Cerebrovascular Disease Hospitalization Rates in End-Stage Kidney Disease Patients with Kidney Transplant and Peripheral Vascular Disease: Analysis Using the National Inpatient Sample (2005-2019)

Individuals with end-stage kidney disease (ESKD) face higher cerebrovascular risk. Yet, the impact of peripheral vascular disease (PVD) and kidney transplantation (KTx) on hospitalization rates for cerebral infarction and hemorrhage remains underexplored. Analyzing 2,713,194 ESKD hospitalizations (2005-2019) using the National Inpatient Sample, we investigated hospitalization rates for ischemic and hemorrhagic cerebrovascular diseases concerning ESKD, PVD, KTx, or their combinations. Patients hospitalized with cerebral infarction due to thrombosis/embolism/occlusion (CITO) or artery occlusion resulting in cerebral ischemia (AOSI) had higher rates of comorbid ESKD and PVD (4.17% and 7.29%, respectively) versus non-CITO or AOSI hospitalizations (2.34%, p < 0.001; 2.29%, p < 0.001). Conversely, patients hospitalized with nontraumatic intracranial hemorrhage (NIH) had significantly lower rates of ESKD and PVD (1.64%) compared to non-NIH hospitalizations (2.34%, p < 0.001). Furthermore, hospitalizations for CITO or AOSI exhibited higher rates of KTx and PVD (0.17%, 0.09%, respectively) compared to non-CITO or AOSI hospitalizations (0.05%, p = 0.033; 0.05%, p = 0.002). Patients hospitalized with NIH showed similar rates of KTx and PVD (0.04%) versus non-NIH hospitalizations (0.05%, p = 0.34). This nationwide analysis reveals that PVD in ESKD patients is associated with increased hospitalization rates with cerebral ischemic events and reduced NIH events. Among KTx recipients, PVD correlated with increased hospitalizations for ischemic events, without affecting NIH. This highlights management concerns for patients with KTx and PVD.

Demographic and regional trends of peripheral artery disease-related mortality in the United States, 2000 to 2019

INTRODUCTION

Peripheral artery disease (PAD) is a common progressive atherosclerotic disease associated with significant morbidity and mortality in the US; however, data regarding PAD-related mortality trends are limited. This study aims to characterize contemporary trends in mortality across sociodemographic and regional groups.

METHODS

The Centers for Disease Control and Prevention Wide-Ranging OnLine Data for Epidemiologic Research (CDC WONDER) was queried for data regarding PAD-related deaths from 2000 to 2019 in the overall sample and different demographic (age, sex, race/ethnicity) and regional (state, urban-rural) subgroups. Crude and age-adjusted mortality rates (CMR and AAMR, respectively) per 100,000 people were calculated. Associated annual percentage changes (APC) were computed using Joinpoint Regression Program Version 4.9.0.0 trend analysis software.

RESULTS

Between 2000 and 2019, a total of 1,959,050 PAD-related deaths occurred in the study population. Overall, AAMR decreased from 72.8 per 100,000 in 2000 to 32.35 per 100,000 in 2019 with initially decreasing APCs followed by no significant decline from 2016 to 2019. Most demographic and regional subgroups showed initial declines in AAMRs during the study period, with many groups exhibiting no change in mortality in recent years. However, men, non-Hispanic (NH) Black or African American individuals, people aged ⩾ 85 years, and rural counties were associated with the highest AAMRs of their respective subgroups. Notably, there was an increase in crude mortality rate among individuals 25-39 years of age from 2009 to 2019.

CONCLUSION

Despite initial improvement, PAD-related mortality has remained stagnant in recent years. Disparities have persisted across several demographic and regional groups, requiring further investigation.

Robotic-assisted laparoscopic colposuspension for female stress urinary incontinence: a prospective series

The suspension of use of sub-urethral mesh in the UK in 2018 has seen the resurgence of colposuspension in female SUI surgery. Open and laparoscopic colposuspension techniques are well recognised. We present data from 28 robotic-assisted laparoscopic colposuspension (RALCp) procedures, reporting on technique, safety and efficacy. Approval was obtained from the hospital New and Novel Procedures Committee. All patients had urodynamic assessment prior to surgery. Data was prospectively gathered and 24-h pad usage and Urinary Incontinence Short Form Questionnaire (ICIQ-UI-SF) scores were used to assess symptom severity and quality of life. PGII scores were used to assess patient satisfaction after the procedure. Paired T test analysis was conducted. Since May 2019, robotic colposuspension has been performed in 28 patients. The mean age and BMI were 49 and 27 (kg/m²), respectively, with a mean follow-up period of 12 months. 67.9% of patients had pure urodynamic SUI and 32.1% of patients had previous anti-SUI surgery. Average operating time was 127 min, blood loss 20 ml and length of stay 2 days. There was a significant 73% improvement in mean 24-h pad usage (p = 0.001) and an improvement in mean ICIQ-UI-SF scores from 18.1 to 9.4 (p = 0.0001). Day 1 mean pain score was 5/10. This is the largest series of its kind. Robotic colposuspension is safe and feasible with significant improvements seen in quality of life scores and number of pads used per day. It presents a minimally invasive treatment option in female SUI, however needs larger volume evaluation and longer follow-up for further evaluation.

Abstract 542: Race, Sex, And Age Differences In Peripheral Arterial Disease-related Mortality In The United States, 2000 To 2019

Introduction: Peripheral arterial disease (PAD) is a progressive atherosclerotic disease associated with significant morbidity and mortality in the US, however, data regarding mortality trends is limited. This study uses national death certificate data to characterize contemporary trends in PAD-related mortality in the US.

Methods: The Centers for Disease Control and Prevention Wide-Ranging OnLine Data for Epidemiologic Research (CDC WONDER) was queried for data regarding PAD-related deaths from 2000 to 2019 in the overall sample and from different demographics (age, sex, race). Crude and age-adjusted mortality rates (AAMR) per 100,000 people were calculated. Associated average percentage changes (APC) were computed using Joinpoint trend analysis software.

Results: Between 2000 and 2019, a total of 1,959,050 PAD-related deaths occurred in the study population. Overall, AAMR decreased from 2000 to 2016, but remained relatively the same between 2016 to 2019. Men, Non-Hispanic (NH) Black or African American, NH American Indian or Alaska Native, and NH Asian or Pacific Islander showed a decline in AAMR. Women, NH White, Hispanic or Latino, ages 55 to 69 years, and 70 to 84 years showed initial declines, with no change in recent years. Ages 40 to 54 only had a change in crude mortality between 2002 and 2010. Overall, men, NH Black or African American individuals, and people aged 85+ were associated with the highest AAMRs of their respective subgroups throughout the study period. Notably, there was an increase in crude mortality rate amongst individuals 25-39 years of age from 2009 to 2019.

Conclusion: PAD-related mortality in the US decreased from 2000 to 2016 but has stabilized in recent years. Despite improvement, disparities amongst sex, race, and age remain.

Figure 1. PAD-related mortality rates by 1.A. sex 1.B. race 1.C. ages 25-54 and 1.D. ages 55-85+ in the United States, 2000 to 2019. *Indicates that APC is significantly different from zero at α=0.05.

Demographic and Regional Trends of Mortality in Patients With Aortic Dissection in the United States, 1999 to 2019

Background

Aortic dissection (AoD) is associated with high morbidity and mortality. However, the burden of AoD mortality is not well characterized, and contemporary data and mortality trends in different demographic and geographic subgroups have not been described.

Methods and Results

Trends in AoD mortality were assessed using a cross‐sectional analysis of the Centers for Disease Control and Prevention Wide‐Ranging Online Data for Epidemiologic Research database. Crude and age‐adjusted mortality rates (AAMR) per 1 million people with associated annual percent changes were determined. Joinpoint regression was used to assess trends in the overall sample and different demographic (sex, race and ethnicity, age) and geographic subgroups. Between 1999 and 2019, a total of 86 855 AoD deaths occurred within the United States. In the overall population, AAMR was 21.1 per 1 million in 1999 and 21.3 in 2019. After an initial decline in mortality, AAMR increased from 2012 to 2019, with an associated annual change of 2.5% (95% CI, 1.8–3.3). Men, older adults (aged ≥85 years), and non‐Hispanic Black or African American individuals had higher mortality rates than women, younger individuals, and other racial and ethnic individuals, respectively. Despite lower AAMRs throughout the study period, women experienced greater increases in AAMR from 2012 to 2019 compared with men. Similarly, non‐Hispanic Black or African American individuals had a pronounced increase in AAMR from 2012 to 2019.

Conclusions

Despite an initial decline in AoD mortality, the mortality rate has been increasing from 2012 to 2019, with pronounced increases among women and non‐Hispanic Black or African American individuals.

Demographic and Regional Trends of Mortality in Patients With Acute Myocardial Infarction in the United States, 1999 to 2019

Acute myocardial infarction (AMI)-related mortality has been decreasing within the United States because of improvements in management and preventive efforts; however, persistent disparities in demographic subsets such as race may exist. In this study, the nationwide trends in mortality related to AMI in adults in the United States from 1999 to 2019 are described. Trends in mortality related to AMI were assessed through a cross-sectional analysis of the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research database. Age-adjusted mortality rates per 100,000 people and associated annual percentage change and average annual percentage changes with 95% confidence intervals (CIs) were determined. Joinpoint regression was used to assess the trends in the overall, demographic (gender, race/ethnicity, age), and regional groups. Between 1999 and 2019, a total of 3,655,274 deaths related to AMI occurred. In the overall population, age-adjusted mortality rates decreased from 134.7 (95% CI 134.2 to 135.3) in 1999 to 48.5 (95% CI 48.3 to 48.8) in 2019 with an average annual percentage change of -5.0 (95% CI -5.5 to -4.6). Higher mortality rates were seen in Black individuals, men, and those living in the South. Patients older than 85 years experienced substantial decreases in mortality. In addition, rural counties had persistently higher mortality rates in comparison with urban counties. In conclusion, despite decreasing mortality rates in all groups, persistent disparities continued to exist throughout the study period.

Mapping the movement for climate change and health in England: a descriptive review and theory of change analysis

Aims:

There are a growing number of organisations working to address the connections between climate change and health. This article introduces the concept of ‘theories of change’ – the methodology by which organisations or movements hope to bring about social change – and applies it to the current climate change and health movement in England. Through movement mapping, the article describes and offers reflections on the climate change and health ecosystems in England.

Methods:

Organisations working on climate change and health in England were identified and publicly available information was collated to map movement characteristics, target stakeholders and methodologies deployed, using an inductive, iterative approach.

Results:

A total of 98 organisations working on health and climate change (and/or sustainability) were initially identified, of which 70 met the inclusion criteria. Most organisations target two or more stakeholders, with healthcare workers, management structures, and government being most commonly cited. Methodological approaches identified include Formal education programmes; Awareness-raising; Purchasing-procurement power; Advocacy; Financial; Media-messaging; Networking; Knowledge generation; and Policy making, of which education, awareness-raising, and advocacy are most commonly used.

Conclusion:

There is a tendency for climate change and health organisations in England to focus on individual level and sectoral change over system change. More could be made of the potential for the healthcare professions’ voice and messaging for the wider climate movement. Given the rapid boom of climate change and health organisations in recent years, a mind-set shift that recognises different players as part of a cohesive ecosystem with better coordination and collaboration may reduce unnecessary work, and facilitate more cohesive outcomes.

Association between serum osteoprotegerin levels and severity of coronary artery disease in patients with acute myocardial infarction

Background

Osteoprotegerin (OPG), a glycoprotein of the tumor necrosis factor (TNF) superfamily is a main biomarker for vascular calcification.

Aim

We aimed to evaluate the association between serum OPG levels and extent of coronary lesions in patients with acute myocardial infarction (MI).

Methods

Consecutive patients hospitalized for an acute MI who underwent coronary angiography were included. SYNTAX score was calculated to assess the severity of coronary artery disease. The population was analysed in low (5 (3–6)), medium (11 (9–13)) and high (20 (18–23)) tertiles of SYNTAX score.

Results

Among the 378 patients included, there was a gradual increase in age, rate of diabetes, anterior wall location, and a reduction in left ventricular ejection fraction across the SYNTAX tertiles. OPG levels significantly increased across the tertiles (962 (782–1,497), 1,240 (870–1,707), and 1464 (1,011–2,129) pg/ml, respectively (p&lt;0.001)). In multivariate analysis, OPG [OR (CI95%): 2.09 (1.31–3.32) p=0. 002], were associated with the high SYNTAX group, beyond hypercholesterolemia, CV history and creatinine.

Conclusion

We found an association between OPG levels and coronary lesions complexity patients with acute MI. Determining OPG levels in combination with an ischemia test could be used in the clinical setting for the early diagnosis of subclinical atherosclerosis.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): CHU Dijon BourgogneConseil Régional Bourgogne Franche Comté

Trends in Race and Ethnicity Among Matriculants to US Oncology Training Programs, 2015-2020

This cross-sectional study assesses underrepresented minority trends across oncology specialties from 2015 to 2020.

Racial and ethnic representation trends in United States oncology training programs

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Background: Utilizing race and ethnicity data from the Accreditation Council for Graduate Medical Education (ACGME), this study aims to assess representation trends across American Society of Clinical Oncology (ASCO) participant specialties from the past five academic years in order to characterize current needs and effectively address these needs moving forward. Methods: Self-reported ethnicity/race data from the ACGME database books were collected from academic years 2015-16 to 2019-2020 for the following oncologic training programs: hematology and medical oncology, medical oncology, gynecologic oncology, pediatric hematology and oncology, radiation oncology, complex general surgical oncology. Summary statistics and chi-square analysis were conducted to compare underrepresented minority (URM) trends across programs. URM groups were cross-referenced with definitions provided by the AAMC and included those who identify as Hispanic, Latino or of Spanish origin, Black or African American, and Native American or Alaskan. Results: Over the study period, only 1,250 (9.0%) of 13,853 oncology trainees identified as URM. Chi-square analysis demonstrated no significant change in URM representation in all oncology specialties combined between 2015-16 and 2019-20 (8.9% [95% CI, 7.8%-10.0%] vs. 9.7% [95% CI, 8.7%-10.8%]; P=.31). Between 2015-16 and 2019-20, Hematology and oncology (+1.3%), pediatric hematology and oncology (+0.3%) all demonstrated insignificant increasing trends in representation while radiation oncology (-0.3%), complex general surgical oncology (-4.0%) had statistically insignificant decreasing trends in representation. Gynecologic oncology (+6.0%) demonstrated a significant increasing trend in representation. Conclusions: This is the first study to characterize the vast disparities in representation in oncologic training programs in the United States. There is a demonstrated lack of representation across all oncology training programs and a lack of significant improvement over the study period. A multiprong approach is needed to improve diversity and representation across the spectrum of the oncology workforce in the United States.

Impact of Nutritional Epigenetics in Essential Hypertension: Targeting microRNAs in the Gut-Liver Axis

PURPOSE OF REVIEW

To review the current knowledge on interactions between dietary factors and microRNAs (miRNAs) in essential hypertension (EH) pathogenesis.

RECENT FINDINGS

There exists an integration of maintenance signals generated by genetic, epigenetic, immune, and environmental (e.g., dietary) factors that work to sustain balance in the gut-liver axis. It is well established that an imbalance in this complex, intertwined system substantially increases the risk for EH. As such, pertinent research has been taken to decipher how each signal operates in isolation and together in EH progression. Recent literature indicates that both macro- and micronutrients interrupt regulatory miRNA expressions and thus, alter multiple cellular processes that contribute to EH and its comorbidities. We highlight how carbohydrates, lipids, proteins, salt, and potassium modify miRNA signatures during EH. The disruption in miRNA expression can negatively impact communication systems such as over activating the renin-angiotensin-aldosterone system, modulating the vascular smooth muscle cell phenotype, and promoting angiogenesis to favor EH. We also delineate the prognostic value of miRNAs in EH and discuss the pros and cons of surgical vs dietary prophylactic approaches in EH prevention. We propose that dietary-dependent perturbation of the miRNA profile is one mechanism within the gut-liver axis that dictates EH development.

HER2-positive metastatic cervical cancer responsive to first and second-line treatment: A case report

Cervical cancer is the fourth most common malignant disease among women, with metastatic disease having a dismal survival rate compared to localized disease when using standard combination chemotherapy. Next-generation sequencing (NGS) of tumors has allowed for targeted treatments of cancers in patients who have progressed on first-line therapy. We present a case of a 46 year-old female with advanced cervical adenocarcinoma and metastatic recurrence in the lungs found to have HER2 mutation who underwent first and second-line HER2-targeted therapy with sustained disease response. We review the standard of care for advanced cervical cancer, toxicity profiles of chemotherapy and immunotherapy that were employed, the economics of NGS and targeted treatment, and future directions for HER2-targeted therapy. This case report highlights a patient with metastatic cervical cancer responsive to first and second-line HER2-targeted therapy.

Antibiofilm potential of purified environmental bacteriophage preparations against early stage Pseudomonas aeruginosa biofilms

AIMS

This paper presents the potential of environmentally sourced bacteriophages to affect the growth of clinical isolates of Pseudomonas aeruginosa biofilms, and assesses the respective plaque morphotypes presented by each bacteriophage, in vitro.

METHODS AND RESULTS

Bacterial host strains were typed for their ability to produce the quorum sensing-controlled virulence factor pyocyanin, and then tested for bacteriophage susceptibility using the spot test method. The bacteriophages were co-administered with ciprofloxacin in order to determine whether the bacteriophages would demonstrate synergistic or antagonistic behaviour to the antibiotic in vitro. Results suggest a potential relationship between the bacteriophage plaque size and biofilm inhibition, where those producing smaller plaques appear to be more effective at reducing bacterial biofilm formation.

CONCLUSIONS

This phenomenon may be explained by a high adsorption rate leading to the rapid formation of smaller plaques, and greater biofilm reduction associated with the loss of viable bacterial cells before the cells can adhere to the surface and form a biofilm. Results from the co-administration of bacteriophage and ciprofloxacin suggest that the two work synergistically to affect P. aeruginosa biofilms.

SIGNIFICANCE AND IMPACT OF THE STUDY

The data indicate enhanced efficacy of ciprofloxacin by ≥50%. This could offer an alternative strategy for targeting antibiotic-resistant infections.

Controlled Release of Herbicides Supported on Polysaccharide Based Hydrogels

Polymeric hydrogels based on polysaccharides, hydroxyethylcellu lose and dextran, were attained by cross-linking with epichlorohydrin. The cross-linked polymer beads were loaded with 2,4-dichlorophenoxyacetic acid by direct esterification in the presence of carbonyldiimidazole. Loads ranging be tween 0.5 and 2.2 mol of 2,4-dichlorophenoxyacetyloyl groups per glucose unit were obtained. The release of 2,4-D herbicide was investigated in buffered aqueous solution at different pH values (4, 7 and 9) and evaluated with respect to different structural parameters, such as nature of the polymer matrices, cross-linking extent and herbicide loading. A fairly slow release, ranging from 10 to 25% after four months, was recorded under neutral and acid conditions, whereas at pH 9 an initial burst in the release profile, reaching almost 90% release of 2,4-D loading, was observed. In the majority of the cases, the release kinetics are reproduced by the combination of two exponential decay processes, that differ by about three orders of magnitude in their absolute rates.

[Psychiatric aspects of rheumatoid arthritis: Review of literature]

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory degenerative disease whose symptoms are mainly joint with significant functional impact, resulting in a restriction of the activities of the patient and increasing the impact on mental well-being. Several studies have been conducted to explore psychiatric disorders comorbid with RA.

OBJECTIVE

The objective of this review is to present the various psychiatric manifestations of RA reported in the medical literature.

METHODS

A literature review was conducted using the Pubmed search with the following keywords: psychiatry, psychiatric manifestations, rheumatoid arthritis. Three hundred and sixty-one articles were reviewed for relevance and 47 references were selected.

RESULTS

Among the major psychiatric disorders found in RA, the anxiety and depressive disorders are prevalent (13 to 48% of patients), as well as suicide, insomnia and tiredness. The impairment of quality of life is markedly after age 65. The association between RA and schizophrenia seems negative so that factors predisposing one is protective for the other.

CONCLUSION

Comorbid psychiatric disorders with RA are prevalent and may increase the impairment of quality of life for patients. The detection and treatment of psychiatric disorders improve the care of patients with RA.

Challenging boundaries: an enhanced recovery programme for radical cystectomy

INTRODUCTION

The implementation of enhanced recovery programmes (ERPs) in colorectal surgery has seen improvements in the length of inpatient stay with no increase in complications. We investigated the role of ERP in radical cystectomy at our institution.

METHODS

Prospective data were collected from 26 consecutive patients prior to the introduction of the ERP and 51 patients who underwent open radical cystectomy within an ERP. Individuals in the ERP cohort did not receive bowel preparation or nasogastric drainage but received preoperative carbohydrate drinks, perioperative epidural analgesia and immediate mobilisation on day 1. Primary outcome measures included duration of intensive care unit (ICU) stay and length of hospital stay. Secondary outcome measures included the time to the passage of flatus and faeces, and time to mobilisation. Other measures that were analysed included operation time and complications.

RESULTS

Baseline characteristics for both groups were similar. The median length of hospital stay fell from 11.5 days to 10.4 days and the mean ICU stay dropped from 2.4 days to 1.0 days (p=0.01). Time to removal of nasogastric tube, and time to passage of flatus and faeces were significantly shorter in the ERP group, as was the time to full oral diet. Clavien complication rates and 30-day mortality rates were similar in both groups. There were no readmissions.

CONCLUSIONS

ERP in radical cystectomy is safe and not associated with any increase in complications or readmissions. It is associated with reductions in ICU stay, and could also reduce length of hospital stay and duration of postoperative ileus.

Regulation of human lung epithelial cell numbers by diesel exhaust particles

Particulate air pollution is associated with respiratory morbidity and has cytotoxic and pro-inflammatory effects. The effects of diesel exhaust particles (DEP) on proliferation and apoptosis of A549 lung epithelial cells were examined. When deprived of serum (serum starvation), epithelial cell numbers fell, but DEP (5-200 microg.mL-1) prevented this. Using flow cytometric analysis of propidium iodide (PI) staining, DEP (10 microg.mL-1) increased cells in the S phase of cell cycle from 12.85 to 18.75% after 48 h, reversing serum starvation-induced G0/1 arrest. DEP also reduced the increase in apoptotic cells, as defined by double expression of annexin V/PI, observed after serum starvation (from 28.35 to 15.46%). The antioxidants, N-acetylcysteine (NAC; 33 mM) and AEOL10113 (10-100 microM), the N-terminal c-jun kinase inhibitor, SP600125 (33 microM), and nuclear factor-kappaB inhibitor, SN50 (33 microM), inhibited DEP-induced cell number increase. NAC inhibited DEP-induced reduction of G0/1 and increase in cells in the S and G2/M phases. Expression of p21CIP1/WAF1 mRNA and protein seen with serum starvation was reduced by DEP. In conclusion, diesel exhaust particles prevented serum starvation-led decreases in A549 epithelial cells by inducing cell cycle progression and preventing apoptosis, processes involving oxidative stress, inhibition of p21CIP1/WAF1 expression and stimulation of N-terminal c-jun kinase and nuclear factor-kappaB. Therefore, low-dose diesel exhaust particle exposure may lead to lung epithelial cell hyperplasia.

Assay of terfenadine in pharmaceutical formulation and human plasma by adsorptive stripping voltammetry

The controlled adsorptive accumulation of Zn(II)-terfenadine complex (1:1) onto a hanging mercury drop electrode (HMDE) provides the basis for determination of the antihistamine drug terfenadine by differential pulse cathodic adsorptive stripping voltammetry. The adsorbed Zn(II)-terfenadine complex (1:1) at the HMDE developed a stripping voltammetry peak at more negative potential than that of the free Zn(II) ions. The peak current was used for the determination of terfenadine in pharmaceutical formulation and human plasma in 0.1 mol l(-1) sodium perchlorate solution under the optimized conditions (E(acc), -0.5 V; t(acc) 360 s; scan rate, 5 mV s(-1) and pulse height 100 mV). The developed peak current (i(p)) showed a linear dependence with terfenadine concentration within the range of 6 x 10(-8) - 9 x 10(-7) mol l(-1). The recoveries were found 98.97-99.35%, 99.72-99.02% and 100.58-101.08% with the R.S.D. 0.16-0.27%, 0.25-0.82% and 0.44-1.14% in authentic form, pharmaceutical formulations and human plasma, respectively. The detection limits were 0.4505 and 0.6115 ng ml(-1) terfenadine in pharmaceutical formulations and human plasma, respectively.

Gliotoxin stimulates the apoptosis of human and rat hepatic stellate cells and enhances the resolution of liver fibrosis in rats

BACKGROUND & AIMS

Hepatic stellate cells (HSCs) play a pivotal role in liver fibrosis and stimulating their apoptosis could be an effective treatment for liver fibrosis.

METHODS

Activated HSCs, hepatocytes, and rats with liver fibrosis were treated with gliotoxin.

RESULTS

Addition of gliotoxin to activated (alpha-smooth muscle actin positive) rat and human HSCs resulted in morphologic alterations typical of apoptosis. Within 2-3 hours of incubation, caspase 3 activity was markedly induced and caspase inhibitor 1 (Z-VAD-FMK)-sensitive oligonucleosome-length DNA fragments were detectable by gel electrophoresis of low molecular weight DNA. Apoptosis was widespread as judged by fluorescence-activated cell sorter analysis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining in both rat and human HSCs at concentrations that had no effect on the viability of rat hepatocytes. Gliotoxin treatment significantly reduced the number of activated stellate cells and mean thickness of bridging fibrotic septae in livers from rats treated with carbon tetrachloride.

CONCLUSIONS

These data demonstrate proof-of-concept that by up-regulating HSC apoptosis, the extent of fibrosis can be decreased in inflammatory liver injury.

Apoptosis of hepatic stellate cells: involvement in resolution of biliary fibrosis and regulation by soluble growth factors

BACKGROUND

Activated hepatic stellate cells (HSC) are central to the pathogenesis of liver fibrosis, both as a source of fibrillar collagens that characterise fibrosis and matrix degrading metalloproteinases and their tissue inhibitors, the TIMPs.

AIMS

To test the hypothesis that HSC apoptosis is critical to recovery from biliary fibrosis and that soluble growth factors may regulate HSC survival and apoptosis.

METHODS

Rats (n=15) were subjected to bile duct ligation for 21 days, after which biliodigestive anastomosis was undertaken (n=13). Livers were harvested at fixed time points of recovery for periods of up to 42 days. Numbers of activated HSCs were quantified after alpha smooth muscle actin staining and HSC apoptosis was detected by terminal UDP-nick end labelling (TUNEL) staining and quantified at each time point. HSC apoptosis was quantified in vitro in the presence or absence of insulin-like growth factor (IGF)-1, IGF-2, platelet derived growth factor (PDGF), and transforming growth factor beta1 (TGF-beta1).

RESULTS

Following biliodigestive anastomosis after 21 days of bile duct ligation, rat liver demonstrated a progressive resolution of biliary fibrosis over 42 days, associated with a fivefold decrease in activated HSC determined by alpha smooth muscle actin staining. TUNEL staining indicated that loss of activated HSC resulted from an increase in the rate of apoptosis during the first two days post biliodigestive anastomosis. Serum deprivation and culture in the presence of 50 microM cycloheximide was associated with an increase in HSC apoptosis which was significantly inhibited by addition of 10 ng/ml and 100 ng/ml IGF-1, respectively (0.05>p, n=5). In contrast, 1 and 10 ng/ml of TGF-beta1 caused a significant increase in HSC apoptosis compared with serum free controls (p<0.05, n=4). PDGF and IGF-2 were neutral with respect to their effect on HSC apoptosis.

CONCLUSION

HSC apoptosis plays a critical role in the spontaneous recovery from biliary fibrosis. Both survival and apoptosis of HSC are regulated by growth factors expressed during fibrotic liver injury.

Hepatic stellate cells express the low affinity nerve growth factor receptor p75 and undergo apoptosis in response to nerve growth factor stimulation

We have examined the expression of p75, a member of the TNF receptor superfamily in hepatic stellate cells (HSC) and pancreatic stellate cells (PSC). Activated HSC and PSC were demonstrated by Western blot analysis to express p75. p75 was immunolocalized to cells with a myofibroblast-like morphology in the fibrotic bands of six fibrotic and cirrhotic liver biopsies and three biopsies of fibrotic human pancreas. Immunostaining of parallel sections indicated that these cells were alpha-smooth muscle actin-positive, identifying them as activated HSC and PSC, respectively. HSC apoptosis in tissue culture in the presence of serum was quantified after addition of 0.1 to 100 ng/ml of nerve growth factor (NGF) a ligand for p75, by in situ counting of apoptotic bodies after addition of acridine orange. HSC demonstrated a significant increase in apoptosis in response to 100 ng/ml NGF (0.05 > P by Wilcoxon's rank; n = 7) after 24 hours. NGF 100 ng/ml had no effect on HSC proliferation, but reduced total HSC DNA by 19% relative to control after 24 hours (n = 3). These data demonstrate that activated HSC express p75 and respond to NGF stimulation by undergoing apoptosis. We therefore report p75 as a novel marker of activated HSC and suggest that signaling via ligand binding to p75 may provide a mechanism for selective apoptosis of HSC.

Vascular endothelial growth factor and its receptor, KDR, in human brain tissue after ischemic stroke

Ischemic stroke results from a reduction in cerebral blood flow to a focal region of the brain after the occlusion of an artery, causing damage to nervous tissue. There is a region of cerebral ischemic tissue (penumbra) surrounding an acute cerebral infarct that is dysfunctional but potentially viable. Restoration of perfusion in the penumbra may ameliorate the tissue damage. The identity and the role of growth factors that control the extent of tissue damage and its repair are poorly understood. Angiogenesis has been demonstrated to occur in brain tissues of patients surviving an acute ischemic stroke. In this paper we have investigated the status of a potent angiogenesis factor, vascular endothelial growth factor (VEGF), in patients after acute ischemic brain stroke. Western blotting and immunohistochemistry were used to determine protein expression, and in situ hybridization was used to quantify and localize mRNA synthesis. The expression of VEGF protein was increased in the penumbra compared with infarcted brain and contralateral hemisphere. Neurones, endothelial cells, and astrocytes in the penumbra in all patients studied had significant up-regulation of both VEGF165 and VEGF189 mRNA (p < 0.01, Wilcoxon Matched-Pairs Signed-Ranks Test) compared with infarcted tissue and the normal looking contralateral hemisphere that was used as a control. Immunohistochemistry demonstrated that kinase insert domain receptor was present in blood vessels within the infarct/penumbra and absent from the normal contralateral hemisphere. VEGF, which is important in angiogenesis, may also influence long term neuronal survival, and possibly its modulation may prove to be of therapeutic value for patients with ischemic stroke.

A putative role for platelet-derived growth factor in angiogenesis and neuroprotection after ischemic stroke in humans

BACKGROUND AND PURPOSE

Growth factors control two important processes in infarcted tissue, ie, angiogenesis and gliosis. We recently reported that transforming growth factor-beta1 (TGF-beta1) might be involved in angiogenesis after ischemic stroke in humans; here we present data of an extensive study on platelet-derived growth factor (PDGF) and its receptors.

METHODS

We studied brain samples from patients who suffered from ischemic stroke for the expression of mRNA encoding PDGF-A, PDGF-B, and PDGF receptors (PDGF-R). Proteins were examined by Western blotting and immunohistochemistry using the antibodies to PDGF-AB, PDGF-BB, PDGF-R alpha, and PDGF-R beta.

RESULTS

At the mRNA level, PDGF-A and PDGF-B were expressed mainly in neurons in penumbra. PDGF-R mRNA was strongly expressed in some astrocytes but mainly in type III/IV neurons in infarct and penumbra. The least expression was seen in the contralateral hemisphere (P<.001). In contrast, both PDGF-AB and PDGF-BB immunoreactive products were present in most cell types: PDGF-R alpha and PDGF-R beta mainly on neurons, and PDGF-R beta on some endothelial cells, with less staining of all the isoforms in the contralateral hemisphere. On Western blots, PDGF-AB and -BB were expressed more within white matter than gray matter of infarct/penumbra, whereas both isoforms of receptor were expressed mainly in gray matter compared with contralateral hemisphere. There was no or very weak expression of the receptor in white matter.

CONCLUSIONS

PDGF proteins are highly expressed in white matter, suggesting that PDGF may exert its function in white matter participating either in regeneration of damaged axons or in glial scar formation. PDGF-BB and its receptor expressed on microvessel endothelial cells might be involved in angiogenesis after stroke. Thus, PDGF is likely to be angiogenic and neuroprotective in stroke.