Development of a Risk Stratification Model for Pre-liver-Transplant Screening Colonoscopy

BACKGROUND AND AIMS

Colonoscopies are routinely obtained before liver transplantation, although their utility is a highly debated topic in the literature. We aimed to determine the risk factors in patients with decompensated cirrhosis (DC) for post-colonoscopy complications (PCC).

MATERIALS AND METHODS

We performed a single-center retrospective study of patients with DC undergoing colonoscopy as part of their pre-liver-transplant evaluation. The primary composite outcome was defined as a complication occurring within 30 days of the colonoscopy. Complications included acute renal failure, new or worsening ascites or hepatic encephalopathy, gastrointestinal bleeding, or any cardiopulmonary or infectious complication. Logistic regression analysis was utilized to derive a risk score in predicting the primary composite outcome.

RESULTS

The strongest predictors of post-colonoscopy complication were MELD-Na ≥21 [aOR 4.0026 ( P =0.0050)] and history of any infection in the 30 days before colonoscopy [aOR 8.4345 ( P =0.0093)]. The area under the receiver operating characteristic curve of the final model was 0.78. The predicted risk of any complication at the lowest quartile was 16.2% to 39.4%, and the observed risk was 30.6% (95% CI: 15.5-45.6%), while the predicted risk at the highest quartile was 71.9% to 97.1%, and the observed risk was 81.3% (95% CI: 67.7-95%).

CONCLUSION

In this cohort of patients with DC undergoing colonoscopy for pre-liver-transplant evaluation, a history of ascites, spontaneous bacterial peritonitis, and MELD-Na were found to be predictive of PCC. This risk score may help to predict PCC in patients with DC undergoing a pre-transplant colonoscopy. External validation is recommended.

Validation of prediction tools for GI bleeding in patients on dual anti-platelet therapy after percutaneous coronary intervention

BACKGROUND AND AIMS

The management of dual anti-platelet therapy after percutaneous coronary intervention (PCI) and GI bleeding (GIB) remains a clinical dilemma. We sought to identify predictors of GIB and recurrent bleeding and to determine whether recurrent bleeding increases the risk of major adverse cardiovascular events (MACEs).

METHODS

In this single-center retrospective study, patients undergoing PCI were identified. The primary and secondary endpoints were GIB at 180 days and recurrent bleeding or MACE at 365 days. Logistic regression was used to identify predictors of GIB and recurrent bleeding. Cox proportional hazards modeling was used to determine whether recurrent bleeding can predict a MACE.

RESULTS

Five hundred thirty-six patients were included. On multivariable analysis, PCI for acute coronary syndrome was associated with a 95% increased odds of GIB (P < .001). The P2Y12 inhibitor was continued in >90% of patients, which trended toward significance for recurrent bleeding (P < .10). The HAS-BLED score (Hypertension, Abnormal renal and liver function, Stroke, Bleeding tendency or predisposition, Labile INRs, Elderly, Drugs), including a labile international normalized ratio and prior major bleeding, was strongly associated with recurrent bleeding (P ≤ .009). Recurrent bleeding was associated with a 115% increased risk of MACEs (P = .02). We derived a novel risk score, named the SIGE score ([S]TEMI at PCI, having a labile [I]NR at PCI, index [G]IB within 180 days of PCI, and previous precatheterization [E]ndoscopy within 6 months), to predict recurrent bleeding at 365 days with a high predictive accuracy (area under the curve, .773; 95% confidence interval, .702-.845).

CONCLUSIONS

The SIGE score may help to predict recurrent bleeding, which was shown to be associated with an increased risk of MACEs. Further external validation is needed.

Clinical and genetic predictors of cardiac dysfunction assessed by echocardiography in patients with hereditary hemochromatosis

PURPOSE

Hereditary hemochromatosis (HH) may cause iron deposition in cardiac tissue. We aimed to describe the echocardiographic findings in patients with HH and identify risk factors for cardiac dysfunction.

METHODS

In this retrospective study, we included patients with HH who underwent transthoracic echocardiography at our tertiary care center between August 2000 and July 2022. We defined three primary outcomes for cardiac dysfunction: 1) left ventricular ejection fraction (LVEF) < 55%, 2) ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e') > 15, and 3) global longitudinal strain (GLS) < 18. Multivariable logistic regression was utilized to identify predictors of cardiac dysfunction.

RESULTS

582 patients (median age 57 years, 61.2% male) were included. The frequency of LVEF < 55%, E/e' > 15 and GLS < 18 was 9.0% (52/580), 9.6% (51/534) and 20.2% (25/124), respectively. In multivariable analysis, non-White race, age, and hypertension were associated with E/e' > 15. No specific HFE genetic mutation was associated with LVEF < 55%. A history of myocardial infarction was strongly associated with both LVEF < 55% and E/e' > 15. In patients with LVEF ≥ 55%, the C282Y/H63D genetic mutation was associated with reduced likelihood of E/e' > 15, p = 0.024. Patients with C282Y/H63D had a higher frequency of myocardial infarction. Smoking and alcohol use were significantly associated with GLS < 18 in unadjusted analysis.

CONCLUSION

We found the traditional risk factors of male sex, and history of myocardial infarction or heart failure, were associated with a reduced LVEF, irrespective of the underlying HFE genetic mutation. Patients with a C282Y/H63D genetic mutation had a higher frequency of myocardial infarction, yet this mutation was associated with reduced odds of diastolic dysfunction compared to other genetic mutations in patients with a normal LVEF.

Metabolic Unhealthiness is Associated With Increased Risk of Critical COVID-19 Pneumonia and Inpatient Mortality in Hospitalized Patients with Obesity or Overweight

Background and aims Being metabolically unhealthy (MU) is defined as having either hypertension, hyperlipidemia, type 2 diabetes mellitus/pre-diabetes, or fatty liver disease. We aimed to determine if MU was associated with severe COVID-19 pneumonia (severe disease). Methods We performed a single-center retrospective study between March 2020 and August 2021 for patients with overweight or obesity hospitalized with COVID-19 pneumonia. Logistic regression analysis was utilized to derive a risk score for severe disease. The accuracy of the model was assessed using the area under the receiver operating characteristic curve (AUROCC) and bootstrap resampling. Results A total of 334 of 450 patients hospitalized with COVID-19 pneumonia (74.2%) were MU. Patients who were MU had higher in-hospital mortality (10.5% vs. 2.6%) and longer length of hospitalization (median 6 vs. 4 days). MU was not associated with severe disease, p=0.311. On multivariable analysis, older age, male sex, and Asian race were associated with severe disease. Not being vaccinated was associated with doubled odds of severe disease. The AUROCC of the final model was 0.66 (95% CI: 0.60 to 0.71). The risk score at the lowest quintile had a 33.1% to 65.5% predicted risk and a 58.7% observed risk of severe disease, whereas, at the highest quintile, there was an 85.7% to 97.7% predicted risk and an 89.7% observed risk of severe disease. Conclusion Being MU was not a predictor of severe disease, even though mortality was higher despite having higher rates of vaccination. This risk score may help to predict severe disease in hospitalized patients with obesity or overweight. External validation is recommended.

Simple risk score to predict the likelihood of a positive EUS in idiopathic acute pancreatitis

BACKGROUND AND AIMS

We sought to derive a risk score, DORM65, of known variables to predict the likelihood of a positive EUS in patients with idiopathic acute pancreatitis (IAP).

METHODS

A retrospective cohort study of 180 patients with IAP was performed across 3 tertiary care centers between January 2018 and December 2021. Multivariate logistic regression modeling was performed to predict a positive EUS. Accuracy of the models was assessed by the area under the receiver-operating characteristic curve (AUROCC).

RESULTS

The diagnostic yield of EUS was 58.9% (95% confidence interval [CI], 51.7-66.1). The DORM65 scores of 5 predictors present before EUS with the best discrimination were a delayed EUS (defined as ≥82 days from the last episode of AP), obesity, not having had a repeated transabdominal US, male sex, and age ≥65 years at the time of EUS. For those at the lowest risk score group, the positive EUS rate was 13.0% compared with 100% in those at the highest risk group (relative risk, 7.67; P < .001). A score of 3 or more had a positive predictive value of 86.0% with a sensitivity of 34.9% and specificity of 91.9%. The model had a high predictive accuracy (AUROCC, .774; 95% CI, .707-.841). Adding 3 additional predictors (no cholecystectomy, no MRCP, and a single episode of AP) did not increase the accuracy significantly (AUROCC, .805; 95% CI, .742-.867).

CONCLUSIONS

DORM65 is easily calculated and accurately predicts a positive EUS in patients with IAP. Further validation is needed.

Incidentalomas are associated with an increase in liver transplantation in patients with cirrhosis: a single-center retrospective study

Background

Incidentalomas, defined as incidental findings on imaging, are a growing concern. Our aim was to determine the impact and outcomes of extrahepatic incidentalomas on liver transplantation.

Methods

Patients at a large liver transplant center, who had an initial MRI for hepatocellular carcinoma screening between January 2004 and March 2020 were identified. Clinical data were collected retrospectively. Survival analysis, utilizing Kaplan Meier estimates and Cox proportional hazards regression analysis, was utilized to determine factors associated with liver transplantation.

Results

720 patients were included. NASH (24.9%), HCV (22.1%) and alcohol (20.6%) were the most common causes of cirrhosis. 79.7% of patients had an extrahepatic incidentaloma. Older age and having received a liver transplant by the end of the study were associated with an incidentaloma. MELD was not associated with the presence of an incidentaloma. On univariate Cox proportional hazards regression, male sex, history of moderate alcohol use, smoking history, MELD, and incidentalomas were predictors of liver transplantation. On multivariate analysis, only MELD and the presence of an incidentaloma were found to be significant. Discovery of an incidentaloma was associated with a 30% increase in the risk of liver transplantation. Median time to transplantation did not differ based on the presence on an incidentaloma. Patients with cirrhosis from alcohol or HCV had a significantly shorter median time to transplantation than those with NASH. Renal and pancreatic lesions comprised 91% of all incidentalomas.

Conclusions

In this single-center retrospective study, extrahepatic incidentalomas were common in patients with cirrhosis. The finding of an incidentaloma was associated with a higher risk of liver transplantation despite a similar median time to transplantation if no incidentaloma was discovered.

Colchicine as an Alternative First-Line Treatment of Sclerosing Mesenteritis: A Retrospective Study

BACKGROUND

Sclerosing mesenteritis is a rare condition characterized by chronic inflammation and fibrotic changes of the mesentery.

AIMS

To determine the long-term management and outcomes of patients with sclerosing mesenteritis.

METHODS

Patients with biopsy-proven sclerosing mesenteritis at the Mayo Clinic between January 2006 and December 2016 were identified. Clinical data were collected retrospectively.

RESULTS

One hundred and three patients were identified, median age 68.0 years (range 35.0-85.3). Most patients were symptomatic (87.4%) at presentation. Patients received no treatment (52.4%), medical therapy (42.7%) or surgery (4.9%) on initial diagnosis. The most common initial regimens were prednisone plus tamoxifen (41.9%), prednisone alone (23.3%), and prednisone plus colchicine (11.6%) with 55.6%, 57.2%, and 60% of patients improving, respectively, p = 0.85 for a difference in response rates. At least half of the patients responded to prednisone plus tamoxifen, prednisone plus colchicine, or prednisone alone at 6.0, 7.2, and 8.4 months, respectively. At a median follow-up of 45.6 months (95% CI 24.1-69.7), 65.4% of patients were receiving medical therapy. Of those receiving tamoxifen-based, steroid-based, or steroid-sparing regimens, 100%, 87.5%, and 77.8% had improved by their last follow-up appointment respectively, p = 0.15.

CONCLUSION

Prednisone plus colchicine has a similar efficacy to prednisone plus tamoxifen for the initial and long-term treatment of sclerosing mesenteritis. The majority of patients were initiated on medical therapy over the long term with most reporting symptomatic improvement within a year. Death from SM was rare.

Splenic injury is an under-recognized adverse event of in-patient colonoscopy: a nationwide analysis

Background and study aims  Splenic injury (SI) during colonoscopy is an underappreciated adverse event. Our aim was to examine the occurrence and outcomes of patients who developed SI after inpatient colonoscopy using a nationwide dataset. Patients and methods  Retrospective, observational study using the National Inpatient Sample (NIS) between 2012 and 2018. All patients with ICD9/10CM procedural codes for colonoscopy with or without SI were included. The primary outcome was the association between SI and inpatient colonoscopy. Secondary outcomes were inpatient morbidity, mortality, resource utilization, splenectomy rates, hospital length of stay and total hospital costs and charges. Comparative analyses were performed between patients with and without SI. Multivariate regression analyses were utilized. Results  A total of 2,258,040 of inpatient colonoscopies were included. Of these, 240 had associated SI and 25 patients required splenectomy (10.4 %). The incidence of colonoscopy-associated SI remained relatively stable between 2012 and 2018 (0.033 % versus 0.020 %, respectively). The mean age of patients with and without SI was 63.7 and 64.1 years, respectively. The occurrence of SI was calculated as 10.63 cases per 100,000 inpatient colonoscopies. Patients who had associated SI displayed significantly higher odds of inpatient mortality (aOR: 14.45) and ICU stay (aOR: 10.11) compared to those without SI. Conclusions  Splenic injury confers significantly higher odds of inpatient mortality, and resource utilization. The incidence of SI related to colonoscopy remained stable during the study period. Although uncommon, SI should be considered when encountering patients with abdominal pain after colonoscopy.

The Medical Management of Gastroesophageal Reflux Disease: A Narrative Review

OBJECTIVE

The medical management of gastroesophageal reflux disease (GERD) continues to evolve. Our aim was to systematically assess the literature to provide an updated review of the evidence on lifestyle modifications and pharmacological therapy for the management of GERD.

BACKGROUND

The cornerstones of GERD medical management consist of lifestyle modifications and pharmacologic agents. Most recently, evidence has emerged linking anti-reflux pharmacologic therapy to adverse events, such as kidney injury, metabolic bone disease, myocardial infarction, and even dementia, among others.

METHODS

A systematic search of the databases of PubMed/MEDLINE, Embase, and Cochrane Library was performed for articles on the medical management of GERD between inception and March 1, 2021.

CONCLUSION

Although pharmacological therapy has been associated with potential adverse events, further research is needed to determine if this association exists. For this reason, lifestyle modifications should be considered first-line, while pharmacologic therapy can be considered in patients in whom lifestyle modifications have proven to be ineffective in controlling their symptoms or cannot institute them. Naturally, extra-esophageal causes for GERD-like symptoms must be considered on suspected high-risk patients and excluded before considering treatment for GERD.

Treatment Approach of Refractory Helicobacter pylori Infection: A Comprehensive Review

H. pylori is the most common infection in the world and is associated with gastrointestinal and extra-gastrointestinal manifestations, including peptic ulcer disease, gastrointestinal bleeding, and lymphoproliferative disorders. Despite being discovered less than half a century ago, antibiotic resistance, exacerbated by medication non-adherence and inefficacy of proton pump inhibitors, has grown substantially, explaining the rising incidence of refractory H. pylori infection. In this review, we discuss risk factors, treatment options, surveillance and follow-up, as well as emerging therapies for refractory H. pylori.

Cladophialophora bantiana and Nocardia farcinica infection simultaneously occurring in a kidney transplant recipient: Case report and literature review

Solid organ transplant recipients are at increased risk of acquiring devastating infections with unusual pathogens. Nocardia are aerobic actinomycetes that affect the lungs, brain, skin and soft tissue. Cladophialophora species are dematiaceous fungi that overwhelmingly cause infections in the brain. Both organisms carry a high mortality rate. We present the first reported renal transplant case with Cladophialophora bantiana involving the renal allograft with concurrent invasive nocardiosis involving the lungs and brain.

Cocaine-induced locomotor stimulation involves autophagic degradation of the dopamine transporter

Cocaine exerts its stimulant effect by inhibiting dopamine reuptake leading to increased dopamine signaling. This action is thought to reflect binding of cocaine to the dopamine transporter (DAT) to inhibit its function. However, cocaine is a relatively weak inhibitor of DAT, and many DAT inhibitors do not share the behavioral actions of cocaine. We previously showed that toxic levels of cocaine induce autophagic neuronal cell death. Here, we show that subnanomolar concentrations of cocaine elicit neural autophagy in vitro and in vivo. Autophagy inhibitors reduce the locomotor stimulant effect of cocaine in mice. Cocaine-induced autophagy degrades transporters for dopamine but not serotonin in the nucleus accumbens. Autophagy inhibition impairs cocaine conditioned place preference in mice. Our findings indicate that autophagic degradation of DAT modulates behavioral actions of cocaine.

Hypoxia modulates the transcriptional immunological response in Oncorhynchus kisutch

Oncorhynchus kisutch is the third most cultivated salmonid species in the Chilean salmon industry and its farming conditions are characterised by high stocking density leading to the generation of high levels of organic matter (food - feces) and decomposition. In addition to the increasingly frequent hypoxic oceanographic events, these inappropriate farming conditions increase the demand for oxygen within the fish farm pen and lead to the appearance of hypoxic events that are harmful to fish.This study aimed to evaluate the stress response (cortisol) and transcription of genes involved in the immune response in head kidney and spleen of Oncorhynchus kisutch subjected to chronic hypoxic stress conditions. The fish were exposed to 100%, 60%, 50%, 35%, and 25% of DO for 28 days, then the blood (plasma), head kidney and spleen were removed. We observed mortality in the 25% DO group at days 15 and 20. Plasma cortisol increased significantly under 35% and 25% DO conditions compared to control. Transcription of Toll-like receptors (TLR1, TLR5M, TLR8, and TLR9) and cytokines (IL-1β, IL6, IL10, TNF-α) increased in the head kidney only in the 50% DO group, while in spleen there was an increase of these markers in the conditions of 60%, 35%, and 25% DO. As for the markers involved in cell-mediated immunity, CD4-MHCII and CD8-MHCI do not have a clear expression pattern, although there was down-regulation in MHCII transcription in the head kidney, in all the hypoxia conditions evaluated. Finally, IgM transcription was increased in the spleen in all hypoxia conditions, although it wasn't always statistically significant compared to the control. These results indicate that chronic hypoxia induces the stress response, increasing plasma cortisol levels and modulating the transcription of genes involved in the innate and adaptive immune response. The expression patterns were tissue-specific, indicating that the degree of hypoxia differentially affects the transcription of genes involved in the immune response of Oncorhynchus kisutch.

Aplicación de la regresión logística para la predicción de roturas de tuberías en redes de abastecimiento de agua

Las roturas de tuberías en redes de abastecimiento de agua provocan serios problemas para las compañías encargadas de su gestión. Con objeto de reducir el número de roturas inesperadas, se propone un método predictivo de clasificación de las tuberías que utiliza la regresión logística, junto con técnicas avanzadas de procesamiento de datos, como el equilibrado de clases o la validación cruzada. La metodología se ha aplicado al caso real de la red de abastecimiento de Sevilla. Los resultados muestran que podría llegar a predecirse el 85.9% de las roturas de tuberías, siendo 76.6% la precisión total del modelo.Palabras clave: Regresión logística; Red de abastecimiento de agua; Predicción de roturas de tuberías; Aprendizaje automático

Magnesium, zinc, arsenic, selenium and platinum urinary excretion from cancer patients of Antofagasta region, Chile: multi-metal approach

Objectives

To evaluate the short-term 24 h urinary excretion of platinum, arsenic, selenium, magnesium and zinc in patients with lung cancer and with cancer other than lungs treated with cisplatin or/and carboplatin from Antofagasta, Chile.

Design

Urine measurements of Pt and Se were made by inductively coupled plasma optical emission spectrometry, As by hydride-generation atomic absorption spectrometry and Mg and Zn by means of flame furnace atomic absorption spectrometry.

Setting

All samples were provided by the Oncological Centre of Antofagasta Regional Hospital (Region of Antofagasta, Chile).

Participants

Ninety 24-h urine samples from cancer patients after the infusion of Pt-base drugs and 10 24-h urine samples from cancer patients not treated with metal-base drugs.

Main outcome measures

Concentrations of Pt, Se, As, Zn and Mg coming from 24-h urine samples.

Results

Pt excreted was not significantly different between patients with lung and other cancers treated with cisplatin. The excretion of Mg, Zn and Se was greater than As. Then, Pt favours the excretion of essential elements. For lung and other types of cancers treated with drugs without Pt, excretion of Mg, Zn and Se was also greater than that of As, suggesting antagonism Mg-Zn-Se–anti-cancer drug relationship.

Conclusions

The amounts of Mg, Zn and Se excreted were greater than for As either with or without Pt-containing drugs, suggesting antagonist Mg-Zn-Se–anti-cancer drug relationships. The excretion of As, Mg, Zn and Se is induced by Pt. Knowledge obtained can contribute to understanding the arsenic cancer mechanism and the As-Mg-Zn-Se-Pt inter-element association for lung cancer and other types of cancer.

Trace metal variability in coastal waters of San Jorge Bay, Antofagasta, Chile: An environmental evaluation and statistical approach to propose local background levels

Between 2008 and 2011, twelve metals from 384 coastal waters samples from San Jorge Bay (Antofagasta, northern Chile) were collected and analyzed. The goal was to evaluate the quality of the bay's water bodies according to the current Chilean Quality Guideline and to establish background levels for these metals. The result suggests that the coastal waters of San Jorge Bay are of very good quality suitable for recreational activities involving human body contact. The natural background thresholds established for this bay were significantly lower than primary and secondary water quality guidelines. The distribution of Cu, Zn and Pb, along the bay's coastline provides evidence of the effects of industrial activity. Both situations suggest that the threshold indicated in the environmental guidelines of the Chilean legislation may be overestimated and do not represent pollution-free environments.

Lipopolysaccharide-Induced Ionized Hypocalcemia and Acute Kidney Injury in Carotid Chemo/Baro-Denervated Rats

The acute kidney injury (AKI) observed during sepsis is due to an uncontrolled release of inflammatory mediators. Septic patients develop electrolytic disturbances and one of the most important is ionized hypocalcemia. AKI adversely affects the function of other organs and hypocalcemia is associated with cardiovascular and respiratory dysfunctions. Since carotid body chemoreceptors modulate the systemic inflammatory response during sepsis syndromes, we used pentobarbitone-anesthetized male Sprague-Dawley rats in control condition (SHAM surgery) and after bilateral carotid neurotomy (carotid chemo/baro-denervated, BCN). We evaluate serum creatinine (CRE), serum neutrophil gelatinase-associated lipocaline (NGAL), ionized calcium (iCa) and cardiac Troponin I (cTnI) 90 min after the IP administration of 15 mg/kg lipopolysaccharide (LPS) or saline. In the SHAM group, LPS failed to induce significant changes CRE, NGAL, or iCa, and increased cTnI. Conversely, in the BCN group LPS increased CRE and NGAL, decreased iCa, and enhanced the increase of cTnI. Our results suggest that carotid chemo/baro-receptors might contribute to the regulation of both renal function and calcemia during sepsis. In addition, results imply that the carotid chemo-baroreceptors serve as an immunosensory organ.

Urinary excretion of platinum, arsenic and selenium of cancer patients from the Antofagasta region in Chile treated with platinum-based drugs

BACKGROUND

Arsenic exposure increases the risk of non-cancerous and cancerous diseases. In the Antofagasta region in Chile, an established relationship exists between arsenic exposure and the risk of cancer of the bladder, lung and skin. Platinum-based drugs are first-line treatments, and many works recognise selenium as a cancer-fighting nutrient. We characterised the short-term urinary excretion amounts of arsenic, selenium and platinum in 24-h urine samples from patients with lung cancer and those with cancer other than lung treated with cisplatin or/and carboplatin. As - Se - Pt inter-element relationships were also investigated.

RESULTS

The amounts of platinum excreted in urine were not significantly different between patients with lung cancer and those with other cancers treated with cisplatin, despite the significant variation in platinum amounts supplied from platinum-based drugs. In general, the analytical amounts of excreted selenium were greater than those for arsenic, which could imply that platinum favours the excretion of selenium. For other types of cancers treated with drugs without platinum, excretion of selenium was also greater than that of arsenic, suggesting an antagonist selenium-anti-cancer drug relationship.

CONCLUSIONS

Regards the baseline status of patients, the analytical amounts of excreted Se is greater than those for As, particularly, for cisplatin chemotherapy. This finding could imply that for over the As displacement Pt favours the excretion of Se. The analytical amounts of excreted Se were greater than those for As, either with and without Pt-containing drugs, suggesting an antagonist Se-anti-cancer drug relationship. However, it seemed that differences existed between As - Se - Pt inter-element associations in patients treated for lung cancer in comparison with those treated for cancer other than lung. Therefore, knowledge obtained in this work, can contribute to understanding the arsenic cancer mechanism and the As - Se - Pt inter-element association for lung cancer and other types of cancer, which in some cases respond at a linear mathematical model.

Metal contents in coastal waters of San Jorge Bay, Antofagasta, northern Chile: a base line for establishing seawater quality guidelines

We measured the concentration of 12 metals in coastal waters of seven sites of San Jorge Bay in Antofagasta (northern Chile), in order to relate the presence of metals with the different uses of San Jorge Bay coastal border, and to evaluate the quality of the bay's bodies of water according to the proposed current Chilean Quality Guide for trace elements in seawater (CONAMA 2003). The results suggest that the coastal water of San Jorge Bay has very good quality according to the proposed regulation mentioned above. However, the distribution of metals such as Cu and Pb along the bay's coast line evidences a notorious effect of the industrial activity, which would involve different behavior patterns for some trace elements in some bodies of water, suggesting that the levels indicated in the environmental guideline of the Chilean legislation do not represent pollution-free environments.

Distribution and temporal variation of trace metal enrichment in surface sediments of San Jorge Bay, Chile

Cu, Pb, and Hg concentrations were determined in surface sediment samples collected at three sites in San Jorge Bay, northern Chile. This study aims to evaluate differences in their spatial distribution and temporal variability. The highest metal concentrations were found at the site "Puerto", where minerals (Cu and Pb) have been loaded for more than 60 years. On the other hand, Hg does not pose a contamination problem in this bay. Cu and Pb concentrations showed significant variations from 1 year to another. These variations seem to be a consequence of the combination of several factors, including changes in the loading and/or storage of minerals in San Jorge Bay, the dredging of bottom sediments (especially at Puerto), and seasonal changes in physical-chemical properties of the water column that modify the exchange of metals at the sediment-water interface. Differences in the contamination factor and geoaccumulation index suggest that pre-industrial concentrations measured in marine sediments of this geographical zone, were better than geological values (average shale, continental crust average) for evaluating the degree of contamination in this coastal system. Based on these last two indexes, San Jorge Bay has a serious problem of Cu and Pb pollution at the three sampling locations. However, only Cu exceeds the national maximum values used to evaluate ecological risk and the health of marine environments. It is suggested that Chilean environmental legislation for marine sediment quality--presently under technical discussion--is not an efficient tool for protecting the marine ecosystem.

Acorn crop size and pre-dispersal predation determine inter-specific differences in the recruitment of co-occurring oaks

The contribution of pre-dispersal seed predation to inter-specific differences in recruitment remains elusive. In species with no resistance mechanisms, differences in pre-dispersal predation may arise from differences in seed abundance (plant satiation) or in the ability of seeds to survive insect infestation (seed satiation). This study aimed to analyse the impact of pre-dispersal acorn predation by weevils in two co-occurring Mediterranean oaks (Quercus ilex and Quercus humilis) and to compare its relevance with other processes involved in recruitment. We monitored the patterns of acorn production and acorn infestation by weevils and we conducted experimental tests of acorn germination after weevil infestation, post-dispersal predation and seedling establishment in mixed forests. Monitoring and experimental data were integrated in a simulation model to test for the effects of pre-dispersal predation in recruitment. In both oaks pre-dispersal acorn infestation decreased with increasing acorn crop size (plant satiation). This benefited Q. ilex which exhibited stronger masting behaviour than Q. humilis, with almost a single and outstanding reproductive event in 6 years. Acorn infestation was more than twice as high in Q. humilis (47.0%) as in Q. ilex (20.0%) irrespective of the number of seeds produced by each species. Although germination of infested acorns (seed satiation) was higher in Q. humilis (60%) than in Q. ilex (21%), this could barely mitigate the higher infestation rate in the former species, to reduce seed loss. Conversely to pre-dispersal predation, no inter-specific differences were observed either in post-dispersal predation or seedling establishment. Our results indicate that pre-dispersal predation may contribute to differences in seed supply, and ultimately in recruitment, between co-existing oaks. Moreover, they suggest that seed satiation can barely offset differences in seed infestation rates. This serves as a warning against overemphasising seed satiation as a mechanism to overcome seed predation by insects.

Incidence and clinical significance of hyperamylasemia after endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic lesions: a prospective and controlled study

BACKGROUND AND STUDY AIM

Acute pancreatitis as a complication of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic lesions is rarely observed. However, there is little information on the incidence of hyperamylasemia after EUS-FNA of the pancreas and its clinical significance. This study aimed to supply this lack of information.

PATIENTS AND METHODS

Patients who underwent EUS-FNA of a pancreatic lesion between October 2004 and October 2005 were studied prospectively. Exclusion criteria were: (i) platelet count under 50,000/mm (3) and/or prothrombin time < 50 %; (ii) performance of surgery, endoscopic retrograde cholangiopancreatography (ERCP), a percutaneous biopsy attempt, or another invasive procedure within 7 days before EUS-FNA; (iii) lack of informed consent. Serum amylase levels were determined before and 8 and 24 h after the procedure. Hyperamylasemia was defined by amylase levels above 104 UI/L (and higher than baseline levels) 8 h after the procedure. Acute pancreatitis was defined by upper abdominal pain (with or without nausea and/or vomiting) accompanied by elevation of serum amylase or lipase to at least twice baseline levels.

RESULTS

A total of 100 patients underwent EUS-FNA of a pancreatic lesion (58 men, 42 women; mean age 60 +/- 13 years). Eleven patients (11 %) showed hyperamylasemia 8 h after the puncture (298 +/- 293 UI/L, range 105 - 1044 UI/L), but only two of them developed acute mild pancreatitis after EUS-FNA. Hyperamylasemia was not related either to the type of lesion (cystic or solid) or to its location, the duration of the procedure, or the number of passes performed.

CONCLUSIONS

Pancreatitis after pancreatic EUS-FNA occurs in 2 % of patients, with some more cases of silent hyperamylasemia. This complication may have to be included in the information given to patients for their informed consent.

Insulin-regulated aminopeptidase/placental leucil Aminopeptidase (IRAP/P-lAP) and angiotensin IV-forming activities are modified in serum of rats with breast cancer induced by N-methyl-nitrosourea

BACKGROUND

In previous reports, changes in oxytocinase activity in human breast cancer tissue and in the serum of N-methyl-nitrosourea (NMU)-induced rat mammary tumors were described. Insulin-regulated aminopeptidase (IRAP) has been identified with oxytocinase and has also been referred to as placental leucine aminopeptidase (P-LAP).

MATERIALS AND METHODS

The IRAP/P-LAP activity in rat serum was assayed to analyze the putative role that IRAP/P-LAP may play in regulating mammary gland carcinogenesis induced by NMU. Furthermore, as it has been recently described that IRAP/P-LAP is the angiotensin IV (Ang IV) receptor AT4, the activities of Ang IV-forming aminopeptidase N (APN) and aminopeptidase B (APB) were also assayed.

RESULTS

Changes in serum IRAP/P-LAP and Ang IV-forming APB activities were found in rats with mammary tumors induced by NMU. Both activities were greatly increased, although the Ang IV-forming APN activity was not modified.

CONCLUSION

These changes in aminopeptidase activities may reflect the local functional status of their substrates, which can be selectively activated or inhibited in the affected tissue as a result of specific conditions brought about by the tumor. Thus, these enzymatic activities may be involved in the promotion and progression of breast cancer through oxytocin (OT), vasopressin (AVP) and/or renin-angiotensin system (RAS) misregulation.

[An outbreak of gram-negative bacteremia (GNB), especially enterobacter cloacae, in patients with long-term tunnelled haemodialysis catheters]

Vascular access through a venous catheter for haemodialysis is associated with increased risk of thrombosis, central venous stenosis, short access survival and inadequate dialysis. The most important catheter-related complications, which determine method survival, are infection and dysfunction. In particular, infectious episodes are in some studies the leading cause for untimely catheter removal and for catheter-related morbidity but also for morbidity in dialysis patients. Double-lumen central venous catheters used for haemodialysis, are common causes of septicaemia. Most cases are caused by staphylococci. Episodes of gram-negative bacteriemia have been traced to bacterial contamination of water and/or dialysate, errors in dialyzer reprocessing, and improper setup procedures. In this paper, we describe and outbreak of gram-negative bacteremia, firstly E. cloacae, in an outpatients haemodialysis unit, in the patients with long-term tunnelled haemodialysis catheters. We describe the epidemic investigation that we achieved to identify the source of contaminating bacteria and the route by which bacteria gained access to the bloodstream. We prove the contamination by gram-negative bacterium of the water-distribution lines and haemodialysis machines. Moreover, E. cloacae strains isolated from the lines and machines are genotypically identical to the isolated from the patients. Also, we prove that the hands of health care personnel are unintentional carriers. The outbreak was finished when decontamination of dialysis machines was enhanced and dialyzer-priming fluid was modified.

Presence of polyclonal Pseudomonas aeruginosa in an intensive care unit: a 27-month prospective study on molecular epidemiology

Pseudomonas aeruginosa was isolated in 22.2% of 305 intensive care unit environmental cultures. A high genetic heterogeneity (18 pulsotypes) was evident. Taps and related surfaces were a stable reservoir for certain pulsotypes. The 15.4% of the P. aeruginosa-positive cultures were polyclonal. Different colony morphotypes should be assayed in surveillance studies.

Thermal inactivation of the plasma membrane H+-ATPase from Kluyveromyces lactis. Protection by trehalose

The activity of the isolated plasma membrane H+-ATPase from Kluyveromyces lactis was measured during incubation at 35-45 degrees C and in the absence or in the presence of 0-0.6 M trehalose. As the temperature of incubation was raised from 35 to 45 degrees C, increasing enzyme inactivation rates were observed. Thermal inactivation kinetics of the H+-ATPase were biphasic exhibiting a first rapid phase and then a second slow phase. The transition from the native state occurred through a temperature-mediated increase in the inactivation rate constants of both phases. A model is proposed where the native H+-ATPase yields a partially active intermediary during the first phase of inactivation and then the intermediary is slowly converted into a totally inactive enzyme in the second phase. At each of these temperatures trehalose protected the enzymatic activity in a concentration dependent manner. Full protection was observed at 0.6 M trehalose in the range of 35-40 degrees C. Whereas, at 42 and 45 degrees C, the trehalose-mediated thermoprotection of the H+-ATPase was only partial. Trehalose stabilized the enzyme mainly by preventing the temperature dependent increase of the first and second inactivation rate constants.

[Excess of mineralocorticoids in essential hypertension: clinical-diagnostic approach]

BACKGROUND

Primary hyperaldosteronism is more frequent among subjects with essential hypertension than previously thought. The prevalence, according to local and international evidence could fluctuate between 9 and 10%.

AIM

To investigate if subjects with essential hypertension have different aldosterone and renin plasma levels than normotensive subjects.

PATIENTS AND METHODS

One hundred twenty five subjects with essential hypertension, not receiving medications for at least two weeks prior to the study and 168 age and sex matched normotensive controls were studied. Blood was drawn between 9 and 10 AM during a sodium free diet to determine plasma aldosterone, plasma renin activity and potassium.

RESULTS

Plasma aldosterone was higher in hypertensive subjects than controls (11.6 +/- 7.6 and 9.9 +/- 5.1 ng/dl respectively; p = 0.04). Plasma renin activity was lower in hypertensives than controls (1.42 +/- 1.28 and 1.88 +/- 1.39 ng/ml/b respectively; p < 0.001). Thus, plasma aldosterone/plasma renin activity ratio was higher in hypertensives (13.8 +/- 13.5 and 8.3 +/- 7.8; p < 0.001). A pathological ratio was defined as over 25, corresponding to the mean plus two standard deviations of the control group. Primary hyperaldosteronism was found in 5/125 hypertensives (4%) and 1/168 normotensive subject (0.6%). None had hypokalemia.

CONCLUSIONS

Subjects with essential hypertension have higher plasma aldosterone and lower plasma renin activity than normal controls. A plasma aldosterone/plasma renin activity over 25 was defined as abnormal.

Primary hyperaldosteronism in essential hypertensives: prevalence, biochemical profile, and molecular biology

There is evidence that primary aldosteronism (PA) may be common in patients with essential hypertension (EH) when determinations of serum aldosterone (SA), plasma renin activity (PRA), and the SA/PRA ratio are used as screening. An inherited form of primary hyperaldosteronism is the glucocorticoid-remediable aldosteronism (GRA) caused by an unequal crossing over between the CYP11B1 and CYP11B2 genes that results in a chimeric gene, which has aldosterone synthase activity regulated by ACTH. The aim of this study was to evaluate the prevalence of PA and the GRA in 305 EH patients and 205 normotensive controls. We measured SA (1-16 ng/dL) and PRA (1-2.5 ng/mL x h) and calculated the SA/PRA ratio in all patients. A SA/PRA ratio level greater than 25 was defined as being elevated. PA was diagnosed in the presence of high SA levels (>16 ng/dL), low PRA levels (<0.5 ng/mL x h), and very high SA/PRA ratio (>50). Probable PA was diagnosed when the SA/PRA ratio was more than 25 but the other criteria were not present. A Fludrocortisone test was done to confirm the diagnosis. GRA was differentiated from other forms of PA by: the aldosterone suppression test with dexamethasone, the high levels of 18-hydroxycortisol, and the genetic detection of the chimeric gene. In EH patients, 29 of 305 (9.5%) had PA, 13 of 29 met all the criteria for PA, and 16 of 29 were initially diagnosed as having a probable PA and confirmed by the fludrocortisone test. Plasma potassium was normal in all patients. The dexamethasone suppression test was positive for GRA in 10 of 29 and 18-hydroxycortisol levels were high in 2 of 29 patients who had also a chimeric gene. In normotensive subjects, 3 of 205 (1.46%) had PA, and 1 of 205 had a GRA. In summary, we found a high frequency of normokalemic PA in EH patients. A high proportion of PA suppressed SA with dexamethasone, but only a few had a chimeric gene or high levels of 18-hydroxycortisol. These results emphasize the need to further investigate EH patients.

Comparison of IS1245 restriction fragment length polymorphism and pulsed-field gel electrophoresis for typing clinical isolates of Mycobacterium avium subsp avium

SETTING

Little is still known about the epidemiology and pathogenesis of Mycobacterium avium subsp avium (MASA) infection.

OBJECTIVE

Examination of the reproducibility and the stability over time of pulsed-field gel electrophoresis (PFGE) and IS1245 restriction fragment length polymorphism (IS1245-RFLP) techniques. The ability of these typing systems for differentiating clinical isolates of MASA was also assessed.

DESIGN

Clinical isolates recovered from 63 patients (59 human immunodeficiency virus [HIV] positive and four HIV-negative) were studied by insertion sequence IS1245 and PFGE. For the study of in vivo and in vitro stability, strains collected over time from four patients and five strains chosen at random, respectively, were used.

RESULTS

The stability of PFGE and IS1245-RFLP in vitro was excellent. PFGE was also stable in vivo, but IS1245-RFLP patterns showed some variation. The discriminatory power of IS1245-RFLP and PFGE was 0.995 and 0.989, respectively. The cluster analysis did not reveal differences between strains recovered from HIV-negative and HIV-positive patients or between patients with colonisation, local infection or disseminated disease.

CONCLUSION

IS1245-RFLP and PFGE are useful tools for typing MASA strains. However, IS1245 variations in vivo may complicate the analysis of epidemiological relationships.

Interactions of arsenate, sulfate and phosphate with yeast mitochondria

In the presence of K(+), addition of ATP or ethanol to yeast mitochondria triggers the depletion of the transmembrane potential (DeltaPsi) and this is prevented by millimolar concentrations of phosphate (PO(4)). Different monovalent and polyvalent anions were tested for their protective effects on mitochondria from Saccharomyces cerevisiae. Only arsenate (AsO(4)) and sulfate (SO(4)) were as efficient as PO(4) to protect mitochondria against the K(+) mediated swelling, depletion of the DeltaPsi, and decrease in the ratio of uncoupled state to state 4 respiration rates. Protection by PO(4), SO(4) or AsO(4) was inhibited by mersalyl, suggesting that these anions interact with a site located in the matrix side. In addition, the effects of SO(4) and AsO(4) on the F(1)F(0)-ATPase were tested: both SO(4) and AsO(4) inhibited the synthesis of ATP following competitive kinetics against PO(4) and non-competitive kinetics against ADP. The mersalyl sensitive uptake of (32)PO(4) was not inhibited by SO(4) or AsO(4), suggesting that the synthesis of ATP was inhibited at the F(1)F(0)-ATPase. The hydrolysis of ATP was not inhibited, only a stimulation was observed when AsO(4) or sulfite (SO(3)) were added. It is suggested that the structure and charge similarities of PO(4), AsO(4) and SO(4) result in undiscriminated binding to at least two sites located in the mitochondrial matrix: at one site, occupation by any of these three anions results in protection against uncoupling by K(+); at the second site, in the F(1)F(0)-ATPase, AsO(4) and SO(4) compete for binding against PO(4) leading to inhibition of the synthesis of ATP.

[Echinococcosis/hydatidosis in the VII Region of Chile: diagnosis and educational intervention]

This study was designed to embrace three areas: a) serologic and radiologic diagnosis and surgical treatment of hydatidosis in an asymptomatic human population, b) animal diagnosis and the treatment of dogs, and c) evaluation of extent of knowledge and performance of educational interventions among rural families and health, livestock, and education professionals and technicians, in order to help control the disease transmission cycle. Indirect hemagglutination and ELISA tests were performed on 5,556 apparently healthy people. Of these, 42 (0.8%) had positive results on both tests, for a seroprevalence of 754.6 per 100,000. These 42 subjects were scheduled for liver ultrasonography and a chest x-ray; of the 26 who complied, 16 showed images compatible with a hydatid cyst. Those 16 cases were sent to the hospital for surgery. In 9 of the cases the diagnosis was confirmed surgically, for a prevalence of 161.7 per 100,000. Arecoline hydrobromide was administered as a laxative to 2,358 dogs to detect the strobilar form of Echinococcus granulosus, and positive results were found in 11% of the dogs. Official data for slaughterhouses indicated the presence of hydatid cysts in 13% of the cattle, 4.4% of the sleep, and 4.2% of the pigs slaughtered in the region. The educational program included an evaluation of the extent of knowledge by surveying heads of household; an educational intervention among families through an informal active participatory process using educational games, in which 1,082 families participated; and an educational intervention with professionals and technicians using distance and in-person approaches. To evaluate the program, the results of knowledge tests before and after educational interventions with 200 families (cases) were compared with those from 95 families who did not participate (controls). Of the 1,423 heads of household initially surveyed about their knowledge of echinococcosis/hydatidosis, 783 of them (55%) said they knew nothing about the infection. It was found that the participatory educational games were well adapted to the lifestyle of people from rural areas and made change possible. Training was provided to 276 health professionals, 201 technical assistants, and 453 rural teachers. The program reached 100% of the staff members of the area's rural primary health care services.

A(-6)G variant of angiotensinogen gene and aldosterone levels in hypertensives

Recently, a novel mutation in the promoter region of the angiotensinogen gene that involves the presence of an adenine instead of a guanine 6 bp upstream from the transcription initiation site (A(-6)G) has been shown to induce an increase in gene transcription. The aim of this study was to determine the prevalence of the A(-6)G mutation in essential hypertensive patients and to correlate it with aldosterone and renin activity levels. We studied 191 hypertensives. We measured levels of aldosterone (plasma and urinary) and plasma renin activity. We determined the variants A and G using a mutagenically separated polymerase chain reaction technique. In 191 hypertensives, the A variant was detected in 266 of 382 (69.6%) and the G variant in 116 of 382 alleles (30.4%). Plasma aldosterone was significantly higher in patients homozygous for AA than in those homozygous for GG (369+/-208 versus 246+/-142 pmol/L). Urinary aldosterone was significantly higher in homozygous AA than in AG or GG patients (62.4+/-39.4 versus 50.8+/-25.2 and 37.4+/-22.3 nmol/d, respectively). When the patients were grouped according to the presence or absence of the A allele, the aldosterone levels and the plasma aldosterone/plasma renin activity ratio were significantly higher in patients with the A allele. The presence of the A variant was associated with higher levels of aldosterone. These results suggest that the presence of the A variant could determine the appearance of arterial hypertension through higher transcription activity of the angiotensinogen gene and concomitant aldosterone production.

Long-term follow-up of patients with biliary atresia successfully treated with hepatic portoenterostomy. The importance of sequential treatment

The outcome of 18 biliary atresia (BA) patients (5 male, 13 female; age range 10.7-22.5 years; mean 15.4+/-0.7 years) treated with hepatic portoenterostomy (HPE) and jaundice-free for more than 10 years without liver transplantation (LT) is analyzed retrospectively. Eight of these patients subsequently required LT (age at LT 12. 8+/-0.5 years, range 10.5-15.2 years); 3 children (aged 11.6, 13.2 and 14.1 years, respectively) had episodes of gastrointestinal variceal bleeding associated with other signs of severe disease and are now candidates for LT; and among the 7 asymptomatic patients (age range 11.2-22.5 years; mean 15.9+/-2.1 years), 5 had sonographic and biochemical signs of moderate portal hypertension (PH). In order to analyze whether the age at transplantation influences the survival of children transplanted for BA, we also reviewed the outcome of 71 BA patients transplanted at our hospital between 1986 and 1996. All the children older than 10 years at the time of LT were alive; only patients younger than 10 years died following LT (n = 15). We conclude that the natural outcome of extrahepatic BA is toward PH, fibrosis, and cirrhosis, even in those cases successfully treated with HPE. In our experience, the results of sequential treatment with HPE and LT were excellent.

Treatment of chronic Chagas' disease with itraconazole and allopurinol

Four hundred four patients with chronic Chagas' disease were treated with itraconazole (6 mg/kg of body weight/day for 120 days), allopurinol (8.5 mg/kg of body weight/day for 60 days), or with a placebo of pure starch. Patients were monitored over a period of four years by clinical examination, serology, xenodiagnosis, hemoculture, and electrocardiogram. Drug tolerance was good, with only four treatments discontinued due to side effects that subsided after suspension of treatment. Parasitologic cure was evident in 44% of the those treated with allopurinol and 53% of those treated with itraconazole, and the electrocardiographic evaluation showed normalization in 36.5% and 48.2%, respectively, of patients with chronic or recent cardiopathy.

Syndrome of Alagille: radiological and sonographic findings. A review of 37 cases

The objective of this study was to evaluate the association of intrahepatic cholestasis, pulmonary stenosis, and hyperlipemia with osseous and renal abnormalities in Alagille's syndrome. A total of 37 patients (25 males and 12 females) with ages ranging between 8 months and 27 years were included. Clinical records as well as radiological and ultrasonographic studies were reviewed. Chronic cholestasis was observed in all patients. Thirteen had favorable clinical outcome and normal hepatic sonograms. Clinical and sonographic evidence of portal hypertension was found in 13 patients and of cirrhosis in 8 patients. The remaining 3 patients required hepatic transplantation due to severe cholestasis. Hyperlipemia correlated with hepatic malfunction. Pulmonary stenosis and renal hypoplasia were the most frequently associated abnormalities. All patients showed a peculiar facies. Abnormal "butterfly" vertebrae were present in 18 patients and ulnar or phalangeal shortening in 11 patients. Ultrasonography allowed hepatobiliary disease assessment and helped to establish indications for hepatic transplantation. Renal and osseous abnormalities were not specific but in the appropriate clinical setting reinforced the diagnosis.