Modelling intravascular delivery from drug-eluting stents with biodurable coating: investigation of anisotropic vascular drug diffusivity and arterial drug distribution

In-stent restenosis occurs in coronary arteries after implantation of drug-eluting stents with non-uniform restenosis thickness distribution in the artery cross section. Knowledge of the spatio-temporal drug uptake in the arterial wall is useful for investigating restenosis growth but may often be very expensive/difficult to acquire experimentally. In this study, local delivery of a hydrophobic drug from a drug-eluting stent implanted in a coronary artery is mathematically modelled to investigate the drug release and spatio-temporal drug distribution in the arterial wall. The model integrates drug diffusion in the coating and drug diffusion with reversible binding in the arterial wall. The model is solved by the finite volume method for both high and low drug loadings relative to its solubility in the stent coating with varied isotropic–anisotropic vascular drug diffusivities. Drug release profiles in the coating are observed to depend not only on the coating drug diffusivity but also on the properties of the surrounding arterial wall. Time dependencies of the spatially averaged free- and bound-drug levels in the arterial wall on the coating and vascular drug diffusivities are discussed. Anisotropic vascular drug diffusivities result in slightly different average drug levels in the arterial wall but with very different spatial distributions. Higher circumferential vascular diffusivity results in more uniform drug loading in the upper layers and is potentially beneficial in reducing in-stent restenosis. An analytical expression is derived which can be used to determine regions in the arterial with higher free-drug concentration than bound-drug concentration.     

Advanced Age and Disease Predict Lack of Symptomatic Improvement after Endovascular Iliac Treatment in Male Veterans

Background: Endovascular angioplasty and stent placement is currently the most frequent treatment for iliac artery occlusive disease. However, despite a successful endovascular procedure, some patients do not experience symptomatic improvement and satisfaction with their care. This study seeks to identify patient-related factors associated with lack of symptomatic improvement after endovascular iliac artery treatment in male veterans.Methods: Retrospective review of patients treated with endovascular methods for iliac artery occlusive disease between January 2008 and July 2012 at VA Connecticut Healthcare System. Symptomatic improvement on the first post-operative visit was evaluated, with bilateral treatments counted separately.Results: Sixty-two patients had 91 iliac arteries treated with angioplasty and stent placement. Forty-seven (52 percent) legs had critical limb ischemia, and 77 (85 percent) had at least two-vessel distal runoff. Angiographic success was 100 percent. Patient-reported symptomatic improvement at the first post-operative visit was 55 percent (50/91). Lack of symptomatic improvement correlated with older age (OR 1.09 [1.03-1.17], p = 0.008), presence of critical limb ischemia (OR 3.03 [1.09-8.65], p = 0.034), and need for additional surgical intervention (OR 5.61 [1.65-17.36], p = 0.006). Survival, primary and secondary patency, and freedom from restenosis were comparable between patients who reported symptomatic improvement and those who did not.Conclusions: Despite angiographically successful revascularization, patients who are older or have critical limb ischemia who are treated with isolated endovascular iliac artery intervention are more likely to require additional interventions and less likely to experience symptomatic improvement. These patients may need more extensive infra-inguinal revascularization than isolated iliac angioplasty and stent placement, despite a preserved ankle-brachial index. Quality of life needs to be measured with formal instruments after iliac artery endovascular treatment, especially to determine long term outcomes.     

Mechanisms of the protective effects of BMSCs promoted by TMDR with heparinized bFGF‐incorporated stent in pig model of acute myocardial ischemia

This study investigates the mechanism by which transmyocardial drilling revascularization combined with heparinized basic fibroblast growth factor incorporated degradable stent implantation (TMDRSI) enhanced effects of bone marrow mesenchymal stem cells (BMSCs) transplantation against acute ischemic myocardial injury. After the mid‐third of left anterior descending artery was ligated, miniswine were divided into none‐treatment group (control, n = 6), BMSCs implantation group (C, n = 6), TMDRSI group (TS, n = 6) and TMDRSI and BMSCs implantation group (TSC, n = 6). Two channels of 3.5 mm diameter were established by a self‐made drill in the ischemic region, into which a stent was implanted for the TS and TSC groups. Autologous BMSCs were transplanted into the ischemic region in C group or around the channels in TSC group. Expression of von Willebrand factor, vascular endothelial growth factor, interleukin‐1β, transforming growth factor‐β₃, cell proliferation and apoptosis, histological and morphological analyses, myocardial remodelling and cardiac function were evaluated at different time‐points. Six weeks after the operation, the above indices were significantly improved in TSC group compared with others (P < 0.05), though C and TS groups also showed better results than the control group (P < 0.05). The new method was shown to have activated paracrine pathway of transplanted BMSCs, increased survival and differentiation of such cells, and enhanced effects of BMSCs transplantation on myocardial remodelling, which may provide a new strategy for cell therapies against acute ischemic myocardial injury.     

康复运动对冠脉支架植入术后患者相关因素的影响

目的：研究心脏康复运动对冠脉支架植入术后患者血脂、血糖、体重指数及生活质量的影响。方法：对实施冠脉支架植入术的146例患者进行比较分析,根据随机原则分为试验组76 例及对照组70 例。对照组患者给予常规的健康教育及冠心病二级预防指导,给予定期随访。试验组患者在此基础上给予规律的康复运动指导。经过6 个月随访,比较两组患者血脂、HbA1C、体重指数及生活质量情况。结果：试验组患者通过为期6 个月的规律的心脏康复运动指导,其血脂、HbA1C等冠心病危险因素控制情况优于对照组,差异有统计学意义(P<0.05)。同时,6个月后,试验组康复运动六月后sF 量表各项评分与对照组同期比较,差异均有统计学意义(P<0.05)。结论：规范的心脏康复运动指导能够有效改善冠脉支架植入术后患者血脂、血糖情况,提高患者生活质量。     

3D-PDUS对成人常染色体显性遗传多囊肾病肾脏血流动力学变化的研究

目的:应用三维能量多普勒超声技术探讨成人常染色体显性多囊肾病(ADPKD)患者肾脏血流灌注的改变与血压的关系。方法:选取79例ADPKD患者;对照组86例,其中包括62例原发性高血压(EH)患者以及24例血压正常的健康成年人。使用三维能量多普勒超声采集肾脏三维能量图像并应用VOCAL分析软件得出相关参数指标:血管指数(VI)、血流指数(FI)、血管血流指数(VFI)及肾脏总体积。结果:(1)与同级别血压水平的对照组比较,在ADPKD患者血压正常时VI就开始减低、肾脏总体积就开始增大(P0.05);(2)ADPKD合并高血压1级、2级、3级患者与同级别血压水平的对照组相比,其VI明显下降、肾脏总体积显著增大(P0.01),预示着ADPKD疾病的进展,ADPKD血流动力学变化与血压的变化关系密切。结论:ADPD患者血流动力学的变化比血压的变化更敏感。故早期对多囊肾患者肾脏血流动力学进行监测,对于评估病情、判定疗效、指导临床治疗具有重要意义。     

Gene therapy for rat renal anemia with implantation of erythropoietin-transgenic myoblasts

To investigate whether an erythropoietin (EPO) gene-based therapy could serve as an alternative to the repeated injection of rhEPO in treatment to renal anemia, the genetically modified myoblasts of rats, named Myo/ EPO, were implanted through intramuscular injection to model rats with renal anemia. The hemoglobin (Hb) and hematocrit (HCT) of the rats increased from (92. 5±3.0) g/L and 0.29 ±0.04 to the peak values of (103.8 ±5.0) g/L and 0. 32 ±0. 04 respectively 14 d after implantation, and sustained the pre-implantation level for 90 d. Otherwise, the control rats implanted with Myo/X, which carried the parent retroviral vector, gradually became severe in anemia. The PCR detection for hEPO cDNA in the rat muscle adjacent to injection sites indicated that the Myo/EPO cells survived for a long period in the muscle of rats. The results primarily demonstrate that myoblast gene transfer of EPO is effective for the treatment of rat renal anemia.     

Comparison of relative renal functions calculated with 99mTc-DTPA and 99mTc-DMSA for kidney patients of wide age ranges

Renal scintigraphy is an imaging method that uses small amount of radioactive materials called radiotracers, a Gamma camera and a computer to evaluate kidney functions and its anatomy. The present work reports the comparison of the relative renal functions (RRF) calculated with technetium-99m dimercaptosuccinic acid (^99mTc‑DMSA) and technetium-99m diethylenetriaminepentaacetic acid (^99mTc‑DTPA) for kidney patients of ages between 5 months and 71 years. A total of 50 patients including 29 male and 21 female has been selected and studied for renography. The mean RRFs have been found to be 52.68 ± 23.63% and 47.32 ± 23.63% respectively for the left and right kidneys with ^99mTc-DMSA measurement. With ^99mTc-DTPA the values are 52.74 ± 23.54% and 47.26 ± 23.54% for the same. In bivariate correlation analysis, a significant positive correlation (r = 0.996, P < .001) has been found between the RRFs calculated with the two methods. Following the patients’ diagnosis, in ANOVA test, no difference has been found between the RRFs calculated for the left and right kidneys. In Bland-Altman plots, the mean difference between the two methods has been found to be 0.1 and the correlation limit lies between −4.3 and 4.2. According to the result obtained in the present work, both the ^99mTc-DMSA and ^99mTc-DTPA scanning methods provide almost the same RRF values. It is, therefore, always not necessary to calculate the RRFs with both the methods. This study suggests that ^99mTc-DMSA may be the primary choice for the evaluation of RRF, but if the glomerular filtration rate (GFR) and renogram curve are required, ^99mTc-DTPA can be the obvious selection.     

终末期肾病患者行甲状旁腺切除对颈动脉钙化的影响

目的:探讨对终末期肾病患者行甲状旁腺切除对颈动脉钙化的影响.方法:选择我院2009年10月至2010年12月收治的20例继发性甲状旁腺功能亢进的终末期肾病患者,行甲状旁腺切除术,对患者术前、术后进行颈动脉彩超检查颈动脉钙化情况,并将患者术前、术后的血钙、血磷、钙磷乘积、PTH、C反应蛋白、血红蛋白、白蛋白等指标进行比较.结果:与术前比较,术后患者颈动脉钙化斑块有明显减少,血钙、血磷、钙磷乘积、PTH、C反应蛋白均明显降低,差异性有显著(P＜0.05);血红蛋白较术前明显升高(P＜0.05).结论:切除甲状旁腺(PTX)能安全有效的降低甲状旁腺素水平、改善钙磷代谢紊乱,并控制颈动脉钙化的进展.     

Coordination conjugates of therapeutic proteins with drug carriers: a new approach for versatile advanced drug delivery

We present here a general system for the coordination attachment of therapeutic proteins to a drug delivery system and its application in combined therapy. Proof of concept is demonstrated by the synthesis and testing of the targeted drug delivery system for cytostatics, which is based on a combination of the drug carrier Zn-porphyrin-cyclodextrin conjugates and their supramolecular coordination complexes with immunoglobulins. This system can be as readily used for a variety of therapeutic and targeting proteins including PAs, MAs, lectins, and HSA. Moreover, it allows combined photodynamic therapy, cell targeted chemotherapy and immunotherapy. When tested in a mouse model with human C32 carcinoma, the therapeutic superiority of the coordination assembly nanosystem was shown in comparison with the efficacy of building blocks used for the construction of the system.     

Nomograms-based prediction of overall and cancer-specific survivals for patients with chromophobe renal cell carcinoma

This study built and tested two effective nomograms for the purpose of predicting cancer-specific survival and overall survival of chromophobe renal cell carcinoma (chRCC) patients. Multivariate Cox regression analysis was employed to filter independent prognostic factors predictive of cancer-specific survival and overall survival, and the nomograms were built based on a training set incorporating 2901 chRCC patients in a retrospective study (from 2004 to 2015) downloaded from the surveillance, epidemiology, and end results (SEER) database. The nomograms were verified on a validation cohort of 1934 patients, subsequently the performances of the nomograms were examined according to the receiver operating characteristic curve, calibration curves, the concordance (C-index), and decision curve analysis. The results showed that tumor grade, AJCC and N stages, race, marital status, age, histories of chemotherapy, radiotherapy and surgery were the individual prognostic factors for overall survival, and that AJCC, N and SEER stages, histories of surgery, radiotherapy and chemotherapy, age, tumor grade were individual prognostic factors for cancer-specific survival. According to C-indexes, receiver operating characteristic curves, and decision curve analysis outcomes, the nomograms showed a higher accuracy in predicting overall survival and OSS when compared with TNM stage and SEER stage. All the calibration curves were significantly consistent between predictive and validation sets. In this study, the nomograms, which were validated to be highly accurate and applicable, were built to facilitate individualized predictions of the cancer-specific survival and overall survival to patients diagnosed with chRCC between 2004 and 2015.     

A practical test for in vitro evaluation of photosensitization: Assessment with hematoporphyrin derivative (HPD)

A simple procedure is described for the determination of the photosensitizing potency of drugs, using three leukemic cell lines, two of lymphocytic origin, L1210 and P388 and one of erythroid type, Friend-745. The procedure allows one to investigate several aspects of the photosensitization properties of tested compounds such as cellular localization and direct (trypan blue exclusion) or delayed (clonogenicity) photomediated toxicities.The method was assessed using crude hematoporphyrin derivative (HPD) as well as dihematoporphyrin ether (DHE) or commercially available Photofrin II. Results were compared to those obtained with normal cells, e.g spleen lymphocytes and erythropoietic stem cells (CFU-e), and discussed in the light of the relative response of normal versus transformed cells.Abbreviations DHE Dihematoporphyrin Ether - FCS Fetal Calf Serum - HPD Hematoporphyrin Derivative - PDT Photodynamic Therapy     

Cystatin C,a novel urinary biomarker for sensitive detection of acute kidney injury during haemorrhagic fever with renal syndrome

To explore the value of cystatin C for evaluating acute kidney injury (AKI) in haemorrhagic fever with renal syndrome (HFRS), the concentrations of cystatin C in serum and urine samples from HFRS patients were determined. The serum and urinary cystatin C concentrations significantly increased in HFRS patients compared with normal controls (p?<?0.001). In the acute phase of HFRS, urinary cystatin C increased to higher levels than serum creatinine, especially in severe or critical cases in the oliguric stage. Furthermore, higher levels of urinary cystatin C in the acute phase positively correlated with increased severity of the subsequent kidney injury. In conclusion, urinary cystatin C is a more sensitive clinical marker for AKI in HFRS, which may enable us to initiate treatment measures as early as possible.     

An immunophenotyping of renal clear cell carcinoma with characteristics and a potential therapeutic target for patients insensitive to immune checkpoint blockade

Renal clear cell carcinoma (RCC) patients who do not achieve optimal control of progression with immune checkpoint blockade (ICB) should be further studied. Unsupervised consensus clustering was used to group 525 RCC patients based on two typical ICB pathways, CTLA-4 and pogrammed death 1 (PD-1)/programmed death-ligand 1 (PD-L1), as well as two new discovered regulators, CMTM6 and CMTM4. Three immune molecular subtypes (IMMSs) with different clinical and immunological characteristics were identified (type I, II, and III), among which there were more stage I and low-grade tumors in type I RCC than in type II and III. The proportion of males was highest in type II RCC. Overall survival of type II and III was similar (5.2 and 6 years) and statistically shorter than that of type I (7.6 years) before and after adjusting for age and gender. When conducting stratified analysis, our IMMSs were able to identify high-risk patients among middle-aged patients, males, and stage IV patients. Among the differentially expressed genes, approximately 84% were highly expressed in type II and III RCC. Genes related to ICB (CTLA-4, CD274, and PDCD1LG2) and cytotoxic lymphocytes (CD8A, GZMA, and PRF1) were all highly expressed in type II and III RCC. These results documented that patients with type II and III cancer may be more sensitive to anti-CTLA-4 therapy, anti-PD-1/PD-L1 therapy, and a combination of immunotherapies. High expression of CMTM4 in type I RCC (69%) and a statistically significant interaction of CD274 and CMTM6 indicated that CMTM4/6 might be new therapy targets for type I, who are resistant to ICB.     

Construction and validation of a seven-gene signature for predicting overall survival in patients with kidney renal clear cell carcinoma via an integrated bioinformatics analysis

ABSTRACT

Kidney renal clear cell carcinoma (KIRC) remains a significant challenge worldwide because of its poor prognosis and high mortality rate, and accurate prognostic gene signatures are urgently required for individual therapy. This study aimed to construct and validate a seven-gene signature for predicting overall survival (OS) in patients with KIRC. The mRNA expression profile and clinical data of patients with KIRC were obtained from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC). Prognosis-associated genes were identified, and a prognostic gene signature was constructed. Then, the prognostic efficiency of the gene signature was assessed. The results obtained using data from the TCGA were validated using those from the ICGC and other online databases. Gene set enrichment analyses (GSEA) were performed to explore potential molecular mechanisms. A seven-gene signature (PODXL, SLC16A12, ZIC2, ATP2B3, KRT75, C20orf141, and CHGA) was constructed, and it was found to be effective in classifying KIRC patients into high- and low-risk groups, with significantly different survival based on the TCGA and ICGC validation data set. Cox regression analysis revealed that the seven-gene signature had an independent prognostic value. Then, we established a nomogram, including the seven-gene signature, which had a significant clinical net benefit. Interestingly, the seven-gene signature had a good performance in distinguishing KIRC from normal tissues. GSEA revealed that several oncological signatures and GO terms were enriched. This study developed a novel seven-gene signature and nomogram for predicting the OS of patients with KIRC, which may be helpful for clinicians in establishing individualized treatments.     

Atomic resolution structures of Escherichia coli and Bacillus anthracis malate synthase A: Comparison with isoform G and implications for structure‐based drug discovery

Enzymes of the glyoxylate shunt are important for the virulence of pathogenic organisms such as Mycobacterium tuberculosis and Candida albicans. Two isoforms have been identified for malate synthase, the second enzyme in the pathway. Isoform A, found in fungi and plants, comprises ～530 residues, whereas isoform G, found only in bacteria, is larger by ～200 residues. Crystal structures of malate synthase isoform G from Escherichia coli and Mycobacterium tuberculosis were previously determined at moderate resolution. Here we describe crystal structures of E. coli malate synthase A (MSA) in the apo form (1.04 Å resolution) and in complex with acetyl‐coenzyme A and a competitive inhibitor, possibly pyruvate or oxalate (1.40 Å resolution). In addition, a crystal structure for Bacillus anthracis MSA at 1.70 Å resolution is reported. The increase in size between isoforms A and G can be attributed primarily to an inserted α/β domain that may have regulatory function. Upon binding of inhibitor or substrate, several active site loops in MSA undergo large conformational changes. However, in the substrate bound form, the active sites of isoforms A and G from E. coli are nearly identical. Considering that inhibitors bind with very similar affinities to both isoforms, MSA is as an excellent platform for high‐resolution structural studies and drug discovery efforts.     

Snake venom: From fieldwork to the clinic: Recent insights into snake biology, together with new technology allowing high-throughput screening of venom, bring new hope for drug discovery

Snake venoms are recognized here as a grossly under-explored resource in pharmacological prospecting. Discoveries in snake systematics demonstrate that former taxonomic bias in research has led to the neglect of thousands of species of potential medical use. Recent discoveries reveal an unexpectedly vast degree of variation in venom composition among snakes, from different species down to litter mates. The molecular mechanisms underlying this diversity are only beginning to be understood. However, the enormous potential that this resource represents for pharmacological prospecting is clear. New high-throughput screening systems offer greatly increased speed and efficiency in identifying and extracting therapeutically useful molecules. At the same time a global biodiversity crisis is threatening the very snake populations on which hopes for new venom-derived medications depend. Biomedical researchers, pharmacologists, clinicians, herpetologists, and conservation biologists must combine their efforts if the full potential of snake venom-derived medications is to be realized.     

Screening for Fabry disease in patients undergoing dialysis for chronic renal failure in Turkey: Identification of new case with novel mutation

Background

Chronic renal failure (CRF) is a serious complication of Fabry disease (FD). The aims of the present study were to determine the prevalence of unrecognized FD in Turkish hemodialysis population and to investigate the molecular background.

Method

Primarily, α-galactosidase A (α-Gal A) activity was investigated on DBS in 1136 patients of both sexes who underwent dialysis for CRF in Turkey. The disease was confirmed by analyzing enzyme activity in leukocyte and GLA gene sequencing in all patients in whom α-Gal A level was 40% of normal or less.

Results

Mean age of the patients (44.5% female, 52.5% male) was 56.46 ± 15.85 years. Enzyme activity was found low with DBS method in 12 patients (four males, eight females). Two men, but no women, were diagnosed with FD by enzymatic and molecular analysis. In consequence of genetic analysis of a case, a new mutation [hemizygote c.638C>T (p.P214S) missense mutation in exon 5] was identified, which was not described in literature. Family screening of cases identified six additional cases.

Conclusion

As a result of this initial screening study performed on hemodialysis patients for the first time with DBS method in Turkey, the prevalence of FD was detected as 0.17%. Although the prevalence seems to be low, screening studies are of great importance for detecting hidden cases as well as for identifying other effected family members.     

Conformational analysis by NMR and molecular dynamics of adamantane-doxorubicin prodrugs and their assemblies with β-cyclodextrin: A focus on the design of platforms for controlled drug delivery

Nanoscale design and construction of affinity-based drug delivery systems (ADDS) is an active research area with enormous potential for the improvement of cancer treatment. For the therapeutic load of these ADDS, a promising strategy is the design of pH-sensitive prodrugs based on the construction of conjugates between adamantane and doxorubicin (Ad-Dox), which stands out as an excellent model system to obtain novel supramolecular materials. Construction of these prodrugs involves a modification of three zones of doxorubicin which in principle does not affect the action mechanism: the carbonyl group C13 (hydrazone linker), the primary alcohol neighboring the carbonyl (ester linker) and the 3′ amino group of daunosamine sugar (amide linker). These modifications are aimed to improve the efficacy and reduce the systemic toxicity of the drug chemotherapy by controlling its release in cancer cells. In this work, we performed 2D NMR experiments and molecular dynamics simulations to characterize the conformational changes of three constructed prodrugs. Our results demonstrated that ring A and the daunsamine sugar of the hydrazone and amide linkers conserve the half-chair state ⁹H₈, while the ester linker disrupts this conformation. Our study also showed that the hydrazone-linked compound (Ad-h-Dox) does not modify the conformation of the original drug and maintains cytotoxic activity. Moreover, the inclusion complex (IC) of Ad-h-Dox with β-cyclodextrin (βCD) generated a highly soluble platform in water, whereas the ester-linked compound (Ad-e-Dox) causes the loss of biological activity. This study proves that Ad-h-Dox prodrug can be an optimum prodrug and act as a building block for a more complex drug transport system.