Simvastatin ameliorates synaptic plasticity impairment in chronic mild stress-induced depressed mice by modulating hippocampal NMDA receptor

BACKGROUND

In our previous study, we showed simvastatin exerts an antidepressant effect and inhibits neuroinflammation. Given the role of synaptic impairment in depression development, we investigate the effect of simvastatin on synaptic plasticity in depression and the related mechanisms.

METHODS

Electrophysiological analysis, Golgi staining, and transmission electron microscope were performed to analyze the effect of simvastatin on synaptic impairment in depression. In addition, the localization and reactivity of N-methyl-D-aspartate receptor (NMDAR) subunits and the downstream signaling were investigated to explore the mechanism of simvastatin's effect on synaptic plasticity.

RESULTS

Simvastatin ameliorated the reduction of the magnitude of long-term potentiation (LTP) in Schaffer collateral-CA1, restored hippocampal dendritic spine density loss, improved the number of spine synapses, reversed the reduction in BrdU-positive cells in chronic mild stress (CMS)-induced depressed mice, and ameliorated NMDA-induced neurotoxicity in hippocampal neurons. Dysfunction of NMDAR activity in the hippocampus is associated with depression. Simvastatin treatment reversed the surface expression and phosphorylation changes of NMDAR subunits in NMDA-treated hippocampal neurons and depressed mice. In addition, simvastatin further increased the levels of mature BDNF, activating TrkB-Akt-mTOR signaling, which is critical for synaptic plasticity.

CONCLUSIONS

These findings suggest that simvastatin can improve the dysfunction of NMDAR and ameliorate hippocampal synaptic plasticity impairment in depressed mice.

DECREASE IN THE PLATELET-TO-LYMPHOCYTE RATIO IN DAYS AFTER ADMISSION FOR SEPSIS CORRELATES WITH IN-HOSPITAL MORTALITY

ABSTRACT

Background: A previous study has linked an increase in platelet-to-lymphocyte ratio (PLR) to a poor prognosis; however, the relationship between early change in PLR and outcomes in sepsis patients is unclear. Methods : The Medical Information Mart for Intensive Care IV database was for this retrospective cohort analysis on patients meeting the Sepsis-3 criteria. All the patients meet the Sepsis-3 criteria. The platelet-to-lymphocyte ratio (PLR) was calculated by dividing the platelet count by the lymphocyte count. We collected all PLR measurements that were available within 3 days of admission for analysis of longitudinal changes over time. Multivariable logistic regression analysis was used to determine the relationship between the baseline PLR and in-hospital mortality. After correcting for possible confounders, the generalized additive mixed model was used to examine the trends in PLR over time among survivors and nonsurvivors. Results: Finally, 3,303 patients were enrolled, and both low and high PLR levels were significantly associated with higher in-hospital mortality in the multiple logistic regression analysis (tertile 1: odds ratio, 1.240; 95% confidence interval, 0.981-1.568 and tertile 3: odds ratio, 1.410; 95% confidence interval, 1.120-1.776, respectively). The generalized additive mixed model results revealed that the PLR of the nonsurvival group declined faster than that of the survival group within 3 days after intensive care unit admission. After controlling for confounders, the difference between the two groups steadily decreased and increased by an average of 37.38 daily. Conclusions : There was a U-shaped relationship between the baseline PLR and in-hospital mortality of sepsis patients, and there was a significant difference between the nonsurvival and survival groups in the change in PLR over time. The early decrease in PLR was related to an increase in in-hospital mortality.

[Outcomes at discharge of preterm infants born <34 weeks' gestation]

Objective: To investigate the incidence and trend of short-term outcomes among preterm infants born <34 weeks' gestation. Methods: A secondary analysis of data from the standardized database established by a multicenter cluster-randomized controlled study "reduction of infection in neonatal intensive care units (NICU) using the evidence-based practice for improving quality (REIN-EPIQ) study". This study was conducted in 25 tertiary NICU. A total of 27 192 infants with gestational age <34 weeks at birth and admitted to NICU within the first 7 days of life from May 2015 to April 2018 were enrolled. Infants with severe congenital malformation were excluded. Descriptive analyses were used to describe the mortality and major morbidities of preterm infants by gestational age groups and different admission year groups. Cochran-Armitage test and Jonckheere-Terpstra test were used to analyze the trend of incidences of mortality and morbidities in 3 study-years. Multiple Logistic regression model was constructed to analyze the differences of outcomes in 3 study-years adjusting for confounders. Results: A total of 27 192 preterm infants were enrolled with gestational age of (31.3±2.0) weeks at birth and weight of (1 617±415) g at birth. Overall, 9.5% (2 594/27 192) of infants were discharged against medical advice, and the overall mortality rate was 10.7% (2 907/27 192). Mortality for infants who received complete care was 4.7% (1 147/24 598), and mortality or any major morbidity was 26.2% (6 452/24 598). The incidences of moderate to severe bronchopulmonary dysplasia, sepsis, severe intraventricular hemorrhage or periventricular leukomalacia, proven necrotizing enterocolitis, and severe retinopathy of prematurity were 16.0% (4 342/27 192), 11.9% (3 225/27 192), 6.8% (1 641/24 206), 3.6% (939/25 762) and 1.5% (214/13 868), respectively. There was a decreasing of the overall mortality (P<0.001) during the 3 years. Also, the incidences for sepsis and severe retinopathy of prematurity both decreased (both P<0.001). However, there were no significant differences in the major morbidity in preterm infants who received complete care during the 3-year study period (P=0.230). After adjusting for confounders, infants admitted during the third study year showed significantly lower risk of overall mortality (adjust OR=0.62, 95%CI 0.55-0.69, P<0.001), mortality or major morbidity, moderate to severe bronchopulmonary dysplasia, sepsis and severe retinopathy of prematurity, compared to those admitted in the first study year (all P<0.05). Conclusions: From 2015 to 2018, the mortality and major morbidities among preterm infants in Chinese NICU decreased, but there is still space for further efforts. Further targeted quality improvement is needed to improve the overall outcome of preterm infants.

Population Pharmacokinetics of Colistin Sulfate in Critically Ill Patients: Exposure and Clinical Efficacy

Background: Presently, colistin is commercially available in two different forms, namely, colistin sulfate and its sulphomethylated derivative, colistimethate sodium (CMS). However, in the currently reported studies, most of the clinical studies on colistin for parenteral use are referred to as CMS. Data on the pharmacokinetics (PK), clinical efficacy, and side effects of colistin sulfate in clinical use have not been reported.

Methods: This retrospective study was performed on carbapenem-resistant organism (CRO)-infected patients treated with colistin sulfate for more than 72 h. The population pharmacokinetic model was developed using the NONMEM program. The clinical outcomes including clinical treatment efficacy, microbiological eradication, and nephrotoxicity were assessed. Monte Carlo simulation was utilized to calculate the probability of target attainment (PTA) in patients with normal or decreased renal function.

Results: A total of 42 patients were enrolled, of which 25 (59.52%) patients were considered clinical treatment success and 29 (69.06%) patients had successful bacteria elimination at the end of treatment. Remarkably, no patient developed colistin sulfate-related nephrotoxicity. A total of 112 colistin concentrations with a range of 0.28–6.20 mg/L were included for PK modeling. The PK characteristic of colistin was well illustrated by a one-compartment model with linear elimination, and creatinine clearance (CrCL) was identified as a covariate on the clearance of colistin sulfate that significantly explained inter-individual variability. Monte Carlo simulations showed that the recommended dose regimen of colistin sulfate, according to the label sheet, of a daily dose of 1–1.5 million IU/day, given in 2–3 doses, could attain PTA &gt; 90% for MICs ≤ 0.5 μg/mL, and that a daily dose of 1 million IU/day could pose a risk of subtherapeutic exposure for MIC ≥1 μg/ml in renal healthy patients.

Conclusion: Renal function significantly affects the clearance of colistin sulfate. A dose of 750,000 U every 12 h was recommended for pathogens with MIC ≤1 μg/ml. The dosage recommended by the label inserts had a risk of subtherapeutic exposure for pathogens with MIC ≥2 μg/ml. Despite higher exposure to colistin in patients with acute renal insufficiency, dose reduction was not recommended.

[Analysis of clinical phenotype and genotype of Chinese children with disorders of sex development]

Objective: To explore the heterogeneity and correlation of clinical phenotypes and genotypes in children with disorders of sex development (DSD). Methods: A retrospective study of 1 235 patients with clinically proposed DSD in 36 pediatric medical institutions across the country from January 2017 to May 2021. After capturing 277 DSD-related candidate genes, second-generation sequencing was performed to analyzed the heterogeneity and correlation combined with clinical phenotypes. Results: Among 1 235 children with clinically proposed DSD, 980 were males and 255 were females of social gender at the time of initial diagnosis with the age ranged from 1 day of age to 17.92 years. A total of 443 children with pathogenic variants were detected through molecular genetic studies, with a positive detection rate of 35.9%. The most common clinical phenotypes were micropenis (455 cases), hypospadias (321 cases), and cryptorchidism (172 cases) and common mutations detected were in SRD5A2 gene (80 cases), AR gene (53 cases) and CYP21A2 gene (44 cases). Among them, the SRD5A2 mutation is the most common in children with simple micropenis and simple hypospadias, while the AMH mutation is the most common in children with simple cryptorchidism. Conclusions: The SRD5A2 mutation is the most common genetic variant in Chinese children with DSD, and micropenis, cryptorchidism, and hypospadias are the most common clinical phenotypes. Molecular diagnosis can provide clues about the biological basis of DSD, and can also guide clinicians to perform specific clinical examinations. Target sequence capture probes and next-generation sequencing technology can provide effective and economical genetic diagnosis for children with DSD.

Association of FIB-4 index and clinical outcomes in critically ill patients with acute kidney injury: a cohort study

Background

The relationship between fibrosis-4 (FIB-4) index and clinical outcomes in patients with acute kidney injury (AKI) is unclear. We aimed to investigate the association between FIB-4 index and all-cause mortality in critically ill patients with AKI.

Methods

We used data from the Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC-III) database (v1.4). The FIB-4 score was calculated using the existing formulas. logistic regression model, and Cox proportional hazards model were used to assessed the relationship between the FIB-4 index and in-hospital,28-day and 90-day mortality, respectively.

Results

A total of 3592 patients with AKI included in the data analysis. 395 (10.99%) patients died during hospitalization and 458 (12.74%) patients died in 28-day. During the 90-day follow-up, 893 (22.54%) patients were dead. An elevated FIB-4 value was significantly associated with increased in-hospital mortality when used as a continuous variable (odds ratio [OR] 1.183, 95% confidence interval [CI] 1.072–1.305, P = 0.002) and as a quartile variable (OR of Q2 to Q4 1.216–1.744, with Q1 as reference). FIB-4 was positively associated with 28-day mortality of AKI patients with hazard ratio (HR) of 1.097 (95% CI 1.008, 1.194) and 1.098 (95% 1.032, 1.167) for 90-day mortality, respectively.

Conclusion

This study demonstrated the FIB-4 index is associated with clinical outcomes in critically ill patients with acute kidney injury.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-02071-2.

Model Based Identification of Linezolid Exposure-toxicity Thresholds in Hospitalized Patients

Evidence supports linezolid therapeutic drug monitoring as the exposure-response relationship has been identified for toxicity among patients receiving linezolid, but the data to establish the upper limit are limited and the published toxicity thresholds range widely. The purpose of this study was to determine the linezolid exposure-toxicity thresholds to improve the safety of linezolid. This is a multicenter retrospective study of adult patients treated with linezolid from 2018 to 2019. The population pharmacokinetic model of linezolid was established based on 270 plasma concentrations in 152 patients, which showed creatinine clearance and white cell count are covariates affecting the clearance of linezolid, and serum albumin is the covariate affecting the volume of distribution. Classification and regression tree analysis was used to determine the linezolid exposure thresholds associated with an increased probability of toxicity. Among 141 patients included for toxicity analysis, the rate of occurring toxicity was significantly higher among patients with an AUC_{0-24, d1} ≥163 mg h/L, AUC_{0-24, d2} ≥207 mg h/L, AUC_{0-24, ss} ≥210 mg h/L, and C_min,d2 ≥6.9 mg/L, C_min,ss ≥6.9 mg/L, while no threshold was discovered for C_{min, d1}. Those exposure thresholds and duration of linezolid treatment were independently associated with linezolid-related toxicity in the logistic regression analyses. In addition, the predictive performance of the AUC_0-24 and C_min thresholds at day 2 and steady state were close. Considering that the AUC estimation is cumbersome, C_min threshold at 48 h and steady state with a value of ≥6.9 mg/L is recommended to improve safety, especially for patients with renal insufficiency and patients with low serum albumin.

[A rare anatomical variation of ileocolic veins involving in gastrocolic vein trunk: case report and literature review]

Objective: Due to its various anatomical variations and numerous branches, the gastrocolic vein trunk (Henle trunk) is the most common site to develop bleeding and other complications in laparoscopic right hemicolectomy for colon cancer. This study aims to investigate the role of ileocolic vein (ICV) joining with Henle trunk, a rare anatomical variation. Methods: A rare case whose ICV was newly found to involve in the formation of Henle trunk during laparoscopic resection of right hemicolon cancer was reported as right gastroepiploic vein+ right colic vein+superior right colic vein+ICV. This anatomical variation was confirmed by multi-slice spiral CT coronal two-dimensional reconstruction of right hemicolon angiography. The literatures about ICV participating in formation of Henle trunk were systematically searched from PubMed, The Cochran Library, CNKI net and Wanfang database, and the occurrence probability and composition of its anatomical variation were analyzed. Results: This was a 47-year-old female patient who underwent laparoscopic right hemicolectomy. When the vessels were dissected during operation, it was found that ICV did not accompany the ileocolic artery, but directly flowed into Henle trunk. Two-dimensional reconstructed CT images of right hemicolon vessels showed that the composition of Henle trunk was rarely varied, which was composed of right gastroepiploic vein, right colonic vein, superior right colonic vein and ICV. Five literatures were enrolled from literature retrieval. A total of 12 cases with ICV participating in the construction of Henle trunk were reported, with a probability of 0.27%-6.31% and 6 forms of the formation of Henle trunk. In this case, Henle trunk was made up of right gastroepiploic vein, right colonic vein, upper right colonic vein and ICV, which was reported for the first time. Conclusions: ICV involving in Henle trunk is a rare vascular variation, and this type of variation should be fully recognized. Careful dissection during operation is necessary to prevent intraoperative bleeding caused by improper operation.

Population pharmacokinetic and optimization of polymyxin B dosing in adult patients with various renal functions

AIMS

Current FDA-approved label recommends that the dosage of polymyxin B should be adjusted according to renal function. However, the correlation between polymyxin B pharmacokinetics (PK) and creatinine clearance (CrCL) is poor. This study aimed to develop a population PK model of polymyxin B in adult patients with various renal functions and to identify a dosing strategy.

METHODS

A retrospective PK study was performed in 32 adult patients with various renal function. Nonlinear mixed effects modelling was applied to build a population PK model of polymyxin B followed by Monte Carlo simulations which designed polymyxin B dosing regimens across various renal function.

RESULTS

Polymyxin B PK analyses included 112 polymyxin B concentrations at steady state from 32 adult patients, in which 71.9% of them were critically ill. In the final PK model, CrCL was the significant covariate on CL (typical value 1.59 L/h; between-subject variability 13%). The mean (SD) individual empirical Bayesian estimate of CL was 1.75 (0.43) L/h. In addition, a new dosing strategy combining the PK/pharmacodynamic (PD) targets and Monte Carlo simulation indicated that the reduction of polymyxin B dose in patients with renal insufficiency improved the probability of achieving optimal exposure. For severe infections caused by organisms with minimum inhibitory concentration (MIC) ≥ 2 mg/L, a high daily dose of polymyxin B might be possible for bacterial eradication, but the risk of nephrotoxicity is increased.

CONCLUSIONS

Renal function plays a significant role in polymyxin B PK, and the dose of polymyxin B should be adjusted according to CrCL in patients with renal insufficiency.

A narrative review of driving pressure as a monitoring indicator during mechanical ventilation with spontaneous breathing

The mortality of acute respiratory distress syndrome (ARDS) remains high, and mechanical ventilation (MV) is an essential means of treatment. During MV, people realize the benefits of spontaneous breathing and the disadvantages of uncontrolled spontaneous breathing. Current methods of monitoring spontaneous breathing include oesophageal manometry, P0.1, and diaphragm function monitoring. However, these methods have limitations and deficiencies. The driving pressure is a new indicator that reflects the strain of the lung, which indicates the volumetric injury of the lung and is independently associated with mortality in ARDS patients. Moreover, in recent studies, driving pressure monitoring has been shown to be feasible in assisted support ventilation. This review summarizes the current state of spontaneous breathing and examines whether it is convenient to monitor driving pressure during spontaneous breathing to achieve lung protection ventilation.

Clinical Characteristics and Outcomes of Severe and Critical Patients With 2019 Novel Coronavirus Disease (COVID-19) in Wenzhou: A Retrospective Study

Information about severe cases of 2019 novel coronavirus disease (COVID-19) infection is scarce. The aim of this study was to report the clinical characteristics and outcomes of severe and critical patients with confirmed COVID-19 infection in Wenzhou city. In this single-centered, retrospective cohort study, we consecutively enrolled 37 RT-PCR confirmed positive severe or critical patients from January 28 to February 16, 2020 in a tertiary hospital. Outcomes were followed up until 28-day mortality. Fifteen severe and 22 critical adult patients with the COVID-19 infection were included. Twenty-six (68.4%) were men. Echocardiography data results suggest that normal or increased cardiac output and diastolic dysfunction are the most common manifestations. Compared with severe patients, critical patients were older, more likely to exhibit low platelet counts and high blood urea nitrogen, and were in hospital for longer. Most patients had organ dysfunction during hospitalization, including 11 (29.7%) with ARDS, 8 (21.6%) with acute kidney injury, 17 (45.9%) with acute cardiac injury, and 33 (89.2%) with acute liver dysfunction. Eighteen (48.6%) patients were treated with high-flow ventilation, 9 (13.8%) with non-invasive ventilation, 10 (15.4%) with invasive mechanical ventilation, 7 (18.9%) with prone position ventilation, 6 (16.2%) with extracorporeal membrane oxygenation (ECMO), and 3 (8.1%) with renal replacement therapy. Only 1 (2.7%) patient had died in the 28-day follow up in our study. All patients had bilateral infiltrates on their chest CT scan. Twenty-one (32.3%) patients presented ground glass opacity (GGO) with critical patients more localized in the periphery and the center. The mortality of critical patients with the COVID-19 infection is low in our study. Cardiac function was enhanced in the early stage and less likely to develop into acute cardiac injury, but most patients suffered with acute liver injury. The CT imaging presentations of COVID-19 in critical patients were more likely with consolidation and bilateral lung involvement.

[Comparative analysis of serum glutamate and gamma-aminobutyric acid levels in patients with bipolar depressive disorder and major depression disorder]

Objective: To investigate the difference of serum glutamate (Glu) and gamma- aminobutyric acid (GABA) levels between depressive patients and bipolar disorder patients with depressive episodes. Methods: From May 2018 to March 2019, forty-seven patients with depression (depression group) and 45 patients with bipolar depressive episode (bipolar depression group) were selected from the department of psychiatry, the First Affiliated Hospital of Jinan University, and 41 healthy controls (healthy control group) were simultaneously recruited from the community. The subjects' depression and anxiety were assessed by 17 items of Hamilton depression scale (HAMD-17) and Hamilton Anxiety Scale (HAMA). The serum levels of Glu, GABA and Glu decarboxylase (GAD) were detected by enzyme-linked immunosorbent assay (ELISA) . Results: The serum Glu level ( (36±7) mg/L, (37±7) mg/L vs (28±4) mg/L, F=10.97, P<0.01) and Glu/GABA ratio (5.77±0.35, 8.18±0.24 vs 3.35±0.33, F=37.68, P<0.01) in depression and bipolar depression groups were higher than those of healthy control group, while the GABA level ((6.1±0.7) μmol/L,(4.1±0.8) μmol/L vs (8.1±1.2) μmol/L, F=21.61, P<0.01) and GAD ((31±6) U/L, (31±6) U/L vs (35±6) U/L, F=5.61, P<0.01) were lower than those of healthy control group. The level of serum GABA in bipolar depression group was lower than that in depression group. However, Glu/GABA was higher in bipolar depression group than that in depression group (P<0.01). The level of serum GABA in depression group was negatively correlated with HAMD sleep disorder factor (r=-0.46, P=0.01). Conclusions: Both depression and bipolar depression have abnormal levels of Glu, GABA neurotransmitters and imbalance between Glu and GABA in peripheral blood circulation. Moreover, these abnormalities are more obvious in patients with bipolar depression.

Red blood cell distribution width is associated with mortality risk in patients with acute respiratory distress syndrome based on the Berlin definition: A propensity score matched cohort study

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a severe inflammatory disorder of the lungs and is associated with oxidative damage. However, red blood cell distribution width (RDW), as an indicator of body response to inflammation and oxidative stress, has not been studied for its relationship with ARDS as diagnosed by the Berlin definition.

OBJECTIVES

To examine the value of RDW in predicting the prognosis of in patients with ARDS.

METHODS

This is a retrospective study based on the Medical Information Mart for Intensive Care III (MIMIC-III) database. Berlin-defined ARDS patients using mechanical ventilation for more than 48 hours were selected using structured query language. The primary statistical methods were propensity score matching and sensitivity analysis, including an inverse probability weighting model to ensure the robustness of our findings.

RESULTS

A total of 529 intensive care unit (ICU) patients with ARDS according to the Berlin definition were enrolled in the study. The adjusted OR showed an adverse effect between the higher RDW group and 30-day mortality [OR 2.33, 95% CI (1.15-4.75), P=0.019]. However, we found that length of ICU stay was not related to RDW (P=0.167), and in the anaemia group, RDW was poorly predictive of 30-day mortality (P=0.307).

CONCLUSION

In unselected ARDS patients, higher RDW was associated with higher 30-day mortality rate. Further investigation is required to validate this relationship with prospectively collected data.

The association of coagulation indicators with in-hospital mortality and 1-year mortality of patients with sepsis at ICU admissions: A retrospective cohort study

BACKGROUND

Coagulation activation is the host's response to pathogens during sepsis and is considered to be one of the reasons for tissue damage and multiple organ failure. This study is designed to evaluate whether the alterations of coagulation indicators are related to in-hospital mortality and 1-year mortality of patients with sepsis.

METHOD

Data of all 2258 patients were extracted from the database Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC III). The relationship between the in-hospital mortality of patients with sepsis and coagulation indicators was analyzed with a receiver operating characteristic (ROC) curve analysis and logistic regression model. Effects of coagulation indicators on patients' 1-year mortality were determined by using a Cox hazard regression model, and clinical experience or quintiles were used to classify the activated partial thromboplastin time (APTT) to determine the cutoff values to explore segmentation effects.

RESULT

International normalized ratio (INR) was positively associated with hospital mortality of patients with sepsis after adjusting confounders with an odds ratio (OR) of 1.86 [95% confidence interval (CI), 1.37-2.52], and a hazard ratio (HR) of 1.465[95%CI(1.24-1.74)] for 1-year mortality, respectively. 1-year mortality of patients with sepsis demonstrated a U-shaped relationship with APTT, ranging from 25 to 37, indicating the lowest risk. The adjusted HR (95% CI) values for 1-year mortality of septic patients with risk values <25 and >37 were 1.493 (1.02, 2.19) and 1.379 (1.06, 1.79), respectively.

CONCLUSION

Increased INR in critically ill septic patients is related to greater in-hospital mortality and 1-year mortality. A U-shaped relationship was found between APTT and 1-year mortality of patients with sepsis.

Prognostic value of hematocrit levels among critically ill patients with acute kidney injury

The aim of this study was to investigate the value of hematocrit (HCT) level in predicting the outcomes of critically ill patients with acute kidney injury (AKI). A retrospective study of a total of 14,350 intensive care unit (ICU) patients, who were selected from Beth Israel Deaconess Medical Center (Boston, MA, USA) and met the inclusion criteria, was carried out. And the patient data were extracted from the Multiparameter Intelligent Monitoring in Intensive Care Database III version 1.3 (MIMIC-III v1.3). In our study, HCT quintiles were used to categorize the subjects into groups. The clinical outcomes were 30- and 90-day mortality in the ICU. Cox proportional-hazards models were used to evaluate the association between the HCT and survival. A total of 2827 30-day deaths and 3828 90-day deaths occurred. In univariate analysis, low HCT was significantly associated with increased 30- and 90-day mortality among females, which, however, was not observed in multivariate analysis adjusted for age, ethnicity, dialysate, continuous renal replacement therapy (CRRT), use of insulin, use of ventilator, AKI stages, and report of obesity. In subgroup analysis, an inverse association between HCT levels and risk of mortality for 90-day outcome was observed for female patients by exclusion of dialysate use, receiving CRRT, and obesity reports. Therefore, these findings suggest that lower HCT was associated with an increased risk of mortality in critically ill patients with AKI, and the effect appears to be stronger among women than men. The prognostic value of HCT seems dependent on other factors, for example, dialysate use, CRRT, and obesity. Further multicenter study is in demand to confirm the validity of the results presented in this article.

Cutaneous protothecosis on the bilateral wrists of a food handler

Cutaneous protothecosis is caused by the achlorophyllic algae Prototheca, typically presenting as a localized plaque in immunocompetent individuals. We report a patient with bilateral erythematous plaques and pustules on her forearms, which had initially been treated with steroids for presumed eczema. Histology showed spherical spore-like bodies with internal morula-like septation, which were positive for periodic-acid-Schiff (PAS) staining, consistent with cutaneous protothecosis. Definitive treatment with oral itraconazole resulted in resolution of the lesions.

Papular angiolymphoid hyperplasia and lymphoplasmacytic plaque: a clinical and histological spectrum

Acral pseudolymphomatous angiokeratoma of children (APACHE) is a rare form of cutaneous pseudolymphoma characterized byangiomatous papules with a predilection for the acral regions of children. Classically, a dense dermal lymphocytic infiltrate composed of both T and B cells is seen in histological specimens, together with prominent vessels lined by plump endothelial cells. Increasing evidence suggests that this condition is neither necessarily acral, pseudolymphomatous, nor angiokeratomatous. It may not always be a pediatric disease. Therefore, the correctness of its nomenclature has been questioned. Herein, we report threecases whose clinical and histological features were consistent with the diagnosis of APACHE. To our knowledge, this is the first report of APACHE from Southeast Asia. We also discuss why we believe "APACHE" to be a misnomer and support "papular angiolymphoid hyperplasia" as a more accurate and encompassing term. In addition, we illustrate a case with significant overlapping features with lymphoplasmacytic plaque in children, suggesting that both entities may exist on a clinical andhistological spectrum.

Quality of life in people with mental illness in non-residential community mental health services in Hong Kong

OBJECTIVE

To identify the subjective quality of life in people with chronic mental health problems who were in non-residential community mental health services, and to investigate factors affecting their quality of life after the illness.

METHODS

People with mental illness (n = 105) were recruited. They were assessed with the self-rated Hong Kong Chinese version of the World Health Organization Quality of Life Brief questionnaire.

RESULTS

The participants had lower total quality-of-life and the 4 domain scores of the questionnaire than the general population. They were particularly dissatisfied with their financial situation. Duration of illness was positively correlated with subjective quality-of-life variables while age at onset of the mental illness was negatively correlated with subjective quality of life, in particular the physical health, psychological health, and environmental domains.

CONCLUSION

This study highlighted the significance of duration and age at onset of illness in subjective quality of life of people with mental illness. A longitudinal study to test the causal relationships between these factors and the quality of life in people with mental illness is recommended.

Obstacles and solutions to screening psoriasis patients for cardiovascular risk factors

BACKGROUND

Psoriasis has been linked with cardiovascular risk factors (CVRFs), including the metabolic syndrome, yet many patients with psoriasis remain unscreened.

OBJECTIVE

To assess the reasons for lack of screening for CVRFs in psoriasis patients, and the impact of an education programme targeting these deficiencies.

METHODS

All patients with psoriasis, regardless of severity, and all dermatologists working at the National Skin Centre (NSC) in Singapore were surveyed over a 2-month period on their attitudes and knowledge regarding psoriasis and cardiovascular risk. This was followed by a targeted programme which was implemented over 2 months to address these identified deficiencies. Patients and doctors were surveyed a second time to assess the effects of the intervention.

RESULTS

Obstacles to screening included lack of patient knowledge, patients not considering screening important, and lack of time during the clinic consultation. After the intervention, there was a significant increase in the proportion of patients who were aware of increased cardiovascular risk in psoriasis (33.0% to 62%), with more patients attending screening (39.1% to 63.2%). While the level of doctors' knowledge did not significantly increase, there was an increase in the proportion of patients who were screened post-intervention (37.1% to 66.2%), and more doctors reported that they were more likely to screen psoriatic patients from an earlier age (30.2% to 58.1%).

CONCLUSIONS

The obstacles in implementing universal screening for CVRFs in psoriasis patients stem from patient, doctor and system factors. A comprehensive programme targeting all aspects of this ecosystem helps to achieve holistic care for patients with psoriasis.

The hedgehog signaling pathway, a new therapeutic target for treatment of ischemic heart disease

The hedgehog (Hh) protein is involved in angiogenesis and cardiovascular development via activation of the classical ligand-dependent signaling transduction. So its potential therapeutic meaning of Hh signaling proteins to the ischemic heart diseases has been greatly explored. Recent studies show that up-regulated expression of hypoxia-induced factor-1 (HIF-1) and inflamemation in ischemic tissues activate the Hh signaling cascade in a GLI-dependent or independent way, resulting in elevated expression levels of pro-angiogenic and agiogenic factors to facilitate angiogenesis. In addition, Hh signaling pathway activation can promote residual myocardial progenitors, endogenous EPCs and MSCs differentiating into cardiomyocytes, inhibit cardiomyocyte apoptosis; thirdly, high level of exogenous Hh signaling can reduce myocardial ischemic/reperfusion injuries(I/R). In conclusion, three kinds of mechanisms induced by Hh signaling pathway participate in the heart repair after myocardial ischemia. Therefore, Hh agonists including Hh protein, Hh gene transfer and small molecule agonist could be part of a potential therapeutic strategy for acute or chronic ischemic heart disease.

Acupressure therapy inhibits the development of diabetic complications in Chinese patients with type 2 diabetes

OBJECTIVES

The objectives of this study were to investigate the effects of acupressure therapy (AT) on the development and progression of diabetic complications in Chinese patients with type 2 diabetes (T2D).

DESIGN AND METHODS

A total of 80 patients with T2D were recruited for a randomized clinical study of the effect of AT on the progression and development of diabetic complications, and 64 patients were followed up for 3 years. All patients with T2D were treated with regular medicines and participated in diet and exercise programs for the control of hyperglycemia and hypertension. The patients in the AT group received additional treatment of a 90-minute AT 4-6 times per week for 3 consecutive years. Their blood lipids, fasting glucose levels, and heart and kidney functions and nerve conduction velocity (NCV) were longitudinally monitored before and every 12 months after AT.

RESULTS

Following AT therapy for 3 years, significantly lower levels of total cholesterol, triglycerides, low-density lipoprotein-cholesterol, and higher levels of high-density lipoprotein-cholesterol (HDL-C) were observed and no significantly increased levels of serum creatinine and urine protein were detected in the AT group, as compared with that in controls. Furthermore, the mean values of NCV in the AT group at 2 years post-treatment were significantly greater than those of controls and were further elevated at the end of this study. Therefore, AT inhibited the progression of hyperlipidemia and improved diabetes-associated kidney function and neuropathy in Chinese patients with T2D.

CONCLUSIONS

AT may be an effective nonpharmacological adjunctive strategy for alleviating the development and progression of T2D-related complications.

[Application of RIFLE criteria for acute renal failure in patients treated with continuous renal replacement therapy]

OBJECTIVE

To determine the optimal timing of treating acute renal failure (ARF) patients in intensive care unit (ICU) with RIFLE (risk of renal failure, injury to the kidney, failure of kidney function, loss of kidney function and end-stage renal failure) classification using continuous renal replacement therapy (CRRT). And to evaluate the association between mortality and RIFLE classification in the same patients.

METHODS

Clinical data were collected from 103 ARF patients in ICU from 2000 to 2007.

RESULTS

The 30-days hospital mortality rate was 45.6%. The 30 days' hospital mortality rates of RIFLE-R, RIFLE-I and RIFLE-F were 25.0%, 20.0% and 57.3% respectively.

CONCLUSION

Survival rate of ARF patients can be manifestly elevated if CRRT is performed before RIFLE-F. The patients in RIFLE-F category have a significantly higher mortality than RIFLE-R and -I patients. The RIFLE criteria is fit for ARF classification system.

[Relationship between P-selectin and cardiac function in hemorrhagic shock resuscitation: experiment with rats]

OBJECTIVE

To investigate the relationship between the left ventricular function and the expression of P-selectin in the serum and cardiac muscle in hemorrhagic shock resuscitation, and to evaluate the effects of L-arginine (L-Arg) against the harmful effect of P-selectin.

METHODS

Thirty SD rats were randomly divided into 3 equal groups: hemorrhagic shock resuscitation (HS) group (undergoing bloodletting until the mean arterial pressure of 40 mm Hg and then re-infusion of the lost blood), L-Arg treatment group (undergoing bloodletting and then re-infusion with L-Arg simultaneously), and normal control (NC) group (undergoing infusion of normal saline). Cannulation was conducted via left carotid artery into the left ventricular to record left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), and left ventricular +/- dp/dtmax. Serum creatine kinase (CK) was detected by colorimetry. Three hours after the HS the rats were killed with samples of blood and apex of heart collected to detect the P-selectin expression by ELISA and immunohistochemistry. Microscopy was used to observe the expression of P-selectin in the vascular endothelial cells and cardiac muscle cells.

RESULTS

The LVSP, maximal rate of LV pressure elevation (+ dp/dtmax), and maximal rate of LV pressure depression (- dp/dtmax) of the HS and L-Arg groups were all significantly lower than those of the NC group (all P < 0.01). The LVEDP of the HS and L-Arg groups were all higher than that of the NC group (both P < 0.01). Three hours after resuscitation, the CK levels of the HS and L-Arg groups were significantly higher than that of the NC group (both P < 0.01), and that of the L-Arg groups was significantly lower than that of the HS group (P < 0.05), the P-selectin levels of the serum and cardiac muscle cells of the HS and L-Arg groups were all significantly higher than those of the NC group (both P < 0.01), and those of the L-Arg group were significantly lower than those of the HS group (both P < 0.05).

CONCLUSION

After hemorrhagic shock and resuscitation P-selectin may play an important role in cardiac injury, L-Arg can inhibit the expression of P-selectin, thus protecting the cardiac function against the harmful effect of P-selectin.

Clinics in diagnostic imaging (116). Ruptured hepatocellular carcinoma

A 37-year-old Chinese man with chronic hepatitis B, who frequently defaulted past follow-up appointments, was admitted for acute abdomen and shock. Computed tomography of the abdomen revealed a ruptured hepatocellular carcinoma involving the left lobe. After fluid resuscitation, gelfoam embolisation was performed to arrest the bleeding, followed by segmental resection of the hepatic lesion. There was aggressive recurrence following left segmental hepatectomy, and despite two courses of transarterial chemoembolisation, the patient died of local and pulmonary recurrences five months after his initial presentation. The management of hepatocellular carcinoma rupture is discussed.

[Experimental therapeutic study for activated coagulation by hemorrhagic shock in rats]

The study was aimed to investigate the changes of blood coagulation factors during hemorrhagic shock in rats and the effects of various of resuscitation fluids on expression of blood coagulation factors in rats with hemorrhagic shock and to clarify its possible mechanism. 50 SD rats were randomly divided into 5 groups: control, sham operation, shock, resuscitation 1 (infusion with Ringer's lactate) and resuscitation 2 (infusion with 6% VOLUVEN), 10 rats per group. The rats in resuscitation 1 and resuscitation 2 groups were subjected to hemorrhagic shock, after hemorrhage shock for 1 hour resuscitation was performed with Ringer's lactate and 6% VOLUVEN. After resuscitation for 2 hours the changes of t-PA, PAI-1, TF were measured. At the same time, the rats in shock and the sham operation groups were blooded out so as to test. The results showed that the levels of plasma t-PA, t-PA/PAI, TF in the shock and resuscitation 1 groups were significantly higher than that in control and sham operation groups (P<0.01). The levels of plasma t-PA, t-PA/PAI in resuscitation 1 group were higher than that in shock group (P<0.01), the levels of plasma t-PA, t-PA/PAI and TF in the resuscitation 2 group were significantly lower than that in shock and resuscitation 1 groups (P<0.01). It is concluded that hemorrhagic shock may trigger the coagulation cascade reaction, results in hyperfunctioning of fiberinolysis and activation of platelets and coagulation system, and so the coagulation factor is greatly consumed. Unbalance of coagulation system plays an important role in the progress of shock. Efficacy of resuscitation with 6% VOLUVEN plus Ringer's lactate may be better than Ringer's lactate alone in regulating blood coagulation after hemorrhagic shock in rats.

[Platelet and tissue factor: review]

It is generally accepted that tissue factor plays an important role in coagulation and intravascular thrombus formation. Tissue factor is not only found primarily on the surface of certain cells that are located outside the vasculature, but also found in circulating cells. Monocyte express tissue factor induced by endotoxin. Recently, many researches indicate that P-selectin, CD40 ligand and GPIIb/IIIa receptor of platelet can also affect expression of tissue factor by monocyters. In addition, a lot of studies showed that tissue factor exist in the circulation including contained platelet. Tissue factor in the platelet releases under certain condition, and initiates coagulation. In this review the relation between platelet and tissue factor was elaborated.

[Therapeutic effect of compound danshen solution on hemorrhagic shock combined with coagulopathy in rats]

To investigate the effects of complex danshen solution and heparin on the changes of blood coagulation factors in rats with hemorrhagic shock, and to explore the therapy of coagulopathy by compound danshen solution, the rat model of hemorrhagic shock was set up, 40 SD rats were randomized into four groups: sham operation, shock, compound danshen solution and heparin groups, each group was composed of 10 SD rats. Plasma SFMC, TM, ATIII, D-D, t-PA, PAI levels and APTT were detected, incidences of bleeding complications between heparin and danshen group were compared. The results showed that plasma SFMC, D-D levels in shock group were higher but ATIII level in shock group was lower than that in sham operation group, compound danshen solution group and heparin group (P < 0.001), TM levels obviously increased in shock group and heparin group (P < 0.001). There was no significant difference between compound danshen solution and sham-operation groups. Plasma t-PA, D-D levels obviously increased after shock for 2 hours, PAI level reached the peak after shock for 4 hours, but t-PA decreased. After shock for 6 hours, plasma PAI descended, t-PA continually drop in, but PAI and D-D remained in higher levels. Plasma D-D level in heparin group was lower than that in shock group, t-PA level was higher than that in shock group, but there was no significant difference between in heparin and shock groups. Plasma t-PA, PAI and D-D levels in compound danshen solution group were lower than that in shock group. APTT of danshen group was lower than that of shock group and heparin group. Bleeding incidences was 30% in heparin group and 0% in danshen group, respectively. It is concluded that compound danshen solution may used to treat hypercoagulation and hyperfibrinolysis. In comparsion with heparin, danshen posses-ses advantages of safety with less bleeding complication and needs not tight monitor.

[Study on changes of blood coagulation factors in rats with hemorrhagic shock]

The study was aimed to observe the changes of blood coagulation factors in the SD rats suffered from hemorrhagic shock, and to investigate the mechanism of coagulation cascade reaction in the course of shock. The model of hemorrhagic shock was established. 40 SD rats were randomized into eight groups: pre-shock, and 1, 2, 4, 6, 8, 12 and 24 hours after shock, and the levels of plasma FVIII, vWF, TF, D-dimer, FIB, APTT and PT were detected respectively. The result showed that APTT and PT were gradually prolonged, which were significant within 4-6 hour after shock (P < 0.05). APTT and PT were 59.7 seconds and 30.2 seconds respectively. The level of plasma D-dimer markedly increased, and peaked at 8 hour after shock. The level of fibrinogen, TF, vWF and FVIIIa increased in the initial stage of shock. With the development of shock, fibrinogen markedly reduced from 2nd hour (P < 0.05) and dropped to the minimum at 7 hours after shock. Plasma TF, vWF, FVIII significantly decreased after 6 hours and 8 hours (P < 0.001). The ratios of the consumed coagulation factors: FVIII of (86.1 +/- 1.8)%, fibrinogen of (89.6 +/- 0.6)%, vWF (55 +/- 1.4)%, TF (62 +/- 2.5)%. Thus, coagulation factor I (fibrinogen) and FVIII were preferentially consumed. The extrinsic coagulation pathway was dominantly activated, whereas the intrinsic coagulation pathway played a less important role. Fibrinogen and D-dimer might be valuable for the prognosis of patients suffered from shock. It is concluded that hemorrhagic shock trigger the coagulation cascade reaction, and the coagulation factors are greatly consumed. Unbalance of coagulation system plays an important role in the progress of shock.

[The effects of lupus anticoagulant on pulmonary thromboembolism]

OBJECTIVE

To evaluate the effects of lupus anticoagulant (LA) on pulmonary thromboembolism (PTE).

METHODS

Thirty-eight patients with PTE (17 massive and 21 submassive) and 30 healthy adults were studied. Russell's viper venom time (RVVT) was used to examine the ratio of LA (LAR), and a colorimetric method was used to detect the activity of plasma protein C (PC:A) and radioimmunoassay (RIA) was employed to measure the level of plasma thromboxane B(2) (TXB(2)) and 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha).

RESULTS

Compared with the normal group, LAR, TXB(2) and TXB(2)/6-keto-PGF1alpha showed significant increase in the massive PTE and the submassive PTE groups (P < 0.01), and the levels were higher in the massive group than in the submassive group (P < 0.01). Both groups showed significant decrease in PC:A and 6-keto-PGF1alpha compared with the normal group (P < 0.01).

CONCLUSIONS

LA can increase TXB(2)/6-keto-PGF1alpha and decrease PC:A in patients with PTE. It is suggested that there may be an association between the increase of LAR and the presence of PTE.

[Down-regulation of ETA receptor of vascular smooth muscle cells by 17 beta-estradiol]

In the present study, the effects of 17 beta-estradiol on vascular reactivity of ovariectomized rats and proliferation of cultured rat aortic smooth muscle cells were studied. The vascular reactivity was significantly increased in ovariectomized rats compared with the sham-operated animals. The selective ETA receptor antagonist BQ123 inhibited the increase in [3H]-TdR incorporation in response to ET-1 on vascular smooth muscle cells (VSMCs). 17 beta-estradiol also attenuated the ET-1 effects in a dose-dependent manner. The results of RT-PCR and Western blot show that expression of ETA receptor was decreased after treatment with 17 beta-estradiol. The effect of 17 beta-estradiol was partially inhibited by estrogen receptor antagonist tamoxifen. The above results demonstrate that proliferation of VSMCs stimulated by ET-1 was mainly mediated through ETA receptor. Due to the down-regulation of ETA receptor and mediation of estrogen receptor, 17 beta-estradiol inhibits the ET-1-induced proliferation of VSMCs and decreases the vascular reactivity of ovariectomized rats.

[Effect of microinjection of L-arginine into the caudal pressor area of medulla oblongata on cardiovascular responses in rats]

AIM

To study the effect of microinjection L-arginine, a precursor for the synthesis of nitric oxide into the functionally identified caudal pressor area (CPA) in ventral surface of medulla oblongata.

METHODS

Artery pressure (AP), renal perfusion pressure (RPP) and heart rate were recorded to study the effects of microinjection of NO related drugs into CPA.

RESULTS

(1) Unilateral microinjection of L-arginine (60 - 100 nmol) into CPA produced prominent dose-related depressor and bradycardic effects and reduced renal perfusion pressure. (2) Unilateral microinjection of L-arginine (100 nmol) 3 min after microinjection of methylene blue (10 nmol) into CPA did not significantly change AP and RPP. (3) Unilateral microinjection of L-glutamate (350 nmol) into CPA elicited pressor effect which was significantly dose-related attenuated by prior microinjection of L-arginine (60-100 nmol) into the same area.

CONCLUSION

Theses results suggest that L-arginine-NO pathway in the CPA participates in the central regulation of arterial pressure and may have a key role in the inhibiting of glutamatergic neurotransmission in the anesthetized rats.

[Effects of microinjection of L-arginine into the depressor area of ventral surface of medulla oblongata on cardiovascular responses]

AIM

To study the effects of L-arginine, a precursor for the synthesis of nitric oxide, when it was microinjected into the functionally identified depressor area in ventral surface of medulla oblongata (VSMd) on cardiovascular responses.

METHODS

Artery pressure (AP), perfusion pressure of the kidney (PPK) and heart rate were recorded to study the effects of microinjection of NO related drugs into VSMd.

RESULTS

(1) Unilateral microinjection of L-arginine (60 - 100 nmol) into VSMd produced prominent dose-related pressor effect and increased PPK but without significant changes in heart rate. (2) Microinjection of L-Arg (100 nmol) 3 min after microinjection of methylene blue (10 nmol) into VSMd did not significantly change AP and PPK. (3) Unilateral microinjection L-glutamate (350 nmol) into VSMd elicited depressor effect (-34.97% +/- 4.33%). The depressor effect was significantly dosed related attenuated by prior microinjection L-arginine (60 - 100 nmol) into the same area.

CONCLUSION

These results suggest that the L-arginine - NO pathway in the VSMd participate in the central regulation of artery pressure and the pathway may have a key role in inhibiting glutamatergic neurotransmission in the anesthetized rats.

Which depressed patients respond to nefazodone and when?

BACKGROUND

Retrospective data analyses were conducted of a single-blind trial of 993 outpatients with nonpsychotic major depression (DSM-III-R) treated for 12 weeks with nefazodone to provide a more specific picture of the nature and timing of response or remission to acute-phase treatment.

METHOD

All patients participated in a single-blind, 16-week lead-in to obtain responders eligible for a subsequent double-blind, randomized continuation phase trial. Outcomes were defined by the 17-item Hamilton Rating Scale for Depression (HAM-D). A > or = 50% reduction from baseline defined response, and a total HAM-D exit score of < or =8 defined remission.

RESULTS

Of all patients who entered the trial, 41.8% (last observation carried forward) responded at or before week 4 (early responders), and an additional 25.2% responded thereafter; 18.3% achieved remission at or before week 4; 33.6% achieved remission after week 4. Thus, 77.3% of those responding ultimately remitted. On average, remission followed response by 2 weeks. The average end-of-treatment dose was 376 mg/day at exit (last observation carried forward). Responders or remitters (as opposed to nonresponders or nonremitters) had lower baseline depressive symptomatology and were more likely to be married or cohabiting.

CONCLUSION

The full symptomatic benefit of antidepressant medication may not be apparent until completion of an 8- to 10-week trial. A high number of responders ultimately attained remission. Baseline demographic and clinical features were not highly predictive of who would or would not benefit from nefazodone. For routine care, a minimal acute-phase trial, using a 50% reduction in baseline symptom severity to define response, should be 8 weeks. Whether ultimate nonresponders can be identified earlier than 8 weeks deserves further study.

[Effect of aldosterone on the secretion of endothelin by ventricular fibroblasts]

Using cell culture, radioimmunoassay for endothelin and RT-PCR, the effect of aldosterone on the endothelin secretion of ventricular fibroblasts was studied. The results showed that aldosterone (1 x 10(-7) mol/L) promoted the expression of ppET-1 mRNA, which began to increase in 2 hours and attained the highest level in 4 hours, thereafter decreased; aldosterone increased the endothelin level in ventricular fibroblasts and fibroblast conditioned growth medium (FCGM) as well, which was blocked by spironolactone (1 x 10(-6) mol/L), an aldosterone receptor antagonist. The results suggest that aldosterone can increase endothelin secretion by ventricular fibroblasts, which can be inhibited by its receptor antagonist spironolactone.

[Role of mitogen-activated protein kinase in the inhibition of myocardial hypertrophy by nitric oxide in renovascular hypertensive rats]

The aim of this study was to examine the effects of L-arginine, a nitric oxide (NO) precursor, on protein expression of endothelial nitric oxide (eNOS), nitrite/nitrate content, protein expression of mitogen-activated protein kinase phosphatase-1 (MKP-1) and the activity of mitogen-activated protein kinase (MAPK) in cardiac tissues in renovascular hypertensive rats (RHR). The Goldblatt renovascular hypertensive model was established by two-kidney one clip method. The rats were divided into four groups, respectively treated with 50, 150 and 450 mg/kg L-arginine and 150 mg/kg L-arginine plus 10 mg/kg L-NAME (an eNOS inhibitor) (i.p.). Another group did not receive specific treatment from the 5th week after renal artery constriction. Control group was sham-operated. Mean arterial blood pressure (MABP) and the ratio of left ventricular weight to body weight (LVW/BW) were measured 8 weeks after treatment. eNOS protein expression, nitrite/nitrate content, MKP-1 protein expression and MAPK activity in cardiac tissues were detected using Western blot analysis, enzyme-reduction method and substrate in-gel kinase assay, respectively. It was found that L-arginine significantly inhibited the increase of MABP and LVW/BW, attenuated the activity of MAPK, increased protein expression of eNOS and MKP-1 and potentiated production of NO in cardiac tissue with the most effective dosage of 150 mg/kg, and these effects of L-arginine could be inhibited by L-NAME. These results suggest that MKP-1 may play an important role in the NO-induced inhibition of myocardial hypertrophy. The anti-hypertrophic effects of L-arginine may involve increase of eNOS protein expression and NO production, potentiation of MKP-1 protein expression, and inhibition of MAPK activity in the cardiac tissue of RHR.

[Role of conditioned growth medium for ventricular fibroblasts in promoting fibroblast collagen synthesis and proliferation]

Ventricular fibroblasts were cultured using conditioned growth medium for ventricular fibroblasts (FCGM). The rate of the total collagen synthesis of ventricular fibroblasts was measured by assaying the incorporation rate of [3H]-proline, whereas the proliferation of ventricular fibroblasts was assessed by determining the incorporation rate of [3H]-TdR and the expression of c-fos genes. FCGM significantly increased the [3H]-proline incorporation rate and [3H]-TdR incorporation rate of fibroblasts in a dose-dependent manner. Furthermore, FCGM promoted the c-fos gene expression of fibroblasts, which attained its maximum in 1 h. BQ123, an ETA receptor antagonist, partially blocked the above effects of FCGM, but AT1 receptor antagonist CV11974 and alpha-adrenergic receptor antagonist regitin did not. It is suggested that the ventricular fibroblast has an autorine function in promotion of collagen synthesis and proliferation of fibroblasts by secreting endothelin and other bioactive substances.

[The effect of aldosterone of promotion on proliferation of ventricular fibroblasts]

AIM

To study the effect of promoting aldosterone on proliferation of ventricular fibroblasts.

METHODS

Assay of [3H]-TdR incorporation rate and RT-PCR were used.

RESULTS

Aldosterone could promote [3H]-TdR incorporation of ventricular fibroblasts, the effective dose of aldosterone was among (1 x 10(-9)-1 x 10(-6))mol/L, and had dose-dependent manner, the c-fos gene was expressed after stimulated by aldosterone for 15 min, and studied the highest in 1 h, then reduced later. Spironolactone, aldosterone receptor antagonist could block the effect of aldosterone.

CONCLUSION

Aldosterone promotes the proliferation of ventricular fibroblasts, mediated by aldosterone receptor.

Nitric oxide inhibits the expression of proto-oncogene c-fos induced by angiotensin II and endothelin-1 in cardiomyocytes

The effect of nitric oxide (NO) on the hypertrophic response and the proto-oncogene c-fos expression induced by angiotensin II (AII) or endothelin-1 (ET-1) was investigated in the primary culture of neonatal rat cardiomyocytes. Total protein content of cardiomyocytes (used as the index of cardiac myocyte hypertrophy) was determined by the Bradford method. The proto-oncogene c-fos expression was assessed using reverse transcription-polymerase chain reaction (RT-PCR) standardized with glyceraldehyde-3-phosphate dehydrogenase (GAPDH). RT-PCR was performed in a single tube using gene-specific primers and the SuperScript One-Step RT-PCR System. Total protein content of cardiomyocytes increased significantly on day 5 after A II treatment or on day 3 after ET-1 treatment and the increased protein content was inhibited by SNP (NO donor). A II, ET-1 and PMA (protein kinase C activator) induced the c-fos gene expression of cardiomyocytes, while L-arginine inhibited it. The L-arginine effect was blocked by L-NAME (NOS inhibitor). SNP inhibited the c-fos gene expression of cardiomyocytes induced by A II,ET-1 or PMA as well. These results suggest that NO can inhibit the hypertrophic response and the proto-oncogene c-fos expression of cardiomyocytes induced by A II or ET-1 and the cross-link may be located at the site of protein kinase C.

[17beta -estradiol induced nitric oxide release in vascular endothelial cells]

Bovine aortic endothelial cells (BAECs) were used to study the effect of 17beta -estradiol (E(2)) on nitric oxide (NO) release, nitric oxide synthase (eNOS) mRNA expression and intracellular free calcium con~cen~tration ([Ca(2+)](I)) and modulation of the effect of E(2) by estrogen receptor (ER) antagonist tamoxifen and NOS inhibitor L-NAME. E(2) (10(-12) 10(-8) mol/L) induced NO release of BAECs in a concentration-dependent manner and the abundant expression of eNOS mRNA in BAECs increased obviously after treatment with E(2) (10(-8)mol/L) for 48 h. These effects were evidently inhibited by tamoxifen (10(-7)mol/L) and L-NAME (10(-6) mol/L). Furthermore treatment with E(2) (10(-8) mol/L) for 48 h significantly increased the resting [Ca(2+)](I) and the rise of [Ca(2+)](I) induced by ATP in BAECs. These results suggest that E(2)-induced NO release and eNOS mRNA expression in BAECs may be mediated by ER and related to calcium mobilization.

[MKP-1 regulates the cardiomyocyte hypertrophic responses induced by angiotensin II]

The aim of this study was to determine the regulation by MKP-1 of MAPK activity and protein expression in cardiomyocyte hypertrophic response induced by Ang II. Neonatal rat cardiomyocyte hypertrophic response was assayed by cell surface area, protein synthesis rate and protein content. MAPK activity was determined by an in-gel kinase assay. Protein expression of MAPK and MKP-1 were detected by Western blotting. The results are as follows. (1) Ang II induced promotion of (3)H-leucine incorporation and increase in cell protein content and cell surface area in a dose-dependent manner. Pretreatment with a selective AT(1) receptor antagonist CV11974 or a specific MEK inhibitor PD098059, cardiomyocyte hypertrophic response induced by Ang II was inhibited by 85% and 32.5%, respectively. (2) After pretreatment with PD098059 or CV11974, AngII-induced increases in p44MAPK and p42MAPK protein expression and enzyme activity (expressed by gamma-(32)P-ATP incorporation) were all inhibited obviously. (3) With treatment of myocytes by Ang II for 5 min, MAPK activity determined by p44MAPK and p42MAPK protein expression began to increase, while MKP-1 protein expression was detected within 30 min and lasted more than 2 h following treatment with Ang II. (4) Pretreatment of cardiomyocytes with actinomycin D (3 microgram/ml) for 30 min inhibited MKP-1 protein expression, while p44MAPK and p42MAPK protein expression was still detected 120 min after Ang II treatment. The above results demonstrate that activation of MAPK plays an important role in Ang II-induced cardiomyocyte hypertrophic response in neonatal rat cardiomyocytes through MKP-1 mediated inactivation of p44MAPK and p42MAPK.cardiomyocyte hypertrophic response in neonatal rat cardiomyocytes through MKP-1 mediated inactivation of p44MAPK and p42MAPK.

[Effect of protein kinase C on inhibition of nitric oxide synthesis in cultured neonatal rat cardiomyocytes by angiotensin II]

The purpose of the present study was to investigate the effect of angiotensin II (Ang II) on nitric oxide (NO) concentration and its signal transduction pathway in cultured neonatal rat cardioymocytes. NO content was measured in cultured neonatal rat cardiomyoctes using a nitrite/nitrate colormetric method kit. NO content was represented by measured nitrite (NO(2)) and nitrate (NO(3)) level (NO(2)/NO(3)). The results are as follows. NO production was decreased by Ang II in a dose dependent manner but increased by L Arg. The Saralasin, an antagonist of Ang II receptor, inhibited the effect of Ang II on NO production. The effect of Ang II on NO production was inhibited by NOS blocker N(G)-nitro-L-arginine methyl ester L-NAME but not by L-Arg. Pretreatment of Phorbol 12-myristate 13-acetate PMA , a PKC activator, decreased NO concentration significantly. This effect was strengthened by L-NAME. Staurosporine, a PKC inhibitor, abolished the inhibiting effect of Ang II on production of NO. The above results suggest that Ang II could decrease NO content in cultured neonatal rat cardiomyocytes significantly. Activity of NOS may be inhibited by Ang II. Ang II receptor was involved in the inhibitory effect of Ang II on NO production. Activation of protein kinase C (PKC) decreased significantly NO production in cultured neonatal rat cardiomyoctes, which appears to be associated with PKC in the signal transduction pathway.

[Nitric oxide changes aortic function in rats with renal hypertension]

This work was undertaken to investigate the effect of nitric oxide (NO) on aortic function of two-kidney and one-clip (2K1C) rats with renal hypertension. Animals were divided into 5 groups: the sham operation, 2K1C, captopril, L-arginine and L-NAME groups. The results are as follows. At the 4th week after constriction of the left renal artery, the mean arterial pressure was significantly elevated. In isolated aortic rings, acetylcholine-induced dilation was attenuated, and phenylephrine induced contractile response was markedly enhanced. The level of aorta cGMP content was significantly lowered. These changes were abolished in 2K1C rats treated with captopril. L-arginine partially reversed the aortic vascular reactivity of 2K1C rats, and elevated aortic cGMP content. In 2K1C rats treated with nitric oxide synthase inhibitor, L-NAME, blood pressure was increased further, acetylcholine-induced aorta diastolic response was attenuated further and cGMP content reduced, while phenylephrine-induced contractile response was unaffected. These results suggest that deficiency of nitric oxide production and increase in renin-angiotensin system activity may contribute to vascular endothelial dysfunction of 2K1C rats, and these factors may be involved in development and maintenance of 2K1C renal hypertension.

[Cardiocyte hypertrophy induced by cultured neonatal rat ventricular fibroblast conditioned growth medium]

The present work demonstrated that cultured neonatal rat ventricular fibroblast conditioned growth medium (FCGM) could significantly increase cell surface area and protein content and promote (3)H -Leucine incorporation on neonatal rat cardiomyocyte. The above effect was strongest on the third day, and was dose-dependent. BQ(123), an ET-A receptor antagonist, significantly blocked the effect, while CV11974, an Ang II I-type receptor antagonist, and regitin, an alpha-adrenergic receptor antagonist, did not. These results suggest that there are some substances promoting hypertrophy of cardiomyocytes in FCGM, which may be ET-1. The FCGM-induced increases in cardiomyocyte protein synthesis and cell surface area were inhibited partially by pertusis toxin (PTX) and PKC inhibitor staurosporine (ST), suggesting that the hypertrophic effect is related with PTX sensitive G protein and PKC.