Clinical and microbiological characteristics of bacterial infections in patients with cirrhosis. A prospective cohort study from Argentina and Uruguay

INTRODUCTION AND OBJECTIVES

there is insufficient data regarding bacterial infections in patients with cirrhosis to support recommendations for empiric antibiotic treatments, particularly in Latin America. This study aimed to evaluate bacterial infection's clinical impact and microbiological characteristics, intending to serve as a platform to revise current practices.

MATERIALS AND METHODS

a multicenter prospective cohort study of patients with cirrhosis and bacterial infections from Argentina and Uruguay. Patients and infection-related information were collected, focusing on microbiology, antibiotic susceptibility patterns, and outcomes.

RESULTS

472 patients were included. Spontaneous bacterial infections and urinary tract infections (UTI) were registered in 187 (39.6%) and 116 (24.6%) patients, respectively, representing the most common infections. Of the 256 culture-positive infections, 103 (40.2%) were caused by multidrug-resistant organisms (reaching 50% for UTI), and 181 (70.7%) received adequate initial antibiotic treatment. The coverage of cefepime and ceftriaxone was over 70% for the empirical treatment of community-acquired spontaneous infections, but ceftazidime´s coverage was only 40%. For all cases of UTI and for healthcare-associated or nosocomial spontaneous bacterial infections, the lower-spectrum antibiotics that covered at least 70% of the isolations were imipenem and meropenem. During hospitalization, a second bacterial infection was diagnosed in 9.8% of patients, 23.9% required at least one organ support, and 19.4% died.

CONCLUSIONS

short-term mortality of bacterial infections in patients with cirrhosis is very high, and a high percentage were caused by multidrug-resistant organisms, particularly in UTIs. The information provided might serve to adapt recommendations, particularly related to empirical antibiotic treatment in Argentina and Uruguay. The study was registered in Clinical Trials (NCT03919032).

Norfloxacin prophylaxis effect on multidrug resistance in patients with cirrhosis and bacterial infections

It is unclear whether norfloxacin predisposes to infections by multidrug-resistant organisms (MDROs). We aimed to evaluate if patients with cirrhosis receiving norfloxacin prophylaxis at the time of the diagnosis of bacterial infections were more likely to present a multidrug-resistant isolate than those without prophylaxis. This is a cross-sectional study of hospitalized patients with cirrhosis and bacterial infections from Argentina and Uruguay (NCT03919032) from September 2018 to December 2020. The outcome variable was a multidrug-resistant bacterial infection. We used inverse probability of treatment weighting to estimate the odds ratio (OR) of norfloxacin on infection caused by MDROs considering potential confounders. Among the 472 patients from 28 centers, 53 (11%) were receiving norfloxacin at the time of the bacterial infection. Patients receiving norfloxacin had higher MELD-sodium, were more likely to have ascites or encephalopathy, to receive rifaximin, beta-blockers, and proton-pump inhibitors, to have a nosocomial or health-care-associated infection, prior bacterial infections, admissions to critical care units or invasive procedures, and to be admitted in a liver transplant center. In addition, we found that 13 (24.5%) patients with norfloxacin and 90 (21.5%) of those not receiving it presented infections caused by MDROs (adjusted OR 1.55; 95% CI: 0.60-4.03; p = 0.360). The use of norfloxacin prophylaxis at the time of the diagnosis of bacterial infections was not associated with multidrug resistance. These results help empiric antibiotic selection and reassure the current indication of norfloxacin prophylaxis in well-selected patients.Study registration number: NCT03919032.

Genetic variants as determinants of outcome in lamin A/C-related cardiac disease

Background

Current guidelines for the diagnosis and management of familial dilated cardiomyopathy highlight the variables “male sex” and “non-missense type variants” as risk factors for malignant ventricular arrhythmias.

Objective

Quantitative evaluation of prognostic differences between different LMNA variants associated with cardio-laminopathy.

Method

Analysis of cardiac event-free survival (sudden death, major arrhythmic events, death from heart failure and transplantation) with Kaplan-Meier approach in relation to gender & variant LMNA type. The data come from a specific database containing information on more than 1200 carriers of disease-causing LMNA variants. In the first analysis, the groups of comparison were truncating-type variants (LMNAtv) VS the global of pathogenic missense variants in the gene associated with cardiolaminopathy (LMNAm), segregated by gender. In the second analysis, it was considered missense LMNA affecting different residues (p.Arg190, p.Arg377 and p.Arg541), located in different functional domains, with enough data for comparison and with statistically different clinical behavior from that of global pathogenic variants in the gene. They were compared with the group of LMNAtv variants, as reference. The variants included were p.Arg377Cys/His, p.Arg541Cys/Ser/Gly/Pro/His and p.Arg190Trp/Gln/Pro, all of them pathogenic and associated with cardio-laminopathy.

Results

No significant differences were observed in survival between LMNAtv versus LMNAm variants (log rank=0.56) with slightly worse outcomes in males (log rank 0.03). Median survival time was 56 years for men compared to 60 years for women with LMNAtv, and 55 years compared to 66 years, respectively, among carriers of LMNAm (analysis A). In analysis B, statistically significant differences were observed between the groups considered (Log Rank p<0.001). These differences were also clinically relevant (median survival time in groups p.Arg377, LMNAtv, p.Arg190 and p.Arg541 was 60, 58, 50 and 35 years, respectively). Importantly, more than 70% of the cardiac events observed were related to major ventricular arrhythmic episodes.

Conclusions

This quantitative analysis demonstrates that certain missense variants in LMNA may have a similar and even more adverse clinical course than the set of truncation-type variants. These findings highlight the relevance of the specific variant rather than the variant type in guiding actionable therapies to prevent adverse outcomes. Regarding the differences observed between genders, even though they are statistically significant, their magnitude could be clinically not relevant.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Health in Code

Specific actin (ACTC1) missense variants are associated with different overlapping clinical phenotypes and outcomes

Introduction

Pathogenic variants in ACTC1 have been associated with hypertrophic (HCM), dilated (DCM), and left ventricular non-compaction (LVNC) cardiomyopathies. Phenotypes often overlap and atrial septal defects have also been reported. Prognostic data on carriers of these variants are scarce.

Methods and results

The proprietary database of a cardiovascular genetic laboratory was examined to assess penetrance and survival in the 438 carriers (191 families) of 75 missense variants in ACTC1 associated with disease. Their mean age at diagnosis was 32.4 (±18.7) years; 52% were male. The diagnosis was isolated HCM in 47%, LVNC in 17%, and DCM in 9%. LVNC with either HCM or DCM was present in an additional 8%; 13% had an atrial septal defect. Among carriers with echocardiographic information, left ventricular dilatation and dysfunction were described in 13% and 16%, respectively. Ventricular arrhythmias and conduction defects were reported in 94 and 93 carriers. Percentages have not been calculated for the latter, as we cannot ensure a denominator in whom cardiac conduction defects and arrhythmias were certainly discarded.

Overall, 50% of carriers were diagnosed by age 45, and 10% had experienced a major cardiac event. The p.Leu10Met and p.His90Tyr variants (23% of all carriers) demonstrated lower penetrance and a better prognosis than the p.Glu101Lys variant and the other missense variants.

Conclusions

Missense variants in ACTC1 are associated with a range of phenotypes that often overlap. Overall, penetrance and outcomes are age-dependent with a moderate rate of major cardiac events, which are highly dependent on the specific disease-causing variant

Funding Acknowledgement

Type of funding sources: None. Figure 1. The graph shows the percentage of carriers of pathogenic or likely pathogenic missense variants in the ACTC1 gene diagnosed at different ages. Considering all the missense variants in ACTC (in red), 50% of carriers had been diagnosed by age 45. It is worth highlighting the percentage of diagnosis (>15%) in the first 15 years of life, which is higher than the figure usually observed in sarcomeric hypertrophic cardiomyopathy.Figure 2. The graph shows the survival free of major cardiovascular events (sudden, heart failure, stroke-related death, appropriate ICD therapy and heart transplant) in individuals with missense variants in ACTC1. Carriers and affected relatives without genetic study were included. Events were infrequent in two of the most informative variants (p.Leu10Met and p.His90Tyr), and significantly different compared with carriers of the other missense variants (p=0.036 for p.Leu10Met and p=0.015 for p.His90Tyr).

Narrowing of the neonatal region in the FBN1 gene

Background

Neonatal Marfan syndrome (MFS) is considered the most severe form of MFS and is characterized by early childhood death due to congestive heart failure. It has been suggested that genetic variants associated with this clinical presentation, cluster in a specific region between exons 24 and 32. It has been reported that patients carrying genetic variants in these exons have worse prognosis.

Purpose

Our purpose was to analyze cardiovascular outcome by location of the genetic variants in the “neonatal region” of the FBN1 gene.

Materials and methods

We analyzed clinical data on 1353 carriers and affected relatives with 683 missense pathogenic or likely pathogenic genetic variants of FBN1 gene (including cases identified in our laboratory and cases described in the literature) in whom age at last follow-up was available. Kaplan-Meier survival curves were generated to examine location of the genetic variant in the FBN1 gene in relation to survival free of surgical intervention or cardiovascular (CV) death (composite of deaths related to aortic dissection, heart failure/transplant, sudden, stroke or CV surgery).

Missense genetic variants were classified as located in the “neonatal region” (residues 952–1363, corresponding to exons 24–32) and in the “non-neonatal region” (residues 45–951 and 1364–2731). In the “neonatal region”, we have also analyzed a sub-region of “over-representation” of heart failure deaths in the first year of life, which we called “critical neonatal region” (amino acids 1028–1088, corresponding to exon 25 and few residues from exon 26) in comparison to the “non-critical neonatal region”.

Results

Data were examined on 1060 patients with missense variants located in the “non neonatal region” and on 293 patients with missense variants located in the “neonatal region”. Of these, 96 patients were carriers of missense variants in the “critical neonatal region”, the rest of patients carried variants in the neonatal region, outside this particular domain (“non-critical neonatal region”).

Patients carrying missense variants in the neonatal region had worse prognosis than those carrying variants outside this region. This poorer outcome was due to events occurring in patients carrying variants in the “critical neonatal region” (see Figure). These patients had the worse prognosis (p=0.000108, vs. the other groups). Furthermore, events in the non-critical neonatal region were similar to other missense variants located outside the neonatal region.

There were no differences in the “neonatal region” when analyzing by gender.

Conclusion

In our cohort, the worse prognosis seen in patients carrying missense pathogenic or likely pathogenic variants in the “neonatal region” compared to the “non-neonatal region”, was due to events in patients carrying missense variants in a small subregion which we called the “critical-neonatal region” (exons 25 and 26). These patients had the worse prognosis, irrespective of gender.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Health in Code Figure 1. Neonatal region FBN1

Molecular characterization of a cohort of individuals referred to genetic testing with suspected CPVT

Background

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is one of the most lethal inherited arrhythmogenic diseases and it mainly affects the young, in the absence of structural heart disease. This condition is difficult to diagnose and the first expression of disease can be an arrhythmic death. In the last years, genetic testing has become a useful tool in the challenging task of CPVT diagnosis.

The diagnostic yield of the genetic study is highly variable and dependent on the phenotypic characteristics of the individuals evaluated.

Purpose

This study aimed to address the clinical characteristics and genetic testing (GT) results in a cohort of individuals referred to genetic analysis with a non-definitive diagnosis of CPVT, in a real world-setting.

Methods

This is a retrospective cohort study of patients referred for GT with clinical suspicion of CPVT, but who did not strictly meet the diagnostic criteria for this disease (according to current guidelines). NGS genotyping was performed with a library of 251 genes. NGS-based genomic testing was performed with classification of identified variants according to American College of Medical Genetics and Genomics guidelines.

Results

One hundred and sixteen unrelated patients with available clinical information (patients' characteristics are summarized in TABLE1) were included in the analysis. Mean age at GT was 36 y/o (±19), 47% were women and 18% had a familial history of sudden cardiac death.

The first clinical manifestation was: exercise or stress induced syncope in 36%, exercise induced ventricular tachycardia in 30% and sudden cardiac arrest in 15.5% (78% during emotional or physical stress - 89% aborted sudden death). Mean age at sudden death was 20 y/o (±14).

GT was positive in 49.1% (n=57), negative in 37.9% (n=44) and inconclusive in 12.9% (n=15). We had identified pathogenic/likely pathogenic variants in CPVT-related genes in 40% of the referred patients: RYR2 (70.2%-n: 40), KCNJ2 (8.8%-n: 5), CASQ2 in homozygous/compound heterozygous carriers (3.5%-n: 2). In the RYR2 gene we detected 36 different genetic variants (13 were novel) in 40 different individuals. In addition, relevant variants were also identified in other genes associated with channelopathies (SCN5A, 3.5%, n: 2 and KCNQ1, 1.7%, n: 1) and in genes associated with structural heart disease: desmosomal genes (6.8%-DSP n: 1 and PKP2 n: 3) and sarcomeric genes (5.1%- MYBPC3 and MYH7) (figure 1A-B).

Conclusions

In our cohort of patients with non-definitive diagnosis of CPVT, the diagnostic yield of genetic testing was almost 50%. GT allowed confirmation of the suspicion of CPVT in 40% of the patients and, in addition, we were able to detect relevant genetic variants in other genes not associated with CPVT in 10% (differential diagnosis). The use of wide genetic panels would be useful in this context.

Funding Acknowledgement

Type of funding sources: None. Suspected CPVT. Genetic Testing.

Marfan syndrome: genetic variant determinants of cardiovascular outcomes

Background

Marfan syndrome is a systemic connective tissue disorder caused by genetic variants in the fibrillin-1 (FBN1) gene. Cardiovascular complications are the leading cause of mortality.

Purpose

To compare cardiovascular outcome by gender and by type of the genetic variant in the FBN1 gene.

Materials and methods

We analyzed clinical data on 1956 carriers and affected relatives with 1430 pathogenic or likely pathogenic genetic variants in the FBN1 gene (including cases identified in our laboratory and cases described in the literature) in whom age at last follow-up was available. We excluded patients with pathogenic or likely pathogenic genetic variants located in the so-called “neonatal region” (exon 24–32); they are recognized to have an early onset/severe phenotype.

Kaplan-Meier survival curves were generated to examine gender and type of genetic variant in relation to survival free of surgical intervention or cardiovascular (CV) death (composite of deaths related to aortic dissection, heart failure/transplant, sudden, stroke or CV surgery). Genetic variants were classified as truncating (nonsense, frameshift and splicing), “missense non-neonatal” and only those missense eliminating a Cysteine residue in the non-neonatal region (“Cys non-neonatal”).

Results

Data were examined on 896 patients with truncating variants (53% male; 47% female) and 1060 with missense variants, located outside the “neonatal region” (54% male; 46% female). Of these, 475 were missense variants substituting a cysteine residue (52% male; 48% female).

Those with truncating variants had worse prognosis versus those with missense and Cys variants (p=0.000108 and p=0.000115), with earlier onset of cardiovascular events. Overall, patients with missense variants had similar prognosis to those with missense variants eliminating a Cysteine residue. By age 65, however, almost 50% of patients with any type of variant had suffered a CV event, and with each variant type males had worse prognosis (see Figure 1). This was most evident in males aged 30 to 50 with missense variants that substituted a Cysteine residue, while female carriers of these variants had a prognosis similar to other missense variants (see Figure 2).

During the first decade carriers of missense and truncating variants mainly died of heart failure. From age 10 to 50, aortic dissection was the most common event, while later other events became more frequent, e.g. vascular intervention and sudden death.

Conclusion

In our cohort, male carriers of pathogenic or likely pathogenic variants had worse prognosis versus females. Carriers of truncating variants had the worst CV outcomes. However, it is noteworthy that by age 65, regardless of gender or mutation type, close to 50% of patients had experienced a major CV event/death.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Health in Code Figure 2. Type by gender

The Importance of Knowing the Local Epidemiology When a Patient With Cirrhosis Acquires a Bacterial Infection

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P5555Predictors of systemic embolisms in a large cohort of left ventricular noncompaction patients

Background

Left ventricular noncompaction (LVNC) is associated with an increased risk of systemic embolisms (SE). However, incidence and risk factors are not well established.

Purpose

To evaluate the rate of SE in LVNC and describe risk factors.

Methods

LNVC patients were included in a multicentric registry. Those with SE were considered for the analysis.

Results

514 patients with LVNC from 10 Spanish centres were recruited from 2000 to 2018. During a median follow-up of 4.2 years (IQR 1.9–7.1), 23 patients (4.5%) had a SE. Patients with SE (Table 1) were older at diagnosis, with no differences in gender and had similar cardiovascular risk factors. They were more frequently under oral anticoagulation (OAC). Besides, they had a more reduced LVEF, and more dilated LV and left atrium (LA). Late gadolinium enhancement (LGE) was more frequent, altogether suggesting a more severe phenotype.

Patients with SE had non-significantly higher rates of hospitalization for heart failure (33% vs 24%, p=0.31) and atrial fibrillation (35% vs 19%, p=0.10). In multivariate analysis, only LA diameter was an independent predictor of SE (OR 1.04, p=0.04). A LA diameter>45 mm had an independent 3 fold increased risk of SE (OR 3.04, p=0.02) (Image 1).

Table 1 Systemic embolisms (n=23) No systemic embolisms (n=491) p Men, n (%) 15 (65) 289 (56) 0.52 Median age at diagnosis (IQR), yr 60 (48–76) 48 (30–64) 0.02 Median follow up (IQR), yr 5.9 (3.1–7.8) 4.2 (1.8–7.1) 0.18 Hypertension, % 8 (33) 118 (24) 0.31 Diabetes mellitus, % 3 (14) 39 (8) 0.41 OAC, % 19 (83) 118 (24) 0.01 LVEF (SD), % 37 (15) 48 (17) 0.01 LVEDD (SD), mm 58 (11) 54 (10) 0.04 LVESD (SD), mm 45 (13) 38 (11) 0.01 LA diameter (SD), mm 46 (9) 39 (9) 0.01 LVEDV CMR (SD), mL 193 (75) 163 (70) 0.12 LVESV CMR (SD), mL 121 (64) 85 (64) 0.04 LGE, % 9 (40) 88 (18) 0.04

Conclusions

LVNC carries a moderate mid-term risk of SE, which appears to be irrespective of atrial fibrillation and associated with age, LV dilatation and systolic dysfunction and mainly LA dilatation. This subgroup of patients should be considered for oral anticoagulation in primary prevention.

Acute Liver Failure due to Wilson Disease: Eight Years of the National Liver Transplant Program in Uruguay

INTRODUCTION AND AIM

Wilson's disease (WD) is an uncommon cause of acute liver failure (ALF). Our aim was to describe clinical features, diagnostic findings, treatments, and outcomes of patients with ALF due to WD.

MATERIAL AND METHODS

Retrospective medical record reviews of all patients with ALF due to WD in eight years in Uruguay.

RESULTS

WD was the cause of six (15%) of thirty-nine ALF cases. All patients were females, with a mean age of 18 years. Four patients presented with hyperacute liver failure and two with acute failure. Jaundice was the main complaint of all patients. Mean total bilirubin (TB), alkaline phosphatase (AP), AST, and ALT were 27.5 mg/dL, 45.5 lU/l, 156 IU/L, and 51 IU/L, respectively. Ceruloplasmin levels were low in four patients, urinary cooper was high in four, and two had Kayser-Fleischer rings. All patients had Coombs-negative hemolytic anemia, acute kidney injury, histochemical identifiable copper, and advanced fibrosis on liver histology. The average MELD score was 36. All patients were treated with d-penicillamine and listed for urgent liver transplantation (LT). Prometheus® was performed in one patient. Three patients died: two without LT and one after LT. Three patients survived: one without LT (New Wilson Index<11) and two with LT. The referral time to the program and the total time (referral plus waiting list time) were longer for non-survivors than for survivors (14 vs. 3 days and 23 vs. 8 respectively).

CONCLUSION

All cases had typical clinical, analytical and histopathology characteristics. Early referral was determinant of prognosis.

Risk Factors of Mortality After Liver Transplantation in Uruguay

INTRODUCTION

Identification of predictive factors of mortality in a liver transplant (LT) program optimizes patient selection and allocation of organs.

OBJECTIVE

To determine survival rates and predictive factors of mortality after LT in the National Liver Transplant Program of Uruguay.

METHODS

A retrospective study was conducted analyzing data prospectively collected into a multidisciplinary database. All patients transplanted since the beginning of the program on July 2009 to April 2017 were included (n = 148). Twenty-nine factors were analyzed through the univariate Kaplan-Meier model. A Cox regression model was used in the multivariate analysis to identify the independent prognostic factors for survival.

RESULTS

Overall survival was 92%, 87%, and 78% at discharge, 1 year, and 3 years, respectively. The Kaplan-Meier survival curves were significantly lower in: recipients aged >60 years, Model for End-Stage Liver Disease score >21, LT due to hepatocellular carcinoma (HCC) and acute liver failure (ALF), donors with comorbidities, intraoperative blood loss beyond the median (>2350 mL), red blood cell transfusion requirement beyond the median (>1254 mL), intraoperative complications, delay of extubation, invasive bacterial, and fungal infection after LT and stay in critical care unit >4 days. The Cox regression model (likelihood ratio test, P = 1.976 e^-06) identified the following independent prognostic factors for survival: LT for HCC (hazard ratio [HR] 4.511; P = .001) and ALF (HR 6.346; P = .004), donors with comorbidities (HR 2.354; P = .041), intraoperative complications (HR 2.707; P = .027), and invasive fungal infections (HR 3.281; P = .025).

CONCLUSION

The survival rates of LT patients as well as the mortality-associated factors are similar to those reported in the international literature.

Tacrolimus Pharmacodynamics and Pharmacogenetics along the Calcineurin Pathway in Human Lymphocytes

BACKGROUND

Although therapeutic drug monitoring has improved the clinical use of immunosuppressive drugs, there is still interpatient variability in efficacy and toxicity that pharmacodynamic monitoring may help to reduce. To select the best biomarkers of tacrolimus pharmacodynamics, we explored the strength and variability of signal transduction and the influence of polymorphisms along the calcineurin pathway.

METHODS

Peripheral blood mononuclear cells from 35 healthy volunteers were incubated with tacrolimus (0.1–50 ng/mL) and stimulated ex vivo. Inhibition of NFAT1 (nuclear factor of activated T cells 1) translocation to the nucleus and intracellular expression of interleukin-2 in CD4+ and CD8+ T cells and the surface activation marker CD25 in CD3+ cells were measured by flow cytometry. We sequenced the promoter regions of immunophilins and calcineurin subunits and characterized selected single nucleotide polymorphisms in the genes of the calcineurin pathway with allelic discrimination assays.

RESULTS

All responses closely fitted an I/Imax sigmoid model. Large interindividual variability (n = 30) in I0 and IC50 was found for all biomarkers. Moreover, strong and statistically significant associations were found between tacrolimus pharmacodynamic parameters and polymorphisms in the genes coding cyclophilin A, the calcineurin catalytic subunit α isoenzyme, and CD25.

CONCLUSIONS

This study demonstrates the consistency and large interindividual variability of signal transduction along the calcineurin pathway, as well as the strong influence of pharmacogenetic polymorphisms in the calcineurin cascade on both the physiological activity of this route and tacrolimus pharmacodynamics.

MRNA and miRNA expression patterns associated to pathways linked to metal mixture health effects

Metals are a threat to human health by increasing disease risk. Experimental data have linked altered miRNA expression with exposure to some metals. MiRNAs comprise a large family of non-coding single-stranded molecules that primarily function to negatively regulate gene expression post-transcriptionally. Although several human populations are exposed to low concentrations of As, Cd and Pb as a mixture, most toxicology research focuses on the individual effects that these metals exert. Thus, this study aims to evaluate global miRNA and mRNA expression changes induced by a metal mixture containing NaAsO2, CdCl2, Pb(C2H3O2)2·3H2O and to predict possible metal-associated disease development under these conditions. Our results show that this metal mixture results in a miRNA expression profile that may be responsible for the mRNA expression changes observed under experimental conditions in which coding proteins are involved in cellular processes, including cell death, growth and proliferation related to the metal-associated inflammatory response and cancer.

Comparison of two wild rodent species as sentinels of environmental contamination by mine tailings

BACKGROUND

Contamination with heavy metals is among the most hazardous environmental concerns caused by mining activity. A valuable tool for monitoring these effects is the use of sentinel organisms. Particularly, small mammals living inside mine tailings are an excellent study system because their analysis represents a realistic approach of mixtures and concentrations of metal exposure.

PURPOSE

We analyzed metal tissue concentrations and DNA damage levels for comparison between genders of a sentinel (Peromyscus melanophrys) and a nonsentinel (Baiomys musculus) species. Also, the relationship between DNA damage and the distance from the contamination source was evaluated.

METHODS

This study was conducted in an abandoned mine tailing at Morelos, Mexico. Thirty-six individuals from both species at the exposed and reference sites were sampled. Metal concentrations in bone and liver of both species were analyzed by atomic absorption spectrophotometry, and DNA damage levels were assayed using the alkaline comet assay.

RESULTS

In general, concentrations of zinc, nickel, iron, and manganese were statistically higher in exposed individuals. A significant effect of the organ and the site on all metal tissue concentrations was detected. Significant DNA damage levels were registered in the exposed group, being higher in B. musculus. Females registered higher DNA damage levels than males. A negative relationship between distance from the mine tailing and DNA damage in B. musculus was observed.

CONCLUSIONS

We consider that B. musculus is a suitable species to assess environmental quality, especially for bioaccumulable pollutants--such as metals--and recommend that it may be considered as a sentinel species.

Prevalence and impact of fibromyalgia on function and quality of life in individuals from the general population: results from a nationwide study in Spain

OBJECTIVE

To estimate the prevalence of fibromyalgia (FM) and to compare some descriptive epidemiological and quality of life data between persons with and without FM criteria in a representative sample of the general Spanish population.

METHODS

Cross sectional study of 2,192 Spaniards aged 20 or above, selected by cluster sampling. Subjects were invited to a structured interview carried out by trained rheumatologists to ascertain various musculoskeletal disorders. The visit included screening and examination, validated instruments for measuring function (HAQ) and quality of life (SF-12) and questions about socio-demographic characteristics and musculoskeletal, mental, and other general symptoms. FM was suspected in subjects with widespread pain for more than three months. FM was defined by theAmerican College of Rheumatology classification criteria. All estimates are adjusted to sampling scheme.

RESULTS

The prevalence of FM in Spain is 2.4% (95% CI: 1.5-3.2). FM is significantly more frequent in women (4.2%) than in men (0.2%), with an OR for women of 22.5 (95%CI: 7.2- 69.9), mainly in the 40-49 years age interval. It is more frequent in rural (4.1%) than in urban settings (1.7%), with an OR for rural settings of 2.5 (95%CI: 1.03-5.9). FM is associated with a low educational level, to a low social class, and to self-reported depression. The scores in the HAQ and in the SF-12 were significantly lower in FM subjects, despite adjustment by covariates.

CONCLUSION

FM has a high prevalence in the general population. FM is associated to female gender, comorbidities, age between 40 and 59 years, and a rural setting. Persons fulfilling FM criteria show impaired functioning and quality of life.

Late entry into HIV/AIDS medical care: the importance of past relationships with medical providers

Data are presented from a qualitative study that explored the impact of relationships with medical providers on late entry into HIV/AIDS medical care. In-depth interviews were conducted with ten males living on the US-Mexico border who entered medical care late in the progression of HIV. The findings focus on past relationships with medical providers and the perception of risk on both the part of the medical provider and the study participant. Current policy and programmatic trends and recommendations are discussed.

DNA damage in outdoor workers occupationally exposed to environmental air pollutants

BACKGROUND

Health concerns about the exposure to genotoxic and carcinogenic agents in the air are particularly significant for outdoor workers in less developed countries.

AIMS

To investigate the association between personal exposure to a group of air pollutants and severity of DNA damage in outdoor workers from two Mexican cities.

METHODS

DNA damage (Comet assay) and personal exposure to volatile organic compounds, PM(2.5), and ozone were investigated in 55 outdoor and indoor workers from México City and Puebla.

RESULTS

In México City, outdoor workers had greater DNA damage, reflected by a longer tail length, than indoor workers (median 46.8 v 30.1 mum), and a greater percentage of highly damaged cells (cells with tail length > or =41 microm); in Puebla, outdoor and indoor workers had similar DNA damage. There were more alkali labile sites in outdoor than indoor workers. The DNA damage magnitude was positively correlated with PM(2.5) and ozone exposure. Outdoor and indoor workers with > or =60% of highly damaged cells (highly damaged workers) had significantly higher exposures to PM(2.5), ozone, and some volatile organic compounds. The main factors associated with the highly damaged workers were ozone, PM(2.5), and 1-ethyl-2-methyl benzene exposure.

CONCLUSIONS

With this approach, the effects of some air pollutants could be correlated with biological endpoints from the Comet assay. It is suggested that the use of personal exposure assessment and biological endpoints evaluation could be an important tool to generate a more precise assessment of the associated potential health risks.

Genotoxic differences by sex in nasal epithelium and blood leukocytes in subjects residing in a highly polluted area

We describe differences by sex in genotoxic damage found in a population of medical students exposed to a highly oxidative atmosphere, compared with a control group, measured by the single-cell gel electrophoresis assay and histological changes in nasal epithelium smears. Cells were obtained from the nasal epithelium and blood leukocytes. Higher DNA damage in nasal cells and leukocytes was found in males compared to females and control subjects. The percentage of squamous metaplastic changes in the nasal epithelium was also higher in males compared with females and controls. The co-mutation of normal nasal epithelium by squamous cells might modify its protective function in the nose, increasing the risk of damage to the lower respiratory tract. Although, as medical students, males and females were exposed to the same environment and activity patterns, male genotoxicity damage was higher in control and exposed subjects. More research should be done in order to identify direct or indirect sexual hormone intervention.

Is the capacity of lead acetate and cadmium chloride to induce genotoxic damage due to direct DNA-metal interaction?

Even though the toxic effects of lead and cadmium compounds have been studied over many years, inconsistent results have been obtained about their mutagenic, clastogenic and carcinogenic properties. However, these metals are considered to be potential human carcinogens. The mechanism of metal-induced carcinogenesis is still unknown, but one possible pathway may involve the interaction of metals with DNA, either directly or indirectly. In this work we explore the capacity of lead, cadmium or a mixture of both metals to interact with acellular DNA, by employing a variant of the comet assay. Our results, using low non-cytotoxic metal concentrations (0.01, 0.1 and 1.0 microM) with the standard protocol for the acellular assay, showed an induction of DNA damage in cells of all organs studied; however, basal DNA damage was different in each organ. To confirm that we were working with pure DNA, proteinase K was added to the lysis solution. With this enriched-lysis solution we found a negative response in the induction of DNA damage in cells derived from the liver, kidney and lung of CD-1 male mice. To support the results obtained by the enriched-acellular assay, we studied the capacity of lead and cadmium (0.1 microM) to induce breaks in pooled genomic DNA in cells of the same organs, with negative results. Consistent with these findings, these metals do not induce DNA breaks in the plasmid pUSE amp+. On the whole, we did not detect direct induction of DNA strand breaks by lead acetate, cadmium chloride or a mixture of both metals, all at low non-cytotoxic concentrations. However, we found an induction of lipid peroxidation and an increase in free radical levels in the different organs of CD-1 male mice after inhalation of lead acetate (0.0068 microg/cc) or cadmium chloride (0.08 microg/cc) for 1 h, suggesting the induction of genotoxicity and carcinogenicity by indirect interactions, such as oxidative stress.

The application of single cell gel electrophoresis or Comet assay to human monitoring studies

OBJECTIVE

In the search of new human genotoxic biomarkers, the single cell gel electrophoresis assay has been proposed as a sensible alternative.

MATERIAL AND METHODS

This technique detects principally single strand breaks as well as alkali-labile and repair-retarded sites.

RESULTS

Herein we present our experience using the single cell gel electrophoresis assay in human population studies, both occupationally and environmentally exposed.

CONCLUSIONS

We discuss the assay feasibility as a genotoxic biomarker.

Evaluation of DNA damage in exfoliated tear duct epithelial cells from individuals exposed to air pollution assessed by single cell gel electrophoresis assay

The search for relevant target cells for human monitoring purposes has increased during the last few years. Cells such as sperm, buccal or nasal and gastric epithelium are being used. In this study, we report the use of exfoliated tear duct epithelial cells as a potential material for human biomonitoring studies, since these cells are a target for environmental pollutants. We employed the alkaline single cell gel electrophoresis (SCGE) assay to evaluate for differences in the basal level of DNA damage between young adults from the south (exposed mainly to high levels of ozone) and from the north (exposed principally to hydrocarbons) regions of Mexico City. We found an increase in DNA migration in tear duct epithelial cells from individuals who live in the southern part of the city compared to those living in the northern part. Moreover, young people who live in the southwest part of the city with the highest values of ozone presented the highest values of DNA damage. These results show the feasibility of using exfoliated tear duct epithelial cells in human biomonitoring studies.

Induction of genotoxicity by cadmium chloride inhalation in several organs of CD-1 mice

In recent years, the concentration of metals in the environment has increased significantly. Metal compounds, as a group, are among the best-documented human carcinogens, but the mechanisms by which they act are not completely understood. In the present study a cadmium inhalation model in mice was implemented in order to detect the induction of genotoxic damage as single-strand breaks and alkali-labile sites in several organs (nasal epithelial cells, lung, whole blood, liver, kidney, bone marrow, brain and testicle) using the single cell gel electrophoresis (SCGE) or Comet assay. We found differences among the studied organs after a single and subsequent inhalations: in the organs analyzed we observed that major DNA damage was induced after a single inhalation; in subsequent inhalations there was a tendency to maintain the same magnitude of damage or in some cases it decreased. A correlation between length of exposure, DNA damage and metal tissue concentration was found. These results suggest that cadmium chloride inhalation induces systemic DNA damage; some organs showed less damage than others (liver, brain, etc.) and this finding could be as a consequence of the capacity to remove the damage induced by long periods of exposure, possibly because of the induction of detoxifying mechanisms such as induction of metallothionein.

Accumulation of DNA damage in the organs of mice deficient in gamma-glutamyltranspeptidase

We have used a differential alkaline single cell gel electrophoresis assay of DNA ("omet assay" at pH 13 and 12.3) to evaluate DNA damage as a function of age in mice with an inherited defect in gluthathione (GSH) metabolism. The mice are homozygous null for gamma-glutamyltranspeptidase (GGT), the enzyme responsible for initiating the catabolism of GSH, and paradoxically have reduced levels of GSH and cysteine in many organs. We found an accumulation of DNA damage in lung, liver and kidney in these mice as a function of age. The largest differences were in assays run at pH 13, suggesting that the accumulation of apurinic/apryrimidinic (AP) sites and oxidative damage of DNA was largely responsible. In contrast, little if any accumulation of these lesions was detected in wild-type mice. Although these findings do not allow a precise analysis of the molecular basis of damage accumulation in GGT-deficient mice, they implicate low GSH and cysteine levels as a cause of accumulative DNA damage in the intact mammal.

Genotoxic studies of vanadium pentoxide (V(2)O(5)) in male mice. II. Effects in several mouse tissues

Vanadium pentoxide (V2O5) was tested for its ability to induce genotoxic damage in six different organs (liver, kidney, lung, spleen, heart, and bone marrow) of mice by using the alkaline Single Cell Gel Electrophoresis (SCGE) assay. Animals were sacrificed 24 h after i.p. administration of the vanadium pentoxide of 23.0, 11.5, or 5.75 microg/g (corresponding to the LD50, 1/2 LD50 and 1/4 LD50, respectively). In all tissues and organs evaluated (except for bone marrow), V2O5 increased the number of cells with damage. Our results showed that i.p. injection of V2O5 induced DNA damage in different organs and tissues, and that this kind of damage can be observed even 24 h after treatment. The analysis of DNA migration and the distribution of DNA damage showed that there are differences in sensitivity between organs and tissues to this compound. In addition the sensitivity of SCGE assay allows the detection of long term DNA damage and the possibility to compare it in various tissues and target organs.

Single cell gel electrophoresis assay: methodology and applications

The single cell gel electrophoresis or Comet assay is a sensitive, reliable, and rapid method for DNA double- and single-strand breaks, alkali-labile sites and delayed repair site detection, in eukaryotic individual cells. Given its overall characteristics, this method has been widely used over the past few years in several different areas. In this paper we review the studies published to date about the principles, the basic methodology with currently used variations. We also explore the applications of this assay in: genotoxicology, clinical area, DNA repair studies, environmental biomonitoring and human monitoring.

Analysis of the DNA damage induced by praziquantel in V-79 Chinese hamster fibroblasts and human blood cells using the single-cell gel electrophoresis assay

The analysis of the genotoxicity of praziquantel, an effective antihelminthic widely used in countries where parasitic infections are still serious public health problems, has been extensively performed using diverse in vitro and in vivo assays and endpoints. However, results are not conclusive, since reports to date indicate either praziquantel is mutagenic, comutagenic, or even antimutagenic. In the present work, the clastogenic potential of praziquantel was investigated in V-79 Chinese hamster fibroblasts and human peripheral blood using a sensitive technique such as the single-cell electrophoresis assay. Results indicate that even though praziquantel induced DNA single-strand breaks both in V-79 cells and unstimulated human leukocytes, this effect was not translated into persistent DNA damage, since neither SCE nor HPRT mutations were induced. This suggests that the effect observed in the SCGE assay is an early event not closely related to praziquantel mutagenicity, because this DNA damage could be efficiently repaired.

DNA damage in leukocytes and buccal and nasal epithelial cells of individuals exposed to air pollution in Mexico City

There is an increased interest in using biological markers to monitor individuals for possible exposure to environmental toxicants. Test systems which permit the sensitive detection of DNA damage and DNA repair are critically important in such studies. The single cell gel electrophoresis (SCG) assay is a rapid and a sensitive method for the evaluation of DNA damage at the single cell level, providing information on the occurrence of DNA single-strand breaks and alkali labile sites using alkaline conditions. In this study, the differences in the basal level of DNA damage between young adults from the south (exposed principally to high levels of ozone) and young adults from the north (exposed principally to hydrocarbons and particles) of Mexico City were investigated by the SCG assay using three different cell types (leukocytes and nasal and buccal epithelial cells). We found an increased DNA migration in blood leukocytes and nasal cells from individuals who live in the southern part of the city compared to those living in the northern part; however, no differences were observed for buccal epithelial cells. These results show the feasability of using the SCG assay to evaluate DNA damage in different tissues and its great potential for use in the monitoring of humans potentially exposed to genotoxic pollutants.

[Gestational diabetes: the use of an intensive treatment program at the regional level]

In this study the results are shown of the application of an intensified treatment program of Gestational Diabetes (GD) in a regional setting. From January 1991 to June 1995, 115 women with GD were attended at Mútua Hospital in Terrassa; 62.6% of them required insulin to optimize the metabolic control. When insulin dependent women were compared with non insulin dependent women, diagnosis was earlier; age, progestational age, serum glucose in the O'Sullivan test and diagnostic basal serum glucose in oral overload (GOO) were higher. Regarding perinatal results, the incidence of gestational hypertensive disturbances, hydramnios, and urinary tract infections were 7%, 1.7%, and 8%, respectively. Perinatal mortality was 0.86%. Delivery occurred after 37 weeks in 96.5% of cases and the cesarean section was performed in 26%; nevertheless, this rate was similar to that in the obstetric population attended at this institution (25%). Birth weight was high for gestational age in 7.8% of newborns (NB) and low in 2.5%. Factors associated with fetal weight included progestational maternal weight, ponderal increase during pregnancy and metabolic control (HbA1c). The present study suggests that the application of an intensified treatment program for GD can be carried out in a regional setting and with overall successful results.

DNA damage in exfoliated buccal cells of smokers assessed by the single cell gel electrophoresis assay

The alkaline single-cell gel electrophoresis assay or comet assay is a sensitive and rapid method for DNA strand breaks and detection of alkali labile sites at the single cell level, it further provides information on the presence of damage among individual cells. In this paper we explore the use of this technique utilizing exfoliated buccal mucosa cells from non-smokers (9 donors) and smokers (11 donors). The extent of DNA image length was found to be significantly increased in the smoker group (89.30 +/- 16.18 microns) than in the non-smoker group (52.01 +/- 10.43 microns). Our results indicate that the single-cell gel electrophoresis assay could be applied to human monitoring using exfoliated buccal epithelial cells.

Genotoxic effects of bistratene A on human lymphocytes

Bistratene A, a toxin isolated from the colonial ascidian Lissoclinum bistratum causes a decrease in mitotic index and retardation of lymphocyte proliferation kinetics when it is added at 48 h to 72-h human lymphocyte cultures. In the same cultures, the incidence of sister chromatid exchanges was not altered by this compound. We also observed an increase in the number of polyploid cells in the cultures, and alterations of the beta-tubulin organization by immunocytochemistry with an antibody against beta-tubulin. Bistratene A induces DNA damage in a dose-dependent fashion in leukocytes, as measured by the alkaline single cell gel electrophoresis assay. These results show that bistratene A interferes with microtubule assembly, is cytotoxic and cytostatic, and that it causes DNA damage.

Genotoxicity of vanadium pentoxide evaluate by the single cell gel electrophoresis assay in human lymphocytes

Vanadium compounds are extensively used in modern industry and occupational exposure to high doses of Vanadium is quite common. In this study, the genotoxicity of vanadium pentoxide (V2O5) was evaluated directly in whole blood leukocytes and in human lymphocyte cultures using the single-cell gel electrophoresis assay (Comet Assay) to detect DNA damage expressed as DNA strand breaks and alkali labile sites. This chemical produces a clear dose-response in DNA migration in whole blood leukocytes and a significative positive effect only with the highest tested concentration in human lymphocyte cultures. After different recovery times the level of DNA damage returned to the control values. These results indicate that V2O5 is capable to induce DNA single-strand breaks and/or alkali-labile damage.

Reprotoxic and genotoxic studies of vanadium pentoxide in male mice

Effects of vanadium pentoxide (V2O5) treatment on reproductive function and testicular DNA in male mice were investigated. These functions were evaluated with fertility rate, implants, resorptions, sperm counts, motility, and morphology. The DNA damage in individual testis cells was analyzed by single-cell gel electrophoresis technique (COMET assay). V2O5 treatment resulted in a decrease in fertility rate, implantations, live fetuses, and fetal weight, and an increase in the number of resorptions/dam. Sperm count, motility, and morphology were impaired with the advancement of treatment. Vanadium treatment induced DNA damage depending on the dose in the testis cells that was expressed and detected as DNA migration in the COMET assay. The distribution of DNA migration among cells, a function of dose, revealed that the majority of cells of treated animals expressed more DNA damage than cells from control animals. It is concluded that vanadium pentoxide was a reprotoxic and genotoxic agent in mice.

[Subcutaneous venous reservoirs: comparative study of their efficacy in patients with AIDS versus oncology and hematology patients]

BACKGROUND

Chronic venous access may constitute a serious problem in some patients and the subcutaneous venous reservoirs have demonstrated to be a useful alternative. AIDS patients require intense pharmacologic treatment, thus the use of subcutaneous venous reservoirs may be specially useful. However, the prevalence of septic type complications following placement of the subcutaneous venous reservoirs in these patients is particularly high.

AIMS

To know the efficacy of subcutaneous venous reservoirs in the AIDS population and compare the results in a non AIDS population.

METHODS

All the subcutaneous venous reservoirs placed between January 1990 and December 1992 were prospectively studied with two groups being established: Group I: patients with positive serology for HIV and who achieved criteria of AIDS requiring placement of a subcutaneous venous reservoirs. Group II: All the remaining patients in whom a subcutaneous venous reservoirs was placed during the same period of time.

RESULTS

The incidence of infection was higher in group I (AIDS) with respect to group II (0.1 versus 0.014 infections/100 catheters/day, p < 0.01) and the non septic complications were higher in group II (3.6% versus 12.7%, p < 0.0004). The catheters were most frequently used in group I with respect to group II (12.7 +/- 7.1 versus 3.3 +/- 4.9 punctures/month) but the period was use longer in group II (13.7 +/- 9.2 versus 4.3 +/- 3.1 months, p < 0.0001).

CONCLUSIONS

The population of AIDS patients may benefit greatly from the systematic use of subcutaneous venous reservoir due to their clinical and therapeutic characteristics. Nonetheless greater risk of infection may occur in these patients because of the greater need for punctures with respect to the other indications for placement of these catheters.