be considered a potential risk factor for AMS , and is positively associated with LLS .DBP may serve as a predic-tive parameter for diagnosis of AMS .However , the clinical application of DBP as a predictive criterion is limited because of its poor specificity or sensitivity .The use of DBP as a predictive criterion should be combined with other indicators for the better predictive value of AMS .

Objective:To analyze the role of patient support system in multidrug-resistant/rifampicin-resistant tuberculosis (MDR/RR-TB) treatment adherence and outcome, and provide evidence for deepening the patient-centered support system.Methods:Based on the stakeholder analysis, definite stakeholders (administrators from the Department of Medical Insurance, and those from the provincial CDC), expectant stakeholders (administrators from regional CDC, health workers from primary CDCs, medical workers from designated MDR/RR-TB hospitals and MDR/RR-TB patients), and latent stakeholders (MDR/RR-TB patient families and their neighbors or colleagues) were selected using a purposive sampling. These stakeholders were subject to a semi-structured interview on patient support. The inclusion of participants ceased after reaching code or thematic saturation and meaning saturation, while thematic framework analysis was applied in interview data.Results:The 25 interviewees included could be categorized into three groups of stakeholders, i. e., 4 definite stakeholders, 19 expectant stakeholders and 2 latent stakeholders. Three themes summarized in this regard were definite stakeholders providing policy support to advance these patients′ access to standardized diagnosis and treatment services; diagnosis and treatment and management support of expectant stakeholders of these patients to encourage their compliance to treatment and enable their access to high quality medical care; and support from latent stakeholders as a critical guarantee for the patients to welcome a desirable treatment outcome. Psychological support provided under MDR/RR-TB basic care program in some provinces contributed positively to raising patients′ compliance. Economic support, treatment support from family menmbers ccould help the patients to welcome desirable outcomes.Conclusions:MDR/RR-TB patient-centered support system operating in the Yangtze River delta provide the patients with MDR/RR-TB diagnostic and treatment services of some accessibility. Given the progress, there are still shortcomings for the respective stakeholders to enhance their attention and collaboration to improve the access and equity to medical service.

Staphylococcal nuclease A (SNA) may be used to produce bacterial ghosts for further inactivation of host bacteria and elimination of residual genetic materials. It is still controversial if SNA without signal peptide can be secreted to extracellular matrix and if fusion with other peptide is required for its function in the cytoplasm of host bacteria. To clarify this dispute, a series of temperature-inducible plasmids carrying SNA alone or SNA fused with partial sequences of λ phage cro gene (cSNA) or Mycobacterium tuberculosis urease gene (uSNA) were constructed and evaluated in Escherichia coli. Results show that the percentages of inactivated E. coli by SNA, cSNA and uSNA after 4 h of induction were 99.9%, 99.8% and 74.2%, respectively. Moreover, SNA and cSNA in the cytoplasm of host bacteria were initially detectable after 30 min of induction, whereas uSNA was after 1 h. In comparison, SNA and cSNA in culture supernatant were initially detectable 1 h later, whereas uSNA was 2 h later. The nuclease activity in the cytoplasm or supernatant was ranked as follows: SNA > cSNA > uSNA, and the activity in the supernatant was significantly lower than that in the cytoplasm. Furthermore, host genomic DNA was degraded by SNA or cSNA after 2 h of induction but not by uSNA even throughout the whole experiment. In conclusion, this study indicates that SNA, cSNA and uSNA expressed in host bacteria all have nuclease activity, the enzymes can be released to culture media, and fusion with exogenous peptide negatively reduces the nuclease activity of SNA.
Bacteriolysis ; Bacteriophage lambda ; DNA ; chemistry ; Escherichia coli ; Genetic Vectors ; Micrococcal Nuclease ; chemistry ; Plasmids ; Protein Sorting Signals