[To investigate the role of the AAC-8 scoring in predicting restenosis or occlusion of lower extremity arteries after dilatation and angioplasty with DCB]

Objective: To investigate the role of the Abdominal Aortic Calcification-8 (AAC-8) scoring system in predicting restenosis or occlusion of lower extremity arteries after dilatation and angioplasty with drug-coated balloon (DCB). Methods: In this retrospective study, 62 patients who underwent dilatation and angioplasty with DCB for lower limb atherosclerotic obliterans (ASO) were enrolled from September 2018 to June 2022 in Nanjing Drum Tower Hospital Affiliated to Nanjing University Medical School. Among them who aged (73.9±11.3) years, 37 were males and 25 were females. Patients were divided into two groups according to the condition of the lower extremity arteries after dilatation and angioplasty with DCB: recurrence group (n=26) and patency group (n=36). Logistic regression was used to analyze the factors associated with restenosis or occlusion of lower extremity arteries after dilatation and angioplasty with DCB. The predictive value of the AAC-8 score for restenosis or occlusion of the lower extremity arteries after dilatation and angioplasty with DCB was analyzed using the receiver operating characteristic curves (ROC curves). Results: The postoperative follow-up was 16.30 (10.97, 24.10) months in the patency group and 9.03 (6.98, 15.31) months in the recurrence group. The results of multifactorial logistic regression analysis showed that an elevated AAC-8 score (OR=1.388, 95%CI: 1.067-1.806, P=0.015) was an associated factor of restenosis or occlusion of the lower extremity arteries after dilatation and angioplasty with DCB. The ROC curve analysis showed that the area under the curve (AUC) of the AAC-8 score for predicting restenosis or occlusion of the lower extremity arteries after dilatation and angioplasty with DCB was 0.687 (95%CI: 0.550-0.824, P=0.013), with a cut-off value of 5.5 points, a sensitivity of 65.4% and a specificity of 69.5%. Conclusions: Elevated AAC-8 score is associated with restenosis or occlusion of the lower extremity arteries after dilatation and angioplasty with DCB. When the cut-off value is 5.5, the AAC-8 score predicts restenosis or occlusion of the lower extremity arteries after DCB dilation and angioplasty with a sensitivity of 65.4% and a specificity of 69.5%.

[Correlation between C-reactive protein to albumin ratio and restenosis after femoral popliteal stenting in patients with lower extremity arteriosclerotic obliterans]

Objective: To investigate the study of the correlation between C-reactive protein to albumin ratio (CAR) and restenosis after stenting in patients with lower extremity atherosclerotic occlusive disease(LEASO). Methods: The clinical data of 95 patients with LEASO admitted to the Department of Vascular Surgery of Nanjing Drum Tower Hospital from June 2020 to December 2022 were retrospectively analyzed. There were 67 males and 28 females,aged (73.1±9.4) years (range:51 to 92 years). The patients were classified into the restenosis group (n=61) and the patency group (n=34) according to the CT angiography results. Independent sample t test,Mann-Whitney U test and χ2 test were used to compare the data between two groups. Risk factors for restenosis after femoropopliteal artery stenting in patients with LEASO were analyzed using multivariate Cox regression. The relationship between preoperative CAR level and restenosis after stent placement was analyzed. Subject operating characteristic(ROC) curves of CAR were plotted to assess the predictive value of CAR for restenosis after stenting,and the results were expressed as area under the curve (AUC). Results: The aortoiliac calcification grade,number of stents,length of stents,C-reactive protein and CAR levels in restenosis group were higher than those in the patency group,and the serum albumin level was lower than that in the patency group(all P<0.05). And the results of multifactorial Cox regression analysis showed that higher pre-procedure CAR level and lower ABI value was an independent risk factor for in-stent restenosis. The AUC of the ROC curve for restenosis was 0.737(95%CI:0.617 to 0.856),the AUC of the ROC curve for 12-month restenosis was 0.709(95%CI:0.602 to 0.815), and the AUC of the ROC curve for 24-month restenosis was 0.702(95%CI:0.594 to 0.811). Conclusion: Higher pre-procedural CAR levels in patients with LEASO is risk factor for in-stent restenosis,and CAR has a predictive value for restenosis after lower extremity arterial stent dilatation and angioplasty.

[Clinical analysis of surgical treatment of infection after interventional operation for major iliac artery disease in 6 cases]

Objective: To explore the surgical treatment strategy of stent graft infection after interventional treatment of major iliac artery related diseases. Methods: Retrospective analysis was performed on the clinical data of 6 patients with secondary stent graft infection after interventional treatment for major iliac artery related diseases admitted to the Department of Vascular Surgery,Affiliated Drum Tower Hospital,Medical School of Nanjing University from November 2021 to August 2022.There were 5 males and 1 female,with a mean age of 64 years (range:49 to 79 years).The infection time was 53 to 3 165 days.All the 6 patients received surgical treatment,including 3 patients who underwent anatomic bypass grafting (axillary arterial-femoral artery bypass,femoral arterial-femoral artery bypass) using artificial vessels,and 3 patients who underwent in situ abdominal aorta reconstruction using bovine pericardium.The perioperative situation,postoperative infection and the occurrence of serious adverse events were recorded,and the safety of different treatment methods and materials was evaluated. Results: All patients successfully completed the operation and no death occurred during hospitalization.Intraoperative blood loss was 2 000~5 000 ml,and intraoperative blood transfusion was 1 600 to 5 350 ml.All the patients were followed up for 81 to 395 days after surgery,and the incision healed well,and no reinfection occurred.Postoperative gastrointestinal bleeding occurred in 1 patient,secondary surgery (retroperitoneal hematoma removal) was performed in 1 patient due to postoperative bleeding at the vascular anastomosis,both lower limb amputations were performed in 1 patient due to postoperative lower limb ischemia,and intermittent claudication occurred in 2 patients.All patients were alive at the last follow-up. Conclusion: For patients with aortic stent graft infection,when the infection is not serious and there is enough space to block the proximal and distal aorta,in situ aortic reconstruction is an effective treatment,and different materials can achieve satisfactory results in a short period of time.

[Application of meandering mesenteric artery in vascular surgery]

In recent years, the therapeutic concepts and surgical methods of the meandering mesenteric artery involved in atherosclerosis have been reported in the literature, and the importance of this lateral branch circulation in the field of vascular surgery has received more attention. With the improvement of imaging techniques, the discovery rate of this collateral circulation increased. In the presence of major iliac artery occlusion, the meandering mesenteric artery may serve as an important collateral circulation to relieve ischemia in the visceral or lower extremities. The meandering mesenteric artery may also lead to type Ⅱ internal leakage after endovascular repair, while the embolization of inferior mesenteric artery may be performed through the meandering mesenteric artery. The role of meandering mesenteric arteries in vascular surgery needs further study.

[Influencing factors for postoperative survival of patients with pneumoconiosis treated by lung transplantation]

Objective: To explore the influencing factors for postoperative survival of patients with pneumoconiosis (silicosis) after lung transplantation in order to improve their clinical outcomes. Methods: In August 2021, retrospective alalysis from December 2015 to July 2021, 29 patients with end-stage pneumoconiosis underwent lung transplantation at Department of Thoracic Surgery, Affiliated Henan Provincial People's Hospital, Zhengzhou University. The survival, postoperative complications, and causes of death were analyzed. Life table and Kaplan-Meier method were used to draw survival curves, the log-rank test was used to compare the influence of each factor on survival rates, and the multivariate Cox proportional hazards regression model was used to evaluate the influence of each factor on survival. Results: All the patients underwent successful lung transplantation, with survival rates of 75% at 6 months, 70% at 1 year, 65% at 2 years, 50% at 3 years and 50% at 5 years. The Kaplan-Meier survival analysis showed that BMI, age and preoperative albumin level were influencing factors for postoperative survival rates (P<0.05) . The multivariate COX regression model showed that BMI≥18.5 kg/m(2) and the albumin level≥35 g/L were the protective factors (P<0.05) . Conclusion: Aging older, preoperative BMI<18.5 kg/m(2) and hypoalbuminemia are independent risk factors for death after lung transplantation. Survival rates are affected by preoperative BMI index, albumin level and age. Early intervention should be made before lung transplantation to promote the BMI index and albumin level to reach the standard.

[Effect of low density carotid plaque on the development of cerebral small vessel disease in patients with carotid stenosis]

Objective: To investigate the correlation between cerebral small vessel disease (CSVD) and carotid low-density plaque on multi-slice spiral CT angiography (MSCTA) in patient with carotid stenosis. Methods: The clinical data of 221 patients with carotid stenosis who admitted to Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, from January 2016 to January 2021 were retrospectively analyzed. There were 195 males and 26 females, with the age of (70.0±8.4) years (range: 48 to 88 years). According to MRI, the patients were divided into carotid stenosis combined with CSVD group (the CSVD group) and carotid stenosis without CSVD group (the non-CSVD group). Lowest density in the carotid atherosclerotic plaque area (CAPALD) was analyzed by MSCTA. The t-test, Mann-Whitney U test and Chi-square test were used for comparison between the two groups. Univariate and multivariate Logistic regression analysis were performed on CAPALD and other clinical indicators with CSVD. Receiver operating characteristic (ROC) curves of CAPALD and CAPALD combined with the demographics (sex, age and body mass index) were plotted for predicting CSVD, and the area under the curve (AUC), sensitivity and specificity were calculated. Results: There were 169 patients in the CSVD group and 52 patients in the non-CSVD group. In the CSVD group, 88.8% (150/169) were males and 11.2% (19/169) were females, with the age of (70.5±8.2) years (range: 48 to 88 years). In the non-CSVD group, 86.5% (45/52) were males and 13.5% (7/52) were females, with the age of (68.4±9.1) years (range: 51 to 85 years). CAPALD and the score of Montreal cognitive assessment were lower in the CSVD group than those in the non-CSVD group (21.0 HU vs. 35.0 HU, Z=-3.760, P<0.01; 22.6±3.9 vs. 24.8±3.3, t=-2.064, P<0.05). Multivariate Logistic regression analysis showed that CAPALD was an independent factor for CSVD (OR=1.044, 95%CI:1.020 to 1.070, P<0.01). The AUC of the ROC curve for CAPALD predicting carotid stenosis with CSVD was 0.672 (P<0.01), with cut-off value of 34.5 HU, sensitivity of 82.8%, and specificity of 50.0%. The AUC of ROC curve for CAPALD combined with the demographics predicting CSVD was 0.733 (P<0.01), with sensitivity of 82.9% and specificity of 64.0%. Conclusions: The decreased CAPALD is a risk factor for CSVD in patients with carotid stenosis. The analysis of carotid plaque density by MSCTA may help to identify the patients at high risk of CSVD.

Development of Laboratory Parameters-Based Formulas in Predicting Short Outcomes for Adult Hemophagocytic Lymphohistiocytosis Patients with Different Underlying Diseases

PURPOSE

Hemophagocytic lymphohistiocytosis (HLH) is a severe disease with high mortality. The purpose of this investigation was to build models to predict 30-day death in total and subgroup HLH patients based on available and cheap laboratory parameters.

METHOD

The research contained 431 adults HLH patients from January 2015 to September 2021 in the hospital. Logistic regression and receiver operating characteristic (ROC) were utilized to build models.

RESULTS

Results suggested that age, ferritin, lymphocyte (LY), international normalized ratio (INR), thrombin time (TT), globulin, uric acid (UA), chloride, activated partial thromboplastin time (APTT), aspartate aminotransferase (AST), triglycerides (TG), total bilirubin (TB), and indirect bilirubin (IB) were independent factors in HLH and subgroups. Then, models adapted to patients with different underlying diseases were established based on these factors. Area under curve (AUC) of these models was excellent: HLH patients: 0.838 (p < 0.001); infection-associated HLH (I-HLH) patients: 0.913 (p < 0.001); malignancy-associated HLH (M-HLH): 0.921 (p < 0.001) and 0.809 (p < 0.001) for two or more different etiologies-associated HLH (Mix-HLH patients). In addition, UA, TT, and chloride were firstly confirmed as independent factors in adult HLH.

CONCLUSION

Four models depending on biomarkers that available and affordable in clinical practice were built. With these models, high-risk patients with different underlying diseases could be easily identified.

The association between systemic inflammatory response index and in-hospital mortality in patients with infective endocarditis

Background

Infective endocarditis (IE) has a significant mortality, and early identification of high‐risk patients and prediction of poor outcomes is of great significance. In recent years, increasing research has revealed the predictors associated with infective endocarditis prognosis. Systemic inflammatory response index (SIRI) is an important new indicator of inflammation. So far, there have been no reports on the relationship between SIRI and the prognosis of IE patients.

Hypothesis

The purpose of this study was to explore the value of SIRI in predicting in‐hospital death for patients with infective endocarditis (IE), so as to provide reference for improving the prognosis of patients with IE.

Method

A retrospective analysis was performed on the clinical data of patients with IE admitted to the First Affiliated Hospital of Nanjing Medical University from January 2017 to December 2019. SIRI was calculated according to the blood routine results of patients at admission; receiver operating characteristic curve was employed to determined the optimal cutoff value of SIRI. Patients were divided into groups (low SIRI group and high SIRI group; nonsurvivor group and survivor group) according to the levels of SIRI or their prognosis, and the general clinical features of the two groups were compared. Univariate and multivariate logistic regression analysis were performed to analyze the independent prognostic factors of in‐hospital death in IE patients.

Results

A total of 147 IE patients meeting the diagnostic criteria were included, including 102 males (69.4%) and 45 females (30.6%). There was statistically significant difference in SIRI level between nonsurvivor group and survivor group (p < .05). After adjusting for the related factors, the risk of in‐hospital death in the high SIRI was still a risk of in‐hospital death with statistical significance (hazard ratio = 5.053, 95% confidence interval: 1.426‒17.905, p = .012).

Conclusions

Higher SIRI level is independently associated with the risk of in‐hospital death in IE patients, and can be an independent predictor of poor outcome in IE patients.

Prognostic Value of Lymphocyte-to-White Blood Cell Ratio for In-Hospital Mortality in Infective Endocarditis Patients

Background

The prognosis of Infective endocarditis (IE) is poor, and we conducted this investigation to evaluate the worth of admission lymphocyte-to-white blood cell ratio (LWR) for prediction of short-term outcome in IE patients.

Methods

We retrospectively assessed the medical records of 147 IE patients from January 2017 to December 2019. Patients were divided into the survivor group and nonsurvivor group. Univariate and multivariate analyses were applied to estimate the independent factors contribution to in-hospital death, and receiver-operator characteristic (ROC) curve was utilized to check the performance.

Results

The levels of LWR (0.17 ± 0.08 vs. 0.10 ± 0.06) were significantly increased among the survivor group compared with the nonsurvivor group (P = 0.001). Multivariate analysis displayed that LWR (hazard ratio (HR): 1.755, 1.304-2.362, P < 0.001) was not interfered by other confounding factors for early death. Moreover, ROC analysis suggested that LWR (cutoff value = 0.10) performed the best among assessed indexes for the forecast of primary outcome (area under curve (AUC) = 0.750, 95% confidence interval (CI) = 0.634-0.867, P < 0.001, sensitivity = 70.0%, specificity = 76.4%), and the proportion of in-hospital mortality was remarkably inferior in patients with LWR > 0.10 than in those with LWR ≤ 0.10. (5.83% vs. 31.8%, P < 0.001).

Conclusions

LMR is an independent, simple, universal, inexpensive, and reliable prognostic parameter to identify high-risk IE patients for in-hospital mortality.

[A prospective study on the associations between dietary intakes of energy and macronutrients before menarche and age at menarche among girls]

Based on the data from China Health and Nutrition Survey (CHNS), 840 girls aged 6-15 years who had information about menarche and participated in dietary survey at least once within 1-5 years before onset of menarche between 1989 and 2015 were included in the study. The median age at baseline of the 840 participants was 10 (9, 11) years. The median age at menarche of the participants was 13 (12, 14) years. After adjusting for the age of birth, place of residence, body mass index Z-score, physical activity level and annual household income per capita, the average age of menarche was advanced by 0.036 (95%CI: -0.068, -0.004) years for every 10 g increase in daily fat intake before menarche. The average age at menarche was 0.008 (95%CI: -0.014, -0.001) years earlier for every 1% increase in the daily energy supply ratio of fat before menarche.

The role of platelet to mean platelet volume ratio in the identification of adult-onset still's disease from sepsis

OBJECTIVES

Inflammatory factors exert a significant role in the development of adult-onset Still's disease (AOSD) and sepsis. Although platelet counts and platelet parameters have long served as indicators for inflammatory diseases, their role in the differential diagnosis between adult-onset stilĺs disease and sepsis remains unclear. We designed this retrospective study to explore whether the platelet to mean platelet volume (MPV) ratio (PMR) can help to distinguish AOSD from sepsis.

METHODS

A total of 110 AOSD patients and 84 sepsis patients were enrolled in the study. Seventy-three AOSD patients and 56 sepsis patients between January 2010 and June 2017 were enrolled in the test cohort to analyze PMR values, which was then validated in the validation cohort (37 AOSD patients and 28 sepsis patients between June 2017 and December 2019).

RESULTS

The values of PMR were significantly higher in AOSD patients than in sepsis patients (test cohort, validation cohort, and entire cohort), In the test cohort, logistic regression analysis showed that PMR was an independent risk factor of AOSD (odds ratios [OR]: 9.22, 95% confidence interval [CI] 2.15-39.46, p=0.003). Further receiver operating characteristic curve (ROC) analysis showed that the area under the ROC curve was 0.735 (95% CI 0.631-0.839, p<0.001) for PMR alone and 0.925 (95% CI 0.869-0.980, p<0.001) for the combination of PMR and serum ferritin. Consistently, the validation cohort exhibited analogous results.

CONCLUSIONS

PMR could be used as a single indicator or a complementary indicator to distinguish AOSD from sepsis.

The short-term prognostic value of serum platelet to hemoglobin in patients with type A acute aortic dissection

PURPOSE

Type A acute aortic dissection (AAD) is an uncommon catastrophic cardiovascular disease with high pre-hospital mortality rate without timely and effectively treated. The aim of this study was to assess the value of serum platelet to hemoglobin (PHR) in predicting in-hospital mortality in type A AAD patients.

METHODS

A total of 183 type A AAD patients were included in this retrospective investigation from January 2017 to December 2019. Admission blood routine parameters were gathered and PHR was computed. The outcome was all-cause in-hospital mortality within 30 days.

RESULTS

The average levels of serum PHR were significant higher in survivor group than those in non-survivor group (1.14 ± 0.57 vs 0.87 ± 0.47, p = 0.006) and serum PHR was an independent factor associated with in-hospital mortality (hazard ratio (HR): 2.831; 95% confidence interval (CI): 1.108-7.231; p = 0.030). ROC noted that 0.8723 was chosen as the ideal cutoff value with a sensitivity of 64.3% and specificity of 72.5%. In addition, the area under the ROC curve (AUC) was 0.693 (95% CI 0.599-0.787, p < 0.001).

CONCLUSION

Admission serum PHR can be used as an independent predictor of in-hospital mortality in patients with type A AAD.

[The association of pre-pregnancy body mass and weight gain during pregnancy with macrosomia: a cohort study]

Objective: To examine the association of pre-pregnancy body mass and weight gain during pregnancy with macrosomia. Methods: From January 2015 to December 2015, a total of 20 477 pregnant women were recruited by probabilistic proportional scale sampling with simple randomization in Sichuan, Yunnan and Guizhou Provinces. Basic information of pregnant women, weight gain during pregnancy and weight of newborn were collected. A multiple logistic regression model was used to assess the association between the pre-pregnancy body mass and gestational weight gain indicators with macrosomia. Results: 20 321 mother-infant were included in the final analysis. 20 321 pregnant women were (30.09±4.10) years old and delivered at (39.20±1.29) weeks, among which 12 341 (60.73%) cases were cesarean delivery. The birth weight of 20 321 infants were (3 292.26±431.67) grams, and 970 (4.77%) were macrosomia. The multiple logistic regression model showed that after adjusting for the age of women, compared to the normal weight group in the pre-pregnancy, the overweight and obesity group elevated the risk of macrosomia, with OR (95%CI) about 1.99 (95%CI: 1.69-2.35) and 4.05 (95%CI: 3.05-5.39), respectively. After adjusting for the age, the pre-pregnancy BMI, delivery weeks, delivery mode and infant's gender, compared to the weight-gain appropriate group, higher weight gain rate in the mid-pregnancy and excessive total gestational weight gain elevated the risk of macrosomia, with OR (95%CI) about 1.99 (95%CI: 1.66-2.39) and 1.80 (95%CI: 1.55-2.08), respectively. Conclusion: The overweight before pregnancy, obesity before pregnancy, the rate of weight gain in the second trimester and the high total weight gain during pregnancy could increase the risk of macrosomia.

Alteration of the phagocytosis and antimicrobial defense of Octodonta nipae (Coleoptera: Chrysomelidae) pupae to Escherichia coli following parasitism by Tetrastichus brontispae (Hymenoptera: Eulophidae)

Although parasites and microbial pathogens are both detrimental to insects, little information is currently available on the mechanism involved in how parasitized hosts balance their immune responses to defend against microbial infections. We addressed this in the present study by comparing the immune response between unparasitized and parasitized pupae of the chrysomelid beetle, Octodonta nipae (Maulik), to Escherichia coli invasion. In an in vivo survival assay, a markedly reduced number of E. coli colony-forming units per microliter was detected in parasitized pupae at 12 and 24 h post-parasitism, together with decreased phagocytosis and enhanced bactericidal activity at 12 h post-parasitism. The effects that parasitism had on the mRNA expression level of selected antimicrobial peptides (AMPs) of O. nipae pupae showed that nearly all transcripts of AMPs examined were highly upregulated during the early and late parasitism stages except defensin 2B, whose mRNA expression level was downregulated at 24 h post-parasitism. Further elucidation on the main maternal fluids responsible for alteration of the primary immune response against E. coli showed that ovarian fluid increased phagocytosis at 48 h post-injection. These results indicated that the enhanced degradation of E. coli in parasitized pupae resulted mainly from the elevated bactericidal activity without observing the increased transcripts of target AMPs. This study contributes to a better understanding of the mechanisms involved in the immune responses of a parasitized host to bacterial infections.

[Research advances in the aortic remodeling after thoracic endovascular aortic repair therapy of Stanford type B aortic dissection]

Aortic dissection is one of the most common vascular emergent disease. Thoracic endovascular aortic repair (TEVAR) therapy which created the new era of treatment of Stanford type B aortic dissection (TBAD) has gradually replaced the surgical treatment and becomes the gold standard for treatment of TBAD. Aortic remodeling after TEVAR is the key factor to evaluate the mid-term survival rate and successful treatment of the aortic dissection victims. However, there are few studies on aortic remodeling and lack of unified criteria to evaluate it. This article was to summarize the domestic and abroad research advances which focused on the morphological changes, the regularity, and the evaluation criteria of aorta remodeling after TEVAR.

[Clinical effectiveness of pleural abrasion in video-assisted thoracic surgery for bullae resection]

Objective: To evaluate the efficacy of pleural abrasion in treatment of spontaneous pneumothorax with video-assisted thoracic surgery (VATS) for bullae resection. Methods: The clinical data of 158 patients with initial spontaneous pneumothorax who underwent video-assisted thoracic wedge resections with or without pleural abrasion in Henan Provincial People's Hospital from June 2010 to June 2015 were retrospectively analyzed. The patients were assigned to two equal groups according to whether pleural abrasion was applied or not: experimental group (with pleural abrasion) and control group (without pleural abrasion); and there were 79 patients in each group.There were 62 males and 17 females aged 15-60 years (mean age 34 years) in pleural abrasion group. And there were 70 males and 9 females aged 18-60 years (mean age 38 years) in non-pleural abrasion group.After surgery, all patients were evaluated for postoperative pain, chest tube removal time, hospital stay and other complications.Independent samples t test was used to compare the data between groups. Results: Surgeries for 158 patients were performed successfully.No mortality occurred.There was no conversion to thoracotomy.Postoperative pain, operation time, intraoperative blood loss, chest tube removal time, pleural canals flowand average hospital stay in non-pleural abrasion group was significantly lower for 4.4, 19 minutes, 10 ml, 21 hours, 87 ml and 1.4 days respectively when compared with those in pleural abrasion group (t=32.478, 7.140, 11.093, 7.288, 10.246, 8.070, all P<0.05). There was no missing case with a follow-up of 30 months.No complications, such as pneumothorax, was observed. Conclusions: Postoperative pain, chest tube removal time and hospital stay in non-pleural abrasion group are all lower than those in pleural abrasion group.And there is no significant difference in the recurrence of pneumothorax between the two groups after VATS bullae resection.

Mode suppression of 53 dB and pulse repetition rates of 2.87 and 36.4 GHz in a compact, mode-locked fiber laser comprising coupled Fabry-Perot cavities of low finesse (F = 2)

Multiplication of the pulse repetition frequency (PRF) of a compact, mode-locked fiber laser by a factor as large as 25 has been achieved with two coupled Fabry-Perot (FP) resonators of low finesse (F = 2). Reducing the FP finesse by at least two orders of magnitude, relative to previous pulse frequency multiplication architectures, has the effect of stabilizing the oscillator with respect to pulse-to-pulse amplitude, dropped pulses, and other effects of cavity detuning. Coupling two Fabry-Perot cavities, each encompassing a 3.3-3.6 cm length of fiber, in a hybrid geometry resembling that of the coupled-cavity laser interferometer has yielded side mode suppressions ≥ 50 dB while simultaneously doubling the laser PRF to 2.87 GHz. Pulses approximately 3.9 ps in duration (FWHM) are emitted at intervals of 27.5 ps, and in groups (bursts) of pulses separated by 350 ps. Thus, the PRF within the pulse bursts is 36 GHz, a factor of 25 greater than the free spectral range for a conventional mode-locked cavity having a length of 6.9 cm. Experimental data are in accord with simulations of the phase coherence and temporal behavior of the mode-locked pulses.

Investigation of rectangular shaped wave packet dynamics in a high-repetition-rate ultrafast fiber laser

We identify a new regime where laser pulses represent the dynamics of rectangular-shaped wave packets (RSWPs) in a passively mode-locked Tm³⁺-doped fiber laser. In this regime the laser consists of a train of mode-locked pulses underneath a rectangular-shaped envelope. The density of pulses within a RSWP can be as high as 2.8 GHz, which is consistent with cavity fundamental repetition rate. The effects of small-signal gain value, pulse repetition rate, and net dispersion on the RSWP performance are analyzed. These results imply that this new regime particularly favors high-repetition-rate ultrafast lasers. We further reproduce the phenomenon from using numerical simulations and understand such behavior by referring to the nonlinear dynamics.

Theoretical and experimental analysis of instability of continuous wave mode locking: Towards high fundamental repetition rate in Tm3+-doped fiber lasers

With increasing demand on a laser source in the gigahertz pulse repetition rate regime, clarification on the mechanism of instability in high repetition rate fiber lasers - a promising alternative to solid state lasers - is of great importance and can potentially offer guideline for continuous wave (CW) mode locking. Here we present a theoretical approach together with relevant experimental corroboration to analyze the instabilities. By means of appropriate approximations, regimes from Q-switched mode locking, CW mode locking and pulsation are theoretically identified. Meanwhile, a critical curve that characterizes pump level for triggering Q-switched mode locking and pulsation for different repetition rates is given by virtue of both analytical and numerical procedures. In experiment, a passively mode-locked fiber laser with 1.6 GHz fundamental repetition rate is realized. The three regimes and corresponding pump power intervals are revealed, which are in consistence with theoretical prediction. Pulsation, as a relatively exotic phenomenon in GHz fiber laser, is well reproduced by the present model, which further verifies the accuracy of the approach as well as enriches the nonlinear dynamics.

Knockdown of the inflammatory factor pentraxin-3 suppresses growth and invasion of lung adenocarcinoma through the AKT and NF-kappa B pathways

Pentraxin-3 (PTX3), a modulator of tumor-associated inflammation, is known to be positively correlated with tumor grade and severity of malignancies, but the function and molecular underlying mechanisms of PTX3 remain unclear. In the present study, the expression of PTX3 in human lung adenocarcinoma (LAC) was examined by immunohistochemical assay using a tissue microarray procedure. A loss-of-function experiment was performed to explore the effects of lentiviral vector-mediated PTX3 shRNA (Lv-shPTX3) on cell growth and invasive potential in LAC cell lines (A549 and LETPα-2), assessed by MTT and Transwell assays, respectively. We found that the expression of PTX3 protein was significantly increased in LAC tissues compared with that in adjacent non-cancerous tissues (ANCT) (60.42% vs. 29.17%, P=0.004), and positively correlated with lymphatic invasion of the tumor (P=0.006). Furthermore, knockdown of PTX3 suppressed tumor proliferation and invasion of LAC cells, followed by decreased expression of p-AKT, p-NF-kappa B, PCNA, and MMP-9. Taken together, our findings demonstrate that upregulation of PTX3 expression is correlated with tumor metastasis of LAC patients, and knockdown of PTX3 blocks the development of LAC through inhibition of the AKT and NF-kappa B pathways, suggesting that PTX3 may serve as a potential therapeutic target for the treatment of cancer.

[Hypoxia induced HIF-1 accumulation and VEGF expression in gastric epithelial mucosa cell: involvement of ERK1/2 and PI3K/Akt]

Hypoxia is a common environmental stress that influences signaling pathways and cells function, which through initiating intracellular signaling pathways and hence leading to the activation of the transcription factor hypoxia-inducible factor-1 (HIF-1). In this study, we initially confirm that hypoxia activates HIF-1alpha protein expression in a time-dependent manner with a maximum reached at 60 min in vitro and 4h in vivo in gastric mucosa epithelial cells. The expression of HIF-1alpha is correlated with the activation of HIF-1 DNA binding and transcriptional activity. Hypoxia dose not affect HIF-1alpha mRNA transcription but regulates HIF-1alpha protein expression through a translation-dependent pathway to regulate protein synthesis. Hypoxia could induce phosphorylation of Akt, MAPK (ERK), and target of p70S6K1. PI3K and MAPK inhibitor, LY294002 and U0126 could inhibit hypoxia-induced HIF-1 and VEGF expression. We also investigated the role of reactive oxygen species (ROS) involved in HIF-1 and VEGF expression Exogenous addition of H2O2 was sufficient to activate Akt and ERK, scavengers of H2O2 significantly inhibited hypoxia-induced Akt and ERK, and subsequent HIF-lax expression and transcriptional activity. In conclusion, our data suggested that hypoxia- PI3K signaling through Akt and ERK kinases regulated ROS-dependent, hypoxia- induced HIF-1 activation and VEGF expression in gastric mucosa epithelial cells.

Phospho Akt mediates multidrug resistance of gastric cancer cells through regulation of P-gp, Bcl-2 and Bax

Phosphatidylinositol 3-kinase/Akt pathway is an important intracellular pathway that is frequently activated in cancer cells. The role of P-AKT in multidrug resistance of gastric cancer cells and the possible underlying mechanisms are here investigated. Up-regulation of P-AKT expression could confer resistance to both P-glycoprotein-related and P-glycoprotein-non-related drugs on AGS cells, and suppress adriamycin-induced apoptosis, along with decreased accumulation and increased releasing amount of adriamycin. P-AKT could significantly up-regulate the expression of Bcl-2, and down-regulate the expression of Bax, but not alter the expression of PTEN in gastric cancer cells. Inhibition of P-AKT expression could partially reverse P-AKT-mediated multidrug resistance and significantly up-regulate P53 expression, and down-regulate the expression of P-glycoprotein and the transcription of the multidrug resistance gene 1. Further studies of the biological functions of P-AKT may be helpful for understanding the mechanisms of multidrug resistance of gastric cancer and developing possible therapeutical strategies.

Zinc ribbon domain containing 1 protein: modulator of multidrug resistance, tumorigenesis and cell cycle

Zinc ribbon domain containing 1 (ZNRD1) gene encoding a protein consisting of two zinc ribbon domains was recently cloned from the human HLA locus. So far, ZNRD1 has been found implicated in transcription regulation and might play potential roles in mediating several biological processes, including multidrug resistance, tumorigenesis and cell cycle. This article reviewed these recent findings and provided additional information to support the role of ZNRD1 gene as a novel candidate DNA damage repair related gene.

The Impact of Gastrocnemius Muscle Cell Changes in Chronic Venous Insufficiency

OBJECTIVE

To investigate the pathological and metabolic changes in the gastrocnemius muscle in patients with chronic vein insufficiency (CVI).

METHOD

Thirty-six patients with varicose veins were investigated by ambulatory venous pressure (AVP) and duplex ultrasonography. Twelve age and height-matched controls were used for comparison. Patients and controls consented to participate in this study. Twenty-one patients with primary vein varicose (group AI) and 15 patients (group AII) with primary deep venous valve incompetence (DVI) underwent biopsies of the gastrocnemius muscle during operation. Adductor biopsies obtained from the same limbs served as a control group (group B) and specimens from controls subjects without venous disease served as the second control group (group C). All the specimens were investigated by superoxide dismutase (SOD), nitric oxide (NO), Na+-K+-ATPase, Ca2+-ATPase and lactic acid (LD) determinations. Samples were subjected to light and electron microscopy following H & E staining, special ATPase, cytochrome oxidase/succinate dehydrogenase (COX/SDH) stains.

RESULTS

Normal muscle architecture was seen following H & E, ATPase and COX/SDH staining and normal cell metabolism was observed in specimens of groups B and C. In group A, pathological changes were encountered in the gastrocnemius muscle including disseminated myofibril atrophy, cell denaturation and necrosis, inflammatory cell infiltration, proliferation and dilation of interfascicular veins. ATPase staining (pH 9.4) demonstrated grouping of atrophic fibres, especially type I myofibril grouping, accompanied by moderate to severe atrophy of type II muscle fibres. However, no patient had selective type I fibre atrophy. Enhanced enzymatic activity in single or multiple myofibrils was demonstrated by COX/SDH staining in approximately half of the specimens in group AII. In group AII, electron microscopy showed swelling, myelin figure denaturation of mitochondria, disruption of the myofibrils and increased lipid droplets in the gastrocnemius muscle. Increased concentration of LD was found in most specimens from group A patients. There were also reductions of SOD, NO, biochemical activity of Na+-K+-ATPase, Ca2+-ATPase with increasing concentration of LD in these patients, most prominently in group AII. We found correlation between AVP assessments and the biochemical measurements as well as morphological appearances of the gastrocnemius muscle.

CONCLUSION

Venous hypertension results in pathophysiological changes in the gastrocnemius muscles of patients with DVI, associated with decreased calf pump function.

Hedgehog signaling pathway is essential for pancreas specification in the zebrafish embryo

Recent studies have implicated the signaling factor Sonic hedgehog (Shh) as a negative regulator of pancreatic development, but as a positive regulator of pancreas function in amniotes [1-4]. Here, using genetic analysis, we show that specification of the pancreas in the teleost embryo requires the activity of Hh proteins. Zebrafish embryos compromised in Hh signaling exhibit disruption in the expression of the pancreas-specifying homeobox gene pdx-1 and concomitantly show almost complete absence of the endocrine pancreas. Reciprocally, ubiquitous activation of the Hh pathway in wild-type embryos causes ectopic induction of endodermal pdx-1 expression and the differentiation of supernumerary endocrine cells. Our results suggest that Hh proteins influence pancreas specification via inductive interactions from the axial midline rather than through their localized expression in the endodermal cells themselves.

Upregulation of drug sensitivity of multidrug-resistant SGC7901/VCR human gastric cancer cells by bax gene transduction

OBJECTIVE

To investigate the role of bax in a vincristine (VCR)-induced multidrug-resistant (MDR) human gastric cancer cell line, SGC7901/VCR, in which the Bax protein expression level was significantly lower compared with that in parent cells.

METHODS

A bax eukaryotic expression vector was constructed and transfected into SGC7901/VCR cells by lipofectamine, and resistant clones were selected by G418. Western blotting detected Bax expression in transfectants. Tetrazolium blue (MTT) assay evaluated the differences in drug sensitivity and cell cycle changes of transfectants were analyzed using flowcytometry (FCM).

RESULTS

The bax eukaryotic expression vector was constructed and transfected into SGC7901/VCR cells. Through G418 selection, resistant clones were obtained. Western blotting demonstrated that the expression of Bax protein was markedly increased in bax transduced cells. These cells were more sensitive to adriamycin (ADR) and VCR than mock vector transducted cells. Moreover, bax transfection enhanced ADR-induced apoptosis and VCR-induced G2/M phase arrest of SGC7901/VCR cells.

CONCLUSION

Bax was involved in the MDR of SGC7901/VCR cells.

[Production of phage-displayed single chain variable fragments of monoclonal antibody MGb1]

OBJECTIVE

To lay a foundation for obtaining a tumor-targeting vehicle for in vivo study on diagnosis and treatment of gastric carcinoma by generating single chain variable fragments (ScFv) of monoclonal antibody MGb1 directed against the cancer.

METHODS

mRNA was isolated from MGb1-producing mouse hybridoma cell line, and the variable regions of heavy and light chain cDNAs were amplified separately and assembled into ScFv DNAs with a specially constructed linker DNA by PCR. The ScFv DNAs were ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into competent E. coli TG1. The transformed cells were infected with M13KO7 helper phage to yield recombinant phage, which display ScFv fragments as a fusion with gene 3 protein on the tips of the phage M13. After two rounds of panning with gastric carcinoma cell line KATO III highly expressing MGb1-binding antigen, the phage clones displayed ScFv fragments of the antibody were selected by enzyme-linked immunosorbent assay (ELISA) from the enriched phages. The affinity of the positive phage clones was detected by competition ELISA.

RESULTS

The VH, VL and ScFv DNAs were about 340 bp, 320 bp and 750 bp respectively. 17 phage clones displayed ScFv of MGb1 were selected from 40 enriched phage clones. 4 out of the 17 phage clones could strongly compete with the original hybridoma antibody MGb1 for binding to the antigen expressed on KATOIII cells.

CONCLUSION

The phage-displayed ScFv fragments of monoclonal antibody MGb1 are successfully produced by phage antibody technology, which may be useful to widen the range of application of the antibody.

[Mimic epitope recognized by monoclonal antibody MG7 against gastric cancer through screening phage displayed random peptide library]

OBJECTIVE

To get mimic peptide epitopes that could be recognized by a monoclonal antibody against gastric cancer named MG7 from random peptide library displayed by phage, and to provide useful information for further study of the interaction between antigen and antibody.

METHODS

Through affinity enrichment and immunoscreening of two phage-displayed non-apeptide libraries constructed in pVIII with MG7 MAb separately, several positive phages were obtained. Fluorescence labeling and dot blot were carried out for further identification of their binding activities. Then, some of the positive phages were sequenced and their corresponding peptide sequence was deduced according to their DNA sequence. Finally, HLA binding prediction software was applied for HLA binding analysis.

RESULTS

Based on several rounds of screening and binding activity detection, we got twelve and thirty positive phage clones respectively from two libraries. Through DNA sequencing, peptide deducing and sequence aligning analysis of the positive phages, some preserved epitope information such as PLX(0 - 2)S, SAVR, XRMX and YARN were obtained. The prediction using HLA binding analysis software showed that most of the sequenced peptide had the potentiality to bind with HLA molecules.

CONCLUSION

PLX(0 - 2)S, SAVR, XRMX and YARN may be some of the motifs which could be recognized by monoclonal antibody MG7.

[The combined therapy of carboplatin, fluorouracil and radiotherapy for moderate and advanced non-small cell lung cancer]

OBJECTIVE

To observe the effect of combined chemotherapy (carboplatin and fluorouracil) with radiotherapy for moderate and advanced non-small cell lung cancer.

METHODS

Eighty patients with moderate and advanced non-small cell lung cancer were randomized into 2 groups, radiotherapy group(R) and carboplatin, fluorouracil plus radiotherapy group (CF + R). All patients in two groups received conventional radiotherapy. Patients in CF + R group received combined chemotherapy with carboplatin(100 mg, d 1-5) 5-fluorouracil(500 mg d 1-5) in the first and fourth weeks during radiotherapy.

RESULTS

The complete response rate was 48% in CF + R group, 25% in R group. The 1-year, 3-year, 5-year survival rates were 63%, 38%, 18% in CF + R group, and 40%, 15%, 8% in R group. The major toxic reactions in CF + R group were grade I-II myelo-suppression and digestive tract reaction.

CONCLUSIONS

Combined chemotherapy(carboplatin and fluorouracil) with radiotherapy is preferable for non-small cell lung cancer.

[Expression regulation of major late promoter tripartite leader sequence in adenovirus late infection]

OBJECTIVE

To investigate the influence of adenovirus major late tripartite leader sequence on specific exportation of virus mRNA in the late phase of adenovirus infection.

METHODS

We constructed a marked, human beta-actin minigene under the control of the glucocorticoid-inducible enhancer and promoter of mouse mammary tumor virus, and inserted it into the left end of the adenovirus type V genome. The promoter gene, designated MA, as well as of a sibling, which differed only in inclusion of a cDNA copy of the adenovirus major late tripartite leader sequence upstream of beta-actin sequences termed MtplA, in recombinant virus-infected cells was strictly dependent on addition of deoxymethesone to the medium. Nuclear and cytoplasmic reporter RNA species were compared by Northern blotting, primer extension and pulse-chase assay.

RESULTS

The high concentrations of newly-synthesized RNA were accumulated in cytoplasm when tripartite leader sequence was present in reporter RNA, despite the equal rates of transcription of the two reporter genes. Nuclear and cytoplasmic reporter RNA species compared by Northern blotting, primer extension, and pulse-chase provided no evidence for altered processing induced by tripartite leader sequence.

CONCLUSION

The tripartite leader sequence, known to facilitate translation of mRNA during the late phase of adenovirus infection, can also modulate mRNA export from the nucleus.

A novel alternative splice domain in zebrafish tenascin-C

We have identified and sequenced clones from a zebrafish library that correspond to tenascin-C (TN-C). The 2036-bp sequence covers the C-terminal segment of the protein. Comparison of this sequence to TN-C from other vertebrates indicates that our sequence starts in FN-III domain 5, continues with one alternative splice domain, then with FN-III domains 6-8 and, finally, the complete fibrinogen-like domain. The alternative splice domain, designated TNfnQ, is not closely identified to any of the domains in other species, and may represent a novel descendent of the alternative splice-domain precursor.

Thermodynamics of the equilibrium unfolding of oxidized and reduced Saccharomyces cerevisiae iso-1-cytochromes c

We report thermodynamic data for the chemical denaturation of iso-1-cytochromes c from Saccharomyces cerevisiae having amino acid substitutions R38A, N52I, and F82S in all possible combinations. The guanidine hydrochloride denaturation of isolated proteins was monitored by fluorescence measurements. The redox potentials, Eo', for both the folded and unfolded conformations have been measured. Free energy changes of chemical unfolding together with direct electrochemical measurement of the free energy changes of reduction for both the native and unfolded proteins yield a complete thermodynamic cycle, which includes four states of cytochrome c: oxidized folded, oxidized unfolded, reduced folded, and reduced unfolded. Completed cycles illustrate that the stability of cytochrome c to denaturing conditions is different for each amino acid substitution by an amount that depends on the heme oxidation state. Thus, the differential protein stability cannot be interpreted simply in terms of a hydrophobic effect, without also considering coupled Coulombic effects.