Achromobacter species (sp.) outbreak caused by hospital equipment containing contaminated water: risk factors for infection

BACKGROUND

Nosocomial outbreaks of urinary tract infections caused by Achromobacter spp. have been rare in recent decades.

AIM

To identify the origin of an Achromobacter sp. outbreak, conduct multi-modal infection control measures, and finally to stop the outbreak. To this end, an epidemiological outbreak investigation and risk factor analysis were performed.

METHODS

Achromobacter sp. was detected in 22 patients in our urology wards and six environmental cultures of specimens obtained from the operating rooms. Strains isolated were submitted for antimicrobial susceptibility testing. An on-site epidemiological investigation, evaluation of patient medical records, and environmental sampling were performed to identify the source of the outbreak, and implementation of infection control intervention. A case-control study was performed to analyse the potential risk factors.

FINDINGS

Environmental sampling showed that the source of the infection for 22 patients was an ISA-IIIA-type medical pressurizer containing contaminated water. A case-control analysis showed that the risk factors for infection were: diagnosis of kidney/ureteral stones, surgery, placement of a double-J stent, and history of hospitalization in the past three months.

CONCLUSION

It was concluded that the outbreak occurred in patients who underwent internal lithotripsy and double-J stent placement, due to contact transmission with the contaminated sensor and connecting tubes of the ISA-IIIA-type medical pressurizer.

An optimized protocol for isolation of murine pancreatic single cells with high yield and purity

Here, we present a protocol for rapidly isolating single cells from the mouse pancreas, minimizing damage caused by digestive enzymes in exocrine cells. We guide you through steps to optimize the dissection sequence, enzyme composition, and operational procedures, resulting in high yields of viable pancreatic single cells. This protocol can be applied across a wide range of research areas, including single-cell sequencing, gene expression profiling, primary cell culture, and even the development of spheroids or organoids. For complete details on the use and execution of this protocol, please refer to Jiang et al. (2023).1.

Negative associations of morning serum cortisol levels with obesity: the Henan rural cohort study

AIMS

To evaluate the associations of morning serum cortisol levels with obesity defined by different indices in Chinese rural populations.

MATERIALS AND METHODS

A cross-sectional study was performed including 6198 participants (2566 males and 3632 females). Serum cortisol was collected in morning and quantified by liquid chromatography-tandem mass spectrometry. Obesity was defined by body mass index (BMI), body fat percentage (BFP), waist-to-height ratio (WHtR), waist circumference (WC), visceral fat index (VFI) and waist-to-hip ratio (WHR). Both multivariable liner regression, logistic regression and restrictive cubic splines models were used to estimate the gender-specific relationships between cortisol levels and obesity defined by different indices, respectively.

RESULTS

After adjusting for potential confounders, serum cortisol was negatively associated with different obesity measures, except obese females defined by BFP (for instance, overall obesity defined by BMI, Quartile 4 vs. Quartile 1, odds ratio (OR) = 0.25, 95% confidence interval (CI):0.15, 0.41 in males, and OR = 0.58, 95% CI: 0.42,0.80 in females, central obesity defined by WC, OR = 0.52, 95% CI:0.39,0.69 in males and OR = 0.63, 95% CI:0.51,0.77 in females). Similarly, restrictive cubic splines showed the nonlinear relationship between high levels of cortisol and different obesity indices. Furthermore, ROC curve analysis indicated that cortisol could improve the discrimination of model with common biomarkers.

CONCLUSION

Morning serum cortisol were negatively related to obesity defined by different indices in Chinese rural populations. In addition, cortisol could be as a biomarker for prediction of obesity in males.

Reappraise role of lymph node status in patterns of recurrence following curative resection of gastric adenocarcinoma

Objective

To examine the association between lymph node status and recurrence patterns in completely resected gastric adenocarcinoma.

Methods

We retrospectively assessed 1,694 patients who underwent curative gastrectomy from January 2010 to August 2014. Patients stratified according to lymph node status and recurrence patterns among different subgroups were compared.

Results

Of all, 517 (30.5%) patients developed recurrent disease, and complete data of recurrence could be obtained in 493 (95.4%) patients. For pN0 patients, the patterns of recurrence were different according to pT stage: locoregional recurrence was most common in patients with pT1−2 disease (57.1%), distant recurrence was most common in patients with pT3 disease (57.1%), and peritoneal recurrence was most common in patients with pT4a disease (66.7%). For pN+ patients, distant metastasis was most common pattern irrespective of pT stage. The site-specific trend of recurrence showed that locoregional recurrence increased within 5 years in patients with pN0−2 disease but plateaued 3 years after surgery in patients with pN3 disease. Time to recurrence was significantly longer for the pN0 patients compared with the pN+ patients (median: 25 vs. 16 months, P=0.001). Moreover, post-recurrence survival was significantly better for the pN0 patients than for the pN+ patients (median: 12 vs. 6 months, P<0.001), especially in patients with non-peritoneal recurrence, late recurrence, single recurrence, and receipt of potential curative treatment.

Conclusions

Among clinicopathologic factors, lymph node status is the most important factor associated with recurrence patterns after curative gastrectomy. Lymph node status may be used as an adjunct in clinical decision-making about postoperative therapeutic and follow-up strategies.

A novel prognosis marker based on combined preoperative carcinoembryonic antigen and systemic inflammatory response for resectable gastric cancer

Background: Carcinoembryonic antigen (CEA) is one of the important indexes for the diagnosis and prognosis of gastrointestinal cancer. Systemic inflammatory response (SIR) is closely related to the occurrence and development of gastrointestinal cancer.

Methods: A total of 803 patients who underwent radical gastrectomy in Qinghai University Affiliated Hospital from January 2012 to December 2016 were included as training set. Multivariable Cox proportional hazard regression was used to identify associations with outcome of gastric cancer (GC). CNLR was established by combining CEA and the neutrophils to lymphocytes ratio (NLR, a typical parameter in SIR) to generate a novel prognostic score system and its prognostic value was externally validated.

Results: Multivariate analysis showed that CEA and NLR were independent prognostic factors for GC patients (both p < 0.05). A higher CNLR was significantly associated with older age, male sex, larger tumor size, vascular invasion and advanced stages (all p < 0.05). Patients with higher CNLR had poor prognosis than those with lower CNLR (p < 0.05). Multivariate analysis showed that CNLR was an independent prognostic factor (p < 0.05). Incorporation of the CNLR into a prognostic model including age and TNM stage generated a nomogram, which predicted accurately 3- and 5-year survival for GC patients. And similar results were obtained in the external validation set.

Conclusions: The CNLR prognostic scoring system established by combining CEA and NLR is an independent prognostic factor for GC, which can be incorporated into the traditional TNM staging to improve the prediction of long-term survival outcomes.

Complete blood count-based inflammatory score (CBCS) is a novel prognostic marker for gastric cancer patients after curative resection

Background

We sought to investigate the prognostic value of complete blood count (CBC)-based biomarkers for patients with resectable gastric cancer (GC).

Methods

Patients with GC who underwent primary surgical resection between December 2008 and December 2013 were included. The estimated area under the curve (AUC) and multivariate Cox regression models were used to identify the best CBC-based biomarker. Time-dependent receiver operating characteristic (t-ROC) curve analysis was used to predict overall survival and compare the prognostic impact.

Results

In the 1810 patients analyzed, the median follow-up period was 51.0 months (range 1–101 months). Based on multivariate analysis, the lymphocyte-monocyte ratio (LMR) and hemoglobin (Hb) level were independent prognostic factors (both P < 0.05). Based on the LMR and Hb level, we established the CBC-based inflammatory score (CBCS). A higher CBCS was associated with older age, female sex, higher American Society of Anesthesiologists (ASA) score, proximal tumor location, larger tumor size, later stage and vascular involvement (all P < 0.05). Univariate analyses showed that a higher CBCS was also associated with worse overall survival (OS), which was consistent in each stage (all P < 0.05). Multivariate analysis revealed that the CBCS was a significant independent biomarker (P < 0.05). The AUC for the CBCS (0.627) was significantly higher than the AUCs for the LMR (0.573) and Hb level (0.605) (both P < 0.05). Furthermore, the t-ROC curve of the CBCS was superior to that of the prognostic nutritional index (PNI), systemic immune-inflammation index (SII), modified Glasgow prognostic score (mGPS) and C-reactive protein/albumin ratio (CRP/Alb) throughout the observation period.

Conclusion

The preoperative LMR and Hb level were optimal CBC-based biomarkers for predicting OS in GC patients after curative resection. Based on the LMR and Hb, we developed a novel and easily obtainable prognostic score called the CBCS, which may improve the prediction of clinical outcomes.

Preoperative Hematocrit (HCT) is a Novel and Simple Predictive Marker for Gastric Cancer Patients Who Underwent Radical Gastrectomy

BACKGROUND

Previous studies have suggested that preoperative anemia negatively influences survival in patients with gastric cancer (GC). We sought to investigate which anemic markers can better predict the prognosis of patients with resectable GC.

METHODS

The study involved 2277 GC patients who underwent curative resection between December 2008 and December 2014. Cox regression models were used to identify the best anemic markers associated with prognosis. Time-dependent receiver operating characteristics analysis (t-ROC) and the estimated area under the curve (AUC) were used to compare the prognostic values.

RESULTS

Of all patients, 1709 (75.1%) were male, and the median age was 61 years. Univariate analyses showed that preoperative hematocrit (HCT), hemoglobin, and mean corpuscular volume were associated with OS (all P < 0.05). However, in a separate analysis of individual stages, only HCT was shown to be significantly prognostic across all tumor stages (all P < 0.05). In the multivariate analysis, preoperative HCT remained an independent prognostic factor for GC. Low HCT was significantly associated with older age, female sex, lower body mass index, higher American Society of Anesthesiologists score, higher preoperative transfusion rate, 90-day mortality, adjuvant chemotherapy, larger tumor size, lymph node metastasis, later stage, and vascular involvement. The t-ROC curve and AUC for HCT were similar to those for the controlling nutritional status and prognostic nutritional index throughout the observation period.

CONCLUSIONS

The preoperative HCT is a novel, simple, and powerful prognostic indicator of poor outcome in patients with GC and can be used as a part of the preoperative risk stratification process.

Association of the age-adjusted Charlson Comorbidity Index and systemic inflammation with survival in gastric cancer patients after radical gastrectomy

PURPOSE

To examine the associations of the Age-Adjusted Charlson Comorbidity Index (ACCI) and preoperative systemic inflammation with survival in gastric cancer (GC) patients who underwent radical gastrectomy.

METHODS

Data from patients with GC who underwent radical gastrectomy between January 2009 and December 2014 in Fujian Medical University Union Hospital were retrospectively analyzed. Univariate and multivariate Cox regression analyses were performed to identify the prognostic factors. The relationship between the ACCI and systemic inflammation of the patients was explored, and the prognostic value of a new scoring system based on the ACCI and systemic inflammation (ANLR) was evaluated.

RESULTS

A total of 2257 patients with GC were included. The ACCI and neutrophil to lymphocyte ratio (NLR) were independent prognostic factors for overall survival (both P < 0.001) by multivariate analysis. A higher ACCI was an independent predictor of the increase in preoperative NLR (P < 0.001). Based on the preoperative ACCI and NLR, we established a novel marker, ANLR. Multivariate analysis showed that the ANLR was a significant independent predictor of 5-year OS (P < 0.001). The Harrell's C-statistics (C-index) of a model combining the ANLR and pTNM was 0.744 (95% CI: 0.728-0.760), which was significantly higher than the pTNM stage (0.717, 95% CI: 0.702-0.731; P < 0.001).

CONCLUSION

The ACCI of patients with gastric cancer was associated with preoperative systemic inflammation. The ACCI combined with the NLR, which are commonly collected biomarkers, could enhance prognostication for GC patients.

Difference in the short-term outcomes of laparoscopic gastrectomy for gastric carcinoma between the east and west: a retrospective study from the IMIGASTRIC trial

Purpose: To compare the clinicopathologic data and short-term surgical outcomes of laparoscopic gastrectomy (LG) for gastric cancer (GC) between the east and west. Methods: Patient demographics, surgical procedures, pathological information, and postoperative recovery were compared among gastric cancer patients who underwent LG in the clinical trial of IMIGASTRIC (NCT02325453) between 2009 and 2016. Results: More younger males, higher BMI, lower ASA score and less neoadjvant chemotherapy were evident in east patient cohort. Eastern patients had a higher proportion of proximal, differentiated and advanced gastric cancers. More total gastrectomies, larger extent of lymph node (LN) dissection, and higher number of retrieved LNs were found in the eastern patients. However, more Roux-en-Y anastomosis procedures during distal gastrectomy and intra-corporeal anastomosis were performed in the western patients. The west patients showed faster postoperative recovery than the eastern patients. The mortality rates of the western patients were comparable to those of the eastern patients. However, fewer III-IV complications were evident in the eastern centers. Multivariate analyses revealed that an elderly age, higher ASA score, and more blood loss were the significant independent risk factors of postoperative complications for eastern patients. However, for the western patients, the independent risk factors were neoadjuvant therapy, more retrieval LNs, and pT3-4 stage. Conclusions: The selections and short-term surgical outcomes of LG for GC were widely different between East and West. To obtain more objective and accurate results, these differences should be considered in future international prospective studies.

Prognostic Value and Association of Sarcopenia and Systemic Inflammation for Patients with Gastric Cancer Following Radical Gastrectomy

OBJECTIVE

The aim of this study was to investigate the prognostic value of preoperative sarcopenia and systemic inflammation for patients with resectable gastric cancer (GC) and develop a novel and powerful prognostic score based on these factors.

MATERIALS AND METHODS

Patients with GC who underwent radical gastrectomy between December 2009 and December 2013 were included. A multivariate Cox regression analysis was performed to identify the prognostic factors. A novel prognostic score (SLMR) was developed based on preoperative sarcopenia and the lymphocyte-monocyte ratio (LMR), and its prognostic value was evaluated.

RESULTS

In total, 1,167 patients with resectable GC were included in the study. On multivariate analysis, preoperative sarcopenia and the LMR were shown to be independent prognostic factors (both p < .001). A low LMR was an independent predictor from sarcopenia (p < .001). Based on preoperative sarcopenia and the LMR, we established the SLMR. An elevated SLMR was associated with older age, higher ASA scores, larger tumor size, advanced stages, and vascular invasion (all p < .05). Multivariate analysis revealed that the SLMR was a significant independent predictor (p < .001). We incorporated the SLMR into a prognostic model that included tumor size and TNM stage and generated a nomogram, which accurately predicted 3- and 5-year survival for GC patients.

CONCLUSION

Preoperative systemic inflammation is significantly associated with sarcopenia. The LMR combined with sarcopenia could enhance prognostication for patients with GC who underwent radical gastrectomy.

IMPLICATIONS FOR PRACTICE

Increasing evidence shows that sarcopenia and systemic inflammation are closely associated with the prognosis of malignant tumors, and it is essential for clinicians to understand the relationship and combined prognostic effects of these factors for gastric cancer (GC). Based on a large data set, this study found that preoperative systemic inflammation was significantly associated with sarcopenia in GC, and combining these two predictors could effectively predict the prognosis and complement the prognostic value of the TNM staging system. These findings may lead to the development of new therapeutic avenues to improve cancer outcomes.

Proposed Modification of the 8th Edition of the AJCC Staging System for Gastric Cancer

Background: The American Joint Committee on Cancer (AJCC) staging system has been the standardized staging system for malignancies since the first edition in 1987. The 8th edition of gastric cancer was released in 2016, and is expected to be used in clinical practice in 2018. The aim of this study was to improve this new gastric cancer staging system. Methods: We conducted median overall survival analyses in a cohort of 8359 gastric cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2014) via Kaplan-Meier curves and log-rank tests, and proposed a modified staging system based on median OS. The concordance index (C-index) was conducted to evaluate the predictive accuracy. Results: Using the 8th AJCC staging system, the median OS of patients at the same stage varied widely between the different substages, especially in stage III. Despite the definitions of T, N, and M, substages in the modified staging system were regrouped based on median OS. The C-index of stage III patients with the modified staging system [0.579, 95% confidence interval (CI) 0.564-0.593] was higher than the 8th AJCC staging system (0.567, 95% CI 0.552-0.581). Moreover, we divided these patients into two groups according to their examined lymph node counts (≥15 or 1-14), and studied the effectiveness of the modified staging system in the two groups. Conclusions: The modified 8th AJCC staging system for gastric cancer proposed in this study generates better prognostic stratifications and may be evaluated for further update. Abbreviations:AJCCAmerican Joint Committee on CancerOSOverall SurvivalSEERSurveillance, Epidemiology, and End Results.

Preoperative Tumor Markers Independently Predict Survival in Stage III Gastric Cancer Patients: Should We Include Tumor Markers in AJCC Staging?

OBJECTIVE

The aim of this study was to determine the prognostic significance of preoperative carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 levels in patients with resectable gastric cancer (GC).

PATIENTS AND METHODS

Patients who underwent a radical resection for GC at the Fujian Medical University Union Hospital between 2007 and 2014 were included in this study. The estimated area under the curve (AUC) was compared to evaluate the discriminatory ability of tumor makers. Additional external validation was performed using a dataset from Sun Yat-sen University Cancer Center.

RESULTS

Preoperative CEA/CA19-9 levels were identified as an independent predictor of overall survival (OS) and disease-specific survival (DSS) (both p < 0.05) in the development group. In a subgroup analysis based on TNM stage, preoperative CEA/CA19-9 levels clearly stratified the survival rates for stage III GC (p < 0.05). A multivariate analysis revealed that preoperative CEA/CA19-9 levels were an independent prognostic factor (p < 0.05) in stage III; the AUC of the preoperative CEA/CA19-9 was equivalent to that of T stage. A prediction model (TNMC) for stage III GC was developed by incorporating preoperative CEA/CA19-9 levels into the American Joint Committee on Cancer (AJCC) staging system. The AUC of the TNMC was significantly higher than that of the TNM staging system at 1, 3, and 5 years postoperatively (all p < 0.05), with similar results also being obtained in the external validation set.

CONCLUSION

Preoperative CEA/CA19-9 levels are an independent predictor of OS and DSS in stage III GC patients. The inclusion of preoperative CEA/CA19-9 levels in AJCC TNM staging provided an optimal prognosis in stage III GC.

Development and Evaluation of a Pliable Biological Valved Conduit. Part II: Functional and Hemodynamic Evaluation

Many congenital cardiac malformations may require a valved conduit for the reconstruction of the right ventricular outflow tract. In spite of many endeavors made in the last 25 years, the clinical results of right ventricular outflow tract reconstruction with currently available valved conduits are still not satisfactory. Specific problems encountered clinically include suboptimal hemodynamic performance, conduit kinking or compression, and fibrous peeling from the luminal surface. To address these deficiencies, we undertook the development of a biological valved conduit: a bovine external jugular vein graft with a retained native valve cross-linked with a diglycidyl ether (DE). This study, using a canine model, was to evaluate the functional and hemodynamic performance of this newly developed valved conduit. Three 14 mm conduits, implanted as bypass grafts, right ventricle to pulmonary artery, were evaluated. The evaluation was conducted with a noninvasive color Doppler flow mapping system at pre-implantation, immediately post implantation, one- and three-months post implantation, and prior to retrieval (five-months post implantation). The two-dimensional tomographic inspection of the leaflet motion at various periods post implantation showed that the valvular leaflets in the DE treated conduit was quite pliable. No cardiac failure or valvular dysfunction was observed in any of the studied cases. The color Doppler flow mapping study demonstrated that the valve in the DE treated conduit was competent, with no conduit kinking or compression observed in any of the three cases. The spectral Doppler velocity study evidenced that the transvalvular pressure gradients of the DE treated conduit were minimal as compared to those of the currently available conduits. In conclusion, from the functional and hemodynamic performance points of view, this newly developed valved conduit is superior to those currently available.

A Preliminary Study of the Fixation Mechanism of Collagen Reaction with a Polyepoxy Fixative

A new biomaterial has been developed by fixing native collagens with a polyepoxy compound (PC) fixative. Prior studies have shown that this biomaterial has comparable properties as compared to collagen fixed with glutaraldehyde (GA) and thus has a great promise for use as an implantable bioprosthesis. The purpose of this study was to understand the mechanism of the amino acids-PC reactions in the fixation process. Bovine arteries were fixed with PC under various pH, concentration and temperature conditions as a function of fixation time. Individual amino acid components in the fresh and the fixed arteries were assayed using a Beckman amino acid analyzer to determine the degree of tanning. The denaturation temperature (Td) was also measured on each sample. Since the denaturation temperature is a direct indication of cross-linking of individual amino acids with the fixative, the difference in the degree of tanning for the same increase in Td may be indicative of the quantity of the masked, non-cross-linked amino acids. The fixation reaction data indicated that not all amino acids were cross-linked upon contacting the PC fixative. Masking appeared to be more substantial with a fixation at higher pH values.

Development and Evaluation of a Pliable Biological Valved Conduit. Part I: Preparation, Biochemical Properties, and Histological Findings

Different types of external valved conduits have been used for the repair of complex congenital cardiac anomalies that may have otherwise been inoperable. However, an ideal conduit has yet to be found due to complications such as stenosis, thrombosis, calcification of the valve and graft wall, and “peeling” of the neointima. To address those problems, a new extracardiac valved conduit made of bovine jugular vein was developed and evaluated in a preliminary animal study. Harvested bovine vein containing a naturally existing valve was initially incorporated with protamine on the inner surface and then was cross-linked in diglycidyl ether (DE). Fixation with DE allowed the vein and its leaflets to retain a tissue-like elasticity. To provide antithrombogenicity to the graft, heparin was introduced into the lumen to bind ionically to the pre-entrapped protamine. The biological valved conduit of approximately 14 mm diameter was implanted from the right ventricle to pulmonary artery as bypass graft in three dogs. After implantation, the native main pulmonary artery was ligated between the anastomotic sites of the bypass conduit. No anticoagulant or antiplatelet drugs were administered after surgery. One DE-fixed valved conduit was retrieved at 3 months, and the others were removed at 5 months. Only small thrombus areas were found on the white luminal surfaces. The valves and the conduits maintained softness and pliability, similar to before implantation. Additionally, the collagen content, shrink temperature, and tanning index of this newly developed biological valved conduit before and after fixation were measured in the study. These preliminary results suggest that the new valved conduit fixed with DE and heparinized on the lumen may help mitigate the problems observed in the currently available conduits.

Evaluation of Collagen Modification and Surface Properties of a Bovine Artery via Polyepoxy Compound Fixation

Collagen of bovine internal thoracic artery (BITA) was treated with glutaraldehyde (GA) or polyepoxy compounds (PC). This study was to evaluate the surface properties as a result of tissue tanning reaction with PC. The fixation resulted in a significant reduction of available lysine, histidine, and other amino acid residues in PC fixed grafts as compared to fresh pre-fixed arteries. Among them, the lysine (Lys) content was reduced by about 80%, indicating that PC reactions mainly involve with Lys residues. Both PC and GA treatment led to crosslinking as evidenced by the increase in the denaturation temperature. The critical surface tension and the Fourier Transform Infrared Spectrum (FTIR) on a preimplant and its 96 days explant were evaluated and found to be similar. The FTIR analysis of a pre-implant and the 96 day explant indicated that there was no lipid deposition.

Heparinization of Biological Vascular Graft Reduces Fibrin Deposition

An alternative graft is needed for coronary bypass operations in patients lacking suitable autologous vessels. We therefore studied Denaflex™, a biologic graft, in a dog ex-vivo shunt model to determine whether heparin treatment makes this graft less thrombogenic. Comparison was also made to Bioflow™, a nonheparinized biologic graft. Fibrinogen deposition during high flow (593 ± 202 ml/min) decreased from 672 ± 467 ngl mm2 in nonheparinized Denaflex grafts to 448 ± 298 ng/mm2 (p<0.05) in heparinized Denaflex grafts. At low flow (117 ± 13 ml/min), heparinization of Denaflex grafts similarly decreased fibrinogen deposition from 1102 ± 601 ng/mm2 to 703 ± 405 ng/mm2 (p<0.05). At both flow rates fibrinogen deposition in Bioflow grafts was less than in nonheparinized Denaflex, but was similar to heparinized Denaflex grafts. Platelet deposition was not influenced by heparinization of Denaflex grafts and was similar among Denaflex and Bioflow preparations. Whether Denaflex performs acceptably in vivo as a xenograft requires extensive study.

A Compliant Biological Vascular Prosthesis

One requirement of the mechanical parameters for an acceptable vascular prosthesis is compliance. The compliance of a vascular prosthesis is defined as the fractional change in luminal volume per unit change in applied pressure. A compliant prosthesis has been correlated to prosthesis patency and long-term efficacy in an animal study. However, there have been very few reports on how to manufacture a compliant prosthesis. It is the objective of this study to research the processing methods to manufacture a reasonably compliant vascular prosthesis. A new fixative, polyepoxy compound, was used to fix an artery. The arteries were fixed under different degrees of longitudinal retraction. By locking in the collagen micro-structure at an overly relaxed state and then crosslinking said collagen, the resulting biological prosthesis exhibited extreme compliance and pliability. A prosthesis matching its arterial origin in tensile modulus was achieved by crosslinking an artery at its 45% retraction longitudinally. This flexible prosthesis showed a volumetric compliance index of 18.4 ± 0.9 %Δ/100 mmHg and a longitudinal tensile modulus of 942 grams/cm2. Our current study indicated that a prosthesis fixed with polyepoxy compounds has shown more pliability than that with glutaraldehyde. Further animal study to correlate prostheses patency to different degrees of compliance is needed to confirm this proposed manufacturing approach.

Relationship between spicy flavor, spicy food intake frequency, and general obesity in a rural adult Chinese population: The RuralDiab study

BACKGROUND AND AIMS

The purpose of this study was to explore the association between spicy flavor, spicy food frequency, and general obesity in Chinese rural adults.

METHODS AND RESULTS

A total of 15,683 subjects (5907 males, 9776 females) aged 35-74 years from the RuralDiab Study were recruited for this cross-sectional study. Analysis of covariance was used to determine the differences of participant characteristics across body mass index (BMI) categories. Logistic regression yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for obesity associated with the level of spicy flavor and frequency of spicy food intake. A meta-analysis was conducted to validate the result of the cross-sectional study. The crude and standardized prevalence of obesity were 16.78% and 17.57%, respectively. Compared with No spicy flavor, the adjusted ORs (95% CIs) of Mild, Middle, and Heavy spicy flavor for obesity were 1.232 (1.117-1.359), 1.463 (1.290-1.659), and 1.591 (1.293-1.958), respectively (P_trend < 0.001). Similarly, compared with no spicy food consumption, the adjusted ORs (95% CIs) of 1 or 2 days/week, 3-5 days/week, and 6 or 7 days/week were 1.097 (0.735-1.639), 1.294 (0.932-1.796), and 1.250 (1.025-1.525), respectively (P_trend = 0.026). The point estimate and 95% CI of mean BMI difference between the spicy food consuming group and spicy food non-consuming group was 0.37 (95% CI: 0.30-0.44) in the meta-analysis.

CONCLUSION

The data indicated that spicy flavor and spicy food frequency were positively associated with general obesity in Chinese rural populations.

Health Care Economics: A Study Guide for Neuroradiology Fellows, Part 2

In this second article, we continue the review of current health care economics as it relates to radiologists, specifically framed by topics defined by the Accreditation Council for Graduate Medical Education in the evaluation of neuroradiology fellows. The discussion in this article is focused on topics pertaining to levels 4 and 5, which are the more advanced levels of competency defined by the Accreditation Council for Graduate Medical Education Neuroradiology Milestones on Health Care Economics and System Based Practice.

Health Care Economics: A Study Guide for Neuroradiology Fellows, Part 1

Few resources are available in the medical literature for a comprehensive review of current health care economics as it relates to radiologists, specifically framed by topics defined by the Accreditation Council for Graduate Medical Education in the evaluation of neuroradiology fellows. Therefore, we present a comprehensive review article as a study guide for fellows to learn from and gain competence in the Accreditation Council for Graduate Medical Education neuroradiology milestones on health care economics.

Effects of Preoperative Malnutrition on Short- and Long-Term Outcomes of Patients with Gastric Cancer: Can We Do Better?

BACKGROUND

The effects of preoperative malnutrition and preoperative correction of hypoalbuminemia (PCH) on the short- and long-term outcomes in patients with gastric cancer are unclear.

OBJECTIVE

This study aimed to examine the effect of preoperative nutritional status on short- and long-term outcomes in patients who underwent radical gastrectomy, and also explored the role of PCH in malnourished patients with gastric cancer.

METHODS

We prospectively reviewed data from patients with gastric cancer who were treated in our department between January 2009 and December 2014. The effect of preoperative nutritional status on short- and long-term outcomes in patients who underwent radical gastrectomy was investigated, and we explored whether PCH could improve the short- and long-term outcomes of these patients.

RESULTS

A total of 1976 patients were analyzed, including 412 patients in the malnourished group and 1564 in the well-nourished group. The overall incidence of complications in the malnourished group was significantly higher than the well-nourished group (21.4 vs. 15.5%, p = 0.005). Except for incision infection (3.2 vs. 1.6%, p = 0.041), there were no significant differences for other complications. In the malnourished group, 98 cases of preoperative hypoproteinemia were corrected (PCH group), whereas 314 cases were not (NPCH group). The incidence of incision infection in the PCH group was significantly lower than in the NPCH group (0 vs. 4.1%, p = 0.041). The median follow-up time was 39 months (1.0-88.0 months), and the 3-year overall survival (OS; 59.1 vs. 75%, p < 0.001) and disease-free survival (DFS; 54.8 vs. 72.5%, p < 0.001) rates were significantly lower in the malnourished group than in the well-nourished group. A multivariate Cox regression analysis showed that malnutrition was an independent prognostic factor for 3-year OS (hazard ratio [HR] 1.211, 95% confidence interval [CI] 1.01-1.452, p = 0.039) and DFS (HR 1.168, 95% CI 1.013-1.398, p = 0.043). For the malnourished group with stage I gastric cancer, the PCH and NPCH groups showed no significant differences in 3-year OS (90.0 vs. 89.0%, p = 0.227) or DFS (90.0 vs. 87.3%, p = 0.363); however, for the malnourished group with stages II-III gastric cancer, the 3-year OS (69.9 vs. 47.6%, p = 0.013) and DFS (55.4 vs. 43.6%, p = 0.046) rates were significantly higher in the PCH group than in the NPCH group.

CONCLUSIONS

The incidence of incision infection was significantly higher in patients with malnutrition than in well-nourished patients. The 3-year OS and DFS rates were significantly lower in malnourished patients than in well-nourished patients. PCH may both reduce the incidence of incisional infection in patients with malnutrition and improve 3-year OS and DFS rates for malnourished patients with stages II-III gastric cancer; however, to confirm our findings, further studies are warranted.

Prostaglandin E2 regulates renal function in C57/BL6 mouse with 5/6 nephrectomy

AIMS

To investigate the roles of cyclooxygenases (COX) and their metabolites in C57/BL6 mice with 5/6 nephrectomy, an animal model of chronic renal failure.

MAIN METHODS

C57/BL6 mice were grouped into sham-operated (2K), one kidney removal (1K) and 5/6 nephrectomy groups (5/6Nx). Renal resistive index was measured by ultrasonography. Blood, aortae, renal arteries and renal cortex were collected for measurement of kidney function, assessment of vascular responsiveness, Western blotting, immuohistochemistry and enzyme-linked immunosorbent assays.

KEY FINDINGS

After four weeks, acetylcholine-induced relaxations were blunted in renal arteries of 1K and 5/6Nx mice; indomethacin, a non-selective COX inhibitor, improved the response in 5/6Nx, but not in 1K renal arteries. In 5/6Nx renal arteries, but not in 1K preparations, the protein presence of endothelial nitric oxide synthase (eNOS) was decreased, while that of COX-2 and its products [prostacyclin and thromboxane A₂] were increased. The renal resistive index was lower in 5/6Nx mice, suggesting a lower resistance in the renal microvasculature. In the renal cortex of 5/6Nx mice, eNOS protein presence was increased; while the presence of COX-2 was not detectable. The prostaglandin E₂ level was lower in the 5/6Nx cortex than in the other two groups.

SIGNIFICANCE

The early stage of renal mass removal is associated with increased renal arterial constriction and reduced microvascular resistance. The former is due to downregulation of eNOS and upregulation of COX-2, leading to an increased production of prostacyclin and thromboxane A₂. A reduced production of PGE₂ in the renal cortex is important for maintaining normal renal function.

[Assessment value of preoperative platelet-lymphocyte ratio in the prognosis of patients with gastric mixed adenoneuroendocrine carcinoma]

OBJECTIVE

To explore the prognostic assessment value of preoperative blood platelet-lymphocyte ratio (PLR) in patients with gastric mixed adenoneuroendocrine carcinoma (gMANEC) treated with radical surgery.

METHODS

Clinical and pathological data of 84 gMANEC patients who underwent radical resection from 2006 to 2016 in Department of Gastric Surgery, Fujian Medical University Union Hospital were analyzed retrospectively. Receiver operating characteristic (ROC) curve analysis was performed to determine the cutoff value of the PLR for predicting prognosis. The Cox proportional hazards regression model was used to identify prognostic factors of gMANEC.

RESULTS

All the patients underwent D2 lymph node dissection, including 26 cases of distal subtotal gastrectomy and 58 cases of total gastrectomy. The postoperative pathological TNM stage system(pTNM) demonstrated that the patients of stage I(, II(, and III( were 9(10.7%), 14(16.7%), and 61(72.6%) cases, respectively. The median follow-up time was 40(3 to 96) months. The recurrence rate was 41.7%(35/84). The median time to recurrence was 10 (1 to 40) months, and 82.9%(29/35) patients experienced recurrence within the first 2 years after operation. The median overall survival time was 27(3 to 39) month, and the median recurrence-free survival time was 21 (1 to 96) months. The 1-, 3-, and 5-year overall survival(OS) rates were 87.6%, 56.6%, and 47.4%, respectively, and the 1-, 3-, and 5-year recurrence-free survival (RFS) rates were 70.5%, 50.7%, and 44.9%, respectively. The best cutoff value of the PLR for predicting prognosis was 133 through ROC curve, which categorized all the patients into low PLR group (≤133) comprising 28 patients and high PLR group (>133) comprising 56 patients. The tumor recurrence rate was significantly higher in high PLR group (50.0%, 28/56) than that in low PLR group(25.0%, 7/28)(P=0.028). The live metastasis rate was significantly higher in high PLR group(35.7%, 20/56) than that in low PLR group(10.7%, 3/28)(P=0.015). Cox regression analysis showed that only pTNM stage (P=0.003) was independent prognostic factors of OS, while both pTNM stage (P=0.000) and blood PLR (P=0.015) were independent prognostic factors of RFS.

CONCLUSION

gMANEC patients with high preoperative PLR tend to present recurrence and metastasis, especially to present live metastasis, so they should be kept under surveillance more frequently after surgery.

[Efficacy evaluation of laparoscopic D2 radical gastrectomy in gastric neuroendocrine carcinoma]

OBJECTIVE

To explore the feasibility and efficacy of laparoscopic D2 radical gastrectomy in patients with gastric neuroendocrine carcinoma (GNEC).

METHODS

Clinical data of 84 patients with GNEC undergoing laparoscopic D2 radical gastrectomy in Union Hospital from January 2006 to December 2012 were analyzed respectively. Among these patients, 44 cases underwent laparoscopic D2 gastrectomy (LAG group) and 40 cases underwent open gastrectomy (OG group). The short- and long-term outcomes, 3-year survival and recurrence-free survival were compared between two groups.

RESULTS

The LAG group and OG group did not differ significantly in terms of clinicopathologic characteristics. All the patients completed operations successfully and no patients in the LAG group ware converted to laparotomy. The operative time was similar (P>0.05). As compared to OG group, LAG group had less intra-operative blood loss [(85±21) ml vs. (192±89) ml, P=0.003], lower ratio of transfusion [2.3%(1/44) vs. 15.0%(6/40), P=0.048], shorter time to ambulation after surgery [(2.5±1.1) days vs. (3.5±1.1) days, P=0.001], faster postoperative gastrointestinal function recovery [(2.9±1.1) days vs. (5.1±1.0) days, P=0.001], shorter time to resume soft diet [(4.1±1.2) days vs. (5.7±1.3) days, P=0.001] and shorter postoperative hospital stay [(12.0±3.4) days vs. (15.0±5.5) days, P=0.002]. No significant difference was observed in average dissected lymph node number between LAG and OG group (35.0±16.4 vs. 31.6±12.1, P=0.204). Morbidity of postoperative complication of LAG group and OG group was 11.4%(5/44) and 17.5%(7/40) respectively (P=0.422). The overall 3-year survival rate was 54.0% for all the patients, while 3-year survival rate was 56.3% in LAG group and 51.4 % in OG group (P=0.478). In addition, there was no significant difference in recurrence-free survival between the two group (33.0 months vs. 31.5 months, P=0.703).

CONCLUSION

Compared with open gastrectomy, laparoscopic D2 radical gastrectomy has the advantages of faster recovery and less blood loss, and similar short-term and long-term outcomes in treatment of patients with GNEC, thus it is a safe and feasible treatment for GNEC.

Current Procedural Terminology: History, Structure, and Relationship to Valuation for the Neuroradiologist

The year 1965 was critical for US health care policy. In that year, Medicare was created as part of the Social Security Act under President Lyndon B. Johnson after several earlier attempts by Presidents Franklin Roosevelt and Harry Truman. In 1966, the American Medical Association first published a set of standard terms and descriptors to document medical procedures, known as Current Procedural Terminology, or CPT. Fifty years later, though providers have certainly heard the term "CPT code," most would benefit from an enhanced understanding of the historical basis, current structure, and relationship to valuation of Current Procedural Terminology. This article will highlight this evolution, particularly as it relates to neuroradiology.

Evaluation of laparoscopic total gastrectomy for advanced gastric cancer: results of a comparison with laparoscopic distal gastrectomy

OBJECTIVE

To validate the efficacy and safety of laparoscopic total gastrectomy (LTG) for advanced gastric cancer (AGC).

BACKGROUND

Laparoscopic distal gastrectomy (LDG) in the treatment of patients with local AGC is becoming increasingly popular, and there have been several multicenter randomized controlled trials focused on this treatment. However, few reports on the procedure of LTG for AGC exist.

METHODS

The data of 976 patients who underwent LTG for AGC were retrieved from a prospectively constructed database of 2170 patients who underwent laparoscopic gastrectomy between 2007 and 2013. Surgical outcomes of LTG were investigated and compared with those of patients who underwent LDG.

RESULTS

LTG was associated with significantly longer operation time, number of dissected lymph nodes, and time of resume soft diet compared with the LDG group. According to Clavien-Dindo classification, the morbidity and mortality rates of the LTG group were comparable to those of the LDG group. Multivariate analyses revealed that elderly patients, more comorbidities, and longer operation time were the significant independent risk factors for determining postoperative complications. The difference in overall survival rates between the two groups was statistically significant. However, a comparative analysis of overall survival showed no statistical significance for any of the stages of cancer between the LTG and LDG groups.

CONCLUSIONS

The study findings suggest that LTG is an oncologically safe procedure for AGC yields comparable surgical outcomes. A well-designed phase III trial can be carried out to provide valuable evidence for the oncologic safety of LTG for the treatment of AGC.

Micro-computerized tomography assessment of fluorescence aided caries excavation (FACE) technology: comparison with three other caries removal techniques

BACKGROUND

The aim of this study was to determine the caries removal effectiveness (CRE) and minimal invasiveness potential (MIP) of four dentine caries removal methods.

METHODS

After carious molars were scanned using micro-computerized tomography (micro-CT), dentine caries were removed by fluorescence aided caries excavation (FACE) technology, laser induced fluorescence (LIF), chemomechanical excavation (CME), and conventional excavation (CE). Micro-CT was then repeated. CRE was determined based on the volume of residual caries/initial caries (RC/IC) and the mean mineral density (MD) at the cavity floor. MIP was determined by measuring the volume of the prepared cavity/initial cavity (PC/IC).

RESULTS

Among the four groups, the LIF group had the smallest RC/IC (0.08), the highest mean MD at the cavity floor (1.32 g/cm(3) ) and the highest MIP (4.47). The CME group had the highest RC/IC (0.24), the lowest mean MD (1.01 g/cm(3) ) and the lowest MIP (2.23). The CE group exhibited a more acceptable CRE (RC/IC = 0.13, mean MD = 1.21 g/cm(3) ) but had a higher MIP (3.95). Both the CRE and MIP parameters of FACE technology were the second most acceptable (RC/IC = 0.12, mean MD = 1.13 g/cm(3) , MIP = 3.20) and did not differ significantly from the most acceptable.

CONCLUSIONS

FACE is an effective caries removal technology for removing infected dentine without significantly increasing cavity size.

Identification of nitrogen-fixing Paenibacillus from different plant rhizospheres and a novel nifH gene detected in the P. stellifer

A total of 534 isolates were selectively obtained from different plant rhizospheres based on their growth on nitrogen-free medium and their resistance to 80 degrees C for 15 min. Of the 534 isolates, 23 isolates had nifH gene and exhibited nitrogenase activities. Based on 16S rDNA sequence, G + C content assay and DNA-DNA hybridization, by the 23 isolates, which were divided into four monophyletic clusters, all belonged to the Paenibacillus genus. NifH gene deduced amino acid alignment analysis revealed that cluster I, including 15 isolates, showed the highest NifH identity with Paenibacillus genus; while cluster II identified as P stellifer by DNA-DNA hybridization was consistent with four uncultured bacterial clones. This study suggested that the nitrogen-fixing Paenibacillus were distributed in various ecosystems and prevalent in different plant rhizospheres. It was the first demonstration that nitrogen fixation existed in P. jamilae and P. stellifer. In eight isolates identified as P. stellfer species, a novel nifH gene was detected in Paenibacillus.

Human PDE5A gene encodes three PDE5 isoforms from two alternate promoters

Sildenafil improves erectile function by inhibiting the cGMP-catalytic activity of phosphodiesterase type V (PDE5). We used rapid amplification of cDNA Ends-polymerase chain reaction (RACE-PCR) to isolate three PDE5 isoforms from human corpus cavernosum. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis on eight human cavernous tissue samples showed that all samples expressed the PDE5A1 at a lower level than the PDE5A2 isoform. Five samples expressed the PDE5A3 isoform at various levels while the other three did not. Analysis on non-penile tissues showed that all tissues expressed the A1 and A2 isoforms while only those that have substantial amounts of smooth muscle expressed the A3 isoform. Cloning and sequencing of the PDE5A gene showed that the isoform-specific 5'-ends of the PDE5 mRNAs are encoded from three alternative first exons arranged in the order of A1-A3-A2. Promoter activities were detected upstream from the A1-specific exon and in the intron preceding the A2-specific exon. The upstream PDE5A promoter is expected to direct the expression of all three PDE5 isoforms while the intronic PDE5A2 promoter only the A2 isoform. Both promoters were upregulated by increasing concentrations of either cAMP or cGMP. Several transcription factor AP2 and Sp1-binding sequences identified in the promoters are likely to be the mediators of cAMP/cGMP-responsiveness.

Age-related decrease of protein kinase G activation in vascular smooth muscle cells

Protein kinase G-I (PKG-I) activation is essential for vascular relaxation; however, its quantitative analysis in intact cells has been difficult. To overcome this difficulty, a monoclonal antibody, VASP-16C2, was recently developed that detects phosphorylated serine residue 239 of vasodilator-stimulated phosphoprotein (VASP), a substrate of PKG-I. In this study, we used this antibody to examine (i) possible functional differences between the alpha and beta isoforms of PKG-I, (ii) ability of cAMP to activate PKG-I, as compared to cGMP, the principal PKG-I-activating cyclic nucleotide, and (iii) time course and levels of PKG-I activation in vascular smooth muscle cells (VSMC) of young and old rats. We created COS-7 cell clones that overexpressed PKG-Ialpha or PKG-Ibeta, treated them with cAMP or cGMP, and analyzed their cell lysates for reactivity with VASP-16C2. The results showed that PKG-Ialpha phosphorylated VASP at a higher level than PKG-Ibeta, and cAMP was slightly weaker than cGMP in PKG-I activation. VSMC of young rats responded to cAMP or cGMP stimulation in a dose-dependent manner with increasing levels of PKG-I activation. The response was detected within 10 min and continued for at least 24 h. In contrast, VSMC of old rats showed no PKG-I activation during the first hour of cAMP or cGMP stimulation and, at 24 h these cells showed only low-level PKG-I activation. We propose that the reduced PKG-I activation may explain why vascular relaxation is decreased in older individuals.

Identification and regulation of human PDE5A gene promoter

PDE5A gene encodes type 5 phosphodiesterase (PDE5), the principal cGMP-catalyzing enzyme in the penis and the primary target of sildenafil (Viagra). We have isolated a 3.7-kb DNA fragment that contains the human PDE5A gene promoter. The DNA fragment contains a sequence of 234 nucleotides at its 3' end that corresponds to most of the untranslated region of the PDE5A1 mRNA. The remaining 3.5-kb upstream flanking sequence contains no apparent TATA box but has several sequences that resemble binding sequences for transcription factors such as androgen receptor (AR), AP1, AP2, AP4, Sp1, MyoD, Myc, and CArG. In search of promoter activities, we used a luciferase reporter system to examine 10 DNA fragments that cover various regions of the 3.7-kb fragment. We found that a full basal promoter activity was confined to a 139-bp region that includes 78 bp of the PDE5A1-specific first exon. A lesser basal promoter activity was still detectable in a 94-bp fragment that contains the same 78-bp PDE5A1-specific exon plus 16 bp of upstream sequence. Either the 139-bp or the 94-bp promoter fragment responded minimally to cAMP or cGMP (2 mM) stimulation. Longer fragments that contain either a 308-bp 5' extension (from the 138-bp fragment) or a 156-bp 3' extension (all exon sequence) responded at higher levels to cAMP and cGMP stimulation. The 5' and 3' extensions cooperated with each other to provide the highest level of responses to cAMP and cGMP stimulation. DNase I footprint analysis identified four AP2- and two Sp1-binding sites in the 5' extension and four Sp1-binding sites in the 3' extensions. Cyclic AMP and cGMP had similar stimulatory effects on the PDE5A promoter.

Regulation of human PDE5A2 intronic promoter by cAMP and cGMP: identification of a critical Sp1-binding site

PDE5A gene encodes type 5 phosphodiesterase (PDE5), the principal cGMP-catalyzing enzyme in the penis and the primary target of sildenafil (Viagra). We have previously reported the isolation of three alternatively spliced PDE5A isoforms in humans. We also reported the identification of three corresponding alternative first exons and an intronic promoter in the human PDE5A gene. The intronic promoter is situated upstream from the PDE5A2-specific first exon but downstream from the PDE5A1- and A3-specific first exons. In the current study we showed that the intronic promoter could be upregulated by either cAMP or cGMP. In order to identify possible regulatory elements in the promoter, we created deletion and base-substitution mutants targeting one AP2- and four Sp1-binding sequences. Loss of function of these mutants to bind to the respective transcription factors was verified by DNase I footprint analysis, and changes in promoter function were analyzed with a luciferase reporter system. Mutation of the AP2-binding sequence and deletion of the 3'-most Sp1-binding site (within the exon) had little effects on the basal or the cyclic nucleotide-inducible promoter functions. Mutation of the 5'-most Sp1-binding site had much more severe effects on the basal and the cyclic nucleotide-inducible promoter functions. Mutation of a neighboring site that contains two overlapping Sp1-binding sequences completely nullified the basal and cyclic nucleotide-inducible promoter activities. Thus, the PDE5A2 intronic promoter depends on the overlapping Sp1-binding site for basal and cyclic nucleotide-inducible functions.

Endogenous Zn(2+) is required for the induction of long-term potentiation at rat hippocampal mossy fiber-CA3 synapses

The functional role of the abundant Zn(2+) found in some hippocampal synapses has been an enigma. We show here, using N-[6-methoxy-8-quinolyl]-P-toluenesulfonamide (TSQ) staining, that chelatable-Zn(2+) can be removed from hippocampal synaptic boutons using dietary depletion or with Zn(2+) chelators. A chronic dietary deficiency of bouton Zn(2+) resulted in the impairment of long-term potentiation (LTP) at mossy fiber-CA3 synapses. The averaged normalized fEPSP slope 30 min after tetanus was 209 +/- 28% of baseline value in control (mean +/- SEM, n = 10), and 118 +/- 12% in Zn(2+)-deficient rats (mean +/- SEM, n = 12, P < 0.01). In the deficient rats with Zn(2+) supplements, mossy fiber LTP returned to normal levels. The acute depletion of bouton Zn(2+) in the hippocampal slice with membrane-permeable Zn(2+) chelators, dithizone, or diethyldithiocarbamic acid (DEDTC) blocked the induction of mossy fiber LTP. The mean amplitudes of EPSCs after tetanus were 194 +/- 22% of baseline value in control (n = 5), compared to 108 +/- 14% in dithizone (n = 6) and 101 +/- 12% in DEDTC (n = 5). The averaged value of LTP, at the associational commisural fiber-CA3 synapses, was 193 +/- 20% in the control (n = 6), compared to 182 +/- 21% (n = 6, P > 0.1) in the presence of dithizone. The blockade of mossy fiber LTP by dithizone was reversible after washout. In addition, normal LTP could be induced by tetanus if exogenous Zn(2+) was applied immediately following dithizone. Our results indicate that the endogenous Zn(2+) is specifically required for LTP induction at the mossy fiber input into CA3 neurons.

Magnetic resonance imaging in patients with central nervous system pathology: a comparison of OptiMARK (Gd-DTPA-BMEA) and Magnevist (Gd-DTPA)

RATIONALE AND OBJECTIVES

The objective of the two pivotal phase 3 studies was to evaluate the safety and efficacy of OptiMARK (Gd-DTPA-bis(methoxyethylamide) [Gd-DTPA-BMEA]) compared with Magnevist (Gd-DTPA) in magnetic resonance imaging of the central nervous system.

METHODS

Two multicenter, randomized, double-blind, parallel group studies were conducted in 395 patients with known or suspected central nervous system pathology. Subjects were randomized to receive a single 0.1 mmol/kg intravenous injection of either Gd-DTPA-BMEA or Gd-DTPA. The safety of Gd-DTPA-BMEA and Gd-DTPA was monitored for up to 72 hours after study drug administration. Precontrast and postcontrast administration magnetic resonance scans were acquired using identical imaging planes and techniques.

RESULTS

No deaths or unexpected adverse events were reported in either group. A comparison of adverse events by intensity and relation demonstrated no statistically significant differences between the two groups. Gd-DTPA-BMEA and Gd-DTPA were equivalent with respect to confidence in diagnosis, conspicuity, and border delineation.

CONCLUSIONS

Gd-DTPA-BMEA and Gd-DTPA demonstrated comparable efficacy profiles, and the safety profiles were considered similar.

Homologous acellular matrix graft for urethral reconstruction in the rabbit: histological and functional evaluation

OBJECTIVE

To evaluate urethral replacement by a free homologous graft of acellular urethral matrix in a rabbit model.

MATERIALS AND METHODS

In 30 male New Zealand rabbits, a 0.8 to 1.1 cm. segment of the urethra was resected, replaced with an acellular matrix graft of 1.0 to 1.5 cm. (mean 1.3 cm.), and placed on an 8F feeding tube. Additionally 4 animals underwent sham operation. At varying intervals before sacrifice (from 10 days to 8 months), the animals underwent urodynamic evaluation and retrograde urethrography (for which 4 untreated rabbits served as control). The grafted specimens were prepared for evaluation histologically and by reverse-transcription polymerase chain reaction (RT-PCR).

RESULTS

In all animals, the acellular matrix graft remained in its original position. Histological examination showed complete epithelialization and progressive vessel infiltration. At 3 months, smooth muscle bundles were first observed infiltrating the matrix at the end-to-end anastomosis; after 6 months, the smooth muscle bundles had grown into one-third of the matrix. Urodynamics did not detect any difference between the control and matrix-grafted animals in bladder volume, leak-point pressure and residual volume. RT-PCR detected an increase in IGF mRNA in the graft between week 3 and month 6 and in HB-EGF mRNA after day 10 through month 3. TGF-alpha mRNA was not detected; TGF-beta mRNA was unchanged from normal urethral tissue. By 8 months, the host and implant could not be differentiated by urethrography.

CONCLUSION

The acellular urethral matrix allows single-stage urethral reconstruction. All tissue components were seen in the grafted matrix after 3 months, with further improvement over time; however, the smooth muscle in the matrix was less than in normal rabbit urethra and was not well oriented. RT-PCR revealed the importance of time-dependent growth factor influences during regeneration.

Identification of three alternative first exons and an intronic promoter of human PDE5A gene

In the accompanying paper we present evidence for the existence of three PDE5A isoforms that differed only in the 5' end of the mRNAs. In this paper we present evidence that the three isoform-specific 5' ends were encoded by three alternative first exons that were arranged in the order of A1-A3-A2. Because the isoform-specific mRNAs could be transcribed from individual promoters, DNA fragments of the two intronic regions (A1-A3 and A3-A2) were tested for possible promoter activities. The intron between A1- and A3-specific exons did not exhibit any promoter activities even in smooth muscle cells that expressed the A3 isoform (see accompanying paper). In contrast, the intron between A3- and A2-specific exons had promoter activities in PDE5A2-expressing COS-7 and smooth muscle cells. This intronic promoter was bound by transcription factors AP-2 and Sp1, but not by AP-1, as shown by DNase I footprint analysis. However, the sequence bound by AP-2 (5'-GGGAAACGCTCGCGGGAGAGTTGG) is unusual in that it bears little resemblance to the consensus AP-2-binding sequence.