Prognostic value of the baseline magnetic resonance score in patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy

AIM

To investigate the prognostic value of the composite posterior circulation Acute Stroke Prognosis Early Computed tomography (CT) Score (ASPECTS)-Collaterals (pcASCO) score, which combines diffusion-weighted imaging (DWI) posterior circulation ASPECTS (pcASPECTS) and the magnetic resonance angiography (MRA)-collateral circulation score at baseline among patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy.

MATERIALS AND METHODS

Patients with acute posterior circulation ischaemic stroke who underwent mechanical thrombectomy were analysed retrospectively. The DWI-pcASPECTS and MRA-collateral circulation score before treatment and the modified Rankin Scale (mRS) at 90 days after treatment were used as the endpoints. An mRS ≤2 was defined as a good prognosis, and an mRS ≥3 was defined as a poor prognosis. Multivariate logistic regression was used to analyse independent predictors of functional outcome 90 days after mechanical thrombectomy.

RESULTS

Mechanical thrombectomy was performed in 57 patients; 38 patients had a good prognosis, 19 patients had a poor prognosis, and 33 patients were successfully recanalised. Univariate logistic regression found that National Institute of Health Stroke Scale (NIHSS) score (OR: 1.18, p<0.001), pcASPECTS (OR: 1.91, p=0.028) and pcASCO score (OR: 0.51, p=0.001) were factors of good functional outcome. Receiver operating characteristic curve (ROC curve) analysis showed that the diagnostic efficiency of the NIHSS and pcASCO was better (AUC = 0.88, 0.83, p<0.05) than that of the pcASPECTS (AUC = 0.65). The prediction model was established by age, NIHSS, and pcASCO, and the diagnostic efficiency of the prediction model was better (AUC = 0.94).

CONCLUSIONS

The composite MR-pcASCO score can be used as an important predictor of the prognosis of patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy.

Auto interpretable depth learning model to analyze the hemodynamic changes and pulmonary complications in laparoscopic gynecologic tumor surgery with nalmefene hydrochloride combined with general anesthesia

OBJECTIVE

In this work, based on intelligent computing, the biological signals of patients were analyzed to investigate the hemodynamic changes and pulmonary complications of Nalmefene Hcl combined with general anesthesia (GA) in laparoscopic gynecological tumor surgery (GTS).

PATIENTS AND METHODS

Eighty computer-aided GTS patients were randomly divided into a control group (n = 40) and an observation group (n = 40). Biomedical electrocardiogram (ECG) signals were detected by wavelet neural network in all patients undergoing laparoscopic gynecological tumor surgery and were computerized according to the android interface definition language model (AIDL). GA was used during surgery. The observation group was injected intravenously with 0.2 μg/kg naproxenacin hydrochloride after operation. The control group was given 1 mL 0.9% sodium chloride solution after operation. Mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), pulse oxygen saturation (SPO), coma score, and adverse reactions (AR) were compared between the two groups at 10, 20, and 30 minutes after wakefulness. The hemodynamic parameters between the two groups were compared. Serum urocholine (URO) and creatinine (Cre) levels were analyzed in patients without complications.

RESULTS

ECG waveform based on wavelet neural network has a high recognition rate and strong generalization ability. 37 patients in the observation group recovered within 10 minutes after surgery, and the recovery rate at 30 minutes was 95%. 30 patients in the control group awoke 10 minutes after the operation, and the recovery rate at 30 minutes m-AR was 75%. The average abstract windows toolkit (AWT) of the observation group and control group was 11.87 ± 5.78 min and 16.46 ± 5.32 min, respectively, and the difference was significant (p < 0.05). There were significant differences in HR, systolic blood pressure (SBP), and diastolic blood pressure (DBP) between the observation group and the control group during the extubation (p < 0.05). Blood gas indexes PaO2, PvO2, PaCO2, and PvCO2 in the observation group were significantly different from those in the control group half an hour after the operation and half an hour after pneumoperitoneum (p > 0.05).

CONCLUSIONS

Intelligent computational biological signal detection was beneficial to the development of surgery. Nalmefene Hcl combined with GA on the basis of the AIDL model has a significant effect on the awakening of GTS patients and can shorten sleep time. Patients with underlying cardiac disease were more likely to develop postoperative lung complications.

[Investigate of the etiology and prevention status of liver cirrhosis]

Objective: To investigate the etiology, prevention and treatment status, and their corresponding regional differences of the patients with liver cirrhosis in China, in order to provide scientific basis for the development of diagnosis and control strategies in China. Methods: Clinical data of patients diagnosed with liver cirrhosis for the first time through January 1, 2018 to December 31, 2020 from 50 hospitals in seven different regions of China were collected and analyzed retrospectively, and the difference of etiology, treatment, and their differences in various regions were analyzed. Results: A total of 11 861 cases with liver cirrhosis were included in the study. Thereinto, 5 093 cases (42.94%) were diagnosed as compensated cirrhosis, and 6 768 cases (57.06%) had decompensated cirrhosis. Notably, 8 439 cases (71.15%) were determined as chronic hepatitis B-caused cirrhosis, 1 337 cases (11.27%) were alcoholic liver disease, 963 cases (8.12%) were chronic hepatitis C, 698 cases (5.88%) were autoimmune liver disease, 367 cases (3.09%) were schistosomiasis, 177 cases (1.49%) were nonalcoholic fatty liver, and 743 cases (6.26%) of other types of liver disease. There were significant differences in the incidence of chronic hepatitis B, chronic hepatitis C, alcoholic liver disease, fatty liver, schistosomiasis liver disease, and autoimmune liver disease among the seven regions (P<0.001). Only 1 139 cases (9.60%) underwent endoscopic therapy, thereinto, 718 cases (6.05%) underwent surgical therapy, and 456 cases (3.84%) underwent interventional therapy treatment. In patients with compensated liver cirrhosis, 60 cases (0.51%) underwent non-selective β receptor blockers(NSBB), including 59 cases (0.50%) underwent propranolol and 1 case (0.01%) underwent carvedilol treatment. In patients with decompensated liver cirrhosis, 310 cases (2.61%) underwent NSBB treatment, including 303 cases (2.55%) underwent propranolol treatment and 7 cases (0.06%) underwent carvedilol treatment. Interestingly, there were significant differences in receiving endoscopic therapy, interventional therapy, NSBB therapy, splenectomy and other surgical treatments among the seven regions (P<0.001). Conclusion: Currently, chronic hepatitis B is the main cause (71.15%) of liver cirrhosis in several regions of China, and alcoholic liver disease has become the second cause (11.27%) of liver cirrhosis in China. The three-level prevention and control of cirrhosis in China should be further strengthened.

Three Novel Structural Variations at MHC and IL12B Predisposing to Psoriasis

BACKGROUND

Structural variations (SVs, defined as DNA variants ≥50 bp) have been associated with various complex human diseases. However, research to screen the whole genome for SVs predisposing to psoriasis is still lacking.

OBJECTIVES

This study aimed to investigate the association of SVs and psoriasis.

METHODS

We performed a genome-wide screen on SVs using an imputation method on 5 independent cohorts with 45,386 subjects from the Chinese Han population. Fine mapping analysis, genetic interaction analysis and RNA expression analysis were conducted to explore the mechanism of SVs.

RESULTS

We obtained 4,535 SVs in total and identified 2 novel deletions (esv3608550, OR=2.73, P<2.00×10^-308 ; esv3608542, OR=0.47, P=7.40×10^-28 ) at 6q21.33 (MHC), 1 novel Alu element insertion (esv3607339, OR=1.22, P=1.18×10^-35 ) at 5q33.3 (IL12B), and confirmed 1 previously reported deletion (esv3587563, OR=1.30, P=9.52×10^-60 ) at 1q21.2 (LCE) for psoriasis. Fine mapping analysis including SNPs and small Insertions/Deletions (InDels) revealed that esv3608550 and esv3608542 were independently associated with psoriasis, and a novel independent SNP (rs9378188, OR=1.65, P=3.46×10^-38 ) was identified at 6q21.33. By genetic interaction analysis and RNA expression analysis, we speculate that the association of 2 deletions at 6q21.33 with psoriasis might relate to their influence on the expression of HLA-C.

CONCLUSIONS

Our study constructed the most comprehensive SV map for psoriasis thus far and enriched the genetic architecture and pathogenesis of psoriasis as well as highlighted the nonnegligible impact of SVs on complex diseases.

Antitumor effects of apoptin expressed by the dual cancer-specific oncolytic adenovirus - a review

Apoptin is a small molecular weight protein derived from chicken anemia virus, which can induce the apoptosis of transformed cells and tumor cells and leave primary and nontransformed cells unharmed. Apoptin's cell localization depends on its own phosphorylation state and cell type. In tumor cells, phosphorylated apoptin enters the nucleus and induces apoptosis. While, in normal cells apoptin mainly exists in the cytoplasm. Apoptin, as a disordered protein in cells, interacts with many proteins in cell signal pathways to induce apoptosis of tumor cells. The specific mechanism of apoptosis induced by apoptin has not been completely elucidated. Therefore, apoptin has become a potential anticancer agent. This review summarizes the research results of apoptin in our laboratory and reveals the specific antitumor mechanism of apoptin expressed by oncolytic virus vector on a variety of tumor cells and mouse models.

Botrytis polygoni, a new species of the genus Botrytis infecting Polygonaceae in Gansu, China

A new species, Botrytis polygoni, was isolated from several species of Polygonaceae in 2011 and 2012 in Tongwei County, Gansu Province, China. The species infects Fagopyrum esculentum, F. tataricum, and Fallopia convolvulus, causing brown leaf spots and large blotches with concentric rings in the field. Botrytis polygoni is morphologically characterized by conidia spherical, unicellular, hyaline to pale brown or brown, (10.2-)14.3-21.4(-23.5) μm; and sclerotia black, spherical to subspherical, allantoid, or irregular-shaped, 0.2-4.1 × 0.1-3.0 mm. Comparison of the nuc rDNA internal transcribed spacer region (ITS1-5.8S-ITS2) sequences confirmed its placement in the genus Botrytis. Phylogenetic analysis based on the protein-coding genes glyceraldehyde 3-phosphate dehydrogenase (G3PDH), heat shock protein 60 (HSP60), and DNA-dependent RNA polymerase subunit II (RPB2) showed that the new species is clustered close but separate from Botrytis pyriformis, which was distant from 37 other Botrytis species and 17 undescribed species. Pathogenicity tests showed that the new species has aggressive pathogenicity to four species of Polygonaceae, specifically Fag. tataricum, Fal. convolvulus, Polygonum sibiricum, and Pol. aviculare, weak pathogenicity to Vicia faba in the Fabaceae, and no pathogenicity to eight other tested plants: Amaranthus retroflexus, Cirsium arvense, Convolvulus arvensis, Kalanchoe blossfeldiana, Lagopsis supine, Mentha canadensis, Plantago asiatica, and Raphanus sativus.

[Effect of omeprazole on plasma concentration and adverse reactions of capecitabine in patients with colon cancer]

Objective: To investigate the effect of omeprazole on plasma concentration, efficacy and adverse reactions of capecitabine in patients with colon cancer. Methods: Seventy-two patients with colon cancer treated with capecitabine were analysed retrospective. The patients treated with capecitabine combined with omeprazole were identified as experimental group and the capecitabine treatment alone as control group.The differences of blood concentration and the side effects of capecitabine between these two groups were compared. Results: The plasma concentration of 5-Fluorouracilum in experimental group was (126.25±50.59) μg/ml, without significant difference of (123.09±56.70) μg/ml in control group (P=0.121). The incidence of Ⅲ to Ⅳ degree bone marrow suppression, nausea, vomiting, diarrhea and hand-foot syndrome in experimental group were 13.8%, 0%, 0% and 19.4%, respectively. In control group, the incidence of Ⅲ to Ⅳ degree bone marrow suppression, nausea, vomiting, diarrhea and the hand-foot syndrome were 11.1%, 0%, 0% and 19.4%, respectively, without significant difference of experimental group (P>0.05). The incidence of acid reflux and heartburn in the control group was 72.2%, significantly higher than 44.4% of the experimental group (P<0.05). The objective response rate (ORR) and progression-free survival time (PFS) in these two groups were 30.6% and 33.3%, and 8.0 month and 8.5 month, respectively, without significant difference (P>0.05). Conclusion: The intravenous omeprazole attenuates reflux and heartburn of colon cancer patients treated with capecitabine, without affecting its plasma concentration and side effects and has no impact on the PFS of these patients.

[Influence of Toll-like receptor 7 on CD8(+) T lymphocytes in patients with breast cancer]

Objective: To investigate the effect of Toll-like receptor 7 (TLR7) in CD8(+) T cells activity from patients with breast cancer. Methods: Thirty-three patients with breast cancer, twenty-three patients with benign breast tumor, and twenty healthy individuals were collected from The First Affiliated Hospital of Xinxiang Medical University between December 2017 and March 2018. Peripheral blood mononuclear cells (PBMCs) were isolated, and CD8(+) T cells were purified. TLR7 protein and mRNA relative expression in CD8(+) T cells was measured using flow cytometry and real-time PCR, respectively. mRNA relative expressions corresponding to perforin, granzyme B, and FasL in CD8(+) T cells were measured in response to TLR7 agonist stimulation. Direct/indirect contact co-culture system of CD8(+) T cells and breast cancer cell line MCF-7 was also used to assess cytolytic and noncytolytic function in response to TLR7 agonist CL097 stimulation. Results: The mean fluorescence intensity corresponding to TLR7 protein in CD8(+) T cells from breast cancer patients was 124.0±15.32, which was significantly down-regulated in comparison with benign breast tumor patients (255.5±54.91) and healthy individuals (261.9±68.65) (P<0.000 1). TLR7 mRNA relative level was also remarkably reduced in CD8(+) T cells from breast cancer patients (1.97±1.18) in comparison with benign breast tumor patients (4.84±1.01) and healthy individuals (4.75±1.40) (P<0.000 1). TLR7 agonist CL097 stimulation notably increased mRNA relative levels of perforin and granzyme B mRNA in CD8(+) T cells (P<0.01), but not elevated FasL mRNA (P>0.05).Furthermore, TLR7 agonist CL097 stimulation enhanced the cytolytic and noncytolytic function of CD8(+) T cells to MCF-7 cells, which presented as the elevation of target cell death and increase of interferon-γ production in direct and indirect contact co-culture system. Conclusion: TLR7 agonist promoted CD8(+) T cells function from breast cancer patients.

Systemic disruption of the homeostasis of transfer RNA isopentenyltransferase causes growth and development abnormalities in Bombyx mori

Isopentenylation at A37 (i⁶ A37) of some transfer RNAs (tRNAs) plays a vital role in regulating the efficiency and fidelity of protein synthesis. However, whether insects, which are well known for their highly efficient protein synthesis machinery, employ this regulatory mechanism remains uninvestigated. In the current study, a candidate tRNA isopentenyltransferase (IPT) gene with three alternative splicing isoforms (BmIPT1-BmIPT3) was identified in Bombyx mori (silkworm). Only BmIPT1 could complement a yeast mutant lacking tRNA IPT. Phylogenetic analysis showed that silkworm tRNA IPT is conserved in the Lepidoptera. BmIPT was expressed in all B. mori tissues and organs that were investigated, but was expressed at a significantly higher level in silk glands of the fourth instar compared to the first day of the fifth instar. Interestingly, BmIPT was expressed at a significantly higher level in the domesticated silkworm, B. mori, than in wild Bombyx mandarina in multiple tissues and organs. Knock-down of BmIPT by RNA interference caused severe abnormalities in silk spinning and metamorphosis. Constitutive overexpression of BmIPT1 using a cytoplasmic actin 4 promoter in B. mori raised its messenger RNA level more than sixfold compared with nontransgenic insects and led to significant decreases in the body weight and cocoon shell ratio. Together, these results confirm the first functional tRNA IPT in insects and show that a suitable expression level of tRNA IPT is vital for silk spinning, normal growth, and metamorphosis. Thus, i⁶ A modification at position A37 in tRNA probably plays an important role in B. mori protein synthesis.

[Application of pegylated recombinant human granulocyte colony-stimulating factor to prevent chemotherapy-induced neutropenia in patients with lymphoma: a prospective, multicenter, open-label clinical trial]

目的

评价聚乙二醇化重组人粒细胞刺激因子（PEG-rhG-CSF）预防淋巴瘤患者化疗后发生中性粒细胞减少症的有效性和安全性。

方法

本研究为多中心、开放、单臂、Ⅳ期临床试验。纳入410例淋巴瘤患者接受多周期化疗并预防性使用PEG-rhG-CSF。主要观察患者各化疗周期Ⅲ/Ⅳ度中性粒细胞减少症和发热性中性粒细胞减少（FN）的发生率，同时观察患者整个化疗期间抗生素的使用率。

结果

①410例患者中，违背入选标准8例（1.95%），失访35例（8.54%），发生不良事件19例（4.63%），出现符合终止研究标准者12例（2.93%），疾病进展或复发15例（3.66%），故最终321例（78.29%）进入符合方案集。②在第1~4个治疗周期，初级预防给予PEG-rhG-CSF后，Ⅳ度中性粒细胞减少症的发生率分别为19.14%（49/256）、12.50%（32/256）、12.18%（24/197）、13.61%（20/147），FN的发生率分别为3.52%（9/256）、0.39%（1/256）、2.54%（5/197）、2.04%（3/147）；次级预防给药后，Ⅳ度中性粒细胞减少症的发生率从61.54%（40/65）降至16.92%（11/65）、18.46%（12/65）、20.75%（11/53），FN的发生率从16.92%（11/65）降至1.54%（1/65）、4.62%（3/65）、3.77%（2/53）。③整个化疗期间接受抗生素治疗的受试者比例为34.39%（141/410）。④与PEG-rhG-CSF相关的不良事件发生率为4.63%（19/410），最常见的不良反应为骨痛[3.90%（16/410）]、乏力（0.49%）和发热（0.24%）。

结论

在淋巴瘤患者化疗过程中，预防性使用PEG-rhG-CSF能够有效降低化疗过程中Ⅲ/Ⅳ度中性粒细胞减少症和FN的发生率，确保淋巴瘤患者接受标准剂量化疗，提高治愈率。

[Effect of anesthesia on cardiopulmonary complications in elderly patients with hip fracture]

Objective: To compare the effects of different types of anesthesia on postoperative cardiopulmonary complications in patients aged 80 years and above who received unilateral hip fracture surgery. Methods: The perioperative data of patients aged 80 and above who underwent unilateral hip fracture surgery in Peking Union Medical College Hospital from July 2009 to June 2014 were collected and grouped based on the types of anesthesia including general anesthesia, neuraxial anesthesia, and peripheral nerve block. Variables were analyzed including preoperative general conditions (age, sex, type of fracture, ASA physical status classification, preoperative cardiopulmonary complications), intraoperative conditions (type of surgical procedure, operative time, blood loss, total intraoperative fluid infusion), and postoperative conditions (length of hospital stay, postoperative hospital stay, ICU stay, postoperative newly developed cardiopulmonary complications, postoperative in-hospital death, hospitalization costs). The incidences of postoperative cardiopulmonary complications of each group were analyzed and compared. Results: A total of 219 cases were finally analyzed including general anesthesia (n=46), neuraxial anesthesia (n=90) and nerve block group (n=83). Fewer cases with preoperative pulmonary complications were noticed in general anesthesia group (15 cases, 32.6%) than in neuraxial anesthesia group (45 cases, 50%) and nerve block group (47 cases, 56.6%) (χ(2)=6.912, P=0.032). No statistical differences were found between groups regarding preoperative cardiovascular complications and other variables. There were no significant differences in postoperative cardiopulmonary complications. However, the cost of hospitalization was lower in neuraxial anesthesia group (45.6±21.4) thousand RMB and nerve block group (48.2±25.8) thousand RMB compared with general anesthesia group (56.3±21.6) thousand RMB, the difference was statistically significant(F=9.951, P=0.007). Conclusions: For elderly patients undergoing unilateral hip surgery, the type of anesthesia does not affect the incidence of postoperative cardiopulmonary complications. However, neuraxial anesthesia and nerve block may reduce the cost of hospitalization.

Nine Novel PAX9 Mutations and a Distinct Tooth Agenesis Genotype-Phenotype

Tooth agenesis is one of the most common developmental anomalies affecting function and esthetics. The paired-domain transcription factor, Pax9, is critical for patterning and morphogenesis of tooth and taste buds. Mutations of PAX9 have been identified in patients with tooth agenesis. Despite significant progress in the genetics of tooth agenesis, many gaps in knowledge exist in refining the genotype-phenotype correlation between PAX9 and tooth agenesis. In the present study, we complete genetic and phenotypic characterization of multiplex Chinese families with nonsyndromic (NS) tooth agenesis. Direct sequencing of polymerase chain reaction products revealed 9 novel (c.140G>C, c.167T>A, c.332G>C, c.194C>A, c.271A>T, c.146delC, c.185_189dup, c.256_262dup, and c.592delG) and 2 known heterozygous mutations in the PAX9 gene among 120 probands. Subsequently, pedigrees were extended, and we confirmed that the mutations co-segregated with the tooth agenesis phenotype (with exception of families in which DNA analysis was not available). In 1 family ( n = 6), 2 individuals harbored both the PAX9 c.592delG mutation and a heterozygous missense mutation (c.739C>T) in the MSX1 gene. Clinical characterization of families segregating a PAX9 mutation reveal that all affected individuals were missing the mandibular second molar and their maxillary central incisors are most susceptible to microdontia. A significant reduction of bitter taste perception was documented in individuals harboring PAX9 mutations ( n = 3). Functional studies revealed that PAX9 haploinsufficiency or a loss of function of the PAX9 protein underlies tooth agenesis.

Effect of epigallocatechin-3-gallate on acrylamide-induced oxidative stress and apoptosis in PC12 cells

Acrylamide (ACR) is a chemical intermediate utilized in industry. ACR is also formed during heating of foods containing carbohydrates and amino acids. Therefore, humans are widely exposed to ACR, and ACR neurotoxicity in humans is a significant public health issue attracting wide attention. In this study, we investigated the potential neuroprotective effects of epigallocatechin-3-gallate (EGCG), the most abundant polyphenolic compound in green tea, in PC12 cells treated with ACR. ACR-treated PC12 cells pretreated with various concentrations of EGCG (2.5, 5 and 10 μM) for 24 h had increased viability and acetylcholinesterase activity and reduced apoptosis and necrosis compared to cells exposed to ACR alone. EGCG reduced the expression of bax mRNA, decreased cytochrome c release, reduced intracellular calcium levels, inactivated caspase 3 and increased mitochondrial membrane potential, suggesting that EGCG prevents ACR-induced apoptosis through a mitochondrial-mediated pathway. In addition, EGCG inhibited the formation of reactive oxygen species and lipid peroxidation while enhancing superoxide dismutase activity and glutathione levels, thereby reducing oxidative stress. Our results indicate that pretreatment of PC12 cells with EGCG attenuates ACR-induced apoptosis by reducing oxidative stress. Therefore, drinking green tea may reduce nerve injury induced by ACR.

Deep Profiling of Proteome and Phosphoproteome by Isobaric Labeling, Extensive Liquid Chromatography, and Mass Spectrometry

Mass spectrometry-based proteomics has experienced an unprecedented advance in comprehensive analysis of proteins and posttranslational modifications, with particular technical progress in liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and isobaric labeling multiplexing capacity. Here, we introduce a deep proteomics profiling protocol that combines 10-plex tandem mass tag (TMT) labeling with an optimized LC-MS/MS platform to quantitate whole proteome and phosphoproteome. The major steps include protein extraction and digestion, TMT labeling, two-dimensional liquid chromatography, TiO₂-mediated phosphopeptide enrichment, high-resolution mass spectrometry, and computational data processing. This protocol routinely leads to confident quantification of more than 10,000 proteins and approximately 30,000 phosphosites in mammalian samples. Quality control steps are implemented for troubleshooting and evaluating experimental variation. Such a multiplexed robust method provides a powerful tool for dissecting proteomic signatures at the systems level in a variety of complex samples, ranging from cell culture, animal tissues to human clinical specimens.

Prognostic significance of preoperative absolute peripheral monocyte count in esophageal squamous cell carcinoma

The objective of this study was to investigate the prognostic value of peripheral blood monocytes in esophageal squamous cell carcinoma (ESCC) patients who underwent esophagectomy. Records from 218 consecutive patients with histologically diagnosed ESCC who underwent esophagectomy at Qilu Hospital of Shandong University from January 2007 to December 2008 were retrospectively reviewed. The median disease-free survival (DFS) of this cohort was 29.0 months, and the 5-year DFS rate was 34.4%. The median overall survival (OS) was 35.0 months, and the 5-year OS rate was 37.6%. The cut-off value of 0.42 × 10⁹ /L for the absolute monocyte count (AMC) was chosen as optimal to discriminate between survival and death by applying receiver operating curve analysis. There were 131 patients (60.1%) who had high AMC (≥0.42 × 10⁹ /L) preoperatively. We found that AMC was significantly associated with gender, tumor location, and platelet count. Kaplan-Meier survival analysis of patients with high preoperative AMC had a significant worse prognosis for DFS (high vs. low: 27.5% vs. 39.0%, P = 0.015) and OS (high vs. low: 31.1% vs. 44.8%, P = 0.009) than those with low preoperative AMC. In a multivariate analysis, preoperative AMC was an independent prognostic factor for DFS (P = 0.025, hazard ratio [HR]: 1.469, 95% confidence interval [CI]: 1.050-2.054) and OS (P = 0.015, HR: 1.547, 95% CI: 1.088-2.200). In addition, among 140 patients without both preoperative and postoperative therapy, significantly worse OS (P = 0.012) and marginally reduced DFS (P = 0.079) were found in the high AMC cohort versus the low AMC cohort. A higher preoperative absolute peripheral monocyte count can be considered as a useful prognostic marker of ESCC patients who underwent esophagectomy.

Effect of embolic microspheres in the treatment of primary hepatic carcinoma

The purpose of this study was to evaluate the clinical effect of embolic microspheres in the treatment of primary hepatic carcinoma. Fifty-eight patients who were confirmed with primary hepatic carcinoma by imaging were retrospectively analyzed. They were firstly perfused with 50 mg of oxaliplatin and 40 mg of epirubicin. Embolic microspheres were then injected into the distal end of targeted blood vessels. After this procedure, dynamic observation was carried out until tumor stain disappeared. Liver function and blood indexes were reexamined on days 5, 6, 7 and 28 after treatment, and moreover, the liver was examined with Magnetic Resonance Imaging (MRI) or computed tomography (CT). Compared to traditional lipiodol embolization, embolic microspheres did not aggregate the damage on liver function and the imaging examination suggested necrosis of some tumor tissues. Embolic microspheres proved to be effective in treating primary hepatic carcinoma. It produces no damage on liver function and can lead to significant shrinkage of hepatic carcinoma and necrosis of some tumor tissues. Embolic microspheres, which merely block distal branches of tumor-feeding artery, can avoid collateral circulation induced by permanent blocking, thus achieve a good treatment effect.

A New Pulse Pileup Rejection Method Based on Position Shift Identification

Pulse pileup events degrade the signal-to-noise ratio (SNR) of nuclear medicine data. When such events occur in multiplexed detectors, they cause spatial misposition, energy spectrum distortion and degraded timing resolution, which leads to image artifacts. Pulse pileup is pronounced in PETbox4, a bench top PET scanner dedicated to high sensitivity and high resolution imaging of mice. In that system, the combination of high absolute sensitivity, long scintillator decay time (BGO) and highly multiplexed electronics lead to a significant fraction of pulse pileup, reached at lower total activity than for comparable instruments. In this manuscript, a new pulse pileup rejection method named position shift rejection (PSR) is introduced. The performance of PSR is compared with a conventional leading edge rejection (LER) method and with no pileup rejection implemented (NoPR). A comprehensive digital pulse library was developed for objective evaluation and optimization of the PSR and LER, in which pulse waveforms were directly recorded from real measurements exactly representing the signals to be processed. Physical measurements including singles event acquisition, peak system sensitivity and NEMA NU-4 image quality phantom were also performed in the PETbox4 system to validate and compare the different pulse pile-up rejection methods. The evaluation of both physical measurements and model pulse trains demonstrated that the new PSR performs more accurate pileup event identification and avoids erroneous rejection of valid events. For the PETbox4 system, this improvement leads to a significant recovery of sensitivity at low count rates, amounting to about 1/4th of the expected true coincidence events, compared to the LER method. Furthermore, with the implementation of PSR, optimal image quality can be achieved near the peak noise equivalent count rate (NECR).

Novel β-carbolines against colorectal cancer cell growth via inhibition of Wnt/β-catenin signaling

Wnt signaling pathway is aberrantly activated in a variety of cancers, especially in colorectal cancer (CRC), because of mutations in the genes encoding adenomatous polyposis coli (APC), β-catenin and Axin. Small-molecule antagonists of Wnt/β-catenin signaling are attractive candidates for developing effective therapeutics for CRC. In this study, we have identified a novel Wnt signaling inhibitor, isopropyl 9-ethyl-1- (naphthalen-1-yl)-9H-pyrido[3,4-b]indole-3- carboxylate (Z86). Z86 inhibited Wnt reporter activities and the expression of endogenous Wnt signaling target genes in mammalian cells and antagonized the second axis formation of Xenopus embryos induced by Wnt8. We showed that Z86 treatment inhibits GSK3β (Ser9) phosphorylation, leading to its overactivation and promoting the phosphorylation and degradation of β-catenin. In vitro, Z86 selectively inhibited the growth of CRC cells with constitutive Wnt signaling and caused obvious G1-phase arrest of the cell cycle. Notably, in a nude mouse model, Z86 inhibited dramatically the xenografted tumor growth of CRC. Daily intraperitoneal injection of Z86 at 5 mg/kg resulted in >70% reduction in the tumor weight of HCT116 cell origin that was associated with decreased GSK3β (Ser9) phosphorylation and increased β-catenin phosphorylation. Taken together, our findings provide a novel promising chemotype for CRC therapeutics development targeting the canonical Wnt signaling.

Adaptive striping watershed segmentation method for processing microscopic images of overlapping irregular-shaped and multicentre particles

Oversegmentation is a major drawback of the morphological watershed algorithm. Here, we study and reveal that the oversegmentation is not only because of the irregular shapes of the particle images, which people are familiar with, but also because of some particles, such as ellipses, with more than one centre. A new parameter, the striping level, is introduced and the criterion for striping parameter is built to help find the right markers prior to segmentation. An adaptive striping watershed algorithm is established by applying a procedure, called the marker searching algorithm, to find the markers, which can effectively suppress the oversegmentation. The effectiveness of the proposed method is validated by analysing some typical particle images including the images of gold nanorod ensembles.

4q27 as a psoriasis susceptibility locus in the Northeastern Chinese Han population

Psoriasis is an autoimmune inflammatory skin disease with genetic components. Chromosome 4q27 is related to many autoimmune diseases, however, the relationship between psoriasis and 4q27 has not been fully established yet. The objective of this study is to investigate the association between chromosome 4q27 and psoriasis in the Northeastern Chinese Han population. Four common single nucleotide polymorphisms (rs2069762, rs4833837, rs6840978, and rs7684187) from chromosome 4q27 were genotyped in 400 psoriasis cases and 398 controls from the Northeastern Chinese Han population using the Multiplex SNaPSHOT method. Single nucleotide polymorphism and haplotype frequencies were analyzed using spss 13.0. Our data indicated that rs2069762 GG, TG genotypes [GG: odds ratio (OR) = 2.6875, 95% confidence interval (CI) = 1.5948-4.5290, P < 0.0001; TG: OR = 1.6159, 95% CI = 1.2044-2.1681, P = 0.0013], and H3 haplotype (OR = 1.717, 95% CI = 1.050-2.808, P = 0.030) increased the risk of psoriasis. Furthermore, rs4833837 GG, GA genotypes (GG: OR = 0.2071, 95% CI = 0.0685-0.6266, P = 0.0022; GA: OR = 0.4711, 95% CI = 0.3289-0.6746, P < 0.0001), and H5 haplotype (OR = 0.482, 95% CI = 0.238-0.978, P = 0.039) were identified as protective factors for psoriasis. 4q27 polymorphisms are associated with psoriasis in the Northeastern Chinese Han population.

Effective Resistance to Wheat Stripe Rust in a Region with High Disease Pressure

Stripe rust is a major fungal disease of wheat. It frequently becomes epidemic in southeastern Gansu province, a stripe rust hot spot in China. Evaluations of wheat germplasm response are crucial for developing cultivars to control the disease. In total, 57 wheat cultivars and lines from Europe and other countries, comprising 36 cultivars with documented stripe rust resistance genes and 21 with unknown genes, were tested annually with multiple races of Puccinia striiformis f. sp. tritici in the field at Tianshui in Gansu province from 1993 to 2013. Seven wheat lines were highly resistant, with infection type (IT) 0 during the entire period; 16 were moderately resistant (IT 0;-2); and 26 were moderately susceptible (IT 0;-4), with low maximum disease severity compared with the susceptible control Huixianhong. 'Strampelli' and 'Libellula', with three and five quantitative trait loci, respectively, for stripe rust resistance have displayed durable resistance in this region for four decades. Ten cultivars, including 'Lantian 15', 'Lantian 26', and 'Lantian 31', with stripe rust resistance derived from European lines, were developed in our breeding program and have made a significant impact on controlling stripe rust in southeastern Gansu. Breeding resistant cultivars with multiple adult-plant resistance genes seems to be a promising strategy in wheat breeding for managing stripe rust in this region and other hot spots.

Optimization of the Energy Window for PETbox4, a Preclinical PET Tomograph With a Small Inner Diameter

Small animal positron emission tomography (PET) systems are often designed by employing close geometry configurations. Due to the different characteristics caused by geometrical factors, these tomographs require data acquisition protocols that differ from those optimized for conventional large diameter ring systems. In this work we optimized the energy window for data acquisitions with PETbox4, a 50 mm detector separation (box-like geometry) pre-clinical PET scanner, using the Geant4 Application for Tomographic Emission (GATE). The fractions of different types of events were estimated using a voxelized phantom including a mouse as well as its supporting chamber, mimicking a realistic mouse imaging environment. Separate code was developed to extract additional information about the gamma interactions for more accurate event type classification. Three types of detector backscatter events were identified in addition to the trues, phantom scatters and randoms. The energy window was optimized based on the noise equivalent count rate (NECR) and scatter fraction (SF) with lower-level discriminators (LLD) corresponding to energies from 150 keV to 450 keV. The results were validated based on the calculated image uniformity, spillover ratio (SOR) and recovery coefficient (RC) from physical measurements using the National Electrical Manufacturers Association (NEMA) NU-4 image quality phantom. These results indicate that when PETbox4 is operated with a more narrow energy window (350-650 keV), detector backscatter rejection is unnecessary. For the NEMA NU-4 image quality phantom, the SOR for the water chamber decreases by about 45% from 15.1% to 8.3%, and the SOR for the air chamber decreases by 31% from 12.0% to 8.3% at the LLDs of 150 and 350 keV, without obvious change in uniformity, further supporting the simulation based optimization. The optimization described in this work is not limited to PETbox4, but also applicable or helpful to other small inner diameter geometry scanners.

MicroRNA-191 correlates with poor prognosis of colorectal carcinoma and plays multiple roles by targeting tissue inhibitor of metalloprotease 3

MicroRNA-191 (miR-191) is reported to be overexpressed in colorectal carcinoma (CRC), but the role of miR-191 in CRC progress remained unclear. This study demonstrated that High miR-191 expression was associated with clinical stage, lymph node metastasis, liver metastasis and depth of tumor invasion. Kaplan-Meier analysis indicated that patients with high miR-191 expression had a poor overall survival. Moreover, multivariate analysis showed that miR-191 was an independent prognostic factor in patients with CRC. Furthermore, we found that tissue inhibitor of metalloprotease 3 (TIMP3) was a direct target of miR-191 in colorectal cancer SW620 cells. TIMP3 downregulation mediated by miR-191 activated matrix metalloproteinases (MMPs) and thus promoted invasiveness of cancer cells. Anti-miR-191 could attenuate the invasiveness, suppress proliferation and induce apoptosis by restoring TIMP3 expression. Our results suggested that miR-191 might be a potential diagnostic and therapeutic target in patients with colorectal cancer.

Mice immunogenicity after vaccination by DNA vaccines containing individual genes of a new type of reovirus

In this study, we investigated humoral and cellular immune responses in mice to DNA vaccines containing individual S or M genes of a new type of reovirus (nRV) isolate from a severe acute respiratory syndrome (SARS) patient in Beijing, China. Mice were immunized intramuscularly (i.m.) with 100 μg of S1, S2, S3, S4, M1, M2, and M3 DNA vaccine each 4 times in 2-week intervals and assayed for humoral IgG, IgG1, IgG2, and IgG2b antibodies by ELISA and for cellular immune response, particularly IFN-γ induction by ELISpot assay. Moreover, CD4+ and CD8+ T cell levels in peripheral blood mononuclear cells were assayed by flow cytometry. We found that all DNA vaccines induced IgG antibodies, predominantly of the IgG2a class and S3 DNA vaccine was the strongest inducer. M2 and S3 DNA vaccines elicited Th1- and Th2-based immune responses, respectively, while S1 and M3 DNA vaccines induced a mixed Th1/Th2 response. M1, S2, and S4 DNA vaccines were poorly immunogenic. To our knowledge, this is the first report characterizing mammalian reovirus DNA vaccines applied to a mouse model.

Efficacy and tolerability of toremifene and tamoxifen therapy in premenopausal patients with operable breast cancer: a retrospective analysis

BACKGROUND

Given the use of tamoxifen as standard treatment for hormone receptor-positive breast cancer, the use of toremifene as an adjuvant endocrine therapy has not been widely examined. The present retrospective study compared the efficacy and safety of toremifene and tamoxifen in the treatment of operable hormone receptor-positive breast cancer in premenopausal women.

METHODS

Premenopausal patients with hormone receptor- positive operable breast cancer were eligible. Enrolled patients (n = 1847) received either 60 mg toremifene (n = 396) or 20 mg tamoxifen (n = 1451) daily for a minimum of 5 years after surgery. Disease-free survival (dfs) was the primary endpoint. Overall survival (os) and time to distant recurrence were secondary endpoints.

RESULTS

Treatment with toremifene and tamoxifen resulted in no between-group differences in dfs (p = 0.659) or os (p = 0.364). Mean dfs was 10.3 years for both groups. Mean os was 11.2 years for the toremifene group and 11.1 years for tamoxifen group. The 5-year dfs rate was 87.0% in the toremifene group and 85.0% in the tamoxifen group. The 5-year survival rate was 94.3% in the toremifene group and 93.5% in the tamoxifen group. Adverse events rates were similar in the two groups, with the exception of irregular menses, which occurred at a higher rate in the tamoxifen group than in the toremifene group (10.0% vs. 6.3%, p = 0.025).

CONCLUSIONS

In this retrospective study, the efficacy and safety profiles of toremifene and tamoxifen for the treatment of operable hormone receptor-positive breast cancer in premenopausal women were similar.

NEMA NU-4 performance evaluation of PETbox4, a high sensitivity dedicated PET preclinical tomograph

PETbox4 is a new, fully tomographic bench top PET scanner dedicated to high sensitivity and high resolution imaging of mice. This manuscript characterizes the performance of the prototype system using the National Electrical Manufacturers Association NU 4-2008 standards, including studies of sensitivity, spatial resolution, energy resolution, scatter fraction, count-rate performance and image quality. The PETbox4 performance is also compared with the performance of PETbox, a previous generation limited angle tomography system. PETbox4 consists of four opposing flat-panel type detectors arranged in a box-like geometry. Each panel is made by a 24 × 50 pixelated array of 1.82 × 1.82 × 7 mm bismuth germanate scintillation crystals with a crystal pitch of 1.90 mm. Each of these scintillation arrays is coupled to two Hamamatsu H8500 photomultiplier tubes via a glass light guide. Volumetric images for a 45 × 45 × 95 mm field of view (FOV) are reconstructed with a maximum likelihood expectation maximization algorithm incorporating a system model based on a parameterized detector response. With an energy window of 150-650 keV, the peak absolute sensitivity is approximately 18% at the center of FOV. The measured crystal energy resolution ranges from 13.5% to 48.3% full width at half maximum (FWHM), with a mean of 18.0%. The intrinsic detector spatial resolution is 1.5 mm FWHM in both transverse and axial directions. The reconstructed image spatial resolution for different locations in the FOV ranges from 1.32 to 1.93 mm, with an average of 1.46 mm. The peak noise equivalent count rate for the mouse-sized phantom is 35 kcps for a total activity of 1.5 MBq (40 µCi) and the scatter fraction is 28%. The standard deviation in the uniform region of the image quality phantom is 5.7%. The recovery coefficients range from 0.10 to 0.93. In comparison to the first generation two panel PETbox system, PETbox4 achieves substantial improvements on sensitivity and spatial resolution. The overall performance demonstrates that the PETbox4 scanner is suitable for producing high quality images for molecular imaging based biomedical research.

Expression of interleukin-18 in a rat model of deep vein thrombosis

AIM

Interleukin-18 (IL-18) is an important proinflammatory cytokine. However, little is known about the roles of IL-18 in the process of venous thrombosis. This study aimed to investigate the roles of IL-18 during deep vein thrombosis (DVT).

METHODS

Fifty rats were randomly divided into 0 (control group), 12, 24, 36 and 48 h groups (10 rats in each group) by observation time. The inferior vena cava (IVC) was ligated to establish the DVT model. Serum samples were extracted to determine the levels of IL-18, tumor necrosis factor-alpha (TNF-α), thromboxane B2 (TXB2) and 6-keto-prostaglandin Fl alpha (6-keto-PG Flα) by enzyme-linked immunosorbent assay (ELISA). The weight and length of IVC was also measured.

RESULTS

The DVT model was successfully established by ligating IVC. The injury of vein endothelium was observed in the model groups. IL-18, TNF-α, TXB2, TXB2/6-keto-PG Flα levels and thrombus weight were significantly increased in the model groups as compared with the control group, and peaked at 24 h after IVC ligation. 6-keto-PG F1α slightly decreased in the model groups comparing with the control group. IL-18 was positively correlated with TNF-α, TXB2, TXB2/6-keto-PG Flα ratio and thrombus weight. However, IL-18 was negatively correlated with 6-keto-PG Flα. There was a positive correlation between TXB2/6-keto-PG Flα ratio and thrombus weight.

CONCLUSION

Serum IL-18 level increased in the process of DVT, which might impair venous endothelial cells and result in venous thrombosis. IL-18 might be a new potential therapeutic target of DVT prevention.

Proteasome inhibitors induce nucleolar aggregation of proteasome target proteins and polyadenylated RNA by altering ubiquitin availability

The ubiquitin-proteasome pathway is essential for most cellular processes, including protein quality control, cell cycle, transcription, signaling, protein transport, DNA repair and stress responses. Hampered proteasome activity leads to the accumulation of polyubiquitylated proteins, endoplastic reticulum (ER) stress and even cell death. The ability of chemical proteasome inhibitors (PIs) to induce apoptosis is utilized in cancer therapy. During PI treatment, misfolded proteins accrue to cytoplasmic aggresomes. The formation of aggresome-like structures in the nucleus has remained obscure. We identify here a nucleolus-associated RNA-protein aggregate (NoA) formed by the inhibition of proteasome activity in mammalian cells. The aggregate forms within the nucleolus and is dependent on nucleolar integrity, yet is a separate structure, lacking nucleolar marker proteins, ribosomal RNA (rRNA) and rRNA synthesis activity. The NoAs contain polyadenylated RNA, conjugated ubiquitin and numerous nucleoplasmic proteasome target proteins. Several of these are key factors in oncogenesis, including transcription factors p53 and retinoblastoma protein (Rb), several cell cycle-regulating cyclins and cyclin-dependent kinases (CDKs), and stress response kinases ataxia-telangiectasia mutated (ATM) and Chk1. The aggregate formation depends on ubiquitin availability, as shown by modulating the levels of ubiquitin and deubiquitinases. Furthermore, inhibition of chromosome region maintenance 1 protein homolog (CRM1) export pathway aggravates the formation of NoAs. Taken together, we identify here a novel nuclear stress body, which forms upon proteasome inactivity within the nucleolus and is detectable in mammalian cell lines and in human tissue. These findings show that the nucleolus controls protein and RNA surveillance and export by the ubiquitin pathway in a previously unidentified manner, and provide mechanistic insight into the cellular effects of PIs.

Effect of surface plasmon resonance on the optical activity of chiral metal nanogratings

We examine the mechanism responsible for the optical activity of a two-dimensional array of gold nanostructures with no mirror symmetry on a dielectric substrate. Measurements with different incident angles, polarizations and sample orientations allow us to reveal that observed polarization effect is enhanced by surface plasmon resonance. By performing numerical simulation with rigorous diffraction theory we also show that the grating chirality can be described in terms of the non-coplanarity of the electric field vectors at the front (air-metal) and back (substrate-metal) sides of the grating layer.

Identification of differentially transcribed genes in human lymphoblastoid cells irradiated with 0.5 Gy of gamma-ray and the involvement of low dose radiation inducible CHD6 gene in cell proliferation and radiosensitivity

PURPOSE

To identify candidate genes specifically involved in response to low-dose irradiation in human lymphoblastoid cells; to better clarify the role of the human chromodomain helicase DNA binding protein 6 gene (CHD6), one of these genes, in cell proliferation and radiosensitivity.

MATERIALS AND METHODS

DNA microarray technology was used to analyse global transcriptional profile in human lymphoblastoid AHH-1 cells at 4 h after exposure to 0.5 Gy of gamma-ray. Gene expression changes were confirmed by semi-quantitative reverse transcription--polymerase chain reaction (RT-PCR) and Northern blot. RNA interfering technology was employed to knock-down the CHD6 gene in A549 cells. Colony-forming ability was used to analyse radiosensitivity.

RESULTS

The microarray assay revealed a set of 0.5 Gy-responsive genes, including 30 up-regulated genes and 45 down-regulated genes. The up-regulated genes include a number of genes involved in: signal transduction pathways, e.g., STAT3, CAMKK2, SIRT1, CREM, MAPK3K7IP2 and GPR56; transcription or DNA-binding, e.g., CHD6, CRSP3, SNURF, SH2 domain binding protein 1 and MIZF. Some of the down-regulated genes are involved in: cytoskeleton and cell movement (WASF2, LCP1, MSN, NIPSNAP1, KIF2C); DNA replication and repair (MCM2, MCM3, MCM7 and XRCC-4). Radiation-increased expression of CHD6 was also found in A549 cells and HeLa cells. The sustained CHD6 induction was restricted to relatively low doses (0.2 Gy or 0.5 Gy), no change occurring after 4 Gy irradiation. Silencing of CHD6 mediated by siRNA increased the growth rate of A549 cells by 40 approximately 60%. Most importantly, silencing CHD6 led to an increased radioresistance of A459 cells to radiation doses up to 2 Gy, but barely affected the sensitivity of cells at 4 and 8 Gy.

CONCLUSION

This study has identified a set of genes responsive to 0.5 Gy of gamma-rays. CDH6 gene can be specifically up-regulated by low dose irradiation, and its inducible expression could be involved in a low dose hypersensitive response.

Using Associated Polymer Gels to Control Conformance for High Temperature and High Salinity Reservoirs

Abstract

Most reservoirs in the Zhongyuan oilfield are characterized by high temperature, high salinity, and serious heterogeneity. Extensive waterflooding in the reservoir has magnified the effect of these heterogeniuties. To improve the poor conformance, a new kind of gel was developed using a water-soluble hydrophobically associating polymer (AP). Effect of the concentration of AP, crosslinker, and additives on gelation time and gel strength were studied. Thermo-stability of the gel was evaluated and results show that the gel can still retain 75 &#x98; 85% of its original strength under conditions of 95 °C and salinity of 150,000 mg/l after six months. Core flooding results have illustrated that the plugging efficiency of the gel is more than 90% for selected applications. Twenty-six wells were treated using the new AP gel in the Zhongyuan oilfield in 2003. The response of treated wells and connected producers is reviewed. The average injected gel volume was 1,100 m3 each well. These treatments have resulted in approximately 6,000 m3 (5,300 tons) of incremental oil. Selection criteria for the optimum type of wells to be treated and injection procedures are summarized from the 26 applications.

Introduction

Gel treatment has been proved to be a cost effective method to control conformance for mature water/CO2 floods reservoirs (1–4).Traditionally, partially hydrolyzed polyacrymide (HPAM) is used to synthesize these crosslinked polymer gels. However, the traditional polymer molecular structure of these polymers tends to degrade under high salinity or hardness conditions in the injected brine, resulting in a sharp drop in viscosity of the polymer solution(5–6). Also, high molecular weight polymer tends to be irreversibly degraded by high shear rates, such as those encountered in pumps in the near wellbore region. Therefore, the application of traditional polymers of this type in high temperature and high salinity reservoirs is limited.

Associating polymer (AP) is a new type of water-soluble polymer in which a small number of special hydrophobic molecular groups are directly attached to the polymer chain(5–10). In aqueous solution, the hydrophobic groups of these polymers can associate to minimize their exposure to the external fluid, resulting in a star type of large spatial network structures, as shown in Figure 1. The association results in an increase of the hydrodynamic size of polymer that increases solution viscosity. This polymer solution can have a high viscosity at a relatively low molecular weight and low concentration. This associated structure is reversible. The fluids tend to be thixotropici in nature (viscosity is reduced by increased shear rates).

Most reservoirs in the Zhongyuan oilfield have high salinity and temperature and serious heterogeneity(11). The harsh reservoir conditions limit the application of traditional polymer HPAM. Therefore, AP associated polymer gel was synthesized and evaluated to control conformance in the Zhongyuan oilfield.

Experiment Results

Synthesis of the AP Gel

AP Concentration Effect

Synthesized Mazai formation water was used to prepare the polymer solution and the gel was formed at 95 °C. After three days' aging, the gel viscosity was measured at a shear rate of 12 rpm.

Analysis of factors influencing the blood levels and activities of tissue-type plasminogen activator (t-PA)

This study aimed to correlate plasmatic tissue-type plasminogen activator (t-PA) levels and activity with parameters of artery blood flow and vessel walls, nail fold microcirculation, hemorheology, serum glucose, and lipids. Thirty healthy volunteers (female/male 12/18) aged 40-60 (average 46) were included in the study. In citrate venous blood, the following parameters were determined: carotid mean velocity, carotid intimal-medial-thickness (IMT), capillary circulation parameters, hemorheology index, serum glucose, and lipids. Analysis of data showed that t-PA concentration was positively and significantly correlated with total cholesterol, triglycerides, and serum glucose (P<0.05, P<0.05, and P<0.01), but t-PA activity showed no correlation with them; among the hemorheology factors investigated, t-PA concentration showed the strongest positive correlation with both whole blood viscosity and reduced blood viscosity at high and low shear rate separately (P<0.01), t-PA activity showed no correlation with any hemorheology factors; t-PA concentration showed no correlation with any investigated nail fold capillary parameters, whereas t-PA activity was significantly and negatively associated with capillary loop number (P<0.05); t-PA concentration and activity was not associated with values of carotid maximum intimal-medial-thickness (mIMT) and mean velocity or systolic, diastolic blood pressure (P>0.05). But subjects with mIMT 1.0 mm showed higher t-PA levels compared with those with mIMT < 1.0 mm (P<0.05) and decreased carotid mean velocity (P<0.01). These findings suggest that multiple vascular disease risk factors would influence the t-PA level; t-PA concentration does not parallelize with t-PA activity.

Model-based normalization for iterative 3D PET image reconstruction

We describe a method for normalization in 3D PET for use with maximum a posteriori (MAP) or other iterative model-based image reconstruction methods. This approach is an extension of previous factored normalization methods in which we include separate factors for detector sensitivity, geometric response, block effects and deadtime. Since our MAP reconstruction approach already models some of the geometric factors in the forward projection, the normalization factors must be modified to account only for effects not already included in the model. We describe a maximum likelihood approach to joint estimation of the count-rate independent normalization factors, which we apply to data from a uniform cylindrical source. We then compute block-wise and block-profile deadtime correction factors using singles and coincidence data, respectively, from a multiframe cylindrical source. We have applied this method for reconstruction of data from the Concorde microPET P4 scanner. Quantitative evaluation of this method using well-counter measurements of activity in a multicompartment phantom compares favourably with normalization based directly on cylindrical source measurements.

Augmentation of anterior vertebral body screw fixation by an injectable, biodegradable calcium phosphate bone substitute

STUDY DESIGN

A biomechanical study to evaluate the effects of a biodegradable calcium phosphate (Ca-P) bone substitute on the fixation strength and bending rigidity of vertebral body screws.

OBJECTIVES

To determine if an injectable, biodegradable Ca-P bone substitute provides significant augmentation of anterior vertebral screw fixation in the osteoporotic spine.

SUMMARY OF BACKGROUND DATA

Polymethylmethacrylate (PMMA) augmented screws have been used clinically; however, there is concern about thermal damage to the neural elements during polymerization of the PMMA as well as its negative effects on bone remodeling. Injectable, biodegradable Ca-P bone substitutes have shown enhanced fixation of pedicle screws.

METHODS

Sixteen fresh cadaveric thoracolumbar vertebrae were randomly divided into two groups: control (no augmentation) (n = 8) and Ca-P bone substitute augmentation (n = 8) groups. Bone-screw fixation rigidity in bending was determined initially and after 10(5) cycles, followed by pullout testing of the screw to failure to determine pullout strength and stiffness.

RESULTS

The bone-screw bending rigidity for the Ca-P bone substitute group was significantly greater than the control group, initially (58%) and after cyclic loading (125%). The pullout strength for Ca-P bone substitute group (1848 +/- 166 N) was significantly greater than the control group (665 +/- 92 N) (P < 0.01). Stiffness in pullout for the Ca-P bone substitute groups (399 +/- 69 N/mm) was significantly higher than the control group (210 +/- 51 N/mm) (P < 0.01).

CONCLUSION

This study demonstrated that augmentation of anterior vertebral body screw fixation with a biodegradable Ca-P bone substitute is a potential alternative to the use of PMMA cement.

[Studies on insulin-like growth factor I receptor in fetal rats with intrauterine growth retardation]

OBJECTIVE

This study was conducted to detect the localization of the insulin-like growth factor I receptor (IGF-I R) in the cells and tissues in the rats with intrauterine growth retardation (IUGR) and normal growth rats.

METHODS

21 pregnant rats were randomly divided into the experimental group (IUGR) (n = 12) and the control group (n = 9). Animal models for IUGR were established by clamping the uterine vasculature of pregnant rats for 20 minutes on day 14 of gestation. The control group rats were subjected to Sham-operation. On day 22 of gestation, fetal rats were delivered by cesarean section. Immunohistochemical assay was performed to detect the IGF-I R expression on liver and lung using specific polyclonal antibodies to rat IGF-I R.

RESULTS

In the experimental group, the IUGR rats' body weight, height, and the weight of their liver, lung and the placenta were significantly lower than those in the control group. In the IUGR rats' liver, the area ratio of IGF-I R was increased and the average gray level was decreased, compared with those in the control group. In the IUGR rats' lung, the area ratio of IGF-I R was increased, compared with that in the control group, but no difference of average gray level was observed between the two groups.

CONCLUSION

The increased expression of IGF-I R in rats with IUGR, may be due to the decrease of IGF-I and the compensative mechanism of the body.

The effect of stem modularity and mode of fixation on tibial component stability in revision total knee arthroplasty

The effect of stem length, diameter, and mode of fixation on the motion and stress transfer of a cemented tibial tray were evaluated for in 12 cadaver knees. There was a significant decrease in motion of the tibial tray with increasing press-fit stem length (75-150 mm) and increasing stem diameter (10-14 mm). Cemented tibial stems showed significantly less tray motion than uncemented stems. The short cemented stems produced tray stability equivalent to long press-fit stems. Although there was a trend for increased proximal tibial stress shielding with the use of cement and longer, wider stems, the trend was not statistically significant. Modular, press-fit stems can achieve tray stability similar to a smaller cemented stem and can avoid the potential problems with cement.

[The relationships of the serum concentrations of insulin-like growth factors in fetal rats with intrauterine growth retardation]

OBJECTIVE

To observe the alterations of serum insulin-like growth factor-I,-II (IGF-I, IGF-II) in rat fetus and to investigate the relationship of serum IGFs with intrauterine growth retardation (IUGR).

METHODS

21 pregnant SD rats were randomly divided into control group (n = 9) and experimental group (IUGR group, n = 12). On day 14 of gestation, the bilateral uterine arteries and veins of experimental group were clamped for 20 minutes to build the rat IUGR models and sham surgeries were performed on control group. Fetal serum concentrations of IGFs, birth weight, the length and weight of fetal liver, lung, brain and placenta of all rats in the two groups were measured and compared.

RESULTS

The serum concentrations of IGF-I,-II of IUGR group were 117.92 +/- 26.58 ng/ml and 223.19 +/- 33.35 ng/ml, respectively, which were significantly lower than those of control group (234.43 +/- 70.65 ng/ml and 397.74 +/- 23.69 ng/ml, respectively, P < 0.01). Likewise, birth weight, the length and weight of liver, lung, brain and placenta in IUGR group were significantly lower than those in control group (P < 0.05).

CONCLUSION

The decrease of fetal serum concentrations of IGF-I,-II may be one of the internal factors contributing to fetal IUGR, and IGFs may play an important role in fetal growth.

Effect of articular step-off and meniscectomy on joint alignment and contact pressures for fractures of the lateral tibial plateau

OBJECTIVES

To determine the effects of intraarticular step-off and lateral meniscectomy on the alignment of the articular axis, contact area, and pressures for lateral tibial plateau fractures.

DESIGN

Biomechanical cadaver study.

INTERVENTION

Six fresh cadaveric knees were used. A simulated split fracture of the lateral tibial plateau was reproducibly created by osteotomies, and articular step-offs of zero, one, two, four, and six millimeters were achieved by using support shims. The knee was loaded with 500 newtons in 0 degrees and 350 newtons in 30 degrees of flexion. A digital camera determined changes in the alignment of the articular axis, and F-Scan sensors were inserted into the medial and lateral joint compartments to determine the pressures and pressure distributions.

MAIN OUTCOME MEASUREMENT

Each specimen was tested at step-offs of zero, one, two, four, and six millimeters, with the presence or absence of the lateral meniscus. The changes in alignment of the articular axis, the contact area, and the average and maximum contact pressures for each condyle were obtained.

RESULTS

Increased articular step-off heights progressively increased valgus angulation and average and maximum contact pressures and progressively decreased contact areas in lateral compartment. At a six-millimeter step-off with 0 degrees of flexion, the valgus angle increased an average of 7.6 degrees, and average contact pressures and maximum contact pressures increased an average of 208 percent and 97 percent, respectively, and contact area decreased an average of 33 percent (p < 0.05). Meniscectomy increased valgus angles by an average of 38 percent and contact pressures by an average of 45 percent and decreased contact areas by 26 percent in the lateral compartment at the same articular step-off heights (p < 0.05).

CONCLUSION

The results of this study show the importance of decreasing articular step-off heights in treating lateral tibial plateau split fractures, particularly if a meniscectomy is performed.